Behavioral Study on Passenger and Driver Dynamics Utilizing 14-DOF Half Car Active Suspension System

The main aim of the current research work is to investigate the behavior of passenger and driver biomechanics when the vehicle is excited under road irregularities. For this purpose, a 14-degrees of freedom (DOF) human-vehicle-road model was proposed. In addition to that, the ride comfort of the occupant with the aid of active suspension and its influence on other performance indices like suspension working space and road holding were also investigated. Besides sprung mass acceleration, the ride comfort was evaluated with pitching acceleration and occupant’s head acceleration representation. Active suspension based on Proportional Integral Derivative (PID) controller with hydraulic actuator was implemented. Then, the parameters of the PID controller are optimally tuned by adopting genetic algorithm (GA) with the assist of integral time absolute error (ITAE) method. The objective function was obtained by combining the ITAE of tire deflection, suspension deflection and sprung mass motion. Various road profiles such as single bump and random profile were generated and tested on the proposed controller vehicle model to guarantee the robustness. Numerical examples were presented under frequency and time domains to clearly demonstrate the effectiveness of the proposed GAPID-based active suspension system over the passive system. Furthermore, the Seat-To-Head transmissibility ratio (STH) for driver and passenger was established to comprehend the behavior.