電気通信大学 明・佐藤研究室

Robot Hand ‌

We are developing the robotic manipulation system with high-speed proximity sensor.

Proximity sensor ‌

Proximity sensor is a sensor which is able to detect target object in the range of 10mm. We implemented the proximity sensor in the robotic hand system and succeeded to control the finger position of multiple-DoF robotic hand without touching the object. In the robotic grasping, visual estimation errors (ex. Position, geometry information) cause significant failure but our method is useful to compensate these errors and grasp the object precisely.

※The proximity sensor was developed by Shimojo lab and our research was inspired by it.

Control method for multi-fingered multi-joint hand using proximity sensor (Pre-Grasp control) ‌

By using the developed proximity sensor for the fingertip of the robot hand, it is possible to perform control to simultaneously adjust the posture around the two axes of the fingertip and the distance to the object. In our laboratory, this control is called “Pre-Grasp”. By performing “Pre-Grasp”, it is possible to place the fingertips along the shape of the target object without touching it and grasp it with a large contact area following the shape of the object.

Application of proximity sensor to remote operation ‌

We developed master slave remote operation system. As information given from the slave side to the master side, proximity information attached to the fingertip of the robot hand is returned to the human finger, and information from the palm proximity sensor is returned to the human wrist as a sense of force. In this research, proximity refers to the sense that the tactile sense spread to the ten and several millimeters upper from the skin. To present proximity information to the human fingertip, we used electro-tactile display (developed at the Kajimoto Lab, UEC) to convert the proximity information into distance and tilt information of electric stimulus. In the remote operation system, visual occlusion problems have an adverse effect on the operator in particular. In that case, it is possible to obtain rich information (ex. Grasping position) by using the proposed method.

Development of a robot hand with proximity sensors on finger belly ,fingertip and nail ‌

In the robotic grasping, occlusion occurs around target object by surrounding objects when using vision sensor. In this case, it may cause the grasping failure due to the collision by the surrounding obstacles. Therefore, In the robotic grasping, In order to solve this problem, we propose a method by installing proximity sensors on fingertip and nail besides on finger belly. These sensors can detect the position and distance information to the surrounding objects for avoiding collision. The proposed method has been implemented to a robot hand system and successful avoiding motion has shown the effectiveness of the method.

Development of a proximity sensor for robot hand to grasp at arbitrary fingertip position ‌

We are developing robot hands with proximity sensors capable of acquiring information on the vicinity of an object. Up to now, a grasp posture at which the fingertip is facing directly to the object is considered and network structure proximity sensors have been designed for the grasping. By using the proximity sensors, it is difficult to realize a grasping at an arbitrary position of the fingertip, which is necessary for complicated grasping tasks. In this paper, a network structure proximity sensor is designed to meet the need and basic characteristics are investigated by experiments using a prototype of the sensor.