JPS62163849A - Windshield wiper controller - Google Patents

Abstract

PURPOSE:To get optimum raindrop eliminating action commensurate to an amount of rainfall at that time as well as to secure a field of view so favorably all the time, by calculating the rainfall on the basis of output of a raindrop sensor, and controlling a sweep rate of a windshield wiper, while controlling a driving interval of the wiper. CONSTITUTION:In this device, there is provided with a raindrop sensor 4 which detects an amount of raindrops 2 sticking to a windshield 1, and this sensor consists of an oscillation circuit 8 generating a high frequency signal S1 to be oscillated by amplitude corresponding to capacitance at a detecting electrode 7 to be varied according to a dielectric constant of the raindrops 2 and a detection circuit 9. According to an output signal S2 out of this sensor 4, an amount of the raindrops 2 is calculated at a raindrop calculating part 5, generating such a signal S7 that has a duty ratio corresponding to this calculated result, and a sweep rate of windshield wiper unit 3 is controlled via a control part 6. And, on the basis of this raindrop calculating part 5, a driving interval of the wiper is controlled by a timer 16 as a driving interval control part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a wiper control device that drives a wiper provided on a vehicle based on the output of a raindrop sensor provided on the vehicle, and particularly relates to a wiper control device that drives a wiper provided on a vehicle based on the output of a raindrop sensor provided on the vehicle. II is a wiper control device that varies the wiper suppression speed and wiper driving interval according to the detected raindrops.
I do it.

(Prior Art) A wiper control device for controlling the drive of a wiper installed on a vehicle according to the output of a raindrop sensor installed on the vehicle is disclosed in Japanese Patent Application No. 59-199 filed earlier by the present applicant.
No. 061 and the December 1988 issue of Nissan Technical Report.

Among these, the one disclosed in Japanese Patent Application No. 59-199061 detects whether or not there are raindrops on the outside of the windshield using a capacitive sensor installed on the inner surface of the windshield of the vehicle. The wiper is activated when there are raindrops, and the wiper is turned off when there are less than a certain amount of raindrops.

Additionally, a system disclosed in the December 1980 issue of the Nissan Technical Report is a system in which an acoustic sensor is installed in the vehicle, and the acoustic sensor detects the sound when raindrops hit the vehicle to control the wiper drive. The wiper is driven when the integral value of the sound of raindrops, etc. reaches a certain value.

(Problems to be Solved by the Invention) By the way, such conventional wiper control devices only have the function of controlling the drive interval of the wiper according to the amount of raindrops, so they suffer from the following problems. be.

(b) When the amount of rain exceeds a certain value, the wiper enters a continuous operation state and cannot further increase its ability to remove raindrops.

(b) In other words, the conventional wiper control device only automates the intermittent operation of the wiper during light rain;
It does not even take into consideration the automation of the wiper sweep speed during heavy rain.

In view of the above circumstances, the present invention controls the sweep speed and drive interval of the wiper according to the amount of rain to prevent light rain.

To provide a wiper control device capable of wiping a famous mountain with a medium to heavy rain cap with an optimal raindrop removing power corresponding to the amount of rain.

(Means for Solving the Problems) In order to solve the above problems, a wiper control device according to the present invention provides a wiper control device that drives a wiper provided on a vehicle based on the output of a raindrop sensor provided on the vehicle. In the apparatus, the rain interval is measured in nm based on the output of the raindrop sensor, and the reason for this is 1. The present invention is characterized in that it includes a control section that controls the sweep speed of the wiper according to the peak, and a drive interval control section that controls the drive interval of the wiper based on the output of the rain amount calculation section.

(Embodiment) FIG. 1 is a circuit block diagram showing an embodiment of a wiper control device according to the present invention.

The wiper control device shown in this figure detects hanging raindrops 2 adhering to a medium-thick windshield 1, and adjusts the wiper sweep speed and driving interval of the wiper device 3 according to this rain. The rain sensor 4, the rain m calculation section 5, the control section 6, the timer 16, and the speed multiplier setting 3 are variable.
18.

A raindrop sensor 4 detects raindrops 2 adhering to the windshield 1.
The device detects the agitation and outputs a signal $2 corresponding to the detection result, and is comprised of a detection electrode 7, an oscillation circuit 8, and a detection circuit 9.

As shown in FIG. 2, the detection electrode 7 is provided inside the wiped surface 1a of the windshield 1 (on the inside of the vehicle interior), and as shown in FIG.
A linear electrode 7a provided in the line electrode 7a, an intermediate ring electrode 7b provided so as to surround the linear electrode 7a, and a ring-shaped ground electrode 7c provided so as to surround the intermediate ring salt ff17b. There is.

When raindrops 2 adhere to the detection area 1b on the outer surface of the windshield 1, the linear electrode 7a and the intermediate ring '1lff(
47b and the capacitance ff1c1 and the intermediate ring salt Vj
The capacitance C2 between 7b and the grounded Sac changes,
This amount of change is detected by the oscillation circuit 8.

The oscillation circuit 8 oscillates with a small amplitude when there are few raindrops 2 suspended, and with a large amplitude when there are many raindrops 2, based on the magnitude of each capacitance ωC1°C2 of the detection electrode 7. It generates a high frequency signal S1, and this high frequency signal $1 is supplied to the detection circuit 9. In this case, if a film of water or the like forms uniformly on the detection area 1b of the windshield 1, such as immediately after the wiper surface 1a is wiped with the wiper blade 25 (see FIG. 2),
This oscillation circuit 8 outputs a high frequency signal S1 with a small amplitude.

The detection circuit 9 detects and smoothes the high frequency signal @S1 and extracts the envelope of this high frequency signal S1,
The envelope obtained here is rain ff1 as signal S2.
It is supplied to the tl output section 5.

The rain amount calculation unit 5 determines the detection order i! based on the signal S2. 11
The time from when there are no raindrops 2 on the detection area 1b to when a certain amount of raindrops 2 are attached on the detection area 1b is calculated, and the data $7 corresponding to this time is outputted, and the time required for the raindrops 2 to fall on the detection area 1b is outputted. 01 Pa signal S when a certain amount of raindrops 2 are attached to
5 and outputs it, the inverting amplifier circuit 10, the micro valve circuit 11, and the reference voltage setting V! AI2 and
Comparison circuit 13, fall detection circuit 14, and counter 1
5.

The inverting amplifier circuit 10 receives the signal S output from the raindrop sensor 4.
2 and inverts and amplifies it, and the signal S3 obtained by this inverting amplification operation is supplied to the differentiating circuit 11.

The differentiating circuit 11 differentiates the signal S3 to remove long-term oscillation amplitude fluctuations and amplification factor changes of the raindrop sensor 4 and the inverting amplifier circuit 10, and removes static electricity on the sensing electrode 7 caused by dirt on the windshield 1. This is used to remove capacitance changes, etc., and this differential result is sent to the comparator circuit 1 as a signal S4.
3 and the falling edge detection circuit 14.

The comparison circuit 13 compares the value of the reference voltage Vref set in the reference voltage setter 12 and the value of the signal S4, and while the value of the signal S4 exceeds the value of the reference voltage Vref, that is, the raindrop 2 The "1" signal S5 is output while the number of outputs is greater than the voltage determined by the reference voltage Vref, and this "1" signal S5 is supplied to the hold terminal 15b of the counter 15 and the start terminal of the timer 1G. Ru.

Further, the fall detection circuit 14 detects when the wiper blade 25 wipes off the wiper 1a and the signal S4 falls, and outputs a constant width signal S6. And this “1 PA 8S
G is supplied to the start terminal 15a of the counter 15.

The counter 15 starts the timekeeping operation when the "1" signal S6 is supplied, and stops the timekeeping operation when the "1" signal $5 is supplied, and the counter 15 The count value, that is, when the wiping surface 1b is wiped off by the wiper blade 25 or when there are no raindrops 2 on the wiping surface 1a, the wiping surface 1a has a suspension determined by the value of the reference voltage Vrcf. It outputs the time until the raindrop 2 is attached as data S7, and continues to output this data S7 until the next "1" signal S5 is supplied or the maximum retention period P has elapsed. S7 is supplied to the input terminal 17a of the wiper speed conversion circuit 17 that constitutes the control section 6.

Further, when the timer 16 receives the "1" signal S5 from the comparator circuit 13, it starts a timing operation and starts outputting the "1" signal S8, and from this time on, the wiper blade 25 is moved at a low speed. The retry timer does not output the "1" signal S8 when the period ΔK, which is set a little longer than the period required for reciprocating, has elapsed, and this "1"1" signal 8 The signal is supplied to the first control terminal 17b of the wiper speed conversion circuit 17.

In other words, this timer 16 starts generating the "1" signal S8 when a raindrop 2 of R determined by the value of the reference voltage vrer is attached to the wiped surface 1a, and after that for a certain period of time 61
within the amount of raindrops 2 determined by the value of the reference voltage vref.
does not stick to the wiped surface 1a again, the "1"
Generation of signal S8 is stopped.

Further, the wiper speed conversion circuit 17
While the 11111 signal @S8 is supplied to the a terminal 17b, it is in the on state, takes the data S7 supplied to the input terminal 17a, and sets the wiper speed value (1/1) corresponding to WIN of this data S7. N)・K [where K is a coefficient], and this is the predetermined minimum speed m.
If it is smaller than A, the wiper speed 1I at the low speed level vO is set at the speed multiplier setter 18.
11tIll signal S9 is output, and if the wiper speed value (1/N)·K is larger than the minimum speed value A, the wiper speed value (1/N) is /N ) · K (for example, medium speed level Vl, high speed level v2, etc.) wiper speed control signal S9 is output, and this wiper speed control signal S9 is supplied to the wiper device 3.

The wiper device 3 receives the wiper speed 1lII signal S9.
is supplied, the wiper blade 25 is turned on and moves at a speed corresponding to the magnitude of the wiper speed control signal S9.
The raindrops 2 attached to the surface 1a are wiped away by the reciprocating motion of the
be removed.

Next, referring to the waveform diagrams shown in FIGS. 4(a) to (e) and (g) and the mode display diagram shown in FIG. The explanation will be divided into the case of application and the case of heavy rain.

(A) In case of light rain.

First, the mountain begins to fall and the wiped surface 1a of the windshield 1
When raindrops start to fall on the raindrops (time 611t1>), the value of the signal 82 outputted from the raindrop sensor 4 increases in accordance with the peak of the raindrops 2, and the value of the signal 82 outputted from the differential circuit 11 increases as shown in FIG. 4(a). The value of the signal S4 gradually increases.

At time t2), when the value of this signal S4 exceeds the 4 quasi-voltage 1) Vrer set in the quasi-voltage setter 12, the comparator circuit 13 outputs 1"1 as shown in FIG. 4(C).
iQs5 is output to start the timer 16, and the timer outputs the °1'° signal S8 as shown in FIG. 4(E). As a result, the wiper speed conversion circuit 17 is turned on and takes in the output of the counter 15 (zero output in this case), and as shown in FIG.
The wiper speed control No. 13 $9 is output and the wiper blade 25 of the wiper device 3 starts reciprocating at a low speed.

Further, at this time (time t2), the 111 II signal S5 is supplied to the counter 15, but in this case, the counter 15+,t has not yet performed a timekeeping operation, so it does not output the data S7.

Next, when the raindrops 2 on the soil are removed from the wiping surface 1a of the glass 1 to the freon 1 by the reciprocating movement of the m-distributing/everb 1 node 25 (time T3), the t output from the raindrop sensor 4 at the corresponding time t = The value of g S 2 rapidly decreases, and the signal S output from the differentiating circuit 11
The value of 4 drops rapidly. As a result, the fall detection circuit 14 outputs the <"1" m number S6 as shown in FIG. 4(b), causing the counter 15 to start the S1 operation.

Then, when a period Δt has passed since the time t2,
The timer 16 no longer outputs the "1" signal S8, and in response, the wiper speed conversion circuit 17 no longer outputs the wiper speed control signal S9, thereby stopping the operation of the wiper device 3.

After this, if the rain does not stop falling and raindrops 2 begin to adhere to the wiped surface 1a, the value of the signal S4 output from the differentiating circuit 11 gradually increases accordingly.

Then, when the value of this signal S4 exceeds the value of the reference voltage Vrcf (time t4), the comparator circuit 13 detects this and “
The timer 16 is restarted with this "1" signal S5, and the timer 16 outputs a "1" signal S8, and the total of the counter 15 is
The timing result at this time after stopping the operation (for example, the value N1
) is output as data $7. This allows the above
i'' The wiper speed conversion circuit 17 that receives the signal $8 starts operating, takes in the data $1, and converts the wiper speed value (1/
Find Nl>・K.

And in this case, it is injection and the wiper speed value (1
/N 1) Since K is smaller than the minimum speed value, the wiper control device outputs $9 at the low speed level vO at the multiplier set by J3 in the wiper speed multiplier 18 to reciprocate the wiper blade 25 at low speed. let

Next, when a period of time Δ has elapsed from the time t4,
The timer 16 no longer outputs the "1" signal QS8, and in response, the wiper speed conversion circuit 17 stops outputting the wiper speed control signal S9, thereby stopping the wiper device 3.

Thereafter, while the wind is falling, the above-mentioned operation is repeated, and the wiper speed conversion circuit 17 intermittently controls the wiper device 3 according to the value of the data S7 output by the counter 15, and the wiper blade 25 is Sweep intermittently at low speed.

In other words, in this embodiment, when the wiper blade 25 is in the intermittent mode, the wiper blade 2
The wiper device 3 stops operating every time the wiper device 3 makes one reciprocation at low speed.

(B) In the case of an offer.

Also, if both states change to the offer state during this time (time j11)
, when the value of the signal S4 outputted by the differentiating circuit 11 exceeds the value of the reference voltage vrer (at time 12), since the timer 16 has not timed up, this time t1
2, the comparison circuit 13 outputs the signal 8 S
5, the timer 16 is restarted and becomes "1".
″Signal S8 is output continuously.

As a result, the wiper speed conversion circuit 17 enters the continuous mode, takes in the data S7 output by the counter 15 at the time t12, and 1i indicated by this data S1.
Find the wiper speed value (1/N3)·K corresponding to lN3.

In this case, a value corresponding to the value N3 of the data S7 output by the counter 15 at time t12 (1/N3>・
Since K is larger than the minimum speed value A, the wiper speed conversion circuit 17 replaces the wiper speed control signal S9 with the low speed level vO with the value (1/N3)·K and the speed multiplier setter 18.
A wiper speed control signal S9 of a level corresponding to the magnification set in (in this case, medium speed level V1) is output to cause the wiper blade 25 to reciprocate at a medium speed.

Thereafter, while the middle thickness is falling, the above-mentioned operation is repeated, and the wiper speed conversion circuit 17 continuously controls the wiper device according to the value of data $7 output by the counter 15, and the wiper blade 25 is Sweep at medium speed.

(C) In case of heavy rain.

Also, even when the application state changes to a heavy rain state, each part of the circuit operates in the same order as in the above-mentioned case of medium thickness (B).

However, in this case, the time from when the wiping surface 1a is wiped off at the end of the offer period (B) (time t21) to when the value of the signal S4 output from the differentiating circuit 11 exceeds the reference voltage Vref (time t22) , that is, counter 15
111 N 7 of data S7 output at time t22
is smaller than the six values N3 to N6 of the data S7 in the case of medium thickness, so the value of the wiper speed control signal $9 output from the wiper speed conversion circuit 17 is equal to the medium speed level v
It becomes high speed level v2 higher than 1. This causes the wiper device 3 to sweep the wiper blade 25 at high speed.

When the rain stops, the value of the signal S4 output from the differentiating circuit 11 will no longer increase, so the timer 16 will not restart, and when the timer 16 times up, the wiper speed conversion circuit 17 will change the wiper speed control signal S9. The output of the wiper device 3 is stopped and the wiper device 3 is stopped.

Along with this, the counter 15 is finally set to 11111.
When the maximum holding period P has elapsed since the signal S5 was supplied, the output of the data S7 is ended.

In this way, in this embodiment, the wiper blade 25 is driven intermittently or continuously depending on the amount of rain, and the sweep speed is varied, so that when the amount of rain is small, Also, if there are many
The wiper blade 25 can be driven at intervals and sweep speeds most suitable for the rain m at that time. Further, in this case, by adjusting the speed magnification setting device 18, the sweeping speed of the wiper blade 25 can be adjusted as a whole.

Further, in the above-described embodiment, the output of the wiper speed conversion circuit 17 is made to change continuously in accordance with the output of the counter 15, but it may be made to change in steps. In this case, the steps are:
It is sufficient to have four steps: a low speed step, a medium speed step, a high speed step, and a super high speed step.

Further, in the above-described embodiment, the presence of raindrops 2 is detected by the capacitance type raindrop sensor 4, but an optical type or ffW sensor may be used instead.

(Effects of the Invention) As explained above, according to the present invention, it is possible to control the sweep speed and repetition rate of the wiper depending on the rain interval. It can be wiped away with optimal raindrop removal power.

[Brief explanation of drawings]

Fig. 1 is a circuit block diagram showing Embodiment 4 of the present invention, Fig. 2 is a front view of the windshield portion where the detection voltage shown in Fig. 1 is provided, and Fig. 4(a) to 4(g) are waveform diagrams for explaining operation examples of the same sub-example, and FIG. 4(f) is an enlarged front view of the sensing electrode shown in FIG.
FIG. 3 is a mode display diagram showing an example of the operation of the same embodiment. 1... Windshield, 3... Wiper device, 4...
. . . Raindrop detection, 5. Rain amount calculation unit, 6. Control unit, 16. Drive interval control unit (timer). Patent applicant Tateishi Electric Co., Ltd. Agent Patent attorney Tetsuji Iwakura (and 1 other person) Figure 2h Figure 3

Claims (1)

[Claims] A wiper control device that drives a wiper provided on the vehicle based on the output of a raindrop sensor provided on the vehicle includes a rain amount calculation unit that calculates the amount of rain based on the output of the raindrop sensor, and a rainfall amount obtained by the rain amount calculation portion. a control unit that controls the sweep speed of the wiper based on the amount of rainfall;
A wiper control device comprising: a drive interval control section that controls a drive interval of the wiper based on the output of the rain amount calculation section.