A load identification method based on wavelet multi-resolution analysis

• A novel load identification method based on wavelet multi-resolution is proposed.
• Qualitative and quantitative selection rules about parameters are proposed.
• The proposed method can correctly distinguish fast and slowly varying signals when parameters are set appropriately.
• Better identification ability and lower noise sensibility than the frequency method.

Load identification, as a kind of indirect identification method, uses system characteristic and responses to calculate loads. A method based on wavelet multi-resolution analysis is proposed in this paper. By wavelet decomposition and transform at certain resolutions, the proposed method transforms the convolution relation between responses and loads in time domain into the linear multiplicative relation between system responses and wavelet responses in the wavelet domain. Loads can be identified as long as the linear multiplicative relation is solved. Qualitative and quantitative rules are proposed for selecting parameters that affect the accuracy of the proposed method, and are illustrated via numerical investigations. The method is illustrated by a multi-input-multi-output numerical simulation. A multi-input-multi-output laboratory experiment is performed to compare the proposed method with the frequency method on the identification ability.