Tracking system configured to be mounted in a vehicle, and associated method

Abstract

The invention relates to a tracking system (S) comprising at least one item of tracking equipment (3) and a detection device (4) which is configured to detect the position and the angular orientation of the item of tracking equipment (3), the detection device (4) comprising a receiver (1) which is configured to receive a projected predetermined standard image (IM1), the receiver (1) comprising an optical sensor (14), which is configured to capture a portion of the projection of the predetermined standard image (IM1) received on a receiving area (11), and a computing device (19), which is configured to determine a deformation of at least one predetermined oriented pattern (M1-M15) of the predetermined standard image (IM1) so as to deduce a position vector (vecR) therefrom.

Description

Tracking system configured to be mounted in a vehicle and associated method

[0001] The present invention relates to the field of tracking an object or individual, in particular in a vehicle, in particular, a light aviation vehicle. The invention is particularly applicable in the field of virtual, mixed or augmented reality.

[0002] As is known, a light aviation vehicle allows movement in the air, in particular between two airfields. For this purpose, such a vehicle has a cabin housing one or more operators to manipulate the movement controls. Locating from the operators' exterior view alone is difficult from the cabin and requires the use of a navigation map, in order to locate oneself on the map using points of interest visible to the naked eye. This implementation has the disadvantage of dividing the operators' attention and increases the risks during piloting. In order to eliminate this disadvantage, the operator can be equipped with a headset with a mixed or augmented reality system displaying an enriched exterior scene.This mixed or augmented reality system allows in particular to display points of interest on the pilot's view, allowing clearer navigation and the pilot to dedicate all his attention to said navigation, and to piloting itself. It is thus known to use a mixed or augmented reality system, comprising a device for detecting the orientation and position of the headset in a reference frame of the cabin, in order to be able to modify the display of the elements superimposed on the external scene according to said orientation and said position of the headset.

[0003] The cabin of such a light aircraft vehicle is subject to many different accelerations during a flight, making the use of inertial sensors unsuitable for angular detection of the operator's helmet.

[0004] In the prior art, several detection devices are known. In particular, a magnetic detection device is known which generates magnetic fields and determines the orientation and position of the helmet by analyzing the magnetic fields. Such a detection device is not suitable for a light aircraft vehicle because it is likely to disturb the electronic equipment of said vehicle.

[0005] A detection device is also known comprising several fixed observation cameras mounted in the vehicle cabin and directed towards the operator wearing the helmet. Markers are positioned on the helmet so as to determine the orientation and position of the helmet by processing the images from the observation cameras. In practice, the installation of observation cameras in the vehicle cabin is complex due to the density of equipment in the cabin. In addition, this requires the provision of a communication device between the observation cameras and the helmet, which is restrictive.

[0006] An alternative solution would be to provide one or more observation cameras directly on the headset and to position markers in the vehicle cabin to detect the orientation and position of the headset. In practice, to detect the orientation and position accurately, it may be necessary to model the interior of the cabin, for example by computer learning, which is time-consuming, computationally expensive and restrictive. Modeling the cabin in real time also induces latencies in determining the orientation and position of the headset, which causes discomfort for the operator who feels a lag when moving his head and the video stream from the external scene displayed in the headset. Another disadvantage is that it is necessary to determine the position of the markers for each type of vehicle, which increases the complexity.

[0007] It is also known to provide one or more observation cameras directly on the helmet and to use tracking algorithms to detect the orientation and position of the helmet. This eliminates the need to determine the position of markers, but it has similar drawbacks to the previously mentioned solution.

[0008] The invention thus aims to eliminate at least some of these drawbacks by proposing a system for tracking an object (helmet, glasses, etc.) that is efficient and robust, and that can be practically installed in any type of vehicle. The invention also aims to allow an operator to view augmented, mixed, or virtual reality without any inconvenience or latency.

[0009] The system is also applicable for systems using virtual reality, for example in the case of simulators.

[0010] US20140225915A1 teaches a pair of glasses onto which a projection is made by a projector. US20150070389A1 teaches a device for superimposing information onto a marker that has been projected by a remote control. PRESENTATION OF THE INVENTION

[0011] The invention relates to a tracking system comprising:At least one tracking equipment configured to be attached to an object to be tracked or to a person to be tracked,at least one detection device configured to detect the position and angular orientation of the tracking equipment.

[0012] The invention is remarkable in that the detection device comprises:A reception device, mounted in a reference frame or on the tracking equipment, configured to receive a predetermined standard image projected by a transmission device mounted on the other of the reference frame or the tracking equipment, the predetermined standard image comprising at least one predetermined oriented pattern,the reception device comprising:at least one reception zone configured to receive at least a portion of the projection of the predetermined standard image andat least one optical sensor configured to capture a current image received on the reception zone,at least one calculation device configured to determine the deformation of at least one predetermined oriented pattern in the current image so as to deduce therefrom a position vector which is specific to the reception device and defined relative to the transmission device from the determined deformation.

[0013] By "oriented pattern" we mean that two axes can be determined to determine the orientation of the pattern in a plane.

[0014] Thanks to the invention, the receiving device locally detects the deformation by analyzing the current image captured on the receiving area. It is therefore not necessary to resort to magnetic means or to modeling of the cabin, which allows a low-cost implementation. The detection system is universal and can be adapted to any vehicle or any reference system. The projection of a predetermined reference image comprising predetermined oriented patterns makes it possible to define the position vector in a practical manner from the sensor of one or more oriented patterns from which all the geometric data specific to the position vector can be deduced. The determination of the position vector can advantageously be carried out locally, which allows real-time operation without latency.

[0015] According to one aspect, the standard image comprises a plurality of predetermined oriented patterns each having its own identity. This makes it possible to determine the current image portion observed and therefore the angles between the emission device and the projection device. The predetermined oriented patterns are thus identifiable.

[0016] According to one aspect, the emitting device emits the predetermined standard image according to a predetermined wavelength range and the optical sensor is sensitive only in the predetermined wavelength range. Such selective operation makes it possible to reduce interference with other light sources in the reference frame, in particular, in the cabin.

[0017] Preferably, the predetermined wavelength range is invisible to the naked eye, preferably in the infrared. This advantageously allows use in the dark. This also prevents blinding the operator.

[0018] According to one aspect, the reception area is in the form of a diffusing transmissive surface configured to receive, on a first face, at least a portion of the projection of the predetermined standard image, the optical sensor being configured to capture the current image on a second face opposite the first. The intersection of the plane of the reception area and the light of the standard image causes a deformation of the latter. This makes it possible to detect a deformation of the standard image with precision to determine the position vector. This also makes it possible to protect the optical sensor optimally while making it possible to capture a current image with great robustness without being noisy by the environment.

[0019] According to one aspect, the detection device comprises at least one transmission device, mounted on the other of the reference frame or the tracking equipment, configured to project the predetermined standard image onto the reception area of ​​the reception device. The transmission device has a limited footprint.

[0020] According to one aspect, the emission device comprises a divergent projection device. This advantageously makes it possible, with a small emission device, to cover a large operating area in which an operator can move.

[0021] In one aspect, the emission device comprises a transparent surface configured to allow the projection of the predetermined standard image to pass through.

[0022] In one aspect, the divergent projection device is in the form of a screen in which each pixel is an independent light source.

[0023] In one aspect, the divergent projection device comprises a reflective member and a light source projecting light onto the reflective member, the reflective member comprising a plurality of reflective elements configured to form the predetermined oriented patterns of the predetermined reference image. This allows for very high contrast, which facilitates image processing by the receiving device.

[0024] In one aspect, the reflective member being configured to form the predetermined standard image in the forward direction, the reflective member comprises a transparent front support and a rear absorbing surface, the plurality of reflective elements being positioned between the rear absorbing surface and the transparent front support. This also makes it possible to obtain a very high contrast while filtering light disturbances, which facilitates image processing by the receiving device.

[0025] According to one aspect, the emission device comprises at least one diffractive element as well as a monochromatic light source making it possible to create an image characterized by a pattern predetermined by the diffractive element.

[0026] According to one aspect, the tracking equipment is configured to display at least one additional data item that is a function of the position vector. This makes it possible to show the operator fixed reference points in the virtual space, for example during a landing maneuver.

[0027] In one aspect, the tracking equipment is a headset. This advantageously allows an operator to wear the tracking equipment in a natural manner while allowing additional data to be displayed.

[0028] The invention also relates to a vehicle, in particular a light aviation vehicle, the vehicle comprising a cabin configured to house at least one operator, the vehicle comprising at least one mixed or augmented reality tracking system, as presented previously, configured to display an augmented, mixed, or virtual exterior scene, enriched according to a position and an angular orientation of the tracking equipment.

[0029] The invention relates to a method of using a tracking system as presented above, the tracking system comprising at least one tracking equipment configured to be attached to an object to be tracked or to a person to be tracked and at least one detection device configured to detect the position and the angular orientation of the tracking equipment, the detection device comprising a transmitting device mounted in the reference frame, and a receiving device mounted on the tracking equipment.The method comprises steps consisting of:Projecting a predetermined standard image by the transmitting device towards the receiving device so as to receive at least a portion of the projection of the predetermined standard image onto a reception area of ​​the receiving device, the predetermined standard image comprising at least one predetermined oriented pattern,Capturing a current image received on the reception area,Determining a deformation of at least one predetermined oriented pattern in the current image andDetermining a position vector which is specific to the receiving device and defined relative to the transmitting device from the determined deformation.

[0030] In one aspect, the projection step and the capture step are performed continuously. This makes it possible to provide a position vector in real time to allow its manipulation without latency.

[0031] According to one aspect, the deformation determination step comprises sub-steps consisting of:Determining a separation distance separating the receiving device from the transmitting device by means of the deformation of at least one predetermined oriented pattern projected into the current image,Determining the angular position of the receiving device relative to the transmitting device by means of the deformation of at least one predetermined oriented pattern projected into the current image andDetermining the angular orientation of the receiving device relative to the transmitting device by means of the deformation of at least one predetermined oriented pattern projected into the current image.

[0032] According to one aspect, the substeps of the deformation determination step are performed in parallel. This makes it possible to reduce the time for determining the position vector, thereby avoiding any latency.

[0033] According to one aspect, the method of use comprises a step of determining the position vector by correlation from the current image and a previous current image for which a previous position vector has already been determined. This makes it possible to reduce the calculation steps by determining the position vector by simple correlation during a small modification of the current image. The computational cost is drastically reduced.

[0034] According to one aspect, the method of use comprises a step of displaying by the tracking equipment an exterior, augmented, mixed, or virtual scene, enriched according to a position and an angular orientation of the tracking equipment. This makes it possible to use the determined data to enable an augmented, mixed, or virtual reality application without requiring any display equipment other than the tracking equipment. PRESENTATION OF FIGURES

[0035] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0036] This is a schematic representation of a vehicle comprising a tracking system according to one embodiment of the invention.

[0037] This is a schematic sectional representation of a detection device according to one embodiment of the invention comprising a transmitting device and a receiving device.

[0038] This is a schematic cross-sectional representation of a reflecting member of the transmitting device.

[0039] It is a schematic representation of a predetermined standard image.

[0040] It is a schematic representation of a current image on the projection of the predetermined standard image at the receiving device.

[0041] This is a schematic representation of a method of using the tracking system.

[0042] It is a schematic representation in a vertical plane of the projection of the predetermined standard image to determine a removal distance.

[0043] It is a schematic representation in a vertical plane of the projection of the predetermined standard image to determine a vertical divergence angle.

[0044] It is a schematic representation in a horizontal plane of the projection of the predetermined standard image to determine a horizontal divergence angle.

[0045] It is a schematic representation in a horizontal plane of the projection of the predetermined standard image to determine a horizontal orientation angle.

[0046] It is a schematic representation in a vertical plane of the projection of the predetermined standard image to determine a vertical orientation angle.

[0047] This is a schematic representation of a deformation between the predetermined standard image and the current image.

[0048] It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention if necessary. DETAILED DESCRIPTION OF THE INVENTION

[0049] With reference to the, a light aviation vehicle 100 is shown comprising a cabin 101 housing an OP operator. In this example, the light aviation vehicle 100 is a pleasure aircraft but it goes without saying that the invention applies to any type of vehicle, for example, a land vehicle, a boat or a submersible. It goes without saying that the invention also applies to any application using virtual, mixed or augmented reality, such as a video game. Similarly, a single OP operator has been presented but it goes without saying that the invention applies to several OP operators in one or more cabins 101 of the vehicle 100. Likewise, the invention also applies to an object to be tracked.

[0050] According to the invention, the vehicle 100 comprises a tracking system S making it possible to track the movements of the operator OP. It goes without saying that any target or object could be tracked by the tracking system S. The tracking system S makes it possible in particular to determine data allowing, for example, a virtual, mixed, or augmented reality application, from the movements of the operator OP.

[0051] The tracking system S comprises tracking equipment 3 configured to be worn by the operator OP. This tracking equipment 3 allows the tracking system S to track the movements of the operator OP. Preferably, seen in this example, the tracking equipment 3 is a helmet. It goes without saying that the tracking equipment 3 could be in another form, such as a vest, a harness, or glasses.

[0052] According to one embodiment, with reference to, in particular in the case of mixed reality, the tracking equipment 3 may comprise one or more cameras 102 configured to capture a video stream V1 of an exterior scene SC. Subsequently, the term exterior video stream V1 refers to the video stream, originating from one or more cameras 102 mounted on the tracking equipment 3, which is supplied to the tracking system S.

[0053] Referring to the, it is shown the tracking system S which receives the external video stream V1.

[0054] According to one aspect, the tracking equipment 3 comprises a display screen (not shown) on which is displayed a part of the external video stream V1 which is a function of the position and angular orientation of the tracking equipment 3 in the cabin 101.

[0055] As illustrated in the, such tracking equipment 3 is configured to receive a position vector vecR, determining the position and angular orientation of the helmet 3 in the cabin 101. The tracking equipment 3 advantageously comprises a communication member for receiving, wired or wirelessly, the position vector vecR and, according to one embodiment, the external video stream V1. Such tracking equipment 3 is known to those skilled in the art and will not be presented in more detail.

[0056] According to a third embodiment, the tracking equipment 3 can receive the position vector vecR and a stream of virtual images.

[0057] According to another aspect, information, for example from satellite data or provided upstream, can be displayed in the tracking equipment 3 as a function of the position and angular orientation of the tracking equipment 3 in the cabin 101, in particular in the context of a mixed or augmented reality system. The tracking equipment 3 then receives the position vector vecR and in the case of mixed reality a part of the external video stream V1. The display of this information adapted to the position of the tracking equipment 3 allows an operator OP to focus his attention on points of interest of the external scene SC as a function of the situation by moving his head in a natural manner. In the case of virtual reality, the tracking equipment 3 can receive the stream of virtual images and display them as a function of the position vector vecR.

[0058] Still with reference to the, the tracking system S further comprises a detection device 4 configured to detect the position and angular orientation of the tracking equipment 3, that is, to determine the position vector vecR.

[0059] The detection device 4 comprises, on the one hand, a transmission device 2 configured to project a predetermined standard image IM1 towards the tracking equipment 3 of the operator OP and, on the other hand, a reception device 1 configured to receive at least a portion of the predetermined standard image IM1 so as to deduce therefrom the position vector vecR. Thus, the reception device 1 does not have to model the cabin 101 to determine the position vector vecR. All the useful information is received directly by the reception device 1. This makes it possible to overcome the specificities of each vehicle, the detection device 4 can thus be mounted in different reference systems, for example, a cabin or other.

[0060] The transmission device 2 will now be presented.

[0061] With reference to the, there is shown a transmission device 2 according to an embodiment of the invention. In this example, the transmission device 2 comprises a divergent projection device 21 of a predetermined standard image IM1. The divergent projection device 21 comprises a projection axis X, oriented from the rear to the front, as well as a divergence point PDD, by theoretical nature, located on the projection axis X at the rear of the divergent projection device 21 as illustrated in the. The divergent projection device 21 is configured to carry out a projection towards the front, that is to say, towards the reception device 1.

[0062] The divergent projection device 21 is oriented to cover an operating zone ZF in which the tracking equipment 3 of the operator OP is likely to evolve. A divergent projection device 21 makes it possible, due to the divergence, to cover a large operating zone ZF while retaining an emission device 2 having a reduced footprint. The divergence also makes it possible to promote a deformation of the predetermined standard image IM1 as will be presented later.

[0063] Each emission device 2 is associated with an operating zone ZF which is aligned with the projection axis X and is a function of a divergence angle. The divergence angle is preferably between 30° and 45°. Also, to cover a very large operating zone, it may be envisaged to provide several emission devices 2.

[0064] With reference to the, we define, along the projection axis X, a standard distance “De” between the predetermined standard image IM1 formed on the emission device 2 and the divergence point PDD which is predetermined.

[0065] In this example, with reference to the, the predetermined standard image IM1 comprises several predetermined oriented patterns M1-M15. The predetermined standard image IM1 will be presented in more detail later.

[0066] In this example, with reference to the, the emission device 2 comprises a housing 20 in which the divergent projection device 21 is mounted. The divergent projection device 21 comprises a light source 5 for illuminating a reflector member 6 and generating the predetermined standard image IM1 through an opening formed in the housing 20. In this example, the divergent projection device 21 comprises, at the opening, a transparent surface 22 allowing the divergent light from the light source 5 to pass through. Advantageously, the transparent surface 22 allows the emission device 2 to be dust-proof and thus to protect the predetermined standard image IM1. The reflector member 6 is configured to form the predetermined standard image IM1 forward following illumination by the light source 5.

[0067] With reference to the, the reflecting member 6 comprises a transparent front support 61 comprising a rear surface on which are mounted reflective elements D1-D15 configured to form the predetermined oriented patterns M1-M15 of the predetermined standard image IM1. The reflecting member 6 further comprises a rear absorbing surface 62 fixed to the transparent front support 61 so that the plurality of reflective elements D1-D15 is positioned between the rear absorbing surface 62 and the transparent front support 61. Thus, the reflection of the reflective elements D1-D15 is transmitted primarily.

[0068] Preferably, the light source 5 emits light in a wavelength not visible to the naked eye so as to limit interference with the light sources present in the cabin 101, while avoiding blinding the user. In this example, the light source 5 emits infrared radiation. Preferably, the light source 5 is coupled to a laser of another wavelength. This advantageously makes it possible to use the infrared radiation at night and the laser in the case of use in broad daylight, thus allowing use at any time. Preferably, the reflector member 6 is formed from a mirror treated for infrared.

[0069] For example, the transparent front support 61 comprises a transparent material belonging to the wavelength range of the light source 5. Preferably, it is the infrared-transparent part of a mirror treated for infrared in the wavelength of the light source 5. The materials used may, for example, be plastics or plexiglass transparent to infrared or glasses based on lead germanate or arsenic pentaselenium As2Se5 or germanium plate or sintered glasses called Irtran (MgF2, ZnS, etc.). For example, the reflective elements D1-D15 are produced by abstracting the surfaces external to the reflective elements D1-D15 on the rear face of the mirror treated for infrared. The abstraction of the infrared-reflecting metal from the mirror may be carried out via a precision laser trace of the fiber laser type.Preferably, the size of the reflective member 6 as well as the number of reflective elements D1-D15 are dimensioned according to the optics of the light source 5 and the operating zone ZF. In this example, the reflective member 6 has a surface area less than 50mm by 50mm, preferably of the order of 30mm by 30mm. For example, the rear absorbent surface 62 can be made from chloroheptamethines (cationic cyanine DD+, anionic cyanine AA-, neutral cyanine DA or other). The absorbent surface 62 is configured to have a low light reflection in the wavelength range of the light emitted by the light source 5 so as to form the predetermined oriented patterns M1-M15 with a high contrast.

[0070] The reflecting member 6 is configured to be oriented so as to have the transparent front support 61 facing the light source 5 and the transparent surface 22 so as to generate the predetermined oriented patterns M1-M15 from the reflective elements D1-D15.

[0071] It goes without saying that the divergent projection device 21 could be presented natively as a divergent projector. For example, the divergent projection device 21 could be in the form of a screen where each pixel is an independent light source, in the form of a matrix of vertical cavity surface emitting laser diodes (VCSEL), in the form of a LASER source combined with a holographic film comprising the oriented patterns, or in the form of a LASER source combined with one or more diffractive films allowing the creation of the oriented patterns.

[0072] With reference to the, the reference image IM1 comprises several predetermined oriented patterns M1-M15. In this example, the reference image IM1 comprises 15 predetermined oriented patterns M1-M15 distributed in three rows and five columns. In this example, the predetermined oriented patterns M1-M15 are spaced the same distance apart on each row and on each column to simplify the calculations. However, it goes without saying that this could be different. Each predetermined oriented pattern M1-M15 makes it possible to locally define an oriented reference frame, which is advantageous for determining the position vector vecR. Preferably, the predetermined oriented patterns M1-M15 are distributed in the form of a grid.

[0073] Preferably, each predetermined oriented pattern M1-M15 is unique. In this example, each predetermined oriented pattern M1-M15 is in the form of a QR-Code but it goes without saying that any pattern identifiable by its shape could be suitable. In practice, the position of each predetermined oriented pattern M1-M15 is perfectly known in the predetermined standard image IM1. In particular, the distance between the predetermined oriented patterns M1-M15, the divergence angles per column (vertical divergence angle) and the divergence angles per line (horizontal divergence angle) defined with respect to the projection axis X for each predetermined oriented pattern M1-M15 are known. The distance "From" between the predetermined standard image IM1 and the divergence point PDD is also known.

[0074] Receiving device 1 will now be presented.

[0075] The receiving device 1 is mounted on the tracking equipment 3 and is configured to receive the predetermined standard image IM1 which has been projected by the transmitting device 2 into the operating zone ZF. Hereinafter, the projection of the predetermined standard image IM1 at the receiving device 1 is referred to as "projected standard image IM1'".

[0076] In detail, with reference to the, the receiving device 1 comprises a housing 10, which is fixed or integrated directly into the tracking equipment 3, and a receiving area 11 for receiving at least a portion of the projected standard image IM1'. The receiving area 11 is in this example flat and belongs to a receiving plane PR. Preferably, the housing 10 is sealed against dust by the receiving area 11.

[0077] The receiving device 1 comprises an optical sensor 14 for capturing a current image IM2 received on the receiving area 11. For this purpose, the optical sensor 14 is positioned inside the housing 10 so that its opening angle covers the entire receiving area 11. The receiving area 11 forms a diffusing transmissive surface so that a projection on one face is visible on an opposite face in order to allow capture by the optical sensor 14. The optical sensor 14 has a high sensitivity to the wavelength of the light source 5, in particular, infrared. According to one aspect of the invention, the receiving area 11 is formed by a microlens surface.

[0078] Thus, the reception zone 11 makes it possible to capture a current image IM2 which corresponds to a part of the projected standard image IM1' when the tracking equipment 3 is in the operating zone ZF. The projected standard image IM1' is deformed, relative to the predetermined standard image IM1, on the reception zone 11 depending on the position and orientation of the tracking equipment 3. With reference to the, the optical sensor 14 comprises a capture axis X14, oriented towards the reception surface 11. The meeting point between the capture axis X14 and the reception surface 11 forms an intersection point PI. The intersection point PI is positioned at the center of the current image IM2.

[0079] In this example, still with reference to the, the reception zone 11 forms a part of the housing 10, in particular, a rear part. The reception zone 11 is opposite the transmission device 2. The optical sensor 14 is fixed inside the housing 10 and oriented towards the reception zone 11.

[0080] In this example, the reception device 1 further comprises a calculation device 19 which is mounted in the housing 10. However, the calculation device 19 could belong to the detection device 4 while being distinct from the reception device 1. The optical sensor 14 is connected to the calculation device 19 so as to transmit to it in real time the current image IM2 formed on the reception zone 11.

[0081] According to the invention, the calculation device 19 is configured to, on the one hand, determine a deformation of at least one predetermined oriented pattern projected M1'-M15' in the current image IM2 and, on the other hand, determine a position vector vecR specific to the reception device 1 relative to the transmission device 2. The position vector vecR can then be provided to the tracking system S to allow a virtual, mixed or augmented reality application based on the movements of the operator OP.

[0082] To implement the present invention, with reference to the, the method comprises steps consisting of: Projecting E1 the predetermined standard image IM1 by the transmission device 2 towards the reception device 1 so that at least a portion of the projection of the projected standard image IM1' is received on the reception area 11 of the reception device 1, Capturing E2 a current image IM2 received on the reception area 11, Determining E3 a deformation of at least one predetermined oriented pattern M1-M15 in the current image IM2, Determining E4 a position vector vecR which is specific to the reception device 1 and defined relative to the transmission device 2 from the determined deformation.

[0083] Steps E3, E4, making it possible to determine the deformation and the position vector vecR of the receiving device 1, are preferably implemented by the calculation device 19 and will now be detailed.

[0084] In this implementation example, as shown in, the current image IM2 includes four projected oriented patterns M9', M10', M14', M15'.

[0085] As illustrated in, the deformation determination step E3 preferably comprises a distance determination sub-step E31, an angular position determination sub-step E32, and an angular orientation determination sub-step E33. The sub-steps are not necessarily all implemented. Preferably, the sub-steps of the determination step E3 are performed in parallel in order to limit the processing time to reduce latency.

[0086] With reference to the, the step of determining the deformation E3 preferably comprises a sub-step consisting of detecting E31 a distance of separation Da between the acquisition point Pa, located at the center of the current image IM2, and the point of divergence PDD along the projection axis X.

[0087] To do this, for example, the position of the projected oriented patterns M9', M10', M14', M15' in the current image IM2 is determined. In practice, the projected oriented patterns M9', M10', M14', M15' are detected by an image processing algorithm, in particular, by shape recognition. Since the projected oriented patterns M9', M10', M14', M15' are unique, this makes it possible to determine the part of the projected reference image IM1' that is visible in the current image IM2.

[0088] Advantageously, with reference to la and la, the spacing distances d1'-d4' between the projected oriented patterns M9', M10', M14', M15' in the current image IM2 can thus be determined by measurement. Since the spacing distances d1-d4 between the predetermined oriented patterns M9, M10, M14, M15 in the predetermined standard image IM1 and the standard distance De are known, a separation distance Da between the reception plane PR and the divergence point PDD along the projection axis X can be determined quickly and practically.

[0089] Thanks to the diverging optics of the emission device 2, the separation distance Da can be determined from the standard distance De, the separation distances d1-d4 between the predetermined oriented patterns M9, M10, M14, M15 and the separation distances d1'-d4' between the projected oriented patterns M9', M10', M14', M15'. For example, the separation distance Da is determined by the following formula, applying Thales' theorem: . It goes without saying, however, that the distance Da could be measured in a different way.

[0090] With reference to the, the step of determining the deformation E3 preferably comprises a sub-step consisting of determining E32 the angular position Pang of the current image IM2, and therefore the angular position of the intersection point PI, relative to the projection axis X. In practice, in this example, the angular position Pang of the current image IM2, and therefore of the intersection point PI, is defined by two divergence angles measured in two orthogonal planes. In this example, with reference to the, the predetermined standard image has a reference point Pa located at the intersection of the diagonal lines of the quadrilateral formed by four predetermined oriented patterns M9, M10, M14, M15. It goes without saying that several reference points can be established.

[0091] With reference to the, a vertical sectional view is shown along a first vertical plane PV passing through the projection axis X. A first straight line DR1 is defined passing through the projection of the acquisition point Pa and the divergence point PDD. A vertical divergence angle βr is determined between a projection of the first straight line DR1 in the first vertical plane PV and the projection axis X. The vertical divergence angle βr is determined in a practical manner given that the vertical divergence angles β9, β10, β14, β15 of the predetermined oriented patterns M9, M10, M14, M15 with respect to the projection axis X are known.

[0092] Similarly, with reference to the, a horizontal sectional view is shown along a second horizontal plane PH passing through the projection axis X. A horizontal divergence angle αr is determined between a projection of the first straight line DR1 in the first horizontal plane PH and the projection axis X. The horizontal divergence angle αr is determined in a practical manner given that the horizontal divergence angles α9, α10, α14, α15 of the predetermined oriented patterns M9, M10, M14, M15 relative to the projection axis X are known.

[0093] In this example, the intersection point PI and the projection Pa' of the reference point Pa are the same. When they are not, as shown in the, the method presented above makes it possible to determine the angles separating the projection Pa' of the reference point Pa and the projection axis X. The angles separating the projection Pa' of the reference point Pa and the intersection point PI are then added to them in order to determine the divergence angles αr, βr.

[0094] The polar position of the intersection point PI with respect to the projection axis X is thus known, that is to say, the angular position Pang of the current image IM2 with respect to the projection axis X is thus known (Pang=(αr;βr)). Knowledge of the separation distance Da and of the angular position Pang makes it possible to precisely determine the position of the receiving device 1 with respect to the transmitting device 2, in particular, with respect to the divergence point PDD.

[0095] The determination step E3 preferably comprises a sub-step consisting of determining E33 the angular orientation OR1 of the current image IM2, and thus the angular orientation of the plane PR, relative to the projection axis X. The angular orientation OR1 can be determined in different ways. In particular, a horizontal angle αorR () can be determined in a horizontal plane PH and a vertical angle βorR () can be determined in a vertical plane PV.

[0096] With reference to the, the projection axis X of the emission device 1 is not parallel to the capture axis X14. The current image IM2 thus corresponds to the projected standard image IM1' distorted obliquely as illustrated in the. The angular orientation OR1 can be determined, for example, by determining the distortion of a quadrilateral Qa defined between the centers of the predetermined oriented patterns M9, M10, M14, M15 into a projected quadrilateral Qa' determined between the centers of the projected oriented patterns M9', M10', M14', M15'. The calculation of the angular orientation can for example be carried out by using the knowledge of the Euclidean geometry of the quadrilateral formed by M9, M10, M14, M15 to deduce the equations in projective geometry which allow to analyze M9', M10', M14', M15' to deduce the desired angle parameters. It goes without saying that other methods based on the use of artificial intelligence can also be used.

[0097] The cumulative knowledge of the separation distance Da, the angular position Pang and the angular orientation OR1 makes it possible to determine (step E4) precisely the position of the receiving device 1 but also its orientation relative to the transmitting device 2. A position vector vecR is thus formed comprising the separation distance Da, the angular position Pang and the angular orientation OR1. The position vector vecR can be supplied directly to the tracking equipment 3 to enable it to determine its position and its angular orientation.

[0098] In practice, the determination of the separation distance Da, the angular position Pang and the angular orientation OR1 are costly in terms of computing power and time. Also, with reference to the, in order to allow real-time operation without latency, the method comprises a step E5 of determining the position vector vecR by correlation. In practice, the position vector vecR is determined from the current image IM2 and a previous current image IM2* for which a previous position vector vecR* has already been determined.

[0099] In other words, the position vector vecR is determined by analyzing the correlations between the current image IM2 and the previous current image IM2*. This makes it possible to significantly reduce the calculation time when the current images IM2*, IM2 are close. Preferably, the calculation of the correlation is carried out by an algorithm using Local Methods known to those skilled in the art. Preferably, if the current images IM2*, IM2 are distant, the position vector vecR is determined in a conventional manner by prior determination of the separation distance Da, the angular position Pang and the angular orientation OR1 in the current image IM2. The resources of the calculation device 19 are thus used sparingly.

[0100] By way of example, in the case where the tracking equipment 3 is a headset 3, the operator OP located in the vehicle 100 simply needs to wear the headset 3 on his head to obtain a suitable display. Preferably, additional data is displayed on the headset 3 as a function of the position vector vecR of the detection device 4. According to one aspect, the external video V1 is also displayed as a function of the position vector vecR of the detection device 4. When the operator OP turns his head, the position and orientation of the headset 3 change. This is detected by the detection device 4 which modifies the position vector vecR. The headset 3 adapts its display to present the additional data, and according to one embodiment the part of the external video stream V1, corresponding to the direction in which the operator OP is looking.This advantageously allows the operator OP to observe the exterior scene SC of the vehicle 100 while being able to receive additional data helping him in his navigation.

[0101] Advantageously, the detection device 4 is simple to produce. In particular, the receiving device 1 is lightweight and can be attached to the helmet 3 without creating any discomfort for the operator OP. In addition, the transmitting device 2 can be simply mounted in the cabin 101 and there is no need to position light marks or to carry out a 3D reconstruction of the cabin 101. The detection device 4 can thus be used universally in any type of vehicle. It goes without saying that the transmitting device 2 could be attached in the helmet 3 and the receiving device 1 on the cabin 101.

[0102] Advantageously, the invention can be used in closed environments which may be subject to vibration, acceleration or attitude constraints, in particular in all types of vehicle, whether maritime, land or air.

[0103] The invention is presented in a fixed frame of reference but it also applies to an orbital frame of reference, in particular, an orbital station.

[0104] The invention advantageously makes it possible to track the position of an object or a person in a dark or even completely dark environment.

[0105] The invention advantageously makes it possible to monitor without contact the relative position between two mechanical parts in all degrees of freedom, such as actuator position sensors or, for example, during the final docking / landing phase of a space capsule.

[0106] Furthermore, the S tracking system can also be used in other applications such as an autonomous vacuum cleaner searching for its charging station.

[0107] The invention has a low total mass and advantageously allows flexible use in multiple fields where weight is a constraint, for example in the field of body movement capture by transmitter / receiver combination on different parts of the body or in the space and aeronautical fields.

Claims

Tracking system (S) comprising:At least one tracking device (3) configured to be attached to an object to be tracked or to a person to be tracked (OP),at least one detection device (4) configured to detect the position and the angular orientation of the tracking equipment (3),Tracking system (S) characterized in that the detection device (4) comprises:A receiving device (1), mounted in a reference frame (100) or on the tracking equipment (3), configured to receive a predetermined standard image (IM1) projected by a transmitting device (2) mounted on the other of the reference frame (100) or of the tracking equipment (3), the predetermined standard image (IM1) comprising at least one predetermined oriented pattern (M1-M15),the receiving device (1) comprising:at least one receiving zone (11) configured to receive at least a portion of the projection of the predetermined standard image (IM1) andat least one optical sensor (14) configured to capture a current image (IM2) received on the receiving zone (11),at least one calculation device (19) configured to determine the deformation of at least one predetermined oriented pattern (M1-M15) in the current image (IM2) so as to deduce therefrom a position vector (vecR) which is specific to the receiving device (1) and defined relative to the transmitting device (2) from the determined deformation., Tracking system (S) according to claim 1, wherein, the transmitting device (2) transmits the predetermined standard image (IM1) according to a predetermined wavelength range, the optical sensor (14) is sensitive only in the predetermined wavelength range, preferably, the predetermined wavelength range is not visible to the naked eye, preferably, in the infrared. Tracking system (S) according to one of claims 1 to 2, in which the reception zone (11) is in the form of a diffusing transmissive surface configured to receive, on a first face, at least a portion of the projection of the predetermined standard image (IM1), the optical sensor (14) being configured to capture the current image (IM2) on a second face opposite the first. Tracking system (S) according to one of claims 1 to 3, in which the detection device (4) comprises at least one transmission device (2), mounted on the other of the reference frame (100) or the tracking equipment (3), configured to project the predetermined standard image (IM1) onto the reception area (11) of the reception device (1). Tracking system (S) according to claim 4, wherein the transmitting device (2) comprises a divergent projection device (21). Tracking system (S) according to claim 5, wherein the emission device (2) comprises a transparent surface (22) configured to allow the projection of the predetermined standard image (IM1) to pass through. Tracking system (S) according to one of claims 5 to 6, wherein the divergent projection device (21) comprises a reflective member (6) and a light source (5) projecting light onto the reflective member (6), the reflective member (6) comprising a plurality of reflective elements (D1-D15) configured to form the predetermined oriented patterns (M1-M15) of the predetermined standard image (IM1). Tracking system (S) according to claim 7, wherein, the reflecting member (6) being configured to form the predetermined standard image (IM1) towards the front, the reflecting member (6) comprises a transparent front support (61) and a rear absorbing surface (62), the plurality of reflective elements (D1-D15) being positioned between the rear absorbing surface (62) and the transparent front support (61). Tracking system (S) according to claims 1 to 8, wherein the tracking equipment (3) is configured to display at least one additional data item which is a function of the position vector (vecR). Tracking system (S) according to one of claims 1 to 9, wherein the tracking equipment (3) is a headset (3). Vehicle (100), in particular a light aviation vehicle, the vehicle (100) comprising a cabin (101) configured to house at least one operator (OP), the vehicle (100) comprising at least one tracking system (S), according to one of claims 1 to 10, configured to display an augmented, mixed or virtual exterior scene (SC), enriched according to a position and an angular orientation of the tracking equipment (3). A method of using a tracking system (S) according to one of claims 1 to 10, the tracking system (S) comprising at least one tracking equipment (3) configured to be attached to an object to be tracked or to a person to be tracked and at least one detection device (4) configured to detect the position and angular orientation of the tracking equipment (3), the detection device (4) comprising a transmission device (2) mounted in the reference frame, and a reception device (1) mounted on the tracking equipment (3), a method characterized in that it comprises steps consisting in: Projecting (E1) a predetermined standard image (IM1) by the transmission device (2) towards the reception device (1) so as to receive at least a portion of the projection of the predetermined standard image (IM1) onto a reception area (11) of the reception device (1), the predetermined standard image (IM1) comprising at least one predetermined oriented pattern (M1-M15),Capturing (E2) a current image (IM2) received on the reception area (11),Determining (E3) a deformation of at least one predetermined oriented pattern (M1-M15) in the current image (IM2) andDetermining (E4) a position vector (vecR) which is specific to the reception device (1) and defined relative to the transmission device (2) from the determined deformation., Method of use according to claim 12 in which the projection step (E1) and the capture step (E2) are carried out continuously. Method of use according to one of claims 12 to 13 wherein the deformation determination step (E3) comprises sub-steps consisting of:Determining (E31) a separation distance (Da) separating the reception device (1) from the transmission device (2) by means of the deformation of at least one predetermined oriented pattern projected (M1'-M15') in the current image (IM2),Determining (E32) the angular position (Pang) of the reception device (1) relative to the transmission device (2) by means of the deformation of at least one predetermined oriented pattern projected (M1'-M15') in the current image (IM2) andDetermining (E33) the angular orientation (OR1) of the reception device (1) relative to the transmission device (2) by means of the deformation of at least one predetermined oriented pattern projected (M1'-M15') in the current image (IM2). Method of use according to claim 14, in which the sub-steps of the deformation determination step (E3) are carried out in parallel. Method of use according to one of claims 12 to 15, comprising a step of determining (E5) the position vector (vecR) by correlation from the current image (IM2) and a previous current image (IM2*) for which a previous position vector (vecR*) has already been determined. Method of use according to one of claims 12 to 16, comprising a step consisting of displaying by the tracking equipment (3) an exterior scene (SC), augmented, mixed or virtual, enriched according to a position and an angular orientation of the tracking equipment (3).

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