Master-slave control system of four-wheel independent drive steering robot for tunnel

Abstract

The invention belongs to the technical field of steering robots, and particularly relates to a master-slave control system of a four-wheel independent drive steering robot for a tunnel, which comprises a master controller, the master controller is controlled by a system control terminal through a gigabit Ethernet, and the master controller can control a slave controller cluster and an environment sensing system. The slave controller cluster can respectively control the slave controller 1, the slave controller 2, the slave controller 3 and the slave controller 4, and the slave controller 1, the slave controller 2, the slave controller 3 and the slave controller 4 can control the driving motor set and the steering motor set. According to the master-slave control system of the four-wheel independent drive steering robot for the tunnel, driving and steering of each wheel are independently controlled, a distributed control framework is adopted, an intelligent energy management strategy is adopted, power output of each wheel is dynamically adjusted according to the motion state, the energy efficiency ratio of the system is further increased, and the long-term operation cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steering robots, and particularly relates to a master-slave control system of a four-wheel independently driven steering robot for tunnels. BACKGROUND

[0002] A tunnel is an underground passage artificially excavated, and its core function is to break through the terrain restrictions and transport resources: a traffic tunnel shortens the mileage and optimizes the route; a water conservancy tunnel realizes cross-basin water resource allocation; its technical breakthroughs are concentrated in complex geological construction and ecological protection, driving the coordinated development of regional economy and ecology, and a tunnel robot can survey the inside of the tunnel.

[0003] However, the existing tunnel robots have the problems of insufficient flexibility and low motion accuracy in the process of use, because the tunnel robots mostly adopt differential steering or fixed steering mechanisms, and in the face of complex tunnel environments, the tunnel robots are difficult to adapt and difficult to freely shuttle in the tunnel, and are prone to collision. SUMMARY

[0004] The purpose of the present application is to provide a master-slave control system of a four-wheel independently driven steering robot for tunnels to solve the problem of insufficient flexibility and low motion accuracy in the background art.

[0005] To achieve the above purpose, the present application provides the following technical scheme: a master controller controlled by a system control terminal through a gigabit Ethernet, the master controller can control a slave controller cluster and an environment perception system, the slave controller cluster can respectively control a slave controller 1, a slave controller 2, a slave controller 3 and a slave controller 4, the slave controller 1, the slave controller 2, the slave controller 3 and the slave controller 4 can all control a driving motor group and a steering motor group, and the environment perception system includes a 16-line laser radar, a binocular camera, an ultrasonic array and an IMU inertial navigation module.

[0006] Preferably, the driving motor group includes a brushless motor, a speed reducer and a hub assembly, and the steering motor group includes a servo motor, a harmonic reducer and a steering mechanism.

[0007] Preferably, the task instruction sends a signal to an instruction type judgment, the instruction type judgment includes global path planning and kinematics inverse solution, dynamic obstacle avoidance algorithm is performed after the global path planning, local trajectory optimization is performed after the dynamic obstacle avoidance algorithm, four-wheel motion instruction generation is performed after the kinematics inverse solution and the local trajectory optimization are both completed, and communication protocol encapsulation is performed after the four-wheel motion instruction generation.

[0008] Preferably, the instructions are parsed, the control mode is selected after the instruction parsing, the drive motor PID control and the steering motor PID control are included in the control mode selection, the PWM output is outputted after the drive motor PID control, the pulse output is outputted after the steering motor PID control, the signal is sent to the actuator after the PWM output and the pulse output, the sensor feedback is transmitted to the signal by the actuator, the data is packaged after the sensor feedback, and the state is reversed after the data packaging.

[0009] Preferably, the fault is triggered, the fault type is judged after the fault triggering, the communication interruption can start a redundant communication channel, the motor overload can reduce half of the output power, the sensor failure can switch the estimation algorithm, the power supply anomaly can switch to the standby power supply, the recovery detection is performed after the start of the redundant communication channel, the reduction of half of the output power, the switching of the estimation algorithm or the switching to the standby power supply, the normal mode is restored after the recovery detection is normal, the safety mode is entered after the recovery detection is not normal, and the audible and light alarms and the uploading of the fault code are performed after the safety mode is entered.

[0010] Preferably, the system control terminal can remotely control the master controller, the drive motor group can control the rolling of the independent wheels, the steering motor group can control the rotation angle of the independent wheels, and the slave controller 1, the slave controller 2, the slave controller 3 and the slave controller 4 control the four wheels of the robot respectively.

[0011] Preferably, the brushless motor controls the rolling of the hub assembly through the reducer, the hub assembly is externally provided with a tire, the servo motor controls the rotation of the steering mechanism through the harmonic reducer, and the steering mechanism can control the angular rotation of the hub assembly.

[0012] Preferably, the global path planning, the dynamic obstacle avoidance algorithm and the local trajectory optimization can be calculated with the aid of AI, the audible and light alarms alarm through sound and light, and the uploading of the fault code can specifically judge the fault.

[0013] Compared with the prior art, the master-slave control system of the four-wheel independent driving steering robot for tunnels has the advantages that: by independently controlling the driving and steering of each wheel, highly flexible omnidirectional movement ability is realized, the master controller solves the movement instructions in real time, the slave controller accurately executes, the robot can smoothly complete complex actions such as lateral translation, oblique movement and in-place rotation, the closed-loop feedback mechanism effectively eliminates the error of the traditional steering mechanism, the robot can still maintain stable trajectory tracking in narrow spaces or dynamic environments, and the working precision and adaptability are significantly improved.

[0014] Meanwhile, this invention adopts a distributed control architecture, with redundant communication between the master and slave controllers to ensure data synchronization. Each wheel-end module has independent safety protection functions. In the event of a single point of failure, the system can automatically adjust the power distribution to maintain basic mobility. Combined with environmental perception and adaptive algorithms, the robot can respond to emergencies in real time, significantly reducing the risk of unexpected downtime and ensuring continuous and stable operation under complex working conditions.

[0015] This invention employs an intelligent energy management strategy to dynamically adjust the power output of each wheel according to the motion state, reducing unnecessary energy consumption. The modular design enables rapid replacement of key components, and the visual diagnostic tools simplify the maintenance process. The standardized interface design facilitates functional expansion, while the regenerative braking technology recovers braking energy, further improving the system's energy efficiency ratio and reducing long-term operating costs. Attached Figure Description

[0016] Figure 1 This is a system architecture diagram of the present invention;

[0017] Figure 2 This is a structural diagram of the motor assembly of the present invention;

[0018] Figure 3 This is a flowchart of the main control layer of the present invention;

[0019] Figure 4 This is a flowchart of the control layer of the present invention;

[0020] Figure 5 is a flowchart of the fault handling process 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 embodiments of the present invention, and not all embodiments. 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] Please see the appendix Figure 1 -5. Several embodiments provided by the present invention:

[0023] A master-slave control system for a four-wheel independent drive steering robot used in tunnels includes: a master controller, which runs a ROS system based on a high-performance processor and is responsible for environmental perception, path planning, and kinematic calculation. It sends speed and steering commands to four slave controllers via a real-time communication bus, while simultaneously receiving status feedback from each wheel and making dynamic adjustments. It integrates fault detection and emergency handling functions to ensure stable and reliable system operation. The master controller is controlled by a system control terminal via gigabit Ethernet. The master controller can control a cluster of slave controllers and an environmental perception system. The slave controllers use STM32 series MCUs, receive master control commands via a CAN / EtherCAT bus, independently execute dual-closed-loop PID control, collect encoder and angle sensor data in real time, and feed back the operating status to the master controller. They have local fault detection and emergency protection functions to ensure accurate execution of motion commands by each wheel. The slave controller cluster can control slave controller 1, slave controller 2, slave controller 3, and slave controller 4 respectively. Each of slave controllers can control the drive motor group and the steering motor group. The environmental perception system includes a 16-line LiDAR, a binocular camera, an ultrasonic array, and an IMU inertial navigation module.

[0024] Furthermore, the drive motor assembly includes a brushless motor, a reducer, and a hub assembly. The brushless motor adopts a three-phase permanent magnet synchronous structure, replacing mechanical brushes with an electronic commutator, offering advantages such as high efficiency, low noise, and long lifespan. Combined with an integrated encoder, it achieves precise speed feedback. The motor driver receives PWM control signals and outputs three-phase AC power, supporting wide-range speed regulation and rapid dynamic response. It is widely used in robot drive systems requiring high-precision motion control. The steering motor assembly includes a servo motor, a harmonic reducer, and a steering mechanism. The harmonic reducer employs a unique structure of a flexible wheel, a rigid wheel, and a wave generator, utilizing elastic deformation... Achieving high reduction ratio transmission, featuring zero backlash, high precision, and high torque density, it can significantly improve the positioning accuracy and rigidity of the steering system when used with a servo motor. It is an ideal reduction device for robot joint drive. The wheel hub assembly is a core component of the automobile driving system, consisting of wheel hubs, bearings, flanges, etc. It connects the wheels to the suspension, supports the weight of the entire vehicle, and ensures smooth rotation. It needs to have high strength, wear resistance, and dynamic balance performance, affecting the vehicle's handling, safety, and comfort. According to the driving method, it is divided into drive wheel hubs and non-drive wheel hubs. The materials are mostly aluminum alloy or steel, and regular maintenance is required to avoid bearing wear or deformation.

[0025] Furthermore, the task instructions send signals to the instruction type determination, which includes global path planning and inverse kinematics. Inverse kinematics, by establishing a robot kinematic model, converts the desired overall vehicle speed into independent speed and steering angle commands for each wheel. It combines wheel system geometric parameters to calculate the motion components of each wheel in real time, ensuring precise omnidirectional movement through four-wheel coordination. This is the core algorithmic foundation for the motion control of a four-wheel independently driven steering robot. After global path planning, a dynamic obstacle avoidance algorithm is implemented. This algorithm is based on real-time environmental perception data from multiple sensors, constructing a local cost map and analyzing the potential field, combined with kinematic constraints... The system generates collision-free paths in real time and dynamically adjusts the speed and steering angle of each wheel, enabling the robot to autonomously avoid static / dynamic obstacles in complex environments while maintaining motion stability and trajectory continuity. After dynamic obstacle avoidance algorithm, local trajectory optimization is performed. After inverse kinematics solution and local trajectory optimization are completed, four-wheel motion commands are generated. After the four-wheel motion commands are generated, the communication protocol is encapsulated. The communication protocol encapsulation standardizes and organizes control commands and status data according to a custom frame format, and ensures transmission reliability through CRC check. It also supports command priority division and frame transmission mechanism to achieve efficient and interference-resistant real-time data interaction between master and slave controllers.

[0026] Further, the instruction is parsed, and then the control mode is selected. The control mode selection includes PID control for the drive motor and PID control for the steering motor. After PID control of the drive motor, PWM output is performed. The PWM output simulates an analog signal by rapidly switching between high and low levels. Its duty cycle change can precisely control the motor speed or actuator position, featuring fast response, high efficiency, and strong anti-interference. Combined with a filtering circuit, it can achieve smooth power output and is widely used in embedded control scenarios requiring precise energy regulation, such as motor speed regulation and LED dimming. After PID control of the steering motor, pulse output is performed. The pulse output precisely adjusts the motor speed and position through the PWM signal generated by the controller, featuring high-frequency response and precise duty cycle control characteristics. It can be used with encoder feedback to achieve closed-loop control, supports multiple output modes, and is suitable for motion control of actuators such as stepper motors and servo motors. It ensures high precision and fast dynamic response of the system. After PWM output and pulse output, the signal is sent to the actuator. The actuator passes the signal to the sensor feedback. After the sensor feedback, the data is packaged. The data packaging is a structured encapsulation of the status information such as motor speed, steering angle, and temperature collected by the sensor according to a predefined communication protocol. Timestamps and data verification fields are added. After being converted into binary data frames, it is transmitted through the bus to ensure efficient integration and reliable transmission of multi-source heterogeneous data. It provides real-time and complete status feedback for upper-level control decisions. The status is rotated after the data is packaged.

[0027] Furthermore, the system triggers a fault and determines its type. If the fault is identified as a communication interruption, a redundant communication channel is activated. If the fault is identified as a motor overload, the output power is reduced by half. If the fault is identified as a sensor failure, the estimation algorithm is switched. If the fault is identified as a power supply abnormality, the backup power supply is switched. After activating the redundant communication channel, reducing the output power by half, switching the estimation algorithm, or switching the backup power supply, detection is restored. If the detection is restored to normal, the system returns to normal mode. If the detection is restored to abnormal, the system enters a safety mode. The safety mode is a protection state that is automatically triggered when the system detects abnormalities such as communication interruption, motor overload, or sensor failure, and immediately cuts off the motor power. Output and lock the steering angle, activate the audible and visual alarm, and upload fault codes through the backup communication channel to ensure the robot stops quickly in case of emergencies, preventing equipment damage or personal injury. After entering the safety mode, the robot will activate the audible and visual alarm and upload fault codes. The code is a set of instructions written in a specific programming language to tell the computer how to perform tasks and achieve specific functions, including data processing, logical operations, and interface design. Efficiency is improved through algorithm optimization and modular development. Maintainability must follow syntax rules and best practices to ensure correctness and reliability and adapt to the needs of different platform environments. Ultimately, it is transformed into a machine-executable program to solve practical problems or create digital tools and services.

[0028] Furthermore, the system control terminal can remotely control the main controller. Developed based on a graphical human-machine interface, the terminal integrates status monitoring, parameter configuration, and fault diagnosis functions. It communicates with the main controller via Ethernet / WiFi, displaying the robot's motion trajectory, wheel status, and sensor data in real time. It supports command issuance and emergency stop operations, providing operators with an intuitive system interaction and monitoring platform. The main controller runs the ROS system on a high-performance processor, responsible for environmental perception, path planning, and kinematic calculations. It issues speed and steering commands to the four slave controllers via a real-time communication bus, while simultaneously receiving status feedback from each wheel. It dynamically adjusts and integrates fault detection and emergency handling functions to ensure stable and reliable system operation. The drive motor group can control the rolling of the independent wheels, and the steering motor group can control the rotation angle of the independent wheels. Slave controller 1, slave controller 2, slave controller 3 and slave controller 4 control the robot's four wheels respectively. The slave controllers use STM32 series MCUs, receive master control commands through CAN / EtherCAT bus, independently execute dual closed-loop PID control, collect encoder and angle sensor data in real time, and feed back the operating status to the master controller. It has local fault detection and emergency protection functions to ensure that each wheel accurately executes motion commands.

[0029] Furthermore, the brushless motor controls the rotation of the wheel assembly through a reducer. The brushless motor employs a three-phase permanent magnet synchronous structure, replacing mechanical brushes with an electronic commutator, offering advantages such as high efficiency, low noise, and long lifespan. Combined with an integrated encoder, it achieves precise speed feedback. The motor driver receives PWM control signals and outputs three-phase AC power, supporting wide-range speed regulation and rapid dynamic response. It is widely used in robot drive systems requiring high-precision motion control. A tire is mounted outside the wheel assembly. A servo motor controls the rotation of the steering mechanism through a harmonic reducer. The servo motor adopts a closed-loop control structure, achieving high-precision position / speed control through encoder feedback. The steering mechanism features fast response, large torque, and wide speed range. When used with a reducer, it can output precise angles and torques. It is widely used in robot joints and steering systems that require precise positioning. The steering mechanism controls the rotation of the wheel hub assembly. The wheel hub assembly is a core component of the vehicle's driving system, consisting of the wheel hub, bearings, flanges, etc. It connects the wheels to the suspension, supports the weight of the entire vehicle, and ensures smooth rotation. It must have high strength, wear resistance, and dynamic balance performance, affecting the vehicle's handling, safety, and comfort. According to the driving method, it is divided into drive wheel hubs and non-drive wheel hubs. The materials are mostly aluminum alloy or steel. Regular maintenance is required to avoid bearing wear or deformation.

[0030] Furthermore, global path planning, dynamic obstacle avoidance algorithms, and local trajectory optimization can all be aided by AI-assisted computation. AI is a technology that simulates human intelligence through computer systems, including machine learning, deep learning, and natural language processing. It enables machines to perceive the environment, learn knowledge, reason and make decisions, and solve problems. Audible and visual alarms provide warnings through sound and light, and uploading fault codes allows for specific fault diagnosis. Codes are a set of instructions written in a specific programming language to tell the computer how to perform tasks and achieve specific functions, including data processing, logical operations, and interface design. Efficiency is improved through algorithm optimization and modular development. Maintainability must follow syntax rules and best practices to ensure correctness and reliability and adapt to different platform environments. Ultimately, it is transformed into machine-executable programs to solve practical problems or create digital tools and services.

[0031] When the system is in use, the main controller first obtains real-time data through the environmental perception system to perform global path planning and kinematic calculations. Then, the decomposed wheel speed and steering commands are sent to four slave controllers through the high-speed bus. Finally, each slave controller independently executes dual closed-loop control, driving the motor to achieve precise speed control, and the steering motor to complete angle positioning. At the same time, the operating status is fed back to the main controller in real time, forming a complete control closed loop.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A master-slave control system for a four-wheel independent drive steering robot used in tunnels, characterized in that, include: The main controller is controlled by the system control terminal via Gigabit Ethernet. The main controller can control the slave controller cluster and the environmental perception system. The slave controller cluster can control slave controller 1, slave controller 2, slave controller 3 and slave controller 4 respectively. Slave controller 1, slave controller 2, slave controller 3 and slave controller 4 can all control the drive motor group and the steering motor group. The environmental perception system includes a 16-line lidar, a binocular camera, an ultrasonic array and an IMU inertial navigation module.

2. The master-slave control system for a four-wheel independent drive steering robot for tunnels according to claim 1, characterized in that: The drive motor assembly includes a brushless motor, a reducer, and a wheel hub assembly, while the steering motor assembly includes a servo motor, a harmonic reducer, and a steering mechanism.

3. The master-slave control system for a four-wheel independent drive steering robot for tunnels according to claim 2, characterized in that: The task instruction sends a signal to the instruction type determination, which includes global path planning and inverse kinematics. After global path planning, a dynamic obstacle avoidance algorithm is performed. After the dynamic obstacle avoidance algorithm, local trajectory optimization is performed. After both inverse kinematics and local trajectory optimization are completed, four-wheel motion instructions are generated. After the four-wheel motion instructions are generated, the communication protocol is encapsulated.

4. The master-slave control system for a four-wheel independent drive steering robot for tunnels according to claim 1, characterized in that: The instruction is parsed, and a control mode is selected after the instruction is parsed. The control mode selection includes PID control of the drive motor and PID control of the steering motor. After the PID control of the drive motor, PWM output is performed, and after the PID control of the steering motor, pulse output is performed. The PWM output and pulse output are then sent to the actuator. The actuator transmits the signals to the sensor for feedback. After the sensor feedback, the data is packaged, and the state is rotated after the data is packaged.

5. The master-slave control system for a four-wheel independent drive steering robot for tunnels according to claim 3, characterized in that: Fault triggering involves determining the fault type. If the fault type is determined to be communication interruption, a redundant communication channel can be activated. If the fault type is determined to be motor overload, the output power can be reduced by half. If the fault type is determined to be sensor failure, the estimation algorithm can be switched. If the fault type is determined to be power supply abnormality, the backup power supply can be switched. After activating the redundant communication channel, reducing the output power by half, switching the estimation algorithm, or switching the backup power supply, detection is restored. If the detection is restored normally, the system returns to normal mode. If the detection is restored abnormally, the system enters a safety mode. After entering the safety mode, an audible and visual alarm is activated, and a fault code is uploaded.

6. The master-slave control system for a four-wheel independent drive steering robot for tunnels according to claim 5, characterized in that: The system control terminal can remotely control the main controller, the drive motor group can control the rolling of the independent wheels, the steering motor group can control the rotation angle of the independent wheels, and the slave controller 1, slave controller 2, slave controller 3 and slave controller 4 respectively control the four wheels of the robot.

7. The master-slave control system for a four-wheel independent drive steering robot for tunnels according to claim 3, characterized in that: The brushless motor controls the rolling of the wheel hub assembly through a reducer. A tire is mounted on the outside of the wheel hub assembly. The servo motor controls the rotation of the steering mechanism through a harmonic reducer. The steering mechanism can control the wheel hub assembly to rotate at an angle.

8. The master-slave control system for a four-wheel independent drive steering robot for tunnels according to claim 5, characterized in that: The global path planning, dynamic obstacle avoidance algorithm, and local trajectory optimization can all be calculated with the help of AI. The audible and visual alarm will sound and light, and the uploaded fault code can be used to make a specific judgment on the fault.

Images