A Coordination Control Method of Wheel Speeds for Planetary Rovers With Passive Suspensions
Planetaryrovers with passive suspensions utilize simplemechanisms andgood stability,and play an important role in extraterrestrial explorations.However,passive joints cause an actuation interference between wheels,which leads to wheel wearing and the decrease of the driving ability of a rover.This paper proposes a coordination control method of wheel speeds based on the estimation of terrain-wheel contact angles.Firstly,the kinematic model of the rover is established,and then the velocity mapping from the rover body to wheel centers is derived.Thus,contact angles can be estimated in real time.Secondly,motion planning of the rover is performed.The constraint equations of wheel speeds are derived from the contact angle,the position and pose of the rover suspension.Accordingly,the driving speeds of each wheel can be calculated.Finally,the joint simulation using MATLAB and COPPERLIASIM software is carried out.The prototype and terrain are built to validate the proposed control method.The maximum error of the estimated contact angles is approximately 9.2％.Moreover,the slippage is decreased by 6％and the driving capability of the rover is improved.
passive suspensionplanetary rovercontact anglecoordination control
NETL
NSTL
万方数据
