【作者】 刘李莹；

【导师】 周文祥；

【作者基本信息】 西南交通大学 ， 载运工具运用工程， 2008， 硕士

【摘要】 对车轮测量精度和速度的要求是随着列车速度的增加而提高的。尽管目前的列车车轮自动检测装置可实现动态检测,但其条件是车轮必须经过特定的区域。显然,对于不便拆卸与人工移动的铁道车轮,其测量工具主要还是便携式仪器。鉴于激光三角传感器受踏面形貌、颜色及环境影响大,且价格昂贵,所以接触式扫描测量方法仍然具有最高的性价比。为此,论文就提高五连杆车轮外形测量仪准确度的相关问题,进行了全面的研究。首先,通过对测量仪的组成、工作原理及测量程序(流程)的系统分析,建立了测量的数学模型。针对测量的全过程,分析了测量系统的误差源,采用全微分理论建立了测量误差解析模型,同时建立了全参数的MATLAB精确数值模型,利用此数值模型分析了单因素误差,多因素误差交互作用对测量结果的影响。结果表明;①各因素在所涉及的范围内完全可认为是线性独立的,这为不确定度的评定提供了依据;②两编码器的量化误差为主要的误差源,从而为仪器的标定和数据处理指明了方向。为实现量值溯源,研究了由易到难,由粗到精,分层次,软件数值仿真与硬件测试相结合的标定/检定方法;设计了相应的标定/检定装置,研究了检定装置的检定方法。多台仪器标定实验验证了该标定方法的可行性和可靠性。标定后的仪器对JM3样板的形状测量误差小于±0.02mm。最后,按《JJF1059—1999测量不确定度的评定与表示》及《JJF 1130-2005几何量测量设备校准中的不确定度评定指南》分析了仪器的测量不确定度,取置信概率P=0.99,包含因子k=2.58,形状参数的扩展不确定度小于±0.03mm,直径的不确定度随被测车轮直径增加而变大,但适当增加仪器尺寸后,可使测量不确定度保证在0.1mm以内。对车轮外形测量仪准确度研究的结果表明;可通过适当的尺寸、位置参数的标定,误差补偿和正确的操作来保证仪器的测量准确度。该类型车轮外形测量仪的测量准确度能够满足高速动车的要求,该项研究具有重要的应用价值。更多还原

【Abstract】 The train speed is highly associated with the accurency and efficiency of the measurement to the train wheel, the more it’s higher, the higher the measuring requests. Although the auto-measuring equipment can realize the dynamic measure, the train wheel has to pass the given region. Obviously, the best measuring equipment is portable instrument because the train wheel is hard to move or tear down. Another, the accurency of the laser triangle sensor is influenced by the figure and color of the train wheel, environment, and the price is very high, so the contact measuring method is worthy of research. Therefor, some researches about the five-bar profilometer and how to improve the measurement accurency of the five-bar profilometer are all intruduced in the thesis.Firstly, by analyzing the composing, operation principle and measuring process, measuring mathematical model is made. Aiming at the process of the measurement, the error sources of the measuring system are analysed, and the error analytic model of the profilometer is also made by differential theroy and the accurate parameter model by MATLAB. Furthermore, the influences to the measure result about the interacion between single-factor error and mult-factor error are analysed. The results of the analysises prove that each factor is linear and unattached, the angle of the two encoders is the biggish factor of the influences to the measure result. These results provides the gist to the demarcate methord of the incertitude and the accurency.Secondly, to accomplish the affiliation of gauge, Calibration method which is from easy to hard, approximate to pinpoint, layered, and hardware test combination with software emulate is studied in the thesis. Testing instrument of the five-bar profilometer is designed and a simple and reasonable calibration method is set, the feasibility of the calibration method is validated by experiments. As a result of measuring JM3 model, error of shape below±0.02mm.Finally, according to JJF1059—1999 Estimation and Demonstration of Measuring Uncertainty and JJF 1130-2005 Guide to the Estimation of Uncertainty in Calibration of Gemetrical Measuring Equipment. The measuring uncertainty of profilometer is analysed. When the believe probability is 0.99 and cover gene is 2.58, the expand uncertainty as follows,shape parameter less than±0.03mm. The uncertainty of the diameter of wheel will expand as the increase of it. However, by increasing the geometry dimension of the profilometer, we can make the uncertainty within 0.1 mm.The study on the accurency of the five-bar profilometer indicates that it can insure the profilometer has the eligible measurement accurency by calibrating proper dimension parameters and locational parameters, compensating error and operating correctly. The measurement accurency of the five-bar profilometer can meet the requirements of the high-speed train. This study has vital pratical value.更多还原