GB2056059A - A method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen - Google Patents
A method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen Download PDFInfo
- Publication number
- GB2056059A GB2056059A GB8025864A GB8025864A GB2056059A GB 2056059 A GB2056059 A GB 2056059A GB 8025864 A GB8025864 A GB 8025864A GB 8025864 A GB8025864 A GB 8025864A GB 2056059 A GB2056059 A GB 2056059A
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- United Kingdom
- Prior art keywords
- quality
- screen
- wiper blade
- assessing
- wiping
- Prior art date
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- 238000000034 method Methods 0.000 title claims abstract description 49
- 238000005406 washing Methods 0.000 claims abstract description 16
- 239000012530 fluid Substances 0.000 claims abstract description 15
- 238000009792 diffusion process Methods 0.000 claims abstract description 3
- 238000005259 measurement Methods 0.000 claims description 12
- 238000012545 processing Methods 0.000 claims description 11
- 150000003839 salts Chemical class 0.000 claims description 10
- 230000000694 effects Effects 0.000 claims description 8
- 238000005286 illumination Methods 0.000 claims description 8
- 239000013078 crystal Substances 0.000 claims description 6
- 238000009826 distribution Methods 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 230000001143 conditioned effect Effects 0.000 claims description 5
- 230000001419 dependent effect Effects 0.000 claims description 5
- 230000002209 hydrophobic effect Effects 0.000 claims description 5
- 230000036962 time dependent Effects 0.000 claims description 5
- 238000009736 wetting Methods 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- 230000001795 light effect Effects 0.000 claims description 3
- 230000000007 visual effect Effects 0.000 claims description 3
- 230000008034 disappearance Effects 0.000 claims description 2
- 238000001704 evaporation Methods 0.000 claims description 2
- 230000008020 evaporation Effects 0.000 claims description 2
- 239000004816 latex Substances 0.000 claims description 2
- 229920000126 latex Polymers 0.000 claims description 2
- 239000004065 semiconductor Substances 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims 1
- 239000007788 liquid Substances 0.000 claims 1
- 239000004094 surface-active agent Substances 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 238000011156 evaluation Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 230000008447 perception Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 239000011521 glass Substances 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000015654 memory Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 210000001525 retina Anatomy 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M99/00—Subject matter not provided for in other groups of this subclass
- G01M99/008—Subject matter not provided for in other groups of this subclass by doing functionality tests
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
- B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
- B60S1/0892—Testing and production of rain sensors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/47—Scattering, i.e. diffuse reflection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
- B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
- B60S1/0833—Optical rain sensor
- B60S1/0844—Optical rain sensor including a camera
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
A method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen (1) by optically observing the diffusion, reflection and diffraction of light by residues of washing fluid remaining in the wiping field during the wiping operation. A light source (2) which is scattered, reflected and diffracted by the said residues is detected by an image sensor (3) and the place and time dependence thus determined are evaluated by analogue and digital electronics for the purpose of assessing the quality of the wiper blade or the quality of the surface of the screen. <IMAGE>
Description
SPECIFICATION
A method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen
The present invention relates to a method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen.
In the field of motor vehicle technology, it is necessary to assess, rationally and objectively, the quality of the system comprising a wiper blade and a windscreen, both in the development phase and in the manufacturing phase and after a long period of operation on the vehicle. In addition to an integral evaluation, data are required with respect to the quality of the wiper blade in part regions of the wiping field and with respect to the surface quality in part regions of the screen, and an evaluation of the residues of water left behind by the wiper and of the scratched and soiled screen with respect to its effect on the driver's perception, taking into account his tasks in traffic.
An automatically operating measuring method suitable for this purpose is proposed.
It is known that, with a wiper blade of poor quality, the stray light caused by residues of water, and by scratches and dirt in the case of windscreen surfaces of poor quality, lead to a reduction in the contrast of the visible object to be perceived by the driver. It is thereby difficult or impossible for the driver to perceive low-contrast visible objects.
Travelling by night on a road without permanent lighting and with oncoming traffic proves to be particularly critical. Conditioned by the high intensity of the light of headlamps of approaching-vehicles and the weak illumination of visible objects to be perceived by the driver, such as pedestrians, the degree of reduction in contrast and thus effects on the perception are chiefly determined by the light emanating from the headlamps of oncoming vehicles and diffused by the water residues on the hydrophobic screen and by the scratches and dirt on the screen. Thus, it is advantageous to assess the quality of the wiper blade with reference to dependence upon place and time, and to assess the quality of the surface of the screen with reference to the placedependence of the intensity of the stray light.
Methods of assessing the quality of wiper
blades have already been proposed. On the other
hand, there are no known methods of assessing the quality of motor vehicle windscreens. Two
methods frequently used for assessing the quality
of wiper blades are the "grey field method" and
the "modified Töpler schlieren method". The "grey
field method" uses the differing reflective
characteristics of wetted and unwetted glass
surfaces and renders visible the regions of the
screen covered by water. The tester assesses the
quality of the wiper blade with reference to the
water residues left in the wiping field by the wiper
blade. The "modified Tippler schlieren method"
integrally detects the light emanating from an
illuminating device and diffused by the water residues left in the wiping field during the wiping operation.For this purpose, the stray light occurring in the wiping field is depicted on a photo-receiver by optical means, and the timedependent intensity of the light thus measured is evaluated for the purpose of assessing the quality of the wiper blade.
A disadvantage of this method is that, when assessing the quality of the wiper blade, insufficient account is taken of the effect which the water residues, left in the wiping field by the wiper blade, have on the driver's perception.
Furthermore, only integral statements on the quality of the wiper blade are made when assessing wipers by means of the "modified Tippler schlieren method".
According to the present invention there is provided a method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen by optically observing the diffusion, reflection and diffraction of light by residues of washing fluid remaining in the wiping field during the wiping operation, in which light which is scattered, reflected and diffracted by residues left in the wiping field by the wiper blade is detected by an image sensor upon illuminating the wiping field or the screen by a source of light, and the place-dependence and time-dependence thus determined, or the place-dependence of the light intensity which is thus determined, are evaluated by analogue and digital electronics for the purpose of assessing the quality of the wiper blade or the quality of the surface of the screen.
A method in accordance with the invention avoids the above-mentioned disadvantages and renders it possible automatically to assess the system comprising the wiper blade and the surface of the screen both in a test installation and also when fitted in the vehicle.
The present invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of the basic measuring assembly;
Fig. 2 is a side view of the measuring assembly of Fig. 1;
Fig. 3 is a side elevation of a second embodiment of a measuring assembly;
Fig. 4 is a block diagram showing the signalprocessing stages of a simple evaluation circuit;
Fig. 5 is a diagrammatic view of a suitable optical arrangement; and
Fig. 6 shows an arrangement for qualitative assessment of new and used wiper blades.
Referring now to the drawings, there is shown a system comprising a wiper blade and a screen 1, having a surface to be wiped by the blade, an illuminating device 2 which illuminates the screen 1, and an image sensor 3 which detects the stray light occurring on the screen 1. It is thereby essential that no direct light from the illuminating device should fall onto the photo-sensitive part of the image sensor 3 which is used during the measurements. Thus, information on the placedependence and time-dependence of the stray light appearing on the screen 1 is made available by the output signal of the image sensor 3 for the purpose of evaluation.The quality of the wiper blade and the quality of the surface of the screen are then assessed by comparing the measured values with the prescribed values of the intensity of the stray light, or by comparing characteristic quantities derived therefrom, the placedependence and the time-dependence of the stray light intensity being taken into account for assessing the quality of the wiper blade, and the place-dependence of the stray light intensity being taken into account for assessing the quality of the surface of the screen.
Using this method, it is basically possible to assess the quality of the wiper blade and screen system under a larger number of differing boundary conditions. Boundary conditions are the illumination of the screen and, when assessing the quality of the wiper blade, also the condition of the screen and the composition of the washing fluid.
They have to be chosen such that evaluable stray light effects occur. Especially when assessing the quality of the wiper blade, the possibilities extend from a uniformly illuminated hydrophilic screen and a light-diffusing additive of, for example 2 to 20% of latex balls or salt crystals, to the washing fluid, to boundary conditions simulating real traffic situations such as illuminating the screen in the same manner in which it is illuminated when travelling at night with oncoming traffic, and a realistic hydrophobic degree of wetting of the system comprising the washing fluid and the screen.However, to obtain an assessment, taking into account the effect on the driver's perception, realistic boundary conditions are desirable and, for reasons of expense for example, admissible departures from reality have to be taken into account when processing the measured values and when determining the reference values and reference characteristics prescribed for assessing the quality of the wiper blade or the quality of the surface of the screen.
The actual effect of the light scattered on the screen, that is to say, the distribution of the stray light effective on the driver's retina, is ascertained in that, conditioned by its position, the focal length and the size of the diaphragm aperture of its optics and the latter's distance from the photosensitive coating of the image converter, the image sensor depicts the screen out of focus analogously to the driver's eye.Moreover, it is possible to depict the screen in a sharply focused manner and, during the subsequent electronic processing of the measured value, to perform accurately or approximately the optical low pass operation which, in reality, is two-dimensional by virtue of the blurred image in the eye, or by a onedimensional low pass operation for, for example, assessing the quality of the wiper blade at right angles to the movement of the wiper blade, that is to say, to approximate in a radially symmetrical wiping field along the radii of the wiping field.
The characteristics of the human visual system, the tasks of the driver in actual traffic, and the boundary conditions, departing from reality, in the
assessment of the quality of the wiper blade and the quality of the surface of the screen are taken into account when establishing the criteria for comparison with the measured values of the
place- and time-dependent or the placedependent stray light intensity or the characteristic quantities derived therefrom.Thus, for example, when assessing the quality of the
wiper blade (and the same applies when assessing the quality of the surface of the screen), the
maximum admissible stray light intensity in a region at a predetermined instant after the pass of
the wiper blade is established such that the
perception capacity does not fall below a limiting value during the assimilation of optical
information by this region of the wiping field. By
way of example, this limiting value can be given by the requirement that the maximum distance for
detecting an obstruction relevant to the traffic,
such as a pedestrian, is 50 metres. The maximum
detection distance is the distance from which an
observer can decide whether a relevant object
exists or does not exist.
Furthermore, to compensate for varying
boundary conditions, such as fluctuations in the
surrounding illumination, changes in the condition
of the surface of the screen etc., it is proposed
automatically to adapt, before, for example, each
series of measurements, the comparison values or
characteristic quantities prescribed for assessing
the quality of the wiper blade or the quality of the
surface of the screen, or the parameters
determining the processing of the measured
values. It is possible to determine the actual
boundary conditions by the control
measurements, for example with wiper blades or
on screens of known quality or by controlled
measurements of some parameters such as the
degree of wetting by washing fluid and the surface
of the screen, the surrounding illumination etc.
It is desirable to assess the quality of the wiper
blade or the quality of the surface of the screen
with regard to the wiping performance in the
entire wiping field and with regard to the
scratches and soiling on the entire surface of the
screen, although this is only possible in special
cases owing to the necessary expense involved in
detecting, by measuring technology, the
distribution of the stray light and in detecting and
processing the measured values. Therefore, when
assessing the quality of the wiper blade or the
quality of the screen, it is proposed to confine
oneself to that portion of the wiping field or of the
screen which is located in the drivers central field
of vision and/or, for the purpose of assessing the
quality of the wiper blade or the quality of the
surface of the screen, to determine and evaluate
the place-dependence of the stray light intensity
one-dimensionally, for example in a radially
symmetrical wiping field along a diameter of the
wiping field, in one or a few representative regions
of the wiping field or of the screen.Disregarding
the addition of light-diffusing substances, or
substances which increase the surface tension, such as wetting agents, to the washing water, and disregarding the use of other washing fluids, a certain disadvantage of the method, proposed above, for assessing the quality of wiper blades resides in the fact that the surface to be wiped must be at least slightly hydrophobic. This can be avoided by changing to a method which uses the differing reflection characteristics of wetted and non-wetted glass surfaces.
The side elevation of Figure 3 shows the principle of the measuring arrangement proposed for this purpose.
The wiper blade 4 to be assessed runs on the test screen 5 which is illuminated by an illuminating device 6 which, for example is flat or which radiates in a diffused manner. An image sensor 7 detects the light reflected from wetted and non-wetted portions of the screen 5. The contrast between the wetted and non-wetted regions is increased by a light-absorbing wall 8 behind the screen or by a light-absorbing coating on the rear wall of the screen. Conditioned by the fact that the reflecting power of the wetted screen is less than that of the dry screen, the water residues remaining in the wiping field appear darker than the dry regions of the screen. The water residues remaining the wiping field can be detected by comparing the distribution of the luminous density, measured during the wiping operation, with the dry screen.The place and the disappearance with respect to time, conditioned by the evaporation effect, of the water residues are evaluated for the purpose of assessing the quality of the wiper blade. By way of example, the areas of the portions of the wiping field which are covered by water residues left behind by the wiper blade are determined at suitable instants during the wiping operation and are evaluated for the purpose of assessment, place-dependent weighting of the individual surface components being advantageous.For reason of expense, it is further proposed to confine oneself to that portion of the wiping field which is located in the driver's central field of vision when assessing the quality of the wiper blade and/or to determine the water residues remaining in the wiping field onedimensionally, for example in a radially symmetrical wiping field along a diameter of the wiping field, and to evaluate them for the purpose of assessing the quality of the wiper blade.
The processing of the measured values necessary in the proposed method is performed by known methods of analogue and digital technology. Figure 4 shows, by way of example, the signal-processing stages of a simple evaluation circuit for assessing the quality of the cleaning of the screen or of the quality of the wiper blade. The output signal of the image sensor 9 is converted by an analogue-to-digital converter and, by means of a comparator 11, is compared work-wise with prescribed values. The comparison results are weighted with predetermined weighting factors by means of a multiplier 12, and the weighted values are added up by an adder 13.
The total thus obtained is displayed as a
measurement result by a display unit 14. The
comparison values and the weighting factors are
stored in memories 15, 16.
Cameras having conventional camera tubes, or
vidicons or semiconductor transducers or one- and
two-dimensional COD arrays are suitable for use
as image sensors. Several image sensors can be
used in order to increase the measurement
accuracy or to simplify the processing of the
measured values.
In a method operating with salt crystals
dissolved in the washing fluid, such as 2% to 20%
in Na CL or NH4 CL in distilled water, the salt
solution is applied to the screen and is wiped off
once with the wiper blade to be tested. Since
residual solution remaining on the screen
evaporates rapidly, the crystallized-out salts are
recorded. This has the following advantages:
The method is independent of the condition of
the screen (hydrophilic or hydrophobic),
temperature, moisture and air flows.
The salt crystals do not diffuse the light in all
directions.
The stray light is an accurate indication, largely
free from interference effects, of the quantities of
water which have passed through below the
wiping lip at the various locations on the screen.
The stray light does not change during
observation or measurement.
The stray light of the salts crystals can also be
recorded from one side of the windscreen. This
simplifies the measuring device.
Figure 5 shows an optical arrangement suitable
for this purpose. An incandescent lamp 101
illuminates the intended test area of the
windscreen 103 by way of a condenser lens 102
at an angle r of approximately 20 to 300. The
stray light receiver, comprising the lens 104, the
field aperture 105, the photo-element 106 and
the microammeter 107, is located substantially at
right angles to the screen 103. The wiper is
actuated after the screen 103 has been sprayed
with an aqueous solution of salt. The residual fluid
left behind evaporates within a few seconds after
a pass by the wiper blade, and the salt crystallizes.
The stray light can then be measured immediately.
Standard wipers can serve to calibrate the device
for measuring the stray light, or a standard diffuser
such as a matt grey paper sample may be used.
An arrangement shown in Figure 6 can serve
for the qualitative visual comparison of used wiper
blades with new wiper blades. The driver looks
from point 1 10 towards a dark wall 1 1 1 from his
normal seated position in the interior of the
vehicle. A headlamp 1 12 illuminates the
windscreen 103 from above, so that precisely the
point 1 10 is not illuminated. The salt which has
crystallized out after a wiping operation becomes
visible, and used wiper blades can be compared
with new ones.
The above-described processing of the
measured values can also be subordinated to this
method.
Claims (25)
1. A method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen by optically observing the diffusion, reflection and diffraction of light by residues of washing fluid remaining in the wiping field during the wiping operation, in which light which is scattered, reflected and diffracted by residues left in the wiping field by the wiper blade is detected by an image sensor upon illuminating the wiping field or the screen by a source of light, and the place-dependence and time-dependence thus determined, or the place-dependence of the light intensity which is thus determined, are evaluated by analogue and digital electronics for the purpose of assessing the quality of the wiper blade or the quality of the surface of the screen.
2. A method as claimed in claim 1, in which the quality of the wiper blade is assessed by comparing the place- and time-dependent values of the stray light intensity measured during the wiping operation, or characteristic quantities derived therefrom, with predetermined values or characteristic quantities.
3. A method as claimed in claim 1, in which the quality of the surface of the screen is assessed by comparing the measured place-dependent values of the intensity of the stray light, or characteristic quantities derived therefrom, with predetermined values or characteristic quantities.
4. A method as claimed in any of claims 1 to 3, in which evaluable stray light effects are produced by the distribution of the luminous density of the surrounding field, for example by illuminating the screen with a strong source of light in a darkened space.
5. A method as claimed in any of claims 1, 2 or 4, in which evaluable stray light effects are produced by adding 2 to 20% of a light-diffusing substance to the washing fluid, or by changing the surface tensions of the washing fluid and/or the surface of the screen by, for example, surfactants and/or water-repelling agents.
6. A method as claimed in claim 5, in which
microscopic latex balls are used as the lightdiffusing substance.
7. A method as claimed in claim 5, in which soluble salt crystals are used as the light-diffusing substance.
8. A method as claimed in claim 5, in which
insoluble salt crystals are used as the light
diffusing substance.
9. A method as claimed in any of claims 5 to 8,
in which the illumination, and the measurement of the stray light, are effected photoelectrically from one side, such as the outside, of the windscreen.
10. A method as claimed in any of claims 5 to
9, in which the stray light emanating from the
illuminated screen is assessed from the light
illuminated driver's seat.
11. A method as claimed in claim 1 or 2, in which boundary conditions based on actual traffic
situations, such as illumination of the wiping field
which occurs when travelling at night with
oncoming traffic, and a hydrophobic degree of wetting of the system comprising the washing fluid and the surface of the screen, are created for the purpose of assessing the quality of the wiper blade.
12. A method as claimed in claim 1 or 3, in which boundary conditions based on actual traffic situations, such as illumination of the screen which occurs when travelling at night with oncoming traffic, are created for the purpose of assessing the quality of the screen.
13. A method as claimed in any of claims 1 to 9, in which boundary conditions departing from reality, such as an unrealistically illuminated screen, are taken into account when processing the measured values and when determining the comparison values and/or characteristic quantities prescribed for assessing the quality of the wiper blade or the quality of the surface of the screen.
14. A method as claimed in any of claims 1 to 13, in which by the position, the focal length and the size of the aperture of the diaphragm of its image-forming optics, and the distance thereof from the photo-sensitive coating of its image converter, the image sensor reproduces the wiping field or the screen out of focus, analogously to the eye of the driver of a motor vehicle.
15. A method as claimed in any of claims 1 to 14, in which a measurement of the distribution of the stray light departing from the features of claim 14 is accurately or approximately compensated for during processing of the measured values.
16. A method as claimed in any of claims 1 to 1 5, in which the values or characteristic quantities prescribed for comparison with the measured place- and time-dependent or place-dependent values of the intensity of the stray light, or characteristic quantities derived therefrom, take into account the characteristics of the human visual system and the tasks of the driver in-actual traffic.
17. A method as claimed in any of claims 1 to 16, in which the prescribed comparison values, characteristic quantities or the parameters, determining the processing of the measured values, of boundary conditions which themselves vary, are automatically adapted, for example before every series of measurements, and that the determination of the actual boundary conditions necessary for this purpose is performed by control measurements such as with wiper blades or on screens of known quality or by controlled measurements of individual parameters such as the degree of wetting of the washing fluid and surface of the screen, the illumination of the surrounding field etc.
18. A method as claimed in any of claim 1 to 17, in which the assessment of the quality of the wiper blade or of the quality of the surface of the screen is confined to that portion of the wiping field or of the screen which is located in the central field of vision of the driver.
1 9: A method as claimed in any of claims 1 to 1 8, in which the place-dependent of the intensity of the stray light is determined one-dimensionally, for example in a radially symmetrical wiping field along a diameter of the wiping field, in some or a few representative regions of the wiping field or of the screen.
20. A method as claimed in claim 1, in which the residues of the washing fluid remaining in the wiping field are detected by comparing the distribution of the luminous density measured in reflection during the wiping operation with that of the dry screen, and that the place and/or the disappearance with respect to time of the residues of the washing liquid, conditioned by the effects of evaporation, are evaluated for the purpose of assessing the wiping quality.
21. A method as claimed in claim 1 or 20, in which the assessment of the quality of the wiper blade is confined to the central region of the wiping field.
22. A method as claimed in claims 1,20 or 21, in which for the purpose of assessing the quality of the wiper blade, the residues left in the wiping field are determined and evaluated onedimensionally, for example in a radially symmetrical wiping field along a diameter of the wiping field, in one or a few representative regions of the wiping field.
23. A method as claimed in any of claims 1 to 22, in which a camera having a conventional camera tube, such as a Vidicon, or having a semiconductor transducer, such as a CCD array, is used as the image sensor.
24. A method as claimed in any of claims 1 to 23, in which the place- and time-dependent or the place-dependent light intensity is detected by several image sensors.
25. A method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen substantially as hereinbefore described with reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792932461 DE2932461A1 (en) | 1979-08-10 | 1979-08-10 | METHOD FOR EVALUATING THE QUALITY OF THE WIPER BLADE / DISC SURFACE SYSTEM |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2056059A true GB2056059A (en) | 1981-03-11 |
Family
ID=6078136
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8025864A Withdrawn GB2056059A (en) | 1979-08-10 | 1980-08-08 | A method of assessing the quality of a system comprising a wiper blade and the surface of a windscreen |
Country Status (5)
| Country | Link |
|---|---|
| BE (1) | BE884706A (en) |
| DE (1) | DE2932461A1 (en) |
| FR (1) | FR2466767A1 (en) |
| GB (1) | GB2056059A (en) |
| IT (1) | IT8023865A0 (en) |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4558590A (en) * | 1984-04-27 | 1985-12-17 | International Business Machines Corporation | Method for measuring the real contact area in connectors |
| GB2229269A (en) * | 1989-02-16 | 1990-09-19 | Atomic Energy Authority Uk | Surface moisture detection |
| EP0589680A2 (en) * | 1992-09-24 | 1994-03-30 | Trico Products Corporation | Wipe analysis system |
| WO1999014088A1 (en) * | 1997-09-16 | 1999-03-25 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US6313457B1 (en) | 1999-01-25 | 2001-11-06 | Gentex Corporation | Moisture detecting system using semiconductor light sensor with integral charge collection |
| US6379013B1 (en) | 1999-01-25 | 2002-04-30 | Gentex Corporation | Vehicle equipment control with semiconductor light sensors |
| US6524968B2 (en) | 2001-07-06 | 2003-02-25 | Oki Electric Industry Co., Ltd. | Method for forming insulating film and for manufacturing integrated circuit |
| US6617564B2 (en) | 2001-10-04 | 2003-09-09 | Gentex Corporation | Moisture sensor utilizing stereo imaging with an image sensor |
| US6681163B2 (en) | 2001-10-04 | 2004-01-20 | Gentex Corporation | Moisture sensor and windshield fog detector |
| EP1507138A3 (en) * | 2003-08-12 | 2005-04-13 | Hitachi, Ltd. | Image processing system |
| US7019275B2 (en) | 1997-09-16 | 2006-03-28 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US8620523B2 (en) | 2011-06-24 | 2013-12-31 | Gentex Corporation | Rearview assembly with multiple ambient light sensors |
| US9207116B2 (en) | 2013-02-12 | 2015-12-08 | Gentex Corporation | Light sensor |
| US9224889B2 (en) | 2011-08-05 | 2015-12-29 | Gentex Corporation | Optical assembly for a light sensor, light sensor assembly using the optical assembly, and vehicle rearview assembly using the light sensor assembly |
| WO2015197253A1 (en) * | 2014-06-27 | 2015-12-30 | Robert Bosch Gmbh | Device and method for checking windscreen wiper blades |
| US9870753B2 (en) | 2013-02-12 | 2018-01-16 | Gentex Corporation | Light sensor having partially opaque optic |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7237445B1 (en) * | 2004-12-21 | 2007-07-03 | Ford Global Technologies, Llc | Test fixture for the aging of wiper blades in a laboratory |
| CN102141470B (en) * | 2010-12-30 | 2012-05-23 | 西安庆安电气控制有限责任公司 | Test method of scraping capability of windscreen wiper and device thereof |
| DE102012024547B4 (en) | 2012-12-17 | 2018-07-05 | Cbb Software Gmbh | Method for determining a quality of a windscreen wiper system |
| CN112977342B (en) * | 2021-03-29 | 2022-05-03 | 奇瑞汽车股份有限公司 | Wiper scraping degree detection method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH535430A (en) * | 1971-02-17 | 1973-03-31 | Gretag Ag | Method and device for the detection of dust-like particles |
| GB1395113A (en) * | 1973-03-16 | 1975-05-21 | Standard Telephones Cables Ltd | Detecting obscuring matter on transparent screens |
| DE2741321C3 (en) * | 1977-09-14 | 1981-05-27 | Wibau Industrie und Verwaltung GmbH, 6466 Gründau | Method for determining the particle size distribution of a falling or flowing stream of material by recording and evaluating video images |
-
1979
- 1979-08-10 DE DE19792932461 patent/DE2932461A1/en not_active Withdrawn
-
1980
- 1980-07-31 FR FR8016981A patent/FR2466767A1/en not_active Withdrawn
- 1980-08-01 IT IT8023865A patent/IT8023865A0/en unknown
- 1980-08-08 GB GB8025864A patent/GB2056059A/en not_active Withdrawn
- 1980-08-08 BE BE0/201698A patent/BE884706A/en unknown
Cited By (38)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4558590A (en) * | 1984-04-27 | 1985-12-17 | International Business Machines Corporation | Method for measuring the real contact area in connectors |
| GB2229269A (en) * | 1989-02-16 | 1990-09-19 | Atomic Energy Authority Uk | Surface moisture detection |
| GB2229269B (en) * | 1989-02-16 | 1993-04-21 | Atomic Energy Authority Uk | Surface moisture detection |
| EP0589680A2 (en) * | 1992-09-24 | 1994-03-30 | Trico Products Corporation | Wipe analysis system |
| EP0589680A3 (en) * | 1992-09-24 | 1994-06-01 | Trico Products Corp | Wipe analysis system |
| US7485844B2 (en) | 1997-09-16 | 2009-02-03 | Gentex Corporation | System and method for controlling vehicle equipment by determining spatial composition of an image of a vehicle window |
| US6946639B2 (en) | 1997-09-16 | 2005-09-20 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US6097024A (en) * | 1997-09-16 | 2000-08-01 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US6262410B1 (en) | 1997-09-16 | 2001-07-17 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US7019275B2 (en) | 1997-09-16 | 2006-03-28 | Gentex Corporation | Moisture sensor and windshield fog detector |
| WO1999014088A1 (en) * | 1997-09-16 | 1999-03-25 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US7199346B2 (en) | 1997-09-16 | 2007-04-03 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US6495815B1 (en) | 1997-09-16 | 2002-12-17 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US5923027A (en) * | 1997-09-16 | 1999-07-13 | Gentex Corporation | Moisture sensor and windshield fog detector using an image sensor |
| CN1116187C (en) * | 1997-09-16 | 2003-07-30 | 金特克斯公司 | Moisture sensor and windshield fog detector |
| US6469291B2 (en) | 1999-01-25 | 2002-10-22 | Gentex Corporation | Moisture detecting system using semiconductor light sensor with integral charge collection |
| US6742904B2 (en) | 1999-01-25 | 2004-06-01 | Gentex Corporation | Vehicle equipment control with semiconductor light sensors |
| US6379013B1 (en) | 1999-01-25 | 2002-04-30 | Gentex Corporation | Vehicle equipment control with semiconductor light sensors |
| US6313457B1 (en) | 1999-01-25 | 2001-11-06 | Gentex Corporation | Moisture detecting system using semiconductor light sensor with integral charge collection |
| US6524968B2 (en) | 2001-07-06 | 2003-02-25 | Oki Electric Industry Co., Ltd. | Method for forming insulating film and for manufacturing integrated circuit |
| US6853897B2 (en) | 2001-10-04 | 2005-02-08 | Gentex Corporation | Windshield fog detector |
| US6861636B2 (en) | 2001-10-04 | 2005-03-01 | Gentex Corporation | Moisture sensor utilizing stereo imaging with an image sensor |
| US6681163B2 (en) | 2001-10-04 | 2004-01-20 | Gentex Corporation | Moisture sensor and windshield fog detector |
| US6617564B2 (en) | 2001-10-04 | 2003-09-09 | Gentex Corporation | Moisture sensor utilizing stereo imaging with an image sensor |
| EP1507138A3 (en) * | 2003-08-12 | 2005-04-13 | Hitachi, Ltd. | Image processing system |
| US7208723B2 (en) | 2003-08-12 | 2007-04-24 | Hitachi, Ltd. | Image processing system which processes an image captured by an imaging device through a lens having a focus which is adjusted to a point beyond the glass |
| US7247838B2 (en) | 2003-08-12 | 2007-07-24 | Hitachi, Ltd. | Rain/moisture and object imaging system for vehicle |
| US8620523B2 (en) | 2011-06-24 | 2013-12-31 | Gentex Corporation | Rearview assembly with multiple ambient light sensors |
| US9224889B2 (en) | 2011-08-05 | 2015-12-29 | Gentex Corporation | Optical assembly for a light sensor, light sensor assembly using the optical assembly, and vehicle rearview assembly using the light sensor assembly |
| US9207116B2 (en) | 2013-02-12 | 2015-12-08 | Gentex Corporation | Light sensor |
| US9870753B2 (en) | 2013-02-12 | 2018-01-16 | Gentex Corporation | Light sensor having partially opaque optic |
| US9961746B2 (en) | 2013-02-12 | 2018-05-01 | Gentex Corporation | Light sensor |
| US11006502B2 (en) | 2013-02-12 | 2021-05-11 | Gentex Corporation | Light sensor |
| US11017741B2 (en) | 2013-02-12 | 2021-05-25 | Gentex Corporation | Light sensor having partially opaque optic |
| WO2015197253A1 (en) * | 2014-06-27 | 2015-12-30 | Robert Bosch Gmbh | Device and method for checking windscreen wiper blades |
| CN106461564A (en) * | 2014-06-27 | 2017-02-22 | 罗伯特·博世有限公司 | Device and method for checking windscreen wiper blades |
| US20170138865A1 (en) * | 2014-06-27 | 2017-05-18 | Robert Bosch Gmbh | Device and method for checking windshield wiper blades |
| US10551324B2 (en) | 2014-06-27 | 2020-02-04 | Robert Bosch Gmbh | Device and method for checking windshield wiper blades |
Also Published As
| Publication number | Publication date |
|---|---|
| BE884706A (en) | 1980-12-01 |
| FR2466767A1 (en) | 1981-04-10 |
| DE2932461A1 (en) | 1981-02-26 |
| IT8023865A0 (en) | 1980-08-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |