JPH07115674B2 - Automatic flight control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic flight control system for automating a guided flight to a target flight point (FTP) in an aircraft (helicopter) and reducing the load on a pilot.
(AFCS).

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 11, an automatic flight control system for a helicopter has been used to manually fly to a target flight point based on the direction, distance and information from the navigation device to the target flight point by the pilot's operation. It is common to do.

[0003]

The conventional automatic flight control system is mainly based on manual pilot operation.
It has the following problems.

(A) The pilot has a large operational load.

(A) The accuracy of reaching the target flight point (FTP) and the time required to reach it greatly depend on the skill of the pilot.

The present invention has been made in view of the above circumstances, and the guidance flight to the target flight point is fully automated to significantly reduce the pilot's operational load and to achieve the target flight point.
It is an object of the present invention to provide an automatic flight control system that makes the accuracy of reaching (FTP) good on average and that enables flight in the shortest required travel time.

[0007]

SUMMARY OF THE INVENTION The present invention provides flight information for automatically flying following a predetermined course to a target flight point.
In helicopter flight control system having the navigation function of calculating the helicopter on the basis of the flight information handed after the automatic flight mode is Engage to the target flight point
The helicopter rotates when it determines whether or not it is in the turning position.
When it is determined that the vehicle is in the turning position, the direction to the next turning position is set.
Deviation between the bearing to the target flight point and the bearing of the helicopter
Amount and the amount of deviation between the above specified course and the actual flight course
Generate a helicopter bank angle control command based on
Means, the control command, roll rate, and roll
Roll system control subsystem consisting of means for driving roll servo based on posture , lateral acceleration, roll level
Command to generate zero lateral acceleration based on
A yaw system control subsystem for driving the over-servo pairs
Automatic flight based on air velocity, pitch rate, and pitch attitude
A command to maintain the airspeed when the mode is engaged.
Pitch system control that generates mands and drives pitch servo
It is characterized by comprising a control subsystem.

[0008]

The automatic flight control system according to the present invention performs flight control by the following four steps.

(1) Step 1 a. The roll system control subsystem uses the flight information to the target flight point FTP input from the navigation function of the aircraft and the size of the deviation between the flight direction and the heading of the aircraft (hereinafter referred to as the drift angle). When the approach course to the target flight point FTP is specified ( specified by the pilot) ,
A command to set the target roll attitude required to turn at a predetermined turn rate toward the predetermined flight course to the turn-in point set by the navigation function, and to make the roll attitude of the aircraft follow the target roll attitude. Is derived and output to the roll servo. Further, when the approach course to the target flight point FTP is not designated, instead of the predetermined flight course to the above turn-in point, the flight to the target flight point FTP is performed.
The same command is output to the roll servo for another predetermined flight course. Here, the navigation function is the body position.
The above flight course is set based on the position and target flight point FTP
Data required to guide the aircraft to the target flight point FTP
(See FIG. 6).

B. The yaw system control subsystem is engaged in the auto turn coordination mode and outputs a command for zeroing the lateral acceleration to the yaw servo.

C. The pitch system control subsystem sets the airspeed when the enroute nab mode is engaged as the target airspeed and derives a command to make the airspeed of the aircraft follow the target airspeed. Output to servo.

D. The mode control subsystem, based on the flight information input from the navigation function method of the aircraft,
The mode switching of the roll system control subsystem is controlled by determining whether the approach course to the target flight point FTP is designated or not designated.

(2) Step 2 The roll system control subsystem returns the roll posture of the machine body to the horizontal position as it approaches the predetermined flight course after the turning, and controls the roll posture so as not to be separated from the predetermined flight course.

The yaw system control subsystem outputs a command to the yaw servo to enable a balanced turn toward a predetermined flight course.

The pitch system control subsystem outputs a command for maintaining the airspeed to the pitch servo.

The mode control subsystem uses the target flight point F
When the approach course to TP is designated, the turning start anticipation distance for determining the transition to step 3 is derived from the airspeed and the anticipatory turning time constant, and is output to the roll system control subsystem. When the approach course to the target flight point FTP is not designated, the FTP on top is determined.

(3) Step 3 When the approach course to the target flight point FTP is designated, the roll system control subsystem turns at a predetermined turn rate toward a predetermined flight course to the target flight point FTP. The target roll attitude necessary for the above is set, and a command for causing the roll attitude of the machine body to follow the target roll attitude is derived and output to the roll servo.

The yaw system control subsystem outputs a command to the yaw servo to enable a balanced turn toward a predetermined flight course.

The pitch system control subsystem outputs a command for maintaining the airspeed to the pitch servo.

(4) Step 4 When the approach course to the target flight point FTP is designated, the roll system control subsystem makes the roll attitude of the aircraft horizontal as the predetermined flight course to the target flight point FTP is approached. Roll back and control the roll attitude so as not to leave the predetermined flight course.

The yaw system control subsystem outputs a command to the yaw servo for enabling a balanced turn toward a predetermined flight course.

The pitch system control subsystem outputs a command for maintaining the airspeed to the pitch servo.

The mode control subsystem makes an FTP-on-top determination based on the flight information input from the navigation function.

As described above, the aircraft (helicopter) is automatically guided to the target flight point FTP from arbitrary flight conditions under the control of steps 1 to 4.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The automatic helicopter flight control system to the target flight point FTP according to the present invention takes the flight route shown in FIG. The control is executed to automatically guide the aircraft to the target flight point FTP.

When the approach course to the target flight point FTP is not designated, the flight route shown in FIG. 2 is taken and the control of steps 1 and 2 is executed to set the aircraft to the target flight point FTP.
To automatically fly to.

Details of steps 1 to 4 will be described later.

The control system for executing the above flight control is composed of the following subsystems (1) to (4).

(1) A mode control subsystem for switching the mode of automatic flight according to the flight situation.

(2) A roll system control subsystem that outputs a command for controlling the roll attitude to the roll servo so that the aircraft is put on a predetermined flight course.

(3) A yaw system control subsystem that outputs a command for controlling sideslip to the yaw servo so that the roll system control subsystem functions effectively.

(4) A pitch system control subsystem for outputting a command for controlling the flight speed to the pitch servo.

Each of the above subsystems is constructed as shown in FIGS.

FIG. 3 is a block diagram showing the structure of the on / top determination / turning start determination unit in the mode control subsystem. Turn from the navigation function
The in-point-on-top determination signal is input to the set terminal S of the flip-flop circuit 2 via the -1 signal rise determination circuit 1. This flip-flop circuit 2
Q output signal is taken out as a turn-in-point-on-top signal A15.

When the approach course to the target flight point FTP is designated, the turning start anticipation distance generator 3 uses the airspeed UA and the anticipatory turning time constant Cp14 to generate the turning start anticipation distance STEN. , And to the on / off determination circuit 5 via the minus terminal of the subtractor 4. The output signal of the ON / OFF determination circuit 5 is input to the set terminal S of the flip-flop circuit 7 via the OR circuit 6 together with the output signal of the flip-flop circuit 2. The Q output signal of the flip-flop circuit 7 is output to the roll system control subsystem shown in FIG. 4 as the turn-in start flag A16.

The turn-in point distance from the navigation function is input to the + terminal of the subtracter 4 and also to the -1 signal rise determination circuit 9 via the on / off determination circuit 8. The flip-flop circuits 2 and 7 are reset by the output signal of the -1 signal rise determination circuit 9.

Further, the FTP on-top determination signal from the navigation function is input to the reset terminal R of the flip-flop circuit 11, and the -1 signal rise determination circuit 12 is supplied.
Is input to the set terminal S of the flip-flop circuit 11 via. The output signal of the flip-flop circuit 11 is output as the FTP on-top signal A17.

FIGS. 4 to 8 show flight information from the configuration and navigation function of each part of the roll control subsystem. FIG. 4 is a lateral guidance control law, FIG. 5 is a drift angle calculation processing part, and FIG. Flight information from the navigation function, FIG. 7 is a nose heading deviation correction processing unit, and FIG. 8 is a roll autopilot control law.

In the lateral guidance control law shown in FIG. 4, the heading ψ of the aircraft is input to the + terminal of the subtractor 21. on the other hand,
Approach course to the target flight point FTP from the navigation function ψ FT
P and turn-in-point TIP approach course direction
ψ TIP is selected by the changeover switch 22 operated by the turn-in start flag A16 from the mode control subsystem shown in FIG. 3, and is input to one terminal of the subtracter 21. Various flight information from the navigation function is shown in FIG.

In FIG. 6, RTIP: distance to turn-in point TIP, RFTP: distance to target flight point FTP, θDTIP: turn-in point course deviation, θDFTP: FTP course deviation, ψ TIP : Orientation course orientation to turn-in point TIP, ψ FTP: Entry course orientation to target flight point FTP. Deviation is based on the set course, and each angle is positive in the clockwise direction from the reference axis. In the example in the figure, θ
Both DTIP and θDFTP are negative, ψ FTP is positive, ψ TIP
Is negative.

Then, in FIG. 4, the output signal ψ e of the subtractor 21 is input to the adder 23. Further, the drift angle A20 from the drift angle calculation processing section 20 shown in FIG. 5 is input to the adder 23 via the switch 24. The drift angle calculation processing unit 20 illustrated in FIG. 5 is “arctan (VB / UB)” based on the vertical ground speed UB and the horizontal ground speed VB.
The drift angle A20 is obtained by performing the calculation processing of.

In FIG. 4, the output signal of the adder 23 is limited to ψ eL by the limiter 25, and is further corrected by the heading deviation correction processing unit 26. The signal ψ eT corrected by the nose heading deviation correction processing unit 26 is input to the adder 28 via a gain (gain heading gain scheduler for the own heading) 27. The heading deviation correction processing unit 26 is configured as shown in FIG. 7, and details thereof will be described later.

The course deviation θDFTP from the navigation function to the target flight point FTP is input to the gain scheduler 29. Also, the distance R to the target flight point FTP
The FTP is input to the multiplier 30a, the airspeed is input to the multiplier 30a via the speed ratio calculation circuit 31 and the gain switching point speed adjustment circuit 32, and the multiplication result is sent to the gain scheduler 29. Further, the speed adjusting circuit 3
The output of 2 is input to gain scheduler 34 via multiplier 30b with the distance RTIP to the turn-in point. Further, the course deviation θDTIP to the turn-in point TIP is input to the gain scheduler 34.

The output signals of the gain schedulers 29, 34 are selected by the change-over switch 33 operated by the turn-in start flag A16, and the gain (coarse deviation proportional gain) 36, 3 via the limiter 35.
Input to 7. The output signal of the gain 36 is the switch 3
It is input to the fade-in / out circuit 39 via 8. Then, the gain 36 and the fade-in / out circuit 3
The output signals of 9 are added by the adder 40, and then input to the bank angle limiter 41 via the adder 28. The air speed UA is input to the bank angle limiter 41 as a bank angle limit value A47 via a rate limiter 42, a gain 43, a function unit 44 of tan ⁻¹ , and a limiter 45. The output signal of the bank angle limiter 41 is output as a reference roll angle shift command A48 via the rate limiter 46.

Thus, the heading deviation correction processing unit 2
6 is a selector switch 51, 5 as shown in FIG.
2, 53. Changeover switch 51, 52
Is provided with switching contacts a, b, and c, the contact a has a left turn command constant 54 (BR31), the contact b has a heading ψ eL from the limiter 25, and the contact c has a right turn command constant 55 (−).
BR31) is input. In the changeover switch 51, the contact a is closed when the left turn command A56 (turn-in point) ON is given, and the contact c is closed when the right turn command A57 (turn-in point) ON is given. Otherwise, the contact b is closed. The changeover switch 5
The signal extracted via 1 is input to the contact a of the changeover switch 53.

On the other hand, in the changeover switch 52, the contact a is closed when the left turn command A58 (FTP) ON is given, the contact c is closed when the right turn command A59 (FTP) ON is given, and other than that. The contact b is closed. The signal extracted via the changeover switch 52 is input to the contact b of the changeover switch 53. This changeover switch 53
Is a contact b when the turn-in start flag A16 is ON.
Is closed, and the contact a is closed otherwise. Then, the signal extracted via the changeover switch 53 becomes the corrected heading ψ eT. The above left turn command and right turn command are used only when the absolute value of the turning angle θ required to get on the turn-in point course or the FTP course is 90 ° or more as shown in FIG. 7 (b). Input from the function.

FIG. 8 shows a roll auto pilot control law in the roll system control subsystem.
As shown in the figure, the roll attitude φ is input to the + terminal of the subtractor 61, the reference roll angle shift command A48 sent from FIG. 4 is input to the − terminal, and the subtraction result is added via the gain 62. Input to the container 63. In addition, the roll rate P is gained (proportional gain) to the adder 63.
64 and 65, and the addition output is the adder 6
6 is input. The output of the subtractor 61 is input to the adder 66 via the gain 67 and the integrator 68. The output of the adder 66 is sent to the roll trim servo as a roll trim shift command A69.

FIG. 9 shows the configuration of the yaw system control servo system. The lateral acceleration Nr is input to the adder 73 via the gain 71 and the integrator 72. Further, the lateral acceleration Nr and the roll rate P are gains 74 and 7, respectively.
It is input to the adder 76 via 5, and the addition output is input to the adder 73. Then, the output signal of the adder 73 is sent to the yaw trim servo as a yaw trim shift command A77.

FIG. 10 shows the configuration of the pitch system control subsystem. The pitch rate q is input to the adder 82 via the gain 81. The pitch attitude angle θ is input to the + terminal of the subtractor 83, and the changeover switch 8
4 is input to the terminal a. The changeover switch 84 has a common contact connected to the-terminal of the subtractor 83, and also connected to its own terminal b via a memory 85 for storing the previous value of the cycle calculation process. In the changeover switch 84, the contact a is closed at the time of cyclic trim release, and the contact b is closed at other times. Then, the output of the subtractor 83 is input to the adder 82 via the gain 86.

On the other hand, the airspeed UA is input to the + terminal of the subtractor 87 and the terminal a of the changeover switch 88. The changeover switch 88 has a common contact connected to the minus terminal of the subtractor 87, and is also connected to its own terminal b via a memory 89 for storing the previous value of the cycle calculation process. In the changeover switch 88, the contact a is closed at the time of cyclic trim release, and the contact b is closed at other times. Then, the output of the subtractor 87 is input to the adder 82 via the gain 90.

The output of the subtractor 87 is input to the integrator 92 via the gain 91. This integrator 92 is reset by cyclic trim release.
The output of the integrator 92 is the output of the adder 82 and the adder 9
3 is added, and the added output is sent to the pitch trim servo as a pitch trim shift command A95.

Next, the operation of the system of the present invention for carrying out the automatic guided flight shown in FIG. 1 will be described.

(1) Step 1 In Step 1, as shown in FIG. 1, the automatic flight mode (hereinafter referred to as enroute nab mode) to the target flight point FTP is engaged, and turning is started (= initial position of the aircraft).
Start to move to the turn-in point TIP
Up to the phase.

Enroute nab mode is engaged
After it is installed, the airframe will be
Near the turning start position on the course set by the navigation function
When it is determined that the
In-point judgment signal is output and flip-flop
Circuit 2 goes into the set state and turns in
A top signal is generated. And this signal
The flip-flop circuit 7 is set via the circuit 6
And the turn-in start flag is turned on and the aircraft makes a turning motion.
To start.

When the turn-in start flag is turned on,
The switch 22 of the lateral guidance control law shown in FIG.
Switch 33 is connected to gain scheduler 34 and
Nose direction ψ and approach to turn-in point TIP
Control to make the deviation from the course azimuth ψTIP close to zero
Control amount is calculated (subtractor 21 to gain 2
7), the flight course set by the navigation function and the position sensor of the aircraft
Zero deviation from the actual flight course required by the service
The control amount for approaching is calculated (gain schedule
The loader 34 to the adder 40). These control amounts are added by the adder 28.
Standard roll angle shift that is added and required for the desired turn
The command is generated. This command is
Input to the auto-pilot control law,
The body flies on the set turning course. In addition, roll
The rate and roll attitude are detected by the airframe sensor.
There is something.

It should be noted that the drift angle is the turn between ψ and
In-point TIP approach course orientation with ψTIP
When the deviation ψe becomes smaller than the predetermined value, that is,
When the turning movement approaches the end, it is added to the deviation,
It enables delicate direction control of the aircraft. Also,
With the heading deviation correction processing shown in FIG. 7, the turning angle is 90 degrees.
If there is more than °, instead of heading ψeL ψeT (> ψ
eL) is output, and the heading of the aircraft is turning in quickly.
・ Tip to the point TIP, heading toward ψTIP
Growling. In addition, the gain scheduler 34 is
The deviation between the designated flight course and the actual flight course is the same
But if the turn-in point distance is large (small)
, Its output value is set to be small (large).
It In addition, the switch 38 is used to set the flight course (target).
-In- point course deviation: The deviation between θDFIP) and the actual flight course is more than the specified value.
Is also turned on when it becomes smaller, and the output value of gain 36
Output value of gain 37 and phased-in / out circuit 39
Can be added to increase the control amount to perform delicate shift control.
It is like this. Also, the rate limiter 42 to the bank angle
The limit value 45 is a command based on the output value of the adder 28.
When calculating the bank (bank angle), the relationship with the airspeed of the aircraft
Control the output value of the bank angle limiter 41.
is there.

The yaw system control subsystem shown in FIG .
Roll auto power based on standard roll angle shift command
To secure the roll motion of the aircraft by the Ylot control
To, enter the lateral acceleration Nr and roll rate P sideslip
Command A7 for smooth and smooth turning motion
7 is generated and output to the yaw trim servo. In addition, the side
Acceleration and roll rate are detected by airframe sensors
It is what

The pitch system control subsystem shown in FIG . 10 is based on the standard roll angle shift command as described above.
The roll motion of the machine by the automatic pilot control
In order to ensure, the airspeed UA when the Enroute Nab Mode engages is set to the target airspeed A94,
To make the airspeed UA of the airframe follow the target airspeed
Generate command A94 and output to pitch, trim and servo
To do. The pitch rate, pitch attitude, and airspeed are
It is detected by the sensor of the airframe.

(2) Step 2 Step 2 is the turn-in point after the turn is completed.
It refers to the phase until it shifts to
The aircraft is set by the azimuth control based on the drift angle described above.
Standard roll angle shift co
A mand is generated and the aircraft flies almost straight. See also
In the turning start anticipation distance generation unit 3 of 3, the airspeed UA and
Anticipatory turning time constant CP14 based on the turning time constant CP14
Distance STEN is calculated and ratio with turn-in point distance
The turn being set by the navigation function.
It has already been reset when the in-point is exceeded.
The turn-in start flag is turned on again. Above anticipation
The turning time constant CP14 is the turn-in-point shown in FIG.
When restarting the turn again, the delay in response is taken into consideration.
Is set by starting the turning motion slightly before
It is a time constant for flying the turning course.

Of the yaw system and pitch system of FIGS. 9 and 10,
Control of airframe motion by the control subsystem
The same is omitted here.

(3) Step 3 Step 3 starts from the turn-in point in FIG.
Phases until the end of the turn towards the line. Up
As mentioned above, at the end of step 2, turn-in start flag
When the gear is turned on, the aircraft will make a turning motion again from this point.
Start. In this case, the switch of the lateral guidance control law shown in FIG.
Switch 22 to ψFTP, switch 33 to gain switch
Connected to the kejuula 29, to the nose direction ψ and FTP
The deviation from the approach course azimuth ψFTP of
Control amount for calculation is calculated (subtractor 21 to gain
27), the flight course set by the navigation function and the actual flight
The control amount to bring the deviation from the
(Gain scheduler 29 to adder 40). these
The control amount is added by the adder 28 as in the case of step 1.
Standard roll angle shift command required for desired turning
Is generated. This command is the roll-on command shown in Figure 8.
It is input to the pilot control law, which causes the aircraft to
Fly on the designated turning course. Others are step 1
Since it is similar, it is omitted.

(4) Step 4 Step 4 is until the target flight point is reached after the turning is completed.
Phase, here as in step 2
Then, the aircraft is set by the azimuth control based on the drift angle described above.
Standard roll angle shift for flying on a fixed straight course
Command is generated, the aircraft heads toward the target flight point
To fly. And when the aircraft reaches the vicinity of the target flight point
The FTP on-top signal is output, and the target
The pilot can recognize that he has reached the flight point.
Wear.

In the case of the automatic guided flight shown in FIG . 2, the first
When turning, the switch 22 in FIG.
Except that the switch 33 connects to the gain scheduler 29.
Steps 1 and 2 above are almost the same, and detailed explanation
The description is omitted.

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

Since the present invention is constructed as described above, it has the following effects.

(1) When the approach course to the target flight point FTP is specified, the target flight point F is made by performing an anticipatory turn when turning toward the target flight point FTP.
It is possible to improve the accuracy of reaching the TP.

(2) Since the enroute nab mode can be engaged depending on whether the approach course to the target flight point FTP is designated or not, the fully automatic guided flight to the target flight point FTP is possible. It is possible.

(3) Since the roll posture during turning can be kept constant, the ride comfort of the pilot is not impaired.

(4) With these, the pilot's operational load can be significantly reduced, and the accuracy of reaching the target flight point FTP and the time required to reach it can be made good on average.

[Brief description of drawings]

FIG. 1 is a flight route diagram when an approach course to a target flight point FTP is designated in an automatic flight control system according to an embodiment of the present invention.

FIG. 2 is a flight route diagram when the approach course to the target flight point FTP is not designated in the embodiment.

FIG. 3 is a block diagram showing a mode control subsystem in the embodiment.

FIG. 4 is a block diagram showing a lateral guidance control law of the roll system control subsystem in the embodiment.

FIG. 5 is a block diagram showing a drift angle calculation process of the roll system control subsystem in the embodiment.

FIG. 6 is an explanatory diagram showing flight information data from a navigation function in the same embodiment.

FIG. 7 is a circuit configuration diagram showing a nose heading deviation correction processing unit of the roll system control subsystem in the embodiment.

FIG. 8 is an explanatory diagram showing a roll autopilot control law of the roll system control subsystem in the embodiment.

FIG. 9 is a block diagram showing a yaw system control subsystem in the embodiment.

FIG. 10 is a block diagram showing a pitch system control subsystem in the embodiment.

FIG. 11 is an explanatory diagram showing a flight path to a target flight point according to a conventional technique.

[Explanation of Codes] 1,9,12 −1 Signal rise determination circuit 2,7,11 Flip-flop circuit 3 Turning start anticipation distance generation unit 5,8 ON / OFF determination circuit 20 Drift angle calculation processing unit 25 Limiter 26 Nose Heading deviation correction processor 27 Gain (gain scheduler for heading of own machine ) 29,34 Gain scheduler 31 Speed ratio calculation circuit 35 Limiter 41 Bank angle limiter 42,46 Rate limiter

Claims (1)

[Claims] 1. Following a predetermined course to a target flight point
In helicopter flight control system having the navigation function of calculating the flight information for automatic flight or helicopter on the basis of the flight information after the automatic flight mode to the target flight point is Engage is in a turning position
Means to determine whether or not the helicopter is in the turning position
When judged, heading to the next turning position or target flight
The amount of deviation between the direction to the point and the direction of the helicopter and the above specified
Helicopter based on the amount of deviation between the actual course and the actual course
Means for generating a control command for the bank angle of the
Based on your command, roll rate, and roll attitude
Roll system control subsystem , which consists of the means for driving the roll servo, and sets the lateral acceleration to zero based on the lateral acceleration and roll rate.
The yaw system control subsystem that generates commands to drive the yaw servo and the automatic flight based on airspeed, pitch rate, and pitch attitude.
Maintain airspeed when row mode is engaged
It generates a command pitch system integration for driving the pitch servo
Automatic flight control system characterized by comprising a control subsystem.