Multisensory gripper and local autonomy of extravehicular mobile robot

This paper presents the development of the multisensory robot gripper for extravehicular mobile robot (EMR) and its sensor based local autonomy. For stable extravehicular walking and performing delicate tasks in unstructured and complex environment, our EMR gripper employed a simple and reliable mechanism and it is equipped with multisensory apparatus. Local autonomy of the space robot is an important requirement for on-orbit manipulation. Detecting contact state between robot gripper and environment is essential to fulfill space robot local autonomy. But we often face the problem of lack of sensory information when we try to know the contact state. A new way to detect: contact state under inadequate sensory information is proposed. By combing force sensor information with gripper geometry and mechanical analysis, some spatial contact information between robot and the trusswork can be derived. Then robot can adjust its position and orientation by fine motion displacement based on contact information to fulfill steady grasping. This method is implemented on a walking/grasping task, which is a simple and important fundamental task for extravehicular space robot.