Research On Gear Measurement Error And Measurement Uncertainty Based On Linear Structured Light Mearsurement System

As one of the most widely used transmission parts in the field of mechanical transmission,gears can be seen from aerospace to watches and toys,and the quality of gears determines the performance of the entire system.With the continuous acceleration of the modernization process,the demand for gears in various industries is also increasing,and the requirements for gear quality are becoming increasingly strict.The detection efficiency of gear quality also determines the speed of gear accuracy improvement.Obviously,the traditional contact measurement is no longer suitable for modern development due to its low efficiency and low measurement accuracy.Although some existing non-contact measurement devices can achieve non-destructive testing with a certain accuracy,but the overall cost is high,cannot be widely used.As a kind of non-contact measurement,linear structured light measurement system is gradually applied in the field of industrial measurement because of its fast detection speed and high measurement accuracy.Aiming at the many testing items and low efficiency in gear measurement,this paper proposes a gear measurement method based on a linear structured light measurement system,and evaluates the measurement uncertainty of the newly built measurement system.(1)The relevant theories and mathematical models used in the measurement are analyzed and deduced.The definition,evaluation principle and evaluation formula of the three regular inspection items(tooth profile,tooth pitch,helical deviation)in conventional gear measurement are analyzed and explained.And then the current mainstream measurement uncertainty evaluation methods are analyzed one by one.Carry out the analysis from the evaluation principle and advantages one by one.For the linear structured light measurement system,its basic measurement principles-laser triangulation,three coordinate systems(camera,image,world coordinate system),CCD model(linear and non-linear)and the mathematical model of the visual measurement model(line-surface model)are analyzed and deduced.(2)The achievable gear measurement accuracy of the new measurement system is verified.A grade 6 precision automobile gear is selected,and the same gear is measured in the gear measurement center and the linear structured light gear measurement system respectively,and the differences in the results of the tooth pitch,tooth profile and helical deviation between the two are compared.Through comparative experiments,it is known that the results obtained by LSLGMS are larger than the results obtained by the gear measurement center.The largest difference is 2.9 μm,the smallest difference is 0.05 μm,and the other differences are all within 2.9 μm.At the same time,the deviations of the gears measured by LSLGMS have reached the allowable value of grade 6 precision gears,indicating that LSLGMS can complete the measurement of grade 6 precision gears.(3)Analyze the measurement uncertainty of LSLGMS.Based on the pitch deviation in the gear measurement error,the factors affecting the uncertainty in LSLGMS are analyzed,and the uncertainty error model of LSLGMS is established according to the influencing factors.Uncertainty is solved and combined,and finally the combined uncertainty is 0.84μm,and the expanded uncertainty is 1.68μm.