SYSTEMS AND METHODS FOR DAMAGE DETECTION

Abstract

A system for detecting damage to a glass surface particularly vehicle glazing panels such as vehicle windscreens. The system uses a sensor unit disposed proximate the surface and a processor in communication with the sensor unit. The processor is configured to analyse data received from the sensor unit in order to determine the integrity of the surface and a communication unit is configured to output a signal in response to the processor determining that the surface has been damaged. For vehicle glass the system is preferably integrated into the vehicle management and control systems such that the system is active when the vehicle is active or moving. The management and or control system may monitor for instances or situations when changes, such as above threshold changes, occur in order to produce an output warning signal.

Claims

1. A system for detecting damage to a glass surface, the system comprising: a sensor unit disposed proximate the surface; a processor in communication with the sensor unit, wherein the processor is configured to analyze data received from the sensor unit to determine the integrity of the surface; and a communication unit configured to output a signal in response to the processor determining that the surface has been damaged.

2. A damage detection system according to claim 1, wherein the sensor unit comprises a microphone and the processor comprises a sound amplification and signal processing system.

3. A damage detection system according to claim 1, wherein the sensor unit comprises a camera arranged to image the surface and the processor comprises image processing software operable to analyze images received from the camera to identify any damage areas; wherein a controller is configured to move, tilt or pivot the camera.

4. A damage detection system according to claim 1, wherein the sensor unit comprises an optical transmitter and an optical detector, and wherein the optical transmitter is configured to at least partially illuminate the surface and the optical detector is arranged to at least partially receive light output from the optical transmitter.

5. A damage detection system according to claim 4, wherein the angle of incidence of light output by the optical transmitter(s) is selected such that the light undergoes total internal reflection through the surface.

6. A damage detection system according to claim 1, further comprising an electrically conductive film disposed on the surface.

7. A damage detection system according to claim 6, wherein the sensor unit comprises an electric circuit operable to measure the electrical resistance of the film.

8. A damage detection system according to claim 1, wherein the sensor unit comprises a transducer configured to output acoustic waves which vibrate the surface and a receiver arranged to measure the vibration of the surface.

9. A damage detection system according to claim 8, wherein the transducer and the receiver are the same device which is configured to output pulses of acoustic waves.

10. A damage detection system according to claim 1, wherein the communication unit is configured to output an alert that the surface has been damaged to a remote location.

11. A damage detection system according to claim 10, wherein the communication unit comprises at least one of a transceiver for outputting the signal, a GPS transmitter, and a GPS receiver.

12. A method for detecting damage to a glass surface, the method comprising: measuring one or more acoustic, electrical, or optical properties of, or proximate to, the surface using a sensor unit; analyzing data received from the sensor unit using a processor to determine the integrity of the surface; and outputting a signal from a communication unit in response to the processor determining that the surface has been damaged.

13. A damage detection method according to claim 12, wherein the glass surface is a vehicle windscreen.

14. A damage detection method according to claim 12, wherein the sensor unit comprises a plurality of sensors, and the method includes the step of instructing the sensor unit to verify whether the surface has been damaged by conducting a further measurement using a different sensor.

15. A damage detection method according to claim 12, wherein the step of measuring one or more properties using the sensor unit comprises recording the sound of a potential damage event using a microphone and converting this sound signal into an electrical signal.

16. A damage detection method according to claim 12, wherein the step of measuring one or more properties using the sensor unit comprises imaging the surface using a camera; wherein the method includes moving the camera to scan across the surface.

17. A damage detection method according to claim 12, wherein the method includes verifying that a damage event has occurred by activating a camera in response to a microphone recording a signal indicative of a potential damage event.

18. A damage detection method according to claim 12, wherein the step of measuring one or more properties of the surface using a sensor unit comprises at least partially illuminating the surface using at least one optical transmitter and recording the amount of light reflected by, or transmitted through, the surface using at least one optical detector.

19. A damage detection method according to claim 12, further comprising selecting the angle of incidence of light output by the optical transmitter(s) such that the light undergoes total internal reflection through the surface.

20. A damage detection method according to claim 12, further comprising disposing an electrically conductive film on the surface and measuring the electrical resistance of the film.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Embodiments of the invention will now be described, by way of example, in the accompanying drawings, of which:

[0065] FIG. 1 is a schematic drawing of a detection system according to an embodiment of the invention;

[0066] FIG. 2 is a schematic drawing of another embodiment of a detection system including an optical system;

[0067] FIG. 3 is a schematic drawing of another embodiment of a detection system including a microphone and a camera; and

[0068] FIG. 4 is a schematic drawing of another embodiment of a detection system including a camera and an acoustic vibration system.

DETAILED DESCRIPTION

[0069] FIG. 1 shows a schematic drawing of a damage detection system of the present invention. The system comprises a sensor unit 14 disposed proximate a glass surface 10. The sensor unit 14 is in communication with a processor 16. The processor 16 is connected to a communication unit 18.

[0070] The sensor unit 14 is configured to measure one or more properties or one or more signals indicative of a damage event occurring to the glass surface 10. A damage event includes a flaw or chip forming on the outer face of the surface 10. The processor 16 is configured to analyse data received from the sensor unit 14 and to determine when the surface 10 has been damaged. When a damage event is detected the processor 16 can instruct the communication unit 18 to output a signal, such as an alert, to a remote location 1. The communication unit 18 is in wireless communication with the remote location (e.g. via a data link) shown by the broken line in FIG. 1.

[0071] Although the connections between the sensor unit 14, processor 16 and communication unit 18 are shown by solid lines in FIG. 1, these may also be wireless connections.

[0072] In some embodiments, the processor 16 may request verification of a damage event from the sensor unit 14 before instructing the communication unit 18.

[0073] In FIG. 2, the glass surface is a vehicle windscreen 20. The windscreen 20 comprises an outer ply of glass 21 and an inner ply of glass 23 separated by an interlayer 22 comprising a plastics material. The interlayer 22 is generally thinner than the inner 21 and outer 23 glass plies, but the layers are not drawn to scale in FIG. 2 to improve the clarity of the illustration.

[0074] The sensor unit in FIG. 2 comprises an array of optical transmitters 24 and an array of optical detectors 25. A controller 27 is in communication with the array of optical transmitters 24 and the processor 26. The processor 26 receives data from the optical transmitters 24 and the optical detectors 25. As in FIG. 1, the processor 26 is connected to a communication unit 28 which is configured to output a signal in response to the processor determining that the windscreen 20 has been damaged.

[0075] The optical transmitters 24 are arranged to output dispersed light 29 which undergoes total internal reflection through the interlayer 22 of the of the windscreen. The wavelength of the light emitted 29 may be in the infrared, visible or ultraviolet spectrum. The angle of incidence a of the incident light 29 on the boundary of the interlayer 22 determines whether total internal reflection will occur. The angle a can be adjusted by the controller 27 moving or tilting the optical transmitters 24. In other embodiments, the optical transmitters 24 are fixed in position and there is no controller 27.

[0076] The array of optical detectors 25 are positioned to receive light output by the optical transmitters 24. In FIG. 2, the optical detectors are arranged proximate an end of the surface 20 to receive light output from the interlayer 22. If the interface between the interlayer 22 and the outer ply 21 or the inner ply 23 of the windscreen becomes damaged, for example by a chip, then this will disrupt the amount of light received by the detectors 25. This change will be detected by the processor 26 which will then instruct the communication unit 28 to output an alert.

[0077] In other embodiments, the array of optical transmitters 24 may be arranged to at least partially illuminate the outer ply 21 of the windscreen. The light emitted 29 may undergo total internal reflection along the outer ply 21. This may allow the optical detectors 25 to detect damage to the external face of the outer ply 21, which does not propagate to the interlayer 22. Optionally, the optical transmitters 24 and/or the optical detectors 25 may be positioned proximate the outer ply 21 (i.e. externally of the windscreen 20). Optionally, the optical transmitters 24 and/or the optical detectors 25 may be positioned proximate to the inner ply 23 (i.e. inside the vehicle).

[0078] In FIG. 3, the sensor unit of FIG. 2 has been replaced by a microphone 34 positioned proximate to the windscreen 20 and a camera 35. The microphone 34 is arranged to convert sound signals into electronic signals which are received by the processor 26. The processor 26 includes a signal amplifier and a signal processor. The processor 26 is programmed to analyse whether the signal received from the microphone 34 matches, or approximates a predetermined signal indicative of a damage event. For example, the sound of a stone or other small projectile impacting the outer ply 21 and causing a chip will result in a signal output from the microphone 34 which has a particular time response and frequency spectrum.

[0079] There is a risk that the microphone 34 may pick up sounds from inside the vehicle, or of objects striking the outer ply 21 of the windscreen which do not result in any damage but are identified by the processor 26 as damage events. Thus, the camera 35 may be used to verify the results of the microphone 34.

[0080] When the processor 26 identifies a possible damage event from the microphone 34 signal, it will activate the camera 35. The camera 35 may be on standby until activated by the processor 26, so as to conserve power. If required, a controller 27 may move, tilt or pivot the microphone 34 and/or the camera 35, such that the camera 35 can image the entire surface 23 of the windscreen. The image, or images, is/are then received by the processor 26 which includes image processing software configured to analyse the image(s) and identify any damage areas on the windscreen 20. As the outer ply 23, interlayer 22 and outer ply 21 are transparent, the camera 35 can be positioned inside of the vehicle and still image any damage areas in the outer ply 21.

[0081] If the processor 26 determines that there is a damage area (e.g. a chip) then the processor 26 will instruct the communication unit 28 to output an alert.

[0082] In FIG. 4, an electrically conductive film 31 is disposed on the external face of the outer ply 21 (i.e. the external face of the windscreen 20). The film 31 is connected to an electric circuit 44 operable to measure the electrical resistance of the film 31. In addition to the electric circuit 44 the sensor unit comprises a camera 35 (as in FIG. 3) and an acoustic vibration system 45.

[0083] One or more of the features of the sensor unit may be in continuous operation. For example, the conductive film 31 and the acoustic vibration system 45 may be used as the primary detection means.

[0084] The processor 26 is configured to compare the electrical resistance of the film 31 (measured by circuit 44) to a predetermined resistance of the film 31 when it is completely intact. The ‘undamaged’ resistance value may be measured by the circuit 44 when the film 31 is initially applied to the windscreen 20. Any damage to the conductive film 31 (such as a discontinuity) caused by damage to the outer ply 21 of the windscreen will change the electrical resistance of the film 31. If the processor 26 determines that the resistance of the film 31 has changed then it may verify that a damage event has occurred using the camera 35 (as described above) and/or the acoustic vibration system 45.

[0085] The acoustic vibration system 45 comprises a transducer configured to output pulses of acoustic waves which vibrate the windscreen 20 and a receiver arranged to measure the vibration of the windscreen 20. In this embodiment the transducer and the receiver are the same piezoelectric device 44, but in other embodiments they can be separate.

[0086] When undamaged the windscreen 20 will vibrate with a specific acoustic signal and temporal profile that can be predetermined. When the windscreen 20 is damaged the signal received by the receiver 44 will be permanently altered. The processor 26 analyses the signals recorded by the receiver 44 and detects if the signal has changed from the undamaged signal.

[0087] If the processor 26 receives multiple acoustic signals indicative of a damage event in a certain time frame (i.e. that the change was not temporary) then the processor may analyse whether the electrical resistance of the film 31 has changed. If the film 31 verifies that a damage event has occurred then the processor 26 may instruct the communication unit 28 to output an alert.

[0088] Alternatively, the processor 26 may seek further verification of damage from the camera 35. The operation of the camera 35 is described above in reference to FIG. 3.

[0089] This two-step verification system ensures that the detection of damage to the windscreen is very accurate and reliable compared to known systems.

[0090] It will be appreciated that the sensor unit could comprise any combination of the features disclosed in FIGS. 2 to 4, and that systems disclosed as providing verification could equally be used as primary detection means, and vice versa. As such, the sensor unit of the present invention may comprise any one or more of: a microphone 34; a camera 35; an optical system 24, 25; a conductive film 31 and electric circuit 44; and/or an acoustic vibration system 45. For example, the optical system of FIG. 2 could be used in the sensor units of FIG. 3 or FIG. 4, either to provide the initial indication of a damage event, or to verify the diagnosis of one of the other components of the sensor unit.

[0091] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word “comprising” and “comprises”, and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. In the present specification, “comprises” means “includes or consists of” and “comprising” means “including or consisting of”. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.