Traction Control of a Sixwheel Robot using （Sixwheel机器人使用的牵引力控制系统）.pdf

Traction Control of a Six-wheel Robot using Wheel Slip Dynamics Viboon Sangveraphunsiri and Mongkol Thianwiboon Robotics and Advanced Manufacturing Laboratory, Department of Mechanical Engineering Faculty of Engineering, Chulalongkorn University, 254 Phyathai Rd., Pathumwan, Bangkok, 10330, Thailand Tel. 66(2)218-6448, 66(2)218-6585, Fax. 66(2)218-6583 E-mail : viboon.s@eng.chula.ac.th, kieng@eng.chula.ac.th Abstract A method for kinematics modeling of a six-wheel Rocker-Bogie mobile robot is described in detail. The forward kinematics is derived by using wheel Jacobian matrices in conjunction with wheel-ground contact angle estimation. Te inverse kinematics is to obtain the wheel velocities and steering angles from the desired forward velocity and turning rate of the robot. Traction Control also developed to improve traction by comparing information from onboard sensors and wheel velocities to minimize slip of the wheel. Finally, a small robot is built and tested in various conditions of surfaces including vertical obstacle, inclined surface and uneven terrain outdoor condition. Keywords : Rocker-Bogie Suspension / Traction Control / Slip Ratio 1. Introduction The effectiveness of a wheeled mobile robot has been proven by NASA by sending a semi-autonomous rover “Sojourner” landed on Martian surface in 1997[1]. Future field mobile robots are expected to traverse much longer distance over more challenging terrain than Sojourner, and perform more difficult tasks. Other examples of rough terrain applications for robotic can be found in hazardous material handling applications, such as explosive ordnance disposal, search and rescue. Corresponding to such growing attention, the researches are varying from mechanical design, performance of the robot, control system, navigation systems, path planning, f