The majority of passenger vehicles use separate hydraulic circuits to drive and control high-power components such as the braking and steering systems. While this approach is acceptable, it is possible for significant improvements in efficiency to be achieved using a centralized system. In order to establish the advantages and disadvantages of the distributed and centralized approaches, a simulation-based feasibility study of the pressure, flow and power requirements of the individual engine cooling, anti-lock braking system (ABS), semi-automatic transmission, active roll control and power assisted steering subsystems was carried out. Using a realistic drive and load cycle together with simulation models accounting for component non-linearities and dynamics, the flow requirements of an integrated hydraulic system were established. It was shown that the steering and roll control suspension requirements were complementary. The steering system requires high flow at low forward speeds, while the suspension requires high flow during conditions of high speed. In addition it was shown that, although the peak flow requirements of an integrated system were high, the mean flow was moderate and the high demands could be met using small accumulator units, suggesting that the system would be feasible for use in passenger cars. Finally, an energy efficient integrated hydraulic circuit including some degree of safety back-up is proposed.
|Number of pages||10|
|Journal||Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering|
|Publication status||Published - 1 May 1999|
ASJC Scopus subject areas
- Aerospace Engineering
- Mechanical Engineering