WO2016173954A1

WO2016173954A1 - Laser sensor for a motor vehicle comprising a parabolic mirror, driver assistance system and motor vehicle

Info

Publication number: WO2016173954A1
Application number: PCT/EP2016/059093
Authority: WO
Inventors: Lin Lin; Peter Horvath
Original assignee: Valeo Schalter Und Sensoren Gmbh
Priority date: 2015-04-29
Filing date: 2016-04-22
Publication date: 2016-11-03
Also published as: EP3289382A1; DE102015106595A1

Abstract

The invention relates to a laser sensor (5) for a motor vehicle (1), comprising a transmission device (6) for emitting a transmission signal (8) in the form of optical radiation, comprising a deflection device (13) for deflecting the transmission signal (8, 8a, 8b, 8c), the deflection device (13) comprising a micromirror, and comprising a reception device (7) for receiving the transmission signal (9, 9a, 9b, 9c) reflected by at least one object (3, 3a, 3b, 3c) in a vicinity (4) of the motor vehicle (1), wherein the laser sensor (5) has a parabolic mirror (16) which is arranged in a beam path of the transmission signal (9, 9a, 9b, 9c), reflected by the at least one object (3, 3a, 3b, 3c), between the at least one object (3, 3a, 3b, 3c) and the reception device (7) and which is configured to deflect the transmission signal (9, 9a, 9b, 9c), reflected by the at least one object (3, 3a, 3b, 3c), to the reception device (7).

Description

Laser sensor for a motor vehicle with parabolic mirror, driver assistance system

motor vehicle

The present invention relates to a laser sensor for a motor vehicle with a transmitting device for transmitting a transmission signal in the form of optical radiation, with a deflection device for deflecting the transmission signal, wherein the

Deflecting means comprises a micromirror, and with a receiving device for receiving the at least one object in a surrounding region of the

Motor vehicle reflected transmission signal. The invention also relates to a

Driver assistance system with such a laser sensor. Finally, the concerns

The present invention relates to a motor vehicle having such a driver assistance system.

In the present case, the interest is directed in particular to laser sensors for motor vehicles. Such laser sensors can be designed, for example, as lidar sensors (lidar - light detection and ranging) or as laser scanners. Such laser sensors are attached, for example, to motor vehicles in order to control the environment or the surrounding area of the vehicle during the journey or during operation of the motor vehicle

To capture motor vehicle. The laser sensor is in particular a scanning optical measuring device by means of which objects or obstacles in the surrounding area of the motor vehicle can be detected. For example, a distance between the motor vehicle and the object can be measured by the light pulse transit time method with the laser scanner. The laser sensor usually comprises a transmitting device which has, for example, a laser diode or a laser with which an optical transmission signal can be transmitted. In addition, the laser sensor comprises a corresponding deflection device with which the transmission signal can be deflected. Finally, the laser sensor comprises a

Receiving device having, for example, at least one photodiode, by means of which the reflected from the object transmission signal can be received.

Furthermore, laser sensors are known from the prior art, whose

Deflection device has a micromirror or a so-called MEMS mirror (MEMS - Micro Electro Mechanical System or microsystem). In the case of laser sensors in which the deflection device and / or other components are designed as a microsystem, the focal point of the transmission signal reflected by the object can travel in accordance with the angle of the transmitted transmission signal. To compensate for this effect, receiving devices are used which comprise an array of photodiodes. Thus, it can be ensured that the reflected transmission signals can be reliably received. The disadvantage here is that you according to the

Scan area requires a more or less large array. This creates

different costs for the receiving array.

In this context, DE 101 60 019 A1 describes a device for aligning the transmission and reception channels of a spatial lidar. The device makes it possible to estimate the deviation of the laser, transmitting and receiving channels of a lidar and in particular the centering of the receiving channel to the backward laser beam. For this purpose, receiver means may comprise a telescope with a parabolic-type concave mirror oriented in a target direction, the focal axis of the mirror and the target direction being parallel as defined by the elements of the transmission channel.

In addition, EP 2 221 683 A1 describes a lidar device with a

A light source that provides light beam transmission pulses, a scanning fan array that directs the light beam transmission pulses at any given beam angle over a certain angular range, and a detection system that directs them

Light beam flyback pulses associated with respective light beam transmission pulses. In addition, a parabolic reflector can be provided, at the focal point of which a lidar unit is arranged and aligned in such a way that the light beam transmission pulses emanating from the scanning fan arrangement coincide in the center line of this angular range with the parabolic axis of the reflector.

It is an object of the present invention to provide a solution, as with a laser sensor comprising a micromirror, objects can be detected more reliable.

This object is achieved by a laser sensor, by a driver assistance system and by a motor vehicle having the features according to the respective independent ones

Claims solved. Advantageous embodiments of the invention are the subject of the dependent claims, the description and the figures.

An inventive laser sensor for a motor vehicle comprises a transmitting device for emitting a transmission signal in the form of optical radiation. Furthermore, the laser sensor comprises a deflection device for deflecting the transmission signal, wherein the

Deflection device comprises a micromirror. Furthermore, the laser sensor comprises a Receiving means for receiving the from at least one object in one

Surrounding area of the motor vehicle reflected transmission signal. Furthermore, the laser sensor has a parabolic mirror, which is arranged in a beam path of the at least one object reflected transmission signal between the at least one object and the receiving device and which is adapted to deflect the reflected from the at least one object transmission signal to the receiving device.

The laser sensor is intended for use in a motor vehicle. The laser sensor can be a motor vehicle fastening device for attaching the laser sensor to the

Have motor vehicle. The laser sensor can be designed in particular as a lidar sensor or as a laser scanner. With the laser sensor, objects in the

Be detected surrounding area of the motor vehicle. In particular, a distance between the motor vehicle and the object can be determined by means of the laser sensor. With the transmitting device of the laser sensor, a transmission signal in the form of optical radiation or laser radiation is emitted. This emitted transmission signal is then reflected by at least one object in the surrounding area of the motor vehicle and returns to the receiving device of the sensor. The transmitted transmission signal is deflected by a deflector. It can also be provided that the transmission signal is transmitted in the form of laser pulses. Thus, the transmission signals can be transmitted within a predetermined detection range or angle range.

The deflection device comprises a micromirror or a so-called MEMS mirror. This micromirror can with the help of a microtechnical

Be manufactured manufacturing process. The micromirror, for example, a

Have mirror element which is rotatably mounted with respect to at least one axis. Furthermore, the micromirror can have a corresponding actuator, for example an electrostatic, a piezoelectric, a thermal microactuator or

have the same, with which the mirror element with respect to the axis of rotation

can be pivoted. The transmission signal reflected by the at least one object first encounters a parabolic mirror before impinging on the receiving device. The parabolic mirror is therefore in the beam path of the reflected from the object

Transmitting signal between the object and the receiving device arranged. With the parabolic mirror, the transmitted signal reflected from the object can be transmitted to the

Receiving device are deflected out. With the help of the parabolic mirror, the change of the focal point described above can be at least partially compensated become. Thus, it becomes possible, for example, to reduce the size of the receiving device in comparison to commonly used receiving devices. By the

Use of the parabolic mirror, it is synonymous with a reduction of the

Receiving device possible to reliably receive the transmitted signal reflected from the object and thus to detect the object in the surrounding area of the motor vehicle.

Preferably, the parabolic mirror is designed and / or arranged such that the transmission signal reflected by the at least one object passes through a focal point of the parabolic mirror. For example, the parabolic mirror may have such a curvature that the transmission signal reflected by the object passes through the focal point of the parabolic mirror. Alternatively or additionally, the parabolic mirror can be arranged within the laser sensor such that the transmission signal reflected by the at least one object passes through the focal point of the parabolic mirror. It can thus be achieved that the transmission signal reflected by the object can be directed in the direction of the detection device, even when the focus point is displaced.

In a further embodiment, the parabolic mirror is designed and / or arranged such that each of a plurality of objects in the

Surrounding region of the motor vehicle reflected transmission signal passes through the focal point. In other words, the transmitted transmission signal can be reflected by a plurality of objects in the surrounding area of the motor vehicle. It may also be the case that chronologically consecutive and possibly in

different angular ranges transmission signals are emitted, and thus are reflected by different objects in the surrounding area transmission signals. In this case, the parabolic mirror is configured and / or arranged such that all these transmission signals reflected by the objects essentially run through the focal point. It can thus be achieved that the transmitted signals reflected by the objects can be reliably detected even for different angular ranges or scan ranges. This can further be achieved that the objects can be reliably detected in the entire detection area or in the area of the laser sensor.

Furthermore, it is advantageous if the parabolic mirror in each case deflects the transmitted signals reflected by the plurality of objects in such a way that they extend substantially parallel from the parabolic mirror in the direction of the receiving device. Of the Parabolic mirror is particularly designed so that a spherical wave, which is generated with a point source, which is arranged in the focal point, as a flat

Wave propagation is reflected as a collimated beam along an axis. Thus, it can be achieved, in particular, that the transmission signals deflected by the parabolic mirror and previously reflected by the respective objects parallel to the

Make detection device. Thus, it can be reliably achieved that the respective beams strike the respective photodiodes of the receiving device and are detected by them.

In one embodiment, a lens is arranged in a beam path of the transmission signal reflected by the at least one object and deflected by the parabolic mirror. The transmitted signals deflected by the parabolic mirror, which run substantially parallel, can be bundled with a corresponding lens. Thus, an area of the receiving device can be reduced or a number of

Photodiodes of the receiving device can be reduced. Thus, a space-saving and cost-effective receiving device can be provided. In one embodiment, the receiving device comprises at least one avalanche photodiode. Such an avalanche photodiode may also be referred to as a lagoon photodiode. These avalanche photodiodes utilize the internal photoelectric effect to create carriers and the avalanche effect for internal amplification. Thus, the transmission signal reflected from the object can be reliably detected. In a preferred embodiment, the

Detection device a single avalanche photodiode. Thus, a

inexpensive detection device can be provided.

Preferably, the deflection device comprises a mirror element, which is pivotable about an axis. In particular, the mirror element is mounted pivotable about only a single axis. For example, the mirror element in the

intended installation position of the laser sensor to be pivotable about the horizontal axis. Thus, a low cost baffle can be provided.

In a further embodiment, the laser sensor comprises a collimator, which in the beam path of the transmission signal between the transmitting device and the

Deflection device is arranged. The collimator is used in particular for generating a parallel beam path. Thus, for example, from the sent

Transmitter signal are bundled a parallel light beam, which then on the Deflection meets. With the deflection device or the micromirror, this parallel light beam can then be deflected. It can thus be achieved that parallel light bundles or the transmission signal can be reliably deflected by the deflection device or the micromirror, and thus can be transmitted within the detection area to the objects in the surrounding area.

An inventive driver assistance system for a motor vehicle comprises a laser sensor according to the invention. For example, a distance between the motor vehicle and an object or obstacle in the surrounding area of the motor vehicle can be detected with the laser sensor. The driver assistance system can be designed, for example, as a proximity control or the like.

A motor vehicle according to the invention comprises an inventive

Driver assistance system. The motor vehicle is designed in particular as a passenger car.

The preferred embodiments presented with reference to the laser sensor according to the invention and their advantages apply correspondingly to the driver assistance system according to the invention and to the motor vehicle according to the invention.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description, as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures, are not only in the respectively indicated combination but also in others

Combinations or alone, without departing from the scope of the invention. Thus, embodiments of the invention are to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, however, emerge and can be produced by separated combinations of features from the embodiments explained. Embodiments and combinations of features are also to be regarded as disclosed, which thus do not have all the features of an originally formulated independent claim.

The invention will now be described with reference to preferred embodiments and with reference to the accompanying drawings.

Showing: 1 shows a motor vehicle according to an embodiment of the present invention

Invention having a driver assistance system with a laser sensor;

Fig. 2 is a schematic representation of a transmitting device and a

Deflection device of the laser sensor; and

Fig. 3 is a schematic representation of the laser sensor, the

Deflection device, a parabolic mirror and a receiving device comprises.

In the figures, the same and functionally identical elements are the same

Provided with reference numerals.

1 shows a motor vehicle 1 according to an embodiment of the present invention

Invention. The motor vehicle 1 is in the present embodiment as

Passenger cars trained. The motor vehicle 1 comprises a

Driver assistance system 2. With the driver assistance system 2, for example, an object 3, which is located in a surrounding area 4 of the motor vehicle 1, are detected. In particular, a distance between the motor vehicle 1 and the object 3 can be determined by means of the driver assistance system 2.

The driver assistance system 2 comprises a laser sensor 5. The laser sensor 5 may be designed as a lidar sensor or as a laser scanner. The laser sensor 5 comprises a transmitting unit 6, with which a transmission signal 8 in the form of an optical signal or in the form of laser light can be emitted. The transmitting unit 6 may comprise, for example, a laser diode. With the transmission unit 6, the transmission signals 8 within a predetermined detection range E or within a predetermined

Angular range are emitted. For example, the transmission signals 8 can be transmitted in a predetermined horizontal angle range.

In addition, the laser sensor 5 comprises a receiving unit 7, which may for example comprise a photodiode 11 (see FIG. 2). With the receiving device 7, the reflected from the object 3 transmission signal 8 can be received as a received signal 9. Furthermore, the laser sensor 5 may include a computing unit, for example may be formed by a microcontroller or a digital signal processor. The driver assistance system 2 further comprises a control device 10, which may be formed for example by an electronic control unit of the motor vehicle 1. The control device 10 is connected to the laser sensor 5 for data transmission. The data transmission can take place via a data bus of the motor vehicle 1.

Fig. 2 shows a schematic representation of the transmitting device 6 and a

Deflection device 13 of the laser sensor 5. In the present case it can be seen that the

Transmitting device 6, the laser diode 1 1 includes. With the laser diode 1 1, the

Transmission signal 8 are emitted in the form of a laser beam. In addition, a collimator 12 is provided, with which the transmitted transmission signal 8 in a in

Substantially parallel beam can be converted. This parallel

Beam is then incident on a deflector 13. The deflector 13 is formed as a micromirror or MEMS mirror. The deflection device 13 comprises a mirror surface, not shown here, which can be pivoted, for example, with a corresponding actuator. In particular, the mirror surface or the

Mirror element about an axis, in particular the horizontal axis, to be pivoted. This is illustrated by way of example by the arrow 14.

By pivoting or rotation of the mirror element can to

Different time points transmit signals in the detection area E and the surrounding area 4 of the motor vehicle 1 are emitted. For example, at a first point in time, the first transmission signal 8a which strikes an object 3a can be emitted. At a later time, the second transmission signal 8b

are emitted, which hits the object 3b. Finally, the transmission signal 8c, which hits the object 3c, can be transmitted at a later time. The angles α between the direction of the first transmission signal 8a and the direction of the second transmission signal 8b and an angle α between the direction of the second transmission signal 8b and a direction of the third transmission signal 8c may each be 72.5 °.

FIG. 3 shows a schematic representation of the laser sensor 5. In the present case, as explained in connection with FIG. 2, the deflection device 13 is shown, with which the transmission signals 8a, 8b and 8c are emitted which strike the objects 3a, 3b and 3c , From the first object 3a, the first transmission signal 8a becomes the first one

Received signal 9a reflected. From the second object 3b, the second transmission signal 8b as a second received signal 9b reflected. Finally, the third transmission signal 8c is reflected by the third object 3c as the third reception signal 9c.

The laser sensor 5 further comprises a parabolic mirror 16. The parabolic mirror 16 is arranged or shaped such that the first received signal 9a, the second received signal 9b and the third received signal 9c all run through a focal point 15 of the parabolic mirror 16. Thus can be achieved that of the

Parabolic mirror 16 deflected receive signals 9a, 9b, 9c are substantially parallel in the direction of the receiving device 7. The essentially parallel

extending beams are focused by a lens 17 and then meet at least one avalanche photodiode 18. In this way it can be achieved that the received signals 9a, 9b, 9c by means of the parabolic mirror 16 even at a

Displacement of a focal point in the direction of the receiving device 7 and the at least one avalanche photodiode 18 are directed. By means of the lens 17, the light beams can also be bundled. Thus, the detection device 7 can be designed to save space especially. Preferably, the detection device 7 may have only a single avalanche diode 18.

Claims

claims

1 . Laser sensor (5) for a motor vehicle (1), with a transmitting device (6) for

Emitting a transmission signal (8) in the form of optical radiation, with a deflection device (13) for deflecting the transmission signal (8, 8a, 8b, 8c), wherein the deflection device (13) comprises a micromirror, and with a

Receiving device (7) for receiving the transmission signal (9, 9a, 9b, 9c) reflected by at least one object (3, 3a, 3b, 3c) in a surrounding area (4) of the motor vehicle (1),

characterized in that

the laser sensor (5) has a parabolic mirror (16), which in one

Beam path of the at least one object (3, 3a, 3b, 3c) reflected transmission signal (9, 9a, 9b, 9c) between the at least one object (3, 3a, 3b, 3c) and the receiving device (7) is arranged and which is designed to deflect the transmission signal (9, 9a, 9b, 9c) reflected by the at least one object (3, 3a, 3b, 3c) towards the receiving device (7).

2. Laser sensor (5) according to claim 1,

characterized in that

the parabolic mirror (16) is designed and / or arranged such that the transmission signal (9, 9a, 9b, 9c) reflected by the at least one object (3, 3a, 3b, 3c) is transmitted through a focal point (15) of the parabolic mirror (16 ) runs.

3. Laser sensor (5) according to claim 2,

characterized in that

the parabolic mirror (16) is designed and / or arranged such that the respective transmission signal (9, 9a, 9b, 9c) reflected by a plurality of objects (3, 3a, 3b, 3c) in the surrounding area (4) passes through the focal point (15) runs.

4. Laser sensor (5) according to claim 3,

characterized in that

the parabolic mirror (16) in each case deflects the transmission signals (9, 9a, 9b, 9c) reflected by the plurality of objects (3, 3a, 3b, 3c) in such a way that they are reflected in the Substantially parallel from the parabolic mirror (16) in the direction of

Receiving device (7) run.

5. Laser sensor (5) according to one of the preceding claims,

characterized in that

a lens (17) is arranged in a beam path of the transmission signal (9, 9a, 9b, 9c) reflected by the at least object (3, 3a, 3b, 3c) and deflected by the parabolic mirror (16).

6. Laser sensor (5) according to one of the preceding claims,

characterized in that

the receiving device (7) comprises at least one avalanche photodiode (18).

7. Laser sensor (5) according to one of the preceding claims,

characterized in that

the deflection device (13) comprises a mirror element, which is pivotable about an axis.

8. Laser sensor (5) according to one of the preceding claims,

characterized in that

the laser sensor (5) comprises a collimator (12) which is arranged in the beam path of the transmission signal (8, 8a, 8b, 8c) between the transmission device (6) and the deflection device (13).

9. driver assistance system (2) for a motor vehicle (1) with a laser sensor (5) according to one of the preceding claims.

10. Motor vehicle (1) with a driver assistance system (2) according to claim 9.