multiple feedback loop的用法和样例：
例句
- And the experimental tests had been carried out to verify the established model as well as the dynamic characteristics under opening loop control.
并通过实验，对所建立的动力学模型及开环控制下平台的实际动态特性进行了验证。 - A standing-wave-type stepping ultrasonic motor using the alternative operation of two bending vibration modes on the stator has no accumulative errors without the feedback.
摘要利用环形定子的两个弯振模态交替工作的原理设计的一种驻波型步进式超声电机具有开环控制下无累积误差的特性。
