High-offset-resistant agv magnetic coupling resonance wireless charging system

Abstract

The application belongs to the technical field of wireless charging and relates to a high-deviation-resistance AGV magnetic coupling resonance wireless charging system, which comprises a vertical cabinet type charging pile, an AGV trolley, a magnetic coupling energy transmission mechanism, a power conversion module, an LCC-S resonance compensation network, a main control module, a wireless communication module and an antenna. The magnetic coupling energy transmission mechanism comprises a transmitting coil and a receiving coil. The power conversion module comprises a full-bridge inverter circuit, a full-bridge rectifier circuit and a Buck-DC-DC voltage regulation circuit. The LCC-S resonance compensation network comprises an LCC compensation loop and an S compensation loop. The receiving end is flat. The vertical cabinet type charging pile, the magnetic coupling energy transmission mechanism, the power conversion module, the LCC-S resonance compensation network, the main control module and the wireless communication module solve the problem that the existing AGV charging technology cannot simultaneously meet the requirements of unmanned operation, low parking positioning accuracy, small installation, high efficiency and stability and safe charging.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and specifically discloses a high-anti-offset AGV magnetic coupling resonant wireless charging system. Background Technology

[0002] AGVs (Automated Guided Vehicles) have become core material handling equipment in smart factories and flexible logistics systems, with the market experiencing rapid and continuous growth. China, as the world's largest single market for industrial robots, has consistently maintained an annual sales growth rate of over 20% for AGVs, making them a significant force driving the transformation and upgrading of intelligent manufacturing. AGVs rely on onboard lithium batteries for power, and their range and charging performance directly determine the overall production line efficiency. Currently, the mainstream charging methods in the industry are divided into two main categories: traditional contact charging and wireless charging.

[0003] 1. Traditional contact charging: Relying on physical plugs and electrode contacts to complete power transmission, it has a simple structure and low cost, but has obvious drawbacks: First, it relies on manual or complex mechanical structures to complete plugging and unplugging, which cannot meet the needs of fully unmanned operation; Second, the charging interface is prone to wear, oxidation and poor contact due to long-term repeated contact, resulting in high failure rate and high maintenance cost; Third, the exposed electrodes are prone to generating electric sparks, which poses a safety hazard in dusty and oily industrial environments. At the same time, frequent contact and impact will accelerate the degradation of battery life, resulting in the overall utilization rate of AGV equipment being less than 80%.

[0004] 2. Existing Wireless Charging Technologies: Currently, wireless charging technologies used in AGVs mainly include three types: electromagnetic induction, microwave, and conventional magnetic coupling resonant. Electromagnetic induction has a short transmission distance and weak anti-offset capability, requiring extremely high AGV docking and positioning accuracy. Microwave has low transmission efficiency and high electromagnetic radiation, making it unsuitable for high-power industrial scenarios. While conventional magnetic coupling resonant can achieve medium-distance, high-power energy transmission, existing mass-produced products still have many shortcomings: First, the magnetic coupling coil and overall module are relatively large, and the limited installation space on the AGV chassis makes it difficult to retrofit and modify. Second, when the coil shifts laterally or the transmission air gap fluctuates, the coupling coefficient and mutual inductance decrease sharply, resulting in a significant drop in transmission efficiency and poor anti-offset performance. Third, conventional SS and other resonant compensation topologies are greatly affected by changes in load and mutual inductance parameters, making the resonant state prone to instability and insufficient system stability. Fourth, the supporting charging control strategies are simple and do not take into account the charging and discharging characteristics of lithium batteries, making them prone to overcharging and overheating, which can damage the battery.

[0005] In summary, existing AGV charging technologies have the following problems: 1. Traditional contact charging suffers from problems such as high reliance on manual labor, easy wear and tear on the interface, potential safety hazards from electrical sparks, and incompatibility with unmanned operations; 2. Existing magnetic coupling wireless charging devices have problems such as weak anti-offset capability, high requirements for AGV docking and positioning accuracy, and significant reduction in transmission efficiency after offset. 3. Existing wireless charging receiver modules are large and thick, making them difficult to install or modify due to space limitations on the AGV chassis; 4. Conventional resonant compensation networks suffer from poor load adaptability, easy instability in resonant states, and low overall system transmission efficiency. 5. Traditional charging control strategies are not compatible with the characteristics of lithium batteries, which can easily lead to overcharging, battery life degradation, and an imperfect fault protection system. Summary of the Invention

[0006] The technical problem to be solved by this invention is that existing AGV charging technology cannot simultaneously meet the multiple requirements of unmanned operation, low docking positioning accuracy, miniaturized installation, high efficiency and stability, and safe charging.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A high-resistance offset AGV magnetic coupling resonant wireless charging system includes: The components include: a cabinet-type charging pile, an AGV trolley, a magnetic coupling energy transfer mechanism, a power conversion module, an LCC-S resonant compensation network, a main control module, a wireless communication module, and an antenna. The magnetic coupling energy transfer mechanism includes a transmitting coil and a receiving coil; the power conversion module includes a full-bridge inverter circuit, a full-bridge rectifier circuit, and a Buck-DC-DC voltage regulation circuit; and the LCC-S resonant compensation network includes an LCC compensation circuit and an S compensation circuit. The cabinet-type charging pile includes an upper functional area and a lower functional area. The upper functional area is used to install the main control module and the wireless communication module, while the lower functional area is used to install the transmitting coil, the full-bridge inverter circuit, the LCC compensation circuit, and the antenna is set on the charging pile. The bottom of the AGV is equipped with a receiver, which is used to install the receiving coil, full-bridge rectifier circuit, Buck-DC-DC voltage regulation circuit, and S-compensation circuit. The receiver is a flat receiver.

[0008] The beneficial effects of this invention are as follows: The wireless charging system, composed of a cabinet-type charging pile, an AGV (Automated Guided Vehicle), a magnetic coupling energy transfer mechanism, a power conversion module, an LCC-S resonant compensation network, a main control module, a wireless communication module, and an antenna, integrates electromagnetic energy transfer, electrical control, and remote interaction. It can complete the entire process of automatic positioning, wireless charging, status monitoring, and fault protection for the AGV, improving transmission efficiency and operational stability, and enhancing safety. This achieves high resistance to deviation, high efficiency, and unmanned wireless power transmission even with low positioning accuracy of the AGV, thereby reducing equipment maintenance costs, improving the overall operational efficiency of the logistics system, and meeting the requirements of industrial scenarios for high protection, high reliability, and long service life of charging equipment. It simultaneously meets multiple needs such as unmanned operation, low positioning accuracy, miniaturized installation, high efficiency and stability, and safe charging.

[0009] Furthermore, both the transmitting and receiving coils are circular planar spiral coils.

[0010] Furthermore, the size of the transmitting coil is larger than the size of the receiving coil.

[0011] Furthermore, the transmitting coil and the receiving coil use Litz wire of different specifications.

[0012] Furthermore, the back of the transmitting coil and the receiving coil are respectively provided with segmented ferrite cores of different sizes.

[0013] The beneficial effects of this invention are: by using circular planar spiral coils, coils of different sizes, Litz wires of different specifications, and Litz wires of different sizes and specifications, the mutual inductance and coupling coefficient attenuation are achieved smoothly, eliminating the need for high-precision AGV vehicle docking, greatly reducing the difficulty of AGV vehicle navigation and positioning control, adapting to non-precise docking conditions on site, significantly improving anti-offset capability, reducing AC loss, ensuring energy stability, and improving transmission efficiency.

[0014] Furthermore, the lower functional area is equipped with a positioning slot, which is a U-shaped nylon positioning slot with a guide tilt. The chassis of the AGV is equipped with a positioning pin that matches the positioning slot.

[0015] The beneficial effects of this invention are: by cooperating with the positioning slot and the positioning pin, the AGV trolley can be automatically centered and aligned, ensuring the charging alignment accuracy and consistency of repeated positioning.

[0016] Furthermore, a matching rubber buffer ring is provided on the positioning slot.

[0017] The beneficial effect of this invention is that the impact force on the AGV trolley when it stops is reduced by the rubber buffer ring.

[0018] Furthermore, the cabinet-style charging station is equipped with an electrical interface, which is a waterproof aviation plug.

[0019] The beneficial effect of this invention is that the waterproof aviation plug can be well adapted to the humid and dusty environment of the workshop.

[0020] Furthermore, the main control module is equipped with an AGV wireless charging control strategy, which includes: Real-time acquisition of output voltage and output current; During the pre-charging phase, a preset first current is used for pre-charging; During the constant current charging phase, a preset second current is used for constant current charging, and it is determined whether the output current is less than or equal to the target current. If not, constant current charging continues. If yes, it is determined whether the output voltage is greater than or equal to the target voltage. If no, constant current charging continues. If yes, constant voltage charging is performed. The first current is less than the second current. During the constant voltage charging phase, constant voltage charging is performed. After outputting the initial duty cycle of the transmitter and performing identification, it is determined whether the receiver has returned data. If not, the initial duty cycle of the transmitter is re-outputted and identification is performed. If yes, communication is established with the receiver, power transmission is started, and the duty cycle is adjusted in real time. Then, it is determined whether charging is complete, whether the receiver has left, or whether a fault has occurred. If not, it returns to start power transmission and adjusts the duty cycle in real time. If yes, power transmission is stopped. It is also determined whether the output current is less than the cutoff current. If yes, charging is complete. Otherwise, constant voltage charging continues.

[0021] The beneficial effect of this invention is that it enables orderly control of the charging process through the AGV wireless charging control strategy.

[0022] Furthermore, the main control module is also equipped with an AGV wireless charging fault protection strategy, which includes: After charging begins, the system monitors voltage, current, temperature, and communication duration in real time, and determines whether there is overvoltage, overcurrent, overtemperature, short circuit, or communication timeout. If so, it sequentially blocks the drive signal, stops energy transmission, uploads fault information to the host computer, records the fault log locally, and resets the system or waits for maintenance. Otherwise, it continues charging and determines whether charging is complete. If so, it ends charging; otherwise, it monitors voltage, current, temperature, and communication duration in real time.

[0023] The beneficial effects of this invention are: by using the AGV wireless charging fault protection strategy, it can achieve a rapid response to abnormalities in the charging process and improve charging safety. Attached Figure Description

[0024] Figure 1 This is a block diagram of a high-anti-offset AGV magnetic coupling resonant wireless charging system according to an embodiment of the present invention; Figure 2This is a front view of the charging pile in an embodiment of the present invention; Figure 3 This is a three-dimensional view of the charging pile in an embodiment of the present invention; Figure 4 This is a 3D view of the AGV vehicle in an embodiment of the present invention; Figure 5 This is a left view of the AGV vehicle in an embodiment of the present invention; Figure 6 This is a front view of the AGV vehicle in an embodiment of the present invention; Figure 7 This is a flowchart of the AGV wireless charging control strategy in an embodiment of the present invention; Figure 8 This is a flowchart of the AGV wireless charging control strategy in an embodiment of the present invention.

[0025] The attached diagram lists the components represented by each number as follows: 1. Vehicle body; 2. Emergency stop button; 3. Operation indicator light; 4. Human-machine interface touch screen. Detailed Implementation

[0026] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0027] A high-resistance offset AGV magnetic coupling resonant wireless charging system, such as Figure 1 As shown, it includes: a charging pile, an AGV (Automated Guided Vehicle), a magnetic coupling energy transfer mechanism, a power conversion module, an LCC-S resonant compensation network, a main control module, and a wireless communication module. The magnetic coupling energy transfer mechanism includes a transmitting coil and a receiving coil. The power conversion module includes a full-bridge inverter circuit, a full-bridge rectifier circuit, and a Buck-DC-DC voltage regulation circuit. The LCC-S resonant compensation network includes an LCC compensation circuit and an S-compensation circuit. The cabinet-type charging pile includes an upper functional area and a lower functional area. The upper functional area is used to install the main control module and the wireless communication module, and the lower functional area is used to install the transmitting coil, the full-bridge inverter circuit, and the LCC compensation circuit. The antenna is set on the charging pile. The bottom of the AGV is equipped with a receiving end, which is used to install the receiving coil, the full-bridge rectifier circuit, the Buck-DC-DC voltage regulation circuit, and the S-compensation circuit. The receiving end is a flat receiving end.

[0028] Among them, such as Figure 2 and Figure 3As shown, the charging pile is a cabinet-type charging pile, which takes into account the convenience of installation, protection requirements, and subsequent maintenance. The charging pile is made of sheet metal with an IP54 protection level, which can adapt to the complex environment of the workshop with a lot of dust and oil. The interior of the charging pile is divided into an upper functional area and a lower functional area. The upper functional area is equipped with a main control module and a wireless communication module, while the lower functional area is equipped with a transmitter. The transmitter is used to install the transmitting coil of the magnetic coupling energy transfer mechanism, the full-bridge inverter circuit of the power conversion module, and the LCC compensation circuit.

[0029] A transmitting coil mounting window is located on the bottom front of the functional area under the charging pile. A special bracket is used to fix the transmitting coil to the charging pile. The transmitting coil mounting window corresponds one-to-one with the receiving coil position on the AGV chassis, ensuring good magnetic field coupling during charging. To ensure the accuracy and consistency of AGV wireless charging, a positioning slot is set at the bottom of the charging pile. The positioning slot is a U-shaped wear-resistant nylon positioning slot with a 15° guide slope. The positioning slot cooperates with the positioning pin on the bottom of the AGV, allowing the AGV to find the correct center point position on its own, that is, to achieve automatic centering and alignment of the AGV. The stopping error of the AGV is controlled within the allowable offset range of ±40mm, ensuring charging alignment accuracy and consistency of repeatability. At the same time, while meeting the coupling requirements between the wireless charging coils, it also improves the stability and efficiency of the entire system. A rubber buffer ring is set outside the positioning slot to reduce the impact force on the AGV when it stops. The charging pile has an integrated base at the bottom with four fixing bolt holes, which can be used to fix the charging pile to the ground charging station with M13 expansion bolts.

[0030] The charging station is equipped with an emergency stop button at the top, which can quickly cut off the power to the charging station in case of an emergency, ensuring the safety of the equipment and personnel; an indicator light is set behind the emergency stop button to indicate the working status of the charging station.

[0031] The front of the charging station features a heat dissipation grille, a quick-release inspection door, an observation window, and a location for the operator's human-machine interface. The heat dissipation grille and quick-release inspection door are installed using guide rails. The heat dissipation grille enhances air convection cooling and prevents dust and liquids from entering the cabinet. The quick-release inspection door and observation window allow staff to monitor the charging station's operating status, perform simple parameter adjustments, or conduct routine maintenance. This design meets the requirements for dust and water resistance, heat dissipation, and ease of future maintenance.

[0032] The back of the charging pile has a reserved installation position for a communication interface, which is connected to the wiring duct. After receiving the data information sent by the AGV, the communication interface will send it to each module.

[0033] Charging piles also include electrical interfaces, communication interfaces, and mechanical interfaces, specifically including: The electrical interfaces utilize waterproof aviation plugs, making them well-suited for humid and dusty workshop environments. The interfaces integrate overcurrent protection and anti-misplugging structures, effectively preventing equipment damage due to wiring errors. The electrical interfaces include a power input interface, a power output interface, and a DC auxiliary power interface. The power input interface supplies power to the equipment, using an industrial-standard AC380V three-phase power supply port, installed on the bottom side of the charging pile. The power output interface transmits high-frequency power to the transmitting coil and has a sufficiently large expansion port to accommodate various operating conditions; it is located at the bottom of the charging pile. The power output interface uses dedicated high-frequency terminals, primarily used to stably connect the high-frequency AC power from the full-bridge inverter circuit to the transmitting coil. Gold-plated terminals effectively reduce contact resistance during high-frequency operation, minimizing power loss and heat generation during circuit operation. The DC auxiliary power interface is located inside the charging pile, facilitating future equipment debugging and functional expansion, and providing a stable DC24V power supply for external detection modules and expansion modules. The communication interface adopts a wireless communication interface, eliminating the original wired communication interface. This avoids the constraints that cable connections would have placed on the automated operation of the AGV, thereby further improving the system's automation level and unmanned operation capabilities. The charging pile uses a wireless communication module (industrial-grade Wi-Fi module) and a high-gain external antenna, which performs well in the complex electromagnetic environment of the workshop and achieves full coverage throughout the entire area. It can realize functions such as AGV start / stop signal, battery status data exchange, upper computer operation and fault information reporting, and remote monitoring.

[0034] Mechanical interfaces include mounting and fixing interfaces, AGV positioning interfaces, and equipment maintenance interfaces. Each interface is designed according to the equipment structure and usage environment to achieve convenient and reliable installation.

[0035] like Figure 4 , Figure 5 and Figure 6As shown, the AGV (Automated Guided Vehicle) is wheel-driven and consists of a chassis and a body 1. The chassis is constructed using a metal frame. A flat cargo platform is designed on top of the body 1, capable of carrying material boxes and tooling fixtures of different sizes to meet the requirements of transporting goods of various sizes in the factory. An emergency stop button 2, a running indicator light 3, a human-machine interface touchscreen 4, and related operation buttons are integrated on the front of the body 1, facilitating on-site debugging and equipment status monitoring. An obstacle avoidance sensor is also installed at the front of the body 1, enabling real-time detection of nearby obstacles and providing excellent safety protection. Meanwhile, a dedicated installation location for a wireless charging receiver is provided on the side of the body 1, facilitating precise alignment and energy transfer with charging piles. The overall structure of the AGV is compact, making efficient use of the space in the body 1, meeting the requirements for cargo carrying and receiving, and providing sufficient electrical wiring and mechanical protection margins, making it well-suited for the complex working environment of industrial sites. The receiver is equipped with an onboard battery management system, which monitors battery status, protects charging, and facilitates communication in real time, making the entire wireless charging process safer and more stable.

[0036] The magnetic coupling energy transfer mechanism is the core of energy transmission, used to complete the wireless conversion and transfer of electrical energy. Its working principle is based on the alternating magnetic field coupling effect to achieve wireless transmission of high-frequency electrical energy. The magnetic coupling energy transfer mechanism includes a transmitting coil and a receiving coil. The transmitting coil is installed at the bottom of the charging pile, and the receiving coil is installed on the chassis of the AGV. The two are installed coaxially and facing each other. The system's performance under all working conditions was tested and verified using the ANSYS Maxwell finite element simulation platform. The operating states under different air gaps and different lateral offsets were simulated, and the magnetic coupling energy transfer mechanism was optimized. Both the transmitting coil and the receiving coil are circular planar spiral coils. To enhance the anti-offset capability of the magnetic coupling energy transfer mechanism, the size of the transmitting coil is larger than that of the receiving coil, which can effectively suppress the attenuation of the coupling coefficient during offset, thereby improving the anti-offset capability. The outer diameter of the transmitting coil is 200mm, the number of turns is 12, and the wire diameter is 2.5mm. The outer diameter of the receiving coil is 180mm, the number of turns is 10, and the wire diameter is 2.0mm. Each coil employs Litz wire of different specifications to mitigate the high-frequency skin effect. The transmitting coil uses 0.1mm × 1000 strand Litz wire, effectively reducing the skin and proximity effects under high-frequency conditions and minimizing AC losses. The receiving coil uses 0.1mm × 2000 strand Litz wire to meet the high current carrying requirements under step-down output. To enhance the coupling strength between coils, reduce leakage flux, and minimize electromagnetic interference, a segmented ferrite core is installed on the back of the coils. This facilitates installation and adaptation to coil dimensions. The ferrite material used is TDK's PC95 series ferrite core, which has high permeability and low loss, effectively concentrating the magnetic field generated by the coils and reducing its diffusion into uncoupled areas, while also reducing electromagnetic interference to the AGV's onboard control system. The ferrite core on the back of the transmitting coil measures 200mm × 200mm × 4mm, and the ferrite core on the back of the receiving coil measures 180mm × 180mm × 4mm. The receiving end adopts a flat design, with an overall thickness controlled within 30mm. Simulation results show that the rated transmission air gap of the magnetic coupling energy transfer mechanism is set to 35-40mm, the lateral offset tolerance is designed to be ±40mm, and the receiver thickness is within 30mm. This can effectively adapt to the narrow installation space of the AGV chassis. Within the allowable offset range, the mutual inductance and coupling coefficient of the magnetic coupling energy transfer mechanism decays slowly, which can ensure energy stability. The overall transmission efficiency of the system remains stable at over 90%, and the transmission efficiency under rated working conditions can reach over 95%. The system has excellent transmission performance and anti-offset capability.

[0037] The power conversion module is responsible for converting the mains frequency AC power into high frequency AC power to power the transmitting coil. The power conversion module includes a full-bridge inverter circuit configured at the transmitting end, and a full-bridge rectifier circuit and a Buck-DC-DC voltage regulator circuit configured at the receiving end.

[0038] The full-bridge inverter circuit utilizes a full-bridge inverter topology, consisting of four power switching transistors (MOSFETs) forming a bridge arm paired with an IR2110 driver chip. By controlling the alternating on and off of the diagonally opposite power switches, it can invert the DC input voltage into a high-frequency AC square wave voltage of 85kHz, meeting the operational requirements of magnetically coupled resonant wireless charging. The full-bridge inverter topology offers advantages such as high output power, low voltage stress, flexible control, and ease of soft-switching, effectively reducing switching losses and improving overall system conversion efficiency. The power switching transistors used are Infineon IPW65R041CFDMOSFETs, with a rated voltage of 650V and a rated drain current of 60A, meeting the operational requirements of a 3kW rated power. The operating frequency of the full-bridge inverter circuit is set to 85kHz, conforming to wireless charging industry standards while simultaneously reducing switching losses and electromagnetic interference.

[0039] The full-bridge rectifier circuit adopts a full-bridge rectifier topology, and its rectifier diodes are fast recovery diodes (FRDs) with a reverse recovery time of ≤200ns, ensuring rectification efficiency.

[0040] The Buck-DC-DC voltage regulation circuit uses a Buck topology to achieve closed-loop regulation of the output voltage, adapting to the 24V-48V charging requirements of the AGV's lithium battery.

[0041] The LCC-S resonant compensation network consists of an LCC compensation circuit configured at the transmitter and an S compensation circuit (single capacitor series compensation) configured at the receiver, achieving resonance at an operating frequency of 85kHz. The primary-side compensation inductor of the LCC-S resonant compensation network is 22μH, the parallel compensation capacitor is 159.4nF, the series compensation capacitor is 34.1nF, and the secondary-side series compensation capacitor is 29.4nF. This ensures that the transmitting coil current is not affected by load disturbances, the magnetic field output is stable, and the energy transmission is stable. At the same time, it simplifies the circuit structure of the receiver, does not excessively increase the overall size of the receiver, achieves miniaturization design, and solves the problems of poor load adaptability and easy instability of traditional compensation topologies.

[0042] The main control module uses an STM32F407ZGT6 as the main control chip, a high-precision operational amplifier, linear optocouplers, and voltage, current, and temperature signal sampling circuits to achieve electrical isolation between strong and weak currents and high-precision data acquisition. It also utilizes mature industrial-grade components: external auxiliary power supply, reset, clock, and protection circuits. When the battery or charging station on the AGV malfunctions, all energy supply can be immediately cut off, effectively preventing abnormal operation of the AGV when it is unattended.

[0043] The main control module is equipped with AGV wireless charging control strategy and AGV wireless charging fault protection strategy. The main control module also includes an STM32 microcontroller, initialization unit, sampling unit, PWM drive unit, closed-loop control unit and protection unit, etc. All units are scheduled and coordinated through a unified state machine to achieve orderly control of the charging process and rapid response to abnormalities.

[0044] The charging process includes: after the system is powered on, the initialization unit first performs hardware initialization and self-test, which includes system clock configuration, GPIO initialization, ADC calibration and channel parameter configuration, advanced timer PWM output configuration, and CAN / serial communication interface initialization; after the initialization and self-test are passed, the system enters standby mode and waits for charging commands from the host computer or charging pile; during this period, the wireless communication module continuously listens for command frames, and the protection unit performs static monitoring of key voltage and temperature signals to ensure that the system is always in a safe operating range.

[0045] Upon receiving a valid charging command, the state machine switches from standby to charging handshake mode, completing identity authentication and communication parameter negotiation with the charging pile. After a successful handshake, it enters coil alignment mode, where the system integrates signals from position sensors and the induced voltage of the auxiliary coil to determine if the transmitting and receiving coils are aligned. Once alignment is confirmed, it transitions to the charging control phase. During this phase, the sampling unit collects analog quantities such as output voltage, charging current, and battery temperature in real time, which are then digitally filtered and sent to the closed-loop control unit. The closed-loop control unit uses a digital PID algorithm as its core, dynamically adjusting the PWM duty cycle according to a preset constant current-constant voltage (CC-CV) segmented charging curve to ensure the system outputs appropriate power at different battery capacities. When the battery voltage reaches the cutoff voltage and the charging current drops to a set threshold, or when a stop command is received from the host computer, the state machine switches to the stop state, gradually shutting off the PWM drive signal, reducing the transmission power to zero, and finally safely returning to standby mode.

[0046] Beyond regular charging operation, a complete fault handling logic is established through the cooperation of the protection unit and the state machine. When the device detects abnormal conditions such as overcurrent, overvoltage, overtemperature, or communication timeout at any stage of operation, the hardware fault flag will immediately trigger an interrupt response, and the state machine will jump to the fault handling mode. At this time, the PWM output signal will be directly blocked, the entire drive circuit will be disconnected in time, the corresponding fault code will be saved, and the abnormal situation can be uploaded to the host computer platform through the wireless communication module. Only after the on-site fault problem has been investigated and the system has received the fault clearance command can the device perform a reset operation and return to the standby state. This ensures the safety and stability of wireless charging operation throughout the entire process.

[0047] The AGV wireless charging control strategy is a three-stage charging control strategy of pre-charging, constant current, and constant voltage, such as... Figure 7 As shown, it specifically includes: Real-time acquisition of output voltage and output current .

[0048] During the pre-charge phase, a preset first current is used for pre-charging. During the constant current charging phase, a low current of 0.1C can be used to pre-charge the deeply discharged battery.

[0049] During the constant current charging phase, a preset second current is used for constant current charging. It is then determined whether the output current is less than or equal to the target current; if not, constant current charging continues. If so, it is determined whether the output voltage is greater than or equal to the target voltage; if not, constant current charging continues; otherwise, constant voltage charging is performed. During the constant current charging phase, a current of 0.9C can be used for rapid constant current charging. During this phase, the battery voltage will continuously increase as the battery charge is replenished. The output current is stabilized at the target value by adjusting the duty cycle.

[0050] During the constant voltage charging phase, the transmitter outputs its initial duty cycle and performs identification. It then checks if the receiver has returned data. If not, it re-outputs the initial duty cycle and performs identification again. If the receiver does return data, communication is established, power transmission is initiated, and the duty cycle is adjusted in real time. The system then checks if charging is complete, if the receiver has left, or if a fault has occurred. If not, it returns to initiating power transmission and adjusting the duty cycle in real time. If the receiver does return, power transmission is stopped. The system also checks if the output current is less than the cutoff current. If so, charging is complete; otherwise, constant voltage charging continues. During the constant voltage charging phase, the output voltage remains stable. The output current gradually decreases as charging progresses. When the output current drops to the preset cutoff current (1A), the charging process ends.

[0051] In actual charging operation, strict requirements are placed on the safety of the charging process and the real-time performance of control. To prevent system malfunctions due to various faults, detection and protection are implemented for all possible abnormalities, including input overvoltage, output overvoltage, overcurrent, power device overheating, load short circuit, and battery failure. When the controller detects any abnormal event, it immediately cuts off all inverter drive signals and stops supplying energy. All fault information is transmitted to a server for storage via a wireless communication module and stored in non-volatile memory. This effectively improves system safety, enabling immediate response to any anomalies and ensuring the overall system's security.

[0052] To further improve the system's real-time response and anti-interference performance, interrupt-based analog-to-digital sampling and core control calculations are employed. This method ensures that control tasks are executed according to a strict time period, thereby enhancing the system's real-time response performance. The PI controller parameters in the voltage and current closed-loop control were retuned. By optimizing the selection of proportional and integral coefficients, the system effectively balances dynamic response speed and steady-state accuracy under load fluctuations. Furthermore, a digital low-pass filter algorithm was introduced into the ADC sampling signal channel. This effectively suppresses sampling noise introduced by electromagnetic interference generated by power conversion, improving the accuracy of the feedback signal and overall control stability. This allows the system to achieve accurate and stable power transmission even in complex electromagnetic environments.

[0053] The AGV wireless charging fault protection strategy is a multi-level fault protection strategy covering overvoltage, overcurrent, overtemperature, short circuit, and communication timeout. Figure 8 As shown, it specifically includes: After charging begins, the system monitors voltage, current, temperature, and communication duration in real time, and determines whether there is overvoltage, overcurrent, overtemperature, short circuit, or communication timeout. If so, it sequentially blocks the drive signal, stops energy transmission, uploads fault information to the host computer, records the fault log locally, and resets the system or waits for maintenance. Otherwise, it continues charging and determines whether charging is complete. If so, it ends charging; otherwise, it monitors voltage, current, temperature, and communication duration in real time.

[0054] The wireless communication module is an industrial Wi-Fi module.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-anti-offset AGV magnetic coupling resonant wireless charging system, characterized in that, include: The components include: a cabinet-type charging pile, an AGV trolley, a magnetic coupling energy transfer mechanism, a power conversion module, an LCC-S resonant compensation network, a main control module, a wireless communication module, and an antenna. The magnetic coupling energy transfer mechanism includes a transmitting coil and a receiving coil; the power conversion module includes a full-bridge inverter circuit, a full-bridge rectifier circuit, and a Buck-DC-DC voltage regulation circuit; and the LCC-S resonant compensation network includes an LCC compensation circuit and an S compensation circuit. The cabinet-type charging pile includes an upper functional area and a lower functional area. The upper functional area is used to install the main control module and the wireless communication module. The lower functional area is used to install the transmitting coil, the full-bridge inverter circuit, and the LCC compensation circuit. The antenna is installed on the charging pile. The bottom of the AGV is equipped with a receiver, which is used to install a receiving coil, a full-bridge rectifier circuit, a Buck-DC-DC voltage regulation circuit, and an S-compensation circuit. The receiver is a flat receiver.

2. The high anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that: Both the transmitting coil and the receiving coil are circular planar spiral coils.

3. The high anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that: The size of the transmitting coil is larger than the size of the receiving coil.

4. The high anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that: The transmitting coil and receiving coil use Litz wire of different specifications.

5. The high anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that: The back of the transmitting coil and the receiving coil are respectively provided with segmented ferrite cores of different sizes.

6. The high anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that: The lower functional area is provided with a positioning slot, which is a U-shaped nylon positioning slot with a guide tilt. The chassis of the AGV is provided with a positioning pin that matches the positioning slot.

7. A high anti-offset AGV magnetic coupling resonant wireless charging system according to claim 6, characterized in that: The positioning slot is equipped with a matching rubber buffer ring.

8. A high-anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that: The cabinet-type charging station is equipped with an electrical interface, which is a waterproof aviation plug.

9. A high-anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that, The main control module is equipped with an AGV wireless charging control strategy, which includes: Real-time acquisition of output voltage and output current; During the pre-charging phase, a preset first current is used for pre-charging; During the constant current charging phase, a preset second current is used for constant current charging, and it is determined whether the output current is less than or equal to the target current. If not, constant current charging continues. If yes, it is determined whether the output voltage is greater than or equal to the target voltage. If no, constant current charging continues. If yes, constant voltage charging is performed. The first current is less than the second current. During the constant voltage charging phase, constant voltage charging is performed. After outputting the initial duty cycle of the transmitter and performing identification, it is determined whether the receiver has returned data. If not, the initial duty cycle of the transmitter is re-outputted and identification is performed. If yes, communication is established with the receiver, power transmission is started, and the duty cycle is adjusted in real time. Then, it is determined whether charging is complete, whether the receiver has left, or whether a fault has occurred. If not, it returns to start power transmission and adjusts the duty cycle in real time. If yes, power transmission is stopped. It is also determined whether the output current is less than the cutoff current. If yes, charging is complete. Otherwise, constant voltage charging continues.

10. A high-anti-offset AGV magnetic coupling resonant wireless charging system according to claim 1, characterized in that, The main control module is also equipped with an AGV wireless charging fault protection strategy, which includes: After charging begins, the system monitors voltage, current, temperature, and communication duration in real time, and determines whether there is overvoltage, overcurrent, overtemperature, short circuit, or communication timeout. If so, it sequentially blocks the drive signal, stops energy transmission, uploads fault information to the host computer, records the fault log locally, and resets the system or waits for maintenance. Otherwise, it continues charging and determines whether charging is complete. If so, it ends charging; otherwise, it monitors voltage, current, temperature, and communication duration in real time.

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