Estimation of Structural Response Using Remote Sensor Locations

A method is presented for estimating the response of a structure during its operation at discrete locations that are inaccessible for measurement using sensors. The prediction is based on measuring response at other locations on the structure and transforming it into the response at the desired locations using a transformation matrix. The transformation is computed using the system Markov parameters determined from a vibration test in which the response is measured both at the locations that will possess sensors during structure operation and at the desired locations thatwill not possess sensors. Two different approachesareconsidered. Thee rst requires as many sensors as there are modes responding in the data. The second approach, a generalization of the e rst, only requires as many sensors as the number of input locations. The transformation matrix is shown to consist of a set of inverse system Markov parameters, which can be related to a corresponding observer formulation. A numerical example is considered using the controls-structures interaction evolutionary model testbed at NASA Langley Research Center. Acceleration response with 10% rms noise at six sensor locations is used to predict the response at four force input locations. The proposed method is not computationally intensive and, combined with the fact that the process is causal, may allow real-time applications.