JP2023103512A - Motor unit and motor control method - Google Patents

Abstract

To improve precision of a position at which a wiper reverses in response to occurrence of disturbance.SOLUTION: A motor unit comprises: a rotary shaft that positively and inversely rotates between two reversing positions; a rotary shaft sensor 65 that outputs an analog signal according to a rotation angle of the rotary shaft; a rotation angle calculating part 71 that calculates the rotation angle of the rotary shaft from the analog signal; a rotation direction calculating part 72 that calculates the rotation direction of the rotary shaft from the analog signal; a vector length calculating part 73 that calculates a vector length of the analog signal; a memorizing part 74 preliminarily memorizing an actual rotation angle of the rotary shaft measured by an external device and an ideal vector length that is a vector length in a state where there is no disturbance; a vector length error calculating part 75 that calculates a vector length error that is an error between the vector length and the ideal vector length, when the rotation angle of the rotary shaft is an angle corresponding to a prescribed position closer to a front side than the reversing positions; and a reversing position changing part 76 that changes the reversing positions, when the vector length error is out of a range of thresholds.SELECTED DRAWING: Figure 8

Description

The present invention relates to a motor unit and a motor control method.

A wiper of a vehicle or the like wipes a target surface such as a window by reciprocating with the power of a motor. In general, a wiper drive motor reverses the direction of rotation (forward/reverse) when the rotation axis reaches a predetermined angle by feedback control using a sensor. The wiper reciprocates in the left-right direction of a target surface such as a window due to the reversal operation of the motor, thereby wiping dust and the like from the target surface. Hereinafter, the wiper drive motor may be referred to as a "wiper motor", a "forward/reverse rotation motor", or the like.

Conventionally, there is a wiper motor that uses an analog output MR sensor to detect the reciprocating angle of the wiper (see Patent Document 1, for example). Analog output sensors have higher resolution and are less expensive than digital output sensors.

JP 2008-245389 A

On the other hand, the MR sensor may generate errors due to various disturbances, particularly due to the influence of magnetic flux from the outside (for example, magnetic flux due to a large current flowing in the drive motor of an electric vehicle). If an error occurs in the MR sensor, the wiper motor may rotate excessively.

In particular, when a wiper motor (rotary shaft and output shaft) for a vehicle rotates excessively, the wiper device may interfere with the vehicle body and damage the vehicle body and the wiper device. For this reason, it has been desired to deal with the problem of the occurrence of errors in the MR sensor due to the above disturbances.

Other subjects of the present invention will become clear from detailed descriptions such as the specification and drawings to be described later.

A motor unit according to the present invention includes:
a rotating shaft that rotates forward and backward between two reversing positions;
a rotating shaft sensor that outputs an analog signal according to the rotation angle of the rotating shaft;
a rotation angle calculation unit that calculates the rotation angle of the rotation shaft from the analog signal;
a rotation direction calculation unit that calculates the rotation direction of the rotation shaft from the analog signal;
a vector length calculator that calculates the vector length of the analog signal;
a storage unit that stores in advance the actual rotation angle of the rotation shaft measured by an external device and the ideal vector length that is the vector length in a state without disturbance;
a vector length error calculation unit for calculating a vector length error, which is an error between the vector length and the ideal vector length, when the rotation angle of the rotating shaft is an angle corresponding to a specified position before the reversal position;
and a reversal position changing unit that changes the reversal position when the vector length error is out of a threshold range.

According to the present invention, it is possible to improve the accuracy of the wiper reversal position in response to the occurrence of disturbance.

It is a figure explaining one specific example of a wiper device. It is a figure explaining one specific example of the motor for wipers. FIG. 5 is a graph illustrating analog output values of an MR sensor for detailing problems of the prior art; FIG. 4 is a diagram for explaining the X, Y coordinates of the waveform of FIG. 3 and the magnetic flux due to disturbance magnetic flux; FIG. 7 is a graph showing the relationship between angle error and vector length error when disturbance magnetic flux is applied; FIG. 5 is a diagram showing disturbance magnetic flux prediction points at wiper up-reversal positions for explaining a method of determining an angle error, etc., in the embodiment of the present disclosure; FIG. 4 is a diagram for explaining control mode transition in the embodiment of the present disclosure; FIG. 3 is a block diagram showing an example of an electrical configuration of a motor unit according to the embodiment of the present disclosure; FIG. 4 is a flowchart for explaining control in a normal mode and a disturbance magnetic flux applied mode according to the present embodiment; FIG. 4 is a diagram showing an example of wiper operating angles in a normal mode and a disturbance magnetic flux applied mode according to the present embodiment;

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each figure, parts having the same or similar functions are denoted by the same or similar reference numerals, and description thereof will be omitted as appropriate.

First, with reference to FIGS. 1 and 2, a specific example of a wiper device and a wiper motor assembly (hereinafter sometimes simply referred to as a motor) to which the rotation angle correcting device of the present disclosure can be applied will be described. . FIG. 1 is a diagram illustrating a specific example of a wiper device. FIG. 2 is a diagram for explaining a specific example of a wiper motor.

As shown in FIG. 1, a vehicle 10 such as an automobile is provided with a windshield 11 as a windshield, and a wiper device 12 is mounted in close proximity to the windshield 11 . The wiper device 12 is activated by turning on a wiper switch (not shown) in the passenger compartment, and wipes off deposits adhering to the windshield 11 .

The wiper device 12 includes a motor 20, a power transmission mechanism 14 that transmits the swinging motion of the motor 20 to the pivot shafts 13a and 13b, a base end fixed to the pivot shafts 13a and 13b, and a tip end to the pivot shafts 13a and 13b. A pair of wiper members 15a and 15b are provided for performing a reciprocating wiping operation on the windshield 11 by the swing motion of the wiper members 13a and 13b. Motor 20 is, for example, a brushless motor. Each wiper member 15a, 15b is provided corresponding to the driver's seat side and passenger seat side, respectively, and includes wiper arms 16a, 16b and wiper blades 17a, 17b attached to the respective wiper arms 16a, 16b.

The motor 20 causes the wiper members 15a and 15b to perform reciprocating wiping operations. That is, when the motor 20 rotates, the swing motion of the motor 20 is transmitted to the pivot shafts 13a and 13b through the power transmission mechanism 14, and the pivot shafts 13a and 13b swing. In this way, the driving force of the motor 20 is transmitted to the wiper members 15a and 15b, and the wiper blades 17a and 17b wipe off deposits adhering to the wipe areas 11a and 11b of the windshield 11. FIG. In the specification, the wiper members 15a and 15b are collectively referred to as the wiper member 15. As shown in FIG.

In FIG. 2 , the motor 20 includes a motor body portion 30 and a speed reduction mechanism portion 40 . The motor main body 30 includes a yoke 31 formed in a cylindrical shape with a bottom by pressing a steel plate or the like. Inside the yoke 31, a stator 32 formed in an annular shape is fixed. U-phase, V-phase, and W-phase (three-phase) coils are wound around the stator 32 in a star connection manner.

As shown in FIG. 2, a rotor 33 is rotatably provided inside the stator 32 with a predetermined gap (air gap) therebetween. The rotor 33 here has an IPM (Interior Permanent Magnet) structure in which permanent magnets of multiple poles are embedded. In the embodiment, a six-pole structure in which permanent magnets with alternate polarities are arranged at intervals of 60° along the circumferential direction of the rotor 33 is taken as an example. good. Further, the rotor 33 is not limited to the IPM structure, and may have an SPM (Surface Permanent Magnet) structure in which a plurality of permanent magnets are attached to the outer peripheral surface of the rotor.

A rotating shaft 33 b is fixed through the center of rotation of the rotor 33 . A base end side (upper side in FIG. 2) of the rotating shaft 33b is rotatably supported by a bearing (not shown) provided at the bottom of the yoke 31, and a distal end side (lower side in FIG. 2) of the rotating shaft 33b. ) extends to the interior of the gear housing 41 that forms the speed reduction mechanism 40 . A portion of the rotating shaft 33 b extending into the gear housing 41 , that is, a tip side and a substantially central portion of the rotating shaft 33 b located within the gear housing 41 are supported by a pair of bearings (not shown) provided in the gear housing 41 . Each is rotatably supported.

A worm 51 forming a reduction mechanism 50 is integrally provided on the tip side of the rotating shaft 33b. A rotating shaft magnet 34 formed in an annular shape is integrally provided in a portion of the rotating shaft 33b near the worm 51 between the worm 51 and the rotor 33. As shown in FIG. The rotary shaft magnet 34 is provided at the portion of the rotary shaft 33b that extends into the gear housing 41, and includes a multi-pole permanent magnet arranged along the circumferential direction of the rotary shaft 33b. The permanent magnets of the rotating shaft magnet 34 are composed of, for example, the same number of poles as the permanent magnets of the rotor 33 described above. It has a polar structure.

The rotating shaft magnet 34 is used not only to detect the rotational speed of the rotating shaft 33b, but also to detect the rotational position of the rotor 33 with respect to the stator 32 via the rotating shaft 33b. Therefore, the permanent magnets of the rotating shaft magnet 34 are attached so that the polarities of the permanent magnets of the rotor 33 with respect to the rotational position of the rotating shaft 33b and the polarities of the permanent magnets of the rotating shaft magnet 34 sequentially match. By matching the polarities with each other in this way, when detecting the rotational position of the rotor 33, correction control for correcting the phase deviation of the polarities, etc., is not required, and complication of the control of the motor 20 can be avoided. become.

The number of permanent magnet poles of the rotating shaft magnet 34 does not necessarily have to be the same as the number of poles of the permanent magnets of the rotor 33, and may be an integer multiple. That is, the rotating shaft magnet 34 may be configured such that the polarity of the permanent magnet of the rotating shaft magnet 34 changes at each rotational position of the rotating shaft 33b at which the polarity of the permanent magnet of the rotor 33 changes. If the number of poles of the permanent magnets of the rotating shaft magnet 34 is set to be at least twice the number of poles of the permanent magnets of the rotor 33, the rotational position of the rotor 33 with respect to the stator 32 can be obtained more finely. control may be possible.

As shown in FIG. 2, the speed reduction mechanism 40 includes an aluminum gear housing 41 and a plastic gear cover 42 that closes an opening 41a (front side in FIG. 2) of the gear housing 41. As shown in FIG. The yoke 31 is fixed to the gear housing 41 via a fastening member (fixing screw or the like) (not shown). As a result, the motor main body 30 and the speed reduction mechanism 40 are integrated, and the worm 51 provided on the rotating shaft 33 b and the rotating shaft magnet 34 are arranged inside the gear housing 41 .

A worm wheel 52 (not shown in detail) is rotatably provided inside the gear housing 41 . The worm wheel 52 is formed in a disc shape from a resin material such as POM (polyacetal) plastic, and gear teeth 52a (not shown in detail) are formed on the outer peripheral portion thereof. The gear teeth 52 a of the worm wheel 52 are meshed with the worm 51 , and the worm wheel 52 and the worm 51 constitute the reduction mechanism 50 .

A proximal end of an output shaft 52b is fixed to the rotation center of the worm wheel 52, and the output shaft 52b is rotatably supported by a boss portion 41b of the gear housing 41 via a bearing (not shown). . The tip side of the output shaft 52b extends outside the gear housing 41, and the power transmission mechanism 14 is fixed to the tip portion of the output shaft 52b as shown in FIG. As a result, the rotational speed of the rotary shaft 33b is reduced through the worm 51 and the worm wheel 52 (reduction mechanism 50), and the output whose torque is increased by this reduction is output to the power transmission mechanism 14 through the output shaft 52b. It is designed to be In addition, the "rotating shaft" in the present invention exclusively means the output shaft 52b, and when the term "rotating shaft" is used without using the reference numeral, it means the output shaft 52b.

As shown in FIG. 2 , a tablet-shaped output shaft magnet 53 is provided via a worm wheel 52 on the portion of the output shaft 52 b (rotating shaft) that extends into the gear housing 41 . The output shaft magnet 53 is attached so as to rotate integrally with the output shaft 52b. The output shaft magnet 53 is magnetized to the south pole in a range of about 180 degrees along the circumferential direction, and is magnetized to the north pole in the other range of about 180 degrees. The output shaft magnet 53 is used to detect the rotational position of the output shaft 52 b with respect to the gear housing 41 .

An opening 41a of the gear housing 41 is formed to accommodate components such as the worm wheel 52 inside the gear housing 41, and the opening 41a is closed by a gear cover (not shown). A sealing member (not shown) is provided between the gear housing 41 and the gear cover to prevent rainwater or the like from entering the speed reduction mechanism 40 from between the gear housing 41 and the gear cover. . A control board 60 is mounted inside the gear cover as shown in FIG. The control board 60 is electrically connected to the external power source 100 and the wiper switch via an external connector (not shown) on the vehicle 10 side connected to a connector connection portion (not shown) provided on the gear cover. .

On the control board 60, as shown in FIG. 2, three rotating shaft sensors 65a, 65b, 65c and an output shaft sensor 66 are mounted. The three rotating shaft sensors 65a, 65b, 65c are provided corresponding to the three phases (U phase, V phase, W phase), respectively, and are composed of Hall ICs. A Hall IC generates a Hall signal (pulse signal) whose logic level changes according to a change in polarity (change from N pole to S pole or change from S pole to N pole). The output shaft sensor 66 is composed of, for example, an MR sensor consisting of a magnetoresistive element. MR sensors produce an output voltage that is dependent on the magnitude of the magnetic field.

Each of the rotary shaft sensors 65a to 65c is mounted at a position facing the rotary shaft magnet 34. As shown in FIG. Specifically, the rotating shaft sensors 65a to 65c are mounted on the control board 60 so as to face the outer peripheral surface (side surface) of the rotating shaft magnet 34 and are arranged at regular intervals. As a result, the rotating shaft sensors 65a to 65c sequentially generate hall signals with a predetermined phase difference as the rotating shaft magnet 34 rotates. In the specification, the rotary shaft sensors 65a to 65c are collectively referred to as the rotary shaft sensor 65. As shown in FIG. The output shaft sensor 66 is mounted on the control board 60 at a position facing the output shaft magnet 53 . As a result, each output shaft sensor 66 generates a sensor signal whose voltage value changes continuously according to the rotation of the output shaft magnet 53 .

The motor 20 is provided with a temperature sensor 45 for detecting the temperature of the motor 20, as shown in FIG. The temperature sensor 45 is, for example, a thermistor element, and is provided near the rotor 33 here. The control board 60 can detect the temperature of the motor 20 (particularly the rotor 33 ) via the temperature sensor 45 .

Problems of the prior art will be described below with reference to FIGS. 3 to 5. FIG. Here, FIG. 3 is a graph illustrating analog output values of the MR sensor for detailing the problems of the prior art. FIG. 4 is a diagram for explaining magnetic flux due to disturbance magnetic flux, with the sine (SIN(a)) wave SW of FIG. 3 as the X coordinate and the cosine (COS(a)) wave CW as the Y coordinate.

Conventionally, the wiper operating angle of the output shaft of the motor 20 is detected as a rotating shaft sensor 65 that is a component of the wiper device 12 (hereinafter, a conventional wiper with a motor and a control function (wiper system) is referred to as a control wiper). In some cases, analog output absolute angle detection MR sensors are used.

Such an analog output absolute angle detection MR sensor has a quadrature phase difference relationship shown as sine (SIN(a)) wave SW and cosine (COS(a)) wave CW in the graph of FIG. In other words, it outputs two sine waves with a phase difference of 90 degrees. In the graph of FIG. 3, the horizontal axis indicates the angle (a) [°] of the output shaft of the motor 20, and the vertical axis indicates each of the sine (SIN(a)) wave SW and the cosine (COS(a)) wave CW. shows the output value of By calculating the arctangent of these two waveforms, the wiper operating angle of the output shaft of the motor 20 is calculated.

In FIG. 4, the output value (value on the vertical axis) of the sine (SIN(a)) wave SW when the output shaft of the motor 20 in FIG. (horizontal axis), and the output value (vertical axis value) of the cosine (COS(a)) wave CW is expressed as the Y coordinate (vertical axis).

A circle indicated by I in FIG. 4 is an ideal figure with no output value error when the motor 20 (rotor 33 having a magnet) rotates. In this case, since a circle of constant distance is drawn centering on the reference point P (that is, X=0, Y=0), the vector length=√(X ² +Y ² ) is a constant value at any angle.

On the other hand, when a disturbance extending in the horizontal direction from the reference point P in FIG. , an X value and a Y value shifted from the reference point P (X=0, Y=0) by the disturbance magnetic flux are output. In this case, the vector length, in other words, the distance from the reference point P changes depending on the angle, and an error in the wiper reversal position occurs according to the change.

FIG. 5 shows a graph showing the relationship between the angle error and the vector length error when the disturbance magnetic flux as described above is applied. In the graph of FIG. 5, the horizontal axis indicates the rotation angle, that is, the angle [°] of the output shaft of the motor 20 as in FIG. 3, and indicates the error value. Further, in FIG. 5, curve AE indicates angle error, and curve BE indicates vector length error.

Here, the curve of the angle error AE is obtained by calculating the sensor value at the actual rotation angle of the output shaft of the motor 20, comparing the calculated value (sensor value) with the actual rotation angle, and plotting the error value on the graph. is the curve shown in . On the other hand, the curve of the vector length error BE compares the calculated vector length at the actual rotation angle of the output shaft of the motor 20 with the vector length reference value which is the average value of the vector lengths obtained in the normal state. and the error values are plotted on the graph. Comparing these curves AE and BE, it can be seen that the relationship between the vector length error BE and the angle error AE appears shifted by about 90° when the disturbance magnetic flux is applied from one direction as described above with reference to FIG.

Based on the problems and findings as described above, the present embodiment proposes a motor control method, a motor, and the like based on the following basic principles. Here, FIG. 6 is a diagram showing disturbance magnetic flux prediction points at the up-reversing position of the wiper for explaining a method of determining an angle error and the like in the embodiment of the present disclosure.

As shown in Figure 6, the two flipped positions of the wiper member are commonly referred to as the "top flipped position" and the "bottom flipped position". Here, when a disturbance magnetic flux is applied to the wiper motor as described above, an error (deviation from the original position where the wiper should be reversed) will occur in the upper and lower reverse positions of the wiper. It affects the durability of components and vehicles.

Therefore, in the present embodiment, using the characteristics described above, it is determined whether or not a disturbance magnetic flux has been applied by the following detection method. It is obvious to those skilled in the art that the processing described below can be executed by any processor (control unit) such as a microcomputer, CPU, GPU, or MPU, and any number of processors can be used. For convenience of explanation, it is assumed that the processing subject is a single processor (control unit). Furthermore, due to space limitations, etc., the description of the subject of processing may be omitted as appropriate.

In the present embodiment, the controller controls the above-described X value and Y value at an angle of 90° in front of the upside-down position or downside position (hereinafter sometimes collectively referred to as the “upside-down position”). Then, the vector length calculation value D (vector length of analog signal) is calculated. Then, the control unit confirms whether or not the calculated vector length calculation value D is within the range of the vector length reference value O and its margin Q. It is determined that a disturbance magnetic flux has been applied at the position (an angular error of the wiper has occurred).

When it is determined that a disturbance magnetic flux has been applied by the above detection method, the control unit recognizes that the value of the MR sensor for absolute angle detection is in error due to the disturbance magnetic flux, Switch to on-force control. In this disturbance magnetic flux application time control, the control unit controls the reversing position of the motor so as to shift the vertical reversing position of the wiper member inward. In this way, by continuing control in a state where the wiper member does not interfere with the body or pillars of the vehicle, the wiper can be continuously operated (the wiper function can be maintained).

FIG. 7 is a diagram for explaining control mode transition in the present embodiment.

In the present embodiment, when it is determined by the above detection method that no disturbance magnetic flux is applied, the control unit maintains the normal mode shown in FIG. are performed in the same way as before. On the other hand, when it is determined that the disturbance magnetic flux is applied by the above detection method, the control unit switches from the normal mode to the disturbance magnetic flux applied mode shown in FIG. control.

The following describes in more detail the control performed by the controller during application of disturbance magnetic flux. The control unit performs switching from the normal mode to the disturbance magnetic flux application mode using the equation shown on the upper side in FIG. 7, that is,
(O−Q)>D or (O+Q)<D
It is done when the following formula is satisfied. Here, the equation (O−Q)>D on the left applies to the top flip position, and the equation on the right (O+Q)<D applies to the bottom flip position.

That is, when the vector length calculated value D is smaller than the value obtained by subtracting the vector length reference value margin Q from the vector length reference value O, the control unit switches from the normal mode to the disturbance magnetic flux applied mode. switch. On the other hand, regarding the lower reversing position, if the vector length calculated value D is greater than the sum of the vector length reference value O and the vector length reference value margin Q, the control unit shifts from the normal mode to the disturbance magnetic flux application mode. switch to This means that switching to the disturbance magnetic flux applied mode can be performed individually for the upper reversal position and the lower reversal position. For example, the control unit keeps the upper reversing position under normal mode control, while controlling the lower reversing position in the disturbance magnetic flux applied mode control so that the reversing position of the wiper member is set to the inner side (front side). Control (reversal operation) can be performed.

On the other hand, the control unit uses the formula shown on the lower side in FIG. 7, that is,
(OR)≤D(up) and D(dn)≤(O+R)
When the following expression is satisfied, the mode is switched from the disturbance magnetic flux applied mode to the normal mode. Note that R indicates the vector length reference value margin like Q described above, but has a smaller value than Q, that is, Q>R.

Thus, when the vector length calculated value D(up) at the time of upward reversal is (OR) or more (the value obtained by subtracting the vector length reference value margin R from the vector length reference value O) or more, the control unit In addition, when the vector length calculation value D(dn) at the time of downward reversal is (O+R) or less (below the sum of the vector length reference value O and the vector length reference value margin R), when the disturbance magnetic flux is applied Switch from mode to normal mode.

Note that the vector length reference value margins Q and R described above are set to values that take into account changes in the vector length due to voltage at the time of output from the MR sensor, temperature, deterioration over time, and the like. In addition, by giving the vector length reference value margin a relationship of Q>R (different values of the margin used for switching between the disturbance magnetic flux applied mode and the normal mode), the mode shifts frequently. Therefore, it is possible to prevent the operation of the wiper member from appearing unnatural.

FIG. 8 is a block diagram showing an example of the electrical configuration of the motor assembly (motor unit of the present disclosure) according to the present embodiment.

The motor assembly includes a motor 20 that drives the wiper member, a rotating shaft sensor 65, an inverter 500 that supplies power to the motor 20, and outputs drive signals to the inverter 500 to operate the motor 20 (two reverse positions). and a control unit 70 that controls forward and reverse rotation between.

In one embodiment shown in FIG. 8, the motor 20 is a three-phase motor with a stator 210 containing delta-connected armature coils 210u, 210v, 210w. A rotor (not shown in FIG. 8), which is a rotating member of the motor 20, has a structure in which magnetism (magnetic poles N and magnetic poles S) is arranged at a phase of 90°. not shown) are linked. Furthermore, the output shaft, which is decelerated by the deceleration mechanism of the motor 20 and coupled to the wiper member, has a structure in which magnetism (magnetic pole N and magnetic pole S) is arranged at a phase of 90° (see FIG. 2 as appropriate). . Also, in one specific example, the output shaft (“rotating shaft” in the present disclosure) is provided with a rotating shaft sensor 65 . The rotating shaft sensor 65 is a sensor that outputs an analog signal (see FIG. 3 as appropriate) according to the rotation angle of the rotating shaft of the motor 20, and can use various encoders.

Inverter 500 includes six switching elements 510a-510f connected by a three-phase bridge and diodes 520a-520f connected in antiparallel between the collectors and emitters of the switching elements. The positive pole of the constant voltage power supply 300 is connected to the cathodes of the diodes 520a to 520c, and the negative pole of the constant voltage power supply 300 is connected to the anodes of the diodes 520d to 520f. Each of the switching elements 510a-510f is, for example, an FET (Field Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor). Each gate of the six bridge-connected switching elements 510 a - 510 f is connected to the control unit 54 of the control section 70 .

The drains or sources (collectors or emitters) of switching elements 510a to 510f are connected to delta-connected armature coils 210u, 210v, 210w. More specifically, the neutral point N1, which is the connection point between the source of the switching element 510a and the drain of the switching element 510d, is connected to the connection point 210a between the armature coils 210w and 210u. A neutral point N2, which is a connection point between the source of the switching element 510b and the drain of the switching element 510e, is connected to the connection point 210b between the armature coils 210w and 210v. A neutral point N3, which is a connection point between the source of the switching element 510c and the drain of the switching element 510f, is connected to a connection point 210c between the armature coils 210v and 210u.

Based on the above configuration, the six switching elements 510a to 510f of the inverter 500 perform a switching operation based on the driving signal (gate signal) output from the driving signal generating section 77 of the control section 70. 300 DC voltage is converted to AC. Then, the inverter 500 supplies three-phase (U-phase, V-phase, and W-phase) AC voltages output from the neutral points N1 to N3 to the armature coils 21u, 21v, and 21w of the motor 20 as energization signals. This rotates the rotor and thus the output shaft.

As shown in FIG. 8, the control unit 70 includes a rotation angle calculation unit 71, a rotation direction calculation unit 72, a vector length calculation unit 73, a storage unit 74, a vector length error calculation unit 75, a reverse position change unit 76, and a drive signal. A generator 77 is provided. Each of these units can use separate hardware (dedicated processor, etc.), or can use single or multiple pieces of hardware (CPU, GPU, MPU, etc.) to may be configured to appropriately share the function of

Of the above, the analog signal output from the rotation axis sensor 65 is supplied to the rotation angle calculation section 71 and the rotation direction calculation section 72, respectively.

The rotation angle calculator 71 calculates the rotation angle of the rotation shaft of the motor 20 from the input analog signal, and supplies the calculated value (rotation angle) to the vector length calculator 73 .

The rotation direction calculator 72 calculates the rotation direction of the rotation shaft of the motor 20 from the input analog signal, and supplies the calculated value (rotation direction) to the vector length calculator 73 . Here, the direction of rotation corresponds to the direction of movement (forward/reverse) of the wiper member.

The vector length calculator 73 calculates the vector length of the analog signal output from the rotation axis sensor 65 from the input rotation angle and rotation direction, and uses the calculated value (vector length at each rotation angle) to calculate the vector length error. 75.

The storage unit 74 is a table that defines the correspondence relationship between the actual rotation angle of the rotation shaft of the motor 20, which is measured in advance by an external device (not shown), and the ideal vector length, which is the vector length in the absence of disturbance. memorize The storage unit 74 can use various storage media such as HDD and flash memory.

The vector length error calculator 75 reads the data (ideal vector length at each rotation angle) from the above table, and calculates the difference between the vector length input from the vector length calculator 73 and the ideal vector length at the corresponding rotation angle. is calculated as the vector length error. The vector length error calculator 75 supplies the calculated vector length error to the reversal position changer 76 .

As a specific example, the vector length error calculator 75 calculates a vector that is the error between the vector length and the ideal vector length when the rotation angle of the rotation shaft of the motor 20 is an angle corresponding to a specified position before the reverse position. Calculate the long error.

Here, the specified position (or the angle corresponding to the specified position) is not particularly limited. position at an angle forming 90° at ). The reason for this is that, as can be understood from the waveforms shown in FIG. 5, the deviation between the waveform (vector) of the angle error AE and the waveform (vector) of the vector length error BE can be seen most clearly at the position of the angle forming 90°. This is because it becomes a position.

In other words, the prescribed position (or the angle corresponding to the prescribed position) may be any position (angle) where the deviation between the waveform (vector) of the angular error AE and the waveform (vector) of the vector length error BE is known. It is not limited to the position at an angle of 90° from the position, and may be other front positions such as 80° from the reverse position (0°), for example.

The inversion position changing unit 76 compares the input vector length error value with a predetermined threshold value to determine whether the vector length error is outside the range of the threshold value. If the inversion position changer 76 determines that the vector length error is not outside the range of the threshold, it continues the above comparison and determination without outputting a signal to the drive signal generator 77 . On the other hand, when the reversing position changing unit 76 determines that the vector length error is outside the range of the threshold value, the reversing position changing unit 76 sends a signal indicating that the mode should be changed from the normal mode to the disturbance magnetic flux applying mode. A signal (inverted position change signal) to the effect of changing to the side is output to the drive signal generator 77 . This reversal position change signal includes information specifying which direction (upward or downward) the reversal position of the motor 20 is to be changed to the near side.

When the reversal position change signal is not input from the reversal position changer 76, the drive signal generator 77 outputs a drive signal to the inverter 500 so as to perform a normal reversal operation. On the other hand, when the reversing position change signal is input from the reversing position changing unit 76, the driving signal generating unit 77 shifts the reversing position of the motor in the specified direction (upward or downward) to the near side in response to this signal. A drive signal is output to the inverter 500 so as to change.

Hereinafter, the flow of processing in the normal mode and the disturbance magnetic flux applied mode will be described with reference to FIG. 9 . FIG. 9 is a flow chart for explaining control in the normal mode and the disturbance magnetic flux applied mode in this embodiment. A series of processes shown in FIG. 9 are executed each time the wiper is operated.

In step S1, the control unit 70 refers to the control history stored in the storage unit 74 or another memory (not shown) to determine whether or not the previous operation mode was the disturbance magnetic flux applied mode.

Here, if the control unit 70 determines that the previous operation mode was not the disturbance magnetic flux application time mode (step S1, NO), it determines that the previous operation mode was the normal mode or there is no history, and the normal In order to process the hour mode, the process proceeds to step S2.

On the other hand, when the control unit 70 determines that the previous operation mode was the disturbance magnetic flux applied mode (step S1, YES), the process proceeds to step S5 to perform the disturbance magnetic flux applied mode.

In step S2 of the normal mode, the control unit 70 determines whether or not the calculation result of the rotation angle calculation unit 71, that is, the rotation angle of the output shaft 52b of the motor 20 has reached a predetermined angle. Here, if the controller 70 determines NO, ie, that the predetermined angle is not reached, it repeats the determination of step S2. On the other hand, when the controller 70 determines that the predetermined angle has been reached (step S2, YES), the process proceeds to step S3.

Here, with reference to FIG. 10, the "predetermined angle" will be described more specifically. FIG. 10 is a diagram showing an example of the operating angles of the wiper in the normal mode and the disturbance magnetic flux applied mode in this embodiment.

In the example shown in FIG. 10, the "predetermined angle" is used when the output shaft 52b and the wiper member (hereinafter referred to as the wiper, etc.) are rotating in the forward (upward) direction and in the reverse (downward) direction. different angles. In this example, as shown in FIG. 10, when the lower reversal position in the normal mode is 0°, when the wiper or the like is rotating in the positive (upward) direction, the angle forming 45° from the lower reversal position is the "predetermined angle" (hereinafter referred to as the first angle), and when the wiper, etc., is rotating in the reverse (downward) direction, the angle forming 90° from the lower reversal position is the "predetermined angle" (hereinafter referred to as the second angle). ).

In other words, in step S2, the control unit 70 determines whether the wiper or the like is rotating in the forward direction and at the first angle, or rotating in the reverse direction and at the second angle. Transition.

In step S3, the controller 70 determines whether the vector length error output from the vector length error calculator 75 is within the first threshold. The first threshold is a value corresponding to the vector length reference value margin Q described above.

If the control unit 70 determines that the vector length error output from the vector length error calculation unit 75 is within the first threshold value (step S3, YES), the control unit 70 determines that there is no disturbance, and continues the normal mode processing. Therefore, the process proceeds to step S4. Then, in step S4, the control unit 70 outputs a drive signal from the drive signal generation unit 77 to the inverter 500 so as to reverse the wipers and the like at the normal position, and returns to step S2 to start the next wiper operation. Continue control.

On the other hand, when the control unit 70 determines that the vector length error output from the vector length error calculation unit 75 is not within the first threshold value (outside the range of the first threshold value) (step S3, NO), there is a disturbance. Then, the process proceeds to step S7 in order to perform the processing of the disturbance magnetic flux application time mode. Then, in step S7, the control unit 70 performs control to reverse the wiper or the like at a correction position on the front side (inner side) of the normal position (in this example, the reverse position changing unit 76 is reversed to the driving signal generation unit 77). A position change signal is output, and the drive signal described above is output from the drive signal generator 77 to the inverter 500). After that, the control unit 70 returns to step S5 in the disturbance magnetic flux application time mode, and continues controlling the operation of the next wiper or the like.

An example of the correction position on the front side (inner side) of the normal position is a position about 5° to 10° inward of the normal reversal position. As a more specific example, as shown in FIG. 10, a position (corrected lower reversal position) forming 5° with respect to the reference position (0°) in the case of downward reversal, and If the normal reversal position (normal upper reversal position) is 135°, the position (corrected upper reversal position) forming 125° with respect to the above 0°, which is 10° inside, can be used.

In step S5 of the disturbance magnetic flux application time mode, the control section 70 determines whether or not the calculation result of the rotation angle calculation section 71, that is, the rotation angle of the wiper or the like has reached a predetermined angle. Here, if the controller 70 determines NO, ie, that the predetermined angle is not reached, it repeats the determination of step S5. On the other hand, when determining that the predetermined angle has been reached (step S5, YES), the control unit 70 proceeds to step S6.

Here, the "predetermined angle" is the same angle as the predetermined angle in the normal mode described above. That is, in step S5, the control unit 70 determines whether the wiper or the like is rotating in the forward direction and at the first angle, or rotating in the reverse direction and at the second angle. If the determination result is YES, the process proceeds to step S6. do.

In step S6, the controller 70 determines whether the vector length error output from the vector length error calculator 75 is within the second threshold.

The second threshold is a value corresponding to the vector length reference value margin R described above, and is a narrower (stricter) value than the vector length reference value margin Q in the normal mode, that is, the relationship Q>R. have. In other words, by making the criteria for transition from the disturbance magnetic flux applied mode to the normal mode stricter (making it difficult to return to the normal mode), the operation of the wipers and the like is likely to be continued.

If the control unit 70 determines that the vector length error output from the vector length error calculation unit 75 is within the second threshold value (step S6, YES), the control unit 70 determines that there is no disturbance, and performs normal mode processing. , through the processing of step S4 described above (reversal processing at the normal position), and then returns to the processing of step S2 described above.

On the other hand, if the control unit 70 determines that the vector length error output from the vector length error calculation unit 75 is not within the second threshold value (outside the range of the second threshold value) (step S6, NO), there is a disturbance. Then, the process proceeds to step S7 in order to continue the process of the disturbance magnetic flux applied mode.

As described above, in step S7, the control unit 70 performs control to reverse the wiper or the like at a correction position closer to the front side (inner side) than the normal position (in this example, the reverse position changing unit 76 to the drive signal generating unit 77, and outputs the above-described drive signal from the drive signal generator 77 to the inverter 500). After that, the control unit 70 returns to step S5 in the disturbance magnetic flux application time mode, and continues controlling the operation of the next wiper or the like.

According to the configuration of the present embodiment that performs control as described above, the error in the upper or lower reversal position, which may interfere with the body or pillar of the vehicle 10, is reduced by a predetermined angle (90° in this example). It is possible to predict and deal with the angle in advance. In other words, according to the configuration of the present embodiment, angle abnormality determination (abnormality prediction) due to disturbance magnetic flux is performed before the interference of the wiper member 15 occurs, and the motor 20 and the wiper member are adjusted in consideration of the error due to the disturbance magnetic flux. By performing the operation of 15, control that does not interfere with the body or pillars of the vehicle 10 becomes possible.

<Alternative example of angle prediction points for wipers, etc.>
Regarding the setting of the angle prediction point of the wiper, etc., in the above example, one prediction point is set for each operation of the wiper, etc., but various other methods are conceivable. For example, a method of calculating the vector length for each "fixed angle" per operation of the wiper, etc., comparing the calculated value with a reference value, and predicting the angle of the vertical reversal position from the change in the vector length error for the angle. is. According to this method, the smaller the value of the "constant angle" for calculating the vector length is set, the larger the vector length error value obtained in one operation of the wiper or the like. can be expected to improve.

In the above example, when it is determined that a disturbance magnetic flux has been applied, the upside-down position of the wiper or the like is switched to the disturbance magnetic flux applied mode. Various control methods are conceivable.

(1) Acquire the above-mentioned X and Y values for each "constant angle", calculate the amount of change from the vector length reference value, specify the direction of the disturbance magnetic flux, and calculate from arctan (X / Y) The angle may be corrected. According to this method, similarly, the smaller the value of the "fixed angle" is set, the larger the value of the amount of change from the vector length reference value in one wiper operation, etc. can be obtained, so the direction of the disturbance magnetic flux can be specified. It can be expected that the accuracy of the correction of the reverse position will be improved.

(2) The error in the vertical inversion position may be predicted from the error from the vector length reference value calculated at the vertical inversion position wiper angle prediction point, and the inversion angle may be determined. This method can be expected to correct the reversal position to a more appropriate position by executing this method at a stage where the reversal position has been changed before the normal position, for example, in the disturbance magnetic flux application time mode described above.

(3) MR sensors (the three rotary shaft sensors 65a, 65b, and 65c described above with reference to FIG. 2) provided to detect the rotation angle of the rotor 33 instead of detecting the rotation angle of the output shaft 52b of the motor 20; You may make it switch to control which counts the numerical value of .

(4) The above-described X and Y values are obtained for each "constant angle", and the maximum amount of error from the vector length reference value is recognized as the reference angle that does not change when the disturbance magnetic flux is applied (deemed ), the numerical value of the MR sensor provided for detecting the rotor rotation angle of the brushless motor may be counted, and the upside down position may be calculated from the reference angle.

As described in detail above, the motor assembly (motor of the present disclosure) according to the present embodiment has a rotating shaft (output shaft 52b or rotating shaft 33b, hereinafter the same) that rotates forward and backward between two reverse positions. , a rotary shaft sensor 65 that outputs an analog signal according to the rotation angle of the rotary shaft, a rotation angle calculator 71 that calculates the rotation angle of the rotary shaft from the analog signal, and the rotation of the rotary shaft from the analog signal. A rotation direction calculation unit 72 that calculates the direction, a vector length calculation unit 73 that calculates the vector length of the analog signal, the actual rotation angle of the rotation shaft measured by an external device, and the vector length in the state without disturbance. and the vector length, which is the error between the vector length and the ideal vector length when the rotation angle of the rotating shaft is the angle corresponding to the specified position before the reversal position. A vector length error calculator 75 for calculating an error and an inversion position changer 76 for changing the inversion position when the vector length error is outside the range of the threshold are provided.

According to the motor assembly having the above configuration, when a disturbance magnetic flux is applied, the motor rotation angle can be changed to a narrow angle, that is, to be shifted before the normal reversal position, so that the rotor 33 and the output shaft The problem of excessive rotation of 52b and wiper member 15 can be prevented.

In addition, the reversing position changing unit 76 shifts the reversing position to the front of the normal position. It is determined whether or not it is outside the range, and if it is determined that it is outside the range of the second threshold, the control of shifting the reverse position to the front of the normal position is continued, and it is determined that it is not outside the range of the second threshold. If so, control is performed to return the reverse position to the normal position.

By performing the above control, it is possible to prevent the reversal position from being changed frequently, and stabilize the behavior of the rotor 33, the output shaft 52b, and the wiper member 15. FIG.

Further, by applying the above configuration to the wiper motor for driving the wiper member 15, excessive rotation of the rotor 33 is suppressed, and the wiping range of the wiper device is changed (corrected) to a position that does not interfere with the vehicle or the like. can do. Furthermore, by returning to normal operation when the vector length error is within the range of the second threshold after the wiping position is changed (corrected), the wiping range can be expanded, for example, to the vicinity of the pillar.

In addition, according to the motor and the motor control method according to the above-described embodiments, the variation in the accuracy of the wiper reversing position is eliminated between products, and the occurrence of defective products at the time of manufacturing can be suppressed. can be suppressed. Therefore, the Sustainable Development Goals (SDGs) led by the United Nations include in particular Goal 7 (Ensure access to affordable, reliable, sustainable and modern energy) and Goal 13 (Combat climate change and its impacts). Therefore, it will be possible to contribute to the implementation of emergency measures.

It should be noted that the above-described embodiments and modifications are only part of specific examples to which the present invention is applied, and can be implemented in various other forms.

10: vehicle, 11: windshield, 12: wiper device, 15: wiper member, 20, 20A: motor, 33: rotor, 33b: rotating shaft, 52b: output shaft (rotating shaft), 65: rotating shaft sensor, 70 : control unit 71: rotation angle calculation unit 72: rotation direction calculation unit 73: vector length calculation unit 74: storage unit 75: vector length error calculation unit 76: reversal position change unit 77: drive signal generation Part, 500: Inverter, AE: Angle error, BE: Vector length error, EM: Disturbance magnetic flux

Claims (6)

a rotating shaft that rotates forward and backward between two reversing positions;
a rotating shaft sensor that outputs an analog signal according to the rotation angle of the rotating shaft;
a rotation angle calculation unit that calculates the rotation angle of the rotation shaft from the analog signal;
a rotation direction calculation unit that calculates the rotation direction of the rotation shaft from the analog signal;
a vector length calculator that calculates the vector length of the analog signal;
a storage unit that stores in advance the actual rotation angle of the rotation shaft measured by an external device and the ideal vector length that is the vector length in a state without disturbance;
a vector length error calculation unit for calculating a vector length error, which is an error between the vector length and the ideal vector length, when the rotation angle of the rotating shaft is an angle corresponding to a specified position before the reversal position;
a reversal position changing unit that changes the reversal position when the vector length error is outside the threshold range;
motor unit. When the vector length error is out of the threshold range, the reversal position change unit changes the reversal position so as to shift it before the normal position.
The motor unit according to claim 1. The prescribed position is a position 90° before the reversal position,
The vector length error calculator determines a position where the rotation angle of the rotary shaft is 90 degrees before the reverse position based on the calculation results of the rotation angle calculator, the rotation direction calculator, and the vector length calculator. calculating the vector length error when
The motor unit according to claim 1 or 2. After changing the reversing position so as to shift the reversing position to the front of the normal position,
determining whether the vector length error calculated by the vector length error calculating unit is outside the range of a second threshold smaller than the threshold;
If it is determined to be out of the range of the second threshold, continuing the control of shifting the reverse position to the front of the normal position,
If it is determined that it is not out of the range of the second threshold, perform control to return the reverse position to the normal position;
The motor unit according to claim 2. wherein the motor unit comprises a wiper motor for driving the wiper member;
The motor unit according to any one of claims 1 to 4. A method for controlling the operation of a motor having a rotating shaft that reciprocally rotates between two reversal positions, comprising:
outputting an analog signal according to the rotation angle of the rotating shaft;
calculating the rotation angle of the rotating shaft from the analog signal;
calculating the direction of rotation of the rotating shaft from the analog signal;
calculating the vector length of the analog signal;
storing in advance the actual rotation angle of the rotation shaft measured by an external device and the ideal vector length, which is the vector length in a state without disturbance;
calculating a vector length error, which is an error between the vector length and the ideal vector length when the rotation angle of the rotating shaft is an angle corresponding to a specified position before the reversal position;
changing the reversal position if the vector length error is outside a threshold;
motor control method.

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