Device for controlling a windscreen wiping system

0001The present invention is directed to a according to the preamble of the main claim conceived means for controlling a Windscreen wiper system of, as it is known from US-A-4,317,073.

0002Such devices are provided, in particular one on the front or the rear window of a motor vehicle existing liquid or solid covering high and quantitatively detect and depending on one of the Disc associated wiper system to automatically influence, ie, the same for cleaning the pane in particular at intervals to put into operation.

0003From DE 33 14 770 C1 discloses a device for controlling a famous wiper motor, the optoelectronic Sensor device and a connected to the drive motor having circuitry such that on in response to the the disk existing lining a control of the drive motor can be made. This device has However, no means to which a determination of a final causing cleansing of the measuring range of the sensor device About last wiping operation based on allowed a wipe cycle. Thus, the device, the wipe cycle frequency Although the during wiper operation quantitatively changing states of the coating on the disk, such as. for example, degree of soiling, volume terms impingement of rain or snow, reasonably unpassed satisfactory automatically. Accurate automatic Adjusting the wiping cycle frequency high in itself and is quantitatively changing states of the coating on the disc However unsatisfactory possible. In addition, such facilities to control enters a Wiper system under certain conditions a hectic Switching on and off or a hectic back and forth between the intermittent wiper operation and the duration of the wiping operation Drive motor on. This is for the motor vehicle user at least very used to, but is also able lead to unpleasant irritation. Furthermore, this has Means no means a determination of the Disc impinging raindrops regarding their size allows. An accurate automatic adjustment of Wiping cycle frequency to be different by the Size of the raindrops impinging resultant different deterioration degree of visibility However, because of the relative to the disc relatively small Measuring surface of the sensor device is not satisfactorily possible. Thus, the vehicle user in the one case the feeling that slightly too frequently and in the other case the feeling that is slightly too infrequently wiped.

0004The present invention therefore has for its object, a device for controlling a windscreen wiper system to provide that the wiping cycle frequency automatically be qualitatively and / or quantitatively changing states of the on the Disc existing coating adapts very sensitively.

0005According to the invention this object is achieved by the dissolved specified main claim. Advantageously, in such an embodiment of a device for controlling a wiper system is that its Switch assembly without a separate switching level for the Interval wiping operation manages, because the device automatically in the switching stage continuous wiping I also intermittent wiper operation the wiper system in accordance with the on the disk existing coating takes over. There are thus at the Switch arrangement only the wiper stages wiper off, Automatic with features intermittent wipe and continuous wiping in the speed I and continuous wiping in Speed ​​II. A significant wiring effort is thus saved.

0006Furthermore, it is particularly advantageous that wiping cycles with harmonious wipe cycle nature arise so that the Motor vehicle user clearly tolerable input or Ausschaltaktivitäten and switching activities between the enter interval wiping operation and the continuous wiping operation and namely in that the circuit arrangement for influencing the Drive motor with a turn-on and a Off threshold for the intermittent wiper operation and an of various other off threshold for the Continuous wiper operation is provided.

0007In addition, is particularly favorable when the wiping operation of a Wiper system as a function of the disc impinging rain forms (large or small raindrops) Voted particularly sensitive is without it a Enlargement of the measurement surface of the sensor device needs. This is achieved in that the switch arrangement having a at least two counter elements Rain shape detection equipment is provided, wherein the Rain form detection means only of the Sensor means during the recording period emitted signals are detected that a predetermined exceed speed of change. In these, the Changing speed border signals detected the Rain form detection means the amplitude of the signal change, wherein in the case where the amplitude is below a specified limit remains a quantified change in the one of the two counter elements is performed and when the Amplitude on this determined threshold goes to a quantified change in the other of the two counter elements shows the contents of the two counters for elements Establishing a wiping strategy of the circuitry be evaluated and to a maximum just before the start of a new Me recording period stored.

0008Further advantageous embodiments of the invention Object are specified in the subclaims and will be with reference to an illustrated in the drawing explained embodiment example. show case<dl tsize="7"><dt>Fig. 1</dt><dd>a block diagram of a windshield wiper system</dd><dt>FIG. 2</dt><dd>a functional diagram with a typical by a sensor device with respect a covering waveform generated</dd><dt>Fig. 3</dt><dd>a functional diagram of a Switch arrangement and a drive motor connected switching contact means</dd><dt>Fig. 4</dt><dd>a diagram with the different switch-on or off thresholds</dd><dt>Fig. 5</dt><dd>a diagram in which the lifting of the Switch-on is shown </dd><dt>Fig. 6</dt><dd>a diagram showing an a typical more specific form rain Waveform, and the corresponding wiper function</dd><dt>Fig. 7</dt><dd>a diagram showing a further for a certain rain form typical waveform, and the corresponding wiper function</dd></dl>As is apparent from the drawing, a device for Controlling a windscreen wiper system essentially consists of a Switch arrangement 1, an optoelectronic sensor device 2 and a circuit 3 via the switch assembly 1 on the one hand, the sensor device 2 or the Circuitry 3 and on the other hand, the Windshield wiper arms and the wiper blades 5 actuatable Driving motor 4 is activated. The drive motor 4 is a associated switching contact device 6, through which for the 3 circuitry associated runtime detection arrangement detecting the parking position and the start or end signal the maturity of the wiper blades 5 is possible addition the circuit arrangement has an integrated 3, as Signal pattern recognition arrangement trained agents and a at least two counter elements having Rain shape detecting device 8.

0009As is apparent in particular from FIG. 1, must for activating the wiper system, the switch assembly 1 from its brought switching stage from O in their shift stage automatic A will. In the automatic switching stage A, the functions Interval wiping and continuous wiping in the speed level I united. In addition, the switch assembly 1 can in the Switching stage continuous wiping II are brought, in the operated windshield wiper system in the speed II becomes. If the switch assembly 1 in its switching stage brought automatic A, is to form a Output reference value definitely a wipe cycle t triggered. Located with activated switching stage A covering an automatic (for example, rain) on the outer surface of the Disk 7, so one of the two passes through the windshield wiper blades 5 to clean the outer surface during a wiping cycle t twice over the measurement range of the sensor device 2. The Sensor device 2 is structured optoelectronic or is opto-electronically operated and is on the inner surface of the Plate 7 is attached so that the windshield wiper blade 5 not in direct contact with the sensor device 2 comes. After this Start a wiping cycle t is first the range of Sensor device 2 during startup and then for the second time wiped over the running back from the windshield wiper blade 5 and therefore cleaned twice. Detects the circuit 2 by the Signals of the sensor device 2 according to the second About wiping operation during a wiping cycle t a again, the view debilitating covering (eg rain) on the outer surface of the disc 7, then, after the wiper blade 5 has reached its parking position has (end of the wiping cycle t), once a new wipe cycle t started. Detects the circuit 3 by the Sensor device 2 but after the second wiping operation over during a wiping cycle t a recently, the view in small scale debilitating covering (eg light rain) on the outer surface of the disc 7, so, after the Wiper blade 5 has reached its parking position (end of Wiping cycle t), this particular for a time (Interval pause tp) by the switching contact 6 in the Park position held. The length of the interval pause tp in dependence of the newly on the disc 7 forming Covering (rain intensity) after every wiping cycle determined. This control of the drive motor 4 to make can be represented by the space available on the disk 7 Covering (eg rain) generated signals of the sensor device 2 the circuit 3 supplied. A change of the signals is by changing qualitatively and / or quantitatively States of the coating caused by the supplied resulting signals of the circuit 3 and are converted by this into control signals, represented by the Operation of the drive motor 4 is affected accordingly. To the space and cabling costs as low as possible keep the sensor device 2 and the Circuitry 3 with its essential elements in a common housing. For evaluating the signals the sensor device 2 includes the circuitry 3 a microprocessor.

0010Thus, the wipe cycle frequency qualitatively and / or quantitatively changing conditions of the present on the disc 7 Coating (eg rain) can be set in a particularly sensitive can, is a precise determination of the valuation time and Review duration of the coating through the circuitry 3 necessary.

0011As is apparent in particular from FIG. 2, on the basis of Sensor signal curve will be recognized when the Wiper blade 5 the measuring range of the sensor device 2 has wiped over. This can be the typical course of Signals for both the first and the second Wiping of the windshield wiper blade 5 during a Wiping cycle t be recognized.

0012To accurately as possible reproducible evaluation conditions obtained, it is therefore on the one hand necessary that the Review the information presented on the plate 7 covering only of the sensor device 2 to the circuit arrangement 3 emitted signals for influencing the driving motor 4 are used, which starting from the time shortly after the About last wiping operation by introducing a new Wiping cycle t is generated by the sensor device the second In this case, a new wipe cycle t is initiated when the signal the sensor device 2 a certain threshold below. However, uncertainty can occur if qualitatively by specific and / or quantitatively occurring states of the covering (for example, rain) on the disc 7 Waveforms are generated that of the typical curve Signals for about wiping the windshield wiper blade 5 are very similar, so that in very rare cases Malfunctions can not be completely ruled out. So is on the other hand to the consideration of certain qualitative and / or quantitative status of the coating (eg rain) on the disc 7 is particularly advantageous in that in addition in front of the Wiping over the measurement range of the sensor device 2 Time region of the wiping operation of the circuit 3 is known in advance.

0013For recognition of the time range of the last wiper crossing process of a wipe cycle t is in the circuit arrangement integrated 3 a runtime detection arrangement. The Duration detection means receives from the contactor 6 the information on when the windscreen wipers 5 their Park position left (start signal), whereby a wiping cycle t is initiated and when the wiper blades 5 their Park position reassume (end signal), whereby this Wipe cycle t is finished. The total active time of the Switching contact means 6 thus corresponds to the total Maturity of the wiper blades 5 during a Wiping cycle t.

0014Thus the circuitry 3 the last wiper crossing operation, of a wipe cycle t, can predetermine exactly is the wipe cycle t of the runtime detection arrangement in individual running times t1 and t2 divided. The duration t1 corresponds to the period from the start signal (ramp-up of Windshield wiper blades 5) of a wiping cycle t to Reaching a measuring range of the sensor device 2 ( Wiping over the measuring range has just not yet begun) and the running time t2 corresponds to the time interval between the Conclusion of the second over-wiping operation (a second Wiping over the measuring range has just been completed) to the termination signal of the wiping cycle t (the wiper blades 5 take their parking position again). The two maturities t1 and t2 are up to negligible small differences of its value almost identical. To determine the two running passing t1 and t2 is - as described above - the entire active time the switching contact means 6 detects this entire active Time of the switching contact means 6 is equipped with a Wiper system specific factor X acted upon so that yields the value for the running OPENING HOURS t1 or t2. With these time values ​​is the circuit 3 in a position calculate the time of the second over-wiping operation or vorberzubestimmen. Factor X is as dependent on the Position of the sensor device 2 to the disc 7 and the Specialty for windshield wiper systems specific ratios. It is important that the factor X on the entire duration a wiping cycle t of the wiper system is normalized, so regardless of eg voltage fluctuations, Aging effects to be temperature changes, etc.. The Runtime detection arrangement and the Signal pattern recognition arrangement are another such linked so that over the life of the wiper system an automatic adjustment of factor X. A automatic adjustment will be made if the Circuitry 3 regularly detects a wiping, which no longer falls within the predetermined time range.

0015Fig. 2 illustrates in a functional diagram of a typical, with respect to an existing on the disk 7 Surface of the sensor device 2 output waveform. On the X-axis of the function chart is the time and applied to the Y-axis of the state of the disc. 7 If the state of the disk 7 as the rain changes Also, the signal value generated by the sensor device 2 with activated switch assembly 1 in the switching stage Automatic A. After a certain period it comes to that the signal value of the sensor device 2, the fixed Threshold below. A wipe cycle t is thus triggered automatically. The signal value falls as further due occurring rain pretty continuously, up to the Time when the windshield wiper blade 5 the measuring range of the has reached the sensor device 2 for the first time. The far elapsed time corresponding to the duration t1. Of the Signal value of the sensor device 2 now drops abruptly because the windshield wiper blade 5 the measuring range for the first time wiped over while a portion of the coating as rain right pushes. The measuring range is after the initial wiping cleaned, whereby then the signal value of the sensor device 2 abruptly rises again. Then the coating eg built by Rain continuously again, whereby the signal value continuously decreases again until the windshield wiper blade 5 to the second time reached the measuring range of the sensor device 2 Has. The signal value of the sensor device 2 falls again abruptly, because the wiper blade the measuring range to second time on wipes, as concerns part of itself eg pushes the rain newly formed coating on. The measuring range of the sensor device 2 is after the second About wiping again cleaned, whereby the signal value turn abruptly rises. The length of time the Wiper blade 5 needed immediately after the second About wiping operation to return to its parked position, corresponding to the duration t2.

0016As is particularly apparent from Figures 2 and 3, begins the active period of the switching contact means 6 with the Initiating a wiping cycle t. The already defined Running times t1 and t2 are just as active time Switching contact means 6 as between these two Running times t1 and t2 lying maturities t3. The Running times t1 and t2 and the maturity range t3 thus represent the one wiping cycle t in question total active time of Switching contact device is. 6 Optionally, per se a wipe cycle t to a pause interval tp. each Wipe cycle t the duration t2 of the circuit arrangement 3 exploited to the switching threshold of a function determined reference value reschedule. By contrast, the Duration t2 and optionally the interval pause tp of the Circuitry 3 exploited to the decision when a new wipe cycle is to be triggered. The shortly after the second about wiping within the Duration t2 adjusting maximum signal value of Sensor device 2 is, for the next wiping cycle t as new reference value is read into the circuitry. 3 Depending on this reference value is automatically as the Start value for the subsequent wiping cycle t serving defined threshold, the magnitude of which about 95% of new reference value is.

0017If the switching threshold at least on reaching the Parking position of the wiper blades 5 by, for example, rain newly forming plaque on the signal value of Sensor device 2 undershot again, so is the Circuitry 3 immediately a new wipe cycle t initiated. If the switching threshold is reached with the Parking position of the windshield wiper blade 5 from the signal value of Sensor device 2 but not below, concludes at the duration t2 Interval pause of tp. The Interval pause tp results as a function of time, elapses until the by the newly forming plaque, as rain caused signal value of the sensor device 2 is undershot.

0018Should during the maximum for the interval break specified period of time (eg one minute) not to sufficient to form a coating, for example come in the rain, so that the signal value of the sensor device 2, the switching threshold not below, is definitely a new wipe cycle t triggered. is the triggering of a new wiping cycle t on the one hand to the formation of a new to enable output reference value and on the other hand this to indicate to the user that the switch assembly 1 in its switching stage automatic A is. Optionally, it is necessary in this situation, the switch assembly 1 in its bringing switching stage from O to disturbing wiping cycles t to avoid.

0019As already described, on the one hand by the typical Extending the sensor signals and by the Signal pattern recognition arrangement of the second over-wiping of Windshield wiper blade 5 on the range of Sensor device 2 are detected. On the other hand, this is by the duration detection means possible that a total wipe cycle t in individual running times t1 and t2 breaks down. The duration t1 corresponds to the time period starting from the starting signal of a wipe cycle t to reach the measuring range of Sensorvorr ichtung 2. The duration t2 corresponds to the time period between the completion of the second Via wiping operation until reaching the parking position of the Windshield wiper blades 5. The duration t2 and optionally Interval pause tp is inclined by the circuitry 3 exploited in order to decide when a new wipe cycle to be triggered. The normally shortly after the About the second wiping operation during the term t2 adjusting maximum signal value of the sensor device 2 is for the next wiping cycle t as a new reference value in the Circuitry 3 is read. Depending on this Reference value will automatically as the start value, as Switching value or a switch-off for the following Wipe cycle t serving on threshold and the Off threshold for the intermittent wiper operation and Another turn-off for the continuous wiping operation set. If during the entire measurement period, however, as by evaporating streaks a higher maximum signal value result, it will be as a new reference value in the Circuitry 3 is read.

0020As is apparent in particular from FIG. 4, is located - Its commitment to clean state of the disk 7 as Rating scale for the sensor signals based on - the Off threshold for the intermittent wiper operation in value to about the switch-on and switch-off the other for the Continuous wiper operation is a value basis on the switch-off for the intermittent wiper operation.

0021Where degradation clean condition of the disc 7 at turned on the switch assembly 1 in its switching stage Automatic A, so first the switch-off for more the continuous wiping operation, and then the turn-off for the Interval wiping operation below the sensor signal. Only but is falling below the switch-on of Driving motor 4 is operated and the windscreen wipers 5 clean the disc 7. The sensor device 2 is determines the extent to which the by wiping Windshield wiper blades 5 reached clean condition of the disc 7 worsened by z. B. the rain again. If dis Switch-on after the second wiping operation over the Sensor device 2 within a predetermined maximum undershot time again, it comes after a corresponding interval pause tp automatically at a renewed wiping. If the switch-on after a Wiping operation within the period prescribed maximum no longer is exceeded, there is also no longer a dependent of the state of the disc 7 wiping. at further switched switch assembly 1 in its switching stage Although automatic A is continuously the state of the disk 7 of the sensor device 2 monitors, a renewed wiping but will only be triggered when the switch-on falls below the sensor signal again. to the making automobile users clearly that the Switch assembly 1 is in its switching stage automatic A, but can after a certain time, for. example, after two Minutes, a check wiping operation regardless of the state of Disk 7 or be initiated by the sensor signal. Will the Wiper system operated in the intermittent wiper operation, monitors the circuitry the sensor signal. At the end of Duration t2 of the term of the detection arrangement Parking position of the wiper blades 5 found. to this Time, the switch-off threshold for the Interval wiping operation queried. Is this undercut, is without Intervallpuase tp immediately a new wipe cycle initiated. If the switch-off, however, the end of the Duration t2 not undershot, is of the Circuitry 3, the turn queried. A Interval pause is initiated and a new wipe cycle is only triggered when the sensor signal the On threshold below again.

0022If the z. B. to substantial precipitation, so it comes depending on the intensity cause the wiper system is continuously operated in the continuous wiping operation. At the end of Duration t2 for controlling the wiper system, the further off threshold queried. Should there by a slight slackening of the precipitate is not to Below the other switch-off coming, there remains the wiper system anyway for a certain number of Wiping cycles z. B. a further wiping cycle in Continuous wiper operation. Only when another after that Wiping cycle the further switch-off no longer is exceeded, it is to switch off the Wiper system. Only after then the switch-on has fallen again, it is possibly a Changing the operating mode, ie, the windshield wiper system is wiping operation in accordance with the sensor signal z. B. in the interval operated. As continuous wiper operation is valid for this device a wiping operation with at least three immediate succession following wiping cycles without an intermediary Interval pause tp. After three such wiping cycles of the 3 circuitry achieve the parking position so no longer the turn-off for the intermittent wiper operation, but the other cut-off threshold of the continuous wiping operation queried.

0023the wiper system is in the continuous wiping operation, is used to assess the sensor signal not only the runtime t2, but also used the term t1. Thereby doubles the probability that the Assessment period z. B. a raindrop on the measuring surface the sensor device 2 falls.

0024Of course, also by the end of the other exchange Modes under comparable conditions possible. By placing the respective different by value Off threshold for the intermittent wiper operation and further Off threshold for the continuous wiping operation occurs but on definitely because of continuous transitions between the Continuous wiping operation and the intermittent wiper operation to one for the motor vehicle user extremely comfortable acting Wiping operation.

0025As shown particularly in FIG. 5, it is in order to further optimizes comfort to prevent malfunctions, above the Switch-a noise level defined. The noise level is represents the maximum sensitivity of the sensor device. The Noise level represents a level of the at large Safety be assumed by a coating on the disk 7 can, it is therefore not likely to undefined Interference concerns. Changes in the sensor signal with respect to the Cleanliness of the disc surface above the noise floor be seen as interfering influence irrelevant and lead to no reaction. A further advantage is that through the Noise level long-term effects offset (z. B. Temperature changes, sunlight) are leading to a incorrect evaluation of the sensor signal with respect to the cleanliness the disc surface may result. If small changes regarding the cleanliness of the disk 7 over a longer Period, for. Example, a min., Observed that above the Interference levels are so no wiping is initiated but the current measured value as the new reference value for the State a maximum clean disk 7 used. If the disc 7 However, for. Example, only slightly wetted, ie, the Cleanliness of the disc 7 is only so impaired that the noise level below, but the turn is not exceeded, so the switch-over will increments a longer period. The size of the Switch-on threshold is thus a function of the time period, in where the level of interference remains below the sensor signal, changed. The change results in the Switch-on is increasingly set more sensitive, that after a certain period, for. example, a min., the Sensor signal, the switch-incremented below, making it one at a triggering Wiping cycle comes. A wipe cycle as will thus be triggered if the disc 7 by a wipe cycle only is slightly wetted by rain, but it started to rain suddenly ceases. However exceeds the sensor signal for a certain period of time the level of interference again, then the incremented on threshold without tripping Wipe cycle is reset to its original size.

0026The newly on the disc 7 forming lining, on the one hand by precipitation of finely divided droplets or small the other by the precipitation of coarse distributed large Drops occur. Often the motor vehicle user of from a few coarse distributed large drop existing coating on the disk 7 as disturbing felt as a multiple of finely distributed small droplets of existing flooring. For the Means for controlling the wiper system comes aggravated by the fact that the probability that one of the few coarsely distributed large drops on the relatively small Measuring surface of the sensor device 2 falls much lower than the probability that a plurality of finely divided small droplets on the measuring surface of the sensor device 2 fall. So it may be that many grossly distributed large, visibility obstructing drops on the window 7 are without that one of the drops on the measurement surface of the sensor device 2 comes to rest. Thus, the wiper operation anyway in such different rain forms are finely tuned voices can, the circuit arrangement 3 with a two- Counter-element rain form detection means 8 provided. be it from the rain form detection means 8 only of the sensor device 2 during a Recording period signals emitted for evaluation used, in which a predetermined Rate of change is exceeded in the waveform. The recording period is in each case the time period represents that elapses starting shortly after the second Wiping a windscreen wiper blade 5 on the Sensor device 2 to the initiation of a new wipe cycle.

0027These signals from the Regenformerfassungseinrichung 8, the amplitude of the signal change used for evaluation.

0028divided to distinguish between the different forms of rain the rain form detection means 8, these signals in two Categories namely in signals, the amplitude of the Signal change above and below a specified limit lie. If the amplitude or remain the amplitudes of Signal change - according to the shown in the figure 6 Graphs - so is taking place in this set limit a quantified change in one of the two counter elements the rain form detection means 8. For the in the figure 6 idealized illustrated signal change relative to Example Precipitation of many finely divided droplets, this means a five-time value changes for the one of the two Counter elements during the defined recording period. Starting from the initial value zero this is the one Counter element per relevant signal change by a factor of one increases up to the value five. If doing the switch-on the wiping operation of the signal falls below this, it comes to Triggering a wiping cycle. After thus triggered Wiping cycle depends triggering further new wiping cycles alone of the autogenous thereafter, of the Sensor device 2 emitted from signal. That is, the On threshold for the wiping operation from the signal after again below, is also a new wipe cycle triggered. However, If there is not to fall below the Switch-on, it is also not a new wipe cycle initiated.

0029If the amplitude or go the amplitudes of the signal change - According to the shown in the Figure 7 diagram - on the determined threshold, then a value changes for the other of the two counter elements Rain form detection means 8. For the in the figure 7 idealized shown typical signal change example based on precipitation of roughly distributed large drops this means a unique value changes for the other the two counter elements during the recording period. If this the turn for the wiping operation from Signal undershot, a wiping cycle is triggered. After a thus triggered wiping cycle is if the Signal for example at a constantly high level (clean pane) stops automatically after a certain period, a new Wiping cycle triggered. If by the precipitate On threshold for the wiper operation time before below automatically downstream new wipe cycle be, a wipe cycle is immediately initiated and the automatic wiping cycle not executed. Instead, the two counter elements to your above-described The method of the circuitry 3 and reevaluated a new, adapted thereto wiping strategy is determined.

0030Of course, in practice also rain forms, the examples of the two idealized differ. Thus, it can be understood that during a recording period due to the simultaneous Precipitation of small and large drops, both the one and the other counter element respectively in terms of value a out change. In this case, the contents of both are Counter elements shortly before initiating to be triggered Wiping cycle for a review of the key 3 circuitry related to each other. Depending on Result is then set the matching wiping strategy that is, it follows - as already described - a wipe cycle with or without automatic downstream new wipe cycle.

0031For more rain form provisions and controls the Wiper system, the two counter elements Rain shape detecting device 8 in each case shortly after the start evaluated the triggered wiping cycle, the wiper strategy is set and the counter elements are on their Output value zero. Thus, a particularly sensitive to various different forms rain coordinated wiper operation of the wiper system realized.