Trajectory Tracking of an Intelligent Mobile Robot on a Slope Surface using the Nonlinear Sliding Mode Control

The wheeled mobile robots have many applications due to their advantages such as wide workspace, mobility and maneuverability. Intelligence of mobile robots to perform autonomous movements is also one of the favorite fields of robotics researches. In this paper, the trajectory tracking of an intelligent mobile robot on a sloping surface is studied using a nonlinear sliding mode control. First, the nonlinear dynamic equations of a wheeled mobile robot are derived on a sloping surface using the Newton-Euler method. A multistage nonlinear control block is then proposed for trajectory tracking. First, the controller calculates the linear and angular velocity of the robot to find the position of the robot, and then, assuming uncertainties in the dynamic model, a sliding model controller is used to track the robot's specific path. Various simulations are presented to validate the control method, which the results show the capability and efficiency of the proposed method.