Performance measures of comfort and rattlespace usage for limited-stroke vehicle suspension systems

The traditional approach to the analysis of suspension systems uses linear analysis and applies RMS or quadratic performance measures. Non-linear systems and more complex performance measures generally require the application of computer techniques such as evolutionary algorithms, as used here. Two performance measures were used in this study. They were specially designed for electronically controlled suspension algorithms applied to passenger vehicles. Electronically controlled suspensions, especially semi-active systems, are prone to force discontinuities and so a comfort performance index based on jerk (the rate-of-change of acceleration) is superior to the standard measure of RMS acceleration. Passenger cars have a more limited stroke than larger vehicles and the performance indicators used here are more appropriate for limited-stroke vehicles. Both active and semi-active controls were examined. These results indicate that there are some semi-active suspensions that have a performance which is comparable to that of the ubiquitous active skyhook suspension control system.