Sliding mode control for longitudinal motion of underground mining electric vehicles

Nowadays, zero-emission electric vehicles (EVs) become more and more attractive personnel transport vehicles for mining industry. However, underground mining electric vehicles (UMEVs) require more stable, reliable and robust vehicle system compared with traditional EVs due to their special working conditions and the complex road conditions. Thus, a proper controller needs to be designed. This paper first presents the modeling of an UMEV for both acceleration and braking. Then, the controller based on the sliding mode control (SMC) is designed to track the longitudinal velocity and keep the longitudinal slip ratio in a desired stable region in the presence of the bounded system uncertainties. The comparison of the simulation results for both the proposed SMC controller and a traditional PID controller shows that the proposed SMC controller has a better performance for the long-distance up/down slopes with varying rolling resistance coefficients.