Robust Control Strategy of Gradient Magnetic Drive for Microrobots Based on Extended State Observer

Area of Science:

• Biomedical Engineering
• Robotics
• Control Systems

Background:

• Microrobots offer significant potential for in vivo biomedical applications.
• Controlling microrobots precisely in complex biological environments is challenging due to various disturbances.
• These disturbances negatively impact micromanipulation tasks and overall effectiveness.

Purpose of the Study:

• To propose a robust motion control method for precise microrobot path tracking.
• To enhance the efficiency and accuracy of microrobots operating in vivo.
• To address the limitations posed by external disturbances and system uncertainties.

Main Methods:

• Utilizing an extended state observer (ESO) to estimate total system disturbances and uncertainties.
• Designing a path tracking controller by integrating sliding mode control (SMC) with disturbance compensation.
• Implementing experiments within a gradient magnetic field drive system for path tracking validation.

Main Results:

• Achieved mean absolute path tracking error below 14 µm and root mean square error below 17 µm in a simulated vascular structure.
• Demonstrated superior suppression of external disturbances and system uncertainties compared to traditional PID control.
• Validated the enhanced anti-interference capability and robustness of the proposed control method.

Conclusions:

• The developed robust motion control method significantly improves microrobot path tracking accuracy and reliability.
• The combination of ESO and SMC effectively compensates for disturbances, enabling precise micromanipulation.
• This approach represents a substantial advancement for in vivo microrobot applications in the biomedical field.