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In this paper, the performance tradeoffs in the design of electronically controlled suspension systems are theoretically studied. Using quarter car model, a new treatment procedure for the control laws is introduced using fully active suspension system with two control strategies. The first strategy is considered for vehicle vibration isolation due to random road excitation only. The second strategy is considered to perform a zero steady-state suspension deflection due to body vehicle attitude variation during maneuvering, braking and aerodynamics as well as vibration isolation due to random road excitation. The two strategies are achieved by using two different optimization techniques combined with PID (Proportional-Integral-Derivative) compensator. The first technique is based on Linear Quadratic Regulation (LQR) technique and the second technique is based on Genetic Algorithm (GA).

One of the main causes of the torsional and bending fluctuations of the driveline is the angularity of the driveshaft and its universal joints. Most of the previous studies of the driveline vibrations have considered constant and equal angularities of these joints. However, the exact equality of the angularity is very difficult to maintain for ground vehicles under different ride vibration modes. This paper is concerned with the coupling between the driveline fluctuations and the ride vibrations of the rear drive vehicles. The coupled motions, which are; drive axle suspension deformation and vehicle body pitch angle and their derivatives, have been used to study the driveshaft and output shaft bending and torsional fluctuations. The results have showed that the fluctuations of the driveshaft due to the base angularity of the joints are superimposed by another fluctuation due to the bounce and pitch of the vehicle body.

Magnetorheological (MR) fluid dampers are the most promising devices for practical vibration control applications because they have many advantages such as mechanical simplicity, high dynamic range, low power requirements, large force capacity and robustness. This paper aims to study the dynamical behavior of a linear MR fluid damper through experiments. Also, an efficient and simple model is developed to identify the damping force as a function of the damper velocity, acceleration and applied voltage to the magnetic coil, without using any complicated mathematical or differential equations, which will be very useful for large and complicated applications. The identified parameters of the MR damper are obtained using trial-and-error methodology. The validation is done using the dynamical behaviour of MR damper for both experimentation and simulation, by solving the modified Bouc-Wen (M B-W) model that can predict the dynamical behavior of MR dampers accurately.