Motor control device, motor control method, and motor unit

Abstract

A motor control device, a motor control method, and a motor unit control a brushless motor including a rotor and three-phase armature coils, the motor control device including: a position detection section that detects a rotational position of the rotor; a control section (54) that outputs first or second drive signals to an inverter (52) in a first or second control mode with a current application timing corresponding to the rotational position of the rotor; and the inverter (52) that outputs first or second current application signals to the three-phase armature coils when the first or second drive signals are input, in the second control mode, a value of a duty cycle at which a voltage is applied simultaneously to any two phases of the three phases is greater than in the first control mode.

Description

Technical Field

[0001] This invention relates to a motor control device, a motor control method, and a motor unit. Background Technology

[0002] Traditionally, windshield wiper devices used in vehicles have employed wiper motors (brushless motors) as the drive source for the oscillation of the wiper arm. By driving the wiper motor, the wiper device causes the wiper arm to oscillate within a specified range on the front glass, thereby wiping away dust or raindrops adhering to the windshield.

[0003] Generally, windshield wiper devices include: a low-speed (Lo) operating mode in which the wiper blade operates at a low speed by driving the wiper motor at a low speed, and a high-speed (Hi) operating mode in which the wiper blade operates at a high speed by driving the wiper motor at a high speed (for example, see Patent Document 1 and Patent Document 2).

[0004] In the wiper device described in Patent Document 1, the drive control for energizing the brushless motor is set to rectangular wave drive in low-speed operating mode and advance angle / wide angle energizing drive in high-speed operating mode.

[0005] In addition, advance angle / wide angle power-on drive refers to a drive that powers the brushless motor with an angle greater than that of a rectangular wave drive in low-speed operating mode, in order to advance the timing of power-on.

[0006] Furthermore, in the wiper device described in Patent Document 2, the drive control for energizing the brushless motor is set to sinusoidal wave drive control in low-speed operating mode and to advance angle / wide angle energizing drive in high-speed operating mode.

[0007] Therefore, in the control of the wiper device described in Patent Document 2, compared with the control of the wiper device described in Patent Document 1, the operating noise of the brushless motor in the low-speed operating mode can be reduced (silentened) (see paragraphs

[0037] ,

[0048] and

[0056] of Patent Document 2).

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2014-195389

[0011] Patent Document 2: International Publication No. 2017 / 159214 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] However, in vehicle electrical devices such as windshield wipers, it is ideal to flexibly control the motor, taking into account factors such as reducing current consumption or increasing motor output.

[0014] This invention was made in consideration of the aforementioned circumstances, enabling flexible motor control while taking into account at least one of reducing current consumption and increasing motor output. The main objective is to provide a motor control device, a motor control method, and a motor unit.

[0015] Technical means to solve the problem

[0016] To address the aforementioned problem, one aspect of the present invention provides a motor control device for controlling a brushless motor comprising a rotor and three-phase armature coils (U-phase, V-phase, and W-phase). The motor control device includes: a position detection unit for detecting the rotational position of the rotor; a control unit capable of selecting a first control mode and a second control mode, wherein in the first control mode, a first drive signal is output to an inverter with a energizing sequence corresponding to the rotational position of the rotor, and in the second control mode, a second drive signal is output to the inverter with a energizing sequence corresponding to the rotational position of the rotor; and the inverter, in the first control mode, outputs a first energizing signal as an applied voltage to the three-phase armature coils, and in the second control mode, outputs a second energizing signal as an applied voltage to the three-phase armature coils, wherein, with respect to any two of the three phases, in the second control mode, the duty cycle value of the applied voltage is greater than that in the first control mode.

[0017] The effects of the invention

[0018] According to the present invention, flexible motor control can be performed while taking into account at least one of reducing current consumption and increasing motor output.

[0019] In addition, according to another embodiment of the present invention, in the high-speed operating mode (second control mode), the brushless motor is driven by a sine wave by inputting a second energizing signal, thereby suppressing the operating noise of the brushless motor in the high-speed operating mode. Attached Figure Description

[0020] Figure 1 This is a diagram showing an example of the schematic structure of the windshield 11 of a vehicle 10, which is equipped with a wiper device 12 including the motor control device of this embodiment.

[0021] Figure 2 This is a diagram showing an example of the appearance of the motor unit 19 in this embodiment.

[0022] Figure 3 This is a bottom view of the motor unit 19 of this embodiment with the under cover removed.

[0023] Figure 4 This is a diagram illustrating an example of the schematic structure of the control system of the wiper device 12 in this embodiment.

[0024] Figure 5 This is a diagram showing an example of the schematic structure of the control unit 54 in this embodiment.

[0025] Figure 6 This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the first drive control unit 641 of this embodiment.

[0026] Figure 7A This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0027] Figure 7B This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0028] Figure 7C This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0029] Figure 7D This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0030] Figure 8A This diagram illustrates the principle of improving the output characteristics of a motor by setting overlapping energizing intervals in a second energizing signal.

[0031] Figure 8B This diagram illustrates the principle of improving the output characteristics of a motor by setting an overlapping energizing interval in a second energizing signal.

[0032] Figure 9 This is a diagram illustrating the motor characteristics of the brushless motor 30 in the third harmonic drive and wide-angle trapezoidal wave drive of this embodiment.

[0033] Figure 10 This is a diagram showing the characteristics of the operating sound of the brushless motor 30 in the drive control used in low output mode or high output mode.

[0034] Figure 11This is a diagram showing the characteristics of the operating sound of the brushless motor 30 in the drive control used in low output mode or high output mode.

[0035] Figure 12 This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0036] Figure 13 This is a timing diagram showing the changes in the software in this implementation.

[0037] Figure 14 This diagram illustrates the processing flow of the control unit 54 in this embodiment.

[0038] Figure 15 This diagram illustrates a variation of the processing flow of the control unit 54 in this embodiment.

[0039] Figure 16 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0040] Figure 17 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0041] Figure 18 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0042] Figure 19 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0043] Figure 20 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0044] Figure 21A This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0045] Figure 21B This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0046] Figure 21C This is a timing diagram showing the energizing sequence of each of the U, V, and W phases executed by the second drive control unit 642 of this embodiment.

[0047] Figure 22This is a graph showing the relationship between the current consumption and the electrical angle when the energizing angle is set to 110° in the second energizing signal.

[0048] Figure 23 This is a graph showing the relationship between the motor speed and the electrical angle when the energizing angle is set to 155° in the second energizing signal.

[0049] Explanation of symbols

[0050] 11: Windshield

[0051] 12: Wiper assembly

[0052] 19: Motor Unit

[0053] 21u, 21v, 21w: Three-phase armature coils

[0054] 22: Rotor

[0055] 52: Inverter

[0056] 54: Control Department

[0057] 61: Position Detection Department

[0058] 62: Load Determination Section

[0059] 63: Pattern Determination Department

[0060] 64: Drive Control Unit

[0061] 641: First Drive Control Unit

[0062] 642: Second Drive Control Unit Detailed Implementation

[0063] The present invention will now be described through embodiments thereof, but these embodiments do not limit the scope of the invention as claimed. Furthermore, not all combinations of features described in the embodiments are necessary for the solution of the invention. Additionally, in the accompanying drawings, the same or similar parts are sometimes labeled with the same symbols and repeated descriptions are omitted.

[0064] The motor control device of this embodiment controls a brushless motor that causes the wiper arm to swing. Furthermore, in a low-output mode (first control mode) where the brushless motor's output is low, the motor control device energizes the brushless motor using a sine wave (first energizing signal) that superimposes higher harmonics onto a sine wave. In a high-output mode (second control mode) where the output is higher than in the low-output mode, the motor energizes the brushless motor using a sine wave (second energizing signal) that makes the first energizing signal a wide-angle trapezoidal wave. The motor control device of this embodiment will be described below using figures.

[0065] Figure 1 This is a diagram showing an example of the schematic structure of the windshield 11 of a vehicle 10, which is equipped with a wiper device 12 including the motor control device of this embodiment.

[0066] like Figure 1 As shown, vehicle 10 includes a windshield 11 and a wiper device 12.

[0067] The wiper unit 12 wipes the windshield 11.

[0068] The wiper assembly 12 includes: wiper arms 14 and 16; wiper blades 17 and 18; motor unit 19; and power transmission mechanism 20.

[0069] Wiper arm 14 swings around pivot 13. Wiper arm 16 swings around pivot 15.

[0070] Wiper blade 17 is mounted on the free end of wiper arm 14. Wiper blade 18 is mounted on the free end of wiper arm 16.

[0071] Motor unit 19 drives wiper arms 14 and 16. In this embodiment, the power of motor unit 19 is transmitted to wiper arms 14 and 16 via power transmission mechanism 20, which includes levers, links, etc.

[0072] Figure 2 This is a diagram showing an example of the appearance of the motor unit 19 in this embodiment. Figure 3 yes Figure 2 The diagram shows the bottom view of the motor unit 19 with the lower cover 28 removed.

[0073] like Figure 2 As shown, the exterior of the motor unit 19 mainly includes a housing 23 and a frame 24.

[0074] The housing 23 has a bottomed cylindrical shape. The frame 24 has a hollow shape. The frame 24 is fixed to the housing 23 by fastening members not shown.

[0075] like Figure 3 As shown, the motor unit 19 includes a brushless motor 30, a rotor shaft 22a, an opening 24a, a worm wheel 25, an output shaft 26, a reduction mechanism 27, a lower cover 28, a control board 29, a sensor magnet 38, and a motor control device 33.

[0076] The brushless motor 30 causes the wiper arms 14 and 16 to swing based on the control instructions of the motor control device 33.

[0077] For example, brushless motor 30 is a three-phase four-pole brushless motor.

[0078] The brushless motor 30 includes a stator 21 and a rotor 22.

[0079] The stator 21 is fixed to the inner circumference of the housing 23. The stator 21 includes three-phase armature coils 21u, 21v, and 21w. The stator 21 is wound with the armature coils 21u, 21v, and 21w. For example, the three-phase armature coils 21u, 21v, and 21w are connected by a delta connection at one end of the neutral point. However, it is not limited to a delta connection and can also be a Y connection. In addition, the brushless motor 30 is a motor in which each armature coil 21u, 21v, and 21w functions as both positive and negative poles.

[0080] For example, the rotor 22 is disposed inside the stator 21. The rotor 22 includes a rotor shaft 22a and four permanent magnets 22b mounted on the rotor shaft 22a. Multiple bearings (not shown) are disposed within the housing 23, and the rotor shaft 22a is supported by the multiple bearings to enable rotation.

[0081] In addition, such as Figure 3 As shown, the rotor 22 is an inner rotor type structure disposed inside the stator 21, but it can also be an outer rotor type structure disposed outside the stator 21.

[0082] Approximately half of the rotor shaft 22a along its length is disposed inside the housing 23, and approximately the remaining half is disposed within the frame 24.

[0083] A reduction mechanism 27 is formed on the outer periphery of the portion of the rotor shaft 22a disposed within the frame 24. The reduction mechanism 27 includes a worm 22c and a gear 25a.

[0084] The worm 22c is disposed on the outer periphery of the rotor shaft 22a, which is located within the frame 24. The gear 25a is formed on the outer periphery of the worm wheel 25, which is located within the frame 24. The gear 25a meshes with the worm 22c.

[0085] The worm gear 25 is configured to rotate integrally with the output shaft 26. When the reduction mechanism 27 transmits power from the rotor 22 to the output shaft 26, it ensures that the rotational speed of the output shaft 26 (output speed) is lower than the rotational speed of the rotor 22 (input speed). Furthermore, in... Figure 2 In the frame 24, a shaft hole (not shown) is provided in the upper part. The end of the output shaft 26 opposite to the end where the worm gear 25 is fixed is exposed to the outside through the shaft hole of the frame 24. Figure 1 As shown, a power transmission mechanism 20 is connected to the portion of the output shaft 26 that protrudes to the outside of the frame 24.

[0086] An opening 24a is provided on the side of the frame 24 opposite to the shaft hole. The opening 24a is formed for mounting a worm gear 25 or the like inside the frame 24. A lower cover 28 is provided to block the opening 24a. The lower cover 28 has a tray shape.

[0087] The control board 29 is disposed in the space surrounded by the lower cover 28 and the frame 24. For example... Figure 2 As shown, for example, a control board 29 is mounted on the lower cover 28. A motor control device 33 for controlling the brushless motor 30 is provided on the control board 29.

[0088] The sensor magnet 38 is disposed within the frame 24 on the rotor shaft 22a. The sensor magnet 38 rotates integrally with the rotor shaft 22a. The sensor magnet 38 is magnetized such that the N pole and S pole are alternately arranged along the circumference of the rotor shaft 22a.

[0089] Hereinafter, the motor control device 33 of this embodiment will be described with reference to the accompanying drawings.

[0090] Figure 4 This is a diagram illustrating an example of the schematic structure of the control system of the wiper device 12 according to this embodiment. The wiper device 12 includes a wiper switch 37, a rotation angle detection unit 39, a vehicle speed sensor 40, and a motor control device 33.

[0091] The wiper switch 37 is located inside the vehicle 10.

[0092] The wiper switch 37 is a switch that causes the wiper arms 14 and 16 to swing.

[0093] The wiper switch 37 can be switched to various modes, including a low-speed operating mode that causes the wiper arms 14 and 16 to operate at a low speed (e.g., a preset speed), a high-speed operating mode that causes the wiper arms 14 and 16 to operate at a higher speed than the low-speed operating mode, and a stop mode that stops the oscillating motion of the wiper arms 14 and 16.

[0094] The wiper switch 37 outputs an operation signal indicating the operation to the motor control device 33 upon driver operation. For example, the driver can switch the wiping speed of the wiper arms 14 and 16 by operating the wiper switch 37 based on conditions such as rainfall or snowfall. When rainfall or snowfall is low, the driver can select a low-speed operating mode by operating the wiper switch 37, which causes the wiper arms 14 and 16 to operate at a predetermined low speed. In this case, the wiper switch 37 outputs a low-speed operating mode signal indicating the low-speed operating mode as an operation signal to the motor control device 33 based on the driver's selection of the low-speed operating mode.

[0095] On the other hand, when there is heavy rainfall or snowfall, the driver can operate the wiper switch 37 to select a high-speed operating mode that causes the wiper arms 14 and 16 to operate at a higher speed than the aforementioned low speed. In this case, based on the driver's operation to select the high-speed operating mode, the wiper switch 37 outputs a high-speed operating mode signal as an operation signal to the motor control device 33.

[0096] In addition, when the driver stops the oscillating motion of the wiper arms 14 and 16 by operating the wiper switch 37, the wiper switch 37 outputs a stop mode signal indicating the stop mode to the motor control device 33 as an operation signal.

[0097] Vehicle speed sensor 40 is installed on vehicle 10. Vehicle speed sensor 40 measures the driving speed (hereinafter referred to as "vehicle speed") V of vehicle 10. Vehicle speed sensor 40 outputs the measured vehicle speed V of vehicle 10 to motor control device 33.

[0098] The rotation angle detection unit 39 detects a signal corresponding to the rotation of the rotor 22. For example, the rotation angle detection unit 39 includes three Hall integrated circuits (ICs) positioned at 120-degree angles to each other in magnetic direction, centered on the rotor shaft 22a. As the rotor 22 rotates, these three Hall ICs output pulse signals with phases staggered by 120 degrees to the motor control device 33. That is, as the rotor 22 rotates, the rotation angle detection unit 39 generates pulse signals based on the change in the magnetic poles of the sensor magnet 38 and outputs them to the motor control device 33.

[0099] The motor control device 33 includes an inverter 52 and a control unit 54.

[0100] The inverter 52 includes six three-phase bridge-connected switching elements 52a-52f and diodes 53a-53f connected in reverse parallel between the collector and emitter of each switching element 52a-52f. Each switching element 52a-52f is, for example, a field-effect transistor (FET) or an insulated-gate bipolar transistor (IGBT). The gate of each of the six bridge-connected switching elements 52a-52f is connected to a control unit 54.

[0101] The drain or source (collector or emitter) of switching elements 52a to 52f is connected to the armature coils 21u, 21v, and 21w connected in a delta configuration.

[0102] More specifically, the neutral point 55a, which serves as the connection point between the source of switching element 52a and the drain of switching element 52d, is connected to the connection point 21a between armature coil 21w and armature coil 21u. The neutral point 55b, which serves as the connection point between the source of switching element 52b and the drain of switching element 52e, is connected to the connection point 21b between armature coil 21w and armature coil 21v. The neutral point 55c, which serves as the connection point between the source of switching element 52c and the drain of switching element 52f, is connected to the connection point 21c between armature coil 21v and armature coil 21u.

[0103] Therefore, the six switching elements 52a to 52f perform switching operations based on the drive signal (gate signal) output from the control unit 54, and supply the power supply voltage of the DC power supply 51 applied to the inverter 52 as a three-phase (U phase, V phase, W phase) AC voltage as an energizing signal to the armature coils 21u, 21v, and 21w.

[0104] The control unit 54 determines the rotational position of the rotor 22 based on the pulse signal supplied from the rotation angle detection unit 39. Additionally, the control unit 54 detects the rotational speed of the rotor 22 based on the pulse signal. Then, the control unit 54 drives the brushless motor 30 in a low-output mode where the output of the brushless motor 30 is low, using a sine wave.

[0105] That is, the control unit 54 outputs a first drive signal to the inverter 52, thereby energizing the armature coils 21u, 21v, and 21w using a sine wave superimposed with higher harmonics (first energizing signal), and driving the rotor 22 to rotate. Here, in this embodiment, the first drive signal corresponds to a first communication signal. That is, the control unit 54 outputs the first drive signal as an indication signal to control the inverter 52. Then, based on the indication signal, the inverter 52 uses the first energizing signal to drive each of the three phases with a sine wave (for details, we will use...). Figure 6 (To be continued).

[0106] On the other hand, in a high-output mode where the output is higher than in the low-output mode, the control unit 54 outputs a second drive signal to the inverter 52. This energizes the armature coils 21u, 21v, and 21w using a sine wave (the second energizing signal) formed from the first energizing signal into a wide-angle trapezoidal wave, thereby driving the rotor 22 to rotate. Here, in this embodiment, the second drive signal corresponds to the second energizing signal. That is, the control unit 54 outputs the second drive signal as an indication signal to control the inverter 52. Then, based on the indication signal, the inverter 52 uses the second energizing signal to drive each of the three phases with a sine wave (for details, we will use...). Figures 7A to 7D (To be continued).

[0107] The following uses Figure 5 The control unit 54 of this embodiment will be described.

[0108] Figure 5 This is a diagram showing an example of the schematic structure of the control unit 54 in this embodiment.

[0109] The control unit 54 includes a position detection unit 61, a load determination unit 62, a mode determination unit 63, and a drive control unit 64.

[0110] The position detection unit 61 detects the rotational position of the rotor 22 based on the pulse signal supplied from the rotation angle detection unit 39. The position detection unit 61 outputs the detected rotational position of the rotor 22 to the drive control unit 64.

[0111] The load determination unit 62 determines whether the vehicle speed V measured by the vehicle speed sensor 40 exceeds a preset value Vth. If the vehicle speed V measured by the vehicle speed sensor 40 exceeds the preset value Vth, the load determination unit 62 determines that the load on the brushless motor 30 is high. If the load determination unit 62 determines that the load on the brushless motor 30 is high, it outputs a high load signal indicating its determination result to the mode determination unit 63. The reason for this is that when the vehicle speed V of the vehicle 10 increases, the airflow to the windshield 11 of the vehicle 10 increases, thereby hindering the movement of the wiper blades 17 and 18 that wipe the windshield 11. In this case, the brushless motor 30 needs to output high power to make the wiper arms 14 and 16 swing. Therefore, when the vehicle speed V exceeds the specified value Vth, the control unit 54 switches from the low output mode to the high output mode, thereby causing the brushless motor 30 to generate a large torque. Furthermore, by using the rotational position of the rotor 22 detected by the position detection unit 61 as a reference, the advance angle is controlled by a specified electrical angle, thereby increasing the speed of the brushless motor 30.

[0112] Furthermore, the load determination unit 62 determines whether the predetermined value of the rotor 22 speed or the brushless motor 30 current value detected based on the pulse signal supplied from the rotation angle detection unit 39, or a predetermined value calculated based on both, exceeds a preset predetermined value. If the predetermined value of the rotor 22 speed or the brushless motor 30 current value detected based on the pulse signal supplied from the rotation angle detection unit 39, or a predetermined value calculated based on both, exceeds a preset predetermined value, the load determination unit 62 determines that the brushless motor 30 is under high load. In the case of determining that the brushless motor 30 is under high load, the load determination unit 62 outputs a high load signal indicating its determination result to the mode determination unit 63. This is because changes in conditions such as rainfall increase the resistance to the movement of the wiper blades 17 and 18 on the windshield 11 (wiping surface) of the vehicle 10, thereby hindering the movement of the wiper blades 17 and 18. In this situation, the brushless motor 30 needs to operate at high output to make the wiper arms 14 and 16 swing. Therefore, when the rotational speed of the rotor 22 or the current value of the brushless motor 30, or the predetermined value calculated based on both, exceeds a preset predetermined value, the control unit 54 switches from a low output mode to a high output mode, thereby causing the brushless motor 30 to generate a large torque. Furthermore, by using the rotational position of the rotor 22 detected by the position detection unit 61 as a reference, the control unit performs advance angle control with a predetermined electrical angle, thereby increasing the rotational speed of the brushless motor 30.

[0113] The mode determination unit 63 determines whether the brushless motor 30 is driven in a low output mode, a high output mode, or a stopped mode.

[0114] When the low-speed operating mode signal is received from the wiper switch 37, the mode determination unit 63 determines that the brushless motor 30 is driven in low output mode, and outputs the low output mode signal indicating the low output mode to the drive control unit 64.

[0115] When a high-speed operating mode signal is received from the wiper switch 37, the mode determination unit 63 determines that the brushless motor 30 is driven in high output mode and outputs a high output mode signal indicating high output mode to the drive control unit 64. Similarly, when a high load signal is received from the load determination unit 62, the mode determination unit 63 determines that the brushless motor 30 is driven in high output mode and outputs a high output mode signal indicating high output mode to the drive control unit 64.

[0116] When a stop mode signal is received from the wiper switch 37, the mode determination unit 63 determines to stop the drive of the brushless motor 30 and outputs a stop signal indicating that the drive of the brushless motor 30 has stopped to the drive control unit 64.

[0117] The drive control unit 64 includes a first drive control unit 641 and a second drive control unit 642.

[0118] When the drive control unit 64 obtains a low output mode signal from the mode determination unit 63, the first drive control unit 641 executes the third harmonic power-on drive of the brushless motor 30.

[0119] Figure 6 This is a timing diagram showing the energizing sequence of each of the U, V, and W phases by the first drive control unit 641 in this embodiment.

[0120] Figure 6 The horizontal axis, representing the angle from 0° to 360°, indicates the electrical angle during one cycle of the first energized signal. Additionally, the vertical axis, FET_Duty[%], represents the duty cycle of the applied voltage to each phase.

[0121] Here, as Figure 6 As shown, the first energizing signal represents the applied voltage of each phase of the three-phase system, which is a sine wave superimposed with the third harmonic.

[0122] That is, in the first control mode, the inverter 52 outputs a first energizing signal representing the energizing timing of each phase of the three-phase motor with the energizing timing corresponding to the rotational position of the rotor, thereby driving each phase of the three-phase motor with a sine wave.

[0123] In the following description, the drive control that powers the brushless motor 30 via the first power signal is sometimes referred to as third harmonic power drive.

[0124] In this way, the first drive control unit 641 outputs a first drive signal to the inverter 52 with a energizing timing corresponding to the rotational position of the rotor 22 detected by the position detection unit 61, thereby causing the inverter 52 to generate a first energizing signal for third harmonic energizing drive of the brushless motor 30.

[0125] like Figure 6As shown, the first energizing signal has a waveform with a third harmonic superimposed on a sine wave (hereinafter referred to as the third harmonic superimposed wave). The peak voltage of the third harmonic superimposed wave has a duty cycle (peak voltage) of approximately 100% (97%–99%) within a certain range, and the trough voltage has a duty cycle of approximately 0% (1%–3%) within a certain range. Furthermore, in the first energizing signal, in the interval between the normal energizing interval where the duty cycle of the applied voltage of only the W phase is approximately 100% (97%–99%) and the normal energizing interval where the duty cycle of the applied voltage of only the U phase is approximately 100%, the applied voltages of the U phase, V phase, and W phase are less than the peak voltage (97%–99%). Additionally, although the illustration is omitted, during the energizing period of one cycle of the first energizing signal, there also exists a normal energizing interval where the duty cycle of the applied voltage of only the V phase is approximately 100% (97%–99%).

[0126] On the other hand, when the drive control unit 64 obtains a high output mode signal from the mode determination unit 63, the second drive control unit 642 executes the wide-angle trapezoidal wave energization drive of the brushless motor 30.

[0127] Figures 7A to 7D This is a timing diagram showing the energizing sequence of each of the U, V, and W phases by the second drive control unit 642 in this embodiment.

[0128] Figures 7A to 7D The horizontal axis, representing the angle from 0° to 360°, indicates the electrical angle during one cycle of the second energizing signal. Additionally, the vertical axis, FET_Duty[%], represents the duty cycle of the applied voltage to each phase.

[0129] Here, as Figures 7A to 7D As shown, the second energizing signal is an energizing sequence corresponding to the rotational position of the rotor 22, a signal within an overlapping energizing interval between the normal energizing interval where only the applied voltage of the first phase is 100% and the normal energizing interval where only the applied voltage of the second phase is 100%, including the overlapping energizing interval where the applied voltages of both the first and second phases are 100% (using...). Figures 7A to 7D (To be discussed later).

[0130] For example, in Figure 6 In the first energizing signal shown, the normal energizing interval during which the applied voltage of phase W has a duty cycle of approximately 100% is different from the normal energizing interval. Figure 6 The applied voltage of phase U shown is approximately 100% within the normal energizing range. Figure 6 In the first phase, the applied voltage of any one of the three phases is less than approximately 100%. In the second energizing signal, the interval is set as an overlapping energizing interval (voltage value repetition interval) where the applied voltage of both phases W and U is 100% duty cycle. Additionally, as... Figures 7A to 7DAs shown, other phases (between U phase and V phase, and between V phase and W phase) are also set as overlapping energization intervals. Therefore, a second energizing signal can be generated from the first energizing signal. Furthermore, a second driving signal corresponding to the second energizing signal can be generated from the first driving signal corresponding to the first energizing signal.

[0131] Here, refer to Figures 7A to 7D The second energizing signal will be explained. Regarding the aforementioned... Figures 7A to 7D , which represents the waveform of interest in a certain interval within the continuous waveform of the second energized signal's time series.

[0132] like Figure 7A As shown, the second energizing signal has an energizing interval (normal energizing interval 711) in which only the applied voltage of phase U is 100% and an energizing interval (normal energizing interval 712) in which only the applied voltage of phase V is 100% and an overlapping energizing interval (overlapping energizing interval 713) in which the applied voltage of both phase U and phase V is 100% occupied.

[0133] In addition, such as Figure 7B As shown, the second energizing signal has an energizing interval where only the applied voltage of phase V is 100% (normal energizing interval 731) and an energizing interval where only the applied voltage of phase W is 100% (normal energizing interval 732), and an energizing interval where the applied voltage of both phase V and phase W is 100% (overlapping energizing interval 733).

[0134] In addition, such as Figure 7C As shown, the second energizing signal has an energizing interval where the duty cycle of the applied voltage of only phase W is 100% (normal energizing interval 751) and an energizing interval where the duty cycle of the applied voltage of only phase U is 100% (normal energizing interval 752), and an energizing interval where the duty cycle of the applied voltage of both phase W and phase U is 100% (overlapping energizing interval 753).

[0135] exist Figures 7A to 7C The text describes the second energizing signal as a signal within an overlapping energizing interval between a normal energizing interval where only the applied voltage of the first phase is 100% and a normal energizing interval where only the applied voltage of the second phase is 100%, including an overlapping energizing interval where the applied voltages of both the first and second phases are 100%. In other words, the second energizing signal can also be described as a signal within an overlapping energizing interval between a normal energizing interval where only the applied voltage of the first phase is 0% and a normal energizing interval where only the applied voltage of the second phase is 0%, including an overlapping energizing interval where the applied voltages of both the first and second phases are 0%.

[0136] Specifically, such as Figure 7D As shown, between the three-phase energizing interval where only the applied voltage of phase U is 0% (normal energizing interval 701) and the three-phase energizing interval where only the applied voltage of phase V is 0% (normal energizing interval 702), there is an overlapping energizing interval where the applied voltages of both phase U and phase V are 0% (overlapping energizing interval 703). Although the diagram is omitted, between the three-phase energizing interval where only the applied voltage of phase V is 0% (normal energizing interval) and the three-phase energizing interval where only the applied voltage of phase W is 0% (normal energizing interval), there is an overlapping energizing interval where the applied voltages of both phase V and phase W are 0% (overlapping energizing interval). In addition, between the second energizing signal and the energizing interval where only the applied voltage of phase W is 0% (normal energizing interval) and the energizing interval where only the applied voltage of phase U is 0% (normal energizing interval), there is an energizing interval where both the applied voltages of phase W and phase U are 0% (overlapping energizing interval).

[0137] In the following description, the drive control that powers the brushless motor 30 via a second power signal is sometimes referred to as wide-angle trapezoidal wave power drive.

[0138] In this way, the second drive control unit 642 outputs a second drive signal to the inverter 52 with a energizing timing corresponding to the rotational position of the rotor 22 detected by the position detection unit 61, thereby causing the inverter 52 to generate a second energizing signal for wide-angle trapezoidal wave energizing drive of the brushless motor 30.

[0139] Furthermore, the wide-angle trapezoidal wave energizing drive of the brushless motor 30 in high output mode is intended to significantly improve the motor's output characteristics compared to the third harmonic energizing drive of the brushless motor 30 in low output mode (hereinafter referred to as Objective 1). Additionally, the wide-angle trapezoidal wave energizing drive of the brushless motor 30 in high output mode is intended to suppress operating noise compared to the rectangular wave drive (wide-angle energizing drive in Patent Documents 1 and 2) in high output mode (hereinafter referred to as Objective 2).

[0140] The following uses Figure 8A and Figure 8B The reasons for using a wide-angle trapezoidal wave to drive the brushless motor 30 in high output mode in order to achieve objectives 1 and 2 will be explained.

[0141] Figure 8A and Figure 8B This diagram illustrates the principle of improving the motor's output characteristics by setting overlapping energization intervals in the second energizing signal. Furthermore, Figure 8A and Figure 8BThe resistors RW, RU, and RV described herein represent the reference resistors in the circuit (called the resistor circuit) comprising the switching elements 52a to 52f of the inverter 52 and the three-phase armature coils 21u, 21v, and 21w. Additionally, Figure 8A and Figure 8B The size of the arrows described is proportional to the value of the current applied to each phase.

[0142] Figure 8A yes Figure 7D The electric angle is around 180° ( Figure 7D Circuit diagram under the energized state of symbol 800a). At an energizing angle of 180°, the duty-bound connection point 21a is energized with 100% of the W phase voltage, the duty-bound connection point 21b is energized with 0% of the V phase voltage, and the duty-bound connection point 21c is energized with 50% of the U phase voltage.

[0143] like Figure 8A As shown, when driving in the normal power-on range (three-phase power-on) of high output mode, all three phases are powered on. Therefore, the inter-terminal resistance Ra in the resistor circuit becomes a structure in which the series resistance RW (resistance value R), the series resistance of the resistor RU and the series resistance of the resistor RV (resistance value 2R) are connected in parallel. Therefore, according to the following formula, Ra = 2R / 3.

[0144] Ra=R×2R / (R+2R)=(2 / 3)R

[0145] In addition, the inter-terminal resistance Ra in a resistive circuit refers to... Figure 4 The resistance value between the positive and negative terminals of the DC power supply 51 shown.

[0146] Here, if we compare the current flowing through resistor RW and the current flowing through the series resistance of resistors RU and RV, the current flowing through resistor RW is greater than the current flowing through the series resistance of resistors RU and RV.

[0147] Figure 8B yes Figure 7A The electric angle is around 210° ( Figure 7A Circuit diagram of symbol 800b) under energized conditions.

[0148] On the other hand, such as Figure 8B As shown, when driving in the overlapping energized interval (two-phase energized) in high output mode, energize both phases. Therefore, the inter-terminal resistor Rb in the resistor circuit becomes a structure in which resistor RW (resistance value R) and resistor RU (resistance value R) are connected in parallel. Therefore, according to the following formula, Rb = R / 2.

[0149] Rb=R×R / (R+R)=(1 / 2)R

[0150] In addition, the inter-terminal resistance Rb in a resistive circuit refers to Figure 4 The resistance value between the positive and negative terminals of the DC power supply 51 shown.

[0151] Here, current flows through resistors RW and RV, but almost no current flows through resistor RU. In other words, a 100% duty cycle voltage is applied to connection points 21a and 21c, and a 0% duty cycle voltage is applied to connection point 21b. Therefore, connection points 21a and 21c are at the same potential, and no current flows between them. Furthermore, the potential difference between connection points 21a and 21b is equal to the potential difference between connection points 21c and 21b, and the current flowing between connection points 21a and 21b is equal to the current flowing between connection points 21c and 21b. As a result, although the magnitude of the current flowing through resistor RW is approximately the same as the magnitude of the current flowing through resistor RV, almost no current flows through resistor RU, and the brushless motor 30 is unaffected by the resistance value of resistor RU.

[0152] In this way, by switching to the overlapping energized interval, the energized circuit changes from three-phase to two-phase, and the resistance calculation result changes from 2R / 3 to R / 2. This can reduce the internal resistance of the motor by (2R / 3-R / 2) / (2R / 3)=1 / 4=25%.

[0153] That is, the internal resistance of the motor is reduced, thereby improving the output characteristics of the motor through the effect of reduced copper loss.

[0154] Figure 9 This is a diagram illustrating the motor characteristics of the brushless motor 30 in the third harmonic drive and wide-angle trapezoidal wave drive of this embodiment.

[0155] exist Figure 9 In the diagram, L1 represents the motor characteristics driven by the third harmonic. H1 represents the motor characteristics driven by the wide-angle trapezoidal wave. H1S represents the motor characteristics driven by the wide-angle trapezoidal wave plus "advance angle > 0°". Here, the wide-angle trapezoidal wave plus "advance angle > 0°" drive refers to a wide-angle trapezoidal wave drive that outputs a second energizing signal with a predetermined electrical angle advanced based on the rotational position of rotor 22, thereby sinusoidally driving each phase of the three phases of the brushless motor.

[0156] Furthermore, the region represented by the output characteristic L indicates the motor characteristics required for one wiping cycle in the low-speed operating mode at low vehicle speeds. Conversely, the region represented by the output characteristic H indicates the motor characteristics required for one wiping cycle in the high-speed operating mode at high speeds.

[0157] like Figure 9As shown, the drive control unit 64 can meet the motor characteristics required for one wiping cycle in the low-speed operating mode by driving the motor with third harmonic power-on in the low-output mode.

[0158] Furthermore, when switching from a low-output mode to a high-output mode, the drive control unit 64 performs a wide-angle trapezoidal wave energizing drive. That is, compared to the third harmonic energizing drive in the low-output mode, the drive control unit 64, through the wide-angle trapezoidal wave energizing drive and the wide-angle trapezoidal wave + "advance angle > 0°" energizing drive, can increase the speed of the brushless motor 30 and prevent the torque decrease caused by the increase in speed, thereby generating high torque. That is, it can be said that the aforementioned objective 1 is achieved. In addition, by performing the wide-angle trapezoidal wave energizing drive and / or the wide-angle trapezoidal wave + "advance angle > 0°" energizing drive, the drive control unit 64 can meet the motor characteristics required within one wiping cycle in the high-speed operating mode.

[0159] Figure 10 , Figure 11 This is a diagram showing the characteristics of the operating sound of the brushless motor 30 in the drive control used in low output mode or high output mode.

[0160] Figure 10 This represents the overall (OA) value obtained by performing a Fast Fourier Transform (FFT) on the operating tone corresponding to the rotation frequency of the rotor 22 within the frequency band (0–15 kHz) during the drive control of the brushless motor 30 using the six drive controls (first to sixth drive controls) in either the low (Lo) or high (Hi) output mode. Here, the OA value refers to the value used to evaluate whether the sound is noisy or quiet, without considering frequency characteristics.

[0161] in addition, Figure 11 This indicates that in low output mode or high output mode, the brushless motor 30 is driven by the following six drive controls (first to sixth drive controls), and the value is obtained by measuring the working tone, i.e. the magnetic tone, corresponding to the rotation frequency of the rotor 22 when the rotation frequency of the rotor 22 is 530Hz to 590Hz (Lo output mode) or 790Hz to 850Hz (Hi output mode).

[0162] (First drive control)

[0163] The first drive control is a drive control performed by rectangular wave drive in low output mode, corresponding to the rectangular wave drive in Patent Document 1.

[0164] (Second drive control)

[0165] The second drive control is a drive control performed in low output mode using third harmonic drive (sine wave drive), corresponding to the sine wave drive in Patent Document 2 and this embodiment.

[0166] (Third drive control)

[0167] The third drive control is a drive control performed by rectangular wave energizing (wide-angle energizing) in high output mode, corresponding to the rectangular wave drive in Patent Document 2.

[0168] (Fourth drive control)

[0169] The fourth drive control is a drive control performed in high output mode using a wide-angle trapezoidal wave energization drive (sine wave drive), which corresponds to the sine wave drive in this embodiment.

[0170] (Fifth Drive Control)

[0171] The fifth drive control is a drive control performed in high output mode using a wide-angle trapezoidal wave + "advance angle 10°" power-on drive (sine wave drive), which corresponds to the sine wave drive in this embodiment.

[0172] (Sixth Drive Control)

[0173] The sixth drive control is a drive control performed in high output mode using a wide-angle trapezoidal wave + "advance angle 30°" power-on drive (sine wave drive), which corresponds to the sine wave drive in this embodiment.

[0174] like Figure 10 , Figure 11 As shown, in low output mode, compared with the first drive control, the working sound, OA value, and magnetic sound are suppressed in the second drive control.

[0175] In addition, it can be seen that in high output mode, the operating noise is suppressed in the fourth to sixth drive controls compared with the third drive control.

[0176] That is, it solves the problem in Patent Document 2 where "the sound pressure difference between the brushless motor operating in low-speed mode and high-speed mode is large, and the sound pressure of the brushless motor in high-speed mode is extremely large compared to the sound pressure of the brushless motor in low-speed mode." Specifically, in this embodiment, in high-output mode, drive control is performed using a wide-angle trapezoidal wave energization. Therefore, in high-output mode, the operating noise can be suppressed for drive control performed under rectangular wave energization (wide-angle energization) (rectangular wave energization (wide-angle energization) in Patent Document 2). In other words, it can be said that objective 2 is achieved.

[0177] Furthermore, when a stop signal is received from the mode determination unit 63, the drive control unit 64 stops the drive of the brushless motor 30 by the first drive control unit 641 or the second drive control unit 642. That is, when a stop signal is received from the mode determination unit 63, the drive control unit 64 stops the drive of the brushless motor 30, thereby stopping the swinging motion of the wiper arms 14 and 16.

[0178] Next, the method for generating the second energizing signal by the inverter 52 in high output mode will be described. In the following description, the duty cycle of the applied voltage applied by the inverter 52 to each phase of the armature coils 21u, 21v, and 21w will be set as FET_Duty[%], and the duty cycle indicated by the command value of the applied voltage applied by the inverter 52 to each phase, which is included in the indication signal output from the control unit 54 (second drive control unit 642) to the inverter 52, will be expressed as Software_Duty[%].

[0179] As described above, in the low output mode, the motor control device 33, such as Figure 6 As shown, the FET_Duty is set to be approximately 100% at the peak of the third harmonic superimposed wave and approximately 0% at the trough.

[0180] like Figures 7A to 7D As shown, in high output mode, the second power-on signal is a wide-angle trapezoidal wave. That is, the second power-on signal has the following waveform: in a waveform where the amplitude of the first power-on signal changes to a value greater than 50% of FET_Duty, FET_Duty is set to 100% in the power-on range where FET_Duty is above 100%, and FET_Duty is set to 0% in the power-on range where FET_Duty is below 0%.

[0181] In other words, the motor control device 33 is configured such that, in high output mode, FET_Duty is greater than 100% at the peak of the third harmonic superposition wave (e.g., any duty cycle exceeding 100% up to approximately 130%), and less than 0% at the trough (e.g., any duty cycle below 0% up to approximately -30%). In practice, the maximum value of the applied voltage that the inverter 52 can physically output is the applied voltage corresponding to FET_Duty = 100%, and the minimum value is the applied voltage corresponding to FET_Duty = 0%. Therefore, in the energizing range where FET_Duty is set to a value greater than 100%, the inverter 52 outputs the applied voltage corresponding to FET_Duty = 100%. Conversely, in the energizing range where FET_Duty is set to a value less than 0%, the inverter 52 outputs the applied voltage corresponding to FET_Duty = 0%. Therefore, near the peaks and troughs of the superimposed third harmonic wave, a range in which a certain voltage is applied will be generated, thus producing a wide-angle trapezoidal wave.

[0182] use Figure 12 and Figure 13 This needs to be explained.

[0183] Figure 12 This is a timing diagram showing the energizing sequence of each of the U, V, and W phases by the second drive control unit 642 in this embodiment. Figure 13 This is a timing diagram showing the changes in the software in this implementation.

[0184] Figure 12 , Figure 13 The horizontal axis shows the angle from 0° to 360° and Figures 7A to 7D Similarly, it represents the electrical angle during the energizing period of one cycle of the second energizing signal. Additionally, the first vertical axis (the left vertical axis in the diagram) represents FET_Duty[%]. Furthermore, the second vertical axis (the right vertical axis in the diagram) represents software_Duty[%].

[0185] Here, Figure 12 This illustration shows an embodiment where the software used when the inverter 52 performs control operations according to the instructions of the control unit 54, and the FETs that apply voltages to each of the U, V, and W phases, have different recognition scales. When software_Duty[%] = 80% to 100%, it becomes FET_Duty[%] = 100% to 130%, but the apparent FET_Duty[%] (the actual duty cycle of the applied voltage to each phase) is as follows: Figure 12 The thick line in the text indicates that it is 100%.

[0186] in addition, Figure 13 An embodiment is shown where the software used when the inverter 52 performs control operations according to the instructions of the control unit 54 is set to be capable of outputting with a duty cycle of 100% or more. When software_Duty[%] = 100% to 130%, it becomes FET_Duty[%] = 100% to 130%, but the apparent FET_Duty[%] (the actual duty cycle of the applied voltage to each phase) is as follows: Figure 13 The thick line in the text indicates that it is 100%.

[0187] The following uses Figure 14 and Figure 15 The processing flow of the control unit 54 in this embodiment will be explained. Figure 14 This diagram illustrates the processing flow of the control unit 54 in this embodiment. Figure 15 This describes the implementation method. Figure 14 A diagram of a variation.

[0188] The control unit 54 determines whether the driver has operated the wiper switch 37 to the low-speed operating side (step S101). For example, if a low-speed operating mode signal is received from the wiper switch 37, the control unit 54 determines that the wiper switch 37 has been operated to the low-speed operating side. If the driver has operated the wiper switch 37 to the low-speed operating side, the control unit 54 performs third harmonic energization drive on the brushless motor 30 (step S102).

[0189] On the other hand, if the driver does not operate the wiper switch 37 to the low-speed operating side, the control unit 54 determines whether the wiper switch 37 has been operated to the high-speed operating side (step S103). For example, if a high-speed operating mode signal is received from the wiper switch 37, the control unit 54 determines that the wiper switch 37 has been operated to the high-speed operating side. If the driver operates the wiper switch 37 to the high-speed operating side, the control unit 54 performs wide-angle trapezoidal wave energization drive on the brushless motor 30 (step S104).

[0190] Alternatively, it can be Figure 14 The processing flow of the control unit 54 in this embodiment is set as follows: Figure 15 The processing flow of the control unit 54 shown.

[0191] The control unit 54 determines whether the driver has operated the wiper switch 37 to the low-speed operating side (step S201). For example, if a low-speed operating mode signal is received from the wiper switch 37, the control unit 54 determines that the wiper switch 37 has been operated to the low-speed operating side. If the driver has operated the wiper switch 37 to the low-speed operating side, the control unit 54 determines whether a high-output mode is needed (step S202). If it is determined that a high-output mode is not needed, the control unit 54 performs third harmonic energization drive on the brushless motor 30 (step S203).

[0192] On the other hand, if the driver does not operate the wiper switch 37 to the low-speed operating side, the control unit 54 determines whether the wiper switch 37 has been operated to the high-speed operating side (step S204). For example, if a high-speed operating mode signal is received from the wiper switch 37, the control unit 54 determines that the wiper switch 37 has been operated to the high-speed operating side. If the driver operates the wiper switch 37 to the high-speed operating side, the control unit 54 determines whether a high-output mode is needed (step S205). If it is determined that a high-output mode is needed, the control unit 54 performs wide-angle trapezoidal wave energization drive on the brushless motor 30 (step S206).

[0193] Furthermore, if it is determined in step S201 that the wiper switch 37 is operated to the low-speed operating side, and in step S202 it is determined that a high output mode is required, the control unit 54 performs wide-angle trapezoidal wave energizing drive on the brushless motor 30. Additionally, if it is determined in step S204 that the wiper switch 37 is operated to the high-speed operating side, and in step S205 it is determined that a high output mode is not required, the control unit 54 performs third harmonic energizing drive on the brushless motor 30.

[0194] With this structure, regardless of whether the wiper switch 37 is in low-speed or high-speed operation, the control unit 54 can appropriately switch between low-output and high-output modes. This allows for adaptation to changes in the condition of the windshield 11 (wiping surface) caused by changes in external environmental conditions such as rainfall or vehicle speed.

[0195] As described above, in this embodiment, the motor control device 33 drives the brushless motor 30 with third harmonic power supply in a low-output mode where the output is low, and drives the brushless motor 30 with wide-angle trapezoidal wave power supply in a high-output mode where the output is higher than in the low-output mode. Thus, by driving the brushless motor 30 with third harmonic power supply in the low-speed operating mode where it is used frequently, the motor control device 33 achieves better efficiency and reduces operating noise compared to the rectangular wave power supply control described in Patent Document 1 (see [reference]). Figure 11 ).

[0196] Furthermore, in high-speed operating modes requiring high performance, the motor control device 33 uses a wide-angle trapezoidal wave drive, which, compared to the sinusoidal wave drive in low-speed operating modes, further improves motor characteristics and meets the motor characteristics required in high-speed operating modes (see reference). Figure 9 Furthermore, compared to the rectangular wave power-on control (wide-angle power-on drive) described in Patent Document 2, it offers better efficiency and reduces operating noise (see [reference]). Figure 11 ).

[0197] In the described embodiment, a motor unit 19 including a brushless motor 30, which serves as a brushless wiper motor for oscillating the wiper arm, and a motor control device 33 has been described. Alternatively, a motor unit may include a brushless motor and a motor control device as described above.

[0198] (Sunroof motor unit)

[0199] A sunroof motor unit includes: a brushless motor that drives the opening and closing of a roof panel mounted on the roof of a vehicle; and a motor control device that applies the switching control of this embodiment according to whether the vehicle is stopped (low load) or moving (high load).

[0200] (Powered Seat Motor Unit)

[0201] A power seat motor unit includes: a brushless motor that drives a vehicle seat; and a motor control device that performs energization drive using a first energizing signal (applied voltage) for fine adjustments to the seat position (adjustment of seat position and angle), and performs energization drive using a second energizing signal (applied voltage) for large changes in the seat position (preventing subsidence when sitting in the rear seat or during a vehicle collision), and performs switching control between the two energizations.

[0202] (Fan motor unit)

[0203] A fan motor unit includes: a brushless motor used as a drive source for a vehicle's radiator cooling device; and a motor control device that, in accordance with a variable speed, performs switching control between two energizations by energizing a first energizing signal and a second energizing signal.

[0204] (Powered sliding door motor unit)

[0205] A power sliding door motor unit includes: a brushless motor, which is an electric motor used for opening and closing a sliding door of a vehicle; and a motor control device for switching between the two energizations by energizing a first energizing signal and a second energizing signal.

[0206] Here, use Figures 16 to 20 A modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit will be described. Here, the description of the schematic structural diagram related to the structure used for controlling the sunroof is omitted; it is equivalent to... Figure 4 , Figure 5 The "wiper switch 37" is replaced with a "sunroof control". The sunroof unit includes a sunroof and a sunroof control for opening and closing the sunroof. The control unit 54 obtains an operation signal corresponding to the operation performed on the sunroof control from the sunroof control, and opens and closes the sunroof according to the obtained operation signal. The sunroof control may be, for example, a switch that specifies which action to perform during opening and closing, or an operation panel such as a touch screen.

[0207] Figure 16 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0208] For example, when the driver operates the sunroof control unit, the control unit 54 obtains the operation signal from the sunroof control unit and determines whether the obtained operation signal is an operation signal for tilting up or closing (step S301).

[0209] When the operation signal is an operation signal for tilting upwards or a signal for closing, (step S301 - YES), the control unit 54 performs the tilting upwards or closing operation by driving the brushless motor 30 with a wide-angle trapezoidal wave (step S302). Thus, when the operation signal indicates a tilting upwards operation, the tilting upwards operation is performed by driving the motor unit 19 with a wide-angle trapezoidal wave. Similarly, when the operation signal indicates a closing operation, the closing operation is performed by driving the motor unit 19 with a wide-angle trapezoidal wave. Furthermore, the tilting upwards operation is, for example, the action of tilting the sunroof upwards to open it, and the closing operation is the action of closing the sunroof.

[0210] On the other hand, in step S301, if the operation signal is not an operation signal for tilting upward or a operation signal for closing (step S301-NO), the control unit 54 determines whether the operation signal is an operation signal for tilting downward or an operation signal for opening (step S303).

[0211] When the operation signal is a downward tilting operation signal or an opening operation signal (step S303 - Yes), the control unit 54 performs the downward tilting operation or the opening operation by energizing the motor unit 19 with its third harmonic (step S304). Therefore, when the operation signal indicates a downward tilting operation, the control unit 54 performs the downward tilting operation by energizing the motor unit 19 with its third harmonic. Similarly, when the operation signal indicates an opening operation, the control unit 54 performs the opening operation by energizing the motor unit 19 with its third harmonic. The downward tilting operation is the action of closing the sunroof by restoring its upward tilt to its original angle, and the opening operation is the action of opening the sunroof by moving it to the fully open position.

[0212] On the other hand, in step S303, if the operation signal is not an operation signal for tilting down or an operation signal for opening (step S303 - No), the control unit 54 determines that there is any one of the following: an unexpected operation input failure, an emergency stop, etc., and stops the drive (step S305).

[0213] As described above, the control unit 54 is configured to perform wide-angle trapezoidal wave energization drive during upward tilting or closing actions, and third harmonic energization drive during downward tilting or opening actions. Therefore, when the vehicle is in motion, compared to the case of downward tilting or opening actions, it is difficult to tilt downwards or close the sunroof due to wind pressure during upward tilting or closing actions. However, by performing wide-angle trapezoidal wave energization drive, the motor unit 19 can be operated smoothly even in this situation.

[0214] Figure 17 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0215] When the driver operates the sunroof control unit, the control unit 54 obtains the operation signal from the sunroof control unit and determines whether the obtained operation signal is an operation signal for tilting upward or for closing (step S311).

[0216] When the operation signal is an operation signal for tilting upwards or a signal for turning off (step S311 - Yes), the control unit 54 performs the tilting upwards or turning off operation by driving the brushless motor 30 with a wide-angle trapezoidal wave (step S312). Therefore, when the operation signal indicates a tilting upwards operation, the control unit 54 performs the tilting upwards operation by driving the motor unit 19 with a wide-angle trapezoidal wave. Similarly, when the operation signal indicates a turning off operation, the turning off operation is performed by driving the motor unit 19 with a wide-angle trapezoidal wave.

[0217] On the other hand, in step S311, if the operation signal is neither an upward tilt operation signal nor a closing operation signal (step S311 - No), the control unit 54 performs an action corresponding to the operation content by performing a third harmonic energization drive on the motor unit 19 (step S314). Here, the operation content is only four types: "tilt upward," "close," "tilt downward," and "open." If any of these operation inputs is received, and if it is determined to be no in step S311, only one of the actions, "tilt downward" or "open," needs to be performed. Therefore, regarding the action performed when it is determined to be no in step S311, the control unit 54 can perform a downward tilt action or an open action by performing a third harmonic energization drive.

[0218] Figure 18 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0219] When the driver operates the sunroof control unit, the control unit 54 obtains the operation signal from the sunroof control unit and determines whether the obtained operation signal is an operation signal for tilting upward or for closing (step S321).

[0220] When the operation signal is an operation signal for tilting upwards or an operation signal for turning off (step S321 - Yes), the control unit 54 detects the vehicle speed or the load of the brushless motor 30 of the motor unit 19, and determines whether a high-output mode is required based on the detection result (step S322). This determination may, for example, determine whether the vehicle speed exceeds a vehicle speed reference value, or whether the load of the brushless motor 30 exceeds a load reference value. This determination may also be based on only one of them. The vehicle speed reference value or the load reference value may, for example, be a pre-stored value in a storage device inside or outside the control unit 54 for reference.

[0221] When the vehicle speed exceeds a reference value, or when the load on the brushless motor 30 exceeds a reference value, the control unit 54 determines that a high output mode is required (step S322 - Yes), and performs an upward tilting action or a shut-off action by driving the brushless motor 30 with a wide-angle trapezoidal wave (step S322). Therefore, when the operation signal indicates an upward tilting operation, the control unit 54 performs the upward tilting action by driving the motor unit 19 with a wide-angle trapezoidal wave. Similarly, when the operation signal indicates a shut-off operation, the control unit 54 performs the shut-off action by driving the motor unit 19 with a wide-angle trapezoidal wave.

[0222] On the other hand, if the vehicle speed does not exceed the vehicle speed reference value, or if the load on the brushless motor 30 does not exceed the load reference value, the control unit 54 determines that a high output mode is not needed (step S322 - No), and performs an upward tilting operation or a shut-off operation by driving the brushless motor 30 with third harmonic current (step S326). Therefore, when the operation signal indicates an upward tilting operation, the control unit 54 performs the upward tilting operation by driving the motor unit 19 with third harmonic current. Similarly, when the operation signal indicates a shut-off operation, the motor unit 19 performs the shut-off operation by driving it with third harmonic current. Thus, even during the upward tilting or shut-off operation, if a high output mode is not needed, it can be driven by driving with third harmonic current.

[0223] On the other hand, in step S321, if the operation signal is not an operation signal for tilting upward or a operation signal for closing (step S321-NO), the control unit 54 determines whether the operation signal is an operation signal for tilting downward or a operation signal for opening (step S324).

[0224] If the operation signal is a downward tilt operation signal or an open operation signal (step S324 - Yes), the vehicle speed or the load of the brushless motor 30 of the motor unit 19 is detected, and a determination is made based on the detection result as to whether a high output mode is required (step S325).

[0225] If the vehicle speed exceeds the vehicle speed reference value, or if the load on the brushless motor 30 exceeds the load reference value, the control unit 54 determines that a high output mode is required (step S325 - Yes), and performs a tilting or opening action by driving the brushless motor 30 with a wide-angle trapezoidal wave (step S323). Therefore, when the operation signal indicates a tilting operation, the control unit 54 performs a tilting operation by driving the motor unit 19 with a wide-angle trapezoidal wave. Similarly, when the operation signal indicates an opening operation, the opening action is performed by driving the motor unit 19 with a wide-angle trapezoidal wave.

[0226] On the other hand, if the vehicle speed does not exceed the vehicle speed reference value, or if the load on the brushless motor 30 does not exceed the load reference value, the control unit 54 determines that a high output mode is not needed (step S325 - No), and the control unit 54 performs a tilting or opening operation by driving the motor unit 19 with third harmonic power (step S326). Thus, when the operation signal indicates a tilting operation, the control unit 54 performs a tilting operation by driving the motor unit 19 with third harmonic power. Similarly, when the operation signal indicates an opening operation, the control unit 54 performs an opening operation by driving the motor unit 19 with third harmonic power.

[0227] On the other hand, in step S324, if the operation signal is not an operation signal for tilting down or an operation signal for opening (step S324 - No), the control unit 54 determines that there is any one of the following: an unexpected operation input failure, an emergency stop, etc., and stops the drive (step S325).

[0228] Thus, even when performing an upward tilting or closing action, if a high output mode is not required, the control unit 54 can drive the motor unit 19 via third harmonic energization. Furthermore, even when performing a downward tilting or opening action, if a high output mode is required, the control unit 54 can perform wide-angle trapezoidal wave energization.

[0229] Figure 19 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0230] When the driver operates the sunroof control unit, the control unit 54 obtains the operation signal from the sunroof control unit and determines whether the obtained operation signal is an operation signal for tilting upward or for closing (step S331).

[0231] When the operation signal is an operation signal for tilting upwards or an operation signal for turning off (step S331 - Yes), the control unit 54 detects the vehicle speed or the load of the brushless motor 30 of the motor unit 19, and determines whether a high-output mode is required based on the detection result (step S332). This determination may, for example, determine whether the vehicle speed exceeds a vehicle speed reference value, or whether the load of the brushless motor 30 exceeds a load reference value. This determination may also be based on only one of them. The vehicle speed reference value or the load reference value may, for example, be preset in a storage device inside or outside the control unit 54 for reference.

[0232] If the vehicle speed exceeds the vehicle speed reference value, or if the load on the brushless motor 30 exceeds the load reference value, the control unit 54 determines that a high output mode is required (step S332 - Yes), and performs an upward tilting action or a shut-off action by driving the brushless motor 30 with a wide-angle trapezoidal wave (step S333). Therefore, when the operation signal indicates an upward tilting operation, the control unit 54 performs the upward tilting action by driving the motor unit 19 with a wide-angle trapezoidal wave. Similarly, when the operation signal indicates a shut-off operation, the motor unit 19 is shut down by driving it with a wide-angle trapezoidal wave.

[0233] On the other hand, if the vehicle speed does not exceed the vehicle speed reference value, or if the load on the brushless motor 30 does not exceed the load reference value, the control unit 54 determines that a high output mode is not needed (step S332 - No), and performs an upward tilting operation or a shut-off operation by driving the brushless motor 30 with third harmonic current (step S335). Therefore, when the operation signal indicates an upward tilting operation, the control unit 54 performs the upward tilting operation by driving the motor unit 19 with third harmonic current. Similarly, when the operation signal indicates a shut-off operation, the motor unit 19 performs the shut-off operation by driving it with third harmonic current. Thus, even during the upward tilting or shut-off operation, if a high output mode is not needed, it can be driven by driving with third harmonic current.

[0234] On the other hand, in step S331, if the operation signal is neither an operation signal for tilting upwards nor an operation signal for turning off (step S331 - No), the control unit 54 detects the vehicle speed or the load of the brushless motor 30 of the motor unit 19, and determines whether a high output mode is required based on the detection result (step S334). If the vehicle speed exceeds the vehicle speed reference value, or if the load of the brushless motor 30 exceeds the load reference value, the control unit 54 determines that a high output mode is required (step S334 - Yes), and performs a tilting downwards operation or an opening operation by driving the brushless motor 30 with a wide-angle trapezoidal wave (step S333). Thus, when the operation signal indicates a tilting downwards operation, the control unit 54 performs a tilting downwards operation by driving the motor unit 19 with a wide-angle trapezoidal wave. Similarly, when the operation signal indicates an opening operation, the control unit 54 performs an opening operation by driving the motor unit 19 with a wide-angle trapezoidal wave.

[0235] On the other hand, if the vehicle speed does not exceed the vehicle speed reference value, or if the load on the brushless motor 30 does not exceed the load reference value, the control unit 54 determines that a high output mode is not needed (step S334 - No), and the control unit 54 performs a tilting or opening operation by driving the motor unit 19 with third harmonic power (step S326). Thus, when the operation signal indicates a tilting operation, the control unit 54 performs a tilting operation by driving the motor unit 19 with third harmonic power. Similarly, when the operation signal indicates an opening operation, the control unit 54 performs an opening operation by driving the motor unit 19 with third harmonic power.

[0236] According to the modified example, if the control unit 54 determines no in step S331, it does not need to perform... Figure 18 Step S324 shows the determination step of whether it is a downward tilting operation or an opening operation.

[0237] Figure 20 This is a diagram illustrating a modified example of the processing flow of the control unit 54 when the motor unit 19 is applied to the sunroof unit.

[0238] When the driver operates the sunroof control mechanism, the control unit 54 receives the operation signal from the sunroof control mechanism, detects the vehicle speed or the load of the brushless motor 30 of the motor unit 19, and determines whether a high-output mode is required based on the detection results (step S341). This determination may, for example, determine whether the vehicle speed exceeds a vehicle speed reference value, or whether the load of the brushless motor 30 exceeds a load reference value. This determination may also be based on only one of these. The vehicle speed reference value or the load reference value may, for example, be preset in an internal or external storage device of the control unit 54 for reference.

[0239] When the vehicle speed exceeds the vehicle speed reference value, or when the load on the brushless motor 30 exceeds the load reference value, the control unit 54 determines that a high output mode is required (step S341 - Yes), and executes the action corresponding to the operation signal by driving the brushless motor 30 with a wide-angle trapezoidal wave (step S342). Thus, when the operation signal indicates an upward tilt operation, the control unit 54 performs an upward tilt operation by driving the motor unit 19 with a wide-angle trapezoidal wave; when the operation signal indicates a closed operation, it performs a closed operation by driving the motor unit 19 with a wide-angle trapezoidal wave. Similarly, when the operation signal indicates a downward tilt operation, the control unit 54 performs a downward tilt operation by driving the motor unit 19 with a wide-angle trapezoidal wave; when the operation signal indicates an open operation, it performs an open operation by driving the motor unit 19 with a wide-angle trapezoidal wave.

[0240] On the other hand, if the vehicle speed does not exceed the vehicle speed reference value, or if the load on the brushless motor 30 does not exceed the load reference value, the control unit 54 determines that a high output mode is not needed (step S341 - No), and executes the action corresponding to the operation signal by performing a third harmonic energization drive on the brushless motor 30 (step S343). Thus, when the operation signal indicates an upward tilt operation, the control unit 54 performs an upward tilt operation by performing a third harmonic energization drive on the motor unit 19; when the operation signal indicates a closed operation, it performs a closed operation by performing a third harmonic energization drive on the motor unit 19. Similarly, when the operation signal indicates a downward tilt operation, the control unit 54 performs a downward tilt operation by performing a third harmonic energization drive on the motor unit 19; and when the operation signal indicates an open operation, it performs an open operation by performing a third harmonic energization drive on the motor unit 19.

[0241] According to the aforementioned variation, the control unit 54 can determine whether to perform wide-angle trapezoidal wave energization or third harmonic energization based on a determination of whether a high-output mode is required, rather than on the type of operation performed by the driver on the sunroof control mechanism. Based on this, the sunroof can be controlled according to the operation performed.

[0242] Figures 21A to 21C This is a diagram showing the results of experiments conducted on the operation of motor unit 19.

[0243] Figures 21A to 21C The horizontal axis, representing the angle from 0° to 360°, indicates the electrical angle during one cycle of the second energizing signal. Additionally, the vertical axis, FET_Duty[%], represents the applied voltage to each phase.

[0244] Figure 21A This is a timing diagram showing the energizing sequence of each of the U, V, and W phases by the second drive control unit 642 in this embodiment.

[0245] exist Figure 21A The waveform of the second energizing signal is shown, as well as the waveform when a wide-angle trapezoidal wave energizing drive is performed with the applied voltage of each phase of the three-phase system superimposed with the third harmonic on a sine wave, i.e., the energizing interval (hereinafter referred to as the 100% energizing angle) (symbol 215) where the FET_Duty[%] is 100% or more, is 110°. Here, for any two of the three phases U, V, and W (at least one of V and W, W and U, or U and V), the duty cycle of the applied voltage is approximately 90% (symbol 210).

[0246] Here, as Figure 6 As shown, in the first energizing signal, for any two of the three phases U, V, and W (at least one of V and W, W and U, or U and V), the duty cycle of the applied voltage is approximately 80% (symbol 600). Therefore, in the second energizing signal (second control mode), the duty cycle of the applied voltage is larger than that of the first energizing signal (first control mode).

[0247] Figure 21B This is a timing diagram showing the energizing sequence of each phase U, V, and W by the second drive control unit 642 in this embodiment.

[0248] Here, in Figure 21B The waveform of the second energizing signal is shown, and the waveform is shown when a wide-angle trapezoidal wave is driven with a 100% energizing angle (symbol 216) of 130°. Furthermore, here, for any two of the three phases U, V, and W (at least one of V and W, W and U, or U and V), the duty cycle of the applied voltage is approximately 100% (symbol 211).

[0249] Therefore, in Figure 6 In the first energizing signal (first control mode) shown, the duty cycle when the applied voltage is the same for any two of the three phases is approximately 80%. In contrast, in the second energizing signal (second control mode), the duty cycle when the applied voltage is the same for any two of the three phases is approximately 100%. Therefore, the duty cycle when the applied voltage is the same in the second energizing signal (second control mode) is larger than that in the first energizing signal (first control mode).

[0250] Figure 21CThis is a timing diagram showing the energizing sequence of each of the U, V, and W phases by the second drive control unit 642 in this embodiment.

[0251] Here, in Figure 21C The waveform of the second energizing signal is shown, and the waveform is shown when a wide-angle trapezoidal wave is driven with a 100% energizing angle (symbol 217) of 155°. The second energizing signal has overlapping energizing intervals. In addition, here, for any two of the three phases U, V, and W (at least one of V phase and W phase, W phase and U phase, and U phase and V phase), the duty cycle of the applied voltage is approximately 120% (symbol 212), and in the overlapping energizing interval, the apparent FET_Duty[%] of both phases is 100%.

[0252] exist Figure 21C Zhongye is, in Figure 6 In the first energizing signal (first control mode) shown, the duty cycle when the applied voltage is the same for any two of the three phases is approximately 80%. In contrast, in the second energizing signal (second control mode), the duty cycle when the applied voltage is the same for any two of the three phases is approximately 120%. Therefore, even when the energizing angle is increased to 155°, the duty cycle value for the second energizing signal (second control mode) is greater than that for the first energizing signal (first control mode).

[0253] Furthermore, regarding the second energizing signal, when controlling the 100% energizing angle within the range of 110° to 155°, the control unit 54 can drive the motor to achieve a balance between current consumption and motor output. For example, when prioritizing current consumption, setting the 100% energizing angle to a value closer to 110° within the range of 110° to 155° is sufficient; setting it to 110° further reduces current consumption. On the other hand, when prioritizing increasing motor output, setting the 100% energizing angle to a value closer to 155° within the range of 110° to 155° is sufficient; setting it to 155° further increases motor output.

[0254] Figure 22 This is a graph showing the relationship between the current consumed in the second energized signal and the 100% energizing angle. In this graph, the vertical axis represents the current consumed, and the horizontal axis represents the 100% energizing angle. Here, as indicated by symbol 220, it is confirmed that the current consumed is minimized when the 100% energizing angle is set to 110°.

[0255] Figure 23This is a graph showing the relationship between the motor speed and the 100% energizing angle when the 100% energizing angle is set to 155° in the second energizing signal. In this graph, the vertical axis represents the motor speed, and the horizontal axis represents the 100% energizing angle. Here, as indicated by symbol 230, it is confirmed that the motor speed is at its maximum when the 100% energizing angle is set to 155°, i.e., the motor output is at its maximum.

[0256] If the energizing angle is increased by 100% from 110°, the motor speed increases as it approaches 155°, reaching its maximum at 155°. Beyond 155°, the speed decreases. This is because increasing the energizing angle by 100% increases the advance of the wave relative to the first energizing signal. However, beyond 155°, the effect of the delayed wave becomes greater than the effect of the advance wave. Consequently, the delayed wave induces drag torque (the force that causes the rotor to rotate in the opposite direction), thus reducing the speed compared to the peak value.

[0257] Furthermore, in the described embodiment, the motor control device 33 determines the rotational position of the rotor 22 based on the pulse signal supplied from the rotation angle detection unit 39, but is not limited to this. For example, the motor control device 33 may also determine the rotational position of the rotor 22 based on the induced voltage generated in each armature coil 21u, 21v, 21w corresponding to the rotation of the rotor 22. Therefore, the rotation angle detection unit 39, which detects the rotational position of the rotor 22, is not required, thus reducing the number of parts and manufacturing cost of the brushless motor 30.

[0258] Additionally, in the described embodiment, the wiper device 12 may also include an output shaft sensor that detects at least one of the rotational speed or absolute position of the output shaft 26. The absolute position refers to the rotational angle of the output shaft 26 relative to a reference position. The reference position can be any position within a 360-degree range. The motor control device 33 may also determine the rotational position of the rotor 22 based on the detection signal from the output shaft sensor.

[0259] Furthermore, in the described embodiment, the wiper device 12 is not limited to the windshield 11 of the vehicle 10, but may also be a wiper device for wiping the rear glass. Additionally, the wiper device 12 may also have a structure in which the wiper arms 14 and 16 swing around the output shaft 26 as a fulcrum.

[0260] Alternatively, in the above embodiment, the wiper unit 12 may also be a structure in which two wiper arms 14 and 16 are driven by different brushless motors. Furthermore, the brushless motor 30 in this embodiment may be a motor with an interior permanent magnet (IPM) structure or a motor with a surface permanent magnet (SPM) structure.

[0261] Furthermore, in the described embodiment, the mode selected by the wiper switch 37 is not limited to low-speed and high-speed operating modes, but may include three or more modes. For example, the mode selected by the wiper switch 37 may be low-speed, medium-speed, and high-speed operating modes. Here, the rotational speed of the rotor 22 in the medium-speed operating mode is higher than that in the low-speed operating mode, but lower than that in the high-speed operating mode. For example, when the medium-speed operating mode is selected by the wiper switch 37, the motor control device 33 may drive the brushless motor 30 with third harmonic current or with wide-angle trapezoidal wave current.

[0262] Furthermore, not limited to high-speed, medium-speed, and low-speed operating modes, when a high load is detected on the brushless motor 30, wide-angle trapezoidal wave energizing drive or wide-angle trapezoidal wave + "advance angle > 0°" energizing drive can also be performed. That is, regardless of the mode selected by the wiper switch 37, when a high load signal is acquired from the mode determination unit 63, wide-angle trapezoidal wave energizing drive or wide-angle trapezoidal wave + "advance angle > 0°" energizing drive can be performed.

[0263] Furthermore, while the method of selecting the operating mode based on switching the wiper switch 37 has been explained, the switching of the operating mode can also be based on the detection results from the rain sensor rather than on the wiper switch 37. For example, the rain sensor has the function of detecting rainfall around the vehicle and is installed in the vehicle. Based on the detection results from the rain sensor, the system can switch to a low-speed operating mode when the rainfall is less than a reference value and to a high-speed operating mode when the rainfall exceeds the reference value. Alternatively, by setting three reference values ​​for rainfall, the system can switch to any of the three modes: low-speed, medium-speed, and high-speed.

[0264] The control unit 54 in the described embodiment can also be implemented by a computer. In this case, the program for implementing this function can be recorded on a computer-readable recording medium, and the computer system can read and execute the program recorded on this recording medium. Furthermore, the "computer system" mentioned here includes hardware such as an operating system (OS) and peripheral devices. Additionally, the term "computer-readable recording medium" refers to portable media such as flexible disks, optical disks, read-only memory (ROM), and compact disc-read-only memory (CD-ROM), as well as storage devices such as hard disks built into a computer system. Furthermore, the term "computer-readable recording medium" can also include components that dynamically maintain the program for a short period of time, such as communication lines used when sending programs via networks such as the Internet or telephone lines, and components that maintain the program for a fixed period of time, such as volatile memory inside a computer system that acts as a server or client in the described case. In addition, the program may be a program used to implement the aforementioned functions, or a program that can further implement the aforementioned functions by combining with a program already recorded in the computer system, or a program implemented using a programmable logic device such as a Field Programmable Gate Array (FPGA).

[0265] Furthermore, in the described embodiment, the load determination unit 62 determines that the load on the brushless motor 30 is high when the vehicle speed V measured by the vehicle speed sensor 40 exceeds a predetermined value Vth, or when the rotational speed of the rotor 22 detected based on the pulse signal supplied from the rotation angle detection unit 39 exceeds a predetermined value. However, this is not a limitation. For example, when the resistance value generated by external force increases relative to the operation of the brushless motor 30 during operation in low output mode, the rotational speed (rotational speed) of the rotor 22 will decrease (deviate) from the predetermined target rotational speed (target rotational speed). At this time, the control unit 54 increases the duty cycle within the range of the low output mode in order to make the rotational speed (rotational speed) of the rotor 22 consistent with the predetermined target rotational speed (target rotational speed). Then, if the control unit 54 detects that the duty cycle exceeds a predetermined threshold, it can switch from the low output mode to the high output mode.

[0266] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments and may include designs that do not depart from the spirit of the present invention.

Claims

1. A motor control device that controls a brushless motor including a rotor and armature coils of three phases of U, V, and W phases, the motor control device including: a position detection section that detects a rotational position of the rotor; a control section that can select a first control mode and a second control mode, and in the first control mode, outputs a first drive signal to an inverter in a conduction timing corresponding to the rotational position of the rotor, in the second control mode, outputs a second drive signal to the inverter in a conduction timing corresponding to the rotational position of the rotor; and the inverter, in the first control mode, outputs a first conduction signal having a waveform in which a third harmonic is superimposed on a sine wave as an applied voltage to the armature coils of the three phases, in the second control mode, outputs a second conduction signal having a waveform in which a third harmonic is superimposed on a sine wave as an applied voltage to the armature coils of the three phases, and the control section, for any two phases among the three phases, in the second control mode, has a duty value that is greater than that of the first control mode when a duty of the applied voltage is the same, the second conduction signal has a waveform that includes: a conduction interval in which the duty of the applied voltage of only the U phase among the three phases is 100% and the duty of the applied voltage of only the V phase is 100%, a conduction interval in which the duty of the applied voltage of only the V phase among the three phases is 100% and the duty of the applied voltage of only the W phase is 100%, a conduction interval in which the duty of the applied voltage of only the W phase among the three phases is 100% and the duty of the applied voltage of only the U phase is 100%, a conduction interval in which the duty of the applied voltage of only the U phase among the three phases is 0% and the duty of the applied voltage of only the V phase is 0%, a conduction interval in which the duty of the applied voltage of only the V phase among the three phases is 0% and the duty of the applied voltage of only the W phase is 0%, and a conduction interval in which the duty of the applied voltage of only the W phase among the three phases is 0% and the duty of the applied voltage of only the U phase is 0%.

2. The motor control device according to claim 1, wherein in the second control mode, the control section outputs the second drive signal to the inverter in a conduction timing that is advanced by an electrical angle that is greater than an advance angle of the first control mode with the rotational position of the rotor as a reference.

3. The motor control device according to claim 1, wherein the second energization signal is a waveform in which, in a waveform in which the amplitude of the first energization signal is changed to a value larger than 50% of the duty of the applied voltage to the armature coil, the duty of the applied voltage is set to 100% in an energization interval in which the duty of the applied voltage becomes 100% or more, and the duty of the applied voltage is set to 0% in an energization interval in which the duty of the applied voltage becomes 0% or less.

4. The motor control device according to claim 1, wherein the control section energizes in a manner in which an energization interval in which the duty of the applied voltage of at least one phase of the three phases is 100% or more is in a range of 110° to 155°.

5. A motor control method which is a motor control method of a motor control device that controls a brushless motor including a rotor and a three-phase armature coil of a U phase, a V phase, and a W phase, the motor control device including: a position detection section that detects a rotational position of the rotor; a control section that can select a first control mode and a second control mode, and in the first control mode, outputs a first drive signal to an inverter in an energization timing corresponding to the rotational position of the rotor, in the second control mode, outputs a second drive signal to the inverter in an energization timing corresponding to the rotational position of the rotor; and the inverter, in the first control mode, outputs a first energization signal as an applied voltage to the three-phase armature coil, in the second control mode, outputs a second energization signal as an applied voltage to the three-phase armature coil, and the control section, for any two phases of the three phases, in the second control mode, controls in a manner in which the duty of the applied voltage is the same, and the value of the duty is larger than in the first control mode, wherein the second energization signal has a waveform including: an energization interval in which the duty of the applied voltage of only the U phase and the duty of the applied voltage of only the V phase are 100% between an energization interval in which the duty of the applied voltage of only the U phase is 100% and an energization interval in which the duty of the applied voltage of only the V phase is 100% among the three phases; an energization interval in which the duty of the applied voltage of only the V phase and the duty of the applied voltage of only the W phase are 100% between an energization interval in which the duty of the applied voltage of only the V phase is 100% and an energization interval in which the duty of the applied voltage of only the W phase is 100% among the three phases; an energization interval in which the duty of the applied voltage of only the W phase and the duty of the applied voltage of only the U phase are 100% between an energization interval in which the duty of the applied voltage of only the W phase is 100% and an energization interval in which the duty of the applied voltage of only the U phase is 100% among the three phases; an energization interval in which the duty of the applied voltage of only the U phase and the duty of the applied voltage of only the V phase are 0% between an energization interval in which the duty of the applied voltage of only the U phase is 0% and an energization interval in which the duty of the applied voltage of only the V phase is 0% among the three phases; between the energization interval in which the duty of the applied voltage of only the V phase becomes 0% and the energization interval in which the duty of the applied voltage of only the W phase becomes 0%, the duty of the applied voltage of the V phase and the W phase both becomes 0%; and between the energization interval in which the duty of the applied voltage of only the W phase becomes 0% and the energization interval in which the duty of the applied voltage of only the U phase becomes 0%, the duty of the applied voltage of the W phase and the U phase both becomes 0%.

6. A motor unit comprising: a brushless motor that is a brushless wiper motor that swings a wiper arm; and the motor control device according to any one of claims 1 to 4.

7. A motor unit comprising: a brushless sunroof motor that opens and closes a roof panel; and the motor control device according to any one of claims 1 to 4.

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