QUINDOS CMM Probing Error SimulationMTW-510-PES-001


Simulation of the Measuring Error of 3D Coordinate Measuring Machines - CMMs.


The measuring errors of 3D Coordinate Measuring Machines / CMMs are described in the ISO standard 10360: "Performance of Coordinate Measuring Machines - CMMs". Usually at least the two most important specifications: "Volumetric length measuring error E" and the "Volumetric probing error P" are specified by the CMM manufacturers.

These errors are valid for clearly defined test procedures only. At the inspection of real parts the errors are different. That is because often probe extensions are used with an increased measuring error. Furthermore the probing error at a datum measurement can lead to a much larger error on a feature a certain distance away from that datum.


The package QUINDOS CMM Error Simulation calculates the actual range of error for each feature.

An existing QUINDOS part program is executed n-times, with the "real" CMM switched off. At every run the virtual CMM generates measuring points, distributed around the nominal points. The range of those points depends on the P value entered. QUINDOS takes this points as if they would come from real Coordinate Measuring Machines / CMMs and calculates all the features.

Finally the range of the result for each feature is evaluated statistically.


Example: Comparison of the measuring error of 2 different CMMs

Range of concentricity result, 50 virtual measuring runs


3D Measuring Machine A: Probing Error P = 1µm 3D Measuring Machine B: Probing Error P = 3µm 
simulation of the error buget, based on the P-specification of a coordinate measuring machine simulation of the error budget for a CMM with a large P-error

By repeating the procedure, using P-values of different Coordinate Measuring Machines / CMMs, the operator can analyze which CMM is capable of inspecting a certain workpiece.
Furthermore the effects on modifications of the measuring strategy (i.e. using shorter extensions, increase the number of probing points at critical datums etc.) on the CMMs performance can immediately be evaluated.

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