Algorithm of Launched Vehicles Mass Calculation at the Early Stage of Designing

2011 ◽  
Author(s):  
A. Gaynutdinova ◽  
T. Gaynutdinova
Keyword(s):  
Numerical Algorithm ◽  
Early Stage ◽  
Flight Time ◽  
Flight Path ◽  
Trajectory Design ◽  
Design Calculation ◽  
Flight Trajectory ◽  
Fuel Mass ◽  
Vehicle Mass ◽  
Flight Path Angle

Launching mass of pilotless vehicle bounds with flight path. Required fuel mass depends from flight trajectory. Design calculation of vehicle mass and flight trajectory are in close bind. We suggest numerical algorithm of design calculation of vehicle flight mass and optimal characteristics of flight trajectory – initial flight-path angle and flight time to target.

Simulation on Torpedo Unsteady Hydrodynamic with the Movement in the Longitudinal Plane

2013 ◽  
Vol 791-793 ◽  
pp. 1073-1076
Author(s):  
Ming Yang ◽  
Shi Ping Zhao ◽  
Han Ping Wang ◽  
Lin Peng Wang ◽  
Shao Zhu Wang
Keyword(s):  
Three Dimensional ◽  
Engineering Application ◽  
Calculation Model ◽  
Trajectory Design ◽  
Design Calculation ◽  
Variable Speed ◽  
Accurate Calculation ◽  
Longitudinal Plane ◽  
Submerged Body ◽  
Mesh Method

The unsteady hydrodynamic accurate calculation is the premise of submerged body trajectory design and maneuverability design. Calculation model of submerged body unsteady hydrodynamic with the movement in the longitudinal plane was established, which based on unsteady three-dimensional incompressible fluid dynamics theory. Variable speed translational and variable angular velocity of the pitching motion in the longitudinal plane of submerged body was achieved by dynamic mesh method. The unsteady hydrodynamic could be obtained by model under the premise of good quality grid by the results. Modeling methods can learn from other similar problems, which has engineering application value.

Effects of Descent Flight-Path Angle on Fuel Consumption of Commercial Aircraft

2019 ◽  
Vol 56 (1) ◽  
pp. 313-323 ◽  
Author(s):  
Enis T. Turgut ◽  
Oznur Usanmaz ◽  
Mustafa Cavcar ◽  
Tuncay Dogeroglu ◽  
Kadir Armutlu
Keyword(s):  
Fuel Consumption ◽  
Flight Path ◽  
Commercial Aircraft ◽  
Flight Path Angle

scholarly journals Finite-Horizon Optimal Tracking Guidance for Aircraft Based on Approximate Dynamic Programming

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Shizheng Wan ◽  
Xiaofei Chang ◽  
Quancheng Li ◽  
Jie Yan
Keyword(s):  
Dynamic Programming ◽  
Approximate Dynamic Programming ◽  
Least Squares Method ◽  
Flight Path ◽  
Finite Horizon ◽  
Dynamic Programming Method ◽  
Reference Trajectory ◽  
Linear Quadratic ◽  
Optimal Tracking ◽  
Flight Path Angle

Referring to the optimal tracking guidance of aircraft, the conventional time based kinematics model is transformed into a downrange based model by independent variable replacement. The deviations of in-flight altitude and flight path angle are penalized and corrected to achieve high precision tracking of reference trajectory. The tracking problem is solved as a linear quadratic regulator applying small perturbation theory, and the approximate dynamic programming method is used to cope with the solving of finite-horizon optimization. An actor-critic structure is established to approximate the optimal tracking controller and minimum cost function. The least squares method and Adam optimization algorithm are adopted to learn the parameters of critic network and actor network, respectively. A boosting trajectory with maximum final velocity is generated by Gauss pseudospectral method for the validation of guidance strategy. The results show that the trained feedback control parameters can effectively resist random wind disturbance, correct the initial altitude and flight path angle deviations, and achieve the goal of following a given trajectory.

Optimal perturbation guidance with constraints on terminal flight-path angle and angle of attack

2019 ◽  
Vol 233 (12) ◽  
pp. 4436-4446
Author(s):  
Penglei Zhao ◽  
Wanchun Chen ◽  
Wenbin Yu
Keyword(s):  
Optimal Control ◽  
Singular Perturbation ◽  
Time Scale ◽  
Angle Of Attack ◽  
Flight Path ◽  
Superior Performance ◽  
Optimal Perturbation ◽  
Optimal Guidance ◽  
Flight Path Angle ◽  
Guidance Problem

This paper presents the design of a singular-perturbation-based optimal guidance with constraints on terminal flight-path angle and angle of attack. By modeling the flight-control system dynamics as a first-order system, the angle of attack is introduced into the performance index as a state variable. To solve the resulting high-order optimal guidance problem analytically, the posed optimal guidance problem is divided into two sub-problems by utilizing the singular perturbation method according to two time scales: range, altitude, and flight-path angle are the slow time-scale variables while the angle of attack is the fast time-scale variable. The outer solutions are the optimal control of the slow-scale subsystem. Thereafter, by applying the stretching transformation, the fast-scale subsystem establishes the relationships between the outer solutions and acceleration command. Then, the optimal command can be obtained by solving the fast-scale subsystem also using the optimal control theory. The proposed guidance can achieve a near-zero terminal acceleration as well as a small miss distance. The superior performance of the guidance is demonstrated by adequate trajectory simulations.

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