CN101657771B - Method of generating variable thrust cutback during aircraft departure - Google Patents

Abstract

A method of producing a variable thrust cutback of an aircraft during aircraft departure is provided. The method includes the steps of storing expected sound exposure levels for an aircraft in memory, and storing a sound exposure level limit for a navigation flight in memory. The method also includes the steps of determining aircraft altitude and determining aircraft airspeed. The method further includes the steps of computing an engine thrust value that complies with the sound exposure level limit based on the altitude, airspeed and the sound exposure levels, and outputting the computed engine thrust value for use in controlling the aircraft during departure.

Description

During aircraft departure, produce the method that variable thrust reduces

Cross reference to related application

The application requires to submit on March 14th, 2007, sequence number is 60/894,803, title is the right of priority of the provisional application of " during aircraft departure, producing flight management system and the method that variable thrust reduces ".

Technical field

Technology described herein relates generally to the aircraft flight management, especially relates to the method that the calculating aircraft engine throttle reduces during aircraft departure.

Background technology

Aircraft is equipped with the flight management system that is used for the managing aircraft flight control, produces the flight profile, mission profile data and navigation information (for example by the specified line of flight of destination through navigation position coordinate representation) is provided usually.In addition, flight management control system is also configurable to be in order to be provided for the manual of motor power or the aircraft engine throttle setting of control automatically.During aircraft takeoff; Flight management system can confirm that engine thrust requirements is fully to promote this aircraft when liftoff from runway (liftoff); Thereby make aircraft with a pitch rate climb fully (typically, according to programme controlled scheduling or by institute of air traffic control system requirement).

Typically, aircraft is equipped with the jet engine that can produce very high sound.If the position, airport is very near the residential block, the sound exposure level (SEL) that is suffered near the community that is caused by aircraft departure has so become serious day by day problem, and its execution that causes noise reduction process is to reduce community's noise during aircraft departure.Recently, national commercial aircraft association (NBAA) has attempted to set up to noise reduction process the national standard of flight operation.Usually, these are crossed the range request aircraft and during departing from port, utilize when liftoff from runway and be in the wing flap that takes off the setting under rises to 1000 feet in the sky, runway airport with the maximum feasible pitch rate flying height.During overhead 1000 feet of horizontal line, the common proposed flight device of this process accelerates to final stage speed and regains wing flap in case arrive at the airport.This process also proposed flight device is reduced to the quiet climb setting with motor power, and the rate of climb that keeps 1000 feet per minute clocks simultaneously and the air speed that is no more than qualification speed are until the flying height of overhead 3000 feet of the horizontal line that arrives at the airport.When 3000 feet level is above, along with applying the power that climbs gradually, aircraft will recover the scheduling of climbing normally.Certainly, aircraft control will submit to aircraft control requirement and other airspeed limitation.In view of the difference of aircraft model and takeoff condition, the pilot of aircraft have determine whether should before the withdrawal wing flap, during or reduce the freedom of takeoff thrust afterwards.

Typically, above-mentioned noise reduction process is used fixed altitudes to carry out thrust to reduce and recovers, and this aircraft that causes usually having Different Weight and different operating temperature is positioned on the different ground locations when the appointment flying height.For example, at cold snap, heavy aircraft will be climbed with the less angle of pitch at hot weather compared to lighter aircraft.In order to guarantee that during whole departure procedure abundant noise reduction, thrust reduce and the flying height recovered is designated as conservative (conservative) usually, this has caused waste of fuel.It has been generally acknowledged that the more effective section that climbs need climb with maximum buoyancy lift, so that aircraft is in the higher usually less time of low flying height place cost of resistance coefficient.

In addition, in the noise reduction process of mentioning in front, the purpose of the climb rate of 1000 feet per minute clocks of appointment provides possible maximum thrust and reduces, and still keeps the security level of performance.Yet, depend on aircraft, utilize the noise of realizing in order to the power setting of the climb rate that reaches 1000 feet per minute clocks to reduce and possibly limit needed noise and reduce less than observing community's ground noise.The function of the normally motor power setting of ground actual noise areal coverage, aircraft speed and aircraft flying height overhead.If motor power is reduced to such an extent that only enough satisfy desired sound exposure level under the current flight condition, the so higher climb rate possibly cause the less time in low flying height, thereby has reduced resistance and improved fuel economy.

Therefore, be desirable to provide a kind of aircraft departure procedure, it can increase fuel economy simultaneously in community's noise criteria, providing enough noises to reduce during the aircraft departure.Further be desirable to provide a kind of effective managing aircraft departure from port, provide optimal engine thrust to reduce flight management system and method simultaneously to realize community's noise reduction effectively.

Summary of the invention

In one aspect of the invention, the method that provides a kind of variable thrust that during aircraft departure, produces aircraft to reduce.The method comprising the steps of: in storer, store the step to the desired sound exposure level of aircraft, and in storer, store the sound exposure level limits to navigation flight.This method also comprises the step of confirming aircraft altitude and definite aircraft airspeed.This method further comprises step: calculate the engine thrust value that meets this sound exposure level limits according to this flying height, air speed and said sound exposure level, and the engine thrust value that output is calculated is to be used for this aircraft of control during departing from port.

Description of drawings

Several embodiment of the technology of the for example clear this paper explanation of accompanying drawing, wherein:

Fig. 1 is that the employing thrust according to an embodiment of the invention section that reduces to climb leaves the front elevation of the aircraft of airfield runway;

Fig. 2 is that the employing thrust according to an embodiment of the invention section that reduces to climb leaves the vertical view of the line of flight of the aircraft of airfield runway;

Fig. 3 is that the employing thrust according to an embodiment of the invention section that reduces to climb leaves the front elevation of the line of flight of the aircraft of airfield runway;

Fig. 4 illustrates according to an embodiment of the inventionly on aircraft, to use and be configured to provide thrust to reduce the block diagram of the flight management system of flight control;

Fig. 5 is the process flow diagram that the dB leg thrust cutback routine that is used for confirming the motor power during the aircraft departure procedure is shown;

Fig. 6 is the process flow diagram that is illustrated in employed calculating thrust routine in the routine of Fig. 5;

Fig. 7 is the form that comprises exemplary aircraft performance data, and these aircraft performance data comprise to be stored in and are used to calculate sound exposure level, motor power and the flying height that thrust reduces in the storer.

Embodiment

According to the present invention,,, the departure from port of aircraft 10 from airfield runway 12 has been described prevailingly according to the aircraft that reduces to realize according to the variable engine thrust section that climbs for community's noise reduction of strengthening efficient referring to Fig. 1.Aircraft 10 can comprise the aircraft that the jet-propelled propelling generally adopted like whole aircraft industry and screw propeller drive.In the example shown, because the difference of aircraft, the difference of weight for example, 3 aircraft 10 with Different Weight are followed the different circuits that takes off.

During taking off or depart from port from airfield runway 12, aircraft 10 adopts the aircraft flaps setting typically to quicken with total power in the takeoff setting, thereby makes aircraft liftoff from the runway according to circuit 14 and angle of climb α with the initial climb rate (pitch rate).The aircraft climb rate possibly change according to size and weight, motor power and the atmospheric conditions (like temperature, wind and other variable) of aircraft.When aircraft 10 arrived quiet climb location or destination 20, the dB voyage in the navigational route database begins and thrust compute routine begins, thereby making thrust with aircraft engine be decreased to satisfy required maximum allows sound exposure level (SEL).It can be variable that motor power reduces, and based on the value that constantly calculates.Destination 20 beginnings from quiet climb region, aircraft 10 continues flight until arriving thrust restoration/acceleration location or destination 22 on circuit 16.When setover 22, dB Completion of the Adventure and thrust compute routine finish, and when continuation was climbed with angle of climb α according to circuit 18, aircraft 10 returned to total power.

Sound monitor 24 also has been illustrated, and it rest on the ground and reduces between position 20 and the thrust restoration/acceleration location 22 to monitor the sound of experiencing on ground owing to aircraft flies in the sky between thrust usually.Typically, sound monitor 24 is positioned near the airport, and can be by governmental power mechanism (for example, air traffic control system) monitoring to guarantee meeting community's noise criteria from the aircraft of runway 12 departures from port.Aircraft departure procedure provided by the present invention has guaranteed that advantageously aircraft meets community's noise criteria with mode efficiently during departing from port.

Referring to Fig. 2 and 3, as substituting of storage and the fixing maximum SEL level that is associated of flight voyage, can be according to calculating the dB voyage along a plurality of sound monitoring point 25 of the circuit 26 that flies.In this embodiment, through between each point 27 of each sound monitoring point abeam direction, carrying out interpolation the SEL level that the line of flight with plan is associated is confirmed as the variable of edge flight circuit.Compared to the distance 29 of the aircraft above the course line, the maximum SEL at each the beam point place on the circuit is based on the distance 28 of the sound monitoring point from this aircraft to this beam point.

Referring to Fig. 4, show an embodiment of flight management system 30 prevailingly, this flight management system 30 utilizes aircraft departure procedure of the present invention and disposes, so that provide motor power to reduce to realize community's noise reduction effectively.In the embodiment shown, flight management system 30 comprises FMS onboard computer processor 32 and storer 34.Storer 34 comprises the navigational route database 36 of storage, and navigational route database 36 storages comprise the aircraft navigation information of dB voyage 37 information.DB voyage 37 comprises one or more sound exposure level limits of navigational waypoints and this voyage.Storer 34 also comprises the aircraft performance database 38 that comprises the aircraft customizing messages, and the aircraft customizing messages is included in the expectation sound exposure level in the SEL table 39.DB leg thrust cutback routine 100 and thrust compute routine 110 also are stored in the storer 34.Onboard computer processor 32 receives the various inputs of air themperature 56 of aircraft speed 54 and the sensing of the aircraft altitude 52 that comprises sensing, sensing from air-data computer 50.In addition, processor 32 receives input from navigation sensor 40, and said input is such as from the position coordinates of GPS (GPS) 42, from the inertial data of inertial sensor 44.In addition, processor 32 receives other input (such as amount of fuel 58) and the variable of conspicuous other sensing for a person skilled in the art from other sensor.

Further showing onboard computer processor 32 communicates with control and display unit (CDU) 60 with display 62.Should be realized that control and display unit 60 are the man-machine interfaces that allow the pilot to import data and receive output data.For example, the output data that provides the motor power that calculates of expression or thrust to reduce in the demonstration page or leaf that can on display 62, be appeared is come operate aircraft with the pilot who allows aircraft according to the output data that flight management system 30 is provided.

Further show flight management system 30 and have Mach/airspeed indicator 64, flying height trafficator 66 and EHSI 68.Symbol generator 78 is coupling between processor 32 and each indicator 66 and 68.Flight management system 30 also comprises the pattern control panel 70 that output is provided to robot pilot 72, and this robot pilot also communicates with processor 32.Robot pilot 72 can be used as the part of flight control system, and can under automatic driving mode, control wheel 74.

Further show flight management system 30 and comprise the throttle control 80 that is used to control engine throttle, this is conspicuous to those skilled in the art.Throttle control 80 can manually be driven by the pilot of aircraft under manual mode.Under automatic flight control pattern, throttle control 80 can automatically be controlled by the auto-throttle signal 82 that processor 32 provides.Should be realized that; Processor 32 can output command signal, to be used for through output command being provided through display 62 or reducing to be worth controlling aircraft through automatically control throttle or the throttle that throttle 80 utilizations according to the present invention are calculated through auto-throttle signal 82.

This illustrate and the flight management system of explaining 30 be to be configured to during aircraft departure procedure an embodiment who carries out the flight management system that aircraft thrust reduces.In this embodiment, in storer 34 storage thrust cutback routine 100, its thrust meter operator routine 110 that is associated, have the dB voyage and sound exposure level (SEL) table 36 of SEL restriction.Should be realized that the navigational route database 36 that store storer 34 and it can comprise the existing navigational route database in the existing flight management system, this existing flight management system is upgraded reduces departure procedure to carry out thrust.A kind of example of existing flight management system is disclosed in United States Patent(USP) No. 5121325.As a kind of upgrading, aircraft performance database 38 also can be added to existing FMS.Should be realized that,, can dispose other flight management system and carry out thrust and reduce according to instruction of the present invention.

DB leg thrust cutback routine 100 produces the variable thrust value that meets the SEL restriction continuously, and the SEL restriction is that the maximum of regulation is no more than noise level (one or more) requirement.Specify the dB voyage through the destination position, and the dB voyage that sound exposure level is distributed to whole voyage that is no more than of regulation, till next destination.When confirming that position of aircraft has passed through the navigational waypoints 20 of beginning dB voyage, thrust cutback routine 100 is calculated the thrust that receives noise limit, can utilize this thrust that this aircraft is remained in the maximum sound exposure level of that section navigation voyage.If in the time of between the mission phase thrust that is suitable for during said value drops on and takes off restriction and the minimum permission thrust, then use the thrust that this receives noise limit, this minimum permission thrust is designated as the minimum minimizing percentage that quota is decided thrust usually.In addition, when in the dB voyage, before using any minimizing, the flying height of this aircraft must be higher than preset height, according to an example, typically, this preset height be the airport of departing from port with reference to flying height on about 800 feet.

The dB leg thrust cutback routine 100 that is stored in the storer 34 and is carried out by processor 32 according to an embodiment has been shown in Fig. 5.Routine 100 is from step 102 beginning, and proceed in step 104, judge aircraft height whether less than 800 feet in the sky, airport.If this aircraft does not reach at least 800 feet height or flying height, then routine 100 is set to normal thrust to motor power in step 124, withdraws from step 126 then.For safety, being in predetermined altitude (like 800 feet of ground level tops) at aircraft does not carry out thrust before and reduces.In case this aircraft arrives at least 800 feet flying height; Whether routine 100 just determines the distance of starting position of dB voyage less than 0 in step 106; If be not less than 0, then proceed to step 108 with the distance that determines dB voyage terminal point whether greater than 0.Step 106 judges whether also not arrive the starting point of dB voyage, and step 108 judges whether to arrive the terminal point of dB voyage.If the position of this aircraft outside the dB voyage, then will not use thrust and reduce, and thrust is set to normal thrust in step 124, and utilize this thrust to carry out aircraft and climb.In this stage of flight, typically, speed is by in departure procedure, being controlled by the aircraft flaps setting of pitch control subsystem regulation.This is commonly called speed on elevator mode (speed on elevator mode), because the elevating rudder of aircraft is used to control pitching.

Be based on the dB voyage in flight in case confirm this aircraft, routine 100 just proceeds to step 110 calculating dB thrust, and this dB thrust is to cause thrust to reduce the thrust magnitude of effective realization of the sound exposure level limits of process defined.According to an embodiment, be stored in the calculating that one group of SEL table 39 in the aircraft performance database 38 is realized dB thrust through processing.An example of such SEL table 39 has been shown in Fig. 7.From aircraft/engine performance data storehouse 38, select to be applicable to the SEL table collection of given aircraft and engine model.The input of this table comprises thrust, above height and the true air speed (TAS) in ground, and their combination causes the sound exposure level that is produced (SEL) like regulation.As hereinafter shown in the subroutine shown in Figure 6 110 with as described in; In this application; Thrust cutback routine 100 is confirmed the required thrust of SEL level of defined, so that the incremental variations (being called thrust magnitude increment (Δ)) of application thrust is till the SEL that is calculated equals the SEL restriction.

Referring to Fig. 6, the dB thrust subroutine is from step 150 beginning, and proceeds to that thrust is set to equal normal thrust in step 152.Next, in step 154, thrust meter operator routine 110 SEL are set to equal the function based on thrust, height and true air speed (TAS).Suppose that SEL, height and TAS are known, then routine 110 can solve this thrust.Next, routine 110 is this SEL and SEL restriction relatively, if equate, then proceeds to step 160 and is set to equal this thrust with dB thrust before the end at step 166 place.If the difference between SEL and the SEL restriction is less than 0, then routine 110 proceeds to step 162 and is set to equal positive thrust increment (+Δ) with thrust, returns step 154 then.If SEL deducts the difference of SEL restriction greater than 0, routine 110 proceeds to step 164 and is set to equal negative thrust increment (Δ) with thrust so, returns step 154 then.

After the calculating of the dB thrust magnitude in subroutine 110; Routine 100 proceed to decision steps 112 with the dB thrust magnitude confirming to be calculated whether greater than normal thrust; And if greater than, proceeded to then before the withdrawing from of step 126 place that thrust is set to equal normal thrust in step 124.Therefore, if the dB thrust that is calculated greater than this normal thrust, is then used this normal thrust, because SEL will be lower than the SEL restriction.If the dB thrust that is calculated is less than normal thrust, then routine 100 proceeds to step 114 and calculates aircraft vertical speed (v/s) to utilize the dB thrust that is calculated.Then, whether routine 100 vertical speed in decision steps 116, confirming to be calculated is less than 1000 feet per minute clocks.If the aircraft vertical speed that is calculated is equal to or greater than 1000 feet per minute clocks, then routine 100 proceeded to before the withdrawing from of step 126 place in step 122 thrust and is set to equal the dB thrust that calculated.If the aircraft vertical speed that is calculated is less than 1000 feet per minute clocks; Then routine 100 target vertical speed in step 118 is set to equal 1000 feet per minute clocks, and thrust mode is set to equal throttle relevant speed (speed on throttle) in step 120 then.In this case, ignore the dB thrust that is calculated and control throttle, to keep minimum appointment aircraft vertical speed, specifying aircraft vertical speed in this embodiment is 1000 feet per minute clocks.Alternatively, can utilize minimum climb gradient (typically, 1.2%) to replace minimum aircraft vertical speed to come the lower limit of calculating aircraft thrust.Like this, when aircraft can not keep minimum climbing performance, will ignore the noise reduction restriction.

Therefore, when the dB thrust that is calculated during, use normal thrust, because this SEL can be lower than the SEL restriction greater than normal thrust.If the dB thrust that is calculated less than this normal thrust, as long as the gradient of climb that then obtains is higher than predetermined restricted (for example, 1000 feet per minute clocks), is just used this dB thrust.In both of these case, aircraft speed is controlled by speed on elevator mode.If dB thrust causes gradient of climb less than 1000 feet per minute clocks, then change pitch mode with the control vertical speed, and will cause SEL to be higher than the SEL restriction by the air speed of resulting Thrust Control.Will be appreciated that, depend on aircraft and condition, can change the regulation gradient of climb of 1000 feet per minute clocks.

Referring to Fig. 7, for example clear is an example of the expectation sound exposure level (SEL) of unit with decibel (dB) to the given aircraft engine under 160 nautical miles/hour specified vacuum speed.The SEL value is the function of true air speed, minor increment (highly) and thrust.In exemplary form illustrated select the example of minor increment during at 3000,4000,7000 and 9000 ft lbfs (lbf) in engine thrust value.For given engine, the thrust of 9000lbf possibly represented the total power motor power at the aircraft takeoff initial stage, and the thrust in the middle of wherein 7000lbf thrust possibly represented reduces level.Should be realized that the expectation SEL value that to confirm in table to be found according to the measurement of carrying out on the airport to the given aircraft engine.It should further be appreciated that the value that in table, is obtained can obtain through simulated flight device and estimation SEL value.To different aircraft speed, can produce other form, each form can be stored in the navigational route database of being stored and be used for calculating aircraft departure from port during thrust reduce.

The technology of sound exposure level at ground location place that is used to calculate the result of the aircraft operation that drives as near the jet-propelled and screw propeller the airport is known.At SAE aerospace information report SAEAIR 1845, be published in an example of the process that discloses near the airport noise the calculating airport in for " calculating near the process (Procedure for Calculation for Airport Noise in the Vicinity ofAirports) of the airport noise the airport " in March, 1986, title.Another part document that openly is used to calculate the process of airport noise was reported in January, 2002, title is Department of Transportation's report of " integrated noise model (INM) 6.0 platemaking technology handbooks (Integrated Noise Model (INM) Version 6.0 Technical Manual) ".Should be realized that these and other process is known and can be used for calculating near the airport noise the airport during the aircraft departure that it can be used to produce the sound exposure level that is stored in the navigational route database.

Should be realized that the illustrated thrust of this paper reduces method and flight management system advantageously provides the efficient departure from port of aircraft, and satisfy community's noise requirements simultaneously.Should be realized that for lightweight aircraft, this aircraft possibly have sufficiently high flying height in the starting point of dB voyage, possibly not need thrust to reduce like this to drop within the SEL restriction.Therefore, only in the time must satisfying the SEL restriction, just reduce thrust, thereby cause the more flight profile, mission profile of fuel-efficient.

The explanation of most preferred embodiment is only thought in top explanation.Those skilled in the art and those realizations or use people of the present invention will expect modification of the present invention.Therefore, should be appreciated that embodiment shown in the figure and that preceding text are illustrated only is used for illustration purpose, rather than be intended to limit scope of invention that scope of the present invention is to be explained and define according to the principle (comprising doctrine of equivalents) of Patent Law by accompanying claims.

Claims (7)

1. method that the variable thrust that during aircraft departure, produces aircraft reduces, said method comprises step:

The a plurality of tables of storage in storer, said a plurality of tables provide the regulation sound exposure level as the function of thrust, flying height and aircraft airspeed;

Storage is to the sound exposure level limits of navigation flight in storer;

Confirm the flying height of aircraft;

Confirm aircraft airspeed;

Calculate the engine thrust value that meets this sound exposure level limits according to said height, air speed and desired sound exposure level;

The engine thrust value that output is calculated is to be used for this aircraft of control during departing from port.

2. the method for claim 1 also comprises outputing to the step that display is checked for the pilot of this aircraft to the engine thrust value of being calculated.

3. the method for claim 1 also comprises outputing to the engine oil door controller to the engine thrust value of being calculated to be used to control engine throttle.

4. the method for claim 1 also comprises when this aircraft arrives navigation position and utilizes the motor power that is calculated to control the step of the engine of this aircraft.

5. the method for claim 1 also comprises and confirms the step of conduct along the sound exposure level limits of the variable of the line of flight.

6. method as claimed in claim 5, the step of wherein said definite sound exposure level limits are to realize through between the point of the abeam direction of a plurality of sound monitoring point, carrying out interpolation.

7. method that the variable thrust that during aircraft departure, produces aircraft reduces, said method comprises step:

The a plurality of tables of storage in storer, said a plurality of tables provide the regulation sound exposure level as the function of thrust, flying height and aircraft airspeed;

Storage is to the sound exposure level limits of navigation flight in storer;

Confirm the flying height of aircraft;

Confirm aircraft airspeed;

Through between the point of the abeam direction of a plurality of sound monitoring point, carrying out interpolation, confirm as sound exposure level limits along the variable of the line of flight;

Calculate the engine thrust value that meets this sound exposure level limits according to said height, air speed and desired sound exposure level;

The engine thrust value that output is calculated is to be used for this aircraft of control during departing from port; And

Utilize the motor power that is calculated to control the engine of this aircraft.

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