基于瞬时转速的旋转激光测量系统测角精度评价  

Angle measurement accuracy evaluation of rotating laser measuring system based on instantaneous rotation speed

作　　者：任永杰[1] 金云超 郭同闯 林嘉睿[1] REN Yong-jie;JIN Yun-chao;GUO Tong-chuang;LIN Jia-rui(State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《光学精密工程》2020年第11期2403-2410,共8页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.51775380,No.51835007,No.51721003);天津市自然科学基金资助项目(No.18JCYBJC19400)。

摘　　要：旋转激光测量系统基于光电扫描的计时方式,利用以时间差测位置差的时空转换思想,借助搭载有线型激光器的匀速转台作为旋转测尺进行测量,系统测角精度与转台匀速性相关。为了研究系统的转速稳定性及它与测角精度的相关规律,对系统测角误差、转速评价指标和瞬时转速算法展开研究。建立了角度测量模型,分析了瞬时转速波动对测角误差的影响机理;引入瞬时转速稳定度作为转速评价指标,并针对低精度码盘提出了一种基于脉宽误差补偿的瞬时转速算法,最后进行了实验验证。结果显示,对比传统M/T法和补偿算法,某气浮轴承发射站的瞬时转速波动测量值从±4.5 r/min降至±0.25 r/min,瞬时转速稳定度降至±4″。补偿算法的瞬时转速测量精度优于传统算法,测角精度与瞬时转速稳定度存在一致性规律,可以使用瞬时转速稳定度对系统测角精度进行快速评价。Based on the timing method of photoelectric scanning,a rotating-laser measuring system leverages the space-time conversion idea of measuring position differences by using time differences.The angle is measured using a uniform rotating platform equipped with linear lasers acting as a rotating measuring ruler.The angle measurement accuracy of the system is related to the uniform velocity of the rotating platform.To research the stability of the instantaneous rotation speed(IRS)of the system and its influence on the angle measurement accuracy,the angle measurement error,speed evaluation index,and instantaneous speed algorithm were investigated.An angle measurement model was established and the influence of the rotation speed on the angle measurement error was first analyzed.Then,we introduced the IRS stability(IRSS)as an index of the stability of the system's IRS.An optimized rotation speed algorithm is proposed to compensate the width error of the encoder pulse for low-precision encoders.Finally,experimental verification was conducted.The results show that the IRS fluctuation of a transmitter equipped with an air bearing decreased from±4.5 r/min to±0.25 r/min and the IRSS decreased to±4″compared to the M/T method with the compensation algorithm.The measurement accuracy of the compensation algorithm was better than that of the traditional algorithm,and the accuracy of angle measurement was consistent with the IRSS.Interestingly,the angle measurement accuracy of the system could be quickly evaluated from the IRSS.

关 键 词：旋转激光扫描 时空转换 测角精度 瞬时转速测量 瞬时转速稳定度 

分 类 号：TP741[自动化与计算机技术—检测技术与自动化装置]