# An Intelligent Wireless Charger Based on the Internet of Things

Authors: Xiaoqiang Zhang
Journal: Security and Communication Networks
 (2021)

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## Abstract

With the development of the times and the progress of science and technology, people continue to explore new possibilities; the leap from wired to wireless is one of them, breaking the limitations. Similar to wireless mice and wireless microphones, this paper aims to study an Internet of Things-based smart wireless charger that, by using mathematical analysis and wireless charging technology, requires experiments to include wireless charging stations, associated chip areas, and home gateways that are used in combination with them. In the experiment, the control circuit, transmit circuit, and reception circuit of wireless charger are studied, and the wireless charging system is analyzed and calculated in detail, and a wireless charger is designed. Electromagnetic field sensing, radio wave transmission, and resonance methods are applied to achieve the shortest charging time and the best quality in order to prevent the charger from heating and burning during charging. Experimental data show that this Internet of Things-based smart wireless charger can fully replace wired chargers for 99% of small appliances; the charging efficiency of large electrical appliances such as desktop computer is also 1.4 to 1.6 times increased. Experimental data show that this Internet of Things-based smart wireless charger can efficiently and conveniently charge electrical appliances; however it is relatively expensive; the required technology is relatively complex but can make charging more efficient. It can be seen that wireless charging has a major breakthrough in the concept of future charging.


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## Body

## 1. Introduction

Wireless charging technology can solve the problem of limited energy of terminal devices and make many portable devices that need to be charged get rid of the charging cable. It is more convenient to use and has a very broad application prospect. The world’s leading electronics manufacturers and wireless charging standards organizations have studied and prepared wireless charging products security, compatibility, and other standards. Wireless charging technology with uniform standards will become one of the future trends. However, inductive or microwave charging is used to radiate electromagnetic waves to the surrounding area, and sensitive electronic devices in the vicinity can be disturbed. In addition, improving the transmission efficiency of the system is also a challenge.Today, everything from mobile phones to iPads and from warm hands to cameras requires multiple charges to meet the needs of life. Once upon a time, the common way to charge was the transmission of wired power, where AC power was connected at one end and the rechargeable battery of an electronic device on the other. It can be seen that if multiple devices are charged at the same time, the charging cables will often be mixed together This approach can easily cause mechanical damage, resulting in a reduction in product life. But if you think about charging with a wireless charger, the charger and the power supply are completely separated. Some wireless chargers also contain more than one transmit coil, which has a very large sensing area and is extremely stable in charging status, which does not break off from time to time. In addition, for the safety of the wireless charging process, some wireless chargers support the latest intelligent charging management technology. It is not difficult to find that the benefits of wireless chargers are multifaceted; the rise of wireless charging technology is the product of the combination of innovation and technology and is the inevitable trend of future development; and how to make high-efficiency and stable rugged smart wireless chargers is something we need to constantly explore [1].Xiang conducted a multifaceted review of 3115 scientific and technological literatures on wireless charging technology as the basic data for discussion. It was found that the electromagnetic induction and electromagnetic resonance wireless charging technologies focusing on wireless charging technology are currently the most popular hot spots [2]. The main transformation in the future is from basic technology to specific applications, which involves technical issues such as distance, power, efficiency, and electromagnetic compatibility, covering multiple application areas and scopes such as healthcare, consumer electronics, and transportation. A total of 29,869 global applications for wireless charging technology patents have been published [3]. Naik M K and other scholars studied the wireless battery charger (WBC) of plug-in electric vehicles (PEVs) and analyzed two configurations of a series of resonant WBC receivers. The first device charges the PEV battery in a straightforward manner through a diode rectifier. The second configuration charges the PEV battery through the cascade of a diode rectifier and a chopper, and its input voltage remains constant. The advantages of WBC, such as the efficiency and size factor of the power supply and transmitter/receiver coils, are determined. Based on this, a discussion and comparison with an example of an electric vehicle WBC were conducted. Xuan et al. pointed out that because smart sensors can interact with people or other objects, wireless rechargeable sensor networks (WRSN) play an important role in advancing SIoT technology. They proposed an improved grid-based joint routing and charging algorithm (IGRC) to realize the path planning of mobile chargers, aiming to achieve energy balance in WRSN by providing real-time charging services [4]. Li et al. applied multiple charging devices to charge sensor nodes in the smart grid monitoring sensor network, where each charging device can charge all sensor nodes within the charging range [5]. For large-scale wireless rechargeable sensor networks, Li et al. used multiple mobile charging devices to power the network and calculated the minimum number of charging devices that can complete the work [6]. Cyber-physical systems (CPS) revolutionize our world in different areas through close interaction and automated decision-making, thereby helping to create new services and applications. The future fifth-generation (5G) cellular network will use different technologies, such as device-to-device (D2D) communication, to promote the realization of CPS communication on the current network infrastructure. Atat et al. discussed the main challenges that cellular providers will face as a large number of CPS devices try to access the cellular spectrum [7]. Their research on GPS is very in-depth, but the chapter mainly focuses on wireless charging. In order to study the security of the Internet of Things, Liao R.-F et al. studied the security threats in the mobile edge computing (MEC) of the Internet of Things and proposed a deep learning- (DL-) based physical (PHY) layer authentication scheme, which uses the channel state information (CSI) to enhance the security of the MEC system by detecting spoofing attacks in the wireless network [8]. Their research on the security of the Internet of Things is very thorough, but if it is based on wireless charging, it is closer to the subject. Despite many security issues, advanced communication and information technologies have made smart grids more intelligent and automated. However, in the power cloud master station mode, a large number of heterogeneous power terminals complicate SSA, and fault information cannot be issued in time. The dynamic and continuous situational space also adds to the challenges of SSA. Wenxin Lei used the advantages of edge intelligence to introduce edge computing between the terminal and the cloud to solve the shortcomings of the traditional power cloud paradigm [9]. He is between the terminal and the smart computing, but is not deeply involved in the Internet of Things. In order to explore the application of the Internet of Things, Chen et al. proposed an edge computing system based on the IoT (Internet of Things) smart grid to overcome the shortcomings of the current power system cloud computing paradigm, many of which have not been resolved, such as fully fulfilling the requirements of the Internet of Things: high bandwidth and low latency. The new system mainly introduces edge computing into the traditional cloud power system and establishes a new hardware and software architecture [10]. The edge computing system of the smart grid of the Internet of Things can overcome the shortcomings of cloud computing in the power system, but there is no connection with wireless charging. In recent years, regarding the development of wireless charging technology, in order to adapt to different charging, each scholar has adopted different methods to realize wireless charging. It is realized by separate circuit and low-frequency magnetic resonance type, suitable for high-power charging at near and medium distances, but the efficiency is relatively low, the size is large, and the radio wave type is suitable for long-distance and low-power generation. The electromagnetic wave suffers more interference and has radiation to the human body. The electromagnetic induction type used in this article has the advantage of short-distance charging and high conversion efficiency, but it needs to be attached to the transmitter board to charge when charging, and metal induction will generate heat. Wireless charging is more secure, flexible, more convenient, and has a stable performance; and, compared with traditional limited chargers, because of less data lines, it also greatly improves the conversion rate of energy. For these reasons, this paper aims to study a smart wireless charger based on the Internet of Things, which is realized by using mathematical analysis and wireless charging technology. In order to assemble a complete charger, the experiment needs to include a wireless charging table, related chip areas, and a home gateway to use in combination with it. Through the study of the control circuit, transmit circuit, and receiving circuit of the wireless charger and the detailed analysis and calculation of the wireless charging system, a wireless charger is designed. Using electromagnetic field sensing, radio wave transmission, and resonance action methods, in the process of preventing the charger from heating, we strive to achieve the shortest charging time and the best quality Experimental data show that although the production cost is relatively high and the required technology is relatively complex, this kind of intelligent wireless charger based on the Internet of Things can make charging more efficient and convenient and bring convenience to people’s life. Experimental data show that this Internet of Things-based smart wireless charger has a major breakthrough for the future of charging concept; wireless chargers instead of wired chargers can be used in the next day. Compared with other methods, the electromagnetic induction method proposed in this article is more suitable for our current mobile phones, iPads, and other small items to charge. Some charging conversion rates are relatively low.Wireless rechargeable sensor network is a new open-source method to solve the energy problem of wireless sensor network. This article focuses on the charging plan of wireless rechargeable sensor network. By analyzing the wireless energy transmission technology of the existing wireless charging sensor network, the network architecture of the wireless charging sensor network is studied, its characteristics and advantages are analyzed, and targeted charging planning and design are carried out according to the challenges it faces. According to different application environments and the charging cycle of the node energy supplement mode in the network, wireless rechargeable sensor networks are divided into periodic wireless rechargeable sensor networks and on-demand wireless rechargeable sensor networks. In the charging planning design, solutions are given to the problems of different types of charging methods, and charging planning schemes in two different application scenarios are designed to achieve the goal of making the network run forever and maximizing energy efficiency.


## 2. Proposed Method

### 2.1. Principles and Characteristics of the Internet of Things

#### 2.1.1. Definition of the Internet of Things

The Internet of Things is essentially an extension of the Internet. It is a science and technology that describes the interconnection between things The term is closely related to RFID as a method of communication, but it may also include other sensor technologies, wireless technologies, or QR codes. The essence of the Internet of Things is the Internet, except that the terminal is no longer a computer (PC, server) but an embedded computer system and its accompanying sensors. The Internet of Things is important because the object itself which can be digitized to represent itself becomes something bigger than the object. Objects are no longer just related to their users but are now connected to surrounding objects and database data. When many objects act in unison, they are called “environmental intelligence.” As long as there is hardware or product connected to the Internet and data interaction, this is called the Internet of Things. The Internet of Things describes a world in which almost anything can be intelligently connected and communicated. In other words, with the Internet of Things, the physical world is becoming a big information system [11, 12].


#### 2.1.2. Features of the Internet of Things

From the perspective of communication objects and communication processes, the basic feature of the Internet of Things is the process of describing and embodying the information interaction between things, people, and things. The basic characteristics of the Internet of Things can be summed up as holistic perception, transmission, and intelligent processing. First, the Internet of Things is connected by things. Second, information is exchanged and there is communication between things. When the Internet of Things connects different items, it always has to do something; otherwise, what is the use of connecting? Because information exchange and communication are the most fundamental requirements of all networks and the Internet of Things is essentially a network, the Internet of Things also has the characteristics of information exchange and communication, but the information exchange and communication are between things and things. Furthermore, the Internet of Things is industrial. The Internet of Things is with industry attributes, leaving its industry concept; the Internet of Things is a pseudoproposition, only in an industry; the Internet of Things programs and applications are universal. Finally, the objects of the Internet of Things are connected to many things connected to connected terminal devices. The End Devices of the Internet of Things are not a few but many. Just like social networks, the more people join, the more valuable they are, and that applies to the Internet of Things. When the Internet of Things collects very little data, it is of little value because it may not be representative; and when a lot of data is collected and a mass is reached , its value is reflected, because we can do big data analysis of this data and discover certain patterns and then develop solutions for specific industries to improve industry efficiency [13, 14].


#### 2.1.3. Weaknesses in the Security of Smart Devices in IoT Systems

The emergence of the Internet of Things has set off a new revolution in the global information industry; with the development of information technology, the Internet of Things has been deeply into every aspect of people’s lives. With the increasing application of the Internet of Things, the information security issues in the environment of the Internet of Things are becoming more and more prominent. Attacks on IoT systems are often carried out step by side from point to surface, and attackers will first attempt to target the target struck. There are usually two ways to select a target: one is to scan the surrounding network environment or specific target network environment to find a possible security vulnerability in the surrounding network environment of intelligent devices; the other is to directly select the value of intelligent devices or intelligent device users to carry out targeted attacks, which are usually more hidden and the corresponding losses are greater [15, 16]. When designing the computer network system, certain windows and back doors will be reserved. Although it brings a lot of convenience for users to use and common resources, it also brings about many security risks. The application of the Internet of Things is oriented to all walks of life in the society. This effectively solves the problems of remote monitoring, control, and transmission. However, the security risks of the Internet of Things in the perception, transmission, and processing stages may extend to the actual industrial network. These security risks have long been lurking in IoT terminals, IoT sensing nodes, and IoT transmission channels, waiting for opportunities to carry out attacks, undermining the security of industrial systems, and even threatening national security. The Internet of Things technology in my country has risen late, and many technologies and standard systems are not yet complete. Compared with the developed countries in the world, the level is still very low. My country has not yet mastered the core technology of the Internet of Things and currently can only rely on foreign countries. Based on this, malicious attackers may set up obstacles in technology, destroy the Internet of Things system, and affect the security of the Internet of Things.


#### 2.1.4. Application of the Internet of Things in Smart Home

The difference between the smart home lighting system and the traditional lighting system is that the intelligent lighting system based on the Internet of Things sensor technology has the function of multipoint operation and centralized control, the function of light lighting and dark adjustment, the full open and the memory function, and the function of timing control and scene setting, which conforms to the principle of energy saving and consumption reduction because the multifunctional meeting meets people’s diversified needs. Based on the three-layer architecture of the perception layer, network layer, and application layer of the Internet of Things, the intelligent home security system uses human detectors, smoke detectors, and so forth to achieve real-time collection of security protection information and uses ZigBee technology to form a wireless sensor network [16, 17].


#### 2.1.5. The Development of the Internet of Things Industry

When cash becomes WeChat and Alipay, when shopping becomes Taobao, when calling a taxi becomes a call to a drip, when “Hello” becomes “What is your WIFI password?,” and when, in reality, each of us unknowingly becomes a node of the connection of all things, digitalization has become an important driving force for the development of modern society; connectivity has become the main theme of the future society; and the Internet of Things has made everything simple and powerful. In recent years, with the rapid development of a new generation of information technology, the Internet of Things as an important part of the new generation of information technology, many countries have considered the development of the Internet of Things industry as a national strategy, while the Internet of Things industry is also an important booster of the future national economy. As the price of IoT devices and infrastructure continues to fall, the use of IoT devices by businesses is becoming more and more popular. This also means that businesses need to pay more attention to the security of the Internet of Things. More intelligent technology will be integrated into the daily family life, intelligent kitchen will make cooking more easily, intelligent monitoring will make the home security system more powerful, and intelligent desk and intelligent wall are expected to enter life. We are going to get more and more free time, and that is all about the changes that IoT technology is bringing about [18, 19].


### 2.2. Principles and Classification of Wireless Charging

#### 2.2.1. Wireless Charging Design

The charger consists of three parts: the transmit controller, the receiving controller, and the charging monitoring. The entire project is designed based on electromagnetic coupling, which generates a magnetic field from the energy transmission coil, and the receiving coil is induced to the electric potential and then processed by the receiving controller to enable the wireless charging of the device. In order to improve the stability of the output voltage, a detection unit is designed to detect the output voltage in real time and transmit the test results to the control unit, which monitors the charging status of the electrical device according to the results, determines the value of the transmission voltage and transmission power, and controls the control signal to the signal modulation unit. According to the results, the control unit monitors the charging status of the electrical device, determines the value of the transmission voltage and transmission power and controls it accordingly, and transmits the control signal to the signal modulation unit, which transmits the control signal back to the transmitter, changes the transmit coil transmission power, and controls the charging process. The output voltage is stabilized. The receiver controller simultaneously completes the indicative control of the working state of the receiving end. The transmission control circuit consists of a high-frequency high-power power supply chip and a power transmission chip as the main components. The receiving controller is mainly composed of electromagnetic coupling receiving circuit and power supply circuit, and the receiver directly affects the transmission efficiency, in order to output stable voltage and current. The power transmitter of a small wireless charging system is integrated on the charging plate, while the power receiving end is integrated on an electrical device (such as a mobile phone), and the power receiver can also be integrated into the specialized electrical device housing in order to improve the versatility of the device. In order to improve the control accuracy, the system transmitter and receiver control are controlled using the supporting intelligent management chips BQ500211 and BQ51013 developed specifically for wireless charging systems by Texas Instruments. When working, the transmitter controller simultaneously receives the detection information on the transmit coil and the information returned by the receiving signal modulation unit, the summary analysis of these two kinds of information, forming the corresponding control information to control the inverter circuit, by changing the current frequency of the transmit coil to change the transmission power. In the design of the voltage current measurement program, the AD conversion is required when making voltage measurement, and the hardware system is designed with a 12-bit AD converter that comes with the inside of the microcontroller, so the appropriate registers need to be configured in the software design. To achieve the effect of modal conversion [20–22], the first step is to configure the control register of the ADC:(1)ut=λ1f1ut+λ2f2ut+⋯+λmfmut.In the above formula,λ represents the weight of f. The control unit monitors the charging status of the electrical equipment, determines the value of the transmission voltage and transmission power and performs corresponding control, and then transmits the control signal to the signal modulation unit, and the signal modulation unit transmits the control signal back to the transmitter and changes the transmission power of the transmitting coil to optimization λ.In the design of charging power measurement program, there are many calculation methods for electrical power based on the data available from the actual circuit, and the common formula is(2)P=Wt+∑i=1nw×2t2.In the above formula,P represents transmission consumption; Wrepresents the height of the receiving antenna; w represents the height of the transmitting antenna; t is the signal constant.(3)w=UItt.In the above formula,w stands for power; U stands for voltage; I stands for current through electrical appliances; t stands for signal constant.(4)t=UI×∑i=1nt3w,p=U2R,z=I2R,where P is the electrical power; when you know the total power consumed in a certain period of time, you can calculate the power, and by knowing the voltage and current the power can also be calculated.The formula is(5)PCharge=UCharge×ICharge.In the hollow coupling coil scheme, the energy stored in sensor is(6)W=12Li2.Depending on the amount of power the charger is to transmit, the wireless transmission inductance of the sender and receiver is calculated to be 33 H. The factors that affect inductor parameters in hollow coupled inductors are wire diameter, coil diameter, and winding number, and the hollow coil inductor can be calculated according to the following formula:(7)L=n×μoRlnRr−1.75,μo=4π×10−7Hm.


#### 2.2.2. Wireless Charger Security Requirements

In recent years, wireless charger technology has developed rapidly. In order to reduce the various safety issues that occur during the use of wireless chargers, we need to regulate the safety issues of wireless chargers and obtain maximum control Wireless chargers work so that they do not need to be cabled to electronics to transfer power to the batteries in your electronics. In order to protect the safety of consumers, wireless chargers must be fully tested. First of all, in order to evaluate the safety performance under normal working conditions of the product, it is necessary to carry out heat test. Products are at excessive temperature for a long time; direct damage for causing burns or making certain parts of the product may become a source of ignition. Indirect damage is the insulation or mechanical properties that affect the product’s own materials. In addition, fire testing is required. Controlling flame spread is a passive method of protection, we can choose and use components, wiring, and materials additional safety protection to reduce flame spread. If necessary, a second additional safety guard is used, such as a fire protection housing. This method is suitable for any type of device. There is also a method of isolation. When required, in order to reduce the likelihood of continuous flame burning or flame spread, a minimum isolation requirement between a potential ignition source and a combustible material can be achieved using distance isolation or the use of fireproof isolation, which in certain cases can be the required PCB board. Therefore, the wireless charger’s housing and internal PCB board fire performance need to meet the standards, in order to ensure that the fire does not spread the flame, to minimize the loss. Finally, foreign object scans are carried out. Foreign object detection is the most important and indispensable safety feature of wireless chargers. Foreign objects in the detection of foreign bodies are mainly ferromagnetic metals, such as pushpins and coins. The ferromagnetic metal itself is a closed circuit [23, 24]. When it is placed in a changing magnetic field, the flux through this closed circuit changes, creating an induced current inside the ferromagnetic metal. The inductive current flows through the metal’s interior and loses, causing the metal to start heating, which is the vortex effect. When the wireless charging system is working properly, there is a changing magnetic field between the transmitter and the receiving end, and when a metal foreign body appears in the magnetic field, the metal raises the temperature. Reaching a certain temperature can damage the wireless charging product. The role of foreign object detection is that when a foreign object is placed on top of the wireless charging base, the wireless charger should be able to detect it [25–27].


#### 2.2.3. Types of Wireless Chargers

Two types of wireless chargers are commonly used in the market: one is electromagnetic induction, and the other is magnetic resonance type. They differ in how they work, making them different in performance and work characteristics. At present, the most common wireless chargers type on the market is electromagnetic induction, which can be made into round plates or square plates or placed directly in the home of small tables; this charging method is safer, more flexible, and more convenient and has stable performance, high energy conversion rate, and a wide range of applications [28]. The composition of the field resonance wireless charger is shown in Figure 1; it consists of an energy transmitter and an energy receiver, and when the two devices are adjusted to the same frequency or resonate at a specific frequency, they can exchange each other’s energy to realize the concept of wireless charging. Compared with electromagnetic induction chargers, electromagnetic resonance can be transmitted over longer distances compared to electromagnetic induction methods and produce smaller electrical power losses. Magnetic resonance is different from electromagnetic induction, eliminating the need for a complete match between coils. Therefore, there is no need to place electronic products precisely in an area [29].Figure 1
Principle of electromagnetic induction.


#### 2.2.4. The Arrangement Algorithm of the Wireless Charger

Conventional sensor nodes are usually powered by batteries. Battery power is limited, and the absence of which limits the overall life of the sensor network. Wireless energy transmission technology wirelessly sends energy from the charger to the sensor, thus solving the problem completely. An important problem in the wireless rechargeable sensor network is the arrangement of wireless chargers, that is, how to efficiently arrange the charger, so as to maximize the overall charging utility of the sensor network [30]. In addition, for the first time, a charging model with a charger was established based on the measured data, and a series of innovative methods were proposed to transform the problem, and an efficient algorithm with an approximate ratio of (1 − 1/e) was designed: TCP CDG algorithm. There are algorithms to solve this problem. The results of the simulation experiment show the validity of the CDG algorithm. Compared to the two other random algorithms proposed, the performance of the CDG algorithm is improved by nearly 300% and 100%, respectively [31]. CDG is actually a traditional algorithm based on packet loss plus an antinoise mechanism. The original algorithm based on packet loss is to continuously fill the buffer as a means until the buffer is filled and packet loss occurs to reduce the window. However, sometimes packet loss may occur for reasons other than congestion. At this time, the window will still be reduced according to the algorithm, which greatly reduces the bandwidth utilization. After adding this CDG’s RTT gradient antinoise mechanism, the utilization of network bandwidth is greatly improved. However, it may aggravate congestion, so CDG has built-in backoff algorithm [32].


#### 2.2.5. Structural Parameters for Wireless Charging

Using the principle of electromagnetic coupling, the electrical energy is transmitted to the equipment to be charged by means of wireless electromagnetic energy. Its structure is mainly composed of power management module, transmit circuit module, receive conversion module, charging module, and solar power supply module. Electromagnetic coupling can be processed through the electromagnetic emission platform through the functional circuit, to achieve contactless one-to-many charging. More targeted wireless charging devices on the market generally use the core coil charging mode, which is more efficient and the device will optimize the circuit to do very thoroughly, using A3941299, TD1410, Schottky diodes, and other high-quality components to make the charging model larger and more versatile and have better performance. This device is to consider solar energy as a second power supply module, not only in line with the mainstream thinking of energy conservation in the current society and for the work to increase the use of the environment, which is now-on-the-market products do not have [33].


#### 2.2.6. Bottlenecks in the Promotion of Wireless Chargers

In the process of popularization and use, wireless chargers are favored by people by virtue of novel charging methods Wireless chargers have been on display for people to choose from at many mobile phone stores, but demand has been much lower than expected. Apple has confirmed that its AirPower wireless charger project has been halted because the technology did not meet its expected high standards. Apple plans to charge up to three different devices at a time, which can be an Apple Watch, an AirPods headset, and an iPhone. This requires a special multicoil technology where the device can operate without having to find a specific location on the charging plate. It also comes with software that shows the current charging of three devices on your iPhone at the same time. However, the actual technical level is not yet able to meet this requirement; therefore, in the promotion process, technical barriers are still the main reason. The wireless charger of the domestic brand Xiaomi can only achieve one-to-one contact charging, with strict position requirements, but, through practical research, Xiaomi charger’s charging speed, FOD foreign object detection function, and cooling function are relatively perfect.


### 2.3. Data Security and Communication Network

When using the Internet or other communication systems for data communication, the system itself often does not fully consider the security measures and security of the information, and the security problems caused by this are becoming more and more serious. Data security in the general sense refers to the security of data stored locally, while the concept of network security generally refers to the security of data transmission over the network.


#### 2.3.1. Threats to Data Communication

The attacker only observes and analyzes a certain protocol data power distribution unit without disturbing the information flow. Even if these data are not easy for an attacker to understand, he can also understand the address and identity of the protocol entity that is communicating by observing the protocol control information part of the power distribution unit and study the length and transmission frequency of the power distribution unit in order to understand the nature of the data exchanged. This passive attack is also called traffic analysis.


#### 2.3.2. The Goal of Data Communication Security

To deal with passive attacks, data encryption technology can be used. It can be said that this is the most effective way to deal with passive attacks. Active attacks are relatively more methods, but they are also very targeted. The combination of identification technology and encryption technology is appropriate. When current computing is dealing with security issues, in addition to the feasibility of the method, the speed of the processor is getting stronger and stronger, and it has begun to enter the era of multicore parallelism.


## 2.1. Principles and Characteristics of the Internet of Things

### 2.1.1. Definition of the Internet of Things

The Internet of Things is essentially an extension of the Internet. It is a science and technology that describes the interconnection between things The term is closely related to RFID as a method of communication, but it may also include other sensor technologies, wireless technologies, or QR codes. The essence of the Internet of Things is the Internet, except that the terminal is no longer a computer (PC, server) but an embedded computer system and its accompanying sensors. The Internet of Things is important because the object itself which can be digitized to represent itself becomes something bigger than the object. Objects are no longer just related to their users but are now connected to surrounding objects and database data. When many objects act in unison, they are called “environmental intelligence.” As long as there is hardware or product connected to the Internet and data interaction, this is called the Internet of Things. The Internet of Things describes a world in which almost anything can be intelligently connected and communicated. In other words, with the Internet of Things, the physical world is becoming a big information system [11, 12].


### 2.1.2. Features of the Internet of Things

From the perspective of communication objects and communication processes, the basic feature of the Internet of Things is the process of describing and embodying the information interaction between things, people, and things. The basic characteristics of the Internet of Things can be summed up as holistic perception, transmission, and intelligent processing. First, the Internet of Things is connected by things. Second, information is exchanged and there is communication between things. When the Internet of Things connects different items, it always has to do something; otherwise, what is the use of connecting? Because information exchange and communication are the most fundamental requirements of all networks and the Internet of Things is essentially a network, the Internet of Things also has the characteristics of information exchange and communication, but the information exchange and communication are between things and things. Furthermore, the Internet of Things is industrial. The Internet of Things is with industry attributes, leaving its industry concept; the Internet of Things is a pseudoproposition, only in an industry; the Internet of Things programs and applications are universal. Finally, the objects of the Internet of Things are connected to many things connected to connected terminal devices. The End Devices of the Internet of Things are not a few but many. Just like social networks, the more people join, the more valuable they are, and that applies to the Internet of Things. When the Internet of Things collects very little data, it is of little value because it may not be representative; and when a lot of data is collected and a mass is reached , its value is reflected, because we can do big data analysis of this data and discover certain patterns and then develop solutions for specific industries to improve industry efficiency [13, 14].


### 2.1.3. Weaknesses in the Security of Smart Devices in IoT Systems

The emergence of the Internet of Things has set off a new revolution in the global information industry; with the development of information technology, the Internet of Things has been deeply into every aspect of people’s lives. With the increasing application of the Internet of Things, the information security issues in the environment of the Internet of Things are becoming more and more prominent. Attacks on IoT systems are often carried out step by side from point to surface, and attackers will first attempt to target the target struck. There are usually two ways to select a target: one is to scan the surrounding network environment or specific target network environment to find a possible security vulnerability in the surrounding network environment of intelligent devices; the other is to directly select the value of intelligent devices or intelligent device users to carry out targeted attacks, which are usually more hidden and the corresponding losses are greater [15, 16]. When designing the computer network system, certain windows and back doors will be reserved. Although it brings a lot of convenience for users to use and common resources, it also brings about many security risks. The application of the Internet of Things is oriented to all walks of life in the society. This effectively solves the problems of remote monitoring, control, and transmission. However, the security risks of the Internet of Things in the perception, transmission, and processing stages may extend to the actual industrial network. These security risks have long been lurking in IoT terminals, IoT sensing nodes, and IoT transmission channels, waiting for opportunities to carry out attacks, undermining the security of industrial systems, and even threatening national security. The Internet of Things technology in my country has risen late, and many technologies and standard systems are not yet complete. Compared with the developed countries in the world, the level is still very low. My country has not yet mastered the core technology of the Internet of Things and currently can only rely on foreign countries. Based on this, malicious attackers may set up obstacles in technology, destroy the Internet of Things system, and affect the security of the Internet of Things.


### 2.1.4. Application of the Internet of Things in Smart Home

The difference between the smart home lighting system and the traditional lighting system is that the intelligent lighting system based on the Internet of Things sensor technology has the function of multipoint operation and centralized control, the function of light lighting and dark adjustment, the full open and the memory function, and the function of timing control and scene setting, which conforms to the principle of energy saving and consumption reduction because the multifunctional meeting meets people’s diversified needs. Based on the three-layer architecture of the perception layer, network layer, and application layer of the Internet of Things, the intelligent home security system uses human detectors, smoke detectors, and so forth to achieve real-time collection of security protection information and uses ZigBee technology to form a wireless sensor network [16, 17].


### 2.1.5. The Development of the Internet of Things Industry

When cash becomes WeChat and Alipay, when shopping becomes Taobao, when calling a taxi becomes a call to a drip, when “Hello” becomes “What is your WIFI password?,” and when, in reality, each of us unknowingly becomes a node of the connection of all things, digitalization has become an important driving force for the development of modern society; connectivity has become the main theme of the future society; and the Internet of Things has made everything simple and powerful. In recent years, with the rapid development of a new generation of information technology, the Internet of Things as an important part of the new generation of information technology, many countries have considered the development of the Internet of Things industry as a national strategy, while the Internet of Things industry is also an important booster of the future national economy. As the price of IoT devices and infrastructure continues to fall, the use of IoT devices by businesses is becoming more and more popular. This also means that businesses need to pay more attention to the security of the Internet of Things. More intelligent technology will be integrated into the daily family life, intelligent kitchen will make cooking more easily, intelligent monitoring will make the home security system more powerful, and intelligent desk and intelligent wall are expected to enter life. We are going to get more and more free time, and that is all about the changes that IoT technology is bringing about [18, 19].


## 2.1.1. Definition of the Internet of Things

The Internet of Things is essentially an extension of the Internet. It is a science and technology that describes the interconnection between things The term is closely related to RFID as a method of communication, but it may also include other sensor technologies, wireless technologies, or QR codes. The essence of the Internet of Things is the Internet, except that the terminal is no longer a computer (PC, server) but an embedded computer system and its accompanying sensors. The Internet of Things is important because the object itself which can be digitized to represent itself becomes something bigger than the object. Objects are no longer just related to their users but are now connected to surrounding objects and database data. When many objects act in unison, they are called “environmental intelligence.” As long as there is hardware or product connected to the Internet and data interaction, this is called the Internet of Things. The Internet of Things describes a world in which almost anything can be intelligently connected and communicated. In other words, with the Internet of Things, the physical world is becoming a big information system [11, 12].


## 2.1.2. Features of the Internet of Things

From the perspective of communication objects and communication processes, the basic feature of the Internet of Things is the process of describing and embodying the information interaction between things, people, and things. The basic characteristics of the Internet of Things can be summed up as holistic perception, transmission, and intelligent processing. First, the Internet of Things is connected by things. Second, information is exchanged and there is communication between things. When the Internet of Things connects different items, it always has to do something; otherwise, what is the use of connecting? Because information exchange and communication are the most fundamental requirements of all networks and the Internet of Things is essentially a network, the Internet of Things also has the characteristics of information exchange and communication, but the information exchange and communication are between things and things. Furthermore, the Internet of Things is industrial. The Internet of Things is with industry attributes, leaving its industry concept; the Internet of Things is a pseudoproposition, only in an industry; the Internet of Things programs and applications are universal. Finally, the objects of the Internet of Things are connected to many things connected to connected terminal devices. The End Devices of the Internet of Things are not a few but many. Just like social networks, the more people join, the more valuable they are, and that applies to the Internet of Things. When the Internet of Things collects very little data, it is of little value because it may not be representative; and when a lot of data is collected and a mass is reached , its value is reflected, because we can do big data analysis of this data and discover certain patterns and then develop solutions for specific industries to improve industry efficiency [13, 14].


## 2.1.3. Weaknesses in the Security of Smart Devices in IoT Systems

The emergence of the Internet of Things has set off a new revolution in the global information industry; with the development of information technology, the Internet of Things has been deeply into every aspect of people’s lives. With the increasing application of the Internet of Things, the information security issues in the environment of the Internet of Things are becoming more and more prominent. Attacks on IoT systems are often carried out step by side from point to surface, and attackers will first attempt to target the target struck. There are usually two ways to select a target: one is to scan the surrounding network environment or specific target network environment to find a possible security vulnerability in the surrounding network environment of intelligent devices; the other is to directly select the value of intelligent devices or intelligent device users to carry out targeted attacks, which are usually more hidden and the corresponding losses are greater [15, 16]. When designing the computer network system, certain windows and back doors will be reserved. Although it brings a lot of convenience for users to use and common resources, it also brings about many security risks. The application of the Internet of Things is oriented to all walks of life in the society. This effectively solves the problems of remote monitoring, control, and transmission. However, the security risks of the Internet of Things in the perception, transmission, and processing stages may extend to the actual industrial network. These security risks have long been lurking in IoT terminals, IoT sensing nodes, and IoT transmission channels, waiting for opportunities to carry out attacks, undermining the security of industrial systems, and even threatening national security. The Internet of Things technology in my country has risen late, and many technologies and standard systems are not yet complete. Compared with the developed countries in the world, the level is still very low. My country has not yet mastered the core technology of the Internet of Things and currently can only rely on foreign countries. Based on this, malicious attackers may set up obstacles in technology, destroy the Internet of Things system, and affect the security of the Internet of Things.


## 2.1.4. Application of the Internet of Things in Smart Home

The difference between the smart home lighting system and the traditional lighting system is that the intelligent lighting system based on the Internet of Things sensor technology has the function of multipoint operation and centralized control, the function of light lighting and dark adjustment, the full open and the memory function, and the function of timing control and scene setting, which conforms to the principle of energy saving and consumption reduction because the multifunctional meeting meets people’s diversified needs. Based on the three-layer architecture of the perception layer, network layer, and application layer of the Internet of Things, the intelligent home security system uses human detectors, smoke detectors, and so forth to achieve real-time collection of security protection information and uses ZigBee technology to form a wireless sensor network [16, 17].


## 2.1.5. The Development of the Internet of Things Industry

When cash becomes WeChat and Alipay, when shopping becomes Taobao, when calling a taxi becomes a call to a drip, when “Hello” becomes “What is your WIFI password?,” and when, in reality, each of us unknowingly becomes a node of the connection of all things, digitalization has become an important driving force for the development of modern society; connectivity has become the main theme of the future society; and the Internet of Things has made everything simple and powerful. In recent years, with the rapid development of a new generation of information technology, the Internet of Things as an important part of the new generation of information technology, many countries have considered the development of the Internet of Things industry as a national strategy, while the Internet of Things industry is also an important booster of the future national economy. As the price of IoT devices and infrastructure continues to fall, the use of IoT devices by businesses is becoming more and more popular. This also means that businesses need to pay more attention to the security of the Internet of Things. More intelligent technology will be integrated into the daily family life, intelligent kitchen will make cooking more easily, intelligent monitoring will make the home security system more powerful, and intelligent desk and intelligent wall are expected to enter life. We are going to get more and more free time, and that is all about the changes that IoT technology is bringing about [18, 19].


## 2.2. Principles and Classification of Wireless Charging

### 2.2.1. Wireless Charging Design

The charger consists of three parts: the transmit controller, the receiving controller, and the charging monitoring. The entire project is designed based on electromagnetic coupling, which generates a magnetic field from the energy transmission coil, and the receiving coil is induced to the electric potential and then processed by the receiving controller to enable the wireless charging of the device. In order to improve the stability of the output voltage, a detection unit is designed to detect the output voltage in real time and transmit the test results to the control unit, which monitors the charging status of the electrical device according to the results, determines the value of the transmission voltage and transmission power, and controls the control signal to the signal modulation unit. According to the results, the control unit monitors the charging status of the electrical device, determines the value of the transmission voltage and transmission power and controls it accordingly, and transmits the control signal to the signal modulation unit, which transmits the control signal back to the transmitter, changes the transmit coil transmission power, and controls the charging process. The output voltage is stabilized. The receiver controller simultaneously completes the indicative control of the working state of the receiving end. The transmission control circuit consists of a high-frequency high-power power supply chip and a power transmission chip as the main components. The receiving controller is mainly composed of electromagnetic coupling receiving circuit and power supply circuit, and the receiver directly affects the transmission efficiency, in order to output stable voltage and current. The power transmitter of a small wireless charging system is integrated on the charging plate, while the power receiving end is integrated on an electrical device (such as a mobile phone), and the power receiver can also be integrated into the specialized electrical device housing in order to improve the versatility of the device. In order to improve the control accuracy, the system transmitter and receiver control are controlled using the supporting intelligent management chips BQ500211 and BQ51013 developed specifically for wireless charging systems by Texas Instruments. When working, the transmitter controller simultaneously receives the detection information on the transmit coil and the information returned by the receiving signal modulation unit, the summary analysis of these two kinds of information, forming the corresponding control information to control the inverter circuit, by changing the current frequency of the transmit coil to change the transmission power. In the design of the voltage current measurement program, the AD conversion is required when making voltage measurement, and the hardware system is designed with a 12-bit AD converter that comes with the inside of the microcontroller, so the appropriate registers need to be configured in the software design. To achieve the effect of modal conversion [20–22], the first step is to configure the control register of the ADC:(1)ut=λ1f1ut+λ2f2ut+⋯+λmfmut.In the above formula,λ represents the weight of f. The control unit monitors the charging status of the electrical equipment, determines the value of the transmission voltage and transmission power and performs corresponding control, and then transmits the control signal to the signal modulation unit, and the signal modulation unit transmits the control signal back to the transmitter and changes the transmission power of the transmitting coil to optimization λ.In the design of charging power measurement program, there are many calculation methods for electrical power based on the data available from the actual circuit, and the common formula is(2)P=Wt+∑i=1nw×2t2.In the above formula,P represents transmission consumption; Wrepresents the height of the receiving antenna; w represents the height of the transmitting antenna; t is the signal constant.(3)w=UItt.In the above formula,w stands for power; U stands for voltage; I stands for current through electrical appliances; t stands for signal constant.(4)t=UI×∑i=1nt3w,p=U2R,z=I2R,where P is the electrical power; when you know the total power consumed in a certain period of time, you can calculate the power, and by knowing the voltage and current the power can also be calculated.The formula is(5)PCharge=UCharge×ICharge.In the hollow coupling coil scheme, the energy stored in sensor is(6)W=12Li2.Depending on the amount of power the charger is to transmit, the wireless transmission inductance of the sender and receiver is calculated to be 33 H. The factors that affect inductor parameters in hollow coupled inductors are wire diameter, coil diameter, and winding number, and the hollow coil inductor can be calculated according to the following formula:(7)L=n×μoRlnRr−1.75,μo=4π×10−7Hm.


### 2.2.2. Wireless Charger Security Requirements

In recent years, wireless charger technology has developed rapidly. In order to reduce the various safety issues that occur during the use of wireless chargers, we need to regulate the safety issues of wireless chargers and obtain maximum control Wireless chargers work so that they do not need to be cabled to electronics to transfer power to the batteries in your electronics. In order to protect the safety of consumers, wireless chargers must be fully tested. First of all, in order to evaluate the safety performance under normal working conditions of the product, it is necessary to carry out heat test. Products are at excessive temperature for a long time; direct damage for causing burns or making certain parts of the product may become a source of ignition. Indirect damage is the insulation or mechanical properties that affect the product’s own materials. In addition, fire testing is required. Controlling flame spread is a passive method of protection, we can choose and use components, wiring, and materials additional safety protection to reduce flame spread. If necessary, a second additional safety guard is used, such as a fire protection housing. This method is suitable for any type of device. There is also a method of isolation. When required, in order to reduce the likelihood of continuous flame burning or flame spread, a minimum isolation requirement between a potential ignition source and a combustible material can be achieved using distance isolation or the use of fireproof isolation, which in certain cases can be the required PCB board. Therefore, the wireless charger’s housing and internal PCB board fire performance need to meet the standards, in order to ensure that the fire does not spread the flame, to minimize the loss. Finally, foreign object scans are carried out. Foreign object detection is the most important and indispensable safety feature of wireless chargers. Foreign objects in the detection of foreign bodies are mainly ferromagnetic metals, such as pushpins and coins. The ferromagnetic metal itself is a closed circuit [23, 24]. When it is placed in a changing magnetic field, the flux through this closed circuit changes, creating an induced current inside the ferromagnetic metal. The inductive current flows through the metal’s interior and loses, causing the metal to start heating, which is the vortex effect. When the wireless charging system is working properly, there is a changing magnetic field between the transmitter and the receiving end, and when a metal foreign body appears in the magnetic field, the metal raises the temperature. Reaching a certain temperature can damage the wireless charging product. The role of foreign object detection is that when a foreign object is placed on top of the wireless charging base, the wireless charger should be able to detect it [25–27].


### 2.2.3. Types of Wireless Chargers

Two types of wireless chargers are commonly used in the market: one is electromagnetic induction, and the other is magnetic resonance type. They differ in how they work, making them different in performance and work characteristics. At present, the most common wireless chargers type on the market is electromagnetic induction, which can be made into round plates or square plates or placed directly in the home of small tables; this charging method is safer, more flexible, and more convenient and has stable performance, high energy conversion rate, and a wide range of applications [28]. The composition of the field resonance wireless charger is shown in Figure 1; it consists of an energy transmitter and an energy receiver, and when the two devices are adjusted to the same frequency or resonate at a specific frequency, they can exchange each other’s energy to realize the concept of wireless charging. Compared with electromagnetic induction chargers, electromagnetic resonance can be transmitted over longer distances compared to electromagnetic induction methods and produce smaller electrical power losses. Magnetic resonance is different from electromagnetic induction, eliminating the need for a complete match between coils. Therefore, there is no need to place electronic products precisely in an area [29].Figure 1
Principle of electromagnetic induction.


### 2.2.4. The Arrangement Algorithm of the Wireless Charger

Conventional sensor nodes are usually powered by batteries. Battery power is limited, and the absence of which limits the overall life of the sensor network. Wireless energy transmission technology wirelessly sends energy from the charger to the sensor, thus solving the problem completely. An important problem in the wireless rechargeable sensor network is the arrangement of wireless chargers, that is, how to efficiently arrange the charger, so as to maximize the overall charging utility of the sensor network [30]. In addition, for the first time, a charging model with a charger was established based on the measured data, and a series of innovative methods were proposed to transform the problem, and an efficient algorithm with an approximate ratio of (1 − 1/e) was designed: TCP CDG algorithm. There are algorithms to solve this problem. The results of the simulation experiment show the validity of the CDG algorithm. Compared to the two other random algorithms proposed, the performance of the CDG algorithm is improved by nearly 300% and 100%, respectively [31]. CDG is actually a traditional algorithm based on packet loss plus an antinoise mechanism. The original algorithm based on packet loss is to continuously fill the buffer as a means until the buffer is filled and packet loss occurs to reduce the window. However, sometimes packet loss may occur for reasons other than congestion. At this time, the window will still be reduced according to the algorithm, which greatly reduces the bandwidth utilization. After adding this CDG’s RTT gradient antinoise mechanism, the utilization of network bandwidth is greatly improved. However, it may aggravate congestion, so CDG has built-in backoff algorithm [32].


### 2.2.5. Structural Parameters for Wireless Charging

Using the principle of electromagnetic coupling, the electrical energy is transmitted to the equipment to be charged by means of wireless electromagnetic energy. Its structure is mainly composed of power management module, transmit circuit module, receive conversion module, charging module, and solar power supply module. Electromagnetic coupling can be processed through the electromagnetic emission platform through the functional circuit, to achieve contactless one-to-many charging. More targeted wireless charging devices on the market generally use the core coil charging mode, which is more efficient and the device will optimize the circuit to do very thoroughly, using A3941299, TD1410, Schottky diodes, and other high-quality components to make the charging model larger and more versatile and have better performance. This device is to consider solar energy as a second power supply module, not only in line with the mainstream thinking of energy conservation in the current society and for the work to increase the use of the environment, which is now-on-the-market products do not have [33].


### 2.2.6. Bottlenecks in the Promotion of Wireless Chargers

In the process of popularization and use, wireless chargers are favored by people by virtue of novel charging methods Wireless chargers have been on display for people to choose from at many mobile phone stores, but demand has been much lower than expected. Apple has confirmed that its AirPower wireless charger project has been halted because the technology did not meet its expected high standards. Apple plans to charge up to three different devices at a time, which can be an Apple Watch, an AirPods headset, and an iPhone. This requires a special multicoil technology where the device can operate without having to find a specific location on the charging plate. It also comes with software that shows the current charging of three devices on your iPhone at the same time. However, the actual technical level is not yet able to meet this requirement; therefore, in the promotion process, technical barriers are still the main reason. The wireless charger of the domestic brand Xiaomi can only achieve one-to-one contact charging, with strict position requirements, but, through practical research, Xiaomi charger’s charging speed, FOD foreign object detection function, and cooling function are relatively perfect.


## 2.2.1. Wireless Charging Design

The charger consists of three parts: the transmit controller, the receiving controller, and the charging monitoring. The entire project is designed based on electromagnetic coupling, which generates a magnetic field from the energy transmission coil, and the receiving coil is induced to the electric potential and then processed by the receiving controller to enable the wireless charging of the device. In order to improve the stability of the output voltage, a detection unit is designed to detect the output voltage in real time and transmit the test results to the control unit, which monitors the charging status of the electrical device according to the results, determines the value of the transmission voltage and transmission power, and controls the control signal to the signal modulation unit. According to the results, the control unit monitors the charging status of the electrical device, determines the value of the transmission voltage and transmission power and controls it accordingly, and transmits the control signal to the signal modulation unit, which transmits the control signal back to the transmitter, changes the transmit coil transmission power, and controls the charging process. The output voltage is stabilized. The receiver controller simultaneously completes the indicative control of the working state of the receiving end. The transmission control circuit consists of a high-frequency high-power power supply chip and a power transmission chip as the main components. The receiving controller is mainly composed of electromagnetic coupling receiving circuit and power supply circuit, and the receiver directly affects the transmission efficiency, in order to output stable voltage and current. The power transmitter of a small wireless charging system is integrated on the charging plate, while the power receiving end is integrated on an electrical device (such as a mobile phone), and the power receiver can also be integrated into the specialized electrical device housing in order to improve the versatility of the device. In order to improve the control accuracy, the system transmitter and receiver control are controlled using the supporting intelligent management chips BQ500211 and BQ51013 developed specifically for wireless charging systems by Texas Instruments. When working, the transmitter controller simultaneously receives the detection information on the transmit coil and the information returned by the receiving signal modulation unit, the summary analysis of these two kinds of information, forming the corresponding control information to control the inverter circuit, by changing the current frequency of the transmit coil to change the transmission power. In the design of the voltage current measurement program, the AD conversion is required when making voltage measurement, and the hardware system is designed with a 12-bit AD converter that comes with the inside of the microcontroller, so the appropriate registers need to be configured in the software design. To achieve the effect of modal conversion [20–22], the first step is to configure the control register of the ADC:(1)ut=λ1f1ut+λ2f2ut+⋯+λmfmut.In the above formula,λ represents the weight of f. The control unit monitors the charging status of the electrical equipment, determines the value of the transmission voltage and transmission power and performs corresponding control, and then transmits the control signal to the signal modulation unit, and the signal modulation unit transmits the control signal back to the transmitter and changes the transmission power of the transmitting coil to optimization λ.In the design of charging power measurement program, there are many calculation methods for electrical power based on the data available from the actual circuit, and the common formula is(2)P=Wt+∑i=1nw×2t2.In the above formula,P represents transmission consumption; Wrepresents the height of the receiving antenna; w represents the height of the transmitting antenna; t is the signal constant.(3)w=UItt.In the above formula,w stands for power; U stands for voltage; I stands for current through electrical appliances; t stands for signal constant.(4)t=UI×∑i=1nt3w,p=U2R,z=I2R,where P is the electrical power; when you know the total power consumed in a certain period of time, you can calculate the power, and by knowing the voltage and current the power can also be calculated.The formula is(5)PCharge=UCharge×ICharge.In the hollow coupling coil scheme, the energy stored in sensor is(6)W=12Li2.Depending on the amount of power the charger is to transmit, the wireless transmission inductance of the sender and receiver is calculated to be 33 H. The factors that affect inductor parameters in hollow coupled inductors are wire diameter, coil diameter, and winding number, and the hollow coil inductor can be calculated according to the following formula:(7)L=n×μoRlnRr−1.75,μo=4π×10−7Hm.


## 2.2.2. Wireless Charger Security Requirements

In recent years, wireless charger technology has developed rapidly. In order to reduce the various safety issues that occur during the use of wireless chargers, we need to regulate the safety issues of wireless chargers and obtain maximum control Wireless chargers work so that they do not need to be cabled to electronics to transfer power to the batteries in your electronics. In order to protect the safety of consumers, wireless chargers must be fully tested. First of all, in order to evaluate the safety performance under normal working conditions of the product, it is necessary to carry out heat test. Products are at excessive temperature for a long time; direct damage for causing burns or making certain parts of the product may become a source of ignition. Indirect damage is the insulation or mechanical properties that affect the product’s own materials. In addition, fire testing is required. Controlling flame spread is a passive method of protection, we can choose and use components, wiring, and materials additional safety protection to reduce flame spread. If necessary, a second additional safety guard is used, such as a fire protection housing. This method is suitable for any type of device. There is also a method of isolation. When required, in order to reduce the likelihood of continuous flame burning or flame spread, a minimum isolation requirement between a potential ignition source and a combustible material can be achieved using distance isolation or the use of fireproof isolation, which in certain cases can be the required PCB board. Therefore, the wireless charger’s housing and internal PCB board fire performance need to meet the standards, in order to ensure that the fire does not spread the flame, to minimize the loss. Finally, foreign object scans are carried out. Foreign object detection is the most important and indispensable safety feature of wireless chargers. Foreign objects in the detection of foreign bodies are mainly ferromagnetic metals, such as pushpins and coins. The ferromagnetic metal itself is a closed circuit [23, 24]. When it is placed in a changing magnetic field, the flux through this closed circuit changes, creating an induced current inside the ferromagnetic metal. The inductive current flows through the metal’s interior and loses, causing the metal to start heating, which is the vortex effect. When the wireless charging system is working properly, there is a changing magnetic field between the transmitter and the receiving end, and when a metal foreign body appears in the magnetic field, the metal raises the temperature. Reaching a certain temperature can damage the wireless charging product. The role of foreign object detection is that when a foreign object is placed on top of the wireless charging base, the wireless charger should be able to detect it [25–27].


## 2.2.3. Types of Wireless Chargers

Two types of wireless chargers are commonly used in the market: one is electromagnetic induction, and the other is magnetic resonance type. They differ in how they work, making them different in performance and work characteristics. At present, the most common wireless chargers type on the market is electromagnetic induction, which can be made into round plates or square plates or placed directly in the home of small tables; this charging method is safer, more flexible, and more convenient and has stable performance, high energy conversion rate, and a wide range of applications [28]. The composition of the field resonance wireless charger is shown in Figure 1; it consists of an energy transmitter and an energy receiver, and when the two devices are adjusted to the same frequency or resonate at a specific frequency, they can exchange each other’s energy to realize the concept of wireless charging. Compared with electromagnetic induction chargers, electromagnetic resonance can be transmitted over longer distances compared to electromagnetic induction methods and produce smaller electrical power losses. Magnetic resonance is different from electromagnetic induction, eliminating the need for a complete match between coils. Therefore, there is no need to place electronic products precisely in an area [29].Figure 1
Principle of electromagnetic induction.


## 2.2.4. The Arrangement Algorithm of the Wireless Charger

Conventional sensor nodes are usually powered by batteries. Battery power is limited, and the absence of which limits the overall life of the sensor network. Wireless energy transmission technology wirelessly sends energy from the charger to the sensor, thus solving the problem completely. An important problem in the wireless rechargeable sensor network is the arrangement of wireless chargers, that is, how to efficiently arrange the charger, so as to maximize the overall charging utility of the sensor network [30]. In addition, for the first time, a charging model with a charger was established based on the measured data, and a series of innovative methods were proposed to transform the problem, and an efficient algorithm with an approximate ratio of (1 − 1/e) was designed: TCP CDG algorithm. There are algorithms to solve this problem. The results of the simulation experiment show the validity of the CDG algorithm. Compared to the two other random algorithms proposed, the performance of the CDG algorithm is improved by nearly 300% and 100%, respectively [31]. CDG is actually a traditional algorithm based on packet loss plus an antinoise mechanism. The original algorithm based on packet loss is to continuously fill the buffer as a means until the buffer is filled and packet loss occurs to reduce the window. However, sometimes packet loss may occur for reasons other than congestion. At this time, the window will still be reduced according to the algorithm, which greatly reduces the bandwidth utilization. After adding this CDG’s RTT gradient antinoise mechanism, the utilization of network bandwidth is greatly improved. However, it may aggravate congestion, so CDG has built-in backoff algorithm [32].


## 2.2.5. Structural Parameters for Wireless Charging

Using the principle of electromagnetic coupling, the electrical energy is transmitted to the equipment to be charged by means of wireless electromagnetic energy. Its structure is mainly composed of power management module, transmit circuit module, receive conversion module, charging module, and solar power supply module. Electromagnetic coupling can be processed through the electromagnetic emission platform through the functional circuit, to achieve contactless one-to-many charging. More targeted wireless charging devices on the market generally use the core coil charging mode, which is more efficient and the device will optimize the circuit to do very thoroughly, using A3941299, TD1410, Schottky diodes, and other high-quality components to make the charging model larger and more versatile and have better performance. This device is to consider solar energy as a second power supply module, not only in line with the mainstream thinking of energy conservation in the current society and for the work to increase the use of the environment, which is now-on-the-market products do not have [33].


## 2.2.6. Bottlenecks in the Promotion of Wireless Chargers

In the process of popularization and use, wireless chargers are favored by people by virtue of novel charging methods Wireless chargers have been on display for people to choose from at many mobile phone stores, but demand has been much lower than expected. Apple has confirmed that its AirPower wireless charger project has been halted because the technology did not meet its expected high standards. Apple plans to charge up to three different devices at a time, which can be an Apple Watch, an AirPods headset, and an iPhone. This requires a special multicoil technology where the device can operate without having to find a specific location on the charging plate. It also comes with software that shows the current charging of three devices on your iPhone at the same time. However, the actual technical level is not yet able to meet this requirement; therefore, in the promotion process, technical barriers are still the main reason. The wireless charger of the domestic brand Xiaomi can only achieve one-to-one contact charging, with strict position requirements, but, through practical research, Xiaomi charger’s charging speed, FOD foreign object detection function, and cooling function are relatively perfect.


## 2.3. Data Security and Communication Network

When using the Internet or other communication systems for data communication, the system itself often does not fully consider the security measures and security of the information, and the security problems caused by this are becoming more and more serious. Data security in the general sense refers to the security of data stored locally, while the concept of network security generally refers to the security of data transmission over the network.


### 2.3.1. Threats to Data Communication

The attacker only observes and analyzes a certain protocol data power distribution unit without disturbing the information flow. Even if these data are not easy for an attacker to understand, he can also understand the address and identity of the protocol entity that is communicating by observing the protocol control information part of the power distribution unit and study the length and transmission frequency of the power distribution unit in order to understand the nature of the data exchanged. This passive attack is also called traffic analysis.


### 2.3.2. The Goal of Data Communication Security

To deal with passive attacks, data encryption technology can be used. It can be said that this is the most effective way to deal with passive attacks. Active attacks are relatively more methods, but they are also very targeted. The combination of identification technology and encryption technology is appropriate. When current computing is dealing with security issues, in addition to the feasibility of the method, the speed of the processor is getting stronger and stronger, and it has begun to enter the era of multicore parallelism.


## 2.3.1. Threats to Data Communication

The attacker only observes and analyzes a certain protocol data power distribution unit without disturbing the information flow. Even if these data are not easy for an attacker to understand, he can also understand the address and identity of the protocol entity that is communicating by observing the protocol control information part of the power distribution unit and study the length and transmission frequency of the power distribution unit in order to understand the nature of the data exchanged. This passive attack is also called traffic analysis.


## 2.3.2. The Goal of Data Communication Security

To deal with passive attacks, data encryption technology can be used. It can be said that this is the most effective way to deal with passive attacks. Active attacks are relatively more methods, but they are also very targeted. The combination of identification technology and encryption technology is appropriate. When current computing is dealing with security issues, in addition to the feasibility of the method, the speed of the processor is getting stronger and stronger, and it has begun to enter the era of multicore parallelism.


## 3. Experiment

### 3.1. Experimental Settings

Based on the research of smart wireless chargers based on the Internet of Things, the model design of smart wireless chargers is realized by using mathematical analysis and wireless charging technology. Mathematical analysis is the oldest and most basic branch of analysis. It generally refers to general theories such as calculus, infinite series, and analytic functions as the main content and includes their theoretical foundations (real numbers, functions, measurements, and limits). Basic theory is a relatively complete subject of mathematics and is also a basic course for university mathematics majors. The content of mathematical analysis research includes real numbers, complex numbers, real functions, and complex variable functions. The method of mathematical analysis is related to its geometry, but as long as any mathematical space has a defined neighborhood (topological space) or a definition of the distance between two objects (metric space), this article will use this to study the relationship between the wireless network and the Internet of Things. In order to assemble a complete charger, the experiment needed to include a wireless charging table, associated chip areas, and a home gateway that was used in combination with it. Through the research of the control circuit, transmitting circuit, and receiving circuit of the wireless charger, as well as the detailed analysis and calculation of the wireless charging system, this paper designs a wireless charger. Applying electromagnetic field sensing, radio wave transmission, and resonance, it tries to achieve the shortest charging time and the best quality in the case of preventing the charger from heating and burning during charging.


### 3.2. Experimental Principles

#### 3.2.1. Electromagnetic Induction Principle

Electromagnetic induction is one of the ways wireless charging is done. The principle of electromagnetic induction is to transmit electrical energy through electromagnetic induction between two coils, each with a coil in the part of the transmit and receive circuits, the transmit coil, and the receiving coil, respectively. The transmit coil will transmit the source electrical energy into space by electromagnetic wave, and the receiving coil will be coupled to generate induction current at both ends, while storing part of the electrical energy in the coil and capacitor, and finally providing the electronic products through a rectifier filter-wave regulator circuit. The core of the electromagnetic induction charger is the AC that produces a certain frequency change in the transmit coil by designing an oscillating circuit, and the changing current generates a changing magnetic field in the space around the coil, which generates a sense of electric potential in the receiving coil, and the alternating current can be generated when the receiving coil partially forms a closed circuit. The AC at the receiving end is then transmitted to the electronic product after reflux and regulatory, thus achieving the purpose of wireless charging.


### 3.3. Circuit Design

#### 3.3.1. Power Amplification Circuit Design

The commonly used power amplification circuits are Class B dual power complementary symmetrical power amplification and Classes A and B single power complementary symmetrical power amplification. The Class B dual power complementary symmetrical power amplification circuit is relatively simple but requires dual power supply and crossover distortion. Classes A and B single-supply complementary symmetrical power amplification circuit can overcome crossover distortion, but the circuit is relatively complex and its bias voltage is not easy to adjust. Considering that the emission coil is mainly used to transmit energy, the distortion of the waveform is not important, and the circuit should be as simple and practical as possible, given that there is sufficient output. Therefore, the design uses Class E power amplification.


#### 3.3.2. Oscillation Circuit Design

The oscillation circuit is partly using the NE555 output PWM wave, which then amplifies the output signal through the push-pull circuit to control the break-off of the MOS tube, which in turn sends electrical energy through the transmit coil. The PWM wave output of the oscillation circuit is a waveform formed by multiple high- and low-level transitions, so the oscillation circuit should be oscillating.


#### 3.3.3. Reception Circuit Design

The main function of the receiving circuit part is to provide the power received by the receiving coil to the electronic product, so the voltage, current, and ripple coefficient of the receiving circuit output are required to be relatively high, and the battery charging protection should also be considered, mainly to prevent voltage mutations and excessive current. However, circuits such as regulated chips and microcontrollers are large and relatively expensive. Considering that the receiving end circuit should be embedded in the electronic products at the end, the circuit structure should be as simple as possible while ensuring the stability of the circuit, so as to reduce the circuit volume and facilitate the integration of the later stage.


### 3.4. Experimental Steps

(1)
A wireless charger is designed under the condition of studying the control circuit, transmit circuit, and receiving circuit of the wireless charger.(2)
Charge electrical appliances of different power, and measure the degree of charging and the heating temperature of the charger.(3)
During the experiment, record all the charging degree and the heating temperature of the charger, analyze its law over time, and then make a summary.


## 3.1. Experimental Settings

Based on the research of smart wireless chargers based on the Internet of Things, the model design of smart wireless chargers is realized by using mathematical analysis and wireless charging technology. Mathematical analysis is the oldest and most basic branch of analysis. It generally refers to general theories such as calculus, infinite series, and analytic functions as the main content and includes their theoretical foundations (real numbers, functions, measurements, and limits). Basic theory is a relatively complete subject of mathematics and is also a basic course for university mathematics majors. The content of mathematical analysis research includes real numbers, complex numbers, real functions, and complex variable functions. The method of mathematical analysis is related to its geometry, but as long as any mathematical space has a defined neighborhood (topological space) or a definition of the distance between two objects (metric space), this article will use this to study the relationship between the wireless network and the Internet of Things. In order to assemble a complete charger, the experiment needed to include a wireless charging table, associated chip areas, and a home gateway that was used in combination with it. Through the research of the control circuit, transmitting circuit, and receiving circuit of the wireless charger, as well as the detailed analysis and calculation of the wireless charging system, this paper designs a wireless charger. Applying electromagnetic field sensing, radio wave transmission, and resonance, it tries to achieve the shortest charging time and the best quality in the case of preventing the charger from heating and burning during charging.


## 3.2. Experimental Principles

### 3.2.1. Electromagnetic Induction Principle

Electromagnetic induction is one of the ways wireless charging is done. The principle of electromagnetic induction is to transmit electrical energy through electromagnetic induction between two coils, each with a coil in the part of the transmit and receive circuits, the transmit coil, and the receiving coil, respectively. The transmit coil will transmit the source electrical energy into space by electromagnetic wave, and the receiving coil will be coupled to generate induction current at both ends, while storing part of the electrical energy in the coil and capacitor, and finally providing the electronic products through a rectifier filter-wave regulator circuit. The core of the electromagnetic induction charger is the AC that produces a certain frequency change in the transmit coil by designing an oscillating circuit, and the changing current generates a changing magnetic field in the space around the coil, which generates a sense of electric potential in the receiving coil, and the alternating current can be generated when the receiving coil partially forms a closed circuit. The AC at the receiving end is then transmitted to the electronic product after reflux and regulatory, thus achieving the purpose of wireless charging.


## 3.2.1. Electromagnetic Induction Principle

Electromagnetic induction is one of the ways wireless charging is done. The principle of electromagnetic induction is to transmit electrical energy through electromagnetic induction between two coils, each with a coil in the part of the transmit and receive circuits, the transmit coil, and the receiving coil, respectively. The transmit coil will transmit the source electrical energy into space by electromagnetic wave, and the receiving coil will be coupled to generate induction current at both ends, while storing part of the electrical energy in the coil and capacitor, and finally providing the electronic products through a rectifier filter-wave regulator circuit. The core of the electromagnetic induction charger is the AC that produces a certain frequency change in the transmit coil by designing an oscillating circuit, and the changing current generates a changing magnetic field in the space around the coil, which generates a sense of electric potential in the receiving coil, and the alternating current can be generated when the receiving coil partially forms a closed circuit. The AC at the receiving end is then transmitted to the electronic product after reflux and regulatory, thus achieving the purpose of wireless charging.


## 3.3. Circuit Design

### 3.3.1. Power Amplification Circuit Design

The commonly used power amplification circuits are Class B dual power complementary symmetrical power amplification and Classes A and B single power complementary symmetrical power amplification. The Class B dual power complementary symmetrical power amplification circuit is relatively simple but requires dual power supply and crossover distortion. Classes A and B single-supply complementary symmetrical power amplification circuit can overcome crossover distortion, but the circuit is relatively complex and its bias voltage is not easy to adjust. Considering that the emission coil is mainly used to transmit energy, the distortion of the waveform is not important, and the circuit should be as simple and practical as possible, given that there is sufficient output. Therefore, the design uses Class E power amplification.


### 3.3.2. Oscillation Circuit Design

The oscillation circuit is partly using the NE555 output PWM wave, which then amplifies the output signal through the push-pull circuit to control the break-off of the MOS tube, which in turn sends electrical energy through the transmit coil. The PWM wave output of the oscillation circuit is a waveform formed by multiple high- and low-level transitions, so the oscillation circuit should be oscillating.


### 3.3.3. Reception Circuit Design

The main function of the receiving circuit part is to provide the power received by the receiving coil to the electronic product, so the voltage, current, and ripple coefficient of the receiving circuit output are required to be relatively high, and the battery charging protection should also be considered, mainly to prevent voltage mutations and excessive current. However, circuits such as regulated chips and microcontrollers are large and relatively expensive. Considering that the receiving end circuit should be embedded in the electronic products at the end, the circuit structure should be as simple as possible while ensuring the stability of the circuit, so as to reduce the circuit volume and facilitate the integration of the later stage.


## 3.3.1. Power Amplification Circuit Design

The commonly used power amplification circuits are Class B dual power complementary symmetrical power amplification and Classes A and B single power complementary symmetrical power amplification. The Class B dual power complementary symmetrical power amplification circuit is relatively simple but requires dual power supply and crossover distortion. Classes A and B single-supply complementary symmetrical power amplification circuit can overcome crossover distortion, but the circuit is relatively complex and its bias voltage is not easy to adjust. Considering that the emission coil is mainly used to transmit energy, the distortion of the waveform is not important, and the circuit should be as simple and practical as possible, given that there is sufficient output. Therefore, the design uses Class E power amplification.


## 3.3.2. Oscillation Circuit Design

The oscillation circuit is partly using the NE555 output PWM wave, which then amplifies the output signal through the push-pull circuit to control the break-off of the MOS tube, which in turn sends electrical energy through the transmit coil. The PWM wave output of the oscillation circuit is a waveform formed by multiple high- and low-level transitions, so the oscillation circuit should be oscillating.


## 3.3.3. Reception Circuit Design

The main function of the receiving circuit part is to provide the power received by the receiving coil to the electronic product, so the voltage, current, and ripple coefficient of the receiving circuit output are required to be relatively high, and the battery charging protection should also be considered, mainly to prevent voltage mutations and excessive current. However, circuits such as regulated chips and microcontrollers are large and relatively expensive. Considering that the receiving end circuit should be embedded in the electronic products at the end, the circuit structure should be as simple as possible while ensuring the stability of the circuit, so as to reduce the circuit volume and facilitate the integration of the later stage.


## 3.4. Experimental Steps

(1)
A wireless charger is designed under the condition of studying the control circuit, transmit circuit, and receiving circuit of the wireless charger.(2)
Charge electrical appliances of different power, and measure the degree of charging and the heating temperature of the charger.(3)
During the experiment, record all the charging degree and the heating temperature of the charger, analyze its law over time, and then make a summary.


## 4. Discussion

### 4.1. Data Analysis

Wireless charging breaks the way that electric energy transmission can only rely on direct contact transmission of wires. It belongs to noncontact transmission and can avoid contact sparks, sliding wear, and explosive electric shocks that may be caused by contact electric energy transmission. There are three main ways of wireless power transmission: electromagnetic induction, electromagnetic resonance, and electromagnetic radiation. Electromagnetic induction is currently the most commonly used wireless power transmission method. Its technology has been mass-produced, and its production cost is lower than other technologies, and it has passed safety and market verification.(1)
This is shown in Figure2 and Table 1; in the same time, measure the ratio of electrical heat, perform multiple experiments to obtain the average, and do the figure as follows. As can be seen from the figure, charging a desktop computer emits the most heat because it requires the most power; and some computer mice and hand warmers and other small power appliances have less heat. However, because the experimental equipment required is limited, multibrand comparison cannot be made, and the data may not be accurate; there is a large error. But the overall heat search related rules are within the scope of the provisions, so the safety of wireless chargers can be ensured, and they can later replace wired chargers.Figure 2
Electrical heating ratio in the same amount of time.Table 1
Electrical heating ratio.
Warm hands treasureMobile phoneLaptop computerDesktop computerMouseWireless charger14572


### 4.2. Analysis of Efficiency

The cable charger realizes the optimized Wsa + Pulse charging characteristic curve through the microcomputer control technology, and the charging current automatically decreases with the increase of the charging voltage of the battery; combined with the pulse charging method at the end of charging, the charging effect is more ideal. The principle of capacity balance is used to intelligently judge the sufficiency of the battery to ensure that the battery is adequate, neither undercharged nor overcharged. Charging also has the function of dynamic tracking and adjustment of charging parameters and complete protection functions.As shown in Table2 and Figures 3 and 4, in order to compare the degree of charging the appliance at the same time, taking the mobile phone as an example, several experiments were carried out and the average value was taken. As can be seen from the data on the left, Apple has the highest charging efficiency, followed by Huawei mobile phones. Compared with the traditional limited charger charging level, the trend of the charging level of each mobile phone has not changed much. However, in general, the charging efficiency of mobile phones of various famous brands has been improved significantly under the charging of wireless chargers. By calculation, the charging efficiency is increased about 1.4∼1.6 times. This indicates that the wireless charger has a high charging efficiency.Table 2
Comparison between a wired charger and a wireless charger.
OPPOAppleMISamsungHuaweiWireless charger5.97.5767.4Cable charger5.56.975.76.8Figure 3
The ratio of charging degree in the same amount of time.Figure 4
Comparison between a wired charger and a wireless charger.


### 4.3. Test Transmission Efficiency

When testing the transmission efficiency of wireless charging equipment, this design mainly tests the relationship between the input current, output voltage, and output current with the distance between the transmitting coil and the receiving coil under a load. In the test, the input voltage U1 at the transmitting end is adjusted to 5 V, and the current at the input end and the current at the output end are measured. The test results show the following: when the input voltage is constant, with the increase of the distance between the transmitting coil and the receiving coil, the output efficiency of the system will be significantly reduced, and whether the geometric center of the two coils is on the same axis has an important effect on the transmission efficiency. The comparison relationship is shown in Figure5 and Table 3.Figure 5
The ratio of charging degree of traditional wired charger in the same time.Table 3
Wireless charger.
OPPOAppleMISamsungHuaweiWireless charger5.97.5767.4


### 4.4. Advantages of the Method in This Paper

Here the wireless charger method designed in this paper and the traditional wireless charger method are analyzed for the number of iterations, and the results are shown in Figure6.Figure 6
Comparative analysis of wireless charger methods designed in this paper.As can be seen from Figure6, value is the number of final iterations of the three. At the same time of wireless charging, the final iteration times when the three different algorithms get the path results, it can be seen that the wireless charging method designed in this paper has a longer working time than the QI standard and the traditional wireless charging method.


## 4.1. Data Analysis

Wireless charging breaks the way that electric energy transmission can only rely on direct contact transmission of wires. It belongs to noncontact transmission and can avoid contact sparks, sliding wear, and explosive electric shocks that may be caused by contact electric energy transmission. There are three main ways of wireless power transmission: electromagnetic induction, electromagnetic resonance, and electromagnetic radiation. Electromagnetic induction is currently the most commonly used wireless power transmission method. Its technology has been mass-produced, and its production cost is lower than other technologies, and it has passed safety and market verification.(1)
This is shown in Figure2 and Table 1; in the same time, measure the ratio of electrical heat, perform multiple experiments to obtain the average, and do the figure as follows. As can be seen from the figure, charging a desktop computer emits the most heat because it requires the most power; and some computer mice and hand warmers and other small power appliances have less heat. However, because the experimental equipment required is limited, multibrand comparison cannot be made, and the data may not be accurate; there is a large error. But the overall heat search related rules are within the scope of the provisions, so the safety of wireless chargers can be ensured, and they can later replace wired chargers.Figure 2
Electrical heating ratio in the same amount of time.Table 1
Electrical heating ratio.
Warm hands treasureMobile phoneLaptop computerDesktop computerMouseWireless charger14572


## 4.2. Analysis of Efficiency

The cable charger realizes the optimized Wsa + Pulse charging characteristic curve through the microcomputer control technology, and the charging current automatically decreases with the increase of the charging voltage of the battery; combined with the pulse charging method at the end of charging, the charging effect is more ideal. The principle of capacity balance is used to intelligently judge the sufficiency of the battery to ensure that the battery is adequate, neither undercharged nor overcharged. Charging also has the function of dynamic tracking and adjustment of charging parameters and complete protection functions.As shown in Table2 and Figures 3 and 4, in order to compare the degree of charging the appliance at the same time, taking the mobile phone as an example, several experiments were carried out and the average value was taken. As can be seen from the data on the left, Apple has the highest charging efficiency, followed by Huawei mobile phones. Compared with the traditional limited charger charging level, the trend of the charging level of each mobile phone has not changed much. However, in general, the charging efficiency of mobile phones of various famous brands has been improved significantly under the charging of wireless chargers. By calculation, the charging efficiency is increased about 1.4∼1.6 times. This indicates that the wireless charger has a high charging efficiency.Table 2
Comparison between a wired charger and a wireless charger.
OPPOAppleMISamsungHuaweiWireless charger5.97.5767.4Cable charger5.56.975.76.8Figure 3
The ratio of charging degree in the same amount of time.Figure 4
Comparison between a wired charger and a wireless charger.


## 4.3. Test Transmission Efficiency

When testing the transmission efficiency of wireless charging equipment, this design mainly tests the relationship between the input current, output voltage, and output current with the distance between the transmitting coil and the receiving coil under a load. In the test, the input voltage U1 at the transmitting end is adjusted to 5 V, and the current at the input end and the current at the output end are measured. The test results show the following: when the input voltage is constant, with the increase of the distance between the transmitting coil and the receiving coil, the output efficiency of the system will be significantly reduced, and whether the geometric center of the two coils is on the same axis has an important effect on the transmission efficiency. The comparison relationship is shown in Figure5 and Table 3.Figure 5
The ratio of charging degree of traditional wired charger in the same time.Table 3
Wireless charger.
OPPOAppleMISamsungHuaweiWireless charger5.97.5767.4


## 4.4. Advantages of the Method in This Paper

Here the wireless charger method designed in this paper and the traditional wireless charger method are analyzed for the number of iterations, and the results are shown in Figure6.Figure 6
Comparative analysis of wireless charger methods designed in this paper.As can be seen from Figure6, value is the number of final iterations of the three. At the same time of wireless charging, the final iteration times when the three different algorithms get the path results, it can be seen that the wireless charging method designed in this paper has a longer working time than the QI standard and the traditional wireless charging method.


## 5. Conclusions

In this experiment, the first group measures the ratio of heat to electrical appliances in the same time period. From the data, after a rigorous grasp of the structure, the experimental measurement of electrical appliances is more than the traditional cable chargers caused by much less heat and by looking for relevant standards to prove that wireless chargers even for a long-time transmission are completely safe and reliable. Then the degree of charging the appliance at the same time is compared. In the case of mobile phones, many experiments were conducted and averaged. It can be seen that the transmission efficiency of wireless chargers can make them completely replace the wired chargers. For tablet computers, notebook computers, and other devices that require higher power, the output power of this article obviously cannot meet the requirements. On the basis of this article, we can study the wireless charger with medium output power to provide wireless charging functions for more portable devices. To reduce the cost of the wireless charger, the demodulation circuit part can be replaced by a program, and proper program design can also ensure the stability of communication.Experimental data show that this Internet of Things-based smart wireless charger can fully replace wired chargers in 99% of small appliances; the charging efficiency of large electrical appliances such as desktop computer is also 1.4 to 1.6 times higher. In the research of related scholars in recent years, their charging efficiency was not as high as our current experimental results. Now, due to the continuous optimization of technical methods, our experimental results are also constantly approaching perfection. This Internet of Things-based intelligent wireless charger requires sophisticated devices, can be relatively expensive, and requires relatively complex technology, requiring large- and medium-sized enterprises that are larger to manufacture in large quantities. But the advantages are obvious: allowing efficient and convenient charging of electrical appliances and being more efficient and safe. Experimental data show that this Internet of Things-based intelligent wireless charger will have a major breakthrough in the future concept of charging.With the increasing innovation of science and technology in China, the electronics industry is booming, and a number of new disciplines are springing up and expanding, and it is no longer a dream for science and technology to change their lives. Wireless chargers have gradually become the new way of life that people pursue, from technology concepts to commercial products. Electronic products should not only be functionally reformed, but also they creatively dominated the market. The rise of wireless charging technology is the product of the combination of innovation and technology. Innovation drives product innovation, and creativity drives the development of core technologies. Wireless charging technology shows a broad prospect of development; of course, this needs further research and improvement of the core technology, and the market will become more and more large; and wireless technology is not only used in battery products as a power source of various equipment, in medical devices, aerospace, transportation, underwater detection, and other fields of wireless charging technology but also has a wide range of applications, involving military, industrial, medical, transportation, electricity, aerospace, space station, satellites, warships, aircraft carriers, energy conservation and environmental protection, portable communications equipment, and other industries. For example, in the field of medical devices, the development of wireless charging technology has changed the way medical implantable electronic systems are powered and promoted the development of the medical electronics industry, such as the development of pacemakers, cochlear implants, and ICPT charging methods Extracorporeal energy transfer and RFPT, for example, can reduce the risk of infection in vivo, while addressing the problem of limited battery life. Therefore, the development potential of wireless charging technology is unlimited, and it is also a topic worth studying.



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*Source: 5558914-2021-11-10.xml*