Question

Tolerance Analysis using Merit Function Criterion

  • 21 March 2024
  • 2 replies
  • 58 views

While tolerancing for an optical system I have chosen the criterion as Merit Function. However when the analysis is performed the nominal criterion is taken as zero. Also no change in the system is taking place for the tilts and decenter. However there is change when TTHI is used, but variation in the Best and Worst is more the accepted range. So why is this so and how can I rectify this problem?


2 replies

Userlevel 3
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When you choose Merit function as a criterion, try to press on the button “Check”. It should show you baseline value. If it is 0, check your MF carefully.

Userlevel 4
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And another note on this… At the beginning of a tolerancing run, OS does a quick optimization of the system with the compensators as variable to determine what the nominal criterion will be during tolerancing, so it may be the case that the compensators are able to solve it exactly, giving a zero result. And that zeros are what are being reported. This process is described on the help page 'How OpticStudio Computes the Tolerance Analysis'. 
 

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