الفهرس | Only 14 pages are availabe for public view |
Abstract This thesis contains theoretical and experimental studies of the hyDROPneumatic vehicle suspensions. Depending on the well-known quarter car model, first techniques for modeling the vehicle and road surface are discussed. The standard linear and nonlinear analysis methods are reviewed. The performances of the proposed suspension systems are compared with both the baseline passive system and an idealized fully active suspension one. Secondly, the analysis and the descriptions of a hyDROPneumatic suspension system is studied based on the existing hyDROPneumatic passive suspension system of CITROEN-BX type. Predicted results for this existing hyDROPneumatic passive suspension system are generated in terms of the I.S.0. weighted body acceleration; dynamic tyre load, and suspension working space. Thirdly, the control laws for active suspension systems using the full and limited state feedback gains are generated. The controller design for the proposed suspension is based on limited state feedback, and the Nelder Mead simplex algorithm is used to calculate the gains to optimise the performance index. The effects of the control law time delay, and the payload variations on the active suspension system performance are discussed. Fourth, two versions of slow active (limited bandwidth) hyDROPneumatic suspension. systems are studied and developed. By using existing hyDROPneumatic suspension system components, that taken off Citroen-BX type, it is capable to form a practical slow active hyDROPneumatic suspension system. By inserting a PlO controller into the error correction signal with the suspension working space feedback signal, a self leveling effect can be obtained, Fifth, the characteristics of the practical hyDROPneumatic passive suspension system (i.e. gas spring stiffness and throttling valve-damping coefficients) are measured, and the quarter car (single wheel station) test rig is designed to evaluate the performance of the hyDROPneumatic passive suspension system which taken off CITROEN-BX type. A controller is designed to drive the practical slow active hyDROPneumatic suspension system using Labview software with the pc mIc, and the data acquisition card. Finally, the theoretical and the experimental results of the slow active hyDROPneumatic suspension system are reasonable and encourage continuing the work in this field with the limited state feedback gains. |