JP2008254614A - Wiper control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiper control device capable of stabilizing movement of wiper blades, in occurrence of wiping mode hunting, by detecting the wiping mode hunting and restrict it. <P>SOLUTION: A wiping mode hunting determination section 53 determines that wiping mode hunting breaks out when the wiping mode hunting determination section 53 detects that mode-down operation, which makes the same wiping mode as the terminal wiping mode, is continuously performed twice. When wiping mode hunting breaks out, a wiping mode determination section 51 enlarges a rainfall range of two wiping modes relative to the wiping mode hunting. With this structure, the wiping mode hunting is restricted and wiping operation of the wiper blades is stabilized, and a trouble in which a driver feels instability about movement of the wiper blades and the driver worries about a breakout of a failure in the wiper control device can be prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wiper control device that controls a reciprocating wiping operation of a wiper blade based on a detection result of a raindrop sensor that detects raindrops, and is suitable for use in an automobile or the like.

  As a conventional wiper control device, for example, when a wiper operation switch is switched to an automatic control mode (Auto mode), the wiper control device sets a wiping mode based on the detection result of a raindrop sensor that detects raindrops, thereby There is one that drives and controls a wiper blade (see Patent Document 1).

In the conventional wiper control device, a relationship between a plurality of wiping modes having different reciprocal wiping operation interval times of the wiper blades and a rainfall amount range in which each wiping mode is implemented is set in advance. When the conventional wiper control device is operating in the Auto mode, the corresponding wiping mode is determined based on the amount of rainfall determined based on the detection result from the raindrop sensor, and the reciprocating wiping operation interval time in the wiping mode is determined. The wiper blade is driven. Accordingly, the wiper blade reciprocating wiping operation interval time is switched by the wiper control device. That is, as the amount of rainfall increases, the wiper control device switches the wiper blade to the wiping mode in which the reciprocating wiping operation interval time of the wiper blade is shorter, and drives and controls the wiper blade.
JP-A-2-57455

  In the conventional wiper control device, the relationship between the plurality of wiping modes in which the reciprocating wiping operation interval time of the wiper blade is different and the rainfall amount range in which each wiping mode is performed, the wiping mode in which the reciprocating wiping operation interval time is shorter, The corresponding rainfall range is set to be on the heavy rainfall side. Moreover, the rainfall amount ranges of two wiping modes in which the reciprocating wiping operation interval time is adjacent to each other partially overlap. A specific example of the wiper blade drive control operation when such a conventional wiper control device is operating in the Auto mode will be briefly described with reference to FIG. FIG. 12 is a graph showing the relationship between each wiping mode set in the conventional wiper control device and the rainfall range within which they are maintained. Although two wiping modes are shown in FIG. 12, the actual number of wiping modes is larger. In FIG. 12, the vertical axis indicates the wiping mode, and the upper and lower wiping mode is shorter in the reciprocating wiping operation interval time. In FIG. 12, the horizontal axis indicates the rainfall, that is, the rainfall per unit time, and the rainfall increases toward the left side.

  In the conventional wiper control device, a certain wiping mode, that is, the wiping mode B in FIG. 12, is selected by the wiping mode determination means, and the wiper blade is driven in the wiping mode. The amount of rainfall at this time is the amount of rainfall R indicated by x in FIG. The rainfall range in which the wiping mode B is maintained is within the range of the mode-down threshold LB and the mode-up threshold UB as shown in FIG. Here, the meaning of the mode-down threshold LB and the mode-up threshold UB will be described. When the wiping mode B is selected, that is, when the rainfall amount is within the range between the mode-down threshold value LB and the mode-up threshold value UB, if the rainfall amount is less than the mode-down threshold value LB, the wiping mode determination means A wiping mode C that is a lower wiping mode than mode B, that is, a wiping mode in which the wiper blade reciprocating wiping operation interval time is one step longer is selected. On the other hand, when the rainfall amount is equal to or higher than the mode-up threshold UB, the wiping mode determination means selects the wiping mode higher than the wiping mode B, that is, the wiping mode A that is a wiping mode in which the wiper blade reciprocating wiping operation interval time is one step shorter. To do. Therefore, the other two wiping modes A and C shown in FIG. 12 also have mode-down thresholds LA and LC and mode-up thresholds UA and UC, respectively.

  As described above, when the wiping mode B is selected and the wiper blade is driven in the wiping mode B when the wiping blade is driven in the wiping mode B, the wiping mode determination means The wiping mode A, which is higher than the wiping mode B, is selected, and the wiper blade is driven in the wiping mode A this time. This switching operation is called mode up. When the amount of rainfall decreases while the wiper blade is being driven in the wiping mode A and becomes less than the mode down threshold LA, the wiping mode determination means selects the wiping mode B lower than the wiping mode A, and this time The wiper blade is driven in the wiping mode B. When the wiper blade is driven in the wiping mode B, if the rainfall increases again and exceeds the mode-up threshold UB, the wiping mode determination means selects the wiping mode A higher than the wiping mode B, and this time In the wiping mode B, the wiper blade is driven. In this way, when the rainfall amount changes between the mode-up threshold UB of the wiping mode B and the mode-down threshold LA of the wiping mode A, which is the higher mode of the wiping mode B, the wiping mode determination means accordingly The selected wiping mode is alternately repeated from the wiping mode B to the wiping mode A and from the wiping mode A to the wiping mode B. When such two adjacent wiping mode operations are repeated, that is, wiping mode hunting occurs, the driver feels that the movement of the wiper blade is unstable, and that the wiper control device may have failed. There is a risk of anxiety.

  The present invention has been made in view of the above problems, and its object is to detect a wiping mode hunting when the wiper control device is operating in the Auto mode and to detect the wiping mode hunting to suppress the wiping mode hunting. To provide a wiper control device capable of stabilizing the movement of a blade.

  In order to achieve the above object, the present invention employs the following technical means.

  The wiper control device according to claim 1 of the present invention is a raindrop sensor that outputs a detection signal corresponding to the amount of raindrops adhering to the detection area, with a predetermined area within the wiper blade wiping range on the windshield as a detection area. A wiper control device for driving a wiper blade based on a detection signal from a rainfall amount determining means for determining a rainfall amount attached to a windshield based on a detection signal, and a rainfall amount determined by the rainfall amount determining means A wiping mode determination unit that determines a wiping mode of the wiper blade based on the wiping mode, and one wiping mode corresponding to the amount of rainfall from a plurality of wiping modes in which the wiper blade reciprocating wiping operation interval time is different by the wiping mode determination unit And the wiper blade is driven by the wiping mode, and the reciprocating wiping of each wiping mode is performed. The operation interval time is set to be shorter as the corresponding rainfall amount is larger, and the rainfall amount range in which each wiping mode is maintained is an operation for transitioning to the wiping mode in which the reciprocating wiping operation interval time is longer than each wiping mode. A mode-up threshold that is a threshold for performing a mode-up operation that is a transition to a wiping mode in which the amount of rainfall as a mode-down threshold that is a threshold for performing a certain mode-down operation and a wiping mode interval time that is shorter than each wiping mode is shorter In the wiper control device in which the rainfall amount of the mode-up threshold is larger than the rainfall amount of the mode-down threshold, the two wiping adjacent to each other as the wiping mode determined by the wiping mode determination means Wiping mode hunting determination means for determining occurrence of wiping mode hunting, which is a phenomenon in which modes appear alternately When the wiping mode hunting is determined to have occurred by wiping mode hunting determining means it is characterized by comprising a wiping mode hunting suppressing means for suppressing the wiping mode hunting.

  This provides a wiper control device that can detect the occurrence of wiping mode hunting when the wiper control device is operating in the Auto mode and suppress the wiping mode hunting to stabilize the movement of the wiper blade. can do.

  The wiper control device according to claim 2 of the present invention is such that the wiping mode hunting determination means is performed when the mode-up operation in which the same wiping mode is set as the starting point wiping mode is continuously performed twice, or when the same wiping mode is ended. It is characterized in that it is determined that wiping mode hunting has occurred when the mode-up operation for wiping mode is performed twice in succession.

  The wiping mode determination operation of the wiping mode hunting determination means in the wiper control device configured as described above will be described with reference to FIG.

  The wiping mode B in FIG. 12 corresponds to the starting point wiping mode in the wiper control device according to claim 2 of the present invention, and the wiping mode A in FIG. 12 is the wiper control device according to claim 2 of the present invention. This corresponds to the higher-level wiping mode that is changed by the mode-up operation in.

  Here, when the wiper control device is performing the wiping operation in the wiping mode B, the rainfall amount is the mode-up threshold UB of the wiping mode B, the upper side of the wiping mode B adjacent to the wiping mode B (the reciprocating wiping operation interval time) Consider a case in which the mode-down threshold LA of the wiping mode A, which is the wiping mode on the shorter side, fluctuates as both ends of the fluctuation range. When the amount of rainfall varies as described above, the wiping mode determined by the wiping mode determination means is two wiping adjacent to each other, such as wiping mode B → wiping mode A → wiping mode B → wiping mode A. The wiping mode B and the wiping mode A which are modes appear alternately, and so-called wiping mode hunting occurs. In this case, the wiping mode B and the wiping mode A are the wiping mode hunting start point wiping mode and end point wiping mode, respectively. When the transition from the wiping mode B to the wiping mode A, that is, the mode-up operation is performed twice in succession, the wiping mode hunting determination means performs the mode-up operation in which the starting point wiping mode is the wiping mode B twice in succession. It is determined that the wiping mode hunting has occurred. Alternatively, it is determined that the mode-up operation in which the end point wiping mode is the wiping mode A has been performed twice in succession, and it is determined that the wiping mode hunting has occurred. As a result, the wiping mode hunting determination means can reliably detect the wiping mode hunting when the wiping mode hunting occurs.

  In the wiper control device according to claim 3 of the present invention, the wiping mode hunting determination means is configured such that the mode wiping mode in which the same wiping mode is the starting point wiping mode is continuously performed twice, or the same wiping mode is terminated. It is characterized in that it is determined that the wiping mode hunting has occurred when the mode down operation for wiping mode is performed twice in succession.

  The wiping mode determination operation of the wiping mode hunting determination means in the wiper control device configured as described above will be described with reference to FIG.

  The wiping mode A in FIG. 12 corresponds to the starting point wiping mode in the wiper control device according to claim 3 of the present invention, and the wiping mode B in FIG. 12 is the wiper control device according to claim 3 of the present invention. This corresponds to the lower-side wiping mode that is changed by the mode-down operation.

  Here, when the wiper control device is performing the wiping operation in the wiping mode A, the rainfall amount is the mode down threshold LA of the wiping mode A, and the lower side of the wiping mode A (reciprocal wiping operation interval time). Consider a case in which the mode-up threshold UB of the wiping mode B, which is the longer wiping mode, fluctuates with both ends of the fluctuation range. When the amount of rainfall varies as described above, the wiping mode determined by the wiping mode determination means is two wiping adjacent to each other, such as wiping mode A → wiping mode B → wiping mode A → wiping mode B. The wiping mode A and the wiping mode B, which are modes, appear alternately, and so-called wiping mode hunting occurs. In this case, the wiping mode A and the wiping mode B are respectively the wiping mode hunting start point wiping mode and the end point wiping mode. When the transition from the wiping mode A to the wiping mode B, that is, the mode down operation is performed twice in succession, the wiping mode hunting determination means performs the mode up operation with the wiping mode A being the wiping mode A twice in succession. It is determined that the wiping mode hunting has occurred. Alternatively, it is determined that the mode down operation in which the end point wiping mode is the wiping mode B has been performed twice in succession, and it is determined that the wiping mode hunting has occurred. As a result, the wiping mode hunting determination means can reliably detect the wiping mode hunting when the wiping mode hunting occurs.

  In the wiper control device according to claim 4 of the present invention, the wiping mode hunting suppression control is performed in the rainfall amount range in which the wiping mode is maintained with respect to at least one of the two wiping modes related to the wiping mode hunting. It is characterized by expanding.

  According to the above configuration, the wiping mode is related to the wiping mode hunting by expanding the rainfall amount range in which the wiping mode is maintained with respect to at least one of the two wiping modes related to the wiping mode hunting. The rainfall range between the mode-up threshold and the mode-down threshold, which is a threshold for transition between the two wiping modes, is expanded while including the actual rainfall variation range. Accordingly, since the wiping mode hunting is eliminated, when the wiping mode hunting occurs, a wiper control device capable of detecting the wiping mode hunting and suppressing the wiping mode hunting to stabilize the movement of the wiper blade is provided. be able to.

  In the wiper control device according to claim 5 of the present invention, the wiping mode hunting suppressing means changes the mode-up threshold value to the heavy rainfall amount side in the lower wiping mode among the two wiping modes related to the wiping mode hunting, In the upper wiping mode of the two wiping modes related to the wiping mode hunting, at least one of the processes of changing the mode down threshold value to the low rainfall amount side is executed.

  The wiping mode hunting suppression operation of the wiping mode hunting suppression means in the wiper control device configured as described above will be described with reference to FIG.

  During the wiping operation in the wiping mode B in which the wiper control device is the lower wiping mode, the amount of rainfall is adjacent to the wiping mode B mode-up threshold UB, the wiping mode B and the upper side of the wiping mode B (reciprocating wiping operation) Consider a case where the mode-down threshold LA of the wiping mode A, which is the wiping mode on the shorter interval time), fluctuates as both ends of the fluctuation range, thereby causing wiping mode hunting between the wiping mode B and the wiping mode A. . The wiping mode hunting suppressing unit starts the wiping mode hunting suppressing operation based on the determination result that the wiping mode hunting is generated by the wiping mode hunting determining unit.

  The wiping mode hunting suppressing means changes the mode-up threshold value UB in the wiping mode B, which is the lower-side wiping mode, to the heavy rain-side mode-up threshold value UBnew as indicated by a broken line in FIG. At the same time, the wiping mode hunting suppressing means changes the mode-down threshold LA in the wiping mode A, which is the upper-side wiping mode, to the mode-down threshold LAnew on the low rainfall side as shown by a broken line in FIG. Then, the rainfall range width between the mode-up threshold UBnew of the wiping mode B and the mode-down threshold LAnew of the wiping mode A after the rainfall range expansion is the wiping mode before the rainfall range expansion, which is the fluctuation range of the rainfall It expands while including the rainfall range width between the mode-up threshold value UB of B and the mode-down threshold value LA of the wiping mode A. Thus, after the wiping mode hunting determination means determines that the wiping mode hunting has occurred, the wiping mode is stably maintained in either the wiping mode A or the wiping mode B if the rainfall fluctuation range does not change. The wiping mode hunting disappears. Accordingly, there is provided a wiper control device capable of detecting the wiping mode hunting when the wiper control device is operating in the Auto mode and detecting it to suppress the wiping mode hunting and stabilize the movement of the wiper blade. be able to.

  In the wiper control device according to claim 6 of the present invention, the wiping mode hunting suppression means wipes the wiping mode as a wiping mode hunting suppression operation during a period from when it is determined that the wiping mode hunting occurs until a predetermined condition is satisfied. The wiping mode hunting suppression operation is canceled when a predetermined condition is satisfied by fixing to one of the two wiping modes related to mode hunting.

  According to the above configuration, when the wiping mode hunting determination unit determines that the wiping mode hunting has occurred, the wiping mode is fixed without transitioning for a predetermined time. Accordingly, since the wiping mode hunting is eliminated, when the wiping mode hunting occurs, a wiper control device capable of detecting the wiping mode hunting and suppressing the wiping mode hunting to stabilize the movement of the wiper blade is provided. be able to.

  In the wiper control device according to claim 7 of the present invention, the predetermined condition is that the two wiping modes related to the wiping mode hunting from the two wiping modes related to the wiping mode hunting in which the rainfall amount determined by the rainfall amount determining means is It is characterized by continuously exceeding a threshold value for transition to different wiping modes a plurality of times.

  The operation of the wiping mode hunting suppressing means in the wiper control device configured as described above will be described.

  In the above-described configuration, the threshold value for transition from the two wiping modes related to the wiping mode hunting to the wiping mode different from the two wiping modes related to the wiping mode hunting is the upper side wiping of the two wiping modes related to the wiping mode hunting Wiping on the lower side of the lower wiping mode of the two wiping modes related to the mode-up threshold (hereinafter referred to as the upper release threshold) and the wiping mode hunting, which is a threshold for transitioning to the wiping mode on the upper side of the mode It means either a mode-down threshold (hereinafter referred to as a lower release threshold) that is a threshold for transitioning to a mode.

  A case is considered in which it is determined that the wiping mode hunting is generated by the wiping mode hunting determination means, and the wiping mode is fixed by the wiping mode hunting suppression means based on the wiping mode hunting determination means. When the fluctuation range of the rainfall amount is not different from that when the wiping mode hunting occurs, the wiping mode hunting suppression operation is continuously executed, and the wiping mode is fixed. If the rainfall increases from this state and the rainfall determination result in the rainfall determination means exceeds the above-described upper release threshold rainfall a plurality of times in succession, or the rainfall decreases and the rainfall determination means In the case where the rainfall amount determination result at is lower than the above-described lower release threshold for a plurality of times, the wiping mode hunting suppression means cancels the wiping mode hunting suppression process. That is, the wiping mode fixing is stopped, and the wiper motor is driven in the wiping mode determined by the wiping mode determination means.

  As described above, according to the wiper control device of the seventh aspect of the present invention, when the wiping mode hunting occurs, the wiping mode hunting can be eliminated by fixing the wiping mode by the wiping mode hunting suppressing means. Also, if the rainfall has changed since the occurrence of the wiping mode hunting, the wiping mode fixing, which is the wiping mode hunting suppression operation, is stopped, and the wiper blade is wiped in the wiping mode adapted to the new rainfall state. be able to. Therefore, when the wiping mode hunting occurs, the wiper blade movement can be reliably stabilized, and if the fluctuation range of rainfall has changed since the wiping mode hunting occurred, the wiper control device can respond quickly to the change. Can be provided.

  Hereinafter, embodiments of the wiper control device according to the present invention will be described with reference to FIGS. 1 to 5 by taking as an example a case where the wiper control device is applied to a wiper control device 1 mounted on an automobile.

(First embodiment)
The wiper control device 1 is mounted on the automobile 100 and controls the operation of the wiper device 10 that wipes raindrops adhering to the front windshield 101 in accordance with the operation position of the wiper control switch 30. In particular, when the automatic control (AUTO mode) position is selected in the wiper control switch 30, the amount of raindrops attached to the front windshield 101 is detected by the raindrop sensor 20, and the operation control of the wiper device 10 is performed based on the determination result. Do.

  First, the overall configuration of the wiper control device 1 will be described.

  As shown in FIG. 1, the wiper control device 1 is a microcomputer that drives the wiper device 10 based on a raindrop sensor 20, a wiper device 10, a wiper control switch 30, a signal from the wiper control switch 30, and a signal from the raindrop sensor 20. 50 or the like. The wiper control device 1 is supplied with electric power from an automobile battery via an automobile ignition switch.

  The wiper device 10 includes a wiper blade 13 that is driven via a link mechanism 12 by a driving torque generated by the wiper motor 11 and performs a reciprocating wiping operation on the front windshield 101. The reciprocating wiping operation of the wiper blade 13 is executed by outputting a drive instruction signal to the wiper motor 11 from the wiping mode determination unit 51 provided in the microcomputer 50.

  The wiper control switch 30 is installed in the driver's seat of the passenger compartment, and stops the reciprocating wiping operation of the wiper blade 13 (OFF mode), automatic control (AUTO mode), low speed operation (LO mode), and high speed operation (HI mode). Is switched by a manual operation of the driver. The wiper control switch 30 is rotated to any one of four operating positions, for example, so that one of these operation modes is selected. When one of the four operation modes is selected, the wiper control switch 30 outputs information on the selected operation mode to the microcomputer 50 (wiping mode determination unit 51) described later.

  As shown in FIG. 3, the raindrop sensor 20 basically includes a light emitting element 21 such as a light emitting diode that emits infrared light toward the detection region Ad of the front windshield 101, and the light emitting element 21. And a light receiving element 22 such as a photodiode that outputs an output value corresponding to the amount of light received and reflected by the front windshield 101. The light emitting element 21 is connected to the microcomputer 50 via a light emitting element driving circuit (not shown), and the microcomputer 50 controls the turning on / off of the light emitting element 21. The light receiving element 22 is connected to the microcomputer 50 via a detection amplification circuit (not shown), and outputs a detection signal corresponding to the detected amount of raindrops to the microcomputer 50. With this configuration, when no raindrop is attached to the detection area Ad, the infrared light emitted from the light emitting element 21 travels as indicated by the solid line arrow in FIG. Most of the light is reflected by the front windshield 101 and received by the light receiving element 22. However, when the raindrop D is attached to the detection area Ad, a part of the infrared light emitted from the light emitting element 21 is broken by the broken line in FIG. 3 via the raindrop D attached to the detection area Ad. It proceeds as indicated by the arrow and exits from the front windshield 101. Therefore, the amount of light received by the light receiving element 22 is reduced. Thus, the amount of raindrops adhering to the detection region Ad is optically detected based on the amount of raindrops adhering to the detection region Ad and the amount of light received by the light receiving element 22. In the raindrop detection apparatus 1 according to the first embodiment of the present invention, the detection signal of the raindrop sensor 20 decreases as the amount of raindrops adhering to the detection area Ad increases, and the raindrop sensor 20 decreases as the amount of raindrops adhering to the detection area Ad decreases. The detection signal becomes larger.

  The microcomputer 50 actually includes a CPU that performs control processing and arithmetic processing, a storage device including a memory such as a read-only memory (ROM) and a writable memory (RAM) for storing various programs and data, A It is configured to include functions of an input circuit such as a / D converter, an output circuit, and a power supply circuit. However, here, as shown in FIG. 2, a rainfall amount determination unit 52 that determines the amount of raindrops attached to the front windshield 101 based on the magnitude of a change in the detection signal output from the raindrop sensor 20, a rainfall amount determination unit The wiping mode related to the operation of the wiper blade 13 is determined based on the rainfall determined in 52, that is, the reciprocating wiping operation interval time of the wiper blade 13 is determined, and the driving signal is output to the wiper motor 11 based thereon. A conceptual description will be given focusing on the mode determination unit 51.

  Further, in the wiper control device 1 according to the present invention, the microcomputer 50 generates the wiping mode hunting, which is a phenomenon in which the wiping mode determination unit 51 continuously and alternately determines two adjacent wiping modes. A wiping mode hunting determining unit 53 as a wiping mode hunting determining unit for determining, and a wiping mode hunting suppressing unit that performs a process of suppressing the wiping mode hunting when the wiping mode hunting is detected by the wiping mode hunting determining unit 53 54. The actions and effects of the wiping mode hunting determination unit 53 and the wiping mode hunting suppression unit 54 will be described later.

  The wiping mode determination unit 51 takes in information on the current rainfall situation from the rainfall amount determination unit 52, information on the operation mode from the wiper control switch 30, and the like, and drives and controls the wiper motor 11 based on these information. That is, when the wiper control switch 30 is operated to stop the wiping operation (OFF mode), to operate at a low speed (LO mode), and to operate at a high speed (HI mode), the wiping mode determination unit 51 receives it and performs predetermined driving. An instruction signal is output to the wiper motor 11. On the other hand, when the wiper control switch 30 is operated to automatic control (AUTO mode), the wiping mode determination unit 51 is based on the rainfall determined by the rainfall determination unit 52 based on the detection signal from the raindrop sensor 20. The wiping mode by the wiper blade 13, that is, the reciprocating wiping operation interval time by the wiper blade 13 is determined, and a drive instruction signal corresponding to the determined wiping mode is output to the wiper motor 11.

  Next, the operation of the wiper control device 1, particularly the wiping mode determination method in the wiping mode determination unit 51 when the wiper control switch 30 is operated in automatic control (AUTO mode) will be described based on FIG. 4. FIG. 4 is a graph showing the relationship between the amount of rainfall per unit time and the wiping mode determined based thereon. In FIG. 4, the horizontal axis indicates the rainfall per unit time determined by the rainfall determination unit 52 based on the detection signal from the raindrop sensor 20, and the vertical axis indicates the wiping mode. In FIG. 4, a line segment or a half line drawn corresponding to each wiping mode indicates a rainfall amount range in which the wiping mode is maintained. The amount of rainfall decreases toward the left and increases as it goes to the right.

  First, each wiping mode will be described. In the “stop mode”, the wipe operation of the wiper blade 13 is literally stopped, and the wiper blade 13 is stopped at its initial position, that is, the position shown in FIG. In the “intermittent 3 mode” to “intermittent 1 mode”, the wiper blade 13 performs an intermittent reciprocating wiping operation. The reciprocating wiping operation interval time is the longest in the “intermittent 3 mode”, and is shorter in the order of “intermittent 2 mode” and “intermittent 1 mode”. In the “Lo mode”, the reciprocating wiping operation interval time is shorter than the “intermittent 1 mode”, and it seems that the wiper blade 13 performs a continuous reciprocating wiping operation. The movement speed of the wiper blade 13 is the same in the “Lo mode” and “intermittent 3 mode” to “intermittent 1 mode”. In the “Hi mode”, the reciprocating wiping operation interval time is the same as the “Lo mode”, and the wiper blade 13 appears to be performing a continuous reciprocating wiping operation, but the movement speed of the wiper blade 13 is faster than the “Lo mode”. .

  Next, the correspondence between the rainfall per unit time and the wiping mode will be described. In FIG. 4, a line segment or a half line drawn corresponding to each wiping mode indicates a rainfall amount range per unit time maintained in each wiping mode. In FIG. 4, among the end points of each line segment or half line, the white circle indicates that the wiping mode is switched to the upper mode, that is, the operation interval time of the wiper blade 13 is shorter when the rainfall per unit time is more than that. That is, the mode-up threshold value is a threshold value at which the mode-up operation is executed. On the other hand, the black circle indicates that the wiping mode is switched to the lower mode, that is, the mode in which the operation interval time of the wiper blade 13 is longer when the rainfall per unit time is less than that, that is, the mode down which is the threshold value for executing the mode down operation The threshold is shown.

  When the rainfall per unit time is less than the rainfall R1, the wiping mode determination unit 51 determines the “stop mode” and outputs a stop instruction signal to the wiper motor 11. When the rainfall increases and exceeds the rainfall R2, that is, the mode up threshold value in the “stop mode”, the wiping mode determination unit 51 determines “intermittent 3 mode” which is the higher mode of the “stop mode”, and the wiper motor 11 In contrast, a drive instruction signal corresponding to the “intermittent 3 mode” is output. During the “intermittent 3 mode” operation, when the rainfall amount further increases and exceeds the rainfall amount R4, that is, the mode up threshold value in the “intermittent 3 mode”, the wiping mode determination unit 51 is a higher mode of the “intermittent 3 mode” The “intermittent 2 mode” is determined, and a drive instruction signal corresponding to the “intermittent 2 mode” is output to the wiper motor 11. On the other hand, during the “intermittent 3 mode” operation, when the rainfall amount decreases and falls below the rainfall amount R1, that is, the mode down threshold in the “intermittent 3 mode”, the wiping mode determination unit 51 is in a lower mode of the “intermittent 3 mode”. A certain “stop mode” is determined, and a stop instruction signal is output to the wiper motor 11. Thereafter, during the “intermittent 3 mode” to the “Lo mode”, the wiping mode is switched with each mode-up threshold and each mode-down threshold as the boundary in the same manner as the above-described operation. During the “Hi mode” operation, the “Hi mode” operation is maintained even if the rainfall increases. On the other hand, when the rainfall amount decreases during the “Hi mode” operation and falls below the rainfall amount R9, that is, the mode down threshold value in the “Hi mode”, the wiping mode determination unit 51 is “Lo mode” which is a lower mode of “Lo mode”. The mode is determined, and a drive instruction signal corresponding to the “Lo mode” is output to the wiper motor 11.

  As described above, as the rainfall amount changes from a small amount to a large amount, the wiping mode determination unit 51 sequentially selects a wiping mode in which the reciprocating wiping operation interval time of the wiper blade 13 is shorter. Further, in two adjacent wiping modes, the mode-up threshold value in the lower mode is set larger than the mode-down threshold value in the upper mode, and so-called hysteresis is provided, so that switching between the wiping modes is performed smoothly.

  In each wiping mode from “intermittent 3 mode” to “Lo mode”, the rainfall amount range per unit time in which each wiping mode is maintained, that is, the rainfall amount widths of the mode-up threshold value and the mode-down threshold value are set equal. .

  Next, a specific example of processing executed by the wiping mode determination unit 51 during the automatic control (AUTO mode) operation will be described with reference to FIG. FIG. 5 is a graph showing the relationship between the amount of rainfall per unit time and the wiping mode determined based thereon, and is an enlarged view of a part of FIG.

  The wiper control device 1 of the automobile is in operation when the wiper control switch 30 is operated to automatic control (AUTO mode). At this time, the rainfall amount per unit time is the rainfall amount RA as shown by x in FIG. 5, and the wiping mode determination unit 51 determines the “intermittent 1 mode” as shown in FIG. The “intermittent 1 mode” drive instruction signal is output to the wiper motor 11. As a result, the wiper blade 13 performs the wiping operation in the “intermittent 1 mode”.

  At this time, when the rainfall amount increases from the rainfall amount RA to the mode-up threshold value RU1 of the “intermittent 1 mode”, the wiping mode determination unit 51 determines “Lo mode” and the wiping mode is set to “ Mode up to “Lo mode”. The rainfall range in which the “Lo mode” is maintained is a range from the mode-down threshold value RLL to the mode-up threshold value RUL, as shown in FIG. On the other hand, when the rainfall amount decreases from the rainfall amount RA to the “intermittent 1 mode” mode-down threshold value RL1, the wiping mode determination unit 51 determines “intermittent 2 mode”, and as shown in FIG. Mode down to “Intermittent 2 mode”. The rainfall amount range in which the “intermittent 2 mode” is maintained is a range from the mode-down threshold value RL2 to the mode-up threshold value RU2, as shown in FIG.

  As the rainfall increases from RA, the wiping mode increases from “intermediate 1 mode” to “Lo mode”, and then the wiping mode decreases to the “Lo mode” mode-down threshold RLL after the wiping mode is increased to “Lo mode”. The mode determination unit 51 determines that the “intermittent 1 mode” is selected, and lowers the wiping mode to the “intermittent 1 mode”. The wiping mode becomes the “intermittent 1 mode” again. Therefore, when the rainfall amount repeatedly increases and decreases between the mode-up threshold value RU1 and the mode-down threshold value RLL, the wiping mode determined by the wiping mode determination unit 51 is also linked to the “intermittent 1 mode” in conjunction with the rainfall amount fluctuation. ”And“ Lo mode ”, a phenomenon in which the two wiping modes are alternately repeated, that is, wiping mode hunting occurs. When the wiping mode hunting occurs, the driver feels that the movement of the wiper blade is unstable, and may be anxious about whether or not a failure has occurred in the wiper control device.

  Therefore, in the wiper control device 1 according to the present embodiment, the microcomputer 50 includes the wiping mode hunting determination unit 53 and the wiping mode hunting suppression unit 54 in order to determine the occurrence of the wiping mode hunting and suppress it. Yes. The wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred when it is detected that the mode down operation in which the same wiping mode is the start point wiping mode is performed twice in succession. The wiping mode hunting suppression unit 54 suppresses the occurrence of wiping mode hunting by expanding the rainfall range of the two wiping modes related to the wiping mode hunting based on the determination result of the wiping mode hunting occurrence by the wiping mode hunting determination unit 53. To do. As a result, it is possible to prevent problems such as the driver feeling that the movement of the wiper blade is unstable and becoming worried that a failure has occurred in the wiper control device.

  Hereinafter, the wiping mode hunting determination process executed in the wiping mode hunting determination unit 53 of the microcomputer 50 of the wiper control device 1 according to the embodiment of the present invention, and the wiping mode hunting suppression unit 54 executed when the wiping mode hunting occurs The wiping mode hunting suppression process performed will be described with reference to the flowchart of FIG. FIG. 6 is a flowchart showing a specific processing procedure of the wiper motor drive control process executed by the microcomputer 50. When the automatic control (AUTO mode) is selected through manual operation of the wiper control switch 30 by the driver of the automobile, the wiper wiping control process shown in FIG. 6 is started. While the wiper control switch 30 is set to automatic control (AUTO mode), the processing according to the flowchart of FIG. 6 is repeated. In the flowchart of FIG. 6, “R” represents the rainfall determined by the rainfall determination unit 52, “UCL” represents the mode-up threshold, and “LCL” represents the mode-down threshold. “Mold” and “Mnew” are wiping modes determined by the wiping mode determination unit 53, “Mold” indicates the wiping mode determined last time, and “Mnew” indicates the wiping mode determined this time. .

  The wiper wiping control flowchart shown in FIG. 6 is for the wiping mode hunting determination unit 53 to determine that wiping mode hunting has occurred when the mode-up operation in which the same wiping mode is set to the starting point wiping mode is performed twice in succession. It is. When the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred, the wiping mode hunting suppression unit 54 sets the mode down threshold of the upper wiping mode among the two wiping modes related to the wiping mode hunting to the low rainfall amount side. Of the two wiping modes related to wiping mode hunting, the mode-up threshold value of the lower-side wiping mode is changed to the heavy rainfall amount side.

  When the wiper wiping control process is started, the microcomputer 50 first performs the rainfall amount R determination by the rainfall amount determination means 52 in step 201.

  Subsequently, in step 202, the microcomputer 50 determines the magnitude relationship between the determined rainfall amount R and the mode-down threshold “LCL” in the wiping mode. As a result of the determination process, when the rainfall amount R is smaller than the mode-down threshold “LCL”, the microcomputer 50 executes the mode-down operation as the subsequent step 203 process, and subsequently determines as the process at step 204. The magnitude relationship between the rainfall amount R and the mode-up threshold “UCL” is determined. On the other hand, if the rainfall R is larger than the mode down threshold “LCL” as a result of the determination processing in step 202, the microcomputer 50 performs the subsequent rainfall processing R and the mode up threshold “ The magnitude relationship with “UCL” is determined.

  If the result of determination in step 204 is that the rainfall amount R is smaller than the mode-up threshold “UCL”, the microcomputer 50 proceeds to “return” as shown in FIG. 6 and repeats the processing from step 201 again. . On the other hand, when the rainfall R is larger than the mode-up threshold “UCL” as a result of the determination process in step 204, the microcomputer 50 replaces the current wiping mode with Mnew as the subsequent process of step 205, and then continues to step As a process of 206, it is determined whether or not “Mnew” replaced in step 205 is the same as “Mold” as the previous wiping mode.

  If “Mold” = “Mnew” as a result of the determination process in step 206, the mode-up operation in which the same wiping mode is set as the start point wiping mode is performed twice in succession. That is, wiping mode hunting has occurred. In response to this determination result, the wiping mode hunting suppression unit 54 of the microcomputer 50 executes the wiping mode holding range expansion process as the wiping mode hunting suppression process as the subsequent process of step 207. Subsequently, the microcomputer 50 replaces “Mnew” = “Mold” as the process of step 209, and then the microcomputer 50 executes a mode-up operation as the process of step 210. Then, the microcomputer 50 proceeds to “RETURN” as shown in FIG. 6 and repeats the processing from step 201 again. In the subsequent processing at this time, as the mode-down threshold value “LCL” and the mode-up threshold value “UCL”, the new threshold values subjected to the wiping mode holding range expansion process in step 207 are used.

  On the other hand, if “Mold” ≠ “Mnew” as a result of the determination processing in step 206, the mode-up operation is performed twice in succession, but the start-point wiping mode of each mode-up operation is different. That is, no wiping mode hunting has occurred. In response to this determination result, the wiping mode hunting suppression unit 54 of the microcomputer 50 cancels the wiping mode holding range expansion process as the wiping mode hunting suppression process as the subsequent process of step 208. Subsequently, the microcomputer 50 replaces “Mnew” = “Mold” as the process of step 209, and then the microcomputer 50 executes a mode-up operation as the process of step 210. Then, the microcomputer 50 proceeds to “RETURN” as shown in FIG. 6 and repeats the processing from step 201 again. In the subsequent processing at this time, as the mode-down threshold “LCL” and the mode-up threshold “UCL”, the respective thresholds after the cancellation of the wiping mode hunting suppression processing performed in step 207 are used.

  Next, with reference to the timing charts shown in FIGS. 7A to 7D, the operation of the present embodiment, that is, the wiping mode hunting detection operation by the wiping mode hunting determination unit 53 and the wiping mode hunting suppression unit 54 are described. The wiping mode hunting suppression operation by is summarized.

  7A shows an AUTO mode selection state in the wiper control switch 30, and FIG. 7B shows an output state of a drive signal output from the wiping mode determination unit 51 to the wiper motor 11. FIG. FIG. 7D shows the time transition of the rainfall amount R per unit time calculated by the rainfall amount determination unit 52, and FIG.

  In FIG. 7, the wiper control switch 30 is operated at time t10 to select the AUTO mode, and the wiper control device 1 starts the wiper automatic control. The wiping mode determination unit 51 determines that the corresponding wiping mode is “intermittent 1 mode” based on the rainfall R determined by the rainfall determining unit 52, and the wiper blade 13 is “intermittent 1 mode”. Wiping operation is in progress.

  In this state, the rainfall amount R increases and, as shown in FIG. 7, the mode-up threshold “RU1” of the “intermittent 1 mode” is exceeded at time t11. Thereby, the wiping mode determination part 51 determined with the corresponding wiping mode being "Lo mode." Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. In this case, the wiping mode hunting determination unit 53 determines that wiping mode hunting has not occurred because the starting point wiping mode of the current mode up and the starting point wiping mode of the previous mode up are different. Then, as shown in FIG. 7, at time t <b> 12, the wiping mode determination unit 51 mode-ups the drive signal output to the wiper motor 11 from “intermittent 1 mode” to “Lo mode”.

  Here, there is a delay time, that is, time (t12−t11) from when the wiping mode determination unit 51 determines “Lo mode” to when the “Lo mode” drive signal is output to the wiper motor 11. This is because, as shown in the flowchart of FIG. 6, the mode-up operation is executed in step 210 after the wiping mode hunting determination is performed in step 206 first. That is, the mode up operation is performed after determining whether or not the mode up operation uses the same wiping mode as the start point wiping mode. In FIG. 7, the time t11 and the time t12 are clearly identifiable in order to make it easy to understand the order of the above-described step processes. However, since the above process is a program process in the controller 50, Actually, time t11 and time t12 are almost the same time.

  The rainfall amount R decreased during the wiping operation in the “Lo mode”, and was below the “Lo mode” mode-down threshold “RLL” at time t13 as shown in FIG. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is “intermittent 1 mode” as shown in FIG. 7, and changes the wiping mode for driving the wiper motor 11 from “Lo mode” to “intermittent 1”. Mode down to "Mode".

  From this state, the rainfall amount R increases again and exceeds the mode-up threshold “RU1” of the “intermittent 1 mode” at time t14 as shown in FIG. Thereby, the wiping mode determination part 51 determined with the corresponding wiping mode being "Lo mode", as shown in FIG. Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. In this case, the mode-up determination is the second time after time t11, and the wiping mode that is the starting point of the mode-up is the “intermittent 1 mode” and is the same wiping mode. Therefore, the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred. In response to this determination result, the wiping mode hunting suppression unit 54 performs the wiping mode hunting suppression process at time t14. That is, among the wiping modes related to the generated wiping mode hunting, the mode-up threshold value of the “intermittent 1 mode”, which is the lower-side wiping mode, is set to the mode-up threshold value “RU1new” on the heavy rainfall side than the mode-up threshold value “RU1”. Among the wiping modes related to the generated wiping mode hunting, the mode down threshold of the “Lo mode”, which is the upper wiping mode, is changed to the mode down threshold “RLLnew” on the side of the lower rainfall than the mode down threshold “RLL”. To "". Then, as shown in FIG. 7, at time t <b> 15, the wiping mode determination unit 51 mode-ups the drive signal output to the wiper motor 11 from “intermittent 1 mode” to “Lo mode”.

  After time t15, as shown in FIG. 7, the rainfall R fluctuates with the same amplitude as when the wiping mode hunting occurs, but the rainfall R at both ends of this fluctuation range is a new mode up of “intermittent 1 mode” The wiping mode is maintained in the “Lo mode” because it is included in the range of the mode up threshold “RU1new” that is the threshold and the mode down threshold “RLLnew” that is the new mode down threshold of the “Lo mode”.

  From this state, the amount of rainfall R decreased, and as shown in FIG. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is “intermittent 1 mode” as shown in FIG. 7, and changes the wiping mode for driving the wiper motor 11 from “Lo mode” to “intermittent 1”. Mode down to "Mode".

  The rainfall amount R further decreased from this state, and as shown in FIG. 7, it fell below the mode-down threshold “RL1” of “intermittent 1 mode” at time t17. As a result, the wiping mode determination unit 51 determines that the corresponding wiping mode is “intermittent 2 mode” as shown in FIG. 7, and changes the wiping mode for driving the wiper motor 11 from “intermittent 1 mode” to “intermittent”. Mode down to “2 mode”.

  The rainfall amount R increased from this state, and as shown in FIG. 7, the mode-up threshold “RU2” of the “intermittent 2 mode” was exceeded at time t18. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is the “intermittent 1 mode” as illustrated in FIG. 7. Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. This mode up is the first time during the execution of the wiping mode hunting suppression control by the wiping mode hunting suppression unit 54. Therefore, the wiping mode hunting determination unit 53 determines that wiping mode hunting has not occurred. Then, as shown in FIG. 7, at time t <b> 19, the wiping mode determination unit 51 mode-ups the drive signal output to the wiper motor 11 from “intermittent 2 mode” to “intermittent 1 mode”.

  From this state, the rainfall amount R further increased and, as shown in FIG. 7, exceeded the mode-up threshold “RU1new” of “intermittent 1 mode” at time t20. Thereby, the wiping mode determination part 51 determined with the corresponding wiping mode being "Lo mode", as shown in FIG. Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. This mode up is the second time during the execution of the wiping mode hunting suppression control by the wiping mode hunting suppression unit 54. Further, the mode-up starting point wiping mode is the “intermittent 1 mode”, which is different from the “intermittent 2 mode” which is the starting point wiping mode in the previous mode-up. That is, the mode-up continues twice, but the starting point wiping mode is different. Therefore, the wiping mode hunting determination unit 53 determines that wiping mode hunting has not occurred. Based on the determination result, the wiping mode hunting suppression unit 54 cancels the wiping mode hunting suppression control being performed. That is, among the wiping modes related to the wiping mode hunting, the mode-up threshold value of the “intermittent 1 mode” that is the lower-side wiping mode is returned from the mode-up threshold value “RU1new” to the mode-up threshold value “RU1” and the upper-side wiping mode The mode down threshold of “Lo mode” is returned from the mode down threshold “RLLnew” to the mode down threshold “RLL”. Then, as shown in FIG. 7, at time t <b> 21, the wiping mode determination unit 51 mode-ups the drive signal output to the wiper motor 11 from “intermittent 1 mode” to “Lo mode”.

  As described above, in the wiper control device 1 according to the first embodiment of the present invention, the wiping mode hunting determination unit 53 and the wiping mode hunting determination unit 53 that determine the occurrence of the wiping mode hunting are wiped by the microcomputer 50. A wiping mode hunting suppression unit 54 that performs wiping mode hunting suppression control when it is determined that mode hunting has occurred. The wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred when it is detected that the mode-up operation in which the same wiping mode is the starting point wiping mode is performed twice in succession. When the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred, the wiping mode hunting suppression unit 54 expands the rainfall amount range of the two wiping modes related to the wiping mode hunting. Specifically, among the wiping modes related to the wiping mode hunting, the mode-up threshold value of the lower wiping mode is changed to the heavy rainfall amount side, and among the wiping modes related to the wiping mode hunting, the mode-down threshold value of the upper wiping mode is reduced. Change to the rainfall side. Thereby, the wiping mode hunting is eliminated and the movement of the wiper blade is stabilized. Therefore, it is possible to prevent such a problem that the driver feels that the movement of the wiper blade is unstable and becomes worried that a failure has occurred in the wiper control device.

  In the wiper device 1 according to the first embodiment of the present invention described above, the wiping mode hunting determination unit 53 detects that the wiping mode hunting generation condition is not established during execution of the wiping mode hunting suppression control. Then, the wiping mode hunting suppression unit 54 cancels the wiping mode hunting suppression control. Accordingly, when the rainfall amount greatly fluctuates since the occurrence of the wiping mode hunting, the wiping mode hunting suppression control can be immediately stopped and the wiper motor 11 can be driven in the wiping mode corresponding to the new rainfall amount state.

  In the wiper device 1 according to the first embodiment of the present invention described above, the wiping mode executed by the wiping mode hunting suppression unit 54 is held when the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred. The wiping mode to be applied for the expansion process of the rainfall range is set to both of the two wiping modes related to the wiping mode hunting, but not both, the wiping mode holding rainfall range is only for one of the wiping modes. An enlargement process may be executed. That is, in FIG. 7, the process of moving the mode-up threshold “RU1” of the “intermittent 1 mode” to the heavy rainfall side to set the mode-up threshold “RU1new” and the mode-down threshold “RLL” of the “Lo mode” are reduced. Only one of the processes of moving to the rain amount side and setting the mode down threshold “RLLnew” may be executed.

(Second Embodiment)
The wiper control device according to the second embodiment of the present invention is different from the first embodiment only in the wiping mode hunting determination method by the wiping mode hunting determination unit 53 of the microcomputer 50. Therefore, when it is determined by the wiping mode hunting determination unit 53 that the wiping mode hunting has occurred, the contents of the wiping mode hunting avoidance measures performed by the wiping mode hunting suppression unit 54, that is, two wiping modes related to the wiping mode hunting are set. On the other hand, it is the same to expand the rainfall range that maintains the wiping mode.

  The first embodiment of the wiper control device according to the present invention determines that wiping mode hunting has occurred when it is detected that the mode-up operation in which the same wiping mode is the starting point wiping mode is performed twice in succession. In contrast, in the second embodiment, the wiping mode hunting occurs when it is detected that the mode-down operation in which the same wiping mode is the starting point wiping mode is performed twice in succession. Judgment.

  Hereinafter, the wiping mode hunting determination process executed in the wiping mode hunting determination unit 53 of the microcomputer 50 of the wiper control device 1 according to the second embodiment of the present invention, and the wiping mode hunting suppression unit 54 when the wiping mode hunting occurs. The wiping mode hunting suppression process executed in step 1 will be described with reference to the flowchart of FIG. Note that description of the same terms and the like in the flowchart shown in FIG. 6 is omitted.

  FIG. 8 is a flowchart showing a specific processing procedure of the wiper motor drive control process executed by the microcomputer 50. When the automatic control (AUTO mode) is selected through manual operation of the wiper control switch 30 by the driver of the automobile, the wiper wiping control process shown in FIG. 6 is started. While the wiper control switch 30 is set to automatic control (AUTO mode), the processing according to the flowchart of FIG. 8 is repeated.

  When the wiper wiping control process is started, the microcomputer 50 first performs the rainfall amount R determination by the rainfall amount determination means 52 in step 301.

  Subsequently, in step 302, the microcomputer 50 determines the magnitude relationship between the determined rainfall amount R and the mode-up threshold “UCL” in the wiping mode. As a result of this determination processing, when the rainfall amount R is smaller than the mode-up threshold “UCL”, the microcomputer 50 executes the mode-up operation as the processing of the subsequent step 303, and subsequently determines as the processing of step 304. The magnitude relationship between the rainfall amount R and the mode-down threshold “LCL” is determined. On the other hand, when the rainfall R is larger than the mode-up threshold “UCL” as a result of the determination processing in step 302, the microcomputer 50 performs the subsequent rainfall processing in step 304 and the mode-down threshold “ Determination of the magnitude relationship with “LCL” is performed.

  As a result of the determination process in step 304, when the rainfall amount R is smaller than the mode down threshold “LCL”, the microcomputer 50 proceeds to “return” as shown in FIG. 8 and repeats the process from step 301 again. . On the other hand, as a result of the determination process in step 304, when the rainfall amount R is larger than the mode down threshold “LCL”, the microcomputer 50 replaces the current wiping mode with Mnew as the process of step 305, and then continues with step In the process of 306, it is determined whether or not “Mnew” replaced in step 305 is the same as “Mold” which is the previous wiping mode.

  If “Mold” = “Mnew” as a result of the determination process in step 306, the mode down determination in which the same wiping mode is the start point wiping mode is performed twice in succession. That is, wiping mode hunting has occurred. In response to this determination result, the wiping mode hunting suppression unit 54 of the microcomputer 50 executes the wiping mode holding range expansion process as the wiping mode hunting suppression process as the subsequent process of step 307. Subsequently, the microcomputer 50 replaces “Mnew” = “Mold” as the process of step 309, and subsequently the microcomputer 50 executes a mode-up operation as the process of step 310. Then, the microcomputer 50 proceeds to “RETURN” as shown in FIG. 8 and repeats the processing from step 301 again. In the subsequent processing at this time, as the mode-up threshold “UCL” and the mode-down threshold “LCL”, the new thresholds subjected to the wiping mode holding range expansion processing in step 307 are used.

  On the other hand, when “Mold” ≠ “Mnew” as a result of the determination processing in step 306, the mode-up operation is performed twice in succession, but the start point wiping mode of each mode-up operation is different. That is, no wiping mode hunting has occurred. In response to this determination result, the wiping mode hunting suppression unit 54 of the microcomputer 50 cancels the wiping mode holding range expansion process as the wiping mode hunting suppression process as the subsequent process of step 308. Subsequently, the microcomputer 50 replaces “Mnew” = “Mold” as the process of step 309, and subsequently the microcomputer 50 executes a mode-up operation as the process of step 210. Then, the microcomputer 50 proceeds to “RETURN” as shown in FIG. 8 and repeats the processing from step 301 again. In the subsequent processing at this time, as the mode-up threshold “UCL” and the mode-down threshold “LCL”, the respective thresholds after the cancellation of the wiping mode hunting suppression processing performed in step 307 are used.

  Next, with reference to the timing charts shown in FIGS. 9A to 9D, the wiping mode hunting detection operation and the wiping mode hunting suppression unit 54 by the wiping mode hunting determination unit 53 in the second embodiment of the present invention. The wiping mode hunting suppression operation by is summarized.

  9A shows the AUTO mode selection state in the wiper control switch 30, and FIG. 9B shows the output state of the drive signal output from the wiping mode determination unit 51 to the wiper motor 11, FIG. 9C. FIG. 9D shows the time transition of the rainfall amount R per unit time calculated by the rainfall amount determination unit 52, and FIG. 9D shows the time transition of the determination result by the wiping mode hunting determination unit 53.

  In FIG. 9, the wiper control switch 30 is operated at time t10 to select the AUTO mode, and the wiper control device 1 starts the wiper automatic control. The wiping mode determination unit 51 determines that the corresponding wiping mode is “intermittent 1 mode” based on the rainfall R determined by the rainfall determining unit 52, and the wiper blade 13 is “intermittent 1 mode”. Wiping operation is in progress.

  In this state, the rainfall amount R increases, and as shown in FIG. 9, the mode-up threshold “RU1” of “intermittent 1 mode” is exceeded at time t11. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is “Lo mode”, and mode-ups the drive signal output to the wiper motor 11 from “intermittent 1 mode” to “Lo mode”.

  The rainfall amount R decreased during the wiping operation in the “Lo mode”, and was below the “Lo mode” mode-down threshold “RLL” at time t12 as shown in FIG. As a result, the wiping mode determination unit 51 determines that the corresponding wiping mode is the “intermittent 1 mode” as illustrated in FIG. 9. Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. In this case, since the start point wiping mode of the current mode down and the start point wiping mode of the previous mode up are different, the wiping mode hunting determination unit 53 determines that wiping mode hunting has not occurred. Then, as shown in FIG. 9, the wiping mode determination unit 51 mode-downs the drive signal output to the wiper motor 11 from “Lo mode” to “intermittent 1 mode” at time t13.

  Here, there is a delay time, that is, time (t12 to t13) from when the wiping mode determination unit 51 determines the “intermittent 1 mode” to when the “intermittent 1 mode” driving signal is output to the wiper motor 11. This is because the mode down operation is executed in step 310 after the wiping mode hunting determination is previously made in step 306 as shown in the flowchart of FIG. That is, the mode down operation is performed after determining whether or not the mode down operation has the same wiping mode as the start point wiping mode. In FIG. 9, the time t12 and the time t13 are clearly identifiable in order to make it easy to understand the order of the above-described step processes. However, since the above process is a program process in the controller 50, Actually, time t12 and time t13 are substantially the same time.

  The rainfall amount R increased during the wiping operation in the “intermittent 1 mode”, and exceeded the mode-up threshold “RU1” of the “intermittent 1 mode” at time t14 as shown in FIG. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is “Lo mode” as shown in FIG. 9, and changes the wiping mode for driving the wiper motor 11 from “intermittent 1 mode” to “Lo mode”. Mode up.

  From this state, the rainfall amount R decreases again, and as shown in FIG. 9, it falls below the “Lo mode” mode-down threshold “RLL” at time t15. As a result, the wiping mode determination unit 51 determines that the corresponding wiping mode is the “intermittent 1 mode” as illustrated in FIG. 9. Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. In this case, the mode down determination is the second time after time t12, and the wiping mode that is the starting point of the mode down is the “Lo mode” and is the same wiping mode. Therefore, the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred. In response to this determination result, the wiping mode hunting suppression unit 54 performs the wiping mode hunting suppression process at time t15. That is, among the wiping modes related to the generated wiping mode hunting, the mode-up threshold value of the “intermittent 1 mode”, which is the lower-side wiping mode, is set to the mode-up threshold value “RU1new” on the heavy rainfall side than the mode-up threshold value “RU1”. Among the wiping modes related to the generated wiping mode hunting, the mode down threshold of the “Lo mode”, which is the upper wiping mode, is changed to the mode down threshold “RLLnew” on the side of the lower rainfall than the mode down threshold “RLL”. To "". Then, as shown in FIG. 9, at time t <b> 16, the wiping mode determination unit 51 mode-downs the drive signal output to the wiper motor 11 from “Lo mode” to “intermittent 1 mode”.

  After time t16, as shown in FIG. 9, the rainfall R varies with the same amplitude as when the wiping mode hunting occurs, but the rainfall R at both ends of this variation range is a new mode up of “intermittent 1 mode” The wiping mode is maintained in the “intermittent 1 mode” because it is included in the range of the mode up threshold “RU1new” that is the threshold and the mode down threshold “RLLnew” that is the new mode down threshold of the “Lo mode”.

  From this state, the rainfall amount R increases, and as shown in FIG. 9, the mode-up threshold “RU1new” of “intermittent 1 mode” is exceeded at time t17. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is “Lo mode” as shown in FIG. 9, and changes the wiping mode for driving the wiper motor 11 from “intermittent 1 mode” to “Lo mode”. Mode up.

  From this state, the rainfall amount R further increased and, as shown in FIG. 9, dropped below the “Lo mode” mode-down threshold “RLLnew” at time t18. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is the “intermittent 1 mode” as illustrated in FIG. 7. Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. This mode down is the first time during the execution of the wiping mode hunting suppression control by the wiping mode hunting suppression unit 54. Therefore, the wiping mode hunting determination unit 53 determines that wiping mode hunting has not occurred. Then, as shown in FIG. 9, at time t <b> 19, the wiping mode determination unit 51 mode-downs the drive signal output to the wiper motor 11 from “Lo mode” to “intermittent 1 mode”.

  The rainfall amount R further decreased from this state, and as shown in FIG. 9, it fell below the mode-down threshold “RU2” of “intermittent 1 mode” at time t20. Accordingly, the wiping mode determination unit 51 determines that the corresponding wiping mode is the “intermittent 2 mode” as illustrated in FIG. 7. This mode down is the second time during the execution of the wiping mode hunting suppression control by the wiping mode hunting suppression unit 54. The mode-down starting point wiping mode is “intermittent 1 mode”, which is different from the “Lo mode” that is the starting point wiping mode in the previous mode up. That is, the mode-up continues twice, but the starting point wiping mode is different. Therefore, the wiping mode hunting determination unit 53 determines that wiping mode hunting has not occurred. Based on the determination result, the wiping mode hunting suppression unit 54 cancels the wiping mode hunting suppression control being performed. That is, among the wiping modes related to the wiping mode hunting, the mode-up threshold value of the “intermittent 1 mode” which is the lower-side wiping mode is returned from the mode-up threshold value “RU1new” to the mode-up threshold value “RU1”, and at the upper-side wiping mode. The mode down threshold value of a certain “Lo mode” is returned from the mode down threshold value “RLLnew” to the mode down threshold value “RLL”. Then, as shown in FIG. 9, at time t <b> 21, the wiping mode determination unit 51 mode-downs the drive signal output to the wiper motor 11 from “intermittent 1 mode” to “intermittent 2 mode”.

  As described above, in the wiper control device 1 according to the second embodiment of the present invention, the wiping mode hunting determination unit 53 of the microcomputer 50 uses the same wiping mode as the starting point wiping mode as the wiping mode hunting determination standard. It is assumed that it is detected that the operation has been performed twice in succession. Also with this configuration, as in the case of the first embodiment, the wiping mode hunting can be reliably detected, and when the wiping mode hunting occurs, the wiping mode hunting can be reliably eliminated. Therefore, it is possible to prevent such a problem that the driver feels that the movement of the wiper blade is unstable and becomes worried that a failure has occurred in the wiper control device.

  In the wiper device 1 according to the first embodiment of the present invention described above, the wiping mode hunting determination unit 53 detects that the wiping mode hunting generation condition is not established during execution of the wiping mode hunting suppression control. Then, the wiping mode hunting suppression unit 54 cancels the wiping mode hunting suppression control. Accordingly, when the rainfall amount greatly fluctuates since the occurrence of the wiping mode hunting, the wiping mode hunting suppression control can be immediately stopped and the wiper motor 11 can be driven in the wiping mode corresponding to the new rainfall amount state.

  In the wiper device 1 according to the first embodiment of the present invention described above, the wiping mode executed by the wiping mode hunting suppression unit 54 is held when the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred. The wiping mode to be applied for the expansion process of the rainfall range is set to both of the two wiping modes related to the wiping mode hunting, but not both, the wiping mode holding rainfall range is only for one of the wiping modes. An enlargement process may be executed. That is, in FIG. 7, the process of moving the mode-up threshold “RU1” of the “intermittent 1 mode” to the heavy rainfall side to set the mode-up threshold “RU1new” and the mode-down threshold “RLL” of the “Lo mode” are reduced. Only one of the processes of moving to the rain amount side and setting the mode down threshold “RLLnew” may be executed.

  In the first embodiment of the wiper control device according to the present invention described above, it is detected that the wiping mode hunting criterion is the mode wiping operation in which the same wiping mode is the starting point wiping mode is performed twice in succession. In the second embodiment of the wiper control device according to the present invention, when it is detected that the mode-down operation in which the same wiping mode is the starting point wiping mode is continuously performed twice as the wiping mode hunting criterion. , And. The start point wiping mode in these may be replaced with the end point wiping mode.

(Third embodiment)
The third embodiment of the wiper control device according to the present invention is different from the first embodiment described above when the wiping mode hunting determination unit 53 of the microcomputer 50 determines that the wiping mode hunting has occurred. The wiping mode hunting avoidance measures implemented by the suppression unit 54 are different. Therefore, the wiping mode hunting occurrence determination method performed by the wiping mode hunting determination unit 53 is the same as that in the first embodiment described above, and the mode-up operation in which the same wiping mode is set as the starting point wiping mode is performed twice in succession. It is determined that the wiping mode hunting has occurred when it has been detected.

  The wiping mode hunting avoidance treatment performed by the wiping mode hunting suppressing unit 54 in the third embodiment of the wiper control device according to the present invention will be described.

  When the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred, the wiping mode hunting suppression unit 54 receives it and performs wiping mode hunting avoidance treatment to eliminate the wiping mode hunting. In other words, the wiping mode is determined to be wiping mode hunting when the wiping mode set when wiping mode hunting occurs, that is, in the third embodiment, when the mode-up operation is performed twice in succession. The upper wiping mode in the wiping mode related to hunting is fixed. The wiping mode hunting avoidance treatment is continuously executed until a predetermined condition is satisfied. In other words, this predetermined condition is a canceling condition for canceling the wiping mode hunting avoidance measure.

  Next, the cancellation conditions for canceling the wiping mode hunting avoidance measure described above will be described. In the third embodiment, the release condition is continuously exceeded twice as a plurality of times from the two wiping modes related to the wiping mode hunting to the wiping mode different from the two wiping modes related to the wiping mode hunting. , And. Here, the threshold for transition from the two wiping modes related to the wiping mode hunting to the wiping mode different from the two wiping modes related to the wiping mode hunting is higher than the upper wiping mode of the two wiping modes related to the wiping mode hunting. To the wiping mode on the lower side of the lower wiping mode of the two wiping modes related to the mode-up threshold (hereinafter, referred to as the upper release threshold) and the wiping mode hunting, which is a threshold for transitioning to the wiping mode on the upper side One of the mode-down thresholds (hereinafter referred to as the lower release threshold), which is a transition threshold.

  If the fluctuation range of the rainfall is the same as when the wiping mode hunting occurs, the rainfall determined by the rainfall determination unit 51 does not exceed the above-described upper release threshold and does not fall below the lower release threshold. . Accordingly, the wiping mode is fixed to the upper wiping mode in the wiping mode related to the wiping mode hunting. When the rainfall increases from this state and the rainfall determination result by the rainfall determination unit 51 exceeds the upper cancellation threshold value twice consecutively, or the rainfall decreases from this state and the rainfall determination unit 51 When the rainfall amount determination result by the value falls below the lower release threshold value twice in succession, the wiping mode hunting suppression unit 54 releases the wiping mode hunting avoidance measure. Then, the controller 50 drives the wiper motor 11 in the wiping mode determined by the wiping mode determination unit 52.

  The wiping mode hunting avoidance treatment performed by the wiping mode hunting suppressing unit 54 in the third embodiment described above can be paraphrased as follows. That is, when it is determined that wiping mode hunting has occurred, the wiping mode is fixed to the wiping mode at the time of wiping mode hunting occurrence, and the rainfall range that maintains the wiping mode is higher than the two wiping modes related to wiping mode hunting. Among the two wiping modes related to the mode wiping mode (upper side cancellation threshold) in the side wiping mode and the wiping mode hunting, the range is increased to the rainfall amount range between the mode down threshold (lower side release threshold) in the lower wiping mode. Then, the cancellation condition of the wiping mode hunting avoidance measure is to exceed either one of the upper cancellation threshold and the lower cancellation threshold twice in succession.

  Next, the wiping mode hunting determination process executed in the wiping mode hunting determination unit 53 of the microcomputer 50 of the wiper control device 1 according to the third embodiment of the present invention, and the wiping mode hunting suppression unit 54 when the wiping mode hunting occurs. The wiping mode hunting suppression process executed in step 1 will be described with reference to the flowchart of FIG. FIG. 10 is a flowchart showing a specific processing procedure of the wiper motor drive control process executed by the microcomputer 50. When the automatic control (AUTO mode) is selected through manual operation of the wiper control switch 30 by the driver of the automobile, the wiper wiping control process shown in FIG. 10 is started. While the wiper control switch 30 is set to automatic control (AUTO mode), the processing according to the flowchart of FIG. 10 is repeated. In the flowchart of FIG. 10, “R” represents the rainfall determined by the rainfall determining means 52, “UCL” represents the mode-up threshold, and “LCL” represents the mode-down threshold. P represents wiping mode hunting avoidance control, P = 1 represents that wiping mode hunting avoidance control is being performed, and P = 0 represents no wiping mode hunting avoidance control. C represents a counter of the number of times when one of the upper release threshold and the lower release threshold which is the wiping mode hunting avoidance control release condition is exceeded. “Mold” and “Mnew” are the wiping modes determined by the wiping mode determination means 53, “Mold” indicates the wiping mode determined last time, and “Mnew” indicates the wiping mode determined this time.

  When the wiper wiping control process is started, the microcomputer 50 first determines the rainfall amount R by the rainfall amount determination means 52 in step 401.

  Subsequently, in step 402, the microcomputer 50 determines the magnitude relationship between the determined rainfall amount R and the mode-down threshold “LCL” in the wiping mode. As a result of this determination processing, when the rainfall R is smaller than the mode-down threshold “LCL”, the microcomputer 50 executes a mode-down operation as the subsequent processing of step 403, and subsequently determines as the processing of step 404. The magnitude relationship between the rainfall amount R and the mode-up threshold “UCL” is determined. On the other hand, when the rainfall R is larger than the mode-down threshold “LCL” as a result of the determination processing in step 402, the microcomputer 50 performs the following processing in step 404 as the determined rainfall R and the mode-up threshold “L”. The magnitude relationship with “UCL” is determined.

  As a result of the determination process in step 404, when the rainfall amount R is smaller than the mode-up threshold “UCL”, the microcomputer 50 sets the counter to C = 0 as the process in step 409, as shown in FIG. The process from step 401 is repeated again. On the other hand, as a result of the determination process in step 404, when the rainfall amount R is larger than the mode-up threshold “UCL”, the microcomputer 50 determines whether the wiping mode hunting avoidance control is being executed as the subsequent process in step 405. Judgment is made.

  If the wiping mode hunting avoidance control is currently being executed as a result of the determination processing in step 405, the counter is set to C = C + 1 as the processing of the subsequent step 406, and whether the counter is C = 2 as the processing of the subsequent step 407 Determine whether or not. On the other hand, if the result of the determination process in step 405 is that the current wiping mode hunting avoidance control is not being executed, the process proceeds to step 412 after setting the counter to C = 0 as the process of step 408.

  If the result of determination in step 407 is that the counter is not C = 2, processing proceeds to “RETURN” as shown in FIG. 10, and the processing from step 401 is repeated again. If the counter is C = 2 as a result of the determination process in step 407, the counter is set to C = 0 as the subsequent step 410, and “Mold” is deleted as the subsequent step 411. Subsequently, as a process of step 412, the current wiping mode is replaced with “Mnew”. In the subsequent step 413, it is determined whether “Mnew” replaced in step 412 is the same as “Mold”, which is the previous wiping mode.

  If “Mold” = “Mnew” as a result of the determination process in step 413, the mode-up operation in which the same wiping mode is set as the start point wiping mode is performed twice in succession. That is, wiping mode hunting has occurred. In response to this determination result, the wiping mode hunting suppressing unit 54 fixes the wiping mode as the wiping mode hunting suppressing process, that is, the above-described upper range of the rainfall amount range for maintaining the fixed wiping mode as the processing of the subsequent step 414. Expansion to the rainfall range between the release threshold and the lower release threshold is executed, and P = 1 is set. Subsequently, as the processing of step 416, “Mnew” is replaced with “Mold”. Subsequently, as a process of step 417, a mode-up operation is executed.

  On the other hand, if the result of the determination process in step 413 is “Mold” ≠ “Mnew”, the rainfall amount R determined by the rainfall amount determination unit 52 is twice between the upper cancellation threshold value and the lower cancellation threshold value. It is beyond either. Therefore, the wiping mode hunting suppression process performed in step 414 is canceled as the subsequent process of step 415. Subsequently, as the processing of step 416, “Mnew” is replaced with “Mold”. Subsequently, as a process of step 417, a mode-up operation is executed.

  Next, referring to the timing charts shown in FIGS. 11A to 11D, the operation of the third embodiment, that is, the wiping mode hunting detection operation by the wiping mode hunting determination unit 53 and the wiping mode hunting suppression unit 54. The wiping mode hunting suppression operation by is summarized.

  11A shows an AUTO mode selection state in the wiper control switch 30, and FIG. 11B shows an output state of a drive signal output from the wiping mode determination unit 51 to the wiper motor 11. FIG. Fig. 11D shows the time transition of the rainfall amount R per unit time calculated by the rainfall amount determination unit 52, and Fig. 11D shows the time transition of the determination result by the wiping mode hunting determination unit 53.

  In FIG. 11, the wiper control switch 30 is operated at time t10 to select the AUTO mode, and the wiper control device 1 starts the wiper automatic control. The wiping mode determination unit 51 determines that the corresponding wiping mode is “intermittent 1 mode” based on the rainfall R determined by the rainfall determining unit 52, and the wiper blade 13 is “intermittent 1 mode”. Wiping operation is in progress.

  In this state, the rainfall amount R increases and, as shown in FIG. 11, exceeds the mode-up threshold “RU1” of “intermittent 1 mode” at time t11. Thereby, the wiping mode determination part 51 determined with the corresponding wiping mode being "Lo mode." Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. In this case, the wiping mode hunting determination unit 53 determines that wiping mode hunting has not occurred because the starting point wiping mode of the current mode up and the starting point wiping mode of the previous mode up are different. Then, as shown in FIG. 7, at time t <b> 12, the wiping mode determination unit 51 mode-ups the drive signal output to the wiper motor 11 from “intermittent 1 mode” to “Lo mode”.

  Here, there is a delay time, that is, time (t12−t11) from when the wiping mode determination unit 51 determines “Lo mode” to when the “Lo mode” drive signal is output to the wiper motor 11. This is because, as shown in the flowchart of FIG. 10, the mode-up operation is executed in step 417 after the wiping mode hunting determination is performed in step 413 first. That is, the mode up operation is performed after determining whether or not the mode up operation uses the same wiping mode as the start point wiping mode. In FIG. 11, the time t11 and the time t12 are clearly identifiable in order to make it easy to understand the order of the above-described step processes. However, since the above process is a program process in the controller 50, Actually, time t11 and time t12 are almost the same time.

  During the wiping operation in the “Lo mode”, the rainfall amount R decreased and, as shown in FIG. 11, fell below the “Lo mode” mode-down threshold “RLL” at time t13. As a result, the wiping mode determination unit 51 determines that the corresponding wiping mode is “intermittent 1 mode” and changes the wiping mode for driving the wiper motor 11 from “Lo mode” to “intermittent 1” as shown in FIG. Mode down to "Mode".

  From this state, the rainfall amount R increases again and exceeds the mode-up threshold “RU1” of the “intermittent 1 mode” at time t14 as shown in FIG. Thereby, the wiping mode determination part 51 determined with the corresponding wiping mode being "Lo mode", as shown in FIG. Based on the determination result, the wiping mode hunting determination unit 53 determines whether wiping mode hunting has occurred. In this case, the mode-up determination is the second time after time t11, and the wiping mode that is the starting point of the mode-up is the “intermittent 1 mode” and is the same wiping mode. Therefore, the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred. This wiping mode hunting occurs between “intermittent 1 mode” and “Lo mode”. In response to this determination result, the wiping mode hunting suppression unit 54 performs the wiping mode hunting suppression process at time t14. That is, the wiping mode is fixed to the “Lo mode” which is one of the wiping modes related to the generated wiping mode hunting. Then, as shown in FIG. 11, at time t15, the wiping mode determination unit 51 mode-ups the drive signal output to the wiper motor 11 from “intermittent 1 mode” to “Lo mode”.

  After time t15, as shown in FIG. 11, the rainfall amount R varies with the same amplitude as when the wiping mode hunting occurs, but the wiping mode is maintained in the “Lo mode”.

  As shown in FIG. 11, the rainfall amount R determined by the rainfall amount determination unit 52 at time t16 is the higher-level wiping mode of the wiping mode related to the wiping mode hunting as shown in FIG. The mode up threshold “RUL” in “Lo mode” was exceeded. At time t17, which is the time when the interval time ΔT when the rainfall amount determination is performed in the rainfall amount determination unit 52 from time t16, the rainfall amount R determined by the rainfall amount determination unit 52 sets the mode-up threshold “RUL”. Beyond. That is, the rainfall amount R determined by the rainfall amount determination unit 52 has continuously exceeded the mode-up threshold “RUL” in the “Lo mode” that is the higher-level wiping mode of the wiping mode related to the wiping mode hunting twice. That is, the cancellation condition for the wiping mode hunting suppression measure is satisfied. Thereby, the wiping mode hunting determination unit 53 determines that the wiping mode hunting has been eliminated, and at the same time, the wiping mode hunting suppression unit 54 stops fixing the non-wiping mode hunting suppression measure, that is, the wiping mode to “Lo mode”. To do. Thus, at time t17, the wiping mode determination unit 51 determines that the corresponding wiping mode is the “Hi mode”, and increases the wiping mode for driving the wiper motor 11 from “Lo mode” to “Hi mode”.

  As described above, in the wiper control device 1 according to the third embodiment of the present invention, when the wiping mode hunting determination unit 53 of the microcomputer 50 determines that the wiping mode hunting has occurred, the wiping mode hunting suppression unit 54 The wiping mode hunting avoidance measure to be performed is fixed to the upper wiping mode in the wiping mode related to the wiping mode hunting. Then, the cancellation condition of the wiping mode hunting avoidance measure is continuously exceeded twice as a threshold value for transitioning from the two wiping modes related to the wiping mode hunting to the wiping mode different from the two wiping modes related to the wiping mode hunting. It is said that. Even with this configuration, as in the case of the first embodiment, when wiping mode hunting occurs, wiping mode hunting can be reliably eliminated. Therefore, it is possible to prevent such a problem that the driver feels that the movement of the wiper blade is unstable and becomes worried that a failure has occurred in the wiper control device.

  In the wiper device 1 according to the third embodiment of the present invention described above, the wiping mode hunting determination unit 53 detects that the wiping mode hunting generation condition is not established during the execution of the wiping mode hunting suppression control. Then, the wiping mode hunting suppression unit 54 cancels the wiping mode hunting suppression control. Accordingly, when the rainfall amount greatly fluctuates since the occurrence of the wiping mode hunting, the wiping mode hunting suppression control can be immediately stopped and the wiper motor 11 can be driven in the wiping mode corresponding to the new rainfall amount state.

  In the wiper device 1 according to the first and second embodiments of the present invention described above, the wiping executed by the wiping mode hunting suppression unit 54 when the wiping mode hunting determination unit 53 determines that the wiping mode hunting has occurred. The wiping mode to be applied to the rain range expansion process that maintains the mode is both the two wiping modes related to wiping mode hunting, but not both, the wiping mode holding rain only for one of the wiping modes A quantity range expansion process may be executed. That is, the mode-up threshold “RU1” of “intermittent 1 mode” is moved to the heavy rainfall side to set the mode-up threshold “RU1new”, and the mode-down threshold “RLL” of “Lo mode” is moved to the low rainfall side Only one of the processes for setting the mode-down threshold “RLLnew” may be executed.

  In the first embodiment of the wiper control device according to the present invention described above, it is detected that the wiping mode hunting criterion is the mode continuation operation in which the same wiping mode is the starting point wiping mode twice. However, it may be when it is detected that the mode-up operation in which the same wiping mode is the end point wiping mode is performed twice in succession.

  Further, in the second embodiment of the wiper control device according to the present invention described above, the wiping mode hunting criterion is detected as the mode wiping mode in which the same wiping mode is the starting point wiping mode is continuously performed twice. When it is detected that the mode-down operation in which the same wiping mode is the end point wiping mode is continuously performed twice.

  In the third embodiment of the wiper control device according to the present invention described above, it is detected that the wiping mode hunting criterion is the mode wiping operation in which the same wiping mode is the starting point wiping mode twice. However, it may be when it is detected that the mode-up operation in which the same wiping mode is the end point wiping mode is performed twice in succession. Further, when it is detected that the mode-down operation in which the same wiping mode is the start point wiping mode has been performed twice in succession, or the mode-down operation in which the same wiping mode is the end point wiping mode is performed twice in succession. It is also possible to detect when it is detected.

  In the third embodiment of the wiper control device according to the present invention described above, the wiping mode hunting avoidance control release condition is changed from the two wiping modes related to the wiping mode hunting to the two wiping modes related to the wiping mode hunting. The threshold value for transitioning to a different wiping mode is said to be exceeded twice in a row, but it is not necessary to limit to two times, and any number of times may be used as long as it is a plurality of times.

  Further, in the specific operation of the wiper control device 1 according to the first to fourth embodiments of the present invention described above, the wiping mode hunting occurs between the “intermittent 1 mode” and the “Lo mode”. Although the case has been described as an example, even when it occurs between two other wiping modes, wiping mode hunting can be detected and suppressed in the same manner.

  In each of the above embodiments, the windshield on which the wiper control device 1 is installed has been described as the front windshield 101 in front of the driver's seat. However, the windshield need not be limited to the front windshield 101, and other windows, for example, rear windows. You may apply to a shield.

  Moreover, in each said embodiment, although the example which mounted the said raindrop amount detection apparatus in the motor vehicle was mentioned, the mounting place is not restricted to a motor vehicle. In addition, it is useful to be widely mounted on mobile objects such as airplanes, railway vehicles, and ships.

1 is a schematic diagram showing a state where a wiper control device 1 according to a first embodiment of the present invention is mounted on an automobile 100. FIG. 1 is a block diagram showing an overall configuration of a wiper control device 1 according to a first embodiment of the present invention. It is sectional drawing explaining the structure of the raindrop sensor 20, and is the III-III sectional view taken on the line in FIG. It is a graph which shows the relationship between rainfall and the wiping mode determined based on it. It is a graph which shows the relationship between the rainfall per unit time, and the wiping mode determined based on it, and expands a part of FIG. It is the flowchart which showed the specific process sequence of the wiper wiping control process performed in the wiper control apparatus 1 by 1st Embodiment of this invention. In the wiper control device 1 according to the first embodiment of the present invention, (a) is an AUTO mode selection state in the wiper control switch 30, and (b) is a drive signal output from the wiping mode determination unit 51 to the wiper motor 11. (C) shows the time transition of the rainfall amount R per unit time calculated by the rainfall amount determination unit 52, (d) shows the time transition of the determination result by the wiping mode hunting determination unit 53, It is a timing chart shown respectively. It is the flowchart which showed the specific process sequence of the wiper wiping control process performed in the wiper control apparatus 1 by 2nd Embodiment of this invention. In the wiper control device 1 according to the second embodiment of the present invention, (a) is an AUTO mode selection state in the wiper control switch 30, and (b) is a drive signal output from the wiping mode determination unit 51 to the wiper motor 11. (C) shows the time transition of the rainfall amount R per unit time calculated by the rainfall amount determination unit 52, (d) shows the time transition of the determination result by the wiping mode hunting determination unit 53, It is a timing chart shown respectively. It is the flowchart which showed the specific process sequence of the wiper wiping control process performed in the wiper control apparatus 1 by 3rd Embodiment of this invention. In the wiper control device 1 according to the third embodiment of the present invention, (a) is an AUTO mode selection state in the wiper control switch 30, and (b) is a drive signal output from the wiping mode determination unit 51 to the wiper motor 11. (C) shows the time transition of the rainfall amount R per unit time calculated by the rainfall amount determination unit 52, (d) shows the time transition of the determination result by the wiping mode hunting determination unit 53, It is a timing chart shown respectively. It is a graph which shows the relationship between the rainfall amount in the conventional wiper control apparatus, and the wiping mode determined based on it.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wiper control apparatus 10 Wiper apparatus 11 Wiper motor 12 Transmission mechanism 13 Wiper blade 20 Raindrop sensor 21 Light emitting element 22 Light receiving element 40 Wiper control switch 50 Microcomputer 51 Wiping mode determination part 52 Rainfall determination part 53 Wiping mode hunting determination part 54 Wiping Mode hunting suppression unit 100 automobile 101 front windshield A wiping area Ad detection area (predetermined area)
D Raindrop R Rainfall t Time ΔT Interval time

Claims (7)

A wiper that drives the wiper blade based on a detection signal from a raindrop sensor that outputs a detection signal corresponding to the amount of raindrops adhering to the detection region, with a predetermined region within the wiping range of the wiper blade on the windshield as a detection region A control device,
Rainfall determination means for determining the amount of rainfall attached to the windshield based on the detection signal;
Wiping mode determining means for determining a wiping mode of the wiper blade based on the rainfall determined by the rainfall determining means,
The wiping mode determining means determines one wiping mode corresponding to the amount of rainfall from a plurality of the wiping modes with different reciprocal wiping operation interval times of the wiper blade, and the wiper blade is driven by the wiping mode. ,
The reciprocating wiping operation interval time of each wiping mode is set to be shorter as the corresponding rainfall amount is larger,
The rain amount range in which each of the wiping modes is maintained is a threshold at which a mode down operation is performed, which is an operation of transitioning to the lower wiping mode that is the wiping mode in which the reciprocating wiping operation interval time is longer than each wiping mode. A mode-up threshold that is a threshold for performing a mode-up operation that is a transition to the upper-side wiping mode that is the wiping mode in which the rainfall amount as a certain mode-down threshold and the reciprocating wiping operation interval time is shorter than each wiping mode As the range between rainfall and
In the wiper control device, the rainfall amount of the mode-up threshold is greater than the rainfall amount of the mode-down threshold.
A wiping mode hunting determination means for determining the occurrence of wiping mode hunting, which is a phenomenon in which two wiping modes adjacent to each other appear alternately as the wiping mode determined by the wiping mode determination means,
A wiper control device comprising: a wiping mode hunting suppressing unit that suppresses the wiping mode hunting when the wiping mode hunting determining unit determines that the wiping mode hunting has occurred.   The wiping mode hunting determination means has a mode-up operation in which the same wiping mode is set to the end point wiping mode when a mode-up operation in which the same wiping mode is set to the start point wiping mode is continuously performed twice. The wiper control device according to claim 1, wherein it is determined that the wiping mode hunting occurs when the wiping mode is performed twice.   The wiping mode hunting determination means has a mode down operation in which the same wiping mode is set to the end point wiping mode when a mode down operation in which the same wiping mode is set to the start point wiping mode is continuously performed twice. The wiper control device according to claim 1, wherein it is determined that the wiping mode hunting occurs when the wiping mode is performed twice.   The wiping mode hunting suppression means expands a rainfall range in which the wiping mode is maintained with respect to at least one of the two wiping modes of the wiping mode hunting. The wiper control device according to any one of claims 1 to 3.   The wiping mode hunting suppression means changes the mode-up threshold value to the heavy rainfall amount side in the lower wiping mode among the two wiping modes related to the wiping mode hunting, and two related to the wiping mode hunting. The wiper according to any one of claims 1 to 3, wherein at least one of the processes of changing the mode-down threshold value to a low rainfall amount side in the upper wiping mode among the wiping modes is executed. Control device.   The wiping mode hunting suppression means sets the wiping mode as the wiping mode hunting suppression operation as a wiping mode hunting suppression operation during a period from when it is determined that the wiping mode hunting occurs until the predetermined condition is satisfied. The wiper control device according to any one of claims 1 to 3, wherein the wiping mode hunting suppression operation is canceled when a predetermined condition is satisfied by fixing to one of the wiping modes. .   The predetermined condition is a threshold value at which the rainfall determined by the rainfall amount determining means transitions from the two wiping modes related to the wiping mode hunting to the wiping mode different from the two wiping modes related to the wiping mode hunting. The wiper control device according to claim 6, wherein the wiper control device continuously exceeds a plurality of times.

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