JP2008230399A - Wiper control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiper control device capable of accurately stopping a wiper at a park position with a low cost. <P>SOLUTION: This wiper control device is equipped with a wiper park switch that switches conduction and cut-off of a detection path commonly grounded with a drive path of a wiper motor for allowing a wiper of a vehicle to perform reciprocating wiping action, and with which the wiper is cut off in a wiper stop section predetermined from a wiper home position in the forward direction to a predetermined angle position, and the wiper is conducted in a predetermined wiper stop preparation section continuing from the wiper stop section in the forward direction. The wiper control device monitors the switched state of the wiper park switch on the detection path after the operation state of a wiper drive-stop operation part for performing operation input of drive and stop of the wiper motor is switched from drive to stop. Based on the conduction state, when the wiper acting in the reverse direction toward the home position is determined to have proceeded to the wiper stop section, the wiper control device cuts off a wiper drive switch and stops the wiper motor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wiper control device used in a vehicle.

  In a wiper control device used in a vehicle, when the wiper operation is stopped, it is necessary to stop after moving the wiper to a predetermined stop position, which is also referred to as a park position, for example, a lower end portion of a wiper wiping area.

  Therefore, the state of the auto park switch linked to the wiper motor can be detected so that the wiper drive can be controlled so that the wiper blade does not stop at a position other than the predetermined stop position when the wiper blade is intermittently operated. A wiper drive control device has been devised (see Patent Document 1).

  Also, a wiper device has been devised that has a pulse generator that generates a pulse depending on the movement of the wiper, and that accurately stores the wiper in each inversion position in the wiping operation (see Patent Document 2).

JP-A-8-198059 Special table 2000-511492 gazette

  In the configuration of the prior art, since the wiper park position is included in the angle section in which the auto park switch is turned on, it is necessary to stop the wiper immediately after detecting a change in the state of the auto park switch. However, when the processing capability of the wiper control device is low, the wiper may not be stopped accurately at the park position.

  Further, in order to stop the wiper, the motor that drives the wiper must be stopped. However, as is well known, a current that is several times the rated value of the motor flows to operate / stop the motor. For this reason, a surge voltage exceeding the rated value is likely to be generated at the motor terminal due to the inductance of the winding or wiring of the motor. In particular, when the auto park switch and the motor are grounded to a common ground line, as in the conventional configuration, if the auto park switch is closed when the wiper is stopped, the ground line and the auto park switch Since a surge voltage is also applied to the auto park switch and the input circuit of the switch via the switch, it is necessary to use a component that can withstand the voltage, leading to an increase in component cost.

  Against the background of the above problems, an object of the present invention is to provide a wiper control device capable of accurately stopping a wiper at a park position at a low cost.

Means for Solving the Problems and Effects of the Invention

  A wiper control device for solving the above-described problems includes a wiper motor that reciprocates a wiper for a vehicle, a wiper drive / stop operation unit that inputs a drive and stop operation for the wiper motor, and a conductive path for the wiper motor. The wiper drive switch that switches between the wiper motor drive path and the detection path that is commonly grounded with the wiper motor is switched between conduction and cutoff, and the wiper is a wiper stop section in which the wiper is defined from the wiper origin position to a predetermined angle position in the positive direction. The operation state of the wiper park switch and the wiper drive / stop operation unit which are in the cut-off state in the positive direction and in the conductive state in the predetermined wiper stop preparation section following the wiper stop section in the positive direction has been switched from driving to stopping. A wiper park switch that monitors the switching state of the wiper park switch on the detection path later As the operation state of the monitoring unit and the wiper driving / stopping operation unit is switched from driving to stopping, the wiper operates in the reverse direction toward the origin position based on the conduction state of the wiper park switch monitored by the wiper park switch state monitoring unit. Wiper stop section entry determining means for determining whether or not the vehicle has entered the wiper stop section, and motor energization control means for stopping the wiper motor with the wiper drive switch shut off when it is determined that the wiper stop section has been entered. It is characterized by providing.

  The outline of the present invention will be described with reference to FIGS. 1 and 2 show the configuration of the prior art, and FIGS. 3 and 4 show the configuration of the present invention. In the prior art, as shown in FIG. 1, the wiper park switch is in an ON state within a predetermined angle θ1 including the lower end position where the angle of the wiping area of the wiper 100 is 0 °, that is, the origin position. In the area, the state is OFF. FIG. 2 is a timing chart showing the state of the wiper park switch when the wiper 100 is operated in the configuration of FIG. In this case, if the wiper park switch changes from the OFF state to the ON state, the park position (origin position) may be overrun unless the wiper 100 is stopped immediately. In addition, there is a problem that it is difficult to specify the origin position of the wiper 100.

  In the configuration of the present invention, as shown in FIG. 3, the wiper park switch is turned on in a range of a predetermined angle θ1 in the positive direction from a position away from the origin position of the wiper 100 by the angle θ2 in the positive direction. In the wiping area, the state is OFF. In this case, the pulse signal from the wiper park switch is generated once in each of the forward and reverse directions per one reciprocating operation of the wiper 100 as shown in FIG. Be identifiable.

  In FIG. 3, the angle section indicated by θ2 corresponds to the wiper stop section of the present invention, the angle section indicated by θ1 corresponds to the wiper stop preparation section of the present invention, and the wiper 100 is wiped from the wiper stop preparation section. The section to the upper end position of the region corresponds to the wiper operation section of the present invention.

  With the above configuration, the wiper park switch (the auto park switch described above) does not include the wiper park position (origin position) in the angle section where the wiper park switch (the above-described auto park switch) is turned on (wiper stop preparation section). Even if it is low, the wiper can be accurately stopped at the park position. In addition, since the auto park switch is not closed when the wiper is stopped, the surge voltage generated when the wiper is stopped is not applied to the auto park switch and the input circuit of the switch. There is also an advantage that the cost of parts does not increase.

  In addition, the wiper stop section entry determining means in the wiper control device of the present invention determines that the wiper park section has entered the wiper stop section by detecting a switching edge from the wiper stop preparation section to the wiper stop section in the conductive state of the wiper park switch. It can also be configured to.

  By the said structure, approach to a wiper stop area can be determined reliably.

  In the wiper control device of the present invention, the wiper park section is set to a wiper operation section that becomes conductive again following the wiper stop preparation section in the forward direction with respect to the wiper park switch. Detects a switching edge from the wiper operation section to the wiper stop preparation section in the conductive state of the wiper park switch during direction operation, and enters the wiper stop section when a predetermined time elapses after detection of the switching edge It can also be configured to estimate that it has been.

  With the above configuration, it is possible to reliably determine the entry into the wiper stop section without being affected by noise that is easily misidentified as an edge.

  Also, the motor energization control means in the wiper control device of the present invention drives the wiper through a predetermined delay time after the occurrence of a switching edge from the wiper stop preparation section to the wiper stop section in the conductive state of the wiper park switch. The switch can be configured to be in a cut-off state.

  With the above configuration, the optimum section for stopping the wiper at the origin position can be set as the wiper stop preparation section. In addition, by providing the delay time, the wiper can be accurately stopped at the origin position even in a slow-processing control device.

  Further, the delay time in the wiper control device of the present invention is configured to be determined so that it expires before the wiper reaches the origin position after the edge of switching from the wiper stop preparation section to the wiper stop section occurs. You can also.

  With the above configuration, it is possible to prevent the wiper from going too far from the origin position. In addition, it is possible to avoid an overcurrent flowing through the motor due to the wiper being pressed against the stopper while being driven.

  In addition, the expiration timing of the delay time in the wiper control device of the present invention is determined so as to correspond to the wiper angular position at which the wiper motor can reach the origin position by inertia force when the wiper motor drive is cut off at the expiration timing. It can also be configured.

  With the above configuration, the wiper can be accurately stopped at the origin position according to the shape and weight of the wiper.

  In the wiper control device of the present invention, the wiper park switch is set in the forward direction to be in the conductive state again in the form following the wiper stop preparation zone in the forward direction, and the wiper park switch is in the conductive state. A conduction state period identifying means for identifying a conduction state period that occurs when the wiper operates in the forward direction and a conduction state period that occurs when the wiper operates in the reverse direction. It can also be configured to determine whether or not the wiper is in the process of returning to the origin position based on the identification result.

  With the above configuration, even when the wiper park switch is in the conductive state in both the forward direction and the reverse direction, the wiper is in the process of returning to the home position, that is, entering the wiper stop preparation section. It can be determined whether or not.

  Further, in the wiper control device of the present invention, the motor energization control means is configured such that the wiper park switch is wiped through a predetermined delay time after a switching edge from the wiper stop preparation section to the wiper stop section occurs in the conductive state of the wiper park switch. The drive switch is turned off, and after the wiper starts operating from the origin position, the time until the start edge of the conduction state period at the time of reverse operation first arrives is measured. A delay time setting means for setting a delay time based on the delay time may be provided.

  Some wiper wiping speeds are switchable. With the above configuration, the wiper can be accurately stopped at the origin position by setting the delay time according to the actual wiping operation time of the wiper.

  In addition, the wiper control device of the present invention determines that the wiper has overrun without stopping at the origin position when the wiper enters the wiper stop preparation section from the wiper stop section before the delay time expires. It can also be configured to comprise means.

  With the above configuration, the wiper overrun can be determined without using other means.

  Further, the motor energization control means in the wiper control device of the present invention can be configured not to cut off the energization to the wiper motor when it is determined that the wiper has overrun.

  With the above configuration, it is possible to prevent the wiper from stopping at a position other than the origin position. Further, the wiper can be stopped at the origin position during the next reverse operation.

  The wiper control device of the present invention will be described below with reference to the drawings. First, FIG. 5 shows a circuit configuration of the wiper control device 1 of the present invention. The wiper control device 1 includes a power source (battery) 11 for supplying power to the wiper control device 1, a relay 12, a wiper motor 13, a wiper park switch 14, a wiper switch 15, and a wiper control module 21 connected thereto. I have.

  The relay 12 is obtained by switching the drive path of the wiper motor 13 between conduction / cutoff and corresponds to the wiper drive switch of the present invention. The relay 12 is interposed between the power line and the wiper motor 13. Further, the wiper motor 13 is a device that causes the wiper to perform a reciprocating wiping operation. The wiper 100 is connected by a well-known link mechanism (not shown). When the wiper motor 13 makes one rotation, the wiper 100 performs one reciprocating wiping operation.

  The wiper park switch 14 is grounded in common with the drive path of the wiper motor 13, and the wiper 100 is cut off in a wiper stop section (section of angle θ2 in FIG. 3) determined from the wiper origin position to a predetermined angle position in the positive direction. In a positive direction, a conductive state is established in a predetermined wiper stop preparation section (section of angle θ1 in FIG. 3) following the wiper stop section.

  An outline of the configuration and operation of the wiper park switch 14 will be described with reference to FIGS. 6 and 7. The wiper park switch 14 has a cam-like contact as shown in FIG. 6, and this contact rotates once every time the wiper motor 13 rotates once. The state (ON / OFF) can be detected by the potential generated by the contact (see FIG. 7). For example, if the “OPEN” state in FIG. 7 is turned ON and the other states (IG, GND) can be detected as OFF states, a pulse signal as shown in FIG. 4 can be extracted. The “ECU brake”, that is, the wiper motor 13 stop command in FIG. 7 is of the prior art configuration, and is issued immediately after the wiper park switch 14 changes state.

  Further, when the “intermediate” state has the same potential as the “IG” state by the switch or the circuit configuration, the “GND” state can be detected as the OFF state and the “IG” state can be detected as the ON state. A pulse signal such as In this case, the contact that generates the “GND” state is attached so as not to include the origin position of the wiper 100.

  Returning to FIG. 5, the wiper switch 15 is operated by the user to input operation for driving and stopping the wiper 100 (wiper motor 13), and corresponds to the wiper driving / stopping operation unit of the present invention.

  The wiper control module 21 includes a diode 22 for supplying power to the control circuit 29, a regulator 23, a capacitor 24, an FET (Field Effect Transistor) 25 for turning on / off the relay 12, and a control. The circuit includes a resistor 26 and 28 that constitute a signal input unit to the circuit 29, a filter circuit 27, and a control circuit 29 connected thereto.

  The control circuit 29 includes a known CPU 291, ROM 292, RAM 293, an input / output circuit (not shown), and the like. The CPU 291 performs control using the control program 292p and data stored in the ROM 292. The control circuit 29 corresponds to a wiper park switch state monitoring unit, a wiper stop section entry determination unit, a motor energization control unit, a conduction state period identification unit, a delay time setting unit, and an overrun determination unit of the present invention.

  The configuration and function of the filter circuit 27 will be described with reference to FIGS. The filter circuit 27 includes a known T flip-flop 27a whose output is inverted when a rising edge of a pulse is detected, and an AND circuit 27b. An inverted signal of the output A from the wiper park switch 14 is input to the input T of the T flip-flop 27a via the inverting element 27c. The logical product of the output Q of the T flip-flop 27 a and the output A from the wiper park switch 14 is obtained, and the result is input to the control circuit 29. Thereby, in the configuration of FIG. 4, it is possible to detect the state of the wiper park switch 14 only in the reverse direction of the wiper wiping operation. The filter circuit 27 corresponds to the conduction state period identifying means of the present invention.

  With the above configuration, in the wiper control device 1, the control circuit 29 performs ON / OFF control of the relay 12 based on the operation content of the user's wiper switch 15 and the states of the wiper motor 13 and the wiper park switch 14.

  The wiper stop control process will be described with reference to FIGS. This process is included in the control program 292p and is repeatedly executed together with other processes of the control program 292p. First, FIG. 10 shows a comparison between the present invention and the prior art. In the prior art, the wiper motor 13 is stopped immediately after detecting the rising edge of the wiper park switch 14 detected after the wiper switch 15 is turned off. However, according to the present invention, the wiper motor 13 is operated according to the operation state of the wiper. The stop timing is controlled.

  As shown in FIG. 11, the time T from when the wiper output of the relay 12 is turned on until the rising edge of the wiper park switch 14 is detected is measured, and based on this, the falling edge of the wiper park switch 14 is determined. The estimated arrival time (delay time) from the detected time point to the target stop position is calculated. Based on the estimated arrival time and the mechanical delay of the wiper, the control circuit 29 controls the timing for stopping the driving of the wiper motor 13.

Details of the wiper stop control process will be described with reference to FIG. As shown in FIG. 10, this processing is used in the case of a configuration that detects the state of the wiper park switch 14 only in the reverse direction of the wiper wiping operation, that is, in any of the following configurations.
A configuration in which the pulse signal is generated only when the wiper park switch 14 is in the reverse direction of the wiper wiping operation.
Using the above-described filter circuit 27, the pulse signal when the wiper wiping operation is in the positive direction is removed.
The odd-numbered pulse signal from the wiper park switch 14 after the wiper operation is started is removed by program processing.

  First, when the wiper switch 15 is operated to operate the wiper (S11: Yes), the control circuit 29 outputs a control signal for turning on the relay 12 to drive the wiper motor 13 (S12). Next, measurement of the wiper driving time T is started (S13).

  Next, when the rising edge (in the reverse direction) of the wiper park switch 14 is detected (S14: Yes), the measurement of the wiper driving time T is terminated and the delay time is calculated (S15). The relationship between the wiper driving time T and the delay time is defined as shown in FIG. 13, for example, and a data table or a calculation formula based on this relationship is stored in the ROM 292. The delay time is determined in consideration of a mechanical stop delay due to the inertial force of the wiper 100 as shown in FIG.

  Returning to FIG. 12, when the falling edge of the wiper park switch 14 is detected (S16: Yes), the timer is started (S17). When the previously calculated delay time has elapsed (S18: Yes), the state of the wiper switch 15 is acquired, and the wiper switch 15 is instructed to stop the wiper (S19: No). Then, the control circuit 29 outputs a control signal for turning off the relay 12 to stop the driving of the wiper motor 13 (S20).

  Another example of the wiper stop control process will be described with reference to FIGS. This process is used in a configuration for detecting the state of the wiper park switch 14 in both the forward and reverse directions of the wiper wiping operation as shown in FIG. As shown in FIG. 15, the time (wiper driving time) T from when the rising edge of the wiper park switch 14 in the forward direction (odd number) is detected to when the rising edge of the wiper park switch 14 in the reverse direction (even number) is detected. And a delay time is calculated based on the wiper driving time T. In this case, since the measurement time immediately before the wiper 100 is stopped can be used, the accuracy of the stop control can be further increased.

  Details will be described below with reference to FIG. First, when the wiper switch 15 is operated to operate the wiper (S31: Yes), the control circuit 29 outputs a control signal for turning on the relay 12 to drive the wiper motor 13 (S32).

  Next, when a rising edge in the positive direction of the wiper park switch 14 is detected (S33: Yes), measurement of the wiper drive time T is then started (S34). When the rising edge in the reverse direction of the wiper park switch 14 is detected (S35: Yes), the measurement of the wiper driving time T is ended, and the delay time is calculated (S36). The relationship between the wiper driving time T and the delay time is defined as shown in FIG.

  Next, a timer is started (S37). When the previously calculated delay time has elapsed (S38: Yes), the state of the wiper switch 15 is acquired, and when the wiper switch 15 is operated to stop the wiper (S39: No) Then, a control signal for shutting off the relay 12 is output from the control circuit 29, and the driving of the wiper motor 13 is stopped (S40).

  14 to 16, it is possible to detect an overrun when the wiper 100 is stopped. FIG. 17 shows the concept of overrun detection. If the positive edge of the wiper park switch 14 is detected while waiting for the delay time to elapse after detecting the wiper stop operation, the wiper 100 is further operated for one period.

  Another example of wiper stop control processing including overrun detection will be described with reference to FIG. Since this process is a modification of FIG. 16, steps S51 to S57, S59, and S60 are the same as steps S31 to S37, S39, and S40 of FIG. Will be omitted.

  After the calculation of the delay time is completed and the timer is started, when the timer has not elapsed the delay time (S58: No), when the positive rising edge of the wiper park switch 14 is detected (S61: Yes) Regardless of the state of the wiper switch 15, the process returns to step S54 to start measuring the wiper driving time.

  Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited to these embodiments, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

The figure which shows the conduction range of the wiper park switch in a prior art. The timing chart which shows the operation | movement of the wiper park switch in a prior art. The figure which shows the conduction | electrical_connection range of the wiper park switch in this invention. The timing chart which shows the operation | movement of the wiper park switch in this invention. The block diagram which shows the structure of a wiper control apparatus. The figure which shows the structural example of a wiper park switch. The figure which shows the outline of operation | movement of the wiper park switch following FIG. The figure which shows the structure of a filter circuit. The figure which shows the function of a filter circuit following FIG. The timing chart explaining the difference with a wiper stop control process and a prior art. The timing chart explaining a wiper stop control process. The flowchart explaining a wiper stop control process. The figure which shows the relationship between wiper drive time and delay time. The timing chart explaining the other example of a wiper stop control process. The timing chart explaining the detail of another example of a wiper stop control process. The flowchart explaining another example of a wiper stop control process. The timing chart explaining the overrun detection of a wiper. The flowchart explaining another example of the wiper stop control process including the overrun detection of a wiper.

Explanation of symbols

1 Wiper control device 11 Power supply (battery)
DESCRIPTION OF SYMBOLS 12 Relay 13 Wiper motor 14 Wiper park switch 15 Wiper switch 21 Wiper control module 27 Filter circuit (conduction state period identification means)
29 Control circuit (wiper park switch state monitoring means, wiper stop section entry judging means, motor energization control means, conduction state period identifying means, delay time setting means, overrun judging means)

Claims (10)

A wiper motor for reciprocating a wiper for a vehicle;
A wiper driving / stopping operation unit for inputting operation for driving and stopping the wiper motor;
A wiper drive switch for switching the drive path of the wiper motor between conduction and interruption;
The driving path of the wiper motor and the detection path that is grounded in common are switched between conduction / shutoff, and the wiper is in a shut-off state in a wiper stop section determined from a wiper origin position to a predetermined angle position in a positive direction, A wiper park switch that becomes conductive in a predetermined wiper stop preparation section following the wiper stop section in the positive direction;
A wiper park switch state monitoring means for monitoring a switching state of the wiper park switch on the detection path after the operation state of the wiper drive / stop operation unit is switched from driving to stopping;
As the operation state of the wiper driving / stopping operation unit is switched from driving to stopping, the wiper park switch state monitoring means performs a reverse operation toward the origin position based on the conduction state of the wiper park switch monitored. Wiper stop section entry determining means for determining whether or not a wiper has entered the wiper stop section;
Motor energization control means for stopping the wiper motor by setting the wiper drive switch to a shut-off state when it is determined that the wiper stop section has been entered;
A wiper control device comprising:   The wiper stop section entry determining means determines that the wiper stop section has been entered by detecting a switching edge from the wiper stop preparation section to the wiper stop section in the conductive state of the wiper park switch. The wiper control device described in 1. With respect to the wiper park switch, a wiper operation section is set in which the wiper operation section becomes conductive again in the positive direction following the wiper stop preparation section.
The wiper stop section approach determining means detects a switching edge from the wiper operation section to the wiper stop preparation section in the conductive state of the wiper park switch during the reverse operation, and is predetermined after detecting the switching edge. The wiper control device according to claim 1, wherein the wiper control device estimates that the vehicle has entered the wiper stop section when a given time has elapsed.   The motor energization control means shuts off the wiper drive switch after a predetermined delay time from the occurrence of a switching edge from the wiper stop preparation section to the wiper stop section in the conductive state of the wiper park switch. The wiper control device according to any one of claims 1 to 3.   5. The delay time according to claim 4, wherein the delay time is determined to expire before the wiper reaches the origin position after a switching edge from the wiper stop preparation section to the wiper stop section occurs. Wiper control device.   The expiration time of the delay time is determined so as to correspond to a wiper angle position at which the wiper motor can reach the origin position by inertia force when the drive of the wiper motor is cut off at the expiration timing. 5. The wiper control device according to 5. With respect to the wiper park switch, a wiper operation section in which the wiper park section is again turned on in the positive direction following the wiper stop preparation section is set,
A conduction state period identifying means for distinguishing between a conduction state period that occurs when the wiper operates in the forward direction and a conduction state period that occurs when the wiper operates in the reverse direction, of the period when the wiper park switch is in the conduction state; ,
The wiper according to any one of claims 1 to 6, wherein the wiper stop section entry determining means determines whether or not the wiper is in the process of returning to the origin position based on the identification result. Control device.   5. The apparatus according to claim 4, wherein after the wiper starts operation from the origin position, the time until the start edge of the conduction state period at the time of the reverse operation first arrives is measured. The wiper control device according to claim 7, further comprising delay time setting means for setting the delay time based on time.   When the wiper enters the wiper stop preparation section from the wiper stop section before the delay time expires, an overrun determination unit is provided that determines that the wiper has overrun without stopping at the origin position. The wiper control device according to any one of claims 4 to 8.   The wiper control device according to claim 9, wherein the motor energization control unit does not cut off the energization to the wiper motor when it is determined that the wiper has overrun.

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