Composite tactile sensor array using fiber bragg grating sensors and measuring system
A composite tactile sensor element using identical fiber Bragg gratings (FBGs) and its 4×4 tactile sensor array were proposed. The structure and fabrication of the composite tactile sensor array were described in detail. The system of measuring the distributed contact forces and temperatures simultaneously was newly designed. Based on the identical FBGs, the measuring system resolved the cross-sensitivity problem of temperature and strain in fiber Bragg grating. The optical system and hardware circuit of measurement system were designed specifically. A field programmable gate array (FPGA) is the core of the hardware circuit, which can collect and process the photoelectric signal voltage shaped into rectangular voltage pulse. The hardware circuit communicated the signal to the computer through the UART and USB. The computer dynamically displayed and calibrated contact forces and temperatures of the measured points. Experiments show that, there are sufficient performance and the possibility to practically utilize the composite tactile sensor array, and the measuring system for distributed tactile forces and temperatures has many advantages, such as high stability, high capacity, high speed of data processing, contact-force resolution of 0.01 N and contact-temperature resolution of 0.5 °C.