Apparatus for and method of measuring workpiece on machine tool

摘要

A workpiece measuring apparatus includes a programmable controller which acquires positional data of a measuring head. At the same time that the programmable controller acquires the positional data, a pulse output unit outputs timing pulses. The measuring head measures a workpiece on a machine tool according to a measurement command which is output positively earlier than the timing of predetermined time intervals by a time difference which is preset by a predictive system. As a result, a first time at which the programmable controller acquires the positional data of the measuring head and a second time at which the measuring head measures the workpiece in response to the measurement command synchronize. The workpiece measuring apparatus is capable of measuring the workpiece highly accurately in a three-dimensional space according to a minimum required amount of measured data without the need for modifying an existing NC apparatus combined with the machine tool.