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Controlling a Chain of Integrators with Constrained Actuation Using Exponential Activation Functions
(Peer reviewed; Chapter; Bokkapittel, 2019-10-24)
This paper shows how to control a chain of integrators with constrained actuation by using exponential activation functions. Specifically, it shows how the control law can be decomposed into several parts that can be activated as they are required, resulting in a simple control law that is able to make the states converge fast to zero.
Curvature Continuous Path Generation for UAVs based on Generalized Expo-Rational B-Splines
(Peer reviewed; Book; Chapter, 2018)
This paper proposes a new path-planning algorithm based on GERBS to generate curvature continuous paths. The algorithm blends between a set of local curves generating a global smooth path which also interpolates the midpoint of the curves. Numerical examples are provided which demonstrates the potential of the proposed algorithm.
A Comparative Study of Different Control Structures for Flight Control with New Results
(Peer reviewed; Book; Chapter, 2018-10-24)
This paper presents several different control structures that facilitate flight control and does a comparison between them. Specifically, this paper considers command-filtered backstepping, nonlinear dynamic inversion (NDI), and a new decoupled approach that decouples the rotational and translational dynamics by estimating the higher order derivatives of the angle of attack and sideslip angle. The ...
Quaternion Path-Following in Three Dimensions for a Fixed-Wing UAV Using Quaternion Blending
(Peer reviewed; Book; Chapter, 2018-10-29)
This paper presents a three dimensional guidance strategy for fixed-wing UAVs using quaternions. The algorithm is based on constructing two quaternions, one which makes the UAV fly towards the path and one that makes the UAV follow the path. These two quaternions are then blended together such that the path-following objective is reached. The guidance algorithm is applied to a simple kinematic model ...
Dual-quaternion backstepping control for a fully-actuated rigid-body
(Peer reviewed; Book; Chapter, 2018-08-16)
In this paper dual-quaternions are used to model a fully actuated rigid-body. A backstepping-controller that solves the trajectory tracking problem is derived and proved to provide uniform asymptotical stabilization of the error dynamics. Numerical simulations are provided where the controller is compared to existing dual-quaternion tracking controllers and it is shown to have similar performance.
Reactive-Based Position Control of an Underactuated Quadrotor
(Chapter; Bokkapittel, 2020-07-20)
This paper addresses the problem of position control
or waypoint tracking for an underactuated quadrotor. The
proposed control law is what is known as reaction based in the
way that the attitude system reacts to errors in the translational
motion. This methodology requires no generation of desired
attitude or angular velocity and the resulting control law is
model-independent in that it does ...
Adaptive Backstepping Control for a Fully-Actuated Rigid-Body in a Dual-Quaternion Framework
(Chapter; Bokkapittel, 2020-03-12)
We address the trajectory tracking problem for
a fully actuated rigid-body with unknown mass and inertia
parameters and unknown disturbance forces, using an adaptive
backstepping controller based on dual-quaternions. We show
that the proposed controller, in closed loop with a nonlinear
model of the system, renders the equilibrium points uniformly
asymptotically stable. The proposed controller ...
Stabilization of Non-Cooperative Satellites in Low Earth Orbits using Inter-Satellite Atmospheric Drag
(Chapter; Bokkapittel, 2023-08-07)
This paper presents a novel solution to the problem of stabilization of non-cooperative satellites in low Earth orbits, which utilizes inter-satellite aerodynamic drag effects for generation of aerodynamics moments in the wake of a controlled satellite. Hence, by altering the position of a smaller controlled satellite, we are able to change the wake region and thus provide aerodynamic moments for ...