Research On Monte Carlo Tolerance Analysis For Lens Opto-mechanical Design

Traditional design of the lens mechanical tolerance mainly depends on theexperience, which lack of the analysis data. Because the structure of lens is notperfectly positioned, the CAT software can not conveniently be used to analyze theassembly tolerance.Tolerance analysis method for the incomplete positioning assembly is proposed,which is based on the Monte Carlo method. The method is applied to assemblytolerance analysis of lens optical system. Take the typical drop-in lens assembly forexample. The lens assembly model is proposed, which include both the mechanicaldimensional tolerances and geometric tolerances. Also, in the model, uncertaintyassembly is taken into account.Two configurations are designed for a dual-separation lens in the lasermeasurement system. On the first configuration, retaining rings are designed in thesame side of the lens. On the second configuration, retaining rings are set in thedifferent sides of the lens. Tolerance analysis data is obtained for each configurationby Monte Carlo simulation. According to the assembly accuracy, program by usingspecial lathes for the assembly of lens is proposed, of which the simulated data showsit can meet the requirement. Ten successful tests for the lens assembly prove thatMonte Carlo tolerance analysis is reasonable. Such assembly program has beensuccessfully used in the actual project.