JP2012095407A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rotationally drive a motor promptly to a target rotation angle without re-executing energization phase learning processing even when a microcomputer (ECU) is reset in the middle of rotationally driving the motor to the target rotation angle by the microcomputer.SOLUTION: Every time the target rotation angle (target range) is changed, the target rotation angle is updated and stored in a backup RAM (rewritable nonvolatile memory). When a range switching ECU is reset and reactivated in the middle of rotationally driving the motor to the target rotation angle, the energization phase of the motor is successively switched by open loop control without using a count value of encoder pulses, and the motor is rotationally driven until a detection value of an output shaft sensor which detects the rotation angle of the output shaft of the motor becomes a value equivalent to the target rotation angle read from the backup RAM. Thereafter, the energization phase learning processing is re-executed.

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, as shown in Patent Document 1 (Japanese Patent No. 3888940), there is one in which a range switching mechanism of an automatic transmission of a vehicle is driven by a motor. 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.

  Although this type of motor is controlled by a microcomputer, the microcomputer may be reset for some reason (for example, an instantaneous power failure or noise) during the motor control. Once the microcomputer is reset, the RAM for storing the target rotation angle (target count value) is also reset, so that the target rotation angle is unknown. For this reason, when the microcomputer is reset and restarted, there is a possibility that the controlled object is arbitrarily switched to an unintended position.

  Therefore, in the invention according to claim 1 of Patent Document 1, the target rotation angle is stored in a rewritable nonvolatile memory, and the microcomputer is reset and restarted while the motor is rotated to the target rotation angle. In the case where it has been done, the rotational drive of the motor is resumed using the target rotation angle stored in the nonvolatile memory.

  In the invention according to claim 5 of Patent Document 1, an output shaft sensor for detecting the rotation angle of the output shaft of the motor is provided, and the rotation angle detected by the output shaft sensor is set as the target rotation at the start-up after resetting the microcomputer. The angle is set.

Japanese Patent No. 3888940

  By the way, if the microcomputer is reset due to an instantaneous power failure or noise during the rotation of the motor to the target rotation angle, all of the energized phase learning value and encoder count value data stored in the RAM before the reset are also reset. Therefore, in the invention according to claim 1 of Patent Document 1, it is necessary to re-execute the energized phase learning process when restarting after reset, and then rotationally drive the motor to the target rotation angle read from the nonvolatile memory. Switching to the target rotation angle is delayed due to the energized phase learning process.

  Therefore, it is conceivable to store the energized phase learning value and encoder count value in the nonvolatile memory, but even if the motor rotates due to inertia during resetting of the microcomputer, the rotation angle cannot be detected (encoder pulse signal). Therefore, the energized phase learning value and encoder count value stored before reset cannot be used after reset, and it is necessary to re-execute the energized phase learning process after reset.

  Further, in the invention according to claim 5 of Patent Document 1, when the microcomputer is started after being reset, the rotation angle detected by the output shaft sensor is set to the target rotation angle, so that the motor is driven to rotate to the target rotation angle. If the microcomputer is reset in, the target rotation angle after reset is set to a value different from the target rotation angle before reset (rotation angle at startup after reset), and the motor was set before reset. Cannot be rotated to the target rotation angle (see FIG. 9).

  Therefore, the problem to be solved by the present invention is that the motor rotates to the target rotation without re-execution of the energized phase learning process even when the microcomputer (control means) is reset during the rotation of the motor to the target rotation angle. It is to provide a motor control device capable of rapidly rotating to an angle.

  In order to solve the above problems, an invention according to claim 1 is directed to an encoder that outputs a pulse signal in synchronization with rotation of a motor that rotationally drives a controlled object, and a count value (hereinafter referred to as “encoder count”) of the pulse signal of the encoder. Learning means for learning the correspondence between the rotation angle of the motor and the energized phase as an energized phase learning value, and sequentially switching the energized phase of the motor based on the encoder count value and the energized phase learned value. In the motor control apparatus comprising the control means for driving the motor to the target rotation angle, the output shaft rotation angle detection means for detecting the rotation angle of the output shaft of the motor or information correlated therewith, and the control means Rewritable non-volatile storage means for holding stored data even when the memory is reset, the storage means includes the target The control means stores the rotation angle, and when the control means is reset and restarted while the motor is rotationally driven to the target rotation angle, the control means does not use the encoder count value but performs the loop by the open loop control. The energized phase of the motor is sequentially switched, and the motor is driven to rotate until the detection value of the output shaft rotation angle detection means reaches a value corresponding to the target rotation angle read from the storage means. In this configuration, when the control means is reset and restarted during the rotational drive of the motor to the target rotation angle, open loop control is performed while checking the rotation angle of the motor based on the detection value of the output shaft rotation angle detection means. Since the motor can be rotationally driven to the target rotational angle read from the storage means, the motor can be rotationally driven quickly to the target rotational angle without re-execution of the energized phase learning process when restarting after reset.

  In this case, as described in claim 2, it is preferable to re-learn the energized phase learning value after completing the rotation driving of the motor by the open loop control. In this way, the correct energized phase learning value after reset can be re-learned after completion of the open loop control.

  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 range switching ECU 20 is reset during the rotational drive of the motor to the target rotation angle (target range) by F / B control. FIG. 10 is a flowchart showing the flow of processing of the backup RAM storage processing routine. FIG. 11 is a flowchart showing the flow of processing of the motor control routine.

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, 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 32 rotates by 7.5 °, and the magnetic poles of the rotary magnet 62 facing the magnetic detection elements 63 and 64 for A-phase and B-phase signals are changed from N poles to S poles. 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 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 this embodiment, the range switching ECU 20 functions as a learning means in the scope of claims, and switches the energized phase of the motor 14 by a 1-2 phase excitation method at the time of initial driving immediately after power-on in a predetermined time schedule. The rotation angle of the rotor 52 and the energized phase coincide with each other in the energized phase, the rotor 52 is rotationally driven, the edges of the A phase signal and the B phase signal of the encoder 61 are counted, An energized phase learning process is performed in which the correspondence relationship between the encoder count value at the end of initial driving, the rotation angle of the rotor 52, and the energized phase is learned as an energized phase learning value. The energized phase is determined based on the value.

Specifically, this energized phase learning process is performed as follows.
For example, when the energized phase learning process 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 → VW phase energization In this order, the energized phase is switched once in a predetermined time schedule, and the rotor 52 is driven in the normal rotation direction (P range → D range rotation direction).

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

  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 22 and the energized phase is known.

  The last energized phase of the initial drive is always the VW phase (2-phase energization), but the encoder count value is not necessarily a constant value. During F / B control after the end of initial drive, the energized phase is determined based on the encoder count value. Therefore, if the deviation of the encoder count value due to initial drive is not corrected, the correct energized phase should be selected during F / B control. I can't.

  Therefore, in this embodiment, the encoder count value at the end of the initial drive is learned as the energized phase learning value, and the encoder count value is corrected with the energized phase learned value during the subsequent F / B control. Deviation between the encoder count value and the energized phase (rotation angle of the rotor 32) is corrected so that the correct energized phase can be selected during F / B control.

  By the way, during the F / B control, encoder count value, energized phase learning value, and target rotation angle (target count value) data are stored in the RAM 71 (see FIGS. 4 and 5) of the range switching ECU 20. If the range switching ECU 20 is reset due to an instantaneous power failure or noise during the F / B control of the motor to the target rotation angle, the encoder count value, energized phase learning value, and target rotation angle data stored in the RAM 71 before the reset are also stored. All are reset.

  Therefore, the backup RAM 72 (see FIG. 5), which is a rewritable non-volatile storage means that retains the stored data of the encoder count value, energized phase learning value, and target rotation angle (target count value) even when the range switching ECU 20 is reset. 4 (see FIG. 5). However, even if the motor 14 rotates due to inertia or the like while the range switching ECU 20 is reset, the rotation angle cannot be detected (the pulse signal of the encoder 61 cannot be counted). The energized phase learning value and encoder count value stored before reset cannot be used after reset, and it is necessary to re-execute the energized phase learning process after reset. For this reason, when the motor 14 is to be rotated and driven to the target rotation angle by F / B control after the reset, switching to the target rotation angle is delayed for the energized phase learning process.

  Further, as in claim 5 of Patent Document 1 described above, when the range switching ECU 20 is reset while the motor 14 is rotationally driven to the target rotation angle (target range), the output shaft sensor is activated at the time of startup after the reset. If the rotation angle detected at 46 is set as the target rotation angle, the target rotation angle after reset is set to a value different from the target rotation angle before reset (rotation angle at start after reset), and the motor 14 is reset. It cannot be rotated to the original target rotation angle set before (see FIG. 9).

  Therefore, in this embodiment, the target rotation angle (target range) and the current motor drive information (the value of the motor drive flag indicating whether or not the motor 14 is being driven) are stored in the backup RAM 72, and FIG. As shown in FIG. 4, when the range switching ECU 20 is reset and restarted while the motor 14 is rotationally driven to the target rotation angle by F / B control, the motor 14 is reset based on the motor drive information read from the backup RAM 72. If the motor 14 is being driven at the time of resetting, the energized phase of the motor 14 is sequentially switched by open loop control without using the encoder count value, and the output shaft sensor 46 The detection value (detection range) corresponds to the target rotation angle read from the backup RAM 72 (target range) The motor 14 is driven to rotate until.

  When driving the motor 14 in the forward rotation direction (P range → D range rotation direction) by open loop control, for example, W phase energization → UW phase energization → U phase energization → UV phase energization → V phase energization → VW phase When switching the energized phase in the order of energization and driving the motor 14 in the reverse rotation direction (D range → P range rotation direction), for example, V phase energization → UV phase energization → U phase energization → UW phase energization → Repeat the switching of energized phases in the order of W phase energization → VW phase energization. The first energized phase at the start of the open loop control may be a predetermined energized phase determined in advance, or the energized phase is updated in the backup RAM 72 every time the energized phase is switched during F / B control. It is also possible to read the energization phase at the time of reset stored in the backup RAM 72 when the range switching ECU 20 is activated after being reset, and use this as the first energization phase at the start of the open loop control.

During open loop control, it may be driven by the 1-2 phase excitation method that alternately switches between the one-phase energization and the two-phase energization as described above, or the one-phase excitation method that is driven only by the one-phase energization, or You may employ | adopt the two-phase excitation system driven only by two-phase electricity supply. After confirming that the rotation angle of the motor 14 has reached the target rotation angle read from the backup RAM 72 by this open loop control with the detection value of the output shaft sensor 46, the energized phase learning process (initial drive) is re-executed.
The control of the motor 14 of the present embodiment described above is executed by the range switching ECU 20 according to the routines shown in FIGS. The processing contents of each routine will be described below.

[Backup RAM storage processing routine]
The backup RAM storage processing routine of FIG. 10 is repeatedly executed at a predetermined cycle during the power-on period of the range switching ECU 20. When this routine is started, first, at step 101, it is determined whether or not the target range (shift range selected by the driver by operating the shift lever) has been switched based on the output signal of the shift range detection device 21, and If it is determined that the target range has been switched, the process proceeds to step 102 where the target range is updated and stored in the backup RAM 72. If it is determined that the target range has not been switched, the process of step 102 is skipped. Thus, each time the target range is switched, the target range is updated and stored in the backup RAM 72.

  Thereafter, the process proceeds to step 103 to determine whether or not the motor 14 is being driven. If the motor 14 is being driven, the process proceeds to step 104 and the motor drive flag stored in the backup RAM 72 is being driven. If the motor 14 is stopped, the process proceeds to step 105, and the motor drive flag stored in the backup RAM 72 is set to "0" meaning that the motor 14 is stopped.

[Motor control routine]
The motor control routine of FIG. 11 is repeatedly executed at a predetermined period during the power-on period of the range switching ECU 20, and serves as a control means in the claims. When this routine is started, first, at step 201, it is determined whether or not the range switching ECU 20 is at the time of reset recovery. If it is determined that it is not at the time of reset recovery, the routine proceeds to step 202 and before the energized phase learning process. If it is before the energized phase learning process, the process proceeds to step 203 to execute an energized phase learning process routine (not shown) to obtain an energized phase learning value. If the phase learning process has been completed, the process of step 203 is skipped.

  Thereafter, the routine proceeds to step 204 where a normal motor control routine (not shown) is executed. Thus, when the target range is switched, the F / B control for rotating the motor 14 by sequentially switching the energized phase of the motor 14 based on the encoder count value corrected by the energized phase learning value is executed, and the encoder count When the value reaches the target count value set according to the target range, it is determined that the target range has been reached, and the F / B control is terminated.

  If the range switching ECU 20 is reset due to an instantaneous power failure or noise during the F / B control, the F / B control is also stopped at that time. In this case, when this routine is started at the time of reset recovery, it is determined as “Yes” in the above step 201, the process proceeds to step 205, and the target range and motor drive flag values stored in the backup RAM 72 are read. In the next step 206, it is determined whether or not the motor 14 is being driven at the time of reset based on whether or not the motor drive flag is “1”, and the motor drive flag = 0 (the motor 14 is stopped at the time of reset). If there is, the routine is terminated without performing the subsequent processing.

  On the other hand, if it is determined in step 206 that the motor drive flag = 1 (the motor 14 is being driven at the time of reset), the process proceeds to step 207, and the energized phase of the motor 14 is changed by open loop control without using the encoder count value. The motor 14 is rotationally driven by sequentially switching. Each time the energized phase is switched, the process proceeds to step 208 to determine whether or not the actual range detected by the output shaft sensor 46 has reached the target range. If the actual range has not yet reached the target range, Returning to step 207, the rotation drive of the motor 14 by the open loop control is continued. Thereafter, when the actual range detected by the output shaft sensor 46 reaches the target range, the process proceeds from step 208 to step 209, and an energized phase learning process routine (not shown) is executed to obtain an energized phase learning value.

  In the present embodiment described above, the target range and the value of the motor drive flag are stored in the backup RAM 72, and the range switching ECU 20 is reset and restarted while the motor 14 is rotationally driven to the target rotation angle by F / B control. When starting up, it is determined whether or not the motor 14 is being driven at the time of reset based on the value of the motor drive flag read from the backup RAM 72. If the motor 14 is being driven at the time of reset, the encoder count value is set. Since the energized phase of the motor 14 is sequentially switched by open loop control without using it, the motor 14 is driven to rotate until the detection range of the output shaft sensor 46 matches the target range read from the backup RAM 72. Without restarting the energized phase learning process at restart, the motor 14 is Can be driven quickly rotated to the target rotational angle corresponding to di.

  In this embodiment, the motor drive flag (motor drive information) is stored in the backup RAM 72 in order to determine whether or not the motor 14 is being driven at the time of resetting. It is determined whether the detection range of the output shaft sensor 46 matches the target range read from the backup RAM 72. If the detection range of the output shaft sensor 46 is different from the target range, the motor 14 is being driven at the time of reset. Therefore, the motor 14 may be rotationally driven until the detection range of the output shaft sensor 46 matches the target range read from the backup RAM 72 by sequentially switching the energization phase of the motor 14 by open loop control. In this case, it is not necessary to store a motor drive flag (motor drive information) in the backup RAM 72.

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 output shaft sensor 46 is not limited to 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. For example, each of P, R, N, and D A fixed contact is provided at a position corresponding to the range, and a movable contact that rotates integrally with the output shaft 25 contacts the fixed contact of any range, thereby detecting each range of P, R, N, and D. You may do it.

  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 (learning means, control means), DESCRIPTION OF SYMBOLS 21 ... Shift range detection apparatus, 22 ... Engine ECU, 23 ... Battery (power supply), 28 ... Detent lever, 29 ... Parking rod, 31 ... Lock lever, 33 ... Parking gear, 35 ... Recessed part, 36 ... Detent spring, 37 ... Engagement part, 38 ... detent mechanism, 43 ... starter, 46 ... output shaft sensor (output shaft rotation angle detecting means), 51 ... stator core, 52 ... rotor, 53, 54 ... drive coil, 55, 56 ... motor driver, 61 ... Encoder, 62 ... Rotary magnet, 63 ... Magnetic detection element for A phase signal, 64 ... Magnetic detection element for B phase signal, 7 ... backup RAM (memory means)

Claims (4)

Correspondence between the encoder that outputs a pulse signal in synchronization with the rotation of the motor that rotates the controlled object, the count value of the pulse signal of the encoder (hereinafter referred to as “encoder count value”), the rotation angle of the motor, and the energized phase Learning means for learning a relationship as an energized phase learning value; and control means for driving the motor to a target rotation angle by sequentially switching the energized phase of the motor based on the encoder count value and the energized phase learned value. In the motor control device provided,
Output shaft rotation angle detection means for detecting the rotation angle of the output shaft of the motor or information correlated therewith;
Rewritable non-volatile storage means for holding stored data even when the control means is reset,
The storage means stores the target rotation angle,
When the control unit is reset and restarted while the motor is rotationally driven to the target rotation angle, the control unit sequentially sets the energized phases of the motor by open loop control without using the encoder count value. A motor control apparatus that switches and drives the motor until the value detected by the output shaft rotation angle detection means reaches a value corresponding to the target rotation angle read from the storage means.   2. The motor control device according to claim 1, wherein the controller re-learns the energized phase learning value after completing the rotation driving of the motor by the open loop control. 3.   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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