The studies of safety and stability systems of small electric vehicles can be divided broadly into two areas of interest, namely skid control by motor sensors and safety improvement by Anti-Lock Braking System (ABS). However, for a small electric vehicle, there is no space to install a brake unit for ABS in driving tire because an in-wheel motor system is used as the driving unit, and there have been no simulations of an ABS that combines a mechanical brake system and a hydraulic brake system. The purpose of the present study is to improve the safety and stability systems of the small electric vehicle. The effect of a regenerative brake on a turning motion and the influences of the weight movement with the suspension were investigated. In this report, the hydraulic-mechanical hybrid brake system was combined with the ABS as a braking system for a small electric vehicle. A hybrid simulation model comprising velocity and the pressure of the brake fluid in the brake piping by the characteristic curve method was constructed for the hydraulic and mechanical brake system. The braking pressure of the braking unit, which included the antilock braking unit modeled by the lumped constant model, was controlled to compensate for the small stiffness value of the mechanical braking system.
