An identification method of multi-source dynamic loads based on independent component analysis

This study proposes an identification method of multi-source dynamic loads based on independent component analysis, in order to detect the wave pattern of the load subjected to a structural system whose configurational information is totally unknown. The method is based on the principle that the response of structure is a convolution of load and corresponding structure impulse response; also, it assumes that individual load sources are statistically independent to each other. When compared with the existing load identification methods, the features of the method developed in this study embody three merits: (1) The structural configuration, such as distribution of structural mass, structural stiffness and damping ratio, could be unknown, and the independence among the actual loads is taken as the goal of optimization; (2) The independence of individual identified loads is measured using their mutual information, and the correlation at different orders is eliminated by the use of gradient degressive algorithm, so that the independence among detected loads is guaranteed; (3) Loads could be identified from the standpoint of wave patterns. Numerical simulation indicates that the algorithm is robust on measuring point, noise, structure and input load. By normalization, the value of the correlation coefficient between identified and actual loads is approximately 1. Therefore, this method successfully integrates the existing knowledge on load into the load detection algorithm, and could make a confident estimation of the actual value, which contributes in the practical significance of the developed method.