Discontinuous Stabilizing Control of Skid-Steering Mobile Robot (SSMR)

A discontinuous stabilizing control of Skid-Steering Mobile Robot (SSMR) is proposed using σ transformation introduced in Astolfi (Syst. Control Lett. 27(1), 37–45, 1996). A linear time-invariant system (LTI) is obtained which is driven by state-dependent disturbance. A linear H_∞ controller is designed to reduce the effect of this disturbance. Two control transformations are carried out in order to bring the system in a form suitable for σ transformation; one for the case of SSMR orientation around 0 and π and the other around ± π/2. The resulting two controllers for the two cases are blended using fuzzy logic. The closed-loop system is simulated using Matlab environment on point stabilization from different initial conditions. Results show that the proposed controller guarantees asymptotic stability with smooth paths. Experimental results are consistent with simulation and show that the proposed controller succeeded to stabilize the SSMR to the desired point without shuttering.