Research On Error Compensation And Measurement Methods For Measuring Instrument Of Axisymmetric Body

Thin-walled rotator which range from parts of automobile and aircraft engine, largevessels as well as industry production equipment to frame and rotor structure ofinertial component are widely used in various fields of industry, agriculture, nationaldefense construction. It plays a significant role in national economy and defenseconstruction. There are strict requirements to the inner and outer diameter ofrotational parts in engineering applications. In addition, there are always chamfer,short arc and some other fine structures on the surface of the rotational parts.Specialized equipment and measuring method needs to be designed to carry out themeasurement of the inner and outer diameter size and these fine structures mentionedabove.General rotator measuring instrument is designed to accomplish the dimensionmeasurement of some cylinder liner. According to special structure of this measuringinstrument, corresponding error compensation model is established. Traditionalcontact measurement system combined with visual measurement system, which isused for detecting fine structure of rotator surface, carry out the measurement quicklyand precisely. Measuring efficiency is significantly improved. The main researchwork is listed as follows:1) Measuring instrument structure including contact measurement system andvisual measurement system is designed according to structural features of thin-walledrotary part and its geometric elements. Contact measurement system consisting offixed bridge structure and rotary table, carry out the measurement involving geometricdimensions such as inner and outer diameter as well as and position errors. Visualmeasurement system using backlight illumination can highlight the contour of part tobe measured. Telecentric lenses with image sensor eliminate perspective effect andimprove the measurement precision.2) Measurement system errors compensation model involving math modelestablishment of contact measurement system fixed bridge structure combining withrotary table, analysis and compensation method of back-to-zero error is establishedaccording to special structure of the rotator measuring instrument. Besides, a joint calibration method of contact measurement system and visual measurement system isdeveloped to measure the size of some special structures.3) Measurement methods are designed for different items to be detected. Thesemeasurement methods can be divided into four groups according to character of sizeand form and position errors to be measured. They are contact measurement ofgeometric dimensions, contact measurement of form and position errors, visual andcontact joint measurement. In addition, auto-measuring program’s track is optimizedfor improving efficiency.