ADRC Based Attitude Control System Design for Unmanned Helicopter

Unmanned helicopter is a typically nonlinear, strong coupling, complex multi-input multi-output system, which has poorly stable reserve and is vulnerable to external interference. To solve this issue, an active-disturbance-rejection controller (ADRC) based design methodology for unmanned helicopter's attitude control system is proposed. A mathematical model of unmanned helicopter is first established, and its attitude dynamic characteristics are analyzed. Moreover, an ADRC algorithm based attitude controller is designed in the frequency domain, the leading compensation of the system is realized by adjusting the angular rate control parameters of the observer. In addition, the closed-loop simulation test and comparison analysis of attitude control are carried out by PID algorithm and ADRC algorithm, respectively. The results reveal that the ADRC algorithm based attitude controller estimates the system state through the extended state observer, both the bandwidth of the closed-loop control system and the robust stability of the unmanned helicopter are improved.