JPS58145000A - Ground approach alarm for aircraft - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to the field of aircraft ground proximity warning systems, and more particularly to ground proximity warning systems having one or more modes of operation.

BACKGROUND OF THE INVENTION Ground proximity warning systems currently used on commercial aircraft have six or six modes of operation. Mode of operation refers to the criteria used to generate pilot alerts. For example, in a ground approach mode of operation, the aircraft's ground altitude is compared to the aircraft's ground approach speed and an alarm is generated if the approach speed exceeds a predetermined speed for a particular ground altitude. This particular mode of operation is described in U.S. Patent No. 3. the law of nature/
j, 77 No., No.? , f J &, No. 796, No. 3.936222, and No. j, ? j t, 2 /
is shown in the issue.

Other warning modes include: negative climb after takeoff, terrain c 1θaranc, excessive sink rate, and below glide slope warning modes. Ground approach warning systems using these types of warning modes are US Patent No. J
, 94(&,,?f). In ground proximity warning systems of the type described in this U.S. patent, various warning modes are used depending on the flight conditions of the aircraft. During takeoff. For example, the negative climb mode after takeoff is activated, and the barge climb is 2 / , ?, 76 meters (
If the aircraft descends to a pressure altitude of 700 feet, it will issue a warning. Various forms of this alarm mode are described in US Patent Nos. 3 and 9. , ff No. 70, and Bateman (Ba
US Patent Application Serial No. 10 (Teman)? ,,
t ff 0, as well as U.S. Patent No. j, ? 4Il...
It is also shown in No. 311. Aircraft on the ground 2 / , 7
．． ,? After reaching an altitude of 4 meters (Oθ feet), the ground approach warning system switches from negative climb mode after takeoff to ground approach mode. Its ground approach mode is
To give a pilot warning even if the aircraft descends below a predetermined altitude relative to the ground. U.S. Patent No. J, ? $6.
J k with No. US Special Pestle No., °, 9 Doug β6g No. and No. 41.030,04! The number describes the ground approach type warning mode. This mode maintains normal operating conditions by allowing the aircraft to land with the landing gear and flaps down.

Applicants believe that by changing the criteria at which the switch is made from negative climb mode to ground approach mode after takeoff, the alert range of the ground approach warning system is enhanced. In particular, this modification is useful when the aircraft is taking off from upwardly sloping terrain and the ground λi3. ．． yt meter (
100 feet). As a result, the aircraft approaches the ground while still climbing relative to pressure altitude without generating a warning.

In addition, for example, if an aircraft is on the ground, 2/J...?
The aircraft climbed above A meter (')00 feet) and switched the ground approach warning system to ground approach mode, but the aircraft's speed was set to JO4t, which issued a warning when the ground approach mode was JO4t, 1 meter (lθθθ feet) or less. Under certain circumstances, it was possible for the prior art device to generate a safety report or an unwanted alarm if the problem occurred. - when the mode change occurs the aircraft is approximately 273.34
meters (700 feet) would result in an alarm that is not justified by the environment.

SUMMARY OF THE INVENTION It is therefore an object of the invention to provide a ground proximity warning device having at least one warning mode with an improved warning range, wherein switching from one mode to another is as a function of radio altitude and time.

Another object of the present invention is to provide a ground proximity warning system having an improved warning range in which the warning is generated according to a predetermined relationship between flight parameters, the predetermined relationship varying as a function of radio altitude and time. It is to provide.

Yet another object of the invention is to provide a ground proximity warning system with improved warning range having a first warning mode; When the aircraft is below a first predetermined radio altitude that decreases as a function of increasing radio altitude and time, generating a warning if the aircraft is descending relative to the pressure altitude during takeoff; In the mode, a warning signal is generated when the aircraft descends below a second predetermined radio altitude that increases as a function of increasing radio altitude and time.

Example Rice aIi18H111 J, t41! b, Jst No. 2 W
To illustrate the operation of a conventional ground approach warning system, which has many different modes of operation, the flight path of an aircraft departing from an airport runway will be described.
yfJ1 is shown in FIG. During the flight separation state, the ground proximity warning system is located in the first shaded area 74 below the flight path 10.
As shown in 1, it operates in negative climb mode after takeoff.

If the aircraft descends relative to pressure altitude at a predetermined speed or above in accordance with the post-takeoff negative climb warning mode described in U.S. Patent No. 3,9 Dac, Jsrt; f l 7,1/D Edict and U.S. Patent Application Serial No. 709,! According to the negative climb warning mode after takeoff described in t0, the aircraft is
/J, if a predetermined amount of altitude is lost before reaching an altitude level of 34 meters (700 feet), an audible warning will be issued, typically using the words 1, Don't Sink.

After the aircraft reaches an altitude of J/3.34 m (700 ft) above the ground, the anti-proximity warning system
At , the negative climb warning mode after takeoff will be switched to the ground approach warning mode shown by the second hatched area 16 in FIG. When the aircraft descends below a predetermined altitude relative to the ground in ground approach mode, an audible warning such as 'Too low, terrain' is generated. Ground approach mode is f 414. J j No. J, f $ 41.? 41, and 6 Oj O,
04! is listed in the issue.

The alarm system shown in FIG. 1 works perfectly well for most situations. However, Applicants believe that the mode switching device shown in Stripe 1 can be modified to issue an alarm under several product terms in addition to the circumstances that caused an alarm in prior devices. An example of a set of environments in which an alarm system can be modified to provide timely alarms is shown in FIG. In this situation, the terrain at it slopes upward, approximately parallel to the aircraft's flight path -0. The flight path that the aircraft would normally be expected to follow is shown at point IIIJ-, but for this example it is assumed that the aircraft is flying a lower flight path JO. are doing. An aircraft's flight path never ends on the ground/JJ
Since the level will not exceed 4 meters (100 feet), the conventional ground approach warning mode aircraft will not switch from the negative climb mode /l after landing to the ground approach mode 16 shown in Figure 1. As a result, the aircraft will gain pressure altitude so no warning will be generated for the aircraft approaching terrain/g at point Q.

A set of environments in which a jamming warning is generated by the device of FIG. 1 is illustrated in FIG.
Significant dimple 24 switched at point 30 to 6
is in the terrain below the aircraft's flight path λg. At three locations on the opposite side of the depression where the topography returns to approximately the level of the runway 12, a warning is issued because the flight path jt is below the altitude at which the ground approach warning 16 is issued.

In fact, depression-6 in the terrain would cause the ground approach warning system to switch prematurely from negative climb mode IQ to ground approach mode/A after takeoff.

Another set of environments in which nuisance alarms may be generated over terrain is shown in FIG. Such an alarm occurs in a ground approach warning system having a ground approach mode of the type described in U.S. Pat. do. - As an example, the maximum altitude at which a warning will be given when the aircraft reaches a speed of Matsuha 0.413 is /j, 2
．． Normal level of 0 meters (3QO feet) 3
0 Da, increased to 1 meter (1000 feet).

As a result, the aircraft with route j4I is at ground level 2.
/ If the aircraft is accelerated to a speed of O,41Z Matsuha before gaining an altitude of 3.34 meters (riθ0 feet), the aircraft will be co/ , ? A jamming alarm will be generated at time 36 above an altitude of 74 meters (700 feet).

To improve the ground proximity warning system described above, a mechanism has been developed for effectively switching from one mode of operation to seven other modes of operation based on a combination of aircraft radio altitude and time.

A block diagram for implementing a preferred embodiment of the invention is provided. The signal source used in the device is represented by the aircraft data bus JK. The flight parameter signals provided by Data Mother-Jt include two wires 4I.

Above radio wave altitude hR; Pressure altitude above M*ko” By 410
Logic signal on 111'lb indicating that the pressure altitude change rate h'' on the top indicates that the aircraft is above a radio altitude of /1.241 meters (jO feet); the landing gear is up or the flaps are up. Logic signals GU and Ftj on j0 and j, respectively;
and the speed signal of the aircraft on line st graduated in knots or matsuha.

The logic portion of Figure S relating to the ground approach mode will first be explained. The basic logic shown is rice 511#h1
1.0.70. The logic is similar to that presented in OA No. 3. 1. In normal operation, the Kikuchi approach mode will issue an alert when the aircraft descends below a predetermined radio altitude when the aircraft is not in a landing configuration, i.e., neither flaps nor landing gear are lowered. The predetermined radio altitude, or ground approach altitude, that serves to generate a warning is such that as the air speed increases, the predetermined radio altitude, or ground approach altitude, increases, thereby increasing the airspeed at higher speeds versus lower altitudes. Preferably, it is varied as a function of the air speed of the aircraft to provide a ground proximity warning. It should be noted that the term "radio altitude" is used to refer to the aircraft's altitude above the ground, as radio altitude is typically used in aircraft to determine the aircraft's altitude above the ground.
Ru.

In the logic circuit of FIG. 3, the function generator sr is M
Switch 1o controlled by flap signal on ja
9 air speed information is received from line j6 via. The position of the landing gear is also clever! 0 to the function generator, 2g. The output of the function generator on II6 is 1/04.4 at a speed of 4 below the landing gear as shown in II6-da for turboprop aircraft. g meters/L, equal to (-j !r O feet) and for other types of aircraft 9 with the landing gear down as shown in line 6.4, right at speeds below J 9 Matsuha. 19/, 4 (4t meters (-3
oo] is limited to the maximum value of -/06j
1 meter (-310 feet) limit or 19/;
The selection of the limit of 49 meters (-jθθ feet) is determined by tightening the function generator 5g by the bin indicating the type of aircraft.
Usually done typically by input from the master. Generator for the number of hours the landing gear is up! rt is 0.3! #tsa for speeds equal to or less than r Matsuha
t equals zero meters (zero feet), and as the speed increases to O,4 IZ Matsuha, line 70
isco, 41 meters (zoo feet) as shown
Outputs a signal that increases to its maximum value. An adder circuit is connected to the six output lines of the function generator Sl, and the adder circuit receives a signal from a signal source representing the 13 lines on the line, Damator (!θθ feet). Each amplifier ≦ receives the output of the adder circuit on the line t, and also receives the output of the adder circuit on the line 4I
Receives hfi signal on O. This circuit is published in US patent no. 0.70. Equivalent to the ground-to-ground logic shown in OA No. 3, in which the aircraft is on line 71'
Comparator 7 when descending below the ground approach altitude generated by
A logic signal is produced on output line 10 of 4.

The logic signal on line go is ORed with the signal on *'lA indicating that the aircraft is above the ground /j, koda meters (SO feet) and that either the flaps or landing gear are in the up position. Line 1 from Loretsk gate t6
AND logic gate f with the logic signal on 41 and 6
J1: Given.

Additionally indicates that the aircraft is not in flight takeoff condition.
It also receives input from the first row state Rosic circuit on ltO.

Ground Proximity Warning - Given the situation, it is necessary to determine what flight conditions the aircraft is in so that the most appropriate warning mode can be selected. The same general type of logic illustrated by flight state logic it is described in U.S. Pat. No. 3,9 J 4. Tade No. 6 and J
,? No. 417,170. In addition to the inputs representing the position of the flaps and landing gear on lines 30 and j, the flight state logic it receives an input from a comparator amplifier 9 on line t, which Aircraft transmits radio waves ^fit hR so that climb mode is deactivated
The operation of this logic is explained in detail below in conjunction with the description of the time-based altitude signal.

Returning to the logic gate explanation, when the aircraft descends below the ground approach altitude generated on line 9g, and either flaps or landing gear are raised, and/or the aircraft is not ready for takeoff. At this time, a logic signal is generated on line 96, and the rosin2 signal is applied to ground proximity warning logic circuit IO- via OR logic gate 9g and across m1oo. Another input representing the position of the flaps and landing gear is input to the ground proximity warning logic 10.
It is given by @SO and j. The logic output from the ground proximity warning logic IO- is sent by line 104 to the audio warning logic circuit 10-. The operation of suitable ground approach logic circuits in combination with audio warning logic is disclosed in U.S. Pat. ? , /J/ issue. The ground approach warning logic 10 and audio warning logic 1o41 cooperate to issue appropriate audio warnings to the pilot by audio generating means such as a speaker/'01. A typical voice warning is “Too low, terrain”
, “Landing gear too low,” and “Flaps too low.” ’During takeoff operating conditions, the modified ground approach mode uses a time-based altitude signal. In a preferred embodiment of the invention, the radio altitude signal hR on line 4to, as shown in FIG. The output of the amplifier tio on the line /l representing the value of 7391 hH is fed to a single pole filter //44 with a time constant of 73 seconds.Filter iiq
is a one-way charging circuit, so the value of the signal on line //4 is the maximum radio altitude reached by the aircraft, Q, ri! remains equal to or less than I. The comparison amplifier//1 which inputs the output 114 of the O6 rjt hR signal/coco filter//4I is (), and the 71bH signal is 111114.
A logic signal on the upper line /, which is larger than the above signal, acts to close the switch, and it acts as an actuator /It,
The output of the upper filter //4I (referred to as the time-based altitude signal) increases as radio altitude increases.

To energize the filter circuit, the logic circuit
Koge responded to the radio altitude signal hR on line 4IQ and said that the aircraft was 41! , a logic signal indicating that a radio altitude of 72 meters (/!rO feet) or higher has been achieved.
II/ Occurs on Colo.

The logic signal on the ml column is combined with the logic signal on the flight state logic EL @/2 at the MMD gate /30, and when the aircraft is in the takeoff operational state,
Time line IJa achieved over meters (iso feet)
The above logic signal energizes the filter circuit //44. In addition, logic circuit 7.2 da is aircraft 1
5. Below the radio altitude of Koda meters (SO feet) ξζ
It serves to reset the output of filter //4I on the descending time line //4 to zero.

The ground proximity warning logic signal is provided when the time-based altitude signal on line //4 exceeds the hH signal on line IIO during takeoff. Comparison amplifier /344 connects lines //4 and 4
The signals on IO are compared and one logic signal is generated on 1IiI 134 when the time-based altitude signal exceeds hR. The time-based altitude signal on the radiation //A acts as a floor that tends to increase with both time and altitude when the aircraft is taking off.

f/iJ/34 Upper Norosic Signal C1141 b Upper (
D ts, xe meters (30 feet) or above with hB signal and line/, takeoff signal on 1 and landing gear or flaps up signal on IIIt41I with mND gate/J
given to l. As a result, AND gate/J1 generates an alarm logic signal on 181440 when the aircraft descends ζ below the time-based altitude floor during takeoff, thereby extending the ground approach view during takeoff conditions.

The time-based altitude signal on line 1ita is sent to comparator amplifier 94.
It also serves as an input to 1. The second input to the comparator 911 is received from the function generator //41 across the tsie.
Function generator 14I4I receives as input the air velocity signal from 91L. Switch/414 is controlled by the flap position signal on switch 113. The time generator with the flap in the up position produces 7 signals on M/4'co, which signals are
JO4 with a minimum of 41 meters (zoo feet) and at 0.415 matsuha or higher
Increases linearly up to 1,1 meters (1000 feet). Comparison amplifier 89 causes the flight state logic to remove the takeoff logic signal from line /Jt when the time-based altitude signal on ls//6 exceeds the value of the signal on line /411a. This means that the aircraft's cable altitude depends on the air velocity l by a factor of at least /, 3 J!
When the distance exceeds λ, ZOO feet to JO#, 1 meter (1000 feet), it has the effect of erasing the takeoff logic signal on @icol.

A post-leave negative climb alarm function using a time-based altitude signal is given by the logic at the top of FIG. A signal ΔhB representing the net loss of the aircraft at pressure altitude hB
is thus generated by the circuit lda l#, and the circuit tug receives as input the following signals: the radio altitude on the line SO hRs the pressure altitude on the line λ hn s II ``the rate of change of pressure altitude on the line h''B , and flap and landing gear position information on lines jO and 5co. Appropriate logic for implementing the circuit/lit is available in US [141, No. 3.94'? ,l
/ Disclosed in No. 0. The ΔhB signal is output on the wiizo, which is then connected to the activation input of the adder circuit/Sco. A line /j41 from an integrator lj4 is connected to the negative terminal of the adder circuit ts, which integrator /S1 preferably has an amplification constant of t, JQXto t/sec. The input to integrator/36 is the radio altitude signal hH on line da0, resulting in a signal on line isq that increases with both time and radio altitude. The signal on this line /j41 is also called a time-based altitude signal. A preferred embodiment of the invention, shown in FIG.
//4 and /j4 (although using the signals generated above, only one time-based signal can be used for both alarm modes.

Alarm logic circuit/3j is addition circuit across line/40/
Upon receiving the output of 3λ and the radio altitude signal hR passing through the line llo, the aircraft enters takeoff mode. - at a predetermined radio wave height [h
11142 when a predetermined amount of pressure altitude hB is lost with respect to R
generates an alarm signal on top. The operation of this type of alarm circuit is specified in US Patent No. 3.947. T, No. 10 and US AI14I patent application serial number 10? , tt0 issue. In response to the alarm signal on line/6, the audio alert logic 1044 generates an audio alert that preferably includes the words lf1''''Don't sink2.

The effect of the time-based altitude signal on the line /jIl is such that it requires a greater altitude loss △hB after takeoff to generate a warning when both radio altitude hR and time increase. It is to bias the negative rise alarm. To this end, the integrator circuit is activated through line 14 by ANDN-gate 6, which A/ND gate 166 inputs the aircraft over 10 feet above the ground. It scatter integrator /j6 calculates the radio altitude while the aircraft is taking off /! , 2'1 meter (go feet), which acts to increase the amount of altitude loss ΔhB required to generate an alarm.

The concept of biasing the ΔhB signal to increase the amount of altitude loss required as a function of radio altitude and time is described in U.S. Pat. It is also strongly applied to the negative climb mode after takeoff using the pressure drop rate hB as disclosed in DE 34,791.

The operation of a ground proximity warning system using a time-based altitude signal is illustrated by the aircraft's flight path /At across flat terrain shown in FIG. As can be seen from Figure 6, the height loss indicated by the line /70 required to generate a negative climb type warning after takeoff such as "Do not sink" is based on the radio altitude hR and increases with increasing time.

Similarly, the radio altitude given the ground proximity warning "Too Low/6" increases as a function of both increasing radio height tLhR and time, as shown by the line/7..2. Negative climb warning IQ after takeoff when reaching the connection point of the elapsed time from takeoff indicated by the dotted line /7M
is deactivated by the signals on lines d and laj of FIG. It is desirable to set various scale factors for the logic and circuit elements of the circuit shown in FIG.
The aircraft has a meter-second (feet-second) radio altitude measured by a time-based altitude signal on the line //& so that the terrain approach floor ), the time-based altitude signal on line /, tII will not significantly advise the altitude loss ΔhB required to generate a post-takeoff negative climb warning.

An example of the increased protection afforded by the apparatus of FIG. 5 is shown in FIG. 87 by flight path /76, which corresponds approximately to flight path 20 in FIG. In this case, the increased ground approach floor of 17 points means that the aircraft has a radio altitude of 273.34 meters < 10
0 feet) will still result in an alarm. ``This protection is effective if the terrain slopes straight upwards after takeoff and the aircraft does not descend to pressure altitude.

Jamming alarms of the type shown in Figures 1gJ and 7G are also eliminated. A depression or a depression in the terrain as shown in Figures 1 and 9. Acceleration up to three feet will not result in any unwanted alarms. This is because the ground proximity warning system is 2/7, like conventional systems. ,．． 74
This is because the negative climb mode after takeoff does not switch to the ground approach mode at a radio altitude of 1,000 feet.

Although the preferred embodiment of the invention, shown in the block diagram of FIG. It is clear that it can easily be used to program a digital computer to implement an alarm system.

[Brief explanation of the drawing]

FIG. 7 is a diagram showing a first aircraft flight path in order to explain the mode switching operation of a conventional ground proximity warning device, and FIG. 2 is a diagram showing a raised terrain Figure 3 is a diagram showing a third aircraft flight path crossing a terrain with depressions, and Figure 3 is a diagram showing a third aircraft flight path crossing a depression. Figure 3 is a diagram showing a second aircraft flight path to explain the mode switching operation of a conventional ground proximity warning system, and Figure 3 is an embodiment of the present invention using a time-based altitude signal for mode switching. FIG. 6 is a block circuit diagram illustrating a ground proximity warning system according to an example, and FIG. 6 is a diagram illustrating the aircraft flight path of FIG. , FIG. 7 is a diagram showing the aircraft flight path of FIG. 1, and FIG. To explain the operation of the ground approach warning system according to the present invention having mode switching based on time, Figure 3 is a diagram showing an aircraft flight path, and Figure 9 has mode switching based on radio altitude and time. FIG. 2 is a diagram showing the aircraft flight path of FIG. In the figure, 3g is aviation 1
# data bus line, sr is function generator, 60 is switch,
Is the wolfberry an adding circuit? A is a comparison amplifier, g is an AND logic gate, 14 is an OR logic gate, it is a flight status logic circuit, tada is a comparison amplifier, dej is an OR logic gate, 10 is a ground proximity warning logic, 1ots is an audio warning logic circuit, 101 is a speaker, //θ is an amplifier, //'l is a single pole filter, 17g is a comparison amplifier,
/Koda is a logic circuit, /30 is an AND gate, /31
1 is a comparison amplifier, 13g is an AND gate, /41 is a function generator, /'It is a switch, /'It is a circuit, 15
ko is an addition circuit, /! 6 is an integrator, irt is an alarm logic circuit, and /66 is an AND gate.

Claims (2)

[Claims] (1) a signal source representative of a flight parameter of the aircraft; a signal source representative of a radio altitude of the aircraft; a first alarm mode device responsive to said flight parameter signal and said radio altitude signal to generate an alarm signal in accordance with a first predetermined relationship between flight parameters; a first alarm mode device responsive to the flight parameter signal and the radio altitude signal to generate the alarm signal according to a predetermined relationship of 2; a ground proximity warning system for an aircraft, comprising: a device connected to the device and responsive to the time-based altitude signal to deactivate the first warning mode device. (2) a signal source representative of a flight parameter of the aircraft; a signal source representative of a radio altitude of the aircraft; an alarm signal generator responsive to the flight parameter signal and the radio altitude for generating an alarm signal according to a predetermined relationship between the flight parameter and the radio altitude; and the time-based altitude. a device operatively connected to the warning signal generator for responding to a signal and varying the predetermined relationship as a function of the time-based altitude signal. (31) to generate a time-based altitude signal that increases as a function of both time and radio altitude. a device responsive to the radio altitude signal; a device responsive to the attitude signal command and the radio altitude signal to generate a signal indicating the flight status of the aircraft; said radio wave altitude signal, said barometric altitude signal, so as to generate a first alarm signal when descending below a first predetermined radio wave altitude;
a first warning device responsive to said time-based altitude signal and said flight condition signal, said first alarm device responsive to said time-based altitude signal for effectively decreasing said first predetermined radio altitude as a function of said time-based altitude signal; a device responsive to a time-based altitude signal; and a device configured to respond to said radio altitude signal and said time signal to generate a second alarm signal when the aircraft descends below a predetermined radio altitude. a first alarm device responsive to the time-based altitude signal to increase the predetermined radio altitude as a function of the time-based altitude signal; ground proximity warning system for aircraft equipped with