Research on the Calibration of High-Precision Wide Range and Multimodal 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 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 article, 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 output’s high-precision 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 force ranging from 100 mN to 10 N at dynamic frequencies of 0.1–10 Hz within a temperature range of 0 °C–60 °C and a humidity range of 30%–60%RH. The maximum relative standard uncertainty is $\le2.5$ %.