| 释义 |
ˈservo-ˌmechanism
Also without hyphen and as two words.
[f. servo n. + ]
a. A powered mechanism in which a controlled motion is produced at a high energy or power level in response to an input motion at a lower energy level; esp. one in which feedback is employed to make the control automatic, and generally comprising a measuring device, a servo-amplifier, and a servo-motor.
1926Encycl. Brit. II. 980/2 Some cars..were fitted with an hydraulic servo mechanism. 1935Jrnl. R. Aeronaut. Soc. XXXIX. 794 The [de-icing] device..comprises two essentials, the ice detector and the servo-mechanism which controls the supply of alcohol. 1959Times Lit. Suppl. 24 Apr. 245/2 All self-regulating machines are servo-mechanisms, in which one part of the machine regulates the operation of the other. 1960Times 29 Jan. 3/1 (Advt.), The applicant should have a good knowledge of servomechanism theory. 1973Sci. Amer. Nov. 129/1 Our seismographs and tiltmeters operate in tunnels several hundred feet underground and are provided with servomechanisms that automatically compensate for temperature changes. 1977D. Fry Homo Loquens vii. 91 For centuries firearms..operated on the ballistic principle of the boy who throws the ball; in the last decades, feedback control has been introduced into this area by the employment of servo-mechanisms.
b. transf. A non-mechanical system that is characterized by self-regulating feedback, esp. in Genetics and Physiol. Also fig.
1953J. S. Huxley Evolution in Action ii. 46 Natural selection..provided a genetic servo-mechanism to regulate the mutant back towards normality in its effects. 1958Times Lit. Suppl. 17 Jan. 34/3 The human or animal body is a remarkable example of servo-mechanisms, in which the expenditure of a small amount of energy is used to release a large amount of energy, and in which a balance..is maintained by ‘feed-back’ processes. 1964M. McLuhan Understanding Media i. iv. 41 This extension of himself by mirror numbed his perceptions until he became the servomechanism of his own extended or repeated image. 1971Nature 10 Dec. 325/1 Natural selection is not a chance process but a feedback servo⁓mechanism between the gene pool and the environment. 1976New Yorker 15 Nov. 157/1 Their basic assumption is that speech can best be understood as the output of a servomechanism—that is, a device with built-in feedback loops which continuously monitors its own performance and modifies its activity accordingly.
Hence servo-meˈchanical a.
1947Proc. IRE XXXV. 770/2 The..servomechanical type of control may be preferable where slow drifts over long periods of time are encountered. 1966S. Beer Decision & Control xvi. 418 In this servomechanical model there is a special facility for identifying precisely what is self-regulating about the system. 1977Lancet 5 Nov. 955/2 The finding of only partial suppression of A.C.T.H. with normal levels of cortisol is difficult to understand in conventional servomechanical concepts. |