High bandwidth control of precision motion instrumentation

Area of Science:

• Control Engineering
• Mechatronics
• Precision Instrumentation

Background:

• Precision motion control is crucial for advanced instrumentation, often limited by system dynamics and resonances.
• Iterative Learning Control (ILC) offers a feedforward approach to improve performance by leveraging trajectory repetition.

Purpose of the Study:

• To develop and evaluate high-bandwidth iterative learning control (ILC) designs for precision motion instrumentation.
• To enhance control system performance for repetitive and nonsmooth trajectories.

Main Methods:

• Presented two ILC designs: one maximizing bandwidth using a system dynamic model, and another with time-varying bandwidth for nonsmooth trajectories.
• Applied and evaluated ILC designs on a multiaxis piezoelectric-actuated flexure system performing a nonsmooth trajectory.

Main Results:

• Achieved significant improvements in bandwidth and precision compared to conventional feedback control.
• Demonstrated the capability of ILC to enable precision motion control at frequencies exceeding system resonances.

Conclusions:

• ILC designs provide a powerful method for achieving high-bandwidth precision motion control in demanding applications.
• The developed ILC strategies are effective for both smooth and nonsmooth trajectories, particularly in systems like piezoelectric-actuated stages.