Power braking is usually required when mine hoist is at reducing stage, but sPeed closed-loop control is difficultly realized.

交流矿井提升机的减速阶段，一般要求主要用动力制动，但速度闭环控制难实现。

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In this paper, the hoist and lower automatic control system for stage and orchestra is designed, which is necessary to high technical equipment for those newly built theaters.

本文以新建剧场所用高技术设备为背景，设计了一个具有升降舞台和升降乐池的舞台自动控制系统。

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