Wide-Range Precision Speed Measurement with Adaptive Optimization Using a Microcomputer

A new speed measurement method using a microcomputer is presented. In the initial part of the measurement, a definite small fraction of time for one revolution is counted using a software technique. A definite bit-size of the count is maintained by continuing counting over an optimum multiple of the initially measured time interval in case the bit-size of the initial count is less than a preset value. The multiple of the initial time period is measured with the help of an external counter, without any break in the continuity of counting. The speed is computed from the time count and displayed. For this measurement, only a standard digital speed transducer, a counter, and a microcomputer kit are required. The method has a small data acquisition and processing time, and gives a high accuracy that is programmable over a wide range of speed. The method is also quite economical.