Adaptive fuzzy PID cross coupled control for multi-axis motion system based on sliding mode disturbance observation

Area of Science:

• Robotics and Control Systems
• Precision Engineering
• Industrial Automation

Background:

• Multi-axis motion systems are crucial in industrial applications like CNC machines and robots.
• Contour accuracy is vital for these systems, depending on both single-axis precision and multi-axis coordination.
• Existing methods often struggle with non-linearity, parameter variations, and external disturbances.

Purpose of the Study:

• To develop an advanced contour control strategy for multi-axis servo motion systems.
• To improve both single-axis tracking accuracy and overall multi-axis contour accuracy.
• To address challenges posed by non-linearity, parameter uncertainty, and external disturbances.

Main Methods:

• A hybrid control strategy integrating sliding mode control (SMC), a disturbance observer (DO), and an adaptive fuzzy PID cross-coupled controller (CCC).
• SMC provides robustness to parameter variations and disturbances.
• DO estimates and compensates for external disturbances, reducing SMC chattering.
• Adaptive fuzzy logic fine-tunes PID parameters for improved axis coordination and contour accuracy.

Main Results:

• The disturbance observer effectively estimated disturbances and significantly reduced the chattering of the sliding mode control signal.
• The adaptive fuzzy PID-CCC demonstrated superior performance over conventional PID-CCC, markedly reducing tracking errors.
• Overall contour accuracy was substantially improved, validated through simulations on a three-axis platform.

Conclusions:

• The proposed control method enhances single-axis tracking accuracy by mitigating disturbances and SMC chattering.
• The adaptive fuzzy PID-CCC effectively compensates for inter-axis dynamic mismatches, boosting contour accuracy.
• The integrated approach offers a robust and effective solution for improving precision in multi-axis motion systems.