Patent Application
20120280986
This application claims priority to foreign French patent application No. FR 1101386, filed on May 5, 2011, the disclosure of which is incorporated by reference in its entirety.
The field of invention is that of aircraft instrument panels. Current instrument panels mainly include display screens for providing pilots the information required for flight control, navigation and more generally to achieve the mission in progress. The crew can interact with the screens by means of man-machine interfaces to select, monitor or modify the displayed data and parameters.
Short- and medium-haul passenger transport planes, called “single aisle” planes, have relatively small cockpits where the successful integration of components required for flight control, navigation, monitoring and communications is essential for flight safety and to optimize the workload of the crew.
At the present time, technology provides for achieving large display screens, typically having a diagonal greater than or equal to 15 inches with excellent resolution. For example, large screens using “LCD” (“Liquid Crystal Display”) technology can be used. The arrival of these large display screens in the field of avionics is confronted by technical installation issues and requires a drastic reduction in the number of screens in the cockpit. The reduction in the number of screens then raises problems of availability of the plane in the event of a single failure able to bring about simultaneously the loss of several functions previously distributed over several screens. To address this issue, of course a minimum number of small screens in the cockpit can be retained. At the present time, the number of screens is a minimum of four and can increase to eight or more. The greater the number of screens, the higher the installation and wiring costs, and the greater the mass of the system.
The avionics architecture according to the invention provides for producing an instrument panel that includes only three large display screens while providing sufficient availability of the avionics system in order to allow continuity of operations in complete safety in the event of a single failure until the next maintenance operation which can take place a few days after the failure is noted. The aim of this architecture, called a dual channel architecture, is to obtain, with only three large screens, the same operational availability as an avionics system with six display screens.
The architecture according to the invention is fully redundant, or “full dual”. Each screen includes two totally independent display half-screens, i.e. six half-screens in total. A single failure cannot cause the total loss of a large screen. The architecture thus provides either total availability of the six half-screens or availability of five half-screens out of six in the event of a single failure. Availability of primary information for the flight after a single failure is therefore ensured, while adhering to the flight safety objectives.
More specifically, the invention relates to a secure avionics system for aircraft, characterized in that it comprises strictly three display units and at least three graphics generation computers connected to the display units;
Advantageously, the avionics system includes only three graphics computers, each graphics computer being capable of generating four half-images.
Advantageously, the avionics system includes only four graphics generation computers.
Advantageously, two of the graphics generation computers include video image processing means and each of the said graphics generation computers is connected to a head-up display unit.
Advantageously, each display unit comprises a single liquid crystal display screen made up of two half-screens, each half-screen being addressed by an independent control circuit assembly, an independent lighting assembly and an independent electrical power supply.
Advantageously, the image generation means of each computer generate either two independent half-images or two half-images forming one and the same continuous image representative of data required for flight control, navigation, aircraft monitoring or airport taxiing.
Advantageously, the four graphics computers are grouped together in pairs, to form two dual graphics computers, each one capable of generating four independent half-images or four half-images forming two continuous images representative of data required for flight control, navigation, aircraft monitoring or airport taxiing.
The invention will be better understood and other advantages will become clear from reading the following description given in a non-limiting manner and with reference to the accompanying drawings in which:
By way of a first non-limiting example,
The display units are arranged in a row in the cockpit. Each pilot has in front of them a side screen displaying the data required for flight control and navigation. A central screen displays information on the engines and systems of the aircraft. The computers are connected to the rest of the avionics system comprising the various sensors of the aircraft and the aircraft data exchange and communications networks.
The functions of the graphics computers are to calculate, from aircraft systems data, the animation logic of the symbols and to plot them. These functions are acquisition, transmission, interaction of signals, calculation of parameters and their graphical representations.
To provide these functions, each graphics generation computer CGG mainly comprises:
In
The image generation means of each computer generate either two independent half-images or two half-images forming one and the same continuous image. These images are representative of data required for flight control, navigation, aircraft monitoring or airport taxiing. These main types of display are called “EFIS” (“Electronic Flight Instrument System”) and “ECAM” (“Electronic Centralized Aircraft Monitoring”). Depending on the displayed data, the displays are called:
The four graphics computers can be grouped together in pairs, to form dual graphics computers, capable of generating four independent half-images or four half-images forming two continuous images representative of data required for flight control, navigation, aircraft monitoring or airport taxiing.
Each display unit DU mainly comprises:
More specifically, the display screen can be an “LCD” (“Liquid Crystal Display”) technology screen including a single display matrix which is made up of two half-screens with separate control, referred to as “double driving”. By way of example, the size of the screen can be 15 inches which corresponds to a screen diagonal of 38 centimetres.
With this arrangement, in the event of a single failure, i.e. in the event that an electrical power supply, a control electronics unit, a backlighting arrangement or a half-screen fails, the other half-screen can be kept operational. Thus, the crew retains five half-screens operational out of six, which is acceptable on the flight safety plan. Under certain conditions, this also allows the plane to continue to be operated for several days, until the next maintenance operation.
It is to be noted that it is then possible to reconfigure this screen such that the primary data to control the plane remain available in the line of the pilot. In the event of the total loss of a screen, the data could be reconfigured on one of the two remaining screens, but control of the plane would be made more difficult insofar as the flight control data required would no longer be in the line of the pilot, considering the size of the large screens. The pilot would need to adapt mentally in order to return to his/her usual frame of reference.
In the architecture with three screens and four computers, each display unit DU is connected to two graphics generation computers. Each computer generates two half-images. The electronic switching means A, which comprise distribution means Sp and selection means Sel for the video signals, are for selecting one of the two computers and sending the images from this computer to the half-screens.
Each display unit DU includes two independent monitoring means MS which are for detecting possible failures. In the event that the selected computer fails, the switching means selects the images from the second computer in order to send them to the two half-screens. It is observed that, in this case, the failure is transparent to the crew members, who retain all of these six half-screens.
By way of example, in
In this architecture with three screens and four computers, under normal operating mode, one of the four computers is unused. This additional computation capacity given by the fourth computer can be used to host additional functions in the cockpit. Thus, as seen in
In the event that a graphics generation fails, the ANF function which is not critical is abandoned in order to reconfigure the main display which has been lost.
An alternative architecture to the preceding one and including only three graphics computers instead of four is represented in
In one variant of this alternative architecture with three screens and three graphics computers, represented in
In these two alternative architectures with three screens and three graphics computers, each computer nominally generates two half-images or one complete image. In the event that a computer fails, one of the two remaining computers then generates four half-images or two complete images, such that the failure is transparent to the crew members, who retain all of their six half-screens.
The electronic switching means A are for selecting one of the computers and sending the images from this computer to the half-screens.
| Number | Date | Country | Kind |
|---|---|---|---|
| 11 01386 | May 2011 | FR | national |
