CN106873615A - Emergent landing speed instruction set design method of giving an encore - Google Patents

Abstract

The invention belongs to flight control technology, a kind of emergent landing speed instruction set design method of giving an encore is proposed, including：(1) quality is built, roll angle, airport is highly, highly, speed parameter grid, calculate the angle of attack that aircraft at the uniform velocity glides, elevator, lift-drag ratio, track angle, deflection ratio, it is determined that with quality, roll angle, airport is highly, the maximum lift-drag ratio speed of height change and empty sliding maximum available velocity, N+1 deciles are carried out to the velocity interval between maximum lift-drag ratio speed and empty sliding maximum available velocity, plus maximum lift-drag ratio speed and empty sliding maximum available velocity, build together vertical N+2 notch speeds degree instruction set, content per notch speed degree instruction set includes the corresponding angle of attack of notch speed degree, elevator, lift-drag ratio, track angle, deflection ratio；(3) aircraft records the N+2 notch speeds degree instruction set, when aircraft is emergent gives an encore, according to Aircraft Quality, airport height, height, speed and distance with airport, the suitable speed command collection gear execution of selection.

Description

Emergent landing speed instruction set design method of giving an encore

Technical field

The invention belongs to flight control technology, and in particular to a kind of aircraft is unpowered to give an encore landing certainly Main Guidance and control technology.

Background technology

When engine cut-off failure occurs in the air in aircraft, aeroplane performance degrades, and can only do down Sliding flight.To ensure flight safety, it is necessary to be controlled modification flight path to the speed of aircraft, Avoiding the occurrence of track excessively pull-up causes the situation of stall, while aircraft glide can also be adjusted Lift-drag ratio is as far as possible by aircraft landing on airfield runway.Document《Wheeled landing unmanned plane is met an urgent need Landing Control rule design》Give a kind of empty sliding refractory gold ores for returning to landing problems and solve way Footpath：1) glided using maximum lift-drag ratio speed in the transition flight stage and flown, maximized and fly Machine can flying distance, it is ensured that got off the plane in various uncertain and disturbing factors and still be able to have Arrive at the airport neighbouring ability；2) flying apart from long when aircraft, that is, arrive at the airport near When Shi Nengliang is too high, unnecessary energy is consumed by the way of drop of spiraling is high.Program physics is anticipated It is adopted clear and definite, it is simple to operate.But it is being applied to lack to three below problem when engineering is actual Consider：1) during the sliding return of sky, engine airstart is carried out, most to rise higher Hindering may be unable to reach the empty velocity conditions for rising of engine than gliding；If 2) using most rising higher Resistance specific rate glides, and flying speed should be less than normal in the range of it can rapidly spend, compared to other speed Speech, flying distance and time are all relatively long, and possible aircraft has not yet slided to airport battery just It is depleted, still cannot safe landing.3) condition of engine flame-out in flight does not know, For identical height but the different Parking situation of distance, energy state, practical flight is apart from but phase Very few, the gliding speed strategy underaction of difference.

The content of the invention

The purpose of the present invention is：The present invention proposes a kind of emergent landing speed instruction set design of giving an encore Method, can provide more flexible changeable instruction selection scheme for the sliding Guidance Law of sky, improve empty sliding Feasibility of the time less than battery pot life.

The technical scheme is that：The emergent landing speed instruction set design method of giving an encore of one kind, Including：

(1) quality, roll angle, airport height, height, speed parameter grid, meter are built The angle of attack, elevator, lift-drag ratio, track angle, deflection ratio that aircraft at the uniform velocity glides are calculated, it is determined that with Quality, roll angle, airport height, the maximum lift-drag ratio speed of height change and empty sliding maximum can With speed, the velocity interval between maximum lift-drag ratio speed and empty sliding maximum available velocity is carried out N+1 deciles, add maximum lift-drag ratio speed and empty sliding maximum available velocity, build together vertical N+2 grades Speed command collection, the content per notch speed degree instruction set includes the corresponding angle of attack of notch speed degree, the lifting Rudder, lift-drag ratio, track angle, deflection ratio；

(3) aircraft records the N+2 notch speeds degree instruction set, when aircraft is emergent gives an encore, root According to Aircraft Quality, airport height, height, speed and distance with airport, what selection was adapted to Speed command collection gear is performed.

Include between step (1) and step (3)：

(2) closed with the height needed for engine over-the-air rekey and empty sliding landing is corresponding with speed System's amendment N+2 notch speed degree instruction set, and update the content per notch speed degree instruction set, including the shelves The corresponding angle of attack of speed, elevator, lift-drag ratio, track angle, deflection ratio.

Step (1) includes：

(11) in Aircraft Quality m, airport height gnd, roll angle φ, height H, speed V In the range of alterable, build and calculate grid；

(12) grid each point is being calculated, aircraft is being carried out at the uniform velocity using the trim condition with roll angle The calculating of gliding ability：

Wherein：W=mg is the gravity of aircraft, and g is acceleration of gravity；L, D are the lift of aircraft And resistance, M_yIt is the pitching moment of aircraft, is with angle of attack, elevator δ_e, height H and The aerodynamic parameter of speed V changes.θ is the angle of pitch of aircraft；

Equation group method of value solving is used, angle of attack, the elevator δ of trim condition is met_e, Pitching angle theta；Lift L and resistance D is solved according to aerodynamic coefficient method；

Calculate lift-drag ratio K_L/D：

K_L/D=L/D

Calculate track angle γ：

γ=θ-α

Calculate deflection ratio V_s：

V_s=Vsin γ

(13) under the conditions of by given quality, roll angle, height, airport height, most rise higher resistance Specific rate as the farthest speed of flight path, max calculation speed as the nearest speed of flight path, to two Interval N+1 deciles between speed, according to the farthest speed of flight path, 1 ... N at equal intervals speed, The nearest speed order's arrangement of flight path, obtains the N+2 speed command set of gear, per notch speed degree The content of instruction set include the corresponding angle of attack of notch speed degree, elevator, lift-drag ratio, track angle, Deflection ratio.

Step (2) includes：

(21) empty window of engine and sky are slided into nearly window considerations, is characterized as corresponding height The speed command of layer, correspondence replaces original speed command；

(22) the smooth place of linear interpolation is carried out to new speed command and the joining place of former speed command Reason, interpolation section shortest length is calculated according to average deflection ratio；

(23) height layer after empty window of engine, the speed command of each gear is selected With the speed command of most intervening gears；

(24) aircraft is more than the speed command updated at 300m with the relative altitude on airport, its The corresponding angle of attack, elevator, lift-drag ratio, track angle, deflection ratio are by parametric grid result of calculation Interpolation is obtained；Aircraft and the speed command of the relative altitude less than renewal at 300m on airport, need The empty sliding angle of attack under gear down state of supplement calculation, elevator, lift-drag ratio, track angle, Deflection ratio.

Step (3) includes：

(31) roll angle φ can be used according to aircraft present speed V and maximum_max, estimation aircraft tune Ultimate run needed for turning direction

According to airport height gnd, height H and with airport apart from Dis, aircraft is calculated empty Average lift-drag ratio K needed for sliding return_need

(32) speed command table is looked into, Aircraft Quality m, airport height gnd, roll angle is obtained φ_maxUnder the conditions of N+2 grades of speed command.I-th speed command of gear is solved from airport Average value of the height to the lift-drag ratio in the range of aircraft altitudeWherein i=1,2 ..., N+2；

(33) if there is i so thatThen selection makesMinimum First gear speed is instructed, for the sliding Trajectory Design for returning of sky and guidance decision-making.Otherwise, current shape State possibly cannot be returned safely, and being used for empty cunning from the 1st grade of maximum speed command of lift-drag ratio returns The Trajectory Design returned and guidance decision-making, play gliding ability as far as possible.

It is an advantage of the invention that：The present invention gives one kind based on the unpowered gliding ability of aircraft and The method that engine restarts condition design sky slip velocity degree instruction set in the air, is that the empty cunning of aircraft is given an encore The Project Realization in land provides more excellent instruction design approach.Resulting multi gear bit instruction collection, Can not only support that engine sky is opened, and identical is restarted rear speed command design and makes flight shape State can converge on desired landing state, while the stepping speed command design at the initial stage of parking makes Guidance Law can be realized being adjusted flexibly to that can fly distance and flight time by on-line scheduling.Compare Maximum lift-drag ratio flies, and multi gear bit rate instruction set can realize more downslide flight paths, in height Under the empty closely primary condition of low energy, the flight time more than 20% can be saved.

Brief description of the drawings

Fig. 1 be certain type when given quality, roll angle are zero, under different height trim rise resistance Than the distribution map with speed.

Fig. 2 be certain type under given quality and airport height, 11 grades of speed commands design knot Fruit is schemed.

Specific embodiment

The present invention is described in further details below.

The emergent landing speed instruction set design method of giving an encore of one kind, including：

(1) quality, roll angle, airport height, height, speed parameter grid, meter are built The angle of attack, elevator, lift-drag ratio, track angle, deflection ratio that aircraft at the uniform velocity glides are calculated, it is determined that with Quality, roll angle, airport height, the maximum lift-drag ratio speed of height change and empty sliding maximum can With speed, the velocity interval between maximum lift-drag ratio speed and empty sliding maximum available velocity is carried out N+1 deciles, add maximum lift-drag ratio speed and empty sliding maximum available velocity, build together vertical N+2 grades Speed command collection, the content per notch speed degree instruction set includes the corresponding angle of attack of notch speed degree, the lifting Rudder, lift-drag ratio, track angle, deflection ratio；

(3) aircraft records the N+2 notch speeds degree instruction set, when aircraft is emergent gives an encore, root According to Aircraft Quality, airport height, height, speed and distance with airport, what selection was adapted to Speed command collection gear is performed.

Include between step (1) and step (3)：

(2) closed with the height needed for engine over-the-air rekey and empty sliding landing is corresponding with speed System's amendment N+2 notch speed degree instruction set, and update the content per notch speed degree instruction set, including the shelves The corresponding angle of attack of speed, elevator, lift-drag ratio, track angle, deflection ratio.

Step (1) includes：

(11) in Aircraft Quality m, airport height gnd, roll angle φ, height H, speed V In the range of alterable, build and calculate grid；

(12) grid each point is being calculated, aircraft is being carried out at the uniform velocity using the trim condition with roll angle The calculating of gliding ability：

Wherein：W=mg is the gravity of aircraft, and g is acceleration of gravity；L, D are the lift of aircraft And resistance, M_yIt is the pitching moment of aircraft, is with angle of attack, elevator δ_e, height H and The aerodynamic parameter of speed V changes.θ is the angle of pitch of aircraft；

Equation group method of value solving is used, angle of attack, the elevator δ of trim condition is met_e, Pitching angle theta；Lift L and resistance D is solved according to aerodynamic coefficient method；

Calculate lift-drag ratio K_L/D：

K_L/D=L/D

Calculate track angle γ：

γ=θ-α

Calculate deflection ratio V_s：

V_s=Vsin γ

(13) under the conditions of by given quality, roll angle, height, airport height, most rise higher resistance Specific rate as the farthest speed of flight path, max calculation speed as the nearest speed of flight path, to two Interval N+1 deciles between speed, according to the farthest speed of flight path, 1 ... N at equal intervals speed, The nearest speed order's arrangement of flight path, obtains the N+2 speed command set of gear, per notch speed degree The content of instruction set include the corresponding angle of attack of notch speed degree, elevator, lift-drag ratio, track angle, Deflection ratio.

Step (2) includes：

(21) empty window of engine and sky are slided into nearly window considerations, is characterized as corresponding height The speed command of layer, correspondence replaces original speed command；

(22) the smooth place of linear interpolation is carried out to new speed command and the joining place of former speed command Reason, interpolation section shortest length is calculated according to average deflection ratio；

(23) height layer after empty window of engine, the speed command of each gear is selected With the speed command of most intervening gears；

(24) aircraft is more than the speed command updated at 300m with the relative altitude on airport, its The corresponding angle of attack, elevator, lift-drag ratio, track angle, deflection ratio are by parametric grid result of calculation Interpolation is obtained；Aircraft and the speed command of the relative altitude less than renewal at 300m on airport, need The empty sliding angle of attack under gear down state of supplement calculation, elevator, lift-drag ratio, track angle, Deflection ratio.

Step (3) includes：

(31) roll angle φ can be used according to aircraft present speed V and maximum_max, estimation aircraft tune Ultimate run needed for turning direction

According to airport height gnd, height H and with airport apart from Dis, aircraft is calculated empty Average lift-drag ratio K needed for sliding return_need

(32) speed command table is looked into, Aircraft Quality m, airport height gnd, roll angle is obtained φ_maxUnder the conditions of N+2 grades of speed command.I-th speed command of gear is solved from airport Average value of the height to the lift-drag ratio in the range of aircraft altitudeWherein i=1,2 ..., N+2；

(33) if there is i so thatThen selection makesMinimum First gear speed is instructed, for the sliding Trajectory Design for returning of sky and guidance decision-making.Otherwise, current shape State possibly cannot be returned safely, and being used for empty cunning from the 1st grade of maximum speed command of lift-drag ratio returns The Trajectory Design returned and guidance decision-making, play gliding ability as far as possible.

Embodiment

By taking certain type as an example, the condition such as Aircraft Quality and airport height 1500m is given, give hair Motivation restarts window for height layer 3-6km sentences speed 450km/h flights, provides design multi gear The key step and result of speed command collection：

The first step：Generation parameter grid, calculating empty slip can simultaneously design multi gear speed command, portion Subnetting lattice point lift-drag ratio is as shown in Figure 1 with velocity distribution curve.

1) with 100m as vertical separation, formed from airport height to the height maximum height The sequence of calculation；Take 0:10:30 roll angle sequence；Inquiry current Quality is corresponding to fly Row envelope, the velocity interval of computed altitude sequence each point simultaneously carries out 50 deciles, obtains Roll angle-height-speed parameter grid；In each point of parametric grid, calculate even The angle of attack of fast downslide trim, the angle of pitch, elevator, lift-drag ratio and deflection ratio.

2) roll angle and high degree of sequence are combined, obtains roll angle-height grid；Roll angle- At each point of height grid, the maximum point of search trim lift-drag ratio, as flight path most Remote speed, using maximal rate point as the nearest speed of flight path；By the farthest speed of flight path and The decile of speed interval 10 that the nearest speed of flight path is constituted, according to the farthest speed of flight path, 1 ... 9 grade of nearest speed tandem arrangement of speed, flight path at equal intervals, will search it 11 points afterwards are arranged, and have just obtained the speed command of 11 gears；1…9 Level trim track angle at equal intervals corresponding to speed, lift-drag ratio and elevator are by performance meter Result interpolation is calculated to obtain.

Second step：Regenerated point according to engine restarting window considerations, landing window considerations etc. Shelves instruction set, speed command design result is as shown in Figure 2：

1) it is empty to play preceding inflight phase (more than 7km inflight phases)：Directly using the instruction of multi gear bit rate Design result.

2) engine is empty plays section (2-7km height section)：Window considerations are played according to engine is empty, Speed command is designed as 450km/h in 3-6km height layers, is calculated by average deflection ratio, Two 1000m transition levels are set at 2-3km and 6-7km, by linear interpolation by speed Degree instruction is seamlessly transitted.

3) engine is empty plays inflight phase after failure：Empty section end of the example engine is relatively high Degree has reached 500m, has arrived near approach aperture, therefore cancels empty failure of engine Inflight phase afterwards.

4) nearly navigation section (1515-2000m) is entered：From landing speed 240km/h, flight Can the corresponding gear down state of parameter.

Claims (5)

1. a kind of emergent landing speed instruction set design method of giving an encore, it is characterised in that including：

(1) quality, roll angle, airport height, height, speed parameter grid, meter are built The angle of attack, elevator, lift-drag ratio, track angle, deflection ratio that aircraft at the uniform velocity glides are calculated, it is determined that with Quality, roll angle, airport height, the maximum lift-drag ratio speed of height change and empty sliding maximum can With speed, the velocity interval between maximum lift-drag ratio speed and empty sliding maximum available velocity is carried out N+1 deciles, add maximum lift-drag ratio speed and empty sliding maximum available velocity, build together vertical N+2 grades Speed command collection, the content per notch speed degree instruction set includes the corresponding angle of attack of notch speed degree, the lifting Rudder, lift-drag ratio, track angle, deflection ratio；

(3) aircraft records the N+2 notch speeds degree instruction set, when aircraft is emergent gives an encore, root According to Aircraft Quality, airport height, height, speed and distance with airport, what selection was adapted to Speed command collection gear is performed.

2. as claimed in claim 1 a kind of emergent landing speed instruction set design method of giving an encore, Characterized in that, including between step (1) and step (3)：

(2) closed with the height needed for engine over-the-air rekey and empty sliding landing is corresponding with speed System's amendment N+2 notch speed degree instruction set, and update the content per notch speed degree instruction set, including the shelves The corresponding angle of attack of speed, elevator, lift-drag ratio, track angle, deflection ratio.

3. as claimed in claim 1 a kind of emergent landing speed instruction set design method of giving an encore, Characterized in that, step (1) includes：

(11) in Aircraft Quality m, airport height gnd, roll angle φ, height H, speed V In the range of alterable, build and calculate grid；

(12) grid each point is being calculated, aircraft is being carried out at the uniform velocity using the trim condition with roll angle The calculating of gliding ability：

$\left.\begin{array}{c}L-W(\sin \mathrm{\α}\sin \mathrm{\θ}+\cos \mathrm{\α}\cos \mathrm{\θ}\cos \mathrm{\φ})-\frac{{\mathrm{Wsin}}^2{\mathrm{\φcos}}^2\mathrm{\θ}}{(\sin \mathrm{\α}\sin \mathrm{\θ}+\cos \mathrm{\α}\cos \mathrm{\θ}\cos \mathrm{\φ})}=0\\ -D+W(-\cos \mathrm{\α}\sin \mathrm{\θ}+\sin \mathrm{\α}\cos \mathrm{\θ}\cos \mathrm{\φ})=0\\ M_y=0\end{array}\right\}$

Wherein：W=mg is the gravity of aircraft, and g is acceleration of gravity；L, D are the lift of aircraft And resistance, M_yIt is the pitching moment of aircraft, is with angle of attack, elevator δ_e, height H and The aerodynamic parameter of speed V changes.θ is the angle of pitch of aircraft；

Equation group method of value solving is used, angle of attack, the elevator δ of trim condition is met_e, Pitching angle theta；Lift L and resistance D is solved according to aerodynamic coefficient method；

Calculate lift-drag ratio K_L/D：

K_L/D=L/D

Calculate track angle γ：

γ=θ-α

Calculate deflection ratio V_s：

V_s=Vsin γ

(13) under the conditions of by given quality, roll angle, height, airport height, most rise higher resistance Specific rate as the farthest speed of flight path, max calculation speed as the nearest speed of flight path, to two Interval N+1 deciles between speed, according to the farthest speed of flight path, 1 ... N at equal intervals speed, The nearest speed order's arrangement of flight path, obtains the N+2 speed command set of gear, per notch speed degree The content of instruction set include the corresponding angle of attack of notch speed degree, elevator, lift-drag ratio, track angle, Deflection ratio.

4. as claimed in claim 2 a kind of emergent landing speed instruction set design method of giving an encore, Characterized in that, step (2) includes：

(21) empty window of engine and sky are slided into nearly window considerations, is characterized as corresponding height The speed command of layer, correspondence replaces original speed command；

(22) the smooth place of linear interpolation is carried out to new speed command and the joining place of former speed command Reason, interpolation section shortest length is calculated according to average deflection ratio；

(23) height layer after empty window of engine, the speed command of each gear is selected With the speed command of most intervening gears；

(24) aircraft is more than the speed command updated at 300m with the relative altitude on airport, its The corresponding angle of attack, elevator, lift-drag ratio, track angle, deflection ratio are by parametric grid result of calculation Interpolation is obtained；Aircraft and the speed command of the relative altitude less than renewal at 300m on airport, need The empty sliding angle of attack under gear down state of supplement calculation, elevator, lift-drag ratio, track angle, Deflection ratio.

5. as claimed in claim 1 a kind of emergent landing speed instruction set design method of giving an encore, Characterized in that, step (3) includes：

(31) roll angle φ can be used according to aircraft present speed V and maximum_max, estimation aircraft tune Ultimate run needed for turning direction

$Cir=\frac{2{\mathrm{\πV}}^2}{g{\mathrm{tan\φ}}_{max}}$

According to airport height gnd, height H and with airport apart from Dis, aircraft is calculated empty Average lift-drag ratio K needed for sliding return_need

$K_{need}=\frac{Dis+Cir}{H-gnd}$

(32) speed command table is looked into, Aircraft Quality m, airport height gnd, roll angle is obtained φ_maxUnder the conditions of N+2 grades of speed command.I-th speed command of gear is solved from airport Average value of the height to the lift-drag ratio in the range of aircraft altitudeWherein i=1,2 ..., N+2；

(33) if there is i so thatThen selection makesMinimum First gear speed is instructed, for the sliding Trajectory Design for returning of sky and guidance decision-making.Otherwise, current shape State possibly cannot be returned safely, and being used for empty cunning from the 1st grade of maximum speed command of lift-drag ratio returns The Trajectory Design returned and guidance decision-making, play gliding ability as far as possible.