GB2091193A - Simulator for simulating, for example, aircraft flight - Google Patents

Abstract

For the training of, for example, pilots and tank drivers, a simulator is provided which comprises an inflatable spherical dome 1 surrounding an exchangeable cockpit 4 said dome 1 being made of a transparent foil which has on its inside a highly light-dispersing surface provided by light-reflecting particles embedded in the foil. With the aid of projectors 8 which are arranged outside the dome 1, fault-free panorama and target representations are achieved. An inner tent 3 can be swung up and closed in an airtight manner to retain the supporting pressure in the dome while one cockpit is exchanged for another. <IMAGE>

Description

SPECIFICATION Simulater for simulating, for example, aircraft flight This invention relates to a simulator, for simulating the terrain which may be encountered by, for example, an aircraft or a tank during its operation, comprising an exchangeable cockpit.

Such simulators for used, for example, to teach pilots on the ground the operation of aircraft, in which respect the pilots take their place in a cockpit which can correspond to any particular type of aircraft, and can perceive an externally artificially represented world through the window panes of the cockpit.

Simulators of this kind are also used to train, for example, tank drivers, in which respect this is effected in accordance with the previously described principle.

The advantage of this procedure lies in that expensive flying or travelling hours can be avoided and the apparatus to be used is not subjected to the high demands which exist when training with conventional aircraft or tanks.

The effective use of such simulators depends on the extent to which both the cockpit environment and the terrain to be represented can be reproduced in a lifelike manner. Examples of such simulators are to be found in United States Patent No. 23 85 291, United States Patent No. 39 11 597, German Offenlegungsschrift No. 25 58 501.

These known arrangements suffer from the disadvantage that, particularly at the boundary positions of fields of vision that are to be represented, visual distortions occur or else the terrain simulated itself seems unreal.

An object of the present invention is to provide a simulator of a kind mentioned at the beginning hereof, with which an unimpeded panoramic view is made possible, and with which, for changing training situations, the cockpits to be used are exchangeable.

With this object in view the present invention provides a simulator for simulating the terrain which may be encountered by, for example, an aircraft or a tank during its operation, comprising an exchangeable cockpit, characterised in that an inflatable spherical dome made of transparent foil of high dimension stability and strength surrounds the cockpit to form a projection wall in which respect a strongly light-dispersing surface is present on the inside of the dome and light-reflecting particles or a reflecting light-transmissive fabric are embedded into the foil, in that the representation of the terrain is effected by back-projection by means of projectors from the outside onto the dome, in that, for the exchanging of the cockpit, an inner tent can be swung up over the cockpit, which screens the cockpit in an airtight manner from the dome, and in that the cockpit is mounted on an adjustable base frame which can be swung up.

With the simulator of the present invention advantageously both the problem of the disturbance-free panoramic view and that of the cockpit change is solved.

In accordance with a further aspect of the invention, advantageously provision is made for the fact that serving as projectors are fixed background projectors having a large projection field and movable target projectors having a small projection field, in which respect one target projector each is associated with a background projector, and in that the image of the target projector is freely positionable by way of one or two swingable deflecting mirrors within the projection field of the background projector and in the edge of the adjacent image.In this way, advantageously the problem of the joining together of the individual images is solved. Ajoining together of several target image parts is avoided, since at the boundary of the swivel range a change over can simply be made from one target projector to the next as soon as the images of both target projectors coincide.

The invention will be described further, by way of example, with reference to the accompanying drawing in which the single Figure is a schematic side view of a preferred embodiment of the simulator of the invention.

Referring to the Figure, the preferred simulator comprises as inflatable dome 1 made of transparent plastics foil of high dimension stability and strength.

Embedded into the transparent foil are particles or a fabric made of reflecting material, which reflect obliquely incident light and thus bring about a lesser drop in brightness in the image corners. The foil is matted on its outside and on its inside in order to achieve a uniform distribution of brightness. The foil serves as a projection wall 2. The seam locations of the dome 1 are, insofar as they are present, realised by butt or flush contiguity of the foil and connection to a transparent adhesive strip on the outside of the dome.

For exchange of a cockpit 4 the inflatable dome 1 must be prevented from suffering from a loss in pressure. The dome 1 is fastened, in a manner which is not shown in detail, to a soiid base or ground ring, which is for its part sealed off against the ground.

The dome 1 is provided with a lock (not shown) by which it can be entered in normal operation.

Mounted onto the base ring or onto another suitable device is an inner tent 3, which can be swung up and can be closed in an airtight manner over the cockpit 4, so that the cockpit region is sealed off in an airtight manner from the rest of the dome 1. The cockpit 4 can be removed downwardly from the dome 1, without a pressure loss occurring in the dome 1.

The inner tent 3 can be in two halves and can consist, for example, of a material which is impervious to air. These halves can be semicircular shaped and can be held inside the base ring, at two locations, on pivot bearings. The inner tent 3 can be erected by inflatable or tubes arranged between supporting arches.

The provision of an unhindered panoramic view by the simulator is ensured by back-projection from the outside onto the projection wall 2 of the dome 1.

In this way an image having a high contrast ratio is achieved, which is scarcely worsened by any stray light which may enter the dome 1 since a large part of the stray light can leave the dome 1 through the transparent wall. Forthis purpose the beam path of projectors 5 outside the dome 1 is screened off laterally by black material, for instance velvet, against stray light from the outside. This screening also absorbs the greater part of the stray light emerging from the inside through the dome 1.

The projectors 5 comprise background projectors 7 and target projectors 8, in which respect these projectors 7,8 are grouped in a suitable manner around the periphery of the dome 1. Associated with each background projector lisa target projector8 having a smaller projection field than that of the background projector 7. The image of the target projector 8 is freely positionable by way of a swingable deflecting mirror 9, which can be provided for example with a servo device, within the projection field of the background projector 7.

In addition to this, the image of the target projector 8 can be positioned in each case at least by the maximum target width into the projection fields of the adjacent background projectors 7, so that, upon the transition of the target from one projector field to the next, the target can be represented by a first target projector 8 until also a second target projector 8 is able to represent fully the target image. Only when this position is reached is the target image transferred from the first to the second target projector.

In this way it is ensured that one image processing chain is sufficient to represent a target. Simultaneous appearance of two target halves in adjacent target projectors 8 would require, for each of the target projectors 8, an image processing chain of its own. Moreover, in highly-resolving a target image no joining together of target halves has to be effected, which would otherwise require an accuracy of the alignment and adjustment of projection rasters, which could be realised only with high expenditure.

Through the actual shape of the dome 1, an error in the perceived position of the target can occur. In order to obviate this, the target projectors 8 are equipped with an arrangement which make it possible in the boundary regions of the view fields which can be achieved in each case by two or more target projectors, to project in each case by a target projector a target mark onto the dome 1 and to follow this mark by way of an optical following system with deflecting mirrors 9. In this way the actual shape of the dome 1 can be measured with great accuracy at the seam locations of the view regions, since the position of the projectors 5 is known and the position offollow-up mirrors is compared with that of a guide mirror. In this way angle errors in the target position which result from shape defects of the dome 1 can be largely eliminated.

In the case of larger targets, in which the geometrical coincidence fields of background projectors and target image are small in relation to the target size, the target image projector 8 can supply, by appropriate filtering of target and background image in a spectral range, a contour outline image of the target which is not covered by the background projector.

This outline image is picked up by way of a key camera 10, which by way of a beam divider 11 has the same angle of vision of the dome 1 as the associated background projector 7, and is fed as key signal to an image mixer which is arranged at a video input of the background projector 7. The background image is scanned dark by this image mixer at those points at which the key camera 10 sees the image of the target. The key camera 10 and the background projector7 are adjusted in the most congruent manner possible in the raster. In this way, all further optical distortions, for instance by oblique projection, shape errors of the sphere, positional errors of the unit consisting of background projector 7 and key camera 10 are automatically corrected.

With this arrangement it is possible, in the case of larger target sizes, to scan the background dark at the location of the target, so that for example a dark target is representable in front of a light background, or, in the case of large targets, the background does not appear through the target image as a result of projection of the two images one over the other.

In accordance with a further aspect of the invention, several target projectors can be so guided jointly that they project a coherent target image of greater area. For this purpose, arranged between the target image projector 8 and the swivel mirror is in each case a reversible prism having aservo control which can rotate the target image about the optical axis. The target projector is further equipped with an arrangement for raster deformation which corrects the optical distortion by oblique projection onto the dome 1, related to the point of sight of the pilot (dome centre point).

With this arrangement there can now be inserted into the background a target image having higher resolution, which represents for example a strip of terrain on the horizon and is fully stabilised onto the horizon in the event of arbitrary flight movements of the simulated aircraft, so that the horizon always remains visible in high resolution and the direction of the video raster relative to the horizon is maintained, so that no interference problem arise upon image representation.

Claims (9)

1. A simulator, for simulating the terrain which may be encountered by, for example, an aircraft or a tank during its operation, comprising an exchangeable cockpit, characterised in that an inflatable spherical dome made of transparent foil of high dimension stability and strength surrounds the cockpit, to form a projection wall in which respect a strongly light-dispersing surface is present on the inside of the dome and light-reflecting particles or a reflecting light-transmissive fabric are embedded into the foil, in that the representation of the terrain is effected by back-projection by means of projectors from the outside onto the dome, in that, for the exchanging of the cockpit, an inner tent can be swung up over the cockpit, which screens the cockpit in an airtight mannerfrom the dome and in that the cockpit is mounted on an adjustable base frame which can be swung up.

2. A simulator as claimed in claim 1, characte rised in that background projectors and target projectors and target projectors of smaller field of projection serve as the projectors, in which respect one target projector each is associated with a background projector and in that the image of the target projector is freely positionable by way of a swingable deflecting mirror within the field of projection of the background projector and in the edge of the adjacent image.

3. A simulator as claimed in claim 2, characterised in that the image of the target projector is positionable at least by the maximum target width into the projection fields of adjacent background projectors and in that upon the transition of the target from one projector field to the next the target is represented by the first target projector until the next target projector can fully represent the target image.

4. A simulator as claimed in claim 2, characterised in that the target projectors have an apparatus with which, in the boundary regions of the fields of vision which can in each case be achieved by two or more target projectors, target marks are projectable onto the dome and are trackable by means of swivel mirrors by way of an optical following system, and in that from the position of the projectors, the position of the followed-up mirrors and that of the guide mirror shape defects of the dome are determinable and are correctable by optical perception by the observer in the cockpit.

5. A simulator as claimed in claim 2, characterised in that for the representation of larger target sizes by the target projector by means of filtering in a spectral region not occupied by the background image projector a contour or outline image of the target is projectable, in that the contour image is picked up by means of a key camera which has the same angle of view as the associated background camera and is feedable to an image mixer at a video input of the background projector as a key signal, and in that the background image is scanned dark by the image mixer at those points at which the key camera sees the image of the target.

6. A simulator as claimed in claim 1, characterised in that seam or joint locations of the dome are connected by butt or flush contiguity of the foil and bonding-on of a transparent foil, and in that the beam path of the projector outside the dome is screened off laterally by black material.

7. A simulator as claimed in any of claims 1 to 6, characterised in that several target projectors are associated with a background projector and are so arranged and guided that they can project a coherent image of high resolution stabilised onto a reference direction.

8. A simulator as claimed in any of claims 1 to 7, characterised in that the target projectors are each equipped with a servo-controlled turning or reversible prism and a raster distortion apparatus which allows a stabilising of the raster direction of the projector onto a reference direction and makes possible a distortion correction of the projected image related to the centre point of the dome.

9. A simulator for simulating the terrain which may be encountered by, for example, an aircraft or a tank during its operation substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.