WO2012089957A1

WO2012089957A1 - Device for detecting an angular direction in which an object is located

Info

Publication number: WO2012089957A1
Application number: PCT/FR2011/053072
Authority: WO
Inventors: Philippe Plantier; Claude N. BUREAU
Original assignee: H2I Technologies
Priority date: 2010-12-31
Filing date: 2011-12-20
Publication date: 2012-07-05
Also published as: FR2970095B1; FR2970095A1

Abstract

The invention relates to a device (D) for detecting an angular direction in which an object (2) is located, which is to be used in an optoelectronic system for determining the position of an object (2) on a predefined geometric structure, said device (D) including at least two receivers (R1, R2), each of which have a receiving surface (S1, S2) on which the radiating power received from the object (2), and thus the raw photocurrent generated as output, is dependent on the angle (α,β) from which the object (2) is viewed along a strictly monotonous dependency curve of the radiating power received with the angle (α,β) from which the object (2) is viewed. Both receiving surfaces (S1, S2) are placed side-by-side, but each receiving surface lies in a separate plane, wherein the two planes formed therebetween form an angle of less than 150º and thus form a so-called device edge (AD). The device makes it possible to determine the angles (α,β) from which the object (2) is viewed by each receiver (R1, R2) while taking into consideration that the brightness for each receiver (R1, R2) is identical, but the radiation has different angles (α,β) of incidence.

Description

Title of the invention

"Device for detecting an angular direction in which there is an object". Background of the invention

The present invention relates to the field of angular direction detection devices in which there is an object.

Such a device is in particular intended to be implemented in a system for determining the position of an object present on a geometrical structure, whether this structure is one-dimensional, two-dimensional or three-dimensional. It can be used in a presence detector, an approach detector, in a light control interface, etc. For example, the device according to the invention can be implemented in a dimmer switch whose output level depends on the distance between the hand of a user and the detection device according to the invention. This distance is then directly a function of the angle at which the hand is viewed by an angular direction detection device. Here we see one of the applications of angular direction detection devices to detect a distance.

There are multiple principles for detecting a presence of a remote object. More specifically, the invention relates to detection devices using light, or any other electromagnetic radiation with close physical properties, including infrared or ultraviolet radiation; that is to say any electromagnetic radiation whose wavelength is between 10 μιτι and 100 nm.

It is common to use such radiation and exploit the reflection of it on the object to be detected. Any visible electromagnetic radiation is therefore concerned with the terms "light" and "optics" used hereafter, but also invisible electromagnetic radiation with wavelengths and near physical properties, namely infrared and ultraviolet radiation.

The light receiver is then used to measure the light intensity reflected by the object. The variation of the signal on the receiver makes it possible to determine the presence of an object. In this area, it is also known compensation techniques or removal of ambient light to allow the device to operate even if the receiver captures, in addition to the reflected signal, a light signal from the environment.

Most often, such a device operates in all or nothing mode by implementing a threshold. The object is detected only if the reflected light crosses this threshold without any other information on its position. These devices provide no reliable information about the detection distance. Indeed, a highly reflective object, for example white or shiny, located far from the device can reflect more radiation than a low-reflective object, black or matte, located near the device. Other factors, such as the size of the object or its orientation, are also factors in the amount of reflected signal. Thus, by taking the amount of reflected signal separately, it is not possible to access information other than the presence of an object.

Various techniques are commonly used by detector designers to solve this problem.

A first family of techniques uses the flight time of radiation. It's the family of radars, lidars and other sonars. These techniques exploit the fact that radio-light or acoustic waves do not propagate instantaneously. Also, these techniques calculate the detection distance by exploiting the previously known radiation velocity. The propagation properties of the wave in the detection medium make it possible to convert the temporary offset between transmission and reception in distance.

These techniques are effective but their applications are limited because the speed of light is extremely high in the air and it is not possible to apply this principle when it comes to making measurements over short distances, typically less than meters. Indeed, the round trip time of a photon over a distance of 100 mm is 667 picoseconds.

To be able to exploit the flight time, in a distance calculation, it is necessary, at least, to emit a pulsed signal whose pulses are of a duration of the order of magnitude of the time to be measured. It is also necessary to have a sufficiently sensitive reception device to be able to measure the time shift of the reflected signal. This can for example be achieved by analyzing the phase shift between two alternative signals. Such components exist but they remain expensive and relatively bulky. The use of these principles is generally reserved for telemetry devices operating over long distances.

Thus, devices using flight time are all the more expensive and complex that the distances to be measured are low. In general, it is observed that the techniques employed in this case are then rather based on triangulation techniques.

The sensors of the GP2 family produced by the SHARP company use such a principle which is moreover described in the Japanese document JP 6 334 819. The device described in this document serves to detect the distance to which an object is located. It includes a transmitter with a lens as a collimator. It further comprises a lens for forming an image of the signal reflected on a linear sensor having a current / voltage conversion circuit and an amplification circuit for measuring the signals by a microprocessor. The sensor described is an imaging sensor. This device is described to measure a distance.

Nevertheless, it is noted that the imaging device 23 produces the image formed by the object reflected on the sensor and this image depends on the angle formed by the object to be detected with the normal sensor. The imaging device 23 coupled to the optical 19 thus makes it possible to detect an angle in which an object is located, whether it is located on a fixed line as described in the device of the document of the prior art or located on a wider surface.

Indeed, the position of the image formed by the object reflected on the linear sensor depends on the angle formed by the object to be detected with the normal sensor. Thus, since the object is at a given distance on a predefined line, the image is formed around a point corresponding to the angle at which the object is viewed from the sensor.

In the case of the location of the object on a wider surface, the device described in this document of the prior art allows to determine an angular direction in which the object is located.

The distance measurement, obtained by detecting an angular direction while the object can move only on a predefined line is then completely independent of the amount of reflected light since it is the location of a luminous point on the sensor that provides access to the position of the object. This technique makes it possible to have precise information on the distance between the sensor and the object by triangulation with detection of an angular direction.

US 2007/0222760 discloses a data entry device using a similar principle for detecting the position of an object transposed on two dimensions. Here again, an imaging sensor makes it possible to locate the object. The device described in this document uses a light plane and a camera, the elements necessary for the implementation of this system being placed in three dimensions. An image of a two-dimensional surface is acquired to detect the position of the object.

As the sensor is two-dimensional, it is able not only to have access to the angle but also to the distance of the finger from the imaged surface.

Many known devices thus use one- or two-dimensional imaging devices to locate an object. This principle makes it possible to obtain good accuracy, but these devices have a relatively high manufacturing cost and a complex mechanical integration. These prior art also have the disadvantage of having to require the implementation of expensive imaging components, especially a camera sensor and optics of sufficient quality to allow to have an image without deformation or aberration. In addition, the size of these devices of the prior art is quite important since the image sensor must be located in height with respect to the predefined surface where the position of the object is detected or staggered on one side. a line where the object is likely to be. This is necessary to have a sufficient angle to be able to see the whole surface or the whole line. The use of this technology is therefore incompatible with the mechanical constraints encountered in many areas.

In addition, these devices are not compatible with the principles of ambient light compensation of the type described in document FR 08 59048, these principles of light compensation being indispensable when the device must be able to be used outdoors and for detection on an unobstructed surface. Known devices using imaging sensors therefore have limited applications since they can not operate outdoors or impose drastic implementation conditions of the type of a mechanical integration maintaining the sensor and the object to be detected at the same time. shadow.

There are still devices using transmitters and receivers placed in staggered rows. These devices are compatible with the use of ambient light compensation but have the disadvantage of being non-linear. Furthermore, in the manner of the device described in document JP 6 334 819, they require locating an object on a predefined line to determine the angle at which the object is seen in the case where a plurality of transmitters and staggered receivers are used.

To date, there is no known device for detecting an angular direction that can be implemented in environments where ambient light is very present and for determining an angular position of an object without locating it on a predefined line. .

Object and summary of the invention

The main object of the present invention is therefore to overcome the disadvantages of the prior art by proposing a device for detecting an angular direction in which there is an object intended to be implemented in an optical and electronic system for determining a position of an object present on a predefined geometric structure,

this device comprising at least two receivers sensitive to electromagnetic radiation of wavelength between 100 nm and 10 μιτι, delivering a raw photo-current output and each having a receiving surface on which the radiant power received from an object, and thus the raw photo-current delivered at the output, is dependent on the angle under which the object is viewed according to a strictly monotonic dependence curve of the radiant power received with the angle under which the object is viewed , the two receiving surfaces being placed side by side but each in a separate plane, the two planes forming an angle between them of less than 150 ° and thus forming a so-called edge of the device, the device being intended to be positioned in such a way that the portion of the space defined between these two planes includes the particular geometrical structure on which the object may be located,

the device further comprising an electronic module comprising means for, upon illumination of the predefined geometric structure with radiation having specific spectral and / or modulation characteristics:

receive the signals received by each of the receivers,

extracting, from each signal received by a receiver, the radiant power from the optical signal having specific spectral and / or modulation characteristics received by this receiver,

- from these radiant powers, determine the angles under which the object is seen by each of the receivers considering that the energy intensity illuminating each receiver is identical, but that the radiation is at different angles of incidence,

- determine the angular direction of a plane passing through the edge of the device and where is the object.

The invention consists in using pairs of receivers located in a particular way, with respect to each other and with respect to the surface to which the predefined geometric structure belongs, these receivers being such that the output signal they deliver is in strictly monotonous dependence with the angle under which is seen the object.

For the same received light intensity, these receivers can advantageously be Lambertian type receivers. The principle of Lambert's law is shown in FIG. 1. This property is, in particular, observed for components devoid of a lens of the photodiode or phototransistor type. Indeed, the angular sensitivity of this kind of components is fixed by the physical and optical laws. They have a surface denoted SD receiving light emitted by an object 2 located in the space facing the SD surface. The vector from the center of the photosensitive surface SD to the emitter object 2 makes an angle noted a with the normal to the surface SD.

According to Lambert's law, the sensitivity is proportional to the cosine of the angle formed by the light source 2 and the normal to the surface SD. If no optical device is installed on the photosensitive surface SD, it then emits an electrical signal proportional to the light signal it receives. The luminous intensity is a flux per solid angle expressed in candela. A candela, basic unit, corresponds to a lumen, unit of luminous flux, per steradian. The luminous intensity on the two receivers is identical, the luminous flux is different because each receiver has a different solid angle (steradians). At fixed luminous intensity, the electrical signal, which corresponds to a received radiant power, is then proportional to the cosine of the angle a.

The luminous power illuminating the surface SD is then written S = S ₀ cos (a),

S ₀ being proportional to the light intensity received.

This cosine dependency is maintained on the signal available at the output of the photosensitive surface SD. Other types of dependence between this signal and the angle of view of the object 2 can be used since this dependence is strictly monotonous.

By providing for placing two receivers of this kind side by side in two different angular positions, the device according to the invention makes it possible to detect the angles under which the object is seen by each of the two receivers, considering that the two receivers receive the same light intensity S ₀ at the moment of detection since they are neighbors.

Since, according to the invention, the two receivers are such that the reception surfaces are placed on intersecting planes at an edge of the device, the angular direction under which the object is viewed is then a plane passing through the edge and making the angles determined according to the invention with each of the receiving surfaces.

The weakest angles between the two planes carrying the receiving surfaces are applicable if it is necessary to make, for example, a detector capable of measuring a distance between 100 cm and 102 cm.

In an advantageous embodiment, the two planes carrying the receiving surfaces form between them an angle of between 60 and 120 °.

These angles make it possible to ensure coverage of an extended surface in front of the receivers while allowing a good distinction between the angle at which the object is viewed with respect to each of the receivers. Advantageously, the two planes carrying the receiving surfaces form between them an angle substantially equal to 90 °.

This angle makes it possible to cover a rectangular area optimally.

According to a preferred characteristic of the invention, the radiation to which the receivers are sensitive is infrared radiation.

Indeed, it is sometimes desirable to use, for detection, visible radiation for the user, for aesthetic reasons or to provide a visual feedback. However, in most cases, however, one will wish to make the detection device invisible to the user. For this purpose, the use of invisible radiation, infrared or ultraviolet, will be preferred.

Advantageously, emitters and receivers operating in the near infrared range will be used: wavelengths ranging from 700 to 1500 nm, typically 950 nm, for reasons of cost and safety.

These angles, which make it possible to open the space in which the predefined structure can be on angular plane portions of 60 to 120 °, are optimal for the accuracy of the device while giving a good opening on the predefined geometric structure.

It is understood here that it will be very advantageous to place the two receivers at 90 °. The surface thus covered will be a quarter space only limited by the range of transmitters / receivers used.

Advantageously, the distance between the two reception surfaces is less than one-third of the shortest distance that can be measured with the device.

This feature ensures that the approximation that the same light intensity is received by the two receivers does not introduce a significant error in the determination of the angular direction.

According to a preferred embodiment, each receiver comprises a reflector bringing the light received on the receiving surface of the receiver on a Lambertian detection surface, the two lambertian detection surfaces of the two receivers being placed in the same plane.

This embodiment makes it possible to place the two lambertian components without lens on the same plane circuit. Indeed, place both components in two planes forming an angle between them as is provided according to the invention is not easy from a point of view of the hardware realization. This feature avoids having to place the receivers on two different planes which requires either multiple printed circuits, or a folding circuit board, type "Flex", which is expensive.

This preferred embodiment makes it possible to overcome this problem by providing each receiver with a reflector making it possible to reduce the light received from the predefined geometric structure towards the same common plane for the two receivers. In addition, advantageously, such a reflector advantageously plays a selective collection optical role selecting only the radiation coming from the predefined geometric structure. This avoids radiation detections from the space around the predefined geometric structure.

In an advantageous embodiment, the reflector has a surface corresponding to one-half of the solid formed by the revolution of the base of a parabola around an axis perpendicular to the focal axis of the parabola, the halves being determined by the another of a plane passing through the focal axis of the parabola, the focus of the dish located in the median plane of the reflector being located on the sensing surface.

Such a reflector shape allows the clustering of the light on the plane facing the reflectors, that is to say the plane perpendicular to each of the receiving surfaces, to be brought together to the Lambertian detection surface.

Thus, the entrance surfaces of the light in the reflectors coincide with the receiving surfaces of the receivers. They are advantageously placed in such a way that they make it possible not only to avoid detections in the three-dimensional space facing the receivers but also to preserve the strict monotony of the dependence between the signal available at the output of the receiver and the angle formed. by the object with the normal to the receiving surface.

In a particular feature, the surface of the detection is centered on the focus of the dish. This feature ensures that the Lambertian detection surface receives an optimal amount of light.

In a particular embodiment, the axis of revolution of the reflector is such that the focus of the dish is inside the reflector.

This feature allows a good compactness of the receiver since the Lambertian detection surface is then located inside the reflector, which is particularly advantageous.

Advantageously, the focal length of the dish is close to the size of the photosensitive surface of the detector, typically between 0.5 and 1.2 times the size of the photosensitive surface.

This characteristic makes it possible to optimize the ratio between incoming energy and size of the device.

Until now, the device described has been to detect the presence of an object on a predefined geometric structure that can be, at most, a two-dimensional surface. Indeed, the device according to the invention can not be discriminating on three dimensions. In other words, the device according to the invention can not best determine an angular direction carried by a plane passing through the edge of the device, the position on this plane can not be discriminated with the device according to the invention. .

The invention also relates to an optical and electronic system for determining a position of an object, characterized in that it comprises a device according to the invention comprising three receivers each having a reception surface on which the radiant power received in origin of an object is dependent on the angle at which the object is viewed according to a strictly monotonic dependence curve of the radiant power received with the angle under which the object is viewed, the three receiving surfaces being placed side by side. to each other but in a separate plane, the three planes forming, in pairs, an angle of less than 150 ° and thus forming three edges of the device, each associated with a pair of planes, the device being intended to be positioned such that way that the portion of the space defined between these three planes includes the predefined geometric structure where the object is likely to be,

the device further comprising an electronic module comprising means for, upon illumination of the predefined geometric structure with radiation having spectral and / or specific modulation characteristics:

receive the signals received by each of the receivers,

- from these radiant powers, determine the angles under which the object is seen by each of the receivers, considering that the receivers receive the same luminous intensity but at different angles,

determining the angular directions of three planes passing through the edges of the device and where the object is located,

- determine the position of the object at the intersection of the three planes.

This application of the invention makes it possible to determine exactly the position where an object is located in the space by intersection of three planes.

Also, the invention relates to an optical and electronic system for determining a position of an object present on a predefined line, the system comprising a transmitter emitting a beam of radiation having specific spectral and / or modulation characteristics allowing to detect it even in the presence of a high intensity natural light, this beam being collimated along the predefined line,

this system comprising a device for detecting an angular direction according to the invention positioned in such a way that the portion of the space defined between the two planes bearing the receiving surfaces of the two receivers includes the predefined line on which is likely to be finding the object, and comprising a position determining module for, knowing the position of the device with respect to the predefined line and the angular direction of the plane passing through the edge of the device and where the object is located, deduce therefrom the position of the object on the predefined line by intersection.

This application in a system for detecting a position of an object provides access to a distance measurement of an object of the type described in document JP 6 334 819. However, the device implemented by the invention is significantly less expensive than the imaging devices used in known devices. With only two photosensitive surfaces, the invention makes it possible to obtain the same result as the prior art but at a lower cost. It suffices for this to use a device according to the invention, the two planes of the receiving surfaces open on the line on which the object may be located.

In a particular embodiment, the predefined line is the beam of a transmitter.

This characteristic makes it possible to materialize the predefined line on which the object can be. In the case where a plurality of emitters is used, this makes it possible to cover a surface and to detect the position of an object on this surface as soon as the emitters are switched on sufficiently rapidly.

However, the invention makes it possible to detect, at a lower cost, the position of an object without using a plurality of transmitters.

Indeed, the invention also relates to an optical and electronic system for determining a position of an object present on a predefined surface, the device comprising at least one emitter emitting a beam of radiation having spectral characteristics and / or specific modulation means for detecting it, even in the presence of high intensity natural light, this beam being collimated in the predefined surface,

this system comprising a device for detecting an angular direction according to the invention, comprising three receivers, positioned in such a way that the portion of the space defined between the three planes bearing the reception surfaces of the three receivers includes the predefined surface on which is likely to be the object and comprising a position determining module for, knowing the position of the device with respect to the predefined surface and the angular direction of the straight line passing through the corner of the device and where is located the object, deduce the position of the object on the predefined line by intersection.

The use of an angular direction detection device comprising three receivers according to the principles of the invention makes it possible, by virtue of the determination of the intersection between the straight line bearing the direction. angle of the object and the predefined surface, to fully determine the position of the object.

In another application, the invention relates to an optical and electronic system for determining a position of an object present on a predefined surface, the device comprising at least one transmitter disposed on a so-called emission side of the predefined surface emitting a beam of radiation having spectral and / or specific modulation characteristics making it possible to detect it, even in the presence of a high intensity natural light, this beam being collimated in the predefined surface,

this system comprising two devices for detecting an angular direction according to the invention, each comprising two receivers, positioned on either side of the emission side so that the portions of the space defined between the two pairs of planes carrying the receiving surfaces of the two receivers of each of the angular direction detecting devices according to the invention each include the predefined surface on which the object may be located, and comprising a position determination module for , knowing the position of the two devices with respect to the predefined surface and the angular direction of the planes passing through the edges of each of the angular detection devices and where is the object, to deduce the position of the object on the predefined line by intersection.

Here, the use of two devices for detecting an angular direction each comprising two receivers makes it possible to determine completely, knowing the predefined surface on which the object is located and two angular directions detected by each of the detection devices of a sensor. angular direction placed on either side of the predefined surface, allows to completely determine the position of the object.

Finally, the invention relates to a method for detecting an angular direction in which there is an object intended to be implemented in an optical and electronic system for determining a position of an object present on a predefined geometric structure,

this process comprising the steps of:

placing at least two receivers sensitive to electromagnetic radiation of wavelength between 100 and nm and 10 μιτι, outputting a raw photo-current and each having a receiving surface on which the radiant power received from an object is dependent on the angle at which the object is viewed according to a dependence curve strictly monotonous of the radiant power received with the angle under which the object is seen, so that the two receiving surfaces are placed side by side but each in a separate plane, the two planes forming an angle between them less than 150 ° and thus forming a so-called edge of the device,

arranging the two receivers in such a way that the portion of the space defined between the two planes bearing the reception surfaces includes the particular geometrical structure on which the object is likely to be located,

illuminate the predefined geometric structure with radiation having specific spectral and / or modulation characteristics,

receiving, within an electronic module, the signals received by each of the receivers,

Such a method incorporating the characteristics of the device according to the invention makes it possible to access an angular direction in a very simple and inexpensive manner while allowing the implementation of means for compensating for ambient light.

Brief description of the drawings

Other features and advantages of the present invention will emerge from the description given below, with reference to the accompanying drawings which illustrate an embodiment having no limiting character. In the figures: FIG. 1 illustrates Lambert's law in optics;

- Figure 2 shows an angular detection device according to the invention schematically;

FIG. 3 shows a preferred embodiment of the invention; FIG. 4 shows a preferred embodiment of a reflector used in a detection device according to the preferred embodiment of the invention;

FIG. 5 shows an application of the invention to a system for detecting the position of an object on a surface;

FIG. 6 shows an application of the invention for detecting the position of an object in space.

Detailed description of an embodiment

FIG. 2 shows an angular direction detection device D according to the invention. The detector D comprises two receivers R1 and R2 each comprising a reception surface SI and S2. On these surfaces S1 and S2, the radiant power received from the object 2 is dependent on the angles a and β under which the object 2 is seen with respect to the normal to these surfaces S1 and S2. This dependence of the radiant power received as a function of the angle at which the object is viewed follows a strictly monotonic dependence curve.

For example, receiving surfaces obey Lambert's law. These may be photosensitive commercial components without a lens. In this case it is necessary that the two components are mounted on two planes at an angle to each other.

Indeed, according to the invention, the two receiving surfaces S1 and S2 are placed side by side but each in a separate plane. In the embodiment of FIG. 2, the two planes form an angle equal to 90 ° between them. The intersection between the two planes forms an edge called "edge of the device" denoted AD. It can be seen here that the portion of the space defined between the two planes includes a predefined surface S on which object 2 may be located. This surface S is the quarter-plane on which the receivers R1 and R2 open. .

The device D includes or is connected to an electronic module M which receives the signals received by each of the two receivers R1 and R2. This module M is able to extract, from each signal received by the receivers R1 or R2, a power radiant having spectral characteristics and / or specific modulations received by this receiver.

Indeed, the commercially available photosensitive components emit an output signal depending on the received light and its modulation. This makes it possible to implement ambient light compensation. The important thing for this is that the component used allows to have the raw photo-current, without any integration device or other current-voltage converter assembly. A current-voltage converter adapted for ambient light compensation can then be used. This is not the case in the devices of the prior art where, in high brightness, conversion devices for imaging are either saturated or have a gain too low for the signal, for example infrared , reflected by the finger is visible.

Assuming that the receiving surfaces have Lambertian behaviors (Lambert's law) that is to say that the radiant power received on a surface is proportional to the cosine of the angle under which the reflective object is seen relative to the normal at this surface, the received radiant powers are expressed then in the form:

5 ₂ = S _2/0 .cos ()

From these radiating powers, the electronic module M considers that the distance between the two receivers is negligible compared to the distances between the transmitter and the object and between the detector and the object.

He considers that the two receivers RI and R2 are merged. Thus the two receivers R1 and R2 receive the same luminous intensity but at different angles and therefore that Si, ₀ = S ₂ , o = S ₀ . Since the two receivers are also placed at 90 ° to one another, β = π / 2 - α.

So :

5 ₁ = So.cos (oc)

5 ₂ = S ₀ .cos (7t / 2 - a) = So.sin (a)

So

5, S cos

arccos = arccos = The value of the reflected signal is then eliminated and the angle a is thus obtained as a function of the two received signals. The module M2 thus determines the angular direction al under which the object 2 is seen by the receiver RI, this angular direction al being that of a plane P passing through the edge AD of the device D.

It can clearly be seen in FIG. 2 that only the angular direction α1 of the plane P can be known and that it is not possible, in this case, to distinguish the difference in position between the two objects 2i and 2 ₂ which are in the same angular direction relative to the detection device of an angular direction D.

Determining the position of the object is possible only if, moreover, it is known that it is located on a line, for example, on the emission beam of a transmitter E. A device of detection of the position of a one-dimensional object.

On the other hand, it can be seen here that the object can exhibit any reflection characteristic of the light emitted. This does not affect the determination of the angular direction in which the object 2 is located.

It is noted here that lambertian receptors are sensitive on space. In this case, with the embodiment shown in FIG. 2, the receiving surfaces S1 and S2 receive the radiation present on the half-space facing them. It can then occur three-dimensional parasitic detections. In this case, an optic is added to restrict the sensitivity of the receivers to the plane without modifying the angular sensitivity of the Lambertian surface. This further increases their sensitivity in this plane. Such optics only act on the sensitivity in the direction perpendicular to the predefined surface S.

It is possible to have the light-sensitive components without optical in the wedge trade as shown in Figure 2. Nevertheless, these, which are generally found in a package devoid of optics, are welded together. general parallel to the printed circuit. The low cost realization of the detection device of an angular direction as shown in Figure 2 with discrete components is difficult.

FIG. 3 shows a preferred embodiment of the receivers R1 and R2 within a device D for detecting an angular direction according to the invention. In this preferred embodiment, the receiving surfaces S1 and S2 are input surfaces in a reflector RF1, RF2. Each of these input surfaces S1 and S2 belongs to a plane. The intersection of the two planes carrying the two receiving surfaces S1 and S2 defines the edge AD of the device D.

The reflectors RF1 and RF2 reflect the radiation passing through the receiving surfaces S1 and S2 respectively to a detection surface SD1 and SD2. The detection surfaces SD1 and SD2 are lambertian. These are typically commercial components without a lens. As the detection surfaces SD1 and SD2 are now coplanar, this is very advantageous for the manufacture of the device according to the invention because it follows the usual procedures for mounting discrete electronic components of the photodiode type.

In the preferred embodiment shown in FIG. 3, the reflector RF1 has particular properties making it possible to reflect the rays striking the reception surface SI coming from the predefined geometric structure so as to bring them back to the Lambertian SD1 detection surface while maintaining the strictly monotonic variation of the latter between received power and angle of vision.

In other words, for the implementation of the invention, it is essential that the radiant power that hits the detection surface SD1 or SD2 is strictly monotonous dependence with the angle at which the object is seen by ratio to the edge AD.

This characteristic makes it possible, assuming that the two receivers R1 and R2 receive the same luminous intensity, to determine the angular direction of the plane passing through the edge AD in which the object is located as described previously and according to the principles of the invention.

In addition, the reflectors are such that they select the radiation perpendicular to the receiving surfaces S1 and S2. Thus, in this embodiment, the predefined geometric structure is typically the surface carried by the plane perpendicular to the edge AD and passing through the detection surfaces SD1 and SD2 in the open quarter of plane in front of the receivers.

The reflector RF1 therefore plays the role of optical selection in space. This prevents parasitic detections in three dimensions. FIG. 4 shows a median section of an RF reflector as used in FIG. 3. This section forms a focus parabolic arc F and focal axis OX. The RF reflector is the solid obtained by revolution of this arc on a half-space around the axis OZ perpendicular to the focal axis OX. This RF reflector makes it possible to maintain the dependence at the angle under which the object is viewed and makes it possible to ensure good planar sensitivity to the detection devices of an angular position. Such an RF reflector also makes it possible to obtain a coverage area of a quarter of usable space for the production of a system according to the invention and to select radiation parallel to the plane perpendicular to the edge AD.

FIG. 5 schematically shows a first optical and electronic system for determining a position of an object using a device according to the invention.

In this system, the object is likely to be on a predefined geometric structure which is a surface S. A plurality of emitters E1 to E7 are disposed on a CE emission side of a surface S. The emitters E1 to E7 are aligned next to each other and optionally each have a lens L1 to L7 to collimate the light emitted into a substantially parallel beam.

FIG. 5 shows two beams F2, F3 emitted by the emitters E2 and E3. We see that these beams are slightly divergent and illuminate the entirety of the predefined surface without hole or dead zone between them on the surface S. The fact of collimating the beams also makes it possible to increase the range of detection and to allow that the detection remains in the predefined area. It should be noted here that, advantageously, the light will be collimated on the predefined surface in order to avoid parasitic three-dimensional detections.

They emit preferably a light, preferably infrared, having specific spectral and modulation characteristics for detecting the radiation emitted by the emitters, including in the presence of invasive natural light. Typically the light is then modulated with a modulation frequency between 30 and 100 kHz. Below 30 kHz, the device will be further disrupted by the lights powered by an electronic switching system, at more than 100 kHz. sensitivity to radio frequency signals becomes troublesome. The spectral sensitivity of the receiver is also chosen as thin as possible, centered on the spectral emissivity peak of the transmitter. Typically, a compensation principle as described in document FR 08 59048 is used. These characteristics are known elsewhere and will not be explained here. Nevertheless it is remarkable that the invention uses simple components but precisely sensitive to the spectral properties and / or modulation of the received signals to allow the implementation of an ambient light compensation.

The plurality of transmitters may be replaced by a single transmitter, provided with a lens transforming its output beam into a plane beam covering the entire predefined area S. It is also possible to use a light plan generator based on on a laser technology.

On each side of the row of emitters E1 to E7 are placed two devices for detecting an angular direction D1 and D2 of the type described in FIG. 3. These devices for detecting an angular direction D1 and D2 are capable of receiving and processing radiation, preferably infrared, having particular modulation characteristics to determine the angular direction of the object 2, under which is seen this object 2 of the detection device of an angular direction D1 and D2.

Thus, upon reception of a radiation having the spectral and / or specific modulation characteristics expected for illumination by one of the emitters and reflection on an object 2 present on the surface S, the detectors D1 and D2 each determine an angular direction, respectively al and a2, in which object 2 is located.

Once each of the two devices has determined the angular direction in which it has detected the object 2, it is sent to a module which determines the position XY of the object 2 on the surface S according to the position of the objects. detection devices D1 and D2 with respect to the predefined surface S and the angular directions al, a2.

Indeed, according to the two angles al, a2 determined by these devices, by triangulation, the module 10 determines the position of the object using the formula: sin (£ U2) cos (al)

sin (or1) cos (or2) + cos (or1) sin (or2)

sin (orl) sin (or2)

sin (or1) cos (or2) + cos (or1) sin (or2)

The detections of angular directions made on each side of the emission side CE make it possible to completely determine the position of the object 2.

FIG. 6 schematically shows a device for detecting the three-dimensional angular direction. This device comprises three receivers R1, R2, R3 placed side by side in planes forming between them angles of 90 °. The device thus obtained is typically useful for detecting the position of an object 2 in space.

Each pair of receivers (R1, R2), (R2, R3), (R1, R3) makes it possible to define a plane, respectively P3, PI and P2, directed with respect to the intersection edge, respectively AD3, AD1 and AD2 of the two planes carrying the receiving surfaces of the receivers, respectively (R1, R2), (R2, R3) and (R1, R3). In Figure 6, only the plane P2 passing through the edge AD2 is shown. The intersection of the three planes PI, P2 and P3 passing respectively through the edges AD1, AD2 and AD3 gives a point on which object 2 is located. When the object is moreover likely to be only on a predefined surface S, it is possible to check the position of the object by checking that the obtained point is on this surface.

Finally, we note that various implementations can be made according to the principles of the invention.

Claims

1. Device for detecting (D) an angular direction in which there is an object (2) intended to be implemented in an optical and electronic system for determining a position of an object (2) present on a predefined geometric structure,

this device (D) comprising at least two receivers (R1, R2) sensitive to electromagnetic radiation of wavelength between 100 nm and 10 μιτι, delivering a raw photo-current output and each having a receiving surface (S1 , S2) on which the radiant power received from an object (2), and therefore the raw photo-current output, is dependent on the angle (α, β) under which the object (2 ) according to a strictly monotonic dependence curve of the radiant power received with the angle (α, β) under which the object (2) is seen, the two receiving surfaces (S1, S2) being placed side by side but each in a separate plane, the two planes forming between them an angle less than 150 ° and thus forming a so-called edge edge of the device (AD), the device (D) being intended to be positioned in such a way that the portion of the space defined between these two planes includes the particular geometric structure e on which object (2) may be found,

the device (D) further comprising an electronic module (M) comprising means for, upon illumination of the predefined geometric structure with radiation having specific spectral and / or modulation characteristics:

receiving the signals received by each of the receivers (R1, R2) extracting, from each signal received by a receiver (R1, R2), the radiant power from the optical signal having specific spectral and / or modulation characteristics received by this receiver (R1, R2),

- from these radiant powers, determine the angles (α, β) under which the object (2) is seen by each of the receivers (R1, R2) whereas the energy intensity illuminating each receiver (R1, R2) is identical, but that the radiation is at angles (α, β) of different incidence,

- Determine the angular direction (oc2) of a plane (P) passing through the edge of the device (AD) and where the object (2).

2. Device according to claim 1, characterized in that the two planes carrying the receiving surfaces (S1, S2) are between them an angle of between 60 ° and 120 °.

3. Device according to one of claims 1 and 2, characterized in that the distance between the two receiving surfaces (S1, S2) is less than 1/3 of the shortest distance that can be measured. with the device.

4. Device according to one of the preceding claims, characterized in that each receiver (R1, R2) comprises a reflector (RF1, RF2) returning the light received on the receiving surface (S1, S2) of the receiver (R1, R2 ) on a Lambertian detection surface (SD1, SD2), the two Lambertian detection surfaces (SD1, SD2) of the two receivers (R1, R2) being placed in the same plane.

5. Device according to claim 4, characterized in that the reflector (RF) has a surface corresponding to one half of the solid formed by the revolution of the base of a parabola about an axis perpendicular to the focal axis of the parabola, the halves being determined on either side of a plane passing through the focal axis of the parabola, the focus (F) of the parabola situated in the median plane of the reflector being located on the detection surface (SD ).

6. Device according to claim 5, characterized in that the detection surface (SD) is centered on the focus (F) of the parabola.

7. Device according to claim 6, characterized in that the axis of revolution of the reflector (RF) is such that the focus (F) of the dish is inside the reflector (RF).

8. Optical and electronic system for determining a position of an object (2), characterized in that it comprises a device according to one of claims 1 to 7 comprising three receivers (R1, R2, R3) each presenting a receiving surface on which the radiant power received from an object is dependent on the angle at which the object is viewed according to a strictly monotonic dependence curve of the received radiant power with the angle under which the object is viewed object (2), the three receiving surfaces being placed side by side but each in a separate plane, the three planes forming, in pairs, an angle of less than 150 ° and thus forming three edges (AD1, AD2, AD3 ) of the device, each associated with a pair of planes, the device being intended to be positioned in such a way that the portion of the space defined between these three planes includes the predefined geometric structure where the object is likely to be located (2 )

the system further comprising an electronic module comprising means for, upon illumination of the predefined geometric structure with radiation having specific spectral and / or modulation characteristics:

receiving the signals received by each of the receivers (R1, R2, R3),

- from these radiant powers, determine the angles under which the object (2) is seen by each of the receivers (R1, R2, R3) while considering that the receivers (R1, R2, R3) receive the same luminous intensity but from different angles,

determining the angular directions of three planes passing through the edges of the device (AD1, AD2, AD3) and where the object (2) is located,

- determine the position of the object (2) at the intersection of the three planes.

An optical and electronic system for determining a position of an object (2) present on a predefined line, the system comprising an emitter (E) emitting a beam of radiation having specific spectral and / or modulation characteristics allowing it to be detected even in the presence of a high intensity natural light, this beam being collimated along the predefined line, this system comprising a detection device (D) of an angular direction according to one of claims 1 to 7 positioned such that the portion of the space defined between the two planes carrying the receiving surfaces of the two receivers (R1 , R2) includes the predefined line on which the object (2) may be located, and comprising a position determining module for, knowing the position of the device (D) with respect to the predefined line and the angular direction (oc2) of the plane (P) passing through the edge of the device (AD) and where is the object (2), deduce the position of the object (2) on the predefined line by intersection.

10. Optical system according to claim 9, characterized in that the predefined line is the beam of a transmitter (E).

11. An optical and electronic system for determining a position of an object (2) present on a predefined surface (S), the system comprising at least one emitter (E) disposed on a so-called emission side (CE) of the predefined surface (S) emitting a beam (F) of a radiation having specific spectral and / or modulation characteristics making it possible to detect it, even in the presence of a high intensity natural light, this beam (F) being collimated in the predefined area,

this system comprising two detection devices (D1, D2) of an angular direction (ocl, oc2) according to one of claims 1 to 7 positioned on either side of the emission side (CE) so that the portions of the space defined between the two pairs of planes carrying the receiving surfaces (S1, S2) of the two receivers (R1, R2) of each of the detection devices (D1, D2) of an angular direction (oc1, oc2) according to one of claims 1 to 7 each include the surface (S) predefined on which the object (2) is likely to be, and comprising a position determining module for knowing the position of the two devices (D1, D2) relative to the predefined surface (S) and the angular direction (oc1, oc2) of the planes passing through the edges (AD1, AD2) of each of the detection devices (D1, D2) of an angular direction and where is the object (2), deduce the position of the object (2) on the predefined line by intersection.

12. A method for detecting an angular direction (α, β) in which there is an object (2) intended to be implemented in an optical and electronic system for determining a position of an object (2) present. on a predefined geometric structure,

this process comprising the steps of:

placing at least two receivers (R1, R2) sensitive to electromagnetic radiation of wavelength between 100 nm and 10 μιτι, delivering at the output a raw photo-current and each presenting a receiving surface (S1, S2) on which the radiant power received from an object (2) is dependent on the angle (α, β) under which the object (2) is viewed according to a dependence curve strictly monotone of the radiant power received with the angle (α, β) under which the object (2) is seen, so that the two receiving surfaces (S1, S2) are placed side by side but each in a plane distinct, the two planes forming between them an angle less than 150 ° and thus forming a so-called edge edge of the device (AD1, AD2),

arranging the two receivers (R1, R2) so that the portion of the space defined between the two planes carrying the reception surfaces (S1, S2) includes the particular geometrical structure on which the object is likely to be located (2)

receiving, within an electronic module, the signals received by each of the receivers (R1, R2),

from these radiant powers, determine the angles (α, β) under which the object is seen by each of the receivers (R1, R2) while considering that the receivers (R1, R2) receive the same luminous intensity but under different angles (α, β),