Load-sensitive Data Acquisition for a Tactile Sensor System of Multi-fingered Robotic Hands

In this paper, we present a data acquisition method to realize a distributed tactile sensor system that can provide wide-range, and high-sensitivity with a small data size for communication. Since the data size is proportional to the number of acquired data and the resolution of the data, we propose systems to increase the resolution of the sensor output values without increasing the amount of data and to reduce the sampling frequency without reducing the time resolution. The system to increase the data resolution is based on a mechanism to dynamically change the gain of an amplifier circuit for a tactile sensor depending on the input value in the local controller. The system to reduce the number of data acquisitions consists of an analog circuit to judge the amount of change in the tactile sensor output based on a threshold at the hardware level. We demonstrate that the system reduces the data size for communication on a sensor system in our robotic hand. The experimental results indicate that the tactile sensor systems could sense high-resolution data with a small data size for communication.