JPS6165182A - Misalarm suppressing system in aircraft clash preventing device - Google Patents

Abstract

PURPOSE:To inhibit surely an useless alarm by calculating estimatingly the atmospheric pressure of an airport near the self-airplane on the basis of the relation between the absolute altitude obtained by an altimeter and the atmospheric pressure at said altitude. CONSTITUTION:A filtering circuit 8 for identifying whether other airplanes exist on the ground or not is connected between a replay detector 5 and a computer 6. Atmospheric pressure information obtained from an aneroid altimeter 9 and absolute altitude information obtained from a radio altimeter 10 are encoded by an encoder 11 and inputted to a ground altitude computer 12 to calculate the surface atmospheric pressure around a near airport. The calculated value is compared with the altitude information due to the atmospheric pressure which is included in a mode replay signal which is the output of the detector 5, whether an ATC transponder replay signal is generated from the airplane on the ground or not is discriminated under the consideration of a required error, and if the replay signal is generated from the airplane on the ground, a signal for inhibiting the operation of the circuit 8 is sent to the circuit 8. Thus, other airplanes standing on the airport and mounting ATC transponders are not displayed on an indicator 7, so that misalarms can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is an aircraft collision prevention system, in particular, suppresses false alarms issued by the aircraft collision prevention system regarding other nearby aircraft, thereby reducing unnecessary warnings and reducing pilot costs. This invention relates to a false alarm suppression method to reduce operations as much as possible.

(Prior art) Conventionally, large and medium-sized aircraft such as airliners and commuters are generally equipped with an aircraft collision prevention bag e that detects the approximate location of other aircraft in the vicinity of the own aircraft and issues a warning. Such a device is an interrogator for other aircraft and an A'['C transponder that responds to interrogation signals from other aircraft.

On the other hand, □Small aircraft such as private aircraft are A.
It is common to install all TC transponders.

Now, in areas around airports where aircraft are most concentrated and where accidents occur frequently, the interrogation signals emitted by the aircraft collision avoidance system interrogators are not necessarily responded to by other aircraft in flight, but also by aircraft parked at the airport. It is a well-known empirical fact that the ATC transponder is mounted on the tower of an aircraft preparing for departure, and in the past, warnings based on the response signal of the ATC transponder mounted on the tower of aircraft with no risk of mid-air collision were frequently issued. The aircraft anti-collision system had a defect in that it was not only troublesome but also extremely dangerous for aircraft pilots before and after takeoff and landing, when they must concentrate the most on flight control.

(Object of the Invention) The present invention was made to eliminate the above-mentioned defects in the conventional aircraft collision avoidance system. It is an object of the present invention to provide a method for detecting and suppressing false alarms in aircraft collision avoidance systems by identifying and reducing unnecessary alarms.

(Structure of the Invention) In order to achieve all of the above-mentioned objects, the following method is adopted in the present invention.

In other words, the atmospheric pressure at the airport near the own aircraft is estimated from the relationship between the absolute altitude measured by the radio altimeter and the atmospheric pressure at that altitude, or the ground pressure information from the airport control safeter is used to respond to other aircraft tower-mounted ATC transponders. The part of the signal that includes altitude information corresponding to the air pressure at the airport is removed by the aircraft collision prevention system mounted on the own aircraft tower so that it is not the subject of a warning or display.

(Embodiments of the Invention) Two embodiments of the present invention will be described below in detail based on embodiments shown in the drawings.

First, the functions of the ATC transponder will be briefly explained to help understand the present invention.

ATC transponders can currently be classified into three types depending on the functions they possess, but the simplest one is the so-called mode A, in which the response signal does not contain any special information, and the interrogation signal emitted by the interrogator does not contain any particular information. The aircraft collision prevention device that receives the response signal simply responds, and if it determines the relative distance from the received electric field strength, and also adds a device that detects the arrival direction of the response signal, it can also determine the general direction. It is something that can be used.

A slightly more sophisticated transponder is called Mode C, which adds altitude information to the response signal, and the altitude information uses the air pressure at the flight altitude of the aircraft carrying the transponder.

The code is included in the response signal.

Therefore, it should be noted that in the method of the present invention, the ATC/sponge that is the object of response signal identification is limited to the above-mentioned modes C and S, that is, those in which the response signal includes altitude information.

Now, FIG. 1 is a block (2) showing an embodiment of the false alarm suppression method according to the present invention.

In this figure, block 1 surrounded by a dashed line is a typical aircraft collision avoidance system. When the transponder response signal is received again by the antenna 2, this response signal is transmitted to the receiver (R/X) 4. The contents are analyzed by a computer (CAS C0NPUTER,) 6 via a response detector 5 and displayed on an indicator (INDIC) if necessary.
A warning is displayed on ATOR, )7.

As explained above, when the conventional aircraft collision prevention system is flying around an airport, it may receive all the ATC transponder response signals of the aircraft parked at the airport and the latch is still on. In such a case, the display 7 will issue a warning even though there is no risk of collision, which is extremely troubling to the operator, as described above.

In order to solve the above-mentioned problems, the present invention provides a filtering circuit (O
N-THE-GR,0UNDSIGNAL FILT
ER, )8i intervention.

And the barometric altimeter (ANgR・OI) mounted on the own aircraft
The encoder (ENCODER・) 11 receives the barometric pressure information from the D ALTIMETER・) 9 and the absolute altitude information from the radio altimeter (R, ADIOALTIMETERl) 10.
β Compare the altitude information based on atmospheric pressure included in the mode C output or the low response signal, and take the necessary error into account and adjust the ATC.
Distinguish whether the transponder response signal is emitted from an aircraft on the ground or not, and if the response signal is emitted from an aircraft on the ground, send a signal to the filtering circuit 8 to prohibit the operation of the filtering circuit 8. It is composed of

By doing this, other aircraft parked at the airport that are equipped with mode C or Hs ATCl-Lance Bonder will not be displayed on the display 7, and the pilot will be troubled by unnecessary warnings. The possibility can be reduced.

The mode S transponder response signal includes a signal indicating that the transponder is on the ground. Therefore, as shown in FIG.
R, 01JND 5IGNALDE TOFt,) 1
3, and a loop may be added that completely prohibits the operation of the filtering circuit 8 by its output. By doing so, it becomes possible to reliably prohibit unnecessary warnings regarding the mode S transponder response signal without comparing the pressure altitudes as described above.

Now, the airport control center always informs aircraft preparing to land of the air pressure on the surface of the airport to ensure safe landing. Therefore, as shown in Fig. 3, general communication receivers (Fl,
The ground pressure information obtained through OR, COMMtJNICATION) 14 is sent to the encoder (ENCODER,).
15 and manually input it to the ground altitude calculator 12, and then compare this with the altitude information in the ATC transponder response signal of another aircraft. In this case, information from the barometric altimeter 9 and the radio altimeter 10 mounted on the own aircraft may be prevented from being input to the ground altitude calculator 12 by the switching circuit 16.

It is obvious that a collision prevention system that relies on ground pressure information at an airport, as described above, is particularly effective as a simple system when applied to Aircraft 2FA, which is not equipped with a radio altimeter.

(Effects of the Invention) Since the present invention is constructed as described above,
Not only in regions such as Europe where most aircraft are equipped with mode C or S ATC transponders, but also in regions such as the United States where most aircraft are equipped with mode C or S ATC transponders.
Even in locations where the ratio of aircraft onboard aircraft is around 60 (as of 1984), unnecessary warnings are issued from aircraft collision prevention systems, which may hinder pilots' mental concentration, especially during takeoff and landing. Since it can be reduced completely, it has a remarkable effect on the safe operation of aircraft.

In addition, since the additional circuitry required to fully construct the present invention can be provided at a relatively low cost, there are few factors that would make it more popular.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the false alarm suppression method according to the present invention, and FIG. 2 is a block diagram showing a partially modified embodiment thereof (Figures W and W3 are complete explanations of a simple embodiment of the present invention. 1. Aircraft collision prevention system. 8-.. Filtering circuit for completely discriminating whether or not another aircraft is on the ground. 9.・・・・・・Barometric altimeter, 10・・・・・・
...Radio altimeter, 12...Ground altitude calculator. Patent applicant: Toyo Tsushin Iso Co., Ltd., qθpE-do pizE Kabute'1 - Procedural amendment February 1982 Related: Applicant 5: Number of inventions increased by amendment None 6: Subject of amendment: Item 2 of the patent application and all nine drawings attached to the specification. L (11-hi ras-xt)

Claims (2)

[Claims] (1) In an aircraft equipped with an aircraft collision avoidance system and a radio altimeter, the air pressure at an airport near the aircraft is determined based on the absolute altitude indicated by the radio altimeter and the air pressure at the altitude at which the aircraft is flying. The aircraft collision avoidance system receives the estimated value and the ATC transponder response signal mounted on the tower of another aircraft in response to the interrogation signal issued by the aircraft collision avoidance system, and determines the altitude based on the atmospheric pressure contained in these response signals. A false alarm suppression system in an aircraft collision prevention system, characterized in that the occurrence of unnecessary alarms is reduced by discriminating and removing ATC transponder response signals emitted by aircraft parked at the airport from information. . (2) Obtain air pressure information on the surface of the airport from the information provided by the airport control center, and use this and altitude information based on air pressure contained in the ATC transponder response signal mounted on the tower of other aircraft while the aircraft is parked at the airport. A emitted by the aircraft of
A false alarm suppression system in an aircraft collision prevention system, characterized in that the generation of unnecessary alarms is reduced by discriminating and removing TC transponder response signals.