JP5535738B2 - Wiper control device and wiper device control method - Google Patents

Description

  The present invention relates to a wiper operation control technique in a reversing wiper system that drives a wiper arm by rotating a motor forward and backward, and more particularly, to a wiper arm stop position control during intermittent stop and storage.

  In recent years, a so-called reversing wiper system that drives a wiper arm by rotating a motor forward and backward is widely used as a wiper device for an automobile. In the reversing wiper system, the operation of the motor is controlled by a controller equipped with a microcomputer, and the upside down position and the stop position can be set to arbitrary positions.

  On the other hand, when the wiper device is intermittently driven, or when the wiper switch is turned off and the wiper blade is retracted, it is necessary to stop the wiper arm at a predetermined stop position or retracted position. At that time, the lip for wiping attached to the wiper blade is made of an elastically deformable material such as rubber, but if the constant state continues for a long time, the deformed state will last longer or completely There is a risk of being left alone. Therefore, in the reversing wiper system, when stopping the wiper, the controller slightly drives the motor in the forward direction to slightly move the wiper arm in the forward direction so that the lip of the wiper blade does not deform in one direction. Stop at the selected position (lip fold position).

  However, in the wiper device, the intermittent stop position or the lip folding position moved slightly from the retracted position is in a state where the link mechanism exceeds the dead center position. It is easy to turn. If the wiper arm is easy to move due to external force, the blade may be moved due to wind pressure during travel, etc. (in such a wiper device having no storage position, storage position = intermittent stop position (lower reverse position)) No problem). Therefore, in order to prevent push-up due to wind pressure, in the reversing wiper system, the gap between the ± brushes of the motor is set to a closed loop, and the motor is in a braking state. In addition, when the wiper arm moves away from the target stop position during intermittent stop or storage by a predetermined value or more on the forward path side, a process of driving the motor to the return path side and returning the wiper arm to the target stop position is also performed.

JP 2004-130876 A

  However, the motor braking by the closed loop is easy to be moved by an external force because the braking force is low. For example, in the case of intermittent stop at high speed traveling, the wiper blade may be moved by traveling wind pressure. In that case, as described above, the wiper blade is driven to a certain degree of movement, and the motor is driven to return to the predetermined stop position again. There was a possibility of giving the user a sense of incongruity.

  Also, when returning the wiper blade to the intermittent stop position or storage position, if there is a snow accumulation near the storage position, even if the motor moves to the target stop position, the blade may not reach that position. Can happen. This state is the same as when the blade is pushed up and the blade is out of the stop position due to the wiper arm, wiper blade, link mechanism deflection, etc., and the controller drives the motor to maintain the stop position. try to. For this reason, continuous energization is performed on the motor, and although there is a safety function for stopping the output when the energization is continued for a long time, there is a problem that it causes deterioration or failure of the motor.

  Furthermore, depending on conditions, there may be a chattering phenomenon in which the blade is returned and pushed up repeatedly. During chattering, unlike the stop position maintenance operation for the previous push-up, the motor does not enter a continuous energization state, so the safety function during continuous energization does not work. For this reason, there is a possibility that chattering will continue endlessly, and there is a problem that the motor is likely to deteriorate or break down, and a countermeasure has been demanded.

  An object of the present invention is to hold a wiper arm so as not to move from a predetermined stop position during intermittent stop or storage, and to prevent an uncomfortable operation of the wiper blade during intermittent stop.

  The wiper control device of the present invention includes a wiper arm that reciprocates between predetermined reversal positions, and an electric motor that drives the wiper arm, and an absolute position signal that is output when the wiper arm is present at a predetermined position; A wiper control device that controls drive of the wiper arm that controls the operation of the wiper arm based on a relative position signal that is output as the electric motor rotates, and stops the wiper arm at a predetermined target stop position. When the electric motor is in a stopped state, the distance between the target stop position and the current position of the wiper arm is recognized using the relative position signal, and the electric motor is controlled based on the recognition to control the electric motor. A wiper arm position holding control unit that performs stop position holding control for holding the wiper arm at the target stop position is provided.

  In the wiper control device of the present invention, in the wiper device driven by the electric motor, for example, when the electric motor is in a stopped state to stop the wiper arm at a predetermined target stop position, such as during intermittent stop or during storage. The wiper arm position holding control unit provided in the wiper control device recognizes the interval between the target stop position and the current position of the wiper arm using a relative position signal, and controls the electric motor based on the recognition to target the wiper arm. Stop position holding control for holding at the stop position is performed to prevent the wiper arm from being moved by wind pressure or the like at the time of intermittent stop or storage at the lip folding position. Moreover, even if the wiper arm is subjected to a large wind pressure during high-speed driving or the like, it is not controlled in such a way that it is moved once and then returned, but fine position holding control in the vicinity of the target stop position is implemented, which makes the user feel uncomfortable. The operation that gives is also suppressed.

  In the wiper control device, the wiper arm position holding control unit includes a pulse count unit that counts the relative position signal, and a current number of the wiper arm based on the number of pulses of the relative position signal counted by the pulse count unit. A stop position determination unit that determines a position and determines whether the wiper arm is positioned within a position holding allowable range set in advance with respect to the target stop position; and the stop position determination unit, When it is determined that the wiper arm is located outside the position holding allowable range, the electric motor is driven to return the wiper arm to the position holding allowable range, and in accordance with the separated state from the target stop position. An output control unit that controls the output to the electric motor and performs the stop position holding control may be provided.

  The wiper arm position holding control unit includes a pulse count unit that counts the relative position signal, a vehicle speed detection unit that detects a speed of a vehicle on which the wiper device is mounted, and the vehicle speed detection unit that detects the vehicle speed detection unit. When the vehicle speed determination unit that compares the vehicle speed with a predetermined threshold value and the vehicle speed determination unit determine that the vehicle speed exceeds the threshold value, the electric motor is driven and the target An output control unit that controls the output to the electric motor and performs the stop position holding control according to a separation state from the stop position may be provided.

  The output controller may increase the output to the electric motor step by step each time the wiper arm moves away from the target stop position by one pulse of the relative position signal. In addition, after the output control unit changes the output to the electric motor, the output to the electric motor may be increased when the relative position signal does not change even after a predetermined time has elapsed. Furthermore, the output control unit may decrease the output to the electric motor step by step each time the wiper arm approaches the target stop position by one pulse of the relative position signal.

  The maximum value of the output to the electric motor by the output control unit is set to a value at which the wiper arm is not pushed up by the wind pressure received while the vehicle equipped with the wiper device is traveling at a predetermined upper limit speed. If the wiper arm moves away from the target stop position even after performing the operation, it may be determined that the load is abnormal and the electric motor may be stopped. Thereby, when the wiper blade is pushed up due to snow accumulation or the like when the wiper is stopped, continuous energization to the motor is suppressed, and deterioration or failure of the motor can be prevented.

In addition, the wiper arm position holding control unit is provided with a time from the output start time for the electric motor when the stop position holding control was performed last time to the output start time for the electric motor in the current stop position holding control. A chattering detection unit may be provided that measures time and determines that chattering occurs when the time is within a certain time. In this case, the wiper arm position holding control unit is further provided with a chattering continuation determining unit that detects whether or not chattering occurrence is detected by the chattering detection unit over a predetermined time, When the output control unit determines that the chattering continuation determination unit continues chattering over a predetermined time, the electric motor may be stopped. Thereby, when the wiper blade is pushed up due to snow accumulation or the like when the wiper is stopped, the continuous chattering operation is suppressed, and the deterioration or failure of the motor can be prevented.

  On the other hand, the wiper device control method of the present invention comprises a wiper arm that reciprocates between predetermined reversal positions, and an electric motor that drives the wiper arm, and is output when the wiper arm is in a predetermined position. A wiper device control method for controlling the operation of the wiper arm based on a signal and a relative position signal output as the electric motor rotates, wherein the wiper arm is stopped at a predetermined target stop position. When the electric motor is in a stopped state, the distance between the target stop position and the current position of the wiper arm is recognized using the relative position signal, and based on the recognition, the electric motor is controlled to control the wiper arm. Stop position holding control for holding at the target stop position is performed.

  In the wiper device control method of the present invention, in the wiper device driven by the electric motor, the electric motor is in a stopped state in order to stop the wiper arm at a predetermined target stop position, for example, at the time of intermittent stop or storage. When the distance between the target stop position and the current position of the wiper arm is recognized using a relative position signal, based on the recognition, stop position holding control is performed to control the electric motor and hold the wiper arm at the target stop position. The wiper arm is prevented from being moved by wind pressure or the like during intermittent stop or when retracted at the lip folding position. Moreover, even if the wiper arm is subjected to a large wind pressure during high-speed driving or the like, it is not controlled in such a way that it is moved once and then returned, but fine position holding control in the vicinity of the target stop position is implemented, which makes the user feel uncomfortable. The operation that gives is also suppressed.

  In the wiper device control method, the current position of the wiper arm is grasped based on the number of pulses of the relative position signal, and the wiper arm is positioned within a position holding allowable range set in advance with respect to the target stop position. And when it is determined that the wiper arm is positioned outside the position holding allowable range, the electric motor is driven to return the wiper arm to the position holding allowable range, and the target The stop position holding control may be performed by controlling the output to the electric motor in accordance with the separation state from the stop position.

  In the wiper device control method, the speed of the vehicle on which the wiper device is mounted is compared with a predetermined threshold, and when it is determined that the speed of the vehicle exceeds the threshold, the electric motor is driven. The stop position holding control may be performed by controlling the output to the electric motor in accordance with the separated state from the target stop position.

  The output to the electric motor may be increased step by step each time the wiper arm is separated from the target stop position by one pulse of the relative position signal. After changing the output to the electric motor, the output to the electric motor may be increased if there is no change in the relative position signal after a lapse of a certain time. Each time the wiper arm approaches the target stop position by one pulse of the relative position signal, the output to the electric motor may be reduced stepwise.

  Further, the maximum value of the output to the electric motor is set to a value at which the wiper arm is not pushed up by the wind pressure received while the vehicle equipped with the wiper device is traveling at a predetermined upper limit speed, and the maximum value is output. When the wiper arm moves away from the target stop position, the electric motor may be stopped based on an abnormal load. Thereby, when the wiper blade is pushed up due to snow accumulation or the like when the wiper is stopped, continuous energization to the motor is suppressed, and deterioration or failure of the motor can be prevented.

In addition, the time from the output start time for the electric motor when the stop position holding control was performed last time to the output start time for the electric motor in the current stop position holding control is counted, and the time is a fixed time. it may be determined that chattering occurs when within of. In this case, when chattering is detected by the chattering detection unit, it is detected whether or not the chattering has continued for a certain time, and the output control unit continues to chatter for a certain time. If it is determined that the electric motor is present, the electric motor may be stopped. Thereby, when the wiper blade is pushed up due to snow accumulation or the like when the wiper is stopped, the continuous chattering operation is suppressed, and the deterioration or failure of the motor can be prevented.

  The wiper control device according to the present invention is a wiper device that drives a wiper arm with an electric motor. In the wiper arm position holding control unit provided in the control device, the interval between the target stop position and the current position of the wiper arm is recognized using a relative position signal output as the electric motor rotates, and based on the recognition, Since the stop position holding control for holding the wiper arm at the target stop position by controlling the electric motor is performed, it is possible to prevent the wiper arm from being moved by wind pressure or the like when intermittently stopping or storing at the lip folding position. It becomes possible.

  According to the wiper control method of the present invention, in a wiper device that drives a wiper arm by an electric motor, for example, when the electric motor is in a stop state to stop the wiper arm at a predetermined target stop position, such as during intermittent stop or storage, The distance between the stop position and the current position of the wiper arm is recognized using a relative position signal output as the electric motor rotates, and based on the recognition, the electric motor is controlled to hold the wiper arm at the target stop position. Since the stop position holding control is performed, it is possible to prevent the wiper arm from being moved by wind pressure or the like during intermittent stop or storage at the lip folding position.

It is a block diagram which shows the structure of the reversing wiper system to which this invention is applied. It is a block diagram which shows the structure of the control system of the controller with which the wiper control method of this invention is performed. It is a flowchart which shows the process sequence of stop position holding | maintenance control which is Example 1 of this invention. It is an image figure which shows the relationship between the wiper arm position at the time of stop position holding | maintenance control, and Duty output. It is a block diagram which shows the structure of the control system of the controller with which the wiper control method which is Example 2 of this invention is performed. It is a flowchart which shows the process sequence of stop position holding | maintenance control of Example 2 of this invention. It is a block diagram which shows the structure of the control system of the controller in one modification of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a reversing wiper system to which the present invention is applied. As shown in FIG. 1, the wiper device 1 includes wiper arms 2 a and 2 b on the driver seat side and the passenger seat side, and the wiper arms 2 a and 2 b are connected by a link mechanism 3. Wiper blades 4a and 4b for wiping the glass surface are attached to the wiper arms 2a and 2b. The link mechanism 3 is connected to the motor unit 5, and the wiper device 1 is driven by the motor unit 5.

  The motor unit 5 includes an electric motor 6 (hereinafter abbreviated as motor 6) and a gear box 7. A sensor for detecting the relative position of the wiper arms 2a and 2b is provided on the motor 6 side, and a sensor for detecting the absolute position (for example, the lower reverse position) of the wiper arms 2a and 2b is provided on the gear box 7 side. . A pulse signal (relative position signal) is emitted from the sensor for detecting the relative position as the motor rotates. Further, a single signal (absolute position signal) is issued from the absolute position detection sensor when the wiper arms 2a and 2b come to the lower inversion position.

  The motor unit 5 is connected to a controller (wiper control device) 8, and the motor 6 is controlled by the controller 8. The controller 8 is provided with a CPU 11 in which a control program is installed and a ROM 12 in which various control data are stored. The controller 8 calculates position information (current position) of the wiper arms 2a and 2b based on signals output from the sensors. Then, with reference to the control data in the ROM 12, the inversion position and the storage position during the wiping operation are controlled according to the control program in the CPU 11.

  The controller 8 calculates the speed of the motor 6 from the input cycle of the pulse signal from the relative position detection sensor. The calculated motor speed is compared with a reference motor speed (target speed MAP value) stored in advance in the ROM 12 of the controller 8. A reference motor speed that is a target speed of the motor 6 is set in correspondence with the positions of the wiper arms 2a and 2b. Based on the current arm position, the controller 8 controls the motor speed to match the current motor speed to the reference motor speed at that position. At this time, the controller 8 controls the motor speed by changing the power supply voltage to the motor 6 by, for example, duty control by the PID method.

  On the other hand, when performing the intermittent operation, the wiper device 1 stops the wiper operation for a predetermined time at the lower inversion position. Further, when the wiper switch is turned off, the wiper arms 2a and 2b are moved to the storage position set lower than the lower inversion position and stopped. These stop positions are grasped by a single signal from the absolute position detection sensor and a pulse signal from the relative position detection sensor, and the controller 8 holds the wiper arms 2a and 2b at a predetermined target stop position. When the wiper arms 2a and 2b move outside the predetermined position holding allowable range, the motor 6 is appropriately controlled to return the arms to the range.

  FIG. 2 is a block diagram showing the configuration of the control system of the controller 8 in which the wiper control method of the present invention is executed. The stop position holding control of the wiper arms 2a and 2b is executed by a control system as shown in FIG. As shown in FIG. 2, a pulse count unit 13, a stop position determination unit 14, an elapsed time determination unit 15, an output control unit 16, and a timer 17 are provided in the CPU 11 that is a wiper arm position holding control unit. The pulse count unit 13 receives a pulse signal from the relative position detection sensor and counts the number of input pulses. The stop position determination unit 14 grasps the current positions of the wiper arms 2a and 2b based on the count pulse number in the pulse count unit 13, and determines whether or not the arm is located within the position holding allowable range. When the wiper arms 2a and 2b are out of the position holding allowable range and the motor 6 is controlled and driven, the elapsed time determination unit 15 uses the timer 17 to measure the elapsed time from the start of motor driving (position holding control start).

  The output control unit 16 appropriately controls the motor 6 to return the wiper arms 2a and 2b to within the position holding allowable range based on the determination results in the stop position determination unit 14 and the elapsed time determination unit 15. That is, when the wiper arms 2a, 2b are away from the target stop position (intermittent stop, storage) by a predetermined value or more on the forward path side (for example, two pulses or more), the motor 6 is driven back to the target stop position. . At that time, the motor 6 is first driven with a small duty (for example, 10%), and when further away, the duty is increased by one level (for example, + 5%: 10% → 15%). Further, after the motor is driven, if the wiper arms 2a and 2b do not move away but do not approach each other, if a certain time or more has elapsed after the duty increase (for example, 20 ms), the duty is further increased by one step (for example, + 5%) : 15% → 20%). On the other hand, when the wiper arms 2a and 2b approach the target stop position due to the increase in duty (for example, −1 pulse), the duty is decreased by one step (for example, 20% → 15%). When the wiper arms 2a and 2b reach the target stop position, the drive of the motor 6 is stopped (Duty = 0).

  FIG. 3 is a flowchart showing the processing procedure of such stop position holding control according to the present invention. The process of FIG. 3 is executed by the control system shown in FIG. 2, and first, in step S1, it is confirmed whether or not the position holding control is in an ON state. In the case of OFF, it is determined whether or not the wiper switch is switched in Step S2. If there is no switching, the routine is exited as it is. If there is switching, the process proceeds to Step S3 and the position holding control is turned ON. .

  When the position holding control is ON, the process proceeds to step S4, and the stop position determination unit 14 determines whether or not the wiper arms 2a and 2b are within the position holding allowable range. When the wiper arms 2a and 2b are within the position holding allowable range, position holding control is not particularly necessary, so the process proceeds to step S5, and the output control unit 16 makes a determination by the stop position determining unit 14 (within the position holding allowable range). Based on the above, the motor operation is stopped (Duty = 0), and the routine is exited. On the other hand, if the wiper arms 2a and 2b are outside the position holding allowable range, the process proceeds to step S6, and it is determined whether or not the wiper arms 2a and 2b are closer to the target stop position than in the previous control process. . The determination in step S6 is also performed by the stop position determination unit 14, and the stop position determination unit 14 compares the previous and current arm positions using the number of count pulses.

  If it is determined in step S6 that the wiper arms 2a and 2b have not approached the target stop position, the process proceeds to step S7, and this time the wiper arms 2a and 2b have moved away from the target stop position as compared to the previous control process. Judgment is made. If it is determined in S7 that it is farther than the previous time, it is determined that the wiper arms 2a and 2b are pushed up for some reason such as traveling wind, and the process proceeds to step S8. In step S8, it is determined whether or not Duty is equal to or greater than an upper limit value (for example, 40%). If the duty does not reach the upper limit value in step S8, the wiper arms 2a and 2b are pushed up, and there is room for increasing the duty. Therefore, the process proceeds to step S9, and the duty is increased by one level (for example, + 5%). , Exit the routine. On the other hand, if the duty is greater than or equal to the upper limit value, the duty is set to the upper limit value in step S10 and the routine is exited.

  If it is determined in S7 that the position is not far from the target stop position than the previous time, it is determined that the wiper arms 2a and 2b are in a stuck state from the process of S6 → S7, and the process proceeds to step S11. In step S11, it is confirmed whether or not a certain time (for example, 1 second) has elapsed since the position holding control is turned on and the duty is changed. The elapsed time is determined by the elapsed time determination unit 15 using the timer 17. If the fixed time has not yet elapsed after the duty change in S11, the process from S8 is executed and the duty is raised to the upper limit value.

  As the upper limit value of the duty, a level that cannot be pushed up by the wind pressure when the vehicle is traveling at a high speed at a predetermined upper limit speed (for example, 250 km / h) + α (a value that does not cause deterioration or failure of the motor even if continuous energization) is used. Even if this duty is output, if the wiper arms 2a and 2b still move away from the target stop position, it may be determined as “abnormal load” and the duty output may be stopped. This makes it possible to maintain the stop position while avoiding continuous energization against blade push-up due to wind pressure during high-speed driving or snow accumulation when the wiper stops, etc., and continuous energization that contributes to motor deterioration and failure Can be prevented.

  On the other hand, if the predetermined time has elapsed after the duty change in S11, the process proceeds to step S12, and the output control unit 16 confirms whether or not the duty output in the position holding control is the first time. If the position holding output is the first time in S12, the process proceeds to step S13, and the output control unit 16 outputs the initial value (for example, 10%) of the position holding output and exits the routine. If the position holding output is not the first time in S12, the process proceeds to step S14, the current duty is maintained, and the routine is exited. That is, when there is no change in the positions of the wiper arms 2a and 2b, the same duty value is maintained until a predetermined time elapses.

  On the other hand, when the wiper arms 2a and 2b are approaching the target stop position in step S6, it is determined that the effect of the position holding control is exerted, and the process proceeds to step S15, where the duty is a lower limit value (for example, 10%). ) It is determined whether or not the following is true. If the duty does not reach the lower limit value in step S15, the wiper arms 2a and 2b are approaching the target stop position and there is room for reducing the duty. Therefore, the process proceeds to step S16, the duty is lowered by one step, and the routine is Exit. On the other hand, if the duty is less than or equal to the lower limit value, the lower limit value duty is secured in step S17, the position holding operation is maintained, and the routine is exited.

  In the stop position holding control shown in FIG. 3, for example, as shown in FIG. 4, when the wiper arms 2 a and 2 b are pushed up by the traveling wind during the intermittent stop and exceed the position holding allowable range (FIG. 4: A), S <b> 4. → S6 → S7 → S11 → S12 → S13. First, the duty initial value (10%) is output. Thereafter, when the wiper arms 2a and 2b are further pushed up, the process proceeds from S4 → S6 → S7 → S8 → S9, and the duty value is increased to 15% (FIG. 4: B). In this state, when the movement of the wiper arms 2a and 2b stops, the process proceeds from S4 → S6 → S7 → S11 → S12 → S14, and the Duty value is kept constant (FIG. 4: C). When the wiper arms 2a, 2b return to the target stop position side, the process proceeds from S4 → S6 → S15 → S16, the duty value is lowered (FIG. 4: D), and the wiper arms 2a, 2b enter the position holding allowable range. , S4 → S5 and the motor 6 is stopped (FIG. 4: E).

  As described above, in the wiper control processing of the present invention, when the wiper arms 2a and 2b are separated from the target stop position by a predetermined value or more, the duty output of the motor 6 is increased stepwise, and finely adjusted according to the behavior of the arm at that time. Adjust the duty. For this reason, it is possible to prevent the wiper arm from being moved by wind pressure or the like during intermittent stop or when stored at the lip folding position. In addition, the wiper arms 2a and 2b are not controlled in such a way that even if they receive a large wind pressure during high-speed traveling, they are moved back and then returned to the position, but they are held in detail based on the pulse signal from the relative position detection sensor. Since the control is performed, an operation that gives the user a sense of incongruity can be suppressed.

  Note that when the apparatus stop condition such as motor lock is established, the stop position holding control as shown in FIG. 3 is stopped. Further, when the stop position holding control is stopped due to the establishment of the device stop condition, the target stop position is set so that the wiper arms 2a and 2b do not return to the intermittent stop position or the storage position when each stop condition is canceled. Is the arm position when the stop position holding control is stopped. This is because if the stop holding position is fixed to the intermittent stop position or the storage position, the stop position holding control is stopped, the wiper is moved by an external force, and the stop position is held away from the intermittent stop position. This is because when the suspension of control is released, it is determined that the vehicle is away from the stop holding position (intermittent stop position or storage position) and the arm is returned to that position.

  Next, as a second embodiment of the present invention, a control process for preventing chattering phenomenon in which the wiper blade is returned and pushed up repeatedly will be described. FIG. 5 is a block diagram illustrating a configuration of a control system of a controller in which the wiper control method according to the second embodiment of the present invention is executed, and FIG. 6 is a flowchart illustrating a processing procedure of stop position holding control according to the second embodiment. . In the following embodiments, the same members and portions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The process of FIG. 6 is executed by the control system shown in FIG. In addition to the controller 8 in FIG. 2, the controller 21 in FIG. 5 is provided with a chattering detection unit 22 and a chattering continuation determination unit 23 in the CPU 11. The chattering phenomenon is a state in which the start / stop of the duty output for holding the stop position is frequently repeated, and the time interval between the output start operations is shorter than in the case of the normal stop position holding control. There are features. Therefore, the chattering detection unit 22 measures the time from the output start time when the stop position holding control process was performed last time to the current output start time, and determines whether or not the chattering detection unit 22 is within a certain time. Determine if it occurs. When the chattering detection unit 22 detects the occurrence of chattering, the chattering continuation determination unit 23 determines whether or not the chattering continuation determination unit 22 continues over a certain time.

  The “stop position holding control” in step S20 in FIG. 6 is the same as the processing in steps S1 to S17 in FIG. In the process of FIG. 6, after the stop position holding control of S20 (S1 to S17), first, the chattering detection unit 22 determines whether or not chattering has occurred (S21), and then the chattering continuation determination unit 23 continuously. The presence or absence of chattering is determined (S24).

In step S21, the time from the output start time when the stop position holding control process was performed last time to the current output start time is counted, and it is determined whether or not it is within a predetermined time. If the time interval between the previous output start and the current output start is within a predetermined threshold (for example, 50 ms), the process proceeds to step S22 regardless of the output duty, and it is determined that chattering has occurred. . On the other hand, when the interval between the previous output start and the current output start exceeds the threshold value, the process proceeds to step S23 and it is determined that there is no chattering. If there is no chattering, the process proceeds to step S26, and the output control unit 16 maintains the position holding control in the ON state in order to continue the stop position holding control.

  If it is determined in step S22 that chattering has occurred, the timer 17 is started, and then the process proceeds to step S24. In step S24, the continuous state of chattering is determined with reference to the timer 17. That is, in S22, it is determined that “chattering has occurred” and the time from when the timer 17 is started until the present time during which chattering is occurring is counted. Is done.

  If it is determined in step S24 that the chattering continuous state exceeds a predetermined threshold (for example, 1 second), the process proceeds to step S25, and the output control unit 16 sets the position holding control to the OFF state (Duty). = 0). As a result, the chattering state in which the safety function during continuous energization does not continue does not continue endlessly, and it becomes possible to prevent deterioration and failure of the motor. On the other hand, if the chattering duration time is within a predetermined time in step S24, it is determined that continuous chattering has not occurred, and the process proceeds to step S26 to maintain the position holding control in the ON state.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described first embodiment, when the wiper arms 2a and 2b are separated from the target stop position by a predetermined value or more (when the wiper arms 2a and 2b are moved out of the position holding allowable range), a duty output is performed to the motor 6 to stop position holding operation Is started (FIG. 3: S4), but determination of the stop position holding operation start may be made based on the vehicle speed. That is, as shown in FIG. 7, a vehicle speed detection unit 24 and a vehicle speed determination unit 25 are further provided in the CPU 11, and the vehicle speed detected by the vehicle speed detection unit is set to a predetermined threshold value (for example, 200 km / When the vehicle speed exceeds the threshold value, the duty output may be started so as to perform the stop position holding operation. When the vehicle speed is less than or equal to the threshold value (at low speed), stop position holding control is not performed.

DESCRIPTION OF SYMBOLS 1 Wiper apparatus 2a, 2b Wiper arm 3 Link mechanism 4a, 4b Wiper blade 5 Motor unit 6 Electric motor 7 Gear box 8 Controller 11 CPU (wiper arm position holding control part)
12 ROM
13 Pulse count unit 14 Stop position determination unit 15 Elapsed time determination unit 16 Output control unit 17 Timer 21 Controller 22 Chattering detection unit 23 Chattering continuation determination unit 24 Vehicle speed detection unit 25 Vehicle speed determination unit

Claims (14)

A wiper arm that reciprocates between predetermined reversal positions; and an electric motor that drives the wiper arm; an absolute position signal that is output when the wiper arm is present at a predetermined position; and as the electric motor rotates. A wiper control device that performs drive control of a wiper device that controls the operation of the wiper arm based on an output relative position signal, the wiper control device comprising:
When the electric motor is stopped to stop the wiper arm at a predetermined target stop position, an interval between the target stop position and the current position of the wiper arm is recognized using the relative position signal, and based on the recognition. Te, and controls the electric motor have a wiper arm position holding control unit for performing stop position holding control for holding the wiper arm to the target stop position,
The wiper arm position holding control unit is
A pulse count unit for counting the relative position signal;
Based on the number of pulses of the relative position signal counted by the pulse count unit, the current position of the wiper arm is grasped, and the wiper arm is within a position holding allowable range set in advance with respect to the target stop position. A stop position determination unit that determines whether or not the vehicle is positioned;
When the stop position determination unit determines that the wiper arm is positioned outside the position holding allowable range, the electric motor is driven to return the wiper arm to the position holding allowable range, and the target Depending on the distance from the stop position, the output to the electric motor is controlled to perform the stop position holding control, and after changing the output to the electric motor, the relative position signal is output even if a certain time elapses. And an output control unit that increases an output to the electric motor when there is no change . The wiper control device according to claim 1 , wherein the wiper arm position holding control unit includes:
A pulse count unit for counting the relative position signal;
A vehicle speed detector for detecting the speed of a vehicle on which the wiper device is mounted;
A vehicle speed determination unit that compares the vehicle speed detected by the vehicle speed detection unit with a predetermined threshold;
When the vehicle speed determination unit determines that the speed of the vehicle exceeds the threshold value, the electric motor is driven, and an output to the electric motor is output according to a separation state from the target stop position. An output control unit that performs the stop position holding control by controlling the wiper control device. The wiper control device according to claim 1 or 2 , wherein the output control unit includes:
A wiper control device that increases the output to the electric motor stepwise each time the wiper arm moves away from the target stop position by one pulse of the relative position signal. 4. The wiper control device according to claim 1 , wherein the output control unit outputs an output to the electric motor each time the wiper arm approaches the target stop position by one pulse of the relative position signal. 5. A wiper control device characterized in that the stepwise decrease is performed. 5. The wiper control device according to claim 1 , wherein the output control unit sets the maximum value of the output to the electric motor while the vehicle on which the wiper device is mounted is traveling at a predetermined upper limit speed. When the wiper arm leaves the target stop position even if the maximum value is output, the electric motor is stopped by determining that the load is abnormal. Wiper control device. The wiper control device according to any one of claims 1 to 5 , wherein the wiper arm position holding control unit includes:
When the time from the output start time for the electric motor when the stop position holding control was performed last time to the output start time for the electric motor in the current stop position holding control is counted, and the time is within a certain time A wiper control device comprising a chattering detection unit that determines that chattering has occurred. The wiper control device according to claim 6 , wherein the wiper arm position holding control unit further includes:
A chattering continuation determination unit that detects whether or not chattering occurrence is detected by the chattering detection unit and that it continues over a certain period of time;
The said output control part stops the said electric motor, when the chattering continuation determination part determines that chattering continues over a fixed time, The wiper control apparatus characterized by the above-mentioned. A wiper arm that reciprocates between predetermined reversal positions; and an electric motor that drives the wiper arm; an absolute position signal that is output when the wiper arm is present at a predetermined position; and as the electric motor rotates. A wiper device control method for controlling the operation of the wiper arm based on an output relative position signal,
When the electric motor is stopped to stop the wiper arm at a predetermined target stop position, an interval between the target stop position and the current position of the wiper arm is recognized using the relative position signal, and based on the recognition. Te, have rows stop position holding control for holding the by controlling the electric motor wiper arm to the target stop position,
The stop position holding control is
Based on the number of pulses of the relative position signal, the current position of the wiper arm is grasped, and it is determined whether or not the wiper arm is located within a preset position holding allowable range with respect to the target stop position. ,
When it is determined that the wiper arm is located outside the position holding allowable range, the electric motor is driven to return the wiper arm to the position holding allowable range, and according to the separated state from the target stop position. The output to the electric motor is controlled, and the output to the electric motor is increased when the relative position signal does not change after a predetermined time has elapsed after the output to the electric motor is changed. A wiper device control method. The wiper device control method according to claim 8 , wherein
Compare the speed of the vehicle on which the wiper device is mounted and a predetermined threshold,
When it is determined that the speed of the vehicle exceeds the threshold value, the electric motor is driven, and the output to the electric motor is controlled according to the separated state from the target stop position to hold the stop position. The wiper apparatus control method characterized by performing control. The wiper device control method according to claim 8 or 9 ,
The wiper device control method characterized in that the output to the electric motor is increased step by step each time the wiper arm moves away from the target stop position by one pulse of the relative position signal. The wiper apparatus control method according to any one of claims 8 to 10 ,
The wiper device control method according to claim 1, wherein the output to the electric motor is decreased step by step each time the wiper arm approaches the target stop position by one pulse of the relative position signal. The wiper apparatus control method according to any one of claims 8 to 11 ,
The maximum value of the output to the electric motor is set to a value that prevents the wiper arm from being pushed up by the wind pressure that the vehicle equipped with the wiper device receives while traveling at a predetermined upper limit speed. Even if the maximum value is output, the wiper arm When the motor moves away from the target stop position, it is determined that the load is abnormal and the electric motor is stopped. In the wiper device control method according to any one of claims 8 to 12 ,
When the time from the output start time for the electric motor when the stop position holding control was performed last time to the output start time for the electric motor in the current stop position holding control is counted, and the time is within a certain time A wiper device control method characterized in that chattering occurs. The wiper apparatus control method according to claim 13 ,
When chattering occurrence is detected in the chattering detection unit, it is detected whether or not it continues over a certain time,
The said output control part stops the said electric motor, when it is judged that chattering continues over a fixed time, The wiper apparatus control method characterized by the above-mentioned.

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