| 摘要 |
PURPOSE:To make effective the failure diagnosis of detection signal, by using the change rate limiter excluding the noise superimposed on detection signal for the check of change rate and detecting failure in the system accurately and quickly. CONSTITUTION:The state amount of controlled units is fed to the computer via the operation terminals such as control valve and control drives, the signal of the transmitter 1 connected to the detector is fed to the change rate limiter D-2 in suitably controlling the computer, the change rate is checked with the limiter D-2 and fed to the monitor relay D-3. The limiter D-2 consists of the subtractor S-1, high gain amplifier S-2, limiter S-3 and integrator S-4, the output of the integrator S-4 is fed back to the subtractor S-1 and compared to exclude the noise superimposed on the detection signal, and the deviation between the output and the input of the limiter D-2 is monitored with the relay S-3. Further, the rationality check and the upper and lower limit check of signal are made by the rationality discrimination circuit D-5 and the relay D-4 and failure is judged with the OR circuit D-6. |
