Kinematic Model and Fast-Terminal Sliding Mode for Four-Mecanum-Wheeled Mobile Robot

Today's omnidirectional wheeled robot is being widely utilized and developed with different types of omnidirectional wheel versions because of its versatility and multi-tasking mobility. This paper proposes a kinematic model for a robot using four omnidirectional Mecanum wheels with hardware-error compensation and a mathematical model of the motors driving the entire system. On this basis, we develop a nonsingular fast-terminal sliding mode controller with finite-time convergence. Satisfaction of the Lyapunov stability criteria and the finite-time stability ensure that the state variables are forced to their desired values, thereby ensuring the ability of the Mecanum wheels to follow the reference speeds in a short finite-time interval. Finally, the velocity and position of the robot are controlled following the desired trajectories generated.