Frequency-domain identification of a small-scale unmanned helicopter with harmony search algorithm

This paper presents a new method to identify the model of a small-scale helicopter in frequency domain using harmony search HS algorithm. The dynamics of the small-scale helicopter are simplified to four single-input/single-output SISO linear subsystems near the hover point, and the HS optimisation algorithm is used to identify each subsystem's parameters. Time-domain verification is made to check the validity of the identified models. The verification results show that the identified models are accurate and effective enough to describe the dynamics of the helicopter. The identified models show that the dynamics of the roll, pitch and yaw channels are mainly dominated by the lightly damped second-order modes. Identification and verification results show that the application of HS algorithm in system identification is suitable and useful.