Research on the calibration of high-precision, wide range and multimodal compressive force for tactile sensors

Tactile sensors are widely used in electronic skin, medical robotics, and other fields, which is a crucial foundation for the future development of artificial intelligence. Their primary function is the accurate measurement of compressive force in various modalities, including temperature, humidity, static, and dynamic conditions. Therefore, the calibration of tactile sensors has become highly important. The traditional force sensor calibration techniques fail to meet the calibration requirements of multimodal tactile sensors. In this paper, a high-precision multimodal calibration method and device for tactile sensors are proposed. The device consists of a temperature and humidity chamber, a six-axis robotic arm, voice coil motors, piezoelectric pressure sensors, control circuits, and a data processing system. The outputs high-precision compressive force based on the electromagnetic control of the voice coil motor, uses a six-axis manipulator to realize the calibration of any position in space, and designs a control algorithm to realize the static and dynamic calibration. The experimental results demonstrate that the device can achieve calibration of compressive force ranging from 100mN to 10N at dynamic frequencies of 0.1Hz to 10Hz within a temperature range of 0-60°C and a humidity range of 30%-60%RH. The maximum relative standard uncertainty is ≤2.5%.