Minimum vehicle slip path planning for automated driving using a direct element method

Abstract

In the UK, the number of fatal accidents on rural roads is approximately double that on urban roads. Statistics have also shown that accidents on rural roads decreased less than on other road types. The narrow width and complex geometry are less forgiving to drivers’ mistakes. A potential remedy for this problem is automated driving in which the ability to plan -in real time- safe and feasible paths is essential. The literature review of recently proposed path planning methods has revealed that most of them utilise either forward simulations of a vehicle dynamics model or describe a priori mathematically a reference path. In this paper, the weaknesses of the reviewed methods are discussed and a new path planning method that belongs to the latter category is presented. The method is based on a direct element concept and as shown and discussed is extremely versatile. It is unique in the sense that for the first time it facilitates the prediction of the maximum vehicle slip angle and the definition of a reference path that minimises it. Contrary to other methods it is very flexible in defining arbitrary boundary and intermediate conditions. The overall computational cost as analysed is very small. Simulations illustrate its performance and comparisons with other methods highlight its strengths.