Communicationless WPT System and Control Method for Inspection Robot with Parameter Estimation Ability

Abstract

The present invention provides a communication-free WPT system for inspection robots with parameter estimation capabilities and a control method. The system includes a transmitting end and a receiving end. The transmitting end is provided with a DC power supply, a high-frequency inverter module, a primary compensation circuit, an energy transmitting coil, a detection circuit, and a primary controller; the receiving end is provided with an energy receiving coil, a secondary compensation circuit, a rectifier filter circuit, and an electrical load; the energy transmitting coil and the energy receiving coil are correspondingly arranged and realize wireless power transmission through electromagnetic coupling. A detection coil is arranged in the detection circuit, and a secondary compensation coil is arranged in the secondary compensation circuit. The detection coil and the secondary compensation coil are correspondingly arranged and realize the feedback of the secondary output current through electromagnetic coupling; the detection circuit determines the state of the receiving end by acquiring the pickup signal of the detection coil, and controls the output state of the high-frequency inverter module through the primary controller. The effect is that it can achieve constant current output without communication and ensure the wireless charging performance of the system.

Description

Technical Field

[0001] The present invention relates to wireless energy transmission technology, and more particularly to a communication-free WPT system and control method for inspection robots with parameter estimation capabilities. Background Art

[0002] Inspection robots can replace manual labor to automatically, efficiently, and round-the-clock monitor the operating status of substation equipment, greatly improving the stability and reliability of substation operation. Currently, inspection robots mainly use contact charging, which has the following problems: 1) frequent plugging and unplugging of plugs easily leads to wear, deformation, and aging, increasing safety hazards; 2) wired autonomous charging requires precise alignment of the charging interface, so complex alignment structures and alignment algorithms are needed.

[0003] With the development of wireless power transmission technology, some researchers have proposed applying wireless power transmission (WPT) technology to charge inspection robots, as Figure 1 shown. Compared with traditional wired chargers, such a WPT system does not require plugging and unplugging wires and can also avoid using complex alignment structures and alignment algorithms, making the inspection robot safer and more convenient.

[0004] Existing inspection robots usually need to adopt constant voltage (CV) or constant current (CC) charging modes. To achieve CC or CV output, one method is to design a compensation network to obtain an approximately load-independent CV or CC output. However, due to the deviation of robot positioning, its parking position may be different each time it charges. Obviously, the open-loop control method is not suitable for charging inspection robots because of its poor anti-interference ability.

[0005] To increase the anti-interference ability, a closed-loop control method can also be adopted. According to the position of the closed-loop controller, it can be divided into secondary-side closed-loop control and primary-side closed-loop control. For the secondary-side closed-loop control method, a CV or CC output can be obtained by adding a DC / DC converter or an active rectifier. However, due to the limited installation space of the inspection robot, adding an additional control module inside the inspection robot is obviously not a wise choice. For the primary-side closed-loop control method, usually the secondary-side information is fed back to the primary side through wireless communication, and then a CV or CC output is obtained by controlling the phase shift or frequency of the inverter. However, it often requires adding an additional communication system, and the stability and real-time performance of signal transmission are still difficult to meet the needs of some application scenarios. Summary of the Invention

[0006] Based on the above requirements, the primary objective of the present invention is to propose a communication-free WPT system for inspection robots with parameter estimation capabilities. This system can directly utilize the electromagnetic coupling between the secondary compensation coil and the primary detection coil to feedback the operating parameters of the secondary side without adding an additional communication system, facilitating the adjustment of the output voltage or output current on the primary side.

[0007] To achieve the above objective, the specific technical solutions adopted by the present invention are as follows:

[0008] A communication-free WPT system for inspection robots with parameter estimation capabilities, comprising a transmitting end and a receiving end. The key lies in that the transmitting end is provided with a DC power supply, a high-frequency inverter module, a primary compensation circuit, an energy transmitting coil, a detection circuit, and a primary controller; the receiving end is provided with an energy receiving coil, a secondary compensation circuit, a rectifier filter circuit, and an electrical load; the energy transmitting coil and the energy receiving coil are correspondingly arranged and achieve wireless power transmission through electromagnetic coupling. A detection coil is arranged in the detection circuit, and a secondary compensation coil is arranged in the secondary compensation circuit. The detection coil and the secondary compensation coil are correspondingly arranged and achieve feedback of the secondary output current through electromagnetic coupling; the detection circuit determines the state of the receiving end by acquiring the pickup signal of the detection coil and controls the output state of the high-frequency inverter module through the primary controller.

[0009] Optionally, the primary compensation circuit includes a primary compensation inductor, a primary parallel compensation capacitor, a primary series compensation capacitor, and a primary mode switching switch. The secondary compensation circuit includes a secondary compensation coil, a secondary parallel compensation capacitor, a secondary series compensation capacitor, and a secondary mode switching switch. When both the primary mode switching switch and the secondary mode switching switch are closed, the primary parallel compensation capacitor and the secondary parallel compensation capacitor are put into use, and an LCC-LCC topology structure is formed between the transmitting end and the receiving end. When both the primary mode switching switch and the secondary mode switching switch are open, the primary parallel compensation capacitor and the secondary parallel compensation capacitor form an open circuit, and an SS topology structure is formed between the transmitting end and the receiving end.

[0010] Optionally, the energy transmitting coil is wound into a DD-type coil, the detection coil is wound into a Q-type coil, and the energy transmitting coil overlaps with the detection coil, and they are naturally decoupled from each other; the energy receiving coil is wound into a DD-type coil, the secondary compensation coil is wound into a Q-type coil, and the energy receiving coil overlaps with the secondary compensation coil, and they are naturally decoupled from each other.

[0011] Optionally, a rectification and filtering module and a sampling resistor are provided in the detection circuit, and a voltage detection module and an A / D sampling module are provided in the primary controller. The end voltage of the sampling resistor is obtained through the voltage detection module, and its detected voltage is obtained through the A / D sampling module.

[0012] Optionally, a secondary controller is provided at the receiving end. The secondary controller includes a frequency detection module for detecting the frequency of the signal picked up by the energy receiving coil and a secondary switch control module for controlling the on / off of the secondary mode switching switch.

[0013] Based on the system described above, the present invention also provides a control method for a communication-free WPT system of an inspection robot with parameter estimation ability, including the following steps:

[0014] S1: After the inspection robot stops, enter the parameter estimation mode. By controlling the closing of the primary mode switching switch and the secondary mode switching switch, an LCC-LCC topology structure is formed between the transmitting end and the receiving end. Set the operating frequency of the high-frequency inverter module to the system natural frequency f of the LCC-LCC topology structure, and the conduction angle to δ 0_LCC , and obtain the sampling voltage U through the detection circuit D0_LCC ;

[0015] S2: Then, by controlling the opening of the primary mode switching switch and the secondary mode switching switch, an SS topology structure is formed between the transmitting end and the receiving end. Set the operating frequency of the high-frequency inverter module to the system natural frequency f of the SS topology structure s , and the conduction angle to δ 0_SS , and obtain the sampling voltage U through the detection circuit D0_SS ;

[0016] S3: Estimate the mutual inductance M between the energy transmitting coil and the energy receiving coil P and the mutual inductance M between the detection coil and the secondary compensation coil D ;

[0017] S4: By controlling the closing of the primary mode switching switch and the secondary mode switching switch, an LCC-LCC topology structure is re-formed between the transmitting end and the receiving end. Obtain the sampling voltage U through the detection circuit D and solve for the current load output current I based on the mutual inductance M between the detection coil and the secondary compensation coil estimated in step S3 D ; L ;

[0018] S5: Compare the current load output current I L with the reference current I LrefThe error between them is sent to the proportional-integral controller, and the processed result is passed to the PSM controller to obtain the final conduction angle δ;

[0019] S6: The primary controller controls the high-frequency inverter module according to the conduction angle δ to adjust the output current so that it maintains a constant current output.

[0020] Optionally, in step S3, according to:

[0021]

[0022] Calculate the mutual inductance M between the energy transmitting coil and the energy receiving coil P and the mutual inductance M between the detection coil and the secondary compensation coil D , where: U D0_LCC is the sampled voltage obtained by the detection circuit in step S1, U D0_SS is the sampled voltage obtained by the detection circuit in step S2, U in0_LCC represents the equivalent output voltage of the high-frequency inverter module in step S1, U in0_SS represents the equivalent output voltage of the high-frequency inverter module in step S2, and the calculation method is:

[0023]

[0024] U dc is the output voltage of the DC power supply, X CT is the capacitive reactance of the primary parallel compensation capacitor, X CR is the capacitive reactance of the secondary parallel compensation capacitor; the working angular frequency ω = 2πf.

[0025] Optionally, in step S4, according to Solve to obtain the current load output current I L .

[0026] Optionally, in step S2, first disconnect the primary mode switching switch at the transmitting end, and the primary controller sets the operating frequency of the high-frequency inverter module to the system natural frequency f s when in the SS topology structure, the conduction angle is δ 0_SS , and the frequency detection module in the secondary controller controls the disconnection of the secondary mode switching switch by detecting the change in the signal frequency picked up by the energy receiving coil.

[0027] The effect of the present invention is:

[0028] A patrol robot non - communication WPT system and control method with parameter estimation ability proposed by the present invention can detect two induced DC voltages of the primary - side circuit by switching between the LCC - LCC and SS topologies, thereby realizing the identification of the mutual inductance coefficient of the system and providing a basis for the closed - loop control of the system. This is very practical for patrol robots because their parking positions may be different each time, that is, the parking positions on the x - axis and z - axis will change. Secondly, this system constructs a control system with the induced voltage of the primary - side detection circuit as the feedback, can achieve non - communication CC output. Compared with the traditional communication - based primary - side control method, this method does not require complex pairing, reduces communication delay, and has better charging performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art.

[0030] Figure 1 FIG. is the architecture diagram of the existing wireless charging system for patrol robots;

[0031] Figure 2 FIG. is the schematic circuit diagram of the system of the present invention;

[0032] Figure 3 FIG. is the coil distribution relationship diagram of the magnetic coupling structure in the specific embodiment of the present invention;

[0033] Figure 4 FIG. is the coil size relationship diagram of the magnetic coupling structure in the specific embodiment of the present invention;

[0034] Figure 5 (a) FIG. is the equivalent circuit diagram in the case of LCC - LCC topology in the specific embodiment of the present invention;

[0035] Figure 5 (b) FIG. is the equivalent circuit diagram in the case of SS topology in the specific embodiment of the present invention;

[0036] Figure 6 FIG. is the control flow chart in the specific embodiment of the present invention;

[0037] Figure 7 FIG. is the mutual inductance change curve of the system parameter estimation value and the measured value;

[0038] Figure 8 FIG. is the key waveform change diagram when the system switches from LCC - LCC topology to SS topology;

[0039] Figure 9 FIG. is for R in the specific embodiment L The dynamic response curve when it changes from 3.6Ω to 4.8Ω and then back to 3.6Ω;

[0040] Figure 10 In the specific embodiment I Lref The dynamic response curve when changing from 10A to 8A and then back to 10A. Specific implementation mode

[0041] Hereinafter, embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and thus are only examples and cannot be used to limit the protection scope of the present invention.

[0042] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meanings understood by those skilled in the art to which the present invention belongs.

[0043] As Figure 2 shown, this embodiment provides a communication-free WPT system for inspection robots with parameter estimation ability, including a transmitting end and a receiving end. The transmitting end is provided with a DC power supply, a high-frequency inversion module, a primary compensation circuit, an energy transmitting coil, a detection circuit and a primary controller; the receiving end is provided with an energy receiving coil, a secondary compensation circuit, a rectification and filtering circuit and an electrical load; the energy transmitting coil and the energy receiving coil are correspondingly arranged and realize wireless power transmission through electromagnetic coupling. A detection coil is arranged in the detection circuit, and a secondary compensation coil is arranged in the secondary compensation circuit. The detection coil and the secondary compensation coil are correspondingly arranged and realize the feedback of the secondary output current through electromagnetic coupling; the detection circuit determines the state of the receiving end by acquiring the pickup signal of the detection coil, and controls the output state of the high-frequency inversion module through the primary controller.

[0044] Through Figure 2 It can be seen that the mutual inductance M between the energy transmitting coil and the energy receiving coil P ensures wireless power transmission, and the mutual inductance M between the detection coil and the secondary compensation coil D feeds back the secondary side output current to the primary side. U D is the DC voltage detected to reflect the output current. As mentioned above, due to the deviation of the positioning accuracy of the inspection robot, its parking position may be different each time it is charged. Therefore, to use U D to control the output current, it is necessary to first identify M D .

[0045] In order to more conveniently implement parameter identification, in this embodiment, the primary compensation circuit includes a primary compensation inductor, a primary parallel compensation capacitor, a primary series compensation capacitor, and a primary mode switching switch, and the secondary compensation circuit includes a secondary compensation coil, a secondary parallel compensation capacitor, a secondary series compensation capacitor, and a secondary mode switching switch. When both the primary mode switching switch and the secondary mode switching switch are closed, the primary parallel compensation capacitor and the secondary parallel compensation capacitor are put into use, and an LCC-LCC topology structure is formed between the transmitting end and the receiving end. When both the primary mode switching switch and the secondary mode switching switch are open, the primary parallel compensation capacitor and the secondary parallel compensation capacitor form an open circuit, and an SS topology structure is formed between the transmitting end and the receiving end. By Figure 2 It can be seen that S1 and S2 are two AC switches used to switch the system topology between LCC-LCC and SS. By detecting U under these two topologies D the mutual inductance coefficient can be identified.

[0046] By Figure 3 It can be seen that in order to reduce the crosstalk between the coils at the transmitting end and the receiving end, in this embodiment, the energy transmitting coil is wound into a DD-type coil, the detection coil is wound into a Q-type coil, and the energy transmitting coil overlaps with the detection coil, and natural decoupling occurs between the two; the energy receiving coil is wound into a DD-type coil, the secondary compensation coil is wound into a Q-type coil, and the energy receiving coil overlaps with the secondary compensation coil, and natural decoupling occurs between the two. Figure 3 where L P and L S are the transmitting-end DD coil and the receiving-end DD coil respectively, L R is the compensation Q coil at the receiving end, L D is the detection Q coil at the transmitting end. In order to form a compact coupling structure, L D overlaps with L P , L R overlaps with L S . The specific parameter design of each coil is as Figure 4 shown. Due to the natural decoupling characteristic between the DD coil and the Q coil, in the actual charging scenario of the inspection robot, for the sake of simplifying the analysis, only the mutually coupled M P (between L P and L S ) and M D (between L D and L R ) are considered during the implementation process.

[0047] In order to better implement the detection of the feedback current, by Figure 2It can be seen that in specific implementation, a rectification and filtering module and a sampling resistor are provided in the detection circuit, and a voltage detection module and an A / D sampling module are provided in the primary controller. The end voltage of the sampling resistor is obtained through the voltage detection module, and its detection voltage is obtained through the A / D sampling module.

[0048] Meanwhile, in order to realize the synchronous switching of the receiving end working mode without adding communication, a secondary controller is provided at the receiving end. The secondary controller includes a frequency detection module for detecting the frequency of the signal picked up by the energy receiving coil and a secondary switch control module for controlling the on / off of the secondary mode switching switch.

[0049] According to the above system design, when S1 and S2 are turned on, the system works in the LCC-LCC compensation topology shown in Figure 5 (a), where L T and L R are the compensation coils of the transmitting coil L P and the receiving coil L S respectively, and R T , R P , R S , R R are the parasitic resistors of L T , L P , L S , L R respectively.

[0050] To simplify the analysis, it is assumed that the detection resistor R DL >>ωL D and Z D >>ω 2 M D 2 , so that Z refD →0, and we can get:

[0051]

[0052] Under the coil size information shown in Figure 4 , the measured parasitic resistors R D , R P , R S , R R can be ignored to simplify the analysis. We can get I R :

[0053]

[0054] When S1 and S2 are turned off, the system works in the series - series (SS) compensation network shown in Figure 5 (b).

[0055] It can be deduced that:

[0056]

[0057] U in the SS topology system D Can be calculated as:

[0058]

[0059] Based on the above analysis, this embodiment also proposes a control method for a communication-free WPT system of an inspection robot with parameter estimation ability, as Figure 6 shown, including the following steps:

[0060] S1: After the inspection robot stops, enter the parameter estimation mode. By controlling the closing of the primary-side mode switching switch and the secondary-side mode switching switch, an LCC-LCC topology structure is formed between the transmitter and the receiver. Set the operating frequency of the high-frequency inverter module to the natural frequency f of the system in the LCC-LCC topology structure, and the conduction angle to δ 0_LCC , and obtain the sampled voltage U through the detection circuit D0_LCC ;

[0061] S2: Then, by controlling the opening of the primary-side mode switching switch and the secondary-side mode switching switch, an SS topology structure is formed between the transmitter and the receiver. Set the operating frequency of the high-frequency inverter module to the natural frequency f of the system in the SS topology structure s , and the conduction angle to δ 0_SS , and obtain the sampled voltage U through the detection circuit D0_SS ;

[0062] S3: Estimate the mutual inductance M between the energy transmitting coil and the energy receiving coil P and the mutual inductance M between the detection coil and the secondary compensation coil D ;

[0063] S4: By controlling the closing of the primary-side mode switching switch and the secondary-side mode switching switch, an LCC-LCC topology structure is re-formed between the transmitter and the receiver. Obtain the sampled voltage U through the detection circuit D and solve for the current load output current I based on the mutual inductance M between the detection coil and the secondary compensation coil estimated in step S3 D ; L ;

[0064] S5: Send the error between the current load output current I L and the reference current I Lref to the proportional-integral controller, and transmit the processed result to the PSM controller to obtain the final conduction angle δ;

[0065] S6: The primary controller controls the high-frequency inverter module according to the conduction angle δ to adjust the output current and maintain a constant current output.

[0066] As can be seen from the above steps, after the inspection robot stops, the system first enters the parameter (i.e., M P and M D ) estimation mode. First, S1 and S2 are turned on, and the system operates in the LCC-LCC topology with a frequency of f. The conduction angle is set to δ 0_LCC , generating a small amount of energy for parameter estimation. The sampling information, i.e., U D0_LCC , can be measured. Secondly, S1 is set to off, and the frequency of the inverter becomes f S , and the conduction angle is set to δ 0_SS . Then, after the frequency discrimination module on the secondary side detects the frequency change, S2 also switches to the off state, and the system operates in the SS topology. The sampling information, i.e., U D0_SS , can be measured. According to:

[0067]

[0068] The mutual inductance M P between the energy transmitting coil and the energy receiving coil and the mutual inductance M D between the detection coil and the secondary compensation coil can be calculated, where: U D0_LCC is the sampling voltage obtained through the detection circuit in step S1, U D0_SS is the sampling voltage obtained through the detection circuit in step S2, U in0_LCC represents the equivalent output voltage of the high-frequency inverter module in step S1, U in0_SS represents the equivalent output voltage of the high-frequency inverter module in step S2, and the calculation method is:

[0069]

[0070] U dc is the output voltage of the DC power supply, X CT is the capacitive reactance of the primary parallel compensation capacitor, X CR is the capacitive reactance of the secondary parallel compensation capacitor; the working angular frequency ω = 2πf.

[0071] When designing the system, U dc , δ 0_LCC , δ 0_SS , ω, C T and C R can be determined. Usually, δ 0_LCC and δ 0_SS are set to 30°. By detecting the DC voltages U D0_LCC and U D0_SS , M P and M D can be estimated.

[0072] M P and M D After the estimation is completed, CC charging starts from the LCC-LCC configuration. The primary controller measures the DC voltage U D , solves for the output current I L , and sends the error between I L and the reference I Lref to a proportional-integral (PI) controller. The processed result is passed to a PSM (pulse-step modulation) controller to calculate the conduction angle δ and regulate the output current.

[0073] To verify the feasibility of the WPT system proposed in this invention, an experimental prototype was fabricated according to the parameters shown in Table 1 for performance testing.

[0074] Table 1 System Parameters

[0075]

[0076] Figure 7 The estimated mutual inductance values (M P-ES and M D-ES ) and the measured actual mutual inductance values (M P-RE and M D-RE ) of the HIOKI IM3536 LCR meter when varying in the x direction (i.e., from -8 cm to 8 cm). It can be seen from Figure 7 that the estimated values are in good agreement with the reference values, and the experimental results verify the feasibility of the estimation method.

[0077] The key waveforms of the system switching from the LCC-LCC topology to the SS topology are as shown in Figure 8 , where x = 0. After measuring U D0_LCC and U D0_SS , M P and M D are 13.19 μH and 3.06 μH respectively.

[0078] The output current I L can be regulated by changing U D . When the load changes, the output current can be maintained at the reference value through closed-loop control. As shown in Figure 9 , only when the load R L changes from 3.6 Ω to 4.8 Ω and then back to 3.6 Ω, the output current can remain stable with a small peak.

[0079] As shown in Figure 2 , the system can regulate I Lref to regulate I L . Figure 10 For I LrefDynamic response when changing. It describes the reference current I Lref being adjusted from 10 A to 8 A and then back to 10 A, and the output current I L can be controlled to the target value.

[0080] In summary, it can be seen that an inspection robot non - communication WPT system and a system and control method with parameter estimation ability proposed by the present invention can achieve constant - current output control of the system without communication. The system architecture is simple and the control is convenient, which can well meet the needs of wireless charging of inspection robots.

[0081] Finally, it should be noted that the above - mentioned embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and such transformations should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A communication-free WPT system for inspection robots with parameter estimation capabilities, comprising a transmitting end and a receiving end, characterized in that, The transmitting end is provided with a DC power supply, a high-frequency inverter module, a primary compensation circuit, an energy transmitting coil, a detection circuit, and a primary controller; the receiving end is provided with an energy receiving coil, a secondary compensation circuit, a rectifying and filtering circuit, and an electrical load; the energy transmitting coil and the energy receiving coil are correspondingly arranged and realize wireless power transmission through electromagnetic coupling. A detection coil is arranged in the detection circuit, and a secondary compensation coil is arranged in the secondary compensation circuit. The detection coil and the secondary compensation coil are correspondingly arranged and realize the feedback of the secondary output current through electromagnetic coupling; the detection circuit determines the state of the receiving end by acquiring the pickup signal of the detection coil, and controls the output state of the high-frequency inverter module through the primary controller. The energy transmitting coil is wound into a DD-type coil, the detection coil is wound into a Q-type coil, and the energy transmitting coil overlaps with the detection coil, and the two are naturally decoupled; the energy receiving coil is wound into a DD-type coil, the secondary compensation coil is wound into a Q-type coil, and the energy receiving coil overlaps with the secondary compensation coil, and the two are naturally decoupled.

2. The communicationless WPT system for inspection robots with parameter estimation ability according to claim 1, characterized in that: The primary compensation circuit includes a primary compensation inductor, a primary parallel compensation capacitor, a primary series compensation capacitor, and a primary mode switching switch. The secondary compensation circuit includes a secondary compensation coil, a secondary parallel compensation capacitor, a secondary series compensation capacitor, and a secondary mode switching switch. When both the primary mode switching switch and the secondary mode switching switch are closed, the primary parallel compensation capacitor and the secondary parallel compensation capacitor are put into use, and an LCC-LCC topology structure is formed between the transmitting end and the receiving end. When both the primary mode switching switch and the secondary mode switching switch are open, the primary parallel compensation capacitor and the secondary parallel compensation capacitor form an open circuit, and an SS topology structure is formed between the transmitting end and the receiving end.

3. The inspection robot non-communication WPT system with parameter estimation ability according to claim 1 or 2, characterized in that: A rectifying and filtering module and a sampling resistor are arranged in the detection circuit, and a voltage detection module and an A / D sampling module are arranged in the primary controller. The end voltage of the sampling resistor is acquired through the voltage detection module, and its detection voltage is obtained through the A / D sampling module.

4. The inspection robot non-communication WPT system with parameter estimation ability according to claim 2, characterized in that: A secondary controller is arranged at the receiving end. The secondary controller includes a frequency detection module for detecting the frequency of the pickup signal of the energy receiving coil and a secondary switch control module for controlling the on / off of the secondary mode switching switch.

5. The control method of the inspection robot non-communication WPT system with parameter estimation ability according to claim 2, characterized in that, It includes the following steps: S1: After the inspection robot stops, it enters the parameter estimation mode. By controlling the closing of the primary side mode switching switch and the secondary side mode switching switch, an LCC-LCC topology structure is formed between the transmitter and the receiver. The operating frequency of the high-frequency inverter module is set to the natural frequency f of the system in the LCC-LCC topology structure, and the conduction angle is set to δ 0_LCC , and the sampling voltage U is obtained through the detection circuit D0_LCC ; S2: Then, by controlling the disconnection of the primary-side mode switching switch and the secondary-side mode switching switch, an SS topology structure is formed between the transmitter and the receiver, and the operating frequency of the high-frequency inverter module is set to the natural frequency f of the system in the SS topology structure s , and the conduction angle is δ 0_SS , and the sampling voltage U is obtained through the detection circuit D0_SS ; S3: Estimate the mutual inductance M between the energy transmitting coil and the energy receiving coil in combination with the initial system parameters P and the mutual inductance M between the detection coil and the secondary compensation coil D ; S4: By controlling the closing of the primary-side mode switching switch and the secondary-side mode switching switch, an LCC-LCC topology structure is re-formed between the transmitter and the receiver, and the sampling voltage U is obtained through the detection circuit D and the mutual inductance M between the detection coil and the secondary-side compensation coil estimated based on step S3 D is solved to obtain the current load output current I L ; S5: Send the error between the current load output current I L and the reference current I Lref to the proportional-integral controller, and transfer the processed result to the PSM controller to obtain the final conduction angle δ; S6: The primary controller controls the high-frequency inverter module to adjust the output current according to the conduction angle δ to maintain a constant current output.

6. The control method of the inspection robot non-communication WPT system with parameter estimation ability according to claim 5, characterized in that, In step S3, according to: Calculate the mutual inductance M between the energy transmitting coil and the energy receiving coil P and the mutual inductance M between the detection coil and the secondary compensation coil D , where: U D0_LCC is the sampled voltage obtained through the detection circuit in step S1, U D0_SS is the sampled voltage obtained through the detection circuit in step S2, U in0_LCC represents the equivalent output voltage of the high-frequency inverter module in step S1, U in0_SS represents the equivalent output voltage of the high-frequency inverter module in step S2, and the calculation method is: U dc is the output voltage of the DC power supply, X CT is the reactance of the primary side parallel compensation capacitor, X CR is the reactance of the secondary side parallel compensation capacitor; the working angular frequency ω = 2πf.

7. The control method of the inspection robot non-communication WPT system with parameter estimation ability according to claim 5 or 6, characterized in that, In step S4, according to the solution, the current load output current I is obtained L .

8. The control method of the communication-free WPT system for the inspection robot with parameter estimation ability according to claim 7, characterized in that, In step S2, first disconnect the primary side mode switching switch at the transmitting end, and set the operating frequency of the high-frequency inverter module by the primary side controller to the system inherent frequency f of the SS topology structure s , and the conduction angle is δ 0_SS , and the frequency detection module in the secondary side controller controls the disconnection of the secondary side mode switching switch by detecting the change in the frequency of the signal picked up by the energy receiving coil

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