Active Disturbance Rejection Control of a Quadrotor: A Comparative Study

This paper presents a performance comparison of PID, linear and nonlinear active disturbance rejection control (ADRC) for a quadrotor based on robustness, disturbance rejection and control actuation. ADRC being model independent is suitable for systems like quadrotor, for which system parameters are not precisely known and dynamics are prone to external disturbances. Its notable features such as error-driven control law, extended state observer and a nonlinear feedback law, makes ADRC a suitable candidate for dealing with disturbances and uncertainties, while minimizing control actuation concurrently. Nonlinear simulations have been carried out to demonstrate the effectiveness of controllers. To check robustness, a Monte-Carlo analysis with different sets of parametric uncertainties has been performed. Furthermore, a disturbance analysis has been carried out to demonstrate disturbance rejection capability. The simulation results are discussed based on the performance of designed controllers and their corresponding control actuation. The results reveal that nonlinear ADRC has an edge over both linear ADRC and PID as it deals effectively with disturbances and uncertainties while minimizing the control energy.