tailieunhanh - Predicting maximum traction to improve maneuverability for autonomous mobile robots on rough terrain

This paper proposes a method to predict maximum traction force for autonomous mobile robots on rough terrain in order to improve maneuverability. For predicting traction force, we utilize friction-slip curves based on modified Brixius model derived empirically in terramechanics, which is a function of mobility number Bn′ and slip ratio S. Friction-slip curves include physical characteristics of various rough terrains such as firm soil, sandy soil and grass-covered soil. | Journal of Automation and Control Engineering, Vol. 1, No. 1, March 2013 Predicting Maximum Traction to Improve Maneuverability for Autonomous Mobile Robots on Rough Terrain Jayoung Kim and Jihong Lee Mechatronics Group at Chungnam National University, Daejeon, Republic of Korea {Jaya, jihong}@ Worldwide, a lot of studies for terrain modeling based on friction-slip characteristic on rough terrain have been performed in order to improve energy efficiency for driving and to maximize mobility of a robot. There are three main methods for terrain modeling: analytical method, empirical method, and semi-empirical method. Analytical method is an approach to model a terrain by mathematically analysis of the interaction between a wheel and terrain. Analytical method facilitates to model accurate terrain based on capability of a computer to numerically analyze minute elements in soil. There are FDM (Finite Difference Method) [4], FEM (Finite Element Method) [5], and DEM (Discrete Element Method) [6] belong to analytical method. Empirical method is an approach to model a terrain based on cone index (CI) which is acquired by penetrating a cone penetration tester into a terrain [7]-[10]. Empirical method facilitates to model a variety of terrains through experiments after driving along various rough terrains. Lastly, semi-empirical method is an approach to model a terrain using experimental data along with mathematical analysis of the interaction mechanism between a wheel and surface of a terrain [1]-[3], [9]. Although empirical method is very simple, it can be applied for modeling of a variety of terrains. Also, recently, predictions obtained by Brixius model which is one of empirical methods were shown to accord with experimental results and DEM simulations [6]. Therefore, Brixius model which is widely known as one of empirical methods is adopted to derive friction-slip curve for predicting maximum traction force in this paper. Maximum coefficient of static friction