JP7831367B2 - Wiper control device - Google Patents

Description

This disclosure relates to a wiper control device.

Conventionally, as described in Patent Document 1, a wiper control device is known that includes a wiper motor for driving a wiper, a semiconductor switch element for switching the power supply to the wiper motor on and off, and a controller for controlling the on/off state of the semiconductor switch element.

Japanese Patent Publication No. 2002-37032

According to the inventors' research, in the wiper control device described in Patent Document 1, it is conceivable that abnormalities such as the inability of the semiconductor switch element to be switched on or off can be determined by detecting the voltage applied to the two terminals of the wiper motor. However, when a voltage is applied to one terminal and the wiper motor rotates, an induced electromotive force is generated at the other terminal by the wiper motor. Therefore, since a voltage is applied to both terminals, it becomes difficult to determine abnormalities in the semiconductor switch element, as well as in the wiring connected to the semiconductor switch element, the wiper motor, and the wiper itself.

This disclosure aims to provide elements for driving a wiper motor, wiring connected thereto, a wiper motor, and a wiper control device for determining abnormalities in the wiper.

The invention described in claim 1 is a wiper control device comprising: a first wiring (37) connected to a first terminal (104) of a wiper motor (100) that drives a wiper (90) by rotating; a second wiring (47) connected to a second terminal (106) which is a terminal different from the first terminal of the wiper motor; a first drive element (35) that, when turned on, applies a power supply voltage (Vb) to the first terminal via the first wiring to rotate the wiper motor; a second drive element (45) that, when turned on, applies a power supply voltage to the second terminal via the second wiring to rotate the wiper motor at a lower speed than when the power supply voltage is applied to the first terminal; and a determination unit (64) for determining abnormalities, wherein the determination unit takes the power supply voltage, the voltage at the first terminal (Vm_Hi), the voltage at the second terminal (Vm_Lo), and the power supply voltage between the first terminal and the second terminal This wiper control device determines whether there is an abnormality in the first drive element, second drive element, first wiring, second wiring, wiper motor, and wiper based on the following values: a first voltage (Vm_Hi_th1), which is the voltage at the first terminal when no power is applied to the child; a second voltage (Vm_Lo_th1), which is the voltage at the second terminal when no power supply voltage is applied to the first and second terminals; a third voltage (Vm_Hi_th2), which is greater than or equal to the voltage at the first terminal (Vf_Hi) generated when the wiper motor rotates while the power supply voltage is applied to the second terminal, and less than or equal to the voltage at the second terminal (Vf_Lo) generated when the wiper motor rotates while the power supply voltage is applied to the first terminal, and greater than the power supply voltage.

Furthermore, the invention described in claim 10 is a wiper control device comprising: a first wiring (37) connected to a first terminal (104) of a wiper motor (100) that drives a wiper (90) by rotating; a second wiring (47) connected to a second terminal (106) which is a terminal different from the first terminal of the wiper motor; a first drive element (71) that applies a power supply voltage (Vb) when turned on; a second drive element (72) connected to the first and second wirings, which applies the power supply voltage from the first drive element to either the first or second terminal when turned on or off; and a determination unit (64) that determines an abnormality. The wiper motor rotates at a lower speed when the power supply voltage is applied to the second terminal via the second wiring than when the power supply voltage is applied to the first terminal via the first wiring. The determination unit determines the power supply voltage, the voltage at the first terminal (Vm_Hi), and the voltage at the second terminal (V This wiper control device determines whether there is an abnormality in the first drive element, second drive element, first wiring, second wiring, wiper motor, and wiper based on the following values: (m_Lo), a value related to the first voltage (Vm_Hi_th1), which is the voltage at the first terminal when no power supply voltage is applied to the first and second terminals; a value related to the second voltage (Vm_Lo_th1), which is the voltage at the second terminal when no power supply voltage is applied to the first and second terminals; a value related to the third voltage (Vm_Hi_th2), which is greater than or equal to the voltage at the first terminal (Vf_Hi) generated when the wiper motor rotates when the power supply voltage is applied to the second terminal, and less than or equal to the voltage at the second terminal (Vf_Lo) generated when the wiper motor rotates when the power supply voltage is applied to the first terminal, and greater than the power supply voltage.

This allows for the detection of abnormalities in the first drive element, second drive element, first wiring, second wiring, wiper motor, and wiper.

The reference numerals in parentheses attached to each component indicate an example of the correspondence between that component and the specific components described in the embodiments described later.

A diagram showing the configuration of a wiper drive system in which the wiper control device of the first embodiment is used. A diagram showing the wiper in a wiper drive system. A diagram illustrating the relationship between voltage and time when the wiper motor of a wiper drive system is energized and when it is not. A flowchart illustrating the processing of the judgment unit of the wiper control device. A flowchart illustrating the processing of the determination unit. A flowchart illustrating the processing of the determination unit. A diagram showing the relationship between the voltage and time of the wiper motor under normal conditions, when the Hi-side is off, and when the wiper is locked. Diagram showing the relationship between the voltage and time of the wiper motor under normal conditions, when the Lo side is ON abnormally, and when the Lo side is OFF abnormally. Diagram showing the relationship between the voltage and time of the wiper motor under normal conditions and when the Hi-side is on abnormally. A diagram showing the configuration of a wiper drive system in which the wiper control device of the second embodiment is used. Diagram showing the relationship between the voltage and time of the wiper motor during normal operation, when it is off, and when it is stuck. Diagram showing the relationship between voltage and time of the wiper motor under normal conditions and when the second element malfunctions.

The embodiments will be described below with reference to the drawings. In the following embodiments, parts that are identical or equivalent to each other are denoted by the same reference numerals, and their descriptions are omitted.

(First Embodiment)
The wiper control device 30 of this embodiment is used in the wiper drive system 1 of a vehicle. First, this wiper drive system 1 will be described.

As shown in Figure 1, the wiper drive system 1 comprises a motor unit 10, a motor ground 12, a motor power supply 14, a wiper switch 16, and a wiper control device 30.

The motor unit 10 includes a wiper motor 100. The wiper motor 100 includes a Hi terminal 104, a Lo terminal 106, and a GND terminal 108. The Hi terminal 104 and Lo terminal 106 are connected to the wiper control device 30 (described later). The GND terminal 108 is connected to the motor ground 12. The wiper motor 100 rotates at a relatively high speed when energized to the Hi terminal 104. Furthermore, the wiper motor 100 rotates at a lower speed than when energized to the Hi terminal 104 when energized to the Lo terminal 106. The rotation of the wiper motor 100 and a link mechanism (not shown) connected to the wiper motor 100 operate the vehicle's wiper 90 as shown in Figure 2. At this time, the wiper 90 reciprocates between a lower inversion position Pd and an upper inversion position Pu on the windshield (not shown).

Furthermore, the wiper motor 100 has the characteristic of generating an induced electromotive force at the unenergized terminal when it rotates due to energization at either the Hi terminal 104 or the Lo terminal 106. Specifically, as shown in Figure 3, when the Hi terminal 104 is energized at the power supply voltage Vb and the Lo terminal 106 is unenergized, the Hi voltage Vm_Hi becomes the power supply voltage Vb. At this time, an induced electromotive force is generated at the Lo terminal 106 as the wiper motor 100 rotates at high speed. Therefore, at this time, the Lo voltage Vm_Lo becomes the Lo induced electromotive force Vf_Lo. Also, when the Hi terminal 104 is unenergized and the Lo terminal 106 is energized at the power supply voltage Vb, the Lo voltage Vm_Lo becomes the power supply voltage Vb. At this time, an induced electromotive force is generated at the Hi terminal 104 as the wiper motor 100 rotates at low speed. Therefore, in this case, the Hi voltage Vm_Hi becomes the Hi induced electromotive force Vf_Hi. The power supply voltage Vb is the voltage of the motor power supply 14. Furthermore, the Hi voltage Vm_Hi is the voltage at the Hi terminal 104. Additionally, the Lo voltage Vm_Lo is the voltage at the Lo terminal 106. When the Hi terminal 104 and Lo terminal 106 are de-energized, the Hi voltage Vm_Hi and Lo voltage Vm_Lo are, for example, zero.

Here, let the rotational speed of the wiper motor 100 when the Hi terminal 104 is energized at the power supply voltage Vb and the Lo terminal 106 is de-energized be defined as the Hi rotational speed Nm_Hi. Furthermore, let the rotational speed of the wiper motor 100 when the Hi terminal 104 is de-energized and the Lo terminal 106 is energized at the power supply voltage Vb be defined as the Lo rotational speed Nm_Lo. In this case, since the wiper motor 100 rotates at a lower speed due to the energization of the Lo terminal 106 than when the Hi terminal 104 is energized, the Lo rotational speed Nm_Lo is smaller than the Hi rotational speed Nm_Hi. For example, the Lo rotational speed Nm_Lo is 2/3 of the Hi rotational speed Nm_Hi. Furthermore, the Hi induced electromotive force Vf_Hi is obtained by dividing the product of the power supply voltage Vb and the Lo rotational speed Nm_Lo by the Hi rotational speed Nm_Hi, as shown in the following relation (1-1). Similarly, the Lo induced electromotive force Vf_Lo is obtained by dividing the product of the power supply voltage Vb and the Hi rotational speed Nm_Hi by the Lo rotational speed Nm_Lo, as shown in the following relation (1-2). Since the Lo rotational speed Nm_Lo is smaller than the Hi rotational speed Nm_Hi, the Hi induced electromotive force Vf_Hi is smaller than the power supply voltage Vb. Furthermore, since the Hi rotational speed Nm_Hi is larger than the Lo rotational speed Nm_Lo, the Lo induced electromotive force Vf_Lo is larger than both the power supply voltage Vb and the Hi induced electromotive force Vf_Hi.

Vf_Hi=Vb×Nm_Lo/Nm_Hi
Vf_Lo=Vb×Nm_Hi/Nm_Lo

Returning to Figure 1, the motor power supply 14 is a secondary battery such as a lithium-ion battery, nickel-metal hydride battery, or lead-acid battery. The voltage of the motor power supply 14 is, for example, 12V.

The wiper switch 16, when operated by the user, outputs a signal to the control unit 60 of the wiper control device 30 (described later) that sets the operating state of the wiper 90 to one of the following modes: Hi mode, Lo mode, or Stop.

The wiper control device 30 controls the wiper motor 100 by controlling the voltage applied to the wiper motor 100. This allows the wiper control device 30 to control the drive of the wiper 90 connected to the wiper motor 100. Specifically, the wiper control device 30 includes a Hi switch 35, Hi wiring 37, Lo switch 45, Lo wiring 47, and a control unit 60.

The Hi switch 35 includes a relay or transistor, etc. One end of the Hi switch 35 is connected to the motor power supply 14. Furthermore, the other end of the Hi switch 35 is connected to the Hi terminal 104 via the Hi wiring 37. The Hi switch 35 is switched on or off by a signal from the control unit 60 (described later). This controls the supply of power to or interruption of current to the Hi terminal 104.

The Lo switch 45 includes a relay or transistor, etc. One end of the Lo switch 45 is connected to the motor power supply 14. Furthermore, the other end of the Lo switch 45 is connected to the Lo terminal 106 via the Lo wiring 47. The Lo switch 45 is switched on or off by a signal from the control unit 60 (described later). This controls the supply of power to or interruption of current to the Lo terminal 106.

The control unit 60 is primarily composed of a microcontroller and includes a CPU, ROM, flash memory, RAM, I/O, drive circuit, A/D converter, comparator circuit, DC-DC converter, low-pass filter, and bus lines connecting these components. The control unit 60 is driven by voltage from the motor power supply 14 or a power supply (not shown). Furthermore, the control unit 60 includes a drive unit 62 and a determination unit 64 as functional blocks.

The drive unit 62 controls the on/off state of the Hi switch 35 and Lo switch 45 based on signals from the wiper switch 16 and the determination unit 64 (described later) by executing a program built into the control unit 60. This allows the drive unit 62 to control the voltage applied to the wiper motor 100. As a result, the operating state of the wiper 90 becomes either Hi mode, Lo mode, or stopped.

The determination unit 64 executes a program built into the control unit 60 to acquire the signal from the wiper switch 16, the power supply voltage Vb, the Hi voltage Vm_Hi, and the Lo voltage Vm_Lo. Based on these acquired values, the Hi induced electromotive force Vf_Hi, and the Lo induced electromotive force Vf_Lo, the determination unit 64 determines whether there is an abnormality in the Hi switch 35, the Hi wiring 37, the Lo switch 45, the Lo wiring 47, the wiper motor 100, and the wiper 90.

As described above, the wiper drive system 1 is configured. Next, we will explain how the operation state of the wiper 90 in the drive unit 62 is set to Hi mode and Lo mode by the execution of a program in the control unit 60. For example, the program in the control unit 60 is executed when the ignition of a vehicle (not shown) is turned on.

(Hi mode)
Assume that the operator's action causes the wiper switch 16 to output a signal to the drive unit 62 that sets the wiper 90 to Hi mode. At this time, the drive unit 62 turns on the Hi switch 35. As a result, voltage is applied to the wiper motor 100 from the motor power supply 14 via the Hi switch 35, Hi wiring 37, and Hi terminal 104. This causes the wiper motor 100 to rotate at a higher speed than when power is supplied to the Lo terminal 106. Therefore, the wiper 90 connected to the wiper motor 100 rotates at high speed. Note that the Lo switch 45 is off at this time.

(Lo mode)
Furthermore, let's assume that the operator's action causes the wiper switch 16 to output a signal to the drive unit 62 that sets the wiper 90 to the Lo mode. At this time, the drive unit 62 turns on the Lo switch 45. As a result, voltage is applied to the wiper motor 100 from the motor power supply 14 via the Lo switch 45, Lo wiring 47, and Lo terminal 106. This causes the wiper motor 100 to rotate at a lower speed than when the Hi terminal 104 is energized. Therefore, the wiper 90 connected to the wiper motor 100 rotates at a lower speed. Note that the Hi switch 35 is off at this time.

As described above, the drive unit 62 controls the on/off state of the Hi switch 35 and the Lo switch 45 to set the operating state of the wiper 90 to Hi mode and Lo mode. When the operator controls the wiper switch 16 and outputs a signal to the drive unit 62 to stop the operation of the wiper 90, the drive unit 62 turns off the Hi switch 35 and the Lo switch 45. This stops the rotation of the wiper motor 100 so that the wiper 90 stops in the downward inversion position Pd.

Next, the abnormality detection process by the determination unit 64 based on program execution by the control unit 60 will be explained with reference to the flowcharts in Figures 4, 5, and 6, and the time charts in Figures 7, 8, and 9.

As shown in the flowchart of Figure 4, in step S100, the determination unit 64 acquires various information. Specifically, the determination unit 64 acquires a signal from the wiper switch 16 to determine whether the wiper 90 is operating in Hi mode, Lo mode, or stopped. The determination unit 64 also acquires the power supply voltage Vb via the wiring connected to the motor power supply 14. Furthermore, the determination unit 64 acquires the Hi voltage Vm_Hi via the Hi wiring 37. Finally, the determination unit 64 acquires the Lo voltage Vm_Lo via the Lo wiring 47.

Next, in step S102, the determination unit 64 determines whether the signal from the wiper switch 16 acquired in step S100 is a signal that sets the wiper 90 to Hi mode. If the signal from the wiper switch 16 is a signal that sets the wiper 90 to Hi mode, the determination unit 64 proceeds to step S104. If the signal from the wiper switch 16 is not a signal that sets the wiper 90 to Hi mode, that is, if the signal sets the wiper 90 to either Lo mode or stopped, the determination unit 64 proceeds to step S200.

Here, when the wiper 90 is set to operating in Hi mode, if the wiper drive system 1 is functioning correctly, the Hi switch 35 is turned on. This applies the power supply voltage Vb to the wiper motor 100 via the Hi switch 35, Hi wiring 37, and Hi terminal 104. Therefore, at this time, as shown in Figures 7 to 9 during the period from time x2 to time x3, the Hi voltage Vm_Hi becomes the power supply voltage Vb. Furthermore, at this time, the high-speed rotation of the wiper motor 100 generates an induced electromotive force at the Lo terminal 106. Therefore, at this time, the Lo voltage Vm_Lo becomes the Lo induced electromotive force Vf_Lo.

Furthermore, let's assume that when attempting to set the wiper 90 to Hi mode, an abnormality occurs, such as the Hi switch 35 not being turned on, the Hi wiring 37 being disconnected, or the wiper motor 100 failing to drive. In this case, since the power supply voltage Vb is not applied to the Hi terminal 104, the Hi voltage Vm_Hi becomes, for example, zero, as shown in Figure 7 during the period from time x2 to time x3. Moreover, since the wiper motor 100 does not rotate at this time, no induced electromotive force is generated at the Lo terminal 106. Therefore, the Lo voltage Vm_Lo becomes, for example, zero. For convenience, in the following text, abnormalities such as the Hi switch 35 not being turned on, the Hi wiring 37 being disconnected, or the wiper motor 100 failing to drive will be referred to as Hi-side off abnormalities.

Furthermore, let's assume that when attempting to set the wiper 90 to Hi mode, an abnormality occurs where the wiper 90 becomes fixed and unable to operate due to external factors such as snow accumulation or foreign matter. At this time, the Hi switch 35 is turned ON. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the Hi switch 35, Hi wiring 37, and Hi terminal 104. Therefore, at this time, the Hi voltage Vm_Hi becomes the power supply voltage Vb. However, since the wiper 90 is fixed, the wiper motor 100 does not rotate, and no induced electromotive force is generated at the Lo terminal 106. Therefore, at this time, the Lo voltage Vm_Lo becomes, for example, zero. For convenience, in the following, the abnormality where the wiper 90 becomes fixed and unable to operate due to external factors such as snow accumulation or foreign matter will be referred to as a wiper fixing abnormality.

Therefore, returning to the flowchart in Figure 4, in step S104 following step S102, the determination unit 64 determines whether the Lo voltage Vm_Lo obtained in step S100 is less than or equal to the first Lo threshold Vm_Lo_th1. Based on this, the determination unit 64 determines whether there is a Hi-side off abnormality or a wiper lock abnormality. The first Lo threshold Vm_Lo_th1 is set, for example, to zero, through experiments or simulations, so that it determines whether there is a Hi-side off abnormality or a wiper lock abnormality.

Furthermore, when the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1, the Lo voltage Vm_Lo is, for example, zero, indicating a Hi-side off abnormality or wiper lock abnormality. In this case, the determination unit 64 proceeds to step S106. Also, when the Lo voltage Vm_Lo is greater than the first Lo threshold Vm_Lo_th1, there is no Hi-side off abnormality or wiper lock abnormality. In this case, the determination unit 64 proceeds to step S112.

In step S106, following step S104, the determination unit 64 determines whether the Hi voltage Vm_Hi obtained in step S100 is less than or equal to the first Hi threshold Vm_Hi_th1. Based on this, the determination unit 64 determines whether the abnormality is a Hi-side off abnormality or a wiper-fixed abnormality. The first Hi threshold Vm_Hi_th1 is set, for example, to zero, through experiments or simulations, so that the determination can be made whether the abnormality is a Hi-side off abnormality or a wiper-fixed abnormality.

When the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, the wiper 90 is in Hi mode, but both the Hi voltage Vm_Hi and the Lo voltage Vm_Lo are, for example, zero. Therefore, the abnormality at this time is a Hi-side off abnormality. Consequently, the determination unit 64 proceeds to step S108. In step S108, the determination unit 64 determines that there is a Hi-side off abnormality. After that, the determination unit 64 returns to step S100.

Furthermore, when the Hi voltage Vm_Hi is greater than the first Hi threshold Vm_Hi_th1, a voltage is applied to the Hi terminal 104. Therefore, at this time, the wiper 90 is in Hi mode, the Hi voltage Vm_Hi is equal to the power supply voltage Vb, but the Lo voltage Vm_Lo is, for example, zero. Thus, since no induced electromotive force is generated, the wiper 90 and wiper motor 100 are not driven, and the abnormality at this time is a wiper lock abnormality. Therefore, at this point, the determination unit 64 proceeds to step S110. In step S110, the determination unit 64 determines that there is a wiper lock abnormality. After that, the determination unit 64 returns to step S100.

Furthermore, let's assume that when attempting to set the wiper 90 to Hi mode, an abnormality occurs, such as the Lo switch 45 not being turned off, or direct conductivity between the motor power supply 14 and the Lo wiring 47. In this case, the Hi switch 35 is turned on. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the Hi switch 35, the Hi wiring 37, and the Hi terminal 104. Therefore, as shown in Figure 8 from time x2 to time x3, the Hi voltage Vm_Hi becomes the power supply voltage Vb. However, due to the above abnormality, the power supply voltage Vb is also applied to the Lo terminal 106. Therefore, the Lo voltage Vm_Lo also becomes the power supply voltage Vb. For convenience, in the following, abnormalities such as the Lo switch 45 not being turned off, or direct conductivity between the motor power supply 14 and the Lo wiring 47, will be referred to as a Lo-side ON abnormality.

Therefore, returning to the flowchart in Figure 4, in step S112 following step S104, the determination unit 64 determines whether the Lo voltage Vm_Lo obtained in step S100 is greater than or equal to the power supply voltage Vb and less than the second Lo threshold Vm_Lo_th2. Based on this, the determination unit 64 determines whether or not there is a Lo-side ON abnormality. The second Lo threshold Vm_Lo_th2 is a value less than or equal to the Lo-induced electromotive force Vf_Lo and greater than the power supply voltage Vb; for example, in this case, it is the Lo-induced electromotive force Vf_Lo. Furthermore, the second Lo threshold Vm_Lo_th2 is set through experiments, simulations, etc., so that it can be determined whether or not there is a Lo-side ON abnormality.

Furthermore, when the Lo voltage Vm_Lo is greater than or equal to the power supply voltage Vb and less than the second Lo threshold Vm_Lo_th2, the Lo voltage Vm_Lo is not the Lo induced electromotive force Vf_Lo, but rather, for example, the power supply voltage Vb, thus indicating a Lo-side ON abnormality. At this point, the determination unit 64 proceeds to step S114. In step S114, the determination unit 64 determines that a Lo-side ON abnormality exists. Afterward, the determination unit 64 returns to step S100.

Furthermore, when the Lo voltage Vm_Lo is greater than the first Lo threshold Vm_Lo_th1 and less than the power supply voltage Vb, or greater than or equal to the second Lo threshold Vm_Lo_th2, there is a high probability that the Lo induced electromotive force Vf_Lo is normal, and therefore the wiper drive system 1 is normal. Consequently, at this point, the determination unit 64 proceeds to step S116. In step S116, the determination unit 64 determines that the wiper drive system 1 is normal. Afterward, the determination unit 64 returns to step S100.

Furthermore, as shown in the flowchart of Figure 5, in step S200 following step S102, the determination unit 64 determines whether the signal from the wiper switch 16 acquired in step S100 is a signal that causes the wiper 90 to operate in the Lo mode. If the signal from the wiper switch 16 is a signal that causes the wiper 90 to operate in the Lo mode, the determination unit 64 proceeds to step S202. If the signal from the wiper switch 16 is not a signal that causes the wiper 90 to operate in the Lo mode, that is, if it is a signal that causes the wiper 90 to stop, the determination unit 64 proceeds to step S300.

Here, when the wiper 90 is set to the Lo mode, if the wiper drive system 1 is functioning correctly, the Lo switch 45 is turned on. This applies the power supply voltage Vb to the wiper motor 100 via the Lo switch 45, Lo wiring 47, and Lo terminal 106. Therefore, as shown in Figures 7 to 9 during the period from time x1 to time x2, the Lo voltage Vm_Lo becomes the power supply voltage Vb. Furthermore, at this time, the wiper motor 100 rotates at a low speed, generating an induced electromotive force at the Hi terminal 104. Therefore, at this time, the Hi voltage Vm_Hi becomes the Hi induced electromotive force Vf_Hi.

Furthermore, let's assume that when attempting to set the wiper 90 to the Lo mode, an abnormality occurs, such as the Lo switch 45 not being turned on, the Lo wiring 47 being disconnected, or the wiper motor 100 failing to drive. In this case, since the power supply voltage Vb is not applied to the Lo terminal 106, the Lo voltage Vm_Lo becomes, for example, zero, as shown in Figure 8 during the period from time x1 to time x2. Moreover, since the wiper motor 100 does not rotate at this time, no induced electromotive force is generated at the Hi terminal 104. Therefore, the Hi voltage Vm_Hi becomes, for example, zero. For convenience, in the following text, abnormalities such as the Lo switch 45 not being turned on, the Lo wiring 47 being disconnected, or the wiper motor 100 failing to drive will be referred to as Lo-side off abnormalities.

Furthermore, let's assume that a wiper locking abnormality occurs when the wiper 90 is set to the Lo mode. At this time, the Lo switch 45 is turned on. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the Lo switch 45, Lo wiring 47, and Lo terminal 106. Therefore, at this time, as shown in Figure 7 from time x1 to time x2, the Lo voltage Vm_Lo becomes the power supply voltage Vb. However, since the wiper 90 is fixed at this time, the wiper motor 100 does not rotate, and therefore no induced electromotive force is generated at the Hi terminal 104. Consequently, at this time, the Hi voltage Vm_Hi becomes, for example, zero.

Therefore, returning to the flowchart in Figure 5, in step S202 following step S200, the determination unit 64 determines whether the Hi voltage Vm_Hi acquired in step S100 is less than or equal to the first Hi threshold Vm_Hi_th1. Based on this, the determination unit 64 determines whether there is a Lo-side off abnormality or a wiper-fixed abnormality. The first Hi threshold Vm_Hi_th1, as described above, is, for example, zero, and is a threshold for determining whether the abnormality is a Hi-side off abnormality or a wiper-fixed abnormality. Furthermore, here, the first Hi threshold Vm_Hi_th1 is also used as a threshold for determining whether there is a Lo-side off abnormality or a wiper-fixed abnormality. Moreover, the threshold for determining whether the abnormality is a Hi-side off abnormality or a wiper-fixed abnormality and the threshold for determining whether there is a Lo-side off abnormality or a wiper-fixed abnormality may be different values.

Furthermore, when the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, the Hi voltage Vm_Hi is, for example, zero, indicating a Lo-side off abnormality or wiper lock abnormality. In this case, the determination unit 64 proceeds to step S204. Also, when the Hi voltage Vm_Hi is greater than the first Hi threshold Vm_Hi_th1, there is no Lo-side off abnormality or wiper lock abnormality. In this case, the determination unit 64 proceeds to step S208.

In step S204, following step S202, the determination unit 64 determines whether the Lo voltage Vm_Lo obtained in step S100 is less than or equal to the first Lo threshold Vm_Lo_th1. Based on this, the determination unit 64 determines whether the abnormality is a Lo-side off abnormality or a wiper-fixed abnormality. The first Lo threshold Vm_Lo_th1, as described above, is, for example, zero, and is a threshold for determining whether there is a Hi-side off abnormality or a wiper-fixed abnormality. Furthermore, here, the first Lo threshold Vm_Lo_th1 is also used as a threshold for determining whether the abnormality is a Lo-side off abnormality or a wiper-fixed abnormality. Moreover, the threshold for determining whether there is a Hi-side off abnormality or a wiper-fixed abnormality and the threshold for determining whether the abnormality is a Lo-side off abnormality or a wiper-fixed abnormality may be different values.

When the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1, the wiper 90 is in Lo mode, but both the Lo voltage Vm_Lo and the Hi voltage Vm_Hi are, for example, zero. Therefore, the abnormality at this time is a Lo-side off abnormality. Consequently, the determination unit 64 proceeds to step S206. In step S206, the determination unit 64 determines that there is a Lo-side off abnormality. After that, the determination unit 64 returns to step S100.

Furthermore, when the Lo voltage Vm_Lo is greater than the first Lo threshold Vm_Lo_th1, a voltage is applied to the Lo terminal 106. Therefore, at this time, the wiper 90 is in Lo mode, the Lo voltage Vm_Lo is equal to the power supply voltage Vb, but the Hi voltage Vm_Hi is, for example, zero. Thus, since no induced electromotive force is generated, the wiper 90 and wiper motor 100 are not driven, and the abnormality at this time is a wiper lock abnormality. Therefore, at this point, the determination unit 64 proceeds to step S110. In step S110, the determination unit 64 determines that there is a wiper lock abnormality. After that, the determination unit 64 returns to step S100.

Furthermore, let's assume that when the wiper 90 is set to the Lo mode, an abnormality occurs, such as the Hi switch 35 not being turned off, or direct conductivity between the motor power supply 14 and the Hi wiring 37. At this time, the Lo switch 45 is turned on. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the Lo switch 45, the Lo wiring 47, and the Lo terminal 106. Therefore, at this time, as shown in Figure 9 from time x1 to time x2, the Lo voltage Vm_Lo becomes the power supply voltage Vb. However, at this time, due to the above abnormality, the power supply voltage Vb is also applied to the Hi terminal 104. Therefore, the Hi voltage Vm_Hi also becomes the power supply voltage Vb. For convenience, in the following, abnormalities such as the Hi switch 35 not being turned off, or direct conductivity between the motor power supply 14 and the Hi wiring 37, will be referred to as Hi-side ON abnormalities.

Therefore, returning to the flowchart in Figure 5, in step S208 following step S202, the determination unit 64 determines whether the Hi voltage Vm_Hi obtained in step S100 is greater than the second Hi threshold Vm_Hi_th2 and less than or equal to the power supply voltage Vb. Based on this, the determination unit 64 determines whether or not there is a Hi-side ON abnormality. The second Hi threshold Vm_Hi_th2 is a value greater than or equal to the Hi induced electromotive force Vf_Hi and less than the power supply voltage Vb; for example, in this case, it is the Hi induced electromotive force Vf_Hi. Furthermore, the second Hi threshold Vm_Hi_th2 is set through experiments, simulations, etc., so that it can be determined whether or not there is a Hi-side ON abnormality.

Furthermore, when the Hi voltage Vm_Hi is greater than the second Hi threshold Vm_Hi_th2 and less than or equal to the power supply voltage Vb, the Hi voltage Vm_Hi is not the Hi induced electromotive force Vf_Hi, but rather, for example, the power supply voltage Vb, thus indicating a Hi-side ON abnormality. At this point, the determination unit 64 proceeds to step S210. In step S210, the determination unit 64 determines that a Hi-side ON abnormality exists. Afterward, the determination unit 64 returns to step S100.

Furthermore, when the Hi voltage Vm_Hi is greater than the first Hi threshold Vm_Hi_th1 and less than or equal to the second Hi threshold Vm_Hi_th2, or greater than the power supply voltage Vb, there is a high probability that the Hi induced electromotive force Vf_Hi is present, and therefore the wiper drive system 1 is normal. Consequently, at this point, the determination unit 64 proceeds to step S116. In step S116, the determination unit 64 determines that the wiper drive system 1 is normal. Afterward, the determination unit 64 returns to step S100.

Furthermore, when the wiper 90 is stopped, if the wiper drive system 1 is functioning correctly, the Hi switch 35 and Lo switch 45 are turned off. At this time, since the power supply voltage Vb is not applied to the Hi terminal 104 and Lo terminal 106, the Hi voltage Vm_Hi and Lo voltage Vm_Lo become, for example, zero, as shown in Figures 7 to 9 during the period from time x0 to time x1. Note that in Figures 7 to 9, when the wiper 90 is stopped, it is indicated as mode OFF.

Furthermore, let's assume that a Lo-side ON abnormality occurs when the wiper 90 is stopped. At this time, the power supply voltage Vb is applied to the Lo terminal 106. Therefore, as shown in Figure 8 during the period from time x0 to time x1, the Lo voltage Vm_Lo becomes the power supply voltage Vb.

Furthermore, let's assume that a Hi-side ON abnormality occurs when the wiper 90 is stopped. At this time, the power supply voltage Vb is applied to the Hi terminal 104. Therefore, as shown in Figure 9 from time x0 to time x1, the Hi voltage Vm_Hi becomes the power supply voltage Vb.

Therefore, as shown in the flowchart of Figure 6, in step S300 following step S200, the wiper 90 is stopped. At this time, the determination unit 64 determines whether the Lo voltage Vm_Lo acquired in step S100 is less than or equal to the first Lo threshold Vm_Lo_th1, and whether the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1. Based on this, the determination unit 64 determines whether there are Lo-side ON abnormalities and Hi-side ON abnormalities.

Furthermore, when the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1, and the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, then both the Lo voltage Vm_Lo and the Hi voltage Vm_Hi are, for example, zero. Therefore, since the Hi switch 35 and the Lo switch 45 are off, and there is no abnormal continuity between the motor power supply 14 and the Hi wiring 37 and Lo wiring 47, the wiper drive system 1 is normal. Thus, at this point, the determination unit 64 proceeds to step S116. In step S116, the determination unit 64 determines that the wiper drive system 1 is normal. After that, the determination unit 64 returns to step S100.

Furthermore, when the Lo voltage Vm_Lo is greater than the first Lo threshold Vm_Lo_th1, the wiper 90 is stopped. However, since the Lo voltage Vm_Lo is likely to be the power supply voltage Vb, there is a Lo-side ON abnormality. Therefore, in this case, the determination unit 64 proceeds to step S302. In step S302, the determination unit 64 determines that there is a Lo-side ON abnormality. After that, the determination unit 64 returns to step S100.

Furthermore, when the Hi voltage Vm_Hi is greater than the first Hi threshold Vm_Hi_th1, the wiper 90 is stopped. However, since the Hi voltage Vm_Hi is likely to be the power supply voltage Vb, there is a Hi-side ON abnormality. Therefore, at this point, the determination unit 64 proceeds to step S302. In step S302, the determination unit 64 determines that there is a Hi-side ON abnormality. After that, the determination unit 64 returns to step S100.

As described above, the determination unit 64 performs abnormality detection on the Hi switch 35, Hi wiring 37, Lo switch 45, Lo wiring 47, wiper motor 100, and wiper 90.

[1-1] Based on the above, in order to perform the above abnormality determination, the wiper control device 30 of this embodiment comprises a Hi wiring 37, a Lo wiring 47, a Hi switch 35, a Lo switch 45, and a determination unit 64. The Hi wiring 37 is connected to the Hi terminal 104. The Lo wiring 47 is connected to the Lo terminal 106. When the Hi switch 35 is turned on, the power supply voltage Vb is applied to the Hi terminal 104 via the Hi wiring 37, thereby rotating the wiper motor 100. When the Lo switch 45 is turned on, the power supply voltage Vb is applied to the Lo terminal 106 via the Lo wiring 47, thereby rotating the wiper motor 100 at a lower speed than when the power supply voltage Vb is applied to the Hi terminal 104. Note that the Hi wiring 37 corresponds to the first wiring. The Hi terminal 104 corresponds to the first terminal. The Lo wiring 47 corresponds to the second wiring. The Lo terminal 106 corresponds to the second terminal. The Hi switch 35 corresponds to the first drive element. The Lo switch 45 corresponds to the second drive element.

Furthermore, the determination unit 64 determines whether there is an abnormality in the Hi switch 35, Lo switch 45, Hi wiring 37, Lo wiring 47, wiper motor 100, and wiper 90 based on the following voltages and values. The following voltages and values are the power supply voltage Vb, the Hi voltage Vm_Hi, the Lo voltage Vm_Lo, the first Hi threshold Vm_Hi_th1, the first Lo threshold Vm_Lo_th1, the second Hi threshold Vm_Hi_th2, and the second Lo threshold Vm_Lo_th2. Note that the Hi voltage Vm_Hi corresponds to the voltage of the first terminal. The Lo voltage Vm_Lo corresponds to the voltage of the second terminal. The first Hi threshold Vm_Hi_th1 corresponds to the value related to the first voltage, which is the voltage of the first terminal when the power supply voltage Vb is not applied to the first and second terminals. The first Lo threshold Vm_Lo_th1 corresponds to a value relating to the second voltage, which is the voltage at the second terminal when the power supply voltage Vb is not applied to the first and second terminals. The second Hi threshold Vm_Hi_th2 corresponds to a value relating to the third voltage, which is a voltage greater than or equal to the voltage at the first terminal and less than the power supply voltage Vb, generated when the wiper motor 100 rotates when the power supply voltage Vb is applied to the second terminal. The voltage at the first terminal, which is generated when the wiper motor 100 rotates when the power supply voltage Vb is applied to the second terminal, corresponds to the Hi induced electromotive force Vf_Hi. The second Lo threshold Vm_Lo_th2 corresponds to a value relating to the fourth voltage, which is a voltage less than or equal to the voltage at the second terminal and greater than the power supply voltage Vb, generated when the wiper motor 100 rotates when the power supply voltage Vb is applied to the first terminal. Furthermore, the voltage at the second terminal, generated when the wiper motor 100 rotates while the power supply voltage Vb is applied to the first terminal, corresponds to the induced electromotive force Vf_Lo.

This allows for the detection of abnormalities in the Hi switch 35, Lo switch 45, Hi wiring 37, Lo wiring 47, wiper motor 100, and wiper 90.

[1-2] For example, when the operating state of the wiper 90 is set to Hi mode, the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that there is a Hi-side off abnormality, as shown in the flowchart of Figure 4 and the time chart of Figure 7. Note that setting the operating state of the wiper 90 to Hi mode corresponds to the case where the wiper motor 100 rotates when the power supply voltage Vb is applied to the first terminal. A Hi-side off abnormality corresponds to an abnormality in at least one of the first drive element, the first wiring, and the wiper motor 100.

[1-3] Furthermore, for example, when setting the operating state of the wiper 90 to Hi mode, the Hi voltage Vm_Hi is greater than the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1. In this case, the determination unit 64 determines that there is a wiper locking abnormality. Note that a wiper locking abnormality corresponds to a locking abnormality of the wiper 90.

[1-4] Furthermore, for example, when setting the wiper 90 to Hi mode, the Lo voltage Vm_Lo is greater than or equal to the power supply voltage Vb and less than the second Lo threshold Vm_Lo_th2. At this time, the determination unit 64 determines that there is a Lo-side ON abnormality, as shown in the flowchart of Figure 4 and the time chart of Figure 8. Note that a Lo-side ON abnormality corresponds to an abnormality in at least one of the second drive element and the second wiring.

[1-5] Furthermore, for example, when the operating state of the wiper 90 is set to Lo mode, the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that there is a Lo-side off abnormality, as shown in the flowchart of Figure 5 and the time chart of Figure 8. Note that setting the operating state of the wiper 90 to Lo mode corresponds to the case where the wiper motor 100 rotates when the power supply voltage Vb is applied to the second terminal. Also, a Lo-side off abnormality corresponds to an abnormality in at least one of the second drive element, the second wiring, and the wiper motor 100.

[1-6] Furthermore, for example, when setting the operating state of the wiper 90 to Lo mode, the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is greater than the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that there is a wiper locking abnormality, as shown in the flowcharts of Figures 4 and 5 and the time chart of Figure 7.

[1-7] Furthermore, for example, when the operating state of the wiper 90 is set to Lo mode, the Hi voltage Vm_Hi is greater than the second Hi threshold Vm_Hi_th2 and less than or equal to the power supply voltage Vb. At this time, the determination unit 64 determines that there is a Hi-side ON abnormality, as shown in the flowchart of Figure 5 and the time chart of Figure 9. Note that a Hi-side ON abnormality corresponds to an abnormality in at least one of the first wiring and the first drive element.

[1-8] Furthermore, for example, when stopping the wiper 90, the Hi voltage Vm_Hi is greater than the first Hi threshold Vm_Hi_th1. In this case, the determination unit 64 determines that there is a Hi-side ON abnormality, as shown in the flowchart of Figure 6 and the time chart of Figure 9. Note that stopping the wiper 90 corresponds to stopping the wiper motor 100.

[1-9] Furthermore, for example, when stopping the wiper 90, assume that the Lo voltage Vm_Lo is greater than the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that there is a Lo-side ON abnormality, as shown in the flowchart of Figure 6 and the time chart of Figure 8.

(Second Embodiment)
As shown in Figure 10, the wiper control device 30 of the second embodiment includes a switching ground 70, a first switching element 71, and a second switching element 72 instead of the Hi switch 35 and Lo switch 45.

The first switching element 71 corresponds to the first drive element and includes a relay or transistor, etc. The first switching element 71 is connected to the motor power supply 14, the switching ground 70, and the second switching element 72 (described later). Furthermore, the first switching element 71 is switched on and off by a signal from the drive unit 62. When the first switching element 71 is on, it is conductive with the second switching element 72 (described later). Furthermore, when the first switching element 71 is off, it is conductive with the switching ground 70.

The second switching element 72 corresponds to the second drive element and includes a relay or transistor, etc. The second switching element 72 is connected to the first switching element 71. Furthermore, the second switching element 72 is connected to the Hi terminal 104 via the Hi wiring 37. Also, the second switching element 72 is connected to the Lo terminal 106 via the Lo wiring 47. Furthermore, the second switching element 72 is switched on and off by a signal from the drive unit 62. In this case, when the second switching element 72 is on, it conducts with the Hi terminal 104 via the Hi wiring 37. Furthermore, when the second switching element 72 is off, it conducts with the Lo terminal 106 via the Lo wiring 47. Alternatively, when the second switching element 72 is on, it may conduct with the Lo terminal 106 via the Lo wiring 47, and when it is off, it may conduct with the Hi terminal 104 via the Hi wiring 37.

As described above, the wiper control device 30 of the second embodiment is configured. Next, the operation state of the wiper 90 in the drive unit 62 of the second embodiment is described in terms of Hi mode and Lo mode.

(Hi mode)
Assume that the operator's action causes the wiper switch 16 to output a signal to the drive unit 62 that sets the wiper 90 to Hi mode. At this time, the drive unit 62 turns on the first switching element 71. As a result, the first switching element 71 becomes conductive with the second switching element 72. At the same time, the drive unit 62 also turns on the second switching element 72. Therefore, the second switching element 72 becomes conductive with the Hi terminal 104 via the Hi wiring 37. Consequently, voltage is applied from the motor power supply 14 to the wiper motor 100 via the first switching element 71, the second switching element 72, the Hi wiring 37, and the Hi terminal 104. As a result, the wiper motor 100 rotates at a higher speed than when power is supplied to the Lo terminal 106. Therefore, the wiper 90 connected to the wiper motor 100 rotates at high speed.

(Lo mode)
Furthermore, let's assume that the operator's action caused the wiper switch 16 to output a signal to the drive unit 62 that sets the operating state of the wiper 90 to Lo mode. At this time, the drive unit 62 turns on the first switching element 71. As a result, the first switching element 71 becomes conductive with the second switching element 72. At this time, the drive unit 62 also turns off the second switching element 72. Therefore, the second switching element 72 becomes conductive with the Lo terminal 106 via the Lo wiring 47. Consequently, voltage is applied to the wiper motor 100 from the motor power supply 14 via the first switching element 71, the second switching element 72, the Lo wiring 47, and the Lo terminal 106. As a result, the wiper motor 100 rotates at a lower speed than when power is supplied to the Hi terminal 104. Therefore, the wiper 90 connected to the wiper motor 100 rotates at a lower speed.

As described above, the drive unit 62 controls the on/off state of the first switching element 71 and the second switching element 72 to set the operating state of the wiper 90 to Hi mode and Lo mode. When the wiper switch 16 outputs a signal to the drive unit 62 to stop the operation of the wiper 90 due to the operator's actions, the drive unit 62 turns off the first switching element 71. As a result, the first switching element 71 becomes conductive with the switching ground 70. Therefore, the voltage from the motor power supply 14 is not applied to the wiper motor 100, and the rotation of the wiper motor 100 stops so that the wiper 90 stops at the downward inversion position Pd.

Next, the abnormality detection by the determination unit 64 in the second embodiment will be explained with reference to the time charts in Figures 11 and 12.

[2-1] The determination unit 64, similar to the first embodiment, determines whether there is an abnormality in the Hi switch 35, Lo switch 45, Hi wiring 37, Lo wiring 47, wiper motor 100, and wiper 90 based on the following voltages and values. The following voltages and values are the power supply voltage Vb, the Hi voltage Vm_Hi, the Lo voltage Vm_Lo, the first Hi threshold Vm_Hi_th1, the first Lo threshold Vm_Lo_th1, the second Hi threshold Vm_Hi_th2, and the second Lo threshold Vm_Lo_th2.

[2-2] When the wiper 90 is set to the Hi mode, if the wiper drive system 1 is functioning correctly, the first switching element 71 and the second switching element 72 are turned on simultaneously. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Hi wiring 37, and the Hi terminal 104. Therefore, at this time, as shown in Figures 11 and 12 from time x2 to time x3, the Hi voltage Vm_Hi becomes the power supply voltage Vb. Furthermore, at this time, the wiper motor 100 rotates at high speed, generating an induced electromotive force at the Lo terminal 106. Therefore, at this time, the Lo voltage Vm_Lo becomes the Lo induced electromotive force Vf_Lo.

Furthermore, let's assume that when attempting to set the wiper 90 to Hi mode, an abnormality occurs, such as the first switching element 71 not being turned on, the Hi wiring 37 being disconnected, or the wiper motor 100 failing to drive. In this case, since the power supply voltage Vb is not applied to the Hi terminal 104, the Hi voltage Vm_Hi becomes, for example, zero, as shown in Figure 11 during the period from time x2 to time x3. Moreover, since the wiper motor 100 does not rotate at this time, no induced electromotive force is generated at the Lo terminal 106. Therefore, the Lo voltage Vm_Lo becomes, for example, zero. Note that in Figure 11, abnormalities such as the first switching element 71 not being turned on, the Hi wiring 37 being disconnected, or the wiper motor 100 failing to drive are described as "off abnormalities."

Therefore, when the wiper 90 is set to the Hi mode, the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that an OFF abnormality exists. Note that an OFF abnormality corresponds to an abnormality in at least one of the first drive element, the first wiring, and the wiper motor 100.

[2-3] Now, let's assume that a wiper locking abnormality occurs when the wiper 90 is set to the Hi mode. At this time, the first switching element 71 and the second switching element 72 are turned on. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Hi wiring 37, and the Hi terminal 104. Therefore, at this time, the Hi voltage Vm_Hi becomes the power supply voltage Vb. However, since the wiper 90 is fixed at this time, the wiper motor 100 does not rotate, and therefore no induced electromotive force is generated at the Lo terminal 106. Consequently, at this time, the Lo voltage Vm_Lo becomes, for example, zero.

Therefore, when the wiper 90 is set to the Hi mode, the Hi voltage Vm_Hi is greater than the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that there is a wiper locking abnormality.

[2-4] Furthermore, when the operating state of the wiper 90 is set to Hi mode, the second switching element 72 is not turned on but turned off. At this time, the second switching element 72 conducts to the Lo terminal 106 via the Lo wiring 47. Also, the first switching element 71 is turned on. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Lo wiring 47, and the Lo terminal 106. Therefore, at this time, as shown in Figure 12 from time x2 to time x3, the Lo voltage Vm_Lo becomes the power supply voltage Vb. Furthermore, at this time, an induced electromotive force is generated at the Hi terminal 104 due to the low-speed rotation of the wiper motor 100. Therefore, at this time, the Hi voltage Vm_Hi becomes the Hi induced electromotive force Vf_Hi. Note that in Figure 12, the failure of the second switching element 72 to be turned on is indicated as a second element malfunction.

Therefore, when the wiper 90 is set to the Hi mode, the Lo voltage Vm_Lo is greater than or equal to the power supply voltage Vb and less than the second Lo threshold Vm_Lo_th2. At this time, the determination unit 64 determines that there is an abnormality in the second switching element 72. Note that an abnormality in the second switching element 72 is equivalent to an abnormality in the second drive element.

[2-5] Furthermore, when the wiper 90 is set to the Lo mode, if the wiper drive system 1 is functioning correctly, the first switching element 71 is turned on and the second switching element 72 is turned off. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Lo wiring 47, and the Lo terminal 106. Therefore, at this time, as shown in Figures 11 and 12 from time x1 to time x2, the Lo voltage Vm_Lo becomes the power supply voltage Vb. Moreover, at this time, the wiper motor 100 rotates at a low speed, generating an induced electromotive force at the Hi terminal 104. Therefore, at this time, the Hi voltage Vm_Hi becomes the Hi induced electromotive force Vf_Hi.

Furthermore, let's assume that when attempting to set the wiper 90 to the Lo mode, an abnormality occurs, such as the first switching element 71 not being turned on, the Lo wiring 47 being disconnected, or the wiper motor 100 failing to drive. In this case, since the power supply voltage Vb is not applied to the Lo terminal 106, the Lo voltage Vm_Lo becomes, for example, zero, as shown in Figure 11 during the period from time x1 to time x2. Moreover, since the wiper motor 100 does not rotate at this time, no induced electromotive force is generated at the Hi terminal 104. Therefore, the Hi voltage Vm_Hi becomes, for example, zero. Note that in Figure 11, abnormalities such as the first switching element 71 not being turned on, the Lo wiring 47 being disconnected, or the wiper motor 100 failing to drive are described as "off abnormalities."

Therefore, when the wiper 90 is set to the Lo mode, the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is less than or equal to the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that an OFF abnormality exists. Note that an OFF abnormality corresponds to an abnormality in at least one of the first drive element, the second wiring, and the wiper motor 100.

[2-6] Now, let's assume that a wiper locking abnormality occurs when the wiper 90 is set to the Lo mode. At this time, the first switching element 71 is turned on, and the second switching element 72 is turned off. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Lo wiring 47, and the Lo terminal 106. Therefore, at this time, as shown in Figure 11 from time x1 to time x2, the Lo voltage Vm_Lo becomes the power supply voltage Vb. However, since the wiper 90 is fixed at this time, the wiper motor 100 does not rotate, and therefore no induced electromotive force is generated at the Hi terminal 104. Consequently, at this time, the Hi voltage Vm_Hi becomes, for example, zero.

Therefore, when the wiper 90 is set to the Lo mode, the Hi voltage Vm_Hi is less than or equal to the first Hi threshold Vm_Hi_th1, and the Lo voltage Vm_Lo is greater than the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that there is a wiper locking abnormality.

[2-7] Furthermore, when the operating state of the wiper 90 is set to Lo mode, the second switching element 72 is not turned off but remains on. At this time, the second switching element 72 conducts to the Hi terminal 104 via the Hi wiring 37. Also, the first switching element 71 is turned on. As a result, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Hi wiring 37, and the Hi terminal 104. Therefore, at this time, as shown in Figure 12 from time x1 to time x2, the Hi voltage Vm_Hi becomes the power supply voltage Vb. Furthermore, at this time, the wiper motor 100 rotates at high speed, generating an induced electromotive force at the Lo terminal 106. Therefore, at this time, the Lo voltage Vm_Lo becomes the Lo induced electromotive force Vf_Lo. Note that in Figure 12, the failure of the second switching element 72 to turn off is indicated as a second element malfunction.

Therefore, when the wiper 90 is set to the Lo mode, the Hi voltage Vm_Hi is greater than the second Hi threshold Vm_Hi_th2 and less than or equal to the power supply voltage Vb. At this time, the determination unit 64 determines that there is an abnormality in the second switching element 72.

[2-8] Furthermore, when the wiper 90 is stopped, if the wiper drive system 1 is functioning correctly, the first switching element 71 is turned off. At this time, since the power supply voltage Vb is not applied to the Hi terminal 104 and the Lo terminal 106, the Hi voltage Vm_Hi and Lo voltage Vm_Lo become, for example, zero, as shown in Figures 11 and 12 during the period from time x0 to time x1. Note that in Figures 11 and 12, when the wiper 90 is stopped, it is indicated as mode OFF.

Furthermore, let's assume that when the wiper 90 is stopped, an abnormality occurs, such as the first switching element 71 remaining on instead of being turned off, or the motor power supply 14 and the Hi wiring 37 becoming directly conductive. In this case, if the second switching element 72 is turned on, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Hi wiring 37, and the Hi terminal 104. Therefore, in this case, the Hi voltage Vm_Hi becomes the power supply voltage Vb.

Therefore, when the wiper 90 is stopped, the Hi voltage Vm_Hi is considered to be greater than the first Hi threshold Vm_Hi_th1. At this time, the determination unit 64 determines that there is an abnormality in at least one of the first switching element 71 and the Hi wiring 37. Note that an abnormality in at least one of the first switching element 71 and the Hi wiring 37 is equivalent to an abnormality in at least one of the first drive element and the first wiring.

[2-9] Furthermore, suppose that when the wiper 90 is stopped, an abnormality occurs, such as the first switching element 71 remaining on instead of being turned off, or the motor power supply 14 and the Lo wiring 47 becoming directly conductive. In this case, if the second switching element 72 is turned off, the power supply voltage Vb is applied to the wiper motor 100 via the first switching element 71, the second switching element 72, the Lo wiring 47, and the Lo terminal 106. Therefore, in this case, the Lo voltage Vm_Lo becomes the power supply voltage Vb.

Therefore, when the wiper 90 is stopped, the Lo voltage Vm_Lo is considered to be greater than the first Lo threshold Vm_Lo_th1. At this time, the determination unit 64 determines that there is an abnormality in at least one of the first switching element 71 and the Lo wiring 47. Note that an abnormality in at least one of the first switching element 71 and the Lo wiring 47 corresponds to an abnormality in at least one of the first drive element and the second wiring.

As described above, the determination unit 64 performs abnormality detection on the Hi wiring 37, Lo wiring 47, first switching element 71, second switching element 72, wiper motor 100, and wiper 90. Therefore, the second embodiment achieves the same effects as the first embodiment.

(Other embodiments)
This disclosure is not limited to the embodiments described above, and modifications can be made to these embodiments as appropriate. Furthermore, it goes without saying that, in each of the embodiments described above, the elements constituting the embodiment are not necessarily essential, except in cases where they are explicitly stated to be particularly essential or where they are clearly considered essential in principle.

The determination unit and method described in this disclosure may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the determination unit and method described in this disclosure may be implemented by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the determination unit and method described in this disclosure may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable, non-transitional tangible recording medium.

The above embodiments may be combined as appropriate.

(Perspective of this disclosure)
[Perspective 1]
A wiper control device,
The first wiring (37) is connected to the first terminal (104) of the wiper motor (100) which drives the wiper (90) by rotating,
A second wire (47) is connected to a second terminal (106), which is a different terminal from the first terminal of the wiper motor,
By turning it on, the first drive element (35) rotates the wiper motor by applying a power supply voltage (Vb) to the first terminal via the first wiring,
A second drive element (45) that, when turned on, applies the power supply voltage to the second terminal via the second wiring, thereby rotating the wiper motor at a lower speed than when the power supply voltage is applied to the first terminal,
A determination unit (64) for determining abnormalities,
Equipped with,
The determination unit,
The aforementioned power supply voltage and,
The voltage at the first terminal (Vm_Hi) and
The voltage at the second terminal (Vm_Lo) and,
The value relating to the first voltage (Vm_Hi_th1), which is the voltage at the first terminal when the power supply voltage is not applied to the first and second terminals,
The value relating to the second voltage (Vm_Lo_th1), which is the voltage at the second terminal when the power supply voltage is not applied to the first and second terminals,
A value (Vm_Hi_th2) relating to a third voltage that is greater than or equal to the voltage at the first terminal (Vf_Hi) and less than the power supply voltage, generated when the wiper motor rotates when the power supply voltage is applied to the second terminal,
A value (Vm_Lo_th2) relating to a fourth voltage that is less than or equal to the voltage (Vf_Lo) at the second terminal generated when the wiper motor rotates when the power supply voltage is applied to the first terminal, and greater than the power supply voltage,
A wiper control device that determines whether or not there is an abnormality in the first drive element, the second drive element, the first wiring, the second wiring, the wiper motor, and the wiper, based on the above.
[Perspective 2]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to viewpoint 1, which determines that there is an abnormality in at least one of the first drive element, the first wiring, and the wiper motor.
[Perspective 3]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is greater than the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
A wiper control device according to viewpoint 1 or 2, which determines that there is a fixing abnormality of the wiper.
[Perspective 4]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the second terminal is greater than or equal to the power supply voltage and less than the value relating to the fourth voltage,
A wiper control device according to any one of viewpoints 1 to 3, which determines that there is an abnormality in at least one of the second drive element and the second wiring.
[Perspective 5]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
A wiper control device according to any one of viewpoints 1 to 4, which determines that there is an abnormality in at least one of the second drive element, the second wiring, and the wiper motor.
[Perspective 6]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is greater than the value relating to the second voltage,
A wiper control device according to any one of viewpoints 1 to 5 for determining that there is a fault in fixing the wiper.
[Perspective 7]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is greater than the value relating to the third voltage and less than or equal to the power supply voltage,
A wiper control device according to any one of viewpoints 1 to 6, which determines that there is an abnormality in at least one of the first drive element and the first wiring.
[Perspective 8]
The determination unit,
When the wiper motor stops,
When the voltage at the first terminal is greater than the value relating to the first voltage,
A wiper control device according to any one of viewpoints 1 to 7, which determines that there is an abnormality in at least one of the first drive element and the first wiring.
[Perspective 9]
The determination unit,
When the wiper motor stops,
When the voltage at the second terminal is greater than the value relating to the second voltage,
A wiper control device according to any one of viewpoints 1 to 8, which determines that there is an abnormality in at least one of the second drive element and the second wiring.
[Perspective 10]
A wiper control device,
The first wiring (37) is connected to the first terminal (104) of the wiper motor (100) which drives the wiper (90) by rotating,
A second wire (47) is connected to a second terminal (106), which is a different terminal from the first terminal of the wiper motor,
The first drive element (71) applies the power supply voltage (Vb) when turned on,
A second drive element (72) is connected to the first and second wiring and, by being switched on and off, applies the power supply voltage from the first drive element to either the first terminal or the second terminal,
A determination unit (64) for determining abnormalities,
Equipped with,
The wiper motor rotates at a lower speed when the power supply voltage is applied to the second terminal via the second wiring than when the power supply voltage is applied to the first terminal via the first wiring.
The determination unit,
The aforementioned power supply voltage and,
The voltage at the first terminal (Vm_Hi) and
The voltage at the second terminal (Vm_Lo) and,
The value relating to the first voltage (Vm_Hi_th1), which is the voltage at the first terminal when the power supply voltage is not applied to the first and second terminals,
The value relating to the second voltage (Vm_Lo_th1), which is the voltage at the second terminal when the power supply voltage is not applied to the first and second terminals,
A value (Vm_Hi_th2) relating to a third voltage that is greater than or equal to the voltage (Vf_Hi) at the first terminal and less than the power supply voltage, generated when the wiper motor rotates when the power supply voltage is applied to the second terminal,
A value (Vm_Lo_th2) relating to a fourth voltage that is less than or equal to the voltage (Vf_Lo) at the second terminal generated when the wiper motor rotates when the power supply voltage is applied to the first terminal, and greater than the power supply voltage,
A wiper control device that determines whether or not there is an abnormality in the first drive element, the second drive element, the first wiring, the second wiring, the wiper motor, and the wiper, based on the above.
[Perspective 11]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to viewpoint 10, which determines that there is an abnormality in at least one of the first drive element, the first wiring, and the wiper motor.
[Perspective 12]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is greater than the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
A wiper control device according to viewpoint 10 or 11, which determines that there is a fixing abnormality of the wiper.
[Perspective 13]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the second terminal is greater than or equal to the power supply voltage and less than the value relating to the fourth voltage,
A wiper control device according to any one of viewpoints 10 to 12 for determining that there is an abnormality in the second drive element.
[Perspective 14]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
A wiper control device according to any one of viewpoints 10 to 13, which determines that there is an abnormality in at least one of the first drive element, the second wiring, and the wiper motor.
[Perspective 15]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is greater than the value relating to the second voltage,
A wiper control device according to any one of viewpoints 10 to 14 for determining that there is a fault in fixing the wiper.
[Perspective 16]
The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is greater than the value relating to the third voltage and less than or equal to the power supply voltage,
A wiper control device according to any one of viewpoints 10 to 15 for determining that there is an abnormality in the second drive element.
[Perspective 17]
The determination unit,
When the wiper motor stops,
When the voltage at the first terminal is greater than the value relating to the first voltage,
A wiper control device according to any one of viewpoints 10 to 16, which determines that there is an abnormality in at least one of the first drive element and the first wiring.
[Perspective 18]
The determination unit,
When the wiper motor stops,
When the voltage at the second terminal is greater than the value relating to the second voltage,
A wiper control device according to any one of viewpoints 10 to 17, which determines that there is an abnormality in at least one of the first drive element and the second wiring.

14 Motor power supply 16 Wiper switch 35 Hi switch 37 Hi wiring 45 Lo switch 47 Lo wiring 60 Control unit 100 Wiper motor 104 Hi terminal 106 Lo terminal

Claims (18)

A wiper control device,
The first wiring (37) is connected to the first terminal (104) of the wiper motor (100) which drives the wiper (90) by rotating,
A second wire (47) is connected to a second terminal (106), which is a different terminal from the first terminal of the wiper motor,
By turning it on, the first drive element (35) rotates the wiper motor by applying a power supply voltage (Vb) to the first terminal via the first wiring,
A second drive element (45) that, when turned on, applies the power supply voltage to the second terminal via the second wiring, thereby rotating the wiper motor at a lower speed than when the power supply voltage is applied to the first terminal,
A determination unit (64) for determining abnormalities,
Equipped with,
The determination unit,
The aforementioned power supply voltage and,
The voltage at the first terminal (Vm_Hi) and
The voltage at the second terminal (Vm_Lo) and,
The value relating to the first voltage (Vm_Hi_th1), which is the voltage at the first terminal when the power supply voltage is not applied to the first and second terminals,
The value relating to the second voltage (Vm_Lo_th1), which is the voltage at the second terminal when the power supply voltage is not applied to the first and second terminals,
A value (Vm_Hi_th2) relating to a third voltage that is greater than or equal to the voltage (Vf_Hi) at the first terminal and less than the power supply voltage, generated when the wiper motor rotates when the power supply voltage is applied to the second terminal,
A value (Vm_Lo_th2) relating to a fourth voltage that is less than or equal to the voltage (Vf_Lo) at the second terminal generated when the wiper motor rotates when the power supply voltage is applied to the first terminal, and greater than the power supply voltage,
A wiper control device that determines whether or not there is an abnormality in the first drive element, the second drive element, the first wiring, the second wiring, the wiper motor, and the wiper, based on the above. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to claim 1, which determines that there is an abnormality in at least one of the first drive element, the first wiring, and the wiper motor. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is greater than the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to claim 1 or 2, which determines that there is a fixing abnormality of the wiper. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the second terminal is greater than or equal to the power supply voltage and less than the value relating to the fourth voltage,
The wiper control device according to claim 1 or 2, which determines that there is an abnormality in at least one of the second drive element and the second wiring. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to claim 1 or 2, which determines that there is an abnormality in at least one of the second drive element, the second wiring, and the wiper motor. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is greater than the value relating to the second voltage,
The wiper control device according to claim 1 or 2, which determines that there is a fixing abnormality of the wiper. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is greater than the value relating to the third voltage and less than or equal to the power supply voltage,
The wiper control device according to claim 1 or 2, which determines that there is an abnormality in at least one of the first drive element and the first wiring. The determination unit,
When the wiper motor stops,
When the voltage at the first terminal is greater than the value relating to the first voltage,
A wiper control device according to claim 1 or 2, which determines that there is an abnormality in at least one of the first drive element and the first wiring. The determination unit,
When the wiper motor stops,
When the voltage at the second terminal is greater than the value relating to the second voltage,
A wiper control device according to claim 1 or 2, which determines that there is an abnormality in at least one of the second drive element and the second wiring. A wiper control device,
The first wiring (37) is connected to the first terminal (104) of the wiper motor (100) which drives the wiper (90) by rotating,
A second wire (47) is connected to a second terminal (106), which is a different terminal from the first terminal of the wiper motor,
The first drive element (71) applies the power supply voltage (Vb) when turned on,
A second drive element (72) is connected to the first and second wiring and, by being switched on and off, applies the power supply voltage from the first drive element to either the first terminal or the second terminal,
A determination unit (64) for determining abnormalities,
Equipped with,
The wiper motor rotates at a lower speed when the power supply voltage is applied to the second terminal via the second wiring than when the power supply voltage is applied to the first terminal via the first wiring.
The determination unit,
The aforementioned power supply voltage and,
The voltage at the first terminal (Vm_Hi) and
The voltage at the second terminal (Vm_Lo) and,
The value relating to the first voltage (Vm_Hi_th1), which is the voltage at the first terminal when the power supply voltage is not applied to the first and second terminals,
The value relating to the second voltage (Vm_Lo_th1), which is the voltage at the second terminal when the power supply voltage is not applied to the first and second terminals,
A value (Vm_Hi_th2) relating to a third voltage that is greater than or equal to the voltage (Vf_Hi) at the first terminal and less than the power supply voltage, generated when the wiper motor rotates when the power supply voltage is applied to the second terminal,
A value (Vm_Lo_th2) relating to a fourth voltage that is less than or equal to the voltage (Vf_Lo) at the second terminal generated when the wiper motor rotates when the power supply voltage is applied to the first terminal, and greater than the power supply voltage,
A wiper control device that determines whether or not there is an abnormality in the first drive element, the second drive element, the first wiring, the second wiring, the wiper motor, and the wiper, based on the above. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to claim 10, which determines that there is an abnormality in at least one of the first drive element, the first wiring, and the wiper motor. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the first terminal is greater than the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to claim 10 or 11, which determines that there is a fixing abnormality of the wiper. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the first terminal,
When the voltage at the second terminal is greater than or equal to the power supply voltage and less than the value relating to the fourth voltage,
The wiper control device according to claim 10 or 11, which determines that there is an abnormality in the second drive element. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is less than or equal to the value relating to the second voltage,
The wiper control device according to claim 10 or 11, which determines that there is an abnormality in at least one of the first drive element, the second wiring, and the wiper motor. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is less than or equal to the value relating to the first voltage, and the voltage at the second terminal is greater than the value relating to the second voltage,
The wiper control device according to claim 10 or 11, which determines that there is a fixing abnormality of the wiper. The determination unit,
When the wiper motor rotates due to the application of the power supply voltage to the second terminal,
When the voltage at the first terminal is greater than the value relating to the third voltage and less than or equal to the power supply voltage,
The wiper control device according to claim 10 or 11, which determines that there is an abnormality in the second drive element. The determination unit,
When the wiper motor stops,
When the voltage at the first terminal is greater than the value relating to the first voltage,
The wiper control device according to claim 10 or 11, which determines that there is an abnormality in at least one of the first drive element and the first wiring. The determination unit,
When the wiper motor stops,
When the voltage at the second terminal is greater than the value relating to the second voltage,
The wiper control device according to claim 10 or 11, which determines that there is an abnormality in at least one of the first drive element and the second wiring.