Study of the Optimal Design for the Gliding Trajectory

2014 ◽  
Vol 568-570 ◽  
pp. 1063-1067
Author(s):  
Jian Jun Wang ◽  
Jian Qiao Yu
Keyword(s):  
Optimal Design ◽  
Trajectory Optimization ◽  
Shooting Method ◽  
Particle Trajectory ◽  
Longitudinal Plane ◽  
Direct Collocation ◽  
Direct Collocation Method ◽  
Direct Shooting ◽  
Particle Trajectory Model ◽  
Drag Ratio

The optimal design for the gliding trajectory is studied. The particle trajectory model in the longitudinal plane is established. Aiming at solving the problems in numerical solution ,the direct shooting method based on the interpolating function of Akima is put forward .In direct collocation method, the parameters of the trajectory with approximate maximum lift-drag ratio is adopted as the starting value of the optimal variables. The trajectory with approximate maximum lift-drag ratio could be obtained by the search method. The transfer approach of turning the problem of trajectory optimization to the problem of parameter optimization by the direct shooting method is illustrated. To one kind of guided vehicles in simulation, the simulation results prove the practicability of the direct shooting method.

Trajectory Optimization for Spacecraft Proximity Rendezvous Using Direct Collocation Method

2012 ◽  
Vol 433-440 ◽  
pp. 6652-6656 ◽  
Author(s):  
Tao Liu ◽  
Yu Shan Zhao ◽  
Peng Shi ◽  
Bao Jun Li
Keyword(s):  
Nonlinear Programming ◽  
Control Problem ◽  
Programming Problem ◽  
Collocation Method ◽  
Trajectory Optimization ◽  
Collocation Methods ◽  
Nonlinear Programming Problem ◽  
Reference Orbit ◽  
Direct Collocation ◽  
Direct Collocation Method

Trajectory optimization problem for spacecraft proximity rendezvous with path constraints was discussed using direct collocation method. Firstly, the model of spacecraft proximity rendezvous in elliptic orbit optimization control problem was presented, with the dynamic equations established in the target local orbital frame, and the performance index was minimizing the total fuel consumption. After that the optimal control problem was transcribed into a large scale problem of Nonlinear Programming Problem (NLP) by means of Hermite-Simpson discretization, which was one of the direct collocation methods. Then the nonlinear programming problem was solved using MATLAB software package SNOPT. Finally, to verify this method, the fuel-optimal trajectory for finite thrust was planned for proximity rendezvous with elliptic reference orbit. Numerical simulation results demonstrate that the proposed method was feasible, and was not sensitive to the initial condition, having good robustness.

Trajectory Optimization for Hypersonic Vehicle Satisfying Maneuvering Penetration

2011 ◽  
Vol 110-116 ◽  
pp. 5223-5231 ◽  
Author(s):  
Ke Nan Zhang ◽  
Wan Chun Chen
Keyword(s):  
Trajectory Optimization ◽  
Shooting Method ◽  
Control Variable ◽  
Optimization Method ◽  
Hypersonic Vehicle ◽  
Quadratic Program ◽  
Sqp Method ◽  
Piecewise Constant ◽  
Path Constraints ◽  
Direct Shooting

A trajectory optimization method for hypersonic vehicle in glide phase satisfying maneuvering penetration is proposed. Divide the dangerous zones that the hypersonic vehicle may encounter during glide phase into avoidable no-fly zones and avoidless no-fly zones. Take the avoidable no-fly zones as path constraints to join the trajectory optimization. To penetrate the avoidless no-fly zones, trajectory is programmed by some maneuvering policy. Direct shooting method is used to discretize the control variable to piecewise constant functions. So the optimal control problem is transferred to a nonlinear programming (NLP) problem, and solved by the serial quadratic program (SQP) method.

Trajectory Optimization Using Analytical Target Cascading

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Xiang Li ◽  
Xiaonpeng Wang ◽  
Houjun Zhang ◽  
Yuheng Guo
Keyword(s):  
Trajectory Optimization ◽  
Large Scale ◽  
Optimization Problems ◽  
Sparse Matrix ◽  
Functional Dependence ◽  
Analytical Target Cascading ◽  
Scale Problem ◽  
Direct Collocation ◽  
Target Cascading ◽  
Direct Collocation Method

In the previous reports, analytical target cascading (ATC) is generally applied to product optimization. In this paper, the application area of ATC is expanded to trajectory optimization. Direct collocation method is utilized to convert a trajectory optimization into a nonlinear programing (NLP) problem. The converted NLP is a large-scale problem with sparse matrix of functional dependence table (FDT) suitable for the application of ATC. Three numerical case studies are provided to show the effects of ATC in solving trajectory optimization problems.

scholarly journals Trajectory Optimization for a Cruising Unmanned Aerial Vehicle Attacking a Target at Back Slope While Subjected to a Wind Gradient

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Tieying Jiang ◽  
Jie Li ◽  
Bing Li ◽  
Kewei Huang ◽  
Chengwei Yang ◽  
...  
Keyword(s):  
Collocation Method ◽  
Unmanned Aerial Vehicle ◽  
Trajectory Optimization ◽  
Time Function ◽  
Full Account ◽  
Direct Collocation ◽  
Motion Features ◽  
Aerial Vehicle ◽  
Direct Collocation Method ◽  
Motion Characteristics

The trajectory of a tubular launched cruising unmanned aerial vehicle is optimized using the modified direct collocation method for attacking a target at back slope under a wind gradient. A mathematical model of the cruising unmanned aerial vehicle is established based on its operational and motion features under a wind gradient to optimize the trajectory. The motion characteristics of  “altitude adjustment” and “suicide attack” are taken into full account under the combat circumstance of back slope time key targets. By introducing a discrete time function, the trajectory optimization is converted into a nonlinear programming problem and the SNPOT software is applied to solve for the optimal trajectory of the missile under different wind loads. The simulation results show that, for optimized trajectories, the average attack time decreased by up to 29.1% and the energy consumption is reduced by up to 25.9% under specified wind gradient conditions.A,ωdire, andWmaxhave an influence on the flight trajectories of cruising unmanned aerial vehicle. This verifies that the application of modified direct collocation method is reasonable and feasible in an effort to achieve more efficient missile trajectories.

scholarly journals Marine macro debris transport based on hydrodynamic model before and after reclamation in Jakarta Bay, Indonesia

2020 ◽  
Vol 5 (2) ◽  
pp. 100-111
Author(s):  
Yudi Nurul Ihsan
Keyword(s):  
Eddy Current ◽  
Hydrodynamic Model ◽  
Particle Trajectory ◽  
Surface Current ◽  
Contamination Level ◽  
Model Data ◽  
The World ◽  
Before And After ◽  
Debris Transport ◽  
Particle Trajectory Model

Jakarta Bay as an area with the densest population in Indonesia became one of the highest contamination level waters in the world includes pollution of debris. Reclamation activities in Jakarta Bay will change the water conditions will also affect the distribution of debris at sea. Therefore, this study conducted to determine the movement of the macro debris before and after island reclamation in Jakarta Bay. The method used is a model that simulated by the hydrodynamic model and particle trajectory model. Data needed for the hydrodynamic model were wind, tides, bathymetry, and shoreline, while for the trajectory of the particles using a data type of macro debris, debris weight, and debris flux. Hydrodynamics simulations indicate if a reclamation island formation does not change surface current patterns significantly, but causes a decrease in the flow velocity of ± 0.002 to 0.02 m/s at some point. The trajectory of particles of debris indicate if after reclamation, debris tends to accumulate in the eastern Jakarta Bay in the rainy season (January) as there are anticlockwise eddy current, as well as in the western and eastern regions during the dry season (July), because there is a clockwise eddy current in the eastern Jakarta Bay.

Optimal Design of Wind Turbines Using BIAS, A Method of Multipliers Code

1988 ◽  
Author(s):  
B. D. Vick ◽  
W. Wrigglesworth ◽  
L. B. Scott ◽  
K. M. Ragsdell
Keyword(s):  
Optimal Design ◽  
Rough Surface ◽  
Wind Turbines ◽  
Lift Coefficient ◽  
Power Coefficient ◽  
Method Of Multipliers ◽  
High Lift ◽  
Small Wind Turbines ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract A method has been developed and is demonstrated which determines the chord and twist distribution for a wind turbine with maximum power coefficient. Only small wind turbines (less than 10 kilowatts) are considered in this study, but the method could be used for larger wind turbines. Glauert determined a method for estimating the chord and twist distribution that will maximize the power coefficient if there is no drag. However, the method proposed here determines the chord and twist distribution which will maximize the power coefficient with the effect of drag included. Including drag in the analysis does not significantly affect the Glauert chord and twist distribution for airfoils with a high lift coefficient at the maximum lift to drag ratio. However, if the airfoil has a fairly low lift coefficient at its maximum lift to drag ratio due to its shape or a rough surface then significant improvement can be obtained in power coefficient by altering the Glauert chord and twist distribution according to the method proposed herein.

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