A high-speed method of detecting contact-state transitions and its implementation in a task-coordinate manipulation system

• Published in: Proceedings of IEEE International Conference on Robotics and Automation Vol. 3; pp. 2012 - 2018 vol.3
• Main Authors: Ken-Ichiro Shimokura, Shin-Yo Muto
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1996
• Subjects: Computer vision; Delay; Force measurement; Humans; Laboratories; Manufacturing; Monitoring; Real time systems; Robot sensing systems; Robotic assembly
• ISBN: 0780329880; 9780780329881
• ISSN: 1050-4729; 2577-087X
• DOI: 10.1109/ROBOT.1996.506167

We have developed a highly reliable method of detecting contact-state transitions in real time. In the detection algorithm, feature variables, which fluctuate abruptly when a contact state transition occurs, are selected. The differential of the feature trajectory is monitored to distinguish the transition region from the stable region. To confirm that a state transition has actually occurred in the region, the duration of the region is measured. With this method, a contact-state transition can be detected with a 40-msec delay. We also have developed an experimental manipulation system, in which motion execution management and motion monitoring and execution modules operate independently. Using transputers and a six-degree-of-freedom direct-drive manipulator, a square-peg insertion task is carried out to evaluate the effectiveness of the detection method in an actual environment. The experimental results show that contact-state transitions can be accurately detected and that motion commands can be quickly switched by using the detected transition information.