JP7014002B2 - Wiper device and control method of wiper device - Google Patents

Description

The present invention relates to a wiper device and a method for controlling the wiper device.

The reverse control type wiper device determines whether or not the wiper blade during the wiping operation has reached the preset reverse position, and performs the reverse operation. Specifically, it has a sensor that detects the rotation angle of the output shaft of the wiper motor and a circuit that drives the wiper motor based on the rotation angle detected by the sensor, and uses a control device such as a microcomputer included in the circuit. Then, the rotation of the wiper motor is controlled to be reversed at the reverse position.

However, there are deposits such as water droplets and dirt on the surface of the windshield glass (windshield), and such deposits may hinder the wiping operation of the wiper blade. Therefore, in the control of reversing the rotation of the wiper motor at the preset reversal position, there is a possibility that the wiper blade does not reverse at the preset reversal position.

Patent Document 1 describes a method for controlling a wiper device that suppresses variation in the stop position of the wiper arm at the inverted position by performing deceleration control from the braking start position calculated based on the speed and load of the wiper arm in the vicinity of the inverted position. Is disclosed.

Japanese Unexamined Patent Publication No. 2004-196195

However, in the control method of the wiper device described in Patent Document 1, the braking start position is determined based on the speed and load of the wiper arm in the vicinity of the reversing position, but the deceleration from the braking start position is performed by the braking start position. Since there is no particular change even if they are different, there is a problem that the stop position of the wiper arm at the inverted position may still vary.

The present invention has been made in view of the above, and controls a wiper device and a wiper device that control the actual inversion position to approach the target inversion position when the actual inversion position deviates from a preset target inversion position. The purpose is to provide a method.

In order to solve the above problems, the wiper device according to claim 1 includes a drive circuit for driving a wiper motor for wiping the wiper blade, a rotation angle detection unit for detecting the rotation angle of the output shaft of the wiper motor, and the above. When the rotation angle of the output shaft detected by the rotation angle detection unit indicates an angle corresponding to a predetermined target inversion position, the drive circuit is controlled so as to reverse the rotation of the wiper motor. The wiper blade is inverted, and the target inversion position is corrected based on the deviation between the rotation angle of the output shaft detected by the rotation angle detection unit at the time of the inversion and the angle corresponding to the target inversion position. The control unit includes, and the control unit sets the rotation speed of the output shaft with respect to the rotation angle of the output shaft between one target inversion position and the other target inversion position according to a predetermined target speed. The drive circuit is controlled so that the rotation speed of the wiper motor changes, and the difference between the rotation angle of the output shaft from one target inversion position to the other target inversion position and the deviation is determined from the one target inversion position. The rotation speed of the wiper motor changes according to the target speed corrected by multiplying each value of the rotation speed indicated by the target speed by the quotient obtained by dividing by the rotation angle of the output shaft to the other inversion position. Controls the drive circuit .

According to this wiper device, by correcting the target inversion position based on the deviation between the actual inversion position and the target inversion position, when the actual inversion position deviates from the preset target inversion position, the actual inversion position is actually performed. It is possible to control the inversion position to be closer to the target inversion position.

Further , according to this wiper device, when the actual reversal position deviates from the preset target reversal position by correcting the target speed based on the deviation between the actual reversal position and the target reversal position, the actual reversal position is actually performed. It is possible to control the inversion position of the to be closer to the target inversion position.

The wiper device according to claim 2 is the wiper device according to claim 1 , wherein the control unit corrects the target inversion position and the target speed with a value obtained by smoothing the deviation with a filter.

According to this wiper device, by smoothing the detected deviation, the actual inversion position can be gradually corrected so that the user does not feel uncomfortable.

In order to solve the above-mentioned problem, the control method of the wiper device according to claim 3 shows that the rotation angle of the output shaft detected by the rotation angle detection unit corresponds to a predetermined target inversion position. Corresponding to the reversing processing step of reversing the rotation of the wiper motor to reverse the wiper blade, the rotation angle of the output shaft detected by the rotation angle detection unit at the time of the reversal, and the target reversal position. A deviation detection step that detects a deviation from an angle, a correction step that corrects the target inversion position based on the deviation, and a rotation angle of the output shaft between one target inversion position and the other target inversion position. The speed control step includes a speed control step of controlling the rotation speed so that the rotation speed of the wiper motor changes according to a predetermined target speed of the rotation speed of the output shaft, and the speed control step is from one target inversion position to the other target. The target speed is the quotient obtained by dividing the difference between the rotation angle of the output shaft to the inversion position and the deviation by the rotation angle of the output shaft from the one target inversion position to the other inversion position. The rotation speed of the wiper motor is controlled according to the target speed corrected by multiplying each value of the indicated rotation speed .

According to the control method of this wiper device, when the actual inversion position deviates from the preset target inversion position by correcting the target inversion position based on the deviation between the actual inversion position and the target inversion position. , It is possible to control the actual inversion position to be closer to the target inversion position.

Further , according to the control method of this wiper device, when the actual inversion position deviates from the preset target inversion position by correcting the target speed based on the deviation between the actual inversion position and the target inversion position. In addition, it is possible to control the actual inversion position to be closer to the target inversion position.

The control method of the wiper device according to claim 4 is the control method of the wiper device according to claim 3 , wherein the deviation detection step smoothes the deviation with a filter, and the correction step and the speed control step are described. The smoothed deviation corrects the target inversion position and the target speed, respectively.

According to the control method of this wiper device, by smoothing the detected deviation, the actual inversion position can be gradually corrected so that the user does not feel uncomfortable.

It is a schematic diagram which shows the structure of the wiper device which concerns on 1st Embodiment of this invention. It is a block diagram which shows the outline of an example of the structure of the wiper control device which concerns on 1st Embodiment of this invention. It is a block diagram which showed an example of the drive circuit when the wiper motor is a motor with a brush. It is a block diagram which showed an example of the drive circuit when the wiper motor is a brushless motor. It is explanatory drawing which showed the outline of the locus of a wiper blade when the output shaft of a wiper motor rotates in a wiper device. In the wiper device according to the first embodiment of the present invention, the actual rotation angle (actual rotation angle) of the output shaft 32 and the actual rotation angle when an overrun in which the wiper blade reverses occurs occurs at a position beyond the upper inversion position. It is a time chart showing the change of the target rotation angle in time series. It is a schematic diagram which showed an example of the change of the angular velocity of the output shaft with respect to the change of the rotation angle of the output shaft when the wiper blade moves from the lower inversion position to the upper inversion position. It is a flowchart which showed an example of the reversal position correction processing of the wiper device which concerns on 1st Embodiment of this invention. In the wiper device according to the second embodiment of the present invention, the actual rotation angle and the target rotation angle of the actual output shaft when an overrun in which the wiper blade reverses occurs occurs at a position beyond the upper inversion position. It is a time chart showing changes in time series. It is a flowchart which showed an example of the reversal position correction process of the wiper device which concerns on 2nd Embodiment of this invention.

[First Embodiment]
FIG. 1 is a schematic view showing the configuration of the wiper device 100 according to the first embodiment of the present invention. The wiper device 100 is for wiping the windshield glass 12 provided in a vehicle such as a passenger car, and includes a pair of wipers 14 and 16, a wiper motor 18, and a link mechanism 20.

The wipers 14 and 16 are composed of wiper arms 24 and 26 and wiper blades 28 and 30, respectively. The base end portions of the wiper arms 24 and 26 are fixed to the pivot shafts 42 and 44, which will be described later, respectively, and the wiper blades 28 and 30 are fixed to the tip portions of the wiper arms 24 and 26, respectively.

In the wipers 14 and 16, the wiper blades 28 and 30 reciprocate on the windshield glass 12 with the operation of the wiper arms 24 and 26, and the wiper blades 28 and 30 wipe the windshield glass 12.

The wiper motor 18 has an output shaft 32 capable of forward / reverse rotation via a reduction mechanism 52 mainly composed of a worm gear. The link mechanism 20 includes a crank arm 34, a first link rod 36, a pair of pivot levers 38 and 40, a pair of pivot shafts 42 and 44, and a second link rod 46.

One end side of the crank arm 34 is fixed to the output shaft 32, and the other end side of the crank arm 34 is operably connected to one end side of the first link rod 36. Further, the other end side of the first link rod 36 is operably connected to a position near the end different from the end having the pivot shaft 42 of the pivot lever 38, and is connected to the end having the pivot shaft 42 of the pivot lever 38. Both ends of the second link rod 46 are operably connected to different ends and ends corresponding to the ends of the pivot lever 38 in the pivot lever 40.

Further, the pivot shafts 42 and 44 are operably supported by a pivot holder (not shown) provided on the vehicle body, and the ends of the pivot levers 38 and 40 having the pivot shafts 42 and 44 are via the pivot shafts 42 and 44. The wiper arms 24 and 26 are fixed respectively.

In the wiper device 100 according to the present embodiment, when the output shaft 32 is rotated forward and reverse at a rotation angle θ1 in a predetermined range, the rotational force of the output shaft 32 is transmitted to the wiper arms 24 and 26 via the link mechanism 20. Then, along with the reciprocating motion of the wiper arms 24 and 26, the wiper blades 28 and 30 reciprocate between the lower inverted position P2 and the upper inverted position P1 on the windshield glass 12. The value of θ1 can take various values depending on the configuration of the link mechanism of the wiper device 100 and the like, but in the present embodiment, it is 110 ° as an example.

In the wiper device 100 according to the present embodiment, as shown in FIG. 1, when the wiper blades 28 and 30 are located at the storage position P3, the crank arm 34 and the first link rod 36 have a linear shape. It is said to be an eggplant structure.

The storage position P3 is provided below the downward inversion position P2. The wiper blades 28 and 30 operate at the retracted position P3 by rotating the output shaft 32 by θ2 from the state where the wiper blades 28 and 30 are in the downward inversion position P2. The value of θ2 can take various values depending on the configuration of the link mechanism of the wiper device 100 and the like, but in the present embodiment, it is set to 10 ° as an example.

When the rotation angle θ2 is “0”, the lower inversion position P2 and the storage position P3 coincide with each other, and the wiper blades 28 and 30 are stopped and stored at the lower inversion position P2.

A wiper motor control circuit 22 for controlling the rotation of the wiper motor 18 is connected to the wiper motor 18. The wiper motor control circuit 22 according to the present embodiment includes a microcomputer 58. Further, the wiper motor control circuit 22 constitutes the wiper control device 10 together with the drive circuit 56 and the like.

The microcomputer 58 of the wiper motor control circuit 22 controls the rotation speed of the wiper motor 18 based on the detection result of the rotation angle sensor 54 that detects the rotation speed and the rotation angle of the output shaft 32 of the wiper motor 18. The rotation angle sensor 54 is provided in the deceleration mechanism 52 of the wiper motor 18, and converts the magnetic field (magnetic force) of the sensor magnet that rotates in conjunction with the output shaft 32 into an electric current for detection.

Since the wiper motor 18 according to the present embodiment has the deceleration mechanism 52 as described above, the rotation speed and the rotation angle of the output shaft 32 are not the same as the rotation speed and the rotation angle of the wiper motor main body. However, in the present embodiment, the wiper motor main body and the reduction mechanism 52 are integrally inseparably configured. Therefore, hereinafter, the rotation speed and the rotation angle of the output shaft 32 are regarded as the rotation speed and the rotation angle of the wiper motor 18. ..

The microcomputer 58 can calculate the positions of the wiper blades 28 and 30 on the windshield glass 12 from the rotation angle of the output shaft 32 detected by the rotation angle sensor 54, and the rotation speed of the output shaft 32 can be calculated according to the position. The drive circuit 56 is controlled so as to change. The drive circuit 56 is a circuit that generates a voltage applied to the wiper motor 18 based on the control of the wiper motor control circuit 22, and switches the electric power of the vehicle battery as a power source to generate a voltage applied to the wiper motor 18.

Further, a wiper switch 50 is connected to the microcomputer 58 of the wiper motor control circuit 22 via a vehicle ECU (Electronic Control Unit) 92 that controls the engine of the vehicle. The wiper switch 50 is a switch that turns on or off the electric power supplied from the vehicle battery to the wiper motor 18. The wiper switch 50 has a low-speed operation mode selection position (LOW) for operating the wiper blades 28 and 30 at a low speed, a high-speed operation mode selection position (HIGH) for operating the wiper blades 28 and 30 at a high speed, and an intermittent operation mode selection for intermittent operation at regular intervals. It is possible to switch between the position (INT) and the stop mode selection position (OFF). Further, a command signal for rotating the wiper motor 18 according to the selected position of each mode is output to the microcomputer 58 via the vehicle ECU 92 and the signal input circuit 62. For example, the wiper switch 50 rotates the wiper motor 18 at high speed in the high-speed operation mode selection position, rotates the wiper motor 18 at low speed in the low-speed operation mode selection position, and intermittently rotates the wiper motor 18 in the intermittent operation mode selection position.

When the signal output from the wiper switch 50 according to the selected position of each mode is input to the microcomputer 58 via the vehicle ECU 92 and the signal input circuit 62, the microcomputer 58 corresponds to the command signal from the wiper switch 50. Control to do. Specifically, the microcomputer 58 reads the rotation signal of the output shaft 32 into the wiper motor 18 so that the wiper blades 28 and 30 operate at a desired reciprocating wiping cycle based on the command signal from the wiper switch 50. Control the applied voltage.

A vehicle speed sensor 94 that detects the speed of the vehicle is connected to the vehicle ECU 92. For communication between the vehicle ECU 92 and the signal input circuit 62, LIN (Local Interconnect Network) is used as a protocol as an example.

FIG. 2 is a block diagram showing an outline of an example of the configuration of the wiper control device 10 according to the present embodiment. The wiper control device 10 shown in FIG. 2 includes a drive circuit 56 that generates a voltage applied to a terminal of a winding of the wiper motor 18, and a microcomputer 58 that controls on and off of switching elements constituting the drive circuit 56. The wiper motor control circuit 22 is included. The electric power of the battery 80 is supplied to the microcomputer 58 via the diode 68, and the voltage of the electric power supplied from the battery 80 is measured by a voltage detection circuit 60 provided between the diode 68 and the microcomputer 58. It is detected and the detection result is output to the microcomputer 58. Further, an electrolytic capacitor C1 is provided in which one end is connected between the diode 68 and the microcomputer 58 and the other end (−) is grounded. The electrolytic capacitor C1 is a capacitor for stabilizing the power supply of the microcomputer 58. The electrolytic capacitor C1 protects the microcomputer 58 by storing a sudden high voltage such as a surge and discharging it to the ground region.

A signal for instructing the rotation speed of the wiper motor 18 is input to the microcomputer 58 from the wiper switch 50 via the vehicle ECU 92 and the signal input circuit 62. The signal from the vehicle speed sensor 94 is also input to the microcomputer 58 via the vehicle ECU 92 and the signal input circuit 62.

Further, the microcomputer 58 is connected to a rotation angle sensor 54 that detects the magnetic field of the sensor magnet 70 that changes according to the rotation of the output shaft 32. The microcomputer 58 identifies the positions of the wiper blades 28 and 30 on the windshield glass 12 by calculating the rotation angle of the output shaft 32 based on the signal output by the rotation angle sensor 54.

Further, the computer 58 refers to the rotation speed data of the wiper motor 18 defined according to the positions of the wiper blades 28 and 30 stored in the memory 48, and the rotation of the wiper motor 18 is specified by the wiper blade 28. , The drive circuit 56 is controlled so that the rotation speed corresponds to the position of 30. Such data is stored in the memory 48.

The drive circuit 56 includes a pre-driver 56A that generates a drive signal for turning on / off the switching element of the voltage generation circuit 56B from the control signal of the drive circuit 56 output by the microcomputer 58, and a switching element according to the drive signal output by the pre-driver 56A. Is included, and includes a voltage generation circuit 56B that generates a voltage applied to the coil of the wiper motor 18 by operating the above.

In the present embodiment, a reverse connection protection circuit 64 and a noise prevention coil 66 are provided between the battery 80 as a power source and the drive circuit 56, and the electrolytic capacitor C2 is provided in parallel with the drive circuit 56. It is provided. The noise prevention coil 66 is an element for suppressing noise generated by switching of the drive circuit 56.

The electrolytic capacitor C2 alleviates noise generated from the drive circuit 56, stores a sudden high voltage such as a surge, and discharges it to the ground region to prevent an excessive current from being input to the drive circuit 56. It is an element for.

The reverse connection protection circuit 64 is a circuit for protecting the elements constituting the wiper control device 10 when the positive electrode and the negative electrode of the battery 80 are connected in the reverse direction of the case shown in FIG. As an example, the reverse connection protection circuit 64 is composed of a so-called diode-connected FET or the like in which its own drain and gate are connected.

A chip thermistor RT that detects the temperature of the substrate as a resistance value is mounted on the substrate of the wiper control device 10 according to the present embodiment. The chip thermistor RT used in this embodiment is, for example, an NTC (Negative Temperature Coefficient) thermistor whose resistance decreases with increasing temperature. A PTC (Positive Temperature Coefficient) thermistor whose resistance value increases as the temperature rises may be used by using an inverting circuit in combination.

The chip thermistor RT constitutes a kind of voltage dividing circuit, and a voltage that changes based on the resistance value of the chip thermistor RT is output from the output end of the voltage dividing circuit configured by the chip thermistor RT. The microcomputer 58 calculates the temperature of the substrate of the wiper control device 10 based on the voltage output from the output end of the voltage divider circuit configured by the chip thermistor RT, and when the temperature exceeds a predetermined threshold temperature, the temperature is calculated. , Performs a process of stopping the operation of the wiper control device 10.

Further, a current detection unit 82 for detecting the current (motor current) between the coil of the wiper motor 18 and the voltage generation circuit 56B is provided between each source of the switching element constituting the voltage generation circuit 56B and the battery 80. Has been done. The current detection unit 82 detects the potential difference between the shunt resistance 82A having a resistance value of about 0.2 mΩ to several Ω and the shunt resistance 82A that changes according to the current of the voltage generation circuit 56B, and detects the signal of the detected potential difference. Includes amplifier 82B for amplification. The microcomputer 58 calculates the current value of the motor current from the signal output by the amplifier 82B, and when the current value exceeds a predetermined threshold value, stops the voltage generation by the voltage generation circuit 56B to rotate the wiper motor 18. Perform the process of stopping.

FIG. 3 is a block diagram showing an example of a drive circuit 56 when the wiper motor 18 is a brushed motor. The drive circuit 56 is based on a predriver 56AP that generates a drive signal for operating the switching element of the voltage generation circuit 56BH based on a control signal input from the microcomputer 58 and outputs the drive signal to the voltage generation circuit 56BH, and a drive signal. It is provided with a voltage generation circuit 56BH that generates power to be supplied to the wiper motor 18 by the operation of the switching element.

As shown in FIG. 3, the voltage generation circuit 56BH is an H-bridge circuit using transistors T1, T2, T3, and T4, which are N-type field effect transistors (FETs), as switching elements. In the transistor T1 and the transistor T2, the drain is connected to the positive electrode of the battery, and the source is connected to the drain of the transistor T3 and the transistor T4, respectively. Further, the sources of the transistor T3 and the transistor T4 are grounded.

Further, the source of the transistor T1 and the drain of the transistor T3 are connected to one end of the winding of the wiper motor 18, and the source of the transistor T2 and the drain of the transistor T4 are connected to the other end of the winding of the wiper motor 18. ..

When an H-level drive signal is input to each gate of the transistor T1 and the transistor T4, the transistor T1 and the transistor T4 are turned on, and the wiper motor 18 has, for example, the wiper blades 28 and 30 as viewed from the passenger compartment side. A current that operates around flows. Further, when one of the transistor T1 and the transistor T4 is on-controlled, the voltage of the current can be modulated by turning the other on and off in small steps by PWM.

Further, when an H-level drive signal is input to each gate of the transistor T2 and the transistor T3, the transistor T2 and the transistor T3 are turned on, and the wiper motor 18 sees, for example, the wiper blades 28 and 30 from the passenger compartment side. A current that operates counterclockwise flows. Further, when one of the transistor T2 and the transistor T3 is on-controlled, the voltage of the current can be modulated by turning the other on and off in small steps by PWM.

FIG. 4 is a block diagram showing an example of the voltage generation circuit 56B when the wiper motor 18 is a brushless motor. The voltage generation circuit 56BI is composed of a three-phase (U-phase, V-phase, W-phase) inverter.

When the wiper motor 18 is a brushless motor, the rotation control of the wiper motor 18 generates a voltage close to a phase three-phase alternating current according to the position of the magnetic pole of the permanent magnet of the rotating rotor 118, and the coil 116U, 116V of the stator 114. , 116W needs to be applied. A rotating magnetic field that rotates the rotor 118 is generated in the coils 116U, 116V, and 116W to which the voltage is applied, and the rotor 118 rotates according to the rotating magnetic field.

The position of the magnetic pole of the rotor 118 is determined from the change in the magnetic field of the rotor 118 or the sensor magnet having the magnetic pole corresponding to the rotor 118 detected by a Hall sensor or the like using a Hall element (not shown). Calculated by the microcomputer 58.

A signal for instructing the rotation speed of the wiper motor 18 (rotor 118) is input from the wiper switch 50 to the microcomputer 58 via the vehicle ECU 92. The microcomputer 58 calculates the phase of the voltage applied to the coil of the wiper motor 18 based on the position of the magnetic pole of the rotor 118, and also calculates the voltage based on the calculated phase and the rotation speed of the rotor 118 indicated by the wiper switch 50. A control signal for controlling the generation circuit 56B is generated and output to the predriver 56AQ.

The predriver 56AQ generates a drive signal for operating the switching element of the voltage generation circuit 56BI based on the input control signal, and outputs the drive signal to the voltage generation circuit 56BI.

As shown in FIG. 4, the voltage generation circuit 56BI has three N-type field effect transistors (FETs) 111U, 111V, 111W (hereinafter referred to as “FET111U, 111V, 111W”), each of which serves as an upper switching element. Each is equipped with three N-type field effect transistors 112U, 112V, 112W (hereinafter referred to as "FET112U, 112V, 112W") as lower switching elements. The FETs 111U, 111V, 111W and FET112U, 112V, 112W are collectively referred to as "FET111" and "FET112" when it is not necessary to distinguish them individually, and "U" when it is necessary to distinguish them individually. , "V", "W" with reference numerals.

Of the FET 111 and FET 112, the source of the FET 111U and the drain of the FET 112U are connected to the terminal of the coil 116U, the source of the FET 111V and the drain of the FET 112V are connected to the terminal of the coil 116V, and the source of the FET 111W and the drain of the FET 112W. The drain is connected to the terminal of the coil 116W.

The gates of the FET 111 and the FET 112 are connected to the pre-driver 56AQ, and a drive signal is input. The FET 111 and the FET 112 are turned on when an H level drive signal is input to the gate, and a current flows from the drain to the source. Further, when an L level drive signal is input to the gate, it is turned off and no current flows from the drain to the source.

By PWM that turns each of the FETs 111 and 112 of the voltage generation circuit 56BI on and off according to the drive signal, the rotor 118 changes according to the position of the magnetic pole of the rotor 118 and rotates at the rotation speed instructed by the wiper switch 50. Generate a voltage to make it.

FIG. 5 is an explanatory diagram showing an outline of the locus of the wiper blade 30 when the output shaft 32 of the wiper motor 18 rotates at the rotation angle θ1 in the wiper device 100. When the output shaft 32 rotates at the rotation angle θ1, the wiper blade 30 wipes between the upper inversion position P1 and the lower inversion position P2, but due to external factors such as the surface condition of the windshield glass 12 and the vehicle speed, the wiper blade 30 operates. The wiper blade 30 may be inverted at a position P1'beyond the upper inversion position P1 or at a position P1'in front of the upper inversion position P1. Further, due to the above-mentioned external factors, the wiper blade 30 may be inverted at a position P2'exceeding the downward inversion position P2 or a position P2'in front of the downward inversion position P2.

FIG. 6 shows the actual rotation angle of the output shaft 32 when the wiper blades 28 and 30 reverse overrun at the position P1'beyond the upper inversion position P1 in the wiper device 100 according to the present embodiment. It is a time chart which showed the change in time series of (actual rotation angle) 122 and a target rotation angle 120. In the present embodiment, the wiper motor control circuit 22 controls the rotation of the wiper motor 18 so that the actual rotation angle 122 of the output shaft 32 becomes the target rotation angle 120, but the actual rotation angle 122 is increased due to the above-mentioned external factors. , The wiper blades 28 and 30 may be inverted in a state where the angle indicates the position P1'beyond the upper inversion position P1.

In the present embodiment, the difference between the angle corresponding to the upper inversion position P1 and the angle corresponding to the position P1'is extracted as the deviation ΔD, and the angle indicating the target inversion position is corrected by using the deviation ΔD. The correction target inversion position G1 shown in FIG. 6 is the angle of the upper inversion position that becomes the correction target inversion position. The wiper motor control circuit 22 inverts the wiper blades 28 and 30 when the rotation angle of the output shaft 32 detected by the rotation angle sensor 54 reaches the inversion position G1 on the correction target.

FIG. 7 is a schematic view showing an example of a change in the angular velocity of the output shaft 32 with respect to a change in the rotation angle of the output shaft 32 when the wiper blades 28 and 30 move from the lower inversion position P2 to the upper inversion position P1. .. As shown in FIG. 7, the angular velocity of the output shaft shows 0 deg / sec at the upper inversion position P1 and the lower inversion position P2, and becomes maximum in the substantially middle between the upper inversion position P1 and the lower inversion position P2. The upper convex curves 124 and 126 are shown.

In FIG. 7, the curve 124 shows the target speed, and the curve 126 shows the corrected target speed. The corrected target speed shown by the curve 126 is, for example, the target speed shown by the curve 124 based on the deviation ΔD shown in FIG. 6 when the wiper blades 28 and 30 overrun at the upper inversion position P1. It is a corrected one.

The wiper motor control circuit 22 controls the rotation speed of the wiper motor 18 based on the target speed stored in the memory 48. As described above, the wiper blades 28 and 30 are affected by the action of an external force on the wiper blades 28 and 30. May overrun beyond the upper inversion position P1. In the present embodiment, in such a case, the rotation speed of the wiper motor 18 is controlled by the target speed corrected based on the deviation ΔD.

As shown in FIG. 7, the curve 124 has an angular velocity of 0 deg / sec when the rotation angle of the output shaft becomes the angle corresponding to the upside-down position P1, while the curve 126 shows the rotation corresponding to the upside-down position P1. The angular velocity becomes 0 deg / sec at an angle closer to the downward inversion position P2 by a deviation ΔD than the angle. Further, the curve 126 has a lower angular velocity than the curve 124 as a whole including the maximum value. Each value of the angular velocity shown by the curve 126 is calculated by changing each value of the angular velocity shown by the curve 124 according to the deviation ΔD. As an example, it was obtained by dividing the difference between the rotation angle of the output shaft 32 from the upper inversion position P1 to the lower inversion position P2 and the deviation ΔD by the rotation angle of the output shaft 32 from the upper inversion position P1 to the lower inversion position P2. By multiplying the quotient by each value of the angular velocity shown by the curve 124, each value of the angular velocity shown by the curve 126 is calculated.

The corrected target speed shown by the curve 126 suppresses the rotational speed of the output shaft 32 and causes the angular velocity of the output shaft 32 to be 0 deg / sec before the upper inversion position P1 so that the output shaft 32 is upside down. Correct the overrun that occurred at position P1.

FIG. 8 is a flowchart showing an example of the reverse position correction process of the wiper device 100 according to the present embodiment. In step 900, it is detected that the wiper blades 28 and 30 have reached the upper inversion position P1 or the lower inversion position P2 based on the rotation angle of the output shaft 32 detected by the rotation angle sensor 54.

In step 902, the deviation ΔD is calculated when the wiper blades 28 and 30 are inverted. Then, in step 904, the target inversion position is corrected based on the deviation ΔD, and in step 906, the rotation of the wiper motor 18 is reversed to start the next inversion operation and return the process.

As described above, according to the wiper device and the control method of the wiper device according to the present embodiment, when the wiper blades 28 and 30 are overrun, the actual reverse position and the preset target reverse position are set. By correcting the target inversion position according to the deviation ΔD, it is possible to control the actual inversion position to be closer to the target inversion position when the actual inversion position deviates from the target inversion position.

[Second Embodiment]
Subsequently, a second embodiment of the present invention will be described. As will be described later, this embodiment differs from the first embodiment in that the target inversion position is corrected by the deviation ΔD smoothed by the filter, but the other configurations are the same as those of the first embodiment. Therefore, detailed description of other configurations will be omitted.

FIG. 9 shows the actual rotation of the output shaft 32 when the wiper blades 28 and 30 reverse overrun at the position P1'beyond the upper inversion position P1 in the wiper device 100 according to the present embodiment. It is a time chart which showed the change in time series of an angle 130 and a target rotation angle 128. In the process shown in FIG. 9, the inversion position and the target speed are gradually corrected by smoothing the deviation ΔD with a filter. For example, a low-pass filter, a band-pass filter, or the like is used to block the higher value of the deviation ΔD and smooth the deviation ΔD. Alternatively, the deviation ΔD may be smoothed by digitizing (binary) the deviation ΔD and discarding the higher-order bits.

In the case of FIG. 9, the inversion position G1A on the correction target is determined based on the smoothed value of the deviation ΔD, the correction target speed is calculated according to the inversion position G1A on the correction target, and the inversion position G1A on the correction target and the correction target speed. , Control the rotation speed of the wiper motor 18.

However, in the control of the rotation angle of the wiper motor 18 based on the correction target inversion position G1A or the like, a deviation ΔE may still occur between the actual rotation angle 130 and the target rotation angle 128. In the present embodiment, the deviation ΔE is also smoothed by a filter, the inversion position G1B on the correction target and the correction target speed are calculated based on the smoothed deviation ΔE, and the wiper motor 18 is subjected to the inversion position G1B on the correction target and the correction target speed. Control the rotation speed. As shown in FIG. 9, when the deviation ΔF still occurs, the rotation speed of the wiper motor 18 is controlled according to the correction target inversion position G1C corrected based on the deviation ΔF smoothed by the filter and the correction target speed. As a result, the actual rotation angle 130 is brought closer to the target rotation angle 128.

FIG. 10 is a flowchart showing an example of the reverse position correction process of the wiper device 100 according to the present embodiment. FIG. 10 differs from the first embodiment in that the deviation ΔD is processed by a filter in step 110 to smooth the value of the deviation ΔD, but steps 900 and 902 are the first embodiments. Since it is the same as the above, a detailed description will be omitted.

In step 904, the target inversion position is corrected based on the smoothed deviation ΔD, and in step 906, the rotation of the wiper motor 18 is reversed to start the next inversion operation and return the process. After that, as shown in FIG. 9, if the deviation ΔE or the like still occurs, the generated deviation ΔE or the like is smoothed by a filter to correct the target inversion position, and the deviation of the inversion position is performed. To prevent the occurrence of.

As described above, according to the wiper device and the control method of the wiper device according to the present embodiment, when the wiper blades 28 and 30 are overrun, the actual reverse position and the preset target reverse position are set. By correcting the target inversion position according to the deviation ΔD, it is possible to control the actual inversion position to be closer to the target inversion position when the actual inversion position deviates from the target inversion position.

Further, according to the wiper device and the control method of the wiper device according to the present embodiment, the target reversal position is corrected by the value obtained by smoothing the deviation ΔD, thereby suppressing a sudden change in the reversal position and actually suppressing the change. By controlling the inversion position to gradually approach the target inversion position, it is possible to correct the overrun of the wiper blades 28 and 30 without discomfort of the user.

10 ... Wiper control device, 12 ... Windshield glass, 14, 16 ... Wiper, 18 ... Wiper motor, 20 ... Link mechanism, 22 ... Wiper motor control circuit, 24, 26 ... Wiper arm, 28, 30 ... Wiper blade, 32 ... Output shaft , 34 ... crank arm, 36 ... link rod, 38, 40 ... pivot lever, 42, 44 ... pivot shaft, 46 ... link rod, 48 ... memory, 50 ... wiper switch, 52 ... deceleration mechanism, 54 ... rotation angle sensor, 56 ... Drive circuit, 56A, 56AP, 56AQ ... Pre-driver, 56B, 56BH, 56BI ... Voltage generation circuit, 58 ... Microcomputer, 60 ... Voltage detection circuit, 62 ... Signal input circuit, 64 ... Reverse connection protection circuit, 66 ... Noise prevention coil, 68 ... diode, 70 ... sensor magnet, 80 ... battery, 82 ... current detector, 82A ... shunt resistance, 82B ... amplifier, 92 ... vehicle ECU, 94 ... vehicle speed sensor, 100 ... wiper device, 111U, 111V , 111W, 112U, 112V, 112W ... Electric current effect transistor, 114 ... Stator, 116U, 116V, 116W ... Coil, 118 ... Rotor, 120 ... Target rotation angle, 122 ... Actual rotation angle, 124, 126 ... Curve, 128 ... Target Rotation angle, 130 ... Actual rotation angle, ΔD, ΔE, ΔF ... Deviation, θ1, θ2 ... Rotation angle, C1, C2 ... Electrolytic capacitor, G1, G1A, G1B, G1C ... Correction target top inversion position, P1 ... Top inversion position , P1 ... inverted position, P1', P1'', P2', P2'' ... position, P2 ... downward inverted position, P3 ... storage position, RT ... chip thermista, T1, T2, T3, T4 ... transistor

Claims (4)

The drive circuit that drives the wiper motor that wipes off the wiper blade,
A rotation angle detection unit that detects the rotation angle of the output shaft of the wiper motor,
When the rotation angle of the output shaft detected by the rotation angle detection unit indicates an angle corresponding to a predetermined target inversion position, the drive circuit is controlled so as to reverse the rotation of the wiper motor. The wiper blade is inverted, and the target inversion position is set based on the deviation between the rotation angle of the output shaft detected by the rotation angle detection unit at the time of the inversion and the angle corresponding to the target inversion position. The control unit to correct and
Including
The control unit sets the rotation speed of the output shaft with respect to the rotation angle of the output shaft between one target inversion position and the other target inversion position so that the rotation speed of the wiper motor changes according to a predetermined target speed. The output shaft that controls the drive circuit and determines the difference between the rotation angle of the output shaft from one target inversion position to the other target inversion position and the deviation from the one target inversion position to the other inversion position. A wiper device that controls the drive circuit so that the rotation speed of the wiper motor changes according to the target speed corrected by multiplying each value of the rotation speed indicated by the target speed by the quotient obtained by dividing by the rotation angle of. .. The wiper device according to claim 1 , wherein the control unit corrects the target inversion position and the target speed with a value obtained by smoothing the deviation with a filter. When the rotation angle of the output shaft detected by the rotation angle detection unit indicates an angle corresponding to a predetermined target inversion position, the rotation of the wiper motor is reversed and the wiper blade is reversed.
A deviation detection step for detecting the deviation between the rotation angle of the output shaft detected by the rotation angle detection unit at the time of the inversion and the angle corresponding to the target inversion position.
A correction step for correcting the target inversion position based on the deviation,
The rotation speed is controlled so that the rotation speed of the wiper motor changes according to a predetermined target speed with respect to the rotation angle of the output shaft between one target inversion position and the other target inversion position. Including speed control steps to
In the speed control step, the difference between the rotation angle of the output shaft from one target inversion position to the other target inversion position and the deviation of the output shaft from the one target inversion position to the other inversion position is set. A method for controlling a wiper device that controls the rotation speed of the wiper motor according to the target speed corrected by multiplying each value of the rotation speed indicated by the target speed by the quotient obtained by dividing by the rotation angle . The wiper device according to claim 3 , wherein the deviation detection step smoothes the deviation with a filter, and the correction step and the speed control step correct the target inversion position and the target speed by the smoothed deviation, respectively. Control method.

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