JP2021010198A - Motor drive device - Google Patents

Abstract

To provide a motor drive device capable of achieving cost reduction.SOLUTION: A rotation direction detection unit 17 detects the rotation direction of a rotor RT based on a main detection signal Hm from a main Hall sensor HSm and an auxiliary detection signal Hs from an auxiliary Hall sensor HSs. A sine wave timing control unit 31 calculates time of rotation for a sine wave necessary to rotate the rotor RT by a predetermined unit electric angle based on the time of an edge interval of the main detection signal Hm. A sine wave pattern generating unit 36 generates duty ratio indication values DT2 (u, v, w) for applying sinusoidal drive voltages Vu, Vv and Vw to three-phase stator coils Lu, Lv and Lw for each time of rotation for a sine wave. A PWM signal generation unit 23 receives the duty ratio indication values DT2 (u, v, w) to generate PWM signals PWM (u, v, w).SELECTED DRAWING: Figure 1

Description

The present invention relates to a motor drive device including a brushless motor.

Patent Document 1 discloses a motor driving device that switches the energization timing every predetermined electric angle (X degrees) instead of every fixed time when the motor is driven by a sine wave. Specifically, the control unit calculates the electric angle X degree rotation time by dividing the time of the edge interval of the Hall sensor (electric angle 60 degree rotation time) by a divisor of 60, and the electric angle X degree rotation. The energization timing is switched by setting the time in the interrupt timer. The rotation time of the electric angle of 60 degrees is updated every time the motor rotates by the electric angle of 60 degrees, and the rotation time of the electric angle of X degrees is also updated accordingly.

Japanese Unexamined Patent Publication No. 2016-201911

For example, as shown in Patent Document 1 and the like, when controlling a brushless motor with a sensor, three Hall sensors are generally required. However, there is a risk that the cost will increase by installing three Hall sensors. Further, if the number of Hall sensors is reduced, the rotor position cannot be detected with high accuracy. Therefore, for example, it becomes difficult to start the motor when performing a sine wave drive as shown in Patent Document 1, and the controllability of the motor becomes difficult. There was a risk of decline.

The present invention has been made in view of the above, and one of the objects thereof is to provide a motor drive device capable of realizing cost reduction.

The motor drive device of the present invention is installed in the vicinity of a brushless motor having a rotor having a plurality of magnetic poles, a stator having a three-phase stator coil, and the rotor, and detecting a change in magnetic flux of the rotor. A main hall sensor that outputs a detection signal, an auxiliary hall sensor that is installed near the rotor at a position different from that of the main hall sensor, detects a change in the magnetic flux of the rotor, and outputs an auxiliary detection signal, and the rotor. The motor has a motor control unit that controls rotation with a PWM signal, and an inverter that applies at least a sinusoidal drive voltage to the three-phase stator coil based on the PWM signal from the motor control unit. The control unit predetermined the rotor based on the rotation direction detection unit that detects the rotation direction of the rotor based on the main detection signal and the auxiliary detection signal, and the edge interval time of the main detection signal. A timing control unit for sine waves that calculates the rotation time for sine waves required to rotate only a unit electric angle, and the sine wave-shaped drive to the three-phase stator coil for each rotation time for sine waves. It has a sinusoidal pattern generation unit that generates a duty ratio indicated value for applying a voltage, and a PWM signal generation unit that receives the duty ratio indicated value and generates the PWM signal.

In another aspect of the present invention, the motor control unit includes a square wave timing control unit that determines a rotation time for a square wave corresponding to the rotation of the rotor at an electric angle of 60 °, and each rotation time for the square wave. In addition, a square wave pattern generation unit that generates a duty ratio instruction value for applying the square wave-shaped drive voltage to the three-phase stator coil and outputs it to the PWM signal generation unit, and a drive request signal of the brushless motor. In response to this, the square wave timing control unit and the square wave pattern generation unit are activated, and when the detection value obtained based on the main detection signal satisfies a predetermined reference value, the square wave timing control is performed. It has a sine wave timing control unit and a pattern switching unit that activates the sine wave pattern generation unit in place of the unit and the square wave pattern generation unit.

In another aspect of the present invention, the motor control unit has a position detection unit that detects the position of an object controlled by the brushless motor based on the main detection signal and the auxiliary detection signal.

In another aspect of the present invention, the rectangular wave pattern generation unit is positioned to determine the position of the rotor by energizing two of the three phases as an initialization process when activated by the pattern switching unit. It has a control unit.

In another aspect of the present invention, the detection value obtained based on the main detection signal is the rotation speed of the rotor.

In another aspect of the present invention, the detected value obtained based on the main detection signal is the amount of rotation of the rotor.

In another aspect of the present invention, the motor control unit controls forward rotation and reverse rotation of the rotor.

According to the present invention, cost reduction can be realized in a motor drive device.

It is the schematic which shows the structural example of the main part of the motor drive device by one Embodiment of this invention. It is a circuit diagram which shows the structural example of the three-phase inverter in FIG. It is the schematic which shows the arrangement configuration example of a rotor and a hall sensor in FIG. It is the schematic which shows the structural example of the main part of the opening / closing body control device for a vehicle which applied the motor drive device of FIG. FIG. 5 is a waveform diagram illustrating an operation example around a sine wave timing control unit and a sine wave pattern generation unit in FIG. 1. FIG. 5 is a waveform diagram illustrating an operation example of a square wave timing control unit and a square wave pattern generation unit in FIG. 1. It is a supplementary view of FIG. It is a flow chart which shows an example of the processing content at the time of starting a motor in the motor control part of FIG. It is a flow chart which shows an example of the processing content at the time of driving a rectangular wave in the motor control part of FIG. FIG. 5 is a flow chart showing an example of processing contents associated with pattern switching in the motor control unit of FIG. 1. It is a flow chart which shows an example of the processing content at the time of a sine wave drive in the motor control part of FIG. It is a flow chart which shows an example of the processing content following FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<< Configuration of motor drive device >>
FIG. 1 is a schematic view showing a configuration example of a main part of a motor drive device according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing a configuration example of the three-phase inverter in FIG. FIG. 3 is a schematic view showing an example of arrangement configuration of the rotor and the hall sensor in FIG. The motor drive device shown in FIG. 1 includes a motor MT, a motor control unit 10, and a three-phase inverter 11. The motor MT is a brushless motor with a sensor, and includes a rotor RT having a plurality of magnetic poles (4 poles in this example), a stator STT having three-phase stator coils Lu, Lv, and Lw, and a main hall sensor HSm. It has an auxiliary Hall sensor HSs.

As shown in FIGS. 1 and 3, the main hall sensor HSm is installed in the vicinity of the rotor RT, detects a change in the magnetic flux of the rotor RT, and outputs a main detection signal Hm. The auxiliary hall sensor HSs is installed near the rotor RT at a position different from that of the main hall sensor HSm, detects a change in the magnetic flux of the rotor RT, and outputs an auxiliary detection signal Hs. In the example of FIG. 3, the main hall sensor HSm and the auxiliary hall sensor HSs are mounted on the wiring board BD installed in the vicinity of the rotor RT.

The three-phase inverter 11 has at least a sinusoidal drive voltage Vu, on the three-phase stator coils Lu, Lv, Lw based on the three-phase PWM (Pulse Width Modulation) signals PWMu, PWMv, PWMw from the motor control unit 10. Vv and Vw are applied. As shown in FIG. 2, the three-phase inverter 11 includes a three-phase upper arm ARhu, ARhv, ARhw, a three-phase lower arm ARlu, ARlv, ARlw, and a gate driver GD.

The three-phase upper arms ARhu, ARhv, and ARhw are connected between the high-potential side power supply VDD and the three-phase output terminals OUTu, OUTv, and OUTw connected to the motor MT, respectively. The three-phase lower arms ARlu, ARlv, and ARlw are connected between the three-phase output terminals OUTu, OUTv, and OUTw and the low-potential side power supply GND, respectively. Drive voltages Vu, Vv, and Vw are generated at the three-phase output terminals OUTu, OUTv, and OUTw by the switching operation of the corresponding arms, respectively.

Each arm includes a switching element (transistor) SW and a freewheeling diode DD connected in parallel to the switching element SW. The gate driver GD controls the gate of the switching element SW in each arm based on the three-phase PWM signals PWMu, PWMv, and PWMw. Specifically, each switching element SW in the u-phase upper arm ARhu and the lower arm ARlu is controlled by switching signals UH and UL, which are u-phase PWM signals PWMu, respectively. Similarly, the switching element SW in each arm (ARhv, ARlv) of the v phase is controlled by the switching signals VH, VL that become the PWM signal PWMv of the v phase, and the switching in each arm (ARhw, ARlw) of the w phase. The element SW is controlled by switching signals WH and WL which are w-phase PWM signals PWMw.

The motor control unit 10 controls the rotation of the rotor RT with a PWM signal via the three-phase inverter 11. The motor control unit 10 is configured by, for example, a microcontroller including a CPU (Central Processing Unit) and is mounted on a wiring board (control board) together with a device constituting the three-phase inverter 11. However, the motor control unit 10 is not limited to the microcontroller, and a part or all of the motor control unit 10 may be configured by an FPGA (Field Programmable Gate Array), dedicated hardware, or the like. That is, the motor control unit 10 may be configured by program processing by the CPU, hardware processing by dedicated hardware, or a combination thereof.

The motor control unit 10 includes a speed detection unit 15, a position detection unit 16, a sequence control unit 20, a timing control unit 21, a pattern generation unit 22, and a PWM signal generation unit 23. The speed detection unit 15 detects the rotation speed of the rotor RT based on the edge spacing of the main detection signal Hm. The position detection unit 16 includes a rotation direction detection unit 17, and detects the rotation amount of the rotor RT and the position of the object controlled by the motor MT based on the main detection signal Hm and the auxiliary detection signal Hs. At this time, the rotation direction detection unit 17 detects the rotation direction (forward rotation and reverse rotation) of the rotor RT based on the main detection signal Hm and the auxiliary detection signal Hs.

The timing control unit 21 includes a square wave timing control unit 30 and a sine wave timing control unit 31 to control the energization timing of the motor MT. The pattern generation unit 22 includes a square wave pattern generation unit 35, a sine wave pattern generation unit 36, an electric angle calculation unit 37, and a sine wave pattern table 38. The pattern generation unit 22 uses each of these units to determine various energization patterns according to the energization timing from the timing control unit 21, and for each energization pattern, the detail ratio indicated value DT1 (u, v,) of the corresponding PWM signal. w), DT2 (u, v, w) are generated and output. The detail ratio indicated value DT1 (u, v, w) is the detail ratio indicated value for the rectangular wave pattern, and the detail ratio indicated value DT2 (u, v, w) is the detail ratio indicated value for the sine wave pattern. is there.

The sequence control unit 20 includes a pattern switching unit 25, a speed control unit 26, and an abnormality monitoring unit 27, and controls various sequences of the entire motor control unit 10. As one of them, the sequence control unit 20 switches between a square wave pattern (square wave drive) and a sine wave pattern (sine wave drive). In response to this switching, the pattern generation unit 22 outputs one of the detail ratio indicated values DT1 (u, v, w) and DT2 (u, v, w). The PWM signal generation unit 23 generates PWM signals PWMu, PWMv, PWMw (that is, each switching signal UH, UL, VH, VL, WH, WL in FIG. 2) in response to the duty ratio indicated value from the pattern generation unit 22. To do.

<< Application example of motor drive device >>
FIG. 4 is a schematic view showing a configuration example of a main part of a vehicle opening / closing body device to which the motor driving device of FIG. 1 is applied. FIG. 4 shows a sunroof device provided in a vehicle such as an automobile as an example of a vehicle opening / closing device. However, the motor drive device of FIG. 1 is not limited to the sunroof device, and may be applied to a power window device, a power slide door device, or the like in some cases. Further, the motor drive device of FIG. 1 is applicable not only to a vehicle opening / closing body but also to various systems controlled by a brushless motor.

The sunroof device shown in FIG. 4 includes a roof panel 45. The roof panel 45 opens and closes an opening 47 formed in the roof 46 of the vehicle. A pair of shoes 48a and 48b are fixed to both sides of the roof panel 45 along the vehicle width direction (vertical direction in the drawing). Further, guide rails 49 extending in the front-rear direction (left-right direction in the drawing) of the vehicle are fixed on both sides of the opening 47 of the roof 46 along the vehicle width direction. The pair of shoes 48a and 48b are guided by the corresponding pair of guide rails 49, so that the roof panel 45 can be moved in the front-rear direction of the vehicle, that is, can be opened and closed.

One ends of the drive cables 50a and 50b with gears are connected to each of the shoes 48b arranged on the rear side (right side in the drawing) of the vehicle. The other ends of these drive cables 50a and 50b are routed to the front side (left side in the drawing) of the vehicle with respect to the opening 47. The motor MT is mounted inside the roof 46 arranged between the opening 47 and the windshield FG on the front side of the vehicle. The motor drive device of FIG. 1 is applied to the motor MT and a controller (not shown) that controls the motor MT. The controller is composed of, for example, a wiring board on which the motor control unit 10 and the three-phase inverter 11 of FIG. 1 are mounted, and is installed near the motor MT or inside a housing for accommodating the motor MT. It may be installed.

In FIG. 4, the other ends of the pair of drive cables 50a and 50b are meshed with the drive gear 51b attached to the output shaft 51 of the motor MT. When the motor MT is driven, the pair of drive cables 50a and 50b move in opposite directions as the drive gear 51b rotates. As a result, the roof panel 45 is pushed and pulled by the pair of drive cables 50a and 50b via the pair of shoes 48b, and is automatically opened and closed.

<< Details of sine wave timing control unit and sine wave pattern generation unit >>
FIG. 5 is a waveform diagram illustrating an operation example around the sine wave timing control unit and the sine wave pattern generation unit in FIG. FIG. 5 shows the drive voltages Vu, Vv, Vw applied to the three-phase stator coils Lu, Lv, Lw, the main detection signal Hm from the main Hall sensor HSm, and the auxiliary detection signal Hs from the auxiliary Hall sensor HSs. The relationship with is shown. When the rotor RT is rotating, the main detection signal Hm switches between the'H'level and the'L'level every 180 ° of the electric angle.

The sine wave timing control unit 31 is required to rotate the rotor RT by a predetermined unit electric angle X ° based on the edge interval time T180 for an electric angle of 180 ° in the main detection signal Hm for the sine wave. The rotation time Tx of is calculated. Specifically, the sine wave timing control unit 31 calculates the sine wave rotation time Tx by multiplying the edge interval time T180 by "X ° / 180 °". The unit electric angle X ° is, for example, 5 °, 10 °, or the like, and is 10 ° in the example of FIG. Then, the sine wave timing control unit 31 outputs a trigger signal for each rotation time Tx for the sine wave.

The sine wave timing control unit 31 sequentially detects the'H'pulse period (T180 in FIG. 5) of the main detection signal Hm and the subsequent'L' pulse period to sequentially detect the rotation time for the sine wave. Tx is updated every 180 ° electric angle. Further, the sine wave timing control unit 31 may calculate the rotation time Tx for the sine wave by using, for example, a moving average process or the like at the time of this update. In this case, for example, fluctuations in the rotation time Tx due to rotation jitter or the like can be suppressed.

The sine wave pattern generation unit 36 has a sine wave shape on the three-phase stator coils Lu, Lv, and Lw for each rotation time Tx for the sine wave (in other words, for each control cycle of the rotation time Tx) determined in this way. The duty ratio indicated values DT2u, DT2v, and DT2w for applying the driving voltages Vu, Vv, and Vw of the above are generated. Specifically, for example, the electric angle calculation unit 37 in FIG. 1 receives a trigger signal from the sine wave timing control unit 31 with the edge of the main detection signal Hm (that is, 0 ° and 180 °) as a base point. By adding the unit electric angle X °, the electric angle θ (0 ≦ θ <360 °) is calculated. Then, the sine wave pattern generation unit 36 receives the electric angle θ from the electric angle calculation unit 37 for each control cycle (Tx), and uses the equations (1) to (3) to drive voltages Vu, Vv, Calculate Vw.
Vu = √ (2/3) × (Vd × cosθ−Vq × sinθ)… (1)
Vv = √ (2/3) × {Vd × cos (θ-2π / 3) −Vq × sin (θ-2π / 3)}… (2)
Vw = -Vu-Vv ... (3)
In equations (1) to (3), "Vd" and "Vq" are d-axis voltage and q-axis voltage in the coordinate system of vector control, respectively. Generally, "Vd" is set to zero and "Vq" is set to a value according to the required torque. Here, the equations (1) and (2) are implemented in advance in the sine wave pattern table 38 of FIG. 1 in order to reduce the calculation load. That is, the sine wave pattern table 38 uses RAM or ROM to obtain, for example, the value of the u-phase drive voltage Vu and the value of the v-phase drive voltage Vv for each electric angle θ (in increments of unit electric angle X °). Hold. The sine wave pattern generation unit 36 acquires the values of the drive voltages Vu and Vv by referring to the sine wave pattern table 38 using the electric angle θ.

Then, the sine wave pattern generation unit 36 generates duty ratio indicated values DT2u, DT2v, DT2w according to the values of the drive voltages Vu, Vv, Vw for each control cycle (Tx), and sends the PWM signal generation unit 23 to the PWM signal generation unit 23. Output. The PWM signal generation unit 23 generates PWM signals PWMu, PWMv, PWMw having a PWM duty ratio corresponding to the duty ratio indicated values DT2u, DT2v, DT2w for each predetermined PWM cycle Tpwm. In FIG. 5, as an example, the relationship between the v-phase duty ratio indicated value DT2v and the corresponding v-phase PWM signal (switching signal VH) is shown. The PWM duty ratio is the ratio of the on-period Ton in the PWM cycle Tpww (Ton / Tpwm [%]).

By using such a sine wave drive, it is possible to improve the controllability of the motor MT, for example, by improving the efficiency of the motor MT and reducing the vibration. Then, since such a sine wave drive can be performed by using one main hall sensor HSm, cost reduction can be realized. In FIG. 5, the case where the rotor RT is rotated in the forward direction is taken as an example, but in the case where the rotor RT is rotated in the reverse direction, for example, instead of the energization order of u phase → v phase → w phase shown in FIG. The energization order of → w phase → v phase may be used. That is, in the equations (1) to (3), the processing may be performed by exchanging the drive voltage Vv of the v phase and the drive voltage Vw of the w phase. Further, in the case of reverse rotation, unlike the case of FIG. 5, the phase of the auxiliary detection signal Hs is ahead of the main detection signal Hm.

<< Details of the square wave timing control unit and square wave pattern generation unit >>
In order to perform the sine wave drive as shown in FIG. 5, the edge of the main detection signal Hm is required, and as a premise, it is necessary to construct a situation in which the rotor RT is rotating in the target rotation direction. .. However, when one main hall sensor HSm is used, the initial position of the rotor RT at the start of the motor MT can be determined only with a resolution of an electric angle of 180 °, so it is difficult to construct the above-mentioned premise situation itself. Can be. Further, when the auxiliary hall sensor HSs is used in addition to the main hall sensor HSm, a resolution such as an electric angle of 90 ° can be obtained, but even in this case, the above-mentioned premise situation can be reliably constructed. Not necessarily.

Therefore, the motor control unit 10 performs a square wave drive using the square wave timing control unit 30 and the square wave pattern generation unit 35 prior to the sine wave drive. FIG. 6 is a waveform diagram illustrating an operation example of the square wave timing control unit and the square wave pattern generation unit in FIG. FIG. 7 is a supplementary view of FIG. FIG. 6 shows an example of an operation waveform using a square wave drive (in other words, a 120 ° energization mode). In the rectangular wave drive, as shown in FIG. 6, six types of energization patterns PT1 to PT6 are predetermined by the combination of the two-phase energized phase and the one-phase non-energized phase, and the six types of energization patterns PT1 to 1 The PT6 is sequentially switched every 60 ° of the electric angle.

For example, the energization pattern PT1 is a pattern in which the u phase and the v phase are the energized phases and the w phase is the non-energized phase, and a drive current is passed from the u phase to the v phase. The energization pattern PT2 is a pattern in which the u phase and the w phase are energized phases and the v phase is a non-energized phase, and a drive current is passed from the u phase to the w phase. Taking the energization pattern PT1 as an example, here, in FIG. 2, the switching element SW in the upper arm ARhu of the u phase is fixed on, and the switching element SW in the lower arm ARlv of the v phase is switched and controlled by the PWM signal PWMv. Therefore, a method of controlling the magnitude of the drive current is used. However, a method may be used in which the lower arm side is fixed on and the upper arm side is switched and controlled.

Further, taking the energization pattern PT1 as an example, here, the switching element SW in the lower arm ARlv of the v phase is controlled by the PWM signal PWMv, and the switching element SW in the upper arm ARhv of the v phase is fixed off. A method is used in which a recirculation current is passed through the recirculation diode DD in the upper arm ARhv of the v phase. However, a method may be used in which a reflux current is passed through the switching element SW by controlling the switching element SW in the upper arm ARhv of the v phase with a complementary PWM signal (/ PWMv).

Here, as shown in FIG. 6, the square wave timing control unit 30 determines the rotation time T60 for the square wave corresponding to the rotation of the rotor RT at an electric angle of 60 °. Then, the square wave timing control unit 30 outputs a trigger signal for each rotation time T60 for the square wave. The square wave pattern generation unit 35 has a square wave-shaped drive voltage Vu, Vv, on the three-phase stator coils Lu, Lv, Lw for each rotation time T60 for the square wave (in other words, for each control cycle of the rotation time T60). The duty ratio indicated values DT1u, DT1v, and DT1w for applying Vw are generated and output to the PWM signal generation unit 23.

For example, in the energization pattern PT1 of FIG. 6, the rectangular wave pattern generation unit 35 sets the u-phase duty ratio indicated value DT1u to on-fixed (for example, 100 [%]) and turns off the w-phase duty ratio indicated value DT1w. Set to fixed (for example, 0 [%]). Then, the rectangular wave pattern generation unit 35 sets the duty ratio indicated value DT1v (= Ton / Tpwm) of the v phase to a predetermined value based on the magnitude of the predetermined drive current (drive voltage). Similarly, in the energization pattern PT2, the square wave pattern generation unit 35 sets the u-phase duty ratio indicated value DT1u to on-fixed, the v-phase duty ratio indicated value DT1v to off-fixed, and the w-phase duty. The ratio indicated value DT1w is set to a predetermined value. The PWM signal generation unit 23 generates PWM signals (specifically, switching signals UH, UL, VH, VL, WH, WL) as shown in FIG. 6 based on the duty ratio indicated values DT1u, DT1v, DT1w. To do.

Further, the rectangular wave pattern generation unit 35 has a positioning control unit 39 as shown in FIG. The positioning control unit 39 determines the position of the rotor RT by energizing two of the three predetermined phases as an initialization process at the start of the rectangular wave drive. That is, the positioning control unit 39 defines any one of the energization patterns PT1 to PT6 shown in FIG. 6 in advance as the positioning pattern, and outputs the duty ratio indicated values DT1u, DT1v, and DT1w based on the positioning pattern.

FIG. 7 shows the relationship between the energization patterns PT1 to PT6 shown in FIG. 6 and the magnetic field generated in the stator STT by the three-phase stator coils Lu, Lv, and Lw. For example, when energization is performed from the u phase to the v phase by the energization pattern PT1, the u phase slot in the stator STT is magnetized to the N pole and the v phase slot is magnetized to the S pole. Further, when energization is performed from the u phase to the w phase by the energization pattern PT2, the u phase slot in the stator STT is magnetized to the N pole and the w phase slot is magnetized to the S pole.

For example, when the positioning control unit 39 defines the energization pattern PT1 as the positioning pattern, the rotor RT rotates so as to balance the N pole generated in the u-phase slot and the S pole generated in the v-phase slot, and then rotates. Stop at this balance point. After determining the position of the rotor RT in this way, the rectangular wave pattern generation unit 35 sequentially changes the energization pattern for each control cycle (T60 in FIG. 6) in the order of PT2 → PT3 →… → PT6 → PT1 →…. By switching, the rotor RT is rotated at a rotation speed corresponding to the control cycle (T60).

As described above, the method of controlling the rotation of the rotor RT while forcibly sucking the rotor RT into the slot of the stator STT is also called synchronous control. In synchronous control, it is necessary to use large drive voltages (drive currents) Vu, Vv, and Vw to increase the magnetic force generated in each slot and to start from a low rotation speed in order to prevent the synchronization from being lost. Here, for example, in a sensorless brushless motor or the like, synchronous control may be used in order to increase the rotation speed of the rotor until the magnitude of the induced voltage becomes a detectable value or more. Therefore, for example, a d-axis drive voltage (d-axis drive current) corresponding to the maximum rated voltage (maximum rated current) is used.

On the other hand, as shown in FIG. 1, in a brushless motor provided with one main hall sensor HSm, unlike a sensorless brushless motor or the like, the main hall sensor HSm is used in a state where the rotor RT is rotated in a desired rotation direction. It suffices if a state in which the detection signal Hm can be obtained can be constructed, and it is not always necessary to increase the rotation speed. Therefore, the values of the drive voltages (drive currents) Vu, Vv, and Vw (that is, the PWM detail ratio (= Ton / Tpwm) in FIG. 6) during synchronous control are, for example, the maximum rated voltage (maximum rated current). The value may be small to some extent, such as 1/2 or less. As a result, for example, in the sunroof shown in FIG. 4, safety can be ensured even when pinching occurs at the time of starting.

In FIG. 6, the case where the rotor RT is rotated in the forward direction is taken as an example, but in the case where the rotor RT is rotated in the reverse direction, for example, the switching order of the energization patterns of PT1 → PT2 →… → PT6 → PT1 →… shown in FIG. Instead of, the switching order of PT1 → PT6 → PT5 → ... → PT1 →… may be used.

<< Details of position detector >>
As described above, the position detection unit 16 shown in FIG. 1 detects the rotation amount of the rotor RT and the position of the object controlled by the motor MT based on the main detection signal Hm and the auxiliary detection signal Hs. .. In the example of FIG. 4, the position detection unit 16 detects the open / closed position of the roof panel 45. Here, for example, as described above, when positioning is performed using the positioning control unit 39, the rotor RT rotates to a predetermined position by forward rotation or reverse rotation. At this time, it is desirable to detect whether the rotation is forward or reverse.

In the example of FIG. 4, the position detection unit 16 detects the rotation amount of the motor RT each time the opening / closing drive is performed, based on the fully closed position of the roof panel 45, for example, so that the roof panel 45 Recognize the relative opening / closing position. Here, for example, it is assumed that the roof panel 45 is repeatedly opened and closed at a position in the middle between the fully closed position and the fully open position. In this case, positioning is performed by the positioning control unit 39 each time, but if the forward rotation amount or the reverse rotation amount at that time is not detected, the rotation amount is accumulated as an error, which may lead to a large position detection error. There is.

Therefore, the position detection unit 16 detects the rotation amount and the rotation direction of the rotor RT, including the positioning period, based on the main detection signal Hm and the auxiliary detection signal Hs, and detects the rotation amount and the rotation direction of the object (roof panel 45). Detect the position. For example, as shown in FIG. 6, when the main detection signal Hm and the auxiliary detection signal Hs with an electric angle of 90 ° are used, the forward rotation amount and the forward rotation amount and the accuracy of the electric angle of 90 ° are used according to the logic level of each signal. The amount of reverse rotation can be detected. Further, not limited to this, for example, the position detection unit 16 can detect the amount of rotation and the direction of rotation even when the rotor RT is rotated by an external force. This detection information can also be used, for example, for various abnormality monitoring.

<< Details of sequence control unit >>
In the sequence control unit 20 of FIG. 1, the pattern switching unit 25 receives the drive request signal RQ of the motor MT and activates the square wave timing control unit 30 and the square wave pattern generation unit 35 by using the start signal EN. .. At this time, the sequence control unit 20 also notifies the rectangular wave pattern generation unit 35 of the rotation direction included in the drive request signal RQ. In response to this, the square wave timing control unit 30 and the square wave pattern generation unit 35 perform the operations as described in FIGS. 6 and 7.

Further, the pattern switching unit 25 determines whether or not the detection value obtained based on the main detection signal Hs satisfies a predetermined reference value. The detected value is, for example, the rotation speed of the rotor RT obtained by the speed detection unit 15, the rotation amount of the rotor RT obtained by the position detection unit 16, or the like. Then, when the detected value satisfies the reference value, the pattern switching unit 25 uses the start signal EN to replace the square wave timing control unit 30 and the square wave pattern generation unit 35 with the sine wave timing control unit 31. And the sine wave pattern generation unit 36 is activated. In response to this, the sine wave timing control unit 31 and the sine wave pattern generation unit 36 perform the operations as described in FIG.

In this way, the pattern switching unit 25 is, for example, when the rotation speed of the rotor RT rises to the reference rotation speed by the rectangular wave drive, or when the rotation amount of the rotor RT reaches the reference rotation amount (in other words, in other words. , When the object to be controlled moves by the reference amount), etc., switch the square wave drive to the sine wave drive. The reference rotation speed or the reference rotation amount may be a sufficiently small value as described in FIG. 7 or the like, and is preferably set to a value such that the main detection signal Hs can be obtained with some stability. Just do it. Further, the reference rotation speed or the reference rotation amount may be determined according to the convenience of the system (for example, the viewpoint of smoothly moving the object).

The speed control unit 26 outputs a command value of the control amount by performing, for example, PI control (proportional / integral control) or the like according to the error between the rotation speed from the speed detection unit 15 and the target rotation speed. The sine wave pattern generation unit 36 of FIG. 1 changes, for example, the value of the q-axis voltage Vq in the equations (1) to (3) according to the command value of the control amount. Specifically, the sine wave pattern generation unit 36 sets the amplitude of the drive voltages Vu, Vv, Vw (duty ratio indicated values DT2u, DT2v, DT2w) obtained from the sine wave pattern table 38 as a command value of the control amount. It may be changed according to.

The abnormality monitoring unit 27 detects an abnormal rotational operation of the motor MT by monitoring the main detection signal Hm and the auxiliary detection signal Hs. As an example, the abnormality monitoring unit 27 detects a case where the rotation direction detection unit 17 detects the reverse rotation of the motor MT even though the drive request signal RQ indicates the forward rotation. Further, the abnormality monitoring unit 27 detects a case where only one detection signal is output within an electric angle of 360 °. In this case, the motor MT is rotating, but one of the main hall sensor HSm and the auxiliary hall sensor HSs is out of order.

<< Operation flow of motor control unit >>
FIG. 8 is a flow chart showing an example of processing contents at the time of starting the motor in the motor control unit of FIG. In FIG. 8, the pattern switching unit 25 in the sequence control unit 20 selects the rectangular wave drive (step S102) when the drive request signal RQ is received (step S101). Specifically, the pattern switching unit 25 activates the square wave timing control unit 30 and the square wave pattern generation unit 35 by using the activation signal EN.

Subsequently, the square wave timing control unit 30 starts the square wave interrupt timer with the predetermined rotation time T60 for the square wave of FIG. 6 as the interrupt cycle (step 103). For example, the rectangular wave pattern generation unit 35 receives the start of the rectangular wave interrupt timer, sets the positioning pattern (step S104), and outputs the duty ratio indicated values DT1u, DT1v, and DT1w corresponding to the positioning pattern (step S104). Step S105).

FIG. 9 is a flow chart showing an example of processing contents at the time of driving a rectangular wave in the motor control unit of FIG. In FIG. 9, when the rectangular wave pattern generation unit 35 receives an interrupt signal based on the rectangular wave interrupt timer defined in step S103 of FIG. 8 (step S201), the rectangular wave pattern generation unit 35 selects the next square wave energization pattern (step S201). Step S202). For example, the positioning pattern in step S104 of FIG. 8 is the energization pattern PT1 of FIGS. 6 and 7, and when the rotor RT is rotated in the forward direction, the next energization pattern for the square wave is the energization pattern PT2. After that, each time the process of step S202 is performed (every time an interrupt signal is received), the energization pattern is sequentially switched such as PT3 → PT4 → ...

After step S202, the rectangular wave pattern generation unit 35 outputs the duty ratio indicated values DT1u, DT1v, and DT1w corresponding to the energization pattern selected in step S202 (step S203). Subsequently, here, taking the case where the rotation speed of the rotor RT is gradually increased as an example, the rectangular wave timing control unit 30 updates the value of the interrupt cycle (T60) set in the rectangular wave interrupt timer. (Step S204). Specifically, the rectangular wave timing control unit 30 gradually shortens the interrupt cycle (T60) every time the process of step S204 is performed (every time an interrupt signal is received).

FIG. 10 is a flow chart showing an example of processing contents associated with pattern switching in the motor control unit of FIG. The process of FIG. 10 is performed periodically, for example, at a predetermined cycle. In FIG. 10, the pattern switching unit 25 acquires the rotation speed of the rotor RT from the speed detection unit 15 (step S301). Subsequently, here, taking the case of performing pattern switching based on the rotation speed as an example, the pattern switching unit 25 determines whether or not the rotation speed has risen to a predetermined reference value (step S302).

When the rotation speed rises to the reference value in step S302, the pattern switching unit 25 stops the rectangular wave interrupt timer (step S303) and selects sine wave drive instead of the square wave drive being executed in FIG. (Step S304). Specifically, the pattern switching unit 25 uses the start signal EN to replace the square wave timing control unit 30 and the square wave pattern generation unit 35 with the sine wave timing control unit 31 and the sine wave pattern generation unit 36. to start.

FIG. 11 is a flow chart showing an example of processing contents at the time of driving a sine wave in the motor control unit of FIG. 1, and FIG. 12 is a flow chart showing an example of processing contents following FIG. The process of FIG. 11 is executed according to the process of step S304 of FIG. In FIG. 11, the sine wave timing control unit 31 detects a change (edge) in the signal level of the main detection signal Hs (step S401). At this time, when the sine wave timing control unit 31 detects a change in the main detection signal Hs to the'H'level, the electric angle θ = 0 ° is set for the electric angle calculation unit 37 ( In step S402a), when a change to the'L'level is detected, the electric angle θ = 180 ° is set in the electric angle calculation unit 37 (step S402b).

Subsequently, the sine wave timing control unit 31 measures the time of the edge interval of the main detection signal Hs (T180 in FIG. 5) using, for example, a timer for measurement (step S403). That is, the sine wave timing control unit 31 measures the time between the edge detected in response to the processing in step S401 this time and the edge detected in response to the processing in step S401 last time.

Next, the sine wave timing control unit 31 calculates the rotation time Tx of the electric angle X ° based on the edge interval time (T180) measured in step S403 as described in FIG. 5 (step S404). ). Then, the sine wave timing control unit 31 starts the sine wave interrupt timer with the rotation time Tx as the interrupt cycle (step S405). The sine wave interrupt timer may also be used as the rectangular wave interrupt timer used in the process of step S103 of FIG.

After that, the sine wave pattern generation unit 36 calculates the PWM duty ratio using the sine wave pattern table 38 (that is, the dq three-phase conversion of the equations (1) to (3)) as described with reference to FIG. Step S406). The electric angle θ at this time is 0 ° or 180 ° output from the electric angle calculation unit 37 in accordance with the processing of steps S402a and S402b. Then, the sine wave pattern generation unit 36 outputs the duty ratio indicated values DT2u, DT2v, and DT2w based on the PWM duty ratio calculated in step S406 (step S407).

After that, in FIG. 12, when the electric angle calculation unit 37 receives the interrupt signal based on the sine wave interrupt timer in step S405 of FIG. 11 (step S501), the electric angle X ° is added to the current electric angle θ. By doing so, the electric angle θ is updated (step S502). Subsequently, the sine wave pattern generation unit 36 calculates the PWM duty ratio by referring to the sine wave pattern table 38 at the electric angle θ updated in step S502 (step S503). Then, the sine wave pattern generation unit 36 outputs the duty ratio indicated values DT2u, DT2v, and DT2w based on the PWM duty ratio calculated in step S503 (step S504).

The interrupt cycle (Tx) set in the process of step S405 of FIG. 11 is updated every time the rotor RT rotates by an electric angle of 180 ° in accordance with the process of step S401. Further, the initial value of the electric angle θ associated with the processing of step S502 in FIG. 12 is updated to 0 ° or 180 ° each time the rotor RT rotates by an electric angle of 180 ° due to the processing of steps S402a and S402b of FIG. To. Then, in the process of step S502, the electric angle X ° is sequentially added to the updated initial value for each interrupt cycle (Tx) associated with step S501.

<< Main effects of the embodiment >>
As described above, when the motor driving device of the embodiment is used, the sine wave can be driven by using one main hall sensor HSm, so that the cost can be reduced. Further, by using the square wave drive (synchronous drive) at the start of the motor MT, the sine wave drive can be reliably performed even with one main hall sensor HSm, and the controllability of the motor can be improved. become.

Further, by providing the auxiliary hall sensor HSs in addition to the main hall sensor HSm, the rotation direction can be detected and the controllability of the motor can be improved. As one of them, the position detection unit 16 can be used to detect the position of the object based on the rotation direction. Further, by providing the auxiliary hall sensor HSs in addition to the main hall sensor HSm, it becomes possible to detect a failure of one hall sensor, an abnormal rotation operation, or the like.

The auxiliary detection signal Hs from the auxiliary hall sensor HSs is different from a signal that determines the energization timing when the rotor RT is rotationally driven. For this reason, when installing the auxiliary hall sensors HSs, there are no restrictions such as even placement at intervals of 120 ° of electrical angles as in the case of three general hall sensors, and it is possible to set them at arbitrary positions to some extent. it can. Therefore, the degree of freedom in layout is improved, and as a result, the cost can be reduced.

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof. In addition, the material, shape, dimensions, number, installation location, etc. of each component in each of the above-described embodiments are arbitrary as long as the present invention can be achieved, and are not limited to the above-mentioned embodiments.

10 Motor control unit 11 3-phase inverter 15 Speed detection unit 16 Position detection unit 17 Rotation direction detection unit 20 Sequence control unit 21 Timing control unit 22 Pattern generation unit 23 PWM signal generation unit 25 Pattern switching unit 26 Speed control unit 27 Abnormality monitoring unit 30 Square wave timing control unit 31 Sine wave timing control unit 35 Square wave pattern generation unit 36 Sine wave pattern generation unit 37 Electric angle calculation unit 38 Sine wave pattern table 39 Positioning control unit 45 Roof panel 46 Roof 47 Opening 47
48a, 48b Shoe 49 Guide rail 50a, 50b Drive cable 51 Output shaft 51b Drive gear ARh (u, v, w) Upper arm ARl (u, v, w) Lower arm BD Wiring board DD Recirculation diode DT1 (u, v, w) w), DT2 (u, v, w) Duty ratio indicated value EN start signal FG Front glass GD Gate driver GR Gear HSm Main hall sensor HSs Auxiliary hall sensor Hm Main detection signal Hs Auxiliary detection signal Lu, Lv, Lw Stator coil MT Motors PT1 to PT6 Energization pattern PWMu, PWMv, PWMw PWM signal RQ drive request signal RT rotor STT stator SW switching element Vu, Vv, Vw drive voltage θ electric angle

Claims (7)

A brushless motor having a rotor with a plurality of magnetic poles and a stator with a three-phase stator coil.
A main hall sensor installed near the rotor that detects changes in the magnetic flux of the rotor and outputs a main detection signal.
An auxiliary hall sensor that is installed near the rotor at a position different from that of the main hall sensor, detects a change in magnetic flux of the rotor, and outputs an auxiliary detection signal.
A motor control unit that controls the rotation of the rotor with a PWM signal,
An inverter that applies at least a sinusoidal drive voltage to the three-phase stator coil based on the PWM signal from the motor control unit.
It is a motor drive device having
The motor control unit
A rotation direction detection unit that detects the rotation direction of the rotor based on the main detection signal and the auxiliary detection signal, and
A sine wave timing control unit that calculates the sine wave rotation time required to rotate the rotor by a predetermined unit electric angle based on the edge interval time of the main detection signal.
A sine wave pattern generator that generates a duty ratio instruction value for applying the sine wave-shaped drive voltage to the three-phase stator coil for each rotation time for the sine wave.
A PWM signal generation unit that receives the duty ratio indicated value and generates the PWM signal,
Have,
Motor drive. In the motor drive device according to claim 1,
The motor control unit
A square wave timing control unit that determines the rotation time for a square wave corresponding to the rotation of the rotor at an electric angle of 60 °,
A square wave pattern generation unit that generates a duty ratio instruction value for applying the rectangular wave-shaped driving voltage to the three-phase stator coil for each rotation time for the square wave and outputs the duty ratio to the PWM signal generation unit. ,
When the square wave timing control unit and the square wave pattern generation unit are activated in response to the drive request signal of the brushless motor, and the detection value obtained based on the main detection signal satisfies a predetermined reference value. , A pattern switching unit that activates the sine wave timing control unit and the sine wave pattern generation unit in place of the square wave timing control unit and the square wave pattern generation unit.
Have,
Motor drive. In the motor drive device according to claim 2,
The motor control unit has a position detection unit that detects the position of an object controlled by the brushless motor based on the main detection signal and the auxiliary detection signal.
Motor drive. In the motor drive device according to claim 2 or 3.
The rectangular wave pattern generation unit has a positioning control unit that determines the position of the rotor by energizing two of the three phases as an initialization process when activated by the pattern switching unit.
Motor drive. The detected value obtained based on the main detection signal is the rotation speed of the rotor.
The motor drive device according to claim 2 or 3. The detected value obtained based on the main detection signal is the amount of rotation of the rotor.
The motor drive device according to claim 2 or 3. The motor control unit controls forward rotation and reverse rotation of the rotor.
The motor drive device according to claim 1 or 2.

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