Rolling stability control of in-wheel electric vehicle based on two-degree-of-freedom control

In this paper, a novel rolling stability control (RSC) on in-wheel electric vehicle based on two-degree-of-freedom control is proposed. Electric motors have several advantages which internal combustion engines or brake actuators do not have. Differential torque by right and left motors can realize novel vehicle motion controls. Although RSC systems have been developed by automobile and several parts companies, the actuators are only brake actuator systems and cannot output positive torque quickly and precisely. Electric motors can output accurate torque in both directions very quickly. In addition to the actuator advantage, two-degree-of-freedom control is applied for RSC. The proposed method realizes following capability to command value and robustness to roll moment disturbance. Roll model identified with experimental result is shown in the third section. Effectiveness of proposed roll stability control is verified with simulation and experimental results utilizing our two in- wheel electric motor on pure electric vehicle. With proposed RSC, peaks of roll rate and roll angle are suppressed for disturbance roll moment comparison to without control.