A tactile sensor system for universal joint sections of manipulators

It is very difficult to place tactile sensors around revolute joints of manipulators, since those joints and surrounding surfaces are not stationary and thus they remain insensitive to contact with obstacles. This interferes with the introduction of sensors for collision avoidance control in manipulators. This paper deals with a tactile sensor system for universal joint sections of manipulators in order to detect collisions with obstacles. Its unique characteristic is the ability to detect, in one sampling period, the positions of more than one collision despite having only one signal line. It is achieved by making use of the resonance phenomenon of the sensor circuit, and all sensor elements can be distinguished from one another by frequency division. The structure of the sensor and the method to detect the label number and position of the sensor elements that are in contact with obstacles are described, followed by analysis of the circuits and experimental results of the sensor system