Active vibration isolation and active vehicle suspension: Igor L. Paul and Erich K. Bender. Massachusetts Inst. Technol., Cambridge. 73 pp. (Nov. 1966)

Abstract

The feasibility of using 'active' elements in suspension systems for high speed ground vehicles to improve vibration isolation characteristics is considered. The characteristics of vehicle excitations (to the suspensions and to the vehicle body) are discussed and a mathematical expression for the suspension input is obtained. Based on data of human tolerance to vertical vibrations a comfort criterion (to vibrations) is established. The problem of vibration isolation to best satisfy this criterion is considered in terms of optimizing the parameters of a given suspension configuration and in terms of finding an optimum tranfer function for an unspecified suspension configuration. The methodology for obtaining these optimum solutions for a given comfort criterion is developed and solutions are obtained for the case of vertical vibrations of a two-degree-of-freedom system in which the root mean square acceleration of the vehicle is to be minimized for a given permissible suspension excursion. The optimum suspension transfer function for this case indicates that feedback of both vehicle and unsprung mass acceleration is required.