A measurement and control system based on USB bus for prosthetic hand

A five-fingered, multi-sensory and biomimetic prosthetic hand is presented in this paper. And the measurement and control system of HIT prosthetic hand based on the DSP and USB chip(ATmega32U2) is presented. The measurement and control system communicate with PC by USB bus, and the measurement and control system use the power supplied by USB electric cable. This system include bottom control subsystem, USB communications subsystem. The ATmega32U2 communicate with DSP by SPI(the pins of SS, SCLK, MOSI, MISO), and the ATmega32U2 configure as master mode, while the DSP configure as slave mode in the SPI. The communication speed of SPI between Atmega32U2 and DSP can achieve 8Mbit/s, and the communication speed of USB between master computer and USB chip is 12Mbit/s. The USB interface circuit, firmware program, drive program and PC application software are design. The proposed impedance control approach allows the fingers to behave as virtual springs. Experiments showed that users were able to successfully operate the device in the control strategies, and that the grasp success increased with more interactive control. The experiment results shows that this measurement and control system have high real-time property and reliability.