Fault-Tolerant Control Achieving Prescribed Tracking Accuracy Within Given Time for Euler-Lagrange Systems Under Unknown Actuation Characteristics and Fading Powering Faults

This paper proposes a fault-tolerant control scheme for Euler-Lagrange systems that ensures the tracking error decays to a pre-specified accuracy level within a prescribed time period, despite unknown actuation characteristics and potential fading powering faults. By performing deliberately designed coordinate transformations on the tracking error, the complex and demanding problem of “reaching specified precision within a given time” is transformed into a bounded control problem, facilitating the development of the control scheme. To enhance practicality, the design incorporates smooth function fitting and dynamic surface control techniques. Additionally, the proposed control algorithm is robust to faults, effectively handling a combination of fading powering faults and additive actuator faults without requiring additional human intervention. Numerical simulations on a two-link robotic manipulator verify the effectiveness of the proposed control algorithm.