Research On The Theory Of Form Error Measurement And Exploration Of The Technology Of Building Block Measurement Platform

The form error is an important index reflecting manufacturing quality of parts.In actual production,precision instruments are usually used to measure the form errors of parts.These instruments guarantee the accuracy of measurement with high manufacturing and assembly accuracy of their own parts.When the manufacturing accuracy of the measured parts approaches or reaches the accuracy of the instrument itself,the instrument cannot measure them accurately.For further improving the measuring accuracy of the instrument,error separation technology is needed.In addition,because advanced measuring instruments in form error measurement are manufactured by professional manufacturers,which are expensive and require high level of measurement environment,they are not suitable for batch measurement on site and are difficult to popularize.Therefore,it is of practical significance to explore the measuring instrument technology with high accuracy,low cost and suitable for industrial field environment.A large number of domestic and foreign literatures illustrate that multi-probe error separation technology requires strictly on sensor installation angle and high consistency of performance,therefore it is difficult to implement and not suitable for industrial field measurement.Therefore,this dissertation focuses on multiple positioning methods of roundness error separation and two-probe straightness error separation,which are convenient for practical application,and proposes simple and effective error separation methods which meets the requirements of conventional measurement and is suitable for implementation on site.The main contents of this dissertation are as follows:(1)The typical methods of multiple positioning method are deeply studied,and a time-domain solution of two-step method is proposed.By comparing with the frequency-domain method,the time-domain method has the same measurement effect as the frequency-domain method,and the two methods are completely homologous.The mathematical model of three-step method of unequal angle transposition is improved.The new model can be solved in frequency domain,which solves the problem that the weight coefficients of the original model are difficult to determine.The three-step method of probe transposition and its solution method in frequency and time domain are studied.The comparison illustrates that its solution method in frequency and time domain are also consistent.(2)The two-probe straightness error separation technology is studied,which is convenient for application on precision linear motion worktable.The related factors are analyzed,especially the initial alignment error of the probes and the error from the neglection of the guide rotation angle.(3)The technical idea of building block form error measurement platform is proposed.That is using the common standard precision motion worktable in the market and servo drive system and the data acquisition and control system based on single chip computer designed by ourselves to construct in modularization and building block type.The related construction technology is explored and studied.Building block form error measurement platform meets the requirement of in-situ measurement of form error and is suitable for batch measurement in industrial field.The platform has low requirements for measuring environment and low cost.After the application of error separation technology,the measurement accuracy of building block measurement platform can be further improved,which can meet the actual production needs of general machinery factories.(4)Measurement experiments of two-probe straightness error,two-step and three-step method of roundness error are implemented on the building block form error measurement platform,and then the measured part is calibrated on Talyrond 385 precision roundness instrument,which verifies the correctness of theoretical research and the practicability of building block measurement platform technology.