Dc Motor Control: A Global Prescribed Performance Control Strategy Based on Extended State Observer

In this paper, we investigate the high-precision motion control problem of DC motors. By designing an extended state observer, system uncertainties and external disturbances can be estimated and compensated in the control law. By introducing a shifting function and a fixed-time prescribed performance, a global prescribed performance control scheme is constructed to achieve desirable transient and steady-state tracking performance. The proposed control strategy ensures that the tracking error can converge to a prescribed region within the user-specified time under any bounded initial tracking error, thereby eliminating the longstanding dependence on accurate initial conditions. Using Lyapunov stability theory, it is proved that all the closed-loop system signals are uniformly bounded. Finally, numerical simulations confirm the effectiveness and advantages of the proposed approach.