Measurement point determination method, non-transitory storage medium, and measurement point determination apparatus

A measurement point determination apparatus for determining a number or an arrangement of measurement points for a coordinate measuring machine that performs measurement processing of a three-dimensional geometry of an object at a plurality of measurement points, the apparatus comprising:

• a memory of a computer that stores an initial value of the number, an arrangement of measurement points, and a target value of the uncertainty of a measurement result of the three-dimensional geometry of the object by the coordinate measuring machine;
• estimation circuitry configured to estimate the uncertainty of the measurement result of the three-dimensional geometry of the object by the coordinate measuring machine that uses to the initial value of the number and the arrangement of the measurement points;
• calculation circuitry configured to calculate a ratio ΔM/Δp which is the result of dividing a variation amount ΔM in the estimation results of the uncertainty of the measurement result of the three-dimensional geometry of the object by the coordinate measuring machine by a variation amount Δp of one measurement point among the measurement points corresponding to the initial value of the number and the arrangement when the arrangement of the one measurement point is changed for every measurement point;
• updating circuitry configured to update the measurement points by moving the arrangement of at least one measurement point to approach to a target position for a predetermined distance, the target position being the position of the measurement point for which the ratio ΔM/Δp is the maximum among the measurement points corresponding to the initial value of the number and the arrangement;
• determination circuitry configured to determine the arrangement of measurement points used by the coordinate measuring machine to be the updated measurement points if the estimation results of the uncertainty of the measurement result of the three-dimensional geometry of the object by the coordinate measuring machine using the updated measurement points is less than the target value, and
• output circuitry configured to output information of the determined measurement points to the coordinate measuring machine to measure the three-dimensional geometry of the object by using the determined measurement points by the coordinate measuring machine,
• wherein the variation amount Δp of the one measurement point is a distance between a first location and a second location, the first location being the location of the one measurement point before the one measurement point is changed, the second location being the location of the one measurement point after the one measurement point is changed;
• and
• the variation amount ΔM in the estimation results is a difference between a first estimation results of the uncertainty and a second estimation results of the uncertainty, the first estimation results of the uncertainty being the estimation results before the one measurement point is changed, the second estimation results of the uncertainty being the estimation results after the one measurement point is changed.