Motor control device and parking lock device

Abstract

The invention provides a motor control device and a parking lock device capable of achieving both rapid arrival of an angular position of a rotor to a target angular position and high precision of a stop position of the rotor. The motor control device includes a position determination unit that determines whether or not an angular position of a rotor obtained from a detection signal of a Hall element reaches a target angular position of the rotor, and a control mode switching unit that switches the angular position of the rotor based on an output determined by feedback control based on a deviation between the angular position and the target angular position. The control mode is switched between a feedback control mode in which energization control is performed on coils of a pair of phases corresponding to the angular position among the three-phase coils, and a stop control mode in which energization control is performed on a final energized coil which is finally energized in the feedback control mode among the three-phase coils. The control mode switching unit is configured to switch the control mode from the feedback control mode to the stop control mode when the position determination unit determines that the angular position reaches the target angular position.

Description

Technical Field

[0001] The present disclosure relates to a control device for a motor and a parking lock device. Background Art

[0002] Conventionally, there is known a control device for a three-phase motor that controls the three-phase motor based on a detection signal of a Hall element.

[0003] For example, Patent Document 1 describes a device that controls a three-phase DC motor based on a signal obtained by converting an output signal of a Hall IC through a pre-prepared table when it is determined that the rotation stop position should be adjusted based on the rotation speed of the three-phase DC motor and the number of remaining pulses until the rotation stops.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-43912 Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] In addition, depending on the purpose of use of the motor, position feedback control is desired to control the motor with an output determined based on a deviation (position deviation) between the angular position of the rotor obtained from a detection signal of the Hall element and a target angular position.

[0009] For example, since the parking lock device needs to quickly move the parking lock pawl between a lock position that fixes the axle and a lock release position that releases the fixation of the axle, it is desirable to control the motor (parking lock actuator) based on position feedback control.

[0010] However, when the rotor is stopped at the target angle position by position feedback control, even if the angle position of the rotor reaches the target angle position and the position deviation is zero, the angle position of the rotor may exceed the target angle position when an external force acts on the output shaft of the motor. For example, when a reducer is connected to the output shaft of the motor, the external force may act on the rotor from the gear of the reducer that continues to rotate due to inertia via the output shaft of the motor.

[0011] In this case, unless the rotor further rotates and receives a detection signal from the Hall element indicating a new angular position, correction of the rotor stop position by the feedback control mode cannot be expected, and the accuracy of the rotor stop position decreases.

[0012] In addition, the control device described in Patent Document 1 is configured to output a PWM signal corresponding to a speed specified by a microcomputer (before braking starts) or a fixed PWM signal for braking (after braking starts) to the motor driver in normal mode, rather than a device for performing feedback position control.

[0013] In view of the above, an object of at least some embodiments of the present invention is to provide a motor control device and a parking lock device that can achieve both rapid arrival of the rotor's angular position at a target angular position and high precision of the rotor's stop position.

[0014] (II) Technical solution

[0015] A motor control device according to at least some embodiments of the present invention is a motor control device including a stator including a three-phase coil, a rotor including a magnet arranged opposite to the stator, and a Hall element for generating a detection signal indicating an angular position of the rotor, and comprising:

[0016] a position determination unit for determining whether the angular position of the rotor obtained from the detection signal of the Hall element has reached a target angular position of the rotor; and

[0017] a control mode switching unit configured to switch the control mode between a feedback control mode for controlling the energization of a pair of phases corresponding to the angular position among the three-phase coils and a stop control mode for controlling the energization of a final energized coil that is energized last among the three-phase coils in the feedback control mode, according to an output determined by feedback control based on a deviation between the angular position of the rotor obtained from a detection signal of a Hall element and a target angular position,

[0018] The control mode switching unit is configured to switch the control mode from the feedback control mode to the stop control mode when the position determination unit determines that the angular position has reached the target angular position.

[0019] (III) Beneficial effects

[0020] In at least some embodiments of the present invention, the control mode switching unit is operated to switch from the feedback control mode to the stop control mode when the rotor reaches the target angle position, and the last coil energized in the feedback control mode (the last energized coil) is energized. Therefore, even if the rotor exceeds the target angle position, regardless of whether the next Hall element detection signal indicating the new angle position of the rotor is received, the rotor can be applied with a torque suitable for returning the rotor to the target angle position, thereby achieving high accuracy of the stop position of the rotor.

[0021] Therefore, by using the feedback control mode and the stop control mode, it is possible to achieve both rapid arrival of the rotor's angular position at the target angular position and high accuracy of the rotor's stop position. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a hardware configuration diagram of a motor control device according to one embodiment.

[0023] Figure 2 This is a schematic diagram showing the structure of a motor according to one embodiment.

[0024] Figure 3A It is a schematic diagram showing the structure of a parking lock device according to one embodiment, and shows a locked released state of the parking lock device.

[0025] Figure 3B It is a schematic diagram showing the structure of a parking lock device according to one embodiment, and shows a locked state of the parking lock device.

[0026] Figure 4 A functional block diagram showing a control device according to an embodiment.

[0027] Figure 5 This is a schematic diagram showing the transition of the energization pattern of the three-phase coils according to one embodiment.

[0028] Figure 6 1 is a timing chart showing an example of a detection signal of a Hall element according to an embodiment.

[0029] Figure 7 This is a timing chart showing an example of the operation of the control device according to one embodiment.

[0030] Figure 8 This is a flowchart showing the flow of control by the control device in one embodiment.

[0031] Fig. 9 This is a functional block diagram of a control device according to another embodiment.

[0032] Fig. 10A 1 is a diagram showing an example of a power-on pattern in the stop control mode.

[0033] Fig. 10B 1 is a diagram showing an example of a power-on pattern in the high-precision stop control mode.

[0034] Description of reference numerals:

[0035] 1 (1A, 1B): Control device 40: Position determination unit

[0036] 50: Control mode switching unit 100: Motor

[0037] 101 (101U~101W): Coil 102: Stator

[0038] 103: Magnet 104: Rotor

[0039] 200A: Parking lock device 210: Parking lock gear

[0040] 220: Parking lock pawl D_fix: second duty cycle

[0041] H (H1~H3): Hall element x: angular position

[0042] x*: Target angle position Δx: Deviation DETAILED DESCRIPTION

[0043] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the contents described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples.

[0044] Figure 1 This is a hardware configuration diagram of a motor control device according to one embodiment. Figure 2 This is a schematic diagram showing the structure of a motor according to one embodiment.

[0045] In some embodiments, Figure 1 As shown, the control device 1 of the motor 100 includes a processor 2 for processing information obtained from external devices (host controller 3, Hall element H described later) and calculating a control command for controlling the motor 100.

[0046] The processor 2 may be a microcontroller (MCU) or a central processing unit (CPU) of a microcomputer.

[0047] The control device 1 has a storage unit 4 including a RAM (Random Access Memory) and a ROM (Read Only Memory) as hardware associated with the processor 2. The ROM of the storage unit 4 stores programs executed by the processor 2 and information required for processing by the processor 2. The RAM of the storage unit 4 is used to read and write temporary data while the processor 2 is executing the program.

[0048] The storage unit 4 may be a RAM or a ROM embedded in a microcontroller or a microcomputer.

[0049] exist Figure 1In the illustrated embodiment, the control device 1 includes a communication circuit 6 responsible for communication between the processor 2 and the host controller 3. The processor 2 obtains the target position of the motor 100 from the host controller 3 via the communication circuit 6, and uses the target position to generate a control instruction. The details of the operation function of the control instruction in the processor 2 will be described later.

[0050] In some embodiments, the control device 1 provides a switch control signal as a control instruction to the inverter 120 for energizing the coils (motor coils) of the motor 100 .

[0051] Inverter 120 has a plurality of switching elements, and each switching element is switched on and off according to a switching control signal from control device 1. The switching control signal may be a pulse width modulation (PWM) signal that adjusts the duty ratio by changing the ratio of the ON time while maintaining a constant switching cycle.

[0052] In this way, the power supply to the motor coil is controlled by the inverter 120 according to the switching control signal, so that the motor 100 is driven under the control of the control device 1 .

[0053] In some embodiments, the motor 100 that is the control target of the control device 1 is a brushless DC motor driven by direct current.

[0054] Figure 2 The motor 100 shown is a brushless DC motor including a stator 102 having three-phase coils 101 (101U, 101V, 101W) and a rotor 104 having magnets 103 (103A, 103B) disposed opposite to the stator 102. The magnets 103 are permanent magnets.

[0055] exist Figure 2 In the exemplary embodiment shown, the motor 100 has a two-pole three-slot structure including a set of magnets 103 consisting of N poles 103A and S poles 103B and a three-phase coil 101 consisting of three coils (101U to 101W) of U phase, V phase, and W phase.

[0056] However, in the present invention, the number of pole pairs of the magnet 103 and the number of coils of the three-phase coil 101 are not particularly limited. In other embodiments, the motor 100 has any structure such as four poles and six slots, six poles and nine slots, eight poles and nine slots, or ten poles and twelve slots.

[0057] exist Figure 2 In the illustrated exemplary embodiment, the motor 100 is an inner rotor type motor in which the rotor 104 rotates radially inside the stator 102 .

[0058] In other embodiments, the motor 100 is an outer rotor type motor in which the rotor 104 rotates radially outside the stator 102 .

[0059] like Figure 1 as well as Figure 2 As shown, the motor 100 includes a Hall element H that generates a detection signal indicating the rotor angular position of the motor 100. The detection signal of the Hall element H is processed by the processor 2 of the control device 1 and used to generate a control command.

[0060] exist Figure 1 as well as Figure 2 3 , three Hall elements H ( H1 to H3 ) are shown in the figure, but the number of the Hall elements H is not limited to this example.

[0061] In some embodiments, Figure 2 As shown, a plurality of Hall elements H (H1 to H3) are equally spaced in the circumferential direction and arranged radially close to the magnet 103 of the rotor 104. In this case, the Hall elements H (H1 to H3) obtain a detection signal indicating the angular position of the rotor 104 by detecting the magnetic field generated by the magnet 103 of the rotor 104.

[0062] In some other embodiments, the Hall element H is disposed close to other magnets rotating together with the rotor 104 of the motor 100. In this case, the Hall element H obtains a detection signal indicating the angular position of the rotor 104 by detecting the magnetic field generated by other magnets different from the magnet 103 of the rotor 104.

[0063] exist Figure 1 In the illustrated exemplary embodiment, the output shaft of the motor 100 as the control target of the control device 1 is connected to the driven device 200 via the speed reducer 130. The driven device 200 receives power from the motor 100 via the speed reducer 130 and is driven.

[0064] In other embodiments, the driven device 200 directly receives power from the motor 100 without passing through the speed reducer 130. In this case, the driven device 200 may include a speed change mechanism inside the driven device 200.

[0065] The motor 100 operated under the control of the control device 1 having the above configuration can be applied to an actuator used in any driven device 200. For example, the motor 100 may be an actuator mounted on a parking lock device of a vehicle.

[0066] Figure 3A as well as Figure 3B is a schematic diagram showing the structure of a parking lock device according to one embodiment. Figure 3A Indicates the unlocked state of the parking lock device. Figure 3BIndicates the locked state of the parking lock.

[0067] In some embodiments, Figure 3A as well as Figure 3B As shown, the parking lock device 200A includes a parking lock gear 210 and a parking lock pawl 220 that can engage with the parking lock gear 210 .

[0068] The parking lock gear 210 is connected to the axle of the vehicle (not shown). The parking lock gear 210 may be directly fixed to the axle or may be indirectly fixed to the axle via other components.

[0069] The parking lock pawl 220 has a protrusion 222 at the front end that can engage with the tooth 212 of the parking lock gear 210. The parking lock pawl 220 is rotatably provided around a support shaft 224, and the protrusion 222 is urged by an urging member 226 in a direction away from the parking lock gear 210. The urging member 226 may also be a spring.

[0070] The parking lock pawl 220 is configured to be able to be moved to a lock release position (ie, a position in which the parking lock pawl 220 is disengaged from the parking lock gear 210) by the power of the motor 100 operated under the control of the control device 1. Figure 3A ) and the locked position ( Figure 3B )

[0071] Specifically, in the unlocked position, the protrusion 222 of the parking lock pawl 220 retreats from the tooth 212 of the parking lock gear 210, and the parking lock device 200A unlocks the axle. When the parking lock pawl 220 receives the power of the motor 100 in the unlocked position, it overcomes the force of the force applying member 226 and moves toward the axle around the support shaft 224. Figure 3A As a result, the parking lock pawl 220 reaches Figure 3B In the locked position shown, the protrusion 222 of the parking lock pawl 220 is engaged with the tooth 212 of the parking lock gear 210. In this way, the axle is locked by the parking lock device 200A. In addition, the parking lock pawl 220 can receive the power of the motor 100 in the locked position, thereby rotating around the support shaft 224. Figure 3B Turn in the direction of the arrow to return Figure 3A Shown in unlocked position.

[0072] In some embodiments, the parking lock device 200A further includes one or more power transmission components ( 230 , 240 ) for transmitting the power of the motor 100 to the parking lock pawl 220 .

[0073] exist Figure 3A as well as Figure 3BIn the illustrated exemplary embodiment, the power transmission member ( 230 , 240 ) includes a parking lock lever 230 rotated by power from the motor 100 , and a parking lock rod 240 provided between the parking lock lever 230 and the parking lock pawl 220 .

[0074] The parking lock lever 230 includes a brake shaft 232 connected to the output shaft of the motor 100 (or the output shaft of the speed reducer 130 in the case of the motor 100 with the speed reducer 130 ), and a pair of recessed portions ( 234A, 234B) with which the stopper 236 can engage.

[0075] The first recess 234A of the pair of recesses (234A, 234B) is Figure 3A The parking lock pawl 220 shown in FIG. 2 is a recessed portion for engaging the stopper 236 in the unlocked position of the parking lock pawl 220. In contrast, the second recessed portion 234B is Figure 3B The locking position of the parking lock pawl 220 is shown as a recess for the stopper 236 to engage.

[0076] The stopper 236 is urged toward the parking lock lever 230 by the urging member 237 which may be a spring. Therefore, when the parking lock lever 230 is rotated by the power of the motor 100 input to the brake shaft 232, the stopper 236 moves between the pair of recesses (234A, 234B) while maintaining the contact state with the parking lock lever 230. Specifically, Figure 3A In the unlocked position of the parking lock pawl 220 shown in FIG. 1 , the stopper 236 engaged with the first recess 234A moves relatively toward the second recess 234B along the outer edge of the parking lock lever 230 as the parking lock lever 230 rotates clockwise. Figure 3B In the locking position of the parking lock pawl 220 shown, the stopper 236 engaged with the second recess 234B relatively moves along the outer edge of the parking lock lever 230 toward the first recess 234A as the parking lock lever 230 rotates counterclockwise.

[0077] The parking lock rod 240 is attached to a portion of the parking lock lever 230 on the opposite side of the pair of recessed portions ( 234A, 234B) across the brake shaft 232 . The parking lock rod 240 is attached to the parking lock lever 230 so as to be rotatable about a rotation shaft 241 .

[0078] The parking lock rod 240 is guided by a guide member (not shown) so as to move forward or backward along the axial direction of the parking lock rod 240. Figure 3A In the unlocked position of the parking lock pawl 220 shown in FIG. 1 , when the parking lock lever 230 rotates clockwise, the parking lock rod 240 moves forward in the axial direction toward the parking lock pawl 220 side. Figure 3B In the locking position of the parking lock pawl 220 shown, when the parking lock lever 230 rotates counterclockwise, the parking lock rod 240 retreats in the axial direction in a direction away from the parking lock pawl 220 .

[0079] The parking lock rod 240 has a tapered tapered portion 242 at the end on the opposite side to the connection end of the parking lock lever 230. On the other hand, the parking lock pawl 220 has an engaging portion 228 at the end on the opposite side (the base end side of the parking lock pawl 220) to the protrusion 222 across the support shaft 224, and the engaging portion 228 of the parking lock pawl 220 is configured to engage with the tapered portion 242 of the parking lock rod 240. Therefore, as the parking lock rod 240 moves forward, the engaging position of the engaging portion 228 relative to the tapered portion 242 is offset toward the base end side of the tapered portion 242, and the parking lock pawl 220 rotates counterclockwise (see FIG. 2 ). Figure 3A In contrast, when the parking lock rod 240 retreats, the engagement position of the engagement portion 228 relative to the tapered portion 242 is offset toward the front end of the tapered portion 242, and the parking lock pawl 220 rotates clockwise (refer to Figure 3B ).

[0080] In addition, the parking lock pawl 220 is urged by the urging member 226 in a direction away from the parking lock gear 210. Figure 3B Even in the retracted position of the parking lock lever 240 shown, the engagement portion 228 and the tapered portion 242 are maintained in contact with each other.

[0081] Next, refer to Figure 4 , the control instruction generation function in the control device 1 is explained.

[0082] Figure 4 1 is a functional block diagram of a control device 1 according to an embodiment. Figure 4 The functions of the control device 1 shown are referred to in Figure 1 This is achieved by the hardware configuration (processor 2 and storage unit 4) of the control device 1 as described above.

[0083] In addition, in this manual, Figure 4 The control device 1 of the embodiment shown in the figure is different from the control device 1 described later. Fig. 9 When the control device 1 of the illustrated embodiment is distinguished, the former may be referred to as a control device 1A, and the latter may be referred to as a control device 1B.

[0084] In some embodiments, Figure 4 As shown, the control device 1 includes a position feedback unit 10 in charge of the feedback control mode and a stop control unit 20 in charge of the stop control mode. The control device 1 can selectively execute either the feedback control mode or the stop control mode.

[0085] The position feedback unit 10 generates a control command for controlling the energization of the motor coil based on an output determined by a deviation Δx between the angular position x of the rotor 104 obtained from the detection signal of the Hall element H (H1 to H3) and the target angular position x*. Specifically, the position feedback unit 10 calculates a duty ratio that enables energization control based on the output determined based on the deviation Δx, and generates a switch control signal corresponding to the duty ratio. As described above, the switch control signal may also be a PWM control signal.

[0086] In addition, when the output (or duty cycle) is determined based on the deviation Δx (=x*-x), operations based on P control, PI control, or PID control may also be performed. Here, P control is a control that calculates the command value based on a proportional term proportional to the deviation Δx. PI control is a control that calculates the command value by considering the integral term of the deviation Δx in addition to the proportional term of the deviation Δx. PID control is a control that calculates the command value by considering the proportional term of the deviation Δx, the integral term of the deviation Δx, and the differential term of the deviation Δx.

[0087] In addition, the target angular position x* of the rotor 104 used in the calculation of the position feedback unit 10 can also be obtained from the reference Figure 1 The host controller 3 described above inputs to the processor 2 via the communication circuit 6 .

[0088] During the feedback control mode executed by the position feedback unit 10, the angular position x of the rotor 104 of the motor 100 changes with time until it reaches the target angular position x*. Therefore, the energized coil among the three-phase coils 101 (101U to 101W) of the motor 100 needs to be appropriately selected according to the angular position x of the rotor 104.

[0089] Reference Figure 5 , the transition of the energization pattern of the three-phase coil 101 corresponding to the change of the angular position x of the rotor 104 is described.

[0090] Figure 5 Schematic diagram showing transition of the energization pattern of the three-phase coil 101 according to one embodiment. Figure 5 The arrows shown on the pair of coils to be energized among the three-phase coils 101 in FIG. 1 indicate the directions of the magnetic fluxes generated by the energized coils.

[0091] Figure 5 The marks of 0 degrees to 300 degrees in represent the electrical angles of the motor 100 in each state. Figure 5 It means about Figure 2In the diagram of the coil power-on pattern of the two-pole three-slot motor 100 shown, the electrical angle is consistent with the mechanical angle. In contrast, in motors 100 of other structures, the electrical angle may be different from the mechanical angle. For example, in the case of a four-pole six-slot motor 100, the three-phase coils are arranged in the order of 101U, 101V, 101W, 101U, 101V, 101V, and 101W at intervals of 60 degrees in the circumferential direction, and the electrical angle changes by two cycles (720 degrees) during one rotation of the rotor 104 (mechanical angle 0 degrees to 360 degrees). In addition, even in the case of motors 100 of structures other than the two-pole three-slot structure, the power-on pattern in each state of the electrical angle 0 degrees to 300 degrees is consistent with the mechanical angle. Figure 5 The same is true for the two-pole, three-slot case shown.

[0092] like Figure 5 As shown in FIG. 1 , when current flows from the W phase (101W) to the V phase (101V) at an electrical angle of 0 degrees (W→V), the W phase coil 101W generates a magnetic flux directed radially inward, and the V phase coil 101V generates a magnetic flux directed radially outward. The synthetic magnetic flux obtained by synthesizing these magnetic fluxes applies a torque that causes the rotor 104 to rotate clockwise to the magnet 103 at the angle position corresponding to the electrical angle of 0 degrees.

[0093] When the angular position x of the rotor 104 changes and the electrical angle reaches 60 degrees, the current is switched to a conduction mode (U→V) in which the current flows from the U phase (101U) to the V phase (101V). As a result, the coil 101U of the U phase generates a magnetic flux toward the radial inside, and the coil 101V of the V phase generates a magnetic flux toward the radial outside. The synthetic magnetic flux obtained by synthesizing these magnetic fluxes applies a torque that causes the rotor 104 to rotate clockwise to the magnet 103 at the angular position corresponding to the electrical angle of 60 degrees.

[0094] In the same manner, the U→W power-on mode is selected at an electrical angle of 120 degrees, the V→W power-on mode is selected at an electrical angle of 180 degrees, the V→U power-on mode is selected at an electrical angle of 240 degrees, and the W→U power-on mode is selected at an electrical angle of 300 degrees. In addition, the next power-on mode of W→U returns to the electrical angle of 0 degrees and the W→V power-on mode is selected.

[0095] As described above, the position feedback unit 10 determines the output (or duty ratio) based on the deviation Δx and selects the energization mode according to the angular position x of the rotor 104 , thereby generating a control command in the feedback control mode.

[0096] In contrast, the stop control unit 20 generates a control command in the stop control mode for controlling the energization of the last energized coil that is energized last in the feedback control mode. That is, the stop control unit 20 generates a control command for controlling the energization of the last energized coil according to the last energization mode (final energization mode) in the feedback control mode.

[0097] In some embodiments, Figure 4 As shown, the stop control unit 20 receives information related to the last energized coil from the position feedback unit 10 during the period when the control device 1 executes the feedback control mode. The stop control unit 20 always keeps the latest information related to the last energized coil, thereby preparing for the switch from the feedback control mode to the stop control mode. At this time, the stop control unit 20 may temporarily store the information related to the last energized coil in the RAM of the storage unit 4, and always continuously update the information related to the last energized coil temporarily stored in the RAM to the latest value.

[0098] In other embodiments, the stop control unit 20 stops the rotor 104 only when the angular position x of the rotor 104 reaches an electrical angle (at a certain time) corresponding to the switching timing of the energization mode. Figure 5 In the example shown, when the electrical angle is one degree before the target angular position x* (0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, 300 degrees), information on the last energized coil is acquired from the position feedback unit 10 .

[0099] The specific control command generation function of the stop control unit 20 can be implemented in various ways.

[0100] For example, regarding the timing of starting to energize the final energized coil in the stop control mode, in one embodiment, the stop control unit 20 starts energizing the final energized coil just after the transition to the stop control mode. In other embodiments, the stop control unit 20 starts energizing the final energized coil after a first predetermined time has passed since the angular position x of the rotor 104 obtained by the detection signal of the Hall element H reaches the target angular position x*.

[0101] In addition, regarding the energization continuation period in the stop control mode, in one embodiment, the stop control unit 20 continues the energization control of the last energizing coil for a predetermined time (second predetermined time).

[0102] In addition, regarding the duty ratio in the stop control mode, in one embodiment, the stop control unit 20 may also control the energization of the final energized coil by PWM control based on a fixed duty ratio (second duty ratio) in contrast to the feedback control mode. In addition, the second duty ratio may be a specified value stored in the ROM of the storage unit 4, and the stop control unit 20 may obtain the second duty ratio from the storage unit 4.

[0103] In addition, regarding the above-mentioned method of stopping the generation function of the control command under the control unit 20, refer to Figure 7 This will be described in detail later.

[0104] In some embodiments, in addition to the above-mentioned position feedback unit 10 and the stop control unit 20, the control device 1 also includes: an angle position acquisition unit 30 for acquiring the angle position x of the rotor 104, a position determination unit 40 for determining the angle position of the rotor 104, and a control mode switching unit 50 for switching the control mode.

[0105] The angular position acquisition unit 30 acquires the angular position x of the rotor 104 from the detection signals of the Hall elements H ( H1 to H3 ).

[0106] Figure 6 1 is a timing chart showing an example of a detection signal of the Hall element H according to one embodiment. Figure 6 The horizontal axis is the electrical angle, and the power-on mode refers to the Figure 5 Six energization modes of the three-phase coil 101 (101U-101W) are shown.

[0107] The detection signal level (Hi or Lo) of each of the Hall elements H1 to H3 changes as the angular position x of the rotor 104 changes. Here, regarding the detection signal level of each Hall element H, Hi is a level obtained by detecting the magnetic field generated by the N pole 103A of the magnet 103, and Lo is a level obtained by detecting the magnetic field generated by the S pole 103B of the magnet 103.

[0108] like Figure 6 As shown, there are 6 combinations of detection signal levels Hi and Lo of each Hall element H1 to H3. The angular position acquisition unit 30 acquires the angular position x of the rotor 104 based on which of the 6 combinations the combination of detection signal levels Hi and Lo of each Hall element H1 to H3 is. At this time, the angular position acquisition unit 30 may also acquire information on the angular position x of the rotor 104 corresponding to each combination of detection signal levels Hi and Lo of the Hall elements H1 to H3 from the ROM of the storage unit 4.

[0109] In addition, since the number of combinations of the detection signal levels Hi and Lo of the Hall elements H1 to H3 is limited, the angular position x that can be acquired by the angular position acquisition unit 30 is discrete. Figure 6 In the illustrated example, there are six combinations of detection signal levels Hi and Lo of the Hall elements H1 to H3 , and the angular position acquisition unit 30 can acquire the angular position x at every 60 degrees.

[0110] The angular position x of the rotor 104 acquired by the angular position acquisition unit 30 is sent to the position feedback unit 10 and the position determination unit 40 for generating a control command based on the deviation Δx, determining a power-on mode, and switching a control mode in the feedback control mode.

[0111] The position determination unit 40 compares the angular position x of the rotor 104 acquired by the angular position acquisition unit 30 from the detection signals of the Hall elements H ( H1 to H3 ) with the target angular position x* to determine whether the angular position x of the rotor 104 has reached the target angular position x*.

[0112] The comparison between the angular position x of the rotor 104 and the target angular position x* in the position determination unit 40 may also serve as a calculation function of the deviation Δx (=x*-x) in the position feedback unit 10. In this case, the position determination by the position determination unit 40 is performed by determining whether the value of the deviation Δx calculated in the position feedback unit 10 is zero.

[0113] The control mode switching unit 50 selects either the feedback control mode or the stop control mode as the control mode of the control device 1 based on the determination result of the position determination unit 40 .

[0114] Specifically, the control mode switching unit 50 selects the feedback control mode when the angular position x of the rotor 104 has not reached the target angular position x*, and selects the stop control mode when the angular position x of the rotor 104 has reached the target angular position x*.

[0115] exist Figure 4 In the illustrated exemplary embodiment, the control mode switching unit 50 receives a control command for the feedback control mode from the position feedback unit 10 and a control command for the stop control mode from the stop control unit 20, and switches the control mode by selecting any one of the control commands based on the determination result of the position determination unit 40. That is, the control mode switching unit 50 selects any one of the control commands generated by the position feedback unit 10 or the control commands generated by the stop control unit 20, and outputs the selected control command to the inverter 120.

[0116] In other embodiments, the control mode switching unit 50 first selects a control mode based on the determination result of the position determination unit 40, and causes either the position feedback unit 10 or the stop control unit 20 to generate a control command corresponding to the selected control mode. The position feedback unit 10 and the stop control unit 20 each generate a control command based on a request from the control mode switching unit 50, and the control command is input to the inverter 120 as an output signal from the control device 1.

[0117] In some embodiments, Figure 4As shown, the control device 1 further includes a limiter 64 for limiting the duty ratio of the control command output from the control device 1. In addition, the control device 1 further includes a current detection unit 62, which detects the motor current based on the detection signal of the current sensor 60 for detecting the motor current and determines whether there is an overcurrent, and the limiter 64 switches the presence or absence of the duty ratio limitation based on the determination result of the current detection unit 62.

[0118] In this way, the functions of the current detection unit 62 and the limiter 64 can prevent an excessive current from flowing through the three-phase coils 101 ( 101U to 101W) of the motor 100 .

[0119] Figure 7 It is a timing chart showing an example of the operation of the control device 1 according to one embodiment. Figure 7 This is an example of a timing chart, and the operation of the control device 1 is not limited to this example.

[0120] In addition, Figure 7 In the figure, regarding the angular position x of the rotor 104, the three positions xH_0 to xH_2 represent discrete angular positions obtained from the detection signal of the Hall element H at time t0 to t2. Among them, the position xH_2 is the angular position of the rotor 104 obtained from the detection signal of the Hall element H when the angular position x of the rotor 104 reaches the target angular position x* at time t=t2, and xH_2=x*. In addition, Figure 7 The position xH_3 shown is a position next to the position xH_2 among the discrete angular positions that can be acquired from the detection signal of the Hall element H.

[0121] exist Figure 7 In the exemplary embodiment shown, the control device 1 performs control based on the feedback control mode during the period (0≤t≤t2) before the angular position x of the rotor 104 reaches the target angular position x* (=xH_2). In the feedback control mode, PWM control based on a variable duty ratio (first duty ratio) is performed, and the variable duty ratio is determined according to the deviation Δx between the angular position x of the rotor 104 and the target angular position x*. The PWM control signal based on the first duty ratio is generated in the position feedback unit 10 of the control device 1.

[0122] In addition, Figure 7 In the example shown, immediately after the motor 100 is started at t=0, the first duty ratio is limited due to the soft start function for suppressing the inrush current. After the motor 100 is started, the first duty ratio gradually increases with the passage of time. In the case where the control device 1 includes the limiter 64, the first duty ratio is limited to Figure 7 When the deviation Δx becomes smaller, the first duty ratio decreases.

[0123] In the execution process of the feedback control mode based on the control device 1, refer to Figure 6 Due to the above principle, the angular position x of the rotor 104 is acquired from the detection signal of the Hall element H (H1~H3) by the angular position acquisition unit 30, sent to the position feedback unit 10 and used for calculating the deviation Δx.

[0124] As described above, the angular position x of the rotor 104 acquired by the angular position acquisition unit 30 is updated to a new position at the timing when the combination of the detection signal levels Hi and Lo of the Hall elements H (H1 to H3) switches. Therefore, even if the angular position x of the rotor 104 actually changes continuously, the angular position detected based on the detection signal of the Hall elements H (H1 to H3) is also updated to a new position. Figure 7 It is discrete like xH_0~xH_4.

[0125] In the execution process of the feedback control mode based on the control device 1, as shown in FIG. Figure 5 As described above, the coil to be energized and the energization direction are selected among the three-phase coils 110 ( 110U to 110W) according to the angular position x of the rotor 104 .

[0126] exist Figure 7 In the example shown, according to the angular position xH_0 ( Figure 5 After the current flows through the U phase and the V phase in sequence (the "U→V" energization mode), according to the angular position xH_1 ( Figure 5 The current is made to flow sequentially through the U phase and the W phase (the "U→W" energization mode).

[0127] In the feedback control mode, the energization of the coil is controlled with an output (first duty cycle) determined by feedback control based on the deviation Δx between the angular position x of the rotor 104 and the target angular position x*. The feedback control mode is advantageous in that the angular position x of the rotor 104 can be quickly brought close to the target angular position x*, compared with the case of controlling with a fixed duty cycle.

[0128] exist Figure 7 The same is true in FIG. 1 , during a period when the deviation Δx is large after the motor 100 is started, the first duty ratio is set to a relatively large value, resulting in a sharp increase in the rotation speed of the rotor 104 immediately after the motor 100 is started. As a result, the time it takes for the angular position x of the rotor 104 to reach the target angular position x* is shortened.

[0129] On the other hand, the feedback control mode requires a deviation Δx to generate a control command. In the case where the angular position x of the rotor 104 exceeds the target angular position x*, the rotor 104 receives a signal indicating a new angular position ( Figure 7 In the example, if the detection signal of the Hall element H (xH_3) is not obtained, the rotor position correction based on the feedback control mode cannot be expected.

[0130] Therefore, if Figure 7 As shown, the control device 1 switches from the feedback control mode to the stop control mode when the angular position x of the rotor 104 reaches the target angular position x*(xH_2) by the operation of the control mode switching unit 50 .

[0131] As described above, the stop control mode is a mode in which the last energized coil that is energized last in the feedback control mode is energized, and the stop control unit 20 generates a control command in the stop control mode. Figure 7 In the example shown, "U→W" at t=t1-t2 is the final energization mode, and the U-phase coil 101U and the W-phase coil 101W are the final energized coils. Figure 7 In the example shown, the control device 1 executes the stop control mode for performing coil energization control in the final energization pattern of “U→W” at t= t3 to t4.

[0132] exist Figure 7 In the exemplary embodiment shown, as the stop control mode, the control device 1 starts the energization control of the last energized coil at time t=t3 after a first predetermined time has passed since the time point (t=t2) when the angular position x of the rotor 104 obtained by the detection signal of the Hall element H reaches the target angular position x*. In this example, the first predetermined time is t3-t2.

[0133] In addition, Figure 7 In the illustrated example, the energization control of the last energized coil in the stop control mode is continued for the second predetermined time (= t4 - t3 ).

[0134] exist Figure 7 In the illustrated embodiment, in contrast to the feedback control mode of performing PWM control based on a variable first duty ratio corresponding to the deviation Δx, the stop control unit 20 performs energization control on the last energized coil by PWM control based on a fixed duty ratio D_fix (second duty ratio).

[0135] Figure 8 This is a flowchart showing the flow of control by the control device 1 in one embodiment.

[0136] As shown in the figure, in the control device 1, the angular position acquisition unit 30 acquires the angular position x of the rotor 104 from the detection signal of the Hall element H (S10), and the position determination unit 40 determines whether the angular position x reaches the target angular position x* (S12).

[0137] When the angular position x of the rotor 104 does not reach the target angular position x* (No in S12), the feedback control mode is selected by the control mode switching unit 50. The position feedback unit 10 calculates the deviation Δx between the angular position x of the rotor 104 and the target angular position x* (S14), further calculates the first duty cycle based on the deviation Δx (S16), and generates a PWM control signal based on the first duty cycle as a control instruction in the feedback control mode. When the feedback control mode is selected by the control mode switching unit 50, the PWM control signal based on the first duty cycle obtained by the position feedback unit 10 is output to the inverter 120 as a control instruction from the control device 1 (S18). Thereafter, the process returns to S10 to obtain the angular position x of the rotor 104.

[0138] When the angular position x of the rotor 104 reaches the target angular position x* (Yes in S12), the control mode of the control device 1 is switched from the feedback control mode to the stop control mode by the control mode switching unit 50 (S20). In the stop control mode, the control device 1 outputs the control command generated by the stop control unit 20. The stop control unit 20 determines the final energized coil that is the object of energization control in the final energization mode in the feedback control mode (S22), and obtains the second duty ratio as a fixed value (S24). The stop control unit 20 determines whether the first prescribed time has passed since the time point when the angular position x of the rotor 104 reaches the target angular position x* (S26), and when the first prescribed time has passed (Yes in S26), a PWM control signal based on the second duty ratio for energizing the final energized coil is generated. Then, the PWM control signal is output to the inverter 120 as a control command based on the stop control mode from the control device 1 (S28). The stop control unit 20 determines whether a second predetermined time has elapsed from the start time of the energization control of the last energizing coil ( S30 ), and continues to execute S28 until the second predetermined time has elapsed.

[0139] Next, refer to Fig. 9 , for Figure 4 A control device 1B which is a different embodiment from the control device 1A shown will be described.

[0140] Fig. 9This is a functional block diagram of a control device 1B of another embodiment. The control device 1B shown in the same figure is different from the control device 1A in that it also includes a high-precision stop control unit 70. The high-precision stop control unit 70 generates a control instruction in a high-precision stop control mode in which the three-phase coil 101 (101U~101W) is energized in a pre-set energization pattern corresponding to the target angle position x*. The high-precision stop control unit 70 can also obtain the energization pattern stored in the ROM of the storage unit 4 to generate the control instruction in the high-precision stop control mode.

[0141] In one embodiment, the control device 1 immediately starts outputting a control command based on the high-precision stop control mode to the inverter 120 after the energization control to the final energization mode in the stop control mode is completed.

[0142] In addition, the duty ratio and duration of the energization control in the high-precision stop control mode may be fixed values ​​determined in advance.

[0143] Below, one side and Figure 7 The energization pattern in the high-precision stop control mode will be described by comparing the stop control mode executed during the period from time t2 to time t4 in the timing chart shown.

[0144] Fig. 10A is a diagram showing an example of a power-on pattern in a stop control mode, and Figure 7 The illustrated example corresponds to a case where the energization pattern of the stop control mode is "U→W". Fig. 10B 2 is a diagram showing an example of a power-on pattern in the high-precision stop control mode. Fig. 10A as well as Fig. 10B , the state in which the rotor 104 is in a balanced position corresponding to the combined magnetic flux of each energization pattern is shown.

[0145] In addition, Fig. 10A as well as Fig. 10B In the embodiment, the target angular position x* of the rotor 104 is the angular position x at which the boundary between the N pole 103A and the S pole 103B is horizontal and the N pole 103A is located below the S pole 103B. In this case, the target angular position x* is equivalent to Figure 5 The angular position x of the rotor 104 when the electrical angle is 180 degrees.

[0146] As described above, the control device 1 operates in the feedback control mode. Figure 5 The power-on mode shown in the figure is controlled until the angle position x of the rotor 104 reaches the target angle position x* (equivalent to an electrical angle of 180 degrees), and when the angle position x reaches the target angle position x*, it is switched to the stop control mode. At this time, in the stop control mode, Fig. 10AAs shown in FIG. 1 , the energization control is performed in the energization mode of "U→W" as the final energization mode in the feedback control mode. The combined magnetic flux 105A of the magnetic fluxes generated by the U-phase coil 101U and the W-phase coil 101W respectively makes the rotor 104 that exceeds the target angle position x* approach the target angle position x*. However, as Fig. 10A As shown, the equilibrium position of the rotor 104 when the synthetic magnetic flux 105A acts is slightly deviated from the target angular position x*.

[0147] In this regard, in the high-precision stop control mode executed after the stop control mode, Fig. 10B As shown, the energization control is performed in the "U→VW" energization pattern, so the equilibrium position when the synthetic magnetic flux 105B of the three-phase coil 101 acts on the rotor 104 is substantially consistent with the target angle position x*. Therefore, the rotor 104 can be stopped at the target angle position x* with higher accuracy.

[0148] The energization pattern of “U→VW” is a energization pattern in which the current flowing through the U-phase coil 101U is divided into half each and flows through the V-phase coil 101V and the W-phase coil 101W.

[0149] The characteristic structures of the control device 1 (1A, 1B) and the parking lock device 200A according to some of the above-mentioned embodiments are summarized as follows.

[0150] [1] A control device (1) in at least some embodiments is a control device (1) for a motor (100) comprising: a stator (102) including a three-phase coil (101), a rotor (104) including a magnet (103) arranged opposite to the stator (102), and a Hall element (H) for generating a detection signal indicating an angular position (x) of the rotor (104), wherein:

[0151] A position determination unit (40) for determining whether the angular position (x) of the rotor (104) obtained from the detection signal of the Hall element (H) reaches the target angular position (x*) of the rotor (104); and

[0152] A control mode switching unit (50) is configured to switch the control mode between a feedback control mode for controlling the energization of a pair of phases of the three-phase coil (101) corresponding to the angular position (x) and a stop control mode for controlling the energization of a final energized coil of the three-phase coil (101) which is energized last in the feedback control mode, according to an output determined by feedback control based on a deviation (Δx) between the angular position (x) of the rotor (104) obtained from a detection signal of a Hall element (H) and a target angular position (x*),

[0153] The control mode switching unit (50) is configured to switch the control mode from the feedback control mode to the stop control mode when the position determination unit (40) determines that the angle position (x) has reached the target angle position (x*).

[0154] According to the structure of [1] above, when the angular position (x) of the rotor (104) reaches the target angular position (x*), the control mode switching unit (50) operates to switch from the feedback control mode to the stop control mode. In the stop control mode, the coil that was last energized in the feedback control mode is energized. Therefore, regardless of whether the next detection signal of the Hall element (H) indicating the new angular position (xH_3) of the rotor (104) is received, a torque suitable for stopping the rotor (104) at the target angular position (x*) can be applied to the rotor (104) by the energization control in the stop control mode, thereby achieving high accuracy of the stop position of the rotor (104).

[0155] [2] In some embodiments, in the structure of [1] above,

[0156] The control device (1) is configured to start energizing control of the final energized coil in a stop control mode after a first specified time (= t3-t2) has passed since the angular position (x) of the rotor (104) obtained by the detection signal of the Hall element (H) reaches the target angular position (x*).

[0157] When the energization control of the final energized coil is started when the angular position (x) of the rotor (104) is at the target angular position (x*), a torque is temporarily applied to the rotor to promote the angular position (x) of the rotor (104) to pass through the target angular position (x*). Figure 7 At time t2, when the energization control in the energization mode of "U→W" in the stop control mode is started, the synthetic magnetic flux ( Fig. 10A The synthetic magnetic flux 105A) exerts a torque on the rotor (104) that promotes the passage of the target angle position (x*). In this case, even if the rotor (104) is finally stopped near the target angle position (x*) by the stop control mode, the deviation from the temporary target angle position (x*) will increase slightly.

[0158] In this regard, in the structure of [2] above, after a first predetermined time (= t3-t2) has passed since the angular position (x) of the rotor (104) reaches the target angular position (x*), the energization control of the final energization coil is started. By appropriately setting the first predetermined time (= t3-t2), it is possible to avoid a situation where the torque that promotes the angular position (x) of the rotor (104) to pass through the target angular position (x*) temporarily acts on the rotor, and selectively apply a torque to the rotor (104) that causes the rotor (104) that has passed the target angular position (x*) to rotate in the opposite direction toward the target angular position (x*).

[0159] [3] In some embodiments, in the structure of [1] or [2] above,

[0160] The control device (1) is configured to continue energizing control of the last energizing coil for a second predetermined time (t4-t3) in the stop control mode.

[0161] According to the structure of [3] above, by appropriately setting the second specified time (= t4 - t3), the angular position (x) of the rotor (104) can be reliably returned to the vicinity of the target angular position (x*) by controlling the energization of the last energized coil.

[0162] [4] In some embodiments, in any one of the structures of [1] to [3] above,

[0163] The control device (1) is configured to control the energization of a pair of phase coils by PWM control based on a first duty ratio determined by feedback control in a feedback control mode.

[0164] In the stop control mode, energization control of the last energized coil is performed by PWM control based on the second duty ratio which is a fixed value.

[0165] According to the structure of [4], in the feedback control mode, by determining the first duty ratio according to the deviation (Δx) between the angular position (x) of the rotor (104) and the target angular position (x*), it is possible to quickly approach the target angular position (x*) when the angular position (x) of the rotor (104) deviates greatly from the target angular position (x*). In contrast, in the stop control mode, by adopting the second duty ratio of a fixed value that is independent of the detection signal of the Hall element (H), it is possible to apply a torque suitable for returning the rotor (104) to the target angular position (x*) regardless of whether the next detection signal of the Hall element (H) is received.

[0166] [5] In some embodiments, in any one of the structures of [1] to [4] above,

[0167] The control mode switching unit (50) is configured to switch the control mode to a high-precision stop control mode after executing the stop control mode, wherein the high-precision stop control mode energizes the three-phase coil (101) in a energization pattern preset corresponding to the target angle position (x*).

[0168] According to the configuration of [5] above, by performing control in the high-precision stop control mode following the stop control mode, the stop position of the rotor (104) can be brought closer to the target angle position (x*).

[0169] [6] At least some embodiments of the parking lock device (200A) include:

[0170] Parking lock gear (210);

[0171] A motor (100) comprising: a stator (102) including a three-phase coil (101), a rotor (104) including a magnet (103) arranged opposite to the stator (102), and a Hall element (H) for generating a detection signal indicating an angular position (x) of the rotor (104);

[0172] A control device (1) according to any one of the above structures [1] to [5] for controlling a motor (100); and

[0173] The parking lock pawl (220) is configured to be driven by a motor (100) so as to be movable between a locking position engaged with a parking lock gear (210) and a lock release position disengaged from the parking lock gear (210).

[0174] According to the structure of the above-mentioned [6], since a control device (1) having any one of the structures of the above-mentioned [1] to [5] is adopted, it is possible to take into account both the rapid arrival of the angular position (x) of the rotor (104) at the target angular position (x*) and the high precision of the stop position of the rotor (104), thereby improving both the responsiveness and the precision of the parking lock device (200A).

[0175] In the present specification, the expression “having”, “including” or “having” a constituent element is not an exclusive expression excluding the presence of other constituent elements.

Claims

1. A motor control device, the motor comprising: a stator including a three-phase coil, a rotor including a magnet arranged opposite to the stator, and a Hall element for generating a detection signal indicating an angular position of the rotor, the motor control device comprising: a position determination unit for determining whether the angular position of the rotor obtained from the detection signal of the Hall element has reached a target angular position of the rotor; and A control mode switching unit is configured to switch the control mode between a feedback control mode for controlling the energization of a pair of phases of the three-phase coils corresponding to the angular position and a stop control mode for controlling the energization of a final energized coil of the three-phase coils that is energized last in the feedback control mode, according to the output, wherein: The output is determined by feedback control based on a deviation between the angular position of the rotor obtained from the detection signal of the Hall element and the target angular position, The control mode switching unit is configured to switch the control mode from the feedback control mode to the stop control mode when the position determination unit determines that the angular position has reached the target angular position.

2. The motor control device according to claim 1, characterized in that: In the stop control mode, the energization control of the final energizing coil is started after a first predetermined time has passed since the angular position of the rotor obtained from the detection signal of the Hall element reaches the target angular position.

3. The motor control device according to claim 1 or 2, characterized in that: The configuration is such that, in the stop control mode, the energization control on the last energizing coil is continued for a second predetermined time.

4. The motor control device according to claim 1 or 2, characterized in that: In the feedback control mode, the energization control is performed on the coils of the pair of phases by PWM control based on a first duty ratio determined by the feedback control, In the stop control mode, the energization control of the final energizing coil is performed by PWM control based on a second duty ratio that is a fixed value.

5. The motor control device according to claim 1 or 2, characterized in that: The control mode switching unit is configured to switch the control mode to a high-precision stop control mode for energizing the three-phase coils in a energization pattern preset in accordance with the target angular position after the stop control mode is executed.

6. A parking lock device, comprising: Parking lock gear; A motor comprising: a stator including a three-phase coil, a rotor including a magnet arranged opposite to the stator, and a Hall element for generating a detection signal indicating an angular position of the rotor; A control device according to claim 1 or 2 for controlling the motor; and The parking lock pawl is configured to be driven by the motor so as to be movable between a locking position in which the pawl is engaged with the parking lock gear and a lock releasing position in which the pawl is disengaged from the parking lock gear.

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