采用激光传感器的同轴度检测技术研究

Research on Coaxiality Detection Technology Based on Laser Sensor

针对车桥减速器桥壳轴承孔的同轴度检测问题,设计了一种基于二维激光位移传感器的同轴度检测装置。该装置通过二维激光位移传感器在孔内旋转一周进行测量数据采集,并利用编码器实现了采集过程的闭环控制,采用该装置可提高数据采集效率。为了进行同轴度计算,提出一种针对三维点云数据的最小二乘迭代法。首先,将采集到的角度、径向距离转换成三维坐标的点云数据形式。接着,以残差最小为优化目标,利用高斯-牛顿迭代方法确定出最优轴线。该方法利用了整个圆柱孔测量数据,并通过基于残差最小的优化方法计算得到两端孔的轴线和它们的公共轴线,然后,以公共轴线为基准计算出同轴度误差。与传统的通过计算多个横截面中心来确定轴线的方法相比,该方法提高了计算精度。同时,针对影响同轴度测量精度的一些因素,如测量装置的安装精度、转轴的径向跳动等进行了分析,并给出误差补偿方案。最后,将该装置的测量结果与三坐标测量结果进行对比,验证了该方法的正确性。

Aiming at the coaxiality detection of axle housing of reducer,a coaxial measuring device is designed by using two-dimensional laser displacement sensor.The measuring data are obtained by rotating the sensor in the hole with one round,and the measuring process is controlled by the encoder to realize the closed loop control.Compared with the traditional contact measurement method,the data acquisition efficiency is improved greatly.In order to determine the coaxiality error,a new method for three-dimensional（3D） point cloud data processing is proposed by using least squares iterative algorithm.First,the acquired data represented with angle and radial distance are transformed into 3D point cloud.Then,the minimum residual error is defined as the optimization target,and the optimal axis is calculated by using the Gauss Newton iterative method,in which the data from the whole cylindrical hole surface is utilized.The axis of two holes and their common axis are determined with the minimum residual.Then,the coaxiality error can be calculated by the common axis.Compared with the traditional methods that calculate the axis by using several cross-section centers,the measuring accuracy is improved by using proposed method.In addition,some factors,such as the installation accuracy of themeasuring device and the radial runout of the shaft,are considered and analyzed for improving measuring accuracy.Finally,experimental result is compared with that of three coordinate measurement machine.