JP2003513852A - Window glass wiping device for wiping window glass and driving method thereof - Google Patents

Abstract

SUMMARY A method for wiping a window glass 12, and in particular a window wiping device with an active adjustment stage for the compensation of periodic disturbances, is shown. For this purpose, a chattering compensation stage 22 is incorporated in the windowpane wiping device in addition to the general position controller 20.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION The present invention relates to a window glass wiping device of the type described in the preamble of the independent claims.

It has long been known that windowpane wiping devices tend to "chatter", especially in relatively dry windowpanes. This chattering tendency of wiper blade rubbers depends on a number of mechanical parameters. It is a vibrating system with different elasticity (wiper blade, wiper arm, linkage)
And the external force, for example-depending on the friction value between the rubber and the window glass and the wiper blade mounting force-on the window glass, and the drive output of the wiper motor. The wiper motor drives the wiper blade via the linkage and the wiper arm. The wiping rubber generates a frictional force depending on its mounting force on the window glass and the friction value of the window glass.

Under certain operating conditions, for example when the window glass is relatively dry, a so-called “adhesion / slip effect” occurs. In that case, in the "adhesion / state", the frictional force gives resistance to the wiping rubber, and the speed of the wiping rubber on the window glass is reduced.

Meanwhile, the wiper motor continues to introduce torque into the system via the wiper arm and linkage. This elastically preloads the components, in particular the linkage, the wiper arm and the wiper blade.

At the moment when the drive torque at the wiper blade becomes greater than the friction torque, the static friction of the wiping rubber is overcome and the wiping rubber is released from its adhesion on the window glass. In this "slip-state", the elastically preloaded component releases its stored energy due to the preload, which significantly accelerates the wiper blade.

The transition from static friction to sliding friction reduces the friction value, which causes the system of wiper arms and wiper blades to advance faster than they should be, which results in excessive vibration. When the elastic energy is exhausted, the wiper blade is braked again and adheres to the window glass again
The slip cycle is started.

This chattering behavior has hitherto been known, for example, in US Pat. No. 4,793,020.
It is intended to be restrained by the most advantageous design of mechanical components as shown in the specification.

ADVANTAGES OF THE INVENTION With the method according to the invention according to the features of claim 1, turbulences due to the influence of external forces can be corrected quickly and accurately, which is particularly advantageous on a window glass. It has been proved that the chattering of the wiper blade of the above is effectively prevented.

The measures defined in the dependent claims result in advantageous refinements and improvements of the method defined in the main claim.

If the turbulence is a turbulence that is repeated or oscillates in a short time, such as the case of chattering of a wiper blade on a window glass, it is possible to take measures beforehand to prevent the turbulence. In that case, it seems to be particularly advantageous to drive and control the wiper motor in the opposite phase with respect to the oscillating disturbance. This is because in that way a uniform movement of the wiper arm along the desired trajectory is obtained.

If the method is carried out by means of an active regulation stage, for example by a vibration compensation controller, various long-lasting periodic disturbances are well eliminated. The vibration compensation controller can be learned, for example, and can be formed as a neural network and also as a fuzzy logic, whereby an adaptive property is obtained.

The use of the wiper motor's auxiliary variable, in particular the electric charge I, as the adjusting variable for the active adjusting stage obviates the need for other sensors in the wiper motor, which reduces costs and wear. It

If the position signal is used as the adjusting variable for the active adjusting stage, maximum accuracy is obtained at high cost. This is because modern wiper motors often already have position sensors. However, the position sensor can also be attached to the wiper linkage itself. Furthermore,
It is also possible to attach an acceleration sensor coupled to the control device to the wiper arm or wiper linkage.

A control device with a frequency selection stage made transparent to the frequencies typical of wiper blade chattering is particularly advantageous if the frequency selection stage is designed as a bandpass filter. Was demonstrated. Frequencies that do not characteristically match the disturbance to be compensated are eliminated. Not only that, bandpass filters are available as mass-produced products of reasonable quality and cost-effective.

The use of phase shifting elements also appears to be another advantage. The phase shifting element precisely adjusts the phase of the output of the active regulation stage. Advantageously, the phase shifting element is formed as a low frequency filter. This is because this low frequency filter is likewise available as a mass-produced product of comparable quality.

Furthermore, it has proved to be advantageous to implement the entire above-mentioned group of components, such as the phase-shifting element, the frequency selection stage and the differential unit, on the basis of software internal to the control unit. .

DESCRIPTION OF THE EMBODIMENTS FIG. 1 is a schematic view of a window glass wiping device for carrying out the method according to the invention according to claim 1. The wiper blade 10 is driven by the wiper motor 14 via the motor shaft 15 to move on the window glass 12. Wiper motor 1
A position sensor 16, for example a Hall sensor or a resistive sensor, is provided in 4 and this sensor emits a signal via the position of the motor shaft 15.
This position signal 17 is received by the controller 18. The control device 18 includes, for example, a position controller 20 and a chattering compensation stage 2 as active adjustment stages.
2 and. The chattering compensation stage 22 is a differential unit 24.
And a frequency selection stage 26 and a phase shifting element 28.

In FIG. 2, the motor speed ω is plotted over time for three wiping cycles when the wiper blade 10 is “chattering” on the window glass. This signal has a large vibration of amplitude A due to the reciprocating movement of the wiper blade 10 between the two reverse positions on the window glass. The amplitude A is controlled by the position controller 20.

Furthermore, the curve has harmonic vibrations of relatively high frequency and relatively small amplitude, which are due to chattering of the wiper blade 10,
And it is transmitted into the wiper motor 14 through the linkage of the window glass wiping device.

When the wiping rubber adheres, the friction torque increases, which reduces the rotation speed and thus the motor speed. This increases the current reception at the wiper motor in this "sticking" state.

The current I of the wiper motor 14 has to be increased further for a short time in order to minimize the duration of deposition, that is to say the time interval during which the wiping rubber 11 is deposited on the window glass 12.

When the wiping rubber 11 is separated from the window glass 12 in the subsequent “slip” state, the wiper blade 10 is accelerated by the released elastic energy. As a result, the rotation speed n of the motor increases.

In order to reduce system over-vibration, the motor current I must be reduced at this moment. In short, the system must be braked by the wiper motor 14.

For this reason, the position sensor signal of the wiper motor 14 is introduced into the chattering compensation stage 22 which serves as a disturbance compensation component. In order to improve the signal quality, a single or plural time sweeping of the signal is performed in the differential unit 24. However, this is in principle not important for the function of the active regulation. Then
The signal is introduced into a frequency selection stage 26, eg a bandpass filter. This bandpass filter transmits typical frequencies for chattering and specifically eliminates the amplitude A due to the reciprocating wiping movement between the two reversal positions of the wiper blade. The following phase-shifting element 28 correspondingly adapts the phase of the transmitted signal to the compensation characteristics described above and correspondingly applies the input current I of the wiper motor 14.

As a result, in short, the input current I of the wiper motor 14 as the output of the position controller 20 is applied by the output of the chattering compensation stage 22.

When the position signal is not supplied, the chattering behavior is the wiper motor 1
It can be perceived and compensated based on the current I received by 4. This current has a behavior similar to that seen in FIG.

The chattering compensation stage 22 can also be formed as an active adjustment stage, for example. A compensating controller of this kind as an adjusting stage is described, for example, in DE-A 1974 0153. This active regulation stage recognizes and compensates for periodic disturbances.

Furthermore, an acceleration sensor can be mounted on the wiper linkage, as is known from unpublished German patent DE 198 45 674, and the signal of the acceleration sensor is fed to the chattering compensation stage 22 for evaluation. Can be supplied. In this way, the motor is startup-controlled in a timely manner so as to prevent the adhesion / slip behavior.

[Brief description of drawings]

[Figure 1]   1 is a schematic view of a window glass wiping device according to the present invention.

[Fig. 2]   FIG. 5 is a velocity diagram of a wiper motor over time t.

─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Klaus Fleischer             Germany Buhl Robert             -Schumannstrasse 2 F term (reference) 3D025 AC01 AD02 AE02 AE57 AG02                       AG44

Claims (19)

[Claims] 1. A wiper motor (14) controlled by a controller (18)
For wiping the window glass (12), in particular the vehicle windshield, by means of at least one wiper blade (10) driven by the window glass (12) to move along the window glass and which disturbs a uniform target movement. A method for driving a windowpane wiping device for wiping a windowpane, characterized in that the disturbance is actively prevented. 2. A method according to claim 1, characterized in that disturbances that are repeated or oscillate in a short time are prevented. 3. Method according to claim 1, characterized in that the disturbance is prevented by an active adjustment stage. 4. Method according to claim 3, characterized in that the active regulation stage serves intelligent features, in particular fuzzy logic or neural networks. 5. A parameter of the wiper motor (14), in particular a position signal (17).
), An acceleration signal, or the current (I) received by the wiper motor serves as a tuning variable for the active tuning.
The method described. 6. The method according to claim 1, wherein the turbulence is selected by a frequency selection stage. 7. The disturbance disturbance is effected in phase, in which case this is effected by a phase-shifting element (28), in particular a low-frequency filter.
7. The method according to any one of 1 to 6. 8. A windowpane wiping device, in particular for carrying out the method according to any one of claims 1 to 7, wherein at least one wiper blade (10) moves along the windowpane (12). A control device of the type having at least one wiper motor (14) for moving at least one wiper blade (10) and an electronic control device (18) for controlling the wiper motor (14). A windowpane wiping device for wiping a windowpane, characterized in that (18) has at least one component (22) that compensates for disturbances. 9. The window glass wiping device according to claim 8, wherein the control device has an active adjustment stage. 10. A windscreen wiper according to claim 9, characterized in that the auxiliary variable of the wiper motor (14) serves as an adjusting variable for the active adjusting stage. 11. A windscreen wiper according to claim 9, characterized in that the current (I) received by the wiper motor (14) serves as an adjusting variable. 12. A windscreen wiper according to claim 9, wherein the position signal (17) of the wiper motor (14) serves as an adjustment variable. 13. The window glass wiping device according to claim 8, wherein a turbulence that repeats or vibrates in a short time is prevented. 14. A wiper motor (18) is provided so that the control device (18) prevents turbulence.
14. A control device (18) for controlling startup of 14).
The window glass wiping device according to any one of 3 to 3. 15. The controller (18) comprises at least one frequency selection stage (26).
) Is included, The window glass wiping device of any one of Claim 8 to 14 characterized by the above-mentioned. 16. A window wiping device according to claim 15, characterized in that the frequency selection stage (26) comprises at least one band filter. 17. Controller (18) comprises at least one phase shifting element (2).
8) The window glass wiping device according to any one of claims 8 to 16, further comprising: 18. A windscreen wiper according to claim 17, characterized in that the phase-shifting element (28) comprises at least one low-frequency filter. 19. Disturbance compensation component (22) is formed at least partly as a computer program stored in a computer unit. Window glass wiping device.