JP5472044B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device that rotationally drives a motor to a target rotation angle by detecting the rotation angle of the motor based on the count value of the pulse signal of the encoder and sequentially switching the energized phase of the motor.

  In recent years, the number of cases in which a mechanical drive system is changed to a system that is electrically driven by a motor has been increasing in order to satisfy the demands for space saving, assembling, and control. . As an example, there is one in which a range switching mechanism of an automatic transmission of a vehicle is driven by a motor, as shown in Patent Document 1 (Japanese Patent No. 3800529). In this system, the motor is equipped with an encoder that detects the rotation angle of the rotor, and when the range is switched, the motor corresponds to the target range based on the count value (hereinafter referred to as “encoder count value”) of the pulse signal of this encoder. The range switching mechanism is switched to the target range by rotating to the target rotation angle (target count value).

  This type of motor with an encoder can only detect the amount of rotation (rotation angle) from the starting position of the rotor based on the encoder count value after starting. Unless the typical rotation angle is detected and the correspondence between the encoder count value and the rotation angle (energized phase) of the rotor is taken, the motor cannot be driven normally.

  Therefore, in Patent Document 1, by switching the energized phase of the motor in a predetermined time schedule at the initial drive after the power is turned on, the rotation angle of the rotor and the energized phase are matched in any energized phase. The rotor is driven to rotate, the pulse signal of the encoder is counted, the energized phase learning process is performed to learn the correspondence between the encoder count value at the end of the initial drive, the rotation angle of the rotor, and the energized phase, and then the normal drive Sometimes, the energized phase is determined by detecting the rotation angle of the rotor from the encoder count value corrected using the energized phase learning value learned in the energized phase learning process.

Japanese Patent No. 3800529

  By the way, since it is necessary to energize the motor continuously in order to execute the energization phase learning process (initial drive), the motor or the motor drive circuit tends to generate heat. Normally, after the power is turned on, the motor power is not turned off for a while, so the initial drive only needs to be performed once. However, if the user repeats the power on / off operation with a sense of fun, the initial drive is repeated many times in a short time. As a result, the temperature of the motor or the motor drive circuit rises, which may cause a reduction in the life or failure of the motor or the motor drive circuit.

  Although it is conceivable to store the energized phase learning value and encoder count value in a non-volatile memory, the rotation angle cannot be detected even if the motor rotates with an external force while the power is off (the encoder pulse signal is counted). Therefore, the energized phase learning value and encoder count value stored before the power is turned off cannot be used after the power is turned on again, and the energized phase learning process needs to be executed again after the power is turned on again.

  Therefore, the problem to be solved by the present invention is that the motor or the motor drive circuit generates heat by the energized phase learning process (initial drive) even when the user repeats the ON / OFF switching operation of the power switch with a sense of play. It is an object of the present invention to provide a motor control device that can prevent a reduction in the life or failure of a motor or a motor drive circuit.

  In order to solve the above-described problem, an invention according to claim 1 includes an encoder that outputs a pulse signal at a predetermined angular interval according to rotation of a motor that rotationally drives a control target, a power switch that switches power on / off, After the power is turned on by turning on the power switch, the energized phase of the motor is sequentially switched in a predetermined pattern by a motor drive circuit, whereby the encoder pulse signal count value (hereinafter referred to as “encoder count value”) and the rotation of the motor An energized phase learning means for executing an energized phase learning process for learning a correspondence relationship between an angle and an energized phase as an energized phase learning value; and a storage means for storing the energized phase learned value and the encoder count value. After phase learning processing, the energized phases of the motor are sequentially switched based on the encoder count value and the energized phase learned value. Thus, in the motor control device that rotationally drives the motor to a target rotation angle, the motor control device includes a power continuation unit that continues a power-on state until a predetermined time has elapsed even after the power switch is turned off, and the energized phase learning unit includes: The energized phase learning process is not executed even when the power switch is turned on during a period in which the power on state is continued by the power continuation means after the power switch is turned off.

  In this configuration, until the predetermined time elapses after the power switch is turned off, the power on state can be continued by the power continuation means and the storage data (energized phase learning value and encoder count value) of the storage means can be held. If the motor is rotated by an external force or the like, the encoder count value can be updated according to the rotation angle. As a result, the energized phase learning value and the encoder count value stored in the storage means are used during the period in which the power on state continues after the power switch is turned off, without executing the energized phase learning process (initial drive). The motor can be correctly rotated to the target rotation angle, and the energized phase learning process (initial drive) can be prevented from being executed even if the power switch is turned on during the period. For this reason, even if the user repeatedly turns on / off the power switch for a sense of fun, etc., the motor or motor drive is suppressed by suppressing the heat generation of the motor or motor drive circuit due to the energized phase learning process (initial drive). It is possible to prevent a reduction in circuit life and failure.

  In this case, as in the second aspect, the predetermined time for continuing the power-on state after the power switch is turned off ensures the time necessary for radiating heat from the motor or the motor drive circuit that has generated heat in the energized phase learning process. It is good to set as follows. In this way, it is possible to more reliably prevent the motor or the motor drive circuit from being overheated by repeating the on / off switching operation of the power switch.

  Further, as in the third aspect, a switched reluctance motor may be used as the motor. The switched reluctance motor is advantageous in that it does not require a permanent magnet and is simple in structure, so that it is inexpensive and has high durability and reliability against temperature environments.

  The invention according to claims 1 to 3 described above can be applied to various position switching devices using a synchronous motor such as a switched reluctance motor as a drive source. For example, as in claim 4, an automatic transmission of a vehicle You may apply to the control apparatus of the motor which drives the range switching mechanism which switches a range. Thus, a highly reliable motor-driven range switching device can be configured.

FIG. 1 is a diagram schematically showing the overall configuration of an automatic transmission control system according to an embodiment of the present invention. FIG. 2 is a perspective view showing the range switching mechanism. FIG. 3 is a diagram illustrating the configuration of the motor. FIG. 4 is a diagram illustrating a circuit configuration for driving a motor. FIG. 5 is a diagram schematically showing the overall configuration of the control system of the range switching device. FIG. 6 is a plan view illustrating the configuration of the rotary magnet of the encoder. FIG. 7 is a side view of the encoder. FIG. 8A is a time chart showing waveforms of the A-phase signal and B-phase signal of the encoder, and FIG. 8B is a time chart showing an energized phase switching pattern. FIG. 9 is a time chart showing a control example when the energized phase learning process (initial driving) is performed in the P range. FIG. 10 is a time chart for explaining the relationship between the ON / OFF state of the ECU relay, the execution timing of the energized phase learning process, and the behavior of the motor temperature when the on / off switching operation of the power switch is repeated. FIG. 11 is a flowchart showing a process flow of the energized phase learning process program.

Hereinafter, an embodiment in which the mode for carrying out the present invention is applied to a vehicle range switching device will be described.
First, a schematic configuration of the entire automatic transmission system will be described with reference to FIG.
The input shaft of the automatic transmission 12 is connected to the output shaft (crank shaft) of the engine 11. Although the internal configuration of the automatic transmission 12 is not shown, a torque converter that is rotationally driven by the output shaft of the engine 11, a transmission gear mechanism that is coupled to the output shaft (turbine shaft) of the torque converter, and the transmission gear mechanism A friction engagement device that switches a combination (gear ratio) of gears that transmit power from among a plurality of gears that constitute the motor, and a hydraulic control circuit that switches the operation state of the friction engagement device with hydraulic pressure are included in the automatic transmission 12. Is provided. The hydraulic control circuit includes a hydraulic control valve 13 for controlling the hydraulic pressure supplied to each friction engagement element such as a clutch and a brake constituting the friction engagement device, and a motor 14 in conjunction with a shift operation of the shift lever. A spool valve 16 of a range switching mechanism 15 (see FIG. 2) to be switched is provided. The spool valve 16 functions as a so-called manual valve that is switched in conjunction with the shift operation of the shift lever.

  The shift control ECU 17 that controls the shift operation of the automatic transmission 12 detects the hydraulic pressure supplied to the friction engagement device by the hydraulic sensor 18, and based on the detected hydraulic pressure and the output signal of the vehicle speed sensor 19, the hydraulic control circuit The gear position is switched to the target gear position by controlling the hydraulic pressure supplied to each friction engagement element by controlling the opening / closing operation of each hydraulic pressure control valve 13.

  On the other hand, the range switching ECU 20 drives and controls the motor 14 based on the output signal of the shift range detection device 21 that detects the operation position of the shift lever, so that the spool of the range switching mechanism 15 is controlled according to the driver's range switching operation. The switching operation of the valve 16 is controlled. The range switching ECU 20, the shift control ECU 17, the engine ECU 22 that controls the operating state of the engine 11, and the meter ECU 42 that controls the display of the display device 41 are connected to the power line 47 from the battery 23 (power source) mounted on the vehicle. Electric power is supplied through. Also, the ECUs 20, 17, 22, and 42 transmit and receive necessary information such as throttle opening and ignition timing to each other through the communication line 24. The engine ECU 22 is connected to various sensors (for example, a crank angle sensor 48 that detects the engine rotation speed) that detect the operating state of the engine 11.

  The engine 11 is provided with a starter 43 that rotationally drives (cranks) the crankshaft at start-up. When the driver operates the ignition key switch 44 from the ON position (IG position) to the START position, the engine ECU 22 starts a starter relay 45. Is turned on and the starter 43 is energized from the battery 23, the starter 43 rotates and the engine 11 is cranked and started, and then the driver returns the ignition key switch 44 from the START position to the ON position. 45 is turned off, and energization to the starter 43 is stopped.

Next, the configuration of the range switching mechanism 15 will be described with reference to FIG.
The range switching mechanism 15 is for switching the shift range of the automatic transmission 12 to, for example, a parking range (P), a reverse range (R), a neutral range (N), and a drive range (D). The motor 14 serving as a drive source of the range switching mechanism 15 has a built-in speed reduction mechanism 50 (see FIG. 5), and an output shaft that detects the rotation angle of the output shaft 25 fitted and connected to the rotation shaft of the speed reduction mechanism 50. A sensor 46 (output shaft rotation angle detection means) is provided, and a shift range is detected based on an output signal of the output shaft sensor 46. The output shaft sensor 46 is constituted by a rotation sensor (for example, a potentiometer) that outputs a voltage corresponding to the rotation angle of the output shaft 25 of the speed reduction mechanism 50 of the motor 14, and the current range is P, R, N depending on the output voltage. , D can be confirmed.

  A detent lever 28 for switching the spool valve 16 of the hydraulic control circuit of the automatic transmission 12 is fixed to the output shaft 25 of the motor 14. An L-shaped parking rod 29 is fixed to the detent lever 28, and a cone 30 provided at the tip of the parking rod 29 is in contact with the lock lever 31. The lock lever 31 is moved up and down around the shaft 32 according to the position of the cone 30 to lock / unlock the parking gear 33. The parking gear 33 is provided on the output shaft of the automatic transmission 12, and when the parking gear 33 is locked by the lock lever 31, the driving wheel of the vehicle is held in a stopped state (parking state).

  Further, the spool 34 of the spool valve 16 is connected to the detent lever 28, and the operation amount of the spool valve 16 (operation position of the spool 34) is switched by rotating the detent lever 28 by the output shaft 25 of the motor 14. Thus, the shift range of the automatic transmission 12 is switched to any one of the P range, the R range, the N range, the D range, and the like. The detent lever 28 is formed with a plurality of recesses 35 for holding the spool 34 of the spool valve 16 at positions corresponding to the above ranges.

  On the other hand, a detent spring 36 for holding the detent lever 28 at a position corresponding to each range is fixed to the spool valve 16, and an engaging portion 37 provided at the tip of the detent spring 36 is a target range of the detent lever 28. By fitting in the recess 35, the detent lever 28 is held at the rotation angle of the target range, and the position of the spool 34 of the spool valve 16 is held at the position of the target range. The detent lever 28 and the detent spring 36 constitute a detent mechanism 38 (moderation mechanism) for engaging and holding the operation amount of the spool valve 16 (operation position of the spool 34) at the position of each range.

  In the P range, the parking rod 29 moves in a direction approaching the lock lever 31, the thick part of the cone 30 pushes up the lock lever 31, and the convex portion 31 a of the lock lever 31 fits into the parking gear 33. The gear 33 is locked, whereby the output shaft (drive wheel) of the automatic transmission 12 is held in the locked state (parking state).

  On the other hand, in ranges other than the P range, the parking rod 29 moves in a direction away from the lock lever 31, the thick part of the cone 30 comes out of the lock lever 31, and the lock lever 31 is lowered. The convex portion 31a is disengaged from the parking gear 33, the parking gear 33 is unlocked, and the output shaft of the automatic transmission 12 is held in a rotatable state (running state).

  Next, the configuration of the motor 14 will be described with reference to FIGS. 3 and 4. In the present embodiment, for example, a switched reluctance motor (SR motor) is used as the motor 14. The motor 14 is a motor in which both the stator core 51 and the rotor 52 have a salient pole structure, and has an advantage that a permanent magnet is unnecessary and the structure is simple. For example, twelve salient poles 51a are formed at equal intervals on the inner peripheral portion of the cylindrical stator core 51. On the other hand, for example, eight salient poles 52a are equally spaced at the outer peripheral portion of the rotor 52. As the rotor 52 rotates, the salient poles 52a of the rotor 52 are sequentially opposed to the salient poles 51a of the stator core 51 via a minute gap. The 12 salient poles 51a of the stator core 51 are wound around the U-phase, V-phase, and W-phase windings of the two-system (a-system and b-system) drive coils 53 and 54 at symmetrical positions. Needless to say, the number of salient poles 51a and 52a of the stator core 51 and the rotor 52 may be changed as appropriate. In the following description, the “U phase”, “V phase”, and “W phase” of the drive coil 53 of one system (a system) are expressed as “Ua phase”, “Va phase”, and “Wa phase”, respectively. The “U phase”, “V phase”, and “W phase” of the drive coil 54 of the other system (b system) are denoted as “Ub phase”, “Vb phase”, and “Wb phase”, respectively.

  The winding sequence of each phase of the two drive coils 53 and 54 is, for example, Ua phase → Va phase → Wa phase → Ua phase → Va phase with respect to the 12 salient poles 51a of the stator core 51. It is wound in the order of Wa phase → Ub phase → Vb phase → Wb phase → Ub phase → Vb phase → Wb phase. As shown in FIG. 4, a total of six windings of Ua phase, Va phase, and Wa phase and a total of six windings of Ub phase, Vb phase, and Wb phase are provided with two systems of drive coils 53 and 54. Wired to make up. One drive coil 53 is configured by Y-connecting a total of six windings of Ua phase, Va phase, and Wa phase (two windings of the same phase are connected in series, respectively). The drive coil 54 is configured by Y-connecting a total of six windings of Ub phase, Vb phase, and Wb phase (two windings of the same phase are connected in series, respectively). The two drive coils 53 and 54 are energized simultaneously in the Ua phase and the Ub phase, energized in the Va phase and Vb phase simultaneously, and energized in the Wa phase and Wb phase simultaneously.

  As shown in FIG. 4, the two systems of drive coils 53 and 54 are driven by separate motor drivers 55 and 56 (motor drive circuits), respectively, using a battery 23 mounted on the vehicle as a power source. As described above, by providing two systems each of the drive coils 53 and 54 and the motor drivers 55 and 56, even if one system fails, the motor 12 can be rotated by the other system. .

  In the circuit configuration example of the motor drivers 55 and 56 shown in FIG. 4, a unipolar drive type circuit configuration is provided in which one switching element 57 such as a transistor is provided for each phase, but two switching elements are provided for each phase. A bipolar drive type circuit configuration provided one by one may be adopted. It goes without saying that the present invention may have a configuration in which one drive coil and one motor driver are provided.

  The motor 14 is provided with an encoder 61 (see FIG. 5) for detecting the rotation angle of the rotor 52. The encoder 61 is composed of, for example, a magnetic rotary encoder. As shown in FIGS. 6 and 7, the specific configuration is such that the N pole and the S pole are alternately arranged at equal pitches in the circumferential direction. A configuration in which a magnetized annular rotary magnet 62 is coaxially fixed to the side surface of the rotor 52, and two magnetic detection elements 63, 64 such as Hall ICs are disposed at a position facing the rotary magnet 62. It has become.

  In this embodiment, the magnetization pitch of the N pole and S pole of the rotary magnet 62 is set to 7.5 °. The magnetizing pitch (7.5 °) of the rotary magnet 62 is set to be the same as the rotation angle of the rotor 52 per excitation of the motor 12. For example, if the energized phase of the motor 12 is switched 6 times in the 1-2 phase excitation method, the switching of all energized phases is completed and the rotor 52 and the rotary magnet 62 are integrally 7.5 ° × 6 = 45. Rotate. The total number of N poles and S poles existing in the 45 ° rotation angle range of the rotary magnet 62 is six poles.

Two magnetic detection elements 63 and 64 are arranged with respect to the rotary magnet 62 in the following positional relationship. The magnetic detection element 63 that outputs an A-phase signal and the magnetic detection element 64 that outputs a B-phase signal are arranged on the same circumference at positions that can face the magnetized portions (N, S) of the rotary magnet 62. . The interval between the two magnetic detection elements 63 and 64 that output 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, as shown in FIG. It is set to be (mechanical angle 3.75 °). Here, the “electrical angle” is an angle when the generation period of the A-phase / B-phase signal is one period (360 °), and the “mechanical angle” is a mechanical angle (one rotation of the rotor 52 is 360 °). The angle at which the rotor 52 rotates from the fall (rise) of the A phase signal to the fall (rise) of the B phase signal is the mechanical angle of the phase difference between the A phase signal and the B phase signal. Equivalent to.
The outputs of the magnetic detection elements 63 and 64 are at a high level “1” when facing the N pole, and at a low level “0” when facing the S pole.

  In this embodiment, the range switching ECU 20 counts both rising / falling edges of the A-phase signal and B-phase signal, and rotates the rotor 52 by switching the energized phase of the motor 14 according to the encoder count value. To drive. At this time, the rotation direction of the rotor 52 is determined based on the generation order of the A-phase signal and the B-phase signal, the encoder count value is counted up in the normal rotation (P range → D range rotation direction), and the reverse rotation (D range → In the P range rotation direction), the encoder count value is counted down. As a result, even if the rotor 52 rotates in either the forward rotation or the reverse rotation, the correspondence relationship between the encoder count value and the rotation angle of the rotor 52 is maintained. However, the rotation angle of the rotor 52 is detected based on the encoder count value, and the rotor 52 is driven to rotate by energizing the winding of the phase corresponding to the rotation angle.

  FIG. 8B shows an output waveform of the encoder 61 and a switching pattern of the energized phase when the rotor 52 is rotated in the reverse rotation direction (rotation direction of the D range → P range) by the 1-2 phase excitation method. Yes. In each of the reverse rotation direction (D range → P range rotation direction) and forward rotation direction (P range → D range rotation direction), one-phase energization and two-phase each time the rotor 52 rotates 7.5 °. During the rotation of the rotor 52 by 45 °, for example, U phase energization → UW phase energization → W phase energization → VW phase energization → V phase energization → UV phase energization The energized phase is switched once. At this time, the windings of each phase of the two drive coils 53 and 54 are energized simultaneously.

  Each time this energized phase is switched, the rotor 52 rotates by 7.5 °, and the magnetic pole of the rotary magnet 62 facing the magnetic detection elements 63 and 64 for the A phase and B phase signals changes from N pole to S pole. Alternatively, the level of the A-phase signal and the B-phase signal is alternately inverted by changing from the S pole to the N pole, so that every time the rotor 52 rotates 7.5 °, the encoder count value is incremented by 2 (or Count down). In this specification, when the A-phase and B-phase signals are at the high level “1”, the A-phase and B-phase signals are sometimes output.

  When range switching control is performed by such a motor 14 with an encoder 61, the rotor 52 is driven to rotate each time the target range is switched from the P range to the D range direction or the opposite direction, based on the encoder count value. Thus, feedback control (hereinafter referred to as “F / B control”) for rotating the rotor 52 toward the target rotation angle by sequentially switching the energization phase of the motor 14 is executed, and the encoder count value corresponds to the target rotation angle. When the set target count value is reached, it is determined that the rotor 52 has reached the target rotation angle, the F / B control is terminated, and the rotor 52 is stopped at the target rotation angle.

  By the way, since the encoder count value is stored in the RAM 71 (storage means) of the range switching ECU 20, when the power of the range switching ECU 20 is turned off, the stored data of the encoder count value is lost. Further, even if the motor 14 rotates with an external force or the like while the power is off, the rotation angle cannot be detected. Due to these circumstances, an energized phase learning process is necessary in which the relationship between the encoder count value and the energized phase is learned by examining the relationship between the encoder count value and the actual rotation angle of the rotor 52 after the power is turned on.

  Therefore, in the present embodiment, the range switching ECU 20 functions as energized phase learning means in the scope of claims, and switches the energized phase of the motor 14 in a predetermined time schedule during initial driving after power-on. An energized phase learning process is performed in which the edges of the A phase signal and the B phase signal of the encoder 61 are counted and the correspondence between the encoder count value at the end of the initial drive, the rotation angle of the rotor 52 and the energized phase is learned as the energized phase learning value. The energized phase is determined based on the encoder count value and the energized phase learning value during the subsequent normal drive. The encoder count value and the energized phase learning value are stored in the RAM 71 of the range switching ECU 20.

This energized phase learning process (initial drive) is specifically performed as follows.
As shown in FIG. 9, when the initial drive is performed when the power is supplied to the range switching ECU 20 in the P range, for example, W phase energization → UW phase energization → U phase energization → UV phase energization → V phase energization → The energized phases are switched in a predetermined time schedule in the order of the VW phase energization, and the rotor 52 is driven in the normal rotation direction (P range → D range rotation direction).

  On the other hand, when the initial driving is performed when the power is supplied to the range switching ECU 20 in the D range, for example, the order of V phase energization → UV phase energization → U phase energization → UW phase energization → W phase energization → VW phase energization Thus, the energized phase is switched once in a predetermined time schedule, and the rotor 52 is driven in the reverse rotation direction (the rotation direction of the D range → P range).

  During this initial drive, the one-phase energization time T1 is set shorter than the two-phase energization time T2, and for example, T1 = 10 ms and T2 = 100 ms are set. Even after the rotation angle of the rotor 52 and the energized phase are synchronized during the initial drive, the rotor 52 vibrates in the one-phase energization with a small torque, so the time T1 of the one-phase energization is shortened as quickly as possible. By switching to the next two-phase energization, the vibration of the rotor 52 is promptly stopped and the output signal of the encoder 61 is stabilized.

  In this way, if the energized phase is switched once during the initial drive, the rotation angle of the rotor 52 and the energized phase always coincide with each other before the initial drive is completed, and thereafter The rotor 52 rotates in synchronization with the phase switching, and the A phase signal and the B phase signal are output from the encoder 61 in synchronization with the rotation of the rotor 52.

  During this initial drive, both the rising and falling edges of the A-phase signal and B-phase signal of the encoder 61 are counted. Therefore, by looking at the encoder count value at the end of the initial drive, the angle (rotation amount) that the rotor 52 has actually rotated in synchronization with the switching of the energized phase before the end of the initial drive can be found, thereby completing the end of the initial drive. The correspondence relationship between the encoder count value at the time, the rotation angle of the rotor 52, and the energized phase is known.

  In the example of FIG. 9, the rotor 52 rotates from the first energized phase (W phase) during the initial drive, and the rotor 52 rotates by 7.5 ° every time the energized phase is switched, and the encoder count value is incremented by 2. At the end of the initial drive, the encoder count value becomes 12.

  On the other hand, for example, when the rotor 52 does not rotate by 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). When the rotor 52 rotates by the amount of excitation three times in synchronization with the rotation angle of the rotor 52 and the energized phase, the rotor 52 is 7.5 ° × 3 = 22.5 ° by the end of the initial drive. Rotate 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 52 actually rotates in synchronization with the switching of the energized phase before the end of the initial drive is found.

  The last energized phase of the initial drive is always the VW phase, but the encoder count value is not necessarily 12 and may be 8 or 4, for example. During normal driving after the end of initial driving, the energized phase is determined based on the encoder count value. Therefore, the correct energized phase can be selected during normal driving by correcting the deviation in the encoder count value due to initial driving.

  After completion of the initial drive, the routine shifts to normal motor control, and as shown in FIG. 9, first, for example, 10 ms is applied to the same phase as the energization phase (VW phase) at the end of the initial drive, and the position of the rotor 52 is initially driven. The position at the end is held, and then, by feedback control, the energized phase is switched based on the encoder count value and the energized phase learning value at that time, and the rotor 52 is rotated in the direction of the target rotation angle. As a result, when the rotation angle (encoder count value) of the rotor 52 reaches within, for example, 0.5 ° from the target rotation angle, the switching of the energized phase is terminated and the rotor 52 is stopped. The energization is continued and the rotor 52 is held in a stopped state, and this holding state is continued for 50 ms, for example. Thereafter, if the target rotation angle does not change, the energization is stopped.

  By the way, since it is necessary to energize the motor 14 continuously in order to execute the energization phase learning process (initial drive), the motor 14 or the motor drivers 55 and 56 of the range switching ECU 20 are likely to generate heat. Normally, since the motor 14 is not turned off for a while after the power is turned on, the initial drive is only required once. However, when the user repeatedly turns the power switch 72 (ignition switch) on and off for a sense of fun, There is a concern that the initial drive is repeated many times in a short time, and the temperature of the motor 14 or the motor drivers 55 and 56 rises, leading to a decrease in the life or failure of the motor 14 or the motor drivers 55 and 56. is there.

  Therefore, in this embodiment, as shown in FIG. 10, the ECU relay 73 (see FIG. 5) is kept on until the predetermined time (T1 or T2) elapses after the power switch 72 is turned off, and the range is switched. The power supply to the ECU 20 is continued, and the energized phase learning process (initial driving) is not executed even if the power switch 72 is turned on during a period in which the power on state is continued after the power switch 72 is turned off.

  In this case, for a predetermined time (T1 or T2) during which the power-on state is continued after the power switch 72 is turned off, the motor 14 or the motor drivers 55 and 56 that have generated heat in the energized phase learning process are radiated and the motor 14 or motor The time required for lowering the temperature of the drivers 55 and 56 within the allowable temperature range is set, and the elapsed time from the first operation of turning off the power switch 72 after the energized phase learning process is set to the predetermined time T1. It may be determined whether or not the power switch 72 has been reached, or it may be determined whether or not the time during which the power switch 72 remains off has reached a predetermined time T2. This predetermined time (T1 or T2) may be a predetermined time set in advance, or may be changed according to the temperature of the motor 14 or the motor drivers 55 and 56. The temperature of the motor 14 or the motor drivers 55 and 56 may be detected by a temperature sensor, or may be estimated based on an energization current amount of the motor 14 at the time of initial driving.

  The energized phase learning process of the present embodiment described above is executed by the range switching ECU 20 according to the energized phase learning process program of FIG. This program is repeatedly executed at a predetermined cycle during power supply to the range switching ECU 20 (while the ECU relay 73 is on). When this program is started, it is first determined in step 101 whether or not the power switch 72 has just been switched from OFF to ON, and if it has just been switched ON, Proceeding to step 102, it is determined whether or not the ECU relay 73 is off. As a result, if it is determined that the ECU relay 73 is in the off state, the process proceeds to step 103, the ECU relay 73 is turned on, the energized phase learning process is performed in the next step 104, and the process proceeds to step 105.

  On the other hand, when it is determined as “No” in any of the above steps 101 and 102, that is, not immediately after the power switch 72 is switched on, or when the ECU relay 73 is in the on state. Steps 103 and 104 are skipped and the process proceeds to Step 105. In this case, the energized phase learning process is not performed.

  Thereafter, in step 105, it is determined whether or not a predetermined time (T1 or T2) has elapsed since the power switch 72 was turned off. At this time, it may be determined whether or not the elapsed time from the first turning-off operation of the power switch 72 after the energized phase learning process has reached a predetermined time T1, or the power switch 72 is kept off. It may be determined whether or not a predetermined time has reached a predetermined time T2. If it is determined in step 105 that the predetermined time (T1 or T2) has not elapsed since the power switch 72 was turned off, the program is terminated as it is. In this case, the ECU relay 73 is kept on even after the power switch 72 is turned off. The processing in step 105 serves as power supply continuation means in the claims.

  Thereafter, when a predetermined time (T1 or T2) has elapsed from the turning-off operation of the power switch 72, it is determined “Yes” in Step 105, and the process proceeds to Step 106, where the ECU relay 73 is turned off and the range switching ECU 20 is entered. Shut off the power supply.

  According to the present embodiment described above, the stored data (energized phase learning value and encoder count value) of the RAM 71 can be maintained and maintained in the power-on state until a predetermined time elapses after the power switch 72 is turned off. At the same time, if the motor 14 is rotated by an external force or the like, the encoder count value can be updated according to the rotation angle. As a result, the energized phase learning value and the encoder count value stored in the RAM 71 are used for the period in which the power switch 72 is maintained in the power-on state after the power switch 72 is turned off without executing the energized phase learning process (initial driving). Thus, the motor 14 can be correctly rotated to the target rotation angle, and the energized phase learning process (initial drive) can be prevented from being executed even if the power switch 72 is turned on during the period. For this reason, even if the user repeats the on / off switching operation of the power switch 72 with a sense of play or the like, the motor 14 or the motor drivers 55 and 56 of the range switching ECU 20 generate heat due to the energized phase learning process (initial driving). Thus, it is possible to prevent the motor 14 or the motor drivers 55 and 56 from being shortened in life or broken.

The encoder 61 is not limited to a magnetic encoder, and for example, an optical encoder or a brush encoder may be used.
Further, the motor 14 is not limited to the SR motor, and other than the SR motor as long as it is a brushless type synchronous motor that detects the rotation angle of the rotor based on the count value of the pulse signal of the encoder and sequentially switches the energized phase of the motor. A synchronous motor may be used.

  In addition, the present invention is not limited to the range switching device, and needless to say, the present invention can be widely applied to various position switching devices using a brushless type synchronous motor such as an SR motor as a drive source.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... Automatic transmission, 13 ... Hydraulic control valve, 14 ... Motor, 15 ... Range switching mechanism, 16 ... Spool valve, 17 ... Shift control ECU, 20 ... Range switching ECU (energized phase learning means, power supply continuation) Means), 21 ... Shift range detection device, 22 ... Engine ECU, 23 ... Battery (power source), 28 ... Detent lever, 29 ... Parking rod, 31 ... Lock lever, 33 ... Parking gear, 35 ... Recess, 36 ... Detent spring , 37 ... engaging portion, 38 ... detent mechanism, 43 ... starter, 46 ... output shaft sensor, 51 ... stator core, 52 ... rotor, 53, 54 ... drive coil, 55, 56 ... motor driver (motor drive circuit), 61 ... Encoder, 62 ... Rotary magnet, 63 ... Magnetic detection element for A-phase signal, 64 ... Magnetic detection element for B-phase signal, 1 ... RAM (storage means), 72 ... power switch, 73 ... ECU relay

Claims (4)

An encoder that outputs a pulse signal at predetermined angular intervals as the motor that rotationally drives the object to be controlled, a power switch that switches power on / off, and an energization phase of the motor after the power is turned on by turning on the power switch The correspondence between the encoder pulse signal count value (hereinafter referred to as “encoder count value”), the rotation angle of the motor and the energized phase is learned as an energized phase learning value by sequentially switching in a predetermined pattern by the motor drive circuit. An energized phase learning means for executing an energized phase learning process; and a storage means for storing the energized phase learning value and the encoder count value. After the energized phase learning process, the encoder count value and the energized phase learned value are stored. The motor is rotated to the target rotation angle by sequentially switching the energized phase of the motor based on In over motor controller,
A power supply continuation means for continuing the power-on state until a predetermined time elapses after the power switch is turned off;
The energized phase learning means does not execute the energized phase learning process even if the power switch is turned on during a period in which the power continuation means continues the power-on state after the power switch is turned off. Control device.   The predetermined time is set so as to secure a time necessary for radiating heat from the motor that has generated heat in the energized phase learning process or a time necessary for radiating heat from the motor drive circuit that switches the energized phase of the motor. The motor control device according to claim 1, wherein:   The motor control apparatus according to claim 1, wherein the motor is a switched reluctance motor.   4. The motor control device according to claim 1, wherein the motor drives a range switching mechanism that switches a range of an automatic transmission of the vehicle.

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