End-effector Trajectory Tracking Control of Mobile Manipulator Based on Whole Body Control

Mobile manipulators significantly extend the operational workspace of conventional robotic arms through their mobile platforms, thereby achieving superior flexibility in complex environments. This advantage has led to their widespread adoption across numerous industrial and service applications. However, the base mobility introduces fundamental control challenges, particularly in maintaining precise end-effector trajectory tracking in inertial space during platform motion. Addressing this stabilization problem represents a critical requirement for realizing the full maneuverability potential of mobile manipulator systems. This paper presents a novel Whole-Body Control (WBC) framework that integrates: (1) an iterative optimization-based position and orientation controller, (2) a velocity controller derived from the system's kinematic model, (3) a proportional-derivative joint torque controller. The unified architecture enables simultaneous stabilization of both positional and orientational end-effector tracking for mobile manipulator systems when achieving millimeter-level precision during dynamic base motions. The proposed control framework implements a hierarchical priority strategy that preferentially maintains attitude tracking over position tracking when kinematic constraints prevent simultaneous achievement of both objectives. Gazebo-based simulation and physical experiment results demonstrate that the proposed control strategy achieves superior tracking performance.