| 摘要 |
PURPOSE:To realize the automatic monitor for the stability of a control system by applying a time series analysis and a root analysis to an output signal by transmitting a difference signal between a target value signal and the control value through a DC eliminating/high frequency noise attenuating filter. CONSTITUTION:The DC components are eliminated and the high frequency noises are attenuated by a filter 4 for a difference signal between the control value y(t) and a target value signal r(t) of a control system. Then, said difference signal is sampled by a sampler 5 in a fixed cycle and this difference signal data undergoes a time series analysis through a time series model estimator 8 via the minimum square method for estimation of the parameter of an AR model. Then, the proper value of the estimated AR model is calculated by a root acquiring means 9 and the stability of the control system is decided by a stability deciding means 10 based on said proper value. The decided stability of the control system is displayed on a display/alarm device 11. Thus, it is possible to monitor automatically the stability of the control system with no disturbance caused by the noises contained the difference signal because the minimum square method is used to perform the time series analysis. |
