Aircraft Flight Routes Optimization
Synthesizing 4D Flight Paths of Civil Aircraft in the Framework of “Free Flight” Concept
Tech Area / Field
- SAT-AER/Aeronautics/Space, Aircraft and Surface Transportation
- INF-SOF/Software/Information and Communications
- MAN-MPS/Manufacturing, Planning, Processing and Control/Manufacturing Technology
- PHY-STM/Structural Mechanics/Physics
3 Approved without Funding
Research Institute of Aviation Systems, Russia, Moscow
- Smiths Industries, USA, MI, Grand Rapids\nBoeing Operations International, Inc., Russia, Moscow
Project summaryThe project goal is to formulate, design and test algorithms that will improve the efficiency of usage of large civil airplanes over long range routes. The algorithms will enable reducing the total cost of flying long range routes by optimizing the trajectory of airplanes in an environment consisting of three dimensional winds and constrained by various time of arrival requirements. These algorithms take advantage of the advent of Air Traffic Management (ATM) policies as opposed to Air Traffic Control (ATC) current policies: the ATM concept will allow airplane crews to fly the trajectory of their choice rather than a pre-assigned trajectory and the Air Traffic authorities will just manage conflicts between airplanes. This opportunity will enable airplanes equipped with sophisticated Flight Management Systems (FMS) to realize large savings in terms of fuel and time over long routes.
We plan to design optimization algorithms and demonstrate the potential operating savings possible in this new environment.
Stable increase in the general intensity of air traffic and increase of the requirements of airlines on reducing the operating costs of airplanes has resulted in originating the new concept of Air Traffic Control – Communication and Navigation Surveillance/Air Traffic Management (ATC - CNS/ATM).
Implementation of its leading particulars, namely:
· Elements of a global navigation system;
· Means of digital satellite radio communication;
· Systems of automatic dependent surveillance
increases importance problems of optimization of flight paths of civil airplanes by selection of the free schedule, free routing and manoeuvring.
But the general problem of simultaneous prediction of flight levels, route and flight modes in view of all limitations (such as weather and trajectory) is still not resolved.
The complexity of the solution is characterized:
· By large dimension of the problem - over a hundred parameters of optimization;
· By essential non-linearity of equations;
· Cost function is relatively flat in the search area:
· By high sensitivity of a point of optimization position on accuracy definition of input data.
The activities in this direction take place in Russia and abroad.
Problems of generation of flight path according to particular effectiveness criteria (minimum fuel consumption, minimum flight time, arrival in required time, minimum trip cost) on fixed routes are practically resolved, including the optimization problem of selection of flight levels of an airplane flight—one at a time.
The purpose of activity consists in the substantiation of statement of an optimization problem covering the different flight management scenarios, realizable by calculation of modes and flight path and in generation of unified algorithms of the solution of this problem. The indicated purpose will be reached by the analysis of the known scenarios of flight management, structure of criteria of optimization, formation of vector of optimized parameters and introducing of the justified simplifications for decomposition of a problem and reducing it to a problem of multilevel optimization.
All activity on the project can be submitted as four sequentially executed problems.
Problem 1. Formulation.
The analysis of a problems, associated with a task of the flight plans generation. Statement of the general research problem, definition of features of the particular tasks. The analysis of criteria, structure of optimized parameters and limitations taken into consideration. Formulation of the problem. Description of the interface of exploratory models and software of flight plan generation process.
Problem 2. Generation of exploratory algorithms and programs.
Generation of the set of models and programs of simulation modeling (such as model of an airplane, wind and temperature, flight management.). Executing (performing) of preliminary researches for the substantiation of an optimization problem. Generating of preliminary algorithms versions of the optimal flight plan synthesizing.
Problem 3. Generation of means of formation of the optimal flight plans.
Performing of researche on the flight plan generation. Clarifying of the efficiency model. Design of the first algorithms and software version for the purpose of the flight plan generation.
Problem 4. Researches of efficiency of proposed means of synthesizing.
Generation of scenarios and technique of evaluation tests execution for the proposed algorithms and software. Refinement of algorithms and programs of flight plan generation. Execution of dynamic and statistical tests by methods of simulation.
Outcomes of activity.
1. Algorithms and general purpose software, realizing them.
2. Results of researches verifying efficiency of algorithms.
3. The guidelines on their usage in concerns of perfecting of an onboard avionics.
Area of outcomes application.
1. Planning and navigating services of air carriers.
2. The manufacturers of an onboard avionics.
3. The manufacturers of airplanes.
Smith Industries Aerospace (Information Management Systems—Grand Rapids, MI) is interested to participate in the resolving of the following problems:
1. Calculation of Multiple Time Constraints (Required Time of Arrival) impact on the Predicted Airplane Trajectory.
2. Calculation of the optimal cruise step points to multiple step altitudes with a three-dimensional wind model.
The activity is supposed to be completed within 8 quarters with approximate manpowers in 280 man-month.
The team of the participants of the project - employees of State Research Institute of Aviation Systems (Moscow, Russia), which is one of leaders in the area of software engineering for airplanes onboard systems and also simulation modeling of complicated dynamic systems, participated in the project of development of a ILUSHIN – 96M/T flight management computer system and algorithms and software design for optimization procedures for the purposes of trajectories calculations.
The fulfilment of the proposed project allows to perform the following ISTC purposes:
· Enables a group of scientists and specialists, possessing weapon know-how, to redirect their efforts in the area of civil tasks;
· Enables the participants of the project to encourage the solution of technical problems, applicable both for Russian Federation and CIS, and at an international level;
· Enables the participants of the project to work in a direction of design of the market product with anticipated demand and adequate to civil purposes.
Technical statement. In enough general view the effectiveness criteria of flight is expedient for presenting as the trip profit:
PR = Ktar*Wcom - (Cf*Wf + Ct*T) - Cunpl - Kpen * | T - Treq |,
where Wcom - weight of payload, Ktar - tariff factor, Cunpl - penalty of unplanned landing to a regular aerodrome at shortage of fuel, Kpen - penal factor for a delayed arrival, Treq – required time of arrival.
The weights of payload Wcom and max. fuel weight - Wfm should respond additional limitation on as much as possible(maximum) an allowable gross weight.
Criteria extremum search should be ensured(supplied) at simultaneous fulfillment of a lot of limitations imposed as on a route, and on flight modes. Major of them, apart from limitations under the consumption and weight of fuel, are following.
· The route is represented by a set of great circle segments;
· The limitations on departure times and arrival one can be represented as limitations - inequalities;
· Limitations imposed on selection of an altitude of flight;
· Constructive constraints on minimum and maximum flight speeds.
· Limitation on a marginal altitude of flight Hmax;
· Limitations, bound with necessity of circumvention of areas of an airspace (both ATC established, and bound with abnormal weather conditions);
· The route should not be farther from alternate destinations on distances that are more than permissible ones.
As components of an optimization vector are considered the following ones:
· Array of piecewise constant values of a flight speed V (i)).
· Array of altitudes of flight on segments H (i).
· Fuel gross weight Wfm.
· Array of coordinates of end points of route segments.
In the project two solution versions of a problem of optimal flight planning will be realized.
In version 1 the process of numerical optimization with definition of array of coordinates of route segments endpoints, arrays of altitudes H (i) and speeds V (i) of cruise flight on each segment will be realized, and also (where it is necessary) and value of a required fuel weight Wf.
In version 2 the process of optimization with definition of arrays of coordinates of route segments, and also supplementary cost index (CIs) and required fuel weight will be realized. Planned altitude and flight speed are calculated pursuant to a cost index CIs.
The complexities, associated with practical implementation of numerical process of optimization under both versions, are connected not only to dimension, but also with flat shape of permissible area of optimized parameters. It can result in convergence of the solution to a local extremum. In tendered algorithms the mixed procedure of the optimization combining algorithms of ordered random search and the solution of a problem of non-linear programming is applied to looking up of a global optimum.
At usage of algorithms of the ordered random search the route is searched as sequence of great circle segments of random length and random direction adequate a number of additional conditions.
As the main algorithm of non-linear programming problem solution the numerical algorithm realizing modified method of a linearization is offered.
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