Adaptive Third-Order Fixed-Time Integral Sliding-Mode Control for Piezoelectric-Driven Microinjectors.

Area of Science:

• Control Engineering
• Mechatronics
• Materials Science

Background:

• Piezoelectric actuators exhibit hysteresis and chatter, complicating precise motion control.
• Existing control methods often require detailed knowledge of system parameters and disturbances.

Purpose of the Study:

• To develop an adaptive control scheme for piezoelectric microinjectors that overcomes hysteresis and chattering.
• To achieve global fixed-time stability with settling times independent of initial conditions.
• To eliminate the need for prior knowledge of disturbance upper bounds.

Main Methods:

• Implementation of an adaptive third-order fixed-time integral sliding-mode control (A3-FTISMC).
• Utilizing high-order sliding-mode and integral control to address actuator nonlinearities.
• Designing adaptive laws for disturbance rejection without prior bound information.

Main Results:

• Demonstrated effectiveness through simulations and experiments on a piezoelectric-driven microinjector.
• Achieved a settling time of 0.276 s and steady-state error of 1.12 µm in simulations for sinusoidal tracking.
• Experimental results showed a settling time of 0.4 s and steady-state error of 2.7 µm.
• Outperformed existing methods in convergence speed and tracking accuracy.
• Exhibited robustness to varying reference trajectories and initial conditions.

Conclusions:

• The A3-FTISMC scheme provides high-performance control for piezoelectric microinjectors.
• The method offers fast stabilization, improved accuracy, and robustness.
• Presents a theoretical basis and practical value for piezoelectric actuation systems in industrial applications.