Battery swapping method using unmanned forklift

Abstract

The present application relates to the technical field of vehicle battery replacement, and specifically relates to a battery replacement method using an unmanned forklift, which uses an unmanned forklift with four or more axis degrees of freedom as a battery replacement carrier, realizes high-precision positioning through the multi-axis adjustment capability of the chassis and portal of the unmanned forklift, and the synergistic effect of a navigation positioning system, a visual recognition system, and a motion control system; the battery replacement station and the vehicle body battery compartment adopt a unified standardized structure, including a compartment body, a battery chassis, a boss, an electrical connector, a tooth insertion channel, a battery mounting plate, a positioning pin, a guide strip, and a guide slope, the battery mounting plate is lifted by inserting the fork teeth into the tooth insertion channel, the insertion and removal of the electrical connector and the transfer of the battery are realized, the guide slope is centered and the positioning pin is positioned, and the docking stability and efficiency are improved. The method has the advantages of low cost, high safety, convenient operation, and wide adaptability, and can be widely applied to battery replacement scenes of various manned or unmanned vehicles such as automobiles and AGVs.

Description

Technical Field

[0001] This invention relates to the field of vehicle battery swapping technology, and more particularly to a battery swapping method using an unmanned forklift. Background Technology

[0002] In the field of manned or autonomous vehicles, battery power is one of the mainstream methods. However, a depleted battery directly affects the vehicle's operating time, and battery swapping is widely used as a way to quickly restore range. However, current battery swapping methods on the market have many shortcomings, which seriously limit the promotion and application of battery swapping technology.

[0003] Current battery swapping technologies involve an extremely complex docking process, requiring sophisticated docking mechanisms to precisely align the backup battery with the battery compartment's six degrees of freedom. This often necessitates addressing initial errors of several centimeters or even tens of centimeters, ultimately achieving a high precision of 1-3mm. NIO's battery swapping stations are a prime example; their design and installation have extremely low fault tolerance, resulting in exorbitant equipment costs—at least 200,000 to 300,000 yuan per station. Furthermore, existing battery swapping methods require vehicles to enter the high-voltage swapping compartment, posing a significant risk of electric shock and compromising safety.

[0004] Furthermore, when storing and charging multiple spare batteries, existing technologies typically employ a complete set of non-standard automated mechanisms to construct the battery storage compartment system. This system is not only structurally complex but also costs hundreds of thousands of yuan. The core problem lies in the fact that when sending multiple spare batteries into the charging compartment, it is necessary to move three or six axes of the batteries to designated compartments, while simultaneously considering the path accessibility of individual batteries in each compartment. This requires the non-standard automated system to be able to adjust each axis of the batteries to be charged to an accuracy of 1-3mm, and to design complex battery channels to ensure the accessibility of each compartment. This results in a complex structure for the entire storage compartment system, increased potential points of failure, and high maintenance costs.

[0005] Meanwhile, existing battery swapping technologies suffer from inadequate electrical connection, mechanical positioning, and forklift compatibility design between batteries and battery compartments / cabins. This often leads to problems such as docking misalignment, unstable positioning, and difficulty in disconnecting electrical connections, further complicating the battery swapping process and reducing swapping efficiency.

[0006] The root cause of the above shortcomings is as follows: On the one hand, the high-precision docking requirement of six degrees of freedom requires the mechanical structure to be adjusted within an error range of tens of centimeters in six directions, and the final accuracy needs to reach 1-3mm. This requires the design of a power mechanism for almost each axis, resulting in structural complexity and increased costs. On the other hand, the multi-axis adjustment and path planning requirements for battery storage and charging, as well as the adaptability design defects of battery and cabin positioning, guidance, and electrical connection, further exacerbate the complexity of the system, making it difficult for existing battery swapping technology to achieve a balance between cost, safety and convenience.

[0007] To address the problems of complex battery swapping interfaces, high costs, insufficient safety, and complex storage systems in existing technologies, this invention proposes a battery swapping method using unmanned forklifts. Through standardized battery compartment / cabin structure design and coordinated multi-axis precision control of unmanned forklifts, it achieves efficient, safe, and low-cost battery swapping, adapting to the battery swapping needs of various manned or unmanned vehicles. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems of the prior art and provide a battery swapping method using an unmanned forklift. This method addresses the issues of complex docking, high cost, and insufficient safety in existing battery swapping technologies, overcomes the defects of unstable battery and cabin positioning, poor guidance, and cumbersome electrical connection, simplifies the battery swapping process, and improves adaptability and reliability.

[0009] The above objectives are achieved through the following technical solutions: A battery swapping method using unmanned forklifts includes: An unmanned forklift with more than four degrees of freedom is used as the battery swapping carrier. The unmanned forklift realizes multi-axis adjustment during battery picking and transfer through the forward, backward, left and right and horizontal rotation of the chassis, the lifting and lowering of the fork mast and / or the tilting of the fork mast. The unmanned forklift is equipped with a navigation and positioning system, a vision recognition system, and a chassis motion control system. The three work together to identify the spatial location information of the target battery compartment and control the unmanned forklift to move precisely, thereby reducing the docking error between the battery and the battery compartment. Both the battery swapping station and the battery compartment of the vehicle to be swapped are equipped with a non-powered floating docking mechanism, a space for the insertion of the unmanned forklift's forks, and spatial feature points for positioning. The planes where the battery swapping station, the battery compartment, and the unmanned forklift are located maintain a preset flatness. Specifically, the non-powered floating docking mechanism is an elastically adaptable structure installed within the battery compartment of the battery swapping station and the battery compartment of the vehicle to be swapped, requiring no additional power drive. Its core consists of elastic material edge docking components and guide strips around the compartment cavity. Through its own elastic deformation capability, it adaptively compensates for residual positional and angular deviations when the battery docks with the compartment, guiding the battery into precise positioning and avoiding hard contact wear. Combined with the multi-axis adjustment of the unmanned forklift, it achieves a smooth and precise docking of the battery with the compartment. Commercially available elastic guide positioning blocks and non-powered floating joints are also available.

[0010] The aforementioned spatial feature points specifically refer to the spatial markings set on the battery compartment of the battery swapping station and the vehicle to be swapped, which are recognized by the unmanned forklift navigation and positioning system and the visual recognition system. These markings include reflectors on the top of the battery swapping station, QR codes on the outside of the battery compartment, and structural markings such as guide strips and positioning pins on the compartment that can be captured by the visual recognition system. Their core function is to provide a precise positioning benchmark for the unmanned forklift and assist in achieving precise docking between the battery and the compartment.

[0011] After the unmanned forklift picks up the spare battery, it obtains the spatial location information of the battery swapping station or the battery compartment through the navigation and positioning system and / or visual recognition system. The docking error is reduced by the multi-axis motion adjustment of the chassis and gantry, and the residual error is eliminated by the non-powered floating docking mechanism, thus completing the precise docking of the battery and the battery compartment. This solves the problems of complex docking, high cost and insufficient safety in the existing battery swapping technology.

[0012] As a further optimization of this method, the chassis of the unmanned forklift achieves precise adjustment in the front-back and left-right directions through the coordinated closed-loop control of the navigation and positioning system, the vision recognition system and the chassis motion control system. At the same time, through the independent drive and angle feedback calibration of the chassis horizontal rotation mechanism, high-precision control of the horizontal rotation direction is achieved. The adjustment accuracy in the front-back and left-right directions is ±10-20mm, and the adjustment accuracy in the horizontal rotation direction is ±1°.

[0013] As a further optimization of this method, the mast of the unmanned forklift collects real-time height information through an encoder, and performs closed-loop comparison and adjustment with the target height issued by the system to achieve precise control of the lifting motion. The lifting range of the mast is preset to adapt to the height range of the battery compartment of the vehicle to be swapped and the battery compartment of the battery swapping station, ensuring full-scenario battery swapping coverage, and the lifting accuracy of the mast is 3-10mm.

[0014] As a further optimization of this method, the mast tilt of the unmanned forklift is monitored by real-time acquisition of pitch angle information via an encoder, and closed-loop fine-tuning is performed in conjunction with the chassis motion control system to achieve high-precision control of the pitch axis, with an adjustment accuracy of 0.2-0.5°. If the unmanned forklift does not have a mast tilt function, the relative difference angle of the pitch axis is kept within a preset range by ensuring that the battery compartment of the vehicle to be swapped, the battery compartment of the swapping station, and the plane where the unmanned forklift is located are coplanar.

[0015] As a further optimization of this method, the navigation and positioning system adopts positioning methods such as QR code positioning, magnetic strip positioning, SLAM positioning, or positioning by fusing precise spatial position information from reflectors. By fusing IMU inertial navigation and odometer information, the positioning stability is improved, providing a precise position reference for multi-axis chassis adjustment. Its own positioning accuracy is 5-10mm.

[0016] As a further optimization of this method, the visual recognition system uses a high-definition depth camera or a binocular camera. It uses one or more algorithms, such as YOLO neural network image recognition, traditional feature recognition, or template matching, to identify spatial feature points of the target battery compartment, such as guide bars, positioning pins, and other positioning marks. It outputs relative pose data to assist the navigation and positioning system in calibration, improves the reliability of docking and positioning, and achieves an identification accuracy of 0.5%-1%.

[0017] As a further optimization of this method, the chassis motion control system adopts MPC control algorithm or PID control algorithm. By optimizing the algorithm parameters under low-speed operation and combining the real-time feedback of the positioning system, the chassis motion parameters are dynamically adjusted. When the chassis is running at a low speed of 0.1-0.2m / s, the motion accuracy is stably controlled within 10mm, ensuring that the battery is smoothly and without deviation when aligning with the guide ramp.

[0018] As a further optimization of this method, the battery swapping station achieves a stackable design by modularly splicing compartments, eliminating the need for a conveyor system to transport batteries to different compartments. Each compartment is a chambered structure with a battery base frame inside. The battery base frame includes a boss located at the center axis and left and right support blocks symmetrically arranged on both sides of the boss. A first electrical connector is provided on the surface of the boss. The left support block and the left side of the boss, and the right support block and the right side of the boss, respectively form toothed insertion channels. Positioning pins are set on the left and right support blocks. Guide strips are symmetrically arranged on the left and right inner walls of the compartment. Guide ramps are provided near the compartment entrance and exit of the guide strips. The two guide ramps form a wide flared opening. Each compartment is equipped with an independent DC charging module, which automatically charges by plugging the first electrical connector into the second electrical connector of the battery. The toothed insertion channels are adapted to the picking and placing actions of unmanned forklifts.

[0019] As a further optimization of this method, the battery compartment of the vehicle to be swapped is a chambered structure with the same internal structure as the battery compartment of the swapping station, including a battery base frame, boss, left support block, right support block, toothed insertion channel, positioning pin and guide strip, and guide ramp. The battery compartment directly provides power to the vehicle body through a quick-plug first electrical connector and a second electrical connector. The battery mounting plate has positioning grooves on both sides that are adapted to the positioning pins. The battery mounting plate is stably positioned on the support surface by the insertion of the positioning pins into the positioning grooves. The preset flatness is achieved by flattening the plane where the swapping station, the battery compartment, and the unmanned forklift are located, so that the relative difference angle of the roll axis of the three is kept within a preset range, ensuring the multi-axis docking accuracy.

[0020] As a further optimization of this method, the unmanned forklift is a traditional forklift modified by adding a navigation and positioning module, a vision recognition module, and a motion control module, or a native unmanned forklift manufactured by directly integrating the above modules; the vehicle to be swapped includes automobiles, AGV forklifts, AGV logistics vehicles, or AGV tractors. The battery compartment of the AGV logistics vehicle and the battery compartment of the swapping station adopt a unified structural design. By adapting to the battery mounting plate size and positioning spatial feature point position of different vehicles, universal battery swapping for multiple types of vehicles can be achieved; when transferring the battery, the unmanned forklift's fork teeth are inserted into the channel and lifted. The surface of the fork teeth acts on the bottom surface of the battery mounting plate, causing the battery to rise and disengage the second electrical connector from the first electrical connector. After translation, the battery transfer is completed.

[0021] This invention provides a battery swapping method using an unmanned forklift. Through a standardized battery compartment structure and coordinated multi-axis precision control of the unmanned forklift, it achieves low-cost and high-adaptability battery swapping. The integrated design of guidance positioning and electrical connection ensures efficient and stable docking, avoiding the risk of high-voltage electric shock. Compared with existing technologies, it has the following significant advantages: 1. Significantly reduced costs: By combining the multi-axis adjustment capability of unmanned forklifts with a standardized battery compartment / warehouse structure, the docking error range is greatly reduced, eliminating the need to design complex multi-axis power mechanisms and non-standard automated storage warehouse systems; the stacked design and unified structure of the battery swapping station further simplify the structure, significantly reducing equipment costs and maintenance costs. 2. Enhanced safety and stability: No vehicle needs to enter the high-voltage battery swapping compartment, completely eliminating the risk of electric shock; the cooperation between the positioning pin and the positioning slot ensures stable battery placement, and the electrical connector achieves insertion and removal through smooth lifting and lowering, reducing contact wear and improving the stability and reliability of system operation; 3. Simplify the battery swapping process and improve efficiency: The standardized structure makes the battery swapping station and the vehicle battery compartment universally compatible. The horn-shaped wide opening design of the guide ramp reduces the difficulty of centering. The cooperation between the tooth insertion channel and the battery mounting plate integrates the fork-picking and insertion / removal actions, making the entire battery swapping process quick and easy, without the need for complex docking mechanisms and battery channel designs. 4. Ensure docking accuracy and reliability: Through the coordinated action of the unmanned forklift's precision control system, non-powered floating docking mechanism, guide bars, and positioning pins, residual docking error is controlled within a small range, and the electrical connector is accurately inserted, fully meeting the accuracy and power supply requirements of battery swapping. 5. Wide adaptability: The structure of the battery swapping station and the main battery compartment can be adjusted according to the battery specifications of different vehicles, covering a wide range of battery-powered vehicles such as automobiles, AGV forklifts, AGV logistics vehicles, and AGV tractors, demonstrating strong versatility. Attached Figure Description

[0022] Figure 1 This is a flowchart of a battery swapping method using an unmanned forklift as described in this invention; Figure 2 This diagram illustrates the interaction between the navigation and positioning system, image recognition system, and motion control system in a battery swapping method using an unmanned forklift as described in this invention. It shows the closed-loop control framework of "perception-decision-execution" and the signal transmission logic of each system. Figure 3 This is a schematic diagram of the mast-lifting control process in a battery swapping method using an unmanned forklift as described in this invention, illustrating the deviation adjustment between the target height and the current height, actuator driving, and closed-loop feedback process; Figure 4 This is a schematic diagram comparing the docking accuracy of each axis in a battery swapping method using an unmanned forklift as described in this invention. It visually demonstrates the error differences between this solution and traditional battery swapping technology in dimensions such as planar translation, rotation, and lifting. Figure 5 This is a schematic diagram of the battery swapping station structure in the battery swapping method using an unmanned forklift described in this invention, which shows the layout and function of the battery (A), edge docking mechanism / guide bar assembly (B), and lower fork insertion position / tooth insertion channel (C). Figure 6 This is a side view of the main battery compartment and the battery compartment of the battery swapping station in a battery swapping method using an unmanned forklift as described in this invention. Figure 7 This is a schematic diagram of the internal structure of the main battery compartment and the battery compartment of the battery swapping station in a battery swapping method using an unmanned forklift as described in this invention. Figure 8 This is a first-view schematic diagram of the battery and battery base frame assembly in the main battery compartment and the battery compartment of the battery swapping station in a battery swapping method using an unmanned forklift as described in this invention. Figure 9 This is a second-view schematic diagram of the battery and battery base assembly in the main battery compartment and the battery compartment of the battery swapping station in the battery swapping method using an unmanned forklift described in this invention.

[0023] Illustration markings: 1-Carrier, 2-Battery base frame, 3-Boss, 4-First electrical connector, 5-Left support block, 6-Right support block, 7-Tooth insertion channel, 8-Battery mounting plate, 9-Battery, 10-Second electrical connector, 11-Through groove, 12-Battery mounting plate support surface, 13-Positioning pin, 14-Positioning groove, 15-Guide strip, 16-Guide ramp. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, this solution provides a battery swapping method using an unmanned forklift, including: A movable forklift with four or more degrees of freedom is used as the battery swapping carrier, preferably an unmanned forklift, including unmanned forklifts modified from traditional forklifts or directly manufactured unmanned forklifts. The unmanned forklift achieves adjustment of four or more axes through chassis movement, mast lifting, and mast tilting. The specific motion dimensions are as follows: 1. Chassis Movement: The forklift chassis has the ability to adjust in the forward and backward, left and right, and horizontal rotation directions to achieve position and posture adjustment in a plane; 2. Mast - Lifting Movement: The forklift mast supports vertical movement, and its lifting range is not less than the height range of the battery compartment on the vehicle body and the battery compartment on the battery swapping station. It is used to realize the vertical position adjustment of the battery and to adapt to the lifting of the battery mounting plate and the plugging and unplugging of the electrical connector. 3. Mast-tilt motion: Most forklifts have tilt and pitch axis adjustment capabilities to adjust the pitch attitude of the battery and reduce docking errors. If a forklift without this function is selected, it is necessary to ensure that the ground of the battery compartment on the vehicle body and the battery compartment on the battery swapping station are on the same horizontal plane so that the tilt and pitch axis angle is almost 0.

[0026] The unmanned forklift is equipped with a navigation and positioning system, a vision recognition system, and a chassis motion control system. These three systems work together to achieve high-precision positioning and motion control, as detailed below: 1. System coordination logic, such as Figure 2 As shown, a closed-loop control framework of "perception-decision-execution" is illustrated, with the signal flow divided into four layers: (1) Input layer: Multi-source localization / identification information acquisition Starting from the "current location", the system can select three types of information sources: Navigation and positioning system: It adopts positioning methods such as QR code, magnetic strip, SLAM or fusion reflector to output the spatial absolute pose of the unmanned forklift / target battery compartment (including X and Y plane coordinates and yaw horizontal rotation angle). After fusing IMU inertial navigation and odometer data, its own positioning accuracy reaches 5-10mm. Visual recognition system: Equipped with a high-definition depth camera / binocular camera, it identifies spatial feature points such as the outline of the target battery compartment, guide strips, and positioning pins through YOLO neural network, traditional feature recognition, or template matching algorithms, and outputs the spatial relative pose of the target battery compartment relative to the forklift, with a recognition accuracy of 0.5%-1%. Navigation and positioning image fusion system: When a single information source is blocked or interfered with by light, it fuses two types of data to improve positioning reliability.

[0027] (2) Processing layer: Pose deviation calculation The outputs from all three types of information sources are aggregated into the "Target Position" module: if the input is an absolute pose, the "deviation between the target position and the current position" (ΔX, ΔY, Δyaw) is calculated; if the input is a relative pose, it is directly used as the deviation value to shorten the response time.

[0028] (2) Execution layer: motion control drive Deviation data is transmitted to the "motion control system," which uses MPC (model predictive control) or PID (proportional integral derivative) algorithms to convert the deviation into motion commands for the forklift chassis and mast. When the chassis is running at a low speed of 0.1-0.2 m / s, the motion accuracy can be controlled within 10 mm, ensuring that the battery can pass smoothly and without collision when aligning itself on the guide ramp.

[0029] (3) Feedback layer: closed-loop adjustment The execution results of the motion control system will be fed back to the "current position" to continuously update the real-time position and posture of the forklift. If the deviation does not meet the docking requirements, the "acquisition-calculation-execution" process will be repeated to form a closed-loop control.

[0030] 2. Technical parameters of each system: Navigation and positioning system: When used indoors, it adopts positioning methods such as QR code positioning, magnetic strip positioning and SLAM positioning (or integrates the precise spatial position information of reflectors), and the positioning accuracy can reach 5-10mm. Visual recognition system: Utilizing high-definition depth cameras or binocular cameras, employing multiple recognition methods such as YOLO neural network image recognition, traditional feature recognition, and template matching, achieving a recognition accuracy of 0.5%-1%; Chassis motion control system: Employing multiple control methods such as MPC or PID, it can adjust the motion accuracy to within 10mm when the chassis is running at a low speed of 0.1-0.2m / s.

[0031] 3. Precision control of each motion dimension: Chassis: Through the joint control of the above systems, the adjustment accuracy in the front-to-back and left-to-right directions can reach ±10-20mm, and the adjustment accuracy in the horizontal rotation direction can reach ±1°. Gantry - Lifting, such as Figure 3 The diagram illustrates the process of adjusting the deviation between the target height and the current height, actuator driving, and closed-loop feedback. Its control process consists of five steps: (1) Target height input: The system issues the target height based on the height information of the battery compartment of the battery swapping station or the battery compartment of the vehicle to be swapped, the thickness of the battery mounting plate and the plugging and unplugging stroke of the electrical connector, to ensure that the height range and action requirements of the two types of equipment are covered. (2) Current height acquisition: An encoder is installed on the gantry lifting mechanism to acquire the current absolute height of the gantry in real time; (3) Height deviation calculation: Compare the target height with the current height. If the deviation meets the requirements, maintain the height. If the deviation exceeds the requirements, proceed to the adjustment stage. (4) Actuator drive adjustment: The hydraulic forklift controls the on / off time and opening degree of the hydraulic solenoid valve, and the electric cylinder forklift controls the motor current of the electric lifting device to realize the slow lifting of the mast (speed ≤ 0.05m / s). (5) Closed-loop feedback verification: The encoder continuously feeds back the current height and repeatedly corrects it until the deviation meets the requirements, ultimately achieving a lifting accuracy of 3-10mm, ensuring smooth insertion and removal of the electrical connector and accurate placement of the battery; Gantry-tilt (pitch angle): The control method is the same as that of gantry-lifting. Precise adjustment is achieved through encoder information, with an accuracy of 0.2-0.5°. Compared with traditional methods, this significantly reduces the requirements for the docking range.

[0032] 4. Comparison of the alignment accuracy of each axis, such as... Figure 4 As shown, the error difference between this solution and traditional battery swapping technology is clearly demonstrated: Traditional battery swapping technology has an error range of tens of centimeters in the front-back / left-right directions, while this solution reduces the error in these directions to 10-20mm through navigation + vision fusion positioning + MPC / PID control. Combined with the horn-shaped wide-mouth design of the guide ramp, the centering fault tolerance is further improved. Traditional battery swapping technology has an error in the horizontal rotation direction on the order of several degrees. This solution uses a chassis horizontal rotation mechanism and encoder closed-loop control to control the error to within 1 degree. Traditional battery swapping technology has a large error range in the lifting direction. This solution achieves an accuracy of 3-10mm through the gantry lifting control process and encoder data acquisition, which is suitable for the plugging and unplugging stroke requirements of the electrical connector. Traditional battery swapping technology has an error of 1-5° in the tilt direction. This solution reduces the error to 0.2-0.5° by using a gantry tilting mechanism and encoder control. Traditional battery swapping technology has an error of 1-5° in terms of ground flatness. This solution significantly reduces the relative difference of the roll axis by flattening the battery compartment of the battery swapping station / vehicle and the forklift ground.

[0033] In this embodiment, the battery compartment of the battery swapping station and the battery compartment of the vehicle to be swapped adopt a unified and standardized structural design, such as... Figure 6-9 As shown, the details are as follows: 1. Unified basic structure design: The cabin 1 is a main structure with a chamber, which is used to house the battery 9 and related supporting components. The inlet and outlet dimensions of the chamber are adapted to the shape of the battery to ensure that the battery can enter and exit smoothly. The battery base frame 2 is located on the bottom wall of the cabin 1 and is an integral support structure, including a boss 3 located at the axial position, and several left support blocks 5 and right support blocks 6 symmetrically arranged with the boss 3 as the axis. The surface of the boss 3 is provided with a first electrical connector 4, and a battery mounting plate 8 is installed on the bottom side of the battery 9. The battery mounting plate 8 has a through groove 11 corresponding to the position of the first electrical connector 4. The second electrical connector 10 on the bottom surface of the battery 9 extends out through the through groove 11. When the battery mounting plate 8 is in contact with the support surface, the first electrical connector 4 and the second electrical connector 10 automatically plug in to achieve electrical connection. The tooth insertion channel 7 is formed by the space between the left support block 5 and the left side of the boss 3, and between the right support block 6 and the right side of the boss 3. The width of the channel is adapted to the size of the unmanned forklift tooth, and the depth meets the requirements for stable forking, allowing the fork teeth to be inserted to support the battery mounting plate 8. Positioning pins 13 are provided on the left support block 5 and the right support block 6. Positioning grooves 14 are provided on both sides of the battery mounting plate 8. The battery mounting plate 8 is stably positioned on the support surface by the insertion and cooperation of the positioning pins 13 and the positioning grooves 14, preventing horizontal displacement. The battery mounting plate support surface 12 is composed of the upper surface of the left support block 5, the right support block 6 and the boss 3, and is set horizontally to provide a stable support surface for the battery mounting plate 8.

[0034] 2. Battery swapping station design, such as Figure 5 As shown, The modular compartment splicing design enables vertical and horizontal stacking, eliminating the need for battery transport tracks and simplifying the structure. Each compartment uses the same basic structure as described above. Guide bars 15 are symmetrically arranged on the left and right inner walls of the chamber of compartment 1. Guide ramps 16 are provided near the entrance and exit of the guide bars 15. The two guide ramps 16 form a horn-shaped wide opening, which is the core part of the edge docking mechanism B, assisting the battery to enter in a centered manner. The first electrical connector 4 of each compartment is electrically connected to an independent DC charging module. After the battery 9 is inserted, charging is automatically started through the plugging of the first electrical connector 4 and the second electrical connector 10. The top of cabin 1 is equipped with obvious spatial feature points (such as reflectors) for the navigation system to identify, ensuring that the positioning accuracy meets the requirements; The relative difference between the roll axis of the battery swapping station and the forklift ground must be kept within a preset range. If a forklift without tilting function is used, the relative difference between the pitch axis must also be kept within a preset range.

[0035] 3. Battery compartment design: It adopts the same basic structure as the battery compartment of the battery swapping station (cabin body, battery base frame, electrical connection structure, tooth insertion channel, positioning structure, etc.) to ensure universal compatibility of unmanned forklifts; The first electrical connector 4 is directly connected to the vehicle's main power supply system. When the second electrical connector 10 of the battery 9 is plugged into the first electrical connector 4, it automatically supplies power to the vehicle. The same guide bar 15 and guide ramp 16 are configured to work with the multi-axis adjustment of the unmanned forklift to achieve rapid battery centering; the non-powered floating docking mechanism is the same as that of the battery swapping station, which uses elastic material and has the elastic deformation capability within a preset range to compensate for residual docking errors. The dimensions of the compartment 1, the specifications of the battery mounting plate 8, and the position of the positioning pin 13 can be adjusted according to the vehicle type, while meeting the flatness requirement of "keeping the relative difference with the forklift ground within a preset range".

[0036] 4. Core Coordination Logic: Initial state: Battery mounting plate 8 is attached to battery mounting plate support surface 12, positioning pin 13 is inserted into positioning groove 14, first electrical connector 4 is plugged into second electrical connector 10, and battery 9 is in charging (battery swapping station) or power supply (vehicle) state. Battery removal: The fork of the unmanned forklift inserts into channel 7, the mast slowly rises, the surface of the fork acts on the bottom surface of the battery mounting plate 8 and drives it to rise, the second electrical connector 10 moves up and disengages from the first electrical connector 4, the positioning pin 13 is pulled out from the positioning groove 14, and after complete disengagement, the battery is moved by the forklift. Battery insertion: The unmanned forklift moves the battery 9 to the entrance / exit of the compartment 1. The battery is guided into the center by the wide, flared opening of the guide ramp 16. The mast slowly descends, the battery mounting plate 8 fits against the support surface, the positioning pin 13 is inserted into the positioning slot 14, and the second electrical connector 10 is precisely connected to the first electrical connector 4 to complete the installation.

[0037] Battery swapping process: S1. Battery swap start: When the battery power of the vehicle to be swapped (such as AGV logistics vehicle) is lower than the preset threshold, it will automatically drive to the preset battery swapping area and send a battery swapping request. S2. Spare battery removal: After receiving a battery swapping request, the unmanned forklift uses a navigation and positioning system and a visual recognition system to identify spatial feature points in the battery compartment of the battery swapping station for positioning, and accurately locates the compartment where the backup battery is located. Adjust the chassis's front-to-back, left-to-right position and horizontal rotation angle, and adjust the gantry's lifting height and tilt angle to ensure the fork teeth accurately insert into the tooth insertion channel 7; The gantry slowly rises, and the fork teeth drive the battery mounting plate 8 to rise, causing the second electrical connector 10 to disengage from the first electrical connector 4, the positioning pin 13 to be pulled out, and the spare battery to be picked up. S3. Target location positioning: The unmanned forklift scans the spatial feature points of the battery compartment of the vehicle to be swapped and the guide strip 15 through the vision recognition system, and determines the target docking position by combining the information from the navigation and positioning system. S4. Precise docking and installation: The unmanned forklift moves to the target position and, through multi-axis adjustment of the chassis and mast, aligns the battery 9 with the entrance and exit of the main battery compartment, achieving initial centering under the guidance of the horn-shaped wide opening of the guide ramp 16; The gantry slowly descends, the battery mounting plate 8 gradually approaches the support surface, the positioning pin 13 is aligned with the positioning slot 14 and inserted, and the second electrical connector 10 is precisely connected to the first electrical connector 4. Residual errors are eliminated by a non-powered floating docking mechanism to complete battery installation and power supply docking; S5. Depleted Battery Recovery: The unmanned forklift adjusts the position of the fork teeth, inserts them into the tooth insertion channel 7 of the main battery compartment, and repeats the "lift-disengage-translate" action to retrieve the depleted battery; S6. Cycle complete: The unmanned forklift will transport the depleted battery to an empty bay of the battery swapping station, and will be placed into the bay through the same "alignment-lowering-plugging" process. The charging module will automatically start charging, and the unmanned forklift will return to the standby position, completing one battery swapping cycle.

[0038] The above description is merely illustrative of the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A battery swapping method using an unmanned forklift, characterized in that, include: An unmanned forklift with more than four degrees of freedom is used as the battery swapping carrier. The unmanned forklift realizes multi-axis adjustment during battery picking and transfer through the forward, backward, left and right and horizontal rotation of the chassis and the lifting and lowering of the fork mast. The unmanned forklift is equipped with a navigation and positioning system, a vision recognition system, and a chassis motion control system. The three work together to identify the spatial location information of the target battery compartment and control the precise movement of the unmanned forklift. Both the battery swapping station and the battery compartment of the vehicle to be swapped are equipped with a non-powered floating docking mechanism, a space for the unmanned forklift forks to insert, and spatial feature points for positioning. The battery swapping station, the battery compartment, and the plane where the unmanned forklift is located maintain a preset flatness. After the unmanned forklift picks up the spare battery, it obtains the spatial location information of the battery swapping station or the battery compartment through the navigation and positioning system and / or visual recognition system. The docking error is reduced by the multi-axis motion adjustment of the chassis and mast, and the residual error is eliminated by the non-powered floating docking mechanism to complete the precise docking of the battery and the battery compartment. Specifically, the non-powered floating docking mechanism is an elastic adaptation structure that does not require additional power to drive the battery compartment of the battery swapping station and the battery compartment of the vehicle to be swapped. The core is the elastic material edge docking component and guide strip matching structure around the compartment cavity. Through its own elastic deformation capability, it adaptively compensates for the residual position deviation and angle deviation when the battery docks with the compartment, and guides the battery to be accurately positioned to avoid hard contact wear. The spatial feature points are specifically: spatial markers set on the battery swapping station and the battery compartment of the vehicle to be swapped, which are recognized by the unmanned forklift navigation and positioning system and the visual recognition system. The battery swapping station adopts a modular compartment splicing design to achieve vertical and horizontal stacking. Each compartment is a cabin structure with a battery base frame inside. The battery base frame includes a boss located at the center axis and left and right support blocks symmetrically arranged on both sides of the boss. The surface of the boss is equipped with a first electrical connector. The left support block and the left side of the boss, and the right support block and the right side of the boss respectively form toothed insertion channels. Positioning pins are set on the left and right support blocks. Guide strips are symmetrically arranged on the left and right inner walls of the cabin. Guide ramps are provided near the cabin entrance and exit of the guide strips. The two guide ramps form a wide horn-shaped opening. Each compartment is equipped with an independent DC charging module, which automatically charges by plugging the first electrical connector into the second electrical connector of the battery. It is adapted to the picking and placing actions of unmanned forklifts in conjunction with the toothed insertion channels. The battery compartment of the vehicle to be swapped has a chambered structure, and its internal structure is consistent with that of the battery compartment of the swapping station. It includes a battery base frame, a boss, a left support block, a right support block, a toothed insertion channel, a positioning pin and guide strip, and a guide ramp. The battery compartment directly provides power to the vehicle body through a quick-plug first electrical connector and a second electrical connector. The battery mounting plate has positioning grooves on both sides that are adapted to the positioning pins. The battery mounting plate is stably positioned on the support surface by inserting the positioning pins into the positioning grooves. The preset flatness is achieved by flattening the plane of the swapping station, the battery compartment, and the unmanned forklift, so that the relative difference angle of the roll axis of the three is kept within a preset range. The battery swapping process is as follows: S1. Battery swap start: When the battery power of the vehicle to be swapped is lower than the preset threshold, it will automatically drive to the preset battery swapping area and send a battery swapping request; S2. Spare battery removal: After receiving a battery swapping request, the unmanned forklift uses a navigation and positioning system and a visual recognition system to identify spatial feature points in the battery compartment of the battery swapping station for positioning, and accurately locates the compartment where the backup battery is located. Adjust the chassis's front-to-back, left-to-right position and horizontal rotation angle, and adjust the gantry's lifting height and tilt angle to ensure the fork tines accurately insert into the tines insertion channel; The gantry slowly rises, and the fork teeth drive the battery mounting plate to rise, causing the second electrical connector to disengage from the first electrical connector, the positioning pin to be pulled out, and the spare battery to be picked up. S3. Target location positioning: The unmanned forklift scans the spatial feature points and guide strips of the battery compartment of the vehicle to be swapped through the vision recognition system, and determines the target docking position by combining the information from the navigation and positioning system. S4. Precise docking and installation: The unmanned forklift moves to the target position and, through multi-axis adjustment of the chassis and mast, aligns the battery with the entrance and exit of the main battery compartment, achieving initial centering under the guidance of the horn-shaped wide opening of the guide ramp; The gantry descends slowly, the battery mounting plate gradually approaches the support surface, the positioning pin is aligned with the positioning slot and inserted, and the second electrical connector is precisely connected to the first electrical connector. Residual errors are eliminated by a non-powered floating docking mechanism to complete battery installation and power supply docking; S5. Depleted Battery Recovery: The unmanned forklift adjusts the position of the fork teeth, inserts them into the tooth insertion channel of the main battery compartment, and repeats the "lift-disengage-translate" action to retrieve the depleted battery; S6. Cycle complete: The unmanned forklift will transport the depleted battery to an empty bay of the battery swapping station, and will be placed into the bay through the same "alignment-lowering-plugging" process. The charging module will automatically start charging, and the unmanned forklift will return to the standby position, completing one battery swapping cycle.

2. The battery swapping method using an unmanned forklift according to claim 1, characterized in that, The chassis of the unmanned forklift achieves precise adjustment in the front-to-back and left-to-right directions through the coordinated closed-loop control of the navigation and positioning system, the vision recognition system and the chassis motion control system. At the same time, it achieves high-precision control of the horizontal rotation direction through the independent drive and angle feedback calibration of the chassis horizontal rotation mechanism.

3. A battery swapping method using an unmanned forklift according to claim 1 or 2, characterized in that, The mast of the unmanned forklift collects real-time height information through an encoder, compares and adjusts it in a closed loop with the target height issued by the system, and achieves precise control of the lifting motion. The lifting range of the mast is preset to adapt to the height range of the battery compartment of the vehicle to be swapped and the battery compartment of the battery swapping station, ensuring full-scenario battery swapping coverage.

4. The battery swapping method using an unmanned forklift according to claim 3, characterized in that, The mast tilt of the unmanned forklift is monitored by real-time acquisition of pitch angle information via an encoder, which is then combined with closed-loop fine-tuning of the chassis motion control system to achieve high-precision control of the pitch axis. If the unmanned forklift does not have a mast tilt function, the relative difference angle of the pitch axis is kept within a preset range by ensuring that the battery compartment of the vehicle to be swapped, the battery compartment of the swapping station, and the plane where the unmanned forklift is located are coplanar.

5. A battery swapping method using an unmanned forklift according to claim 1, characterized in that, The navigation and positioning system employs positioning methods such as QR code positioning, magnetic strip positioning, SLAM positioning, or positioning that integrates precise spatial location information from reflectors. By integrating IMU inertial navigation and odometer information, it improves positioning stability and provides a precise position reference for multi-axis chassis adjustments.

6. The battery swapping method using an unmanned forklift according to claim 1, characterized in that, The visual recognition system uses a high-definition depth camera or a binocular camera to identify spatial feature points of the target battery compartment and output relative pose data to assist the navigation and positioning system in calibration.

7. A battery swapping method using an unmanned forklift according to claim 1, characterized in that, The chassis motion control system adopts MPC control algorithm or PID control algorithm. By optimizing the algorithm parameters under low-speed operation, the chassis motion parameters are dynamically adjusted in combination with the real-time feedback of the positioning system.

8. A battery swapping method using an unmanned forklift according to claim 1, characterized in that, The unmanned forklift is a traditional forklift modified by adding a navigation and positioning module, a visual recognition module and a motion control module, or a native unmanned forklift manufactured by directly integrating the above modules.

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