System identifications of three-axis gyro model and base model of a RC helicopter without stabilizer bar

Abstract

The three-axis gyro as a black box, always hinders the control development of a helicopter without stabilizer bar. In this paper, a comprehensive research on three-axis gyro model and base model of RC helicopter was concluded. Four-direction frequency sweep flights were conducted on yaw, roll, pitch, and heave channels. For obtaining the dynamic model, the system identification process was completed in CIFER. By using a threestage method, the yaw dynamic was separated into three parts, which were identified respectively and formed a whole yaw model. The parameters in coupled roll-pitch dynamic were identified, indicating an increase trend from before gyro to after. The derivatives of base model of coupled roll-pitch were closer to the real ones. A single heave model was concluded due to the direct control of heave direction. This work gives a better view for control of helicopter that containing gyro part.