DE19752145A1 - Optical supervision arrangement for vehicle interior - Google Patents

Abstract

The arrangement has a sensor with a light source (4), to produce at least one light beam in a fixed direction, and a detector (6) arranged at a determined distance and alignment to the light beam. The light source produces several beams formed as light stripes, which travel in planes outside the detector and parallel to each other. The detector determines the viewpoints to the points of impact of the light beam and supplies them to a computer for evaluation. The detector preferably comprises a camera with a CCD chip, and a processing unit to determine the angles of the points of impact or their mutual distances in the image.

Description

The invention relates to a device for monitoring vehicle interiors and a sensor that can preferably be used for this purpose.

The visual monitoring of vehicle interiors can vary widely Purposes are carried out, e.g. B. to identify one in the vehicle located object, its position or z. B. to determine a possible change in movement of this object and the direction of movement.

The monitoring of vehicle interiors is currently carried out essentially  through cameras that e.g. B. directly on a monitor in a traffic control center transfer. The image material is evaluated there and, if necessary, appropriate measures to prevent a dangerous situation be taken.

The observation system described is suitable for. B. for subway trains etc., is but for obvious reasons B. for the monitoring of motor vehicle interiors too expensive. Due to their large number must be used in motor vehicles monitoring is done with an autonomous device that is capable is to carry out automatic image processing independently and, if necessary suitable measures for the protection of the vehicle or in it Initiate people.

The object of the invention is to provide an automatically operating device with the to create the above properties.

The object is achieved with a device which has the features of the claim 1 has.

The device according to the invention works on the triangulation principle and can in principle be used with the appropriate design, Art and determine the position of an object in the vehicle. This is As described in claim 1, a sensor is required which has at least one light transmitter has several parallel and angularly offset in fixed directions aligned light beams generated. At a fixed distance and fixed alignment the beams and the light transmitter, a detector is provided, the viewing angle determined to the impact points of the rays on the scanned object, and feeds it to a computer for evaluation. From this, the computer determines the respective one Distance of the impact location as well as their position in the area and then created  if desired a surface profile.

To facilitate processing, it is provided that the in the device provided light transmitter does not generate punctiform rays, but one or several fanning rays, the several, in particular, parallel rays Generate strips of light. To measure here according to the triangulation principle enable, it is necessary that the light rays lie in planes that are outside of the detector.

According to the invention, a sensor is therefore used which has more than one in parallel Streaks of light send rays to an object. Is advantageous in such a sensor as a detector a camera with a CCD chip with parallel line-shaped evaluation areas used. If you align the chip its line-shaped evaluation areas perpendicular to the parallel light strips particularly simple image processing and evaluation is possible. This will be discussed further below.

As a chip z. B. serve a PSD or CCPD chip. The chip can do one Have readout connection. However, to increase the speed, it is possible to read out the line-shaped evaluation areas individually in parallel.

The data transmitted by the detector can have different objectives to be processed further. So it is z. B. possible that at a time determined angle or the positions calculated therefrom with the memory of the Computer for different objects stored angle or position information compared and, if necessary, assigned to an object. The preferred sensor aligned to a vehicle seat can, for. B. Identification enable an object located on a seat, e.g. B. you can differentiate in this way, whether in the seat an adult or a child  sits or whether there may be a baby seat or child seat on the seat etc. is located. This information can, as explained below, e.g. B. important for triggering an airbag in the event of an accident. Furthermore can the computer in particular after identifying the object from the one The angles determined or the positions of the light impingement points calculated therefrom determine the position of the object. Another important use case again in connection with the airbag control, namely the determination of a person's sitting position, in particular their head position. If the head leans z. B. on the door spar, the computer would after determining this Head position in the event of an accident or a side airbag, or do not ignite at full power etc.

Furthermore, it is of course possible for the computer to consist of several possible changes in angles measured at different times the position of the object in terms of speed and direction of movement determined and again, if necessary, an adapted airbag control makes. It would be conceivable, for. B. that the airbag performance depending on the speed of a z. B. adapted to the windshielded person becomes.

Of course, the computer can depend on the determined Control angle information also other vehicle equipment. So it is z. B. possible that the belt is tightened based on the information supplied to the computer is, a warning signal is generated or z. B. activated a transmitter is, the corresponding in the event of unauthorized entry into the vehicle Notification to a receiving device that is spatially separate from the vehicle delivers. It is also conceivable that the camera used as a detector the complete captured image for accident documentation at a specified time or save evidence or to the nearest rescue station  sends.

Of course, it is also possible to use additional sensors, e.g. B. an acceleration sensor. In this way you can see the subject the data determined to the sensor of the invention to a plausibility check. In the case mentioned, when the computer is linked to an acceleration sensor would it be z. B. possible to determine whether the of the invention Device transmitted data with rapid movement of a body in the Vehicle actually indicate an accident or is no longer an accident rapid movement of the object not caused by an accident (e.g. Hitting with a newspaper on the dashboard), which in no way hides an airbag ignition as a result. This additional protection can always then be of interest if the object recognition is not sufficient, d. H. the sensor does not recognize that there is actually only one hand holding a newspaper approaches the dashboard and not the whole person or when on one differentiated object recognition is dispensed with.

The invention will be explained in the following with the aid of several figures.

Fig. 1 to 4 show the principle of triangulation of multiple sensors.

Fig. 5 and 6 show an insertable in an embodiment of the invention the light transmitter.

Fig. 7 shows a detector that can be used in the inventive device CCD chip with line-shaped readout areas.

FIG. 8 schematically shows a sensor with a detector according to FIG. 7 and a light transmitter according to FIG. 6.

FIG. 9 shows the sensor according to FIG. 8 when measuring an object.

FIG. 10 enlarges the detector from FIG. 9.

Figs. 1 to 4 are used to illustrate the principle according to which the inventive device operates.

In Fig. 1, a sensor 10 is shown with a light transmitter 4 , which emits a light beam 3 a to objects 1 or 2 at different distances. A position-sensitive detector 6 is arranged at a fixed distance and in a fixed alignment to the beam (i.e. to the light transmitter = base of the triangle), which detects the light reflected by objects 1 or 2 , represented by beams 13 a and 23 a via a receiving lens 5 in positions 7 a and 7 b receives. There is a distance 7 between positions 7 a and 7 b, which is directly proportional to the distance between objects 1 and 2 . The positions 7 a and 7 b on the detector 6 correspond to viewing angles with which the detector 6 sees impact points 2 a and 1 a of the light beam 3 a on the objects 1 and 2 . Knowing these angles and knowing the structurally predetermined (known) distance between light transmitter 4 and detector 6 , the distance of objects 1 and 2 from light transmitter 4 can easily be calculated.

In FIG. 2, a sensor 10 a is shown, the two light beams 3 a and 3 b on the arranged at different distance objects 1 and 2 emits. Here too, a detector 6 is again provided, onto which the impact points 1 a, 1 b, 2 a, 2 b of the light beams 3 a and 3 b on the objects 1 and 2 in position areas 7 a ', 7 b', 8 a ' and 8 b 'are shown. The distances between positions 7 a 'and 8 a' or 7 b 'and 8 b' are in turn directly proportional to the distance between objects 1 and 2. Here, too, positions 7 a ', 7 b', 8 a ' and 8 b 'on the detector 6 can be inferred directly from an angle by means of a distance calculation. In principle, what has been said for FIGS. 1 and 2 also applies to FIG. 3. The only difference is that in Fig. 3 still further light beams are emitted. In contrast to the sensor shown in FIG. 1, not only the distance, but also the extent of the areas 1 and 2 and, if appropriate, their height profile can be measured with sensors corresponding to FIGS. 2 and 3.

FIG. 4 shows an enlarged detail of the detector 6 from FIG. 3. A number of positions 7 a ", 8 a" to 7 f ", 8 f" can be seen here, which in turn, as discussed above, can each be assigned to angle values or their distances to one another ( 7 a "to 8 a", 7 b "to 8 b" etc.) are proportional to the distance of the illuminated objects.

As already said above, FIGS. 1-4 serve only for a better understanding of the invention, in particular the following explanation of FIGS. 5-10, which represent an exemplary embodiment of the invention or partial aspects thereof.

FIG. 5 shows a light transmitter 4 ', which is able to produce a strip-shaped light beam. For this purpose, a point light source 9 is provided, which emits through an upstream cylindrical lens 11 , which leads to a strip of light 3 'striking an object. FIG. 6 shows a light transmitter 4 ″ based on this principle, in which a plurality of point light sources 9 a to 9 f emit offset from one another through a cylindrical lens 11 and produce parallel light strips 3 a ′ to 3 f ′.

FIG. 7 shows a CCD chip 12 used in conjunction with the light transmitter 4 ″ shown in FIG. 6, preferably as a detector 6 '. It is a two-dimensional PSD chip with parallel line-shaped evaluation areas 14 , in which the interrupted black ones Bars 30 a to 30 f, which are shown by the detected light strips 3 a 'to 3 f' excited positions on the chip 12. This becomes clearer when looking at Fig. 8. The overall structure is shown here Auswertbereiche 14 of the chip 12 are formed perpendicular to the light strip 3 a 'to 3 f'. the excited positions a f in Fig. 7 or in Fig. 8 of the light stripes 3 to 3 30 till 30 f on the chip 12 correspond to a a measurement in which the object to be measured is flat and lies in a plane parallel to the plane of the chip 12 .

FIG. 9 shows how an object 20 lying in the beam path can be measured by means of the sensor 10 c. The light strips 3 a to 3 f are imaged where they strike the object 20 in accordance with its height profile. This leads to streaks of light, e.g. B. light strips 3 c ', which are detected in regions by the CCD chip 12 from different viewing angles and then, as shown again in FIG. 10, lead to a region-by-region shift of the positions 30 a to 30 f. If one considers the positions 30 c assigned to the light strip 3 c, it can be seen that in line-shaped readout areas 14 a and 14 f the positions have been shifted to the right in relation to the illustration in FIG. 7. The height profile of the measured object can easily be deduced from the degree of displacement. So interpret z. B. in the line-shaped evaluation range 14 a to 14 c and 14 f evenly shifted positions indicate that it is an object with a flat surface and aligned parallel to the chip, on which another body further advanced to the chip with a flat surface is also formed, as can be seen from the excited positions in the evaluation regions 14 d and 14 e, which are in turn shifted by the same distance. The width and height of the detected object 20 can be determined from the number of evaluation areas in which a position shift takes place, and from the number of light strips 3 a 'to 3 f' for which a shift of the positions on the chip 12 compared to a zero value ( as shown in Fig. 7).

An object determination is c with the sensor 10 in a particularly simple manner. The accuracy depends on the chip used and the number of light strips emitted. Furthermore, the sensor allows easy determination of the position of the object and any changes in the position. In this way it is e.g. B. also possible, e.g. B. to differentiate whether a person sitting on a seat moves towards the dashboard or whether z. B. only one movement with one body part, e.g. B. an arm, etc. takes place.

The CCD chip used in the preferred embodiment of the sensor is a special chip, and it can z. B. is a CCPD chip which only one readout output is provided. To accelerate the reading process However, each line-shaped readout area can have its own Have output. You can get chips that are about 600 times a second can be read out, in particular in connection with the airbag control is sufficient in an accident.

The device for interior surveillance according to the invention will continue addressed above, in particular assigned to the seats. It is Z. B. in particular possible to arrange them next to the sun visor facing the seat. Of course, the device can also be assigned to other areas of the interior and be positioned accordingly.

Claims (13)

1. Device for the optical monitoring of vehicle interiors, with at least one sensor which has a light transmitter generating at least one light beam aligned in a fixed direction, and a detector arranged at a fixed distance and fixed alignment to the beam and to the light transmitter, which detects the viewing angles to the points of incidence of the beam determined and fed to a computer for evaluation, characterized in that the light transmitter generates a plurality of beams in the form of light strips which run in planes outside the detector and in particular at a parallel distance from one another. 2. Device according to claim 1, characterized in that the detector an imaging camera and a processing unit for determining the angles the point of impact or their distances from one another in the picture. 3. Apparatus according to claim 2, characterized in that the camera has a CCD chip.   4. The device according to claim 3, characterized in that the CCD Chip has line-shaped evaluation areas that are perpendicular to the one or more parallel light strips generated by the light transmitter are aligned. 5. The device according to claim 4, characterized in that the line-shaped Evaluation areas each have a readout connection. 6. The device according to claim 1, characterized in that the light transmitter has a plurality of individual light sources arranged offset from one another, the radiate through a common cylindrical lens. 7. The device according to claim 1, characterized in that the computer the angles of the impact point determined at a time for identification an object with angles stored in the computer memory for defined objects compares. 8. The device according to claim 7, characterized in that the computer recognizes and / or recognizes an object from the angles determined at a point in time Position determined. 9. The device according to claim 1, characterized in that the computer a change in position from angles determined at different times calculated from objects. 10. The device according to claim 7 to 9, characterized in that the Calculator depending on the type, position, speed and / or acceleration generates a signal of an identified object.   11. The device according to claim 10, characterized in that the Computer generated signal to control the ignition timing and / or the inflation rate and / or direction of an airbag is used. 12. Device according to one of the preceding claims, characterized in that that the camera provided as a detector to a computer the complete captured image is saved at the specified time. 13. The apparatus according to claim 12, characterized in that the computer has a transmitter with which the recorded by the camera Image can be transmitted remotely.