A Compound Control Based on the Piezo-Actuated Stage with Bouc-Wen Model

Area of Science:

• Mechatronics
• Control Systems Engineering
• Materials Science

Background:

• Piezoelectric actuators (PAs) are crucial for micro-positioning stages.
• Hysteresis non-linearity in PAs introduces significant positioning errors.
• Existing models struggle to accurately capture PA hysteresis across different frequencies.

Purpose of the Study:

• To develop and validate a modified Bouc-Wen model for PA hysteresis.
• To implement a control strategy for compensating hysteresis non-linearity.
• To improve the accuracy of piezo-actuated stages.

Main Methods:

• A modified Bouc-Wen hysteresis model was developed, distinguishing between rate-independent and rate-dependent types.
• Particle Swarm Optimization (PSO) was used for accurate parameter identification of the hysteresis model.
• An inverse model feedforward compensator was designed and integrated with a fuzzy PID controller.

Main Results:

• The modified Bouc-Wen model effectively described PA hysteresis.
• PSO successfully identified model parameters for improved accuracy.
• The combined fuzzy PID controller and feedforward compensator significantly reduced hysteresis-induced errors.

Conclusions:

• The proposed control strategy demonstrates high efficacy in compensating for piezoelectric actuator hysteresis.
• Accurate modeling and advanced control techniques are vital for precision micro-positioning.
• This approach enhances the performance and reliability of piezo-actuated systems.