Extended state observer-based nonlinear cascade proportional-integral-derivative control of the nano quadrotor

The nano quadrotor is a nonlinear multi-input and multi-output system with strong coupling, which causes difficulties in control law design. In order to achieve a favorable performance, an extended state observer-based nonlinear cascade proportional-integral-derivative controller is proposed in this article. First, the nano quadrotor platform is built, and the dynamic model is established. Second, a novel and practical measuring method is given to obtain model parameters. Then, based on the active disturbance rejection control method, the design procedure of the extended state observerbased nonlinear cascade proportional-integral-derivative controller is presented. In the developed controller, a tracking differentiator is involved to extract the signals of gyroscope, and extended state observer is used to estimate the disturbance. To obtain a better performance of tracking differentiator and extended state observer, a systematic parametertuning method is studied. Finally, simulation results are given to demonstrate the efficiency of the proposed controller.