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The main objective of this work is to enhance the occupant ride comfort. Ride comfort is quantified in terms of measuring distinct accelerations like sprung mass, seat and occupant head. For this theoretical evaluation, a 7- degrees of freedom (DOF) human-vehicle-road model was established and the system investigation was limited to vertical motion. Besides, this work also focused to guarantee other vehicle performance indices like suspension working space and tire deflection. A proportional-integral-derivative (PID) controller was introduced in the vehicle model and optimized with the aid of the genetic algorithm (GA). Actuator dynamics is incorporated into the system. The objective function for PID optimization was carried out using root mean square error (RMSE) concept.

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.

To achieve the simultaneous improvement in ride comfort of the passenger as well as the stability of the vehicle, a second-order sliding mode controller is proposed in this study. Super twisting algorithm attenuates the chattering effect present in the conventional sliding mode controller without affecting the stability of the system. The Lyapunov stability analysis is carried out to verify the stability of the controller. The effectiveness of the designed super twisting algorithm used second-order sliding mode controller is validated in a semiactive quarter car suspension with seat model. Modified Bouc-wen magnetorheological (MR) damper model is used as a semiactive damper and the voltage that has to be supplied to the magnetorheological damper is controlled by a super twisting algorithm and sliding mode controller. Continuous modulation filtering algorithm is adopted to convert the force signal of a controller into the equivalent voltage input to the MR damper.

This paper illustrates the problem of improving ride and handling characteristics of an All Terrain Vehicle (International BAJA) using Input based control. Based on the virtual model seven DOF mathematical model is developed. Fuzzy control system is developed and incorporated to assist MATLAB SIMULINK program in the simulation process, to suppress vertical heave motion of the ATV as well as improve the handling characteristics also. In ATV front wheels (both left and right fitted with conventional dampers) are provided with IR sensor, which gives the input to the rear suspensions through the developed Fuzzy control system. Rear suspensions are fitted with OEM MR Dampers (MRD). Steering wheel sensor gives the direction of the steering position and this input is given to Fuzzy. Simulation results show that the projected process furnish better results of both ride and handling characteristics.

This paper presents a mathematical approach for creating a vehicle model incorporating the characteristics of tires, suspension, forces acting at the tire/road interface, suspension forces, wind forces and gravitational forces. The model has been made for a middle class limousine. Two sets of equations, one set for the translatory motion and the other set for rotational motion have been derived. Torques, forces and angular or longitudinal velocities have been chosen as variables to act as interface between different sub - models. The complexity of the vehicle model created has been optimized for vehicle dynamics simulation. All the forces have been found in the undercarriage co-ordinate system. While substituting them in the equations of motion they are multiplied with the transformation matrix for the transformation from the undercarriage to the inertial co-ordinate system.

The objective of this paper is to study the influence of a suspension system on the human body with the effect of the controller behavior. For this work, 2-Degree of Freedom (DoF) quarter car suspension system with 4 DoF seated human body is modeled. The mathematical equation is developed by using a lumped mass parameter method. Governing equations of motions are generated by Newton’s Law of motion. Random road profile is also considered for this study. MATLAB/SIMULINK software is used to simulate the system results and system analysis is limited to a Proportional Integral Derivative (PID) controller with hydraulic actuator. Seat to Head transmissibility ratio of the active suspension system is analyzed and compared with the passive suspension system. Finally, to illustrate the effectiveness of the proposed active system, simulated results are compared with ISO 2631 comfort curves.