Optimal trajectory for time-on-target of a guided projectile using direct collocation method

2013 ◽  
Author(s):  
Qi Chen ◽  
Zhongyuan Wang
Keyword(s):  
Collocation Method ◽  
Optimal Trajectory ◽  
Direct Collocation ◽  
Direct Collocation 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.

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 Multiphase Trajectory Generation for Planar Biped Robot Using Direct Collocation Method

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yubin Liu ◽  
Shuai Heng ◽  
Xizhe Zang ◽  
Zhenkun Lin ◽  
Jie Zhao
Keyword(s):  
Energy Efficiency ◽  
Collocation Method ◽  
Biped Robot ◽  
Contact Forces ◽  
Two Phase ◽  
Double Support ◽  
Direct Collocation ◽  
Direct Collocation Method ◽  
The Stability ◽  
Support Phase

Stability and energy efficiency are the main focuses in the bipedal robot field. In this paper, we apply a multiphase gait, which is different from the widely used two-phase gait, to improve the stability at the moment, when a biped robot transfers from the double support phase to the single support phase. Then, we create dynamic equations with contact forces in each phase using Lagrangian formulation. Furthermore, the direct collocation method is utilized to generate the optimal trajectory toward both stability and energy efficiency. Finally, the comparison between multiphase gait and two-phase gait is performed with numerical simulations. The results prove that multiphase gait increases the stability margin in the cost of slightly decreasing energy efficiency. Besides, both gaits show a similar human-like characteristic in hip height variation during walking.

Optimal Level Flight Trajectories of Stratospheric Airship

2011 ◽  
Vol 383-390 ◽  
pp. 5216-5221 ◽  
Author(s):  
Feng Ping Qin ◽  
Li Chen
Keyword(s):  
Quadratic Programming ◽  
Collocation Method ◽  
Optimal Level ◽  
Programming Algorithm ◽  
Optimal Trajectories ◽  
Optimal Method ◽  
Stratospheric Airship ◽  
Level Flight ◽  
Direct Collocation ◽  
Direct Collocation Method

This paper focuses on the stratospheric airship in the level flight state, and designs a optimal method which combines the direct collocation method and sequentially quadratic programming algorithm to get the optimal trajectories. Both the minimum time and fuel are considered. The result indicates that this method is very efficient to the problem and can supply the idea to utilize the wind to save fuel and time in the actual flight.

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