Disturbance Observer-Based Robust Control of a Quadrotor Subject to Parametric Uncertainties and Wind Disturbance

Abstract

We propose a disturbance observer-based controller to deal with the trajectory tracking problem of a quadrotor subject to parametric uncertainties and wind disturbance. The design is based on the combination of a recursive robust linear-quadratic regulator and a Kalman filter. Robust regulation deals with uncertainties of state and input matrices of the quadrotor in order to minimize, mainly, its trajectory tracking error. Filtering aims to estimate wind disturbance based on an augmented state-space model of the quadrotor. We finish the approach with a compensation controller whose task is to perform disturbance attenuation. We develop indoor experiments where a wind disturbance source provides a measurable speed pattern. We provide a comparative study among the robust control approach proposed with a feedback linearization controller, a proportional-integral-derivative controller, and a nominal linear-quadratic regulator.

Synthesis of a Control System for a Waste Heat Boiler with Forced Circulation under Restrictions on Control Actions

“…Ensuring inequalities (7) at the design stage is necessary but not sufficient to fulfill the goal of control under constraints (6). The system of inequality for the choice of feedback parameters k, M = const > 0, under which both inequalities (6) are satisfied, has the form…”

“…This system is compatible if together with a priori requirements (7), the following relation is provided at the design stage…”

“…In conclusion, we note that both considered variants of control u 3 synthesis have a common drawback, namely, they are not robust to the parametric uncertainties of system (60). To obtain robust steam temperature control algorithms in system (60), one should refer to the results of [7], where a solution to the tracking problem in non-minimal phase linear systems with one input and one output under conditions of parametric uncertainty and incomplete information about the state vector was proposed.…”

“…On the other hand, it is difficult to use known approaches for synthesis under conditions of parametric uncertainty of the control plant model based on the methods of parameter identification [7,8] and adaptive control [9,10] with incomplete measurements of the state vector and under the influence of external disturbances. A whole range of problems arising in the synthesis of feedback under uncertainty is solved using sliding mode control and deep feedback, which have already become classical methods for ensuring invariance [11][12][13].…”

Dynamic Stiffness Enhancement of the Quadcopter Control System

“…In [19], with motor fault and external disturbance, an adaptive attitude control for multi-rotor UAVs is given. In [20], a disturbance observer-based controller is proposed with parametric uncertainties and wind disturbance. Therefore, according to related works in the literature, how to reduce the vibration generated by external disturbance, wind disturbance, and motor/propeller faults is the key point for the quadcopter operation.…”