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.
• Synchronous control of four motors is achieved via the CANopen bus protocol, employing PDO synchronization mode to ensure consistent motion.
• The host computer monitors each motor's torque and position feedback in real time, dynamically adjusting motion parameters.
3. Problems and Solutions
1. Problems Encountered
Multi-motor synchronization issues
Asynchronous movement of the four motors caused creeper deviation
Low-speed stuttering
Motion stuttering at 0.08 m/s, normal operation at 0.02 m/s
Insufficient parameter adaptability
Motor response lag during acceleration and deceleration at 0.2 m/s²
2. Solution
Enable CANopen PDO synchronization mode and optimize bus communication cycles
Replace a high-power power supply to ensure stable power supply to the motor at high speeds
Adjust the speed loop PID parameters to reduce the acceleration slope
4. Application Results
1. 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.
2. Improved speed stability: Smooth operation in the entire speed range of 0.02 to 0.4 m/s, completely eliminating stuttering.
3. 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 pipe 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.
