JP2019110674A - Motor control device - Google Patents

Abstract

To provide a motor control device capable of appropriately controlling driving according to the rotation speed of a motor.SOLUTION: An angle calculation unit 51 calculates an encoder count value θen on the basis of a detection value obtained by an encoder 13 for detecting the rotation position of a rotor 103. A speed calculation unit 52 calculates a motor rotational speed N on the basis of the detection value obtained by the encoder 13. A driving control unit 56 controls driving of a motor 10 so as to rotate the rotor 103 from the stopped state of the rotor 103 and stop the rotor 103 at a motor angle target value θcmd which is a set target rotation position. The driving control unit 56 controls on/off operations of switching elements 411-413 such that, when the rotation speed of the rotor 103 is relatively higher, an electrification on angle θon which is an angle range of one electric angle cycle of electrification of phases of coils 111 to 113 becomes larger. As a result, shortage of torque during high speed rotation due to a delay in current rising, can be suppressed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motor control device.

  BACKGROUND Conventionally, there has been known a motor control device which detects a rotational position of a rotor and sequentially switches an energized phase to rotate the rotor to a target position. For example, in patent document 1, the amount of phase lead of the energized phase is corrected according to the rotor rotational speed.

Patent No. 3888278

  In patent document 1, the period which supplies with electricity to the coil of each phase is made into the predetermined | prescribed angle range irrespective of a rotational speed. Therefore, when the rotational speed is high, the current supply time is short as compared to the case where the rotational speed is low, and there is a possibility that the current can not be increased due to the influence of the inductance of the coil.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a motor control device capable of appropriately controlling driving according to the rotation speed of the motor.

  The motor control device according to the present invention comprises driving a motor (10) having a stator (101), coils (111 to 113) wound around the stator, and a rotor (103) rotatably provided relative to the stator. It controls, Comprising: A motor driver (41) and a control part (50) are provided. The motor driver has switching elements (411 to 413) provided corresponding to the respective phases of the coil.

  The control unit has an angle calculation unit (51), a speed calculation unit (52), and a drive control unit (56). The angle calculation unit calculates the rotation angle of the rotor based on the detection value of the rotation angle sensor (13) that detects the rotation position of the rotor. The speed calculation unit calculates the rotation speed of the rotor based on the detection value of the rotation angle sensor. The drive control unit rotates the rotor from a state in which the rotor is stopped, and controls the drive of the motor such that the rotor is stopped at the set target rotational position.

  The drive control unit controls the on / off operation of the switching element such that the energization on angle which is an angular range in one cycle of the electrical angle conducted to each phase of the coil becomes larger as the rotational speed is relatively larger. As a result, it is possible to suppress the shortage of torque at the time of high speed rotation caused by the rise delay of the current.

FIG. 1 is a perspective view of a shift-by-wire system according to one embodiment. FIG. 1 is a schematic block diagram illustrating a shift-by-wire system according to one embodiment. FIG. 1 is a schematic view of a motor according to an embodiment; FIG. 1 is a circuit diagram illustrating a motor driver according to one embodiment. It is a time chart explaining the switching state and current waveform of the switching element by one embodiment. It is a flow chart explaining motor control processing by one embodiment. It is a flow chart explaining acceleration control processing by one embodiment. It is a flowchart explaining the deceleration control processing by one embodiment. It is explanatory drawing explaining the switching state in the low speed area | region by one Embodiment. It is explanatory drawing explaining the switching state in the medium speed area | region by one Embodiment. It is explanatory drawing explaining the switching state in the high-speed area | region by one Embodiment. It is a time chart explaining motor control processing by one embodiment.

(One embodiment)
Hereinafter, a motor control device according to the present invention will be described based on the drawings. A motor controller according to one embodiment is shown in FIGS. As shown in FIGS. 1 and 2, the shift-by-wire system 1, which is a shift range switching system, includes a motor 10, a shift range switching mechanism 20, a parking lock mechanism 30, and a shift range control device 40 as a motor control device. Prepare.

  The motor 10 is rotated by being supplied with electric power from a battery 45 as a power source mounted on a vehicle (not shown), and functions as a drive source of the shift range switching mechanism 20. As shown in FIGS. 3 and 4, the motor 10 includes a stator 101, a rotor 103, and a winding set 11. The winding set 11 includes a U-phase coil 111, a V-phase coil 112, and a W-phase coil 113, and is wound around the salient pole 102 of the stator 101. The coils 111 to 113 are connected by the connection portion 115. The wire connection portion 115 is connected to the ground. The motor 10 of the present embodiment is a switched reluctance motor (hereinafter, “SR motor”), and the inductance of the coils 111 to 113 is relatively large.

  The rotor 103 is provided on the stator 101 so as to be capable of relative rotation, and is rotationally driven by switching the energized phase of the coils 111 to 113. In the present embodiment, the number of salient poles of the stator 101 is twelve, and the number of salient poles of the rotor 103 is eight.

  As shown in FIG. 2, the encoder 13 as a rotation angle sensor detects the rotational position of the rotor 103 of the motor 10. The encoder 13 is a magnetic rotary encoder, and includes a magnet rotating integrally with the rotor 103, a Hall IC for magnetic detection, and the like. The encoder 13 outputs A-phase and B-phase pulse signals at predetermined angles in synchronization with the rotation of the rotor 103. In the present embodiment, the A-phase signal and the B-phase signal are configured to switch high and low at every electrical angle of 60 °, and to output the phases of the A-phase signal and the B-phase signal with an electrical angle of 30 °. (See Fig. 8 etc.). Therefore, the resolution of the encoder 13 of the present embodiment is 30 ° in electrical angle, and 12 counts in one electrical angle cycle.

  The reduction gear 14 is provided between the motor shaft of the motor 10 and the output shaft 15, and decelerates the rotation of the motor 10 and outputs it to the output shaft 15. Thus, the rotation of the motor 10 is transmitted to the shift range switching mechanism 20. The output shaft 15 is provided with an output shaft sensor 16 that detects the angle of the output shaft 15. The output shaft sensor 16 is, for example, a potentiometer.

  As shown in FIG. 1, the shift range switching mechanism 20 has a detent plate 21 and a detent spring 25 and the like, and the rotational driving force output from the reduction gear 14 is a manual valve 28 and a parking lock mechanism 30. Transmit to The detent plate 21 is fixed to the output shaft 15 and driven by the motor 10. In the present embodiment, the direction in which the detent plate 21 separates from the base of the detent spring 25 is the forward rotation direction, and the direction in which the detent plate 21 approaches the base is the reverse rotation direction.

  The detent plate 21 is provided with a pin 24 projecting in parallel with the output shaft 15. The pin 24 is connected to the manual valve 28. When the detent plate 21 is driven by the motor 10, the manual valve 28 reciprocates in the axial direction. That is, the shift range switching mechanism 20 converts the rotational movement of the motor 10 into a linear movement and transmits it to the manual valve 28. The manual valve 28 is provided on the valve body 29. The manual valve 28 reciprocates in the axial direction, thereby switching the hydraulic pressure supply path to the hydraulic clutch (not shown), and switching the engagement state of the hydraulic clutch changes the shift range. On the detent spring 25 side of the detent plate 21, four recesses 22 for holding the manual valve 28 at positions corresponding to the respective ranges are provided. The recess 22 corresponds to each range of D (drive), N (neutral), R (reverse), and P (parking) from the base side of the detent spring 25.

  The detent spring 25 is an elastically deformable plate-like member, and the detent roller 26 is provided at the tip. The detent roller 26 fits into any of the recesses 22. The detent spring 25 biases the detent roller 26 toward the rotation center of the detent plate 21. When a rotational force of a predetermined value or more is applied to the detent plate 21, the detent spring 25 elastically deforms and the detent roller 26 moves in the recess 22. By the detent roller 26 being fitted in any of the recessed portions 22, the swing of the detent plate 21 is restricted, the axial position of the manual valve 28 and the state of the parking lock mechanism 30 are determined. The shift range of is fixed.

  The parking lock mechanism 30 has a parking rod 31, a cone 32, a parking lock pole 33, a shaft 34 and a parking gear 35. The parking rod 31 is formed in a substantially L-shape, and one end 311 side is fixed to the detent plate 21. A conical body 32 is provided on the other end 312 side of the parking rod 31. The conical body 32 is formed to decrease in diameter toward the other end 312 side. When the detent plate 21 swings in the reverse rotation direction, the conical body 32 moves in the direction of the arrow P.

  The parking lock pole 33 abuts on the conical surface of the conical body 32 and is provided so as to be able to pivot about the shaft 34. A protrusion capable of meshing with the parking gear 35 on the parking gear 35 side of the parking lock pole 33 331 are provided. When the detent plate 21 rotates in the reverse rotation direction and the cone 32 moves in the arrow P direction, the parking lock pole 33 is pushed up, and the convex portion 331 and the parking gear 35 mesh with each other. On the other hand, when the detent plate 21 rotates in the normal rotation direction and the conical body 32 moves in the arrow NotP direction, the engagement between the convex portion 331 and the parking gear 35 is released.

  The parking gear 35 is provided on an axle (not shown), and is provided so as to be able to mesh with the convex portion 331 of the parking lock pole 33. The engagement of the parking gear 35 and the convex portion 331 restricts the rotation of the axle. When the shift range is the NotP range, which is a range other than P, the parking gear 35 is not locked by the parking lock pole 33, and the rotation of the axle is not blocked by the parking lock mechanism 30. Further, when the shift range is the P range, the parking gear 35 is locked by the parking lock pole 33, and the rotation of the axle is restricted. In the present embodiment, when the shift range is the P range and the vehicle speed is equal to or less than a predetermined speed (for example, 5 km / h), the parking lock mechanism 30 locks the axles.

  As shown in FIG. 2, the shift range control device 40 has a motor driver 41 and an ECU 50 as a control unit. As shown in FIG. 4, the motor driver 41 has switching elements 411 to 413. For example, MOSFETs are used as the switching elements 411 to 413, but IGBTs or the like may be used.

  U-phase switching element 411 is connected to U-phase coil 111. When the U-phase switching element 411 is turned on, energization to the U-phase coil 111 is permitted, and when it is turned off, energization to the U-phase coil 111 is interrupted. V-phase switching element 412 is connected to V-phase coil 112. When the V-phase switching element 412 is turned on, energization to the V-phase coil 112 is permitted, and when it is turned off, energization to the V-phase coil 112 is cut off. W-phase switching element 413 is connected to W-phase coil 113. When the W-phase switching element 413 is turned on, energization to the W-phase coil 113 is permitted, and when it is turned off, energization to the W-phase coil 113 is interrupted. In the present embodiment, the on / off operation of the switching elements 411 to 413 is controlled at an energization phase difference of 120 ° to each phase.

  A motor relay 42 is provided between the motor driver 41 and the battery 45. The motor relay 43 is on. By controlling the on / off operation of the motor relay 42, it is possible to switch permission or prohibition of energization from the battery to the motor 10 side.

  As shown in FIG. 2, the ECU 50 is mainly composed of a microcomputer or the like, and internally includes a CPU, a ROM, an I / O, and a bus line connecting these components, which are not shown. Each process in the ECU 50 may be a software process by executing a program stored in advance in a tangible memory device (that is, a readable non-transitory tangible recording medium) such as a ROM by a CPU, or may be dedicated It may be hardware processing by an electronic circuit.

  The ECU 50 controls the switching of the shift range by controlling the drive of the motor 10 based on the driver request shift range, the signal from the brake switch, the vehicle speed, and the like. Further, the ECU 50 controls the driving of the shift hydraulic control solenoid 6 based on the vehicle speed, the accelerator opening degree, the driver's requested shift range, and the like. By controlling the shift hydraulic control solenoid 6, the gear is controlled. The transmission hydraulic control solenoid 6 is provided in a number corresponding to the number of shift stages and the like. Although one ECU 50 controls the drive of the motor 10 and the solenoid 6 in the present embodiment, the motor control ECU for controlling the motor 10 may be divided into an AT-ECU for solenoid control. Hereinafter, drive control of the motor 10 will be mainly described.

  The ECU 50 includes an angle calculation unit 51, a speed calculation unit 52, a target setting unit 55, a drive control unit 56, and the like. The angle calculation unit 51 counts rising and falling edges of the A-phase signal and the B-phase signal output from the encoder 13. The encoder count value θen, which is the count value of pulse edges of the encoder 13, is a value corresponding to the rotational position of the rotor 103, and corresponds to the “rotational angle of the rotor”.

  In this embodiment, the encoder count value θen is incremented by 1 when the rotor 103 rotates in the positive direction by 3.75 ° in mechanical angle, and the encoder count value θen is decremented by 1 when the rotor 103 is rotated in the reverse direction by 3.75 ° in mechanical angle. Ru. As described in FIG. 3, the motor 10 is a three-phase motor in which the number of salient poles of the stator 101 is 12 and the number of salient poles of the rotor 103 is eight, so that the mechanical angle 3.75 ° is an electrical angle of 30 °. It corresponds. Since the mechanical angle and the electrical angle can be converted, the conduction angle and the like will be described below in terms of the electrical angle.

  The speed calculator 52 calculates the motor rotation number N based on the A-phase signal and the B-phase signal output from the encoder 13. The motor rotation speed N is, for example, a rotation speed per unit time represented by a unit rpm or the like, and can be regarded as a "motor rotation speed".

  The target setting unit 55 sets a target shift range based on a driver request shift range based on a shift switch or the like, a vehicle speed, a signal from a brake switch, and the like. Further, the target setting unit 55 sets a motor angle target value θcmd according to the target shift range.

  The drive control unit 56 controls the drive of the motor 10 by feedback control or the like so that the motor 10 is stopped at the rotational position where the encoder count value θen becomes the motor angle target value θcmd. As shown in FIG. 12, in the present embodiment, a region where an angle deviation Δθ, which is an absolute value of a difference between the motor angle target value θcmd and the encoder count value θen, is larger than the first angle determination threshold θth1 is an acceleration region and rotation speed Accelerate or maintain a relatively high rotational speed. A region where the angle deviation Δθ is larger than the second angle determination threshold θth2 and smaller than or equal to the first angle determination threshold θth1 is set as a deceleration region, and the rotational speed is reduced. A region where the angle deviation Δθ is equal to or less than the second angle determination threshold θth2 is a stop region, and the rotor 103 is stopped by the stationary phase energization. The first angle determination threshold θth1 is arbitrarily set according to the performance or the like of the motor 10 so that the rotor 103 can be stopped at the motor angle target value θcmd. The second angle determination threshold θth2 is set according to the control range in which the motor 10 is stopped.

  FIG. 5 shows on / off control of switching elements 411 to 413 and a current waveform. Hereinafter, although the V phase is described as an example, the same applies to the U phase and the W phase. Hereinafter, in one cycle of the electrical angle, an angle range in which the switching elements 411 to 413 are turned on is referred to as a conduction on angle θon, and an angle range in which the switching elements 411 to 413 are turned off is a conduction off angle θoff.

In FIG. 5A, the motor rotational speed N is the first rotational speed N1 (for example, 1000 rpm).
The switching state and the current waveform when the energization on angle θon is 180 ° electrical angle are shown. FIG. 5B shows the switching state and the current waveform when the motor rotation speed N is the second rotation speed N2 (for example, 2000 rpm) larger than the first rotation speed N1 and the energization on angle θon is 180 ° electrical angle. It shows. FIG. 5C shows the switching state and the current waveform when the motor rotation speed is the second rotation speed N2 and the energization on angle θon is 240 electrical degrees.

  As shown in FIGS. 5 (a) and 5 (b), when the energization on angle θon is made the same, the larger the motor rotational speed N, the shorter the energization time. For example, when the second rotation speed N2 is x times the first rotation speed N1, the energization time at the second rotation speed N2 is (1 / x) times the energization time at the first rotation speed N1.

  Since the coil 112 has an inductance, a delay occurs in the rising of the current. Therefore, when the motor rotation speed N becomes large and the energization time becomes short, there is a possibility that the switching element 412 is turned off and the energization is finished before the current rises. In such a state, the current is less likely to flow, so that the torque is insufficient and the acceleration is reduced.

  Therefore, in the present embodiment, as shown in FIG. 5C, when the motor rotational speed N is large, the electric angle range in which the switching element 412 is turned on is enlarged, and the energization time is secured to secure the amount of energization. Control the torque drop. In the present embodiment, in order to secure a period in which at least one of the three phases is turned off, the energization on angle θon is increased up to an electrical angle of 240 °. However, if the motor ON speed θon is too large when the motor rotation speed N is small, the braking force becomes large and the torque decreases, so that the adaptation according to the motor rotation speed N is necessary.

  The motor control process of the present embodiment will be described based on the flowchart of FIG. This process is executed by the drive control unit 56 at a predetermined cycle when the required shift range is switched. Hereinafter, the “step” of step S10 is omitted and simply referred to as the symbol “S”. The other steps are similar.

  In S10, the drive control unit 56 determines whether an angle deviation Δθ, which is an absolute value of a difference between the motor angle target value θcmd and the encoder count value θen, is larger than a first angle determination threshold θth1. If it is determined that the angle deviation Δθ is larger than the first angle determination threshold θth1 (S10: YES), the process proceeds to S30 and acceleration control is performed. If it is determined that the angle deviation Δθ is equal to or less than the first angle determination threshold θth1 (S10: NO), the process proceeds to S20.

  In S20, the drive control unit 56 determines whether the angle deviation Δθ is larger than the second angle determination threshold θth2. If it is determined that the angle deviation Δθ is larger than the second angle determination threshold θth2 (S20: YES), the process proceeds to S40 and deceleration control is performed. If it is determined that the angle deviation Δθ is less than or equal to the second angle determination threshold θth 2 (S20: NO), the process proceeds to S50, and stop control by stationary phase energization is performed.

  The acceleration control process will be described based on the flowchart of FIG. In S301, the drive control unit 56 determines whether the motor rotational speed N is equal to or less than a first speed determination threshold Nth1. The first speed determination threshold Nth1 can be arbitrarily set, and is, for example, 1000 rpm. If it is determined that the motor rotation number N is equal to or less than the first speed determination threshold Nth1 (S301: YES), the process proceeds to S303. When it is determined that the motor rotation number N is larger than the first speed determination threshold Nth1 (S301: NO), the process proceeds to S302.

  In S302, the drive control unit 56 determines whether the motor rotation number N is equal to or less than a second speed determination threshold Nth2. The second speed determination threshold Nth2 can be set to any value larger than the first speed determination threshold Nth1, and is, for example, 1500 rpm. If it is determined that the motor rotation number N is equal to or less than the second speed determination threshold Nth2 (S302: YES), the process proceeds to S305. When it is determined that the motor rotation number N is larger than the second speed determination threshold Nth2 (S302: NO), the process proceeds to S307.

  In S303, which is shifted when the motor rotation speed N is equal to or less than the first speed determination threshold Nth1, the drive control unit 56 sets the phase lead amount Ks of the energized phase to the rotational phase to zero. The phase lead amount Ks is set so that the coils 111 to 113 are energized at the timing when the optimum torque according to the position of the rotor 103 is obtained. In S304, the drive control unit 56 sets the energization on angle θon to 180 °.

  In S305, in which the motor rotation number N is larger than the first speed determination threshold Nth1 and smaller than or equal to the second speed determination threshold Nth2, the drive control unit 56 sets the phase lead amount Ks to +1. In S306, the drive control unit 56 sets the energization on angle θon to 210 °.

  In S307, in which the motor rotation number N is larger than the second speed determination threshold Nth2, the drive control unit 56 sets the phase lead amount Ks to +2. In S308, the drive control unit 56 sets the energization on angle θon to 240 °.

  The deceleration control process will be described based on the flowchart of FIG. In S401, the drive control unit 56 determines whether the motor rotational speed N is equal to or less than a third speed determination threshold Nth3. The third speed determination threshold Nth3 can be arbitrarily set, and is, for example, 1000 rpm. In the present embodiment, the first speed determination threshold Nth1 and the third speed determination threshold Nth3 are equal to each other, but may be different. When it is determined that the motor rotation number N is larger than the third speed determination threshold Nth3 (S401: NO), the process proceeds to S403. If it is determined that the motor rotation number N is equal to or less than the third speed determination threshold Nth3 (S401: YES), the process proceeds to S402.

  In S402, the drive control unit 56 determines whether the motor rotational speed N is equal to or less than a fourth speed determination threshold Nth4. The fourth speed determination threshold Nth4 can be set to an arbitrary value smaller than the third speed determination threshold Nth3, and is, for example, 300 rpm. If it is determined that the motor rotation number N is larger than the fourth speed determination threshold Nth 4 (S402: NO), the process proceeds to S405. If it is determined that the motor rotation number N is equal to or less than the fourth speed determination threshold Nth4 (S402: YES), the process proceeds to S406.

  In S403, in which the motor rotation number N is greater than the third speed determination threshold Nth3, the drive control unit 56 sets the phase lead amount Ks to -4. In S404, the drive control unit 56 sets the energization on angle θon to 240 °.

  In S405, which is performed when the motor rotation number N is larger than the fourth speed determination threshold Nth4 and smaller than or equal to the third speed determination threshold Nth3, the drive control unit 56 sets the phase lead amount Ks to -3. The drive control unit 56 sets the phase lead amount Ks to 0 in S406, which is transitioned to when the motor rotation speed N is equal to or less than the fourth speed determination threshold Nth4.

  In S407, which is a transition from S405 or S406, the drive control unit 56 sets the energization on angle θon to 180 °. That is, in the present embodiment, in the deceleration control, when the motor rotational speed N is larger than the third speed determination threshold Nth3, the rapid on-speed control is performed by setting the energization on angle θon to 240 °, and the motor rotational speed N is the third When the speed determination threshold value Nth3 or less, soft ON control is performed by setting the energization on angle θon to 180 °. In the present embodiment, the fourth speed determination threshold Nth4 is not used to switch the energization on angle θon. Further, although the speed judgment threshold other than the fourth speed judgment threshold Nth4 is commonly used for switching of the phase lead amount Ks and switching of the energization on angle θon, the judgment threshold for switching the phase lead amount Ks and energization on It may be different from the determination threshold for switching the angle θon.

  The energization on angle θon will be described based on FIGS. 9 to 11. In FIG. 9 to FIG. 11, the electrical angle is taken on the horizontal axis, and from the upper stage, the A-phase signal and B-phase signal of the encoder 13, on-off state of U-phase switching element 411, on-off state of V-phase switching element 412, W-phase switching element Indicates the on / off state of the The energization on angle θon and the energization off angle θoff are described for the V phase.

  FIG. 9 shows energization in a low speed region in which the motor rotation number N during acceleration control is less than or equal to the first speed determination threshold Nth1 or when the motor rotation number N during deceleration control is less than or equal to the third speed determination threshold Nth3. It is a pattern. In the low speed region, the on / off operation of the switching elements 411 to 413 is controlled at the energization on angle θon = 180 ° and the energization off angle θoff = 180 °. In the present embodiment, since one count of the encoder 13 is 30 °, in the low speed region, the switching elements 411 to 413 turn on six counts of the encoder count value θen and turn off six counts. In the low speed region, a two-phase conduction section in which the two phases of the coils 111 to 113 are energized and a one-phase conduction section in which the one phase is energized are equal. By setting the conduction on angle θon and the conduction off angle θoff to 180 °, the maximum torque can be output in the low speed region.

  FIG. 10 is an energization pattern in a medium speed region in which the motor rotation number N at the time of acceleration control is larger than the first speed determination threshold Nth1 and smaller than the second speed determination threshold Nth2. In the middle speed region, the on / off operation of the switching elements 411 to 413 is controlled at the energization on angle θon = 210 ° and the energization off angle θoff = 150 °. That is, in the middle speed region, the switching elements 411 to 413 are turned on for 7 counts of the encoder count value θen and turned off for 5 counts. In the middle speed region, the two-phase current passage is longer than the one-phase current passage.

  FIG. 11 shows energization in a high speed region where the motor rotation speed N during acceleration control is greater than the second speed determination threshold Nth2 or the motor rotation speed N during deceleration control is greater than the third speed determination threshold Nth3. It is a pattern. In the high speed region, the on / off operation of the switching elements 411 to 413 is controlled at the energization on angle θon = 240 ° and the energization off angle θoff = 120 °. That is, in the high speed region, the switching elements 411 to 413 are turned on for 8 counts of the encoder count value θen and turned off for 4 counts. In the high speed region, all the sections of one cycle of the electrical angle are two-phase conduction sections, and there is no one-phase conduction section. That is, as in the present embodiment, it can be understood that increasing the energization on angle θon lengthens the two-phase energization section. When the conduction on angle θon in each phase is longer than 240 °, a three-phase conduction state occurs, so the maximum value of the conduction on angle θon is 240 °.

  In the deceleration control, by setting the energization on angle θon to 240 ° at the start of deceleration, a sudden braking is applied and the vehicle is rapidly decelerated, so the control of the middle speed region shown in FIG. 10 is not performed. That is, in the present embodiment, the number of switching times of the energization on angle θon is different between the acceleration control time and the deceleration control time. In detail, the number of switching of the energization on angle θon at the time of deceleration control is smaller than the number of switching of the energization on angle at the time of acceleration control. In the present embodiment, the number of switching of the energization on angle θon at the time of deceleration control is one, and the number of switching of the energization on angle θon at the time of acceleration control is two.

  A time chart for explaining motor drive control of this embodiment is shown in FIG. In FIG. 12, the common time axis is taken as the horizontal axis, the motor angle is shown on the upper stage, and the motor rotational speed is shown on the lower stage. As for the motor rotational speed, a solid line in this embodiment and a reference example when the energization on angle θon is 180 ° regardless of the motor rotational speed N is indicated by a one-dot chain line.

  As shown in FIG. 12, when the required shift range is switched at time t1, the motor angle target value θcmd according to the required shift range is set, and the driving of the motor 10 is started. At the initial stage of driving the motor 10, acceleration control is performed. The drive of the motor 10 is controlled at the energization on angle θon = 180 ° in a period until the time t2 when the motor rotational speed N becomes the first speed determination threshold Nth1. Further, the drive of the motor 10 is controlled at the energization on angle θon = 210 ° in the period from time t2 to time t3 in which the motor rotation speed N is larger than the first speed determination threshold Nth1 and smaller than the second speed determination threshold Nth2. After time t3 at which the motor rotational speed N is larger than the second speed determination threshold Nth2, the drive of the motor 10 is controlled at the energization on angle θon = 240 °.

  When the angle deviation Δθ between the motor angle target value θcmd and the encoder count value θen becomes equal to or less than the first angle determination threshold θth1 at time t4, the control shifts from acceleration control to deceleration control. The drive of the motor 10 is controlled at the energization on angle θon = 240 ° in the period from time t4 to time t5 when the motor rotation speed N becomes equal to or less than the third speed determination threshold Nth3. That is, in the present embodiment, the high-speed rotation region is from time t3 to time t5, and the two phases are always energized by setting the energization on angle θon = 240 °. That is, in the present embodiment, the second speed determination threshold Nth2 and the third speed determination threshold Nth3 correspond to the "high speed rotation determination threshold".

  The drive of the motor 10 is controlled at the energization on angle θon = 180 ° in the period from the time t5 when the motor rotational speed N becomes equal to or less than the third speed determination threshold Nth3 to the time t7 when the fixed phase energization control is started. Further, the phase lead correction amount Ks is changed at times t2, t3, t4, t5, and t6.

  When the angle deviation Δθ becomes equal to or less than the second angle determination threshold θth2 at time t7, the control shifts from the deceleration control to the stop control by stationary phase energization. Then, after the stationary phase energization is continued for a predetermined energization continuation time, the energization to the motor 10 is turned off.

  In the present embodiment, the current is made easier to flow by increasing the energization on angle θon at the time of high speed rotation, and the torque is improved. Further, since the energization on angle θon is set based on the signal timing of the encoder 13, a complicated angle calculation is not required, and for example, compared to the case where the energization on angle θon is calculated by linear interpolation etc. Can be reduced.

  Further, in the deceleration control, it is possible to apply a sharp brake by increasing the energization on angle θon at the time of high speed rotation. Therefore, as shown by arrow Y in FIG. 12, the energization on angle θon is always 180 °. The period for performing the acceleration control can be extended as compared with the reference example. In addition, since the performance on the acceleration side is also improved, the maximum speed can be increased. Since the change amount of the encoder count value θen corresponds to the number of rotations × time, that is, the area surrounded by the solid line or the one-dot chain line, the maximum speed increases and the acceleration period becomes longer. The time to reach can be shortened.

  As described above, the shift range control device 40 of the present embodiment includes the stator 101, the coils 111 to 113 wound around the stator 101, and the motor 10 having the rotor 103 provided rotatably with respect to the stator 101. The motor driver 41 and the ECU 50 are provided. Motor driver 41 has switching elements 411-413 provided corresponding to each phase of coils 111-113.

  The ECU 50 has an angle calculation unit 51, a speed calculation unit 52, and a drive control unit 56. The angle calculation unit 51 calculates an encoder count value θen based on a detection value of the encoder 13 that detects the rotational position of the rotor 103. The speed calculation unit 52 calculates the motor rotation number N which is the rotation speed of the rotor 103 based on the detection value of the encoder 13. The drive control unit 56 rotates the rotor 103 from a state where the rotor 103 is stopped, and controls the drive of the motor 10 such that the rotor 103 is stopped at the target motor rotational position θcmd that is the set target rotational position. .

  The drive control unit 56 performs switching such that the energization on angle θon, which is an angle range in one cycle of the electrical angle supplied to each phase of the coils 111 to 113, becomes larger as the rotational speed of the rotor 103 is relatively larger. The on / off operation of the elements 411 to 413 is controlled. As a result, it is possible to suppress the torque shortage at the time of high speed rotation due to the delay of the rising of the current. Further, since the time required for the brake can be shortened at the time of deceleration control, the time required for position control of the motor 10 can be shortened, which contributes to the improvement of responsiveness.

  The encoder 13 which is a rotation angle sensor is a rotary encoder, and the energization on angle θon is switched stepwise according to the resolution of the encoder 13. This eliminates the need for complicated operations and facilitates software setting.

  The motor 10 is a three-phase motor, and the drive control unit 56 sets the energization on angle θon so that the two phases are always energized in the high speed rotation region where the rotation speed is larger than the high speed rotation determination threshold. In the present embodiment, the high-speed rotation determination threshold is different between acceleration control and deceleration control. Specifically, a second speed determination threshold Nth2 which is a high speed rotation determination threshold at the time of acceleration control and a third speed determination threshold Nth3 which is a high speed rotation determination threshold at the time of deceleration control are different. Then, in the high-speed rotation area from the motor speed N exceeding the second speed judgment threshold Nth2 to the point falling below the third speed judgment threshold Nth3, by setting the conduction on angle θon to 240 °, two-phase conduction is always performed. There is. The conduction on angle θon may not be exactly 240 °, for example, a control error and a deviation of about the dead time may be tolerated, and the one-phase conduction state is temporarily established as the conduction phase is switched. Shall be acceptable. At the time of high speed rotation, the conduction amount can be secured by maximizing the conduction on angle θon and performing two-phase conduction at all times, so that torque can be improved.

  The shift range control device 40 is applied to the shift by wire system 1 that switches the shift range by controlling the drive of the motor 10, and the motor angle target value θcmd is set according to the required shift range. Thereby, the shift range can be switched appropriately with high responsiveness.

(Other embodiments)
In the above embodiment, the motor is an SR motor. In other embodiments, the motor is not limited to the SR motor, but may be any motor such as a DC brushless motor. Also, the configuration of the motor driver may be any circuit configuration capable of changing the energization on angle. In the above embodiment, the motor is a three-phase motor. In another embodiment, the number of motor phases is not limited to three, and may be, for example, a four-phase motor. Further, in the above embodiment, the winding set is one. In other embodiments, two or more sets of windings may be provided.

  In the above embodiment, the rotation angle sensor is an encoder, and the resolution is 30 ° in electrical angle. In other embodiments, the resolutions of the encoders may be different. In addition, the number of switching of the energization on angle may be different from that in the above embodiment according to the resolution. In the above embodiment, the number of switching of the energization on angle is different between the acceleration control and the deceleration control. In another embodiment, the number of switching of the energization on angle may be equal between the acceleration control time and the deceleration control time. Further, the speed determination threshold value related to the switching determination of the energization on angle may be the same or different between the acceleration control time and the deceleration control time. In another embodiment, the rotation angle sensor is not limited to a rotary encoder, and any one such as a resolver may be used. Further, the rotational speed of the rotor may be changed to the motor rotational speed, and the rotational angular velocity [deg / s] or the like may be used. As the output shaft sensor, one other than the potentiometer may be used, or the output shaft sensor may be omitted.

  In the above embodiment, the detent plate is provided with four valleys. In other embodiments, the number of valleys is not limited to four, but may be any number. For example, the number of valleys of the detent plate may be two, and the P range and the Not P range may be switched. In addition, the shift range switching mechanism, the parking lock mechanism, and the like may be different from the above embodiment.

  In the above embodiment, a reduction gear is provided between the motor shaft and the output shaft. Although the details of the reduction gear are not mentioned in the above embodiment, for example, a cycloid gear, a planetary gear, a spur gear that transmits torque from the reduction mechanism substantially coaxial with the motor shaft to the drive shaft, or these Any configuration may be used, such as one using a combination of In other embodiments, the reduction gear between the motor shaft and the output shaft may be omitted, or a mechanism other than the reduction gear may be provided.

  In the above embodiment, the motor control device is applied to a shift-by-wire system to control a motor that drives a shift range switching mechanism of a vehicle. In other embodiments, the motor controller may be applied to devices other than shift-by-wire systems. As mentioned above, the present invention is not limited to the above-mentioned embodiment at all, and can be implemented in various forms in the range which does not deviate from the meaning of an invention.

10: Motor 101: Stator 103: Rotor 111 to 113: Coil 13: Encoder (rotational angle sensor)
40 ... Shift range control device (motor control device)
41: Motor driver 411 to 413: Switching element 50: ECU (control unit)
51 · · · Angle calculation unit 52 · · · Speed calculation unit 56 · · · Drive control unit

Claims (5)

A motor control device for controlling driving of a motor (10) having a stator (101), coils (111 to 113) wound around the stator, and a rotor (103) rotatably provided with respect to the stator There,
A motor driver (41) having switching elements (411 to 413) provided corresponding to the respective phases of the coil;
An angle calculator (51) for calculating the rotation angle of the rotor based on the detection value of the rotation angle sensor (13) for detecting the rotation position of the rotor; the rotational speed of the rotor based on the detection value of the rotation angle sensor A speed calculation unit (52) for calculating the rotation speed, and a drive that controls the drive of the motor to rotate the rotor from the stopped state of the rotor and stop the rotor at a set target rotation position A control unit (50) having a control unit (56);
Equipped with
The drive control unit performs the on / off operation of the switching element such that the energization on angle, which is an angle range in one cycle of an electrical angle supplied to each phase of the coil, becomes larger as the rotational speed is relatively larger. Control unit that controls the The rotation angle sensor is a rotary encoder,
The motor control device according to claim 1, wherein the energization on angle is switched according to the resolution of the rotation angle sensor. The motor is a three-phase motor, and
The motor control device according to claim 1 or 2, wherein the drive control unit sets the energization on angle so that two phases are always energized in a high speed rotation region where the rotation speed is larger than a high speed rotation determination threshold.   The motor control device according to claim 3, wherein the high speed rotation determination threshold is different at the time of acceleration control and at the time of deceleration control. The present invention is applied to a shift range switching system (1) that switches a shift range by controlling the drive of the motor,
The motor control device according to any one of claims 1 to 4, wherein the target rotational position is set according to a required shift range.

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