Optimal Control Theory with Aerospace Applications

Ben-Asher, Joseph Z.

doi:10.2514/4.867347

Cited by 96 publications

(42 citation statements)

References 3 publications

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“…In this paper, the continuous optimal control problem is parameterized as a finite dimensional problem and then solved numerically by standard algorithms for constrained parameter optimization [9]. The control input can be parameterized as: (21) in which, 's are some constant parameters and can be any function.…”

Section: Optimization Approachmentioning

confidence: 99%

“…3): (8) where and are the liquid piston length and velocity, and is the constant water density, and is the friction factor which is a function of Reynolds number and the relative roughness . The friction factor is given by the Colebrook formula [8] and the Moody Chart: (9) a and b are constants that specify relative roughness. The viscous liquid friction power is then given by: (10) where is the rate of change of air volume or the negative liquid flow rate.…”

Section: B Viscous Frictionmentioning

confidence: 99%

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Optimal trajectories for a liquid piston compressor/expander in a Compressed Air Energy Storage system with consideration of heat transfer and friction

Saadat,

Li,

Simon

2012

2012 American Control Conference (ACC)

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Abstract-For a Compressed Air Energy Storage (CAES)approach to be viable, the air compressor/expander must be sufficiently powerful and efficient. Since efficiency is governed by heat transfer, there is a generally a tradeoff between efficiency and compression/expansion time (or power). In this paper, we determine Pareto optimal compression/expansion profiles for a liquid piston air compressor/expander that maximizes efficiency (power) for a given power (efficiency). Compared to previous works, a numerical optimization approach is proposed that allows for more general heat transfer model, the consideration of the viscous friction, and system limitations in the optimization. The resulting optimal profiles are compared to other trajectories. At compression ratio of 10, the optimal profile results in 10%-40% increase in power density relative to other methods. Optimal geometries that trades off friction and heat transfer improvement can also be determined using this method.

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Section: Optimization Approachmentioning

confidence: 99%

Section: B Viscous Frictionmentioning

confidence: 99%

Optimal trajectories for a liquid piston compressor/expander in a Compressed Air Energy Storage system with consideration of heat transfer and friction

Saadat,

Li,

Simon

2012

2012 American Control Conference (ACC)

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“…Through a simple transformation, one may obtain a model in which the inputs are acceleration along the flight path and the rates of change of two angles defining the flight path (e.g., the "climb angle" and the "course angle"). This representation, related to the Serret-Frenet description of a regular curve [6], is often preferred for trajectory optimization problems; see [1], for example.…”

Section: A Rigid Vehicle In An Unsteady Nonuniform Flowmentioning

confidence: 99%

Vehicle Motion in Currents

Thomasson

Woolsey

2013

IEEE J. Oceanic Eng.

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In this paper, we present a nonlinear dynamic model for the motion of a rigid vehicle in a dense fluid flow that comprises a steady, nonuniform component and an unsteady, uniform component. In developing the basic equations, the nonuniform flow is assumed to be inviscid, but containing initial vorticity; further rotational flow effects may then be incorporated by modifying the angular rate used in the viscous force and moment model. The equations capture important flow-related forces and moments that are absent in simpler models. The dynamic equations are presented in terms of both the vehicle's inertial motion and its flow-relative motion. Model predictions are compared with exact analytical solutions for simple flows. Applications of the motion model include controller and observer design, stability analysis, and simulation of nonlinear vehicle dynamics in nonuniform flows. As illustrations, we use the model to analyze the motion of a cylinder in a plane laminar jet, a spherical Lagrangian drifter, and a slender underwater vehicle. For this last example, we compare predictions of the given model with those of simpler models and we demonstrate its use for flow gradient estimation. The results are applicable to not only underwater vehicles, but also to air vehicles of low relative density such as airships and ultralights.

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“…Such a scenario may require the ability to minimize fuel consumption to improve mission endurance [12][13][14] and/or to minimize the time it takes to approach the loitering area or to circle a predefined area of interest. 10,15 It has repetitively been shown that applying optimal control theory 16,17 to improve mission performance is an effective approach. For example, there have been substantial developments in numerical optimization methods for the purpose of obtaining optimal control trajectories.…”

Section: 11mentioning

confidence: 99%

Minimum-Time Hover-to-Hover Maneuver of a Single Coaxial Rotor UAV : Example and Experimental Results

Harada

Ito

Nagata

et al. 2012

AIAA Guidance, Navigation, and Control Conference

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This paper investigates the application of optimal control results to the experimental flight of a Single Coaxial Rotor (SCR) Unmanned Aerial Vehicle (UAV) conducted in the indoor flight facility of the National Defense Academy of Japan (NDA). The optimal control problem is prescribed as a minimum-time hover-to-hover maneuver of the SCR UAV and it is solved using pseudospectral (PS) optimal control theory. The computed optimal results are applied as open-loop commands to the real UAV system. Additionally, a PID control is used for hovering flight before and after the minimum-time maneuver. Preliminary experimental results demonstrate the feasibility of commanding the UAV with open-loop optimal solutions generated offline.

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Optimal Control Theory with Aerospace Applications

Cited by 96 publications

References 3 publications

Optimal trajectories for a liquid piston compressor/expander in a Compressed Air Energy Storage system with consideration of heat transfer and friction

Optimal trajectories for a liquid piston compressor/expander in a Compressed Air Energy Storage system with consideration of heat transfer and friction

Vehicle Motion in Currents

Minimum-Time Hover-to-Hover Maneuver of a Single Coaxial Rotor UAV : Example and Experimental Results

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