The Optimization Design Of Precision Displacement Motion Stage Of An On-line Measurement System For Grinding Wheel Surface Topography Detection

Accurate measurement of 3D surface topography of grinding wheels is very important for effective prediction and control of the mechanical part. In the off-line measurement of grinding wheel, grinding wheel which is removed from the grinding machine loading on the measuring instrument, not only change the original datum,affect the location and the measurement precision. Disassembly process from on-line to off-line also increase the positioning. In order to obtain the grinding wheel surface topography parameters and accurately acquiring the change process of the wheel life surface morphology, it’s necessary to develop the on-line measurement system.However, in order to achieve the function, on the one hand it requires detection system with multi degree of freedom precise motion function for adapting to the series of grinding wheel size range of surface detection. On the other hand it also requires the system to achieve precise positioning of the submicron in the direction of the optical axis of the optical system. All of these require a new challenge for the development of the on-line measurement equipment.This paper aims to design integrated measurement precision displacement for the measurement of grinding wheel surface topography with vertical scanning white light measurement system and the depth of field of the tomographic measurement system.It analyzes the overall plan layout of on-line precision displacement motion stage from the requirement of the function and the accuracy. It focuses on the analysis of displacement oriented design and the key parts of the selection analysis, and the major structure finite element analysis and optimization. Finally it validated by experimental tests. The main contents are as follows:(1) Based on the analysis detecting application background of the displacement, it puts forward the functional requirements and the technology index for meeting the wide range of precision measurement. It designed the whole scheme and the control strategy of the measurement system. And also completed the stage oriented design and the selection analysis for the key components including guide rail, screw rod,stepping motor, piezoelectric ceramic micro positioning platform and metrologicalgrating feedback. And then it calculated the related parts machining dimension tolerances about the main assembly through the assembly dimension chain.(2) Analyzed the key degree of freedom of motion mechanism about parametric optimization design by finite element. According the pillar load on the analysis of the permissible value of the maximum allowable deformation calculation, it is necessary to complete the Z displacement pillar of the finite element analysis, and carry on the improvement of pillar structure and structure optimization to improve the structure of the performance. The maximum deformation of the pillar which has been optimized reaches 5.62μm. And natural frequencies of the fundamental frequency increases20.5% compared with before optimization. The reliability of the pillar structure has been guaranteed. Meanwhile it has finished the structure statics analysis of the key fittings and judged the rationality and feasibility of the structure.(3) It has manufactured the physical prototype of the on-line precision displacement motion stage for testing and verification, including position accuracy and straightness evaluation. It realizes position accuracy of X-axis with 4.50μm,Y-axis with 6.97μm, Z-axis with 5.87μm, and the straightness of all axis reach measurement requirement.Through theoretical analysis and experimental research of the work, the precision displacement motion stage of an on-line measurement system satisfies the measurement demands of the grinding wheel.