Research On The On-Line Outside-Diameter Measuring System On NC Grinding Machine

To improve the quality of grinded workpieces, on-line measuring technology is adopted on NC grinding machine to form a closed-loop grinding system. Taking example for the outside-diameter measurement of the spindle, method of how to use the traditional air-gap inductance-type transducer to realize the on-line measuring system on the NC grinding machine is introduced in this article.To ensure the high precision of the on-line measuring system, the static error and the dynamic capability of the whole system must be good enough. The principle and the mechanical structure of the air-gap inductance-type transducer are analyzed in this article, and the static parameters are calibrated. Dynamic calibration is applied to air-gap inductance-type transducer which is not good in dynamic capability, to obtain the dynamic parameters of the transducer and its measuring circuit. Based on the result of the dynamic calibration, the transducer and its serving circuit are modeled so that the method of how to improve the dynamic performance can be found. Then a dynamic compensating system is designed and added into the measuring system to accomplish the compensation. Furthermore, a MCU system is designed to acquire, process and display the output of the transducer's serving circuit, and to feed back the workpiece's real time dimension to the NC grinding machine. Errors of the whole on-line measuring system are analyzed at the final part of the article.