A disturbance observer-based adaptive control approach for flexure beam nano manipulators

Area of Science:

• Mechatronics and Control Systems
• Precision Engineering
• Robotics

Background:

• Conventional mechatronic systems face challenges in micro/nano manipulation, including cross-axis coupling, dynamical uncertainties, and input saturations.
• These challenges can significantly degrade system performance in high-precision applications.
• Flexure beam-based servo stages are utilized for micro/nano manipulations but require advanced control strategies.

Purpose of the Study:

• To develop a systematic modeling and control methodology for a two-dimensional flexure beam-based servo stage.
• To address and overcome control challenges such as cross-axis coupling, dynamical uncertainties, and input saturations.
• To achieve high-precision servo manipulation for micro/nano tasks.

Main Methods:

• A novel disturbance observer-based adaptive backstepping-like control approach was developed.
• An auxiliary system was introduced to compensate for input saturations.
• The control architecture was implemented on a custom nano-manipulating system with a flexure beam structure and voice coil actuators (VCAs).

Main Results:

• The proposed control approach effectively accommodated model uncertainties and coupling dynamics.
• Input saturations were successfully compensated by the auxiliary system.
• Real-time experiments demonstrated precision errors of less than 1% for trajectory and contour tracking tasks.

Conclusions:

• The developed control methodology provides a robust solution for high-precision micro/nano manipulation.
• The disturbance observer-based adaptive backstepping-like control effectively handles system uncertainties and coupling.
• The system's performance, validated through real-time experiments, shows significant improvements in precision.