DE29822554U1 - Lighting device for illuminating certain interior areas of a motor vehicle - Google Patents

Description

Lighting device for illuminating certain interior areas of a motor vehicle

The invention relates to the field of lighting the interior of a motor vehicle. In particular, the invention relates to a lighting device for illuminating certain interior areas of a motor vehicle.

To illuminate the interior of a motor vehicle, one or more lighting devices are installed in the interior of the vehicle. To ensure that, for example, the vehicle can be safely entered and exited even in dark surroundings, a lighting device is installed in motor vehicles that illuminates the entire interior as far as possible when a door is opened. In addition, lighting devices have become known that only illuminate a small area of the interior, such as a reading light directed at the area of the passenger seat. In order not to impair the driver with this light in the dark, the light cone of such a reading light only has a very small opening angle. This ensures that only part of the passenger area is actually illuminated.

When using such a reading light, the object to be illuminated must be held in a stable position so that the light beam produced by the reading light illuminates the desired object. In particular, when changing

To change the sitting position, the object to be illuminated must either be held in the light cone of the reading light or the reading light itself must be manually adjusted to the changed sitting position.

Based on this discussed prior art, the invention is therefore based on the object of proposing a lighting device for illuminating certain interior areas of a motor vehicle, with which object lighting is possible without manual intervention even when the object position changes.

This object is achieved according to the invention by a lighting device for illuminating certain interior areas of a motor vehicle, which lighting device comprises a sensor system for detecting movements in the interior of the motor vehicle including an evaluation unit for evaluating detected movements in the interior area, lighting means for illuminating the interior area or areas and means for adapting the lighting to a lighting requirement changed by the movement.

By providing a lighting device with the aforementioned features, an automatic lighting adaptation can be carried out to a changing lighting requirement, such as the movement of an object to be illuminated from a previously illuminated area. The prerequisite is that an object to be illuminated is defined for the sensor system, whereby a movement can be detected by the sensor system as long as it takes place in the detection range of the sensor system. By appropriately controlling the lighting adaptation means, the lighting can be adapted to the lighting requirement that changes as a result of the object moving away. In this case, it can be provided that a servomotor is arranged on a light source for the lighting adaptation, with which the light source can be pivoted in one or more directions, whereby the pivoting movement and the amount of pivoting depend on the movement of the object detected by the detection sensors. Furthermore, it can be provided that several lamps illuminating individual areas of the interior are arranged in the motor vehicle, of which one or more individual lamps are energized depending on the changed lighting requirements and thus

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irradiate this assigned area. These two designs follow the principle of lighting tracking according to the movement of the object to be illuminated. By illuminating with a light cone with a small opening width, these lighting devices light up (small) areas in an essentially constant manner. In a further embodiment, a light cone adjustment element assigned to a lamp is provided as a means of adapting the light source to a changed lighting requirement. With such a light cone adjustment element, depending on the movement

γ of the object, an adaptation can be made by changing the opening width of the light cone. If the object is in the core area of the lamp, the light cone adjustment element is arranged so that the light cone of the lamp has only a small opening angle. If the object is moved out of this core area, the light cone adjustment element increases the opening width of the light cone up to a certain maximum. As the light cone angle increases, the luminance of the illuminated area decreases, whereby it is provided that the driver is not hindered at the maximum light cone opening angle. In addition, with such a design, it can also be provided that the lamp can also be pivoted by a servomotor.

According to one embodiment, the sensor system for detecting movements in the interior includes a recording unit for recording images of the interior, an evaluation unit for digitally evaluating the images obtained by the recording unit and a processing system actuated by the evaluation unit for controlling the lighting devices depending on the evaluated image data. The evaluation unit includes a differential image generator for determining the intensity difference of identically positioned pixels between an input image acting on the evaluation unit and a reference image that is older in time. The differential image generator is assigned a storage element for displaying the pixel-resolved intensity differences, with the differential image generator acting on the storage element. With such a sensor system, a pixel-resolved evaluation of the exposure intensity differences of two temporally successive images is possible. By forming the difference between the content of identically positioned pixels of two images to be compared, those pixels of the difference to be displayed are

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The value "zero" is assigned to the reference image in which no change in exposure and thus no movement has occurred in the time interval between the two images. Only those pixels in which a change in exposure and thus a movement has occurred are sent to a subsequent image evaluation. Consequently, only those pixels in which movements have actually been detected as a result of changes in exposure intensity need to be sent to a further processing. The processing time required is correspondingly low.

&iacgr;&ogr; data volume, which has a positive effect on the hardware components to be used as well as on the evaluation speed. It is expedient to use a temporally recursive high-pass filter as the difference image generator. It is also advantageous to connect a calculation and summation element downstream of the difference image generator, which contains a buffer that can be read in line by line and read out block by block and a linear memory as well as two calculation units for block-by-block differential image energy calculation and for calculating and summing up the energy gradients. With such an arrangement, individual detection areas of the recording unit can be processed individually and independently of one another. If, for example, a camera sensor is used as the recording unit and the sensor for motion detection is aimed at the entire interior of the motor vehicle, these data stored in certain blocks of the buffer can be read out and processed differently or independently of the data in other blocks for lighting tracking of areas assigned to the passenger seat. In addition to this advantage, such an arrangement also serves to eliminate undesirable offset values in the difference image, which can be reflected globally in the difference image energy determination. For this purpose, the difference image energy is calculated block by block and the energy gradients are calculated and summed up. By examining the energy gradients of individual image sections (sub-blocks of the difference image), it is possible to determine in a cost-effective implementation whether a similar change has occurred in all of the image sections considered.

Global illumination changes would thus be equally noticeable in all blocks or image sections considered.

To accurately distinguish the movements within the monitoring

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In order to protect the detection area in the motor vehicle from short-term local changes, for example due to light reflections, an advantageous further development provides for the energy gradient sums determined for the difference images to be subjected to a temporally recursive low-pass filter. The short-term local changes that only extend over individual image periods are then separated from the movements caused by people that extend over several image periods. In this case, it is expedient to provide for the temporal recursiveness of the low-pass filter to be adjustable. It is also advantageous to use a comparator element connected downstream of the low-pass filter, in which an evaluation of the detected movement change takes place depending on the threshold value.

Further advantages and embodiments are part of further subclaims and the following description of embodiments with reference to the attached figures. They show:

Fig. 1 is a schematic representation of the functionality of a

Lighting device for illuminating a specific interior area of a motor vehicle,

Fig. 2 a schematic representation of another application

the lighting device of Figure 1,

Fig. 3 is a schematic representation of the functionality of a

additional lighting device for illuminating a

specific interior area of a motor vehicle,

Fig. 4 is a schematic flow chart for detecting motion

in the interior of a motor vehicle and

Fig. 5 is a block diagram of an implementation of the system shown in Figure 4.

flow chart.

A lighting device 1 comprises a recording unit 2 for imaging an interior area of a motor vehicle (not shown in detail), as well as an evaluation unit 3, to which a processing system is assigned, and a lamp 3, which is connected in a manner not shown in detail to a servomotor for pivoting the lamp 4.

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The recording unit 2 contains a camera sensor, in whose detection range the motor vehicle interior area marked with the reference number 5 in Figure 1 is arranged. The detection sensor system formed by the recording unit 2 and the evaluation unit 3 serves to detect movements within the interior area 5. The lamp 4 illuminates a part of the interior area 5 with a light cone 6, the illumination area 7 of which corresponds to a current lighting requirement. An object is located in the light cone 6, for example a handkerchief on the hands of a passenger (not shown in detail).

β a sheet of paper 8 located in the β²². The sheet of paper 8 is thus illuminated by the lamp 4, so that text or drawings located on it can be recognized. If the sheet of paper 8 is moved within the interior area 5 recorded by the recording unit 2, this movement is detected by the motion sensors 2, 3 and the actuator of the lamp 4 is controlled to guide the lamp 4 by pivoting it. The pivoting movement of the lamp 4 is shown schematically by the arrow cross assigned to it.

The lighting device 1 shown in Figure 1 is also used, as shown in Figure 2, to illuminate the ignition switch area when a user enters the vehicle in the dark. The sensor system is designed in such a way that darkness is detected and the lamp 4 is automatically pivoted by the servomotor assigned to it so that it illuminates the ignition switch area. After inserting the key into the switch, the lamp 4 returns to its original position illuminating the passenger area.

Figure 3 shows a further lighting device 9 which, like the lighting device 1, comprises a recording unit 10, an evaluation unit 11 and, in contrast to the lighting device 1, several lights 12, 13, 14. The lights 12, 13, 14 are each aligned to illuminate a specific area of the interior, with the light cones slightly overlapping. Depending on the lighting area in which an object 15 is located in the detection area of the recording unit 10, either the light 12, 13 or 14 is switched on, or two lights 12, 13 or 13, 14 are switched on in the transition area between two lighting areas.

To illustrate motion detection in the interior of a motor vehicle, please refer to Figures 4 and 5, with reference initially to Figure 4. The image is captured via a camera sensor 15. The digitized output signal of the camera sensor 15 is applied to an evaluation unit 16. The evaluation unit 16 has a high-pass filter 17 on the input side, which is provided for temporally recursive high-pass filtering of the camera sensor signal and for generating a difference image as a result array of a subtraction of one- or two-dimensional number arrays corresponding to the image to be evaluated or the reference image. In a subsequent step, the difference image energy is first calculated block by block, followed by a calculation of the energy gradient matrix and an image-by-image or area-by-area summation of the energy gradients in a calculation and summation element 18. The output of the calculation and summation element 18 is applied to the input of a low-pass filter 19 that operates recursively in time. Both the low-pass filter 19 and the above-mentioned high-pass filter 17 can be adjusted in terms of their recursiveness in time. The output of the low-pass filter 19 is connected to the input of a comparator element 20, in which the camera sensor signal processed up to that point is compared with a predetermined or adaptive threshold value.

The output signal of the comparator element 20 is applied to the input of a downstream processing system 21, which, depending on the detected movement, adjusts the lamp 4 or controls one of the lamps 12, 13, 14, as shown for example in Figure 4.

The block diagram shown in Figure 5 shows the evaluation unit with individual modules, some of which are shown in Figure 4. The high-pass filter 17, which is acted upon by the input signal S ₀ , filters the signal S ₀ with a recursion depth g. The recursion depth g is adjustable. It can be provided that the recursion depth g can be changed under microprocessor control depending on the operating mode of the interior monitoring system. This makes it possible to adapt automatically to changing circumstances. The output signal of the high-pass filter 17 is connected to the input of an image memory 22 that can be written to line by line and read out block by block. To estimate the energy content of an individual block b _m, the pixel values are summed up.

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squares of all pixels of a block. Squaring makes a previous calculation of the absolute value unnecessary. The result, namely the energy content of a block, is saved as a block vector.

The block vector serves as an input value for the subsequent image- or area-wise summation of the gradients of the energy values stored in the block vector. The subsequent low-pass filtering in the low-pass filter 19 runs in the same way as the high-pass filtering and can also be set with regard to its temporal recursiveness by the variable e. The comparator element 20 connected to the output of the low-pass filter 19 is shown schematically. This comparator element only emits the signal D ₀ when a threshold value is exceeded, which is then passed on to the processing system 21 shown in Figure 4.

From the description of the invention it becomes clear that the lighting device according to the invention is particularly suitable for integration into an interior monitoring system, which can serve for seat occupancy detection and/or anti-theft protection and/or other applications.

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1 Lighting equipment 2 Recording unit 3 Evaluation unit 4 lamp 5 Interior area 6 Light cone 7 Illuminated area 8th sheet of paper 9 Lighting equipment 10 Recording unit 11 Evaluation unit 12 lamp 13 lamp 14 lamp 15 Camera sensor 16 Evaluation unit 17 High pass filter 18 Calculation and summation element 19 Low-pass filter 20 Comparator element 21 Processing system 22 Image storage

Claims (10)

-10-Protection claims 1. Lighting device for illuminating certain interior areas of a motor vehicle comprising a sensor system (2, 10) for detecting movements in the interior of the motor vehicle including an evaluation unit (3, 11, 16) for evaluating detected movements in the interior, lighting means (4; 12, 13, 14) for illuminating the interior area or areas and &iacgr;&ogr; means for adapting the lighting to a movement changed lighting requirements. 2. Lighting device according to claim 1, characterized in that a servomotor pivoting the lighting means (4) is provided as a means for adapting the lighting means (4) to a changed lighting requirement, the pivoting movement and the amount of pivoting being dependent on the movement detected by the detection sensor (2, 3). 3. Lighting device according to claim 1, characterized in that several lights (12, 13, 14) illuminating individual areas of the interior are provided as lighting means, of which one or more lights (12, 13, 14) are energized depending on the changed lighting requirements in the interior. 4. Lighting device according to claim 1, characterized in that a light cone adjustment element which can adjust the light cone of the lamp is provided as a means for adapting the lighting means to a changed lighting requirement. 5. Lighting device according to one of claims 1 to 4, characterized in that the sensor system for detecting the movements in the interior of the motor vehicle comprises a recording unit (2, 10, 15) for recording images of the interior, an evaluation unit (3, 11, 16) for digitally evaluating the images obtained by means of the recording unit (2, 10, 15) and a processing system acted upon by the evaluation unit (3, 11, 16). (21) for controlling the lighting means (4; 12, 13, 14) depending on the evaluated image data, wherein the evaluation unit (3, 11, 16) comprises a differential image generator (17) for determining the intensity difference of identically positioned pixels between an input image applied to the evaluation unit (3, 11, 16) and a chronologically older reference image, which differential image generator (17) applies a memory element for displaying the pixel-resolved intensity differences. &iacgr;&ogr; 6. Lighting device according to claim 5, characterized in that a temporally recursive high-pass filter (17) is provided as the difference image former. 7. Lighting device according to claim 5 or 6, characterized in that the difference image generator (17) is followed by a calculation and summation element (18) in which a buffer which can be read in line by line and read out block by block (22) and a linear memory as well as two calculation units for block-wise difference image energy calculation and for calculating and summing the energy gradients. 8. Lighting device according to one of claims 5 to 7, characterized in that a time-recursive low-pass filter (19) is connected to the calculation and summation element (18). 9. Lighting device according to claim 6 or 8, characterized in that the filters (17, 19) are adjustable with respect to their temporal recursiveness. 10. Lighting device according to one or more of claims 6 to 9, characterized in that a comparator element (20) is assigned to the evaluation unit (3, 11, 16) for a threshold value comparison.