Workshop on Trajectory Optimization Methods and Applications, Presentations from the 1992 AIAA Atmospheric Flight Mechanics Conference

1992 ◽  
Author(s):  
Harry A. Karasopoulos ◽  
Kevin J. Langan
Keyword(s):  
Trajectory Optimization ◽  
Optimization Methods ◽  
Flight Mechanics

Trajectory Optimization for DDE Models of Supercavitating Underwater Vehicles

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Carlo L. Bottasso ◽  
Francesco Scorcelletti ◽  
Massimo Ruzzene ◽  
Seong S. Ahn
Keyword(s):  
Optimal Control ◽  
Differential Equations ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Trajectory Optimization ◽  
Past History ◽  
Flight Mechanics ◽  
Multiple Shooting ◽  
Supercavitating Vehicles ◽  
Delay Differential

In this study we first develop a flight mechanics model for supercavitating vehicles, which is formulated to account for the dependence of the cavity shape from the past history of the system. This mathematical model is governed by a particular class of delay differential equations, featuring time delays on the states of the system. Next, flight trajectories and maneuvering strategies for supercavitating vehicles are obtained by solving an optimal control problem, whose solution, given a cost function and general constraints and bounds on states and controls, yields the control time histories that maneuver the vehicle according to a desired strategy, together with the associated flight path. The optimal control problem is solved using a novel direct multiple shooting approach, which is formulated to properly handle conditions dictated by the delay differential equation formulation governing the dynamic behavior of the vehicle. Specifically, the new formulation enforces the state continuity line conditions in a least-squares sense using local interpolations, which supports local time stepping and drastically reduces the number of optimization unknowns. Examples of maneuvers and resulting trajectories demonstrate the effectiveness of the proposed methodology and the generality of the formulation. The results are also compared with those obtained from a previously developed model governed by ordinary differential equations to highlight the differences and demonstrate the need for the current formulation.

Method to Calculate Aircraft VNAV Trajectory Cost Using a Performance Database

2014 ◽  
Author(s):  
Alejandro Murrieta-Mendoza ◽  
Ruxandra Botez
Keyword(s):  
Trajectory Optimization ◽  
Calculated Data ◽  
Optimization Methods ◽  
Fast Method ◽  
Computing Power ◽  
Flight Plan ◽  
Aerodynamic Model ◽  
The Given ◽  
Equations Of Motions ◽  
A Performance

Vertical Navigation (VNAV) trajectory optimization has been identified as a means to reduce fuel consumption. Due to the computing power limitations of devices such as Flight Management Systems (FMSs), it is very desirable to implement a fast method for calculating trajectory cost using optimization algorithms. Conventional trajectory optimization methods solve a set of differential equations called the aircraft equations of motions to find the optimal flight profile. Many FMSs do not use these equations, but rather a set of lookup tables with experimental, or pre-calculated data, called a Performance Database (PDB). This paper proposes a method to calculate a full trajectory flight cost using a PDB. The trajectory to be calculated is composed of climb, acceleration, cruise, descent and deceleration flight phases. The influence of the crossover altitude during climb and step climbs in cruise were considered for these calculations. Since the PDB is a set of discrete data, Lagrange linear interpolations were performed within the PDB to calculate the required values. Given a takeoff weight, the initial and final coordinates and the desired flight plan, the trajectory model provides the Top of Climb coordinates, the Top of Descent coordinates, the fuel burned and the flight time needed to follow the given flight plan. The accuracy of the trajectory costs calculated with the proposed method was validated for two aircraft; one with an aerodynamic model in FlightSIM, software developed by Presagis, and the other using the trajectory generated by the reference FMS.

Guidance Performance Benchmarking for Autonomous Rotorcraft

2014 ◽  
Vol 59 (4) ◽  
pp. 1-16 ◽  
Author(s):  
Bérénice Mettler ◽  
Zhaodan Kong ◽  
Chad Goerzen ◽  
Matthew Whalley
Keyword(s):  
Trajectory Optimization ◽  
Numerical Optimization ◽  
Performance Metrics ◽  
Optimization Methods ◽  
Urban Environments ◽  
Performance Benchmarking ◽  
Digital Terrain ◽  
Motion Primitive ◽  
Terrain Elevation ◽  
Methods Numerical

This paper describes a framework for performance evaluation of autonomous guidance systems. The elements of the framework consist of a set of spatial geometries, flight tasks, performance metrics, a flightdynamic model, and baseline solutions. The spatial benchmarks consist of six tasks in simple geometrical environments and 10 tasks in more complex urban environments based on a real digital terrain elevation map. The framework also includes a set of performance metrics used to compare trajectories. The performance baselines used in the proposed framework are near-optimal solutions computed using one of two trajectory optimization methods: numerical optimization based on nonlinear programming for the simple geometric environments and a motion primitive automaton for problems involving the urban environments. The paper concludes with a demonstration of the benchmarking framework using the Obstacle Field Navigation system developed by the Army Aeroflightdynamics Directorate.

scholarly journals Creating Better Collision-Free Trajectory for Robot Motion Planning by Linearly Constrained Quadratic Programming

2021 ◽  
Vol 15 ◽  
Author(s):  
Yizhou Liu ◽  
Fusheng Zha ◽  
Mantian Li ◽  
Wei Guo ◽  
Yunxin Jia ◽  
...  
Keyword(s):  
Quadratic Programming ◽  
Motion Planning ◽  
Trajectory Optimization ◽  
Optimization Technique ◽  
Optimization Methods ◽  
Linear Constraints ◽  
Task Constraints ◽  
Probabilistic Sampling ◽  
Smooth Path ◽  
Linearly Constrained

Many algorithms in probabilistic sampling-based motion planning have been proposed to create a path for a robot in an environment with obstacles. Due to the randomness of sampling, they can efficiently compute the collision-free paths made of segments lying in the configuration space with probabilistic completeness. However, this property also makes the trajectories have some unnecessary redundant or jerky motions, which need to be optimized. For most robotics applications, the trajectories should be short, smooth and keep away from obstacles. This paper proposes a new trajectory optimization technique which transforms a polygon collision-free path into a smooth path, and can deal with trajectories which contain various task constraints. The technique removes redundant motions by quadratic programming in the parameter space of trajectory, and converts collision avoidance conditions to linear constraints to ensure absolute safety of trajectories. Furthermore, the technique uses a projection operator to realize the optimization of trajectories which are subject to some hard kinematic constraints, like keeping a glass of water upright or coordinating operation with dual robots. The experimental results proved the feasibility and effectiveness of the proposed method, when it is compared with other trajectory optimization methods.

scholarly journals An Empirical Study on Low Emission Taxiing Path Optimization of Aircrafts on Airport Surfaces from the Perspective of Reducing Carbon Emissions

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1649 ◽  
Author(s):  
Nan Li ◽  
Yu Sun ◽  
Jian Yu ◽  
Jian-Cheng Li ◽  
Hong-fei Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Emission Reduction ◽  
Trajectory Optimization ◽  
Optimization Methods ◽  
Optimization Method ◽  
Path Optimization ◽  
Pollutant Emissions ◽  
Future Research ◽  
Aircraft Emissions ◽  
Fuel Consumption And Emissions

Aircraft emissions are the main cause of airport air pollution. One of the keys to achieving airport energy conservation and emission reduction is to optimize aircraft taxiing paths. The traditional optimization method based on the shortest taxi time is to model the aircraft under the assumption of uniform speed taxiing. Although it is easy to solve, it does not take into account the change of the velocity profile when the aircraft turns. In view of this, this paper comprehensively considered the aircraft’s taxiing distance, the number of large steering times and collision avoidance in the taxi, and established a path optimization model for aircraft taxiing at airport surface with the shortest total taxi time as the target. The genetic algorithm was used to solve the model. The experimental results show that the total fuel consumption and emissions of the aircraft are reduced by 35% and 46%, respectively, before optimization, and the taxi time is greatly reduced, which effectively avoids the taxiing conflict and reduces the pollutant emissions during the taxiing phase. Compared with traditional optimization methods that do not consider turning factors, energy saving and emission reduction effects are more significant. The proposed method is faster than other complex algorithms considering multiple factors, and has higher practical application value. It is expected to be applied in the more accurate airport surface real-time running trajectory optimization in the future. Future research will increase the actual interference factors of the airport, comprehensively analyze the actual situation of the airport’s inbound and outbound flights, dynamically adjust the taxiing path of the aircraft and maintain the real-time performance of the system, and further optimize the algorithm to improve the performance of the algorithm.

Solar-Cell Degradation Model for Trajectory Optimization Methods

2019 ◽  
Vol 56 (3) ◽  
pp. 844-853 ◽  
Author(s):  
Craig A. Kluever ◽  
Scott R. Messenger
Keyword(s):  
Solar Cell ◽  
Trajectory Optimization ◽  
Optimization Methods ◽  
Degradation Model

Technology Application on Two-Stage Model of Horizontal Well in the Block Oilfield

2014 ◽  
Vol 508 ◽  
pp. 169-172
Author(s):  
Hong Wei Liu
Keyword(s):  
Numerical Simulation ◽  
Reservoir Simulation ◽  
Trajectory Optimization ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Optimization Methods ◽  
Simulation Methods ◽  
Stage Model ◽  
Technology Application ◽  
Production Parameters

The technology of horizontal well emerges in 1970s-1980s, mainly from the standard length of the horizontal well, the reasonable level in the reservoir, trajectory optimization of the level to ensure the level and get the best production results. Numerical simulation is the most effective and accurate way to optimize the parameters of horizontal well, to understand the geology in this article, based on the use of reservoir simulation methods, looking for the benefit of regional development of horizontal well, and the Optimization methods to determine the length of the horizontal wells and production parameters, design two-level horizontal well in TZ422 oilfield of Tower, and achieved good results.

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