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.
Claims34
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) controlling the machine into a plurality of different target poses in each of which a target point associated with a moveable part of the machine remains in substantially the same position, at least based on the existing set of model parameters;
- (b) for each of the target poses of step (a), (i) measuring a separation between the target point and a pivot point associated with a fixed part of the machine 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;
- (c) determining an overall error measure from the error values;
- and
- (d) determining a new set of model parameters that would result in a lower overall error measure than for the existing set of model parameters.
Dependencies are inferred from the claim text.