| In the mechanical transmission system, torque is a mechanical quantity which reflects the system performances of equipment. Now, Non-contact, micro and intelligence is the trend of torque sensor .Using optical method for measuring torque in principle has more advantages which are non-intervention, non-contact, anti-electromagnetic interference and signals are easy to handle. These are the trends of torque measurement.Field programmable gate array is a circuit with high integration, which complete extreme complicated function of timing and combinational logic, FPGA is suitable for high-speed, high-density and upmarket digital logic circuit design. The signal acquisition and process circuit by used of FPGA, can overcome disadvantages of complicated compilation and huge integrated circuits when circuit boards and single chip is used to achieve system. In order to increase the anti-interference and sensitivity of photoelectric torque measurement system, the torque measurement system based on FPGA and multi-state comparison is designed, in which torque is measured using rotation angle measurement of photoelectric multi-code code disk. The state subdivision method and characteristics of multi signals output by Multi-code encoder is introduced, and the principle of torque Measurement is analyzed. FPGA is used to achieve logical control and data count in hardware which simplify the system circuit. At last, Count and status signals is transferred to the host computer to be processed and displayed, so as to Real-time analysize the vibration of the torque signal.Using LabVIEW virtual instrument software design parts of the host computer which receives data from the microcontroller through the serial port to complete functions of displaying and storing real-time waveform,doing historical data and processing data. With the method, we not only improve the intelligence system, but also reduce the cost of the hardware resource.Test results show torque measurement system Based on FPGA and multi-state comparison, overcomes disadvantages caused by analyzing data with the single chip. Applications of high precision measurement of the motor shaft is achieved using combination of counts and the state subdivision. A lot of signal processing work is integrated in FPGA miniaturization and integration higher frequency data process is realized. |
