Wireless ultra-thin carrier master-slave walking motion synchronization control method and related equipment

Abstract

The application is suitable for the technical field of carrier control, and provides a wireless ultra-thin carrier master-slave walking motion synchronous control method and related equipment.The method comprises the following steps: a master vehicle PLC sends a state query frame to a slave vehicle PLC through a wireless link; the slave vehicle PLC returns a state return frame to the master vehicle PLC for verification, and sets a system ready flag; when the system ready flag is displayed, a carrying instruction issued by an upper computer is packaged as a synchronous instruction frame and sent to the slave vehicle PLC; the slave vehicle PLC replies to a receiving confirmation frame; the master vehicle PLC and the slave vehicle PLC complete walking pre-start interlocking confirmation and synchronous start control of the master vehicle and the slave vehicle according to the receiving confirmation frame, the speed compensation amount is calculated by the master vehicle PLC and speed compensation is performed; after the speed compensation is completed, when a proximity switch detects a track metal bump block, the position of the master vehicle and the slave vehicle is corrected, the application realizes accurate synchronization of the walking motion of two independent carriers, and ensures the operation safety of the cable-free scheme under abnormal communication conditions.

Description

Technical Field

[0001] This invention relates to the field of transporter control technology, and in particular to a method and related equipment for synchronous control of master-slave walking motion of a wireless ultra-thin transporter. Background Technology

[0002] Intelligent mechanical parking garages utilize automated equipment to achieve three-dimensional vehicle storage. The wheel-clamping transporter is the core actuator, typically consisting of two independent vehicles: a front vehicle (master vehicle) and a rear vehicle (slave vehicle), responsible for clamping the front and rear wheels and driving the vehicle, respectively. Existing transporters generally employ a wired solution: the master and slave vehicles are connected by a physical cable, and an external AC power source supplies power to the transporter via a cable reel. Control signals between the master and slave vehicles are transmitted via wired communication lines.

[0003] However, this wired solution has inherent drawbacks. The cable reel is a mechanical moving part; during the high-frequency reciprocating movement of the transporter, the cable is repeatedly bent and stretched, leading to insulation wear and breakage, and spring failure, resulting in a high equipment failure rate and high maintenance costs. The mechanical winding and unwinding speed of the reel directly limits the upper limit of the travel speed. The volume occupied by the reel assembly, inverter, and frequency converter is a decisive factor in the difficulty of reducing the overall height, preventing the transporter from operating under low-chassis vehicles. There is a physical cable connection between the master and slave vehicles, and the relative movement of the two vehicles is constrained by the cable geometry, making completely independent speed control impossible. Therefore, how to ensure precise motion synchronization of two mechanically and electrically independent transporters throughout the entire travel process, without completely eliminating the physical cable connection between the master and slave vehicles, remains a technical problem that current technology has not yet solved. Summary of the Invention

[0004] This invention provides a method and related equipment for synchronous control of master-slave movement of a wireless ultra-thin transporter, in order to solve the technical problem of how to ensure precise motion synchronization of two mechanically and electrically independent transporters throughout the entire walking process, under the premise of completely eliminating the physical connection cable between the master and slave vehicles.

[0005] In a first aspect, embodiments of this application provide a method for synchronous control of master-slave walking motion of a wireless ultra-thin transporter, including: The master vehicle PLC sends a status query frame to the slave vehicle PLC via a wireless link. The slave vehicle PLC sends the status feedback frame back to the master vehicle PLC for verification. After the verification is successful, the system is set to the ready flag. When the system is ready, the master vehicle PLC encapsulates the transport instructions issued by the host computer into a synchronization instruction frame and sends it to the slave vehicle PLC. The slave vehicle PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame. The master vehicle PLC and the slave vehicle PLC complete the pre-start interlock confirmation of the journey based on the received confirmation frame and synchronously start the master vehicle and slave vehicle to move. The master vehicle PLC calculates the speed compensation amount and performs speed compensation. After speed compensation is completed, when the proximity switch detects a metal block on the track, the positioning deviation between the master vehicle and the slave vehicle is calculated, and the positions of the master vehicle and the slave vehicle are corrected according to the positioning deviation.

[0006] Optionally, in a first implementation of the first aspect of the present invention, the master vehicle PLC sends a status query frame to the slave vehicle PLC via a wireless link, and the slave vehicle PLC sends a status feedback frame back to the master vehicle PLC for verification. After successful verification, a system ready flag is set, including: Establish a wireless link between the master vehicle and the slave vehicle; The master vehicle PLC sends a status query frame to the slave vehicle PLC via the wireless link; The slave vehicle PLC receives the status query frame, reads the first status word of each servo driver on the slave side and the first charge state of the battery management system, and obtains the slave side self-test data; the master vehicle PLC reads the second status word of each servo driver on the master vehicle side and the second charge state of the battery management system, and obtains the master vehicle side self-test data. The slave PLC encapsulates the slave-side self-test data into a status feedback frame, and transmits the status feedback frame back to the master PLC via the wireless link; The main vehicle PLC verifies the status feedback frame and the main vehicle side self-test data, and sets the system ready flag after the verification is passed.

[0007] Optionally, in a second implementation of the first aspect of the present invention, the main vehicle PLC verifies the status feedback frame and the main vehicle-side self-test data, and sets a system ready flag after the verification passes, including: The main vehicle PLC verifies the first status word and the first charge status in the status feedback frame, as well as the second status word and the second charge status in the main vehicle side self-test data. When both the first status word and the second status word meet the normal state, and both the first charge state and the second charge state are higher than the operating threshold, the verification is confirmed to be successful and the system ready flag is set.

[0008] Optionally, in a third implementation of the first aspect of the present invention, when the system ready flag is displayed, the master vehicle PLC encapsulates the transport instruction issued by the host computer into a synchronization instruction frame and sends it to the slave vehicle PLC. The slave vehicle PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame, including: When the system is ready, the main vehicle PLC receives the transport instruction from the host computer. The main vehicle PLC performs a legality check on the transport command; The legality verification of the handling instruction, the master vehicle timestamp of the master vehicle PLC and the synchronization sequence number are encapsulated into a synchronization instruction frame, and the synchronization instruction frame is sent to the slave vehicle PLC. After the slave PLC writes the synchronization instruction frame into its local register, it replies with a reception confirmation frame.

[0009] Optionally, in a fourth implementation of the first aspect of the present invention, the slave PLC encapsulates the received confirmation frame with an additional slave timestamp, and transmits the received confirmation frame back to the master PLC via the wireless link. The master vehicle PLC calculates the difference between the slave vehicle timestamp in the received confirmation frame and the master vehicle timestamp when the synchronization command frame was sent to obtain the link transmission delay. If the link transmission delay exceeds the transmission delay threshold, a communication fault code is reported to the host computer.

[0010] Optionally, in a fifth implementation of the first aspect of the present invention, the master vehicle PLC and the slave vehicle PLC complete the pre-start interlock confirmation of travel according to the received confirmation frame and synchronously start controlling the master vehicle and the slave vehicle to travel. The master vehicle PLC calculates the speed compensation amount and performs speed compensation, including: The master vehicle PLC sends a travel pre-start request frame to the slave vehicle PLC according to the received confirmation frame. The slave vehicle PLC sends back a pre-start ready frame. After receiving the pre-start ready frame, the master vehicle PLC and the slave vehicle PLC complete the travel pre-start interlock confirmation within the same control cycle. The master vehicle and slave vehicle are controlled to move synchronously. The master vehicle PLC reads the first moving position of the master vehicle, and the slave vehicle PLC reads the second moving position of the slave vehicle. The master vehicle PLC calculates the speed compensation amount based on the first travel position and the second travel position, and sends the speed compensation amount to the slave vehicle PLC to perform speed compensation.

[0011] Optionally, in a sixth implementation of the first aspect of the present invention, the master vehicle PLC calculates a speed compensation amount based on the first travel position and the second travel position, and sends the speed compensation amount to the slave vehicle PLC to perform speed compensation, including: The main vehicle PLC calculates the position deviation based on the first traveling position and the second traveling position; Calculate the speed compensation amount based on the position deviation; The slave PLC adds the target speed to the speed compensation amount and writes it into the corresponding speed setting register to perform speed compensation.

[0012] Optionally, in a seventh implementation of the first aspect of the present invention, after speed compensation is completed, when the proximity switch detects a metal contact block on the track, calculating the positioning deviation between the master vehicle and the slave vehicle, and correcting the positions of the master vehicle and the slave vehicle based on the positioning deviation, includes: After speed compensation is completed, when the proximity switch detects a metal block on the track, the positioning deviation between the master vehicle and the slave vehicle is calculated. When the positioning deviation exceeds the positioning tolerance, a jog command is written to the master vehicle PLC or the slave vehicle PLC in micro-motion mode until the positioning deviation converges to the positioning tolerance range.

[0013] Optionally, in the eighth implementation of the first aspect of the present invention, if the master vehicle PLC or the slave vehicle PLC does not receive a data frame within N consecutive control cycles, the corresponding enable signal is blocked, causing the brake coil to lose power and the brake pads to mechanically lock the motor shaft under the action of spring force.

[0014] Secondly, embodiments of this application provide a wireless ultra-thin transporter master-slave walking motion synchronization control device, comprising: The verification module is used for the master vehicle PLC to send a status query frame to the slave vehicle PLC via a wireless link. The slave vehicle PLC sends the status feedback frame back to the master vehicle PLC for verification. After the verification is passed, the system is ready. The synchronization module is used to encapsulate the transport instructions issued by the host computer into a synchronization instruction frame and send it to the slave PLC through the master PLC when the system is ready. The slave PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame. The speed compensation module is used by the master vehicle PLC and the slave vehicle PLC to complete the pre-start interlock confirmation of the journey based on the received confirmation frame and synchronously start the movement of the master vehicle and the slave vehicle. The master vehicle PLC calculates the speed compensation amount and performs speed compensation. The position correction module is used to calculate the positioning deviation between the master vehicle and the slave vehicle after the speed compensation is completed and the proximity switch detects a metal block on the track, and to correct the position of the master vehicle and the slave vehicle according to the positioning deviation.

[0015] Thirdly, embodiments of this application provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the aforementioned wireless ultra-thin transporter master-slave walking motion synchronization control method.

[0016] Fourthly, embodiments of this application provide a readable storage medium storing a computer program that, when executed by a processor, implements the steps of the aforementioned wireless ultra-thin transporter master-slave walking motion synchronization control method.

[0017] Fifthly, embodiments of this application provide a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the aforementioned wireless ultra-thin transporter master-slave walking motion synchronization control method.

[0018] In one of the solutions provided by the aforementioned wireless ultra-thin transporter master-slave walking motion synchronization control method and related equipment, a dual PLC position closed-loop interlock control architecture based on a point-to-point wireless bridge is constructed, which achieves precise synchronization of the walking motion of two independent transporters without completely eliminating the physical connection cable between the master and slave vehicles. Each of the master and slave vehicles is equipped with an independent PLC. They exchange their current travel positions, calculated from the accumulated pulses of their respective travel servo drive encoders, bidirectionally within a fixed control cycle via a wireless link. The master vehicle PLC performs a proportional calculation on the position difference to obtain the speed compensation amount and sends it to the slave vehicle PLC in real time to write into its travel servo drive speed setting register. Within each fixed control cycle, the master vehicle PLC and slave vehicle PLC exchange their current travel positions, calculated from the accumulated pulses of their respective travel servo drive encoders, bidirectionally via a wireless link. The master vehicle PLC performs a proportional calculation on the difference between the current travel positions of the master and slave vehicles to obtain the speed compensation amount and writes it to the slave vehicle's travel servo drive speed setting register in real time. This forms a continuously converging position closed-loop compensation circuit within each control cycle, effectively eliminating the cumulative position deviation caused by speed control errors, load differences, and mechanical friction differences between the two independent servo drives. This ensures the synchronization accuracy of the master and slave vehicle travel movements. By eliminating the cable reel, inverter, and frequency converter, the overall height of the machine is no longer limited by wired solutions, and the range of vehicle types applicable to the transporter is correspondingly expanded. The travel speed is also no longer constrained by the mechanical winding and unwinding speed of the cable reel, significantly shortening the single-operation cycle time. In terms of safety, the master and slave PLCs are each set with independent communication timeout detection logic. When the link is interrupted, both sides block the enable signal of the walking servo drive. The brakes are mechanically locked in the power failure state. Autonomous braking can be completed without relying on the other side's command, ensuring the operational safety of the cableless solution under abnormal communication conditions. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a master-slave walking motion synchronization control system for a wireless ultra-thin transporter according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating a master-slave motion synchronization control method for a wireless ultra-thin transporter according to an embodiment of the present invention. Figure 3 yes Figure 2 A schematic diagram of the implementation process of step S10; Figure 4 yes Figure 2 A schematic diagram of the implementation process of step S20; Figure 5 yes Figure 2 A schematic diagram of the implementation process of step S30; Figure 6 yes Figure 2 A schematic diagram of the implementation process of step S40; Figure 7 This is a schematic diagram of a master-slave walking motion synchronization control device for a wireless ultra-thin transporter according to an embodiment of the present invention. Figure 8 This is a schematic diagram of the layout of the master vehicle and slave vehicle in one embodiment of the present invention; Figure 9 This is a schematic diagram of the electrical main circuit of the transporter in one embodiment of the present invention; Figure 10 This is a schematic diagram of the electrical control circuit and network topology of the transporter in one embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of a computer device according to one embodiment of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only 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.

[0022] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. It should also be understood that, as used in this specification and the appended claims, the term "and / or" refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0023] Furthermore, in the description of this invention and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of the invention include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0025] It should be understood that the sequence number of each step in the following embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0026] To illustrate the technical solution of the present invention, specific embodiments are described below.

[0027] To address the problems mentioned above in the background art, this application proposes a method and related equipment for synchronous control of master-slave walking motion of a wireless ultra-thin transporter. The method for synchronous control of master-slave walking motion of a wireless ultra-thin transporter provided by this invention can be applied to applications such as... Figure 1 The wireless ultra-thin transporter master-slave walking motion synchronization control system shown includes a client and a server.

[0028] In one embodiment, the wireless ultra-thin transporter master-slave motion synchronization control system adopts a layered wireless communication network architecture to achieve fully wireless data interaction between the transporter and the host computer, and between the master and slave vehicles. The first layer is the communication layer between the transporter and the host computer. An external industrial wireless router is deployed at the parking garage site. This external industrial wireless router is connected to the host computer scheduling system via an Ethernet interface and simultaneously connected to a handheld touchscreen via WiFi. The master vehicle PLC is connected to the master vehicle-side industrial wireless router via an Ethernet interface. A wireless bridge is established between the master vehicle-side industrial wireless router and the external industrial router, forming a transparent Ethernet data channel. The host computer scheduling system sends scheduling instructions to the master vehicle PLC via the Modbus TCP protocol through this wireless bridge channel. The scheduling instructions include parameters such as operation type, target parking space number, walking direction, and walking distance. The master vehicle PLC provides real-time feedback of transporter status information to the host computer through the same channel. The transporter status information includes position status, operating status, battery level, and fault codes. The second layer is the internal communication layer between the master and slave vehicles, which is the physical implementation layer of the wireless link described in this invention. A dedicated point-to-point wireless communication link is established between the master and slave vehicles via their respective installed wireless bridges. The master and slave wireless bridges support factory pairing, and the two devices automatically establish a connection during system initialization, transmitting full-duplex high-speed data via a preset frequency band. This dedicated link specifically carries synchronous control data frames, status exchange data frames, and fault alarm data frames between the master and slave PLCs, forming the physical communication foundation for synchronous control of master-slave movement. The wireless signal transmission delay between the two vehicles is controlled within a preset threshold to meet the synchronous control requirements of the fixed control cycle described in this invention. The third layer is the handheld operating terminal communication layer. The handheld touchscreen connects to an external industrial wireless router via WiFi, enabling manual operation, jog debugging, parameter setting, and fault monitoring of the transporter. The handheld operating terminal supports managing multiple transporters simultaneously from a single unit. Through the above three-layer wireless communication network architecture, the transmission of scheduling instructions between the transporter and the host computer, the transmission of synchronous control data between the master and slave vehicles, and the human-machine interaction operation of the handheld terminal all run on independent wireless links. The three links do not interfere with each other in terms of communication frequency band, transmission content, and transmission real-time requirements. This enables the master vehicle PLC to maintain a stable transmission delay of no more than a preset threshold when sending status query frames, synchronization instruction frames, speed compensation amounts, and other data to the slave vehicle PLC via the wireless link, thus providing a reliable communication foundation for the various synchronous control logics described in steps S10 to S40.

[0029] In one embodiment, such as Figure 2 As shown, a method for synchronous control of master-slave walking motion of a wireless ultra-thin transporter is provided, which is applied to... Figure 1 The following steps are used as an example to illustrate the master-slave walking motion synchronization control system of a wireless ultra-thin transporter: S10: The master vehicle PLC sends a status query frame to the slave vehicle PLC via a wireless link. The slave vehicle PLC sends the status feedback frame back to the master vehicle PLC for verification. After the verification is passed, the system ready flag is set. S20: When the system is ready, the master PLC encapsulates the transport instructions issued by the host computer into a synchronization instruction frame and sends it to the slave PLC. The slave PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame. S30: The master vehicle PLC and slave vehicle PLC complete the pre-start interlock confirmation of travel based on the received confirmation frame and synchronously start the control of the master vehicle and slave vehicle to travel. The master vehicle PLC calculates the speed compensation amount and executes the speed compensation. S40: After speed compensation is completed, when the proximity switch detects a metal block on the track, the positioning deviation between the master car and the slave car is calculated, and the positions of the master car and the slave car are corrected according to the positioning deviation.

[0030] In this embodiment, by constructing a dual PLC position closed-loop interlock control architecture based on a point-to-point wireless bridge, precise synchronization of the walking motion of two independent transporters is achieved without completely eliminating the physical connection cable between the master and slave vehicles. Each of the master and slave vehicles is equipped with an independent PLC. They exchange their current travel positions, calculated from the accumulated pulses of their respective travel servo drive encoders, bidirectionally within a fixed control cycle via a wireless link. The master vehicle PLC performs a proportional calculation on the position difference to obtain the speed compensation amount and sends it to the slave vehicle PLC in real time to write into its travel servo drive speed setting register. Within each fixed control cycle, the master vehicle PLC and slave vehicle PLC exchange their current travel positions, calculated from the accumulated pulses of their respective travel servo drive encoders, bidirectionally via a wireless link. The master vehicle PLC performs a proportional calculation on the difference between the current travel positions of the master and slave vehicles to obtain the speed compensation amount and writes it to the slave vehicle's travel servo drive speed setting register in real time. This forms a continuously converging position closed-loop compensation circuit within each control cycle, effectively eliminating the cumulative position deviation caused by speed control errors, load differences, and mechanical friction differences between the two independent servo drives. This ensures the synchronization accuracy of the master and slave vehicle travel movements. By eliminating the cable reel, inverter, and frequency converter, the overall height of the machine is no longer limited by wired solutions, and the range of vehicle types applicable to the transporter is correspondingly expanded. The travel speed is also no longer constrained by the mechanical winding and unwinding speed of the cable reel, significantly shortening the single-operation cycle time. In terms of safety, the master and slave PLCs are each set with independent communication timeout detection logic. When the link is interrupted, both sides block the enable signal of the walking servo drive. The brakes are mechanically locked in the power failure state. Autonomous braking can be completed without relying on the other side's command, ensuring the operational safety of the cableless solution under abnormal communication conditions.

[0031] In one embodiment, such as Figure 3 As shown, step S10 specifically includes the following steps: S11: Establish a wireless link between the master vehicle and the slave vehicle; S12: The master vehicle PLC sends a status query frame to the slave vehicle PLC via a wireless link; S13: The vehicle PLC receives a status query frame, reads the first status word of each servo drive on the vehicle side and the first charge state of the battery management system, and obtains the vehicle-side self-test data; the master vehicle PLC reads the second status word of each servo drive on the master vehicle side and the second charge state of the battery management system, and obtains the master vehicle-side self-test data. S14: The slave PLC encapsulates the self-test data from the vehicle side into a status feedback frame and transmits the status feedback frame back to the master PLC via a wireless link. S15: The main vehicle PLC verifies the status feedback frame and the self-test data on the main vehicle side, and sets the system ready flag after the verification is passed.

[0032] In this embodiment, after the master vehicle and slave vehicle are powered on, they complete their basic initialization, enabling the master vehicle PLC, slave vehicle PLC, wireless bridge, battery management system, servo driver, and necessary sensors to enter a communicable state. A point-to-point wireless communication link is established between the master vehicle TL-CPE501 and the slave vehicle TL-CPE501. The link can operate in a dedicated master-slave vehicle internal communication layer, with the master vehicle acting as the control core and the slave vehicle acting as the execution slave node. The two sides transmit synchronous control data frames, status exchange data frames, and fault alarm data frames through the wireless link. The master vehicle PLC can set a link handshake waiting window, and periodically check the online status of the wireless bridge, the port connection status, and the response status of the slave vehicle PLC within the window. If the link is not established, the system ready flag is reset and feedback to the host computer indicates that communication is not ready. If the link is established and the communication cycle meets the control requirement of not exceeding 30ms, the status query process is initiated.

[0033] In this embodiment, the master vehicle PLC sends a status query frame to the slave vehicle PLC via a wireless link. The status query frame may include a frame header, device identifier, query command word, synchronization sequence number, master vehicle timestamp, and checksum field. The device identifier distinguishes between the master and slave vehicles, the synchronization sequence number prevents duplicate or out-of-order frames from being mishandled, the master vehicle timestamp provides a basis for timing consistency judgment, and the checksum field determines whether errors occurred during wireless transmission. Upon receiving the status query frame, the slave vehicle PLC performs basic checks on the frame header, command word, sequence number, and checksum field to confirm... After confirming that the frame is a valid query request, the first status word of each servo drive on the vehicle side and the first charge status fed back by the battery management system are read. The first status word of the servo drive on the vehicle side mainly reflects whether the drive is in standby, enabled, alarm, emergency stop, overcurrent, overvoltage, encoder abnormality, etc. The first charge status is fed back by the battery management system to determine whether the vehicle battery meets the minimum operating requirements. At the same time, the vehicle PLC can also synchronously collect its own emergency stop button, collision switch, proximity switch, wireless bridge status and current fault code to form vehicle-side self-test data. Meanwhile, the master vehicle PLC does not wait for the slave vehicle to complete the feedback before starting its own check. Instead, it reads the second status word of each servo drive on the master vehicle side and the second charge status fed back by the battery management system during the same initialization phase. Combined with the master vehicle side emergency stop, collision, anti-stacking, positioning proximity switch, wireless bridge connection status and fault register, it forms master vehicle-side self-test data, reducing waiting time and ensuring that the self-test data of the master and slave sides are within a similar time window. The slave PLC encapsulates the self-test data from the vehicle side into a status feedback frame and transmits it back to the master PLC via a wireless link. The status feedback frame contains the slave device identifier, the corresponding synchronization sequence number, the first status word, the first charge state, the fault code, the slave timestamp, and a verification field. If the synchronization sequence number in the status query frame matches the synchronization sequence number in the status feedback frame, the master PLC can confirm that the feedback frame matches the current query, thus preventing the misuse of residual data from the previous cycle. After the master vehicle PLC receives the status feedback frame, it performs an overall verification, confirming that the feedback frame format is complete, the verification fields are correct, the serial number matches, the slave vehicle status has no alarm, the master vehicle status has no alarm, the first charge state and the second charge state are both higher than the preset operating threshold, and both servo drives on both sides are in the start-up or standby enable state. Only when all these conditions are met will the master vehicle PLC set the system ready flag and send a standby or system ready signal to the host computer. If any condition is not met, the system ready flag is kept reset, the corresponding fault type is written to the fault register, and information such as servo fault alarm, encoder position abnormality alarm, spacing sensor fault alarm, communication fault alarm or low battery power is displayed on the host computer or handheld terminal, thereby ensuring that the master vehicle, slave vehicle, battery, wireless link and servo execution link are all in a controllable state before the handling command is issued.

[0034] In one embodiment, step S15 specifically includes the following steps: The main vehicle PLC verifies the first status word and the first charge status in the status feedback frame, as well as the second status word and the second charge status in the main vehicle side self-test data. When both the first status word and the second status word meet the normal state, and both the first charge state and the second charge state are higher than the operating threshold, the verification is confirmed to be successful and the system ready flag is set.

[0035] In this embodiment, after receiving the status feedback frame from the slave PLC, the master vehicle PLC performs a consistency check on the frame header, frame length, device identifier, synchronization sequence number, timestamp, and verification field to confirm that the status feedback frame does indeed correspond to the current round of status query frames. This avoids mistaking old data as the current self-test result when duplicate frames, delayed frames, or erroneous frames appear in the wireless link. After the frame-level verification passes, the master vehicle PLC parses the first status word and the first charge state from the status feedback frame, and simultaneously reads the second status word and the second charge state from the local self-test register. The first status word is used to characterize the current operating status of the slave vehicle-side walking servo driver and the wheel-holding servo driver, and the second status word is used to characterize the current operating status of each servo driver on the master vehicle side. The first charge state and the second charge state are the battery remaining power status fed back by the slave vehicle-side and master vehicle-side battery management systems, respectively. The normal conditions for the servo drive status word can be set to no servo alarm, no emergency stop trigger, no encoder abnormality, no overvoltage or overcurrent fault, and the drive is in standby enabled or start-up enabled state. The operating threshold is preset to 20%. When the first state of charge is greater than 20% and the second state of charge is greater than 20%, it is considered that both batteries meet the requirements for startup and short-term operation. If any status bit in the first or second status word shows a fault, or if any state of charge is less than or equal to 20%, the master vehicle PLC will not set the system ready flag, but will write the source of the abnormality into the fault register, such as slave servo fault, master servo fault, slave power insufficient, master power insufficient, or status frame abnormality, and will prompt the corresponding alarm information through the host computer or handheld terminal. At the same time, it will prohibit entering the handling instruction reception and walking pre-start process. Only when the status feedback frame itself is valid, both the first status word and the second status word are in normal condition, and both the first charge state and the second charge state are higher than the operating threshold, will the main vehicle PLC confirm that the verification has passed, set the system ready flag to the valid state, and simultaneously send back the original standby or ready signal to the host computer, so that the system has the prerequisites to receive handling instructions.

[0036] In one embodiment, such as Figure 4 As shown, step S20 specifically includes the following steps: S21: When the system is ready, the main vehicle PLC receives the transport instructions from the host computer. S22: The main vehicle PLC performs a legality check on the handling instructions; S23: Encapsulate the legality-verified handling instruction, the master vehicle timestamp of the master vehicle PLC, and the synchronization sequence number into a synchronization instruction frame, and send the synchronization instruction frame to the slave vehicle PLC; S24: After the slave PLC writes the synchronization instruction frame into the local register, it replies with a reception confirmation frame.

[0037] In this embodiment, the master vehicle PLC opens the host computer instruction receiving interface only after the master-slave status verification has been completed and the system ready flag is in a valid state. At this time, the host computer scheduling system sends a transport instruction to the master vehicle PLC through the wireless bridging channel formed by the external industrial wireless router and the industrial wireless router on the master vehicle side, using Modbus TCP communication. After receiving the instruction, the master vehicle PLC writes the instruction frame into the verification buffer and latches the receiving time, the current system status word, and the current fault word to prevent false start due to status changes during instruction reception. The transport instruction may include fields such as operation type, target parking space number, target travel direction, target travel distance, and target wheelbase value of the vehicle to be transported. The operation type is used to distinguish between parking or retrieval processes, the target parking space number is used to match the storage location table, the target travel direction and target travel distance are used to generate travel control targets, and the target wheelbase value is used to ensure that the master vehicle and the slave vehicle maintain a relative position adapted to the vehicle wheelbase before performing wheel-clamping transport. The main vehicle PLC performs a validity check on the transport command. The check follows the order of "valid command source, complete fields, reasonable parameter range, execution status, and target parking space conditions met." The main vehicle PLC first confirms that the command comes from the established communication channel of the host computer and confirms that the fields such as operation type, parking space number, direction, distance, and wheelbase in the command frame are not missing or out of bounds. Then, it checks whether the target parking space number exists in the configured parking space table and whether the target wheelbase value is within the preset adaptive wheelbase range of the transporter. The adaptive wheelbase range is determined based on the target vehicle model range in the garage, the travel of the wheel clamping mechanism, and the adjustment range of the relative position of the master and slave vehicles. The system pre-configures whether the target travel distance matches the current position of the transporter and the target parking space. It also confirms that the transporter is still in a system-ready state, that neither the master nor slave vehicle has any unreset faults, that the emergency stop has not been triggered, that the servo drive has no alarms, and that the battery status meets the operating requirements. Furthermore, it combines the parking space occupancy status to determine whether the target parking space is vacant when parking and whether there is a vehicle waiting to be retrieved when retrieving the vehicle. If any item fails to meet the requirements, the master vehicle PLC does not generate a synchronization instruction frame, but instead writes the illegal reason into the fault or prompt register and sends an instruction rejection message to the host computer, enabling the host computer to reissue the correct task or prompt manual handling. If the validity check passes, the master PLC encapsulates the transport instruction, the master PLC's master timestamp, and the synchronization sequence number into a synchronization instruction frame. The master timestamp is used to identify the reference time when the instruction was generated, and the synchronization sequence number is used to identify the unique execution order of this task, preventing the slave PLC from mistaking duplicate frames, delayed frames, or residual frames from the previous task as the current task. The synchronization instruction frame can also carry a frame header, frame length, master / slave device identifiers, command words, task parameter area, and verification field, which facilitates the slave PLC to perform integrity and consistency checks after receiving the data.The master vehicle PLC sends a synchronization command frame to the slave vehicle PLC via a point-to-point wireless link. Upon receiving the frame, the slave vehicle PLC verifies the frame header, length, device identifier, command word, synchronization sequence number, and check field. After confirming the synchronization command frame is valid, it writes the job type, target parking space number, travel direction, travel distance, target wheelbase value, master vehicle timestamp, and synchronization sequence number into its local task register, motion target register, and synchronization control register, respectively. It also updates the local task status from standby to received or ready-to-start state. After writing, the slave vehicle PLC generates a reception confirmation frame and transmits it back to the master vehicle PLC via the wireless link. The reception confirmation frame contains the slave vehicle device identifier, the corresponding synchronization sequence number, the reception result, the slave vehicle timestamp, and a check field, enabling the master vehicle PLC to confirm that the slave vehicle has correctly received the same task. After receiving the reception confirmation frame, the main vehicle PLC matches the reception confirmation frame with the synchronization sequence number of the current synchronization command frame. If the match is successful and the reception result is normal, it enters the pre-start interlock preparation for travel. If no confirmation is received within the timeout period or the confirmation frame shows a write failure, it keeps the task in the inactive state and reports a communication or command synchronization abnormality to the host computer.

[0038] In one embodiment, the slave PLC encapsulates the received confirmation frame with an appended slave timestamp and transmits the received confirmation frame back to the master PLC via a wireless link; The master vehicle PLC calculates the link transmission delay by subtracting the slave vehicle timestamp from the received confirmation frame from the master vehicle timestamp when the synchronization command frame was sent. If the link transmission delay exceeds the transmission delay threshold, a communication fault code will be reported to the host computer.

[0039] In this embodiment, after receiving the synchronization command frame sent by the master vehicle PLC, the slave vehicle PLC performs an integrity check on the synchronization command frame, confirming that the frame header, command word, device identifier, synchronization sequence number, and check field are all valid, and confirming that the synchronization sequence number is not a previously processed historical sequence number. The slave vehicle PLC writes the transport command parameters, master vehicle timestamp, and synchronization sequence number from the synchronization command frame into the local task register and synchronization control register. After writing, the slave vehicle PLC immediately reads its current clock value as the slave vehicle timestamp, and encapsulates the slave vehicle timestamp, synchronization sequence number, reception result, write status, slave vehicle device identifier, and check field together into a reception confirmation frame, which is then transmitted back to the master vehicle PLC through the point-to-point wireless link between the master and slave vehicles. During the wireless link establishment and status query phases, the time base alignment between the master vehicle PLC and the slave vehicle PLC can be completed in advance, or the master-slave clock offset compensation can be stored on the master vehicle PLC side so that the slave vehicle timestamp can be converted to the master vehicle time base for judgment. Otherwise, if the two PLCs keep independent time, the direct difference calculation will be affected by the clock deviation. During initialization, the master-slave clock offset can be estimated by multiple short frame handshakes, and the master-slave clock offset can be written into the synchronization parameter area of ​​the master vehicle PLC. When the subsequent confirmation frame arrives, the master vehicle PLC first looks up the master vehicle timestamp latched when the current synchronization instruction frame was sent according to the synchronization sequence number, then reads the slave vehicle timestamp carried in the confirmation frame, and performs difference calculation under the same time base to obtain the link transmission delay. The link transmission delay reflects the timing of the synchronization command frame being sent from the master vehicle side, reaching the slave vehicle side via the wireless link, and being acknowledged by the slave vehicle side. If the link transmission delay is within the preset transmission delay threshold, the master vehicle PLC can consider that the timing of this command issuance meets the synchronization control requirements, and mark the corresponding synchronization sequence number as confirmed, allowing entry into the travel pre-start interlock process. If the link transmission delay exceeds the transmission delay threshold, it indicates that there is congestion, retransmission, interference in the wireless link, or a delayed response from the slave vehicle PLC. The master vehicle PLC does not rely on this synchronization command to directly trigger the travel action, but keeps the current task in an inactive or waiting-for-acknowledgment state, and reports a communication fault code to the host computer. The transmission delay threshold can be preset according to the internal communication cycle of the master and slave vehicles, wireless link jitter, control response time, and the allowable range of synchronization error. When the link transmission delay exceeds the transmission delay threshold, the master vehicle PLC writes the fault type into the communication fault register and prohibits entry into the servo enable release, travel preparation request, and synchronization start stages. If a timeout occurs only once, the process of retransmission or reconfirmation can be initiated. However, if the continuous confirmation still exceeds the threshold, or if the received confirmation frame does not match the current synchronization sequence number, it should be treated as a communication error to avoid asynchronous operation between the slave PLC and the master PLC after the slave PLC receives the old instructions with a delay.

[0040] In one embodiment, such as Figure 5 As shown, step S30 specifically includes the following steps: S31: The master PLC sends a travel pre-start request frame to the slave PLC based on the received confirmation frame. The slave PLC sends back a pre-start ready frame. After receiving the pre-start ready frame, the master PLC and the slave PLC complete the travel pre-start interlock confirmation within the same control cycle. S32: Synchronous start control of the master vehicle and slave vehicle movement. The master vehicle PLC reads the first movement position of the master vehicle, and the slave vehicle PLC reads the second movement position of the slave vehicle. S33: The master PLC calculates the speed compensation amount based on the first and second travel positions, and sends the speed compensation amount to the slave PLC to perform speed compensation.

[0041] In this embodiment, after receiving the reception confirmation frame from the slave PLC, the master vehicle PLC matches the synchronization sequence number, reception result, and slave vehicle timestamp in the reception confirmation frame with the synchronization sequence number and master vehicle timestamp latched in the current synchronization instruction frame to confirm that the slave vehicle has correctly received and written the same transport task, and that the link transmission delay has not exceeded the preset transmission delay threshold. Only then does the master vehicle PLC generate a travel pre-start request frame and send it to the slave vehicle PLC through the point-to-point wireless link between the master and slave vehicles. The travel pre-start request frame can carry the current task sequence number, travel direction, target speed level, target travel distance, pre-start command word, and verification field. After receiving the travel pre-start request frame, the slave PLC performs a pre-start check on its own side, including confirming that the slave-side travel servo driver is in an enabled state, the servo alarm is not set, the emergency stop and collision detection inputs are not triggered, the wheel clamping mechanism or clamp arm is not in a prohibited travel state, the wireless link is still online, the battery charge status still meets the operating requirements, and the synchronization sequence number in the slave-side task register is consistent with the synchronization sequence number in the travel pre-start request frame. When all these conditions are met, the slave PLC releases or prepares to release the travel servo motor brake, enabling the iSMK braking module to enter the runnable state. At the same time, the slave PLC sets its own pre-start state to ready and encapsulates a pre-start ready frame to send back to the master PLC. After receiving the pre-start ready frame, the master vehicle PLC also performs the same judgment on the serial number, status word and verification field, and combines the pre-start conditions of the master vehicle with the pre-start ready status of the slave vehicle. Only when the master vehicle's walking servo drive, brake, safety input, battery status and task status are all normal, and the slave vehicle has also returned the pre-start ready status, will the master vehicle PLC complete the walking pre-start interlock confirmation with the slave vehicle PLC in the same control cycle.

[0042] In this embodiment, after the interlock confirmation is completed, the master vehicle PLC and the slave vehicle PLC enter the synchronous start-up process according to the same task sequence number. Both parties write start commands to their respective travel servo drives at the agreed control cycle boundary, so that the master vehicle and the slave vehicle start moving in the same travel direction and preset acceleration and deceleration logic. In the initial stage of travel start-up, a ramp acceleration method can be used to smoothly transition the motor from zero speed to the target speed, avoiding mechanical shock caused by sudden speed input or amplification of the start-up difference between the master and slave vehicles. After start-up, the master vehicle PLC reads the encoder cumulative pulse value fed back by the master vehicle travel servo drive through the local CAN bus, and converts the encoder cumulative pulse value into the first travel position according to the origin or starting reference latched at the start. The slave vehicle PLC reads the encoder cumulative pulse value fed back by the slave vehicle travel servo drive through the local CAN bus, and converts it into the second travel position according to the starting reference latched when the slave vehicle starts the interlock. Since the two starting references are established in the same pre-start interlock confirmation, the first travel position and the second travel position both represent the travel distance of their respective vehicles from the same starting point, and are comparable. The slave PLC encapsulates the second travel position, the slave vehicle's current speed feedback value, the slave vehicle's running status word, and the control cycle sequence number into travel status feedback data, which is then sent to the master PLC via a wireless link. The master PLC then matches the first travel position it reads with the second travel position returned by the slave vehicle to the corresponding cycle. After confirming that the two belong to the same control cycle, it calculates the speed compensation amount based on the position difference between the two vehicles and encapsulates the speed compensation amount into a speed fine-tuning instruction, which is then sent to the slave PLC. This causes the slave PLC to perform compensation writing based on the target speed, thereby enabling the slave vehicle to appropriately increase its speed when lagging behind and appropriately decrease its speed when leading, and gradually converge the master-slave travel position deviation within a continuous control cycle.

[0043] In one embodiment, step S33 specifically includes the following steps: The main vehicle PLC calculates the position deviation based on the first and second travel positions; Calculate the speed compensation amount based on the position deviation; The vehicle's PLC adds the target speed and the speed compensation amount together and writes the result to the corresponding speed setting register to perform speed compensation.

[0044] In this embodiment, after synchronous startup, the master vehicle PLC reads the encoder cumulative pulses fed back by the master vehicle's travel servo driver according to a fixed control cycle, and calculates the first travel position by combining it with the master vehicle's initial reference value latched during startup interlocking. Simultaneously, it receives the second travel position, the slave vehicle's current speed, and the slave vehicle's running status word from the slave vehicle PLC within the same control cycle. The master vehicle PLC verifies the control cycle sequence number, synchronization sequence number, and status word in the slave vehicle's returned frame. After confirming that the slave vehicle data corresponds to the master vehicle data for the current cycle and that the slave vehicle is not in an alarm or disabled state, it records the first travel position as... Record the second walking position as And calculate the signed positional deviation. ,in A positive value indicates that the lead vehicle is ahead of the follower vehicle. A negative value indicates that the master vehicle lags behind the slave vehicle. The master vehicle PLC compares the absolute value of the position deviation with a preset allowable deviation threshold, which can be set to ±10mm. When the position deviation does not exceed this range, it indicates that the synchronization of the two vehicles meets the requirements, and the master vehicle PLC does not generate a speed intervention amount; the master and slave vehicles continue to run stably at the original target speed. When the position deviation exceeds ±10mm, the master vehicle PLC calculates the speed compensation amount based on the position deviation. ,in This is a proportional adjustment coefficient, which can be determined as a fixed value based on on-site debugging. The unit can be configured in (m / min) / mm, allowing position deviations to be converted into speed correction values. The master PLC encapsulates the speed compensation value along with the current task sequence number, direction of motion, control cycle sequence number, and verification field into a speed fine-tuning instruction frame, which is then sent to the slave PLC via a wireless link. Upon receiving the frame, the slave PLC first confirms that the speed fine-tuning instruction belongs to the current task and has not timed out. Then, it superimposes the target speed with the speed compensation value and writes the superimposed speed setpoint into the speed set register of the slave vehicle's travel servo drive. This indicates that the slave vehicle is lagging behind the master vehicle. The slave vehicle's PLC will increase the target speed so that the slave vehicle can accelerate appropriately to catch up. This indicates that the slave vehicle is ahead of the master vehicle. The slave vehicle PLC will reduce the target speed to make the slave vehicle slow down and wait. In the subsequent control cycle, the master vehicle PLC continues to receive feedback from the slave vehicle and repeats the comparison to make the position deviation gradually converge. When the position deviation recovers to within ±10mm, the slave vehicle PLC restores the original target speed setting value.

[0045] In one embodiment, such as Figure 6 As shown, step S40 specifically includes the following steps: S41: After speed compensation is completed, when the proximity switch detects a metal block on the track, calculate the positioning deviation between the master car and the slave car. S42: When the positioning deviation exceeds the positioning tolerance, write a jog command to the master PLC or slave PLC in micro-motion mode until the positioning deviation converges to the positioning tolerance range.

[0046] In this embodiment, after the master vehicle and slave vehicle complete speed compensation and enter the vicinity of the target position, the master vehicle PLC controls the travel speed to decrease to a low-speed approach state. Simultaneously, it sends synchronous deceleration or positioning preparation commands to the slave vehicle PLC via a wireless link, ensuring that the travel servo drives on both sides operate according to consistent deceleration logic. This avoids new relative deviations caused by premature stopping on one side or inertia differences when approaching the target parking space. When the positioning proximity switch installed at the bottom of the transporter enters the effective sensing range of the track metal contact block, the proximity switch outputs a switch signal indicating that the vehicle is in position. The PLC program captures the rising edge of this signal and uses it as the trigger condition for entering the coarse positioning area of ​​the target parking space. At this time, the master vehicle PLC first writes a zero-speed control command to the master vehicle travel servo drive, causing the master vehicle to decelerate and stop. Simultaneously, it sends a positioning stop command to the slave vehicle PLC via a wireless link, causing the slave vehicle PLC to synchronously decelerate and stop. Zero-speed control commands are written to the vehicle's servo drive. After both vehicles stop, the master vehicle PLC reads the current pulse count value of the encoder of the master vehicle's servo motor and compares it with the target pulse value pre-calibrated for the target parking position. The pulse difference is converted into the master vehicle's positioning deviation. Similarly, the slave vehicle PLC reads the current pulse count value of its own encoder and compares it with the target pulse value of the slave vehicle to obtain the slave vehicle's positioning deviation. Then, the slave vehicle PLC sends the slave vehicle's positioning deviation and its own positioning status back to the master vehicle PLC. The master vehicle PLC makes a unified judgment on the master vehicle's positioning deviation and the slave vehicle's positioning deviation. For example, the positioning tolerance can be ±3mm. When both the master vehicle's positioning deviation and the slave vehicle's positioning deviation are within ±3mm, the master vehicle PLC determines that both the master and slave vehicles have met the positioning accuracy requirements and reports the target position status to the host computer, allowing the vehicle to enter the clamping arm placement or wheel retrieval process.When the positioning deviation on either side exceeds ±3mm, the master vehicle PLC generates a micro-motion correction command based on the side with the deviation and the direction of deviation. If the master vehicle exceeds the positioning tolerance, the master vehicle PLC writes a jog command to its own travel servo driver. If the slave vehicle exceeds the positioning tolerance, the master vehicle PLC sends a corresponding jog command to the slave vehicle PLC via a wireless link, which is then written into the speed setting or jog control register of its own travel servo driver. The micro-motion mode uses a low-speed jog method. The jog speed, single jog duration, and jog stop conditions can be preset according to the transporter model, servo response time, positioning tolerance, and on-site calibration results. When the encoder feedback indicates that the vehicle body has passed the target position, a reverse micro-motion is executed. When the encoder feedback indicates that the target position has not yet been reached, a forward micro-motion is performed. After each micro-motion, the encoder feedback is reread, the positioning deviation is recalculated, and it is re-determined whether it falls within the positioning tolerance range to prevent repeated overshoots caused by an excessive micro-motion. During the correction process, the master vehicle PLC continues to monitor the slave vehicle status frame, proximity switch signal, servo status word, and communication status. If an emergency stop, servo alarm, wireless communication abnormality, or proximity switch status abnormality occurs during micro-motion, the micro-motion correction is immediately stopped and the fault is reported. The position correction is only confirmed to be complete when the positioning deviation on the out-of-tolerance side converges to within ±3mm after one or more micro-motions, and the other side remains within the positioning tolerance range.

[0047] In one embodiment, taking a vehicle storage operation as an example, the application of steps S10 to S40 above in the actual operation process of the transporter is explained. The host computer scheduling system issues a vehicle storage instruction, which includes the target parking space number and the target wheelbase value. After receiving the storage instruction, the master vehicle PLC controls the slave vehicle to move to the wheelbase position that matches the vehicle to be stored, thus completing the wheelbase adjustment. After the wheelbase adjustment is completed, the master vehicle PLC and the slave vehicle PLC confirm that both are in a ready state according to the walking pre-start interlock confirmation logic described in step S30. Then, they simultaneously start the master and slave vehicle walking servo drives to rotate forward, so that the transporter moves from the standby position into the bottom of the vehicle at a preset walking speed. During this process, the master vehicle PLC continuously reads the measurement value of the laser rangefinder to detect the current position of the transporter at the bottom of the vehicle. After the transporter reaches the predetermined area under the tire, the main vehicle PLC controls the travel servo drive to stop. The main vehicle PLC and the slave vehicle PLC then activate their respective ultrasonic sensors to scan and detect the positions of the front and rear tires. If a tire is detected within the preset detection range, the tire position data is recorded and the vehicle enters the wheel clamping stage. If no tire is detected, a tire detection fault is identified, an alarm is triggered, and the subsequent wheel clamping process is prohibited. After the tire position is confirmed, the main vehicle PLC and the slave vehicle PLC control their respective wheel clamping servo drives, causing the clamping arms to move in the sequence of opening, extending, and clamping to lift the tire off the ground. The clamping arm's final clamping position is confirmed by the corresponding proximity switch. After both front and rear tires are in position, the master vehicle PLC and slave vehicle PLC, according to the interlocking logic described in step S30, confirm that the clamping arms of both vehicles are in normal condition, and then simultaneously start the master and slave vehicle walking servo drives to rotate forward, so that the transporter carries the vehicle to the target parking space. During this loaded walking phase, the synchronous control logic described in step S30, in which the master vehicle PLC reads the first walking position, the slave vehicle PLC reads the second walking position, and the master vehicle PLC calculates the speed compensation amount based on the first and second walking positions and sends it to the slave vehicle PLC to execute the speed compensation, runs continuously throughout the entire process to ensure that the master and slave vehicles move synchronously under loaded conditions. During the walking process, the chassis collision switch is in real-time monitoring mode. If an obstacle height is detected to exceed the preset safety distance, an emergency stop is immediately triggered. When the transporter approaches the target parking space, the master vehicle PLC triggers a deceleration command based on the real-time reading of the laser rangefinder sensor, and synchronously sends it to the slave vehicle PLC according to the logic described in step S40. At the same time, the diffuse reflection photoelectric switch installed on the forward direction side of the transporter emits a detection beam towards the target parking space. If a diffuse reflection light signal is received, it indicates that the parking space has been occupied. The master vehicle PLC immediately triggers an anti-stacking alarm and stops the travel servo drive. If no reflection signal is received, it indicates that the parking space is empty, and the stop process continues.After the transporter reaches the target parking space at low speed, according to the logic described in step S40, once the proximity switch detects the metal contact block on the track, the positioning deviation between the master and slave vehicles is calculated. If the positioning deviation exceeds the positioning tolerance, position correction is performed in micro-motion mode until the positioning deviations on both sides converge within the positioning tolerance range. After positioning is completed, the master and slave PLCs control their respective wheel servo drives to reverse, causing the clamping arms to open outward and release the tires to the ground. Subsequently, the clamping arms retract inward to the closed state, completing the release of the vehicle. After the vehicle is released, the master PLC controls the master and slave vehicle travel servo drives to simultaneously reverse and start according to the synchronous control method described in steps S10 to S40, causing the transporter to return to the initial origin position along the original travel path. Upon reaching the origin, the origin proximity switch detects the origin metal contact block, the transporter stops, and the master PLC reports the standby status to the host computer, completing a single vehicle storage operation cycle.

[0048] In another embodiment, the vehicle retrieval process corresponds to the basic steps of the above-described vehicle storage process, with the main difference being the reverse direction of operation and the different execution order of some stages. At the start of retrieval, the transporter departs from its origin position unloaded and travels to the target parking space according to the synchronous control method described in steps S10 to S40. Upon reaching the target parking space, a diffuse reflection photoelectric switch performs anti-stacking detection to confirm that a vehicle is indeed in the space. Then, the transporter controls the movement of the slave vehicle to complete wheelbase adjustment to match the vehicle. Subsequently, the clamping arm opens and clamps, lifting the vehicle. After lifting the vehicle, the transporter travels under load according to the synchronous control logic described in step S30, transporting the vehicle to the garage entrance / exit. After placing the vehicle down, the transporter returns to its origin unloaded according to the synchronous control method described in steps S10 to S40 and reports its standby status to the host computer. The entire vehicle retrieval process also utilizes the master-slave wireless synchronous control method described in steps S10 to S40 of this invention, as well as the automatic master-slave vehicle spacing adjustment method and various safety detection mechanisms.

[0049] In one embodiment, if the master vehicle PLC or slave vehicle PLC does not receive a data frame within N consecutive control cycles, the corresponding enable signal is blocked, causing the brake coil to lose power and the brake pads to mechanically lock the motor shaft under the action of spring force.

[0050] In this embodiment, after entering wireless synchronous control, the master vehicle PLC and slave vehicle PLC establish independent communication monitoring counters respectively, and use each fixed control cycle as a detection cycle. The control cycle can be set to no more than 30ms, and the number of consecutive times N that no data frame is received can be preset to 3 to 5. During normal travel, deceleration positioning, or micro-motion correction, the master vehicle PLC waits for the slave vehicle PLC to send back status data frames in each control cycle, and the slave vehicle PLC also waits for the master vehicle PLC to send or refresh synchronous control data frames. As long as the received data frame passes the frame header, device identifier, synchronization sequence number, check field, and status word verification, the local communication monitoring counter is cleared to zero, and the travel servo drive continues to be enabled. If no valid data frame is received in a certain control cycle, or if the received data frame has verification errors, discontinuous sequence numbers, abnormal status fields, etc., it is not considered a valid communication, and the local communication monitoring counter is cleared. The communication monitoring counter increments by one and maintains the current safe transition state of motion control to prevent occasional wireless jitter from immediately triggering an emergency stop and causing mechanical shock. When the master vehicle PLC does not receive a valid data frame from the slave vehicle PLC for N consecutive control cycles, the master vehicle PLC determines that the internal wireless link between the master and slave vehicles has lost the synchronization control condition. It immediately blocks the enable output of the master vehicle's travel servo drive, freezes the current transport task status, and writes a communication fault code to the host computer. If the wireless link can still transmit unidirectionally, it synchronously issues a stop or disable command. If it can no longer transmit, the master vehicle will still independently complete the machine's safety braking. Similarly, when the slave vehicle PLC does not receive a valid synchronization data frame or control refresh frame from the master vehicle PLC for N consecutive control cycles, the slave vehicle PLC does not wait for further instructions from the master vehicle but autonomously blocks the enable signal of the slave vehicle's travel servo drive, so that the slave vehicle no longer executes the speed setpoint or jog command left over from the previous cycle. After the enable signal is blocked, the travel servo driver stops outputting to the motor to maintain operation, and the brake coil related to the motor brake is de-energized. Since the brake adopts the safety logic of energized release and de-energized braking, after the coil is de-energized, the brake pads are pressed and mechanically locked by the spring force, so that the corresponding vehicle can complete the parking protection without relying on the command of the other side when the communication is abnormal.

[0051] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0052] In one embodiment, a master-slave motion synchronization control device for a wireless ultra-thin transporter is provided, which corresponds one-to-one with the master-slave motion synchronization control method for a wireless ultra-thin transporter described in the above embodiments. For example... Figure 7 As shown, the master-slave walking motion synchronization control device for the wireless ultra-thin transporter includes: The verification module 701 is used for the master vehicle PLC to send a status query frame to the slave vehicle PLC via a wireless link. The slave vehicle PLC sends the status feedback frame back to the master vehicle PLC for verification. After the verification is passed, the system is ready flag is set. Synchronization module 702 is used to encapsulate the transport instructions issued by the host computer into a synchronization instruction frame and send it to the slave PLC through the master PLC when the system is ready. The slave PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame. The speed compensation module 703 is used by the master vehicle PLC and the slave vehicle PLC to complete the pre-start interlock confirmation of the travel based on the received confirmation frame and to synchronously start the travel control of the master vehicle and the slave vehicle. The master vehicle PLC calculates the speed compensation amount and executes the speed compensation. The position correction module 704 is used to calculate the positioning deviation between the master car and the slave car after the speed compensation is completed and the proximity switch detects the metal block on the track, and to correct the position of the master car and the slave car according to the positioning deviation.

[0053] Figure 8 This diagram illustrates the layout of the master and slave vehicles in a wireless ultra-thin transporter device. The master vehicle is on the left, and the slave vehicle is on the right. The two vehicles are mechanically and electrically independent, with no physical cables or mechanical connections between them. The master vehicle has front wheel clamping arms 1 and 2, located at the front and rear of the vehicle body respectively, for clamping the vehicle's front wheels. The slave vehicle has rear wheel clamping arms 1 and 2, located at the front and rear of the vehicle body respectively, for clamping the vehicle's rear wheels. Each vehicle has two drive wheels inside, responsible for driving its independent movement. The distance between the master and slave vehicles (i.e., the wheelbase) can be detected in real-time by a laser rangefinder and continuously and automatically adjusted via wireless communication to control the slave vehicle's motor.

[0054] Figure 9This is the schematic diagram of the main electrical circuit of the transporter, including a 48V lithium battery pack (BMS). Its positive (48V+) and negative (48V-) terminals are led out through the BMS's charging and discharging management interface and connected to the main power supply bus (201 / 101) via a 50A DC circuit breaker (Q0). The main power supply bus distributes power to downstream electrical equipment after passing through the main contacts of a 40A DC contactor (-KM0). The coil control circuit of contactor-KM0 contains normally closed contacts of an emergency stop button (-SQ1) and a limit switch (-SQ2), as well as the contactor-KM0's own self-locking auxiliary contacts, forming an emergency stop and power-off self-locking protection circuit: when any emergency stop button is pressed or a limit switch is activated, the contactor coil is de-energized, the main contacts open, cutting off the power supply circuit to all servo drives. Simultaneously, the iSMK power-off brake built into the servo motor mechanically locks the motor shaft under spring force, achieving power-off self-locking protection. The step-down module (-K1) converts the 48V DC bus voltage to 24V DC (24V+ / 24V-), providing power to 24V control circuit devices such as PLCs, sensors, and indicator lights.

[0055] Figure 10 This diagram illustrates the electrical control circuit and network topology of the transporter, including all controllers, communication devices, and drive devices in the 24V control power supply circuit of the main vehicle. The 24V+ / 24V- lines are the control power bus, supplied by a step-down module. The PLC acts as the main controller, connected to a router via an Ethernet interface. The router handles wireless data communication between the main vehicle and the host computer scheduling system. The PLC also connects to a wireless bridge via an Ethernet interface. The wireless bridge provides a dedicated point-to-point wireless communication link between the main vehicle PLC and the slave vehicle PLC, carrying travel synchronization control data frames, status exchange data frames, and fault alarm data frames, with a transmission delay not exceeding 30ms. Distance sensors connect to the PLC via corresponding interfaces, providing real-time feedback on the distance between the main and slave vehicles and the current position of the transporter. On the right side of the diagram, the servo motors of the forearm and rear arm are connected via terminal blocks. The servo motors are connected to their respective servo drivers via their motor I / O lines. The servo drivers communicate with the PLC in real time via the CAN bus, receive speed and position control commands from the PLC, and feed back data such as motor encoder pulse count, actual speed, and driver status word to the PLC, forming a closed-loop control circuit for the walking motion and the wheel-holding motion.

[0056] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0057] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0058] This application also provides a computer device, such as... Figure 11 As shown, the computer device includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor. When the processor executes the computer program, it implements the steps in any of the above method embodiments, or when the processor executes the computer program, it implements the functions of each module / unit in the above device embodiments.

[0059] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the computer device.

[0060] Those skilled in the art will understand that Figure 11 The computer device described is merely an example and does not constitute a limitation on the computer device. It may include more or fewer components than shown, or combine certain components, or different components. For example, the computer device may also include input / output devices, network access devices, buses, etc.

[0061] The aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0062] The memory can be an internal storage unit of the computer device, such as a hard drive or RAM. The memory can also be an external storage device of the computer device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory can include both internal and external storage units of the computer device.

[0063] This application also provides a readable storage medium storing a computer program, which, when executed by a processor, can implement the steps in the above-described method embodiments.

[0064] This application provides a computer program product that, when run on an electronic device, enables the electronic device to implement the steps described in the various method embodiments above.

[0065] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a photographing device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0066] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0067] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0068] In the embodiments provided in this application, it should be understood that the disclosed apparatus / devices and methods can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0069] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0070] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for synchronous control of master-slave walking motion of a wireless ultra-thin transporter, characterized in that, include: The master vehicle PLC sends a status query frame to the slave vehicle PLC via a wireless link. The slave vehicle PLC sends a status feedback frame back to the master vehicle PLC for verification. After successful verification, a system ready flag is set. Specifically, this includes: establishing a wireless link between the master and slave vehicles; the master vehicle PLC sending a status query frame to the slave vehicle PLC via the wireless link; the slave vehicle PLC receiving the status query frame, reading the first status word of each servo driver and the first state of charge of the battery management system on the slave side, and obtaining slave-side self-test data; and the master vehicle PLC reading the second status word of each servo driver and the battery... The system manages the second charge state and obtains the self-test data from the master vehicle side; the slave vehicle PLC encapsulates the slave vehicle side self-test data into a status return frame and transmits the status return frame back to the master vehicle PLC through the wireless link; the master vehicle PLC verifies the first status word and the first charge state in the status return frame, as well as the second status word and the second charge state of the master vehicle side self-test data; when both the first status word and the second status word conform to the normal state, and both the first charge state and the second charge state are higher than the operating threshold, the verification is confirmed to be successful and the system ready flag is set; When the system is ready, the master vehicle PLC encapsulates the transport instructions issued by the host computer into a synchronization instruction frame and sends it to the slave vehicle PLC. The slave vehicle PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame. The master vehicle PLC and the slave vehicle PLC complete the pre-start interlock confirmation of travel based on the received confirmation frame and synchronously start controlling the master vehicle and the slave vehicle to travel. The master vehicle PLC calculates the speed compensation amount and performs speed compensation. Specifically, the process includes: the master vehicle PLC sends a pre-start request frame to the slave vehicle PLC based on the received confirmation frame; the slave vehicle PLC sends back a pre-start ready frame; after receiving the pre-start ready frame, the master vehicle PLC and the slave vehicle PLC complete the pre-start interlock confirmation of travel within the same control cycle; synchronously start controlling the master vehicle and the slave vehicle to travel; the master vehicle PLC reads the first travel position of the master vehicle, and the slave vehicle PLC reads the second travel position of the slave vehicle; the master vehicle PLC calculates the position deviation based on the first travel position and the second travel position; calculates the speed compensation amount based on the position deviation; and the slave vehicle PLC adds the target speed and the speed compensation amount and writes it into the corresponding speed setting register to perform speed compensation. After speed compensation is completed, when the proximity switch detects a metal block on the track, the positioning deviation between the master vehicle and the slave vehicle is calculated, and the positions of the master vehicle and the slave vehicle are corrected according to the positioning deviation.

2. The master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in claim 1, characterized in that, When the system is ready, the master vehicle PLC encapsulates the transport instructions issued by the host computer into a synchronization instruction frame and sends it to the slave vehicle PLC. The slave vehicle PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame, including: When the system is ready, the main vehicle PLC receives the transport instruction from the host computer. The main vehicle PLC performs a legality check on the transport command; The legality verification of the handling instruction, the master vehicle timestamp of the master vehicle PLC and the synchronization sequence number are encapsulated into a synchronization instruction frame, and the synchronization instruction frame is sent to the slave vehicle PLC. After the slave PLC writes the synchronization instruction frame into its local register, it replies with a reception confirmation frame.

3. The master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in claim 2, characterized in that, The slave PLC encapsulates the received confirmation frame with an additional slave timestamp, and transmits the received confirmation frame back to the master PLC via the wireless link; The master vehicle PLC calculates the difference between the slave vehicle timestamp in the received confirmation frame and the master vehicle timestamp when the synchronization command frame was sent to obtain the link transmission delay. If the link transmission delay exceeds the transmission delay threshold, a communication fault code is reported to the host computer.

4. The master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in claim 1, characterized in that, After speed compensation is completed, when the proximity switch detects a metal contact block on the track, the positioning deviation between the master vehicle and the slave vehicle is calculated, and the positions of the master vehicle and the slave vehicle are corrected according to the positioning deviation, including: After speed compensation is completed, when the proximity switch detects a metal block on the track, the positioning deviation between the master vehicle and the slave vehicle is calculated. When the positioning deviation exceeds the positioning tolerance, a jog command is written to the master vehicle PLC or the slave vehicle PLC in micro-motion mode until the positioning deviation converges to the positioning tolerance range.

5. The master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in claim 4, characterized in that, If the master vehicle PLC or the slave vehicle PLC does not receive a data frame within N consecutive control cycles, the corresponding enable signal is blocked, causing the brake coil to lose power and the brake pads to mechanically lock the motor shaft under the action of spring force.

6. A wireless ultra-thin transporter master-slave walking motion synchronization control device, characterized in that, The steps for implementing the master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in any one of claims 1 to 5 include: The verification module is used for the master vehicle PLC to send a status query frame to the slave vehicle PLC via a wireless link. The slave vehicle PLC sends the status feedback frame back to the master vehicle PLC for verification. After the verification is passed, the system is ready. The synchronization module is used to encapsulate the transport instructions issued by the host computer into a synchronization instruction frame and send it to the slave PLC through the master PLC when the system is ready. The slave PLC writes the synchronization instruction frame into its local register and replies with a reception confirmation frame. The speed compensation module is used by the master vehicle PLC and the slave vehicle PLC to complete the pre-start interlock confirmation of the journey based on the received confirmation frame and synchronously start the movement of the master vehicle and the slave vehicle. The master vehicle PLC calculates the speed compensation amount and performs speed compensation. The position correction module is used to calculate the positioning deviation between the master vehicle and the slave vehicle after the speed compensation is completed and the proximity switch detects a metal block on the track, and to correct the position of the master vehicle and the slave vehicle according to the positioning deviation.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in any one of claims 1 to 5.

8. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in any one of claims 1 to 5.

9. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the steps of the master-slave walking motion synchronization control method for the wireless ultra-thin transporter as described in any one of claims 1 to 5.

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