Velocity control of a spherical rolling robot using a grey-PID type fuzzy controller with an adaptive step size

This paper proposes a grey-PID type fuzzy controller (GPIDFC) with an adaptive step size to control the velocity of a spherical rolling robot characterized by a highly nonlinear system model. The proposed control structure consists of a grey predictor and a PID type fuzzy controller (PIDFC). Another fuzzy controller is proposed to tune the step size of the grey predictor. The simulation results show that the PIDFC coupled to a grey predictor with an adaptive step size is able to control the spherical rolling robot with a better transient response, e.g. lower overshoot, when compared to a conventional PIDFC