基于单个时栅读数头冗余采样的自标定方法

Redundant sampling self-calibration method based on single reading head of time grating sensor

极端、特殊应用场合中工作的嵌入式时栅,受恶劣工作环境影响,其安装状态、电气参数等容易发生非预期的变化,进而导致其测量精度下降。在这些应用场合,通常缺乏高效安装比对标准器的条件,难以频繁在线标定以保持其测量精度。针对这一问题,提出一种单个时栅读数头即可实现的自标定方法,该方法利用冗余采样序列中提取的具有固定初始位置差的多组采样序列与系统误差函数的映射关系,解算出包含安装误差在内的传感器系统误差。在工程应用现场,以某大型回转机床为对象,搭建了自标定应用平台。实验结果表明,该自标定方法能够有效补偿传感器的短周期系统误差,使其测量误差峰峰值由约450″降低到约33″,其中,自标定方法有效的误差频次残余误差不超过1%。分析并验证了该自标定方法有效的条件,为后续研究中针对特定应用场合准确选择最适合的自标定方法提供了可靠的理论依据。

Affected by the harsh working environment,the installation status and electrical parameters of embedded time grating sensor always working in special applications are prone to unexpected changes.As a result,this would lead to lower stability and accuracy.However,in these special applications,it is hard to calibrate the sensors frequently to maintain measurement accuracy due to lack of efficient installation of an additional standard.To address this issue,a self-calibration method based on single reading head of time grating sensor is proposed.The proposed method employs the mapping relationship between multiple sets of sampling data with a fixed offset extracted from redundant sampling data and systematic error to calculate the system errors including installation error.On the application site,an experimental device is developed by a huge rotary table.The experimental results show that the short-period system errors are significantly reduced from 450 ″ to 33 ″ using this self-calibration method.What is more,errors that suit this self-calibration method could be reduced to less than 1 %.This study provides a criterion to distinguish errors that suit this self-calibration,and reliable theory foundation for further research that the most suitable self-calibration method could be chosen for a particular application.