JP2012249497A - Motor controller and motor controlling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance pulse resolution to thereby improve control accuracy of motor speed and inversion position, in a motor which controls rotational speed and direction of the motor on the basis of motor pulses.SOLUTION: A wiper drive control unit has a CPU 22 connected to Hall ICs 17a and 17b. An absolute position signal of a blade from a Hall IC 20, and an A-phase pulse signal Sp1 and a B-phase pulse signal Sp2 from the Hall ICs 17a and 17b, are input into the CPU 22. The CPU 22 has a motor rotation number detection section 41 for calculating a rotation number of motor on the basis of the pulse signal Sp1, a rotation number determination section 43 for determining a level of the rotation number of the motor, and a signal selection section 44 for selecting a signal to be used for the control in accordance with the rotation number of the motor. The signal selection section 44 regulates such that only one of the pulse signals is input into the motor rotation number detection section 41 in a high rotation region, and the motor rotation number detection section 41 calculates the number of motor rotation using only the one of the pulse signals.

Description

  The present invention relates to a motor control technique for controlling the rotation speed and direction of a motor based on a pulse output corresponding to the rotation angle of a motor rotation shaft, and more particularly to a correct angle range such as a wiper motor. The present invention relates to a control device and a control method for a motor that performs reverse operation.

  2. Description of the Related Art Conventionally, in a wiper device provided in a vehicle, a system using a motor (wiper motor) as in Patent Document 1 that performs forward / reverse operation is known as a drive source for swinging and driving a wiper arm. Such a motor is provided with a rotation sensor for detecting the rotation of the motor rotation shaft, and a pulse signal having a period corresponding to the rotation speed of the rotation shaft is output from the rotation sensor. Two rotation sensors are provided at positions 90 ° out of phase to identify the rotation direction, and two pulse signals (A phase and B phase) are output from both sensors.

  On the other hand, the control device for the forward / reverse motor recognizes the rotational speed (rotational speed) of the motor rotation shaft based on the A-phase pulse signal and determines the rotational direction of the motor according to the B-phase level at the A-phase switching edge. Recognize. For example, when the A phase signal rises, the rotation direction is identified in the form of forward rotation when the B phase is HI and reverse rotation when the LO phase is LO. The motor control device recognizes the rotation angle of the output shaft, that is, the absolute position of the wiper arm, based on the count value (integrated value) of the A-phase pulse signal. Based on the recognition information, the forward / reverse operation of the wiper motor is controlled so that the wiper arm is swung between the upper reverse position and the lower reverse position.

JP 2008-160941 A

  As described above, in a system using a motor that operates in forward and reverse directions, the drive control of the motor is performed by appropriately using the pulse signals (A phase and B phase) from the rotation sensor according to the application. However, in recent years, in such a system, improvement in the reversal accuracy of the motor is required, and high resolution is also required in detecting the rotation angle of the motor. For example, in a wiper device for a luxury car, a specification is required so that the wiper arm can be accurately and smoothly reversed at a predetermined position, and accordingly, it is necessary to further refine the pulse resolution in the control system. Yes.

  However, when the pulse resolution is increased, there is a possibility that problems may occur in terms of processing capability of the control device (microcomputer) and rotation detection accuracy, and countermeasures have been demanded. In other words, the conventional system uses an external interrupt to the microcomputer for the pulse period to calculate the pulse period.If the pulse resolution is increased, the pulse period becomes very short in the high-speed rotation range, and the microcomputer process is in time. There was a problem that it might disappear. In addition, when the pulse interval is narrowed as the resolution is improved, there is a problem that the rotation detection accuracy may be lowered because the structure is easily affected by structural variations.

  An object of the present invention is to increase the resolution of a pulse without increasing the processing speed of a control device in a motor that controls the rotation speed and rotation direction of the motor based on a pulse output corresponding to the rotation angle of the motor rotation shaft. It is to improve the control accuracy of the motor speed and the reverse position.

  A motor control device according to the present invention is a motor control device that detects the rotation of a motor rotation shaft using two rotation sensors and controls the operation of the motor based on pulse signals respectively output from the rotation sensors. The motor rotation number detection unit that calculates the rotation number of the motor based on the pulse signal, and the motor rotation number calculated by the motor rotation number detection unit and a predetermined threshold are compared to determine the motor rotation number. When it is determined by the rotation number determination unit that determines the height and the rotation number determination unit that the motor is rotating at a predetermined rotation number or more, only one of the pulse signals of the two rotation sensors is the A signal selection unit that restricts input of the pulse signal to the motor rotation number detection unit so as to be input to the motor rotation number detection unit, and the motor rotation number detection unit If it is at a predetermined rotation number or more, and calculates the rotation speed of the motor using only one of the pulse signal.

  In the present invention, in the motor high-speed rotation range, one of the two pulse signals is used to calculate the motor rotation speed. Thereby, the input frequency of pulses in the high-speed rotation region is reduced, and the burden on the motor control device is reduced.

  In the motor control device, when the rotation number determination unit determines that the motor is rotating below a predetermined rotation number, the signal selection unit causes the motor rotation number detection unit to perform the two rotations. The input of both pulse signals to the motor rotation speed detection unit is allowed so that both of the pulse signals of the sensor are input, and the motor rotation speed detection unit causes the motor to rotate below a predetermined rotation speed. If so, the rotational speed of the motor may be calculated using both of the two pulse signals. Thereby, the detection accuracy of the rotation speed in the low rotation region with less burden on the motor control device is improved.

  The motor control device further includes a reversal timing determination unit that detects reversal timing for reversing the motor rotation axis based on the pulse signal and reversely drives the motor, and the signal selection unit includes the rotation speed. When the determination unit determines that the motor is rotating below a predetermined number of rotations, the inversion timing is set so that both of the pulse signals of the two rotation sensors are input to the inversion timing determination unit. The both pulse signals may be input to the determination unit, and the inversion timing determination unit may detect the inversion timing using both of the two pulse signals. This makes it possible to increase the resolution of the inversion position as compared with the case where the inversion timing is detected using only one of the pulse signals.

  The motor motor control method of the present invention is a motor control method for detecting the rotation of the motor rotation shaft using two rotation sensors and controlling the operation of the motor based on the pulse signals respectively output from the rotation sensors. And calculating the number of rotations of the motor based on the pulse signal, comparing the calculated number of rotations of the motor with a predetermined threshold value, and determining whether the motor rotation number is high or low. When it is determined that the motor is rotating as described above, the rotational speed of the motor is calculated using only one of the pulse signals of the two rotation sensors.

  In the present invention, in the motor high-speed rotation range, one of the two pulse signals is used to calculate the motor rotation speed. Thereby, the input frequency of pulses in the high-speed rotation region is reduced, and the burden on the motor control device is reduced.

  In the motor control method, when it is determined that the motor is rotating at less than a predetermined rotation number, the rotation number of the motor is calculated using both pulse signals of the two rotation sensors. Also good. Thereby, the detection accuracy of the rotation speed in the low rotation region with less burden on the motor control device is improved.

  In addition, when a reversal timing for reversing the motor rotation shaft is detected based on the pulse signal, the motor body is driven to reverse rotation, and it is determined that the motor rotation shaft is rotating at less than a predetermined number of rotations. The inversion timing may be detected using both pulse signals of the two rotation sensors. This makes it possible to increase the resolution of the inversion position as compared with the case where the inversion timing is detected using only one of the pulse signals.

  According to the motor control device of the present invention, the motor control device detects the rotation of the motor rotation shaft using the two rotation sensors and controls the operation of the motor based on the pulse signal output from each rotation sensor. A motor speed detector that calculates the motor speed based on the pulse signal, a motor speed detector that compares the calculated motor speed with a predetermined threshold value to determine whether the motor speed is high or low, A signal selection unit that restricts the input of the pulse signal so that only one of the pulse signals of the two rotation sensors is input to the motor rotation number detection unit when it is determined that the rotation is greater than the rotation number. The motor rotation speed detection unit calculates the motor rotation speed using only one of the pulse signals when the motor rotates at a predetermined rotation speed or higher. It is possible to suppress the pulse input frequency to the motor rotation speed detection unit in frequency, it is possible to reduce the load of the motor control device.

  According to the motor control method of the present invention, in the motor control method for detecting the rotation of the motor rotation shaft using two rotation sensors and controlling the operation of the motor based on the pulse signal output from each rotation sensor. The motor rotation number is calculated based on the pulse signal, the calculated motor rotation number is compared with a predetermined threshold value to determine whether the motor rotation number is high or low, and the motor is rotating at a predetermined rotation number or more. When the determination is made, the motor rotation speed is calculated using only one of the pulse signals of the two rotation sensors, so the frequency of pulse input to the motor rotation speed detector in the motor high-speed rotation range is suppressed. Thus, the burden on the motor control device can be reduced.

It is explanatory drawing which shows the structure of the motor unit provided with the motor by which the motor control process of this invention is implemented. It is sectional drawing which shows the structure of a multipolar magnetized magnet and Hall IC. It is a diagram which shows the pulse signal which Hall IC of FIG. 2 outputs. It is explanatory drawing which shows the structure of the control system of a motor. It is a block diagram which shows the structure of the signal selection processing system in CPU. It is a flowchart of the control processing which is one Example of this invention. It is explanatory drawing which shows the state of the output pulse signal of Hall IC.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram illustrating a configuration of a motor unit (wiper motor) including a motor in which the motor control process of the present invention is performed. The motor unit 1 in FIG. 1 is used as a drive source for vehicle electrical components such as an automobile wiper device, for example. The motor unit 1 is connected to a wiper arm or a wiper blade (hereinafter abbreviated as a blade) via a link mechanism or the like (not shown), and when the blade reaches the upside down position, the forward / reverse rotation is switched.

  The motor unit 1 includes a motor body 2 and a gear box 3. The rotation of the rotation shaft (motor rotation shaft) 4 of the motor body 2 is decelerated in the gear box 3 and is output to the output shaft 5. The rotating shaft 4 is rotatably supported by a bottomed cylindrical yoke 6. An armature core 7 around which a coil is wound and a commutator 8 are attached to the rotating shaft 4. A plurality of permanent magnets 9 are fixed to the inner surface of the yoke 6. The commutator 8 is in sliding contact with a power supply brush 10. The speed (number of rotations) of the motor body 2 is controlled by the amount of current supplied to the brush 10.

  A case frame 11 of the gear box 3 is attached to the opening side edge of the yoke 6. The tip of the rotating shaft 4 protrudes from the yoke 6 and is stored in the case frame 11. A worm 12 is formed at the tip of the rotating shaft 4. A worm gear 13 rotatably supported by the case frame 11 is engaged with the worm 12. The worm gear 13 is integrally provided with a first gear 14 having a small diameter on the same axis. A large-diameter second gear 15 is engaged with the first gear 14. An output shaft 5 that is rotatably supported by the case frame 11 is integrally attached to the second gear 15. Although not shown, the rotating shaft 4 is formed with another worm adjacent to the worm 12 in the direction opposite to the screw direction. The worm power is transmitted to the second gear 15 by a reduction member similar to the worm gear 13 and the first gear 14.

  The driving force of the motor body 2 is output to the output shaft 5 while being decelerated through the worm 12, the worm gear 13, the first gear 14, and the second gear 15. A crank arm (not shown) of a wiper device is attached to the output shaft 5. When the motor body 2 is operated, the crank arm is driven via the output shaft 5 and the wiper arm is operated via a link mechanism connected to the crank arm.

  A multipolar magnetized magnet 16 (hereinafter abbreviated as magnet 16) is attached to the rotating shaft 4. On the other hand, in the case frame 11, a Hall IC 17 is provided as a rotation sensor so as to face the outer peripheral portion of the magnet 16. 2 is a cross-sectional view showing the configuration of the magnet 16 and the Hall IC 17, and FIG. 3 is a diagram showing a pulse signal output from the Hall IC 17 of FIG. As shown in FIG. 2, the magnet 16 is formed in an annular shape (ring shape), and 10 poles are magnetized on the outer periphery thereof so that N poles and S poles are alternately arranged in the circumferential direction. On the other hand, two Hall ICs 17 are provided at positions having an angle difference of 90 degrees with respect to the center of the rotating shaft 4 (17a, 17b). When the rotating shaft 4 rotates once, pulse signals for 10 cycles are output from the Hall ICs 17a and 17b, and the two Hall ICs 17a and 17b output pulse signals Sp1 (A phase) and Sp2 whose phases are shifted by 90 °. (Phase B) is output.

  The phases of the pulse signals Sp1 and Sp2 are shifted from each other by 90 °, and the shift direction of the pulse signals Sp1 and Sp2 is inverted according to the rotation direction of the rotary shaft 4. Therefore, by detecting the appearance timing of the pulse signals Sp1 and Sp2, the rotation direction of the rotating shaft 4 can be determined, and thus the forward / return path of the wiper operation can be determined. Moreover, the rotational speed of the rotating shaft 4 can also be detected from the pulse output period of either one of the Hall ICs 17a and 17b. There is a correlation based on the speed reduction ratio and the link operation ratio between the rotation speed of the rotation shaft 4 and the blade speed, and the blade speed can also be calculated from the rotation speed of the rotation shaft 4.

  An absolute position detection magnet 18 is attached to the bottom surface of the second gear 15. A printed circuit board 19 is attached to the case frame 11. A Hall IC 20 is disposed on the printed circuit board 19 so as to face the magnet 18. One magnet 18 is provided on the bottom surface of the second gear 15, and faces the Hall IC 20 when the blade comes to the lower inversion position. The second gear 15 is attached with a crank arm as described above, and rotates 180 degrees to reciprocate the blade. When the second gear 15 rotates and the blade comes to the lower reverse position, the Hall IC 20 and the magnet 18 face each other and a pulse signal is output.

  The pulse output from the Hall ICs 17 and 20 is sent to a wiper drive control device (motor control device) 21. FIG. 4 is an explanatory diagram showing the configuration of the motor control system in the present invention. The CPU (control unit) 22 of the wiper drive control device 21 is connected to the battery 32 via the ignition switch 31 so that the operation mode (OFF, INT, LO, HI) of the wiper device can be switched by the wiper switch 33. It has become.

  The CPU 22 is connected to the Hall ICs 20, 17a and 17b, and recognizes the blade position using the pulse output from the Hall IC 20 as the absolute position signal of the blade and the pulse signal from the Hall ICs 17a and 17b as the relative position signal of the blade. To do. Further, the CPU 22 uses the pulse signal Sp1 from the Hall IC 17a as the A phase and the pulse signal Sp2 from the Hall IC 17b as the B phase. The CPU 22 recognizes the current position of the blade by counting the number of pulses after the absolute position signal is obtained. Here, the CPU 22 recognizes the absolute position signal indicating the downward inversion position from the Hall IC 20 and the A from the Hall IC 17a. The current position of the blade is detected by a combination of the number of phase pulse outputs.

  Further, the CPU 22 detects the speed (number of rotations) of the motor body 2 from the pulse signal Sp1 (A phase) of the Hall IC 17a. The motor body 2 is feedback controlled based on the detected speed. PWM control is executed on the motor body 2, and the CPU 22 appropriately turns on and off the applied voltage according to the control conditions and the detection speed, and changes the ON time ratio as appropriate. That is, the CPU 22 calculates the motor speed based on the motor pulses of the Hall ICs 17a and 17b, and sets the duty ratio (Duty) of the PWM control ON period according to the value. Thereby, the applied voltage to the motor body 2 is effectively changed, and the speed of the motor body 2 is controlled to a desired value. Note that the CPU 22 processes the motor pulse cycle (Hz) as a speed as it is, but the control may be performed by the number of revolutions (rpm) obtained from the pulse cycle.

  Further, the CPU 22 recognizes the rotation direction of the motor based on the pulse signals Sp1 and Sp2. That is, the rotational direction of the motor is detected based on the level of the B phase at the A phase switching edge. Here, when the A phase signal rises, when the B phase is HI, it is determined to be forward rotation (forward wiping), and when it is LO, it is determined to be reverse rotation (return wiping). In this way, the wiper drive control device 21 recognizes the current position, speed, and movement direction of the blade, and these data are appropriately stored in the RAM 23 in the wiper drive control device 21. The CPU 22 controls the motor body 2 based on these data while referring to various reference values, maps, and the like stored in the ROM 24 in the wiper drive control device 21.

  The motor body 2 is feedback controlled based on the detected motor speed. PWM control is executed in the motor main body 2, and the CPU 22 appropriately turns ON / OFF the applied voltage according to the control conditions and the detection speed, and changes the ON time ratio as appropriate. That is, the CPU 22 calculates the motor speed based on the pulse signal Sp1, and sets the duty ratio (Duty) of the PWM control ON period according to the value while referring to the map of the ROM 24 and the like. Thereby, the applied voltage to the motor body 2 is effectively changed, and the speed of the motor body 2 is controlled to a desired value. Note that the CPU 22 processes the motor pulse cycle (Hz) as a speed as it is, but the control may be performed by the number of revolutions (rpm) obtained from the pulse cycle.

  Here, in the conventional system, as described above, when the pulse resolution is increased, there is a possibility that a problem may occur in terms of processing capability of the control device and rotation detection accuracy. In particular, in the high-speed rotation range, the pulse period becomes very short, and the processing of the control device may not be in time. In the case of the wiper device, the blade starts from the upside down position, gradually increases in speed, and reaches the highest speed near the middle point of the upside down position. Thereafter, the blade gradually decreases in speed, stops at the upside down position, and performs the reverse operation. That is, in the wiper device, there are a region where the speed of the motor body 2 is slow and a region where the motor body 2 is slow, and the pulse cycle is short near the intermediate point, while the pulse cycle is long near the inversion position.

  Therefore, in the control processing according to the present invention, the A-phase and B-phase pulse signals, which are conventionally used for speed detection and rotation direction detection, regardless of the motor speed (blade position), according to the motor speed. This is selected to reduce the processing load on the control device and improve the reversal position accuracy. FIG. 5 is a block diagram showing a configuration of a signal selection processing system in the CPU 22. As shown in FIG. 5, the CPU 22 calculates the motor rotation speed based on the A-phase pulse signal Sp1 in addition to the motor drive command unit 40 that feedback-controls the motor 2 based on the motor speed, blade position, and the like. A motor rotation number detection unit 41 and a motor rotation direction detection unit 42 that detects the rotation direction of the motor based on the A-phase and B-phase pulse signals Sp1 and Sp2 are provided. Further, the CPU 22 includes a rotation speed determination unit 43 that determines whether the motor rotation speed is high, a signal selection unit 44 that selects a signal used for control according to the motor rotation speed, and a reversal that detects the reverse position and reverses the motor. A position determination unit (inversion timing determination unit) 45 is provided.

  In the motor unit 1 having such a device configuration and processing system, the motor body 2 is driven and controlled as follows. FIG. 6 is a flowchart thereof. First, when the ignition switch 31 is turned on, power is supplied to the CPU 22 and the like in the wiper drive control device 21. At this time, the CPU 22 recognizes the position of the blade from the absolute position signal from the Hall IC 20 when the blade is in the lower inverted position. When the wiper switch 33 is turned on from this state, the CPU 22 operates the motor main body 2 in the selected operation mode so as to move the blade toward the upper reverse position.

  When the motor body 2 is activated, the CPU 22 detects the number of rotations (rotation speed) of the motor body 2 in step S1. This rotational speed detection is performed by the motor rotational speed detector 41, and the rotational speed of the rotary shaft 4 is calculated using the A-phase pulse signal Sp1 from the Hall IC 17a. The motor rotation direction detection unit 42 detects the rotation direction of the motor body 2 based on the A-phase and B-phase pulse signals Sp1 and Sp2. The CPU 22 controls the speed of the motor body 2 with reference to the target speed map stored in the ROM 24 from the recognized rotational speed. In this speed control, for example, when the blade moves from the lower reverse position toward the intermediate position, the movement speed is gradually increased, and when the blade moves from the intermediate position toward the upper reverse position, the movement speed is gradually increased. The motor main body 2 is controlled so as to be lowered.

  After detecting the motor rotational speed in step S1, the process proceeds to step S2, and the rotational speed determination unit 43 determines whether or not the rotational speed is in a high-speed rotational state. The determination of the rotational speed is performed by comparing the current rotational speed with a threshold value stored in the ROM 24. When the current rotational speed exceeds a predetermined threshold value, it is determined as “high speed”. If it is determined in S2 that it is “high speed”, the process proceeds to step S3, where the signal selector 44 prohibits interruption of the B-phase pulse signal Sp2. The CPU 22 always receives pulse signals Sp1 and Sp2 from the Hall ICs 17a and 17b during motor operation. In the conventional system, the rotational speed and the rotational direction are always detected based on these signals. However, in the wiper device, at the time when the motor becomes high speed, that is, at the intermediate position of the wiping area, the rotation direction is known and unchanged. Therefore, detection of the rotation direction is unnecessary in the high speed range, and the B-phase pulse signal Sp2 is also unnecessary. Therefore, in the processing of the present invention, when it is determined that the speed is “high speed” in S2, the interruption of the B-phase pulse signal Sp2 is prohibited, and the rotation speed detection is executed only by the A-phase pulse signal Sp1. As a result, the pulse input interval in the high speed region is widened, and the processing load on the CPU 22 is reduced.

  After restricting the B-phase interrupt in S3, the process proceeds to step S4 to determine whether or not the A-phase pulse signal Sp1 is interrupted. That is, it is determined whether or not the next A-phase pulse signal Sp1 has been input, and if there is no interrupt (when there is no next A-phase input), the motor rotation speed is calculated from the current period of the A-phase pulse signal Sp1. (Step S5). Thereafter, in step S6, the CPU 22 (reverse position determination unit 45) determines whether the blade has reached the reverse position from the count number of the A-phase pulse signal Sp1 after the absolute position signal is obtained, If the inversion position has been reached, inversion output is performed in step S7, and the routine is exited. On the other hand, if it is determined in step S6 that the blade has not reached the reverse position, the feedback control of the motor body 2 is continued (step S8) and the routine is exited. If it is determined in step S4 that the A-phase pulse signal Sp1 has been interrupted, the process proceeds to step S9, and the time from the previous A-phase pulse signal Sp1 to the A-phase interrupt pulse is set as the pulse period. . Then, in step S10, an angle corresponding to the pulse signal Sp1 is added to calculate the blade movement angle, and the processing in step S5 and subsequent steps is performed.

  On the other hand, if it is determined at S2 that it is not "high speed", the process proceeds to step S11, and B-phase interruption is permitted. In step S12, it is determined whether or not the B-phase pulse signal Sp2 is interrupted. That is, it is determined whether or not the next B-phase pulse signal Sp2 has been input. If there is no interrupt (when there is no next B-phase input), the process proceeds to step S4 to determine whether or not there is an interrupt of the A-phase pulse signal Sp1. Then, the processing from S5 onward is performed. On the other hand, if it is determined in step S12 that the B-phase pulse signal Sp2 has been interrupted, the process proceeds to step S13, and the time from the previous B-phase pulse signal Sp2 to the B-phase interrupt pulse is defined as the pulse period. To do. The period set here is used as it is in step S5 for calculating the motor rotation speed when there is no interruption of the A-phase pulse in step S4. That is, when it is not the high speed region (low speed region), the B-phase pulse signal Sp2 is also used for detecting the motor speed. As a result, even when the pulse interval is widened in the low speed region, the frequency of detection of the motor rotation speed is increased, and the detection accuracy of the rotation speed is improved.

  In addition, after setting the pulse cycle in step S13, the process proceeds to step S14, and it is determined whether or not “B-phase inversion setting” is present. Here, as described above, the CPU 22 detects the current position of the blade by the combination of the absolute position signal from the Hall IC 20 and the A-phase pulse signal Sp1. That is, the motor reverse rotation operation at the upside down position is performed by recognizing that the cumulative number of A phase pulses has reached a predetermined value and the blade has reached the reverse position. Therefore, the motor reverse output is performed using the A-phase pulse signal Sp1 as a trigger, and the B-phase pulse signal Sp2 is not involved in this. On the other hand, “B-phase inversion setting” is a control setting that allows the B-phase pulse signal Sp2 to be used for the determination of the inversion position. In step S14, when this setting is performed, it is determined whether or not the A-phase pulse signal Sp1 is one edge before the inversion position. In this case, “one edge before the inversion position” indicates a state in which the B-phase pulse signal Sp2 is input immediately before the inversion position as shown in FIG. 7 (FIG. 7: point P).

  If the B-phase reversal setting has been made in step S14, and if it is one edge before the reversal position, the process proceeds to step S15 to add the angle corresponding to the B-phase pulse signal Sp2 to calculate the blade movement angle. That is, before the next A-phase pulse signal Sp1 is input, the blade movement angle is calculated using the B-phase pulse signal Sp2, and the processes in and after step S4 are performed. Therefore, compared with the case where the blade movement angle is calculated only by the A-phase pulse signal Sp1, the reversal position resolution can be improved, and the blade can be reversed at a more accurate position.

  When the processing of FIG. 6 is performed and the blade reaches the upper reversal position, the CPU 22 recognizes that the blade has reached the upper reversal position in step S6, and reverses the operation direction of the motor body 2 based on the recognition. The blade is moved from the upper reverse position to the lower reverse position. Also in this return path, the CPU 22 controls the speed of the motor body 2 based on the pulse signals Sp1 and Sp2 from the Hall ICs 17a and 17b. When the blade reaches the lower reverse position, the CPU 22 recognizes that the blade has reached the lower reverse position based on the absolute position signal from the Hall IC 20. Then, the CPU 22 reverses the operating direction of the motor main body 2 again, and drives the motor main body 2 so as to move the blade from the lower reverse position toward the upper reverse position. Thereafter, the blade is swung within a predetermined angle range by the motor body 2 by repeating the same process.

  As described above, in the control processing according to the present invention, in the high-speed rotation region (intermediate region of the wiper wiping process), one of the two phases (A phase in the present invention) is used during the interrupt processing, and the motor body 2 is calculated. As a result, the frequency of pulse input is reduced, and the burden on the CPU 22 is reduced. Further, in the rotation speed region (low rotation region) smaller than the predetermined rotation speed, the rotation speed is calculated using both the A phase and the B phase in the interrupt process. Thereby, the detection accuracy of the rotational speed is improved as compared with the case where the rotational speed is detected using only the A phase. Further, when performing reverse output, the B-phase edge can also be set for reverse position detection. This makes it possible to increase the resolution of the inversion position as compared with the case where the inversion position is detected using only the A phase.

  Therefore, according to the present invention, the resolution of the speed control and the reversal position can be increased without increasing the processing performance of the CPU 22, and the motor control accuracy can be improved without increasing the cost. For this reason, if the present invention is applied to a wiper motor, it becomes possible to improve the accuracy of blade speed control and reversal position, so that smooth blade operation and accurate reversal operation can be realized, and the performance of the wiper device can be improved. It will be compatible with luxury car specifications.

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 embodiment, an example in which the present invention is applied to a parallel wiping type wiper device in which one motor unit 1 is used as a drive source and the wiper arms on the driver's seat side and the passenger seat side are interlocked by a link mechanism has been described. However, the application target of the present invention is not limited to this, and the present invention can also be applied to a counter-wiping wiper device in which motor units are arranged on the driver's seat side and the passenger seat side, respectively.

  In this embodiment, the motor speed and the blade value are detected using the A-phase pulse signal from the Hall IC 17a, but these may be detected using the B-phase pulse signal. Further, in this embodiment, the blade position is detected using the absolute value signal from the Hall IC 20 and the pulse signals from the Hall ICs 17a and 17b. However, the non-contact type detects the change in the magnetic field as the change in the electrical resistance. Blade position detection may be performed using a magnetic sensor. In this case, an angle detection signal proportional to the rotation of the rotating shaft is output from the magnetic sensor, and the rotation angle of the rotating shaft, that is, the blade position can be detected based on the signal value. In addition, in this embodiment, the Hall ICs 17a and 17b are used as rotation sensors. However, the configuration of the rotation sensor is not limited to this, and any pulse signal corresponding to the rotation speed of the magnet can be output. For example, other magnetic sensors such as a magnetoresistive element sensor may be used.

  On the other hand, in the above-mentioned embodiment, the example in which the present invention is applied to the control of the wiper motor is shown, but the present invention can be applied to other than the wiper motor. For example, the present invention can be widely applied to motors that control the rotation speed and direction of a motor based on pulses output corresponding to the rotation angle of a motor rotation shaft, such as an in-vehicle motor other than a wiper motor and a motor for driving a machine. .

DESCRIPTION OF SYMBOLS 1 Motor unit 2 Motor main body 3 Gear box 4 Rotating shaft 5 Output shaft 6 Yoke 7 Armature core 8 Commutator 9 Permanent magnet 10 Brush 11 Case frame 12 Worm 13 Worm gear 14 First gear 15 Second gear 16 Multipole magnetized magnet 17 Hall IC
17a, 17b Hall IC
18 Magnet 19 Printed circuit board 20 Hall IC
21 Wiper drive control device (motor control device)
22 CPU
23 RAM
24 ROM
31 Ignition Switch 32 Battery 33 Wiper Switch 40 Motor Drive Command Unit 41 Motor Rotation Number Detection Unit 42 Motor Rotation Direction Detection Unit 43 Rotation Number Determination Unit 44 Signal Selection Unit 45 Reverse Position Determination Unit (Reverse Timing Determination Unit)
Sp1 A phase pulse signal Sp2 B phase pulse signal

Claims (6)

A motor control device that detects rotation of a motor rotation shaft using two rotation sensors and performs operation control of the motor based on pulse signals respectively output from the rotation sensors,
A motor rotation number detector that calculates the rotation number of the motor based on the pulse signal;
A rotation number determination unit that compares the rotation number of the motor calculated by the motor rotation number detection unit with a predetermined threshold value and determines the level of the motor rotation number;
When the rotation speed determination unit determines that the motor is rotating at a predetermined rotation speed or higher, only one of the two rotation sensor pulse signals is input to the motor rotation speed detection unit. And a signal selection unit for restricting the input of the pulse signal to the motor rotation number detection unit,
The motor rotation number detection unit calculates the rotation number of the motor using only one of the pulse signals when the motor rotates at a predetermined rotation number or more. . The motor control device according to claim 1, wherein the signal selection unit detects the motor rotation number when the rotation number determination unit determines that the motor is rotating below a predetermined rotation number. Allowing both of the pulse signals to be input to the motor rotation number detection unit so that both of the pulse signals of the two rotation sensors are input to the unit,
The motor control device according to claim 1, wherein the motor rotational speed detection unit calculates the rotational speed of the motor using both of the two pulse signals when the motor is rotating at a speed lower than a predetermined rotational speed. The motor control device according to claim 1, wherein the motor control device includes:
An inversion timing determination unit for detecting inversion timing for inverting the motor rotation axis based on the pulse signal and for inverting driving the motor;
When the rotation number determination unit determines that the motor is rotating below a predetermined rotation number, the signal selection unit receives both the pulse signals of the two rotation sensors in the inversion timing determination unit. As input, both the pulse signal input to the inversion timing determination unit,
The inversion timing determination unit detects the inversion timing using both of the two pulse signals. A motor control method for detecting rotation of a motor rotation shaft using two rotation sensors and performing operation control of the motor based on pulse signals output from the rotation sensors,
Calculating the number of rotations of the motor based on the pulse signal, comparing the calculated number of rotations of the motor with a predetermined threshold value to determine the level of the motor rotation number,
When it is determined that the motor is rotating at a predetermined rotation speed or more, the motor control method calculates the rotation speed of the motor using only one of the pulse signals of the two rotation sensors. .   5. The motor control method according to claim 4, wherein when it is determined that the motor is rotating at a speed lower than a predetermined rotational speed, the rotational speed of the motor is determined using both pulse signals of the two rotational sensors. The motor control method characterized by calculating. The motor control method according to claim 4 or 5,
Detecting a reversal timing for reversing the motor rotation axis based on the pulse signal, reversing the motor body,
When it is determined that the motor rotation shaft is rotating at less than a predetermined number of rotations, the inversion timing is detected using both pulse signals of the two rotation sensors.

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