Hybrid Tactile Sensor System for a Robot Hand and Estimation of Fine Deformation Using the Sensor System

In this paper, the authors propose a hybrid tactile sensor system consisting of a Carbon Micro Coil (CMC) touch sensor and a force sensor. This sensor system has the capability of measuring fine deformation of several micrometers occurring to a CMC sensor element, as well as the compression force. The sensor element is made of silicon rubber containing CMCs, and it is considered that the sensor element constitutes an LCR circuit. When the sensor element is deformed mechanically, the CMC sensor produces signals due to the modification of the circuit. In the experiment, the CMC sensor’s outputs are sampled in response to the fine deformations of 1 to 9 µm. And it is found that the CMC sensor’s outputs depend on the magnitude of the compression force since the sensor output for a fine deformation increases gradually as the compression force increases. Therefore, to measure the amount of the fine deformation regardless of the compression force, the measurement method for extracting the CMC sensor’s output for the fine deformation from the overall sensor output for the deformation that includes the compressive deformation and the fine deformation is developed. In addition, the performance of the sensor system in measuring fine deformations is evaluated in the experiments.