Prescribed performance tracking control for a class of nonlinear system considering input and state constraints

Area of Science:

• Control Systems Engineering
• Robotics
• Fault-Tolerant Control

Background:

• Actuator failures and state constraints pose significant challenges in control system performance.
• Existing control methods may struggle to maintain accuracy and speed under saturation conditions.

Purpose of the Study:

• To develop a novel anti-saturation tracking control strategy for state-constrained systems experiencing actuator failure.
• To ensure robust performance and maintain predetermined control indexes despite system constraints.

Main Methods:

• Introduction of an auxiliary variable with a performance guider to establish a feedback control loop.
• Design of a robust fault-tolerant control law with variable gains to suppress tracking errors.
• Development of an anti-saturation algorithm to address input constraints without performance degradation.

Main Results:

• The proposed method effectively suppresses tracking errors within a specified range after a defined time.
• The anti-saturation algorithm successfully manages input constraints while preserving control capabilities.
• The feedback control loop meets fast and accurate requirements for constrained tasks.

Conclusions:

• The developed anti-saturation tracking approach provides effective control for state-constrained systems with actuator failure.
• The method demonstrates robustness and maintains performance under saturation and fault conditions.
• Simulations on a robot manipulator validate the efficacy of the proposed control strategy.