The Design Of Measurement System Based On Strain Type Torque Sensor

In the mechanical drive system, torque is the one of the most typical parameters which reflects the performance of system. Torque measurement is widely used in various fields of industrial production. And it has become indispensable for all kinds of mechanical products in development research, quality inspection, optimizing control, condition monitoring and fault diagnosis. As a major means of working condition real-time monitoring, torque sensor is paid more and more attention on its research and development. We use the torque sensor to monitor and control torque in real-time, which can guarantee the test system to operate safely.There are various ways to measure torque. The most traditional one is sticking strain gauges and its technology is the most mature. The paper analyzes measuring principle of torque sensor from the perspective of mechanics of materials and we make a torque sensor by sticking resistance strain gauges on the elastic element. Considering the dynamic measurement, we design the collector ring. In order to solve the problem of nonlinearity, we take advantage of curve fitting method to realize the nonlinear self-correcting of input-output characteristic. We complete the calibration experiment by lever-weight method. According to the experiment data, the functional relationship between the torque and the stress is deduced. After analysis of the maximum relative error, we realize the nonlinear self-correction of torque sensor. The functional relationship is stored in single chip microcomputer (SCM).We design a set of stress and torque intelligence measure system which includes direct current regulation circuit, amplifying circuit, low-pass filter circuit, alarming circuit, A/D convert circuit, key-press circuit, watchdog/reset circuit, display circuit and serial communication circuit. System software is completed by the Keil C51programming. Finally the real-time measurement and display of torque is realized.