Decoupled Motion Planning of a Wheeled Mobile Manipulator for Planetary Exploration Considering Obstacle Avoidance

In this paper, a motion planning framework is proposed for achieving obstacle avoidance with a six-wheeled planetary rover, ensuring collision-free movement during both the rover's traversal and the tracking of the manipulator's end-effector trajectory. Initially, an equivalent kinematic model of the six-wheeled planetary rover is established to provide an accurate basis for subsequent trajectory tracking, and an in-verse kinematic model for the seven-degree-of-freedom redundant manipulator is established using the vector product method. Furthermore, based on the inverse kinematic models, motion planning for the mobile platform is conducted using modified artificial potential field algorithm, while achieving dual trajectory tracking of the manipulator's end-effector and its fifth joint based on task prioritiy. A simulation environment based on the ROS platform is constructed to validate the obstacle avoidance capability of the mobile platform and the manipulator's ability to navigate narrow passages for target retrieval.