Charging device, system and method for unmanned aerial vehicle and nonvolatile storage medium

Abstract

The invention discloses a charging device, system and method for an unmanned aerial vehicle and a nonvolatile storage medium. The charging equipment of the unmanned aerial vehicle comprises a charging circuit, an inverter and a direct-current power supply, the direct current power supply is used for providing direct current; the inverter is connected with the direct-current power supply and is used for converting direct current provided by the direct-current power supply into alternating current; the charging circuit is connected with the inverter and used for sending an electric signal corresponding to the alternating current to an electric energy receiving end circuit of the unmanned aerial vehicle in a non-contact mode, the charging circuit comprises a combined transmitting coil composed of a first coil and a second coil, the second coil is an auxiliary coil of the first coil, and the second coil is an auxiliary coil of the second coil. The first coil is used for compensating magnetic field intensity of the first coil. The technical problem that the unmanned aerial vehicle cannot accurately stop at the charging position and cannot keep stable charging voltage due to errors and magnetic field depression problems existing in manual operation or automatic homeward voyage in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of wireless power transmission, and more specifically, to a charging device, system, method and non-volatile storage medium for an unmanned aerial vehicle. Background Art

[0002] With the continuous development of science and technology, the production and life of society are becoming more and more intelligent, and the demand for electricity is also increasing. In order to detect and solve the faults of base stations early, it is more and more necessary to inspect base stations. However, manual inspection is not only time-consuming and laborious, but also inaccurate and comprehensive. It is often accompanied by dangers. UAV inspection came into being. In related technologies, the energy supply of UAV inspection is mainly powered by batteries. However, in order to reduce the weight of the UAV, the battery capacity is generally not large, which leads to the need for the UAV to return to replace the battery after working for dozens of minutes, which greatly reduces the efficiency of the work. When the UAV returns to charge, there may be errors in manual operation or automatic return, and there is a situation of central magnetic field depression (the central magnetic field at a certain height of a single transmitting coil is weaker than the surrounding magnetic field, and the magnetic field is mainly concentrated at the edge of the coil. The central magnetic field intensity is small, resulting in the collapse of the entire magnetic field), which causes the UAV to be unable to dock accurately at the charging position when docking, and the transmission efficiency and output voltage of the system cannot be kept stable.

[0003] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0004] The embodiments of the present application provide a charging device, system, method and non-volatile storage medium for a drone, so as to at least solve the technical problem in the related art that the drone cannot accurately dock at the charging position and cannot maintain a stable charging voltage due to errors in manual operation or automatic return and magnetic field depression problems.

[0005] According to one aspect of an embodiment of the present application, a charging device for an unmanned aerial vehicle is provided, comprising: a charging circuit, an inverter and a DC power supply; the DC power supply is used to provide DC power; the inverter is connected to the DC power supply and is used to convert the DC power provided by the DC power supply into AC power; the charging circuit is connected to the inverter and is used to send an electrical signal corresponding to the AC power to a power receiving end circuit of the unmanned aerial vehicle in a contactless manner, the charging circuit comprising: a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, wherein the power receiving end circuit is used to convert the electrical signal into a target DC power.

[0006] In some embodiments of the present application, the second coil and the first coil are concentric circles and the radius of the second coil is smaller than the radius of the first coil.

[0007] In some embodiments of the present application, the charging circuit further includes: a K converter for circuit tuning, wherein the K converter is located between the inverter and the combined transmitting coil.

[0008] In some embodiments of the present application, the K converter includes: a T-type inductor network circuit, the T-type inductor network circuit includes an inductor, a first capacitor and a second capacitor, the inductor is connected in series between the inverter and the combined transmitting coil, and the first capacitor and the second capacitor are connected in parallel to one end of the inductor.

[0009] In some embodiments of the present application, the inverter is a full-bridge inverter, the first switch and the second switch of the field effect transistor in the inverter are connected in series, the third switch and the fourth switch of the field effect transistor are connected in series, and the circuit composed of the first switch and the second switch connected in series is connected in parallel with the circuit composed of the third switch and the fourth switch connected in series.

[0010] In some embodiments of the present application, the inverter converts direct current provided by a DC power supply into alternating current in the following manner: by controlling the switching states of a first switch, a second switch, a third switch, and a fourth switch, direct current is converted into alternating current, wherein the waveform of the output voltage of the alternating current is a square wave, and the frequency of the alternating current matches the resonant frequency of the charging device of the drone.

[0011] In some embodiments of the present application, the charging circuit sends the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone in a contactless manner in the following manner: adjusting the characteristic parameters of the K converter of the charging circuit and performing circuit tuning; based on the circuit tuning performed by the K converter, the combined transmitting coil of the charging circuit resonates with the resonant circuit of the power receiving end circuit of the drone at a predetermined wireless charging frequency, and sends the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone.

[0012] According to another aspect of the embodiment of the present application, a charging system for a drone is also provided, including: a charging device for the drone and a drone, wherein the charging device includes: a charging circuit, an inverter and a DC power supply; a DC power supply for providing DC power; the inverter is connected to the DC power supply and is used to convert the DC power provided by the DC power supply into AC power; the charging circuit is connected to the inverter and is used to send an electrical signal corresponding to the AC power to the power receiving end circuit of the drone in a contactless manner, the charging circuit includes a K converter for circuit tuning, a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, and the K converter is located between the inverter and the combined transmitting coil; the drone includes: a power receiving end circuit, wherein the power receiving end circuit is used to convert the electrical signal into target DC power to charge the drone.

[0013] In some embodiments of the present application, the load voltage corresponding to the target DC power is determined by a first functional relationship between the load resistance, the equivalent parasitic resistance of the power receiving circuit of the drone, the voltage of the AC power, and the characteristic parameters of the K converter.

[0014] In some embodiments of the present application, the load voltage corresponding to the target DC power is determined by a second functional relationship between the mutual inductance between the charging circuit and the power receiving circuit of the drone, the voltage of the AC power, the characteristic parameters of the K converter, and the resonant frequency of the charging system of the drone.

[0015] According to another aspect of the embodiment of the present application, a charging method for a drone is also provided, including: converting the direct current provided by the direct current power supply of the charging system of the drone into alternating current based on an inverter, wherein the charging system of the drone includes a charging device of the drone and a drone, the charging device includes: a charging circuit, an inverter and a direct current power supply, the charging circuit includes a K converter for circuit tuning, a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, the K converter is located between the inverter and the combined transmitting coil, the drone includes: an electric energy receiving end circuit; sending an electrical signal corresponding to the alternating current to the electric energy receiving end circuit of the drone in a contactless manner; converting the electrical signal into a target direct current through the electric energy receiving end circuit of the drone; and using the target direct current to charge the drone.

[0016] In some embodiments of the present application, an electrical signal corresponding to the alternating current is sent to a power receiving circuit of a drone of a charging system of the drone in a contactless manner, including: adjusting characteristic parameters of a K converter of the charging circuit and performing circuit tuning; based on the circuit tuning performed by the K converter, a combined transmitting coil resonates with a resonant circuit of the power receiving circuit of the drone at a predetermined wireless charging frequency, and the electrical signal corresponding to the alternating current is sent to the power receiving circuit of the drone.

[0017] According to another aspect of an embodiment of the present application, a charging device for a drone is also provided, including: a conversion module, used to convert direct current power provided by a direct current power supply of a charging system of the drone into alternating current power based on an inverter, wherein the charging system of the drone includes a charging device for the drone and a drone, the charging device includes: a charging circuit, an inverter and a direct current power supply, and the drone includes: a power receiving end circuit; a sending module, used to send an electrical signal corresponding to the alternating current to the power receiving end circuit of the drone of the charging system of the drone in a contactless manner; a conversion module, used to convert the electrical signal into a target direct current power through the power receiving end circuit of the drone; and a charging module, used to charge the drone using the target direct current power.

[0018] According to another aspect of an embodiment of the present application, a non-volatile storage medium is further provided, in which a program is stored, wherein when the program is running, a device where the non-volatile storage medium is located is controlled to execute any one of the above-mentioned methods for charging a drone.

[0019] According to another aspect of an embodiment of the present application, a computer program product is also provided, including computer instructions, where the computer instructions are executed by a processor to implement any of the above-mentioned methods for charging a drone.

[0020] In an embodiment of the present application, a charging device for a drone is provided, comprising: a charging circuit, an inverter and a DC power supply; the DC power supply is used to provide DC power; the inverter is connected to the DC power supply and is used to convert the DC power provided by the DC power supply into AC power; the charging circuit is connected to the inverter and is used to send the electrical signal corresponding to the AC power to the power receiving circuit of the drone in a contactless manner, the charging circuit comprises: a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, wherein the power receiving circuit is used to convert the electrical signal into a target DC power. The DC power provided by the DC power supply is converted into AC power by the inverter, and then sent to the power receiving circuit of the drone in a contactless manner through the charging circuit, the second coil in the charging circuit is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, thereby achieving the purpose of compensating for the concave magnetic field, thereby solving the technical problem in the related art that the drone cannot accurately dock at the charging position and cannot maintain a stable charging voltage due to errors in manual operation or automatic return and the problem of concave magnetic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0022] Figure 1 It is a structural block diagram of a computer terminal of a charging device for a drone provided in an embodiment of the present application;

[0023] Figure 2 is a structural schematic diagram of a charging system for a drone provided according to an embodiment of the present application;

[0024] Figure 3 is an equivalent circuit diagram of a charging system for a drone provided according to an embodiment of the present application;

[0025] Figure 4This is an operation flow chart of a charging device for a drone provided according to an embodiment of the present application;

[0026] Figure 5 is a schematic diagram of the spatial position of a combined transmitting coil and a receiving coil provided according to an embodiment of the present application;

[0027] Figure 6 is a circuit equivalent transformation diagram of a charging system for a drone provided according to an embodiment of the present application;

[0028] Figure 7 is a flow chart of a charging method for a drone provided according to an embodiment of the present application;

[0029] Figure 8 is a schematic structural diagram of a charging device for a drone provided according to an embodiment of the present application;

[0030] Fig. 9 is a curve diagram of simulation results of load voltage changing with load resistance provided in an embodiment of the present application;

[0031] Fig.10 is a transmission efficiency variation curve diagram of a charging system of a drone provided according to an embodiment of the present application;

[0032] Fig.11 The present invention is a load voltage variation curve diagram of a charging system of a drone provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0034] The information collected in the embodiments of the present application is information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of the relevant data comply with the relevant laws, regulations and standards of the relevant regions, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or reject automated decision-making results; if the user chooses to reject, the expert decision-making process will be entered.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] In order to better understand the embodiments of the present application, the technical terms involved in the embodiments of the present application are explained as follows:

[0037] Magnetic Coupling Resonant Wireless Power Transfer (MCR-WPT) is a technology that uses the principle of electromagnetic resonance for contactless energy transmission.

[0038] In the related art, when the drone returns to charge, there may be errors in manual operation or automatic return, and there may be a concave central magnetic field (the central magnetic field at a certain height of a single transmitting coil is weaker than the surrounding magnetic field, and the magnetic field is mainly concentrated at the edge of the coil. The central magnetic field strength is small, causing the entire magnetic field to collapse in the center), resulting in the drone being unable to accurately dock at the charging position when docking, and the transmission efficiency and output voltage of the system cannot be kept stable. Therefore, there is a technical problem in the related art that due to errors in manual operation or automatic return and the problem of concave magnetic field, the drone cannot be accurately docked at the charging position and cannot maintain a stable charging voltage. In order to solve this problem, a relevant solution is provided in the embodiment of the present application, which is described in detail below.

[0039] According to an embodiment of the present application, an embodiment of a charging device for a drone is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be performed in a charging device such as a drone, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be performed in an order different from that shown here.

[0040] The method embodiments provided in the embodiments of the present application can be executed in a charging device of a drone or a similar computing device. Figure 1 The figure shows a structural block diagram of a charging device for a drone. Figure 1As shown, the charging device of the drone includes a charging circuit 106, an inverter 104 and a DC power supply 102, wherein the DC power supply 102 is used to provide DC power; the inverter 104 is connected to the DC power supply 102 and is used to convert the DC power provided by the DC power supply 102 into AC power; the charging circuit 106 is connected to the inverter 104 and is used to send an electrical signal corresponding to the AC power to the power receiving circuit of the drone in a contactless manner, such as Figure 1 As shown, the charging circuit 106 further includes: a combined transmitting coil 108 composed of a first coil 110 and a second coil 112, the first coil 110 and the second coil 112 are connected in series, the second coil 112 is an auxiliary coil of the first coil 110, and is used to compensate for the magnetic field strength of the first coil 110, wherein the power receiving end circuit is used to convert the electrical signal into the target direct current. The second coil 112 and the first coil 110 of the charging device of the drone are concentric circles and the radius of the second coil 112 is smaller than the radius of the first coil 110. The above-mentioned charging circuit also includes a K converter (or compensation network, T-type inductor network circuit) for circuit tuning, wherein the K converter is located between the inverter and the combined transmitting coil.

[0041] like Figure 2 FIG. 1 is a schematic diagram of a charging system for a drone according to an embodiment of the present application. The charging system for the drone (for example, an MCR-WPT system) includes a charging device for the drone (i.e. Figure 1 The charging device of the drone) and the drone, as shown in the figure, the base station inspection drone and the receiving coil are an inseparable whole structure, the drone includes the power receiving end circuit of the drone, and the drone power receiving end circuit includes the base station inspection drone and the receiving coil. Among them, the receiving coil in the figure is the receiving coil of the power receiving end circuit of the above-mentioned drone, and the charging device of the drone includes a combined transmitting coil, a K converter, an inverter, and a DC power supply. Among them, the combined transmitting coil and the K converter are used as a charging circuit as a whole, that is, the charging device includes: a charging circuit, an inverter and a DC power supply; a DC power supply for providing DC power; the inverter is connected to the DC power supply and is used to convert the DC power provided by the DC power supply into AC power; the charging circuit is connected to the inverter and is used to send the electrical signal corresponding to the AC power to the power receiving end circuit of the drone in a contactless manner. The charging circuit includes a K converter for circuit tuning, a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil. The K converter is located between the inverter and the combined transmitting coil. The K converter includes a T-type inductor network circuit, and the T-type inductor network circuit includes L t (L t Indicates inductance, i.e. compensation inductance), two C t (Ct Represents capacitor (compensation capacitor), i.e., the first capacitor and the second capacitor mentioned above), T type refers to L in K converter t (L t Indicates inductance, i.e. compensation inductance), two C t The connection structure between them is T-shaped. t In series between the inverter and the combined transmitting coil, the first capacitor and the second capacitor are connected in parallel to one end of the inductor. In the related art, a certain degree of anti-deviation is generated by adopting a large-scale transmitting coil, for example, multiple solenoid coils are evenly distributed in the same plane according to the circumference, which makes the coil too complicated, the cost is high, the equipment space is large, it is not easy to integrate and miniaturize, and it is not easy to promote. The charging device of the present application uses a simple structure, low cost, and easy-to-control structure without increasing the burden of the drone as much as possible. C (capacitor), L (inductor), C (capacitor) (i.e. CLC type) K converter is added between the DC power supply and the transmitting coil to achieve voltage-load independent characteristics. Compared with the transmitting coil composed of the resonant capacitor and the transmitting coil in parallel and then in series with the compensation inductor, and the receiving coil structure composed of the resonant capacitor and the receiving coil in parallel and then in series with the compensation inductor in the related art, the K converter of the present application is simpler to tune, will not be affected by the drone load and the mutual inductance between the coils, and improves the transmission performance.

[0042] The inverter in the charging device of the drone is a full-bridge inverter. The first switch and the second switch of the field effect transistor in the inverter are connected in series, and the third switch and the fourth switch of the field effect transistor are connected in series. The circuit composed of the first switch and the second switch connected in series and the circuit composed of the third switch and the fourth switch connected in series are connected in parallel. The inverter converts the DC power provided by the DC power supply into AC power in the following way: by controlling the switching states of the first switch, the second switch, the third switch, and the fourth switch, the DC power is converted into AC power, wherein the waveform of the output voltage of the AC power is a square wave, and the frequency of the AC power matches the resonant frequency of the drone charging device.

[0043] The charging circuit sends the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone in a contactless manner in the following manner: adjusting the characteristic parameters of the K converter of the charging circuit and performing circuit tuning; based on the circuit tuning performed by the K converter, the combined transmitting coil of the charging circuit resonates with the resonant circuit of the power receiving end circuit of the drone at a predetermined wireless charging frequency, and sends the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone.

[0044] The following are specific embodiments: Figure 3As shown, it is an equivalent circuit diagram of a charging system for an unmanned aerial vehicle according to an embodiment of the present application. The inverter receives a DC power supply to provide a DC voltage. As shown in the figure, the field effect tube of the inverter includes 4 switches (for example, the switch is composed of a field effect transistor or an insulated gate bipolar transistor, which is used to control the conversion of the DC power supply voltage and generate a high-frequency AC voltage), switch S1 (i.e., the above-mentioned first switch), switch S2 (i.e., the above-mentioned second switch), switch S3 (i.e., the above-mentioned third switch), switch S4 (i.e., the above-mentioned fourth switch), the first switch and the second switch are connected in series, and the third switch and the fourth switch of the field effect tube are connected in series. The inverter converts the DC power into the inverter output voltage Vs (i.e., the voltage of the above-mentioned AC power) of the full-bridge inverter by controlling the switching states of the first switch, the second switch, the third switch, and the fourth switch. The waveform of the inverter output voltage Vs of the full-bridge inverter is a square wave with an amplitude value of V dc The L in the transmitting coil (i.e. the above charging circuit, including the K converter and the combined transmitting coil) t (L t Indicates inductance, i.e. compensation inductance), two C t (C t The capacitor (compensation capacitor) is the K converter part. The receiving coil is the receiving coil of the power receiving end circuit of the above-mentioned drone, L n (n=1,2),C n (n=1,2) and R n (n=1,2) are the inductance, compensation capacitance and equivalent parasitic resistance of the coil, specifically: L1 is the inductance of the combined transmitting coil, L2 is the inductance of the receiving coil (the receiving coil of the power receiving end circuit of the drone), C1 is the compensation capacitance of the combined transmitting coil, C2 is the compensation capacitance of the receiving coil (the receiving coil of the power receiving end circuit of the drone), R1 is the equivalent parasitic resistance of the combined transmitting coil, R2 is the equivalent parasitic resistance of the receiving coil (the power receiving end circuit of the drone), M 12 It is the mutual inductance between the charging circuit (specifically the combined receiving coil of the charging circuit) and the receiving coil (the receiving coil of the power receiving end circuit of the drone), reflecting the degree of mutual coupling between the combined receiving coil of the charging circuit and the receiving coil of the power receiving end circuit of the drone. L It is the load resistance of the power receiving circuit of the drone. K1 and K2 are the characteristic parameters of the K converter (the values ​​of K1 and K2 are preset). K1 is related to the AC frequency output by the inverter and the inductance of the transmitting coil. Its adjustment can make the transmitting coil and the receiving coil resonate at the predetermined wireless charging frequency. K2 involves the inductance and load resistance of the receiving coil. Its tuning ensures the resonant state of the receiving coil circuit under various load conditions.

[0045] The inverter converts the DC power provided by the DC power supply into AC power in the following manner: by controlling the switching states of the first switch, the second switch, the third switch, and the fourth switch, the DC power is converted into AC power, wherein the waveform of the output voltage of the AC power is a square wave, and the frequency of the AC power matches the resonant frequency of the charging device of the drone. Specifically: the four switches (S1, S2, S3, S4) are arranged into a full-bridge structure, wherein S1 and S2, S3 and S4 are connected in series, respectively, and the two groups S1-S2 and S3-S4 are connected in parallel, respectively, to form a bridge circuit. Ensure that each switch is connected in series with an appropriate diode to provide a reverse conduction path. Implement a pulse width modulation control strategy to control the switching states of the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 through a microcontroller or a digital signal processor. The specific control logic is:

[0046] Make S1 and S4 turned on, S2 and S3 turned off, and the inverter outputs a square wave voltage of the positive half cycle;

[0047] Make S2 ​​and S3 turned on, S1 and S4 turned off, and the inverter outputs a square wave voltage of the negative half cycle.

[0048] Repeat the above steps to generate a square wave voltage (i.e. the above-mentioned AC power), the frequency of which needs to match the resonant frequency of the drone charging device (by adjusting the pulse width modulation control signal of the inverter, ensure that the output frequency of the AC power is consistent with the resonant frequency of the drone charging device). Frequency analysis tools, such as spectrum analyzers, can be used to monitor and adjust the frequency of the AC power generated by the inverter to achieve efficient magnetically coupled resonant wireless energy transmission. Then, through the pulse width modulation control strategy of the inverter, adjust the output voltage waveform to a square wave to ensure the purity and stability of the waveform. The amplitude of the square wave should be equal to the voltage value of the DC power supply to achieve efficient energy conversion. An oscilloscope can be used to monitor the AC voltage waveform output by the inverter and ensure the waveform quality.

[0049] The charging circuit sends the electrical signal corresponding to the alternating current to the power receiving circuit of the drone in a contactless manner (for example, magnetic coupling resonance) by adjusting the characteristic parameters K1 and K2 of the K converter of the charging circuit and performing circuit tuning. The circuit tuning is specifically based on the resonant frequency of the K converter and the charging device of the drone. Match the resonant frequency of the K converter after tuning and make the resonant frequency of the charging device of the drone consistent with the resonant frequency of the charging device of the drone (represented by ω0), ensuring that the K converter and the charging device of the drone resonate at a predetermined resonant frequency. This is the key to achieving efficient wireless energy transmission, because only at the same or similar frequencies can the two circuits produce effective resonant coupling. The tuned charging circuit can make the combined transmitting coil and the power receiving circuit of the drone resonate at a predetermined wireless charging frequency (equal to the resonant frequency of the charging device of the drone) (meaning that the two effectively exchange energy through magnetic coupling), thereby efficiently transmitting the AC signal to the drone in a contactless manner.

[0050] like Figure 4 As shown, it is an operation flow chart of a charging device for an unmanned aerial vehicle provided according to an embodiment of the present application, which shows the operation process of the charging device for the unmanned aerial vehicle. First, low-frequency direct current provided by a direct current power supply is received, and then high-frequency inversion is performed (this step is performed by an inverter, that is, the direct current provided by the direct current power supply is converted into alternating current), and then magnetic coupling resonance is performed, specifically, the transmitting coil (that is, the above-mentioned charging circuit) performs resonant transmission and matching (that is, the above-mentioned charging circuit is connected to the inverter, and is used to send the electrical signal corresponding to the alternating current to the power receiving end circuit of the unmanned aerial vehicle in a contactless manner), and the receiving coil (that is, the power receiving end circuit of the above-mentioned unmanned aerial vehicle) performs resonant transmission and matching. The receiving coil of the circuit) is resonantly received and matched: the alternating current is transmitted through the transmitting coil to form a source of wireless energy transmission. The energy between the transmitting coil and the receiving coil is transmitted through magnetic coupling and resonance effect. The AC signal of the receiving coil is matched and optimized through the resonant circuit of the receiving end to ensure the energy receiving efficiency. Finally, rectification and filtering are performed (the received alternating current is rectified and filtered and converted into smooth direct current). Finally, the converted target direct current powers the battery (i.e., the load) of the drone (i.e., the above-mentioned power receiving end circuit is used to convert the electrical signal into the target direct current to charge the drone), completing the wireless charging process.

[0051] It should be noted that the load voltage corresponding to the target DC power is determined by the first functional relationship between the load resistance, the equivalent parasitic resistance of the power receiving circuit of the drone, the voltage of the AC power, and the characteristic parameters of the K converter. The load resistance refers to the impedance of the actual load of the power receiving circuit, that is, the resistance presented by the drone battery or battery management system when receiving power. The equivalent parasitic resistance of the power receiving circuit refers to the internal resistance caused by non-ideal factors in the receiving coil and its circuit, including the DC resistance of the receiving coil, the loss of the circuit board, and the resistance of any connecting wires or contacts, which affects the internal loss and energy transmission efficiency of the power receiving end. For example, the first functional relationship is determined by the following formula:

[0052]

[0053] Among them, V L Indicates the load voltage corresponding to the target DC, R L represents the load resistance (specifically the load resistance of the power receiving circuit of the drone), V S represents the voltage of alternating current, K1 and K2 are the characteristic parameters of the K converter, and R2 is the equivalent parasitic resistance of the receiving coil (the power receiving circuit of the drone).

[0054] In another optional method, the load voltage V corresponding to the target DC L It can also be determined by a second functional relationship between the mutual inductance between the charging circuit and the power receiving end circuit of the drone, the voltage of the alternating current, the characteristic parameters of the K converter, and the resonant frequency of the charging system of the drone. For example, the second function can be expressed by the following formula:

[0055]

[0056] Among them, V L represents the load voltage corresponding to the target DC power, ω0 represents the resonant frequency of the UAV’s charging system (the same as the resonant frequency of the UAV’s charging device), K1 is the characteristic parameter of the K converter, V S Indicates the voltage of alternating current, M 12 It represents the mutual inductance between the charging circuit and the power receiving circuit of the drone (specifically, the receiving coil of the power receiving circuit of the drone).

[0057] The mutual inductance between the charging circuit and the power receiving end circuit of the drone in the above steps can be determined by a third functional relationship between the number of coil turns of the combined transmitting coil of the charging circuit, the number of coil turns of the receiving coil of the power receiving end circuit of the drone, the vacuum magnetic permeability, the coil radius of the combined transmitting coil and the coil radius of the receiving coil, the offset angle of the receiving coil, the angle variable used to describe the position on the combined transmitting coil, the angle variable used to describe the position on the receiving coil of the power receiving end circuit of the drone, and the distance between the current element on the receiving coil and the current element on the combined transmitting coil. For example, the third function is expressed by the following formula:

[0058]

[0059] Among them, M 12 represents the mutual inductance between the charging circuit and the power receiving circuit of the drone, μ0 represents the vacuum magnetic permeability, N1 and N2 represent the number of turns of the combined transmitting coil of the charging circuit and the number of turns of the receiving coil of the power receiving circuit of the drone, r1 and r2 represent the coil radius of the combined transmitting coil (specifically the radius of the first coil) and the coil radius of the receiving coil, θ is the angle variable on the combined transmitting coil used to describe the position, is the angle variable used to describe the position of the receiving coil of the power receiving circuit of the drone, α represents the offset angle of the receiving coil, and r 12 Represents the distance between the current element on the receiving coil and the current element on the combined transmitting coil.

[0060] like Figure 5 FIG. 1 is a schematic diagram of the spatial position of a combined transmitting coil and a receiving coil provided in an embodiment of the present application, showing the spatial position relationship between the combined transmitting coil (i.e., coil 1 in the figure) and the receiving coil (i.e., coil 2 in the figure). Two coordinate systems are established in the figure, namely, the x1, y1, z1 coordinate system with O as the origin and the x1, y1, z1 coordinate system with O' as the origin. 2‘ 、z 2‘ Coordinate system, corresponding to coil 1 and coil 2 respectively. The two coils are in different spatial positions, with a vertical spacing of d and a horizontal spacing of h. r1 and r2 represent the coil radius of coil 1 (i.e., the first coil in the combined transmitting coil) and the coil radius of coil 2 (i.e., the receiving coil of the power receiving circuit of the drone), respectively. θ is the angle variable on coil 1 used to describe the position. (Φ in the same figure) is the angle variable used to describe the position on coil 2, α represents the offset angle of the receiving coil, and r 12 It represents the distance between the current element on the receiving coil and the current element on the combined transmitting coil, dI1 represents the current element on coil 1, and dI2 represents the current element on coil 2.

[0061] like Figure 6 As shown, it is a circuit equivalent transformation diagram of a charging system of a drone provided in an embodiment of the present application. Through a series of equivalent transformations, the original coupled inductor circuit on the far left is gradually transformed into a form that is easier to analyze and calculate. In the circuit on the far left, L1 is the inductance of the combined transmitting coil (specifically, the self-inductance of the combined transmitting coil), L2 is the inductance of the receiving coil (the receiving coil of the power receiving end circuit of the drone) (specifically, the self-inductance of the receiving coil), C1 is the compensation capacitor of the combined transmitting coil, and C2 is the compensation capacitor of the receiving coil (the receiving coil of the power receiving end circuit of the drone). Its function is to form a resonant circuit with the corresponding inductance, adjust the resonant frequency of the circuit, so that the transmitting end (i.e., the charging circuit) and the receiving end (i.e., the power receiving end circuit of the drone) can achieve efficient energy transmission at a specific resonant frequency. 12 It is the mutual inductance between the charging circuit (specifically the combined receiving coil of the charging circuit) and the receiving coil (the receiving coil of the power receiving circuit of the drone). The circuit on the far left describes the electrical structure of the charging circuit in the drone's charging system and the receiving coil of the power receiving circuit of the drone. The power of the charging circuit is coupled to the power receiving circuit of the drone in the form of an alternating magnetic field, realizing wireless energy transmission. Figure 6 The circuit in the middle is an equivalent form of the circuit on the far left. In this equivalent process, the original inductors L1 and L2 are equivalent to L1-M 12 and L2-M 12 , mutual inductance M 12 This equivalent transformation is based on the coupled inductor equivalent principle in circuit theory. By recombining self-inductance and mutual inductance, the analysis and calculation of the circuit are easier. This equivalent form helps to more clearly understand the interaction between the charging circuit and the receiving coil of the drone's power receiving circuit when analyzing the circuit's impedance, current and voltage distribution characteristics. It is especially important for studying key performance indicators such as coupling coefficient and energy transmission efficiency. The circuit on the far right is a further equivalent of the middle circuit, with the mutual inductance M 12 It is equivalent to a new component, and its characteristic parameter is expressed as K 12 , in ohms. The operating frequency of the drone charging system in the resonant state is ω. In the AC circuit, this equivalent method combines the mutual inductance with the operating frequency of the drone charging system in the resonant state, and converts the role of the mutual inductance into a component with specific characteristic parameters, which is convenient for analyzing the circuit in the frequency domain. The characteristic parameter K of the new component 12 = ... 12Through this equivalence, when studying the frequency response, power transfer characteristics and performance of the circuit under resonant state, it is more convenient to use relevant methods and tools in circuit theory, such as impedance matching and resonance analysis, so as to optimize the design and performance of the wireless power transmission system.

[0062] In the above operating environment, the embodiment of the present application also provides a flowchart of a charging method for a drone, such as Figure 7 It should be noted that the steps shown in the flowchart of the accompanying drawings can be performed in a Figure 1 UAV charging equipment and Figure 2 The charging system of the drone is executed, and although a logical order is shown in the flow chart, in some cases, the steps shown or described may be performed in an order different from that shown here.

[0063] like Figure 7 FIG. 1 is a flowchart of a charging method for a drone according to an embodiment of the present application, comprising:

[0064] Step S702: Convert the DC power provided by the DC power supply of the charging system of the drone into AC power based on an inverter.

[0065] In the technical solution provided in step S702, the charging system of the drone includes a charging device of the drone and a drone, the charging device includes: a charging circuit, an inverter and a DC power supply, the charging circuit includes a K converter for circuit tuning, a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, the K converter is located between the inverter and the combined transmitting coil, and the drone includes: an electric energy receiving end circuit.

[0066] Step S704: Send the electrical signal corresponding to the alternating current to the power receiving circuit of the drone in a contactless manner.

[0067] In the technical solution provided in step S704, there are many ways to implement the method of sending the electrical signal corresponding to the alternating current to the power receiving circuit of the drone of the charging system of the drone in a contactless manner, for example: adjusting the characteristic parameters of the K converter of the charging circuit and performing circuit tuning; based on the circuit tuning performed by the K converter, the electrical signal corresponding to the alternating current is sent to the power receiving circuit of the drone by resonating with the resonant circuit of the power receiving circuit of the drone at a predetermined wireless charging frequency through the combined transmitting coil.

[0068] Step S706, converting the electrical signal into target direct current through the power receiving circuit of the drone.

[0069] Step S708: Use the target direct current to charge the drone.

[0070] The present application embodiment provides a schematic diagram of the structure of a charging device for a drone, such as Figure 8 As shown, including:

[0071] The conversion module 802 is used to convert the DC power provided by the DC power supply of the charging system of the drone into AC power based on an inverter, wherein the charging system of the drone includes a charging device of the drone and the drone, the charging device includes: a charging circuit, an inverter and a DC power supply, and the drone includes: an electric energy receiving end circuit.

[0072] The sending module 804 is used to send the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone of the charging system of the drone in a contactless manner.

[0073] The conversion module 806 is used to convert the electrical signal into target direct current through the power receiving circuit of the drone.

[0074] The charging module 808 is used to charge the drone using the target direct current.

[0075] It should be noted that Figure 8 The charging device of the drone shown is used to perform Figure 7 The charging method of the drone shown, therefore Figure 7 The relevant explanations and instructions in the charging method of the drone in also apply to the charging device of the drone and will not be repeated here.

[0076] It should be noted that the various modules in the charging device of the above-mentioned drone can be program modules (for example, a set of program instructions to implement a certain specific function) or hardware modules. For the latter, it can be expressed in the following forms, but is not limited to this: the expression form of each of the above-mentioned modules is a processor, or the functions of each of the above-mentioned modules are implemented by a processor.

[0077] In order to verify the implementation effect of the charging system of the drone of this application, simulation tests were carried out, such as Fig. 9 As shown, it is a curve diagram of simulation results of load voltage changing with load resistance provided by an embodiment of the present application, showing a curve diagram of magnetic flux changing with operating frequency under different load resistance values, the horizontal axis is the resonant frequency (freq), the unit is kilohertz (KHz), the vertical axis is the load voltage amplitude mag (VL), the unit is volt (V), reflecting the size of the load voltage (VL, that is, the load voltage corresponding to the target DC). The figure contains multiple curves, each curve corresponds to a specific load resistance (RL, the same as R L) values ​​(2Ω, 4Ω, 6Ω, 8Ω, 10Ω). As can be seen from the curve, the load voltage (VL, i.e. the load voltage corresponding to the target DC) drops rapidly within a specific resonant frequency (freq) range (about 80-90KHz), and tends to be stable in a higher frequency range. However, the load voltages of different resistance values ​​at the resonant frequency point of 100KHz will intersect at one point, that is, the voltages of different loads at the resonant frequency point of 100kHz are the same, indicating that the load voltage will not change with the change of the load.

[0078] like Fig.10 As shown, it is a transmission efficiency change curve of a charging system of a drone provided according to an embodiment of the present application; the horizontal axis is the lateral offset distance of the receiving coil, and the vertical axis is the system efficiency. Within the offset distance of 0cm to 9cm, the transmission efficiency of the system fluctuates around 1.1%, and the variation range is very small. Fig.11 This is a load voltage variation curve of a charging system of a drone provided according to an embodiment of the present application. The horizontal axis is the lateral offset distance of the receiving coil, and the vertical axis is the load voltage. Within the offset distance of 0cm to 9cm, the load voltage fluctuates around 0.45V, with a small variation. The charging system of the drone of the present application meets the stable charging requirements within the offset distance of 0cm to 9cm.

[0079] The embodiment of the present application also provides a non-volatile storage medium, the non-volatile storage medium includes a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute the above charging method for the drone. For example, the DC power provided by the DC power supply of the charging system of the drone is converted into AC power based on an inverter, wherein the charging system of the drone includes a charging device of the drone and the drone, the charging device includes: a charging circuit, an inverter and a DC power supply, the charging circuit includes a K converter for circuit tuning, a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, the K converter is located between the inverter and the combined transmitting coil, and the drone includes: a power receiving end circuit; an electrical signal corresponding to the AC power is sent to the power receiving end circuit of the drone in a non-contact manner; the electrical signal is converted into a target DC power by the power receiving end circuit of the drone; and the target DC power is used to charge the drone.

[0080] According to another aspect of the embodiment of the present application, a computer program product is also provided, including a computer program, which implements the above charging method of the drone when executed by the processor. For example, the DC power provided by the DC power supply of the charging system of the drone is converted into AC power based on an inverter, wherein the charging system of the drone includes a charging device of the drone and the drone, the charging device includes: a charging circuit, an inverter and a DC power supply, the charging circuit includes a K converter for circuit tuning, a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, the K converter is located between the inverter and the combined transmitting coil, and the drone includes: a power receiving end circuit; an electrical signal corresponding to the AC power is sent to the power receiving end circuit of the drone in a non-contact manner; the electrical signal is converted into a target DC power by the power receiving end circuit of the drone; and the target DC power is used to charge the drone. When the circuit involved in the charging system of the drone is simulated, the above modules can be modules in the simulation model.

[0081] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0082] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0083] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0084] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0085] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the relevant technology or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc. Various media that can store program codes.

[0086] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A charging device for an unmanned aerial vehicle, characterized in that: include: Charging circuit, inverter and DC power supply; The DC power supply is used to provide DC power; The inverter is connected to the DC power supply and is used to convert the DC power provided by the DC power supply into AC power; The charging circuit is connected to the inverter, and is used to send the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone in a contactless manner. The charging circuit includes: a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, wherein the power receiving end circuit is used to convert the electrical signal into target direct current.

2. The charging device according to claim 1, characterized in that: The second coil and the first coil are concentric circles, and the radius of the second coil is smaller than the radius of the first coil.

3. The charging device according to claim 1, characterized in that: The charging circuit further includes: a K converter for circuit tuning, wherein the K converter is located between the inverter and the combined transmitting coil.

4. The charging device according to claim 3, characterized in that: The K converter includes: a T-type inductor network circuit, the T-type inductor network circuit includes an inductor, a first capacitor and a second capacitor, the inductor is connected in series between the inverter and the combined transmitting coil, and the first capacitor and the second capacitor are connected in parallel to one end of the inductor.

5. The charging device according to claim 1, characterized in that: The inverter is a full-bridge inverter, in which a first switch and a second switch of a field effect transistor are connected in series, a third switch and a fourth switch of the field effect transistor are connected in series, and a circuit consisting of the first switch and the second switch connected in series and a circuit consisting of the third switch and the fourth switch connected in series are connected in parallel.

6. The charging device according to claim 5, characterized in that: The inverter converts the DC power provided by the DC power supply into AC power in the following manner: by controlling the switching states of the first switch, the second switch, the third switch, and the fourth switch, the DC power is converted into AC power, wherein the waveform of the output voltage of the AC power is a square wave, and the frequency of the AC power matches the resonant frequency of the charging device of the drone.

7. The charging device according to claim 3, characterized in that: The charging circuit sends the electrical signal corresponding to the alternating current to the power receiving circuit of the drone in a contactless manner in the following manner: Adjusting characteristic parameters of the K converter of the charging circuit and performing circuit tuning; Based on the circuit tuning performed by the K converter, the combined transmitting coil of the charging circuit resonates with the resonant circuit of the power receiving end circuit of the drone at a predetermined wireless charging frequency, and sends the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone.

8. A charging system for an unmanned aerial vehicle, characterized in that: include: A charging device for a drone and a drone, wherein the charging device comprises: a charging circuit, an inverter and a DC power supply; The DC power supply is used to provide DC power; The inverter is connected to the DC power supply and is used to convert the DC power provided by the DC power supply into AC power; The charging circuit is connected to the inverter and is used to send the electrical signal corresponding to the alternating current to the power receiving end circuit of the drone in a contactless manner. The charging circuit includes a K converter for circuit tuning, and a combined transmitting coil composed of a first coil and a second coil. The first coil and the second coil are connected in series, and the second coil is an auxiliary coil of the first coil and is used to compensate for the magnetic field strength of the first coil. The K converter is located between the inverter and the combined transmitting coil. The drone comprises: a power receiving end circuit, wherein the power receiving end circuit is used to convert the electrical signal into target direct current to charge the drone.

9. The charging system according to claim 8, characterized in that: The load voltage corresponding to the target direct current is determined by a first functional relationship among a load resistor, an equivalent parasitic resistance of a power receiving circuit of the drone, a voltage of the alternating current, and characteristic parameters of the K converter.

10. The charging system according to claim 8, characterized in that: The load voltage corresponding to the target direct current is determined by a second functional relationship between the mutual inductance between the charging circuit and the power receiving end circuit of the drone, the voltage of the alternating current, the characteristic parameters of the K converter, and the resonant frequency of the charging system of the drone.

11. A method for charging a drone, characterized in that: include: The DC power provided by the DC power supply of the charging system of the drone is converted into AC power based on an inverter, wherein the charging system of the drone includes a charging device of the drone and the drone, the charging device includes: a charging circuit, an inverter and a DC power supply, the charging circuit includes a K converter for circuit tuning, a combined transmitting coil composed of a first coil and a second coil, the first coil and the second coil are connected in series, the second coil is an auxiliary coil of the first coil, and is used to compensate for the magnetic field strength of the first coil, the K converter is located between the inverter and the combined transmitting coil, and the drone includes: a power receiving end circuit; Sending an electrical signal corresponding to the alternating current to a power receiving circuit of the drone in a contactless manner; The electrical signal is converted into target direct current through the power receiving end circuit of the drone; The target direct current is used to charge the drone.

12. The method according to claim 11, characterized in that The power receiving circuit of the drone that sends the electrical signal corresponding to the alternating current to the charging system of the drone in a contactless manner includes: Adjusting characteristic parameters of the K converter of the charging circuit and performing circuit tuning; Based on the circuit tuning performed by the K converter, the combined transmitting coil resonates with the resonant circuit of the power receiving end circuit of the drone at a predetermined wireless charging frequency, and the electrical signal corresponding to the alternating current is sent to the power receiving end circuit of the drone.

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