作者:
Stuart, Jeffrey R.Howell, Kathleen C.Wilson, Roby S.Purdue Univ
Sch Aeronaut & Astronaut 701 West Stadium Ave W Lafayette IN 47907 USA Purdue Univ
Sch Aeronaut & Astronaut Aeronaut & Astronaut 701 West Stadium Ave W Lafayette IN 47907 USA CALTECH
Jet Prop Lab Mission Design & Nav Sect Nav & Mission Design Syst Engn Grp 4800 Oak Grove Dr Pasadena CA 91109 USA CALTECH
Jet Prop Lab Mission Design & Nav Sect Inner Planet Mission Anal Grp 4800 Oak Grove Dr Pasadena CA 91109 USA
The sun-Jupiter Trojan asteroids are celestial bodies of great scientific interest as well as potential natural assets offering mineral resources for long-term human exploration of the Solar System. Previous investiga...
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The sun-Jupiter Trojan asteroids are celestial bodies of great scientific interest as well as potential natural assets offering mineral resources for long-term human exploration of the Solar System. Previous investigations have addressed the automated design of tours within the asteroid swarm and the transition of prospective tours to higher-fidelity, end-to-end trajectories. The current development incorporates the route-finding antcolonyoptimization algorithm into the automated tour-generation procedure. Furthermore, the potential scientific merit of the destination asteroids is incorporated such that encounters with higher-value asteroids are preferentially incorporated during sequence creation.
optimization for active debris removal using multiple spacecraft is investigated. The main challenge is to determine the rendezvous sequences of the targets considering the J(2) perturbation, which is a large-scale dy...
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optimization for active debris removal using multiple spacecraft is investigated. The main challenge is to determine the rendezvous sequences of the targets considering the J(2) perturbation, which is a large-scale dynamic combinatorial optimization problem. A framework to solve this problem is presented. First, a semi-analytical method of fast estimation for characteristic velocity is proposed to help construct the sequences. The K-medoid method is applied to distribute all the targets to multiple spacecraft so that each spacecraft can remove as many targets as possible with limited propellant. Given a distribution of targets, the sequences for each spacecraft are searched separately;thus the original combinatorial optimization problem is split into multiple small-scale ones that can be efficiently solved by tree search algorithms. An evolutionary algorithm nested with a tree search algorithm is proposed to improve the distribution of the targets, so that the spacecraft can remove all the targets with a low cost. Then optimal sequences are further searched using an antcolonyoptimization algorithm, and the rendezvous epochs are refined by a nonlinear programming algorithm. The efficiency of these methods is demonstrated by two scenarios of active debris removal.
Mission design for multiple debris removal is performed by selecting the most favorable sequences of objects to be removed. Debris items among a population with similar inclination values are considered. The chaser re...
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Mission design for multiple debris removal is performed by selecting the most favorable sequences of objects to be removed. Debris items among a population with similar inclination values are considered. The chaser rendezvouses with the objects and attaches a removal kit. An approximate analysis, based on the use of the J2 effect to minimize propellant consumption, provides estimations of transfer times and Delta V between any object pair in order to evaluate the costs of any possible sequence. Estimations, which are verified by using an evolutionary optimization of four-impulse transfers that take J2 perturbation into account, are fast and accurate;and they permit evaluation of all available sequences when the number of objects to be removed is limited. The object sequence determination problem is converted to a traveling salesman problem, and an antcolonyoptimization algorithm is introduced to analyze longer sequences. The mass of the removal kit for any debris item is then evaluated, depending on the selected removal method. The overall mission mass budget is finally computed, and the best opportunities in terms of the mass and mission time are selected. Different removal techniques exploiting chemical and electric propulsion are compared. The results prove that removal of four to eight objects in less than a year is feasible with current technologies.
The paper presents an approach to transcribe a multigravity assist trajectory design problem into an integrated planning and scheduling problem. A modified antcolonyoptimization algorithm is then used to generate op...
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The paper presents an approach to transcribe a multigravity assist trajectory design problem into an integrated planning and scheduling problem. A modified antcolonyoptimization algorithm is then used to generate optimal plans corresponding to optimal sequences of gravity assists and deep space maneuvers to reach a given destination. The modified antcolony Algorithm is based on a hybridization between standard antcolonyoptimization paradigms and a tabu-based heuristic. The scheduling algorithm is integrated into the trajectory model to provide a fast time-allocation of the events along the trajectory. The approach demonstrated to be very effective on a number of real trajectory design problems.
This Paper proposes a two-step binary linear programming formulation for task scheduling of a constellation of low-Earth-orbit satellites and demonstrates its applicability and scalability to obtain high-quality solut...
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This Paper proposes a two-step binary linear programming formulation for task scheduling of a constellation of low-Earth-orbit satellites and demonstrates its applicability and scalability to obtain high-quality solutions using a standard mixed-integer linear programming solver. In this instance, the goal of satellite constellation task scheduling is to allocate each task for the satellites and to determine the task starting times in order to maximize the overall mission performance metric. The scheduling problem is formulated to find the solution by first finding a set of candidate communication time intervals for each satellite/ground-station pair as one of the key constraints and time tabling the observation task to acquire the user-requested data, with the incorporation of key constraints for satellite constellation operation. Numerical experiments are designed for investigating the trends, sensitivity, and characteristics of scheduling outputs based on multiple representative instances. The performance of the scheduling solutions by the proposed two-step binary linear programming method exhibits significant improvement of up to 35% in the number of assignments and the sum of profits over the general greedy algorithm.
Finding the optimal solution to NP-hard problems requires at least exponential time. Thus, heuristic methods are usually applied to obtain acceptable solutions to this kind of problems. In this paper we propose a new ...
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ISBN:
(纸本)9783540735533
Finding the optimal solution to NP-hard problems requires at least exponential time. Thus, heuristic methods are usually applied to obtain acceptable solutions to this kind of problems. In this paper we propose a new type of heuristic algorithms to solve this kind of complex problems. Our algorithm is based on river formation dynamics and provides some advantages over other heuristic methods, like antcolonyoptimization methods. We present our basic scheme and we illustrate its usefulness applying it to a concrete example: The Traveling Salesman Problem.
As a complex engineering problem, the hybrid layout design with behavioural constraints is difficult to resolve by using conventional approaches. The challenges stem from three aspects: computational complexity, engin...
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ISBN:
(纸本)9781424426928
As a complex engineering problem, the hybrid layout design with behavioural constraints is difficult to resolve by using conventional approaches. The challenges stem from three aspects: computational complexity, engineering complexity, and engineering practicability. This paper addresses the major issue in establishing three-dimensional layout models to support optimization calculation and constructing the efficient optimization algorithm to get the layout scheme. Based on the octree modeling algorithm, a three-dimensional solid model expression method on layout design is proposed to solve the corresponding problems. The error analysis of the octree expression model is given by comparing with design schemes. The mathematics models of layout problem are established on the design requirements, and then an efficient layout algorithm base on improved ant colony optimization algorithms is given for solving combinatorial optimization problems on layout design. The flow chart of algorithms is given. At last, the design examples are given to illustrate effectiveness with respect to the layout design scheme.
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