A High-Precision General Flexible Bar Measuring Instrument Based On Machine Vision Design

In these years, with the development of Astronautics and Aeronauticsin China, the requirements of inertia instrument’s performance areenhanced. As one of the most important unit of inertial navigation system,accelerometer has a direct effect on the measurement accuracy,measurement stability and navigation accuracy of the whole system.Flexible bar is a key component of accelerometer, and its performanceaffects the accuracy and stability. Because the flexible bar is so small andyielding, along with much shortage such as complex processing technic,little rigidity, difficult clamping and positioning, in this paper, ahigh-precision and general flexible bar measuring instrument system basedon machine vision was developed.The main content of this paper includes:1. The paper determined the final solution of the testing system. Thispaper first introduced the general develop situation of flexible bar, and putforward three solutions: laser displacement detection solution, machine vision and light path adjustment device solution and simplified machinevision solution. After analysis and simulation, this paper selected thesimplified machine vision solution.2. The paper introduced the design of hardware and software of themeasuring instrument. Based on the modularization principle, the hardwarepart included computer system, servo driving system, image acquisitionsystem and adjustment device system, and the software part is comprisedof users management module, parameters setting module, servo levelingmodule, image acquisition module, image processing module, databasemodule, system self-checking module and system standardization module.Then this paper explained the reasons of model selection and designing.3. After needle gauge and flexible bar were tested, the paper analyzedthe results, including their accuracy, repeatability and reproducibility. Andthe analysis results demonstrated the validity and stability of the measuringinstrument.4. As the measuring instrument has much unfinished work, the paperput forward the next research direction, such as optimizing the mechanism,completing other testing targets and improving the software.