Articulation measuring arm having rotatable part-carrying platen

In a spatial coordinate measurement apparatus comprising in association an articulated arm referenced to a point of origin and an electronic data processor, an improvement for reducing the required travel of the arm around a workpiece, said improvement comprising:

• a carrier shaped and dimensioned to hold said workpiece, said carrier being rotatively supported about an adjustably orientable axis;
• an angular orientation sensor associated with said carrier and positioned to provide said electronic data processor with an indication of the rotational position of said carrier and workpiece about said axis;
• and
• program means in said electronic data processor responsive to said indication, to virtually translate said point of origin around said axis;
• whereby the relative coordinate measurements of locations on said workpiece are not affected by rotation movements of said carrier and workpiece between said measurements.

A method for ascertaining the spatial coordinates of a plurality of locations on a body in reference to a point of origin by means of a spatial measurement probe irrespective of the rotational orientation of said body, said method comprising:

• securing said body on a carrier rotatively supported about an axis having adjustable position and orientation;
• adjusting said position and orientation for maximum flexibility of movement of the body in relation to the probe;
• measuring the coordinates of a first location on said workpiece
• rotating said carrier about said axis by a given angle;
• calculating a virtual, circularly-translated position for said point of origin about said axis as a function of said given angle;
• rotating said carrier and body about said axis to place at least a location to be measured within reach of said probe;
• and
• referencing a subsequent measurement of location coordinates on said body to said translated position.

In the measurement of the spatial coordinate of a plurality of points dispersed over a workpiece in reference to an origin by means of an articulated spatial measurement arm device and associated electronic data processor, an improvement for reducing the need to displace said arm around said workpiece, said improvement comprising:

• mounting said workpiece on a carrier rotatably supported around an adjustable axis;
• adjusting the position and orientation of said axis for maximum flexibility of movement of the body in relation to the probe;
• entering into said electronic data electronic data processor the spatial location and orientation of said axis;
• entering into said electronic data processor the angular orientation of said carrier about said axis in reference to a home position;
• and
• virtually translating the location of said origin circularly around said axis as a function of said angular orientation.