Patent Publication Number: US-2020300923-A1

Title: Automatic test system of wireless charging system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This present application is a continuation of International Patent Application No. PCT/CN2018/083639, filed on Apr. 19, 2018, titled “Automatic Test System of Wireless Charging System”, which claims the benefit of and priority to Chinese Patent Application No. 201711324093.3, filed on Dec. 13, 2017. The above-referenced applications are herein incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to a wireless charging system, particularly, to an automated testing system for testing and characterizing a wireless charging system. 
     BACKGROUND 
     Wireless charging is an evolving technology that may bring a new level of convenience of charging electronic devices. In a wireless charging system, particularly an inductive wireless charging system, energy is transferred from one or more power transmitter (TX) coils to one or more power receiver (RX) coils through coupling of magnetic fields. 
     A magnetic coil can generate magnetic fields, and the coupling of the magnetic fields between TX and RX coils may influence a charging efficiency of a wireless charging system. To improve user experiences and guarantee a reliability of the wireless charging, a wireless charging system should be thoroughly tested and characterized. Commonly used testing systems for characterizing a wireless charging system usually involve lots of human interactions, such as manually adjusting testing setups. Human interactions may introduce experimental errors and affect reliability of testing results. In addition, testing of a wireless charging system may include different testing conditions and scenarios for a wireless charging system at different stages, and the currently available testing systems cannot meet all different testing requirements and support all different testing scenarios. 
     The present application proposes an automated testing system for testing a wireless charging system. This automated testing system is able to evaluate a plurality of parameters for a wireless charging system at all development stages. In addition, it can be controlled both manually and automatically by a software program, thus the reliability and consistency of the testing results can be guaranteed. 
     SUMMARY 
     One aspect of the present disclosure is directed to an automated testing system for testing a wireless charging system. The automated testing system may include a mechanical arm, a testing plane, a dock station and a controller computer. The mechanical arm is configured to hold a first device-under-test (DUT) clamp. The testing plane is configured to hold a second DUT clamp. The dock station is connected to the mechanical arm. The controller computer is configured to control the mechanical arm and receive testing data. The second DUT clamp is configured to hold a device-under-test of the wireless charging system, and the first DUT clamp is configured to hold a testing device for testing the device-under-test and generating the testing data. 
     Another aspect of the present disclosure is directed to an automated testing system for testing a wireless charging system. The system may include a mechanical arm, a testing plane configured to hold a device-under-test of the wireless charging system, a dock station connected to the mechanical arm, and a controller computer configured to control the mechanical arm and receive testing data. The mechanical arm may comprise a distal section configured to be releasably coupled to a plurality of types of devices selected from a clamp, a probe, and a testing device. The controller computer may comprise a non-transitory computer-readable medium that stores program code to control testing processes, measure and analyze the testing data. 
     Another aspect of the present disclosure is directed to an automated testing system for testing a wireless charging system. The system may include a mechanical arm configured to hold a first DUT clamp, a testing plane configured to hold a second DUT clamp, a dock station connected to the mechanical arm, and a controller computer configured to control the mechanical arm and receive testing data. The first and second DUT clamps may include a connector configured to be electrically coupled with devices for testing. The mechanical arm may comprise an internal data line through which the device coupled by the first DUT clamp communicates with the controller computer. 
     It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which constitute a part of this disclosure, illustrate several non-limiting embodiments and, together with the description, serve to explain the disclosed principles. 
         FIG. 1  is a graphical representation illustrating an automated testing system, consistent with exemplary embodiments of the present disclosure. 
         FIG. 2  is a graphical representation illustrating an automated testing system installed with a device-under-test (DUT) clamp, consistent with exemplary embodiments of the present disclosure. 
         FIG. 3  is a graphical representation illustrating an automated testing system for measuring magnetic fields generated by a magnetic coil, consistent with exemplary embodiments of the present disclosure. 
         FIG. 4  is a graphical representation illustrating an automated testing system for measuring an efficiency and charging area of a wireless charging system, consistent with exemplary embodiments of the present disclosure. 
         FIG. 5  is a graphical representation illustrating an automated testing system for measuring a coupling coefficient of a wireless charging system, consistent with exemplary embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments consistent with the present invention do not represent all implementations consistent with the invention. Instead, they are merely examples of systems and methods consistent with aspects related to the invention. 
     A development of a wireless charging system may go through a plurality of stages, and at each stage, testing and characterization of the wireless charging system may request different conditions and scenarios. For example, in an early coil-design stage, the wireless charging system may need to be evaluated for uniformity of magnetic fields generated by magnetic coils. In a prototype validation stage, an estimation of efficiency and critical voltages (such as a rectifier voltage) of the wireless charging system may be required. In a post product stage, a charging area and a temperature of the wireless charging system may need to be characterized. Further, in a product certification stage, a radiation of the wireless charging system may need to be tested and limited. In this disclosure, we present an automated testing system for testing and characterizing a wireless charging system. The automated testing system can be used to test a wireless charging system in various stages, and meet various testing conditions and scenarios. 
       FIG. 1  shows an automated testing system  100 , consistent with exemplary embodiments of the present disclosure. The system  100  may comprise a number of components, some of which may be optional. In some embodiments, the system  100  may include many more components than those shown in  FIG. 1 . However, it is not necessary that all of these components be shown in order to disclose an illustrative embodiment. 
     As shown in  FIG. 1 , the system  100  may include a mechanical arm  101 , a device-under-test (DUT) clamp  102 A mounted on the mechanical arm  101 , a testing plane  103 , a stationary DUT clamp  102 B mounted on the testing plane  103 , a dock station  104 , and a controller computer  105 . 
     In some embodiments, a DUT clamp can have any form suitable for holding a testing device or a device-under-test. For example, the DUT clamp can be a brace, a screw, a socket, etc. The testing device and device-under-test can be, for example, a magnetic coil, a printed circuit board (PCB), a magnetic probe, a mobile phone, or any wireless charging related electronic product. 
     The mechanical arm  101  may include a distal section configured to be releasably coupled to a plurality of types of devices selected from a clamp, a probe, a magnetic coil testing device, etc. In some embodiments, the mechanical arm  101  is configured to hold the DUT clamp  102 A. In order to move and rotate in x, y and z directions, the mechanical arm  101  may include sliding and rotating motors. The mechanical arm  101  may be configured to hold and rotate the DUT clamp  102 A in a [−180, 180] degree range about a center axis of the DUT clamp  102 A, and move the DUT clamp  102 A along the x, y and z directions to reach different positions. 
     The testing plane  103  may be a flat plane that is horizontally positioned with the surface of the plane parallel to the ground, and is also parallel to the x-y plane. The DUT clamp  102 B (i.e., stationary DUT clamp) may be installed on the testing plane  103 , and may be used to secure a device-under-test during testing. 
     Positions of the testing device and the device-under-test may be interchangeable. In one embodiment, the testing device may be secured on a movable DUT clamp  102 A on the mechanical arm  101 , and the device-under-test may be secured on a stationary DUT clamp  102 B on the testing plane  103 . In another embodiment, the testing device may be secured on a stationary DUT clamp  102 B on the testing plane  103 , and the device-under-test may be secured on a movable DUT clamp  102 A on the mechanical arm  101 . 
     The dock station  104  may include the controller computer  105 . The mechanical arm  101  may be rotatably mounted on the dock station  104 . The testing plane  103  may also be connected to the dock station  104 . The controller computer  105  may drive the motors on the mechanical arm  101  to move the movable DUT clamp  102 A to a target position. The controller computer  105  may provide a user-friendly interface and provide several pre-defined testing processes for user to choose. The controller computer  105  may be coupled with the mechanical arm  101  and the testing plate  103 , and may control the mechanical arm  101  by driving the sliding and rotating motors. The controller computer  105  may also provide a user-friendly interface and software programs to control the testing process and analyze the testing results. In addition, the controller computer  105  may read testing data from instrument or DUT clamps to complete a post-processing procedure automatically. 
       FIG. 2  is a graphical representation illustrating a DUT clamp  202  installed on an automated testing system  200  according to exemplary embodiments of the present disclosure. In addition to holding a testing device and a device-under-test, the DUT clamp  202  may be also configured to communicate with the controller computer  205  through internal data lines built in the mechanical arm  201 , and accordingly the DUT clamp  202  may be designed with different interfaces  206 . 
     In some embodiments, the interface  206  may include one or more electrical connectors including a plurality of hook-up wires for measuring voltages. The hook-up wires can couple with testing pins of a testing device, for example, a RX PCB. Through the coupling of the hook-up wires and the testing pins, output voltages from the testing device can be measured. The measured data then can be sent to the controller computer  205 , so that the controller computer  205  can monitor and record voltage values detected by the testing device during testing. 
     In some embodiments, the interface  206  may include a data connector, and the data connector can couple with the testing device for data exchange between the testing device and the controller computer  205 . The controller computer  205  may send controlling commends and receive feedbacks during the testing. The interface  206  allows the testing device to be electrically coupled and communicate with the controller computer  205 . Thus, the automated testing system  200  can perform an in-situ testing on the wireless charging system. 
       FIG. 3  shows an automated testing system  300  for measuring magnetic field (H-field) generated by a magnetic coil, consistent with exemplary embodiments of the present disclosure. The system  300  may comprise a number of components, some of which may be optional. In some embodiments, the system  300  may include many more components than those shown in  FIG. 3 . However, it is not necessary that all of these components be shown in order to disclose an illustrative embodiment. 
     As shown in  FIG. 3 , the system  300  may include a mechanical arm  301 , an H-field probe  302 , a testing plane  303 , a dock station  304 , a controller computer  305 , as well as a magnetic coil  311 , a feeding power supply  312 , a cable  313 , an amplifier  314 , a testing instrument  315  and a data cable  316 . 
     In some embodiments, a stationary DUT clamp may be placed on the testing plane  303  to hold a DUT, for example, the magnetic coil  311 , a PCB prototype or a wireless charging related product. A device-under-test is interchangeable based on different testing requirements and scenarios. In some embodiments, the DUT is a magnetic coil. In some embodiments, the DUT is a TX coil. 
     In some embodiments, a movable DUT clamp may be used to hold the H-field probe  302  to measure the magnetic fields generated by the magnetic coil  311 . The H-field probe  302  may have different types. In one embodiment, the probe  302  is an H-field strength probe that can detect magnitude and frequency of the magnetic fields. In another embodiment, the probe  302  is an H-field phase probe that can detect phase information of the magnetic fields. The probe  302  may also differ in frequency ranges, H-field sensitivity levels, etc. Based on testing scenarios and requirements, a specific H-field probe can be selected. The H-field probe  302  is connected to the controller computer  305 , which controls and moves the H-field probe  302  to different positions. 
     The magnetic coil  311  may be configured to couple with the feeding power supply  312 . The feeding power supply  312  may be configured to supply power, e.g., an electrical current, to the magnetic coil  311 . The amplifier  314  is configured to couple with the H-field probe  302  and the testing instrument  315 , and amplify the testing data measured by the H-field probe  302 . The cable  313  may be a 50 Ohm coaxial cable, and may be configured to connect the H-field probe  302 , the amplifier  314  and the testing instrument  315 . 
     The testing instrument  315  may be different depending on the testing requirements. In some embodiments, the testing instrument  315  may be a spectrum analyzer. It may be configured to receive the testing data from the amplifier  314 , and perform a spectrum analysis on the testing data (the measured magnetic fields) to extract spectrum information of the measured magnetic fields. The testing instrument  315  may also be configured to connect with the controller computer  305  through the data cable  316 . The data cable  316  can be a USB cable, a general purpose interface bus (GPIB) cable, or an Ethernet cable. The controller computer  305  may send controlling commands to the testing instrument  315 , and the testing instrument  315  may deliver the analyzed testing data to the controller computer  305 . 
     In some other embodiments, the system  300  may include a separate computer system, not mounted on the dock station  304 , that is connected with the testing instrument  315 , and is used to receive and analyze the testing data. 
     The above-discussed automated testing system  300  may also be used for different testing requirements and scenarios. In some embodiments, the system  300  may be configured to evaluate uniformity of the magnetic fields generated by the magnetic coil; in some embodiments, the system  300  may be used to identify a position of a main radiation source of a prototype PCB or a wireless charging related product; in some other embodiments, the system  300  may also be used to estimate strength and frequency of magnetic fields generated by a wireless charging related product (for example, a charging pad). 
       FIG. 4  shows an automated testing system  400  for measuring an efficiency and charging area of a wireless charging system, consistent with exemplary embodiments of the present disclosure. The system  400  may comprise a number of components, some of which may be optional. In some embodiments, the system  400  may include many more components than those shown in  FIG. 4 . However, it is not necessary that all of these components be shown in order to disclose an illustrative embodiment. 
     As shown in  FIG. 4 , the system  400  may include a mechanical arm  401 , a DUT clamp  402 A mounted on the mechanical arm  401 , a testing plane  403 , a DUT clamp  402 B mounted on the testing plane  403 , a dock station  404 , a controller computer  405 , as well as a RX board  411  with a RX coil, a TX board  412  with a TX coil, and a power source  413 . 
     The DUT clamp  402 A is a movable DUT clamp, mounted on the mechanical arm  401 , and is configured to hold and move the RX board  411 , or a wireless power receiver related product. The DUT clamp  402 B is a stationary DUT clamp, placed on the testing plane  403 , and is configured to hold the TX board  412 , or a wireless charging pad. 
     The power source  413  is configured to supply power, e.g., an electrical current, to the TX board  412 , which is configured to input the power to the TX coil. The TX coil may be magnetically coupled with the RX coil, and the RX coil is wireless charged by the TX coil. The power transferred during the wireless charging may be delivered to the RX board  411 , which may be further output to a load. 
     The RX board  411  and TX board  412  may include a plurality of testing pins which can couple with the connectors, e.g., hook-up wires, on the DUT clamps  402 A and  402 B. The connectors allow the devices for testing to be electrically coupled and communicate with the controller computer or other testing instruments. Through the coupling between the testing pins and hook-up wires, an input voltage and current of the TX board  412 , and an output voltage and current of the RX board  411  can be detected and transferred to the controller computer  405 . Other parameters, such as a rectifier voltage on the RX board  411 , can also be measured and transferred to the controller computer  405 . The controller computer  405  may also determine a relative position between the TX and RX coils by moving the RX board  411  to any position within a defined range by the mechanical arm  401 . Thus, the controller computer  405  is able to obtain parameters used for calculating a wireless charging efficiency at any relative position. The wireless charging efficiency at any relative position can be defined as: 
     
       
         
           
             η 
             = 
             
               
                 
                   V 
                   out 
                 
                  
                 
                   I 
                   out 
                 
               
               
                 
                   V 
                   in 
                 
                  
                 
                   I 
                   in 
                 
               
             
           
         
       
     
     Here, V out , I out , V in  and I in  stand for an output voltage, an output current of the RX coil and an input voltage, an input current of the TX coil respectively. 
     The above-discussed automated testing system  400  may also be used for different testing requirements and scenarios. In some embodiments, the system  400  may be configured to measure a charging efficiency at different distances and offsets between the TX and RX coils; in some embodiments, the system  400  may be used to characterize a charging area; in some other embodiments, the system  400  may also be used to monitor changes of parameters (e.g., rectifier voltage) during a wireless charging process. 
       FIG. 5  shows an automated testing system  500  for measuring coupling coefficients, consistent with exemplary embodiments of the present disclosure. The system  500  may comprise a number of components, some of which may be optional. In some embodiments, the system  500  may include many more components than those shown in  FIG. 5 . However, it is not necessary that all of these components be shown in order to disclose an illustrative embodiment. 
     As shown in  FIG. 5 , the system  500  may include a mechanical arm  501 , a DUT clamp  502 A fixed on the mechanical arm  501 , a testing plane  503 , a DUT clamp  502 B fixed on the testing plane  503 , a dock station  504 , a controller computer  505 , as well as a RX coil  511 , one or more TX coil  512 , a cable  513 , a testing instrument  514 , and a data cable  515 . 
     The DUT clamp  502 A which is mounted on the mechanical arm  501 , is a movable DUT clamp, and is configured to hold and move the RX coil  511 . The DUT clamp  502 B which is placed on the testing plane  503 , is a stationary DUT clamp, and is configure to hold the TX coil  512 . The TX coil  512  may include one or more TX coils that are placed at different positions. In some embodiments, additional magnetic materials, such as ferrite sheets can be attached to the TX and RX coils. 
     The cable  513  may be a 50 Ohm coaxial cable, and may be configured to connect the RX coil  511 , the TX coil  512  and the testing instrument  514 . 
     The testing instrument  514  may be different depending on the testing requirements. In some embodiments, the testing instrument  514  may be a vector network analyzer (VNA). The VNA  514  may include two ports: port 1 and port 2 which are connected with the TX and RX coils by the cable  513  respectively. The VNA  514  may also be configured to connect with the controller computer  505  through the data cable  515 . The data cable  515  can be a USB cable, a general purpose interface bus (GPIB) cable, or an Ethernet cable. The controller computer  505  may send controlling commands to the VNA  514 , and the VNA  514  may deliver testing results to the controller computer  505 . 
     A VNA is a testing system that may be used to enable a radio frequency (RF) performance of RF and microwave devices to be characterized in terms of network scattering parameters (S-parameters). The S-parameters describe electrical behaviors of linear electrical networks when undergoing various steady state stimuli by electrical signals. Many electrical properties of networks of components (for example, inductors, capacitors, resistors) may be expressed using S-parameters. The S-parameters of the wireless charging system can be measured using the VNA  514  and sent to the controller computer  505 . A coupling coefficient between the TX and RX coils then can be extracted from the S-parameters. Also, the measured S-parameters can help to build coil models for further simulation work. 
     The above-discussed automated testing system  500  may also be used for different testing requirements and scenarios. In some embodiments, the system  500  may be used to measure a coupling coefficient between the TX and RX coils at different distances and offsets; in some other embodiments, the system  500  may also be used to obtain parameters of a wireless charging system, such as self-inductance, mutual inductance, to establish simulation models. 
     Note that one or more of the functions described above can be performed by software or firmware stored in memory and executed by a processor, or stored in program storage and executed by a processor. The software or firmware can also be stored and/or transported within any non-transitory computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “computer-readable medium” can be any medium that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable read-only memory (EPROM) (magnetic), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory such as compact flash cards, secured digital cards, USB memory devices, memory sticks, and the like. 
     The invention described and claimed herein is not to be limited in scope by the specific preferred embodiments disclosed herein, as these embodiments are intended as illustrations of several aspects of the invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.