轨道几何动态惯性测量误差评估方法

Evaluation Method of Dynamic Inertial Measurement Error of Track Geometry

针对轨道动态测量应用场景建立了一套空间相关性的动态测量误差传播评估方法,研究了多种因素对测量准确性的影响,探究切实可行的轨道检测系统误差分析手段。将两类惯性基准测量方法简化成线性时不变系统,输入为特性一致的观测白噪声,由此得到的测量误差序列是平稳随机过程;提出了动态测量信噪比指标来描述传感器随机噪声、行车速度、波长和测量误差间的函数关系。结果表明:角速度测量法的信噪比与检测速度无关,加速度测量法的信噪比与检测速度正相关,二者均与轨道不平顺波长负相关;加速度测量法适用于高速检测,而角速度测量法适用于低速检测;为实现200 m轨道长波不平顺的有效测量,须将陀螺仪零偏稳定性指标提升至0.2°/h。

Aiming at the application scenario of track dynamic measurement,a set of spatial correlation dynamic measurement error propagation evaluation method was established,the influence of various factors on measurement accuracy was studied,and a practical error analysis method of track detection system was explored.Two kinds of inertial reference measurement methods were simplified into linear time invariant system,the input was the observation white noise with consistent characteristics,and the obtained measurement error sequence is a stationary random process.A dynamic measurement signal-noise ratio index was proposed to describe the functional relationship among sensor random noise,driving speed,wavelength and measurement error.The results show that the signal-noise ratio of angular velocity measurement method is independent of the detection speed,the signal-noise ratio of acceleration measurement method is positively correlated with the detection speed,and both are negatively correlated with the track irregularity wavelength.The acceleration measurement method is suitable for high-speed detection,while the angular velocity measurement method is suitable for low-speed detection respectively.In order to realize the effective measurement of 200 m track long wave irregularity,the zero bias stability index of gyroscope must be increased to 0.2°/h.