This article estimates the uncertainty for measuring a tool tip using dual Leica T-Mac sensors set up on opposite sides of an NC machine head and measured with tracking interferometers at opposite ends of a machine bed. Performance testing compares the estimated and measured uncertainties and comments on the nature of the setup.

Background

The T-Mac is a special sensor for the Leica tracking interferometer, relying on a camera mounted on the tracking interferometer head to watch the sensor and estimate its angular orientation. (T-Mac “sensor” is used rather than T-Mac “target” because the T-Mac is a hybrid of a cooperative target, a corner cube for determining positions, and a set of active LEDs that strobe to determine orientation.) The tracking interferometer laser ADM simultaneously measures the distance to the sensor. Proposed applications include measuring and correcting NC head locations, in-process inspection, and augmenting inspection equipment on a machine head or robot with certifiable location and orientation information. The benefit of using T-Mac technology is that calibration and certification of the T-Mac is simpler than calibration and certification of all linkages making up the NC machine.

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