Abstract
At least one detector (2) for visible and/or IR radiation on board of a vehicle (100) is used to determine if an entity (200) is approaching the vehicle (100). If so, sensors (4) for vibration and/or acceleration are activated. Signals from these sensors (4) are used to determine if a contact between the entity (200) and the vehicle (100) has occurred. The contact may be classified based on these signals. The at least one detector (2) may include a camera (21). At least one camera (5, 21) on board of the vehicle may be used to record image data pertaining to a time-interval about the contact. A warning may be triggered if a contact between the entity (200) and the vehicle (100) is likely.
Claims
1. A system for a vehicle, the system comprising at least one detector for radiation in the visible or the infrared portion of the electromagnetic spectrum; at least one sensor, the at least one sensor including at least one sensor for vibration or acceleration; a control and evaluation unit connected to the at least one detector and the at least one sensor, configured to receive and evaluate signals from the at least one detector; and the control and evaluation unit further configured to activate the at least one sensor if the control and evaluation unit determines from the signals received from the at least one detector that an entity is approaching the vehicle.
2. The system according to claim 1, wherein the at least one detector includes at least one camera operating in the visible range or the infrared range of the electromagnetic spectrum.
3. The system according to claim 1, wherein the system further comprises at least one camera in addition to the at least one detector, and the control and evaluation unit is further configured to activate the at least one camera if the control and evaluation unit determines that an entity is approaching the vehicle.
4. The system according to claim 1, further comprising the at least one detector includes at least one of a thermoelectric or a pyroelectric detector.
5. The system according to claim 1, further comprising wherein the at least one sensor includes at least one body sound sensor or at least one inertial sensor.
6. The system according to claim 1, further comprising wherein the at least one sensor further includes at least one of a capacitive sensor, a conductive sensor and an ultrasonic sensor.
7. The system according to claim 1, further comprising wherein the control and evaluation unit is further configured to classify a contact between the vehicle and the entity based on signals received from the at least one sensor.
8. The system according to claim 1, further comprising wherein the control and evaluation unit is further configured to trigger a warning signal if the control and evaluation unit determines that a contact between the entity and the vehicle is likely.
9. The system according to claim 1, further comprising wherein the system includes at least one camera, and the system is configured to store image data from the at least one camera captured within a time-interval stretching from a predefined temporal distance before to a predefined temporal distance after a contact between the vehicle and the entity.
10. A vehicle including a system according to claim 1.
11. The vehicle according to claim 10, configured to activate the system when the vehicle is in parking position.
12. The vehicle according to claim 10, wherein at least one of the at least one detector is integrated into a rear-view mirror of the vehicle.
13. A method for monitoring a vehicle, the method including the steps: operating at least one detector for radiation in the visible or the infrared portion of the electromagnetic spectrum, the detector provided on board of the vehicle; evaluating signals from the detector to determine if an entity is approaching the vehicle; and activating at least one sensor for vibration or acceleration on board of the vehicle if it is determined in the previous step that an entity is approaching the vehicle.
14. The method according to claim 13, further comprising the steps: capturing image data with at least one camera on board of the vehicle if it is determined that an entity is approaching the vehicle; storing image data captured with the camera, wherein the image data stored pertain to a time-interval stretching from a predefined temporal distance before to a predefined temporal distance after a contact between the vehicle and the entity.
15. The method according to claim 13, further comprising the step: triggering a warning signal if it is determined that a contact between the entity and the vehicle is likely.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Below, the invention and its advantages will be described with reference to the accompanying figures.
[0034] FIG. 1 shows a system according to an embodiment of the invention.
[0035] FIG. 2 shows a vehicle with fields of view related to the system.
[0036] FIG. 3 shows a vehicle with fields of view related to the system.
[0037] FIG. 4 shows an embodiment of a method according to the invention as a flow diagram.
[0038] FIG. 5 shows a further embodiment of a method according to the invention as a flow diagram.
[0039] FIGS. 6 to 9 show various envelope curves of signals from sensors.
[0040] FIG. 10 shows the relation between a signal and the corresponding envelope curve.
[0041] FIG. 11 exemplifies the effect of a threshold for a signal.
[0042] FIG. 12 shows time relations between signals and operations.
[0043] The figures are schematic illustrations related to embodiments of the invention. The figures therefore are not intended to be construed as limitations of the invention to these specific embodiments.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0044] FIG. 1 shows a system 1 according to the invention for a vehicle. At least one detector 2 for visible and/or infrared radiation is connected to control and evaluation unit 3; in the example shown, four such detectors 2 are in connection with the control and evaluation unit 3. Via this connection, the control and evaluation unit 3 can receive signals from the detectors 2. The control and evaluation unit 3 analyses the signals received from the detectors 2 to determine whether an entity is approaching the vehicle. If it is determined that an entity is approaching the vehicle, the control and evaluation unit 3 activates the at least one sensor 4. Plural sensors 4 are shown in the depicted example; at least one of these sensors 4 is a sensor for vibration and/or acceleration. The control and evaluation unit 3 receives signals from the activated sensors 4. The control and evaluation unit 3 can determine from the signals received from the sensors 4 whether a contact between the vehicle and an entity has occurred and may furthermore classify the contact. For performing its functions, the control and evaluation unit 3 comprises a processor 31 and a memory unit 32. The memory unit 32 stores program instructions 33 to be carried out by the processor 31 so that the control and evaluation unit 3 performs its functions. The memory unit 32 may store further data, e.g. data representing signals from the detectors 2 and/or data representing signals from the sensors 4. In the example shown, the system 1 furthermore includes two cameras 5. These cameras 5 can be activated by the control and evaluation unit 3 if the control and evaluation unit 3 determines that an entity is approaching the vehicle. The detectors 2 may for example include a thermoelectric detector, a pyroelectric detector, or a camera operating in the visible and/or the infrared range.
[0045] FIG. 2 shows a vehicle 100 with fields of view of detectors and cameras of a system according to the invention (not fully shown), which system is implemented in the vehicle 100 shown. In a rear-view mirror 102 of the vehicle 100 detectors (not shown) are integrated, which detectors have fields of view 110. These detectors may operate in the visible and/or infrared range. Among the detectors of the system according to the invention implemented in the vehicle 100 shown furthermore are cameras 21 with fields of view 111. These cameras 21, together with the detectors in the rear-view mirrors 102, serve to provide signals to the control and evaluation unit (not shown) to determine whether an entity 200 is approaching the vehicle 100. In the example shown, the system also includes an additional camera 5, which is activated along with the sensors, as described in the context of FIG. 1. This camera 5 has fields of view 112. Both the cameras 21 and the camera 5 may also serve further purposes. While these cameras may be specifically provided for purposes of the invention, they need not be restricted thereto. The vehicle 100 may in particular be configured such that the system according to the invention is activated if the vehicle 100 is in a parking position.
[0046] FIG. 3 shows a further example of a vehicle 100 with fields of view of detectors and cameras of the system according to an embodiment of the invention. The elements shown have already been discussed in the context of FIG. 2. The essential difference with the example of FIG. 2 is that the fields of view 110 of the detectors integrated in the rear-view mirrors 102 cover a larger angle. Together with the fields of view 111 of the cameras 21 this example provides a total field of view (comprising all fields of view 110 and 111) of 360 degrees about the vehicle 100 in a plane (here the plane of the drawing) parallel to a surface on which the vehicle 100 is located.
[0047] FIG. 4 shows a flow diagram illustrating an embodiment of a method 400 according to the invention. In step 402 at least one detector for radiation in the visible and/or the infrared portion of the electromagnetic spectrum is operated. The at least one detector is on board of a vehicle. Each of the at least one detector may, independently of further detectors, be for example a thermoelectric detector, a pyroelectric detector, or a camera; such a camera may operate in the visible and/or the infrared range of the electromagnetic spectrum. The at least one detector provides signals, which are evaluated in step 404 to determine whether an entity is approaching the vehicle. If it is determined that an entity is approaching the vehicle, at least one sensor for vibration and/or acceleration on board of the vehicle is activated in step 406. An activated sensor provides signals which can be analysed, for example to determine if a contact between the vehicle and the entity has occurred, and if so, to classify that contact. In the embodiment shown, if it is determined that a contact between the entity and the vehicle is likely, a warning signal is triggered in step 408.
[0048] The method according to the invention, and thus in particular the embodiment described here, may be carried out by a system according to the invention, in particular under control by a control and evaluation unit carrying out suitable program instructions. One possibility to determine if a contact between the entity and the vehicle is likely may rely on a distance between the entity and the vehicle. For example, by definition, a contact between the entity and the vehicle may be deemed likely if a distance between the entity and the vehicle is below a predefined threshold.
[0049] FIG. 5 shows a flow diagram illustrating a further embodiment of a method 500 according to the invention. In step 502 at least one detector for radiation in the visible and/or the infrared portion of the electromagnetic spectrum is operated. The at least one detector is on board of a vehicle. Each of the at least one detector may, independently of further detectors, be for example a thermoelectric detector, a pyroelectric detector, or a camera; such a camera may operate in the visible and/or the infrared range of the electromagnetic spectrum. The at least one detector provides signals, which are evaluated to determine if an entity is approaching the vehicle. If, in step 504, no entity approaching the vehicle has been detected, the method returns to step 502, i.e. the at least one detector simply continues operating. If in step 504 an entity approaching the vehicle has been detected, the method proceeds to step 506 and activates at least one sensor for vibration and/or acceleration on board of the vehicle. An activated sensor provides signals which can be analysed, for example to determine if a contact between the vehicle and the entity has occurred, and if so, to classify that contact. The method proceeds to step 508 and records images with a camera on board of the vehicle; the field of view of the camera covers a portion of an environment of the vehicle. In step 510 it is checked whether the entity is moving away from the vehicle; this may be done based on signals from the at least one detector. If the entity remains in the proximity of the vehicle, the method loops back to step 508, i.e. the recording of images continues. Otherwise, if the entity moves away from the vehicle, the recording of images is stopped in step 512. Subsequently, in step 514, it is determined, based on signals received from the at least one sensor, whether a contact between the vehicle and the entity occurred. If it is determined that a contact occurred, images recorded according to step 508 are kept in step 516, e.g. stored in a memory on board of the vehicle. The images kept are those which pertain to a predefined time-interval about the contact, for example a time-interval stretching from a predefined temporal distance before the contact to a predefined temporal distance after the contact. On the other hand, if it is determined that no contact between the vehicle and the entity occurred, the recorded images are deleted in step 518.
[0050] FIGS. 6-9 show graphs of envelope curves pertaining to signals from sensors of the system according to the invention. Each of the graphs shows time on abscissa 601 and values of the envelope curve on ordinate 602. The signals from which the envelope curves shown have been derived are signals from body sound sensors. FIG. 6 shows an envelope curve 606 resulting from an impact event, FIG. 7 shows an envelope curve 607 resulting from a scratch, FIG. 8 shows an envelope curve 608 resulting from communication, FIG. 9 shows an envelope curve 609 resulting from background noise or background music. The shape of the envelope curve may be used to classify the event giving rise to the signal from which the envelope curve was derived. While an elaborate fitting procedure to template envelope curves is not dismissed as a possibility, classification may also be done based on a number of characteristics of the envelope curve. For example, an impact may be reflected in the shape of the envelope curve 606 by single peak of large amplitude, for example an amplitude above a predefined threshold, and a width of the peak, e.g. at half-maximum, below a predefined maximal width. This choice reflects that an impact is a single short-duration event involving high energy, and therefore high amplitude of sound propagating in the material of the vehicle. Envelope curve 607, reflecting a scratch, is characterised by an amplitude lower than that of an impact, and thus for example below a predefined threshold. The duration of a scratch typically is longer than that of an impact, therefore a peak width, e.g. at half-maximum, above a predefined threshold may be required. Communication, corresponding to envelope curve 608, may be characterised by several peaks, all with an amplitude above a lower and below an upper threshold. Background sound, e.g. noise or music, may be characterised by an envelope curve remaining below an upper threshold, and for example not fitting any of the other types of envelope curve. Generally speaking, the shape of the envelope curve may be used to identify the type of event or contact between the vehicle and the entity, the amplitude of the envelope curve may be used to assess the energy involved in the event or contact, and therefore for example the severity of damage caused to the vehicle by the contact. Furthermore, if plural sensors, e.g. plural body sound sensors, are used, the positions of the sensors may be used to estimate the location of the contact on the vehicle. For example, it may be assumed that the contact occurred nearest to that sensor of the plural sensors which yielded the highest envelope curve.
[0051] FIG. 10 shows a graph of a signal 610 and the corresponding envelope curve 611 derived therefrom. The graph shows time on abscissa 601 and signal values on ordinate 602. The signal 610 here is a body sound signal, but the relation between a signal and its envelope curve does not depend on the type of signal, just on the values of the signal.
[0052] FIG. 11 shows a graph with time on the abscissa 601 and signal values on the ordinate 602. Shown is a signal 610 and a threshold 603 for the signal value. Further illustrated is a time-interval 604 during which the maxima of the signal 610 are above the threshold 603. Only the length of this time-interval 604 may, for purposes of analysing a contact or event, be considered the duration of an event or contact causing the signal 610.
[0053] FIG. 12 shows exemplary time relations between some signals and operations. To this end, four curves are shown in a graph with common abscissa 601 showing time, and ordinate 602 showing signal strength for the respective signal (i.e. the units of the ordinate 602 may be different for the four curves shown, and for each curve the ordinate 602 has a respective zero where it is intersected by the respective abscissa 601). Curve 612 shows a signal from a detector, here, as an example, from a detector for infrared radiation. Curve 613 shows the envelope curve from a sensor, here a body sound sensor. Curve 614 shows the activity curve of a camera. Curve 615 shows the intensity of a warning signal.
[0054] At time 620 the detector outputs signals which lead to the determination that an entity is approaching the vehicle. For a subsequent time-interval 621 no further action is taken, to avoid spurious false alarms. If the detector signal 612 still indicates an approaching entity after time-interval 621, at time 622 sensors (e.g. sensors 4 in FIG. 1) and camera (e.g. camera 5 in FIG. 1) are activated. Both camera and sensors require some time-interval 623 to become fully active. Also triggered at time 622 is the warning signal, as shown by its intensity curve 615. Here the detector indicates proximity of an entity up to a time 624, after which time 624 sensors, camera and warning signal are deactivated. The detector continues operation to detect potential further approaching entities.
[0055] While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.
