DE1556436A1 - Device for improving the safety of aircraft during automatic landings in the longitudinal area - Google Patents

Description

SUI) -AVIATION, in Paris (France)

Device to improve the security of plug-in tools automatic landings in the longitudinal area.

Priority «France, April 5, 1967

The invention relates to further developments of the device, which are mainly in the lateral area the safety of the plug-in tools during automatic landings has been improved and the subject matter of the applicant on August 7, 1967 under the name of Mr. S 110 * 865 XI / 62G filed patent application forms · These training courses mainly concern the longitudinal area.

The said patent application states that

in the longitudinal area the device for each of the following parameters, namely the deviation of the path from the longitudinal guide

bundle, the longitudinal position and the pitching speed, a detector element for setting the values of this parameter, such a member assigned to one of the first two parameters actuates an arrangement of safety circuits so that the pilot is alerted if the parameter in question exceeds a certain threshold value, while such a member associated with the pitching speed actuates an arrangement of safety circuits in such a way that the servomotor of the altitude control of the automatic pilot is neutralized if the pitching speed exceeds a certain threshold value, and that the pilot is alerted when this neutralization is triggered and by the automatic pilot a servomotor fault reinforcing B _e fail is given.

The invention relates to;

- a modification of the safety circuits relating to the longitudinal position in such a way that this longitudinal position is not directly is monitored, but its changes via an average Time versus its long-term mean,

- a change in the pitching speed relevant safety circuits, in such a way that not this pitching speed alone is monitored, but a combination the same with the vertical downward velocity,

- the addition of safety circuits to monitor the vertical downward speed during the Transition between approach and touchdown (hereinafter referred to as "transition" for short) and

- the addition of safety circuits to monitor the landing length.

With regard to the longitudinal position, it is initially to

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BATH ORIGINAL

notice that the average altitude of the aircraft in each Approach is different because it depends on the inclination of the longitudinal guide bundle, depends on the wind, the total mass and the shape of the aircraft, so that the actual longitudinal position is not monitored must, but the changes in the same over a mean time compared to their mean over a fairly long period For this purpose, according to the invention, the signal of the vertical gyroscope can be passed through a high-pass filter, the time constant of which is preferably at least 15 seconds.

Furthermore, the alarm only needs for excessive changes in the longitudinal position given its mean value in the Sturdy flight sense must be given, since these changes alone pose the risk of becoming dangerous in a short period of time « According to the invention, this makes it possible not to use a rectifier between the amplifier and the relay with a threshold value.

A suitable value for this change

the threshold to be selected in the swooping direction is preferably on the order of 1 to 2 degrees during the straight line Descent. In general, however, the Alann threshold must be during of the transition can be given a lower value in order to better alert the pilot in the event of a malfunction which the Risk of impact on the front wheel. According to the invention, the seed bulb change to be carried out can then either by one preferably of the order of magnitude 15 meters controlled switching, or continuously by use of the output signal of the radio altimeter can be obtained.

Regarding the monitoring of the ramming speed it should be noted that instead of just this speed

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ability to monitor to alert the pilot and selectively neutralize the longitudinal axis of the automatic pilot, man according to the invention at the input of the amplifier on the one hand the signal "pitch speed", which is obtained by deriving the from the Vertical gyroscope delivered signal preferably by means of a high-pass filter with a small time constant of e.g. large order 0.2 second, and on the other hand, can combine a signal showing the "changes in vertical speed" of the plug stuff expresses itself over a medium time.

This latter signal can according to the invention

can be obtained by electrically that from a vertical accelerometer delivered signal is integrated by means of a low-pass filter, the time constant of which is preferably of the order of magnitude 6 seconds, the main purpose of this signal being to prevent untimely weather conditions To prevent alarms and unnecessary neutralizations that interfere with the correct functioning of the automatic pilot can.

Incidentally, the phase of this signal can be

should be chosen in such a way that when the aircraft is e.g. a descending gust hits, the neutralization system is made less sensitive on the one hand in the sense of overtaking, so that it does not prevent the automatic pilot from pulling the plug-in as far as is necessary to counteract the gust, while it is made more sensitive in the dive sense, so that any error of the automatic pilot, which affects the aircraft in the dive direction is better corrected, whereby the neutralization system gives the alarm faster, if a descending Bo is added to this error.

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It should be noted, however, that this enlargement the sensitivity in the dive sense for safety It is not essential, which is sufficiently guaranteed by the sole signal of the pump speed. If therefore the signal of the change in the vertical speed fails due to a disturbance, it is only to be feared that when moving Weather more frequent untimely alarms occur.

The response thresholds, which one is correct

Sohutz guarantee, without untimely alarms in a moving atmosphere are expediently defined by the following approximate values:

a) If there is no change in the tertiary speed of the plug tool due to a gust, the selective one takes place Neutralization preferably when the pounding speed 0.7 degrees per second when diving or 1.2 degrees per second when diving overtake achieved ·.

b) In the absence of the ramming speed, the selective neutralization is preferably carried out for a change the terticai speed of 1.20 m per second in descent flight or 2 m per second when climbing if this change is very rapid. Obviously, this does not correspond to a scientific one Tall, but allows the definition of the relative size to be given to the expression "change in vertical speed".

According to the invention, it is useful while

the transition, preferably in a m in der.Nähe 15 lying level to interrupt to a faster protective case of a sudden failure of the automatic pilot to obtain during the swoop * Namely, when the beginning of the transition is normal, the signal of change of Tertikaigeschwindigkeit would

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the signal of the change in the vertical speed while maintaining the protection of the pitching speed in the dive direction Make it less sensitive and thereby the neutralization and the alarm in the event of a malfunction of the automatic pilot in the Delay a dive φ

The interruption of the signal of change

the vertical speed can expediently by an automatic Switching takes place, which is done e.g. by a contact of the point altimeter.

Regarding the monitoring of the vertical speed During the transition it should be noted that this monitoring is intended to prevent the aircraft from being caught during of the orbit flown through is dangerous or to one leads to violent touchdown. So its main purpose is to give the pilot the alarm when the downward speed is reached of the plug stuff is too big or becomes too big during the transition, and as an additional precaution also the servomotor to neutralize the automatic pilot in the sense of stalling, so that the danger during the time it takes the pilot to pick up the plug stuff again, is not enlarged.

The threshold of the rate of descent, or more precisely the rate of approach to the ground h · during the transition must not be fixed, but must also be in accordance with the decrease in height h above the ground decrease.

The cheapest law for this in meters ever Second expressed speed h 'in puncture of the in Meters expressed height h depends on the plug stuff and the

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this equipping automatic pilot from, in particular from his transition computer.

A law which is often suitable and which is easy to apply ■ is the linear law

where h 'and K are constants, the values of which are preferred of the order of magnitude of 1 or 0.2.

Sometimes it can be useful to

to choose a more winding law, which e.g. by the sequence of two linear laws is formed.

h »= h · ■ + Kh
- - ο o—

h ¹ = h ·., + K ₁ Ji

which are above or below a useful order of magnitude 10 meters height h can be used, where

and K- is smaller than K, where the constants k't K »h ¹ - and K- preferably have approximately the following values: h ' _o = -0.5 ^ ₁ = 1.5 K ₀ = 0.3 K ₁ = 0.1

The signal h is given by a radio height meter

delivered. It is an electrical signal, which according to the invention proportional to the height of the aircraft above the ground up to a certain height, which ζ »Β. Is 20 keter, and is chosen so large that it covers the transition, but not too. large, so that any uneven ground is avoided trigger untimely alarms in front of the runway entrance. The signal should remain constant above this level. For this purpose, according to the invention, ζ · Β * can be used with the radio altimeter Potentiometers can be connected to several taps, with all heights over 20 meters short-circuited to corresponding taps

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so that only those existing below this height of 20 meters Usable zone is retained.

The signal h ¹ according to the invention can be obtained by, for example, that the signal _f h electrically derived
that will be done by a suitable way in the plug stuff
built-in normal accelerometer specified vertical acceleration h "is integrated electrically, and that this
both signals can be combined in a suitable manner.

Finally, as far as the monitoring of the landing length is concerned, which is supposed to prevent landings that are too long, the punk altimeter activates a "time relay" when the plug stuff goes through a given height of around 15 meters
after a certain time determined by experience of around 12 to 15 seconds for the amount of 15
Meters triggers the alarm when the plug stuff has expired
Deadline has not yet set.

The invention is described below with zugnahme B _e illustrated in the drawing by way of example.

Pig. 1 is a block diagram of a device for monitoring the longitudinal position.

Pig. Figure 2 is a block diagram of an apparatus for monitoring pitch rate.

■ flg. 3 is a block diagram of a device for monitoring the vertical speed during the
Transition.

4 shows a circuit diagram of a device for monitoring the landing length.

In these figures they are normally

existing in aircraft systems prior to the application of the invention

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Parts are shown with dashed lines and the parts according to the invention are shown schematically with continuous lines.

Pig. 1, which shows an embodiment of the invention shows a device for monitoring the longitudinal position is with Pig. 6 of the patent application mentioned at the beginning S 110.865 Xl / 6c compare ^

The detectors used are two tertiary

Gyroscopes 1 and 2, which are part of the equipment of every transport aircraft. These gyroscopes give pounding information in the form of alternating current signals, the amplitude of which is proportional to the deviation 0 of the position angle around a certain zero point around, and the phase of which depends on the sense of the deviation.

The gyroscope 1 is connected to the automatic pilot 3 and the signals coming from the gyroscope 2 are applied to the actual safety circuits.

. These circles contain one in turn

High pass 4 with a large time constant (15 seconds), an amplifier 5 and an Beiais with threshold value 6, weloaes a Alarm 7 can be triggered if the change in the deviation θ des Isagewinkeis in the dive the ¥ ert corresponding to the previously set threshold reached «

Furthermore, a comparator may be provided which give 8 siaea _s alarm when a disagreement between the outputs of the two gyroscopes 1 and 2 erschalst ο

lißpiekt stomach 9 for setting the threshold values sifid jaoefo at the entrance of the lelais with Setosllemfert 6 Bai a special execution shows this Ein = eia Islais on _s wiglehes at 15 meters voa dea

(Y 0 ^e ! 8 Π R / Π R 4 ζ "

υ y ο y ϋ υ / υ w * c? «J

altimeter 25 is operated, and its contact one of the Bias resistances bridged. Above 15 meters, the relay is at rest and the bias is on set so that 3 the relay is energized with threshold value 6, which turns off the alarm. If the change is in the sense of diving becomes too large, the signal exiting the amplifier is subtracted from the bias signal and it occurs a moment when the relay drops out and gives the alarm. The preload is now set so that this takes place, if the change reaches e.g. 1.5 degrees. Below 15 meters, the relay is energized, so that is actually connected to the relay Threshold applied bias voltage is smaller, so that then a weaker change signal is sufficient to trigger the alarm. This brings the threshold value from 1.5 degrees to a few tenths of a degree.

In another version, one of the

Resistances by a potentiometer controlled by the point altimeter replaced in order to obtain a steady change in the threshold between 15m and the ground, with all turns of the potentiometer are short-circuited above 15m.

Pig. 2, which shows an exemplary embodiment according to the invention a device for monitoring the ramming speed with alarm and selective neutralization of the Represents the servomotor of the altitude control of the automatic pilot, is to be compared with Pig · 7 of the above-mentioned patent application S 110.855 Xl / 62c.

The pitch speed Q ¹ is thereby

f- atg ·.?, divides that electrically by means of a high pass 10 the 'gn'. 9 is derived from the one not used with the automatic

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table pilots 3 connected vertical gyroscope 2 is supplied.

The time constant of the filter must be pretty

be chosen small, and experience has shown that one Value of 0.2 seconds is appropriate for transport aircraft.

The change Ah ^{1 in} the vertical speed

is determined by the fact that electrically by means of a low pass 11 with a time constant of the order of magnitude 6 seconds the signal h "is integrated, which! By a Vertical accelerometer 12, which is supplied by the normal vertical accelerometer connected to the automatic pilot 3 is different.

The variables Θ ¹ and Ah ¹ are then mixed at the input of an amplifier 14.

The actual safety circuits connected to the gyroscope 2 and the accelerometer 12 which are not used by the automatic pilot 3, thus consist of a connected to the gyroscope 2 High pass 10 with a time constant of 0.2 seconds, one on the accelerometer 12 connected to the low-pass filter 11 a time constant of 6 seconds, an amplifier 14, at the input of which comes from the two filters 10 and 11 Signals are mixed, as well as two relays 15 and 16 with threshold value, which are connected in parallel to the output of amplifier 14 and neutralize the servomotor 3a of the altitude control of the automatic pilot 3 when pulling over or when diving should.

Potentiometric resistors 17 and 18, which are arranged between the input of the relay 15 or the output of the amplifier 14 and the body, the protective

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Threshold expand a little in the overturning sense to include the automatic To allow pilots to stall the aircraft during the transition without the neutralization system preventing it. The asymmetry introduced in this way in the protection is possible because a disturbance when overdrawn is apparently less dangerous, as a nuisance during a dive when the plug stuff is in Is close to the ground.

The safety circuits listed above are doubled with a filter that is identical to filter 10, A filter 19 connected to the gyroscope 1, a filter 19 identical to the filter 11 and connected to the accelerometer 13 Filter 20 and an amplifier 21, which is identical to amplifier 14, and at its input that of filters 19 and 20 incoming signals are mixed. Finally, there is a comparator 22 with the output of the two amplifiers 14 and 21 connected in order to notify the pilot by means of an alarm 23 in the event of a discrepancy.

The two detectors used are in fact the aircraft's two normal vertical gyroscopes, i. the same as in Fig. 1.

One can also use the signal of the change in the vertical speed Ah * during the transition, i.e. interrupt below 15m by means of an interrupt relay 24, which is located at the exit of the filter 11 and is operated at 15m by the radio altimeter 25

Fig. 3 shows an embodiment according to the invention a device for monitoring the vertical speed during the transition with alarm. and more selective Neutralization of the servomotor of the height control of the automatic

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BATH ORIGINAL

see pilots «

The aforementioned accelerometers 12 and 13 determine the vertical acceleration h ″. Two 'Punk altimeters 25 and 26, the first of which with the automatic Pilots 3 is connected, set the height h of the plug stuff stuck above the ground.

The signals coming from the accelerometer 12 and the point altimeter 26 which are not the automatic pilot 3 connected to the actual Safety circuits created.

These circles initially contain an already mentioned low pass 11 with a time constant of 6 seconds, which is connected to the output of the accelerometer 12 and ^{delivers the change Ah 1 in} the vertical speed through electrical integration, and then a high pass 27 connected to the output of the point altimeter 26

This high pass 27, which is used to electrically derive the signal h coming from the point altimeter 26, supplies an output signal h ¹ which expresses the rapid changes in the vertical speed the better the smaller its time constant. However, this can not be pushed too far, since a very small time constant requires a very grosso gain so that then the signal obtained h contains' _r considerable noise, which can cause untimely alarms. Experience has shown that a time constant of the order of 1.3 seconds is appropriate.

Under these conditions, the received signal h » _{r is} not exactly the desired information h ¹ , and the processes proceed as if this information were passed through a

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Low pass would be delayed by 1.3 seconds. Such a delay is too great to ensure a correct alarm and protection in the event of a poor automatic transition. This delay must therefore be compensated for by mixing a complementary signal Ah ^{1 with the signal h 1} , which signal can express the rapid changes in the vertical speed over a short period of time. This signal Ah ¹ is now just the one received at the output of the low-pass filter 11

The mixture of h ¹ and Ah ¹ would theoretically be a perfect signal h ¹ if the time constants of the low pass 11 and the high pass 27 had the same value, namely 1.3 seconds. However, it can be proven, and experience confirms it, that although the low-pass 11 has a considerably larger time constant, here 6 seconds, the resulting error is practically negligible, which allows the same low-pass 11 as the one previously in FIG. 2 used to monitor the pitching speed.

This is done by mixing the signals h * _r and

Ah ^{1 signal h 1} obtained in a part 28 and the signal h coming from the radio altimeter 26 are applied to a mixing amplifier 29, so that the output signal of this amplifier is proportional to su h * - ILh.

This latter signal is activated in turn

the input of a relay with threshold value 30 is applied at the same time with a fixed bias signal 31 with the vert k ^f ₀ + β , in such a way that it is sucked off from this, where s_ is the triggering wave of the heat.

The excitation phase of the Beiais with threshold value

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30, for which an embodiment is described with reference to FIG. 5 of the above-mentioned patent application S 110.865 XI / 62c, is selected such that the gate voltage signal h + £ makes it conductive, and therefore quite small ^{under the conditions of a normal transition (h 1} ). the winding 32 of a relay 33 connected to the output of the relay with threshold value 30 remains constantly energized, so that the alarm light signal 34 remains extinguished.

Since h ¹ -Kh is subtracted from h · + s, - o ~~ - ο - ■

apparently if h ^! - Kh increases during the transition and becomes greater than h *, which would result in a hard impact, the signal applied to the input of the relay with threshold value 30 is less than s_. This relay is therefore no longer conductive and drops a contact 35 of the relay 33, which then triggers the alarm 34, while the servomotor 3a of the altitude control of the automatic pilot 3 in the sense of "nosedive" is neutralized by another contact 36 of the relay 33 .

Further, a comparator 37 is provided which can trigger the alarm 34 ₉ when a discrepancy between the output signals of the two radio altimeter 25 and 26 occurs.

Finally is at the entrance of the filter 27 a potentiometer 38 is provided with several taps, in which all heights of over 20 m corresponding taps are short-circuited, so that only the Butzzone below this height of 20m is retained.

It should be noted that the above circle leads to

monitoring of the transition does not require any switchover for its commissioning. As stated above, the signal given by the Furikh knife remains constant above a certain height fixed at over 20 meters. So the signal h ' _{r is}

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zero, and the signal h ¹ expresses only the changes in the vertical velocity around the mean velocity during the approach with a constant slope. Under these conditions, there is no risk of the circle triggering the alarm if there is any unevenness in the ground overflown.

If the plug stuff is below the height of 20 meters

goes down, the signal h begins to change in proportion to the height above the ground. The signal h ¹ then develops gradually and becomes sufficiently correct after 2 to 3 seconds, ie from about 15 meters on. This period, which is tied to the time constant of the high-pass filter 27, would become inadmissible if this time constant were considerably greater than the value of 1.3 seconds selected for the case of FIG.

As shown in Fig. 4, which an inventive Representing an embodiment of a gate direction for monitoring the landing distance, this device contains in series two heaters 39 and 40, one relay 41 with switch-on delay and an alarm 42.

The relay 39 turns on when the plug stuff goes down below 15m and is activated by what has already been mentioned Relays for changing the threshold when monitoring the longitudinal position are formed. The relay 40 is attached to a damper The contact attached to the landing gear is excited when the damper is depressed, i.e. when the aircraft touches down. ^ Finally, the timing relay 41 is designed so that ea after oo his excitation by the relay 39 does not switch on immediately,

oo but after an adjustable time of e.g. 12 to 1 | Selp »

° the. The alarm is only given when the relay 40 is inaccessible co has not responded, i.e. if the aircraft has not yet opened.

has set. In the opposite case, the relay prevents

40 that the alarm is given unnecessarily.

BAD ORiG »μAi.

Claims (1)

Claims 1.) Device to improve the safety TOä Plugzeugen during automatic landings in the Longitudinal area, characterized in that each of the four following, know the movement of the aircraft during landing drawing parameters, namely the longitudinal position, the pitching speed, the vertical speed during the transition from approach to touchdown (called transition for short) and the Landing length, a detector element to determine the values of the relevant parameter is assigned, with that of the long position associated detector element (2) shows the changes in this longitudinal position over a medium time versus hers over a fairly long time Determines the mean value taken over a period of time and an arrangement of safety circuits (4 »5, 6) is actuated so that the pilot receives the Alarm (7) is given when this situation exceeds a certain trigger threshold exceeds, while that associated with the pitching speed Detector element (2) with a detector element (12) for determining the vertical speed when flying downwards cooperates that an arrangement of safety circuits (10, 11, 14 * 15 »16) is operated so that on the one hand the Servomotor (3g) of the altitude control of the automatic pilot (3) is neutralized when the pitching speed is a certain Exceeds the exhaust threshold, and on the other hand the pilot is given the alarm (23), the vertical speed during the "transition associated detector element (12, Pig. 3) an arrangement of safety circuits (11, 28, 29 »30) is operated in such a way that that the pilot is given the alarm (34) when this Speed exceeds a certain triggering threshold «, where 00980 8/0 6 ", * the detector element (39) assigned to the landing length has an arrangement operated by safety circuits (40, 41) so that the pilot (42) is given the alarm when the height of the plug stuff has not become null within a certain period of time. 2.) Device according to claim 1, characterized in that the main safety circuit is one of the three first parameter at least one element with threshold value (6, 15, 16, 30), which responds when the parameter exceeds the specific threshold value. 3 ·) Device according to claim 1, characterized in that each safety circuit is one of the first three Parameter has a member for electrical derivation (4, 10, 11, Pig. 3 /, which with the associated detector member (2, 12) is connected in series. 4.) Device according to claim 1, characterized in that each safety circuit has one of the three first parameters an amplifier (5 _f 14, 29) connected downstream of the associated detector element (2, 12). 5 x) device according to claim 1, characterized in that the assigned long ply main safety circuit means (9, 17 _t 18, 31) for setting the threshold value of the element with threshold value (6, 15, 16, 30) · 6.) Device according to claim 1, characterized in that that the main safety circuit (12, 11, 28 ", 29» 30, 32) of the vertical speed during the transition in the swooping direction the servomotor (3a) of the honing expensive des automatic pilot (3.) neutralized » UJ «. ^: »J ■ - 'U v / ' J 7 ·) Device according to claim 1, characterized characterized in that the entirety of the safety circuits of one of the three first parameters contains a comparator (8, 22, 37), which on the one hand between the detector element or elements (2, 12) and one or more elements (1, 13) for doubling them Detector elements (2, 12), which are also connected to the automatic pilot (3) of the aircraft, and on the other hand the associated alarm element (7> 23 »34) is switched. 8.) Device according to claim 1, characterized characterized in that the pounding speed is assigned Main safety circuit (10, 14, 15) two heiais with threshold value 15 »16), one of which (15) for the overlay and the other (16) is intended for the dive. 9o) device according to claim 1, characterized in that that the detector element (2) and its doubling element (1), \ * which are assigned to the longitudinal position, vertical gyroscopes and that the devices (9) for regulating the limb (6) with threshold value are connected to a point altimeter (25) are. · 10 ») Device according to claim 1, characterized in that the detector element (1) and its doubling element (2) j which are assigned to the pitching speed, Tertical gyroscopes are each connected to an amplifier (14, 21) by an electrical derivation member (10, 20) is c 11) Device according to claim 1, characterized in that that the detector element (12) for determining the vertical speed during descent flight and its doubling 009808/06 9 5 member (13) f which the monitoring of the S-f battle speed or the monitoring of the vertical speed during the Assigned transition are accelerometers (12, 13). 12o) Device according to claim 1, characterized in that the D _e tektorglied and its doubling element, which are assigned during the transition of the vertical velocity, are punk altimeter (25 »26). 13.) Device according to claim 8, characterized characterized in that the link with threshold value (15) for the overtaking the main safety circuit, which is the pitching speed is assigned, made less sensitive by resistors (17, 18) connected to one input will. 14 ·) Device according to claim 8, characterized characterized in that the pounding speed is assigned Main safety circuit behind its accelerometer (12) has a breaker glass (24), which in a given Height is controlled by a punk altimeter (25). 15 · Device according to claim 1, characterized in that that the safety circuit assigned to the landing length is a relay speaking below a given height (39) »a relay that responds when it touches the ground (40) and a time relay (41, Fig. 4) contains 009808/0695 Blank page