A kinematic-based rough terrain control for traction and energy saving of an exploration rover

Abstract

This paper proposes a novel algorithm to control wheels of a rover in rough terrains with keeping traction and minimizing energy consumption on the basis of observing a change of a robot velocity from a 4WD Kinematic model. Proposed kinematic-based rough terrain control (KRTC) can satisfy a rover to meet an integrated performance of following a desired velocity while keeping maximum traction and minimizing energy use without an estimator of wheel sinkage and an observer of a dynamic parameter. KRTC consists of two main parts; a slip optimizer and a slip controller. For slip optimization, optimal slip values regarding maximum traction and tractive efficiency are derived from indoor experimental data during a wheel-terrain interaction. Optimized slip ratio is used as an input of a PID slip controller. KRTC only uses the desired velocity of the robot as an input value and gets the two feedback data of actual slip and actual velocity of each wheel. For verification, KRTC was applied to a 4WD rover and the performance was analyzed based on acquired experimental data on a variety of rough terrains.