Coal mine gas pipeline robot control system

Abstract

The invention discloses a coal mine gas pipeline robot control system, which belongs to the field of pipeline robot control and mainly comprises a plurality of coal mine gas pipeline robot units, a pipeline robot control end and a plurality of pipeline robot execution ends. The pipeline robot control end mainly comprises a two-bus module master station, an optical fiber transceiver, a network switch, a signal conversion module and an industrial PC (Personal Computer), and the pipeline robot execution end mainly comprises a low-voltage direct-current carrier module slave station, a motion motor, a controller, a sensor, a camera module, a micro switch and an optical fiber transceiver. And the pipeline robot execution end communicates with the control end through the two-bus module slave station, feeds back sensor information to the control end and monitors an instruction sent by the control end. In order to clearly and quickly transmit images in the pipeline, video images shot by the camera module are fed back to the pipeline robot control end through the switch and the optical fiber transceiver.

Description

Technical Field

[0001] This invention relates to the field of coal mine gas pipeline robot technology, and in particular to an intelligent control system for coal mine gas robots based on two-bus technology. Background Technology

[0002] Pipeline transportation is a crucial mode of transport in modern industrial production. It offers advantages such as speed, efficiency, large capacity, small footprint, stability, reliability, and low cost in transporting fluids like water, oil, natural gas, and methane. Most coal mines in China are methane-rich mines, and cast iron pipes, seamless steel pipes, and plastic pipes are commonly used for transporting methane. While cast iron and seamless steel pipes offer high strength and mature manufacturing processes, they have short lifespans and are susceptible to corrosion. Pipelines exposed to the elements or buried underground will inevitably develop corrosion and cracks over time. Leaks in methane pipelines not only cause economic losses and energy waste, affecting pipeline transport efficiency, but can also lead to major safety accidents such as fires and explosions. Therefore, regular inspection and maintenance of coal mine methane pipelines are essential to ensure their safety during operation.

[0003] Coal mine gas pipeline networks have complex structures, including vertical pipes, butterfly valves, bends, and reducing pipe diameters. They also contain obstacles such as coal slag, sludge, and rust. Pipeline robots must navigate these gas pipelines, performing maneuvers such as navigating bends, climbing walls, and passing butterfly valves, while maintaining stable movement even under the influence of obstacles like sludge.

[0004] The complex structure of coal mine gas pipeline networks makes wireless communication between robots and the outside world impossible. Therefore, using wired connections to meet the robot's power and communication needs is not feasible. However, excessive cables can increase the robot's load during long-distance operations, occupy more pipeline space, affect the robot's movement and safety, and hinder the robot's ability to perform complex movements such as climbing walls within the pipeline.

[0005] Once a coal mine gas pipeline robot enters the pipeline, its position and posture information cannot be directly observed except through images returned by cameras. The robot's position information significantly impacts its ability to navigate curves, overcome obstacles, and achieve accurate localization. Maintaining a stable posture is crucial for the pipeline robot's movement. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies. This invention aims to provide an intelligent control system for a coal mine gas pipeline robot, which uses multiple pipeline robots to form the pipeline robot execution end. It achieves wired communication and power supply for multiple pipeline robots through two-bus technology, solving the problem of excessive cables. Multiple sensors provide feedback on the status information of the pipeline robots.

[0007] The method of this invention is achieved through the following technical solution: a control system for a coal mine gas pipeline robot, comprising a control end for controlling the operation of the pipeline robot and an execution end for the operation of the pipeline robot; the pipeline robot control end includes a PC, a two-bus module master station, a signal conversion module, a network switch, and a fiber optic transceiver; the industrial PC communicates with the signal conversion module through the two-bus module master station and transmits video images through the fiber optic transceiver and the network switch; the pipeline robot execution end consists of multiple pipeline robots mounted on power line carrier cables. Each pipeline robot includes a microcontroller, a two-bus module slave station, a sensor system, a motion control system, a fiber optic transceiver, and a micro-switch; the microcontroller communicates with the two-bus module slave station and supplies power to the pipeline robot through the two-bus module slave station; the pipeline robot control end and the pipeline robot execution end are connected through power line carrier cables; the pipeline robot control end sends control commands to the pipeline robot execution end through the two-bus module master station and the power line carrier cable; the pipeline robot execution end feeds back sensor information to the pipeline robot control end through the two-bus module slave station.

[0008] The pipeline robot execution end includes multiple pipeline robots, which complete the functions of transporting power line carrier cables and pipeline inspection. The pipeline robots are mounted on the power line carrier line via a two-bus module. Each pipeline robot can communicate with the pipeline robot control end via RS485 signal through the power line carrier cable.

[0009] The pipeline robot includes an STM32F4 microcontroller and an RS485 signal conversion module. The STM32F4 microcontroller includes a USART serial port, which sends sensor detection information. The RS485 signal conversion module converts the serial port signal into an RS485 signal and sends it to the bus.

[0010] The pipeline robot includes an STM32F4 microcontroller and an RS485 signal conversion module. The STM32F4 microcontroller includes a USART serial port, which sends sensor detection information. The RS485 signal conversion module converts the serial port signal into an RS485 signal and sends it to the bus.

[0011] The coal mine pipeline robot sensor system includes two ultrasonic sensors, two servo motors for adjusting the angle of the ultrasonic sensors, an attitude sensor, and three odometers. The ultrasonic sensors obtain the accurate distance between the coal mine pipeline robot and bends and butterfly valves to achieve smooth cornering and obstacle crossing, and correct static deviations of the attitude sensors. The attitude sensors provide feedback on the robot's motion attitude to prevent abnormal posture during movement. The odometers provide feedback on the robot's position. Sensor information is fed back to the host computer from the slave station via the USART serial port, signal conversion module, and two-wire bus module.

[0012] The ultrasonic sensor of the coal mine pipeline robot improves the accuracy of fixed-distance ultrasonic ranging through the Kalman recursive algorithm, and combines the odometer and ultrasonic sensor to provide feedback on the position of the pipeline robot in the pipeline and the accurate distance between the pipeline robot and the bend and butterfly valve.

[0013] The control system program of the pipeline robot uses the FreeRTOS kernel to complete the task execution requirements, making full use of the computing power of the microcontroller and increasing the frequency of monitoring important status information.

[0014] Compared with existing technologies, this invention effectively reduces the burden of wired communication and power supply through a two-bus module. Furthermore, by connecting multiple coal mine pipeline robots, it enriches the functionality of the coal mine gas pipeline robot's actuator and extends its working distance. Secondly, the actuator of this invention uses multiple sensors to provide feedback on the pipeline robot's position and attitude, allowing operators to intuitively understand the robot's status. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and examples;

[0016] Figure 1 This is a schematic diagram of the bus mounting on the execution end of the coal mine gas pipeline robot of the present invention.

[0017] Figure 2 This is a schematic diagram of the power supply and communication of the two-bus slave station of the coal mine gas pipeline robot of the present invention.

[0018] Figure 3 This is a hardware block diagram of the coal mine gas pipeline robot control system of the present invention.

[0019] Figure 4 This is a schematic diagram of the positioning of the odometer with ultrasonic sensor according to the present invention.

[0020] Figure 5 This is a flowchart of the Kalman filter process for the ultrasonic sensor of the present invention.

[0021] Figure 6This is the Kalman filtering effect of the ultrasonic ranging method of the present invention. Detailed Implementation

[0022] The embodiments of the method of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] like Figure 1 The diagram shows the power supply and communication of a multi-pipeline robot in the execution end of a coal mine gas pipeline robot control system according to the present invention. It includes a two-bus module master station, two-bus module slave stations, power line carrier cables, and pipeline robots. Multiple pipeline robots are mounted on the power line carrier cables via multiple two-bus module slave stations, including pipeline robots responsible for pipeline inspection and pipeline robots transporting the power line carrier cables.

[0024] like Figure 2 The diagram shown illustrates the power supply and communication of the pipeline robot control system of this invention. An industrial PC converts the signal into an RS485 signal via USB and a signal conversion module, loads it onto the master station of the two-bus module, and then sends it to the slave station of the two-bus module. The slave station of the two-bus module converts the signal into a TTL level signal and sends it to the pipeline robot controller to complete communication. Simultaneously, 24V DC power is transmitted to the pipeline robot through the master and slave stations of the two-bus module.

[0025] like Figure 3 As shown in the diagram, the coal mine gas pipeline robot control system uses an STM32F407 microcontroller to communicate with an industrial PC via a USART serial port; it generates PWM signals to control the motor speed and servo angle, and detects the motor's operating speed and current; it drives attitude sensors, ultrasonic sensors, and an odometer to provide feedback on the coal mine gas pipeline robot's status information. The attitude sensor provides feedback on the robot's attitude information, and two ultrasonic sensors correct the static yaw angle deviation of the attitude sensor and provide accurate distance feedback from the bend in the pipeline; the odometer provides feedback on the robot's location; the coal mine gas pipeline robot control system uses FreeRTOS as the system scheduler, calculates PID control signals every 20ms, and obtains the coal mine gas pipeline robot's status information every 25ms.

[0026] like Figure 4 As shown. The positioning scheme using an ultrasonic sensor and odometer provides feedback on the position of the coal mine gas pipeline robot within the pipeline through the odometer, but it cannot provide accurate distance information. By using an ultrasonic sensor to measure the accurate distance between the coal mine gas pipeline robot and bends and butterfly valves, the coal mine gas pipeline robot can smoothly navigate bends and overcome obstacles.

[0027] like Figure 5 As shown. This describes the ultrasonic ranging Kalman filtering process and algorithm.

[0028] The iterative formula for the Kalman recursive algorithm is as follows.

[0029]

[0030] Where is the ultrasonic ranging estimate at the current moment, is the ultrasonic ranging estimate at the previous moment, Zk is the ultrasonic ranging measurement at the current state, and Kk is the Kalman gain.

[0031] like Figure 6 As shown in the figure. The ultrasonic ranging Kalman filter algorithm produces stable ultrasonic ranging data that closely approximates the actual data.

[0032] The overall process of this invention is as follows:

[0033] Step 1: On the human-machine interface of the coal mine gas pipeline robot control terminal, input control commands, including movement direction, movement speed, execution action, feedback of current status, emergency stop, and servo motor angle control.

[0034] Step 2: After receiving the control command, the microcontroller of the coal mine gas pipeline robot parses the address word in the control command and verifies whether the command is correct.

[0035] Step 3: The coal mine gas pipeline robot executes actions according to control commands.

[0036] Step 4: The coal mine gas pipeline robot periodically acquires motor speed, current, ultrasonic ranging information, odometer information, and attitude information.

[0037] Step 5: The microcontroller of the coal mine gas pipeline robot uses feedback motor speed and current information to perform closed-loop control of the motor speed.

[0038] Step Six: The microcontroller of the coal mine gas pipeline robot obtains the ranging distance by filtering the ultrasonic ranging information through a Kalman recursive algorithm.

[0039] Step 7: After receiving the feedback information from the industrial PC, the status of the coal mine gas pipeline robot is judged to confirm that the status is correct.

[0040] This completes the construction and experimentation of the control system.

[0041] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make several modifications without departing from the principles of the present invention, and these modifications should also be considered to fall within the scope of protection of the present invention.

Claims

1. A robot control system for coal mine gas pipelines. Its characteristics are: The system includes a pipeline robot, a pipeline robot control unit, and a pipeline robot execution unit. The pipeline robot control unit includes a two-bus module master station, a network switch, a fiber optic transceiver, an industrial PC, and a signal conversion module. The pipeline robot execution unit includes a two-bus module slave station, a controller, a micro-switch, a fiber optic transceiver, a motion system, and a sensor system. The two-bus module master station of the control unit and the two-bus module slave station of the execution unit are connected via a power line carrier cable. Multiple pipeline robots are mounted on the power line carrier cable. The pipeline robot control unit and the pipeline robot execution unit send control commands and provide feedback sensor information through the two-bus module and the power line carrier cable.

2. The robot control system for coal mine gas pipelines according to claim 1, characterized in that, The industrial PC converts the USB signal into an RS485 signal via the signal conversion module and loads it onto the power line carrier cable to send control commands to the actuator. It also receives sensor information, motor current, and speed feedback from the pipeline robot actuator. Images of the pipeline interior captured by the actuator's network camera are received via a network switch and fiber optic transceiver.

3. The robot control system for coal mine gas pipelines according to claim 1, characterized in that, The pipeline robot actuator controller communicates with the pipeline robot actuator through the two-bus module slave station, and supplies power to the controller, micro switch, fiber optic transceiver, motion system and sensor system through the two-bus module slave station.

4. The robot control system for coal mine gas pipelines according to claim 1, characterized in that, The pipeline robot actuator consists of multiple pipeline robots with different functions.

5. The robot control system for coal mine gas pipelines according to claim 1, characterized in that, The pipeline robot control terminal is connected to the multiple pipeline robots via an RS485 bus. The pipeline robots are mounted as nodes on the RS485 bus to form the pipeline robot execution terminal, which is expandable.

6. The robot control system for coal mine gas pipelines according to claim 1, characterized in that, The aforementioned pipeline robot's actuator motion system and sensor system include a motor driver, a drive motor, a linear motor, an attitude sensor, an ultrasonic sensor, a servo motor, an odometer and an odometer controller. There are three odometers and two ultrasonic sensors. The motor driver integrates a current acquisition module.

7. A robot control system for coal mine gas pipelines according to claim 1, characterized in that, The pipeline robot's execution end uses FreeRTOS preemptive operation mode. Its main tasks are to receive control commands issued by the pipeline robot's control end, and periodically send status detection tasks and DC motor motion control tasks.

8. A robot control system for coal mine gas pipelines according to claim 6, characterized in that, The ultrasonic sensor ranging data is filtered through a Kalman recursive algorithm after the effective data interval is removed to obtain accurate ultrasonic ranging data.

9. A coal mine gas pipeline robot control system according to claim 6, characterized in that, The position information of the pipeline robot is fed back through a position feedback system consisting of an odometer and two ultrasonic sensors.

10. A robot control system for coal mine gas pipelines according to claim 6, characterized in that, The attitude feedback system, consisting of an attitude sensor and two ultrasonic sensors, provides feedback on the attitude information of the pipeline robot. Static deviation correction of the attitude sensor is achieved by adjusting the emission angle of the ultrasonic sensor through two servo motors.

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