loop n. 1.(用线、带等打成的)圈,环,匝,框,环孔,线圈;【医学】(常 the loop)宫内避孕环。 2.环状物,塔环,拎环。 3.(铁路上的)让车道,环道。 4.【无线电】回路,回线,波腹,环形天线。 5.【数学】自变;【计算机】循环;(程序中)一群指令的重复。 6.【航空】翻圈飞行,翻筋斗;【溜冰】(单脚)打圈儿。 7.〔美国〕闹市区;〔the L-〕 芝加哥的商业区。 a safety loop保险圈。 a wire loop钢丝套圈。 knock [throw] for a loop 〔美俚〕 1. 使神志不清;打昏,使醉倒。 2. 给人极好的印象。 3. 出色地通过[做成]。 on the loop 〔美国〕在匆匆旅行中。 out of the loop 在圈内人物之外的,不在…圈子内的。 vt. 1.使(绳等)成圈,打成圈;【电学】 把导线连成回路。 2.用圈围住;(用环)箍住。 (up back). 3.使作成环状运动;【航空】翻筋斗。 vi. 1.打环,成圈。 2.【航空】翻筋斗。 3.(像尺蠖似的)伸屈前进。 loop the loop 【航空】翻筋斗;(骑自行车等)兜圈子。
In the positioning servo - system , which generally is configured by the d . c . pulse width modulator ( pwm ) velocity governing system and position servo - loop , the parameter perturbance of pwm velocity loop really exist by reason of such as the load behavior ; power voltage supply ; operating setting value , etc . 1 , 2 , and it cannot be ignored . by using the identification technique to form the mathematical model of the system , authors have confirmed the facts . therefore , to design the discrete sliding mode controller ( dsmc ) of the positioning servo - system , the perturbed parameters value bounds of the pwm velocity loop , which is as the controlled plant of position servo - loop , should be accounted . consequently , the design principle of dsmc for accounting system with parameter perturbance is proposed by the authors . the proposed method can ensure the stability of system with parameter perturbance and the behavior of non - overshoot , fast precise positioning . in order to reveal the effects of the design method , the comparative research work is done by the authors . also , it has been tested in an industrial experiment , the results proved it is satisfactory 由直流脉宽调速系统( pwm )和位置环构成的定位系统中,速度环的参数随负载特性;电网电压;给定工况而摄动是不容忽视的.作者通过系统辨识建模也证实了这一事实1 , 2 .因此在设计位置环的离散滑模控制时,必须针对速度环(即位置环的控制对象)的参数摄动范围采用“对象参数摄动离散滑模控制器的设计方法” ,以确保系统在参数摄动时的稳定性和快速、无超调、准确定位的优良动态品质.为剖析该设计方法的控制效果,本文作了对比性研究,并将该设计方法用于工业试验中,取得了满意的结果