SYSTEM FOR DISPLAYING CRITICAL AND NON-CRITICAL INFORMATION

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to the field of displaying critical and non-critical information for piloting a vehicle and more particularly an aircraft.

[0002] In avionics, critical information is that which is essential for piloting the aircraft and which, if erroneous, can directly lead to the loss of the aircraft. Key critical information includes, for example, airspeed, a sideslip indicator, an attitude indicator, altitude, vertical speed, and heading. For this reason, the critical data display system is itself a critical component, and its use on board an aircraft is preceded by a qualification, or certification, procedure involving rigorous testing to demonstrate the robustness, accuracy, and reliability of the display system under all circumstances. The design and manufacture of such a display system are therefore costly.

[0003] To improve crew comfort, it is common practice to display useful but not critical information in the cockpit. This information includes, for example, interior and exterior temperatures, time data, data relating to the operation of aircraft equipment, navigation data, and other similar information. The display device for this information can be either a non-critical display or the critical display device itself.

[0004] In the most sophisticated systems, the display also includes relatively complex, non-critical information. One example is map data, specifically terrain rendering images that represent in three dimensions the area of ​​the Earth's surface overflown by the aircraft. Another example is images from onboard cameras.

[0005] Displaying such complex information requires a central processing unit (CPU) to process the critical information for display, a graphics processing unit (GPU) to construct images incorporating non-critical information and to graphically represent the critical information (alphanumeric characters, symbols, curves, histograms, scales), and an FPGA-type circuit to transform these images into electrical signals for display on a screen. For example, typically, the central processing unit calculates that a straight line must be drawn from point A (0, 0) to point B (100, 100), and the graphics processing unit creates an image in which all pixels (i, j) for which i = j, ranging from 0 to 100, are illuminated.

[0006] Document WO-A-2011 / 066920 describes a display device for creating images that include both critical and non-critical information. Document EP-A-3495778 describes a method for displaying critical information on a non-certified display. Document US-A-2015 / 109340 describes a method for displaying images that include critical information in the foreground and non-critical information in the background. SUBJECT OF THE INVENTION

[0007] The invention aims in particular to ensure that the critical information displayed has not been altered during its processing for display. SUMMARY OF THE INVENTION

[0008] To this end, the invention provides a system for displaying critical and non-critical information on a screen. The system comprises, within a single housing, at least one electronic processing circuit (110) and one electronic monitoring circuit. The electronic processing circuit is programmed to process the critical information to be displayed, construct at least one image from the non-critical information, and incorporate the critical information to be displayed into this image in order to form, at an output of the electronic processing circuit, an image signal intended for transmission to the screen. The electronic monitoring circuit has an input connected to said output and is programmed to determine the critical information expected for display and to verify whether the image signal contains information corresponding to the expected critical information.

[0009] Thus, the presence of critical information is verified in the image signal intended for transmission to the display screen, which limits the risk of displaying critical information altered by the processing it has undergone for display. The fact that the data to be displayed is processed by electronic circuits housed in a single package facilitates this verification.

[0010] The invention also relates to an aircraft equipped with a display screen connected to the output of the electronic control circuit of such a system.

[0011] Other features and advantages of the invention will become apparent from the following description of particular and non-limiting embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Reference will be made to the attached drawings, including: There figure 1 is a partial schematic top view of an aircraft according to the invention; The figure 2 is a block diagram of a display system according to a first embodiment of the invention; The figure 3 is a block diagram of a display system according to a second embodiment of the invention; The figure 4 is a block diagram of a display system according to a third embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] With reference to the figure 1 The aircraft, here an airplane, comprises a fuselage 1 in which a cockpit 2 is fitted.

[0014] The aircraft is equipped with a number of systems that provide information to the pilot, enabling them to fly the aircraft safely from its point of departure to its point of arrival. This information includes: critical information enabling the pilot to take off and land the aircraft, and to keep it airborne; and non-critical information enabling, for example, the pilot to visualize his surroundings.

[0015] Thus, in a manner known in itself, the aircraft is equipped with a set of 3 external sensors comprising: a barometric altimeter 3 which provides, in association with an outside temperature sensor, an altitude measurement from the atmospheric pressure surrounding the aircraft; Pitot probes to measure the airspeed of the aircraft.

[0016] The aircraft's altitude and airspeed are among the critical information to be displayed.

[0017] The aircraft also carries an electronic navigation system 4 connected, on the one hand, to an inertial measurement unit 5 comprising linear inertial sensors (accelerometers) and angular inertial sensors (gyroscopes) to provide inertial positioning data (attitude, position, and speed) and, on the other hand, to a satellite signal receiver 6 configured to provide satellite positioning data for the aircraft (pseudo-ranges) from signals originating from a constellation of satellites belonging to a global positioning system (or GNSS; such as GPS, GALILEO, GLONASS, BEIDOU, etc.). The electronic navigation system 4, known in itself, determines, by combining inertial and satellite positioning data, the aircraft's speed and position, which is then plotted on a map of the area overflown.We are only interested here in the attitude, provided by the inertial measurement unit 5, which is part of the critical information to be displayed.

[0018] A front-facing camera 7 is mounted at the front of the fuselage 1 to provide, in the form of a video feed, images of the environment in front of the aircraft. These images are part of the non-critical information to be displayed.

[0019] A rear camera 8 is mounted at the rear of the fuselage 1 to provide, in the form of a video feed, images of the environment behind the aircraft. These images are part of the non-critical information to be displayed.

[0020] A display screen 9, connected to a display system generally designated as 100, is mounted in the cockpit 2 to present critical and non-critical information to the pilot. Of course, the amount of information displayed could vary, with more or less critical and / or non-critical information: this is simply an example to explain the invention.

[0021] The display system 100 comprises a housing 101 equipped with connectors defining at least one input 102.1 connected to the barometric altimeter 3 to receive the altitude, a second input 102.2 connected to the electronic navigation unit 4 to receive the airspeed, a third input 102.3 connected to the front camera 7 to receive a video feed representing the aircraft's forward environment, a fourth input 102.4 connected to the rear camera 8 to receive a video feed representing the aircraft's rear environment, and an output 103 to provide the electrical signal corresponding to the images to be displayed. The connectors forming inputs 102.1 to 102.4 and output 103 allow the electrical connection of the display system 100 to the equipment to which it is intended to be connected.

[0022] The housing 101 contains at least one electronic computing circuit 110 (commonly called COM) and one electronic monitoring circuit 120 (commonly called MON) connected to the electronic computing circuit 110. Each of these electronic circuits 110, 120 includes at least one processor and a memory set containing computer programs executable by the processor.

[0023] The computer programs executed by the processor of the electronic computing circuit 110 include instructions arranged so that the electronic computing circuit 110 forms a central processing unit (commonly called a CPU) which processes (prepares and formats) critical information to be displayed, constructs an image from the non-critical information and incorporates the processed critical information, in order to form, on an output of the electronic computing circuit 110, an image signal intended to be transmitted to the display screen 8.

[0024] The computer programs executed by the processor of the electronic monitoring circuit 120 include instructions arranged so that the electronic monitoring circuit 120 determines critical information expected for display and determines whether the image signal contains information corresponding to the expected critical information.

[0025] The various functions and tasks performed by the electronic computing circuit 110 and the electronic monitoring circuit 120 will now be described, in relation to the figures 2 à 4 , in three modes of embodiment.

[0026] The electronic computing circuit 110 performs the same functions and tasks in all three embodiments. The electronic computing circuit 110 receives the aircraft's altitude and speed, which are the critical information, from inputs 102.1 and 102.2. The program executed by the electronic computing circuit 110 includes a program section 111 arranged to group the critical information and present it in the format in which it will be displayed, thus obtaining the critical information to be shown.

[0027] A part of program 112 executed by the electronic computing circuit 110 then incorporates the critical information to be displayed in a detail layer (commonly called a "layer") called α which includes a transparent background and is intended to form an overlay layer in the images to be displayed.

[0028] The electronic computing circuit 110 receives the video stream from the front camera 7 through input 102.3 and the video stream from the rear camera 8 through input 102.4. The program executed by the electronic computing circuit 110 includes program parts 113, 114 arranged to display the two video streams in two windows of a background detail layer of the image (classically called the RGB layer).

[0029] A program component 115 then merges the background detail layer with the α detail layer so that the latter appears superimposed on the background detail layer. The electronic processing circuit 110 provides an image signal (more precisely, a video stream) via an output 104.1 connected to the output 103 to which the screen 9 is connected.

[0030] In practice, the electronic computing circuit 110 can be programmed to emulate the operation of a graphics processing unit (GPU). The emulation program then handles the creation and blending of detail layers. Such emulation programs are currently commercially available and can be configured and used to implement the invention.

[0031] The electronic computing circuit 110 can alternatively be programmed to use pre-calculated images.

[0032] Alternatively, the 110 computing electronic circuit may include at least one FPGA forming a video accelerator arranged to fuse the detail layers together. The FPGA is then preferably programmed to perform at least some of the processing functions traditionally handled by a GPU. Aircraft flight computers contain FPGAs that can be used for this purpose.

[0033] In all three embodiments also, the output 104.1 of the computing electronic circuit 110 is connected to an input 105.1 of the monitoring electronic circuit 120, enabling the computing electronic circuit 110 to transmit the image signal to the monitoring electronic circuit 120.

[0034] According to the first embodiment illustrated on the figure 2 The electronic computing circuit 110 includes an output 104.2 connected to an input 105.2 of the electronic monitoring circuit 120, enabling the electronic computing circuit 110 to transmit the detail layer α to the electronic monitoring circuit 120. The detail layer α includes the critical information considered to be expected by the electronic monitoring unit 120.

[0035] The electronic monitoring unit 120 executes a program, part 121 of which is designed to use the received detail layer α as a mask and apply it to the image signal received at input 105.1 to obtain a result signal. A program part 122 executed by the electronic monitoring circuit 120 verifies, using the result signal, that the detail layer α received at input 105.2 is indeed present in the image signal received at input 105.1. In fact, the result signal must correspond to the detail layer α received at input 105.2, with other information masked. If so, the critical information is displayed correctly.If not, the critical information was altered either during the merging process, during the transfer between the computing unit 110 and the monitoring unit 120, or there was a failure of the monitoring unit 120: the electronic monitoring unit 120 issues an alert informing the pilot that the displayed critical information cannot be taken into account. According to the second embodiment illustrated in Figure 1. figure 3 The electronic computing circuit 110 includes an output 104.3 connected to an input 105.3 of the electronic monitoring circuit 120, enabling the electronic computing circuit 110 to transmit to the electronic monitoring circuit 120 the critical information processed, which will be considered as the critical information expected by the electronic monitoring circuit 120.

[0036] The program executed by the electronic monitoring unit 120 includes a program section 123 designed to create the detail layer α incorporating the processed critical information received by input 105.2 and transmit it to the program section 121, which will use it as a mask applied to the image signal received at input 105.1 to obtain a result signal. The result signal corresponds to the image resulting from filtering the image received at input 105.1 using the α layer as a mask. The program section 122, executed by the electronic monitoring circuit 120, verifies from the result signal that the detail layer α created by the electronic monitoring unit 120 is indeed present in the image signal received at input 105.1. In fact, the result signal must correspond to the detail layer α created by the electronic monitoring unit 120, with the other information masked.If yes, the critical information is correctly displayed. If no, the critical information has been altered, either during the creation of the detail layer α by the electronic computing unit 110, or during the merging, or during the transfer between the computing unit 110 and the monitoring unit 120, or it is a failure of the monitoring unit 120: the electronic monitoring unit 120 issues an alert informing the pilot that he cannot take into account the critical information displayed.

[0037] According to the third embodiment illustrated on the figure 4 The electronic monitoring circuit 120 is connected to inputs 102.1, 102.2 to directly receive critical information.

[0038] The program executed by the electronic monitoring unit 120 includes a program section 124 arranged to process, like program section 111, critical information from that received directly from inputs 102.1 and 102.2, thus obtaining the expected critical information. The critical information thus processed is theoretically identical to that produced by the electronic computing circuit 110 and is transmitted to program section 123, which creates the detail layer α incorporating the critical information processed by program section 124. The detail layer α created by program section 123 is transmitted to program section 121, which uses it as a mask applied to the image signal received at input 105.1 to obtain a result signal.Program section 122, executed by the monitoring electronic circuit 120, verifies from the output signal that the detail layer α created by the monitoring electronic unit 120 is indeed present in the image signal received at input 105.1. In fact, the output image must correspond to the detail layer α created by the monitoring electronic unit 120, with other information masked. If so, the critical information is displayed correctly.If not, the critical information has been altered, either during processing by the electronic computing unit 110, or during the creation of the detail layer α by the electronic computing unit 110, or during the merging process, or during the transfer between the computing unit 110 and the monitoring unit 120, or it is due to a failure of the monitoring unit 120: the electronic monitoring unit 120 issues an alert informing the pilot that it cannot take into account the critical information displayed. Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0039] In particular, the system may have a different structure than described, and for example, several computing and / or monitoring units. The monitoring unit may include at least one voter (an autonomous selector within the computing unit providing an image with critical information deemed correct) or at least one relay (controlled by other equipment or a human). For example, the computing electronic circuit 110 and the monitoring electronic circuit 120 may belong to the same electronic circuit. They may each be formed by one or more cores of the same processor. The electronic circuits 110 and 120 may be part of the same flight computer.

[0040] Alternatively, the 102 inputs can be grouped in a separate box (interface module) connected by an electrical connection cable to the box 101 which contains the calculation and monitoring circuits.

[0041] The invention can be implemented using one or more single-core or multi-core processors and / or one or more FPGA circuits incorporating one or more processors.

[0042] Critical and non-critical information can be provided by means other than those described, for example a radio altimeter for altitude.

[0043] Critical information may include information other than that mentioned.

[0044] Non-critical information may include aircraft operating parameters, meteorological data, visible or infrared images, radar data...

[0045] Non-critical information may also include terrain-following images. The aircraft then includes: an altitude database containing the coordinates of points in a grid of the territory overflown by the aircraft and the altitudes associated with each point in this grid, a photographic database containing the coordinates of points in this same grid of the territory overflown by the aircraft and aerial photographs associated with these points.

[0046] Alternatively, the computing electronic circuit 110 has at least one input connected to a measurement source, and the monitoring electronic circuit 120 has an input connected to said measurement source, so that the critical information to be displayed and the expected critical information are obtained from the same measurement source. The computing electronic circuit 110 incorporates the critical information to be displayed in a first detail layer merged with at least one background detail layer to form the image to be displayed, the first detail layer also being transmitted to the monitoring electronic circuit 120.

[0047] The invention is applicable to any type of aircraft, fixed-wing or rotary-wing, piloted or unpiloted, atmospheric or space-based... The invention is also applicable to naval or land vehicles.

Claims

1. System for displaying critical and non-critical information on a screen (9), the system comprising, in one same housing (101), an output (103) of which is connected to the screen, at least one electronic computing circuit (110) and one electronic monitoring circuit (120), the electronic computing circuit (110) being programmed to process the critical information to be displayed, construct at least one image from the non-critical information and incorporate therein the critical information to be displayed in order to form, on an output (104.1) of the electronic computing circuit (110), an image signal intended to be transmitted to the screen; the electronic monitoring circuit (120) having an input (105.1) connected to said output (104.1) of the electronic computing circuit (110) and being programmed to determine the expected critical information for the display and verify whether the image signal contains information corresponding to the expected critical information.

2. System according to claim 1, wherein the electronic computing circuit (110) has at least one input connected to a measurement source and the electronic monitoring circuit (120) has an input connected to said measurement source, the critical information to be displayed and the expected critical information therefore being obtained from the same measurement source.

3. System according to claim 1 or 2, wherein the electronic computing circuit (110) incorporates the critical information to be displayed in a first detail layer combined with at least one background detail layer to form the image to be displayed.

4. System according to claim 3, wherein the electronic monitoring circuit (120) develops a second detail layer, wherein the expected critical information is incorporated.

5. System according to claim 4, wherein the electronic monitoring circuit (120) uses the second detail layer as a mask applied to the image signal to obtain a result signal and verifies that the result signal corresponds to the second detail layer.

6. System according to claim 3, wherein the first detail layer is transmitted to the electronic monitoring circuit (120).

7. System according to claim 6, wherein the electronic monitoring circuit (120) uses the first detail layer as a mask applied to the image signal to obtain a result signal and verifies whether the result signal corresponds to the first detail layer.

8. System according to claim 1, wherein the electronic computing circuit (110) transmits the critical information to be displayed to the electronic monitoring circuit (120), and the electronic monitoring circuit (120) considers said critical information to be displayed as the expected critical information and verifies whether the expected critical information is present in the image signal.

9. Aircraft equipped with at least one screen (9) to which the output (103) of a display system (100) is connected, according to any one of the preceding claims.