rigid feedback controller

例句：

1. 1. The material is very rigid and hard to bend.
   这种材料非常坚硬且难以弯曲。
2. 2. The law is very rigid and strict.
   法律非常严格和严格。
3. 3. The bridge is very rigid and cannot be moved easily.
   这座桥非常坚固，不能轻易移动。