时间序列分析, 时栅, 动态模型, 预测, 全闭环数控系统

In order to apply a novel displacement sensor named time grating to full closed-loop CNC rotary table as an angle detector, it is necessary to transform temporal information to spatial information with time-space transformation algorithm for time grating sensor. According to time series analysis theory, dynamic model of dynamic characteristics of time grating CNC rotary table can be established. Therefore, the next measurement value can be predicted based on past measurement values with the dynamic model. At a result, original absolute displacement signals sampled in equal time interval can be transformed to continuous incremental pulses required by full closed-loop CNC system. Furthermore, the principles of selection criteria for dynamic models, parameters estimation, model checking were presented. In addition, regarding error control, last predicted errors were always corrected by current measurement values in real time so as to eliminate accumulated errors for realizing precision measurement. Experimental results prove that dynamic measurement displacement errors are within ±3″ with the dynamic model. And precise full closed-loop angular displacement measurement is realized.