JP2009029216A - Wiper device control method and wiper control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent overrun of a wiper blade at an upper reversing position and a collision of the wiper blade with a pillar by considering deflection of a wiper arm and the blade in high speed traveling. <P>SOLUTION: In a wiper device for making the wiper blade perform a reciprocal wiping action by a PWM (Pulse Width Modulation) controlled motor, a Duty value for the PWM control corresponding to the position of the blade is set in advance (set Duty value). When the blade reaches a reversing predictive position (S2), the present Duty value (present Duty value) of the motor is compared with the set Duty value (S3). In the case of the present Duty value ∠the set Duty value, the presence of wind pressure is judged and a reversing angle is set to be a narrower angle (S4: setting 1) and a blade reversing position is changed to a lower side. After setting the reversing angle, it is judged whether or not the brake is required (S7), and a braking output is performed as necessary (S8). After confirming the set reversing angle (S10), the motor is reversed (S11 and S12) at the set angle (setting 1), and the overrun by wind pressure, etc. is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control technology for a vehicle wiper device, and more particularly, to a technology for suppressing overrun of a wiper blade by wind pressure during high-speed traveling.

  In recent years, in a wiper device for a vehicle such as an automobile, in particular, a wiper device of the opposite wiping type (opposite type), a method of individually driving the wiper arms on the driver seat side and the passenger seat side as in Patent Document 1 has been adopted. ing. In such a wiper device, the motors are individually controlled while looking at the position angle of each blade so that the left and right wiper blades (hereinafter abbreviated as blades as appropriate) do not interfere on the wiping surface. For example, in the device described in the above publication, the position angle of the left and right blades is constantly monitored by the wiper control device. A target angle difference is set in advance between both blades, and the left and right motors are individually speed controlled so that the difference between the target angle difference and the measured angle difference is reduced while referring to the position angle of the other blade. .

On the other hand, in such a wiper device, the rotation shaft of the motor is controlled to stop at a predetermined angle corresponding to the blade reversing position in order to suppress the blade overrun at each of the upper and lower reversing positions. In particular, when the blade overruns at the upper reversal position, the blade may collide with the pillar portions at both ends of the windshield, and therefore control for suppressing overrun becomes more important. However, when the vehicle travels at a high speed, the wind pressure increases the force that pushes the blade upward, making it difficult to reliably stop the blade at the upper reversal position. Therefore, in order to suppress overrun due to wind pressure, a control stage (SM) for changing the motor control signal (uM) depending on the wind load is provided as in Patent Document 2, for example, when the blade speed is high. The control form such as reducing the wiper speed is adopted.
Japanese Patent Laid-Open No. 11-301417 Special Table 2002-512919

  However, the overrun at the upper reversal position during high-speed running is not caused only by the blade speed increase due to the wind pressure, so even if the control form as in Patent Document 2 is adopted, the overrun is reliably suppressed. There was a problem that could not. That is, not only does the blade speed increase during high-speed traveling, but also a phenomenon occurs in which the wiper arm and the blade are deflected by the wind pressure, and the blade tip position spreads outward when turning up. For this reason, if the blade operation is not controlled in consideration of these displacements, the tip of the blade opens more than expected at the upper reversal position, and the blade may collide with the pillar portion.

  An object of the present invention is to suppress the blade overrun and the collision with the pillar portion at the upper reversal position in consideration of the deflection of the wiper arm and the blade during high speed traveling.

  The wiper apparatus control method of the present invention uses a motor controlled by PWM with a predetermined duty value as a drive source, and reciprocally wipes the wiper blade on the wiping surface between the upper and lower inversion positions by rotating the motor forward and backward. A method of controlling a wiper device to be operated, wherein a duty value for driving the motor is set in advance corresponding to a position of the wiper blade on the wiping surface, and a duty value currently applied to the motor If the difference between the set duty value and the current duty value is different, the preset duty value set in advance and the current duty value indicating the detected current duty value are compared. The rotation direction switching position of the motor is changed, and the reversing position of the wiper blade is changed.

  In the present invention, when the wiper blade is operated in a state of receiving an external force, paying attention to the fact that the currently applied duty value becomes different from the set duty value due to this external force, there is a difference between both duty values. In some cases, the rotation direction switching position of the motor is changed, and the reversing position of the wiper blade is changed. As a result, for example, even when the blade is pushed up by wind pressure during high-speed driving, it can be detected accurately, the blade overruns the upper reversal position, or the blade collides with the pillar portion due to the wiper arm or blade deflection. It can be suppressed.

  In the wiper device control method, when the current duty value is smaller than the set duty value, the rotation direction switching position of the motor at the upper reverse position is changed to the lower reverse position side, and the upper reversal of the wiper blade is performed. The position may be changed to the lower reverse position side.

  Further, a reverse predicted position for predicting the reverse position of the wiper blade is set before the reverse position of the wiper blade, and when the wiper blade reaches the reverse predicted position, the set duty value and the current duty value May be set to set the rotation direction switching position. In this case, when the wiper blade reaches the expected reversal position, the braking to the motor is performed based on the rotational speed of the motor according to the relationship between the motor rotational speed and the braking stop angle when the braking output is applied to the motor. You may make it implement a process.

  On the other hand, the wiper control device of the present invention uses a motor that is PWM-controlled with a predetermined duty value as a drive source, and by reversing the motor forward and backward, the wiper blade on the wiping surface is reciprocated between upper and lower inversion positions. A wiper control device that performs drive control of a wiper device that performs wiping operation, a control information storage unit that stores a preset duty value corresponding to the position of the wiper blade on the wiping surface, and a current value in the motor A current duty detection unit for detecting an applied duty value; a duty comparison unit for comparing the preset duty value set to the current duty value indicating the detected current duty value; and the set duty value And the current Duty value, the reversal angle setting unit for changing the rotation direction switching position of the motor, and the motor based on the rotation direction switching position set by the reversal angle setting unit. Drive control And a motor drive control unit that changes the reverse position of the wiper blade.

  In the present invention, when the wiper blade is operated in a state of receiving an external force, paying attention to the fact that the currently applied duty value becomes different from the set duty value due to this external force, there is a difference between both duty values. In some cases, there is provided a reverse angle setting unit for changing the rotation direction switching position of the motor, and a motor drive control unit for controlling the driving of the motor based on the rotation direction switching position set by the reverse angle setting unit. When the blade receives an external force, its reverse position is changed. As a result, for example, even when the blade is pushed up by wind pressure during high-speed driving, it can be detected accurately, the blade overruns the upper reversal position, or the blade collides with the pillar portion due to the wiper arm or blade deflection. It can be suppressed.

  In the wiper control device, when the current duty value is smaller than the set duty value, the reverse angle setting unit changes the rotation direction switching position of the motor at the upper reverse position to the lower reverse position side, and You may make it change the upper reversal position of a braid | blade to the lower reversal position side.

  Also, a reverse predicted position for predicting the reverse position of the wiper blade is set before the reverse position of the wiper blade, and when the wiper blade reaches the predicted reverse position, the duty comparison unit sets the set duty value. And the current duty value may be compared, and based on the comparison result, the reverse angle setting unit may set the rotation direction switching position. In this case, when the wiper blade reaches the reversal expected position, the motor drive control unit follows the relationship between the motor rotation speed and the braking stop angle when the braking output is performed to the motor. The braking process for the motor may be performed based on the above.

  According to the wiper device control method of the present invention, the wiper blade can be reciprocated between the upside down positions by rotating the PWM controlled motor forward and backward, and the wiper device control method corresponds to the position of the wiper blade. When the set duty value is set in advance, the duty value currently applied to the motor is detected, the set duty value is compared with the current duty value indicating the current duty value, and there is a difference between both duty values For example, the rotation direction switching position of the motor is changed to change the reversal position of the wiper blade. For example, even when the wiper blade is operated under wind pressure during high-speed driving, it is accurately detected. Thus, the reverse position of the wiper blade can be changed. As a result, for example, even when the blade is pushed up by wind pressure during high-speed driving, the blade overruns the upper reversal position, and the blade collides with the pillar due to the wiper arm or blade bending. be able to.

  Further, according to the wiper control device of the present invention, the wiper blade control device moves the wiper blade back and forth between the up and down positions by rotating the PWM controlled motor forward and backward. Correspondingly compares the set duty value and the detected current duty value with the control information storage unit that stores the preset duty value that is set in advance, the current duty detection unit that detects the duty value currently applied to the motor When there is a difference between the duty comparison unit to be set and the set duty value and the current duty value, the reversing angle setting unit for changing the motor rotation direction switching position and the rotation direction switching position set by the reversing angle setting unit A motor drive control unit that controls the drive of the motor and changes the reversing position of the wiper blade based on the motor drive control unit is provided. It is possible to change the reversal position of the wiper blade with. As a result, for example, even when the blade is pushed up by wind pressure during high-speed driving, the blade overruns the upper reversal position, and the blade collides with the pillar due to the wiper arm or blade bending. be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing an overall configuration of a wiper device driven by a control method / control device according to an embodiment of the present invention. The wiper device 1 of FIG. 1 is a so-called counter-wiping type wiper in which a driver side (hereinafter abbreviated as DR side) and a passenger seat side (hereinafter abbreviated as AS side) wiper blades 2a and 2b are arranged to face each other. It is a device. A DR motor 3a and an AS motor 3b (hereinafter abbreviated as motors 3a and 3b) are separately provided on the DR side and the AS side, respectively. The blades 2a and 2b are driven by motors 3a and 3b and face each other between an upper reversal position set at both ends of the windshield (wiping surface) and a lower reversal position set at the lower end central portion of the windshield. Perform wiping operation. Note that “a, b” in the reference numerals indicates members and portions related to the DR side and the AS side, respectively.

  A blade rubber member (not shown) is attached to the blades 2a and 2b. The rubber member is brought into close contact with the windshield of the vehicle and moved to be present in the wiping areas 11a and 11b indicated by broken lines in FIG. Water droplets to be wiped away. The blades 2a and 2b are supported by wiper arms 13a and 13b fixed to the distal ends of the wiper shafts 12a and 12b, and perform swinging motions left and right by drive systems 14a and 14b using the motors 3a and 3b as drive sources. . The drive systems 14a and 14b are composed of motors 3a and 3b and a link mechanism including crank arms 15a and 15b, connecting rods 16a and 16b, drive levers 17a and 17b, and wiper arms 13a and 13b.

  Driving levers 17a and 17b are further attached to the wiper shafts 12a and 12b to which the wiper arms 13a and 13b are fixed. Connecting rods 16a and 16b are attached to the end portions of the drive levers 17a and 17b. The other ends of the connecting rods 16a and 16b are connected to the tip ends of crank arms 15a and 15b fixed to the output shafts 18a and 18b of the motors 3a and 3b. When the motors 3a, 3b are driven and the output shafts 18a, 18b rotate, the crank arms 15a, 15b rotate, and this movement is transmitted to the drive levers 17a, 17b via the connecting rods 16a, 16b. Thereby, the rotational motion of the motors 3a and 3b is converted into the swing motion of the wiper arms 13a and 13b, and the blades 2a and 2b reciprocate between the upside down positions.

  The motors 3a and 3b are accommodated in the motor units 4a and 4b, and in the motor units 4a and 4b, a relative position signal (motor pulse) indicating a blade movement amount in proportion to the motor rotation angle or a specific blade position There is provided a sensor for outputting an absolute position signal indicating. The motor units 4a and 4b are further provided with motor controllers 5a and 5b that drive and control the motors 3a and 3b while calculating the position information of the blades 2a and 2b based on the sensor output signals. The DR-side motor unit 4a is connected to a switch controller 6 that is a vehicle-side control device via an in-vehicle LAN 7. Switch information such as ON / OFF of the wiper switch, Lo, Hi, INT (intermittent operation), vehicle speed information, and the like are input from the switch controller 6 to the motor unit 4a. The motor units 4a and 4b are connected to each other via a communication line 8. The motor 3a connected to the switch controller 6 is on the master side, and the motor 3b connected to the motor 3a on the communication line 8 is on the slave side. Thus, both motors are controlled.

  The motor control units 5 a and 5 b of both units 4 a and 4 b obtain the blade position information of the other party via the communication line 8. Here, the relative position signal described above is a pulse signal generated with the rotation of the motor, and a pulse number proportional to the rotation angle of the motor is output. On the other hand, the absolute position signal is a single signal generated when the blades 2a and 2b come to the lower inverted position. Since the rotational speeds of the motors 3a and 3b and the rotational speeds of the output shafts 18a and 18b are in a fixed relationship based on the reduction ratio, the operating angle of the output shafts 18a and 18b can be calculated from the number of pulses. On the other hand, the operating angle of the output shafts 18a and 18b and the movement angle of the blades 2a and 2b have a certain correlation based on the link mechanism of the drive systems 14a and 14b. Therefore, the movement angle of the blades 2a and 2b can be known by integrating the number of pulses of the relative position signal.

  Therefore, the motor control units 5a and 5b detect the current positions of the blades 2a and 2b based on the combination of the absolute position signal indicating the lower reverse position and the number of pulses. The motor control units 5a and 5b exchange the position information via the communication line 8 and drive the motors 3a and 3b synchronously based on the positional relationship between the blades. That is, the motor control units 5a and 5b first control the motors 3a and 3b in forward and reverse directions based on the blade positions on their own sides. As a result, the blades 2a and 2b perform a reciprocating wiping operation between the upside down positions. At the same time, the motor control units 5a and 5b control the motors 3a and 3b based on the blade position information of both blades 2a and 2b, and control the wiper device 1 so that the blades do not interfere with each other and the angle difference does not increase. To do.

  FIG. 2 is a block diagram showing the configuration of the motor control system in the wiper device 1. In the following, the control of the motor 3a will be described, but the motor 3b is similarly driven and controlled. The motor control unit 5 a is provided with a control microcomputer 21, an FET drive circuit 22, and a motor rotation number detection circuit 23, and power is supplied from a battery 24. As the control microcomputer 21, a one-chip microcomputer including a CPU 25 is used, and power is supplied from the battery 24 through the power supply circuit 26. The control microcomputer 21 is provided with a watch dog timer (WDT) circuit 27 for system reset when an error occurs. The control microcomputer 21 is connected to the motor control unit 5 b of the motor 3 b through the communication circuit 28, and exchanges various data via the communication line 8.

  The FET drive circuit 22 appropriately controls the bridge circuit 29 based on an instruction from the control microcomputer 21 to drive the motor 3a to rotate. At this time, the motor control unit 5a drives and controls the motor 3a by PWM control (Pulse Width Modulation) that performs drive control by changing the on / off ratio of the pulse width of the motor applied voltage. In the PWM control, the CPU 25 sets a duty ratio (Duty) of the pulse voltage on period, and sends a control signal to the FET drive circuit 22. The FET drive circuit 22 receives this control signal, controls the bridge circuit 29, and applies the set duty pulse voltage to the motor 3a. Thereby, the amount of current supplied to the motor 3a is effectively changed, and the rotational speed of the motor 3a is appropriately controlled.

  The number of rotations of the motor 3a is detected using the pulse signal generating means 30. The pulse signal generating means 30 is composed of a magnet and a Hall IC, and outputs a pulse signal (motor pulse) as the motor 3a rotates. The pulse signal output from the pulse signal generation means 30 is sent to the motor rotation speed detection circuit 23. The motor rotation speed detection circuit 23 integrates the motor pulses from the pulse signal generation means 30 and calculates the rotation speed (operating speed of the wiper arm) of the motor 3a from the pulse frequency. The pulse signal is also sent to the control microcomputer 21, and the relative operating angle of the motor 3a (the relative operating angle of the wiper arm) is calculated by appropriately integrating the pulses. The control microcomputer 21 calculates a PWM duty value based on the detected motor rotation speed, and feedback-controls the motor 3a.

  FIG. 3 is a control block diagram of the CPU 25 provided in the control microcomputer 21. The CPU 25 is provided with a motor control drive unit 31 that determines the control duty value of the motor 3a based on the position information of the blades 2a and 2b, the motor rotation speed, and the like. In this case, the position information of the blade 2 a is calculated by the motor rotation angle calculation unit 32 provided in the CPU 25 using the motor pulse sent from the motor rotation number detection circuit 23. Further, the position information of the partner blade 2 b is acquired from the motor control unit 5 b via the communication circuit 28 and the communication line 8. On the other hand, the motor rotation number uses the motor rotation number information sent from the motor rotation number detection circuit 23. The motor control drive unit 31 calculates a control duty value based on these information while referring to a control map 34 in a ROM (control information storage unit) 33 provided in the CPU 25.

  In the control map 34, a predetermined duty value (setting duty) corresponding to the blade position on the wiping surface is indicated by parameters such as the motor rotation speed, the motor ambient temperature, and the power supply voltage. The motor control drive unit 31 selects a setting duty from the control map 34 based on the current blade position, motor rotation speed, and the like obtained by the motor rotation angle calculation unit 32, and calculates a control duty value. The calculated control duty value is output to the FET drive circuit 22, and the bridge circuit 29 is controlled based on this.

  The control duty value is sent to the current duty detection unit 35 provided in the CPU 25 together with the FET drive circuit 22, and the currently output duty value (current duty value) is measured and grasped. The CPU 25 is further provided with a duty comparison unit 36 that compares the set duty with the current duty value. The comparison result between the current duty value and the set duty value in the duty comparison unit 36 is sent to the reverse angle setting unit 37, and the rotation direction switching position of the motor 3a, that is, the blade reverse position is changed based on the comparison result. The motor control drive unit 31 controls the motor 3a by appropriately setting a control duty value based on the set rotation direction switching position so that the blade 2a stops and reverses at the changed and set position. Thereby, the inversion position of the blade 2a changes according to the comparison result between the current duty value and the set duty value. At that time, the motor control drive unit 31 refers to the brake necessity map 38 in the ROM 33 and determines whether or not the brake is necessary according to the position and speed (motor rotation speed) of the blade 2a.

  FIG. 4 is a flowchart showing a procedure of overrun suppression processing in the wiper apparatus 1, and is executed by the control microcomputer 21 based on a processing program stored in the ROM 33. When the wiper switch is turned on, the control microcomputer 21 first calculates the rotation angle of the motor 3a in step S1. There is a correlation between the motor rotation angle and the blade movement angle, and the control microcomputer 21 detects the current position of the blade 2a by a combination of the absolute position signal and the number of motor pulses. Therefore, by calculating the rotation angle of the motor 3a in step S1, the movement angle of the blade 2a can be grasped, and the current position of the blade 2a is grasped. After calculating the motor rotation angle, the process proceeds to step S2, and it is determined whether or not the blade 2a has reached the “reversed predicted position”.

  This “reversal predicted position” indicates a point for predicting where the blade reversal position will be (when the blade 2a will be reversed) when the blade 2a is operated in the current state. It is set before the top reversal position. In the wiper device 1, a point 30 degrees before the upper inversion position is set as the inversion prediction position. The control microcomputer 21 detects the current position of the blade 2a based on the combination of the absolute position signal and the number of pulses. In step S2, the control microcomputer 21 determines whether or not the blade 2a has reached this point. If the blade 2a has not yet reached the reverse inversion position, it is determined that the overrun suppression process is unnecessary, and the routine is exited.

  On the other hand, when the blade 2a has reached the inversion predicted position, the process proceeds to step S3, where the duty comparison unit 36 sets the set duty value (setting duty) corresponding to the current blade position and the current duty detection unit. The current control duty value grasped at 35 (current duty) is compared. At this time, if the current duty is smaller than the set duty (current duty <set duty), the load on the blade is lighter than in normal wiper operation, and the motor 3a can be driven with a duty value smaller than the specified set value. It means that there is. For example, when the blade is pushed upward by an external force during high speed traveling or the like, the blade load becomes light in this way, and the current duty (control duty value) becomes smaller than the set duty. In this state, if the control is performed in the same way as normal, when the blade comes to the upper reversal position, the blade overruns or the wind pressure causes the wiper arm or the blade to bend outward and the blade collides with the pillar part. There is a risk that.

  Therefore, in the control process, if current duty <setting duty, the process proceeds to step S4, the reversing angle is narrowed and the upper reversing position is set lower than normal, and the dynamic overrun of the blade 2a is suppressed. In addition, the motor is controlled so that the blade 2a does not collide with the pillar portion even if the wiper arm or the like is bent. FIG. 5 is an explanatory diagram showing the state of such control processing. As indicated by the alternate long and short dash line, when the blade 2a is pushed by the wind pressure, the current duty becomes smaller than the set duty indicated by the solid line. . For this reason, in the control microcomputer 21, a new motor rotation direction switching position is set by the reverse angle setting unit 37 based on the comparison result of the duty comparison unit 36 (setting 1).

  For example, as shown in FIG. 5, when the motor operating angle is 200 °, the setting duty is 70%, whereas when the current duty is 60%, the motor operating angle is set to 5 corresponding to the difference of 10%. ° Narrow. As a result, a new motor rotation direction switching position is set at a position 5 degrees before the normal (lower reversing position side), and the upper reversing position of the blade 2a is changed to the lower reversing position side. That is, when it is determined that the blade 2a is pressed by an external force, the reversal angle is set so that the wiping area becomes narrower according to the difference between the current duty and the set duty (step S4).

  On the other hand, when the current duty is greater than or equal to the set duty (current duty ≥ set duty), it means that the load on the blade 2a is heavier than that during normal wiper operation. In this case, it is considered that no upward pushing force is applied to the blade 2a, and there is little possibility that the blade 2a will collide with the pillar portion even if the wiper arm or the like is bent overrun at the upper reversal position. Rather, there may be a situation where a predetermined upper inversion position is not reached due to some load. Therefore, in this case, the process proceeds to step S5, and control is performed so that the upper inversion position is the same as in the normal state by setting the inversion angle to a normal setting or wider than that. That is, when it is determined that the blade load is normal or higher, the operating angle of the motor is set to a specified value or more according to the difference between the current duty and the set duty, and the reverse position is the specified position. Thus, the inversion angle is set (step S4: setting 2).

  After setting the reverse angle to setting 1 or 2 in steps S4 and S5, the process proceeds to step S6 to refer to the brake necessity map. When the reversal angle is set to the above setting 1 or 2, if the blade speed is too large, there is a possibility that the blade 2a cannot be stopped at the position where the setting 1 or 2 (especially setting 1) is planned. It is difficult to suppress overrun of the blade 2a. For this reason, in the control process, braking is performed in steps S6 to S9 so that the blade 2a is surely stopped at the position where the setting 1 is scheduled based on the relationship between the reverse angle setting and the blade speed (motor rotational speed). Process and adjust blade speed. The braking process referred to here includes not only a so-called brake for reducing the blade speed but also a process for selecting normal drive control without performing the brake.

  Here, in the ROM 33, a brake necessity map 38 is stored in which the braking angle when the motor braking is output for each motor rotation number is tabulated. In step S7, based on this map, the motor control drive unit 31 determines whether braking is necessary. The brake necessity / unnecessity map 38 shows the relationship of how many rotations of the motor the motor brake output will make and how many times the motor rotates before the motor stops. Accordingly, the motor control drive unit 31 obtains the rotation angle (braking stop angle) until the motor stops at the time of braking output from the brake necessity map 38 based on the current motor rotation number, and the inversion set in steps S4 and S5. If the angle (settings 1 and 2) is less than or equal to this braking stop angle, it is determined that “braking is required”.

  If it is determined in step S7 that braking is necessary, the process proceeds to step S8, and a brake command is output from the motor control drive unit 31 to the FET drive circuit 22 (braking output) in order to decelerate the motor 3a. In this case, an instruction to set the control duty value to 0% (Duty = 0) is given as a braking output, a motor closed loop is configured in terms of electric circuit, and electromagnetic braking is applied to the motor 3a. Thereby, even if the reversal angle is appropriately changed to the above setting 1 or 2, the blade 2a can be stopped at the position where the setting 1 or 2 is scheduled regardless of the blade speed. On the other hand, if it is determined in step S7 that the brake is not required, the process proceeds to step S9, and normal motor drive control processing is performed based on the control map 34.

  After determining the necessity of braking by setting the reverse angle, the process proceeds to step S10, where the reverse angle is confirmed. Here, it is determined whether or not the reverse angle is set 1. If the reverse angle is set 1, the process proceeds to step S11 to determine whether or not the current motor operating angle has reached set 1. If the setting 1 has not been reached, the operation is continued as it is and the routine is exited. On the other hand, when setting 1 is reached, it is necessary to perform the reversing operation immediately. Therefore, in this case, the process proceeds to step S12, where a motor reverse command is output from the motor control drive unit 31 to the FET drive circuit 22 (reverse output), the blade 2a is reversed, and the routine is exited.

  As described above, according to the control process shown in FIG. 4, when the current duty is less than the set duty, when the operating angle of the motor 3a becomes the reversal angle (setting 1) calculated based on the difference between the two, 2a performs an inversion operation. In this case, the blade reversal position according to setting 1 is reversed in the vicinity of the predetermined upper reversal position without overrun even when the blade 2a is pushed up by an external force such as wind pressure, and even if the wiper arm or the like is bent, 2a is a position where there is no possibility of colliding with the pillar portion. For this reason, even if the blade 2a is pushed up by wind pressure during high speed traveling, it can be detected accurately and the reversing position of the blade 2a can be changed, and the blade 2a can overrun the top reversing position during high speed traveling, It is possible to prevent the blade 2a from colliding with the pillar portion.

  Further, in the control process, since the reversal angle is set according to the difference between the actual current duty and the set duty, the reversal position appropriately changes according to the magnitude of the wind pressure (external force). For this reason, the wiper wiping angle can be set as wide as possible while avoiding a collision with the pillar portion, and a wide field of view can be secured during rainfall. In addition, the reversing position is set and the necessity of braking is determined, and braking output is appropriately performed according to the blade speed. Therefore, even when the reversing position is changed, the blade is reliably stopped and reversed at the changed position. Is possible.

  On the other hand, if it is determined in step S10 that the reverse angle is not set 1, the process proceeds to step S13 to determine whether or not the current motor operating angle has reached set 2. If the setting 2 is not reached, the operation is continued as it is and the routine is exited. On the other hand, when setting 2 has been reached, the process proceeds to step S14, where a motor reverse command is output from the motor control drive unit 31 to the FET drive circuit 22 (reverse output), and the blade 2a is reversed to execute the routine. Exit.

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, the setting of the “reversal predicted position” in the above-described embodiment (30 ° before the upper reversal position) and the example of setting 1 (narrow by 5 ° with a difference of 10%) are merely examples, and the control of the present invention The form is not limited to the above values.

It is explanatory drawing which shows the whole structure of the wiper apparatus driven by the control method and control apparatus which is one Example of this invention. It is a block diagram which shows the structure of the motor control system in the wiper apparatus of FIG. It is a control block diagram of CPU provided in the control microcomputer. It is a flowchart which shows the procedure of the overrun suppression process in the wiper apparatus of FIG. It is explanatory drawing which shows the mode of the control processing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wiper apparatus 2a, 2b Wiper blade 3a DR side motor 3b AS side motor 4a, 4b Motor unit 5a, 5b Motor control part 6 Switch controller 7 Car interior LAN
8 Communication lines 11a, 11b Wiping areas 12a, 12b Wiper shafts 13a, 13b Wiper arms 14a, 14b Drive systems 15a, 15b Crank arms 16a, 16b Connecting rods 17a, 17b Drive levers 18a, 18b Output shaft 21 Control microcomputer 22 FET drive circuit 23 Motor rotation speed detection circuit 24 Battery 25 CPU
26 Power supply circuit 27 Watchdog timer circuit 28 Communication circuit 29 Bridge circuit 30 Pulse signal generation means 31 Motor control drive unit 32 Motor rotation angle calculation unit 33 ROM (control information storage unit)
34 Control map 35 Current duty detection unit 36 Duty comparison unit 37 Reverse angle setting unit 38 Brake necessity map

Claims (8)

This is a control method for a wiper device in which a motor that is PWM controlled with a predetermined duty value is used as a drive source, and the wiper blade on the wiping surface is reciprocated between upper and lower inversion positions by rotating the motor forward and backward. And
While presetting the Duty value corresponding to the position of the wiper blade on the wiping surface,
Detects the duty value currently applied to the motor,
Compare the preset Duty value set in advance with the current Duty value indicating the detected current Duty value,
A wiper device control method comprising: changing a rotation direction switching position of the motor and changing a reversal position of the wiper blade when there is a difference between the set duty value and the current duty value.   2. The wiper device control method according to claim 1, wherein when the current duty value is smaller than the set duty value, the rotational direction switching position of the motor at the upper reverse position is changed to the lower reverse position side, and the wiper blade A wiper device control method characterized by changing an upper inversion position to a lower inversion position.   The wiper device control method according to claim 1 or 2, wherein a reverse predicted position for predicting the reverse position of the wiper blade is set before the reverse position of the wiper blade, and the wiper blade has reached the predicted reverse position. The wiper device control method is characterized in that the rotation direction switching position is set by comparing the set duty value with the current duty value.   4. The wiper apparatus control method according to claim 3, wherein when the wiper blade reaches the expected reverse position, the rotation of the motor is determined according to a relationship between a motor rotation speed and a braking stop angle when a braking output is applied to the motor. A wiper device control method comprising: performing braking processing on the motor based on the number. Drive control of the wiper device that performs a reciprocating wiping operation of the wiper blade on the wiping surface between the upper and lower inversion positions by using a motor controlled by PWM with a predetermined duty value as a drive source and rotating the motor forward and backward. A wiper control device,
A control information storage unit for storing a preset duty value corresponding to the position of the wiper blade on the wiping surface;
A current duty detection unit for detecting a duty value currently applied to the motor;
A Duty comparison unit that compares the preset Duty value set in advance with a current Duty value indicating the detected current Duty value;
When there is a difference between the set duty value and the current duty value, a reverse angle setting unit that changes the rotation direction switching position of the motor;
A wiper control device comprising: a motor drive control unit that controls driving of the motor based on a rotation direction switching position set by the reverse angle setting unit and changes a reverse position of the wiper blade.   6. The wiper control device according to claim 5, wherein when the current duty value is smaller than the set duty value, the reverse angle setting unit changes the rotation direction switching position of the motor at the upper reverse position to the lower reverse position side. And a wiper control device that changes the upper reversal position of the wiper blade to the lower reversal position.   The wiper control device according to claim 5 or 6, wherein a reverse predicted position for predicting the reverse position of the wiper blade is set before the reverse position of the wiper blade, and the Duty comparison unit is configured so that the wiper blade is reversed. When the predicted position is reached, the set duty value is compared with the current duty value, and the reverse angle setting unit sets the rotation direction switching position based on the comparison result. .   8. The wiper control device according to claim 7, wherein the motor drive control unit has a relationship between a motor rotation speed and a braking stop angle when a braking output is applied to the motor when the wiper blade reaches the expected reverse position. A wiper control device that performs braking processing on the motor based on the rotational speed of the motor.

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