Split type AGV control method based on 2.4 GHz wireless communication

Abstract

The invention relates to the technical field of AGVs, in particular to a split type AGV control method based on 2.4 GHz wireless communication, which comprises the following steps: a communication pairing step: configuring an AGV pairing strategy, scheduling a master device and a slave device by an RCS to perform master-slave pairing, and establishing 2.4 GHz wireless connection; a period synchronization step: configuring a time synchronization strategy, transmitting time synchronization information between the master device and the slave device, and keeping time synchronization within a preset time difference range; a motion decomposition step: configuring a differential decomposition strategy, and after the master device receives the RCS motion instruction, decomposing the linear velocity and course angle of the master device and the slave device to generate motion control parameters; an instruction synchronization step: configuring an instruction transmission strategy with a timestamp, and issuing the timestamp of the motion control parameter marking execution moment to the slave device by the master device and executing the timestamp; and a state monitoring step: configuring a real-time state feedback strategy, and uploading a real-time motion control parameter by the slave device according to a fixed frequency. The method has the effects of reducing the delay of multi-AGV cooperative carrying and improving the control precision and stability.

Description

Technical Field

[0001] This application relates to the field of AGV (Automated Guided Vehicle) technology, and in particular to a split-type AGV control method based on 2.4GHz wireless communication. Background Technology

[0002] AGVs are handling equipment in the field of automated material handling, and are widely used in industrial production, logistics and warehousing and other scenarios. As the handling needs expand to large vehicles and heavy goods, the load capacity and operating range of a single AGV can no longer meet the actual needs. Multiple AGVs need to work together to complete the automated handling of heavy goods.

[0003] In related technologies, multi-AGV collaborative handling operations achieve synchronous control during AGV handling by directly issuing tasks and execution times to each controlled AGV through an upstream and downstream scheduling system. This solution relies on a WIFI wireless network for data transmission. However, WIFI wireless networks require multiple steps during transmission, including protocol stack physical layer, MAC layer processing, and AP forwarding. Theoretically, this results in a delay of 2 to 7 milliseconds. Furthermore, interference from co-channel interference and equipment roaming can amplify the delay fluctuation to 50 to 500 milliseconds, and communication jitter will also increase. In the absence of effective delay adjustment technology, the control delay far exceeds the AGV's delay time control cycle.

[0004] Regarding the aforementioned technologies, when collaborative AGVs receive scheduling instructions, the delay fluctuations caused by the transmission through multiple processing stages result in a longer response cycle for the AGVs. This affects the control synchronization of multiple AGVs, leading to poor handling control accuracy and stability, which is detrimental to improving the efficiency and safety of automated handling operations. Summary of the Invention

[0005] To reduce the delay in multi-AGV collaborative handling, improve control accuracy and stability, and promote automated handling efficiency, this application provides a split-type AGV control method based on 2.4GHz wireless communication.

[0006] Firstly, this application provides a control method for a split-type AGV based on 2.4GHz wireless communication: A control method for a split-type AGV based on 2.4GHz wireless communication includes: The communication pairing process involves configuring an AGV pairing strategy. The control system RCS schedules the movement of the master and slave devices of the split AGVs to perform master-slave pairing. After establishing a 2.4GHz wireless communication module connection, the slave device's command reception to the control system RCS is disabled. The periodic synchronization step is configured with a time synchronization strategy. The master device and the slave device transmit time synchronization information through 2.4GHz wireless communication to keep the time difference between the master device and the slave device within the preset time difference range. The motion decomposition step is configured with a differential decomposition strategy. After receiving the motion command from the control system RCS, the master device decomposes the chassis linear velocity and heading angle into its own linear velocity and heading angle and the heading angle of the slave device based on the kinematic model to generate motion control parameters. The instruction synchronization step is configured with a timestamped instruction transmission strategy. The master device sends the timestamp of the decomposed motion control parameters to the slave device, and the master device and slave device perform motion control according to the timestamp and motion control parameters. The status monitoring step is configured with a real-time status feedback strategy, which transmits real-time motion control parameters from the device via 2.4GHz wireless communication at a fixed frequency.

[0007] By adopting the above technical solution, the five steps of communication pairing, cycle synchronization, motion decomposition, command synchronization, and status monitoring work together. With the collaborative work of AGV pairing strategy, time synchronization strategy, differential speed decomposition strategy, timestamped command transmission strategy, and real-time status feedback strategy, it is helpful to achieve rapid pairing of split AGV master and slave devices, high-precision time synchronization, accurate motion parameter decomposition and synchronous execution, and real-time monitoring of equipment operating status. This effectively solves the problems of cumbersome pairing, large time synchronization deviation, asynchronous command execution, and lagging status feedback in traditional split AGV collaborative control. It is less likely to cause collaborative failure due to unstable wireless communication, and improves the synchronization and reliability of multi-vehicle joint control of AGVs.

[0008] Optionally, the AGV pairing strategy includes: The control system RCS sends the address codes of the master and slave devices to each other, and controls the master and slave devices to send wireless communication pairing requests to each other for matching based on the received address codes; After receiving a pairing request from the device, the device will send a matching success command when the address code sent by the control system RCS matches the request address code sent by the master device. Based on the successful matching command, the communication connection between the slave device and the control system RCS is closed, and the slave device is kept to only respond to commands issued by the master device via 2.4GHz wireless communication; When the handling task is completed, a release command is triggered to disconnect the communication connection between the control system RCS and the master device, as well as between the slave device and the master device.

[0009] By adopting the above technical solution, the control system RCS first completes the master-slave device address code exchange, and then achieves accurate pairing through address code verification. After successful pairing, the direct communication between the slave device and RCS is closed, and only the 2.4GHz wireless communication link with the master device is retained. After the task is completed, orderly unpairing is triggered, which helps to ensure the accuracy and uniqueness of master-slave device pairing, avoids control chaos caused by pairing errors or command conflicts. At the same time, the pairing unpairing process is conducive to the device quickly returning to independent operation after the handling task is completed, improving the system's flexibility and reusability, reducing the interference of invalid communication links on collaborative control, and further ensuring the stability and timeliness of command transmission.

[0010] Optionally, the time synchronization strategy includes: Time synchronization data is generated based on the time reference of the master device, and the time synchronization data is transmitted to the slave device via 2.4GHz wireless communication for time reference calibration. Time synchronization adjustment is triggered when the time deviation exceeds the preset reference deviation. Time synchronization data is continuously transmitted according to a preset synchronization period to keep the transmission jitter duration of wireless communication within the set allowable jitter duration range.

[0011] By adopting the above technical solution, using the master device's time reference as a standard, time synchronization data is transmitted via 2.4GHz wireless communication to calibrate the slave device's time. Simultaneously, continuous synchronization at a preset cycle helps control the time difference between the master and slave devices within a preset range, solving the problems of low time synchronization accuracy and easy drift in traditional collaborative control. At the same time, the continuous synchronization mechanism can effectively suppress the transmission jitter of wireless communication, ensuring that the jitter duration is within the allowable range, providing a time reference guarantee for the synchronous execution of timestamped instructions, improving the consistency and accuracy of AGV motion control, and avoiding the deviation of the transport trajectory caused by time deviation.

[0012] Optionally, the periodic synchronization step is further configured with a dynamic channel selection strategy to reduce delay fluctuations caused by co-channel interference, including: Multiple initial channel parameters of the 2.4GHz wireless communication module are obtained in advance, including signal-to-noise ratio, packet loss rate, and co-channel interference intensity; The channel quality index of each channel is calculated using a pre-defined channel quality assessment model, and the optimal channel is determined by ranking the channels according to their channel quality indices. The channel quality index is recalculated based on a preset communication interval period, and the optimal channel is dynamically selected for communication transmission.

[0013] By adopting the above technical solution, initial parameters such as signal-to-noise ratio, packet loss rate, and co-channel interference intensity of each channel of the 2.4GHz wireless communication module are obtained in advance. The channel quality index is calculated using the channel quality assessment model, and the optimal channel is selected. The assessment results are dynamically updated and the channel is switched at preset intervals. This helps to avoid channels with severe co-channel interference and poor communication quality in real time. It solves the problems of large delay fluctuations and unstable transmission caused by co-channel interference in traditional fixed channel communication. It ensures that the AGV master and slave devices always communicate on the optimal channel, reduces the impact of interference on time synchronization and command transmission, and improves the stability of communication delay.

[0014] Optionally, the channel quality assessment model is calculated using the following formula: ; in, This represents the channel quality index for channel i. , , , These are preset weighting coefficients for signal-to-noise ratio, packet loss rate, master-slave device distance, and the impact of warehouse obstruction. This refers to the real-time channel signal-to-noise ratio. For real-time channel packet loss rate, To adapt to the distance attenuation factor during collaborative handling by master and slave AGVs, the distance change value between the master and slave devices is detected and matched to determine the factor. The signal blocking coefficient caused by warehouse racks, columns, and other carriers is determined by matching the detection of obstructions.

[0015] By adopting the above technical solution, the channel quality assessment model integrates four core parameters: signal-to-noise ratio, packet loss rate, master-slave device distance attenuation factor, and warehouse obstruction coefficient. It also balances the impact of each factor on channel quality through preset weighting coefficients. This helps to accurately quantify the actual channel quality in AGV handling scenarios, solving the problem of inaccurate assessments caused by traditional channel quality assessment models that do not consider dynamic changes in AGV master-slave distance and warehouse environment obstruction. Simultaneously, the model's calculation logic is simple and can quickly adapt to dynamic scenarios such as distance fluctuations and obstruction changes in the warehouse environment, providing accurate basis for dynamic channel selection, further reducing latency fluctuations caused by interference, and ensuring the stability and reliability of the communication link.

[0016] Optionally, an adaptive power adjustment strategy is also configured to shorten communication latency by precisely adjusting the transmit power to balance signal stability and interference suppression, including: Based on the master-slave device spacing and the current channel quality index, the optimal transmit power is determined by calculation using a preset power optimization model. The trigger state is determined by comparing the real-time communication link signal strength collected by the main device with the preset link reference signal strength. Based on the trigger state, the transmission power is dynamically increased or decreased according to the optimal transmission power to keep the single communication delay of the channel within the set minimum delay threshold.

[0017] By adopting the above technical solution, the optimal transmission power is calculated based on the master-slave device spacing and the current channel quality index. Then, the transmission power is dynamically adjusted by combining the comparison results of the real-time communication link signal reception strength and the benchmark value. This helps to balance signal transmission stability and environmental interference suppression, and solves the contradiction that excessive power leads to increased co-channel interference and insufficient power leads to signal attenuation and delay in the traditional fixed transmission power mode. At the same time, dynamic power adjustment can ensure that the single communication delay of the channel is within the set minimum delay threshold, avoid the increase in transmission delay caused by signal attenuation or interference, improve the real-time performance and reliability of wireless communication, and provide stable communication support for AGV collaborative control.

[0018] Optionally, the power optimization model is calculated using the following formula: ; in, This is the minimum transmit power for the 2.4GHz module. This represents the maximum transmit power of the 2.4GHz module. This is the preset signal transmission power adjustment coefficient. This refers to the real-time distance between the master and slave devices obtained through UWB positioning. The maximum effective distance for collaborative operation set for AGVs.

[0019] By adopting the above technical solution, the power optimization model integrates parameters such as the minimum / maximum transmit power of the 2.4GHz module, channel quality index, real-time distance between master and slave devices, and maximum effective distance for collaborative operation, and accurately calculates the optimal transmit power under different operating conditions. This helps to achieve nonlinear adaptive adjustment of transmit power and solves the problems of poor adaptability and easy signal fluctuation caused by traditional linear power adjustment.

[0020] Optionally, a pairing release step is also included, configured with a safe release strategy, including: after the handling task is completed, RCS sends a pairing release command to the master device; after the master device detects that both itself and the slave device are in a stationary state, it sends a pairing release request to the slave device via 2.4GHz wireless communication. After receiving a request from the device, it disconnects from the master device, resumes independent operation, and reports the disconnection result to the master device via 2.4GHz wireless communication. After receiving the release result from the slave device, the master device resumes independent operation and reports the pairing release completion information to the control system RCS. The RCS (Regulatory Control System) is instructed to disconnect the pairing association between the master and slave devices on the system side.

[0021] By adopting the above technical solutions, it is helpful to ensure the safety and orderliness of the pairing and unpairing process, and avoid safety hazards such as vehicle falling and equipment collision caused by mispairing and unpairing while the equipment is in motion. At the same time, after unpairing, both master and slave devices resume independent operation and can be quickly put into the next round of tasks, improving equipment utilization. In addition, the status is updated synchronously on the RCS system side to ensure the accuracy of subsequent scheduling instructions and improve the operational efficiency and safety of the entire AGV system.

[0022] Optionally, the differential decomposition strategy includes: Based on the relatively stationary spatial relationship between the master device and the slave device, the linear velocity and common heading angle of the master device and the slave device are calculated using a preset kinematic model, and the command synchronization step is triggered. When the local time of the master device and the slave device reaches the timestamp, parameter conversion and drive command issuance are performed synchronously.

[0023] By adopting the above technical solution, based on the relatively static spatial relationship between the master and slave devices, the linear velocity and common heading angle of the master and slave devices are accurately calculated using a preset kinematic model. Then, parameter conversion and drive command issuance are executed synchronously according to timestamps. This helps to solve the problems of inaccurate parameter calculation and asynchronous command execution in traditional motion decomposition strategies. At the same time, the combination of motion decomposition and timestamp synchronous execution ensures that the master and slave devices execute the corresponding motion commands at the same time, avoiding problems such as unstable handling and vehicle tilting caused by motion parameter deviations or execution time differences. This improves the stability and accuracy of collaborative handling of split AGVs and is suitable for the handling needs of large and high-precision goods.

[0024] Optionally, the status monitoring step is further configured with a two-way security strategy, including: After receiving the linear speed and heading angle reported by the slave device, the master device compares them with the preset expected values. When the deviation exceeds the set safety threshold, it immediately sends a deceleration and stop command to the slave device via 2.4GHz wireless communication. If the device receives a timeout threshold from a preset instruction, and no control instruction is received from the master device after the timeout threshold is exceeded, the device will automatically decelerate to a stop at a preset acceleration. The master device has a preset feedback reception timeout threshold. If the slave device does not receive status report data after the timeout threshold is exceeded, it will automatically decelerate to a stop according to the preset acceleration.

[0025] By adopting the above technical solution, based on the relatively static spatial relationship between the master and slave devices, the linear velocity and common heading angle of the master and slave devices are accurately calculated using a preset kinematic model. Then, parameter conversion and drive command issuance are executed synchronously according to timestamps. This helps to solve the problems of inaccurate parameter calculation and asynchronous command execution in traditional motion decomposition strategies. At the same time, the combination of motion decomposition and timestamp synchronous execution ensures that the master and slave devices execute the corresponding motion commands at the same time, avoiding problems such as unstable handling and vehicle tilting caused by motion parameter deviations or execution time differences. This improves the stability and accuracy of collaborative handling of split AGVs and is suitable for the handling needs of large and high-precision goods.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The five steps of communication pairing, cycle synchronization, motion decomposition, instruction synchronization, and status monitoring work together. With the collaborative efforts of AGV pairing strategy, time synchronization strategy, differential speed decomposition strategy, timestamped instruction transmission strategy, and real-time status feedback strategy, it helps to achieve rapid pairing of split AGV master and slave devices, high-precision time synchronization, accurate motion parameter decomposition, and synchronous execution. At the same time, after establishing a 2.4G wireless communication connection, multiple AGV slave devices only retain one-way communication with the master device. Compared with the scheduling system and multiple slave devices, which need to issue tasks and transmit communication, it reduces frequent forwarding links. It does not need to go through multiple protocol stacks, which reduces delays and interferences such as device roaming and communication jitter. It is more conducive to improving the control synchronization and response speed of multiple AGVs and improving handling efficiency. 2. Using the master device's time reference, time synchronization data is transmitted via 2.4GHz wireless communication to calibrate the slave device's time. Simultaneously, continuous synchronization is performed according to a preset cycle, which helps to control the time difference between the master and slave devices within a preset range. This solves the problems of low time synchronization accuracy and easy drift in traditional collaborative control. At the same time, the continuous synchronization mechanism can effectively suppress the transmission jitter of wireless communication and ensure that the jitter duration is within the allowable range. 3. Pre-acquire initial parameters such as signal-to-noise ratio, packet loss rate, and co-channel interference intensity of each channel of the 2.4GHz wireless communication module. Calculate the channel quality index using a channel quality assessment model and select the optimal channel. Dynamically update the assessment results and switch channels at preset intervals. This helps to avoid channels with severe co-channel interference and poor communication quality in real time, solving problems such as large delay fluctuations and unstable transmission caused by co-channel interference in traditional fixed-channel communication. This ensures that the AGV master and slave devices always communicate on the optimal channel, reducing the impact of interference on time synchronization and command transmission, and improving the stability of communication delay. Attached Figure Description

[0027] Figure 1 This is a flowchart of steps S100 to S500 in this application.

[0028] Figure 2 This is a flowchart of steps S101 to S104 in this application.

[0029] Figure 3 This is a flowchart of steps S201 to S202 in this application.

[0030] Figure 4 This is a flowchart of steps S203 to S205 in this application.

[0031] Figure 5 This is a flowchart of steps S206 to S208 in this application.

[0032] Figure 6 This is a flowchart of steps S601 to S604 in this application.

[0033] Figure 7 This is a flowchart of steps S301 to S302 in this application.

[0034] Figure 8 This is a flowchart of steps S501 to S503 in this application. Detailed Implementation

[0035] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figure 1-8 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0036] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0037] This application discloses a split-type AGV control method based on 2.4GHz wireless communication. By leveraging the collaborative work of AGV pairing strategies, time synchronization strategies, differential speed decomposition strategies, timestamped instruction transmission strategies, and real-time status feedback strategies, it helps to achieve rapid pairing of split-type AGV master and slave devices, high-precision time synchronization, accurate motion parameter decomposition, and synchronous execution. Furthermore, after establishing a 2.4G wireless communication connection, multiple slave devices only retain unidirectional communication with the master device. Compared to the scheduling system distributing tasks and transmitting communication data between multiple slave devices, this reduces frequent forwarding steps and eliminates the need for multiple protocol stacks, reducing delays and interference from device roaming and communication jitter. This is more conducive to improving the control synchronization and response speed of multiple AGVs, thereby increasing handling efficiency.

[0038] Reference Figure 1 The method flow of the split-type AGV control method based on 2.4GHz wireless communication includes the following steps: Step S100: Communication pairing step. An AGV pairing strategy is configured. The control system RCS schedules the movement of the master and slave devices of the split AGV to perform master-slave pairing. After establishing a 2.4GHz wireless communication module connection, the slave device's command reception to the control system RCS is turned off. The Robot Control System (RCS) is the central scheduling and control core of the AGV system. It is responsible for macro-management functions such as task allocation, equipment scheduling, and status monitoring. It is the command center for the collaborative operation of the master and slave devices of the split AGV.

[0039] Split-type AGV main equipment: refers to AGV equipment that undertakes core functions such as motion command decomposition, slave equipment control, and status summary in collaborative operations. It has independent movement capabilities and can cooperate with slave equipment to complete the transportation of large vehicles. In this embodiment, the main equipment model is D1, and the size is 1.2m×0.4m.

[0040] A split-type AGV slave device refers to an AGV device that receives instructions from the master device and cooperates with the master device to complete motion execution in collaborative operations. It also has independent motion capabilities and has the same structure as the master device. In this embodiment, the slave device model is D2, and its size is the same as the master device.

[0041] 2.4GHz wireless communication module: refers to circuit equipment that operates in the 2400M-2483MISM frequency band without application, supports automatic frequency scanning upon power-on and one-key automatic code pairing function, has 50 working channels, can realize short-range low-latency wireless communication, and is the core carrier for data transmission between master and slave devices.

[0042] AGV pairing strategy: refers to the logical scheme used to achieve precise association between master and slave devices. The core is to ensure unique pairing of master and slave devices through processes such as address code verification and communication link establishment, so as to avoid command conflicts.

[0043] After receiving the warehousing and handling task, the control system RCS first identifies the size of the vehicle required for the task. In this embodiment, the pallet width is 1.2m, requiring one master device D1 and one slave device D2 to work together. Then, it queries the information of the AGV devices that are currently idle and issues movement scheduling instructions to D1 and D2 respectively, controlling them to move to the preset pairing area near the pallet. This area is unobstructed and has little interference, which facilitates the rapid establishment of communication connections.

[0044] Upon reaching the pairing area, RCS sends D2's unique address code to D1, and simultaneously sends D1's unique address code to D2. After receiving D2's address code, D1 sends a pairing request signal to D2 corresponding to the target address code via its onboard 2.4GHz wireless communication module. After receiving the pairing request, D2 compares the D1 address code carried in the request with the address code sent by RCS. If they match, D2 sends a successful pairing response back to D1.

[0045] After the master and slave devices establish a stable communication link through the 2.4GHz wireless communication module, D2 automatically closes the direct command receiving channel with RCS and only retains the communication link with D1 to ensure that subsequent responses are only to control commands issued by D1, thus avoiding interference from multiple command sources.

[0046] Step S200: Periodic synchronization step, configured with a time synchronization strategy, the master device and the slave device transmit time synchronization information through 2.4GHz wireless communication to keep the time difference between the master device and the slave device within a preset time difference range; Time synchronization information: refers to the data packet generated by the master device that contains its current system time, time base identifier, etc., and serves as the basis for the slave device to calibrate its time.

[0047] Preset time difference range: refers to the maximum time deviation threshold allowed by the master and slave devices in advance. In combination with the accuracy requirements of AGV collaborative control, this threshold is set to ≤10 microseconds in this embodiment.

[0048] After the master and slave devices complete pairing, they immediately initiate the first time synchronization: the master device generates a time synchronization information data packet based on its own high-precision clock module's time and sends it to the slave device via a 2.4GHz wireless communication module. Upon receiving the synchronization data packet, the slave device parses the master device's time reference, compares it to its own system time, and calculates the time deviation. If the deviation exceeds 10 microseconds, it automatically calibrates its own time to ensure consistency between the two systems; if the deviation is within the allowable range, it maintains its current time.

[0049] After the initial synchronization is completed, the system continues to execute the time synchronization process according to the preset synchronization cycle: the master device periodically generates and sends time synchronization information, and the slave device receives and calibrates the time in real time to ensure that the time deviation between the master and slave devices remains stable within 10 microseconds during long-term collaborative operation, thus avoiding asynchronous instruction execution due to time drift.

[0050] Step S300: Motion decomposition step, configured with differential decomposition strategy, after the master device receives the motion command from the control system RCS, it decomposes the chassis linear velocity and heading angle into its own and slave device's linear velocity and heading angle based on the kinematic model to generate motion control parameters; Kinematic model: refers to the mathematical model that describes the relationship between the motion state of an AGV and its control parameters. In this embodiment, a dual-wheel differential kinematic model is used to adapt to the motion characteristics of a split-type AGV.

[0051] Chassis linear speed refers to the overall linear motion speed of the AGV's carrying vehicle during collaborative operations, issued by the RCS based on the handling task requirements. Heading angle refers to the overall turning angle of the AGVs during collaborative operations, issued by the RCS based on path planning requirements. Motion control parameters refer to the individual linear speed and heading angle parameters of the master and slave devices, which are the direct basis for the equipment's drive motors to execute motion.

[0052] The main device D1 receives motion commands from the control system RCS, which include the target chassis linear velocity V and the target heading angle ω for collaborative operations.

[0053] After receiving the instruction, D1 calls the built-in dual-wheel differential kinematic model and, combined with the spatial position relationship between the master and slave devices (in this embodiment, the lateral distance between D1 and D2 is r=1.2m, and they are relatively stationary), performs motion parameter decomposition: based on the formula V=ω×r, where V is the linear velocity, ω is the angular velocity, and r is the lateral distance, the linear velocity V1 and heading angle ω1 of the master device D1, and the linear velocity V2 and heading angle ω2 of the slave device D2 are calculated.

[0054] After decomposition, a set of motion control parameters for each master and slave device is generated, which includes specific values ​​for linear velocity and heading angle, providing data support for subsequent synchronous command issuance.

[0055] Step S400: Command synchronization step, configured with a timestamped command transmission strategy, the master device sends the timestamp of the decomposed motion control parameters marked with the execution time to the slave device, and the master device and slave device perform motion control according to the timestamp and motion control parameters; A timestamp refers to the instruction execution time identifier generated by the master device based on its own time base, and is the core basis for synchronous execution between master and slave devices. Motion control parameters refer to the linear velocity and heading angle parameters of the master and slave devices generated in step S300, and are the core data for motion execution.

[0056] After generating the motion control parameters for both master and slave devices, master device D1 marks each set of parameters with a corresponding execution time timestamp Tn based on its own high-precision time base. Subsequently, D1 sends the slave device motion control parameters marked with timestamp Tn to slave device D2 via a 2.4GHz wireless communication module, while simultaneously storing its own motion control parameters locally.

[0057] After receiving the command data packet via the 2.4GHz wireless communication module, slave device D2 quickly parses the motion control parameters and timestamp Tn. Combined with its own calibrated system time, it monitors in real time whether the current time has reached Tn. When the local time of both master device D1 and slave device D2 reaches Tn, they synchronously convert the motion control parameters into motor speed and steering wheel angle signals, and send them to their respective servo drivers to drive the motors to move at the set linear speed and heading angle.

[0058] Step S500: Status monitoring step, configured with a real-time status feedback strategy, the device uploads real-time motion control parameters via 2.4GHz wireless communication at a fixed frequency.

[0059] Fixed frequency refers to the period at which status data is reported from the device. In this embodiment, it is set to 5-20 milliseconds, taking into account the AGV control cycle requirements. Real-time motion control parameters refer to status data such as linear velocity, heading angle, and motor speed during the actual operation of the device, serving as the basis for the master device to judge the effectiveness of coordinated execution.

[0060] Reference Figure 2 AGV pairing strategies include: Step S101: The control system RCS sends the address codes of the master device and the slave device to each other, and controls the master and slave devices to send wireless communication pairing requests to each other for matching based on the received address codes; The address code is a unique identifier for both the master and slave devices, used to distinguish different AGV devices and ensure the uniqueness and accuracy of pairing. In this embodiment, a 64-bit binary code is used, and the address code of each device is fixed and assigned at the factory, with no possibility of duplication.

[0061] A wireless communication pairing request is an association request signal initiated by a master or slave device based on the received address code of the other party. It contains core information such as its own address code and pairing identifier, and is used to trigger the pairing verification process between the two parties. The control system RCS is the central scheduling core of the AGV system, responsible for task allocation, equipment scheduling, and pairing coordination, and has the ability to communicate with multiple AGV devices simultaneously.

[0062] In practice, after receiving the handling task, the control system RCS determines the master and slave devices participating in the collaborative operation. Through the system's built-in communication link, it sends the address code of the master device to the slave device and at the same time sends the address code of the slave device to the master device.

[0063] After receiving the address code from the slave device, the master device verifies the validity of the address code format. If it confirms that the format is correct, it generates a wireless communication pairing request containing its own address code and sends it to the slave device corresponding to that address code via a 2.4GHz wireless communication module. After receiving the address code from the master device, the slave device also completes the format verification. Upon receiving the pairing request from the master device, it proceeds to the subsequent verification process.

[0064] Step S102: After receiving the pairing request from the device, if the address code sent by the control system RCS matches the request address code sent by the master device, a matching success command is issued. The successful pairing instruction is a confirmation signal generated by the slave device after completing the address code verification. It is used to inform the master device and control system that the RCS pairing verification has been passed, and the subsequent communication link establishment process can be initiated. The request address code is the master device's own address code carried in the wireless communication pairing request, and it is the core basis for the slave device to verify.

[0065] In practice, after receiving the wireless communication pairing request sent by the master device, the slave device extracts the request address code carried in the request and retrieves the master device address code previously received from the control system RCS. The two address codes are then compared bit by bit.

[0066] If the two address codes are completely identical, it indicates that the pairing is correct. The slave device immediately generates a matching success command and feeds it back to the master device through the 2.4GHz wireless communication module. At the same time, it sends a pairing verification success status information to the control system RCS. If the address codes are inconsistent, the slave device refuses to pair and sends a pairing failure signal to the control system RCS, which then reschedules the pairing process.

[0067] Step S103: Based on the successful matching command, close the communication connection between the slave device and the control system RCS, and keep the slave device responding only to commands issued by the master device via 2.4GHz wireless communication; Communication connection closure refers to the slave device actively disconnecting the direct command receiving channel from the control system RCS, retaining only the status reporting channel to avoid conflicts between multiple commands in subsequent collaborative operations. Responding only to master device commands means the slave device sets its communication priority to the master device's 2.4GHz wireless communication link, shielding control commands from other sources to ensure consistency in collaborative actions.

[0068] In practice, after receiving the matching success command from the slave device, the master device establishes a stable bidirectional communication link with the slave device via a 2.4GHz wireless communication module. Once the link is established, it sends a communication lock command to the slave device. Upon receiving the communication lock command, the slave device immediately closes the control command receiving channel with the RCS of the control system, retaining only the necessary status reporting function. This ensures that it only receives and responds to motion control, status query, and other commands issued by the master device via 2.4GHz wireless communication, and no longer processes control commands directly issued by the RCS of the control system, thus avoiding coordination disorder caused by command conflicts.

[0069] Step S104: When the handling task ends, a release command is triggered to release the communication connection between the control system RCS and the master device, as well as between the slave device and the master device.

[0070] Closing the communication connection means that the device actively disconnects the direct command receiving channel from the control system RCS, retaining only the status reporting channel to avoid conflicts between multiple sources of commands in subsequent collaborative operations.

[0071] Responding only to master device commands means that the slave device sets the communication priority to the master device's 2.4GHz wireless communication link, shields control commands from other sources, and ensures consistency in coordinated actions.

[0072] In practice, after receiving the matching success command from the slave device, the master device establishes a stable bidirectional communication link with the slave device via a 2.4GHz wireless communication module. Once the link is established, it sends a communication lock command to the slave device. Upon receiving the communication lock command, the slave device immediately closes the control command receiving channel with the RCS of the control system, retaining only the necessary status reporting function. This ensures that it only receives and responds to motion control, status query, and other commands issued by the master device via 2.4GHz wireless communication, and no longer processes control commands directly issued by the RCS of the control system, thus avoiding coordination disorder caused by command conflicts.

[0073] Reference Figure 3 Time synchronization strategies include: Step S201: Generate time synchronization data based on the time reference of the master device, and transmit the time synchronization data to the slave device via 2.4GHz wireless communication for time reference calibration. When the time deviation exceeds the preset reference deviation, trigger time synchronization adjustment. The time base is a unified time reference provided by the high-precision clock module built into the main device. This clock module has an accuracy of nanoseconds, providing a stable time anchor point for the entire collaborative system.

[0074] Time synchronization data consists of data packets containing the master device's current time base, synchronization identifier, and checksum. The checksum is used to ensure that the data is not tampered with during transmission, guaranteeing the accuracy of the time information. Time base calibration is the process of comparing and correcting the device's own system time with the master device's time base after receiving the time synchronization data; its core purpose is to reduce the time difference between the two.

[0075] The preset reference deviation is the maximum time difference allowed between the master and slave devices. In this embodiment, the value is set to 10 microseconds, taking into account the synchronization accuracy requirements of AGV collaborative control.

[0076] Time synchronization adjustment is an active calibration action initiated when the device detects a time deviation exceeding the reference deviation. It adjusts its own clock frequency or directly resets the time to keep the time consistent with the master device.

[0077] In practice, after the master device completes pairing with the slave device, it immediately generates the first time synchronization data based on its own time base. This data includes the master device's current precise time, synchronization sequence number, and CRC32 checksum. The time synchronization data is then sent to the slave device via a 2.4GHz wireless communication module. Upon receiving the data, the slave device first verifies the data integrity using the checksum. After confirming that it is correct, it extracts the master device's time base, compares it with its own current system time, and calculates the time deviation between the two.

[0078] If the calculated time deviation is greater than 10 microseconds, the device will synchronize with the startup time by adjusting the oscillation frequency of the internal clock crystal to quickly calibrate its own time to the time reference of the main device; if the time deviation is less than or equal to 10 microseconds, the device will maintain its current time and only record the deviation data for subsequent tracking.

[0079] Step S202: Continuously transmit time synchronization data according to the preset synchronization period to keep the transmission jitter duration of wireless communication within the set allowable jitter duration range.

[0080] The preset synchronization period refers to a fixed time interval for repeatedly sending time synchronization data. Considering the time drift characteristics of AGV collaborative operations, this period is set to 1 second in this embodiment, and can be flexibly adjusted between 0.5 seconds and 2 seconds depending on the complexity of the operating environment. Continuous transmission means that the master device generates and sends time synchronization data cyclically according to the preset synchronization period, ensuring continuous calibration of the master and slave device time during long-term collaborative operations.

[0081] Transmission jitter duration refers to the fluctuation difference between the actual transmission time and the theoretical transmission time during the 2.4GHz wireless communication transmission of time synchronization data, and it is a key factor affecting synchronization accuracy. The set allowable jitter duration range is a pre-defined upper limit for acceptable transmission jitter. In this embodiment, this range is set to no more than 10 microseconds to ensure the stability of time synchronization.

[0082] In practice, after the initial time synchronization is completed, the master device periodically generates new time synchronization data according to a preset 1-second synchronization cycle and sends it through the 2.4GHz wireless communication module. Each time the slave device receives synchronization data, it repeats the time reference calibration process, correcting the time deviation between itself and the master device in real time. The continuously transmitted time synchronization data constantly calibrates the time drift between the master and slave devices. Simultaneously, the low latency of the 2.4GHz wireless communication module keeps the transmission delay within 100 microseconds. Combined with the short frame structure design of the synchronization data, this effectively reduces time fluctuations during transmission. Through this continuous synchronization mechanism, the time deviation between the master and slave devices remains stable within the preset reference deviation, and the transmission jitter duration of wireless communication is strictly controlled within the allowable range of 10 microseconds.

[0083] Reference Figure 4 The periodic synchronization step is also configured with a dynamic channel selection strategy to reduce delay fluctuations caused by co-channel interference, including: Step S203: Pre-acquire multiple initial channel parameters of the 2.4GHz wireless communication module, including signal-to-noise ratio, packet loss rate, and co-channel interference intensity; Initial channel parameters are the basic communication characteristic data of each channel in the initial stage of communication, providing the original basis for subsequent channel quality assessment. They cover indicators related to signal purity, transmission integrity, and anti-interference capability. The signal-to-noise ratio (SNR) is the ratio of the effective signal strength to the ambient noise strength, reflecting the purity of the channel signal. A higher value indicates that the signal is less affected by noise interference and the communication quality is better.

[0084] Packet loss rate is the proportion of data packets lost during data transmission out of the total number of transmitted data packets. It directly reflects the integrity of channel transmission; the lower the proportion, the stronger the transmission stability. Co-channel interference intensity is the degree of interference caused by other devices operating in the 2.4GHz band to the current channel. The stronger the interference, the greater the channel transmission delay fluctuation and the worse the communication stability.

[0085] In practice, after the master device completes pairing with the slave device, it initiates the full-channel scanning function of the 2.4GHz wireless communication module to collect parameters for each of the 50 working channels supported by the module. The scanning dwell time for each channel is set to 10 milliseconds to ensure accurate acquisition of the signal-to-noise ratio (SNR) data and packet loss rate data within 10 milliseconds. Simultaneously, the module's built-in interference detection unit senses the intensity of co-channel interference. After data collection, the master device organizes and archives the SNR, packet loss rate, and co-channel interference intensity corresponding to each channel, forming a complete set of initial channel parameters.

[0086] Step S204: Calculate the channel quality index of each channel using a preset channel quality assessment model, and sort the channels according to the channel quality index to determine the optimal channel; The pre-defined channel quality assessment model is a mathematical model that integrates multi-dimensional channel parameters and quantifies the overall channel quality. This model can transform scattered channel parameters into unified quantitative indicators, facilitating the comparison of channel performance.

[0087] The channel quality index is a quantitative value output by a preset channel quality assessment model. It is used to intuitively characterize the overall communication quality of the channel. The larger the value, the higher the signal-to-noise ratio, the lower the packet loss rate, the weaker the co-channel interference, and the better the communication stability.

[0088] The optimal channel is the channel with the highest value in the channel quality index ranking. This channel has the core characteristics of low interference, low packet loss, and high signal-to-noise ratio, and can minimize transmission delay fluctuations.

[0089] In practice, the master device inputs the initial parameters of each channel collected in step S203 into a preset channel quality assessment model. Through model calculations, the channel quality index corresponding to each channel is obtained, and then all channels are sorted in descending order of their channel quality indices. After sorting, the channel ranked first is selected as the optimal channel for current communication, and the master device records the identification information of this channel to prepare for subsequent channel switching.

[0090] Step S205: Recalculate the channel quality index based on the preset communication interval period, and dynamically select the optimal channel for communication transmission.

[0091] The preset communication interval period is a fixed time interval for periodically re-evaluating channel quality, which is adapted to the dynamic changes in co-channel interference in the warehousing environment. In this embodiment, the period is set to 50 milliseconds, which can be flexibly adjusted according to the complexity of interference in the working environment.

[0092] Recalculating the channel quality index involves the main device repeatedly collecting real-time parameters of each channel at preset communication intervals and recalculating them using a preset channel quality assessment model to update the quality assessment results of each channel, ensuring the real-time nature of the channel quality assessment.

[0093] Dynamically selecting the optimal channel involves switching to the channel with the best overall quality in real time based on the updated channel quality index. This avoids the degradation of the original optimal channel quality due to changes in environmental interference, ensuring that the communication link is always in a high-quality state.

[0094] In practice, the master device repeats the channel parameter acquisition process in step S203 at a preset communication interval of 50 milliseconds to obtain the real-time signal-to-noise ratio, packet loss rate, and co-channel interference intensity for each channel. The real-time parameters are input into a preset channel quality assessment model to recalculate and sort the channel quality index for each channel, determining the optimal channel at the current moment. If the newly determined optimal channel is inconsistent with the currently used channel, the master device initiates a seamless channel switching mechanism to quickly switch to the new optimal channel, avoiding data transmission interruption during the switching process through a buffering mechanism. If the new optimal channel is consistent with the currently used channel, the current channel is maintained, and channel quality assessment continues periodically.

[0095] The channel quality assessment model is calculated using the following formula: ; in, This represents the channel quality index for channel i. , , , These are preset weighting coefficients for signal-to-noise ratio, packet loss rate, master-slave device distance, and the impact of warehouse obstruction. This refers to the real-time channel signal-to-noise ratio. For real-time channel packet loss rate, To adapt to the distance attenuation factor during collaborative handling by master and slave AGVs, the distance change value between the master and slave devices is detected and matched to determine the factor. The signal blocking coefficient caused by warehouse racks, columns, and other carriers is determined by matching the detection of obstructions.

[0096] Reference Figure 5 It is also equipped with an adaptive power adjustment strategy, which shortens communication latency by precisely adjusting the transmit power to balance signal stability and interference suppression, including: Step S206: Based on the master-slave device spacing and the current channel quality index, calculate the optimal transmit power using a preset power optimization model; The master-slave device interval distance is the real-time actual distance between the master and slave devices, which is accurately collected by the UWB positioning module. This module has a positioning accuracy of centimeters and can provide real-time feedback on the relative position changes between the two devices, adapting to distance fluctuation scenarios during AGV collaborative handling.

[0097] The current channel quality index is a quantitative value of the overall channel quality that is updated in real time in the dynamic channel selection strategy. It directly reflects the channel's signal-to-noise ratio, packet loss rate, and anti-interference capability, and is the core reference for power adjustment.

[0098] The preset power optimization model is a mathematical model that integrates the master-slave device spacing and channel quality index to calculate the transmission power adapted to the current operating conditions. Its core is to balance signal transmission stability and environmental interference suppression to avoid communication problems caused by excessively high or low power.

[0099] The optimal transmit power is the target power value output by the preset power optimization model. This value can ensure stable signal transmission under the current distance and channel conditions, and minimize co-channel interference to surrounding equipment, thus providing a basis for shortening communication delay.

[0100] In practice, the master device acquires real-time distance data between itself and the slave device via the UWB positioning module, and simultaneously retrieves the channel quality index of the currently used channel from the dynamic channel selection strategy. These two sets of data are then synchronously input into a preset power optimization model. The model, combined with the power output range of the 2.4GHz wireless communication module, calculates the optimal transmit power under the current operating conditions.

[0101] The optimal transmit power is limited to the range between the module's minimum and maximum transmit power to ensure that the power adjustment is within the hardware's allowable range and to avoid exceeding the rated power, which could damage the module.

[0102] Step S207: Determine the trigger state by comparing the real-time communication link signal received strength collected by the main device with the preset link reference signal strength; The Real-Time Communication Link Signal Received Strength (RSSI) is the strength value of the signal received by the master device from the slave device through the 2.4GHz wireless communication module. It is characterized by RSSI and directly reflects the degree of signal attenuation. The higher the value, the more stable the signal.

[0103] The preset link reference signal strength consists of two sets of signal strength thresholds pre-calibrated according to the AGV operation scenario, including the minimum effective signal strength of the link and the saturation signal strength of the link, which correspond to the lower limit of stable signal transmission and the upper limit of increased interference risk, respectively.

[0104] The trigger state is a power adjustment command type derived by comparing the real-time communication link signal reception strength with the preset link reference signal strength, including two types: power increase trigger state and power decrease trigger state.

[0105] In practice, the master device monitors the received signal strength of the slave device in real time via a 2.4GHz wireless communication module at a 10-millisecond acquisition cycle. The acquired real-time communication link signal received strength is compared with the preset link reference signal strength: if the real-time received strength is lower than the minimum effective signal strength of the link, it is determined to be a power boost trigger state; if the real-time received strength is higher than the link saturation signal strength, it is determined to be a power degrade trigger state.

[0106] Step S208: Based on the trigger state, dynamically increase or decrease the transmission power according to the optimal transmission power to keep the single communication delay of the channel within the set minimum delay threshold.

[0107] Dynamically increasing the transmit power involves gradually increasing the transmit power of the 2.4GHz wireless communication module according to the optimal transmit power under the power boost trigger state until the signal reception strength reaches a stable range. The core is to compensate for signal attenuation.

[0108] Dynamically reducing transmit power involves gradually decreasing the transmit power of the 2.4GHz wireless communication module according to the optimal transmit power under the power reduction trigger state until the signal reception strength falls back to a safe range. The core is to suppress co-channel interference.

[0109] The minimum delay threshold is a predefined upper limit for single-communication delay of the channel. In combination with the low latency requirement of AGV collaborative control, this threshold is set to 10 to 20 microseconds in this embodiment to ensure the real-time transmission of instructions.

[0110] In specific implementation, the main equipment performs the corresponding power adjustment action according to the trigger state determined in step S207: when in the power increase trigger state, the transmission power is gradually increased in steps of 1dBm with the target of optimal transmission power, and the signal reception strength is re-acquired after each increase in 5 millisecond interval until the preset range is reached; when in the power decrease trigger state, the transmission power is gradually decreased in steps of 1dBm with the target of optimal transmission power until the signal reception strength meets the requirements.

[0111] The power optimization model is calculated using the following formula: ; in, This is the minimum transmit power for the 2.4GHz module. This represents the maximum transmit power of the 2.4GHz module. This is the preset signal transmission power adjustment coefficient. This refers to the real-time distance between the master and slave devices obtained through UWB positioning. The maximum effective distance for collaborative operation set for AGVs.

[0112] Reference Figure 6 It also includes step S600: pairing release step, configured with a secure release policy, including: Step S601: After the handling task is completed, RCS sends a pairing release command to the master device; after the master device detects that both itself and the slave device are in a stationary state, it sends a pairing release request to the slave device via 2.4GHz wireless communication. The pairing release command is a control signal issued by the RCS after the handling task is completed, terminating the master-slave device collaboration relationship. It includes a task completion identifier and release authorization information, and serves as the trigger signal to initiate the pairing release process. Stationary state detection is a verification process where the master device confirms the absence of movement by using its own sensors and feedback from the slave device's status. Its core purpose is to avoid safety risks caused by dispairing during movement. The pairing release request is a signal sent by the master device to the slave device to disconnect the collaboration association. It includes the master device identifier and release timing instructions, ensuring the slave device responds accurately to the release operation.

[0113] In practice, after the master and slave devices deliver the vehicle to the designated location, the master device sends a task completion confirmation signal to the RCS, which includes information such as the current location and device status. Upon receiving the signal, the RCS verifies the task completion status and, if correct, issues a pairing release command to the master device. After receiving the command, the master device uses its built-in motor speed sensor to check if it is stationary and simultaneously retrieves real-time motion status data reported by the slave device to confirm that the slave device is also stationary. Once both devices meet the stationary condition, the master device sends a pairing release request to the slave device via its 2.4GHz wireless communication module. If either device is not stationary, the master device will delay sending the request until the stationary condition is met.

[0114] Step S602: After receiving the request from the device, disconnect the pairing relationship with the master device, restore the independent operation state, and report the disconnection result to the master device via 2.4GHz wireless communication; Pairing termination involves disconnecting the dedicated communication link between the device and the master device, and clearing collaborative control logic parameters, including deleting the master device's address code and disabling the collaborative response mechanism. Independent operation mode means the device reverts to its unpaired operating mode, can autonomously receive RCS scheduling commands, and independently complete tasks such as movement and operation, no longer under the master device's control. Termination result reporting is a signal from the device to the master device indicating that pairing termination is complete, including its own status information, ensuring the master device is aware of the termination progress.

[0115] In practice, the slave device receives the pairing cancellation request from the master device via its 2.4GHz wireless communication module and immediately initiates the pairing cancellation process: disconnecting the bidirectional communication link with the master device, clearing stored master device address codes, cooperative motion parameters, and other data, and disabling the restriction mechanism that only responds to master device commands. After completing the above operations, the slave device resumes independent operation and can normally receive various commands issued by RCS. Subsequently, the slave device generates a cancellation result data packet and reports it to the master device via the 2.4GHz wireless communication module, informing it that it has successfully cancelled the pairing.

[0116] Step S603: After receiving the release result from the slave device, the master device resumes independent operation and reports the pairing release completion information to the control system RCS; Independent operation state recovery involves the master device clearing the collaborative control logic with the slave device and disabling the slave device's status monitoring mechanism, restoring it to its initial state where it can independently receive RCS scheduling. Pairing cancellation completion information is a signal from the master device to the RCS indicating successful cancellation throughout the entire process. It includes master / slave device identifiers, cancellation time, and other data, serving as the basis for the RCS to update the system status.

[0117] In practice, after receiving the disconnection result report from the slave device, the master device confirms that the slave device has successfully disconnected from the pair and then initiates its own independent operation status recovery process: clearing the collaborative parameters related to the slave device and disabling the status monitoring and command issuance mechanism for the slave device. After recovery, the master device generates disconnection completion information and reports it through the communication link with RCS. The information clearly marks the master and slave device numbers and the disconnection completion status to ensure accurate identification by RCS.

[0118] Step S604: Instruct the control system RCS to disconnect the pairing association between the master and slave devices on the system side.

[0119] System-side pairing and association removal involves RCS deleting the master-slave device pairing records from internal storage and updating the device status ledger. The core is to eliminate the system-level collaborative binding, allowing the master and slave devices to be rescheduled and paired.

[0120] In practice, after receiving the pairing cancellation completion information reported by the master device, the RCS retrieves the master-slave device pairing ledger stored in the system, finds the corresponding pairing record and deletes it. At the same time, it updates the system status of the master and slave devices to idle and schedulable. After the update is completed, the RCS can reschedule the master and slave devices to pair with other devices or form a collaborative group again according to the new handling task requirements, ensuring flexible reuse of equipment resources.

[0121] Reference Figure 7 Differential decomposition strategies include: Step S301: Based on the spatial relationship of the master device and the slave device being relatively stationary, calculate the linear velocity and common heading angle of the master device and the slave device using a preset kinematic model, and trigger the command synchronization step; The relatively static spatial relationship refers to the fixed distance and posture maintained by the master and slave devices during collaborative transport. They exhibit no relative displacement during movement, only moving synchronously with the overall vehicle. In this embodiment, the lateral distance between the master and slave devices is fixed at 1.2 meters to accommodate the pallet width requirements. The preset kinematic model is a mathematical model adapted to the differential motion characteristics of the split-type AGV's dual wheels. Its core utilizes spatial geometry and principles of motion mechanics to transform the overall motion requirements into individual device motion parameters.

[0122] Linear velocity is the linear motion rate of the master or slave device along the direction of motion, and it is a core control parameter of the drive motor. Common heading angle is the unified steering angle when the master and slave devices move in tandem, ensuring consistent steering actions and preventing vehicle deviation. The command synchronization step is the timestamped command transmission strategy described in step S400, used to synchronously send the calculated motion parameters to the slave device, ensuring coordinated execution.

[0123] In practice, the master device receives the overall motion command from the RCS control system. This command includes the chassis linear velocity and target heading angle required by the vehicle. Based on its relatively stationary spatial relationship with the slave device, the master device calls upon a preset kinematic model, inputting the chassis linear velocity, target heading angle, and lateral spacing parameters between the master and slave devices. Through model calculations, the linear velocities of the master and slave devices, as well as the shared heading angle, are decomposed to ensure that the decomposed parameters enable the master and slave devices to synchronously drive the vehicle's motion. After the calculation is completed, the master device triggers the command synchronization step, preparing for subsequent parameter timesting and distribution.

[0124] Step S302: When the local time of the master device and the slave device reaches the timestamp, parameter conversion and drive command issuance are performed synchronously.

[0125] A timestamp is a unified execution moment marked in the instruction synchronization step. It is generated by the master device based on its own time base, accurate to the microsecond level, ensuring that the execution timing of the master and slave devices is consistent. Parameter conversion is the process of converting control parameters such as linear velocity and heading angle into motor speed and steering wheel angle signals to adapt to the control requirements of the servo driver. Drive command issuance is the operation of transmitting the converted motor control signals to the servo driver to drive the motor to move according to the set parameters.

[0126] In practice, the master device marks its own linear velocity and common heading angle with the same timestamp as the slave device's linear velocity and common heading angle, and transmits the motion parameters and timestamps from the slave device via 2.4GHz wireless communication. Both the master and slave devices store their corresponding motion parameters and monitor their local time in real time to ensure the timestamps are reached. When both devices' local times reach the set timestamps, they synchronously initiate a parameter conversion process, converting the linear velocity into motor speed signals and the heading angle into steering wheel angle signals. The converted drive commands are then sent to their respective servo drivers, driving the motors to move synchronously.

[0127] Reference Figure 8 The status monitoring process is also equipped with a two-way security strategy, including: Step S501: After receiving the linear speed and heading angle reported by the slave device, the master device compares them with the preset expected values. When the deviation exceeds the set safety threshold, the master device immediately sends a deceleration and stop command to the slave device via 2.4GHz wireless communication. The preset expected values ​​are the linear velocity and heading angle standard parameters sent from the master device to the slave device after decomposition, serving as the benchmark for judging whether the slave device's motion state is normal. The set safety thresholds are the upper limits of allowable deviations of motion parameters pre-calibrated according to the AGV's collaborative accuracy requirements. In this embodiment, the linear velocity deviation threshold is set to 0.05 meters per second, and the heading angle deviation threshold is set to 0.02 radians, ensuring that the deviations are within a safe and controllable range. The deceleration and stop command is an emergency control signal sent from the master device to the slave device, including deceleration acceleration and a stop command, used to quickly correct abnormal motion states.

[0128] In practice, the master device reports the status of the slave device at a frequency of 10 milliseconds, as per this embodiment, receiving the actual linear velocity and heading angle uploaded by the slave device in real time. Each time data is received, the master device compares the actual parameters with the preset expected values ​​one by one, calculating the deviation values ​​of linear velocity and heading angle.

[0129] If any deviation value exceeds the corresponding set safety threshold, it indicates that the movement state of the slave device is abnormal. The master device immediately generates a deceleration and stop command and quickly sends it to the slave device through the 2.4GHz wireless communication module. The command includes a preset safety deceleration acceleration to ensure that the slave device decelerates smoothly to a stop.

[0130] Step S502: Receive a timeout threshold from the device's preset command. If the timeout threshold is exceeded and no control command from the master device is received, automatically decelerate to a stop according to the preset acceleration. The preset acceleration is a fixed acceleration during emergency deceleration of the equipment, which is consistent with the safe deceleration acceleration in step S501, to ensure a smooth deceleration process and avoid vehicle inertial deviation.

[0131] In practice, after the slave device starts collaborative operation, the reception of control commands from the master device is monitored in real time, and the timestamp of each received command is recorded. If the slave device does not receive any control commands from the master device for 20 consecutive milliseconds, it is determined that the communication is interrupted or the master device is malfunctioning, and an emergency deceleration program is automatically initiated. The motor speed is gradually reduced at a preset acceleration of 0.5 meters per second squared until it comes to a complete stop, while maintaining communication with the master device. If communication is restored, the movement can be restarted according to subsequent commands.

[0132] Step S503: The master device presets a feedback reception timeout threshold. If the slave device does not receive status report data after the timeout threshold is exceeded, it automatically decelerates to a stop according to a preset acceleration.

[0133] The feedback reception timeout threshold is the maximum allowed time set by the master device for not receiving status report data from the slave device. It is consistent with the slave device's command reception timeout threshold, both being 20 milliseconds, ensuring symmetry in bidirectional protection. The preset acceleration is a fixed acceleration during emergency deceleration of the master device, also 0.5 meters per second squared, ensuring consistent deceleration characteristics between the master and slave devices and avoiding uneven force distribution on the vehicle.

[0134] In practice, the master device receives status reports from the slave device every 10 milliseconds, synchronously recording the timestamp of each received data. If the master device does not receive status reports from the slave device for 20 consecutive milliseconds, it determines that the slave device is malfunctioning or communication is interrupted, and immediately initiates its own emergency deceleration program. The master device gradually reduces the motor speed according to a preset acceleration until it comes to a complete stop, while continuously sending status query commands to the slave device. If communication is restored, subsequent operations are adjusted based on the slave device's status.

[0135] Steps S501 to S503 establish a two-way linkage security mechanism between master and slave devices, solving the problems of only one-way monitoring and delayed response in traditional AGV collaboration. Through triple protection—real-time comparison of motion deviations by the master device, monitoring of command reception status by the slave device, and monitoring of feedback reception status by the master device—it can quickly respond to motion anomalies and communication interruptions.

[0136] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0137] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features.

Claims

1. A control method for a split-type AGV based on 2.4GHz wireless communication, characterized in that, include: The communication pairing process involves configuring an AGV pairing strategy. The control system RCS schedules the movement of the master and slave devices of the split AGVs to perform master-slave pairing. After establishing a 2.4GHz wireless communication module connection, the slave device's command reception to the control system RCS is disabled. The periodic synchronization step is configured with a time synchronization strategy. The master device and the slave device transmit time synchronization information through 2.4GHz wireless communication to keep the time difference between the master device and the slave device within the preset time difference range. The motion decomposition step is configured with a differential decomposition strategy. After receiving the motion command from the control system RCS, the master device decomposes the chassis linear velocity and heading angle into its own linear velocity and heading angle and the heading angle of the slave device based on the kinematic model to generate motion control parameters. The instruction synchronization step is configured with a timestamped instruction transmission strategy. The master device sends the timestamp of the decomposed motion control parameters to the slave device, and the master device and slave device perform motion control according to the timestamp and motion control parameters. The status monitoring step is configured with a real-time status feedback strategy, which transmits real-time motion control parameters from the device via 2.4GHz wireless communication at a fixed frequency.

2. The method for controlling a split-type AGV based on 2.4GHz wireless communication according to claim 1, characterized in that, The AGV pairing strategy includes: The control system RCS sends the address codes of the master and slave devices to each other, and controls the master and slave devices to send wireless communication pairing requests to each other for matching based on the received address codes; After receiving a pairing request from the device, the device will send a matching success command when the address code sent by the control system RCS matches the request address code sent by the master device. Based on the successful matching command, the communication connection between the slave device and the control system RCS is closed, and the slave device is kept to only respond to commands issued by the master device via 2.4GHz wireless communication; When the handling task is completed, a release command is triggered to disconnect the communication connection between the control system RCS and the master device, as well as between the slave device and the master device.

3. The method for controlling a split-type AGV based on 2.4GHz wireless communication according to claim 1, characterized in that, The time synchronization strategy includes: Time synchronization data is generated based on the time reference of the master device, and the time synchronization data is transmitted to the slave device via 2.4GHz wireless communication for time reference calibration. Time synchronization adjustment is triggered when the time deviation exceeds the preset reference deviation. Time synchronization data is continuously transmitted according to a preset synchronization period to keep the transmission jitter duration of wireless communication within the set allowable jitter duration range.

4. The method for controlling a split-type AGV based on 2.4GHz wireless communication according to claim 3, characterized in that, The periodic synchronization step is also configured with a dynamic channel selection strategy to reduce delay fluctuations caused by co-channel interference, including: Multiple initial channel parameters of the 2.4GHz wireless communication module are obtained in advance, including signal-to-noise ratio, packet loss rate, and co-channel interference intensity; The channel quality index of each channel is calculated using a pre-defined channel quality assessment model, and the optimal channel is determined by ranking the channels according to their channel quality indices. The channel quality index is recalculated based on a preset communication interval period, and the optimal channel is dynamically selected for communication transmission.

5. A split-type AGV control method based on 2.4GHz wireless communication according to claim 4, characterized in that, The channel quality assessment model is calculated using the following formula: ； in, This represents the channel quality index for channel i. , , , These are preset weighting coefficients for signal-to-noise ratio, packet loss rate, master-slave device distance, and the impact of warehouse obstruction. This refers to the real-time channel signal-to-noise ratio. For real-time channel packet loss rate, To adapt to the distance attenuation factor during collaborative handling by master and slave AGVs, the distance change value between the master and slave devices is detected and matched to determine the factor. The signal blocking coefficient caused by warehouse racks, columns, and other carriers is determined by matching the detection of obstructions.

6. The method for controlling a split-type AGV based on 2.4GHz wireless communication according to claim 3, characterized in that, It is also equipped with an adaptive power adjustment strategy, which shortens communication latency by precisely adjusting the transmit power to balance signal stability and interference suppression, including: Based on the master-slave device spacing and the current channel quality index, the optimal transmit power is determined by calculation using a preset power optimization model. The trigger state is determined by comparing the real-time communication link signal strength collected by the main device with the preset link reference signal strength. Based on the trigger state, the transmission power is dynamically increased or decreased according to the optimal transmission power to keep the single communication delay of the channel within the set minimum delay threshold.

7. A split-type AGV control method based on 2.4GHz wireless communication according to claim 6, characterized in that, The power optimization model is calculated using the following formula: ； in, This is the minimum transmit power for the 2.4GHz module. This represents the maximum transmit power of the 2.4GHz module. This is the preset signal transmission power adjustment coefficient. This refers to the real-time distance between the master and slave devices obtained through UWB positioning. The maximum effective distance for collaborative operation set for AGVs.

8. The method for controlling a split-type AGV based on 2.4GHz wireless communication according to claim 1, characterized in that, It also includes a pairing release step, configured with a safe release strategy, including: after the handling task is completed, RCS sends a pairing release command to the master device; after the master device detects that both itself and the slave device are in a stationary state, it sends a pairing release request to the slave device via 2.4GHz wireless communication; After receiving a request from the device, it disconnects from the master device, resumes independent operation, and reports the disconnection result to the master device via 2.4GHz wireless communication. After receiving the release result from the slave device, the master device resumes independent operation and reports the pairing release completion information to the control system RCS. The RCS (Regulatory Control System) is instructed to disconnect the pairing association between the master and slave devices on the system side.

9. A split-type AGV control method based on 2.4GHz wireless communication according to claim 1, characterized in that, The differential decomposition strategy includes: Based on the relatively stationary spatial relationship between the master device and the slave device, the linear velocity and common heading angle of the master device and the slave device are calculated using a preset kinematic model, and the command synchronization step is triggered. When the local time of the master device and the slave device reaches the timestamp, parameter conversion and drive command issuance are performed synchronously.

10. A split-type AGV control method based on 2.4GHz wireless communication according to claim 9, characterized in that, The aforementioned status monitoring steps are also configured with a two-way security strategy, including: After receiving the linear speed and heading angle reported by the slave device, the master device compares them with the preset expected values. When the deviation exceeds the set safety threshold, it immediately sends a deceleration and stop command to the slave device via 2.4GHz wireless communication. If the device receives a timeout threshold from a preset instruction, and no control instruction is received from the master device after the timeout threshold is exceeded, the device will automatically decelerate to a stop at a preset acceleration. The master device has a preset feedback reception timeout threshold. If the slave device does not receive status report data after the timeout threshold is exceeded, it will automatically decelerate to a stop according to the preset acceleration.

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