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In this paper, we tackle the problem of trajectory tracking for a particular class of underactuated vehicles with full torque actuation and a single force direction (thrust), which is fixed relative to a body attached frame. Additionally, we consider that thrust reversal is not available. Under some given assumptions, the control law that we propose is able to track a smooth reference position trajectory while minimizing the angular distance to a desired orientation. This objective is achieved robustly, with respect to bounded state disturbances, and globally, in the sense that it is achieved regardless of the initial state of the vehicle. The proposed controller is tested in an experimental setup, using a small scale quadrotor vehicle and a motion capture system.

In this paper, we tackle the problem of trajectory tracking for a particular class of underactuated vehicles with full torque actuation and a single force direction (thrust) that is fixed relative to a body attached frame. Additionally, we consider that thrust reversal is not available. We present the design of a hybrid controller that, under some given assumptions, is able to globally asymptotically stabilize the vehicle to a reference position trajectory while minimizing the angle to the desired attitude trajectory. This objective is achieved robustly and globally, in the sense that small perturbations do not lead to instability and it is achieved regardless of the initial state of the vehicle. The algorithm is tested in a experimental setup, using a small scale quadrotor vehicle and the VICON motion capture system.

In this paper, we address the problem of trajectory tracking for a class of underactuated vehicles with full torque actuation and only one dimensional force actuation (thrust). For this class of vehicles, the desired thrust is defined by a saturated control law that achieves global asymptotic stabilization of the position tracking error. The proposed control law also assures that the third component of the angular velocity is regulated to zero. To accomplish this task we propose a hybrid controller that is designed using backstepping techniques and recent developments on synergistic Lyapunov functions. Simulations validating the results are also provided. © 2013 AACC American Automatic Control Council.

This paper presents a control solution for the problem of slung load transportation, with simultaneous damping of oscillations, using an underactuated autonomous quadrotor vehicle in the presence of external disturbances. The strategy put forward is divided into two parts: (i) resorting to an error definition that encompasses the pendular motion of the suspended load, a controller inspired in sliding‐mode theory is developed to compute a vectored thrust actuation that actively damps out the system's oscillations; (ii) two different approaches are illustrated for the stage of attitude tracking: one stemming from the conventional backstepping technique, which controls the vehicle in angular velocity commands; and another, also based on sliding‐mode theory, and built intrinsically in SO(3)$$ \mathsf{SO}(3) $$, that produces torque commands. The overall control scheme is proved to be robust and stable, with the load oscillations shown to be damped out in the process. Simulation and experimental results are presented in a trajectory tracking scenario to validate and assess the robustness and efficiency of the proposed technique. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of trajectory tracking for a quadcopter subject to parametric uncertainties and disturbances. Using the backstepping technique and ignoring parametric uncertainties and disturbances, a nominal controller is proposed for the quadcopter. In order to ensure that the controller is adaptive to parametric uncertainties (i.e. unknown but constant mass and tensor of inertia) and external disturbances, an exponentially stable estimator is designed based on the Kalman–Bucy filter. The closed-loop system resulting from the interconnection of the plant, the controller, and the estimator is such that the backstepping error is uniformly ultimately bounded. Furthermore, simulation and experimental results are presented, validating the stability and robustness properties of the proposed control strategy. [ABSTRACT FROM AUTHOR]