System identification for the unmanned helicopter yaw channel based on the switch model

For the saturation nonlinear in the yaw channel of the small-scale unmanned helicopter, this paper proposes a identification method for the yaw dynamics based on the switch model. Specifically, working from analyzing the structure of the yaw channel, the switch model that includes the saturation unit is derived. The experiment data for the model identification is collected with the sweep frequency control signals, and the parameters of the switch model are identified from the flight-data through genetic algorithm (GA). The residual error model is established and added the identified yaw dynamics model to modify the yaw model. The effectiveness of the approach is validated by other flight data that are not used to identify and a yaw rate set-point control experiment. These results all demonstrate the accuracy of the identified yaw model.