Wheel's Slip Ratio and Sinkage Estimation for Planetary Rovers Moving on Deformable Terrain

Planetary rover plays a significant role in the lunar and Mars exploration missions and wheel's move status such as sinkage and slip ratio are the critical Factor to estimate the moving ability of the Mars rover. A method is proposed to estimate wheel's sinkage and skid angle based on terramechanic model and estimate slip ratio based on rover's dynamic model using Extended Kalman Filter algorithm. The proposed method can avoid the errors caused by Visual Odometry and improves the estimation accuracy of rover state through the fusion with other sensors' data. The effectiveness of the estimation method for planetary rovers is verified by comparing with the results obtained from dynamic simulation of Mars rovers.