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Ya-zhong Luo - One of the best experts on this subject based on the ideXlab platform.

  • Uncertainty-Dependent Warning Threshold for Spacecraft Rendezvous Collision Probability
    IEEE Transactions on Aerospace and Electronic Systems, 2019
    Co-Authors: Zhenjiang Sun, Ya-zhong Luo
    Abstract:

    This paper proposes a warning threshold calculation method for instantaneous collision probability in a spacecraft Rendezvous mission. By introducing missing alarm probability, the warning threshold is determined as a function of the propagated Trajectory uncertainty and a semianalytical calculation model is presented. The simulation results show that the proposed method makes good use of Trajectory uncertainty information and provides a reasonable and accurate method for evaluating the safety of a Rendezvous Trajectory with uncertainty.

  • Robust Planning of Nonlinear Rendezvous with Uncertainty
    Journal of Guidance Control and Dynamics, 2017
    Co-Authors: Zhen Yang, Ya-zhong Luo, Zhang Jin
    Abstract:

    Practical uncertainties are not considered by optimal Rendezvous Trajectory designs proposed in many current studies. In this study, a robust optimization method for on-ground Rendezvous Trajectory design is proposed by considering the uncertainties and orbital replanning process. Two robust performance indices related to the final Rendezvous errors and the total velocity increment Δv are first defined, then a multi-objective optimization model (including the minimum Δv and minimum Rendezvous errors) is formulated. The unscented transformation method is used to efficiently compute the robust indices in optimization process, and a multi-objective, nondominated sorting genetic algorithm is employed to obtain a Pareto-optimal solution set. It is shown that the proposed approach can be used to design a Rendezvous Trajectory with the Δv and final Rendezvous errors that are both robust against uncertainties. Furthermore, the proposed approach can identify the most preferable design space in which specific solut...

  • CEC - Analysis of multiple asteroids Rendezvous optimization using genetic algorithms
    2015 IEEE Congress on Evolutionary Computation (CEC), 2015
    Co-Authors: Jin Zhang, Ya-zhong Luo, Guo-jin Tang
    Abstract:

    The optimization of a multiple asteroids Rendezvous Trajectory is a mixed integer nonlinear programming problem, and is hard to solve due to the combination of multiple local minima and its extraordinary sensitivity to discrete variables. This study tries to solve it using a mixed-code genetic algorithm (GA), a variation of that GA with enhancing the continuous variable search for the best solution in each generation, and a two-level GA. These algorithms are tested by solving three cases with four, eight, and sixteen asteroids to visit respectively. The results show that the mixed-code GA with search enhancement presents the best performance and the two-level GA presents the worst performance. The treatment by enhancing the continuous variable search for the best solution in each generation has improved the performance of the algorithm considerably.

  • Spacecraft Rendezvous Trajectory safety quantitative performance index eliminating probability dilution
    Science China Technological Sciences, 2014
    Co-Authors: Zhenjiang Sun, Ya-zhong Luo, Zhiyong Niu
    Abstract:

    In view of the probability dilution problem of the existing quantitative indexes of Rendezvous Trajectory safety performance using collision probability, this paper proposes a new quantitative index of Rendezvous Trajectory safety performance by well combining collision probability with warning threshold. The proposed new index increases monotonously as the position errors of the chaser spacecraft increase, therefore it can effectively overcome the problems of the reduction in the largest performance value and the advancement in the most dangerous time induced by the probability dilution. The proposed new index is applied to the safety design of close range Rendezvous missions. The mission’s safety requirements for initial navigation precision and the safe region of initial and final keeping points’ positions with a certain navigation precision are analyzed, and several valuable conclusions about the relation between position navigation precision and velocity navigation precision as well as the relation between keeping points’ positions and navigation precision are obtained.

  • Robust optimization of nonlinear impulsive Rendezvous with uncertainty
    Science China Physics Mechanics and Astronomy, 2014
    Co-Authors: Ya-zhong Luo, Zhen Yang, Li Hengnian
    Abstract:

    The optimal Rendezvous Trajectory designs in many current research efforts do not incorporate the practical uncertainties into the closed loop of the design. A robust optimization design method for a nonlinear Rendezvous Trajectory with uncertainty is proposed in this paper. One performance index related to the variances of the terminal state error is termed the robustness performance index, and a two-objective optimization model (including the minimum characteristic velocity and the minimum robustness performance index) is formulated on the basis of the Lambert algorithm. A multi-objective, non-dominated sorting genetic algorithm is employed to obtain the Pareto optimal solution set. It is shown that the proposed approach can be used to quickly obtain several inherent principles of the Rendezvous Trajectory by taking practical errors into account. Furthermore, this approach can identify the most preferable design space in which a specific solution for the actual application of the Rendezvous control should be chosen.

Guo-jin Tang - One of the best experts on this subject based on the ideXlab platform.

  • CEC - Analysis of multiple asteroids Rendezvous optimization using genetic algorithms
    2015 IEEE Congress on Evolutionary Computation (CEC), 2015
    Co-Authors: Jin Zhang, Ya-zhong Luo, Guo-jin Tang
    Abstract:

    The optimization of a multiple asteroids Rendezvous Trajectory is a mixed integer nonlinear programming problem, and is hard to solve due to the combination of multiple local minima and its extraordinary sensitivity to discrete variables. This study tries to solve it using a mixed-code genetic algorithm (GA), a variation of that GA with enhancing the continuous variable search for the best solution in each generation, and a two-level GA. These algorithms are tested by solving three cases with four, eight, and sixteen asteroids to visit respectively. The results show that the mixed-code GA with search enhancement presents the best performance and the two-level GA presents the worst performance. The treatment by enhancing the continuous variable search for the best solution in each generation has improved the performance of the algorithm considerably.

  • Survey of orbital dynamics and control of space Rendezvous
    Chinese Journal of Aeronautics, 2014
    Co-Authors: Ya-zhong Luo, Jin Zhang, Guo-jin Tang
    Abstract:

    Abstract Rendezvous orbital dynamics and control (RODC) is a key technology for operating space Rendezvous and docking missions. This paper surveys the studies on RODC. Firstly, the basic relative dynamics equation set is introduced and its improved versions are evaluated. Secondly, studies on Rendezvous Trajectory optimization are commented from three aspects: the linear Rendezvous, the nonlinear two-body Rendezvous, and the perturbed and constrained Rendezvous. Thirdly, studies on relative navigation are briefly reviewed, and then close-range control methods including automated control, manual control, and telecontrol are analyzed. Fourthly, advances in Rendezvous Trajectory safety and robust analysis are surveyed, and their applications in Trajectory optimization are discussed. Finally, conclusions are drawn and prospects of studies on RODC are presented.

  • Safety-Optimal Linearized Impulsive Rendezvous with Trajectory Uncertainties
    Journal of Aerospace Engineering, 2014
    Co-Authors: Ya-zhong Luo, Li-bo Liang, Zhiyong Niu, Guo-jin Tang
    Abstract:

    AbstractDifferent from the current studies on the impulsive Rendezvous which are mainly normal propellant-optimal or time-optimal designs, the safety-optimal impulsive Rendezvous with consideration of practical Trajectory uncertainties is investigated in this paper. An optimization model for safety-optimal Rendezvous is established based on the Clohessy-Wiltshire (C-W) equations, which employs one new, recently proposed quantitative performance index of the Rendezvous Trajectory safety as the objective function. A real-coded genetic algorithm is adopted to locate the optimal solution. The safety index and the optimization approach are tested by several Rendezvous problems with different numbers of impulses and different approach directions. The practical application value of the safety-optimal Rendezvous Trajectory is demonstrated by comparing with the traditional propellant-optimal and time-optimal Rendezvous trajectories.

  • Quantitative Performance for Spacecraft Rendezvous Trajectory Safety
    Journal of Guidance Control and Dynamics, 2011
    Co-Authors: Ya-zhong Luo, Li-bo Liang, Hua Wang, Guo-jin Tang
    Abstract:

    Safety requirement represents one of the most critical aspects when defining the operational profile for a Rendezvous mission, especially with the development of autonomous spacecraft Rendezvous. A quantitative safety performance index of spacecraft Rendezvous Trajectory with considering navigation errors and control errors is proposed, which involves the minimum distance between the 3σ ellipsoid of the chaser vehicle and the control zone of the target vehicle and the maximum instantaneous collision probability of these two vehicles. The former is to quantity degree of safety under the condition of no intersection between the 3σ ellipsoid and the control zone, while the latter is to quantity the collision probability when they intersect. The detailed definition of the safety performance index and the simplified calculation methods are provided. The efficiency and effectiveness of this safety index are testified by an example. The different influences of the transfer time, the number of impulses, and the intervals of impulses on the Trajectory safety characteristic are analyzed. Several conclusions that would be useful for further safe Rendezvous Trajectory design are obtained.

  • Space Rendezvous and Docking Mission Planning System Using Object-Oriented Method
    AIAA Modeling and Simulation Technologies Conference, 2010
    Co-Authors: Ya-zhong Luo, Jin Zhang, Guo-jin Tang
    Abstract:

    The mission planning system plays an important role in executing Rendezvous and Docking (RVD) missions. This paper introduces the Rendezvous and Docking Mission Planning System (RVD_MPS) developed by the authors. First, the RVD mission planning problem is described in a three-level decomposition approach. Second, the main planning methods employed in RVD_MPS are described, including mission scenario planning methods, flight segment planning methods and Rendezvous Trajectory planning methods, wherein the Rendezvous Trajectory planning methods are described more detailed in terms of dynamics equations, optimization algorithms, Rendezvous algorithms and perturbed nonlinear Trajectory planning approaches. Then, the software architecture using object-oriented method is provided. Finally, the applications of the RVD_MPS and its further improvements are simply summarized.

Tang Guo-jin - One of the best experts on this subject based on the ideXlab platform.

  • Multi-objective Optimization of Multi-impulse Rendezvous Trajectory for Exploring Asteroids
    Journal of National University of Defense Technology, 2011
    Co-Authors: Tang Guo-jin
    Abstract:

    The current studies on optimal Rendezvous trajectories for exploring asteroids always concentrate on the fuel-optimal two-impulse Rendezvous,while the aim of this paper is aimed to investigate the multi-objective optimization problem of multiple-impulse Rendezvous for exploring asteroids.A multiple-impulse Rendezvous optimization model using Lambert algorithm for exploring asteroids including earth departure and heliocentric transfer phases was established,which utilized minimum-fuel cost and minimum-time transfer as two objective functions.The NSGA-II algorithm,a very representative multi-objective evolutionary algorithm,was employed to obtain the Pareto solution set.The effectiveness of the proposed optimization model and algorithm was testified by solving two asteroids mission design problems.The results show that the proposed method can effectively and efficiently demonstrate the relations among the mission characteristic parameters such as launch time,transfer time and total fuel cost,and analyze the influences of different impulse numbers,and also compare and evaluate different exploration missions.The proposed method has good application value for preliminary mission design for asteroid exploration.

  • Characteristic Analysis of Space Rendezvous Trajectory Safety
    Journal of National University of Defense Technology, 2010
    Co-Authors: Tang Guo-jin
    Abstract:

    The Trajectory safety characteristic of space Rendezvous was studied.First of all,the quantitative performance index of space Rendezvous Trajectory safety was proposed.The 3σellipsoid of relative position dispersal resulting from the navigation errors and control errors was investigated to describe quantificationally the relative Trajectory safety between chaser and target vehicles.And then the orthogonal design of experiment method was adopted to analyze the influence of the transfer time,the number of impulses,and the intervals of impulses on the Trajectory safety characteristic.The results show that the transfer time is the most significant among all the factors,the number of impulses is the secondary,and the interval influence is very small.Finally,the influence of initial Rendezvous condition was analyzed by numerical simulation,and the results illustrate that-R-bar coplanar Rendezvous makes the Trajectory safety index the smallest.Furthermore,the influence on fuel consumption was analyzed,and the effect is opposite to that on safety index.The study points out the direction of the design of safe Rendezvous Trajectory,and provides the way to design the multi-objective optimal Rendezvous Trajectory.

  • Study on the Quantitative Performance Index of Space Rendezvous Trajectory Safety
    2010
    Co-Authors: Tang Guo-jin
    Abstract:

    For the fact that the quantitative analysis of safety for safe Trajectory design is poor in the current research, two quantitative performance indexes of space Rendezvous Trajectory safety are investigated in consideration of navigation er- rors and control errors. One index is defined as the minimum distance between 3σ ellipsoid of the chaser vehicle and control zone of the target vehicle after the arbitrary failure of the Rendezvous process,and the other is the maximum instantaneous collision probability of the two vehicles. The simplified,but more quickly calculation method for these two indexes is pro- posed. Based on the covariance analysis description equation technique ( CADET) ,propagation models of mean vector and the covariance matrix of relative state are deduced for nonlinear Rendezvous in consideration of the navigation errors and con- trol errors. Rationality,efficiency and accuracy of the two performance indexes are testified by two simulation examples. The results show that both of the indexes could be used for on-orbit safety performance analysis and are available for both linear and nonlinear Rendezvous safe Trajectory design.

  • Survey on Space Rendezvous Phasing Trajectory Design and Maneuver Plan
    Manned Spaceflight, 2009
    Co-Authors: Tang Guo-jin
    Abstract:

    The phasing Trajectory design and maneuver plan is one of critical problems for Rendezvous and docking Trajectory design and control.A survey on the development of this domain is made.The advantages for Rendezvous Trajectory including phasing stage are firstly analyzed,and the main constraints for phasing Trajectory design are summarized.The phasing Trajectory maneuver strategy applied in engineering is described,and two representative maneuver strategies including special -point maneuver and combined maneuver are compared in terms of propellant cost,etc.The state-of-the-art of phasing maneuver planning is surveyed according theoretical foundations and practical methods.Finally,the prospect on the further work is presented according to two parts: practical researches required by engineering application and new theory and method research work under new background.

  • Glideslope Guidance Algorithm for Close Range Rendezvous of Spacecraft
    Journal of National University of Defense Technology, 2009
    Co-Authors: Tang Guo-jin
    Abstract:

    The multi-impulse glideslope guidance algorithm for close range Rendezvous of spacecraft is presented.The algorithm takes the fuel economy and the constraints of field-of-view of navigation facilities,the minimum interval of impulses,and the maximum value of impulse into consideration.Furthermore,a consolidated model of glideslope algorithm to guide close range Rendezvous(both proximity and departure) is described.By designing the relationship of exponential function between distance and speed of ideal Rendezvous Trajectory,the algorithm can be applied to any specified Rendezvous time,and satisfies the need of decelerating during the proximity operation and accelerating during the departure operation.By defining the logarithmic mapping function,the optimized impulses can be obtained.Finally,several scenarios of the proximity and departure operations are simulated.In some scenarios,compared with the optimization method,the using of logarithmic mapping function can also economize fuel at a cost of low computational complexity.The other scenarios illustrate that the guidance algorithm can ensure a close range Rendezvous motion in any direction,at any time with the fuel economy and under the constraints as well.

Lobo F. Pereira - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Rendezvous Trajectory for Unmanned Aerial-Ground Vehicles
    IEEE Transactions on Aerospace and Electronic Systems, 2018
    Co-Authors: Alessandro Rucco, Pedro A. Aguiar, P. B. Sujit, João Borges De Sousa, Lobo F. Pereira
    Abstract:

    Fixed-wing unmanned aerial vehicles (UAVs) can be an essential tool for low-cost aerial surveillance and mapping applications in remote regions. There is, however, a key limitation, which is the fact that low-cost UAVs have limited fuel capacity and, hence, require periodic refueling to accomplish a mission. Moreover, the usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in the fuel wastage and inefficient mission operation time. Alternatively, one strategy could be the use of an unmanned ground vehicle (UGV) as a mobile refueling unit, where the UAV will Rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal Trajectory in three-dimensional taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV Trajectory for Rendezvous on a moving UGV that also addresses the possibility of the presence of wind disturbances. By a suitable choice of the value of an aggressiveness index that we introduce in our problem setting, we are able to control the UAV Rendezvous behavior. Several numerical results are presented to illustrate the reliability and effectiveness of our approach.

  • Optimal Rendezvous Trajectory for unmanned aerial-ground vehicles
    2018
    Co-Authors: Alessandro Rucco, Pedro A. Aguiar, João Borges De Sousa, Sujit Baliyarasimhuni, Lobo F. Pereira
    Abstract:

    Fixed-wing unmanned aerial vehicles (UAVs) can be an essential tool for low cost aerial surveillance and mapping applications in remote regions. There is however a key limitation, which is the fact that low cost UAVs have limited fuel capacity and hence require periodic refueling to accomplish a mission. Moreover, the usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in fuel wastage and inefficient mission operation time. Alternatively, one strategy could be the use of an unmanned ground vehicle (UGV) as a mobile refueling unit, where the UAV will Rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal Trajectory in 3D taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV Trajectory for Rendezvous on a moving UGV that also addresses the possibility of the presence of wind disturbances. By a suitable choice of the value of an aggressiveness index that we introduce in our problem setting, we are able to control the UAV Rendezvous behavior. Several numerical results are presented to illustrate the reliability and effectiveness of our approach

Alessandro Rucco - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Rendezvous Trajectory for Unmanned Aerial-Ground Vehicles
    IEEE Transactions on Aerospace and Electronic Systems, 2018
    Co-Authors: Alessandro Rucco, Pedro A. Aguiar, P. B. Sujit, João Borges De Sousa, Lobo F. Pereira
    Abstract:

    Fixed-wing unmanned aerial vehicles (UAVs) can be an essential tool for low-cost aerial surveillance and mapping applications in remote regions. There is, however, a key limitation, which is the fact that low-cost UAVs have limited fuel capacity and, hence, require periodic refueling to accomplish a mission. Moreover, the usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in the fuel wastage and inefficient mission operation time. Alternatively, one strategy could be the use of an unmanned ground vehicle (UGV) as a mobile refueling unit, where the UAV will Rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal Trajectory in three-dimensional taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV Trajectory for Rendezvous on a moving UGV that also addresses the possibility of the presence of wind disturbances. By a suitable choice of the value of an aggressiveness index that we introduce in our problem setting, we are able to control the UAV Rendezvous behavior. Several numerical results are presented to illustrate the reliability and effectiveness of our approach.

  • Optimal Rendezvous Trajectory for unmanned aerial-ground vehicles
    2018
    Co-Authors: Alessandro Rucco, Pedro A. Aguiar, João Borges De Sousa, Sujit Baliyarasimhuni, Lobo F. Pereira
    Abstract:

    Fixed-wing unmanned aerial vehicles (UAVs) can be an essential tool for low cost aerial surveillance and mapping applications in remote regions. There is however a key limitation, which is the fact that low cost UAVs have limited fuel capacity and hence require periodic refueling to accomplish a mission. Moreover, the usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in fuel wastage and inefficient mission operation time. Alternatively, one strategy could be the use of an unmanned ground vehicle (UGV) as a mobile refueling unit, where the UAV will Rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal Trajectory in 3D taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV Trajectory for Rendezvous on a moving UGV that also addresses the possibility of the presence of wind disturbances. By a suitable choice of the value of an aggressiveness index that we introduce in our problem setting, we are able to control the UAV Rendezvous behavior. Several numerical results are presented to illustrate the reliability and effectiveness of our approach

  • Optimal Rendezvous Trajectory for Unmanned Aerial-Ground Vehicles
    arXiv: Optimization and Control, 2016
    Co-Authors: Alessandro Rucco, P. B. Sujit, João Borges De Sousa, Pedro Aguiar, Fernando Lobo Pereira
    Abstract:

    Fixed-wind unmanned aerial vehicles (UAVs) are essential for low cost aerial surveillance and mapping applications in remote regions. One of the main limitations of UAVs is limited fuel capacity and hence requires periodic refueling to accomplish a mission. The usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in fuel wastage and inefficient mission operation time. Alternatively, unmanned gound vehicle (UGV) can be used as a mobile refueling unit where the UAV will Rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal Trajectory in 3D taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV Trajectory for Rendezvous on a moving UGV taking wind disturbances into account. By a suitable choice of the value of an aggressiveness index in our problem setting, we are able to control the UAV Rendezvous behavior. Several numerical results are presented to show the reliability and effectiveness of our approach.