Robust-optimal control design for current-controlled electromagnetic levitation system with unmatched input uncertainty

This article introduces the robust-optimal control design for the current-controlled electromagnetic levitation system (CC-EMLS). Because of the uncertain nature of the electromagnetic levitation system, it is essential to propose a robust regulator such that it will handle the system’s uncertainties. The dynamics of CC-EMLS are transformed in terms of the unmatched input uncertainty. The robust control issue in terms of uncertainties is reflected in the cost function, which is translated and solved using the optimal control problem. The controller developed using the optimal control method for the electromagnetic levitation system becomes the solution to the robust control problem to handle the uncertainties of the system. The Lyapunov stability theorem is used to establish the required stability proof. A simulation results demonstrates the proposed controller’s effectiveness, robustness, and efficiency. The integral error indices such as integral absolute error, integral square error, integral time absolute error, and integral time square error, are calculated to validate the effectiveness of the designed regulator.