Living Object Protection and Foreign Object Protection for a Wireless Power Transmission System and Method for Operating a Wireless Power Transmission System

Abstract

An object protection for a wireless power transmission system and a method for operating a wireless power transmission system are disclosed. In an embodiment a wireless power transmission system includes a detection system configured to be sensitive to a material selected from the group consisting of a dielectric material and a metallic material and to monitor at least two parameters selected from the group consisting of a presence of an object, a distance of the object, a temperature of the object, a thermal behavior of the object, a presence of a metallic object, a presence of a dielectric object, and a coverage of the detection system with metallic or dielectric matter, wherein the detection system includes at least one or more sensors selected from the group consisting of an infrared sensor, an ultrasonic sensor, a capacitive sensor and an inductive sensor.

Claims

1-11. (canceled)

12. A wireless power transmission system comprising: a detection system configured to: be sensitive to a material selected from the group consisting of a dielectric material and a metallic material; and monitor at least two parameters selected from the group consisting of a presence of an object, a distance of the object, a temperature of the object, a thermal behavior of the object, a presence of a metallic object, a presence of a dielectric object, and a coverage of the detection system with metallic or dielectric matter, wherein the detection system comprises at least one or more sensors selected from the group consisting of an infrared sensor, an ultrasonic sensor, a capacitive sensor and an inductive sensor.

13. The wireless power transmission system of claim 12, wherein at least one sensor is immune to magnetic and/or electric fields.

14. The wireless power transmission system of claim 12, wherein the wireless power transmission system comprises a plurality of sensor blocks, wherein each sensor block comprises at least one or more sensors, wherein each sensor block is arranged at a position of a perimeter of the wireless power transmission system (WPTS), and wherein each sensor block is aligned to monitor a different segment of an environment of the wireless power transmission system.

15. The wireless power transmission system of claim 12, wherein the sensors are arranged and aligned to monitor the material for each azimuthal angle in a range [0, 360].

16. The wireless power transmission system of claim 12, wherein the sensors are arranged and aligned to monitor the material for each polar angle in a range [0, 90].

17. The wireless power transmission system of claim 12, wherein the wireless power transmission system comprises one or more infrared sensors, and wherein each infrared sensor has an observable area characterized by a field view angle between 120 and 150 in a horizontal plane and in a vertical plane and a search depth between 2 m and 4 m.

18. The wireless power transmission system of claim 12, wherein the wireless power transmission system comprises one or more ultrasonic sensors, and wherein each ultrasonic sensor has an observable area characterized by a field view angle between 80 and 100 in a horizontal plane and in a vertical plane and a search depth between 1 m and 3 m.

19. The wireless power transmission system of claim 12, wherein the wireless power transmission system comprises one or more capacitive sensors, and wherein each capacitive sensor has search depth between 3 cm and 8 cm.

20. The wireless power transmission system of claim 12, wherein the wireless power transmission system comprises one or more inductive sensors, and wherein each inductive sensor has search depth between 3 cm and 8 cm.

21. The wireless power transmission system of claim 12, further comprising a control and processing circuit electrically connected to the sensors and configured to evaluate sensor readings.

22. A method for operating a wireless power transmission system, the method comprising: monitoring a system environment utilizing a plurality of two or more sensors before activating a primary coil; monitoring the system environment during normal operation; and reducing a power rate when a presence of an unwanted object is realized.

23. A wireless power transmission system comprising: a detection system configured to: be sensitive to a material selected from the group consisting of a dielectric material and a metallic material; and monitor at least two parameters selected from the group consisting of a presence of an object, a distance of the object, a temperature of the object, a thermal behavior of the object, a presence of a metallic object, a presence of a dielectric object and a coverage of the detection system with metallic or dielectric matter, wherein the detection system comprises at least one or more sensors selected from the group consisting of an infrared sensor, an ultrasonic sensor, a capacitive sensor and an inductive sensor, wherein the sensors are arranged and aligned to monitor the material for each azimuthal angle in a range [0, 360], and wherein the sensors are arranged and aligned to monitor the material for each polar angle in a range [0, 90].

24. A wireless power transmission system comprising: a detection system that configured to be: sensitive to a material selected from the group consisting of a dielectric material and a metallic material; and monitor at least two parameters selected from the group consisting of a presence of an object, a distance of the object, a temperature of the object, a thermal behavior of the object, a presence on a metallic object, a presence of a dielectric object, and a coverage of the detection system with metallic or dielectric matter, wherein the detection system comprises at least one or more sensors selected from the group consisting of an infrared sensor, an ultrasonic sensor, a capacitive sensor, an inductive sensor, one or more infrared sensors, wherein each infrared sensor has an observable area characterized by a field view angle between 120 and 150 in a horizontal plane and in a vertical plane and a search depth between 2 m and 4 m; and one or more capacitive sensors, wherein each capacitive or inductive sensor has a search depth between 3 cm and 8 cm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In the figures.

[0050] FIG. 1 shows a possible basic distribution of components of a wireless power transmission system WPTS.

[0051] FIG. 2 shows another possible distribution of components.

[0052] FIG. 3 shows a version of a wireless power transmission system including an evaluation circuit.

[0053] FIG. 4 shows an equivalent circuit diagram of an infrared/heat sensor utilizing a thermopile.

[0054] FIG. 5 shows an equivalent circuit diagram of an ultrasonic sensor utilizing two ultrasonic transducers.

[0055] FIG. 6 shows time dependent activities of the two transducers.

[0056] FIG. 7 shows an equivalent circuit diagram of an ultrasonic sensor that needs only a single ultrasonic transduce.

[0057] FIG. 8 illustrates the meanings of azimuth angle and polar angle in a spherical coordinate system.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0058] FIG. 1 shows possible positions of sensors and sensor blocks SB of a wireless power transmission system WPTS. The wireless power transmission system can have a mainly rectangular footprint. Within the footprint, a primary coil PC for transmitting magnetic energy is arranged. The perimeter n of the footprint has a rectangular shape with four edges and four corners. It is possible that each corner and each edge has one sensor block SB that carries the sensors. The sensor blocks and the sensors within the sensor blocks are arranged and aligned in such a way that as much as possible of the environment can be monitored, e.g. one sensor of one sensor block SB can have an observation area OA as illustrated as a cone. The plurality of sensors within the plurality of sensor blocks allows arranging corresponding observation areas that overlap in such a way that a solid angle of n, i.e., the upper hemisphere, can be observed.

[0059] FIG. 2 shows a possible arrangement of sensor blocks SB where each of the four edges of the mainly rectangular footprint carries two sensor blocks SB. Again, the sensor blocks and the sensors within the sensor blocks are arranged and aligned such that observation areas or observation volumes OV are positioned relative to each other that any position that has a minimum distance to the center of the wireless power transmission system is monitored and observed by at least one sensor.

[0060] FIG. 3 illustrates an embodiment of a wireless power transmission system having an evaluation circuit EC that comprises circuitry to evaluate the sensor readings from the sensors within the sensor blocks SB. The results determined by the evaluation circuit EC can be provided to a central processor unit of the wireless power transmission system.

[0061] FIG. 4 shows a possible equivalent circuit diagram of a heat sensor using a thermopile TP. The sensor has a supply terminal ST and an output terminal OUT. Such a sensor is one embodiment of an infrared sensor IS.

[0062] The driver circuit of the sensor has two operational amplifiers electrically connected in series between one terminal of the thermopile TP or the output port OUT. That is, the thermopile TP is electrically connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is electrically connected to the non-inverting input terminal of the second operational amplifier. The output terminal of the second operational amplifier is electrically connected to the output terminal OUT.

[0063] FIG. 5 shows a possible equivalent circuit diagram of an ultrasonic sensor US. The sensor US has a first ultrasonic transducer USTX that may be utilized as a transmitter. Further, the sensor US has a second ultrasonic transducer USRX that may be utilized as a reception unit. A first circuit block B1 comprises circuit elements associated with the first ultrasonic transducer USTX. A second circuit block B2 comprises circuit elements associated with the second ultrasonic transducer USRX. The first block B1 has a first operational amplifier OA1. The second block B2 has a second operational amplifier OA2.

[0064] FIG. 6 illustrates a possible mode of operation where in a first time period TX, voltage pulses are transmitted to the sensor US which converts electric energy to acoustic energy. Thus, ultrasonic pulses corresponding to the voltage pulses are emitted by the first transducer USTX. After that, a time period of reception RX is needed without activity of the transmitter. In this time period, echoes of possible objects near the wireless power transmission systems are received. From the time needed for the pulses to be reflected and received by the reception transducer USRX, the distance between the object and the respective sensor of the wireless power transmission system can be determined.

[0065] FIG. 7 shows a possible equivalent circuit diagram of an ultrasonic sensor utilizing a single ultrasonic transducer USTXRX that can act as a transmitter and a receiver. The driver circuit of this ultrasonic sensor US has three operational amplifiers OA and the circuit elements establishing interconnections between input ports, supply terminals, the terminals of the operational amplifiers OA and the transducer USTXRX.

[0066] FIG. 8 illustrates the meaning of the quantities , , r to determine a position in a spherical coordinate sys-tern. Angle determines the angle of the rotation within the xy-plain, i.e., within the horizontal plain. Angle determines the rotation away from the z-axis. R determines the distance between the center of the coordinate system and the respective object o.

[0067] The wireless power transmission system is not limited to the embodiments and details described above. The method for operating a transmission system is not limited to the steps described above.

LIST OF REFERENCE SIGNS

[0068] B1: first circuit block [0069] B2: second circuit block [0070] EC: evaluation circuit [0071] IS: infrared sensor/thermal sensor [0072] o: object [0073] OA: observable area [0074] OA: operational amplifier [0075] OUT: output terminal [0076] OV: observable volume [0077] P: perimeter [0078] PC: primary coil [0079] r: distance [0080] SB: sensor block [0081] ST: supply terminal [0082] ST1: first supply terminal [0083] ST2: second supply terminal [0084] t: time [0085] US: ultrasonic sensor [0086] USRX: reception transducer [0087] USTX: transmission transducer [0088] USTXRX: common transceiver transducer [0089] V: voltage [0090] WPTS: wireless power transmission system [0091] : polar angle [0092] : horizontal/azimuthal angle