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This is a theoretical investigation into the effect of various suspension configurations on a tracked vehicle performance over bump terrains. The model developed is validated using published experimental data of the modal characteristics of the vehicle. The desired performance is based on ride comfort via the mixed objective function (MOF), which combines the crest factor of bounce acceleration, bounce displacement, angular acceleration, and pitch angle. The optimisation process involves evaluating the MOF for different numbers and locations of dampers and under different rigid bump road conditions and speeds. The system responses of the selected suspension configurations in the time and frequency domains are compared against the undamped suspension. The results show that the suspension configurations have a significant effect on the vehicle mobility over bump road profiles. For a five-road-wheel half model of a tracked vehicle, the maximum number of dampers to use for ride comfort over these road bumps is three with the dampers located at wheel positions 1, 2 and 5. This confirms the current practice for many tracked vehicles with 10 road wheels. However, it is further shown that the suspension fitted with two dampers at the extreme road wheels offer the best performance over various rigid bump terrains.

Magnetorheological (MR) dampers are a semi active control device that becoming a promising actuators in vibration mitigation. The unique properties of MR fluids are used to control the damping force without consuming large power source. Despite MR dampers are fail-safe, efficient, and robustness devices, they poses significant nonlinear characteristics. A well-known Bouc-Wen models and their extension modified Bouc-Wen are the most accurate models that predict the hysteresis of the MR dampers. However, these models suffer from some complexity and limitations and they miss a good fitting to the measured data. In this paper, the existing modified Bouc-Wen (MBW) models are introduced and their dynamic characteristics are simulated using MATLAB Simulink environment. The robustness of the model is judged by a comparison between the experimental tests of the MR damper (on and off state) on the MTS damper test machine in MTC and the simulated characteristics. To better understand the damper nonlinearity, an investigation into the effect of the model parameters on the dynamic characteristics of the damper is studied. A parametric study is proposed to identify the optimal model parameters that best fits the experimental data. The response of the model with the obtained parameters is validated across the measured MR damper characteristics under different sinusoidal excitations and command current. The results show a good agreement between the simulated and measured responses of the MR damper.

A dual-axis inertially stabilized platform (DISP) was designed, modelled, and manufactured to control the pitch and yaw rotations continuously about Y and Z axes respectively for the purpose of tracking and observation of moving objects from a moving platform. The DISP structure consists of an inner gimbal that carries the payload (sensors) and revolves in the elevation direction about the trunnion -axis, and an outer gimbal that makes the cross-elevation rotation (azimuth). At first, 3D model of the DISP was constructed using the parametric computer-aided design (CAD) software. Then, to investigate the kinematic and dynamic performance of the systems under various excitations, A MATLAB model is generated. The designed model is optimized using CAD software to reduce and redistribute the DISP masses for better output of the model performance. The results show a small inertia effect due to the great reduction of masses of the inner and outer frames. In addition, the elevation and azimuth torques are also decreased.

Hydro-gas suspension systems cushion shocks and damp oscillations of vehicle hull when it moves on uneven terrain. The hydro-gas suspension provides the vehicle with proper ride comfort due to non-linear characteristics of hydro-gas units. The hydro-gas suspension system can store a large amount of potential energy; accordingly, it can withstand higher shocks than the torsion bar suspension. Consequently, it is preferred to be used in the design of vehicle suspension. In this paper, a mathematical model for hydro-gas unit used in BMR wheeled vehicle is established to evaluate its characteristics using Matlab /Simulink program. The mathematical model is validated experimentally using the data measured for the unit in laboratory using MTS (793) damper test system. The unit is tested using an input sine wave excitation by a frequency and amplitude corresponding to real road conditions.A f floating piston area V 2 volume of upper chamber A p piston area Vo initial volume of gas chamber A r rod area X floating piston displacement v vehicle speed Z main piston displacement a road wave length