Developing and Implementing a Quantum Algorithm for the Sliding Mode Controller Using Multiple Qubit Operators: Application to DC Motor Speed Drive

With the advent of quantum computing, almost all classical computing concepts must be translated into quantum equivalents. Control theory, in particular, requires a large numbers of calculations. This paper designs and presents a quantum sliding mode controller. The controller uses two qubit states, one for detecting tracking errors and the other for determining the signs of the errors. The control signal to be applied to the system is stored in the third qubit state. This new controller is implemented on a DC motor to control the angular velocity using electrical current as an input signal. In terms of tracking error energy performance, the results show that the quantum sliding mode controller is just as efficient as the classical sliding mode controller. However, the quantum controller outperforms its predecessor by using 76% to 79% less control energy, allowing for smaller actuators. This represents a significant advancement in control theory in the era of quantum computers. Indeed, actuator control energy is the main drawback of the classical sliding mode control and reducing this energy is one of the main challenges for the control community.