Three optimal principles of sensor placement,Error Discerned Minimum?Displacement Energy and Model Reduction,have been discussed on the relativity of modes and the displacement.

• 从各阶模态向量的相关性和变形能出发，讨论了识别误差最小度准则和变形能准则，以及模型缩减准则等三种传感器优化配置的准则；