JP2004015849A - Motor control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To learn correspondence between a rotational position of a rotor and an energized phase after power-on, in a brushless type motor such as a switched reluctance motor. <P>SOLUTION: At the initial driving stage after power-on, for example, when switching by the prescribed time schedule the energized phases of the motor in the sequence of W-phase energization, UW-phase energization, U-phase energization, UV-phase energization and VW-phase energization so as to count the output signal of an encoder, the device learns the encoder count value and the correspondence between the rotational position of the rotor and energized phase at the completion of the initial driving stage. At the subsequent regular driving stage, the energized phase is decided based on the encoder count value and the result of learning at the completion of the initial driving stage. At the initial driving stage, the time T1 of the first phase energization is made shorter than the time T2 of the second phase energization, for instance, T1 is set at 10ms and T2 at 100ms. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor control device that rotates a rotor by sequentially switching the energized phase of a motor based on an output signal of an encoder.
[0002]
[Prior art]
In recent years, brushless motors such as switch reluctance motors, which have been increasing in demand as simple and inexpensive motors, are equipped with an encoder that outputs a pulse signal in synchronization with the rotation of the rotor. There is a type in which the rotor is rotationally driven by detecting the rotational position of the rotor based on the count value and sequentially switching the energized phase.
[0003]
[Problems to be solved by the invention]
By the way, this type of motor with an encoder can only detect the amount of rotation (rotation angle) from the start position of the rotor based on the count value of the output signal of the encoder after startup. If the absolute rotation position of the rotor is detected by the method and the correspondence between the rotation position of the rotor and the energized phase is not established, the motor cannot be driven normally.
[0004]
Thus, for example, in a switched reluctance motor, as shown in Japanese Patent Application Laid-Open No. 2000-69779, two phases are simultaneously excited (energized) at the start of startup, and after a lapse of a predetermined time, the rotational position of the rotor at that time is determined. In some cases, the current-carrying phase is determined on the basis of.
[0005]
However, simply exciting the two phases simultaneously at the start of startup does not necessarily mean that the rotor will necessarily rotate to the position corresponding to the two energized phases, and that the rotational position of the rotor and the energized phase may not correspond. is there.
[0006]
In addition, the above-mentioned publication states that there may be unstable points even when two-phase current is applied. As a countermeasure, the above publication discloses that one-phase current is supplied, and then two phases are simultaneously excited. First, by exciting one phase, the unstable region caused by exciting two phases is removed, and then, by exciting two phases, the rotor can be rotated to only one stable point, It is described that the reference position of the rotor can be surely learned.
[0007]
However, when one phase is excited, the rotor is less likely to rotate to a position corresponding to one phase because the torque is smaller than when two phases are excited. Therefore, if only one phase is first excited, the unstable region when the two phases are excited cannot be excluded, and the reference position of the rotor may still be erroneously learned.
[0008]
The present invention has been made in view of these circumstances, and accordingly, an object of the present invention is to provide a motor control device capable of securely associating the rotational position of the rotor with the energized phase by initial driving after power-on. To provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the motor control device according to claim 1 of the present invention counts the output signal of the encoder by making a cycle of switching the energized phase of the motor at a predetermined time schedule at the time of initial driving after power-on. Learns the correspondence between the count value at the end of the initial drive, the rotational position of the rotor, and the energized phase, and then energizes based on the count value of the output signal of the encoder and the learning result at the end of the initial drive during normal drive. The phase is determined. As described above, if the switching of the energized phase is performed once during the initial drive, the rotational position of the rotor and the energized phase always match in one of the energized phases before the end of the initial drive. The rotor rotates in synchronism with the switching, and a pulse signal is output from the encoder in synchronization with the rotation of the rotor. Therefore, by looking at the count value of the output signal of the encoder at the end of the initial drive, the angle (rotation amount) at which the rotor actually rotates in synchronization with the switching of the energized phase before the end of the initial drive can be determined. Since the correspondence between the count value of the output signal of the encoder at the end of the initial drive, the rotational position of the rotor, and the energized phase can be understood, by learning this correspondence, the count value of the output signal of the encoder during normal drive thereafter. The correct energizing phase can be selected based on the learning result at the end of the initial drive and the motor can be normally rotated.
[0010]
Further, a switch reluctance motor may be used as the motor, and one-phase energization and two-phase energization may be alternately switched at the time of initial driving. Switched reluctance motors have the advantage that they are inexpensive and have high durability and reliability against temperature environments and the like because they do not require permanent magnets and have a simple structure. If the one-phase energization and the two-phase energization are alternately switched at the time of the initial drive, compared with the one-phase excitation system in which only one phase is always energized or the two-phase excitation system in which two phases are always energized, one phase energization is performed. Since the rotation angle of the rotor per step (one excitation) is halved, the rotation position of the rotor and the energized phase can be reliably synchronized during the initial drive, and the rotor can be energized by two-phase energization with a large torque. Is stopped, and the output signal of the encoder can be stabilized.
[0011]
In this case, the one-phase energization time during the initial drive may be shorter than the two-phase energization time. In other words, even after the rotational position of the rotor and the energized phase are synchronized during the initial drive, the rotor oscillates in the one-phase energization with a small torque, so that the one-phase energization time is shortened and the next By switching to the two-phase energization, the vibration of the rotor can be stopped quickly, the output signal of the encoder can be stabilized, and the time of the initial drive can be shortened.
[0012]
Further, the initial drive may be started from two-phase energization. In this way, even if the rotor position at the beginning of the initial drive does not exactly match the position corresponding to the first two-phase energization, if it is within the range where the large torque of the two-phase energization can reach. In addition, the rotational position of the rotor and the energized phase can be synchronized from the beginning of the initial drive.
[0013]
Further, when it is necessary to terminate the initial drive and shift to the normal drive during the initial drive, the next two-phase energization (the shift to the normal drive during the execution of the two-phase energization) is performed. When it is necessary to perform the two-phase energization, the operation shifts to the normal drive after the end of the two-phase energization, and the count value of the output signal of the encoder, the rotational position of the rotor, and the energized phase at the end of the two-phase energization The correspondence may be learned, and the energized phase may be determined based on the count value of the output signal of the encoder and the learning result at the end of the two-phase energization during the subsequent normal driving.
[0014]
As described above, in the two-phase energization, since the torque is large, even if the position of the rotor is slightly shifted from the position corresponding to the two-phase energization, the rotor can be rotated to the position corresponding to the two-phase energization. Therefore, it is considered that there is a high probability that the rotation position of the rotor and the energized phase can be synchronized only by performing the two-phase energization once or twice during the initial drive. Therefore, when it is necessary to terminate the initial drive and shift to the normal drive during the initial drive, the normal drive is switched to the normal drive after the next two-phase energization (or the current two-phase energization) ends. Then, during the initial drive, the correspondence between the count value of the output signal of the encoder, the rotational position of the rotor, and the energized phase can be learned, and then the normal drive can be quickly shifted to.
[0015]
In addition, the encoder outputs the A-phase signal and the B-phase signal having a predetermined phase difference (generally, a phase difference of 90 degrees in electrical angle) in synchronization with the rotation of the rotor. The Z-phase signal is output at the reference rotation position of the rotor, and the edges of the A-phase signal and the B-phase signal are counted at the time of the initial drive, and the count value at the end of the initial drive, the rotation position of the rotor, and the energized phase are counted. The energizing phase is determined based on the count value of the output signal of the encoder and the learning result at the end of the initial drive at the time of normal driving, and the count value at the time of outputting the Z-phase signal. It is determined whether or not the correspondence between the rotational position of the rotor and the rotational position of the rotor and the energized phase are not shifted, and if there is a shift, the shift may be corrected (hereinafter, this correction is referred to as “Z-phase correction”). .
[0016]
In this configuration, since the reference rotation position of the rotor can be accurately detected by the Z-phase signal output from the encoder, for example, the energized phase (count value) when the Z-phase signal is output corresponds to the reference rotation position of the rotor. By determining whether the current phase is the current phase (count value), it is possible to confirm whether the correspondence between the rotational position of the rotor and the current phase (count value) is not shifted. If so, by correcting the deviation, highly reliable motor control can be performed.
[0017]
In this case, if the Z-phase correction is repeatedly performed, there is a possibility that an erroneous Z-phase correction has been performed. Therefore, the Z-phase correction is performed a predetermined number of times during normal driving. In such a case, the Z-phase correction may be prohibited by the Z-phase correction prohibiting means. By doing so, it is possible to prevent the motor from stopping and malfunctioning due to repeated incorrect Z-phase correction.
[0018]
Further, the Z-phase correction may be executed by edge interrupt processing of the A-phase signal or the B-phase signal. This makes it possible to synchronize the Z-phase correction with the switching timing of the energized phase.
[0019]
The invention according to claims 1 to 8 described above can be applied to various devices using a brushless type motor such as a switch reluctance motor as a drive source. The present invention may be applied to a control device for a motor that drives a range switching mechanism that switches between a range and a range. Thus, a highly reliable motor-driven range switching device can be configured.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment in which the present invention is applied to a range switching device for a vehicle will be described below with reference to the drawings.
[0021]
First, the configuration of the range switching mechanism 11 will be described with reference to FIG. The motor 12 serving as a drive source of the range switching mechanism 11 is constituted by, for example, a switch reluctance motor, has a built-in speed reduction mechanism 26 (see FIG. 4), and is provided with an output shaft sensor 14 for detecting the rotational position of the output shaft 13. Have been. A detent lever 15 is fixed to the output shaft 13.
[0022]
An L-shaped parking rod 18 is fixed to the detent lever 15, and a conical body 19 provided at the tip of the parking rod 18 is in contact with the lock lever 21. The lock lever 21 moves up and down about the shaft 22 in accordance with the position of the cone 19 to lock / unlock the parking gear 20. The parking gear 20 is provided on the output shaft of the automatic transmission 27. When the parking gear 20 is locked by the lock lever 21, the driving wheels of the vehicle are held in a state where they are prevented from rotating (parking state).
[0023]
On the other hand, a detent spring 23 for holding the detent lever 15 in a parking range (hereinafter referred to as “P range”) and another range (hereinafter referred to as “NotP range”) is fixed to the support base 17. When the engaging portion 23a provided at the tip of the spring 23 is fitted into the P range holding concave portion 24 of the detent lever 15, the detent lever 15 is held at the position of the P range. The detent lever 15 is held at the position of the NotP range when 23a is fitted into the NotP range holding recess 25 of the detent lever 15.
[0024]
In the P range, the parking rod 18 moves in a direction approaching the lock lever 21, and the thick portion of the cone 19 pushes up the lock lever 21, and the projection 21 a of the lock lever 21 fits into the parking gear 20 to park. The gear 20 is locked, whereby the output shaft (drive wheel) of the automatic transmission 27 is maintained in a locked state (parking state).
[0025]
On the other hand, in the NotP range, the parking rod 18 moves in a direction away from the lock lever 21, the thick portion of the cone 19 comes out of the lock lever 21, and the lock lever 21 descends. 21a is disengaged from the parking gear 20, the lock of the parking gear 20 is released, and the output shaft of the automatic transmission 27 is maintained in a rotatable state (runnable state).
[0026]
The output shaft sensor 14 described above is constituted by a rotation sensor (for example, a potentiometer) that outputs a voltage corresponding to the rotation angle of the output shaft 13 of the speed reduction mechanism 26 of the motor 12, and the current range is set to the P range by the output voltage. And the NotP range.
[0027]
Next, the configuration of the motor 12 will be described with reference to FIG. In the present embodiment, a switched reluctance motor (hereinafter referred to as “SR motor”) is used as the motor 12. The SR motor 12 is a motor in which both the stator 31 and the rotor 32 have a salient pole structure, and has an advantage that a permanent magnet is not required and the structure is simple. For example, twelve salient poles 31a are formed at equal intervals on the inner peripheral portion of the cylindrical stator 31, whereas, for example, eight salient poles 32a are formed at equal intervals on the outer peripheral portion of the rotor 32. The respective salient poles 32a of the rotor 32 are sequentially opposed to the respective salient poles 31a of the stator 31 via a minute gap with the rotation of the rotor 32. The twelve salient poles 31a of the stator 31 have a total of six windings 33 of U-phase, V-phase, and W-phase, and a total of six windings 34 of U'-, V'-, and W'-phases. It is wound in order. It goes without saying that the number of salient poles 31a and 32a of the stator 31 and the rotor 32 may be changed as appropriate.
[0028]
The winding order of the windings 33 and 34 in the present embodiment is, for example, V phase → W phase → U phase → V phase → W phase → U phase → V ′ for the twelve salient poles 31a of the stator 31. The phases are wound in the order of phase → W ′ phase → U ′ phase → V ′ phase → W ′ phase → U ′ phase. As shown in FIG. 3, a total of six windings 33 of U-phase, V-phase and W-phase and a total of six windings 34 of U′-phase, V′-phase and W′-phase are two-system motors. They are connected so as to form the excitation units 35 and 36. One motor excitation unit 35 is configured by connecting a total of six windings 33 of U-phase, V-phase, and W-phase in a Y-connection (two windings 33 of the same phase are connected in series). The other motor excitation unit 36 is configured by connecting a total of six windings 34 of U ′ phase, V ′ phase, and W ′ phase in a Y connection (two windings 34 of the same phase are connected in series, respectively). It is connected to the). In the two motor excitation units 35 and 36, the U phase and the U 'phase are simultaneously energized, the V phase and the V' phase are simultaneously energized, and the W phase and the W 'phase are simultaneously energized.
[0029]
These two motor excitation units 35 are driven by separate motor drivers 37 and 38 using a battery 40 mounted on the vehicle as a power supply. In this way, by providing the motor excitation units 35 and 36 and the motor drivers 37 and 38 each in two systems, even if one system fails, the SR motor 12 can be rotated in the other system. ing. The circuit configuration example of the motor drivers 37 and 38 shown in FIG. 3 has a unipolar drive circuit configuration in which one switching element 39 such as a transistor is provided for each phase, but two switching elements are provided for each phase. Alternatively, a circuit configuration of a bipolar drive system provided for each may be adopted. It is needless to say that the present invention may be configured such that one system is provided for each of the motor excitation unit and the motor driver.
[0030]
ON / OFF of each switching element 39 of each motor driver 37, 38 is controlled by the ECU 41 (control means). As shown in FIG. 4, the ECU 41 and the motor drivers 37 and 38 are mounted on a range switching control device 42. The range switching control device 42 includes a P range switch 43 for performing a switching operation to a P range, An operation signal of a NotP range switch 44 for performing a switching operation to the NotP range is input. The range selected by operating the P range switch 43 or the NotP range switch 44 is displayed on a range display section 45 provided on an instrument panel (not shown).
[0031]
The SR motor 12 is provided with an encoder 46 for detecting the rotational position of the rotor 32. The encoder 46 is constituted by, for example, a magnetic rotary encoder. As shown in FIGS. 5 and 6, the specific configuration of the encoder 46 is such that north poles and south poles are alternately arranged at equal pitches in the circumferential direction. A magnetized annular rotary magnet 47 is coaxially fixed to the side surface of the rotor 32, and three magnetic detecting elements 48, 49, 50 such as Hall ICs are arranged at positions facing the rotary magnet 47. It has a configuration. In the present embodiment, the magnetization pitch between the N pole and the S pole of the rotary magnet 47 is set to 7.5 °. The magnetization pitch (7.5 °) of the rotary magnet 47 is set to be the same as the rotation angle of the rotor 32 per excitation of the SR motor 12. As will be described later, when the energized phase of the SR motor 12 is switched six times by the 1-2-phase excitation method, all energized phases are switched once, and the rotor 32 and the rotary magnet 47 are integrally 7.5 °. × 6 = 45 ° rotation. The number of N poles and S poles present in the rotation angle range of 45 ° of the rotary magnet 47 is a total of six poles.
[0032]
Further, the N pole (N ') at the position corresponding to the reference rotation position of the rotor 32 and the S poles (S') on both sides thereof are formed so as to be wider in the radial direction than the other magnetic poles. In the present embodiment, considering that the rotor 32 and the rotary magnet 47 rotate integrally by 45 ° during one cycle of the switching of the energized phase of the SR motor 12, a wide width corresponding to the reference rotation position of the rotor 32 is taken into consideration. The large magnetized portions (N ′) are formed at a 45 ° pitch, so that a total of eight wide magnetized portions (N ′) corresponding to the reference rotation position are formed as the rotary magnet 47 as a whole. The wide magnetized portion (N ′) corresponding to the reference rotation position may be configured such that only one magnet is formed as the whole rotary magnet 47.
[0033]
Three magnetic detecting elements 48, 49, 50 are arranged with respect to the rotary magnet 47 in the following positional relationship. The magnetic detecting element 48 that outputs the A-phase signal and the magnetic detecting element 49 that outputs the B-phase signal are composed of a narrow magnetized portion (N, S) and a wide magnetized portion (N ′, S ′) of the rotary magnet 47. ) Are arranged on the same circumference at positions that can face both. On the other hand, the magnetic detection element 50 that outputs the Z-phase signal is located at a position radially outside or inside the narrow magnetized portion (N, S) of the rotary magnet 47 and has a wide magnetized portion (N ′). , S ′) only. As shown in FIG. 7, the interval between the two magnetic detecting elements 48 and 49 for outputting the A-phase signal and the B-phase signal is such that the phase difference between the A-phase signal and the B-phase signal is 90 ° in electrical angle (mechanical angle). 3.75 °). Here, “electric angle” is an angle when the generation period of the A / B phase signal is one cycle (360 °), and “mechanical angle” is a mechanical angle (one rotation of the rotor 32 is 360 °). The angle at which the rotor 32 rotates from the fall (rise) of the A-phase signal to the fall (rise) of the B-phase signal corresponds to the mechanical angle of the phase difference between the A-phase signal and the B-phase signal. I do. The magnetic detection element 50 that outputs the Z-phase signal is arranged so that the phase difference between the Z-phase signal and the B-phase signal (or the A-phase signal) becomes zero.
[0034]
The output of each of the magnetic detection elements 48, 49, and 50 becomes a high level "1" when facing the N pole (N 'pole), and becomes a low level "0" when facing the S pole (S' pole). Become. The output of the magnetic detection element 50 for the Z-phase signal becomes high level "1" every time it faces the wide N 'pole corresponding to the reference rotation position of the rotor 32. At other positions, the output becomes low level "1". 0 ".
[0035]
In the present embodiment, the ECU 41 counts both rising and falling edges of the A-phase signal and the B-phase signal in accordance with an encoder counter routine of FIG. , The rotor 32 is rotationally driven. At this time, the rotation direction of the rotor 32 is determined based on the generation order of the A-phase signal and the B-phase signal, and the encoder count value is counted up in the forward rotation (P direction → NotP range rotation direction), and the reverse rotation (NotP range → In the (P-range rotation direction), the encoder count value is counted down. Accordingly, even if the rotor 32 rotates in either the forward direction or the reverse direction, the correspondence between the encoder count value and the rotational position of the rotor 32 is maintained. However, the rotation position (rotation angle) of the rotor 32 is detected based on the encoder count value, and the windings 33 and 34 of the phase corresponding to the rotation position are energized to drive the rotor 32 to rotate.
[0036]
FIG. 7 shows an output waveform of the encoder 46 and a switching pattern of the energized phase when the rotor 32 is rotated in the reverse rotation direction (the rotation direction from the NotP range to the P range). In both the reverse rotation direction (the rotation direction from the NotP range to the P range) and the normal rotation direction (the rotation direction from the P range to the NotP range), one phase energization and two phases are performed every time the rotor 32 rotates 7.5 °. The energization and the energization are alternately switched, and during the rotation of the rotor 32 by 45 °, for example, in the order of U-phase energization → UW-phase energization → W-phase energization → VW-phase energization → V-phase energization → UV-phase energization The switching of the energized phase is performed once. Each time the energized phase is switched, the rotor 32 rotates by 7.5 ° so that the magnetic pole of the rotary magnet 47 facing the magnetic detection elements 48 and 49 for the A-phase and B-phase signals changes from N pole to S pole. (N ′ pole → S ′ pole) or S pole → N pole (S ′ pole → N ′ pole), and the levels of the A-phase signal and the B-phase signal are alternately inverted. The encoder count value is incremented (or decremented) by 2 for every .5 ° rotation. Each time the switching of the energized phase completes one cycle and the rotor 32 rotates 45 °, the magnetic detection element 50 for the Z phase faces the wide N ′ pole corresponding to the reference rotation position of the rotor 32, and The signal becomes high level "1". In this specification, the fact that the A-phase, B-phase, and Z-phase signals are at the high level “1” may be referred to as the output of the A-phase, B-phase, and Z-phase signals.
[0037]
By the way, since the encoder count value is stored in the RAM of the ECU 41, when the power of the ECU 41 is turned off, the storage of the encoder count value disappears. Therefore, the encoder count value (0) immediately after the power supply of the ECU 41 is turned on does not correspond to the actual rotational position (energized phase) of the rotor 32. Therefore, in order to switch the energized phase according to the encoder count value, it is necessary to make the encoder count value correspond to the actual rotational position of the rotor 32 after power-on, and to make the encoder count value correspond to the energized phase.
[0038]
Therefore, in the present embodiment, the initial drive routine shown in FIGS. 8 and 9 to be described later is executed by the ECU 41 of the range switching control device 42, so that the initial phase of the SR motor 12 is turned on when the ECU 41 is powered on. Is cycled in a predetermined time schedule to count the edges of the A-phase signal and the B-phase signal of the encoder 46, and learn the correspondence between the encoder count value at the end of the initial drive, the rotational position of the rotor 32, and the energized phase. Then, during the subsequent normal driving, the energized phase is determined based on the encoder count value and the learning result at the end of the initial driving.
[0039]
The learning at the time of the initial drive is specifically performed as follows. As shown in FIG. 12, when the initial drive is performed when the power is supplied to the ECU 41 in the P range, for example, W-phase energization → UW-phase energization → U-phase energization → UV-phase energization → V-phase energization → VW-phase The energization phase is switched in a predetermined time schedule in the energization order, and the rotor 32 is driven in the normal rotation direction (P range → Not P range rotation direction).
[0040]
On the other hand, when the initial drive is performed when the power is supplied to the ECU 41 in the NotP range, for example, energization is performed in the order of V-phase energization → UV-phase energization → U-phase energization → UW-phase energization → W-phase energization → VW-phase energization. The phase switching is performed once in a predetermined time schedule, and the rotor 32 is driven in the reverse rotation direction (the rotation direction from the NotP range to the P range).
[0041]
During this initial drive, the one-phase energization time T1 is set shorter than the two-phase energization time T2, for example, T1 = 10 ms and T2 = 100 ms. Even after the rotational position of the rotor 32 and the energized phase are synchronized during the initial drive, the rotor 32 vibrates in the one-phase energization with a small torque, so the time T1 of the one-phase energization is shortened, and as soon as possible. By switching to the next two-phase energization, the vibration of the rotor 32 is stopped immediately and the output signal of the encoder 46 is stabilized.
[0042]
As described above, if the switching of the energized phase is performed once during the initial drive, the rotational position of the rotor 32 and the energized phase always match in any energized phase before the end of the initial drive. The rotor 32 rotates in synchronization with the phase switching, and the A-phase signal and the B-phase signal are output from the encoder 46 in synchronization with the rotation of the rotor 32.
[0043]
During this initial drive, both rising and falling edges of the A-phase signal and the B-phase signal of the encoder 46 are counted. Therefore, by looking at the encoder count value at the end of the initial drive, the angle (rotation amount) at which the rotor 32 actually rotates in synchronization with the switching of the energized phase before the end of the initial drive can be determined. The relationship between the encoder count value at the time, the rotational position of the rotor 32, and the energized phase can be understood.
[0044]
In the example of FIG. 12, the rotor 32 rotates from the first energized phase (W phase) during the initial drive, and the rotor 32 rotates by 7.5 ° every time the energized phase is switched, and the encoder count value is incremented by two. At the end of the initial drive, the encoder count value becomes 12.
[0045]
On the other hand, for example, if the rotor 32 does not rotate in the first three excitations (W-phase energization → UW-phase energization → U-phase energization), that is, the fourth and subsequent excitations (UV-phase energization → V-phase energization → VW-phase) In the case where the rotation position of the rotor 32 and the energized phase are synchronized with each other in the energized state and the rotor 32 rotates by three times of excitation, the rotor 32 is 7.5 ° × 3 = 22.5 ° by the end of the initial drive. It rotates and the encoder count value becomes 2 × 3 = 6. Therefore, by looking at the encoder count value at the end of the initial drive, the angle (rotation amount) at which the rotor 32 actually rotates in synchronization with the switching of the energized phase before the end of the initial drive is determined.
[0046]
Although the last energized phase of the initial drive is always the VW phase, the encoder count value is not always 12 and may be, for example, 8 or 4. At the time of normal drive after the end of the initial drive, the energized phase is determined based on the encoder count value. Therefore, unless the deviation of the encoder count value due to the initial drive is corrected, the correct energized phase cannot be selected at the time of normal drive.
[0047]
Therefore, in the present embodiment, the encoder count value at the end of the initial drive is learned as the initial position deviation learning value, and the encoder count value at the time of the subsequent normal drive is corrected with the initial position deviation learning value. The deviation between the encoder count value and the energized phase (the rotational position of the rotor 32) is corrected so that the correct energized phase can be selected during normal driving.
[0048]
After the end of the initial drive, as shown in FIG. 12, first, for example, 10 ms is applied to the same phase as the energized phase (VW phase) at the end of the initial drive to maintain the position of the rotor 32 at the position at the end of the initial drive. By the feedback control (hereinafter referred to as “F / B control”) described later, the energized phase is switched based on the encoder count value at that time and the initial position deviation learning value to rotate the rotor 32 in the direction of the target position Acnt. Let it. Thereby, when the rotational position (encoder count value) of the rotor 32 reaches, for example, within 0.5 ° from the target position Acnt, the switching of the energized phase is completed and the rotor 32 is stopped. The stationary state of the rotor 32 is maintained by continuing the energization, and this maintained state is continued for, for example, 50 ms. Thereafter, if the target position Acnt does not change, the energization is stopped.
[0049]
When the P range switch 43 or the NotP range switch 44 is operated to generate a range switching request during the initial drive, the next two-phase energization (when the range switching request occurs during the execution of the two-phase energization) is performed. After the completion of the two-phase energization, the operation shifts to the normal drive, and the correspondence between the encoder count value at the end of the two-phase energization, the rotational position of the rotor 32, and the energized phase is learned. The energized phase is determined based on the encoder count value and the learning result at the end of the two-phase energization.
[0050]
In the two-phase energization, since the torque is large, even if the position of the rotor 32 is slightly shifted from the position corresponding to the two-phase energization, the rotor 32 can be rotated to the position corresponding to the two-phase energization. Therefore, it is considered that there is a high probability that the rotation position of the rotor 32 and the energized phase can be synchronized only by performing the two-phase energization once or twice during the initial driving. Therefore, when a range switching request is generated during the initial drive, the normal two-phase energization (or the current two-phase energization) is terminated before the normal drive is started. After learning the correspondence between the count value, the rotational position of the rotor 32, and the energized phase, it is possible to quickly shift to the normal drive.
[0051]
For example, as shown in the time chart of FIG. 13, when a range switching request from the P range to the NotP range occurs during the second excitation (UW phase energization) of the initial drive, the initial drive is performed by the UW phase energization. At the same time, the process is shifted to the normal drive, and the correspondence between the encoder count value at the end of the UW phase energization, the rotational position of the rotor 32, and the energized phase is learned. In the present embodiment, even when shifting to the normal drive in the middle of the initial drive, the encoder count value at the end of the original initial drive is estimated assuming that the initial drive has been executed to the end, and the estimated value is initialized. The position deviation learning value is set. For example, as shown in FIG. 13, when the initial drive is ended by two excitations of the W-phase energization and the UW-phase energization, the initial drive is ended without performing the four scheduled excitations thereafter. Assuming that four unexcited excitations (U-phase energization → UV-phase energization → V-phase energization → VW-phase energization) have been performed, the count-up value (2) corresponding to the rotation angle for the four excitations × 4 = 8) is added to the encoder count value at the end of the UW-phase energization to obtain an initial position deviation learning value.
[0052]
The learning process of the initial drive described above is executed by the ECU 41 of the range switching control device 42 in accordance with the initial drive routine shown in FIGS. This routine is executed at a predetermined cycle (for example, 1 ms cycle) immediately after the power supply to the ECU 41 is turned on (immediately after the ignition switch is operated from the OFF position to the ACC position) until the end of the initial drive.
[0053]
When this routine is started, first, in step 101, it is determined whether the open loop control execution flag Xopen = ON or the recovery processing execution flag Xrcv = ON. Here, the open-loop control execution flag Xopen is a flag that determines whether or not open-loop control (fail-safe processing) that is executed when the encoder 46 or the SR motor 12 has failed is being executed. Means that it is. The recovery process execution flag Xrcv is a flag for determining whether or not a recovery process (open loop control) that is temporarily executed when a temporary operation abnormality occurs is executed, and ON is executed. Means that.
[0054]
If “Yes” is determined in step 101, the present routine is terminated without performing the subsequent processing, and if “No” is determined, the process proceeds to step 102 and the output from the initial processing of the ECU 41 is performed. It is determined whether a predetermined time (for example, 100 ms) for waiting for the output voltage of the axis sensor 14 to stabilize has elapsed. Then, when a predetermined time has elapsed from the initial processing, the process proceeds to step 103, where the output voltage of the output shaft sensor 14 is read, and whether or not the current range is the P range is determined by whether or not this output voltage is equal to or less than the range determination value. It is determined whether the range is the NotP range. If the range is the P range, the process proceeds to step 104, where the range determination flag Xnp is set to “0” meaning the P range. If the range is the NotP range, the process proceeds to step 105 and the range determination flag Xnp Is set to “1” meaning NotP range.
[0055]
Thereafter, the process proceeds to step 106, where it is determined whether or not the range determination flag Xnp = 0 (P range). If the range determination flag Xnp = 0 (P range), the process proceeds to step 107, where P The range initial drive routine is executed, and if the range determination flag Xnp = 1 (NotP range), the routine proceeds to step 108, where the NotP range initial drive routine of FIG. 11 is executed.
[0056]
When the P range initial drive routine of FIG. 10 is started in step 107, in steps 201 to 206, it is determined whether the excitation number counter CASE for counting the number of excitations during the initial drive is 0 to 5. . The excitation number counter CASE has an initial value of 0 set in the initial processing, and is incremented by one each time excitation is performed once (step 114 in FIG. 9). Then, the energizing phase and the energizing time T are set as follows according to the determination result of the excitation number counter CASE.
[0057]
If CASE = 0 (first excitation), the process proceeds to step 207, where W-phase energization is selected, and the energization time T is set to T1 (for example, 10 ms).
If CASE = 1 (second excitation), the process proceeds to step 208, where UW-phase energization is selected, and the energization time T is set to T2 (for example, 100 ms).
[0058]
If CASE = 2 (third excitation), the process proceeds to step 209 to select U-phase energization and set the energization time T to T1 (for example, 10 ms).
If CASE = 3 (fourth excitation), the process proceeds to step 210, where UV phase energization is selected, and the energization time T is set to T2 (for example, 100 ms).
[0059]
If CASE = 4 (fifth excitation), the process proceeds to step 211, where V-phase energization is selected, and the energization time T is set to T1 (for example, 10 ms).
If CASE = 5 (sixth excitation), the process proceeds to step 212, where VW-phase energization is selected, and the energization time T is set to T2 (for example, 100 ms).
[0060]
Thus, when the initial drive is performed in the P range, the energized phases are switched in the order of W-phase energization → UW-phase energization → U-phase energization → UV-phase energization → V-phase energization → VW-phase energization, and the rotor 32 is rotated. Driving is performed in the forward rotation direction (P range → NotP range rotation direction). At this time, the one-phase energization time T1 is set shorter than the two-phase energization time T2.
[0061]
On the other hand, when the NotP range initial drive routine of FIG. 11 is started in step 108, it is determined in steps 221 to 226 whether the excitation number counter CASE is 0 to 5 and the energization is performed according to the determination result. The phase and the energizing time T are set as follows.
[0062]
If CASE = 0 (first excitation), the process proceeds to step 227, where V-phase energization is selected, and the energization time T is set to T1 (for example, 10 ms).
If CASE = 1 (second excitation), the process proceeds to step 228, where UV phase energization is selected, and the energization time T is set to T2 (for example, 100 ms).
[0063]
If CASE = 2 (third excitation), the process proceeds to step 229, where U-phase energization is selected, and the energization time T is set to T1 (for example, 10 ms).
If CASE = 3 (fourth excitation), the process proceeds to step 230, where UW-phase energization is selected, and the energization time T is set to T2 (for example, 100 ms).
[0064]
If CASE = 4 (fifth excitation), the process proceeds to step 231, where W-phase energization is selected, and the energization time T is set to T1 (for example, 10 ms).
If CASE = 5 (sixth excitation), the process proceeds to step 232, where VW-phase energization is selected, and the energization time T is set to T2 (for example, 100 ms).
[0065]
Thus, when the initial drive is performed in the NotP range, the switching of the energized phases is performed in the order of V phase energization → UV phase energization → U phase energization → UW phase energization → W phase energization → VW phase energization, and the rotor 32 Drive is performed in the reverse rotation direction (the rotation direction from the NotP range to the P range). Also in this case, the one-phase energization time T1 is set shorter than the two-phase energization time T2.
[0066]
After executing the P range initial drive routine of FIG. 10 or the NotP range initial drive routine of FIG. 11 as described above, the process proceeds to step 109 of FIG. 8, and the range switching operation (P range switch 43 or NotP It is determined whether or not the range switch 44 has been operated). If the range switch operation has been performed during the initial drive, the process proceeds to step 110, where the range switch operation flag Xchg is set to ON, and the range switch operation is performed. If not, the routine proceeds to step 111, where the range switching operation flag Xchg is set to OFF.
[0067]
Thereafter, the process proceeds to step 112 in FIG. 9, in which the energizing time counter CT for counting the energizing time of the current energizing phase is counted up. It is determined whether or not the energization time T (= T1 or T2) set in the routine 11 has been exceeded, and if not, this routine is terminated without performing the subsequent processing. Thereby, the energization to the current energized phase is continued until the energized time CT of the current energized phase exceeds the energized time T (= T1 or T2) set in the routine of FIG. 10 or FIG.
[0068]
Thereafter, when the energization time CT of the current energization phase exceeds the energization time T (= T1 or T2) set in the routine of FIG. 10 or FIG. 11, the routine proceeds to step 114, where the excitation number counter CASE is counted up by one. Then, the energized phase is switched to the next energized phase. Then, in the next step 115, after resetting the energization time counter CT, the routine proceeds to step 116, where it is determined whether or not the excitation number counter CASE has reached "6" indicating the end of the initial drive. If the number counter CASE has reached "6", the routine proceeds to step 118, where the initial drive end flag Xend is set to "ON" indicating the end of the initial drive.
[0069]
If the number-of-excitations counter CASE has not reached "6", that is, if the initial drive is being performed, the process proceeds to step 117, and it is determined whether the condition for ending the initial drive is satisfied. The condition for terminating the initial drive halfway is determined by the following three conditions (1) to (3).
(1) The range determination flag Xnp is 0 (P range)
{Circle around (2)} The excitation number counter CASE is 2 or 4, that is, the end of two-phase energization.
(3) The range switching operation flag Xchg is ON, that is, the range switching operation has been performed during the initial drive.
[0070]
If at least one of these three conditions (1) to (3) is not satisfied, the condition for ending the initial drive is not satisfied, and the initial drive is continued. On the other hand, if all of the three conditions (1) to (3) are satisfied, the condition for terminating the middle of the initial drive is satisfied, the process proceeds to step 118, and the initial drive end flag Xend indicates the end of the initial drive. Set to “ON”.
[0071]
Thereafter, the process proceeds to step 119, where it is determined whether or not the range determination flag Xnp = 1 (whether or not the initial drive was performed in the NotP range). If the range determination flag Xnp = 1, the process proceeds to step 120, The encoder count value Ncnt at the end of the initial drive is stored as an initial position deviation learning value Gcnt. Then, in the next step 121, the encoder count value Ncnt is corrected to a value based on the NotP range by the following equation.
Ncnt = Ncnt + 288
[0072]
In the present embodiment, the encoder count value Ncnt is counted up by setting the holding position of the P range to the zero point position, and when the rotor 32 rotates to the holding position of the NotP range, the encoder count value Ncnt becomes, for example, 288. ing. Therefore, when the initial drive is performed in the NotP range, the encoder count value Ncnt is corrected to a value based on the NotP range by adding 288 to the encoder count value Ncnt at the end of the initial drive.
[0073]
On the other hand, if it is determined in step 119 that the range determination flag Xnp = 0 (initial driving in the P range), the process proceeds to step 122, where the initial position deviation learning value Gcnt is calculated using the encoder count value Ncnt at the end of the initial driving. It is calculated by the following equation.
Gcnt = Ncnt + 2 × (6-CASE)
[0074]
In this case, if the initial drive is performed to the end, CASE = 6 by the processing of step 114, so that the encoder count value Ncnt at the end of the initial drive becomes the initial position deviation learning value Gcnt as it is, but the initial drive in the P range is performed. Is performed, when the range switching operation is performed during the initial driving, the next two-phase energization (or when a range switching request occurs during the execution of the two-phase energization, the two-phase energization) ends. To the normal drive, the initial drive is assumed to have been executed to the end, the encoder count value Ncnt at the end of the initial drive is estimated, and the estimated value is used as the initial position deviation learning value Gcnt. ing. 2 × (6-CASE) is a count-up value (hereinafter referred to as “Ncnt correction amount”) corresponding to the rotation angle for the number of unfinished excitations.
[0075]
FIG. 14 is a time chart for explaining the relationship among the excitation number counter CASE, the Ncnt correction amount, the energized phase, the A-phase signal, the B-phase signal, and the encoder count value Ncnt during the initial drive. For example, if the initial drive is to be terminated at the end of the UW-phase energization (when the number-of-excitations counter CASE has changed from 1 to 2) during the initial drive, the Ncnt correction amount = 2 × (6-CASE) = 2 × ( 6-2) = 8, and when ending the initial drive at the end of the UV-phase energization (when the number-of-excitations counter CASE changes from 3 to 4), Ncnt correction amount = 2 × (6-CASE) = 2 × (6-4) = 4.
[0076]
Next, the processing content of the encoder counter routine shown in FIG. 15 will be described. This routine is started in synchronization with both the rising / falling edges of the A-phase signal and the B-phase signal by the AB-phase interrupt processing, and the rising / falling edges of the A-phase signal and the B-phase signal are set next. Count as follows. When this routine is started, first, in step 301, the values A (i) and B (i) of the A-phase signal and the B-phase signal are read, and in the next step 302, the count-up value ΔN calculation map of FIG. A search is performed to calculate the current values A (i) and B (i) of the A-phase signal and the B-phase signal and the count-up value ΔN according to the previous values A (i−1) and B (i−1). .
[0077]
Here, the reason why the present values A (i) and B (i) of the A-phase signal and the B-phase signal and the previous values A (i-1) and B (i-1) are used is that the A-phase signal and the B-phase signal are used. This is because the rotation direction of the rotor 32 is determined based on the order in which the signals are generated. As shown in FIG. Is counted up, and in the reverse rotation (the rotation direction from the NotP range to the P range), the count-up value ΔN is set to a negative value, and the encoder count value Ncnt is counted down.
[0078]
After calculating the count-up value ΔN, the process proceeds to step 303, where the count-up value ΔN calculated in step 302 is added to the previous encoder count value Ncnt to determine the current encoder count value Ncnt. Thereafter, the process proceeds to step 304, where the current values A (i) and B (i) of the A-phase signal and the B-phase signal are changed to A (i-1) and B (i-1) for the next count processing. And the routine ends.
[0079]
Next, the processing content of the motor F / B control routine shown in FIG. 18 will be described. This routine is executed by an AB-phase interrupt process. When the motor F / B control execution condition is satisfied after the end of the initial drive, the rotational position (the encoder count value Ncnt) of the rotor 32 is set to 0. Until the angle reaches 5 °, the energizing phase is switched based on the encoder count value Ncnt and the initial position deviation learning value Gcnt to rotate the rotor 32 in the direction of the target position Acnt. Here, the motor F / B control execution condition is satisfied, for example, when all of the following conditions (1) to (4) are satisfied.
[0080]
(1) After the end of the initial drive (initial drive end flag Xend = ON)
(2) Fail-safe processing (open loop control) is not performed (open loop control execution flag Xopen = OFF)
{Circle around (3)} Recovery processing is not being performed (recovery processing execution flag Xrcv = OFF)
(4) A predetermined stop holding time (for example, 10 ms) has elapsed since the end of the initial drive, or a predetermined stop holding time (for example, 10 ms) has elapsed since the start of motor energization.
[0081]
The stop holding time (4) is provided to determine the position of the rotor 32 at the start of the F / B control.
When all of the above conditions (1) to (4) are satisfied, the motor F / B control execution condition is satisfied, and the F / B permission flag Xfb is set to ON.
[0082]
When the motor F / B control routine of FIG. 18 is started, first, in step 311, whether the F / B permission flag Xfb is set to ON (whether the motor F / B control execution condition is satisfied or not) ), And if the F / B permission flag Xfb is OFF (the F / B control execution condition is not satisfied), the routine ends without performing the subsequent processing.
[0083]
On the other hand, if the F / B permission flag Xfb is set to ON, the routine proceeds to step 312, where the energized phase setting routine shown in FIG. 19 described later is executed, and the current encoder count value Ncnt and the initial position deviation learning value are set. The energization phase is set based on Gcnt, and in the next step 313, an energization processing routine (not shown) is executed to energize the energization phase set in step 312.
[0084]
On the other hand, when the energization phase setting routine of FIG. 19 is started in step 312, the rotation direction instruction value D is "1" meaning forward rotation (rotation direction from P range to NotP range) in step 321. It is determined whether or not. The rotation direction instruction value D is set based on the magnitude relationship between the current encoder count value Ncnt and the target value Acnt.
[0085]
If the rotation direction instruction value D = 1 (forward rotation), the process proceeds to step 322, where it is determined whether the rotation direction has been reversed in reverse to the rotation direction instruction (whether the encoder count value Ncnt has decreased). If not, the process proceeds to step 323, and the energized phase determination value Mptn is calculated using the current encoder count value Ncnt, the initial position deviation learning value Gcnt, the forward rotation direction phase lead amount K1, and the speed correction amount Ks by the following equation. Update.
Mptn = Ncnt−Gcnt + K1 + Ks
[0086]
Here, the forward rotation direction phase lead amount K1 is the phase lead amount of the conduction phase necessary for rotating the rotor 32 in the forward direction (the phase lead amount of the conduction phase with respect to the current position of the rotor 32). For example, K1 = 4 Is set.
[0087]
The speed correction amount Ks is a phase lead correction amount set according to the rotation speed of the rotor 32. In the low speed range, the speed correction amount Ks is set to 0, and as the speed increases, the speed correction amount Ks is increased to, for example, 1 or 2. Thus, the energized phase determination value Mptn is corrected so that the energized phase is suitable for the rotation speed of the rotor 32.
On the other hand, if it is determined in step 322 that the rotation direction has been reversed against the rotation direction instruction, the energized phase determination value Mptn is not updated to prevent reverse rotation.
[0088]
If it is determined in step 321 that the rotation direction instruction value D = 0 (reverse rotation), that is, the rotation direction is from NotP range to P range, the process proceeds to step 324, where the rotation direction is reversed against the rotation direction instruction. It is determined whether or not the encoder count value Ncnt has increased. If the rotation has not been reversed, the process proceeds to step 325, where the current encoder count value Ncnt, the initial displacement learning value Gcnt, and the phase in the reverse rotation direction are advanced. The energized phase determination value Mptn is updated by the following equation using the amount K2 and the speed correction amount Ks.
Mptn = Ncnt-Gcnt-K2-Ks
[0089]
Here, the amount of phase advance K2 in the reverse rotation direction is the amount of phase advance of the energized phase required to rotate the rotor 32 in the reverse direction (the amount of phase advance of the energized phase with respect to the current position of the rotor 32). Is set. The speed correction amount Ks is the same as in the case of the forward rotation.
On the other hand, when it is determined in step 324 that the rotation direction has been reversed against the rotation direction instruction, the energized phase determination value Mptn is not updated to prevent the rotation from being reversed.
[0090]
After the current energized phase determination value Mptn is determined as described above, the process proceeds to step 326, where the energized phase determination value Mptn is divided by “12” to obtain the remainder mod (Mptn / 12). Here, “12” corresponds to the increase / decrease amount of the encoder count value Ncnt during one cycle of the energized phase.
[0091]
After the calculation of mod (Mptn / 12), the process proceeds to step 327, where the conversion table of FIG. 20 is searched to select an energized phase corresponding to mod (Mptn / 12), and set this as the current energized phase.
[0092]
FIG. 21 is a time chart for explaining a phase that is first energized when rotation is started from the U phase. In this case, since the speed correction amount Ks = 0, when the forward rotation (rotation in the direction from the P range to the NotP range) is started, the energized phase determination value Mptn is calculated by the following equation.
Mptn = Ncnt−Gcnt + K1 = Ncnt−Gcnt + 4
[0093]
When starting the normal rotation from the U phase, mod (Ncnt−Gcnt) becomes 6, so that mod (Mptn / 12) = 6 + 4 = 10, and the first energized phase becomes the V phase.
[0094]
On the other hand, when the reverse rotation (rotation from the NotP range to the P range direction) is started from the U phase, the energized phase determination value Mptn is calculated by the following equation.
Mptn = Ncnt-Gcnt-K2 = Ncnt-Gcnt-3
When the reverse rotation is started from the U phase, mod (Mptn / 12) = 6-3 = 3, and the first energized phase is the W phase.
[0095]
In this way, by setting the forward rotation direction phase lead amount K1 and the reverse rotation direction phase lead amount K2 to 4 and 3, respectively, the switching pattern of the energized phase in the forward rotation direction and the reverse rotation direction can be made symmetric. In both the forward rotation direction and the reverse rotation direction, the phase at a position shifted by two steps from the current position of the rotor 32 can be first excited to start rotation.
[0096]
By the way, while the SR motor 12 is rotating, as shown in FIG. 23, the A-phase signal and the B-phase signal are alternately output from the encoder 46 in synchronization with the rotation of the rotor 32, and the switching of the energized phase goes through one cycle. Each time the rotor 32 rotates 45 °, a Z-phase signal is output. Since the reference rotational position of the rotor 32 can be accurately detected from the Z-phase signal, the energized phase (encoder count value) when the Z-phase signal is output changes to the energized phase (encoder count value) corresponding to the reference rotational position of the rotor 32. ), It is possible to confirm whether or not the correspondence between the rotational position of the rotor 32 and the energized phase (encoder count value) is not shifted. By performing the Z-phase correction for correcting the deviation, highly reliable motor control can be performed.
[0097]
This Z-phase correction is executed by a Z-phase correction routine shown in FIG. This routine is started in synchronization with both rising and falling edges of the A-phase signal by the A-phase interrupt processing. When this routine is started, first, in step 401, it is determined whether or not the value Z of the Z-phase signal is 1 (high level) and the encoder failure flag Xfail is set to OFF which means that there is no failure of the encoder 46. When it is determined that the value Z of the Z-phase signal is 0 (low level) or when the encoder failure flag Xfail is set to ON indicating that the encoder 46 has a failure, it is determined as “No” in step 401. Then, this routine ends without performing the subsequent processing.
[0098]
On the other hand, if "Yes" is determined in step 401, the process proceeds to step 402, where the position detection count value Nzon at the time of outputting the Z-phase signal (when the Z value of the Z-phase signal is inverted to 1) is stored. I do. The position detection count value Nzone is obtained by correcting the encoder count value Ncnt at the time of outputting the Z-phase signal with the initial position deviation learning value Gcnt. The reference rotation position of the rotor 32 (when the Z-phase signal is Output position) is detected.
Nzone = Ncnt−Gcnt
[0099]
After that, the process proceeds to step 403, and whether the rotation direction of the rotor 32 is the forward rotation direction (the rotation direction from the P range to the NotP range) is determined by whether or not the current activation timing of this routine is the rising of the A-phase signal. Determine whether or not.
[0100]
As shown in FIG. 23, since the A-phase signal and the Z-phase signal are output with a phase difference of 90 ° in electrical angle, the Z-phase signal output period in the forward rotation direction (the rotation direction from the P range to the NotP range). During the Z-phase signal output period, the A-phase signal falls in the reverse rotation direction (NotP range → P range rotation direction). Therefore, whether the A-phase signal rises or falls during the Z-phase signal output period can determine whether the rotation direction is the normal rotation direction or the reverse rotation direction.
[0101]
If it is determined in step 403 that the activation timing of this routine is the rising timing of the A-phase signal, that is, the rotation direction of the rotor 32 is the forward rotation direction (the rotation direction from the P range to the NotP range), Proceeding to 404, a deviation gz between the design value and the actual value of the energized phase when the Z-phase signal is output is calculated.
gz = K1-mod (Nzon / 12)
[0102]
Here, K1 is a forward rotation direction phase lead amount of an energized phase required for rotating the rotor 32 in the forward direction, and is set to, for example, K1 = 4. mod (Nzone / 12) is the remainder when the position detection count value Nzon at the time of outputting the Z-phase signal is divided by "12".
[0103]
In the present embodiment, as shown in FIG. 23, the mod (Nzone / 12) is designed to be 4 in the forward rotation direction (the rotation direction from the P range to the NotP range). If it operates normally, gz = K1-mod (Nzon / 12) = 0.
[0104]
On the other hand, when it is determined in step 403 that the current activation timing of this routine is the falling timing of the A-phase signal, that is, the rotation direction of the rotor 32 is the reverse rotation direction (the rotation direction from the NotP range to the P range). Proceeds to step 405, and calculates a deviation gz between the design value and the actual value of the energized phase when the Z-phase signal is output.
gz = K2-mod (Nzon / 12)
Here, K2 is the amount of phase advance in the reverse rotation direction of the energization phase required to rotate the rotor 32 in the reverse direction, for example, K2 = 3.
[0105]
In the present embodiment, as shown in FIG. 23, the mod (Nzone / 12) is designed to be 3 in the reverse rotation direction (the rotation direction from the NotP range to the P range), so that the control system is If it operates normally, gz = K2-mod (Nzon / 12) = 0.
[0106]
After calculating the deviation gz between the design value and the actual value, the process proceeds to step 406, and it is determined whether the deviation gz between the design value and the actual value of the energized phase at the time of outputting the Z-phase signal is 0, and If the deviation gz from the actual value is 0, the control system is operating normally, and this routine ends without performing the subsequent processing such as Z-phase correction.
[0107]
On the other hand, if the deviation gz between the design value and the actual value of the energized phase at the time of outputting the Z-phase signal is not 0, it is determined that the Z-phase correction is necessary, and the process proceeds to step 407, where the number of times of the Z-phase correction is The Z-phase correction number counter Cgz to be counted is counted up, and the routine proceeds to step 408, where the deviation of the initial position deviation learning value Gcnt is corrected by the deviation gz between the design value and the actual value.
Gcnt = Gcnt−gz
[0108]
Thereafter, it is determined whether or not the value of the Z-phase correction number counter Cgz (the number of Z-phase corrections) has exceeded a determination value. If the value is equal to or less than the determination value, it is not determined that the encoder 46 has failed yet. If the value of the number-of-corrections counter Cgz (the number of Z-phase corrections) exceeds the determination value, it is determined that the encoder 46 has failed, and the routine proceeds to step 410, where the encoder failure flag Xfail is set to ON indicating that the encoder 46 has a failure. And the routine ends.
[0109]
When the encoder failure flag Xfail is set to ON, even if the present routine is started by the A-phase interrupt processing, “No” is always determined in step 401 and the present routine is forcibly terminated. No phase correction is performed. This function corresponds to the Z-phase correction prohibiting means described in the claims.
[0110]
In the present embodiment described above, at the time of the initial drive after the power supply to the ECU 41 is turned on, the switching of the energized phase of the SR motor 12 is made to complete a predetermined time schedule. In the energized phase, the rotational position of the rotor 32 always coincides with the energized phase. Thereafter, the rotor 32 rotates in synchronization with the switching of the energized phase, and the encoder 46 outputs A A phase signal and a B-phase signal are output. During the initial driving, both the rising and falling edges of the A-phase signal and the B-phase signal of the encoder 46 are counted. Therefore, if the encoder count value at the end of the initial driving is viewed, the initial driving ends. By this time, the angle (rotation amount) at which the rotor 32 actually rotates in synchronization with the switching of the energized phase is known, and the correspondence between the encoder count value at the end of the initial drive, the rotational position of the rotor 32, and the energized phase is thereby determined. I understand.
[0111]
Therefore, in the present embodiment, the encoder count value at the end of the initial drive is learned as the initial position deviation learning value, and the encoder count value is corrected by the initial position deviation learning value at the time of normal driving thereafter. The deviation between the encoder count value at the time and the energized phase (the rotational position of the rotor 32) can be corrected, and the correct energized phase can be selected during normal driving.
[0112]
In addition, in the present embodiment, the one-phase energization and the two-phase energization are alternately switched during the initial drive. Therefore, the one-phase excitation system in which only one phase is always energized and the two-phase excitation system in which two phases are always energized are used. In comparison, the rotor rotation angle per one step (one excitation) is reduced to 、, so that the rotational position of the rotor 32 and the energized phase can be reliably synchronized during the initial drive, and the torque is large. The vibration of the rotor 32 is stopped by the phase energization, and the output signal of the encoder 46 can be stabilized.
[0113]
In this case, even after the rotational position of the rotor 32 and the energized phase are synchronized during the initial drive, the rotor 32 vibrates in the one-phase energization with a small torque. If the time for one-phase energization is set shorter than the time for two-phase energization, the time for one-phase energization in which the rotor 32 vibrates is shortened, and the rotor 32 is switched to the next two-phase energization as soon as possible. Can be stopped immediately to stabilize the output signal of the encoder 46, and the time of the initial drive can be shortened.
[0114]
However, in the present invention, the one-phase energizing time and the two-phase energizing time may be set to be the same, and even in this case, the intended object of the present invention can be sufficiently achieved.
[0115]
Further, in the present embodiment, the initial drive is started from one-phase energization, but the initial drive may be started from two-phase energization. In this way, even if the position of the rotor 32 at the beginning of the initial drive does not exactly match the position corresponding to the first two-phase energization, the rotor 32 may be within the range where the large torque of the two-phase energization can reach. Thus, the rotational position of the rotor 32 and the energized phase can be synchronized from the beginning of the initial drive.
[0116]
The present invention is not limited to a configuration in which one-phase energization and two-phase energization are alternately switched at the time of initial driving. May be executed.
[0117]
As described above, in the two-phase energization, the torque is large. Therefore, even if the position of the rotor 32 is slightly shifted from the position corresponding to the two-phase energization, the rotor 32 can be rotated to the position corresponding to the two-phase energization. it can. Therefore, it is considered that there is a high probability that the rotational position of the rotor 32 and the energized phase can be synchronized only by performing the two-phase energization once or twice during the initial drive.
[0118]
Therefore, in the present embodiment, when the range switching operation from the P range to the NotP range is performed during the initial driving in the P range, the next two-phase energization (the range switching operation is performed during the execution of the two-phase energization). When the two-phase energization ends, the operation shifts to the normal drive after the end of the two-phase energization, and the correspondence between the encoder count value at the end of the two-phase energization, the rotational position of the rotor 32, and the energized phase is learned. Therefore, when the range switching operation from the P range to the NotP range is performed during the initial drive, the correspondence between the encoder count value, the rotational position of the rotor 32, and the energized phase is learned, and then the normal drive is performed immediately. Then, it is possible to quickly switch from the P range to the NotP range, so that the driver does not feel uncomfortable.
[0119]
In a normal case, the ignition switch is not started in the NotP range (because the ignition switch cannot be turned off in a range other than the P range). However, under special conditions, a case in which the engine is started in the NotP range may occur. For example, when an instantaneous power failure occurs in the ECU 41 during traveling, or when maintenance and inspection are performed at a maintenance shop, the vehicle may start in the NotP range.
[0120]
In order to simplify the control specifications, the logic that starts in the NotP range may be omitted, but in the present embodiment, in order to deal with the case of initial driving in the NotP range, When the range switching operation from the NotP range to the P range is performed, the initial drive is performed to the end, and then the normal drive is performed to switch from the NotP range to the P range.
[0121]
Of course, the present invention is also applicable to the case where the initial drive is performed in the NotP range, as in the case of the initial drive in the P range. When the operation is performed, the two-phase energization is completed, and then the operation is shifted to the normal drive. At the same time, the correspondence between the encoder count value at the end of the two-phase energization, the rotational position of the rotor 32, and the energized phase is learned. You may do it.
[0122]
Alternatively, even when the range switching operation from the P range to the Not P range is performed during the initial driving in the P range, learning of the initial position shift is prioritized, and the initial driving is performed to the end, and then the normal driving is performed. To switch from the P range to the NotP range.
[0123]
In the present embodiment, it is determined whether the energized phase (encoder count value) when the Z-phase signal of the encoder 46 is output is the energized phase (encoder count value) corresponding to the reference rotation position of the rotor 32. By doing so, it is checked whether or not the correspondence between the rotational position of the rotor 32 and the energized phase (encoder count value) has been shifted, and if so, Z-phase correction for correcting the shift is performed. Therefore, highly reliable motor control can be performed.
[0124]
In this case, when the Z-phase correction is repeatedly performed, there is a possibility that an erroneous Z-phase correction is performed. Therefore, in the present embodiment, when the Z-phase correction is performed a predetermined number of times during the normal driving, the Z-phase correction is prohibited. Therefore, the stop / malfunction of the SR motor 12 due to the erroneous Z-phase correction is repeated. Can be prevented.
[0125]
In the Z-phase correction routine of FIG. 22, it is determined whether or not the correspondence between the energized phase (encoder count value) when the Z-phase signal of the encoder 46 is output and the rotational position of the rotor 32 is out of alignment. However, for example, the energized phase (encoder count value) and the rotation of the rotor 32 are determined based on whether the increase / decrease amount of the encoder count value from the previous Z-phase signal output timing to the current Z-phase signal output timing is 12. It may be determined whether or not the correspondence with the rotational position is not shifted.
[0126]
The present invention may use an encoder that does not output a Z-phase signal (an encoder that outputs only an A-phase signal and a B-phase signal). In this case, the configuration is such that the function of Z-phase correction is omitted.
Further, the encoder 46 is not limited to a magnetic encoder, and for example, an optical encoder or a brush encoder may be used.
[0127]
In this embodiment, the SR motor 12 is used. However, any brushless motor that detects the rotational position of the rotor based on the count value of the output signal of the encoder and sequentially switches the energized phase of the motor is limited to the SR motor. However, other types of brushless motors may be used.
[0128]
The range switching device of the present embodiment is configured to switch between the two ranges of the P range and the NotP range. For example, the range switching valve and the manual valve of the automatic transmission are interlocked with the turning operation of the detent lever 15. The present invention can also be applied to a range switching device that switches the ranges P, R, N, D,.
[0129]
In addition, it goes without saying that the present invention is not limited to the range switching device but can be applied to various devices using a brushless type motor such as an SR motor as a drive source.
[Brief description of the drawings]
FIG. 1 is a perspective view of a range switching device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of an SR motor.
FIG. 3 is a circuit diagram showing a circuit configuration for driving an SR motor.
FIG. 4 is a diagram schematically showing a configuration of an entire control system of the range switching device.
FIG. 5 is a plan view illustrating a configuration of a rotary magnet of the encoder.
FIG. 6 is a side view of the encoder.
FIG. 7A is a time chart showing an output waveform of an encoder, and FIG. 7B is a time chart showing an energized phase switching pattern;
FIG. 8 is a flowchart showing a flow of processing of an initial drive routine (part 1);
FIG. 9 is a flowchart (part 2) showing a flow of processing of an initial drive routine.
FIG. 10 is a flowchart showing the flow of processing of a P range initial drive routine.
FIG. 11 is a flowchart showing the flow of processing of a NotP range initial drive routine.
FIG. 12 is a time chart showing a control example when initial driving is performed in a P range.
FIG. 13 is a time chart showing a control example when a range switching operation is performed during initial driving;
FIG. 14 is a time chart for explaining an initial position deviation learning method when a range switching operation is performed during initial driving;
FIG. 15 is a flowchart showing the flow of processing of an encoder counter routine;
FIG. 16 is a diagram showing an example of a count-up value ΔN calculation map.
FIG. 17 is a time chart showing a relationship among a command range shift, an A-phase signal, a B-phase signal, and an encoder count value.
FIG. 18 is a flowchart showing the flow of processing of a motor F / B control routine;
FIG. 19 is a flowchart illustrating the flow of a process of an energized phase setting routine.
FIG. 20 is a diagram showing an example of a conversion table from mod (Mptn / 12) to an energized phase.
FIG. 21 is a time chart illustrating an energization process.
FIG. 22 is a flowchart showing the flow of processing of a Z-phase correction routine.
FIG. 23 is a time chart illustrating Z-phase correction.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Range switching mechanism, 12 ... SR motor, 14 ... Output shaft sensor, 15 ... Detent lever, 18 ... Parking rod, 20 ... Parking gear, 21 ... Lock lever, 23 ... Detent spring, 24 ... P range holding concave part, 25 ... NotP range holding concave part, 26 ... reduction mechanism, 27 ... automatic transmission, 31 ... stator, 32 ... rotor, 33,34 ... winding, 35,36 ... motor excitation part, 37,38 ... motor driver, 41 ... ECU (Control means, Z-phase correction prohibiting means) 43 ... P range switch, 44 ... NotP range switch, 46 ... Encoder, 47 ... Rotary magnet, 48 ... Magnetic detection element for A-phase signal, 49 ... B-phase signal Magnetic detecting element, 50: Magnetic detecting element for Z-phase signal.

Claims (9)

An encoder that outputs a pulse signal in synchronization with the rotation of the rotor of the motor, and detects the rotational position of the rotor based on the count value of the output signal of the encoder, and sequentially switches the energized phase of the motor to thereby control the rotor. A motor control device comprising:
The control means counts the output signal of the encoder by switching the energized phase of the motor in a predetermined time schedule at the time of initial driving after power-on, and counts the count value at the end of initial driving and the rotation of the rotor. A motor that learns a correspondence relationship between a position and an energized phase, and determines an energized phase based on a count value of an output signal of the encoder and a learning result at the end of the initial drive during normal driving thereafter. Control device. The motor is a switched reluctance motor,
2. The motor control device according to claim 1, wherein the control unit alternately switches between one-phase energization and two-phase energization during the initial driving. 3. The motor control device according to claim 2, wherein the control unit makes the one-phase energization time shorter than the two-phase energization time. 4. 4. The motor control device according to claim 2, wherein the control unit starts the initial drive from the two-phase energization. 5. When it is necessary to terminate the initial drive and shift to the normal drive during the initial drive, the control means may control the next two-phase energization (the shift to the normal drive during the execution of the two-phase energization is necessary). When the two-phase energization ends, the operation shifts to the normal drive after the end of the two-phase energization. At the end of the two-phase energization, the relationship between the count value of the output signal of the encoder, the rotational position of the rotor, and the energized phase is determined. The energized phase is determined based on a learned value at the time of normal driving after that, based on a count value of an output signal of the encoder and a learning result at the time of termination of the two-phase energization. Motor control device. The encoder outputs an A-phase signal and a B-phase signal having a predetermined phase difference in synchronization with the rotation of the rotor, and outputs a Z-phase signal at a reference rotation position of the rotor,
The control means counts the edges of the A-phase signal and the B-phase signal at the time of the initial drive, learns the correspondence between the count value at the end of the initial drive, the rotational position of the rotor, and the energized phase, During normal drive, the energizing phase is determined based on the count value of the output signal of the encoder and the learning result at the end of the initial drive, and the count value when the Z-phase signal is output and the count value of the rotor. 2. The method according to claim 1, wherein it is determined whether or not the correspondence between the rotational position and the energized phase is shifted, and if so, the shift is corrected (hereinafter, this correction is referred to as "Z-phase correction"). 6. The motor control device according to any one of claims 1 to 5. 7. The motor control device according to claim 6, further comprising a Z-phase correction prohibiting unit that prohibits the Z-phase correction when the Z-phase correction is performed a predetermined number of times during the normal driving. 8. The motor control device according to claim 6, wherein the control unit executes the Z-phase correction by edge interrupt processing of the A-phase signal or the B-phase signal. 9. 9. The motor control device according to claim 1, wherein the motor drives a range switching mechanism that switches between a parking range of the vehicle and another range.

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