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Showing 1 to 17 of 17 for “"Clohessy Wiltshire"”.
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Optimal variable-specific-impulse trajectories in simple gravitational fields
Minimum-fuel trajectories in the Clohessy-Wiltshire orbital model are investigated. Low-thrust variable-specific-impulse propulsion is assumed. The necessary conditions for an optimal solution and the equations of motion are combined to produce a single equation. Every solution to this equation is …
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Optimization of relative orbit transfers via particle swarm and primer vector theory
… solution vectors for the particle swarm, and the Clohessy-Wiltshire-Hill equations are used to define the motion of the satellites. These trajectories are then analyzed according to primer vector theory, in order to check the optimality of the trajectories developed via the particle swarm …
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Optimal cooperative power-limited rendezvous
… gravitational field models are investigated: the Clohessy-Wiltshire linearized field and the inverse-square field. Analytical solutions are obtained for the linearized gravity field. A direct method using direct collocation with nonlinear programming is used for the nonlinear problem. Solutions …
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Neural network control of space vehicle orbit transfer, intercept, and rendezvous maneuvers
… with another orbiting vehicle using the Clohessy-Wiltshire equations of relative motion in two dimensions. A combination of open-loop and closed-loop neural network controllers is shown to work effectively for this problem. Noise is added to the neural network inputs to demonstrate the …
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Cooperative Power-Limited Optimal Rendezvous Between Many Spacecraft
… gravitational field models investigated are the Clohessy-Wiltshire field and the inverse-square gravity field. Numerical solutions using a shooting method and the finite difference method are used in order to determine the trajectories of the spacecraft. Unlike previous investigations, this work …
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Six degree of freedom optimal trajectories for satellite rendezvous
… burns. The method makes use of the linear Clohessy-Wiltshire equations to describe translational motions, Euler's equations of rigid body motion for describing the attitude motions, and a sequential quadratic programming optimization code. Initial solutions are found assuming no coupling …
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Low thrust augmented periodic orbits in the two- and three-body problems
… non-Keplerian orbits are generated in the Hill-Clohessy-Wiltshire approximation using position-only feedback. The same strategy is also applied to the linearised dynamics around collinear libration points in the circular restricted three-body problem. In the Earth-Moon system, position-only …
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Optimal pursuit/evasion spacecraft trajectories in the hill reference frame
… work, the minimax problem is solved in the Hill-Clohessy-Wiltshire (HCW) reference frame with Earth as the central body and each spacecraft uses continuous low-thrust propulsion. The thrust-pointing direction is the control for each spacecraft. Each vehicle has a finite specific impulse and …
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Mission design and trajectory analysis for inspection of a host spacecraft by a microsatellite
… forced - is analyzed using the solution to the Clohessy-Wiltshire (CW) differential equations. Utilizing the natural dynamics for inspection minimizes fuel costs, while still providing excellent opportunities to inspect and image the surface of the host spacecraft. The accessible natural motions …
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Swarm keeping strategies for spacecraft under J2 and atmospheric drag perturbations
… progresses by eliminating drift using the Hill-Clohessy-Wiltshire equations, removing drift due to nonlinearity, and minimizing the $J_2$ drift. In order to verify these guidance methods, a new dynamic model for the relative motion of spacecraft is developed. These dynamics are exact and include …
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Enhancing Satellite Constellations with Scalable Network Simulation and Rapid Passive Safety Assessment
… By mapping satellite dynamics to the Hill–Clohessy–Wiltshire equations and leveraging analytical solutions to ellipse intersections, this method delivers fast and accurate passive safety analysis. Built on an open-source platform that runs on standard off-the-shelf hardware, the proposed …
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Rendezvous approach guidance for uncooperative tumbling satellites
… a guidance algorithm based on the flight proven Clohessy-Wiltshire (CW) and space shuttle glideslope equations which command a sequence of burns to close the distance between the servicer and client while matching the client satellite's rotation rate. The author validates the guidance algorithm …
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The analysis and control of nonlinear systems using Lyapunov stability theory
… is then developed for use with the orbital Clohessy-Wiltshire equations of relative motion. When an engine unpredictably fails, this controller automatically accounts for the new conditions and the desired rendezvous is thus, still obtained. These Lyapunov based controllers are shown not …
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Effects of propagation techniques on relative GPS navigation
… state transition matrix, and (4) the use of the Clohessy-Wiltshire equations of relative motion. GPS measurements were simulated and included errors due to Selective Availability, clock bias, clock drift, and receiver noise. The relative navigation filter used pseudorange and delta-range …
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Long-duration proximity operations flexibly optimized for efficient inspection and servicing using free-orbit dynamics
… of linearizing Keplerian gravity using the Hill-Clohessy-Wiltshire model. Error in relative position, angular rate of circumnavigation, and fuel use to enforce linearized periodic trajectories are characterized. It was determined that proximity operations utilizing low-thrust …
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Health Management and Adaptive Control of Distributed Spacecraft Systems
… allowing dynamics to be expressed using the Clohessy-Wiltshire-Hill equations. Additionally, based on desired points of inspection, the observers have specific attitude requirements that are achieved using Reaction Wheels as the control moment device. An adaptive control based on Deep …
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Safety-Driven, Time-Sensitive Approach Strategies for Rendezvous with the Lunar Gateway
… RPOD understandings through models such as the Clohessy–Wiltshire equations break down in a three-body dynamics-based orbit like the NRHO, requiring proven approach strategies currently used for approaching the ISS to be redesigned. This thesis studies trajectory design within a three-body …