Kinematic modeling of a six-wheeled robotic rover with a passive/active suspension

A six-wheeled robotic rover with passive/active suspensions was designed considering the uneven terrain. The rover suspension consists of two 3-DOF articulated frames, and each joint of the suspensions can rotate passively or be driven by a motor. So the rover is capable of locomotion in a passive mode or an active mode according to terrain. Based on the rover mechanical characteristics, reference frames for describing the rover locomotion are set up and a closed chain coordinate transformation graph is given. A kinematics modeling method of the rover for passive locomotion mode and active locomotion mode is presented. Kinematics models of the rover in passive locomotion mode and wheel-walking locomotion mode on rough terrain are constructed considering some key factors such as terrain characteristics, joint movement of suspensions, wheel slippage and so on. Some calculation results show validity of the kinematics models of the rover.