Robust Attitude Tracking Control for a Quadrotor Based on the Uncertainty and Disturbance Estimator

Journal of Guidance, Control, and Dynamics

2018

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This paper presents an autonomous landing control approach for a quadrotor unmanned aerial vehicle subject to wind disturbance and three-dimensional movements of the landing platform. To achieve an accurate relative position estimation of the quadrotor to the landing platform, a camera, a distance sensor, and a single-board computer are integrated to the quadrotor. The coordinate transformation is introduced to deal with the constraint that only the relative position information is available. The impacts of unknown ship motions are treated as part of the lumped uncertainty terms. Then, the uncertainty and disturbance estimator-based controllers are developed to achieve the accurate relative position control of the quadrotor while dealing with unknown ship motions, ground effect, state couplings, and external disturbances. The uncertainty and disturbance estimator filter is designed based on the internal model principle to enhance the performance of the developed controller. The reference model of the relative altitude controller is modified to ensure the accurate tracking of descending commands. To maximize the capability of the developed controller, a parameter selection guideline based on the derived ship heave acceleration spectrum is provided. Both numerical simulations and flight experiments are carried out to demonstrate the effectiveness of the developed approach.

Section: Nomenclaturementioning

confidence: 99%

Shipboard Landing Control Enabled by an Uncertainty and Disturbance Estimator

Journal of Guidance, Control, and Dynamics

2018

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“…demonstrated through real flight experiment studies. Compared with previous UDE works on quadrotor attitude and height control [25,28], this paper mainly focuses on the horizontal position controller development.…”

Section: The Effectiveness Of the Developed Control Strategy Ismentioning

confidence: 99%

“…From the block diagram of the overall control system (Fig. 2), it could be seen that the cascaded inner-outer loop control structure is utilized to deal with the underactuation, where the inner loop is the attitude controller and the outer loop is the position [25], this paper will focus on the controller development for the position subsystems. From the x, y dynamics (1) and (2), it could be seen that the control inputs for horizontal motions are in nonaffine forms, which leads to the failure of using feedback linearization.…”

Section: Control Design Ude-based Position Controller Developmentmentioning

confidence: 99%

“…The basic idea of the UDE method is that in the frequency domain an engineering signal (the model uncertainty and external disturbance) can be approximated by putting it through a filter with the appropriate bandwidth. The remarkable performance of the UDE strategy has been demonstrated in recent years through both theories [22,23,24] and practical applications [25,26,27,28].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Robust Position Control of a Quadrotor Using Onboard Optical Flow Sensor

Volume 1: Advances in Control Design Methods, Nonlinear and Optimal Control, Robotics, and Wind Energy Systems; Aerospace Appli

et al. 2016

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In this paper, the uncertainty and disturbance estimator (UDE)-based position controllers are developed to achieve the robust position control of a quadrotor using only onboard sensing. Firstly, in order to accurately estimate the positions of the quadrotor in GPS-denied environments, an open source high speed optical flow sensor PX4FLOW is adopted. Secondly, the UDE-based controllers are developed to handle the challenges brought by the highly nonlinear quadrotor position dynamics, including underactuation, coupling, nonaffine inputs, model uncertainties and external disturbances. Real flight experiments, including hover and disturbance rejection are carried out to demonstrate the effectiveness of the developed UDE-based controllers.

Uncertainty and Disturbance Estimator-Based Robust Trajectory Tracking Control for a Quadrotor in a Global Positioning System-Denied Environment

Journal of Dynamic Systems, Measurement, and Control

et al. 2017

This paper addresses the problem of autonomous trajectory tracking control for a quadrotor in a global positioning system (GPS)-denied environment using only onboard sensing. To achieve that goal, it requires accurate estimation of quadrotor states followed by proper control actions. For the position estimation in a GPS-denied environment, an open source high speed optical flow sensor PX4FLOW is adopted. As for the quadrotor control, there are several challenges due to its highly nonlinear system dynamics, such as underactuation, coupling, model uncertainties, and external disturbances. To deal with those challenges, the cascaded inner–outer uncertainty and disturbance estimator (UDE)-based robust control scheme has been developed and applied to the attitude and position control of a quadrotor. Extensive real flight experiments, including attitude stabilization, hover, disturbance rejection, trajectory tracking, and comparison with the proportional–integral–derivative (PID) controller are carried out to demonstrate the effectiveness of the developed UDE-based controllers.