Trajectory Tracking Control of Pneumatic Servo System: A Variable Gain ADRC Approach

Area of Science:

• Control Engineering
• Robotics
• Mechatronics

Background:

• Pneumatic servo systems are widely used in automation.
• Achieving precise trajectory tracking and effective disturbance rejection remains challenging.
• Existing control methods may struggle with dynamic uncertainties and noise.

Purpose of the Study:

• To develop a novel error-driven variable gain active disturbance rejection control (ADRC) approach for pneumatic servo systems.
• To enhance trajectory tracking accuracy and disturbance rejection capabilities.
• To improve the robustness and performance of pneumatic servo control.

Main Methods:

• A variable gain active disturbance rejection control (ADRC) strategy was designed.
• The ADRC incorporates a variable gain tracking differentiator (TD) for noise tolerance and improved signal tracking.
• A variable gain extended state observer (ESO) was developed for enhanced estimation accuracy, driven by estimation errors.
• A variable gain error feedback controller (EFC) was implemented to further refine control precision.

Main Results:

• The proposed variable gain TD demonstrated improved tracking and derivative extraction, with noise tolerance.
• The variable gain ESO showed enhanced estimation performance due to its error-driven gain adjustment.
• The variable gain EFC contributed to significant improvements in overall control accuracy.
• Simulations and experimental results validated the effectiveness of the proposed ADRC approach.

Conclusions:

• The developed error-driven variable gain ADRC effectively guarantees desired performance in trajectory tracking and disturbance rejection for pneumatic servo systems.
• The modular design with variable gain TD, ESO, and EFC offers enhanced adaptability and precision.
• The proposed control strategy presents a viable solution for improving the performance of pneumatic servo applications.