Research On The Measuring Instrument Of Gun Barrel Axis Straightness

As a most basal item of geometrical product measurement, Straightness measurement is the base of many measurements such as flatness, parallelism, squareness and concentricity. Straightness measurement is a very important content of machine manufacturing. As one factor of form error, Straightness directly influences precision, capability, quality of the instrument, sometimes may be determinate factor. Axis Straightness of gun barrel directly influences sending precision and hitting precision. While the inspecting methods that most internal workshops are using are very old, inefficient and have low precision, so the instrument can't work well. High-precision Straightness measurement, especially for space Straightness, is very difficult, the nowadays methods of measurement can't give attention to both accuracy and economy. So we take measuring instrument of gun barrel axis Straightness as object of research. Under the precondition that the measurement can get high accuracy and can be economical, we have accomplished the design of the instrument.The paper mainly discusses the research on the measuring instrument of gun barrel axis Straightness, which is based on image processing.First, the traditional methods of Straightness measurement are analyzed and compared, optical axis method for measurement based on image processing is improved.Second, through the analyzing for principle, characteristic and practical demand of the measurement, the structure design is been accomplished. In the first part, the blue print of the whole structure of the measuring instrument and main parts is brought forward. In the second part, the detailed design is brought forward. In the system of laser beaming and collimating, we have solved the problem on the straightness and directional stability. In the optical imaging system, optical magnify theory and CCD imaging theory is expatiated, the concrete optical route is designed and analysis on choosing the main accessory is given. In the drive device system, detailed design on metrical element is processed and analysis on choosing the other accessories is given. All the three systems are parts of the detailed design. In the last part, the whole course of the measurement is advanced.Third, we have brought forward the general design and detailed design of the software system. In the first part, the blue print of the whole structure of the software system and main parts is brought forward. In the second part, the principle of image processing being analyzed and compared, the method of image processing that most fits this measurement is chosen out and method of software realization is given out. The image processing software system can not only fit the purpose of image processing but also gives a stage for farther exploitation on image processing. In the third part, the method of software realization on measure-controlling is given out, so we can automatically control the measurement course, data collecting and data processing, build straightness data file automatically. In the forth part, traditional methods to evaluate straightness error is general compared, and the realizing method by software for each one is given out. The way to evaluate space straightness error by genetic algorithm is brought forward. The system can evaluate straightness error in given plane and along given direction as also. The system has the function to create, look over, modify and print straightness data file. Thewhole software system is programmed in Windows 98 and Microsoft Visual C++6.0. The system has perfect function, friendly interface and simple operation.At last, the conclusion that the instrument can fit the demand is gained, trough academic error analysis and calculation on resolution and measuring rang-e.The result indicates that the system fits measurement demand well, and fits the demand of accuracy and economy. It can collect data and process data automatically. The research will supply certain base for developing the measuring instrument for deep hole straightness in future.