Robust Adaptive Fuzzy Control for Planetary Rovers While Climbing up Deformable Slopes with Longitudinal Slip

Li Zhengcai,Wang Yang

doi:10.1155/2014/620890

Abstract

Mobility control is one of the most essential parts of planetary rovers’ research and development. The goal of this research is to let the planetary rovers be able to achieve demand of motion from upper level with satisfied control performance under the rough and deformable planetary terrain that often lead to longitudinal slip. The longitudinal slip influences the mobility efficiency obviously, especially on the major deformable slopes. Compared with the past works on normal stiff terrains, properties of soil and interaction between wheels and soil should be considered additionally. Therefore, to achieve the final goal, in this paper, wheel-soil dynamic model for six-wheel planetary rovers while climbing up deformable slopes with longitudinal slip is first built and control based in order to account for slip phenomena. These latter effects are then taken into account within terramechanics theory, relying upon nonlinear control techniques; finally, a robust adaptive fuzzy control strategy with longitudinal slip compensation is developed to reduce the effects induced by slip phenomena and modeling error. Capabilities of this control scheme are demonstrated via full scale simulations carried out with a six-wheel robot moving on sloped deformable terrain, whose real time was computed relying uniquely upon RoSTDyn, a dynamic software.

Highlights

In the field of special mobile robots environment, including planetary exploration missions, caravan survey, polar expedition, and wild fire spreading, rovers may need to traverse on deformable terrains, and the interaction between rigid wheels and soft soil has become a meaningful research topic because of longitudinal slip influence mobility control obviously [1]
We develop a slope-based wheel-soil dynamic model for WMR based on a simplified interaction model and uniwheel slope-based experiment, in which the draw-bar pull can be denoted as a linear function of driving force, normal force, and slip; it is suitable for describing the rigid wheels on sloped deformable terrain
The slip is the important state variable; in order to deal with this problem, we deemed as measurement model using the methods like the relevant literature. Capabilities of this control scheme is demonstrated via full scale simulations carried out with a sixwheel robot moving on sloped deformable terrain, whose real time computed relying uniquely upon RoSTDyn, a dynamic software

Summary

Introduction

In the field of special mobile robots environment, including planetary exploration missions, caravan survey, polar expedition, and wild fire spreading, rovers may need to traverse on deformable terrains, and the interaction between rigid wheels and soft soil has become a meaningful research topic because of longitudinal slip influence mobility control obviously [1]. We develop a slope-based wheel-soil dynamic model for WMR based on a simplified interaction model and uniwheel slope-based experiment, in which the draw-bar pull can be denoted as a linear function of driving force, normal force, and slip; it is suitable for describing the rigid wheels on sloped deformable terrain. The slip is the important state variable; in order to deal with this problem, we deemed as measurement model using the methods like the relevant literature Capabilities of this control scheme is demonstrated via full scale simulations carried out with a sixwheel robot moving on sloped deformable terrain, whose real time computed relying uniquely upon RoSTDyn, a dynamic software.

Slope-Based Wheel-Soil Dynamic Model for Uniwheel

Slope-Based Wheel-Soil Dynamic Model for Planetary Rover

Robust Adaptive Fuzzy Controller Design

Stability Analysis

Simulation Results