Abstract:
An electronic lock that interacts with a mobile device is presented. In accordance with some embodiments, an electronic lock includes a wireless power receiver configured to receiver power from a mobile device; a processor coupled to receive power from the wireless power receiver; a memory coupled to the processor and to receive power from the wireless power receiver; a communication unit coupled to the processor and to receive power from the wireless power receiver, the communication unit configured to communicate with the mobile device; and an actuator coupled to the processor and to receive power from the wireless power receiver. The processor executes instructions stored in a memory for authenticating the mobile device, and providing signals to the actuator according to instructions received from the mobile device once it is authenticated. The mobile device provides power to the electronic lock and instructs it to lock or unlock a locking mechanism.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Application Ser. No. 62/357,289, filed on Jun. 30, 2016, entitled “Wireless Powered Digital Lock” which is herein incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    Embodiments of the present invention are related to wireless power receivers and, specifically, to wireless powered digital locks. 
       DISCUSSION OF RELATED ART 
       [0003]    Mobile devices, for example smart phones and tablets, are increasingly using wireless power charging systems. However, there are multiple different standards for wireless transfer of power, which utilize a variety of different transmission frequencies. Frequencies used can vary widely, for example from less than 200 KHz to over 6.78 MHz. 
         [0004]    The more common standards for wireless transmission of power include the Alliance for Wireless Power (A4WP) standard and the Wireless Power Consortium standard, the Qi Standard. Under the A4WP standard, for example, up to 50 watts of power can be inductively transmitted to multiple charging devices in the vicinity of a coil at a power transmission frequency of around 6.78 MHz. Under the Wireless Power Consortium, the Qi specification, an inductive coupling system is utilized to charge a single device at the resonance frequency of the device. In the Qi standard, the receiving device coil is placed in close proximity with the transmission coil while in the A4WP standard, the receiving device coil is placed near the transmitting coil, potentially along with other receiving coils that belong to other charging devices. 
         [0005]    Devices that can utilize wireless power transmission incur the cost and the space limitations of power coils and circuitry associated with the wireless power. Therefore, there is a need to develop uses for the wireless power equipment. 
       SUMMARY 
       [0006]    In accordance with aspects of the presents, an electronic lock that interacts with a mobile device is presented. In accordance with some embodiments, an electronic lock includes a wireless power receiver configured to receiver power from a mobile device; a processor coupled to receive power from the wireless power receiver; a memory coupled to the processor and to receive power from the wireless power receiver; a communication unit coupled to the processor and to receive power from the wireless power receiver, the communication unit configured to communicate with the mobile device; and an actuator coupled to the processor and to receive power from the wireless power receiver. The processor executes instructions stored in a memory for authenticating the mobile device, and providing signals to the actuator according to instructions received from the mobile device once it is authenticated. 
         [0007]    In some embodiments, authenticating the mobile device includes generating a pseudo random number; transmitting the pseudo random number to the mobile device; receiving a device session key from the mobile device; and confirming that the device session key is valid. 
         [0008]    A mobile device according to some embodiments includes a wireless power receiver/transmitter; a power storage coupled to the wireless power receiver/transmitter; a processor coupled to the wireless power receiver/transmitter; a communications coupled to the processor; and a memory coupled to the processor, wherein the processor executes instructions stored in the memory for providing power to the electronic lock, receiving a pseudo-random number from the electronic lock, convoluting the pseudo-random number with a pairing key to generate a device session key, transmitting the device session key to the electronic lock, and providing instructions to the electronic lock to open or close a locking mechanism once the electronic lock validated the mobile device. 
         [0009]    These and other embodiments are further discussed below with respect to the following figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  illustrates a wireless power transmission system according to some embodiments of the present invention. 
           [0011]      FIG. 2  illustrates a mobile device utilizing the wireless power transmission to communicate with a digital electronic lock according to some embodiments of the present invention. 
           [0012]      FIG. 3A  illustrates an initial configuration communications between a mobile device and an electronic lock according to some embodiments. 
           [0013]      FIG. 3B  illustrates a locking/unlocking session between the mobile device and the electronic lock according to some embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    In the following description, specific details are set forth describing some embodiments of the present invention. It will be apparent, however, to one skilled in the art that some embodiments may be practiced without some or all of these specific details. The specific embodiments disclosed herein are meant to be illustrative but not limiting. One skilled in the art may realize other elements that, although not specifically described here, are within the scope and the spirit of this disclosure. 
         [0015]    This description and the accompanying drawings that illustrate inventive aspects and embodiments should not be taken as limiting—the claims define the protected invention. Various changes may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known structures and techniques have not been shown or described in detail in order not to obscure the invention. 
         [0016]    Elements and their associated aspects that are described in detail with reference to one embodiment may, whenever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment. 
         [0017]      FIG. 1  illustrates a system  100  for wireless transfer of power. As illustrated in  FIG. 1 , a wireless power transmitter  110  receives power from a power supply  104  into power transmitter  102  to drive a coil  106 , producing a magnetic field. Power supply  104  can be, for example, a battery based supply or may be powered by alternating current for example 120V at 60 Hz. Wireless power transmitter  102  drives coil  106  at, typically, a range of frequencies, typically according to one of the wireless power standards. 
         [0018]      FIG. 1  further shows a mobile device  120  that can be charged with wireless power transmitter  110 . The magnetic field produced by coil  106  induces a current in coil  112 , which results in power being received in a receiver  116 . Receiver  116  receives the power from coil  112  and provides power to the remainder of mobile device  120 . As shown in  FIG. 1 , power receiver  112  may be coupled to charge storage device  130 , which in turn powers the remainder of mobile device  120 . 
         [0019]    As is further illustrated in  FIG. 1 , mobile device  120  may include a processor  122 , a user interface  126 , specific functional circuitry  128  (e.g. cell phone receivers or other functionality used by mobile device  120 ), and memory  124 . Memory  124  can include both volatile and non-volatile memory in order store programming instructions executed by processor  122  and data. 
         [0020]    Mobile device  120  also includes communications  118  coupled with processor  122 . In some embodiments, communications  118 . In some embodiments, communications  118  is coupled to interface  132 , which provides communications with other devices. In some embodiments, interface  132  transmit and receive data using wireless transmission protocols, for example Bluetooth, Zigbee, WiFi or other radio links. In some embodiments, communications  118  may further be coupled to power receiver  116  in order to transmit data through the wireless power coupling by modulating the load. In some embodiments, communications  118  may modulate the load of power receiver  116  with the same frequency as the transmitted power (in-band communications) or at a different frequency (out-of-band communications). In embodiments where communications  118  is coupled to power receiver  116 , transmission of data can be achieved by modulating the load and receipt of data can be achieved through monitoring a frequency modulation of the wireless power received, for example. 
         [0021]    In some embodiments, as shown in  FIG. 1 , wireless power transmitter includes communications  108 , which allows wireless transmitter  110  to receive communications from a receiver through load modulation. Further, transmitter  110  may transmit data by, for example, frequency modulating the wireless power transmitted between coil  106  and coil  112 . 
         [0022]    As shown in  FIG. 1 , then, mobile device  120  can transmit and receive data through the wireless interface  132  and/or, in some embodiments, power receiver  116 . However, mobile device  120  can also utilize power receiver  116  as a power transmitter, thereby wirelessly transferring power from power storage  130  to another device. 
         [0023]      FIG. 2  illustrates use of mobile device  120  with an electronic lock  202 . As illustrated in  FIG. 2 , electronic lock  202  includes a power receiver  206  that wirelessly receives power from a coil  216 . Power receiver  206  provides power to processor  212 , memory  210 , actuator  214 , communications  208 , and interface  218 . As is illustrated, electronic lock  202  may have no internal power source and is powered completely from wireless power through power receiver  206 . As is further illustrated in  FIG. 2 , power receiver  116  of mobile device  120  may function as a wireless power transmitter to transfer power stored in power storage  130  to electronic lock  202  when mobile device  120  is placed in proximity to electronic lock  202 . 
         [0024]    Processor  212  is coupled to memory  210 , which includes both volatile and non-volatile memory to store programming instructions and data. Processor  212  is also coupled to actuator  214 . Actuator  214  receives an actuation signal from processor  212  and, in response, activates an electromechanical interface (for example an armature) to engage or disengage the locking mechanism  204  of lock  202 . 
         [0025]    Processor  212  is further coupled to communications  208 . Communications  208  is coupled to an interface  218  and/or to power receiver  206 . In some embodiments, communications  208  can transmit and receive data through wireless power receiver  206  by monitoring the wireless power for frequency modulation and by applying load modulation. In some embodiments, communications  208  can transmit and receive data through interface  218 , which may represent any wireless transmission such as, for example, Bluetooth, Zigbee, WiFi or other radio links. 
         [0026]    Consequently, mobile device  120  provides power to operate electronic lock  202 . Once in operation, electronic lock  202  can authenticate mobile device  120  and can lock or unlock lock  204 . Electronic lock  202  is powered during the process by mobile device  120  through a wireless power transfer and therefore electronic lock  202  may not include an independent power source such as a separate battery. This prevents the problem that, when using a separate battery to power an electronic lock that fails or is discharged, there is no way to authenticate a user or to lock/unlock lock  204  electronically. 
         [0027]    As is illustrated in  FIG. 2 , mobile device  120  can execute an application that operates power receiver  116  as a transmitter of wireless power and interfaces with electronic lock  202 . Instructions for the application can be stored in memory  124  and be executed by processor  122 . Executing these instructions, processor  122  can operate power receiver  116  as a transmitter of wireless power and communicate with electronic lock  202  through communications  118 . Similarly, memory  210  may include instructions to be executed by processor  212  so that when electronic lock  202  is powered by receiving wireless power in power receiver  206 , processor  212  can communicate with mobile device  120  through communication  208  and unlock and/or lock lock  204  through actuator  214 . 
         [0028]      FIG. 3A  illustrates an initiation process  300  executed by mobile device  120  and electronic lock  202  to initialize lock  202  with mobile device  120 . As shown in  FIG. 3A , device  120  initiates by transmitting power in step  308 . The power is received in step  302 . In steps  304  and  310 , a key Key 0  is negotiated between device  120  and lock  202 . In some embodiments, the initial pairing between device  120  and lock  202  can be accomplished by procedures similarly to that used in Bluetooth pairing of devices. In other communications standards, the negotiation between device  120  and lock  202  establishes that device  120  is an authorized user of lock  202  and assigns the key Key 0  to device  120 . In step  306 , lock  202  stores Key 0  in a non-volatile portion of memory  210 . In step  312 , device  120  stores Key 0  in a non-volatile portion of memory  124 . Storage of Key 0  in non-volatile memory insures that Key 0  is not lost when electronic lock  202  is without power or if power storage  130  of device  120  becomes discharged. Key 0  is the initial pairing key that is established privately when lock  202  is first paired with device  120 . Device  120  may store multiple ones of initial pairing keys that correspond with different ones of locks  202 . Similarly, lock  202  may include multiple ones of initial pair keys that correspond with different ones of devices  202 . 
         [0029]    An example of subsequent interactions between device  120  and lock  202  are illustrated in  FIG. 3B . Again, the interaction begins in step  334  when device  120  transmits power to lock  202  and power is received in step  322 . When powered, lock  202  in step  324  lock  202  can generate a pseudorandom number (PSN), which when convoluted with Key 0  provides a session key KeyN. In step  326 , lock  202  transmits the PSN to step  336  in device  120 . In some embodiments, PSN is encrypted during transmission. In step  338 , device  120  calculates the session key KeyN by convoluting the pairing key Key 0  with the PSN. KeyN is the session key that device  120  must correctly provide to lock  102  in order to operate lock  102  (either open lock  102  or lock lock  102 ). KeyN is the convolution of the decrypted PSN generated in step  324  and the previously established pairing key Key 0  and therefore changes every session to thwart unauthorized use by EM filed interception. 
         [0030]    In step  340 , device  120  transmits the session key KeyN to step  328  of lock  202 . In step  330  of lock  320 , lock  202  validates KeyN. If KeyN is not valid, then lock  202  proceeds to step  344  and stops. If KeyN is valid, then lock  202  proceeds to step  332  to receive instructions. In step  342 , device  120  transmits instructions to lock  202  to lock or unlock lock  202 . In step  344 , lock  202  executes the instructions by providing signals to actuator  214  to lock or unlock locking mechanism  204 . 
         [0031]    The above detailed description is provided to illustrate specific embodiments of the present invention and is not intended to be limiting. Numerous variations and modifications within the scope of the present invention are possible. The present invention is set forth in the following claims.