Motion Planning for Bandaging Task With Abnormal Posture Detection and Avoidance

Abstract

With the aim of enabling the aged to obtain timely nursing care and improve their quality of life, a novel method of motion planning for a six-degree-of-freedom (6-DoF) anthropomorphic robot arm to perform bandaging tasks is proposed. The motion planning of bandaging tasks is challenging because the collision avoidance problem and maintaining tension in the bandage should be considered simultaneously. To solve such problems, a new planning strategy is proposed, including: 1) collision detection criterion to detect abnormal posture beforehand, 2) a collision avoidance strategy by extending the bandage along the tangential direction (EBATD) to adjust the end effector's trajectory, enabling the robot to avoid collision and singularity posture, and 3) velocity planning of the end effector to keep the bandage tight during application. In addition, a new end effector that can be passively rotated for releasing the bandage was designed. The simulation experimental results in MATLAB demonstrated that the proposed strategies allowed the designed 6-DoF robot to avoid collision with an injured arm and complete the bandaging task. Compared with planning without EBATD, the proposed method effectively enlarges the bandaging space of the robot arms (approximately 1.5 times in a human forearm bandaging task). In addition, the proposed method was successfully tested using a prototype robot arm to perform bandaging on a human arm.