Discrete-Time Estimation/Approximation-Avoidance Control With Prescribed Performance

We address the problem of tracking control for uncertain discrete-time systems with unknown and unavailable plant dynamics, aiming to achieve prescribed performance within a preset convergence time for tracking errors. Our proposed control protocol is independent of the knowledge of system dynamics or the utilization of approximators/estimators. Instead, we employ transformed errors to develop novel nonlinear functions for control feedback. Consequently, we establish a new estimation/approximation-free indirect stabilization framework that serves as a standard paradigm for discrete-time prescribed performance control synthesis. Finally, simulation results applied to the missile seeker stabilized platform demonstrate the effectiveness of our approach.