Adaptive Estimated Inverse Output-Feedback Quantized Control for Piezoelectric Positioning Stage

Area of Science:

• Control Systems Engineering
• Robotics and Automation
• Materials Science (Piezoelectric Materials)

Background:

• Piezoelectric positioning stages are crucial for high-precision applications.
• Quantization, hysteresis, and the need for state estimation pose significant control challenges.
• Existing control methods often require precise parameter identification or direct state measurements.

Purpose of the Study:

• To develop an adaptive estimated inverse output-feedback quantized control scheme for piezoelectric positioning stages.
• To address the challenges of quantization, hysteresis, and unmeasured states in control systems.
• To achieve precise tracking performance and system stability without explicit parameter identification.

Main Methods:

• Introduced a linear time-varying quantizer model with online parameter estimation.
• Employed a fuzzy approximator to avoid piezoelectric stage parameter identification.
• Developed an estimated inverse compensator to mitigate actuator hysteresis nonlinearities.
• Designed a states observer to eliminate the need for velocity and acceleration measurements.

Main Results:

• Demonstrated that all signals in the piezoelectric positioning stage are uniformly ultimately bounded.
• Achieved prespecified tracking performance for the quantized control system using an error transformed function.
• Validated the effectiveness of the proposed quantized controller through computer-controlled experiments.

Conclusions:

• The proposed adaptive quantized control scheme effectively addresses quantization and hysteresis in piezoelectric positioning stages.
• The controller achieves robust stability and high tracking accuracy without requiring detailed system parameter knowledge.
• Experimental results confirm the practical applicability and performance of the developed control strategy.