Abstract
In this study, a decoupled backstepping sliding mode controller is designed for a ball and beam system as an example of underactuated mechanical systems. The decoupled backstepping sliding mode control method which is a combination of backstepping and sliding mode with a decoupling algorithm is considered to control a ball and beam system. The stability of the system is guaranteed by the design procedure of the controller which is based on the Lyapunov theorem. The effectiveness of the designed controller is verified by simulation tests. Simulation results show that the decoupled backstepping sliding method provides a robust control signal under external disturbances compared to the conventional decoupled sliding mode control method.