| 摘要 |
1,221,869. Automatic control. INTERNATIONAL BUSINESS MACHINES CORP. May 23, 1968 [June 15, 1967], No.24574/68. Heading G3R. In an electrical error-actuated closed-loop process control system the sensitivity of the control system to fluctuations is automatically reduced when the error is less than a value corresponding to substantially three times the standard deviation of the noise signals in the system. In Fig.2, a number of variables of a process 10 are measured and interrelated in accordance with predetermined control laws by an analogue or digital computer 12 outputs of which control the process through control devices such as 14. As shown, the difference between one computer output signal and a signal from a follow-up transducer 16, representing the position of control device 14, is periodically sampled at 22 and applied as an error signal through a variable gain, damping, phase-shifting, amplifying, averaging and integrating system 20 to correct the position of control device 14. The error output of sampling device 22 is compared at 34 with a signal from an adjustable source 32 which is set to correspond in magnitude with three times the standard deviation of the noise level in the system. Then, whenever the error exceeds this level, the output of comparator 34 varies the gain of system 20. |
