Acoustic sensor and method of using same for determining the position of a tool relative to a workpiece

摘要

An acoustic sensor and method of using same for determining the position of a tool from a workpiece are disclosed in which a piezoelectric transducer having a curved surface emits a sound wave which strikes the workpiece and is reflected back to the sensor. The sensor and tool are positioned relative to one another so that the workpiece will be near the focal point of the curved surface when the tool is operating. This positioning substantially overcomes the attenuation problems of high frequency sound waves transmitted through air.