Evolution Trajectory Planning and Control on Uneven Terrain for Wheeled Mobile Robots and Hybrid Wheeled Legged Robots

Abstract

In recent years there has been an increased use of wheeled mobile robots for outdoor and unstructured newlineterrain navigation. While traversing uneven terrain wheeled mobile robots are subject to various kinds newlinewheel slip which can lead to localization errors and decrease motor efficiency. The objective of this work newlineis to develop robust modelling techniques for simulating the kinematics, quasi-statics , and dynamics of newlinewheeled mobile robots subject to kinematic and dynamic no-slip constraints and also develop state-ofthe- newlineart suspension mechanisms for hybrid wheeled-legged robots in order to obtain reduced slip while newlinetraversing on fully 3D uneven terrain. In order to achieve slip free motion on uneven terrain the wheeled newline/ wheeled-legged robots have to be equipped with essential degrees of freedom that would enhance its newlineability to negotiate undulations on the terrain. newlineFirst we perform the analysis of a wheeled mobile robot with a passive variable camber (PVC). We newlinedevelop a methodology for simulating the kinematics of this robot using the techniques of kinematics newlinefor dexterous manipulation of multi-fingured palm. We also develop a framework for simulating the newlinequasi-static motion of the robot on uneven terrain .The framework at each instant estimates the contact newlineforces and velocity of the vehicle platform for a given set of joint velocities of the robot. This ensures newlinethat the vehicle satisfies not only kinematic no slip constraints but as well as no slip constraints that arise newlinedue to relations between traction and contact forces. In general a complete simulation of a WMR on a newlinefully 3D terrain has been a difficult problem to solve. The best efforts so far have provided a simulation newlinethat incorporates the wheel ground contact constraints into a set of differential algebraic equations newline(DAEs) to estimate the full 6dof pose of the vehicle. This work integrates the quasi static contraints newlinewithin the DAE framework to provide a complete 6dof evolution of vehicle on 3D terrain that respects newlineboth kinematic and quasi static constrai