WO2001077751A1

WO2001077751A1 - Visual restitution device with 3 window large fields

Info

Publication number: WO2001077751A1
Application number: PCT/FR2001/001046
Authority: WO
Inventors: Bernard Mallet
Original assignee: Bernard Mallet
Priority date: 2000-04-07
Filing date: 2001-04-06
Publication date: 2001-10-18
Also published as: FR2807527A1; FR2807527B1

Abstract

The invention concerns a visual restitution device with 3 window large fields for visual restitution providing an artificial visual environment of flight simulator and more particularly for a helicopter. The invention is characterised in that with only 3 windows it provides very great visibility pattern and it also provides a simple and inexpensive solution to a complex problem. Its horizontal field very easily attains ?110°. Its front vertical field reaches up to +90°. Its lateral fields reach down to 70°. The device is based on a structure of right angles, arranged in a specific manner, and enabling an the whole field of vision to be inscribed within the images. In accordance with the principle of overhead projection, the observer, in schematic eye position, is located somewhere inside said volume and sees each of the 3 faces beneath the horizontal and vertical fields which form large base viewing pyramids. In fact he is immersed in the action. The concept can be used for all simulation systems requiring restitution of visual environment: 1) replacing a sphere site; 2) any form of visual restitution with 3 windows for various simulators: aeroplanes, cars, ships, for sports, such as skiing/bobsleigh/ canoeing and the like; 3) virtual reality for architect firm, exhibition parks and the like.

Description

3 WINDOWS LARGE FIELD VISUAL RESTORATION DEVICE

The present invention relates to a system for rendering the visual environment for a simulator. Application to the flight simulator.

The objective of flight simulators is to restore the most realistic environment possible, in which the user feels "immersed". For this it is necessary that the surfaces of the images are as large as possible so that the vision pyramid has instantaneous fields greater than the visual characteristics of the eye, that is to say that the peripheral vision of the observer is engaged. in visual perception.

The most widespread means currently is the use of a sphere on which are projected synthesized and / or prerecorded images, and in the vicinity of the center of which is arranged a cabin in which the user takes place. The images are projected by several projection devices.

These devices have certain drawbacks, however. They are very bulky since the diameter of the sphere can reach 8 to 10 meters and they are very expensive to deliver, to assemble, to paint, to arrange. Upstream studies of physical location of projectors, calculation and image correction are tricky. The study of a new structure is therefore quite heavy. To be effective, it requires more than three imaging channels (windows).

Patent WO 98/01841 proposes, to remedy the problems of high costs of studying and assembling a sphere as well as the significant difficulties of harmonizing the many imaging channels, a flight simulator comprising a plurality of front, side and top screens. The flat screens are arranged in such a way that they fit into an imaginary sphere. This is centered on the theoretical eye where the observer is placed. The side screens are trapezoidal and not orthogonal to the background screen.

However, such an embodiment has the drawback of using at least four screens and at least as many imaging channels. Harmonizing images is therefore delicate and the manufacturing cost remains high.

Gaps in existing techniques. It is possible to summarize, starting from the sphere example which is the solution which comes closest to wide field use by: 1) very high cost of acquiring structures, 2) minimum number of channels from 4 to 6 with identical resolution, 3) very high cost of projection systems, 4) great complexity of a complete system, 5) significant difficulty of harmonization and obtaining a correct contrast, 6) difficult maintainability and only by specialists.

Gap 1: a sphere 8 m in diameter, delivered, mounted, painted, fitted (electricity, air conditioning, walkways) with the supporting structures of the projectors, the doors and ready to receive a simulation cabin ≈ 2.5 MF.

Gap 2: to cover a horizontal field of ± 100 ° and a vertical field of ± 60 ° with a resolution of 5 'of arc, 6 channels of high definition imagery are required. With 3 channels only the vertical and horizontal fields are impossible to reach or the resolution is too low (below the minimum acceptable value).

Gap 3: The performance required for projectors to correctly restore sphere images is much more severe than for the rear projection technique. The coefficient of "technicality" is between 2.5 and 6 for equipment which must be very high-end professional.

Gap 4: Upstream studies of physical location of projectors, calculation and image correction are delicate and long. The study of a new structure is quite heavy.

Gap 5: The harmonization which consists in that an element of an image is seen exactly under the good angles of Euler by the observer and coherent of its instruments (in particular head-up viewfinder in aeronautics) or with reality, in general poses problem as a realization of the sights, as writing of the procedures and development (adjustment). In addition, by construction, a sphere of which we illuminate a point, reflects light through its screen (the skin of the painted sphere diffuses and is reflected endlessly) and re-emits this light which "lights up" the sphere (therefore which destroys the image) as soon as the image surfaces are a little large. This point known as the spherical integration phenomenon is intrinsic to the means of direct projection (cinema room or simulator).

The object of the invention is to remedy all these shortcomings by proposing a simpler solution, of easy design and implementation, which offers by construction a very satisfactory real visual immersion in order to achieve a remarkable quality / cost ratio. .

The present invention respects the positions and sizes of all the elements of the images as they are in reality. The observer therefore has the restitution of the outside world from the right angles.

The visual rendering system with large horizontal and vertical fields according to the invention comprises a plurality of flat screens associated two by two in dihedra characterized in that said dihedra are straight and are not orthogonal to the reference trihedron of the theoretical eye .

The visual rendering system according to the invention comprises at least three screens and is fully operational from three screens, each one associated with an image production device. The screens have a polygonal shape. In a configuration with three screens, the middle one can be square and the other two rectangular. But the most satisfactory version consists of a rectangle front face of 5/4 or 4/3 format and the two side faces of the same format, either 5/4 or 4/3.

The following description refers to the appended drawings which represent, without any limiting character, an exemplary embodiment with three screens of a visual reproduction system with large horizontal and vertical fields in accordance with

1 invention.

FIG. 1a represents the original three-sided cube, the deformation of which makes it possible to obtain the configuration with 3 screens, FIG. 1b being a variant,

FIG. 2 is a view of the cube being deformed,

FIG. 3 is a perspective view of the arrangement of the screens,

FIGS. 4a, 4b, 4c represent the possible trace of a horizontal plane on the screens,

FIG. 5 is a side view of the screens 11 and 12 with the cabin and the user,

FIGS. 6a and 6b represent the arrangements of the projectors, FIG. 7 is a section view of the assembly of the screens by bevel,

FIG. 8 is the development of the three faces,

Figure 9 is the sketch of visibility.

With reference to the appended figures we see a visual rendering system with large horizontal and vertical fields operational from only 3 flat screens arranged in a particular way in space. The architecture of the screens will be described by proceeding in stages.

According to the figure la, let us consider a cube 10 of only 3 faces (the face 11 of the bottom, the face 12 right side, the face 13 of the bottom), of which each face has for dimension, as example, 4 x 4 m. The faces 11 and 12, on the one hand, and the faces 11 and 13, on the other hand, thus form two straight dihedrons of edge 14 and 15 respectively, the two other edges of the face 11 not common to the faces 12 and 13 being intersecting at point A. Let us move the faces 12 and 13 by translation, as indicated in FIG. 2, respectively along the edges 14 and 15.

Then consider a virtual horizontal plane 16 carrying a frame of reference 23 of axis X, Y, Z and whose origin 0 is the theoretical eye 24 (position in space where the observer is located who would use only one eye - eye Cyclops).

Let us consider that the cube 10 is located at a height z <4 m; it therefore intercepts the plane 16. The edges 14 and 15 are then parallel or orthogonal to the three axes. From Figure 2, rotate the cube 10 by an angle φ = 45 ° around an axis collinear with the X axis of the repository 23, then rotate the cube 10 for example by an angle θ = 36 ° (value of the application) around an axis collinear with the axis Y of the reference frame 23. Let us move the cube 10 compared to the reference frame 23 so that the origin 0 of the reference frame is located in the cube 10 with vertically point A. This configuration is shown in the figure

3. The edges 14 and 15 are no longer parallel or orthogonal to the three axes of the frame of reference (23). Figures 4a, 4b and 4c show the trace 17 of the intersection of the plane 16 with the cube 10 seen from inside the cube 10 by the theoretical eye.

The use of this device in simulation always implies the presence of an observer 18. For an aircraft simulator for example, the latter is seated in a simulated cockpit 19. The carrying structure generating a shadow for the observer, there is no need for an image under the cockpit and outside the visibility zone (sketch of visibility). For this reason the faces 12 and 13 can be translated along the edges 14 and 15 and thus free up a space 20 for the physical support of the cockpit 19, while optimally adjusting the low lateral vision. Figure 5 shows the user 18 seated in a cockpit 19, the latter being located in the space 20.

As indicated in FIG. 6a, the selected projection system consists in physically linking a projector 21 to a screen (11, 12, 13). The projector should be placed behind the screen. If space is limited, a mirror 22 can be used, as shown in FIG. 6b, which deflects the beam and therefore shortens the distance to the screen.

The flat surfaces that the screens form must be perfectly connected to the adjoining surfaces. To do this, the bevel 25, as shown in Figure 7, will advantageously be chosen. The goal is to make the junction between screens as invisible as possible so that the eye is nothing to hang onto. The eye must be taken by the content (the image) and not by the container (the support). The bevel allows a stronger physical bond than the edge to edge and is less sensitive to sources of stray light.

Figure 9 shows the advantage provided by this screen arrangement. Two lines of visibility are represented for 3 windows of the same surface, one 27 concerning a sphere, the other 28 concerning the new concept (symmetrical left part of the right part).

The theoretical eye is here placed at an "arbitrary" point determined approximately therefore not optimized. The values calculated from this choice are in the table in FIG. 8. The diagram of the drawing immediately shows the whole point of applying this new principle. The angle Ψ in the first row of the table represents the horizontal scan corresponding to a rotation around the z axis. The angle θ appearing in the second and third lines represents the vertical scan θ corresponding to the rotation around the y axis as a function of a rotation of angle Ψ. The use of this new device is not limited to an aircraft simulator but can be used in the simulation of driving, naval driving and even for fun purposes such as for a shooting range or ski or toboggan courses . Another application consists in making the outline of visibility asymmetrical by slight rotation of the assembly around an axis to be defined. In this way, we can favor the left or right part of the visual rendering for specific applications such as landing on an aircraft carrier, dropping for military transport, which both are always on the same side.

The present invention also makes it possible to embed in

The frontal image is a head-up type symbology which is generally situated around the horizontal plane.

According to a variant not shown of the device, one can add 1 or 2 faces and / or work with non-rectangular surfaces. It is in particular possible to work with a screen 11 not of square shape but polygonal, by filling the gaps located between the free edges of the screen

II and screens 12 and 13.

The development of the three faces, with a variant described below, is interesting on the geometric level. Indeed, all the simplicity of the construction can appear and make understand the geometrical links between the horizontal plane and the three faces.

In FIG. 8, it is possible graphically to find almost all of the angular values there from knowledge of the distances from the theoretical eye to the faces alone. Is shown on this flat view, a dotted variant on the front face to go from square format to rectangle in the horizontal direction. It can be, of course, rectangle in the vertical plane (direction which is represented on figure 9). Variants: the classic variant consists of adding one or two faces and, or, working with non-rectangular surfaces.

The addition of one or two faces (according to the principle of the right dihedral) is possible, but this amounts to building a cube or a box with four or five faces placed flat. The interest is reduced accordingly.

A fully satisfactory variant of detail is to say that the front face is not of square format but polygonal in the general case and of the same format as the lateral faces in particular. This does not change anything for image generation machines. Only the calculations of the associated fields are to be resumed. In this way, the outline of visibility dissymmetrizes (which means choosing a side to be favored) and significantly increases the high vertical field between 0 ° and around 75 ° of deposit (see the variant in Figure 9)

This variant must be included in the first version of this concept, given the advantage in terms of fields, very suitable for sources of synthetic images and paltry investment. In addition the complexity is unchanged.

Applications envisioned: 1) replacement of a sphere site, 2) creation of a low cost large field visual restitution site, 3) experimental visual restitution site for: - helmet viewfinder, - Database demonstrator, 4 ) any form of visual rendering from three windows for various simulators: -planes, - cars, - boats, etc. 5) any form of visual rendering of three windows for various real or virtual fun simulators: skiing, sledging, shooting, etc. - immersive journey, - digital cinema man, etc. 6) any form of visual rendering of three windows for professional or institutional use: - architectural firm, - urban planner, regional technical service, etc. - institutes, universities, etc. exhibition center: de la Villette, etc. The set can also be produced on a scale other than one. Example: 1, 5 or 0, 8 or 0, 5 see 0.3 which allows you to put your head comfortably in the "box".

We can even consider a scale at 0.2 or 0.8 m x 0.8 m or 0.8 x l m and replace the rear projection with collimation. This results in a more expensive but very high-end system with only three viewing windows. Associated with the concept of "glass cockpit" it is particularly well suited to virtual reality. Specific adaptation. In the case of a visual environment for a fun activity such as kayaking or rafting for example, there is no need for an image upwards (zenithal zone), we can therefore with the same concept put a theta angle θ void at the device. If the device is used as a parachuting training simulator, then the overhead vision is essential to "believe it". It must be straightened up to the vertical θ = 90 °, no longer shift the red and blue faces (they remain contiguous), and probably use 16/9 format faces, to favor vertical scrolling and take into account filmed sources in HDTV.

The visibility sketch allows a comparative view for three windows of the same surface in a sphere and with this new concept (symmetrical left part of the right part). The theoretical eye is here placed at an "arbitrary" point determined approximately therefore not optimized. The values calculated from this choice are in the table below.

The diagram of the diagram immediately shows all the interest of the application of this new principle. Although the Cartesian representation is not the best (a Hammer pro ection which keeps the angles is better), it nevertheless allows a comparison. Fig la cuoe

Fig lb cuoe with larger faces

Fig 2 cube with square faces

Fig 3 perspective of the screens

Fig 4a '4o 4c traces of the horizontal plane on the screens

Fig 5 side view with user in the cabin

Fig 6a ι 5D top and side views of the projector

Fig 7 top view of the bevels

Fig 8 developed from three sides

Fig 9 visibility diagram element 10 cube element 11 white face element 12 red face element 13 blue face element 14 edge between white and red faces element 15 edge between white and blue faces element 16 horizontal plane element 17 trace on the horizontal plane on screens element 18 user element 19 cabin element 20 space to house the cabin element 21 pro ector element 22 mirror element 23 reference tπèdre element 24 theoretical eye element 25 bevels element 26 horizontal plane element 27 vertical plane element 28 image surfaces in sphere element 29 image surfaces with l 'invention

Claims

1 Visual display device comprising a plurality of screens

(11, 12, 13) dishes associated two by two in dihedra characterized in that said dihedra are straight and that the edge (14, 15) of each is neither orthogonal m parallel to each of the axes of the reference tπèdre (23) of the theoretical eye (24).

2 visual rendering device according to claim 1 characterized in that it comprises at least three screens (11, 12, 13)

3 Visual rendering device according to claim 1 characterized in that the two side screens (12, 13) are arranged along the edge (14) orthogonal to the edge (15) of the front screen (11)

4 Visual rendering device according to claim 1 characterized in that the two side screens (12, 13) can be moved by sliding along the edges (14, 15) orthogonal to the front screen (11).

5 visual rendering device according to claim 2 characterized in that all three screens (11, 12, 13) can be aligned in any way relative to the reference trihedron (23) 6 visual rendering device according to claim 2 characterized in that each screen is associated with at least one image production device (21) 7 Visual reproduction device according to claim 1 characterized in that two contiguous screens are connected by a bevel (25) and edge to edge. 8 Visual rendering device according to one of the preceding claims caractéπse in that the screens are polygons with four sides of precise format