The problems of camera measurements in tracking-error fuzzy control of mobile robots

This paper deals with Takagi-Sugeno modelling and control of nonholonomic mobile robots in the case when the measurements are given by the camera. The measurements in such case are difficult to deal with: they are given only in discrete time samples, usually they are delayed, a high-level noise is present on the measurements. The nonlinear tracking error-model is solved analytically under the premise of ZOH present at the system input. The nonlinear discrete model is developed. Several discretization issues are discussed and the modelling errors are analysed. The sector nonlinearity approach is used for constructing the Takagi-Sugeno model. The control is designed in the LMI framework. Some performance issues are discussed on the simulation cases. Key-Words: Takagi-Sugeno, PDC control, Mobile robot, Kinematic model, Discretization, Delay, Decay rate