Ride comfort is an important aspect of any passenger vehicle. The challenge is to provide a comfortable, yet safe, ride for the driver and the passengers and there is often a trade-off between ride comfort and safety performance.
In the case of small wheelchair-accessible vehicles the challenge increases. The weight of a wheelchair with person may span from 50 kg to 500 kg, which means that the suspension must be tuned to have a broad working range. Also, a wheelchair-accessible vehicle has many restrictions on design space and tuning possibilities due to, e.g., the space needed for the wheelchair passenger to get in and out of the vehicle. Hence, there is an additional need to evalute ride comfort and performance before the vehicle is built in order to find the optimal design. Traditionally, this is done by computer simulations of vehicle handling complemented with testing followed by chassis tuning prior to production. However, some performance parameters regarding comfort, especially in the case of wheelchair passengers, are still not well investigated and documented, and there is a need to subjectively evaluate the ride comfort in early design phases.
In this paper we investigate the use of a motionbase simulator as a platform for evaluating ride comfort with different suspension setups. We are using a reversible sleeve air suspension bellow equipped with an adaptor cylinder giving the spring characteristics. The characteristics of four different adaptors have been measured in a universal test machine. The force-compression characteristics are imported into the simulation. The simulation model used is a half-car, two-degree of freedom producing bounce and pitch movement data for either the driver or the passenger positions. The data from the simulations are used as input to a motionbase simulator for subjective assessment of the ride comfort.
The primary results indicate that a motionbase simulator can be a useful tool when designing/developing suspension systems. Also, the results indicate that a motionbase simulator is useful for investigation of comfort parameters in order to determine objective assessment of subjective parameters.
