Stiffness And Damping Design Of A Bus Fitted With Anti-Roll Hydraulically Interconnected Suspension System

Since the invention of the Anti-Roll Hydraulically Interconnected Suspension(HIS) System, it began to be used in the racing car and luxury SUV, Because of its superior anti-roll and anti-twist performance. However, it is rarely equipped in the bus. In the research field of domestic Anti-Roll HIS, research and development from the perspective of the vehicle chassis design is rarely found. Stiffness and damping characteristics design of the suspension is the most important part in the chassis design and matching work of passenger vehicle factory. Aiming to furthering the industrialization of hydraulically interconnected suspension system in Chinese passenger car market, this paper has a research a nd development of HIS System bus. What’s more, with more and more vehicle equipped with this technology in china, the performance of vehicle safety can be improved, rollover accident rate can be less. The main research works of this paper are as following:(1) Anti-roll HIS has different damping characteristics under different road surface excitation. This phenomenon is analyzed in detail. According to the results of the analysis, the single actuator test program is proposed. By using the program, pipeline damping characteristics and front/rear suspension damping characteristics of Anti-roll HIS system can be tested. In general, the single actuator test program provides a tuning base for the damping characteristics to match the targeted bus.(2) Making full use of parameter identification method applied in vehicle, the linear suspension stiffness design method and the strong nonlinearity of stiffness characteristics possessed in HIS System, the stiffness parameter design of the bus fitted with Anti-roll HIS System is proposed. Finally, the feasibility of stiffness parameters is verified through steady-state model and suspension adjustments of vehicle.(3) On the damping characteristics design, the ideal damping characteristics is the same between HIS and shock absorbers, since they are all passive suspension system. The damping characteristics of the HIS system consists of pipeline damping and damper damping. By using the program of single actuator test, pipeline damping characteristics can be estimated. Then the ideal damper damping curve of the designed HIS damping valve can be obtained by deducting the pipeline damping from the ideal suspension damping. For the convenience of suspension adjustment operating by bus factory, five different damping characteris tics are obtained via the single actuator test program. After designed, manufactured and tested, five damper valves were used in the suspension adjustment which confirmed the front and rear suspension damping characteristics of the HIS System.(5) The result of the vehicle dynamic test, ride performance test and handing performance test indicate that the HIS system has better performance in improving anti-roll performance of the bus, compared to the leaf spring suspension. Furthermore, the feasibility of the proposed stiffness and damping design method has also been verified, which is considered having a good industrialization value.In a word, in order to meet the design requirements of the vehicle, considering the vehicle suspension design process and HIS system characteristics, the dissertation has a deeply research on the HIS System based on vehicle suspension design method and presents a practical method of stiffness and damping characteristics of anti-roll HIS to replace the anti-roll bar and shock absorbers. This method approved by bus factory also has good industrialization value.