GB2195861A

GB2195861A - External view system for training equipment

Info

Publication number: GB2195861A
Application number: GB08721818A
Authority: GB
Inventors: Peter Guldenpfennig; Wolfgang Metze
Original assignee: Messerschmitt Bolkow Blohm AG
Current assignee: Airbus Defence and Space GmbH
Priority date: 1986-09-20
Filing date: 1987-09-16
Publication date: 1988-04-13
Anticipated expiration: 2007-09-16
Also published as: IT1222669B; DE3632098A1; GB2195861B; DE3632098C2; IT8721926A0; FR2604273A1; GB8721818D0

Abstract

A method of generating visual information for a digital external view system for training equipment having pre-programmed mobile eyepoints in a sighting image generator. Extensive use is made of disc storage whereby the required scene, as determined by the programmed viewpoint and simulated position, can be called up and displayed. <IMAGE>

Description

SPECIFICATION External view system for training equipment This invention relates to a method of generating visual infomation for a digital external view system.

Digital external view systems, as have been used in the past for flight simulators or training systems for tank turret crews with simulated proper motion, have the disadvantage that the real-time dynamics in all six degrees of freedom have to be bought at the price of large hardware expenditure. Additionally, the real-time generation of the scenes means that, even upon use of cell texturing, reductions have to be made with respect to the trueness to nature or life-likeness of the scene content.

From DE-AS 21 28 961 is known equipment for practicing firing with guided weapons in which the target tracking procedure can be practiced with a realistically designed sighting device and a landscape representation which is true to nature is effected.

In DE-AS 26 58 501 is the prior art disclosure of a further method of simulating a mobile target in which the image of the mobile target is superimposed electronically on the photographed image of the environment. What has been said above applies here, too.

In the case of the sighting image generator, a great abundance of detail of the represented scenes is achieved, but the eyepoint is fixed with respect to the position of the person to be trained. This means that the system allows in real time only the dynamics of two degrees of freedom (elevation and azimuth). In the case of this external view system, a considerable proportion of the data processing processes is performed off-line, i.e. environment and moving models are stored digitally and are depending on azimuth and elevation called up and represented. The stored environment and the model aspect have a two-dimensional character.

An object of the present invention is to provide a method, of the kind mentioned at the beginning hereof, by which partial functions of the digital external view system are transposed out of real time into the off-line region and the previously necessary hardware for the image generators can be reduced.

With this object in view the present invention provides a method of generating visual information for a digital external view system for training equipment having pre-programmed movable eyepoints in a sighting image generator, characterised in that the known technologies of digital external view systems and sighting image generators are so combined with one another that a) the projection of three-dimensional stored surroundings infom ation into a two-dimensional plane of sighting is effected in the offline part, b) the data base is produced by the digital external view system, c) the dynamics of the two degrees of freedom of azimuth and elevation are retained, d) the terrain infom ation is storable in longer (e.g. seconds) intervals, and e) image manipulations such as changes of scale. translatory and rotary displacements, fadings, etc., are carried out during the seconds intervals and an image generation of environment and targets is calculable separately.

The invention will be described further, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a block diagram of a preferred embodiment of the digital external view system of the invention; Fig. 2 is a block diagram of the data-base generating system DBGS and of the preferred digital external view system shown in Fig. 1; Fig. 3 is a block diagram of a sighting image generator VBG with representation of the panoramic horizon sectors; Fig. 4a is a block diagram regarding the storage and call-up of the panoramic infom ation in the seconds interval; Fig. 4b shows a sketch regarding a panoramic horizon representation.

In the case of, for example, training installations for tank turret crews, a start is made from the fact that the proper motion of the vehicle to be simulated is preprogrammed.

That is to say the terrain in which the eyepoint moves, together with the extraneous vehicles that are to be represented, including the specific events can be dealt with off-line by means of a data-base generating system and a conventional digital external view system and then stored. That is to say, in the present exemplified method a combination of a conventional digital external view system and a sighting image generator is proposed.

The aim of the proposal of the present invention is in future to transpose partial functions of the digital external view system out of real time into the off-line region and to reduce the necessary hardware for the image generators in the case of training systems. In this respect, the real-time calculations undertaken in the case of conventional digital external view systems in frame il are in future, at least in the case of training systems having pre-programmed proper motion, to be carried out off-line. However, two degrees of freedom have to be taken into account upon the image generation for training systems for tank turret crews in real time. It is a matter, in this respect, of azimuth (+180 ) and elevation (e.g.

20 + 110 ). Thus this means that aiming gunner and commander can move their sights at any time during the course of the preprogrammed proper motion at will in the training system in these two degrees of freedom.

This means that the projection, undertaken in the case of conventional digital external view systems with a fully freely movable eyepoint, of the three-dimensional data base lying in the visual range, including the targets that are to be shown, into a two-dimensional plane of sighting is undertaken off-line and stored.

This two-dimensional visual information in digital form now has to be able to be called up at any point in time in real time, i.e. in real form. Thus, at any actual point in time, the panoramic horizon information including the targets shown has to be available. The result of this is that along the pre-programmed trajectories not only terrain and events with a single angle of view have to be stored, but additionally also the panoramic view or the variation of the angle of view in elevation respectively has to be possible.

The objection that such a method requires great store expenditure is justified. Of course, it has to be taken into account that great digital storage capacity is currently offered considerably more cheaply than previously.

For a panoramic view with a-magnification factor of, for example, 12-fold and an apparent angle of view of 60 , 72 frames, i.e. individual panoramic horizon sectors with an angle of view of 5 , have to be available in the sighting image generator. Thus upon use for tank simulation, the angle-of-elevation range for the sights can be limited to 200. The consequence of-this is that about 3DO horizon sectors are available for the panoramic view in the case of this limited angle-of-elevation range stored for call-up. The images are called up 25 times per second, since the image repetition rate amounts to 25 Herz; this means that per second of simulated movement a#bout 7500 images have to be stored.

Now it is known that television pict#ures of high quality can be laid down or filed with 256 kbytes. By appropriate coding measures, an image or pictures can be stored with 25 kbytes. For one second of simulation in the proposed training system for tank turret crews, the view contents would accordingly have to be able to be filed with a storage capacity of 187.5 megabytes.

At present storage media having a high capacity of, for example, 1 gbyte (gigabyte) are available (e.g. Gigadise of Messrs. Thomson). In the case of the above-quoted procedure, visual information will therefore be available merely for 5.5. seconds of simulation.

This disc stores information optico-digitally in contrast to the video disc, which enables the filing of optico-analog information. The giga-disc of Messrs. Thomson is with respect to the storage capacity also superior to the magnetic disc, with which digital information can be stored.

Now, provision is, for example, made for carrying out the storage of an item of panoramic information merely every second along the pre-programmed trajectories upon the simulation of the proper motion. This would for example with a gigabyte disc increase the simulation time from 5.5 seconds to 2 minutes. The use of several discs with appropriate scanning device can readily increase the simulation time to 10 minutes, as required for most training systems for tank turret crews.

Within this interval of 1 second, image manipulation can now also be undertaken which impart an impression of motion. In this respect it is taken into account that in the case of tank simulators the proper speed is not particularly high, so that by manipulation the impression of the proper motion can be imparted, without necessarily occurring image distortions and discontinuities showing up in a disturbing manner. Thus it is, for example, possible to perform variations of scale. As a result of an increasing enlargement of the image content, a motion in the direction of view or the line of vision is simulated. The perspective remains, in this respect, constant, whereas it would have to change constantly in the case of a genuine motion. However, this is not disturbingly conspicuous, since only slight errors of perspective arise.The actual angle of view through the simulated optical system is comparatively small.

A scene having pronounced staggering in foreground and background can be split up into several distancedependant wings or backdrops, which can be dealt with independantly of one another. In this way it can be ensured that the perspective relationship between foreground and background is preserved during the motion cycle. The markings for the distance-dependant wings are normally present in the case of the sighting image generator and are also necessary for the correct masking calculation of the objects that are to be represented, so that it merely has to be ensured that the image contents can be continuously mutually shifted without disturbing effects occurring.

A further possibility of bridging the intervals between two specific panoramic horizons is the technology of fading, i.e. the two image or picture contents can be gently blended at the beginning and at the end of an interval thus of two consecutive positions.

In the case of the method recited above, the data processing for targets and surroundings is performed separately. The targets have to be calculated actually, whilst the surroundings are defined anew at intervals of 1 second.

The advantage of the proposed method lies unequivocally in that considerable parts of the image calculation are performed off-line and hardware expenditure for the on-line generation is considerably minimised.

In contrast to the video disc technique, no actual photographs are necessary, but the representation of terrain and events is effected by means of known CGI technology. This has the advantage that upon the off-line generation of the terrain or of the events and targets respectively, digital manipulations are possible.

To increase the realism of the scene, naturally digital external view systems having cell texturing should be used for the image generation. The drawings accompanying this application supplement the above description and disclosure, so that they do not need to be gone into in detail.

Claims

1. A method of generating visual information for a digital external view system for training equipment having pre-programmed movable eyepoints in a sighting image generator, characterised in that the known technologies of digital external view systems and sighting image generators are so conbined with one another that a) the projection of three-dimensional stored surroundings information into a two-dimensional plane of sighting is effected in the offline part, b) the data base is produced by the digital external view system, c) the dynamics of the two degrees of freedom of azimuth and elevation are retained, d) the terrain information is storable in longer (e.g. seconds) intervals, and e) image manipulations such as changes of scale, translatory and rotary displace#ments fadings, etc., are carried out during the seconds intervals and an image generation of en vironment and targets is calculable separately.

2. A method as claimed in claim 1, characterised in that the terrain, covered and traversed by the eyepoint, including the vehicles that are to be represented and the specific situations are generated off-line by means of a data-base generating system and the conventional digital external view system and are stored in the sighting image generator.

3. A method as claimed in claims 1 or 2, characterised in that the two-dimensional visual information is available at any point in time for call-up in real time.

4. A method as claimed in claims 1 to 3, characterised in that panoramic horizon sectors with an angle of view of, for example, 50 to 200 are available in the sighting image generator.

5. A method as claimed in claims 1 to 4, characterised in that a storage is effected of panoramic informatiop in the interval of 1 sec along the pre-programmed trajectories upon the simulation of the proper motion.

6. A method as claimed in any one of claims 1 to 5, characterised in that a video disc or similar mass stores are used as storage disc and hereof several discs with appropriate scanning device are provided.

7. A method as claimed in any one of claims 1 to 6, characterised in that a scene having pronounced staggering of foreground and background can be split up into several distance-dependant wings or backdrops in the sighting image generator which can be dealt with independantly of one another.

8. A method as claimed in any one of claims 1 to 7, characterised in that the intervals between two specified panoramic horizons are bridgeable by dissolving technology.

9. A method as claimed in any one of claims 1 to 8, characterised in that the data processing for targets and surroundings is carried out separately.

10. A method of generati g visual information for a digital external view system substantially as hereinbefore described with reference to the accompanying drawings.