JPH0518749A - Radio altimeter failure detecting system - Google Patents

Abstract

PURPOSE:To secure flight safety by providing a flight control system with the function of detecting the failure of a radio altimeter so as to perform the processing of detaching a radio altitude information line, informing a pilot of failure, and the like at the time of detecting the failure. CONSTITUTION:Radio altitude information outputted from a radio altimeter 2 is inputted into a flight control computer 4 with a built-in failure detecting logic 5. The failure detecting logic 5 takes the radio altitude information from the radio altimeter 2 into the flight control computer 4 at the set time intervals and checks whether the radio altitude information is normal. Upon detecting the failure of the radio altimeter 2, the failure detecting logic 5 takes failure time flight control action such as detaching a radio altitude information line from a flight control line, and also performs radio altimeter related alarm display on a display 7 and also output to a voice warning 6 simultaneously in order to emit an alarm to a pilot.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure detection system for detecting a failure of a radio altimeter in a flight control system.

[0002]

2. Description of the Related Art Conventionally, in a flight control system such as an altitude maintaining function in an aircraft, flight control is carried out by using altitude information from a barometric altimeter, but recently, flight control is carried out using altitude information from a radio altimeter. It is starting to take control. However, the conventional flight control system using this radio altimeter does not have a function of detecting a failure of the radio altimeter.

[0003]

As described above, the conventional flight control system has a problem that the reliability of flight control is low because it does not have the failure detection function of the radio altimeter.

For example, if the aircraft is set to the altitude holding mode during flight at a certain altitude, if the radio altimeter is normal, the altitude information is input to the flight control computer, and the steering angle of the stabilizer or the like corresponding thereto is input. The altitude is maintained after being set. However, if the radio altimeter is out of order, abnormal altitude information other than the original altitude is input to the flight control computer. For this reason, an abnormal steering angle is set in the stabilizer or the like, and the motion of the aircraft is suddenly lowered or raised, which may cause the aircraft to crash.

The present invention has been made in view of the above circumstances, and has a function of detecting a failure of a radio altimeter, and when a failure is detected, flight safety is provided by disconnecting the radio altitude information line and notifying the pilot of the failure. It is an object of the present invention to provide a radio altimeter failure detection system which can be secured.

Further, the present invention provides a radio altimeter failure detection system which can prevent erroneous detection of a failure in the radio altimeter even when an aircraft encounters a special event and can obtain extremely high reliability. With the goal.

[0007]

[Means for Solving the Problems]

(1) A radio altimeter failure detection system according to the present invention includes a radio altimeter that is mounted on an aircraft and outputs altitude information measured by radio waves, and a flight control computer that performs flight control based on the altitude information from the radio altimeter. , Failure detection logic provided in this flight control computer to detect the failure of the radio altimeter, and when the failure of the radio altimeter is detected by this failure detection logic, the processing at the time of failure such as disconnection of the radio altitude information line is performed. Control means to perform,
It is characterized in that it is provided with an informing means for informing the occurrence of a failure by a failure detection signal from the failure detection logic, and an initialization switch for initializing the flight control computer.

(2) A radio altimeter failure detection system according to the present invention comprises a radio altimeter, an air data computer,
The flight control computer is equipped with a failure detection logic and a failure erroneous detection prevention logic, the altitude information from the radio altimeter and the atmospheric pressure altitude information from the air data computer are input, and the flight control computer has The effective range of the radio altimeter is set in advance, and when the difference between the barometric altitude and the set altitude exceeds the limit value within the allowable range of the radio altimeter, the failure detection information is changed to prevent erroneous detection. To do.

[0009]

[Action]

In the invention of (1), the flight control computer is initialized at the time of starting. After that, when the flight control computer starts the flight control operation, the failure detection logic fetches the radio altitude information from the radio altimeter into the flight control computer at a predetermined time interval and also checks whether the radio altitude information is normal or not. To check. The fault detection logic is
When a failure of the radio altimeter is detected, flight control measures are taken at the time of failure such as disconnecting the radio altitude information line from the flight control line.Also, a warning is issued to the pilot to alert the pilot at the same time. Output to voice warning. The pilot operates the initialization switch in response to the above alarm to initialize the flight control computer.

If the radio altimeter fails as described above,
Flight control measures are taken when a failure occurs in response to a failure detection signal from the failure detection logic, and the pilot can take necessary measures such as operating the initialization switch when the failure is notified to ensure flight safety. be able to.

In the invention of (2), the fault erroneous detection prevention logic causes the flight control computer to previously set the effective altitude limit value of the radio altimeter and the allowable limit value of the difference between the barometric altitude information and the effective altitude limit value of the radio altimeter. Set. Then, the air pressure altitude information from the air data computer is taken into the flight control computer, and whether or not the difference between the air pressure altitude information and the effective altitude limit value is less than or equal to a preset allowable limit value, that is, the flight condition is in a normal state. It is determined whether or not there is a special state. At this time, if the difference between the atmospheric pressure altitude information and the effective altitude limit value is equal to or less than the preset allowable limit value, it is determined that the flight condition is normal, and the failure detection process is performed by the failure detection logic. However, if the difference between the barometric altitude information and the effective altitude limit value exceeds the preset allowable limit value, it is judged that there is special flight condition and the failure detection process is skipped. The information is fetched and the above determination processing is performed.

By providing the fault erroneous detection prevention routine as described above and skipping the fault detection processing when the aircraft encounters a special event, it is possible to prevent erroneous detection of the fault of the radio altimeter.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram of a radio altimeter failure detection system according to a first embodiment of the present invention.

As shown in FIG. 1, a radio altimeter failure detection system 1 according to the present invention includes a radio altimeter (RDR ALT) 2 mounted on an aircraft to obtain altitude information by radio waves, a flight control computer initialization switch (hereinafter, referred to as F).
CC initialization switch) 3, a flight control computer (FCC) 4, a radio altimeter failure detection logic 5 which is built in the flight control computer 4 and detects a failure of the radio altimeter 2, and a failure is detected by the failure detection logic 5. When detected, it is composed of a voice warning 6 for issuing an abnormal alarm by voice and a display 7 for displaying a message of occurrence of an abnormality. Next, the operation of the above embodiment will be described with reference to the flowchart shown in FIG. The fault detection logic 5 incorporated in the flight control computer 4 executes the processing shown in the flowchart of FIG.

When operating the radio altimeter failure detection system 1, first, the flight control computer 4 is initialized (step A1). After that, when the flight control computer 4 starts the flight control operation, the failure detection logic 5
Receives the radio wave altitude information HR from the radio altimeter 2 into the flight control computer 4 at a predetermined time interval (step A2), and determines whether it is a track state or a no-track state (step A3).

The radio altitude information HR contains information indicating the track / no-track state of the radio altimeter itself. The fact that the radio altimeter is in the "track state" refers to the state in which the radio altimeter 2 indicates the effective altitude, and the radio altimeter 2 has information indicating the track state inside.
Further, the fact that the radio altimeter is in the "no-track state" refers to the state in which the radio altimeter 2 does not indicate the effective altitude, and the radio altimeter 2 has information indicating the no-track state inside.

In step A3, it is determined whether the radio altimeter 2 is in the track state or the no-track state. If the radio state is in the track state, the radio altitude information HR at that time is stored in a latch circuit (not shown) in the failure detection logic 5. Latch (step A4) and return to step A1. If it is determined in step A3 that there is no track, the radio altitude information immediately before no track held in the latch circuit is set as HR '(step A5).
It is determined whether ′ is within the radio altimeter failure detection altitude range HRD (step A6). This radio altimeter failure detection altitude range HRD is any altitude below the radio altimeter effective altitude limit HRV.

If it is determined in step A6 that the altitude is out of the fault detection altitude range, the process returns to step A2 for capturing the radio wave altitude information HR. Also, step A
If it is determined to be within the fault detection altitude range in step 6,
It is judged whether or not the number of continuous no-tracks reaches a predetermined number N of consecutive times (step A7). If the number of consecutive times is less than N, the process returns to step A2. If the number of consecutive times is N or more, the radio altimeter 2 It is determined that there is a failure, the radio altimeter failure information is stored (step A8), and flight control measures at the time of failure such as disconnecting the radio altitude information line from the flight control line are taken (step A9).

Further, in order to give a warning to the pilot, a warning related to the radio altimeter is displayed on the display 7 (step A10), and at the same time, an output to the voice warning 6 is carried out (step A11). The pilot operates the FCC initialization switch 3 in response to the above warning to initialize the flight control computer 4.

When the radio altimeter 2 has a failure as described above, the failure is detected by the failure detection logic 5 to take flight control measures at the time of failure and to notify the pilot of the occurrence of the failure. Therefore, the pilot can take necessary measures such as the operation of the FCC initialization switch 3 and can ensure flight safety.

In the above process, the radio wave height information is latched in step A4, but this is for the following reason. That is, the aircraft does not always fly only within the effective altitude limit of the radio altimeter, and may fly over the effective altitude limit HRV. At this time, the radio altimeter 2 always changes from the track state to the no-track state. Since the fault detection logic 5 is checking the no-track condition, if the flight exceeds the effective altitude limit HRV, the fault occurrence will be detected.
As shown in 5, by latching the altitude just before the no-track condition, the aircraft will have a radio altimeter 2
Due to the effective altitude limit, the failure is not notified when flying over this limit value. (Second embodiment)

According to the radio altimeter failure detection system shown in the first embodiment of FIG. 1, it is possible to detect a failure of the radio altimeter 2 and take flight control measures at the time of failure, but under special conditions such as an aircraft. May fly out of the effective altitude range of the radio altimeter, and when the next event is encountered, the failure detection operation may become unstable.

(A-1) When an aircraft flies over a radio wave reflection object such as a cloud in a fault detection area as shown in FIG. 3 (a), the fault detection system judges that the altitude is lower than the actual altitude, Acquire altitude information from altimeter 2. However, when it passes through the above-mentioned reflector, it again falls outside the effective altitude range of the radio altimeter, so the radio altimeter 2 enters the no-track state, and the radio-altitude information immediately before the no-track state is latched. As a result, the failure detection system may erroneously detect that the radio altimeter 2 has failed. In the figure, HB is barometric altitude information, HR is altimeter information, and HRD
Is the radio altimeter failure detection altitude range, and HRV is the radio altimeter failure detection limit value.

(A-2) If water droplets or the like are attached to the cover surface between the transmitting and receiving antennas of the radio altimeter, the radio waves are scattered as shown in FIG. May occur. At this time, the radio altimeter becomes unstable because it repeats the track or no-track condition.

(A-3) As shown in FIG. 3 (c), the reflected wave of the radio wave transmitted from the radio altimeter of another aircraft may be received by the radio altimeter of the aircraft, depending on the level of reception sensitivity. May track the reflected wave. That is, in X in the figure, since the timing is HRV or more, no track is made. However, in the case of ◯, the timing is below HR, and when the reception sensitivity level is exceeded, the track is made. However, since the above-mentioned reception sensitivity level fluctuates depending on the altitude of the aircraft, the radio altimeter repeats the track or no-track state and becomes unstable. The embodiment shown in FIG. 4 enables stable failure detection even under special conditions except for such an unstable point of failure detection.

The second embodiment shown in FIG. 4 is different from the first embodiment shown in FIG. 1 in that an air data computer 11 is provided to input atmospheric pressure altitude information HB to the flight control computer 4 and a failure detection logic 5 is also provided. A logic altimeter failure erroneous detection prevention logic 12 is provided therein. In this embodiment, the alarm tone 14 and the warning light 14 notify the occurrence of a failure. Flight control computer 4
The failure detection logic 5 and the radio altimeter failure erroneous detection prevention logic 12 built in the CPU execute the processing shown in the flowchart of FIG.

In the radio altimeter fault erroneous detection prevention logic initialization routine B1, the effective altitude limit value HRV of the radio altimeter 2 and the allowable limit value α of the difference between the barometric altitude information HB and the effective altitude limit value HRV of the radio altimeter 2 are set. The flight control computer 4 is set in advance (step B2), and the flight control computer 4 is initialized (step B3).

In the radio altimeter fault erroneous detection prevention routine B4, the atmospheric pressure altitude information HB from the air data computer 11 is fetched into the flight control computer 4 (step B5), and the atmospheric pressure altitude information HB and the effective altitude limit value HRV are acquired.
It is judged whether or not the difference from the difference is less than or equal to a preset allowable limit value α (step B6). At this time, the difference between the atmospheric pressure altitude information HB and the effective altitude limit value HRV is the preset allowable limit value α.
In the following cases, it is determined that the flight condition is normal, and the failure detection routine B7 shown in FIG. 2 is executed. However, if it is determined in step B6 that the difference between the atmospheric pressure altitude information HB and the effective altitude limit value HRV exceeds the preset allowable limit value α, it is determined that the flight condition is the special flight condition, and the failure detection routine B7 is performed. The fault detection due to is skipped, the routine returns to the radio altimeter fault erroneous detection prevention routine B4, and the atmospheric pressure altitude information HB is fetched again (step B5).

By providing the radio altimeter fault erroneous detection prevention routine as described above and skipping the fault detection routine when the aircraft encounters the special event, the radio altimeter 2 is erroneously detected as a fault even though the radio altimeter 2 is not faulty. There is no fear of doing it.

[0030]

As described in detail above, according to the present invention, in a flight control system using a radio altimeter, when the radio altimeter fails, the failure is detected by a failure detection logic and flight control measures are taken at the time of failure. It is possible to notify the pilot of the occurrence of the failure. Therefore, the pilot should operate the FCC initialization switch, etc.
The necessary measures can be taken and flight safety can be ensured.

Further, in the present invention, even if the aircraft flies over the effective altitude of the radio altimeter and encounters a special event, the failure detection routine is skipped, so that the false detection of the failure of the radio altimeter can be prevented. It is possible to ensure flight safety.

[Brief description of drawings]

FIG. 1 is a block diagram of a radio altimeter failure detection system according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is an explanatory diagram of special events encountered by an aircraft.

FIG. 4 is a block diagram of a radio altimeter failure detection system according to a second embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

1 ... Radio altimeter failure detection system, 2 ... Radio altimeter, 3
... FCC initialization switch, 4 ... Flight control computer, 5 ... Fault detection logic, 6 ... Voice warning, 7 ... Display, 11 ... Air data computer, 12 ... Radio altimeter fault erroneous detection prevention logic, 13 ...
Oral tone, 14 ... Warning light.

Claims (2)

[Claims] 1. A radio altimeter that is mounted on an aircraft and outputs altitude information measured by radio waves, a flight control computer that performs flight control based on the altitude information from this radio altimeter, and is provided in this flight control computer. A failure detection logic for detecting a failure of the radio altimeter, a control means for performing a failure process such as disconnection of the radio altitude information line when the failure of the radio altimeter is detected by the failure detection logic, and the failure detection logic A failure detection system for a radio altimeter, comprising: a notification means for notifying the occurrence of a failure by a failure detection signal from the device, and an initialization switch for initializing the flight control computer. 2. A radio altimeter, an air data computer, and a flight control computer, wherein the flight control computer has a failure detection logic and a failure erroneous detection prevention logic, and the altitude information from the radio altimeter and the air data computer. Input the altitude information of the air pressure, set the effective range of the radio altimeter in advance in the flight control computer, and detect the failure when the difference between the atmospheric altitude and the set altitude exceeds the limit value within the allowable range of the radio altimeter. A fault detection system for radio altimeters that changes information to prevent erroneous detection.