Identification of the Model

Abstract

Now that we have estimated the frequency responses and developed a linear parameterized model for our small-scale rotorcraft, we can proceed with the identification of the model parameters. In this chapter, we summarize the identification process and present the results obtained for the Yamaha R-50. We first explain how the estimated frequency responses are related to the transfer functions derived from the state-space model, and also describe how to account for the kinematic effects introduced by a sensor position offset. Then, we describe the identification procedure we developed for the R-50, i.e. how we broke down the identification of the state-space model into subsystems, selected the frequency responses and frequency ranges, and refined the model parameterization. Finally, we present the frequency response fit, discuss the identified model parameters, demonstrate the accuracy of the model through a time-domain validation, and, to conclude, provide a comparison of the key identified parameters’ values with the values predicted by helicopter theory.