JPH04138956A - Wiper control device - Google Patents

Abstract

PURPOSE:To regulate sensitivity accurately reflected in the will of an operator by regulating sensitivity through variation of a maximum intermittent time, in an auto wiper control device to control wiper operation based on an output from a raindrop sensor. CONSTITUTION:In a wiper control device 1, a control circuit 3, a wiper motor 5 controls drive, responds to an output from a raindrop sensor 4 to control drive of a wiper motor 5, and causes execution of wiping operation through reciprocating displacement of a wiper blade. Namely, in a processing circuit 12 of the control circuit 3, when an auto wiper switch 2 is energized, an output from the raindrop sensor 4 is integrated, and drive the wiper motor 5 at a point of time, being earlier, of a point of time when an integrating value exceeds a predetermined threshold in a predetermined maximum intermittent time and a point of time when a maximum intermittent time elapses, whichever it may be. The maximum intermittent time is selectable into three modes of a long, a middle, and a short mode. At each mode, seven steps are set, and the mode is switched based on the set value of a sensitivity regulating volume 35 operated by a driver.

Description

[Detailed Description of the Invention] Overview The output from the raindrop sensor is integrated, and the integrated value reaches or exceeds a predetermined threshold within a predetermined maximum intermittent time from the end of the previous wiping operation of the wiper blade, or If the integrated value is less than the threshold at the time when the maximum intermittent time has elapsed, the wiper control device that drives the wiper blade determines the maximum intermittent time based on the integrated value and the threshold, that is, the maximum intermittent time. When the integrated value exceeds the threshold value within 80% of the intermittent time, the maximum intermittent time is shortened, and when the maximum intermittent time set during the previous wiping operation has elapsed, the integrated value becomes the threshold value. For example, when the maximum intermittent time is less than 1/2, the maximum intermittent time is extended.

Further, the maximum intermittent time is changed in response to an input operation by an operator from the sensitivity adjustment means.

This makes it possible to adjust the sensitivity, which has been difficult to achieve by correcting the raindrop sensor output or threshold value.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper control device that is suitably installed on a vehicle and that drives a wiper blade at a wiping interval suitable for rainy conditions.

BACKGROUND ART A so-called automatic wiper control device that controls wiper operation based on the output of a raindrop sensor integrates the output of the raindrop sensor, and when the integrated value exceeds a predetermined threshold, starts the wiping operation of the wiper blade.

In a typical conventional technique, such sensitivity adjustment of an auto wiper control device is achieved by using a variable resistor in a voltage dividing resistor circuit that generates a threshold voltage and changing the resistance value of the variable resistor. In another conventional technique, the sensitivity adjustment is realized by counting pulses from the raindrop sensor using a microcomputer and increasing or decreasing the number of threshold pulses for level discrimination of the counted value.

Problems to be Solved by the Invention In the prior art described above, detection sensitivity is determined by changing the threshold level. On the other hand, the detection range of the raindrop sensor is extremely narrow compared to the area of the windshield, and therefore variations occur even under the same rainfall condition. Furthermore, rainfall conditions change from moment to moment.

Therefore, by simply adjusting the threshold as described above, the operator (driver) cannot perceive a clear improvement in the wiping interval, and it is difficult to accurately reflect the driver's intentions. be.

An object of the present invention is to provide a wiper control device that can perform sensitivity adjustment that accurately reflects the operator's intention.

Means for Solving the Problems The present invention comprises: a raindrop sensor that detects rainfall conditions; a drive means that drives a wiper blade to reciprocate on the surface to be wiped; The point in time when the outputs from the sensitivity adjustment means operated by a person and the raindrop sensor are integrated, and the integrated value reaches a predetermined threshold value or more within a predetermined maximum intermittent time after the end of the previous wiping operation of the wiper blade. , output a drive signal indicating that the wiper blade should be driven to the drive means at the earlier of the time when the maximum intermittent time has elapsed, and output the output of the sensitivity adjustment means and the integrated value. and a control means for updating the maximum intermittent time based on the threshold value and the wiper control device.

According to the present invention, the control means integrates the output from the raindrop sensor, and determines when the integrated value becomes equal to or greater than a predetermined threshold within a predetermined maximum intermittent time from the end of the previous wiping operation of the wiper blade. A drive signal is output to the drive means at the earlier of either the time point or the time point when the maximum intermittent time has elapsed. In response to the drive signal, the drive means drives the wiper blade to reciprocate over the surface to be wiped, such as a windshield, to remove raindrops or the like adhering to the surface to be wiped.

On the other hand, the maximum intermittent time is updated based on the output of the sensitivity adjustment means operated by the operator, the integrated value, and the threshold value. That is, for example, when the integrated value exceeds the threshold within 80% of the maximum intermittent time, the maximum intermittent time is shortened, and on the other hand, when the maximum intermittent time has elapsed, the integrated value becomes equal to or greater than the threshold. When it is less than 1/2, the maximum intermittent time is changed to be longer. Further, when the sensitivity adjustment means inputs an input to set the sensitivity higher, the maximum intermittent time is changed to be shorter.

By changing the maximum intermittent time in this manner, sensitivity adjustment that accurately reflects the operator's intention is performed without being affected by variations in rainfall conditions.

Embodiment FIG. 1 is a block diagram showing the electrical configuration of a wiper control device 1 according to an embodiment of the present invention. This wiper control device 1
is used for automobiles, and by turning on the auto wiper switch 2, the control circuit 3 responds to the output from the raindrop sensor 4 to drive and control the wiper motor 5, which is the driving means, to move the wiper blade (not shown) to the front. This is a so-called automatic wiper control device that performs a wiping operation by reciprocating the wiper on the glass.

The raindrop sensor 4 is an optical raindrop sensor that includes, for example, a pair of light receiving and emitting elements, and detects the amount of rainfall based on a change in the level of light received when the raindrop passes through an optical path formed by these light receiving and emitting elements. It is a sensor. The output of this raindrop sensor 4 is input to the control circuit 3, shaped into a rectangular wave pulse by a waveform shaping circuit 11, and then input to a processing circuit 12 realized by a microcomputer or the like.

The output of the auto wiper switch 2 is input to the processing circuit 12 after noise components such as so-called chattering are removed by a waveform shaping circuit 13.

Electric power is supplied from a battery 23 to each circuit in the control circuit 3 including the processing circuit 12 through a constant voltage port 129 from the power supply line 12 . The processing circuit 12 is
When power is being supplied from the constant voltage circuit 29 and the auto wiper switch 2 is conductive, the output of the raindrop sensor 4 is integrated, and the integrated value M1 is a predetermined threshold value within a predetermined maximum intermittent time T1. The wiper motor 5 is driven at the earlier of either the time when RP is exceeded or the time when the maximum intermittent time T1 has elapsed.

As shown in Table 1, the maximum intermittent time T1 can be selected from, for example, three modes: long, medium, and short, and seven steps are set for each mode. Therefore, for example, when the medium mode is set and the wiper motor 5 is selected for the first step, the wiper motor 5 is placed in a high-speed continuous operation state, and when the second step is selected, the wiper motor 5 is placed in a low-speed continuous operation state. When 3 steps are selected, it is in an intermittent operation state for 1.5 seconds, and below,
The intermittent operation is performed for 3 seconds at the fourth step, 6 seconds at the fifth step, 12 seconds at the sixth step, and 24 seconds at the longest step, the seventh step.

(The following is a margin) Table Maximum Intermittent Time TI (Seconds) Each mode is switched based on the setting value of the sensitivity adjustment volume 35 operated by the driver, who is the operator. The processing circuit 11 outputs a starting pulse from the output terminal P3 to the test pulse generation circuit 36 in order to read the set value of the sensitivity adjustment volume 35. The test pulse generating circuit 36 outputs the line 111 in response to the activation pulse.
Outputs a test pulse to The test pulse is applied to the sensitivity adjustment volume 35 through the input circuit 37, and from the input circuit 37, an output at a voltage level corresponding to the set value of the sensitivity adjustment volume 35 is sent to the processing circuit W112 through the line 112. derived.

The test pulse generation circuit 36 includes resistors R11 to R13 and a transistor Tri 1,
The starting pulse is applied to the transistor Tr via the resistor R11.
given to the base of ll.

The base of the transistor Trll is also connected to the high-level power supply line Vce via a pull-up resistor R12, and the emitter of the transistor Tr11 is also connected to the power supply line Vec. The test pulse output from the collector of transistor Trll is
The signal is applied from the resistor R13 to one terminal of the sensitivity adjustment volume 35 via the resistor R14 of the input circuit 37.

The input circuit 37 includes resistors R14 to R16 and a capacitor C.
1l and a transistor Tr12. The other terminal of the sensitivity adjustment volume 35 is grounded, and a capacitor C1l is interposed in parallel with the sensitivity adjustment volume 35 and the resistor R14, which are connected in series. The output voltage of the capacitor C1l is applied to the base of the transistor Tr12 via the resistor R15. The collector of this transistor Tr12 is connected to the power supply line Vcc via a pull-up resistor R16, and is also connected to the processing circuit 12 via the line 112, and its emitter is grounded.

Therefore, in response to the activation pulse derived from the output terminal P3 of the processing circuit 12 shown in FIG. 2(1), the test pulse generator circuit 36 outputs the test pulse shown in FIG. 2(2). Ru. In response to said test pulse, capacitor C11 derives an output voltage as shown in FIG. 2(3), which causes a pulse as shown in FIG. is output.

In this FIG. 2, when the resistance value of the sensitivity adjustment volume 35 is high, as shown between time t1 and t2, the output voltage of the capacitor C1l shown in FIG. 2 (3) is
The output voltage rises in response to the high-level test pulse shown in FIG. 2 (2), and after the output of the test pulse is stopped, the output voltage gradually decreases. The pulse width W1 of the output pulse to the processing circuit 12 shown in 4) becomes longer.

On the other hand, when the resistance value of the sensitivity adjustment volume 35 is low, as shown in FIG. 2 (
The output voltage of the capacitor C1l indicated by 3) rises in response to the test pulse and quickly falls. Therefore, the pulse width W1 of the output pulse to the processing circuit 12, indicated by 4) in Figure 2, becomes short. In this way, the processing circuit 12 sets the mode for the maximum intermittent time T1 based on the pulse width W1 of the pulse input from the input circuit 37 in response to the activation pulse output from the output terminal P3. .

Further, each step is updated every time the wiper motor 5 is driven, based on the integrated value M1 and the threshold value RP. That is, for example, within 80% of the set maximum intermittent time T1 of steps, the integrated value M1 reaches the threshold R.
When the maximum intermittent time T1 is greater than or equal to P, the step of the maximum intermittent time T1 is 1.
Only the step is set lower, and the intermittent time is changed to be shorter.

On the other hand, when the integrated value M1 is less than 1/2 of the threshold RP after the maximum intermittent time T1 has elapsed, the maximum intermittent time T1 is increased by one step. Such an operation of updating the maximum intermittent time T1,
Auto wiper control is realized by performing the operation of integrating the output of the raindrop sensor 4.

The processing circuit 12 outputs a drive signal to the line 13 from the output terminal P2 when driving the wiper motor 5 at a low speed. This drive signal is applied to the base of the transistor Tr2 via a resistor R3 and a bias resistor R4.

The emitter of the transistor Tr2 is grounded, and the collector is connected to the power supply line 12 via a relay coil 27 of a relay 26.

On the other hand, the relay switch 28 of the relay 26 is provided with two individual contacts 28a and 28b, and the negative individual contact 2
8b is connected to the power supply line 12, and the other individual contact 28a is connected to the common contact 30c of the cam switch 30 via the line 14. Further, the common contact 24c of the relay switch 24 of the relay 21 is connected to the common contact 28c of the relay switch 28, and the individual contact 24a is connected to the low-speed power input terminal 5a of the wiper motor 5.

When the wiper motor 5 is continuously driven at high speed, the processing circuit 12 also outputs a line 11.1 from the output terminals PL and P2.
A drive signal is output to 3. The drive signal on line 11 is input to the base of transistor Trl via resistors R1, R2, and the drive signal on line 13 is input to the base of transistor Trl via resistors R1, R2, and - the drive signal on line 13 is input to the base of transistor Trl via resistors R1, R2.
4 to the base of the transistor Tr2.

The emitter of the transistor Tri is grounded,
The collector is connected to the power supply line 12 via a relay coil 22 of a relay 21.

One individual contact 24 of the relay switch 24 of the relay 21
b is connected to the high-speed power input terminal 5b of the wiper motor 5.

A cam switch 30 is provided in association with the wiper motor 5, and the cam switch 30 is electrically connected to the individual contact 30a when the wiper blade is in the initial position, and when the wiper motor 5 is activated and the wiper blade is wiped. When the wiper blade starts its operation and moves away from the initial position, the individual contact 30b becomes conductive, and when the wiper blade finishes the wiping operation and returns to the initial position, the individual contact 30a
conducts to.

The individual contact 30a is grounded together with the ground terminal 5c of the wiper motor 5, and the individual contact 30b is connected to the power supply line 12. Further, the common contact 30c is connected to the individual contact 28 of the relay switch 28 via the line 14.
The potential of this common contact 30c is detected by the processing circuit 12 via the line 15 and the signal processing circuit 31.

Therefore, when driving the wiper motor 5 at low speed, the processing circuit 12 outputs a drive signal to the line 13 from the output terminal P2. As a result, the transistor Tr2 becomes conductive, the relay coil 27 is excited, and the contact 28b of the relay switch 28 is turned on.

28c is electrically connected. Therefore, the power line 12
Power from the battery 23 via these contacts 28
b, 28c to contacts 24c, 24 of relay switch 24
a, the low speed power input terminal 5a of the wiper motor 5
supplied to

In this way, the wiper motor 5 is activated and the cam switch 30
is switched from the individual contact 30a to the individual contact 30b, and then when the wiper blade returns to its initial position, the cam switch 30 is switched from the individual contact 30b to the individual contact 30a again, and the processing circuit 12 stops outputting the drive signal.

As a result, the low speed power input terminal 5 of the wiper motor 5
A includes contacts 30a and 30c, contacts 28a and 28c of the relay switch 28, and contact 2 of the relay switch 24.
A brake current flows through 4c and 24b, and the wiper motor 5 is stopped.

Further, when driving the wiper motor 5 at high speed, the processing circuit 12 outputs a drive signal from the output terminals PL and P2,
This causes the transistor Trl.

Tr2 conducts, relay coils 22 and 27 are both excited, relay switch 24 conducts to individual contact 24b, and relay switch 28 conducts to individual contact 28b. Accordingly, power from the battery 23 is supplied to the high-speed power input terminal 5b of the wiper motor 5 via the relay switch 28.24.

The processing circuit 12 detects whether the wiper blade has returned to the initial position from the output voltage level of the cam switch 30, and until the wiper blade returns to the initial position, the terminals PL,
Continue to derive the drive signal from P2. In this way, the wiper motor 5 can be driven at low speed and high speed.

t processing port W! 12 has built-in timers 32 and 33, and the timer 32 is connected to the output terminal PI.

When the drive signal is outputted from P2, the time counting operation is started, and the maximum intermittent time T1 is timed. The timer 33 is
The maximum intermittent time TI is measured, and each time T1 elapses, the latest time T1 is set and the time measurement is restarted.

FIG. 3 is a flowchart for explaining the auto wiper control operation. When the auto wiper switch 2 is turned on, the process moves to step n1, and flags Fl and Fil, which will be described later, are set.
~F13 and the integrated value Ml.

Initialization processing such as initialization of M2 and initial value setting of maximum intermittent time T1 is performed.

In step n2, a test pulse is output from the test pulse generation port 1lI36, and in step n3, the pulse width W1 of the pulse from the input circuit 37 in response to the test pulse is output.
is equal to or greater than a predetermined threshold value Wl1. If so, the process moves to step n4, and the mode is set to the short mode.

In step n3, when the pulse width W1 is less than the threshold value W11, the process moves to step n5, and the pulse width W1
is equal to or greater than a threshold value W12, which is smaller than the threshold value Wll. If so, the process moves to step n6 and the medium mode is set; otherwise, the long mode is set in step n7.

Said step n4. n6. From n7, the process moves to step n8, where the count value T3 of the timer 32 is incremented by 1 and a counting operation is performed, and in step n9, the count value T3 of the timer 32, which was counted in step n8, reaches the maximum intermittency. It is determined whether time T1 has been reached;
Otherwise, the process moves to step nlo.

In step nlo, the output signal of the raindrop sensor 4 is integrated (integrated values Ml, M2). In step n11, it is determined whether the integrated value M1 is equal to or greater than the threshold value RP, and if so, the process moves to step n12. In step n12, from the previous wiping operation, the step nl
It is determined whether the count value T3 up to the threshold value RP or more at l is within 80% of the maximum intermittent time T1, and if so, in step n13, the step of the maximum intermittent time T1 is decreased. The flag F11 is set to 1, and the flag F12 for holding the step and the flag F13 for increasing are reset to zero. Further, in the step n12, when the count value T3 exceeds 80% of the maximum intermittent time T1, the process moves to step n14, the flag F12 is set to 1, and the flag Fi1. F13 is reset to zero.

Thus step n13. Flags F11 to F1 at n14
3 is completed, and when the count value T3 has reached the maximum intermittent time T1 in step n9, the process moves to step n15, the maximum intermittent time T1 is updated to the step corresponding to the set flag, and the step At n16, the integrated value M1 and the count value T3
is reset to zero.

From step n16, the process moves to step n17, where a drive signal is output from the terminals PI and P2 of the processing circuit 12, and the wiper motor 5 is activated.

In step n18, the common contact 30 of the cam switch 30
It is determined whether or not the contact point c has been switched to the individual contact 30b, that is, whether the wiper blade has left the initial position and started the wiping operation, and once the wiping operation has started, the process moves to step n19. In step n19, it is determined whether the common contact 30c of the cam switch 30 has been switched to the individual contact 30a, that is, whether the wiping operation has been completed. When the wiping operation is completed, the process moves to step n20. step n2
0, the output of the drive signal is stopped, the wiper motor 5 is stopped, and then the process returns to step n2.

When the integrated value M1 is less than the threshold RP in the step nil, the process moves to step n21, where the count value T2 of the timer 33 is updated by adding 1, and the process proceeds to step n2.
22, the count value T2 is equal to the maximum intermittent time T1.
It is determined whether or not it has been reached, and if not, the process returns to the step n2, and if so, the process returns to the step n2.
Move on to 3.

In step n23, the integrated value M2 is 17 of the threshold value RP.
It is determined whether or not the value is less than 2, and if so, the process moves to step n24, where the flag F13 is set to 1, and the flag F11. F12 is reset to zero; otherwise, in step n25, the flag F12 is set to 1, and the flags Fi1.
F13 is reset to zero.

Thereafter, in step n26, the integrated value M2 and the count value T2 are cleared, and the process returns to step n2.

As described above, in the wiper control device N1 according to the present invention, the sensitivity is adjusted by switching the mode of the maximum intermittent time T1 by operating the sensitivity adjustment volume 35, so that the driver can enjoy the The wiping interval can be changed to a perceptible extent, and sensitivity adjustment can be made to accurately reflect the driver's intention.

Note that, instead of the volume 35, other means such as a switch may be used as the sensitivity adjustment means.

Effects of the Invention As described above, according to the present invention, the sensitivity is adjusted by changing the maximum intermittent time, so that the operation can be sufficiently perceived without being affected by variations in rainfall, etc. You can change the wiping interval,
Sensitivity adjustments can be made that accurately reflect the operator's intentions.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical configuration of a wiper control device 1 according to an embodiment of the present invention, and FIG. 2 shows a sensitivity adjustment volume 35.
Waveform diagram for explaining the setting value reading operation, No. 3''
The figure is a flowchart for explaining the auto wiper control operation. DESCRIPTION OF SYMBOLS 1... Wiper control device, 2... Auto wiper switch, 3... Control circuit, 4... Raindrop sensor, 5...
Wiper motor, 12... processing circuit, 32.33...
Timer, 35... Sensitivity adjustment volume, 36... Inspection pulse generation circuit, 37... Input circuit agent patent attorney number of strokes Keiichi

Claims (1)

[Scope of Claims] A raindrop sensor that detects rain conditions; a drive means that drives a wiper blade to reciprocate on the surface to be wiped, and a wiper blade that removes raindrops adhering to the surface to be wiped; and operated by an operator. The point in time when the output from the sensitivity adjusting means and the raindrop sensor becomes equal to or greater than a predetermined threshold within a predetermined maximum intermittent time after the end of the previous wiping operation of the wiper blade; outputting a drive signal indicating that the wiper blade should be driven to the drive means at the earlier of the time when the intermittent time has elapsed, and outputting the output of the sensitivity adjustment means, the integrated value, and the threshold value; and control means for updating the maximum intermittent time based on.