Coordinate positioning machine
AssigneeRenishaw PLC
InventorJulius Duprez
Life of this patent
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Abstract
A method of calibrating a coordinate positioning machine is described. The machine is controlled into a pivot pose in which a target point associated with a moveable part of the machine and a pivot point associated with a fixed part of the machine are separated from one another by a known separation. An error value for that pose is determined based on the known separation and a separation expected for that pose from the existing model parameters of the machine. The machine is controlled into a plurality of different target poses, and for each target pose a separation between the target point and the pivot point is measured and an error value for that pose is determined based on the measured separation and a separation expected for that pose from the existing model parameters.
Claims38
A method of calibrating or otherwise characterizing a coordinate positioning machine, wherein a geometry of the machine is characterized by a parametric model and wherein the method is intended to determine a new set of model parameters that characterizes the geometry of the machine better than an existing set of model parameters, and wherein the method comprises:
- (a) coupling a measuring device between a target point associated with a moveable part of the machine and a pivot point associated with a fixed part of the machine, the measuring device being adapted to measure a separation between the target point and the pivot point;
- (b) controlling the machine into a plurality of different target poses;
- (c) for each of the target poses of step (b), (i) using the measuring device to measure the separation between the target point and the pivot point and (ii) determining an error value for that target pose based on the measured separation and a separation expected for that target pose from the existing set of model parameters;
- (d) determining an overall error measure from the error values determined in step (c) for the plurality of different target poses of step (b) and for the target point and the pivot point of step (a);
- and
- (e) determining the new set of model parameters that would result in a lower overall error measure in step (d) than for the existing set of model parameters.
Dependencies are inferred from the claim text.