【作者】 李德维；

【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， 2006， 硕士

【摘要】 轮对几何参数的非接触自动测量,可以提高铁路运营部门轮对检修的质量,有助于实现铁路信息化管理的目标,而且可为研究轮轨接触几何关系提供重要的数据。因此,研究轮对自动测量技术具有重要意义。 本文研究一种新的非接触测量方法的精度,测量方法的核心是:采用车辆段普遍使用的转轮器实现被测轮对的粗定位;采用车轴基准探尺确定被测轮对的轴线;采用并联式伸缩机构和旋转测头座,带动电涡流位移传感器扫描车轮外形轮廓线,得到相关参数。 论文首先分析了测量系统的机构原理和并联伸缩杆的运动几何关系,针对轮对几何参数测量,完成测控系统设计:采用光栅尺、光电编码器测量可动部件的运动量,分辨率高、误差小;采用细分驱动的步进电机装置,定位精度高、可控性好。 研究了机构中各单因素几何误差对测量结果的影响,找出了在测量范围内对测量结果影响较大的几何参数误差源,为进行精度设计提高测量装置的精度提供了依据。 论文分析了测量机构在已知位置的测量不确定度,结果表明:测量机构的测量精度受编码器零位角影响较大,应进行准确标定;采用IT7级加工精度就能基本满足测量精度的要求。 为了进一步提高精度,本文提出了一种基于接触式测头的机构几何参数自标定方法,并通过了单因素仿真验证。设计了电涡流位移传感器标定方法,并进行了车轮外形测量试验,结果证明了采用电涡流位移传感器进行非接触测量的可行性。更多还原

【Abstract】 The non-contact and automatical measurement of wheelset geometric parameters not only can help to improve the quality of wheelset test, to realize the goal of railway’ s information management, but also can give much information on the studying wheel-rail geometric contract. Therefore, the study on technology of automatical measurement of wheelset is of much importance.The precision of a new project for measuring the wheelset geometric parameters is studied once again in this paper. First, the wheelset is fixed and rotated by the device used in vehicle depot as usual. Second, the center line of wheelset axis is determined by a device called axis-center probe. Last, the acting device for sensor can draw a whole felloe profile, which is made up of parallel-pole device and rotating-probe. The wheelset profile is scanned by the eddy current sensor, thus, the geometric parameters of wheelset will be get.The theory of the measuring system and the kinematics of parallel-pole are analyzed. The whole electric components are implemented in the measuring system by employing grating sensors and optical encoder with resolution and low error. The measuring system also has a position and control precision with stepping motor.The influence which the single error has on the measuring result of measurement system is studied. The source of error that has great influence on measuring result is found, and this offer evidence to precision design for improving the measurement precision of measuring machine.The uncertainty of measurement machine at assured point are analyzed. It can be known that the encoder’ s zero angle has great influence on measuring precision, and it must be calibrated. The machining precision of IT7 can satisfy requirement of measuringmachine.A self-calibration mathematics model for contact measurement machine is set up in this paper, and it is proved by emulational method for single error. A calibrating scheme that calibrating module are scanned and measured with the eddy current sensor is designed. The result of experiment about the wheel profile show that the feasibility of non-contact measurement using eddy current sensor is turned out.更多还原