Design and analysis of test signals for system identification

For multi-channel process, due to disadvantages of the open-loop single variable step method, multi-channel test method is used. That means all of the channels are tested at the same time. In order to eliminate cross-effect of the different test signals, it requires that all the test signals are uncorrelated. Several test signals are introduced and analyzed. Based on two familiar identification methods: correlation analysis method and least-squares method, we put our strength on the way to get uncorrelated test signals. A novel design for the period length of uncorrelated pseudo random binary sequence (PRBS) is proposed. Use this design method, identifiable PRBS signals can be gained and their periods are the shortest. Simulation results show the effectiveness.