EP1769480A1

EP1769480A1 - Device for monitoring a body on a motor vehicle

Info

Publication number: EP1769480A1
Application number: EP05791122A
Authority: EP
Inventors: Jérôme Grando
Original assignee: Plastic Omnium SE
Current assignee: Plastic Omnium SE
Priority date: 2004-07-19
Filing date: 2005-07-19
Publication date: 2007-04-04
Also published as: US20060092006A1; FR2873201B1; WO2006016074A1; FR2873201A1

Abstract

The invention relates to a device for monitoring a body (10), fixed in relation to a motor vehicle, said body having at least one position for correct operation and a position for faulty operation. Said device comprises measuring means (20) for the measurement of a geometric parameter characterising the position of at least a part of the body (10) with relation to another fixed body on the vehicle and for providing a signal, comparator means (22), connected to the measuring means (20), for comparing the signal with a set of reference signals, corresponding to at least one correct operating position, said set being stored in the comparator means and providing a positive result when the measured signal falls within the set of reference signals and a negative result in the opposite case and warning means (24), connected to the comparator means, for triggering an alarm for faulty operation when the result from the comparator means is a negative one.

Description

DEVICE FOR MONITORING AN ORGAN ON A MOTOR VEHICLE

The present invention relates to a device for monitoring an organ on a motor vehicle and an assembly of an organ and a device for monitoring this organ.

It is known that current motor vehicles have more and more organs whose position on the vehicle must be very precise to ensure their proper operation. For example, detection systems are known whose purpose is to improve the safety of passengers, pedestrians or to avoid vehicle degradation.

When detecting an impact or an obstacle, such detection systems trigger an action to prevent a hazard, such as for example the deployment of an airbag or the emission of an audible signal to alert the driver that he is about to collide with an obstacle. It is very important, especially for systems ensuring the safety of passengers or pedestrians, that these detection systems function properly at all times during the life of the vehicle, particularly following a relatively small shock that has not not damaged outside the vehicle but that could have moved one of these systems, without the driver being aware of it. But since these systems are generally not very visible from the outside of the vehicle, it is necessary that the owner controls them regularly, and as they are not very accessible, it generally requires the dismantling of parts of the vehicle by professionals, which is expensive. . This check generally consists of checking their correct positioning on the vehicle following the impact. In addition to the detection systems, it is also necessary to check the position of other non-visible organs from outside the vehicle to ensure that they have not been degraded following a small impact, for example a shock absorber, or a lighthouse whose beam is very precise.

For these bodies too, surveillance is expensive but a lack of control can be dangerous if they do not perform their function when the time comes.

The present invention aims to provide a device for monitoring the position of such organs, avoiding regular use of a professional to check the proper functioning of the body, while ensuring the driver at all times that the organ is properly positioned on the vehicle. For this purpose, the present invention relates to a device for monitoring a fixed member relative to a motor vehicle, the member having at least one position of smooth operation and a malfunctioning position, characterized in that it comprises:

measurement means able to measure a geometric quantity characteristic of the position of at least one part of the member relative to another fixed member of the vehicle and to provide a signal;

comparison means connected to the measuring means, able to compare the signal with a set of reference signals corresponding to at least one operating position, this set being stored in the comparison means and supplying a positive result when the signal measured is part of the set of reference signals and a negative result in the opposite case; and

warning means connected to the comparison means and able to trigger a malfunction alert when the result provided by the comparison means is negative.

By "geometric magnitude characteristic of the position of at least a part of the organ" is meant a magnitude indicative of the state in which the organ is located from a geometrical point of view, that is to say measurable in space, for example distance, thickness, orientation, etc. This magnitude may be in particular the distance separating a part of the member from another fixed member, its orientation, its deformation. Thus, if the member has been biased, for example during an impact, and if it has been deformed for example beyond a certain threshold, it may no longer be in a position of good operation. In this case, the measuring means provide the comparison means a signal after which the result of the comparison is negative, which triggers the alert to the owner of the wrong position and therefore the malfunction of the organ, even when the deformation is not visible from the outside. Therefore, the owner knows that as long as he is not alerted, the organ is in a position to function properly.

As the measured magnitude is characteristic of a position relative to another fixed member of the vehicle, the measurement reference used is the vehicle, not an external reference, such as could be the ground on which the vehicle rolls. Thus, it does not take into account the position variations experienced by the entire vehicle, the measurement performed being independent of the movements of the vehicle, including its inclination. This is particularly advantageous since these positional variations are not characteristic of a malfunctioning position of the organ. A monitoring device according to the invention may further comprise one or more of the following features: the measuring means comprise an optical fiber network and an optical sensor;

the measuring means comprise a generator and an electromagnetic field sensor; the measuring means comprise a generator and an eddy current sensor;

the measuring means comprise a generator and an ultrasound sensor;

the measuring means comprise a generator and a Lamb wave sensor;

the measuring means comprise a shape memory alloy or a resistive strain gauge and an electrical resistivity measuring apparatus;

- The measuring means comprise fusible elements which break during an impact likely to cause the malfunction of the organ; the warning means comprise means for deactivating the organ; and

the set of reference signals is a continuous interval of signals. The subject of the invention is also an assembly of an organ and a device for monitoring this organ as described above, in which the organ is a system for detecting a danger.

Such a set may further comprise one or more of the following features:

the detection system is an impact detector;

the detection system is an obstacle detector; the organ is a projector;

the member is arranged at the front of the vehicle. ;

the organ is arranged behind a bumper shield;

the organ is arranged behind a wing of the vehicle;

the measuring means belong to the organ; the measuring means comprise on the one hand two substantially parallel electrically conductive surfaces, and on the other hand an electronic circuit, so as to create a capacitive system;

- The measuring means further comprises a third electrically conductive surface; it comprises a contact sensor arranged in the vicinity of the body; and -AT-

it comprises two differential accelerometers, one of which is arranged on the organ.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings in which: FIG. 1 is a diagram of a monitoring device according to a first embodiment embodiment of the invention; Figure 2 is a diagram of a monitoring device according to a second embodiment;

FIG. 3 is a diagram of a monitoring device according to a third embodiment;

FIG. 4 is a diagram of a monitoring device according to a fourth embodiment; and

- Figure 5 is a diagram of a monitoring device according to a fifth embodiment. A device according to the invention can monitor a system 10 for detecting shocks, installed on a motor vehicle, such as the system shown in FIG.

The detection system 10 can detect a shock suffered by a bumper 12. More specifically, it detects the deformations of a shock absorber 14 arranged behind a shield 16, and triggers, when the deformation exceeds a certain threshold, the deployment airbags in the passenger compartment of the vehicle to protect passengers.

The detection system 10 is fixed on the vehicle, in a position allowing its proper operation, that is to say the detection of the deformations of the absorber 14. However, it may happen that its position is modified following a shock, without being seen from the outside if the shock is small. Depending on the change, it can take a position that prevents it from working properly.

A monitoring device makes it possible to control that the system 10 is in a position of good operation. This monitoring device comprises measuring means 20 fixed to a fixed member of the vehicle, namely a bumper beam 18, comparison means 22 and warning means 24. In this embodiment, the means 20 are composed of an ultrasonic transceiver which measures at regular intervals the wave travel time reflected on the detection system 10. As the measured time depends on the distance traveled by the waves, is a geometric quantity characteristic of the detection system 10, which size reflects the distance separating said detection system from the transceiver 20. The transceiver 20 is connected to the comparison means 22 and sends signals representative of the measurements made.

The comparison means comprise an electronic box 22 capable of processing the received signals. This housing comprises a memory in which has been previously defined a set of reference signals corresponding to positons of good operation of the detection system 10.

The comparison means 22 are connected to the warning means 24, capable of triggering an alert to the driver, for example a light or sound signal. Optionally, the warning means are connected to a service company.

The warning means can trigger in parallel the deactivation of the detection system 10.

The control unit 22 is capable of comparing the received transceiver signal 20 with the set of reference signals. When the result of the comparison is positive, that is, when the received signal is part of the set of reference signals, no action is triggered.

When the result of the comparison is negative, that is to say when the signal received is not part of the set of reference signals, the housing 22 triggers the warning means 24. According to another embodiment not shown, the detection system is an obstacle detector arranged on the shield, or a camera to identify a risk of impact with a walker.

According to another embodiment of the invention, represented in FIG. 2, the measuring means comprise a shape memory alloy 26 fixed between the detection system 10 and a fixed bearing surface 27 integral with the beam 18. The alloy 26 is connected to a device 28 measuring its electrical resistivity. As the alloy 26 is shape memory, it changes phase when it undergoes deformations, which results in a variation of its resistivity. Comparison means 30 are capable of processing the signal received from the apparatus 28 and comparing it with a set of reference signals, corresponding to a range of resistivities for which the deformations of the alloy

26 translate a slight displacement of the detection system 10 does not prevent its proper operation.

In the embodiment of FIG. 3, the measuring means are included in the detection system. This detection system is composed of an absorber 32, whose inner and outer faces are covered by two electrically conductive parallel layers 34, 36 forming conductive surfaces, connected to an electronic circuit 38 capable of measuring the capacity of the capacitive system formed by the two layers 34, 36. The electronic circuit 38 is connected to means 40 for processing this measurement. As the measured capacitance is significant of the distance d separating the two conductive layers 34, 36, itself characteristic of the intensity of a shock, the capacitive system is used as a danger detection system.

During a violent shock, the processing means 40 detect that the variation of the distance d is characteristic of a hazard. They then trigger protection means 42 constituted here by air bags deploying in the passenger compartment of the vehicle. Optionally, the detection system comprises a third electrically conductive surface, not shown, arranged between the outer layer 34 and the shield 16, creating a shielding of the capacitive system, to avoid unwanted interference with the outside of the vehicle.

The detection system constituted by the capacitive system 34, 36, 38 and the processing means 40 is provided with a monitoring device according to the invention, comprising comparison means 44, connected to the electronic circuit 38, and means for warning 46 capable of alerting the driver when the detection system is not in a functioning position.

The operation of this monitoring device is as follows. In a small shock, the distance d may have been altered but not in a dangerous manner, ie the shock to the vehicle was not followed by the airbag deployment or In this case, the comparison means 44 receive a signal characteristic of the distance d and compare it to a set of signals corresponding to distances for which the detection system is in a position of good operation. If the signal received is not part of this set of signals, the comparison means 44 triggers the warning means 46.

According to another embodiment, shown in FIG. 4, the monitored organ is not a detection system but the absorber 14 itself, which is verified to have not undergone deformation degrading its capabilities. shock absorption. The measuring means are constituted by a contact sensor 48, arranged on one side of the bumper beam 18 in contact with the absorber 14, for measuring the pressure exerted by the absorber 14 on the beam 18.

During an impact, the absorber 14 is compressed against the beam 18, which results in an increase in the pressure measured by the sensor 48. If the pressure received may cause the absorber 14 to malfunction, that is, if the signal sent by the sensor 32 to the comparison means 50 is not part of a set of signals corresponding to non-interfering pressures, an alert is given by the monitoring means 24.

According to another embodiment of the invention, represented in FIG. 5, the monitored device is a projector 52. The monitoring device comprises a sensor 54, for example an optical sensor, measuring a characteristic quantity of the orientation of the sensor. projector 52, for example the distance separating the sensor 54 from the projector 52. The sensor is secured to a fixed member 56. When the projector 52 is in a bad position, comparison means 58 trigger warning means 24. II is particularly advantageous to monitor the correct positioning of the projector

52, especially if it is a xenon headlight that emits a highly directional beam and whose orientation must therefore be very precise.

Finally, note that the invention is not limited to the embodiments described above.

Claims

REVEND1CATIONS

1. Device for monitoring a member (10, 14, 52) fixed relative to a motor vehicle, the member having at least one operating position and a malfunctioning position, characterized in that it comprises:

measuring means (20, 26, 38, 48, 54) capable of measuring a geometrical quantity characteristic of the position of at least one part of the member (10, 14, 52) relative to another fixed member the vehicle and to provide a signal;

comparison means (22, 30, 44, 50, 58) connected to the measuring means (20, 26, 38, 48, 54), able to compare the signal with a set of reference signals corresponding to at least one operating position, this set being stored in the comparison means and providing a positive result when the measured signal is part of the set of reference signals and a negative result in the opposite case; and warning means (24) connected to the comparison means and able to trigger a malfunction alert when the result provided by the comparison means is negative.

2. Monitoring device according to claim 1, wherein the measured geometric magnitude is the distance between a portion of the member of another fixed member.

The monitoring device of claim 1 or 2, wherein the measuring means (54) comprises an optical fiber array and an optical sensor.

4. Monitoring device according to any one of claims 1 to 3, wherein the measuring means comprises a generator and an electromagnetic field sensor.

5. Monitoring device according to any one of claims 1 to 4, wherein the measuring means comprise a generator and an eddy current sensor.

6. Monitoring device according to any one of claims 1 to 5, wherein the measuring means (20) comprise a generator and an ultrasonic sensor.

7. Monitoring device according to any one of claims 1 to 6, wherein the measuring means comprise a generator and a Lamb wave sensor.

8. Monitoring device according to any one of claims 1 to 7, wherein the measuring means (26) comprise a shape memory alloy or a resistive strain gauge and an electrical resistivity measuring apparatus.

9. Monitoring device according to any one of claims 1 to 8, wherein the measuring means comprise fusible elements which break during an impact likely to cause the malfunction of the organ.

10. Monitoring device according to any one of claims 1 to 9, wherein the warning means comprise means for deactivating the organ.

The monitoring device of any one of claims 1 to 10, wherein the set of reference signals is a continuous range of signals.

12. An assembly and a device for monitoring this member according to any one of claims 1 to 11, wherein the member is a detection system (10) of a hazard.

13. An assembly and a device for monitoring this member according to any one of claims 1 to 11, wherein the member is a shock absorber (14).

14. An assembly and a device for monitoring this member according to any one of claims 1 to 11, wherein the member is a projector (52).

15. An assembly and a device for monitoring this member according to any one of claims 1 to 11, wherein the member is arranged behind a shield (16) bumper.

16. An assembly according to any one of claims 12 to 15, wherein the measuring means (34, 36, 38) belong to the member (34, 36, 38).

17. The assembly of claim 16, wherein the measuring means comprise first two electrically conductive layers (34, 36) substantially parallel, on the other hand an electronic circuit (38), so as to create a capacitive system.

18. The assembly of claim 17, wherein the measuring means further comprises a third electrically conductive layer.

19. An assembly according to any one of claims 12 to 18, comprising a contact sensor (48) arranged in the vicinity of the body.

20. An assembly according to any one of claims 12 to 19, comprising two differential accelerometers, one of which is arranged on the organ.