Algorithm 902

Rao, Anil V.; Benson, David A.; Darby, Christopher L.; Patterson, Michael; Francolin, Camila; Sanders, Ilyssa; Huntington, Geoffrey T.

doi:10.1145/1731022.1731032

Cited by 498 publications

(109 citation statements)

References 37 publications

(48 reference statements)

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“…To transform the continuous optimal control problem of Eq. (22) into an NLP, we use the software GPOPS [29], a Matlab implementation of a Gauss pseudospectral direct collocation method. Both state and control are approximated by Lagrange interpolating polynomials, and the differential-algebraic equations are collocated at Legendre-Gauss points.…”

Section: Optimal Control Problemmentioning

confidence: 99%

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Perigee Attitude Maneuvers of Geostationary Satellites During Electric Orbit Raising

Prieto

Roberts

2017

Journal of Guidance, Control, and Dynamics

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When full-electric orbit-raising trajectories begin in a classic geostationary transfer orbit with low initial perigee altitude, the need for deployed solar arrays to power the propulsion system significantly increases the aerodynamic and gravity gradient torques. In fact, the torque magnitudes in the first few perigee passages may become a challenging requirement for the attitude control system. Apart from oversizing actuators, other solutions may include the need for a backup thruster system or raising the perigee altitude, implying mass penalties and cost. This paper presents the design of an optimal attitude maneuver at the perigee that can be undertaken using nominal reaction wheels. Attitude paths avoiding saturation of the wheels while dumping accumulated momentum are obtained performing a physically consistent modeling of aerodynamic torques and using pseudospectral methods to solve the trajectory optimization problem. The optimization of solar array positions is also explored to further constrain the problem or improve the maneuver performance. Resulting mass and cost savings can be significant, which could be used for additional payload or to significantly extend the operational life of the satellite.

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Section: Optimal Control Problemmentioning

confidence: 99%

“…The solution is obtained with MATLAB by means of PS methods using a combination of codes: Gauss Pseudospectral Optimization Software (GPOPS) [29] and the nonlinear programming (NLP) solver provided in the Numerical Algorithms Group (NAG) toolbox [30].…”

mentioning

confidence: 99%

Perigee Attitude Maneuvers of Geostationary Satellites During Electric Orbit Raising

Prieto

Roberts

2017

Journal of Guidance, Control, and Dynamics

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“…In this research, we choose to solve the optimal control problem of Eqs. (6-9) using the open-source pseudospectral optimal control software GPOPS [13] together with the nonlinear programming solver SNOPT [14,15]. To obtain a solution to the optimal control problem of Eqs.…”

Section: A Optimal Waypoint Generatormentioning

confidence: 99%

“…and the boundary conditions EQ-TARGET;temp:intralink-;d13;40;391 xt 0 x 0 ; yt 0 y 0 ; xt f x f ; yt f y f (13) where x 0 ; y 0 is the current position of the ASV, and x f ; y f is the position of the waypoint generated by the optimal waypoint generator described in Sec. IV.A.…”

Section: B Guidance Algorithm and Onboard Controllermentioning

confidence: 99%

“…It is important to observe that the rate constraint on the angle has been omitted from the optimal control problem of Eqs. (11)(12)(13) because including the rate constraint on leads to an optimal control problem that does not have an analytic solution. Figure 2 is an example of an ASV path obtained by solving the control problem of Eqs.…”

Section: B Guidance Algorithm and Onboard Controllermentioning

confidence: 99%

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Optimal Control of a Surface Vehicle to Improve Underwater Vehicle Network Connectivity

Francolin¹,

Rao²,

Duarte³

et al. 2012

Journal of Aerospace Computing, Information, and Communication

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The use of an autonomous surface vehicle as an auxiliary agent to improve connectivity in a network of autonomous underwater vehicles is investigated. An algorithm is developed that consists of an optimal waypoint generator and a minimum-time guidance law that is used to steer the vehicle to the waypoint. This algorithm is used together with a communication architecture to improve underwater vehicle connectivity in a region of interest. The approach is simulated using various underwater vehicle configurations, both with and without the autonomous surface vehicle, where it is found that network connectivity is improved significantly via the inclusion of the autonomous surface vehicle. An in-water hardware test is then performed and is shown to be consistent with the simulation results. The results of this study show that adding an autonomous surface vehicle to an underwater vehicle network can improve the connectivity of the network.

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A novel adaptive Gauss pseudospectral method for nonlinear optimal control of constrained hypersonic re‐entry vehicle problem

Xiao

Liu

et al. 2018

Adaptive Control & Signal

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SummaryOptimal control of constrained hypersonic re‐entry vehicle is difficult due to the complex nonlinear dynamics and nonlinear constraints. A novel adaptive Gauss pseudospectral method with some new strategies is therefore proposed to deal with the optimal control problem of hypersonic re‐entry vehicle to ensure that the complex constraints are satisfied all the way. First, state transformation is applied to make the variables more uniform in quantities. Second, some extreme points are applied in designing appropriate subintervals to track the control profiles effectively and the collocation points are adaptively redistributed based on the evaluated approximation errors. Third, a detection procedure is proposed to ensure that the constraints are satisfied all the way during the whole re‐entry process. The proposed method is illustrated by testing a hypersonic re‐entry vehicle problem. The results reveal that path constraints and terminal conditions are well satisfied. The research results, including the comparison with other methods, such as the classical Gauss pseudospectral method and the control vector parameterization method, show the effectiveness of the proposed adaptive approach.

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Algorithm 902

Cited by 498 publications

References 37 publications

Perigee Attitude Maneuvers of Geostationary Satellites During Electric Orbit Raising

Perigee Attitude Maneuvers of Geostationary Satellites During Electric Orbit Raising

Optimal Control of a Surface Vehicle to Improve Underwater Vehicle Network Connectivity

A novel adaptive Gauss pseudospectral method for nonlinear optimal control of constrained hypersonic re‐entry vehicle problem

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