Wireless power supply system and method for unmanned aerial vehicle

Abstract

The invention discloses a wireless power supply system and method for an unmanned aerial vehicle, and belongs to the technical field of wireless charging, and the system comprises an unmanned aerial vehicle body, a power receiving mechanism connected with the unmanned aerial vehicle body, a power transmission mechanism wirelessly connected with the power receiving mechanism, and a power control mechanism connected with the power transmission mechanism. The power control mechanism is used for performing calculation according to voltage and current values of a battery load of the unmanned aerial vehicle so as to control output of electric power, and the electric power receiving mechanism and the electric power transmission mechanism jointly form a coupling device. The wireless power supply system and method for the unmanned aerial vehicle can adapt to the structure of the unmanned aerial vehicle, a complex device does not need to be arranged on the unmanned aerial vehicle body, the coupling capacity is improved, closed-loop control over the charging process can be achieved, and the practicability of the device is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless charging, and specifically provides a wireless power supply system and method for an unmanned aerial vehicle. Background Art

[0002] There are currently two ways to extend the flight time of a drone: the first is to increase the capacity of the lithium battery, but the drone’s load capacity is limited and a heavy lithium battery will affect its performance; the second is to charge the drone in a timely manner. If the traditional wired plug-in charging method is used, it will consume a lot of manpower and reduce the flexibility of the drone. Therefore, the drone needs to be charged through wireless power supply.

[0003] Wireless charging can achieve wireless energy transmission through non-physical direct contact, and has the advantages of high safety, strong reliability and easy automation of the charging process. Therefore, wireless charging technology has been widely studied in many fields such as electric vehicle charging and robot charging. Efficient and autonomous wireless charging of drones will be an innovative way to promote the development of drones.

[0004] At present, there is little research on wireless charging technology for drones, and the application of wireless charging technology in the field of drone charging is not yet mature. There are some problems that need to be solved urgently. For example, the traditional face-to-face magnetic coupling device has poor adaptability to the drone structure and insufficient coupling ability. Therefore, it is necessary to design a new wireless power supply system. The present invention solves this technical problem. Summary of the invention

[0005] The present invention provides a wireless power supply system and method for a drone, which can adapt to the structure of the drone, does not need to set up complex devices on the drone body, improves the coupling capability, and can realize closed-loop control of the charging process, thereby improving the practicability of the device.

[0006] A wireless power supply system for an unmanned aerial vehicle comprises an unmanned aerial vehicle body, a power receiving mechanism connected to the unmanned aerial vehicle body, a power transmission mechanism wirelessly connected to the power receiving mechanism, and a power control mechanism connected to the power transmission mechanism, wherein the power control mechanism is used to control the output of power by calculating according to the voltage and current values ​​of the unmanned aerial vehicle battery load, and the power receiving mechanism and the power transmission mechanism together constitute a coupling device.

[0007] Furthermore, the power transmission mechanism includes a transmitting coil 1 and a transmitting coil 2, a ferrite and an aluminum plate connected to the transmitting coil 1 and the transmitting coil 2, the transmitting coil 1 and the transmitting coil 2 are respectively connected to the power control mechanism, and the power control mechanism includes a primary side control mechanism and a secondary side control mechanism electrically connected to the primary side control mechanism.

[0008] Furthermore, the primary control mechanism includes an inverter bridge electrically connected to the transmitting coil 1 and the transmitting coil 2, a DC power supply and a primary control unit electrically connected to the inverter bridge, and a primary wireless communication module electrically connected to the primary control unit.

[0009] Furthermore, the secondary side control mechanism includes a rectifier bridge electrically connected to the drone battery, a secondary side detection control unit electrically connected to the drone battery, and a secondary side wireless communication module connected to the secondary side detection control unit, and the secondary side wireless communication module is electrically connected to the primary side wireless communication module.

[0010] Furthermore, the power receiving mechanism includes a landing gear connected to the UAV body, a receiving coil connected to the landing gear, the receiving coil is electrically connected to the rectifier bridge, and the transmitting coil 1 and the transmitting coil 2 are respectively perpendicular to the receiving coil.

[0011] A wireless power supply method for a drone, based on the wireless power supply system for the drone, comprises the following steps:

[0012] S1. Establish a circuit model;

[0013] S2, determine the power transmission efficiency of the entire circuit;

[0014] S3, wirelessly charge the drone’s battery;

[0015] S4, the secondary side control mechanism collects battery related data and sends it to the primary side control mechanism;

[0016] S5, the primary side control mechanism calculates the obtained data through PID, and controls the PWM output according to the calculated result;

[0017] S6. Complete the charging of the drone.

[0018] Furthermore, the circuit model includes a primary side part and a secondary side part, and the primary side part includes a voltage source U s , and the voltage source U s Connect the resistor R s , and the resistor R s A resistor R1 connected to the resistor R1, a compensation capacitor C1 connected to the resistor R1, an inductor L1 connected to the compensation capacitor C1, and the inductor L1 is connected to the voltage source U s connect;

[0019] The secondary side includes an inductor L2, a compensation capacitor C2 connected to the inductor L2, a resistor R2 connected to the compensation capacitor C2, and a resistor R2 connected to the resistor R2. L , the resistor RL connected to the inductor L2;

[0020] The resistor R s As the internal resistance of the input circuit, the resistor R1 is used as the resistance of the transmitting coil 1 and the transmitting coil 2, and the resistor R2 is used as the resistance of the receiving coil. L As a load for the drone battery.

[0021] Furthermore, the specific steps of S2 are as follows:

[0022] S21. Calculate the input impedance of the primary side:

[0023]

[0024] Where jωL1 represents the inductive reactance of inductor L1, Represents the capacitive reactance of compensation capacitor C1;

[0025] S22. Calculate the secondary impedance:

[0026]

[0027] S23, secondary side impedance converted to primary side input impedance:

[0028]

[0029] Where, M represents the mutual inductance coefficient;

[0030] S24, equivalent input impedance: Z in =Z 11 +Z1

[0031] S25, the primary current is expressed as:

[0032]

[0033] The secondary current is expressed as:

[0034]

[0035] S26. According to Kirchhoff's current law and Kirchhoff's voltage law, the circuit relationship between the primary and secondary sides is expressed as:

[0036]

[0037] S27, the conditions that the inductor and compensation capacitor need to meet are:

[0038] ω 2 L1C1=ω 2 L2C2=1

[0039] S28. According to the above relationship, the output power of the system is calculated as:

[0040]

[0041] S29. According to the above content, the transmission efficiency of the system is obtained:

[0042]

[0043] Furthermore, the specific steps of S4 are as follows:

[0044] S41, performing ADC sampling at regular intervals;

[0045] S42, collecting the voltage and current values ​​of the drone battery;

[0046] S43, performing data filtering;

[0047] S44, using the SCI function, sending data to the primary side control mechanism through the secondary side wireless communication module;

[0048] S45. According to the collected data, when the voltage value of the drone battery does not reach the voltage setting value for switching from constant current charging to constant voltage charging, the secondary control mechanism continues to collect the voltage and current values ​​of the battery;

[0049] S46. When the voltage value of the battery of the drone reaches the set value, the secondary control mechanism no longer continues to collect the voltage and current values ​​of the battery.

[0050] Furthermore, the specific steps of S5 are as follows:

[0051] S51, the primary wireless communication module receives the voltage and current values ​​of the battery transmitted by the secondary wireless communication module through the receiving interrupt of the SCI module;

[0052] S52, calculating, through the PID calculation program, whether the voltage value of the drone battery at this time reaches the voltage setting value for switching from constant current charging to constant voltage charging;

[0053] S53, when the voltage value of the drone battery does not reach the voltage setting value for switching from constant current charging to constant voltage charging, constant current charging is performed;

[0054] S54, when the voltage value of the battery of the drone reaches the set value, the driving signal of the inverter is changed through the PID to perform constant voltage charging;

[0055] S55. During constant voltage charging, as the charging process proceeds, the current value gradually decreases. When the current value reaches the set stop value, the PWM stops outputting and the charging process ends.

[0056] The technical effects of the present invention are as follows:

[0057] (1) The coupling device in the system can realize wireless power supply for the UAV. The receiving coil can effectively receive the magnetic flux emitted by the transmitting coil 1 and the transmitting coil 2 to realize effective coupling. In addition, there is no need to set up complex mechanical devices on the UAV body and the appearance of the UAV is not changed. The wireless charging function can be realized. The weight is light, which can reduce the impact on the UAV body and improve the practicality.

[0058] (2) The aluminum plate in this system can not only increase the mechanical strength of the power transmission mechanism, but also play the role of leakage magnetic shielding, further improving the practicality of this system;

[0059] (3) This method uses a secondary control mechanism to collect voltage and current data of the drone battery during charging, and can transmit the data to a primary control mechanism, and control the charging process through the primary control mechanism to charge the battery at a constant voltage or a constant current, thereby realizing closed-loop control of the charging process;

[0060] (4) Through the content of this method, the power transmission efficiency of the entire system can be determined, and the output power p of the system can be understood out With coupling coefficient K, battery load R L The relationship between the output efficiency, coupling coefficient and battery load is convenient for subsequent research and optimization of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic diagram of the coupling device model in the present invention.

[0062] Figure 2 It is a schematic diagram of the power control mechanism in the present invention.

[0063] Figure 3 It is a schematic diagram of the circuit model in the present invention.

[0064] Figure 4 It is a flow chart of the secondary side control mechanism in the present invention.

[0065] Figure 5 It is a flow chart of the original edge control mechanism in the present invention.

[0066] Among them, the figures are marked as: 1. Transmitting coil 1; 2. Receiving coil; 3. Ferrite; 4. Transmitting coil 2; 5. Aluminum plate. DETAILED DESCRIPTION

[0067] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments and drawings.

[0068] See also Figure 1-Figure 2 A wireless power supply system for an unmanned aerial vehicle comprises an unmanned aerial vehicle body, a power receiving mechanism connected to the unmanned aerial vehicle body, a power transmission mechanism wirelessly connected to the power receiving mechanism, and a power control mechanism connected to the power transmission mechanism, wherein the power control mechanism is used to control the output of power by calculating according to the voltage and current values ​​of the unmanned aerial vehicle battery load, and the power receiving mechanism and the power transmission mechanism together constitute a coupling device.

[0069] Furthermore, the power transmission mechanism includes a transmitting coil 1 and a transmitting coil 2 4, a ferrite 3 and an aluminum plate 5 connected to the transmitting coil 1 and the transmitting coil 2 4, the transmitting coil 1 and the transmitting coil 2 4 are respectively connected to the power control mechanism, and the power control mechanism includes a primary control mechanism and a secondary control mechanism electrically connected to the primary control mechanism. The aluminum plate 5 in this embodiment is placed below the ferrite 3.

[0070] Furthermore, the primary control mechanism includes an inverter bridge electrically connected to the transmitting coil 1 and the transmitting coil 2, a DC power supply and a primary control unit electrically connected to the inverter bridge, and a primary wireless communication module electrically connected to the primary control unit. Figure 2 In this embodiment, the primary side control mechanism is also connected to a primary side compensation capacitor.

[0071] Furthermore, the secondary side control mechanism includes a rectifier bridge electrically connected to the drone battery, a secondary side detection control unit electrically connected to the drone battery, and a secondary side wireless communication module connected to the secondary side detection control unit, and the secondary side wireless communication module is electrically connected to the primary side wireless communication module. Figure 2 In this embodiment, a secondary side compensation capacitor is also connected to the secondary side control mechanism.

[0072] Furthermore, the power receiving mechanism includes a landing gear connected to the UAV body, a receiving coil 2 connected to the landing gear, the receiving coil 2 is electrically connected to the rectifier bridge, and the transmitting coil 1 and the transmitting coil 2 4 are respectively perpendicular to the receiving coil 2.

[0073] See also Figure 1 In this embodiment, the transmitting coil 1 and the transmitting coil 2 4 are kept horizontal, and the receiving coil 2 is placed vertically and located between the transmitting coil 1 and the transmitting coil 2 4, forming an orthogonal coupling device. Figure 1 The figure only shows the positional relationship between the receiving coil 2 and the transmitting coil 1 and the transmitting coil 2 4. In the actual charging process, the receiving coil 2 is connected to the landing gear of the drone body. When charging is required, the landing gear of the drone is placed between the transmitting coil 1 and the transmitting coil 2 4, and then wireless charging is performed.

[0074] See also Figure 3-Figure 5 A wireless power supply method for a drone, based on the wireless power supply system for the drone, comprises the following steps:

[0075] S1. Establish a circuit model;

[0076] S2, determine the power transmission efficiency of the entire circuit;

[0077] S3, wirelessly charge the drone’s battery;

[0078] S4, the secondary side control mechanism collects battery related data and sends it to the primary side control mechanism;

[0079] S5, the primary side control mechanism calculates the obtained data through PID, and controls the PWM output according to the calculated result;

[0080] S6. Complete the charging of the drone.

[0081] Furthermore, the circuit model includes a primary side part and a secondary side part, and the primary side part includes a voltage source U s , and the voltage source U s Connect the resistor R s , and the resistor R s A resistor R1 connected to the resistor R1, a compensation capacitor C1 connected to the resistor R1, an inductor L1 connected to the compensation capacitor C1, and the inductor L1 is connected to the voltage source U s connect;

[0082] The secondary side includes an inductor L2, a compensation capacitor C2 connected to the inductor L2, a resistor R2 connected to the compensation capacitor C2, and a resistor R2 connected to the resistor R2. L , the resistor R L connected to the inductor L2;

[0083] The resistor R s As the internal resistance of the input circuit, the resistor R1 is used as the resistance of the transmitting coil 1 and the transmitting coil 2 4, and the resistor R2 is used as the resistance of the receiving coil 2. L As the load of the drone battery. The circuit model used in this solution adopts a compensation network design, specifically an SS compensation structure. Figure 3 , Figure 3 I1 and I2 are the currents on the primary and secondary sides respectively, and the arrows are the directions of the currents.

[0084] Furthermore, the specific steps of S2 are as follows:

[0085] S21. Calculate the input impedance of the primary side:

[0086]

[0087] Where jωL1 represents the inductive reactance of inductor L1, Represents the capacitive reactance of compensation capacitor C1;

[0088] S22. Calculate the secondary impedance:

[0089]

[0090] S23, secondary side impedance converted to primary side input impedance:

[0091]

[0092] Where, M represents the mutual inductance coefficient;

[0093] S24, equivalent input impedance: Z in =Z 11 +Z1

[0094] S25, the primary current is expressed as:

[0095]

[0096] The secondary current is expressed as:

[0097]

[0098] S26. According to Kirchhoff's current law and Kirchhoff's voltage law, the circuit relationship between the primary and secondary sides is expressed as:

[0099]

[0100] S27, the conditions that the inductor and compensation capacitor need to meet are:

[0101] ω 2 L1C1=ω 2 L2C2=1

[0102] S28. According to the above relationship, the output power of the system is calculated as:

[0103]

[0104] S29. According to the above content, the transmission efficiency of the system is obtained:

[0105]

[0106] Furthermore, the specific steps of S4 are as follows:

[0107] S41, performing ADC sampling at regular intervals;

[0108] S42, collecting the voltage and current values ​​of the drone battery;

[0109] S43, performing data filtering;

[0110] S44, using the SCI function, sending data to the primary side control mechanism through the secondary side wireless communication module;

[0111] S45. According to the collected data, when the voltage value of the drone battery does not reach the voltage setting value for switching from constant current charging to constant voltage charging, the secondary control mechanism continues to collect the voltage and current values ​​of the battery;

[0112] S46. When the voltage value of the battery of the drone reaches the set value, the secondary control mechanism no longer continues to collect the voltage and current values ​​of the battery.

[0113] In the data filtering of this embodiment, moving average filtering can be used, and its formula is as follows:

[0114]

[0115] Among them, SMA n represents the nth moving average, N represents the window size, that is, the number of data points, x i represents the i-th data point.

[0116] Furthermore, the specific steps of S5 are as follows:

[0117] S51, the primary wireless communication module receives the voltage and current values ​​of the battery transmitted by the secondary wireless communication module through the receiving interrupt of the SCI module;

[0118] S52, calculating, through the PID calculation program, whether the voltage value of the drone battery at this time reaches the voltage setting value for switching from constant current charging to constant voltage charging;

[0119] S53, when the voltage value of the drone battery does not reach the voltage setting value for switching from constant current charging to constant voltage charging, constant current charging is performed;

[0120] S54, when the voltage value of the battery of the drone reaches the set value, the driving signal of the inverter is changed through PID to perform constant voltage charging;

[0121] S55. During constant voltage charging, as the charging process proceeds, the current value gradually decreases. When the current value reaches the set stop value, the PWM stops outputting and the charging process ends.

[0122] When the secondary control mechanism detects that the battery has reached the standard voltage, it will no longer collect the battery voltage and current data, thereby not triggering the reception interruption of the primary control mechanism, so that the primary control mechanism no longer receives voltage and current data. When the current value reaches the set stop value, the primary control unit controls the PWM to stop output, and the charging process ends, thereby completing the wireless charging of the drone battery.

[0123] The above embodiments are only preferred embodiments of the present invention. The above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention and are not intended to limit the scope of the present invention. For those skilled in the art, various modifications and improvements can be made on the basis of the present invention without departing from the spirit and essence of the present invention. These modifications and improvements are also regarded as the protection scope of the present invention. Therefore, this application protects not only the above embodiments, but also the scope consistent with the principles and features of the present invention.

Claims

1. A wireless power supply system for an unmanned aerial vehicle, characterized in that: It includes a UAV body, a power receiving mechanism connected to the UAV body, a power transmission mechanism wirelessly connected to the power receiving mechanism, and a power control mechanism connected to the power transmission mechanism. The power control mechanism is used to control the output of power by calculating according to the voltage and current values ​​of the UAV battery load. The power receiving mechanism and the power transmission mechanism together constitute a coupling device.

2. The wireless power supply system for an unmanned aerial vehicle according to claim 1, characterized in that: The power transmission mechanism comprises a transmitting coil 1 (1) and a transmitting coil 2 (4), a ferrite (3) and an aluminum plate (5) connected to the transmitting coil 1 (1) and the transmitting coil 2 (4), the transmitting coil 1 (1) and the transmitting coil 2 (4) are respectively connected to the power control mechanism, and the power control mechanism comprises a primary side control mechanism and a secondary side control mechanism electrically connected to the primary side control mechanism.

3. The wireless power supply system for an unmanned aerial vehicle according to claim 2, characterized in that: The primary control mechanism includes an inverter bridge electrically connected to the transmitting coil 1 (1) and the transmitting coil 2 (4), a DC power supply and a primary control unit electrically connected to the inverter bridge, and a primary wireless communication module electrically connected to the primary control unit.

4. The wireless power supply system for an unmanned aerial vehicle according to claim 3, characterized in that: The secondary side control mechanism includes a rectifier bridge electrically connected to the drone battery, a secondary side detection control unit electrically connected to the drone battery, and a secondary side wireless communication module connected to the secondary side detection control unit, and the secondary side wireless communication module is electrically connected to the primary side wireless communication module.

5. The wireless power supply system for an unmanned aerial vehicle according to claim 4, characterized in that: The power receiving mechanism comprises a landing gear connected to the drone body, a receiving coil (2) connected to the landing gear, the receiving coil (2) being electrically connected to the rectifier bridge, and the transmitting coil 1 (1) and the transmitting coil 2 (4) being respectively perpendicular to the receiving coil (2).

6. A wireless power supply method for an unmanned aerial vehicle, based on the wireless power supply system for an unmanned aerial vehicle as claimed in claim 4, characterized in that: The following steps are involved: S1. Establish a circuit model; S2, determine the power transmission efficiency of the entire circuit; S3, wirelessly charge the drone’s battery; S4, the secondary side control mechanism collects battery related data and sends it to the primary side control mechanism; S5, the primary side control mechanism calculates the obtained data through PID, and controls the PWM output according to the calculated result; S6. Complete the charging of the drone.

7. The wireless power supply method for an unmanned aerial vehicle according to claim 6, characterized in that: The circuit model includes a primary side part and a secondary side part, wherein the primary side part includes a voltage source U s , and the voltage source U s Connect the resistor R s , and the resistor R s A resistor R1 connected to the resistor R1, a compensation capacitor C1 connected to the resistor R1, an inductor L1 connected to the compensation capacitor C1, and the inductor L1 is connected to the voltage source U s connect; The secondary side includes an inductor L2, a compensation capacitor C2 connected to the inductor L2, a resistor R2 connected to the compensation capacitor C2, and a resistor R2 connected to the resistor R2. L , the resistor R L connected to the inductor L2; The resistor R s As the internal resistance of the input circuit, the resistor R1 serves as the resistance of the transmitting coil 1 (1) and the transmitting coil 2 (4), the resistor R2 serves as the resistance of the receiving coil (2), and the resistor R L As a load for the drone battery.

8. The wireless power supply method for an unmanned aerial vehicle according to claim 7, characterized in that: The specific steps of S2 are as follows: S21. Calculate the input impedance of the primary side: Where jωL1 represents the inductive reactance of inductor L1, Represents the capacitive reactance of compensation capacitor C1; S22. Calculate the secondary impedance: S23, secondary side impedance converted to primary side input impedance: Where, M represents the mutual inductance coefficient; S24, equivalent input impedance: Z in =Z 11 +Z1 S25, the primary current is expressed as: The secondary current is expressed as: S26. According to Kirchhoff's current law and Kirchhoff's voltage law, the circuit relationship between the primary and secondary sides is expressed as: S27, the conditions that the inductor and compensation capacitor need to meet are: oh 2 L1C1=ω 2 L2C2=1 S28. According to the above relationship, the output power of the system is calculated as: S29. According to the above content, the transmission efficiency of the system is obtained:

9. The wireless power supply method for a drone according to claim 6, characterized in that: The specific steps of S4 are as follows: S41, performing ADC sampling at regular intervals; S42, collecting the voltage and current values ​​of the drone battery; S43, performing data filtering; S44, using the SCI function, sending data to the primary side control mechanism through the secondary side wireless communication module; S45. According to the collected data, when the voltage value of the drone battery does not reach the voltage setting value for switching from constant current charging to constant voltage charging, the secondary control mechanism continues to collect the voltage and current values ​​of the battery; S46. When the voltage value of the battery of the drone reaches the set value, the secondary control mechanism no longer continues to collect the voltage and current values ​​of the battery.

10. The wireless power supply method for a drone according to claim 9, characterized in that: The specific steps of S5 are as follows: S51, the primary wireless communication module receives the voltage and current values ​​of the battery transmitted by the secondary wireless communication module through the receiving interrupt of the SCI module; S52, calculating, through the PID calculation program, whether the voltage value of the drone battery at this time reaches the voltage setting value for switching from constant current charging to constant voltage charging; S53, when the voltage value of the drone battery does not reach the voltage setting value for switching from constant current charging to constant voltage charging, constant current charging is performed; S54, when the voltage value of the battery of the drone reaches the set value, the driving signal of the inverter is changed through PID to perform constant voltage charging; S55. During constant voltage charging, as the charging process proceeds, the current value gradually decreases. When the current value reaches the set stop value, the PWM stops outputting and the charging process ends.

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