Application case of integrated servo motor in special robot (furnace pipe crawler)

In the field of industrial high-temperature furnace tube inspection and maintenance, furnace tube crawlers are key equipment for automated operations within pipelines. To address the poor motion stability and insufficient multi-axis coordination accuracy of traditional crawlers, the PMMP40 integrated servo motor is adopted, coupled with CANopen bus synchronous control technology, significantly improving the device's motion accuracy and reliability in high-temperature and complex environments.

1. Introduction to Furnace Tube Crawler

A furnace tube crawler is a specialized robot used for the inspection, cleaning, or maintenance of high-temperature industrial furnace tubes. It must meet the following core requirements:

1. High-temperature adaptability: Long-term tolerance to temperatures exceeding 300°C;

2. Multi-axis coordination: Strict synchronization of the four drive motors ensures smooth movement of the crawler;

3. Low-speed stability: Precise operation within a speed range of 0.02-0.4 m/s to avoid stalling or slipping.

2. Application Solutions and Products

• Servo Motor Model: PMMP4010B-CANopen (integrated design, integrated controller and encoder);

• Drive System: High-precision gear set with a reduction ratio suitable for low-speed, heavy-load conditions;

• Control Mode: PP (Profile Position) mode, supporting preset position trajectory planning;

• Bus Synchronization: Synchronous control of four motors is achieved via the CANopen bus protocol, employing PDO synchronization mode to ensure consistent motion;

• Real-time Monitoring: The host computer monitors each motor's torque and position feedback in real time, dynamically adjusting motion parameters.

3. Problems and Solutions

ProblemSolutionProblem 1: Multi-motor synchronization issues: Asynchronous movement of the four motors caused creeper deviationEnable CANopen PDO synchronization mode and optimize bus communication cyclesProblem 2: Low-speed stuttering: Motion stuttering at 0.08 m/s, normal operation at 0.02 m/sReplace a high-power power supply to ensure stable power supply to the motor at high speedsProblem 3: Insufficient parameter adaptability: Motor response lag during acceleration and deceleration at 0.2 m/s²Adjust the speed loop PID parameters to reduce the acceleration slope

4. Application Results

• Improved synchronization accuracy: Position synchronization error of the four motors is ≤ 0.05 mm, meeting the requirements for operation in the narrow furnace tube space;

• Improved speed stability: Smooth operation in the entire speed range of 0.02 to 0.4 m/s, completely eliminating stuttering;

• Enhanced reliability: No performance degradation after 200 hours of continuous high-temperature operation, and a 60% reduction in failure rate.

5. Summary

The application of an integrated servo motor overcomes the technical bottlenecks of multi-axis coordination and low-speed stability in furnace tube crawlers. This case demonstrates the superior performance of the PMMP4010B servo motor in high-temperature, high-precision applications, providing a standardized solution for specialized robotic drive systems. This solution can be expanded to more demanding applications such as chemical pipeline inspection and nuclear facility maintenance.