| 摘要 |
PURPOSE:To improve the reliability of a control device without stopping the operation of a main machine when the control device is failed by triplicating a part of sensors and control circuits and outputting signals generated by the triplication through intermediate value selecting circuits. CONSTITUTION:Output signals detected by the triplicated sensors 1a-1c are transferred to main control circuits 15a-15c through the intermediate value selecting circuits 20a-20c. The respective circuits 15a-15c execute prescribed operations and output positional signals of respective valves to valve position control circuits 21a1-21a3 respectively. The respective circuits 21a1-21a3 similarly constituted feed back valve opening signals to adders 7a1-7a3 through a cylinder 11a, compare the fed back signals with valve position requesting signals from the circuits 15a-15c and output the difference signals to a servo valve 10a through servo amplifiers 9a1-9a3. The respective circuits 20a-20c are provided with low value and high value priority circuits to output the detected signals of the sensors 1a-1c to the circuits 15a-15c. A part of the sensors 1a-1c and the circuits 15a-15c is triplicated to improve the reliability of the control device. |
