A novel paradigm of exact steering mechanisms

Abstract

In this theoretical work, a new paradigm of a set of mechanisms that can trace the exact steering condition for a front-two-wheels steered car were analyzed and discussed with examples. The central idea was to go beyond the traditional 4 bar-linkages to a 5 bar-linkage that had a joint following a rather simple to implement locus. The set of loci were calculated for small and large turns angles along with how to choose a locus based on fabrication ease, smoothness of actuation and potential stress concentrations was discussed. The standard go-to Ackermann mechanism was discussed in detail and it was shown that it fails miserably when the aspect ratio of a car is larger than those in standard road-plying cars. It was observed that since most steering assemblies are designed based on adjustments built on the Ackermann mechanism—which was shown inadequate in spite of the savior Jeantaud-correction—higher aspect ratio vehicles—if not others—need a steering assembly designed with our proposed mechanisms that we call the Wani mechanisms as a starting point. Here, no optimization is required and rather a unique set of loci are found using simple computations and easy trigonometric and algebraic formulas. This is unlike even the advanced and high accuracy 6 and higher bar mechanisms that require optimization and are rack and pinion friendly.