JP2802938B2 - Wiper control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a wiper control device that automatically controls an intermittent operation cycle of a wiper by integrating raindrop pulses. When the pulses are integrated and the integrated value reaches a predetermined control threshold value, the wiper control device that clears the integrated value and operates the wiper sets a predetermined time for determining the integrated time of the raindrop pulse. A threshold value and a level threshold value for determining a level of the integrated value lower than the predetermined control threshold value. When the integrated time exceeds the time threshold value, the integrated value is set to the level. It is configured to judge whether the threshold value has been reached, and if not, a means for clearing the integrated value without operating the wiper is provided.

The present invention relates to a wiper control device that automatically controls an intermittent operation cycle of a wiper by integrating raindrop pulses.

The automatic wiper, in which the operation cycle of the wiper automatically changes according to the amount of rainfall, is convenient because the operation burden on the driver is small and the driving visibility can be kept good. However, it is difficult to optimize the operation during a minute rainfall.

[Conventional technology]

A general auto wiper detects raindrops with a raindrop sensor and integrates its output (raindrop pulse). And
When the integrated value reaches a predetermined control threshold, the wiper is set to 1
Operation, and at the same time, clears the integrated value and restarts the integration from there. Therefore, the intermittent operation cycle of the wiper changes in inverse proportion to the amount of rainfall.

There are also two types of this type of automatic wiper. One is a full-auto type (infinite intermittent type) in which there is no limitation on the intermittent operation cycle, and the other is a semi-auto type in which the maximum value of the intermittent operation cycle is determined. That is, the full-auto type operates the wiper only when the integrated value of the raindrop pulse reaches the control threshold. On the other hand, the semi-auto type measures the elapsed time after the start of integration, and even if the pulse integration value does not reach the control threshold,
When the elapsed time (integrated time) exceeds a predetermined time threshold, the wiper is operated once, and simultaneously the pulse integrated value and the integrated time are cleared.

By the way, even if the raindrops at the time of minute rainfall adhere to the windshield, they do not obstruct the driving view much, and may evaporate naturally during traveling. If it continues for a long time even in such a small rainfall state, the pulse integration value eventually reaches the control threshold value in the fully automatic method, and the wiper is set to 1 at that time.
Works twice. This wiper operation is unpleasant because the driver does not expect it at all and does not expect it. Such a sudden wiper operation also occurs when a sudden noise is mixed in and the pulse integrated value suddenly increases.

In the semi-auto type, since the pulse integration value is cleared by the time threshold, there is almost no unexpected wiper operation. However, since the time threshold value is a finite value, an infinite cycle wiper operation like a full-auto type cannot be expected. That is, an unnecessary wiper operation is performed during a minute rainfall.

[Problems to be solved by the invention]

An object of the present invention is to solve the problems of the conventional full-auto type or semi-auto type, and to realize an infinite cycle intermittent operation which is ideal as an automatic wiper and does not malfunction.

[Means for solving the problem]

FIG. 1 is a block diagram of the present invention, in which 10 is a raindrop sensor, 20 is a wiper control device, and 30 is a wiper. The raindrop sensor 10 is, for example, an optical type, and outputs a raindrop pulse when the raindrop passes between the opposing light emitting element and light receiving element. The wiper control device 10 includes a microcomputer (CPU) 11 and input circuits 12 and 13.
The first input circuit 12 binarizes an analog raindrop pulse and inputs it to the CPU 11. CPU11
Accumulates raindrop pulses, and when a certain condition is satisfied, sends a signal to the wiper drive circuit 14 to operate the wiper 30 once.
The wiper 30 is switched to a wiper motor 31 for swinging a wiper blade (not shown) and a power source iG side during operation of the wiper (O
N), cam that returns (OFF) to the earth side at the end of the operation
An SW (switch) 32 is provided. The second input circuit 13 is for inputting the state of the cam SW32 to the CPU 11 to confirm the wiper operation. The wiper drive circuit 14 outputs a drive signal to rotate the motor 31 during the wiper operation, and outputs a control signal at the end of operation (detected by the cam SW 32) to output the motor signal.
31 is forcibly stopped. The above is a general configuration.

In the present invention, a level threshold value and a time threshold value at which the CPU 11 only clears the pulse integration value and does not operate the wiper 30 are set.

[Action]

As shown by A and A 'in FIG. 2, the raindrop pulse is integrated from the integration time T = 0 (clear time, that is, the previous wiper operation timing), and when the integrated value R reaches a predetermined control threshold value R1, Clear the integrated value R (R ← 0) and set the wiper to 1
It is the basis of an auto wiper that it is operated multiple times, and all fully automatic types follow this principle.

On the other hand, the semi-automatic auto wiper has an integrated value R
When the accumulated time T passes the predetermined time threshold T1 without reaching the control threshold R1, such as B, the accumulated value R is cleared and the wiper is performed once when T = T1. Make it work. Of course, in the case of A, the operation is the same as that of the fully automatic type.

In the present invention, the level threshold R2 lower than the control threshold R1
Is set, and if R <R2 when T = T1, the integrated value R
Clear However, at this time, the wiper is not operated. Note that this time threshold is not necessarily the same as the semi-auto time threshold.

When such a level threshold value R2 and a time threshold value T1 are set, an unnecessary wiper operation at the time of a minute rainfall and a sudden malfunction due to noise are eliminated in the fully automatic method.

On the other hand, in the case of the semi-automatic method, a case occurs in which the wiper does not operate after reaching the time threshold value T1, so that the intermittent period becomes long at the time of minute rainfall, which is close to that of the fully automatic method.

〔Example〕

FIG. 3 is a flowchart of the first embodiment of the present invention. After initialization such as RAM clear is performed in step S1, raindrop pulses are integrated in step S2. Then, in step S3, the integrated value is compared with the control threshold value R1, and if the integrated value is small, the timer is incremented in step S4. This timer is for measuring the accumulated time. Step S5 is a comparison between the accumulated time and the time threshold value T1, and if the accumulated time is short, the process returns to step S2. The above is the range of R <R1 and T <T1 in FIG.

On the other hand, when the integrated value becomes maximum in step S3, the integrated value is cleared in step S6, the timer is cleared in step S7, and the wiper is turned on in step S8. After this cam
When it is confirmed that the SW is once turned on and then returned to the off state, the wiper is turned off (steps S9 to S11). This is the case in FIG. 2A.

On the other hand, if it is determined that T1 has elapsed in step S5, step S1
At 2, the integrated value is compared with the level threshold value R2. If it is determined that the integrated value is small, the integrated value is cleared in step S13,
In step S14, the timer is cleared, and the process returns to step S2.
This is the case in FIG. 2C.

It should be noted that when it is determined in step S12 that the integrated value is large, the process proceeds to step S6 in the case of FIG. 2B.

The above-described time threshold T1 is, for example, 30 seconds, and the level threshold R2 is set to, for example, a value that is 1/10 of the control threshold R1.

Next, an example of application to a semi-auto type that performs mode switching will be described. Mode switching means that if there is a wiper mode as shown in the table below, The mode is automatically changed according to the amount of rainfall.
Mode switching includes mode up for shortening the cycle and mode down for increasing the cycle. Maintaining the current status is called mode keeping.

Conventional mode switching is performed as shown in FIG. In this figure, 0 to R1 and 0 to T1 correspond to FIG. 2, and the outside of the range is used for displaying each mode. When R1 and T1 have the same values as those in FIG. 2, for example, a mode down threshold (level) R3 of about R1 / 2 and a mode up threshold (time) T2 of about 0.8T1 are set. When the integration characteristic is A, the mode is up, when it is B, the mode is kept, and when it is C, the mode is down. In this example, T1 is set to WOT (wiper
Operating time).

FIG. 6 is a flow chart of a semi-automatic system for performing the mode switching described above. The initialization in step S21, the integration of the raindrop pulse in step S22, and the comparison of the integration values in step S23 are the same as steps S1 to S3 in FIG.

If it is determined in step 23 that the integrated value has reached the control threshold value R1, the integrated time at that time is determined in step S24. Here, if it is determined that the mode-up threshold T2 has not yet elapsed, since the amount of rainfall is large, the mode is increased in step S25 (for example, transition from the 10S mode to the 5S mode) so as to shorten the operation cycle, and the WOT is reduced in step S26. Set again.

On the other hand, in step S23,
If it is determined that T has elapsed, in step S28, the integrated value at that time is compared with the mode down threshold value R3. If the integrated value is small, the amount of rainfall is small, and the operation cycle (intermittent time) is extended so that the operation cycle (intermittent time) is increased. Mode down (for example, from 10S mode
Move to 20S mode), and reset WOT in step S30.

In other cases, that is, when the accumulated value reaches R1, T2
In the case where it took longer (steps S23 and S24), and in the case where R3 exceeded but did not reach R1 at the time when the WOT had elapsed (steps S23, S27 and S28), the operation cycle was generally suitable for rainfall. Judgment is made, the mode is kept in step S31, and the same operation cycle WOT as the previous time is reset in step S32.

After the above mode switching, the wiper control corresponding to each mode is performed in step S33 and subsequent steps. That is, step
In S33, it is determined whether the mode is the Hi mode. If Y (yes), Hi is turned on and Lo is turned off in steps S34 and S35, and the process returns to step S22. If N (No) in step S33, Lo in step S36
Mode, and if Y, Hi is set to O in steps S37 and S38.
FF and Lo ON. If N in step 36, the wiper is operated only once because it is an intermittent operation. This can be done as follows. That is, Hi is set to O in step S39.
When it is set to FF and Lo is turned ON in step S40, the wiper starts low-speed operation. After this, the cam SW is driven in steps S41 and S42, and when it changes from ON to OFF, Lo is turned off in step S43.
To Thus, the wiper operation can be limited to one time.

When the level threshold R2 shown in FIG. 2 is introduced to the semi-auto type automatic wiper which performs such mode switching,
Mode switching as shown in FIG. 9B or 10C can be performed.

FIG. 5 (b) shows that in the longest mode (20s mode in the example of FIG. 4), further mode down cannot be performed by the mode down threshold R3. This is a classification method. In other words, the mode keep 1 can perform the integrated value, the clear, and the wiper control similarly to the conventional mode keep. Instead of expanding this area from R3 to R2, a new mode keep 2 that cannot control the wiper is installed. In this mode keep 2, only the integrated value is cleared.

FIG. 7 is a flowchart in this case. In this example, steps S28, S29 and S31 in FIG. 6 are changed to steps S51, S52 and S53. Step S51 is a comparison between the integrated value and R2. If the integrated value is small, the process branches to mode keep 2 in step S52, and if the integrated value is large, the process branches to mode keep 1 in step S53. In the case of mode keep 1, the accumulated value is cleared and the wiper operation is performed after the elapse of the WOT. In the case of mode keep 2, the accumulated value is cleared and the wipe operation is not performed. Other processes are the same as those in FIG.

FIG. 5 (c) classifies the mode down into two types by the threshold value R2. That is, if the integrated value is equal to or less than R2 when WOT has elapsed, mode down 2 is set, and if the integrated value is between R2 and R3, mode down 1 is set. Mode down 1 is a mode down accompanied by a wiper operation, while mode down 2 is not accompanied by a wiper operation.

In such a mode down 2, for example, when rain suddenly stops during operation in the Lo mode (for example, entering a tunnel), in the conventional mode down, the wiper operates while switching from Lo → 2s → 5s → 10s → 20s. However, this point can be prevented (the integrated value is rearranged while the mode is down, but the wiper operation is not performed). On the other hand, mode down 1 involves a wiper operation, which is necessary to cope with a gradual decrease in rainfall as in the conventional case.

FIG. 8 is a flowchart showing this processing. In this example, step S29 in FIG. 6 is changed to steps S61 to S66. Step S61 is a comparison of the integrated value and R2,
If it is determined that the integrated value is large, the process of mode down 1 is performed in step S66. In this case, the WOT is reset in step S30, and the process moves to step S33. On the other hand, if it is determined in step S61 that the integrated value is small, the process of mode down 2 is performed in step S62, and the WOT is reset in step S63. At this time, both Hi and Lo are turned OFF in steps S64 and S65, and the wiper operation is prohibited. Other processes are the same as those in FIG.

〔The invention's effect〕

As described above, according to the present invention, there is an advantage that the automatic wiper operation at the time of minute rainfall can be optimized, particularly a malfunction of a full automatic type can be prevented, and an infinite intermittent operation of a semi-automatic type can be achieved.

[Brief description of the drawings]

1 is a block diagram of the present invention, FIG. 2 is an explanatory diagram of the present invention, FIG. 3 is a flowchart of a first embodiment of the present invention, FIG. 4 is an explanatory diagram of a wiper mode, and FIG. FIG. 6 is a flowchart showing the processing of FIG. 5 (a), FIG. 7 is a flowchart of the second embodiment of the present invention, and FIG. 8 is a flowchart of the third embodiment of the present invention. . In the figure, 10 is a raindrop sensor, 20 is a wiper control device, and 30 is a wiper.

Claims (1)

(57) [Claims] When the integrated value of a raindrop pulse from a raindrop sensor reaches a predetermined control threshold value (R1),
A wiper control device for clearing the integrated value and operating the wiper, wherein a predetermined time threshold value (T1) for determining an integrated time of the raindrop pulse and the integrated value lower than the predetermined control threshold value (R1). A level threshold value (R2) for determining a value level, and when the integrated time exceeds the time threshold value (T1), the integrated value reaches the level threshold value (R2). A wiper control device for determining whether or not the integrated value has been reached without operating the wiper.