The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Dynamic inversion is a category of control design techniques that employ feedback linearization. In recent years; this technique has been applied to different types of nonlinear systems. This paper presents its usefulness with nonlinear electromechanical systems. Dynamic inversion method is employed to ensure robustness and stability of the system. Moreover, the inputs can be found and achieve high-precision...
Control aspects of a tethered undersea kite (TUSK) energy system are studied. A TUSK system consists of a rigid undersea wing (or kite) attached by a flexible tether to a support structure on the ocean surface or floor. A turbine is mounted on the undersea kite to harness hydrokinetic energy from an ocean current when the kite moves in high-speed, cross-current motions. In this paper, we adopt a six...
Implementing a control law on an Unmanned Aerial Vehicle can be problematic when the existing autopilot system is incompatible with the controller structure. This paper extends the control strategy that incorporates a pre-existing autopilot system in a closed-loop control law design [1]. In [1], the control scheme explicitly involves the autopilot in the controller derivation, based on an assumption...
This paper addresses the problem of driving a quadrotor vehicle along a predefined 3-D trimming path. The proposed solution relies on the definition of a path-dependent error space to express the dynamic model of the vehicle, which results in linear time-invariant dynamics for the error system. The controller synthesis problem is then formulated as a linear quadratic regulator problem for LTI systems...
This paper newly presents how to apply the Computed Torque Control scheme to the flight control of a 4-DOF controllable aerospace craft, such as a multicopter and a rocket, by using a nonlinear inverse model to track a reference trajectory arbitrarily given in the 3D space of gravity condition and it shows the simulation results for some cases. Aerodynamics is neglected for the clarity of the explanation...
Batch processes are inherently irreversible. In fact, design parameters and initial states can affect irreversibility and controllability of a batch process. Current design methodologies do not include controllability as a criterion for process specification. In this work, the case of Bacillus thuringiensis process is studied in batch operation, and its operational conditions are defined according...
In order to study the parachute payload performance during the steady descent phase, a twelve degree freedom rigid parachute-payload with elastic suspension model is established, and its trajectory will be displayed with animation. The parachute and payload usually cannot be observed clearly for its comparatively small scale model during animation. In this paper, the reference background is built...
This paper presents a method that enables highspeed, steady flight in confined spaces for tethered quadrocopters. Thanks to the centripetal force exerted by the tether, high-speed trajectories along circles at different velocities, accelerations, and orientations in space can be flown. Various circular maneuvers are experimentally demonstrated, and tangential velocities of up to 15 m/s and centripetal...
This paper presents a nonlinear control approach for quadrotor Micro Aerial Vehicles (MAVs), which combines a backstepping-like regulator based on the solution of a certain class of global output regulation problems for the rigid body equations on SO(3), a robust controller for the system with bounded disturbances, as well as a trajectory generator using a model predictive control method. The proposed...
The dual range air-to-air missile (DRAAM) is a next-generation AAM concept capable of all-aspect target intercept at very close range, as well as beyond visual range (BVR). A composite guidance strategy for DRAAM with initial side jet control (SJC) is synthesized in this study. The initial side jet thrusters integrated into the aft section of the rocket motor are used when high levels of agility are...
In the reentry process of hypersonic vehicles, unavoidable uncertainties can always crucially impact the trajectory performance. Therefore, even variable robust design algorithms have been proposed, both in areas of reference trajectory design and guidance algorithm design, effect analysis of the uncertainties still needs to be carefully taken. In this paper, a deviation condition strategy (DCS) is...
Several municipalities are investigating smart road infrastructures to help reducing pollution and traffic congestion. In this paper, a road to vehicle assistance system is presented. The system continuously suggests the optimal velocity the driver should adopt in order to minimize fuel consumption in a long urban road with frequent intersection controlled by traffic lights. Fuel saving is enabled...
We study the control of an Airborne Wind Energy (AWE) system where a turbine is mounted on a rigid glider (or kite) with a fixed length tether connected between the kite center of gravity (CG) and the ground. The turbine on the kite in an AWE system extracts wind power in a high speed cross wind motion to efficiently harness energy. The model incorporates the full aircraft and inverted pendulum dynamics...
This paper considers continuously differentiable functions of two vector variables that have (possibly a continuum of) min-max saddle points. We study the asymptotic convergence properties of the associated saddle-point dynamics (gradient-descent in the first variable and gradient-ascent in the second one). We identify a suite of complementary conditions under which the set of saddle points is asymptotically...
This paper considers modeling and control of a planar kite system with flexible cables used to harvest energy from high-altitude winds. The kite is tethered to flexible cables at its leading and trailing edges. The flexible cables are reeled in and out by ground-based winches. The change in winch inertia and cable stiffness as the cable is reeled in and out is also explicitly modeled. The equations...
This paper is focused on adaptively controlling a linear infinite-dimensional system to cause it to track an infinite-dimensional reference model. Given a linear continuous-time infinite-dimensional plant on a Hilbert space and disturbances of known waveform but unknown amplitude and phase, we show that there exists a stabilizing direct model reference adaptive control law with certain disturbance...
In this paper a semi-analytical technique for generating quadrotor trajectories using the projection of sub-Riemannian curves on SE(3) onto ℝ3 is presented. The benefits of using these trajectories are that they have constant speed and acceleration magnitude, are smooth and analytically defined in terms of standard functions. Also, they are sub-optimal with respect to a weighted quadratic cost function...
This paper presents a trajectory tracking controller for multi-rotor UAVs to improve their flight performance in the presence of various uncertainties. The proposed tracking system consists of a velocity guidance law based on relative distance and an L1 adaptive augmentation loop for tracking velocity commands. In the proposed structure, the desired velocity generated by the guidance law is the reference...
This paper presents an optimal conflict resolution method for multiple unmanned aerial vehicles based on pseudospectral collocation which solves numerically optimal control problems by using non-linear programming. The trajectory of each aerial vehicle is defined by a set of waypoints and the time of arrival at each waypoint. The maneuvers allowed to solve the conflicts are the changes of speed of...
This paper describes the theory and implementation of a trajectory optimization layer operating within an energy-aware, airborne, dynamic data-driven application system (EA-DDDAS). The work addresses wind field data estimation, trajectory optimization, and implementation of communication protocols to increase sUAS endurance in persistent sensing missions. The trajectory optimization layer acts as...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.