JP6992481B2 - Motor control device - Google Patents

Description

The present invention relates to a motor control device.

Conventionally, there is known a motor control device that rotates a rotor to a target position by detecting the rotation position of the rotor and sequentially switching the energizing phase. For example, in Patent Document 1, the phase lead amount of the energized phase is corrected according to the rotor rotation speed.

Japanese Patent No. 3888278

In Patent Document 1, the period in which the coil of each phase is energized is set as a predetermined angle range regardless of the rotation speed. Therefore, when the rotation speed is high, the energization time is shorter than when the rotation speed is slow, and there is a possibility that the current cannot be fully increased due to the influence of the inductance of the coil.

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

The motor control device of the present invention drives 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. It controls and includes a motor driver (41) and a control unit (50). The motor driver has switching elements (411 to 413) provided corresponding to each phase of the coil.

The control unit includes 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 the state in which the rotor is stopped, and controls the drive of the motor so that the rotor stops at the set target rotation position.

The angle range in one cycle of the electric angle energized in each phase of the coil is defined as the energization on angle. The drive control unit has an energization on angle of 180 ° at which the two-phase energization section and the one-phase energization section are equal in the low-speed region, and the rotation speed is set so that the two-phase energization section becomes longer as the rotation speed becomes relatively larger . The energization on angle is gradually increased accordingly . As a result, it is possible to suppress a torque shortage during high-speed rotation due to a delay in the rise of current.

It is a perspective view which shows the shift-by-wire system by one Embodiment. It is a schematic block diagram which shows the shift-by-wire system by one Embodiment. It is a schematic diagram which shows the motor by one Embodiment. It is a circuit diagram which shows the motor driver by one Embodiment. It is a time chart explaining the switching state and the current waveform of the switching element by one Embodiment. It is a flowchart explaining the motor control processing by one Embodiment. It is a flowchart explaining the 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 a low speed region by one Embodiment. It is explanatory drawing explaining the switching state in the medium speed region by one Embodiment. It is explanatory drawing explaining the switching state in the high-speed region by one Embodiment. It is a time chart explaining the motor control processing by one Embodiment.

(One embodiment)
Hereinafter, the motor control device according to the present invention will be described with reference to the drawings. The motor control device according to one embodiment is shown in FIGS. 1 to 12. 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, a shift range control device 40 as a motor control device, and the like. Be prepared.

The motor 10 rotates 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 has a stator 101, a rotor 103, and a winding set 11. The winding set 11 has a U-phase coil 111, a V-phase coil 112, and a W-phase coil 113, and is wound around a salient pole 102 of the stator 101. The coils 111 to 113 are connected by the connection portion 115. The 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 relatively rotatable, and is rotationally driven by switching the energized phases of the coils 111 to 113. In the present embodiment, the number of salient poles of the stator 101 is 12, and the number of salient poles of the rotor 103 is 8.

As shown in FIG. 2, the encoder 13 as a rotation angle sensor detects the rotation position of the rotor 103 of the motor 10. The encoder 13 is a magnetic rotary encoder, and is composed of a magnet that rotates integrally with the rotor 103, a Hall IC for magnetic detection, and the like. The encoder 13 outputs phase A and phase B 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 so that high and low are switched every 60 ° of the electric angle, and the phases of the A-phase signal and the B-phase signal are output with an electric angle of 30 °. (See Fig. 8 etc.). Therefore, the resolution of the encoder 13 of the present embodiment is 30 ° in the electric angle, and 12 counts are made in one cycle of the electric angle.

The speed reducer 14 is provided between the motor shaft of the motor 10 and the output shaft 15, and decelerates the rotation of the motor 10 to output to the output shaft 15. As a result, 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, a detent spring 25, and the like, and the rotational driving force output from the speed reducer 14 is applied to the manual valve 28 and the parking lock mechanism 30. Communicate 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 that protrudes 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 motion of the motor 10 into a linear motion and transmits it to the manual valve 28. The manual valve 28 is provided on the valve body 29. When the manual valve 28 reciprocates in the axial direction, the hydraulic pressure supply path to the hydraulic clutch (not shown) is switched, and the engagement state of the hydraulic clutch is switched to change the shift range. On the detent spring 25 side of the detent plate 21, four recesses 22 for holding the manual valve 28 at a position corresponding to each range 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 a plate-shaped member that can be elastically deformed, and a detent roller 26 is provided at the tip thereof. The detent roller 26 fits into any of the recesses 22. The detent spring 25 urges the detent roller 26 toward the center of rotation of the detent plate 21. When a predetermined or greater rotational force is applied to the detent plate 21, the detent spring 25 is elastically deformed, and the detent roller 26 moves in the recess 22. By fitting the detent roller 26 into any of the recesses 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, and the automatic transmission 5 is used. The shift range of is fixed.

The parking lock mechanism 30 includes a parking rod 31, a cone 32, a parking lock pole 33, a shaft portion 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 cone 32 is provided on the other end 312 side of the parking rod 31. The conical body 32 is formed so that the diameter is reduced toward the other end 312 side. When the detent plate 21 swings in the reverse rotation direction, the cone 32 moves in the direction of the arrow P.

The parking lock pole 33 is in contact with the conical surface of the conical body 32 and is provided so as to be swingable around the shaft portion 34. On the parking gear 35 side of the parking lock pole 33, a convex portion capable of engaging with the parking gear 35 is provided. 331 is 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 forward rotation direction and the conical body 32 moves in the arrow NotP direction, the meshing between the convex portion 331 and the parking gear 35 is released.

The parking gear 35 is provided on an axle (not shown) so as to be able to mesh with the convex portion 331 of the parking lock pole 33. By engaging the parking gear 35 and the convex portion 331, the rotation of the axle is restricted. 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 hindered 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 a predetermined speed (for example, 5 km / h) or less, the axle is locked by the parking lock mechanism 30.

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

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

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

As shown in FIG. 2, the ECU 50 is mainly composed of a microcomputer or the like, and includes a CPU, a ROM, an I / O, and a bus line connecting these configurations, which are not shown in the inside. Each process in the ECU 50 may be a software process by executing a program stored in advance in a substantive memory device such as a ROM (that is, a readable non-temporary tangible recording medium) on the CPU, or a dedicated process. 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 required shift range, the signal from the brake switch, the vehicle speed, and the like. Further, the ECU 50 controls the drive of the hydraulic pressure control solenoid 6 for shifting based on the vehicle speed, the accelerator opening degree, the driver required shift range, and the like. By controlling the hydraulic pressure control solenoid 6 for shifting, the shifting stage is controlled. The number of shifting hydraulic control solenoids 6 is provided according to the number of shifting stages and the like. In the present embodiment, one ECU 50 controls the drive of the motor 10 and the solenoid 6, but the motor ECU for controlling the motor 10 and the AT-ECU for solenoid control may be separated. Hereinafter, the 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 the 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 the pulse edge of the encoder 13, is a value corresponding to the rotation position of the rotor 103 and corresponds to the “rotation angle of the rotor”.

In the present embodiment, when the rotor 103 is rotated in the positive direction by 3.75 ° at the mechanical angle, the encoder count value θen is incremented by 1, and when the rotor 103 is rotated in the reverse direction by 3.75 ° at the mechanical angle, the encoder count value θen is incremented by -1. To. As described with reference to FIG. 3, since 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 8, the mechanical angle of 3.75 ° is changed to the electric angle of 30 °. handle. Since the mechanical angle and the electric angle can be converted, the energization angle and the like will be described below by the electric angle.

The speed calculation unit 52 calculates the motor rotation speed 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 expressed in a unit rpm or the like, and can be regarded as a “motor rotation speed”.

The target setting unit 55 sets the target shift range based on the driver required shift range based on the shift switch or the like, the vehicle speed, the signal from the brake switch, or the like. Further, the target setting unit 55 sets the 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 stops at a rotation position where the encoder count value θen becomes the motor angle target value θcmd. As shown in FIG. 12, in the present embodiment, the region where the angle deviation Δθ, which is the absolute value of the difference between the motor angle target value θcmd and the encoder count value θen, is larger than the first angle determination threshold θth1 is set as the acceleration region, and the rotation speed is set. Accelerate or maintain a relatively high rotational speed. The region where the angle deviation Δθ is larger than the second angle determination threshold value θth2 and is equal to or less than the first angle determination threshold value θth1 is set as the deceleration region, and the rotation speed is decelerated. The region where the angle deviation Δθ is equal to or less than the second angle determination threshold value θth2 is set as the stop region, and the rotor 103 is stopped by the stationary phase energization. The first angle determination threshold value θth1 is arbitrarily set according to the performance of the motor 10 and the like so that the rotor 103 can be stopped at the motor angle target value θcmd. The second angle determination threshold value θth2 is set according to the control range for stopping the motor 10.

FIG. 5 shows on / off control and current waveforms of the switching elements 411 to 413. Hereinafter, the V phase will be described as an example, but the same applies to the U phase and the W phase. Hereinafter, in one cycle of the electric angle, the angle range in which the switching elements 411 to 413 are turned on is defined as the energization on angle θon, and the angle range in which the switching elements 411 to 413 are turned off is defined as the energization off angle θoff.

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

As shown in FIGS. 5A and 5B, when the energization on angle θon is the same, the energization time becomes shorter as the motor rotation speed N increases. For example, if 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, there is a delay in the rise 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 ends before the current rises completely. In such a state, it becomes difficult for the current to flow, so that the torque is insufficient and the acceleration decreases.

Therefore, in the present embodiment, as shown in FIG. 5C, when the motor rotation speed N is large, the electric flux range for turning on the switching element 412 is increased and the energization time is lengthened to secure the energization amount. However, the decrease in torque is suppressed. In the present embodiment, the energization on angle θon is increased up to an electric angle of 240 ° in order to secure a period for turning off at least one of the three phases. However, if the energization on angle θon is made too large when the motor rotation speed N is small, the braking force increases and the torque decreases, so it is necessary to adapt to the motor rotation speed N.

The motor control process of this embodiment will be described with reference to the flowchart of FIG. This process is executed by the drive control unit 56 in 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 same is true for the other steps.

In S10, the drive control unit 56 determines whether or not the angle deviation Δθ, which is the absolute value of the difference between the motor angle target value θcmd and the encoder count value θen, is larger than the first angle determination threshold value θth1. When it is determined that the angle deviation Δθ is larger than the first angle determination threshold value θth1 (S10: YES), the process proceeds to S30 and acceleration control is performed. When it is determined that the angle deviation Δθ is equal to or less than the first angle determination threshold value θth1 (S10: NO), the process proceeds to S20.

In S20, the drive control unit 56 determines whether or not the angle deviation Δθ is larger than the second angle determination threshold value θth2. When it is determined that the angle deviation Δθ is larger than the second angle determination threshold value θth2 (S20: YES), the process proceeds to S40 and deceleration control is performed. When it is determined that the angle deviation Δθ is equal to or less than the second angle determination threshold value θth2 (S20: NO), the process proceeds to S50, and stop control is performed by energizing the fixed phase.

The acceleration control process will be described with reference to the flowchart of FIG. In S301, the drive control unit 56 determines whether or not the motor rotation speed N is equal to or less than the first speed determination threshold value Nth1. The first speed determination threshold value Nth1 can be arbitrarily set, and is, for example, 1000 rpm. When it is determined that the motor rotation speed N is equal to or less than the first speed determination threshold value Nth1 (S301: YES), the process proceeds to S303. When it is determined that the motor rotation speed N is larger than the first speed determination threshold value Nth1 (S301: NO), the process proceeds to S302.

In S302, the drive control unit 56 determines whether or not the motor rotation speed N is equal to or less than the second speed determination threshold value Nth2. The second speed determination threshold value Nth2 can be set to an arbitrary value larger than the first speed determination threshold value Nth1, and is, for example, 1500 rpm. When it is determined that the motor rotation speed N is equal to or less than the second speed determination threshold value Nth2 (S302: YES), the process proceeds to S305. When it is determined that the motor rotation speed N is larger than the second speed determination threshold value Nth2 (S302: NO), the process proceeds to S307.

In S303, which shifts to the case where the motor rotation speed N is equal to or less than the first speed determination threshold value Nth1, the drive control unit 56 sets the phase lead amount Ks of the energized phase with respect to the rotation phase to 0. The phase lead amount Ks is set so that the coils 111 to 113 are energized at the timing when the optimum torque corresponding to the position of the rotor 103 is generated. In S304, the drive control unit 56 sets the energization on angle θon to 180 °.

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

In S307, which shifts to the case where the motor rotation speed N is larger than the second speed determination threshold value Nth2, the drive control unit 56 sets the phase advance 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 with reference to the flowchart of FIG. In S401, the drive control unit 56 determines whether or not the motor rotation speed N is equal to or less than the third speed determination threshold value Nth3. The third speed determination threshold value Nth3 can be arbitrarily set, and is, for example, 1000 rpm. In the present embodiment, the first speed determination threshold value Nth1 and the third speed determination threshold value Nth3 are equal to each other, but may be different. When it is determined that the motor rotation speed N is larger than the third speed determination threshold value Nth3 (S401: NO), the process proceeds to S403. When it is determined that the motor rotation speed N is equal to or less than the third speed determination threshold value Nth3 (S401: YES), the process proceeds to S402.

In S402, the drive control unit 56 determines whether or not the motor rotation speed N is equal to or less than the fourth speed determination threshold value Nth4. The fourth speed determination threshold value Nth4 can be set to an arbitrary value smaller than the third speed determination threshold value Nth3, and is, for example, 300 rpm. When it is determined that the motor rotation speed N is larger than the fourth speed determination threshold value Nth4 (S402: NO), the process proceeds to S405. When it is determined that the motor rotation speed N is equal to or less than the fourth speed determination threshold value Nth4 (S402: YES), the process proceeds to S406.

In S403, which shifts to the case where the motor rotation speed N is larger than the third speed determination threshold value Nth3, the drive control unit 56 sets the phase advance amount Ks to -4. In S404, the drive control unit 56 sets the energization on angle θon to 240 °.

In S405, which shifts to the case where the motor rotation speed N is larger than the fourth speed determination threshold value Nth4 and is equal to or less than the third speed determination threshold value Nth3, the drive control unit 56 sets the phase advance amount Ks to -3. In S406, which shifts to the case where the motor rotation speed N is equal to or less than the fourth speed determination threshold value Nth4, the drive control unit 56 sets the phase lead amount Ks to 0.

In S407 that shifts following 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 rotation speed N is larger than the third speed determination threshold Nth3, the sudden deceleration control is performed by setting the energization on angle θon to 240 °, and the motor rotation speed N is the third. When the speed determination threshold Nth3 or less, the energization on angle θon is set to 180 ° to perform soft landing control. In the present embodiment, the fourth speed determination threshold value Nth4 is not used for switching the energization on angle θon. Further, the speed determination threshold values other than the fourth speed determination threshold value Nth4 are commonly used for switching the phase advance amount Ks and switching the energization on angle θon, but the determination threshold value for switching the phase advance amount Ks and the energization on. It may be different from the determination threshold value for switching the angle θon.

The energization on angle θon will be described with reference to FIGS. 9 to 11. In FIGS. 9 to 11, the electric angle is the horizontal axis, and from the top, the A-phase signal and B-phase signal of the encoder 13, the on / off state of the U-phase switching element 411, the on / off state of the V-phase switching element 412, and the W-phase switching element. Indicates the on / off state of. 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 when the motor rotation speed N during acceleration control is equal to or less than the first speed determination threshold value Nth1, or when the motor rotation speed N during deceleration control is equal to or less than the third speed determination threshold value Nth3. It is a pattern. In the low speed region, the on / off operation of the switching elements 411 to 413 is controlled by 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 are turned on for 6 counts of the encoder count value θen and turned off for 6 counts. In the low speed region, the two-phase energization section in which the two phases of the coils 111 to 113 are energized and the one-phase energization section in which the one phase is energized are equal. By setting the energization on angle θon and the energization 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 where the motor rotation speed N at the time of acceleration control is larger than the first speed determination threshold value Nth1 and is equal to or less than the second speed determination threshold value Nth2. In the medium speed region, the on / off operation of the switching elements 411 to 413 is controlled by the energization on angle θon = 210 ° and the energization off angle θoff = 150 °. That is, in the medium 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 medium speed region, the two-phase energization section is longer than the one-phase energization section.

FIG. 11 shows energization in a high speed region when the motor rotation speed N during acceleration control is larger than the second speed determination threshold value Nth2, or when the motor rotation speed N during deceleration control is larger than the third speed determination threshold value Nth3. It is a pattern. In the high-speed region, the on / off operation of the switching elements 411 to 413 is controlled by 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 sections of one cycle of electric angle are two-phase energization sections, and there is no one-phase energization section. That is, it can be considered that lengthening the energization on angle θon as in the present embodiment lengthens the two-phase energization section. If the energization on angle θon in each phase is longer than 240 °, a three-phase energization state occurs. Therefore, the maximum value of the energization on angle θon is 240 °.

In the deceleration control, by setting the energization on angle θon to 240 ° at the start of deceleration, sudden braking is applied and the vehicle decelerates suddenly. Therefore, the medium speed region shown in FIG. 10 is not controlled. That is, in the present embodiment, the number of times the energization on angle θon is switched differs between the acceleration control and the deceleration control. Specifically, the number of times the energization on angle θon is switched during deceleration control is less than the number of times the energization on angle is switched during acceleration control. In the present embodiment, the energization on angle θon is switched once during deceleration control, and the energization on angle θon is switched twice during acceleration control.

FIG. 12 shows a time chart illustrating the motor drive control of the present embodiment. In FIG. 12, the common time axis is the horizontal axis, the upper row shows the motor angle, and the lower row shows the motor rotation speed. Regarding the motor rotation speed, the present embodiment is shown by a solid line, and a reference example when the energization on angle θon is 180 ° regardless of the motor rotation speed N is shown by a alternate long and short dash line.

As shown in FIG. 12, when the required shift range is switched at time t1, the motor angle target value θcmd corresponding 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 the period until the time t2 when the motor rotation speed N becomes the first speed determination threshold value Nth1. Further, 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 equal to or less than the second speed determination threshold Nth2, the drive of the motor 10 is controlled at the energization on angle θon = 210 °. After the time t3 when the motor rotation speed N is larger than the second speed determination threshold value Nth2, the drive of the motor 10 is controlled at the energization on angle θon = 240 °.

At time t4, 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 value θth1, the acceleration control is shifted to the deceleration control. During the period from the time t4 to the time t5 when the motor rotation speed N becomes the third speed determination threshold value Nth3 or less, the drive of the motor 10 is controlled at the energization on angle θon = 240 °. That is, in the present embodiment, the high-speed rotation region is from time t3 to time t5, and by setting the energization on angle θon = 240 °, the two phases are always energized. That is, in the present embodiment, the second speed determination threshold value Nth2 and the third speed determination threshold value Nth3 correspond to the “high-speed rotation determination threshold value”.

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

When the angle deviation Δθ becomes equal to or less than the second angle determination threshold value θth2 at time t7, the deceleration control shifts to the stop control by the fixed phase energization. Then, after the fixed 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 flow is facilitated and the torque is improved by increasing the energization on angle θon at the time of high-speed rotation. Further, since the energization on angle θon is set based on the signal timing of the encoder 13, complicated angle calculation is unnecessary, and the calculation load is compared with the case where the energization on angle θon is calculated by linear interpolation or the like. Can be reduced.

Further, in deceleration control, it is possible to apply a sudden brake by increasing the energization on angle θon during high-speed rotation. Therefore, as shown by the arrow Y in FIG. 12, the energization on angle θon is always 180 °. Compared with the reference example, the period for accelerating control can be lengthened. In addition, the performance on the acceleration side has also improved, so the maximum speed can be increased. Since the amount of change in the encoder count value θen corresponds to the number of revolutions × time, that is, the area surrounded by the solid line or the alternate long and short dash line, the maximum speed increases and the acceleration period becomes longer, so that the motor angle target value θcmd It is possible to shorten the time to reach.

As described above, the shift range control device 40 of the present embodiment is a motor 10 having a stator 101, coils 111 to 113 wound around the stator 101, and a rotor 103 rotatably provided with respect to the stator 101. The motor driver 41 and the ECU 50 are provided to control the drive of the motor driver 41. The motor driver 41 has switching elements 411 to 413 provided corresponding to each phase of the coils 111 to 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 the encoder count value θen based on the detection value of the encoder 13 that detects the rotation position of the rotor 103. The speed calculation unit 52 calculates the motor rotation speed 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 the state in which the rotor 103 is stopped, and controls the drive of the motor 10 so that the rotor 103 stops at the motor angle target value θcmd, which is the set target rotation position. ..

The drive control unit 56 switches so that the larger the rotation speed of the rotor 103, the larger the energization on angle θon, which is the angle range in one cycle of the electric angle energized in each phase of the coils 111 to 113. It controls the on / off operation of the elements 411 to 413. As a result, it is possible to suppress a torque shortage during high-speed rotation due to a delay in the rise of current. Further, since the time required for braking can be shortened during 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 settings.

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 value. In the present embodiment, the high-speed rotation determination threshold value is different between the acceleration control and the deceleration control. Specifically, the second speed determination threshold Nth2, which is the high-speed rotation determination threshold during acceleration control, and the third speed determination threshold Nth3, which is the high-speed rotation determination threshold during deceleration control, are different. Then, in the high-speed rotation region from when the motor rotation speed N exceeds the second speed determination threshold value Nth2 to when it falls below the third speed determination threshold value Nth3, the energization on angle θon is set to 240 °, so that the two-phase energization is always performed. There is. It should be noted that the energization on angle θon does not have to be strictly 240 °, and for example, a control error or a deviation of about dead time is allowed, and the energization phase is temporarily switched to the one-phase energization state. That shall be acceptable. At the time of high-speed rotation, the torque can be improved because the energization amount can be secured by maximizing the energization on angle θon and always performing two-phase energization.

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. As a result, the shift range can be appropriately switched with good responsiveness.

(Other embodiments)
In the above embodiment, the motor is an SR motor. In another embodiment, the motor is not limited to the SR motor, and may be any motor such as a DC brushless motor. Further, the configuration of the motor driver may be any circuit configuration in which the energization on angle can be changed. In the above embodiment, the motor is a three-phase motor. In another embodiment, the number of phases of the motor is not limited to 3, and may be, for example, a 4-phase motor or the like. Further, in the above embodiment, the winding set is one set. In another embodiment, two or more winding sets 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 encoder resolution may be different. Further, depending on the resolution, the number of times the energization on angle is switched may be different from that of the above embodiment. In the above embodiment, the number of times the energization on angle is switched differs between the acceleration control and the deceleration control. In another embodiment, the number of times the energization on angle is switched may be the same between the acceleration control and the deceleration control. 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 and the deceleration control. In another embodiment, the rotation angle sensor is not limited to the rotary encoder, and any resolver or the like may be used. Further, as the rotation speed of the rotor, the rotation angular velocity [deg / s] or the like may be used instead of the motor rotation speed. As the output shaft sensor, a sensor 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 and may be any number. For example, the number of valleys of the detent plate may be two, and the P range and the NotP range may be switched. Further, the shift range switching mechanism, the parking lock mechanism, and the like may be different from those in the above embodiment.

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

In the above embodiment, the motor control device is applied to the shift-by-wire system and controls the motor that drives the shift range switching mechanism of the vehicle. In other embodiments, the motor control device may be applied to devices other than the shift-by-wire system. As described above, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the invention.

10 ... Motor 101 ... Stator 103 ... Rotor 111-113 ... Coil 13 ... Encoder (rotation 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 that controls the drive 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 a switching element (411 to 413) provided corresponding to each phase of the coil, and a motor driver (41).
The angle calculation unit (51) that 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, and the rotation speed of the rotor based on the detection value of the rotation angle sensor. The speed calculation unit (52) that calculates A control unit (50) having a control unit (56),
Equipped with
Assuming that the angle range in one cycle of the electric angle energized in each phase of the coil is the energization on angle,
The drive control unit has the energization on angle of 180 ° at which the two-phase energization section and the one-phase energization section are equal in the low-speed region, and the two-phase energization section becomes longer as the rotation speed becomes relatively larger . A motor control device that gradually increases the energization on angle according to the rotation speed . 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.
The motor control device according to claim 1 or 2, wherein the drive control unit sets the energization on angle so that the two phases are always energized in a high-speed rotation region where the rotation speed is larger than the high-speed rotation determination threshold value. The motor control device according to claim 3, wherein the high-speed rotation determination threshold value is different between acceleration control and deceleration control. It is applied to the shift range switching system (1) that switches the 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 rotation position is set according to a required shift range.

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