Discrete-time sliding-mode control of four driving/steering wheels mobile platform

In this paper a discrete-time sliding mode controller for the trajectory tracking problem of four-driving-steering wheels (4DW/SW) mobile platform. Seekur is a holonomic, all-weather, outdoor robot platform for outdoor security, inspection and research. Seekur has an unique shape that combined with omni-directional steering allows truly holonomic movement. The discrete-time sliding mode controller has been designed using a discrete time nonholonomic model of Seekur, instead of the usual continuous-time model and the problems caused by the discretization of the continuous-time controller are avoided. The efficiency of the discrete-time sliding mode controller is proved by simulations and real time results.