HBMC (Hydraulic Body Motion Control System) for Production Vehicle Application 2011-01-0563

In order to satisfy increasing customer demands on ride quality as well as expectations for off-road performance of sport-utility vehicles (SUVs), it is necessary to develop technologies which offer enhanced levels of both performances. For ride quality, it is important to minimize body roll angle during cornering, which is achieved by suppressing suspension travel, and also to reduce vertical motion during straight-ahead travel. While for off-road performance, it is necessary to allow a long suspension stroke to allow a high level of off-road traction by delivering driving force reliably to the surface. These two performance parameters require a tradeoff with respect to vehicle roll stiffness.

To reconcile these conflicting performance requirements, for first time in the world we adopted for production vehicles the system which connects the four shock absorbers together. It has been reported in the literature that this system can be effective[1], however, application of such a system to production vehicles has been regarded as being difficult. This paper describes design methods of an accumulator, which is one of the key components in this newly developed hydraulic body motion control system, as a representative case in applying such a system to production vehicles. Additionally, this system has been demonstrated to achieve high levels of performance for both parameters while not affecting a vehicle's limit handling performance.