A unified approach to the kinematic synthesis of five-link, four-link, and double-wishbone suspension mechanisms with rack-and-pinion steering control

Abstract

This paper presents a unified approach to the problem of dimensional synthesis of the five-link, four-link, and three-link (double-wishbone) suspension mechanisms with a rack-and-pinion steering input. In a simplified approach, the guiding links are assumed to be removed from their joints, allowing the wheel to be exactly driven through a number of prescribed jounce–rebound and steering positions during the kinematic synthesis process. Alternatively, the tie rod is maintained in place, and the rack length and the lengths of the remaining four guiding links are allowed to vary. An optimization problem based on the aggregated change in distance between the released ball joints evaluated in the aforementioned positions is then defined. By prescribing to the wheel a jounce–rebound motion only, rear-suspension mechanisms of the five-link, four-link, and three-link types can be conveniently synthesized by following the same procedure. Several solutions obtained through synthesis are then analyzed for their changes in steering error, recessional wheel motion, wheel track, toe angle and camber angle, showing very promising results. Additionally, a comprehensive review of nearly 150 publications relevant to the suspension design of automobiles is provided in the paper.