JP2016220322A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller capable of detecting a rotation angle while reducing the number of sensor elements.SOLUTION: A motor controller has: a first sensor element and a second sensor element converting a periodic magnetic signal generated by rotation of a motor into a digital signal; and a driver unit controlling the motor on the basis of a first sensor signal outputted by the first sensor element and a second sensor signal outputted by the second sensor element respectively. The first sensor element and the second sensor element are arranged apart in the rotation direction of the motor at 120° degrees of electric angle of the magnetic signal. The driver unit measures time when signal levels of the first sensor signal and the second sensor signal are the same respectively and estimates a rotation angle of the motor on the basis of the measurement time and the respective signal levels of the first sensor signal and the second sensor signal.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a motor control device that controls rotation of a motor.

  As disclosed in Patent Document 1, a variable internal combustion engine that includes a motor in which a crankshaft, a camshaft, and an output shaft are connected via a phase variable mechanism, and a motor rotation angle sensor that outputs a rotation angle signal of the motor. A valve timing control device is known. This variable valve timing control device for an internal combustion engine calculates the actual phase difference (actual phase difference) of the camshaft relative to the crankshaft and the target phase difference (target phase difference), and calculates the deviation between them and the engine speed. It has ECU (electronic control unit) which calculates a target motor rotational speed based on it. The variable valve timing control device for an internal combustion engine also includes an EDU (motor drive circuit) that feedback-controls the motor duty ratio so as to reduce the deviation.

JP2013-24065A

  As described above, the variable valve timing control device for an internal combustion engine disclosed in Patent Document 1 includes a motor rotation angle sensor. As such a sensor, a Hall element can be employed. For example, three Hall elements are provided in the vicinity of the rotor of the motor so that the electrical angle differs by 120 °, and sensor signals having phases different by 120 ° are output. These three sensor signals are input to the ECU, and the ECU calculates the actual rotation angle of the motor based on the three sensor signals. In the case of such a configuration, there is a problem that the number of Hall elements (sensor elements) is large.

  Accordingly, an object of the present invention is to provide a motor control device capable of detecting a rotation angle while reducing the number of sensor elements.

One of the disclosed inventions for achieving the above object is a first sensor element (51) and a second sensor element for converting a periodic magnetic signal generated by the rotation of the motor (200) into a digital signal. (52)
A driver unit (20) for controlling the motor based on each of the first sensor signal output from the first sensor element and the second sensor signal output from the second sensor element;
The first sensor element and the second sensor element are arranged 120 ° apart from each other in the electrical angle of the magnetic signal in the rotation direction of the motor,
The driver unit measures the time when the signal levels of the first sensor signal and the second sensor signal are the same, and rotates the motor based on the measurement time and the signal levels of the first sensor signal and the second sensor signal. Estimate the angle.

  When the Hi level is 1 and the Lo level is 0, and the two sensor signals are expressed as 00, 01, for example, the sensor signal changes in order of 00, 10, 11, 01 when the magnetic signal changes periodically. However, the sensor signal becomes 00, 11 while the motor (200) rotates by 60 °, and the sensor signal becomes 10, 01 when the motor (200) rotates by 120 °.

  For example, if the rotation angle at which the sensor signal is 00 is 0 ° -60 °, the rotation angle at which the sensor signal is 10 is 60 ° -180 °. Similarly, the rotation angle at which the sensor signal is 11 is 180 ° -240 °, and the rotation angle at which the sensor signal is 01 is 240 ° -360 °. Therefore, the time when the sensor signal becomes 00 is the time when the motor (200) rotates from 0 ° to 60 °, and the time when the sensor signal becomes 11 is the time when the motor (200) rotates from 180 ° to 240 °. .

  Unless the rotational speed of the motor (200) changes transiently, the motor (200) rotates at a constant speed. Therefore, it can be considered that the time for which the motor (200) rotates in 60 ° increments is substantially equal. Thereby, for example, the time when the sensor signal becomes 00 can be measured, and the rotation angle of the motor (200) can be estimated based on the measurement time and the signal level of the sensor signal.

  For example, when the time when the sensor signal is 00 is measured, the rotation angle can be estimated as follows. That is, it can be estimated that the rotation angle of the motor (200) is 60 ° -120 ° from the timing when the sensor signal switches from 00 to 10 until the measurement time elapses. Until the measurement time elapses, the rotation angle of the motor (200) can be estimated to be 120 ° -180 °. However, when the rotation angle reaches 180 °, the sensor signal is switched from 10 to 11. When the sensor signal is 11, the rotation angle of the motor (200) can be calculated as 180 ° -240 ° as described above. Similarly, it can be estimated that the rotation angle of the motor (200) is 240 ° -300 ° from the timing when the sensor signal switches from 11 to 01 until the measurement time elapses. Until the measurement time further elapses, the rotation angle of the motor (200) can be estimated to be 300 ° -360 °.

  As described above, even if the number of sensor elements (51, 52) is two, the rotation angle of the motor (200) can be detected.

  In another disclosed invention, the driver unit controls the motor so that the actual rotational speed of the motor reaches the target rotational speed input from the electronic control device (10) of the vehicle. When the target rotation speed changes after measuring the time, a correction coefficient is calculated based on the change amount, and the measurement time is corrected by multiplying the measurement time by the correction coefficient.

  When the target rotational speed changes transiently, the actual rotational speed of the motor (200) changes accordingly, and the motor (200) does not rotate at a constant speed. Therefore, the time for which the motor (200) rotates in 60 ° increments is not equal. Therefore, as in the above-described invention, a correction coefficient based on the amount of change in the target rotational speed is calculated, and the measurement time is corrected using the correction coefficient. As a result, for example, because the target rotational speed has decreased, the time until the motor (200) rotates from 60 ° to 120 ° is longer than the time during which the motor (200) rotates from 0 ° to 60 ° (measurement time). , It is possible to suppress the estimation of the rotation angle of 60 ° -120 °.

One of the other disclosed inventions is that the motor includes an embedded magnet rotor (210) to which an output shaft is fixed, and a magnet torque and a reluctance torque combined in the embedded magnet rotor when an electric current flows. A permanent magnet synchronous motor having a stator (220) having a plurality of stator coils (224 to 226) for generating a rotating torque,
The driver unit estimates the rotation angle of the inverter (40) for supplying current to the stator coil and the motor, generates a control signal for controlling the inverter based on the estimated rotation angle, and outputs the control signal to the inverter A driver (30),
The plurality of stator coils include a first stator coil (224), a second stator coil (225), and a third stator coil that are sequentially spaced 120 ° in electrical angle of the magnetic signal in the rotational direction of the embedded magnet rotor. There is a stator coil (226),
The first sensor element is arranged with an electrical angle of 30 ° shifted backward from the first stator coil with respect to the rotational direction,
The second sensor element is arranged with an electrical angle of 30 ° shifted backward from the second stator coil with respect to the rotational direction,
The driver
Every time the rotation angle changes by 60 ° in electrical angle, the control signal is changed so that the embedded magnet type rotor rotates.
When starting a stopped motor,
When the signal level of each of the first sensor signal and the second sensor signal is the same, a control signal having an angle range of 60 ° corresponding to the signal level of the first sensor signal and the second sensor signal is generated.
When the signal levels of the first sensor signal and the second sensor signal are different, the angle range of 120 ° corresponding to the signal levels of the first sensor signal and the second sensor signal is equally divided into two of 60 ° and 60 °. A control signal corresponding to an angle range of 60 ° on the reverse side with respect to the rotation direction of the motor when
After that, every time the rotation angle changes by 60 degrees in electrical angle according to the fluctuation of the signal level of each of the first sensor signal and the second sensor signal to rotate the motor in the rotation direction, the embedded magnet rotor The control signal is changed so as to rotate.

  As described in detail in the detailed description of the present invention, the generation of a control signal corresponding to the reverse-side angle range generates the embedded magnet type rotation rather than the generation of a control signal corresponding to the forward-side angle range. The rotational torque generated in the child (210) is large. Therefore, the motor (200) can be started efficiently.

  As described above, even if the number of sensor elements is two, the motor (200) can be started based on the sensor signal. Therefore, for example, the embedded magnet type rotor (210) is not forcibly moved to the initial position in order to start the motor (200), or the initial position of the embedded magnet type rotor (210) is not stored in advance. Get better.

  In addition, as a rotation direction as described in the said invention, there exist a normal rotation direction and the reverse rotation direction of the reverse, and has shown either one of these two directions.

  In addition, the elements described in the claims described in the claims and the means for solving the problems are indicated with parentheses. The reference numerals in parentheses are for simply indicating the correspondence with each component described in the embodiment, and do not necessarily indicate the element itself described in the embodiment. The description of the reference numerals with parentheses does not unnecessarily narrow the scope of the claims.

It is a block diagram which shows schematic structure of the motor control apparatus which concerns on 1st Embodiment. It is sectional drawing which shows schematic structure of a motor. It is a circuit diagram which shows schematic structure of an inverter and a stator coil. It is a graph which shows the relationship between the sensor signal with respect to a rotation angle, and a control signal. It is a graph which shows the relationship of the control signal with respect to a rotation angle. It is a timing chart which shows a command signal, a sensor signal, a reference control signal, and a control signal. It is a model figure which shows a rotational torque. It is a model figure for demonstrating the difference in the rotational torque which arises with a control signal. It is a flowchart which shows the estimation process of a rotation angle. It is a flowchart which shows the correction process of measurement time. It is a flowchart which shows the starting process of a motor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The motor control device according to the present embodiment will be described based on FIGS. In addition to the motor control device 100, FIG. 1 illustrates a motor 200, an internal combustion engine 300, a valve timing conversion unit 310, a cam angle sensor 340, and a crank angle sensor 350. In FIG. 2, an electrical angle, which will be described later, is shown in parentheses, and the rotation angle sensor 50 is hatched. Further, in FIG. 2, the W-phase Hall element is indicated by a broken line for reference, and in FIG. 4, the W-phase sensor signal output from the W-phase Hall element is illustrated for reference. In FIG. 6, the reference control signal output by three sensor signals is shown for reference, and the reference control signal and the control signal are schematically shown as stepped signals.

  The motor control device 100 controls the phase difference between the camshaft 320 and the crankshaft 330 of the internal combustion engine 300 by controlling the rotation of the motor 200. As shown in FIG. 1, the motor control device 100 is electrically connected to the motor 200 via three stator wires 95 to 97, and the motor 200 is mechanically connected to the internal combustion engine 300 via a valve timing conversion unit 310. Has been. In the following, the motor 200, the valve timing conversion unit 310, and the internal combustion engine 300 will be described first, and then the motor control device 100 will be described in detail.

  The motor 200 is a permanent magnet type synchronous motor, and has a rotor 210 having an output shaft and a stator 220 provided around the rotor 210 as shown in FIG. The rotor 210 is an embedded magnet type rotor having a cylindrical iron core 211 and a permanent magnet 212 embedded in the iron core 211. In the present embodiment, the N poles and S poles of the permanent magnet 212 are embedded at equal intervals around the axis of the iron core 211 so that the N poles and S poles are alternately adjacent to each other, and the adjacent interval between the adjacent N poles and S poles is 45 °. It has become. Thereby, the magnetic flux generated by the plurality of permanent magnets 212 periodically changes every time the rotor 210 rotates 90 °, and the electrical angle is 360 ° with respect to the mechanical angle 90 °. A magnetic flux generated from the permanent magnet 212 is detected by a rotation angle sensor 50 described later.

  On the other hand, the stator 220 (stator) has a cylindrical case 221, a salient pole 222 provided on the inner peripheral surface of the case 221, and a stator coil 223 wound around the salient pole 222. . Twelve salient poles 222 are provided at equal intervals on the inner peripheral surface of the case 221, and the shortest adjacent interval between the two salient poles 222 is 30 ° in mechanical angle (120 ° in electrical angle) around the axis of the rotor 210. It has become.

  As shown in FIG. 3, the stator coil 223 includes a U-phase stator coil 224, a V-phase stator coil 225, and a W-phase stator coil 226. As indicated by symbols U, V, and W in FIG. 2, three stator coils 224, 225, and 226 are wound around twelve salient poles 222 so as to be adjacent to each other in order, and the adjacent interval is 90 ° in mechanical angle ( It is wound around four salient poles 222 having a relationship of 360 ° in electrical angle. The U-phase stator coil 224 corresponds to the first stator coil described in the claims, and the V-phase stator coil 225 corresponds to the second stator coil described in the claims. The W-phase stator coil 226 corresponds to the third stator coil recited in the claims.

  As shown in FIG. 3, the three stator coils 224 to 226 are Y-connected, and are respectively connected to the midpoints of the two switches of the corresponding inverter 40. For example, when the switches 41 and 44 shown in FIG. 3 are turned on, the stator coils 224 and 225 are connected to the positive terminal and the negative terminal of the power source, and current flows through the stator coils 224 and 225. Due to this current flow, magnetic flux is generated from the stator coils 224 and 225, and this magnetic flux acts on the permanent magnet 212 and the iron core 211 of the rotor 210, thereby generating rotational torque in the rotor 210. Thereby, the output shaft of the motor 200 rotates autonomously.

  The output shaft of the motor 200 described above is connected to the camshaft 320 via the valve timing conversion unit 310. The valve timing converter 310 is connected to the crankshaft 330 via a chain. When the crankshaft 330 starts to rotate by driving the internal combustion engine 300, the camshaft 320 and the output shaft of the motor 200 together with the valve timing conversion unit 310 also start to rotate. This rotation causes the cam lobe provided on the cam journal of the camshaft 320 to rotate. The intake valve and the exhaust valve move up and down with respect to the combustion chamber by the rotation of the cam lobe. Intake into the combustion chamber is performed by the intake valve, and exhaust from the combustion chamber is performed by the exhaust valve.

  When the internal combustion engine 300 is, for example, a four-cycle engine, the cam lobe of the camshaft 320 corresponding to the intake valve or the exhaust valve rotates once when the crankshaft 330 rotates twice. Normally, the phases of the intake valve and the exhaust valve are shifted by approximately 180 ° when converted by the rotation angle of the camshaft 320. The phase difference of the exhaust valve with respect to the intake valve can be adjusted by controlling the phase difference of the camshaft 320 with respect to the crankshaft 330 by the motor control device 100, the motor 200, and the valve timing conversion unit 310.

  Although not shown, the valve timing conversion unit 310 transmits the rotational torque of the crankshaft 330 transmitted through the above-described chain to the camshaft 320, and rotates the camshaft 320 relative to the crankshaft 330. It has a gear mechanism. The valve timing conversion unit 310 includes an annular ring gear to which the above-described chain is connected, and a disk-shaped pinion gear and a valve gear provided in the ring gear. The ring gear is connected to the crankshaft 330 via a chain, and the valve gear is connected to the camshaft 320. The pinion gear is connected to the output shaft of the motor 200. Teeth are formed on the inner surface of the ring gear, and teeth are formed on the outer surfaces of the pinion gear and the valve gear. The teeth of the inner surface of the ring gear and the teeth of the pinion gear mesh with each other, and the teeth of the pinion gear and the teeth of the valve gear mesh with each other. Therefore, when the crankshaft 330 rotates, the rotational torque is transmitted to the ring gear through the chain, and thereby the ring gear rotates. Then, the pinion gear revolves around the valve gear, thereby rotating the valve gear. As a result, the camshaft 320 rotates together with the crankshaft 330.

  When maintaining the phase difference between the camshaft 320 and the crankshaft 330 (hereinafter simply referred to as a phase difference), the motor control device 100 causes the motor 200 to revolve around the valve gear without rotating the pinion gear, so that the valve gear and the ring gear are rotated. And rotate at the same speed. However, when the phase difference is advanced or retarded, the motor control device 100 revolves around the valve gear while rotating the pinion gear by the motor 200, thereby rotating the valve gear relative to the ring gear. When the output shaft of the motor 200 revolves faster than the crankshaft 330, the phase difference is advanced, and when the output shaft revolves later than the crankshaft 330, the phase difference is retarded. When the phase difference reaches a target phase difference (hereinafter referred to as a target phase difference) by the advance angle or the retard angle, the output shaft of the motor 200 is revolved at the same speed as the ring gear. As a result, the adjusted phase difference is maintained. By controlling the phase difference by the motor 200, the intake timing and the exhaust timing are adjusted.

  As shown in FIG. 1, the internal combustion engine 300 is provided with a cam angle sensor 340 and a crank angle sensor 350. The cam angle sensor 340 and the crank angle sensor 350 detect the rotation angle of the cam shaft 320 and the rotation angle of the crank shaft 330. The motor control device 100 calculates an actual phase difference (hereinafter referred to as an actual phase difference) based on the rotation angle of the camshaft 320 and the rotation angle of the crankshaft 330, and calculates the rotation speed of the internal combustion engine 300. As will be described later, the motor control device 100 calculates the rotation angle of the motor 200 and controls the motor 200 based on the calculated rotation angle of the motor 200 and the rotation speed of the internal combustion engine 300. By doing so, the motor control device 100 controls the actual phase difference.

  In order to control the actual phase difference, the above target phase difference must be calculated. This target phase difference is determined by the motor control device 100 based on various sensor signals indicating the running state of the vehicle, such as an accelerator opening sensor indicating the accelerator depression amount of the user and an air flow meter that measures the intake air amount of the internal combustion engine 300. Is calculated. Hereinafter, the motor control device 100 will be described in detail.

  As shown in FIG. 1, the motor control device 100 includes an engine ECU 10, a driver unit 20, and a rotation angle sensor 50. The engine ECU 10 is electrically connected to the driver unit 20 via signal lines 91 to 94, and the driver unit 20 is electrically connected to the motor 200 via stator wires 95 to 97. The driver unit 20 is electrically connected to the rotation angle sensor 50 through sensor wires 98 and 99.

  A command signal including a target rotation speed (target rotation speed) of the motor 200 is output from the engine ECU 10 to the driver unit 20 via the command signal line 91. On the contrary, a rotational speed signal including the actual rotational speed (actual rotational speed) of the motor 200 is output from the driver unit 20 to the engine ECU 10 via the rotational speed signal line 92. A rotation direction signal including the rotation direction of the motor 200 is output from the driver unit 20 to the engine ECU 10 via the rotation direction signal line 93, and an inspection signal including the inspection result of the driver unit 20 is transmitted via the inspection signal line 94. Is output. Then, a rotation current for controlling the rotation of the motor 200 is output from the driver unit 20 to the motor 200 via the stator wires 95 to 97. Finally, a sensor signal corresponding to the rotation angle of the motor 200 is output from the rotation angle sensor 50 to the driver unit 20 via the sensor lines 98 and 99.

  The engine ECU 10 determines the target rotational speed of the motor 200 based on the various sensor signals indicating the traveling state of the vehicle described above, the rotational speed of the internal combustion engine 300, and the actual rotational speed output from the driver unit 20. First, the engine ECU 10 calculates a target phase difference suitable for the running state of the vehicle based on the various sensor signals. Next, the engine ECU 10 calculates a target rotational speed for setting the actual phase difference as the target phase difference based on the various information described above, and outputs a command signal including the target rotational speed to the driver unit 20.

  The driver unit 20 includes a driver 30 and an inverter 40. The driver 30 controls the inverter 40 based on a command signal input from the engine ECU 10 and a sensor signal input from the rotation angle sensor 50. First, the driver 30 detects the rotation angle of the motor 200 based on the sensor signal, and calculates the actual rotation speed and rotation direction of the motor 200.

  Since detection of the rotation angle by the driver 30 is long, it will be described later. First, calculation of the actual rotation speed and rotation direction of the motor 200 will be described. The actual rotational speed of the motor 200 can be calculated by counting the rising and falling edges of the two sensor signal pulses shown in FIG. As will be described later, since the rotation angle sensor 50 has only two Hall elements 51 and 52, unlike the configuration having three Hall elements, even if the rotation of the motor 200 is constant, the pulse of the two sensor signals The frequency of rising and falling edges is indefinite. However, for example, as shown in FIG. 6, the time from when the pulse of the V-phase sensor signal rises until the pulse of the U-phase sensor signal falls, and the pulse of the U-phase sensor signal after the pulse of the V-phase sensor signal falls. The time to start up is the shortest compared to other cases. This time interval corresponds to the time for which the motor 200 rotates 60 degrees in electrical angle. Therefore, the actual rotational speed of the motor 200 can be calculated based on the time interval and the electrical angle of 60 °. The driver 30 outputs to the engine ECU 10 a rotational speed signal having a pulse period corresponding to the actual rotational speed.

  Further, the driver 30 stores the relationship between the rotation angle and the sensor signal shown in FIG. 4, and calculates the rotation direction of the motor 200 based on this relationship and the sensor signal. The driver 30 determines how the signal levels of the two sensor signals have changed over time. For example, as shown in FIG. 4, when the signal levels of the U-phase sensor signal and the V-phase sensor signal change from Lo, Lo to Hi, Lo, the driver 30 determines that the motor 200 is rotating forward. In contrast to this, when the signal levels of the U-phase sensor signal and the V-phase sensor signal change from Lo, Lo to Lo, Hi, the driver 30 determines that the motor 200 is rotating in reverse. As described above, the driver 30 indicates that the motor 200 is rotating forward when the combination of the signal levels of the two sensor signals shown in FIG. 4 changes from the left to the right as indicated by the solid line arrows as time elapses. judge. On the other hand, when the combination of the signal levels of the two sensor signals shown in FIG. 4 changes from right to left as indicated by the dashed arrows with the passage of time, the driver 30 indicates that the motor 200 is reversed. judge. The driver 30 switches the signal level of the rotation direction signal according to the rotation direction and outputs the signal to the engine ECU 10.

  As described above, the W-phase sensor signal shown in FIG. 4 is a reference, and the driver 30 does not store the W-phase sensor signal. As information to supplement the W-phase sensor signal, the driver 30 measures the time when each of the U-phase sensor signal and the V-phase sensor signal is at the Lo level or the Hi level. This will be described in detail later.

  The driver 30 determines the increase / decrease direction and the generation amount of the rotational torque based on the actual rotational speed and rotational direction calculated as described above and the target rotational speed included in the command signal. When the target rotational speed is higher than the actual rotational speed, the driver 30 determines that the increase / decrease direction of the rotational torque is a direction in which the rotation of the motor 200 is promoted. On the other hand, if the target rotational speed is lower than the actual rotational speed, the driver 30 determines that the rotational torque is generated in a direction in which the rotation of the motor 200 is prevented. Further, the driver 30 calculates the generation amount of the rotational torque based on the deviation width between the target rotational speed and the actual rotational speed. The amount of generation is determined by the time (pulse width) during which the lower switches 42, 44, and 46, which will be described later, are turned on while the motor 200 rotates 60 degrees in electrical angle.

  In addition to the relationship shown in FIG. 4, the driver 30 stores the relationship between the rotation angle and the control signal shown in FIG. When the driver 30 detects the current rotation direction (actual rotation direction) of the rotor 210, the driver 30 compares the actual rotation direction with the calculated increase / decrease direction (torque direction) of the rotation torque. The driver 30 controls the drive of the inverter 40 so that the amount of generated rotational torque increases when both the actual rotation direction and the torque direction match (in the direction that promotes rotation). Specifically, for example, when the motor 200 is rotating forward, the control signal is sequentially changed from I to VI as shown in FIG. 5 and the above-described pulse width is increased. By doing so, the rotation of the output shaft is promoted and the rotation speed is increased. Further, the driver 30 controls the drive of the inverter 40 so that the generation amount of the rotational torque is reduced when both the actual rotational direction and the torque direction are different (in the direction of preventing the rotation). More specifically, for example, when the motor 200 is rotating forward, the control signal is sequentially changed from I to VI as shown in FIG. 5 and the pulse width is reduced. By doing so, the rotation of the output shaft is hindered and the rotation speed is reduced. Further, when the rotational speed is suddenly decreased, for example, when the control signal I is output, the control signal VI advanced (delayed) by 180 ° from the rotational angle is output. The control signal is output in the reverse direction from IV to I and from VI to I.

  As described above, the driver 30 controls the inverter 40 based on the actual rotation speed, the rotation direction, the target rotation speed, and the rotation angle. As a result, a rotational current flows through the stator coils 224 to 226 so that the actual rotational speed of the motor 200 matches the target rotational speed, and rotational torque is generated in the rotor 210. As a result, the actual phase difference varies so as to match the target phase difference, and the phase difference is advanced, retarded, or maintained.

  As described above, the driver 30 outputs an inspection signal to the engine ECU 10. The inspection signal is a digital signal indicating the inspection result by duty. For example, the duty is set to 80% in the normal state and 50% in the abnormal state. The abnormal state includes a disconnection, a power fault, a ground fault, and the like, and a different duty may be assigned to each of these abnormal states.

  As shown in FIG. 3, the inverter 40 includes switches 41 to 46, which are controlled to open and close by control signals I to VI output from the driver 30, so that a rotational current is supplied to the stator coils 224 to 226 of the motor 200. It is a flow. In this embodiment, the switches 41 to 46 are N-channel MOSFETs. The U-phase switches 41 and 42, the V-phase switches 43 and 44, and the W-phase switches 45 and 46 are connected in series from the positive terminal to the negative terminal of the power source, and the two switches that form these pairs are connected in parallel. Yes. One end of the U-phase stator coil 224 is connected to the midpoint of the U-phase switches 41 and 42, and one end of the V-phase stator coil 225 is connected to the midpoint of the V-phase switches 43 and 44. One end of a W-phase stator coil 226 is connected to the midpoint. The other ends of the stator coils 224 to 226 are connected to each other, and the stator coils 224 to 226 are Y-connected.

  When one of the control signals I to VI is output from the driver 30, one of the three upper switches 41, 43, 45 is turned on as shown by symbol Hi in FIG. As indicated by P, one of the three lower switches 42, 44, 46 is intermittently turned on. As a result, the upper switches 41, 43, 45 connected to the positive terminal side of the power source are sequentially turned on, and the lower switches 42, 44, 46 connected to the negative terminal side of the power source are sequentially turned on. The By doing so, two of the three stator coils 224 to 226 are intermittently connected in series to the positive terminal and the negative terminal of the power source, and a rotating current intermittently flows through the stator coil. As a result, rotational torque is intermittently generated in the rotor 210, and the output shaft of the motor 200 rotates. The magnitude of the rotational torque generated in the rotor 210 is determined by the pulse width of the control signal input to the lower switches 42, 44, 46.

  The rotation angle sensor 50 includes a U-phase hall element 51 and a V-phase hall element 52 as sensor elements. Each of the hall elements 51 and 52 generates an analog detection signal corresponding to the rotation angle and the rotation direction of the motor 200. Although not shown, the rotation angle sensor 50 has an AD converter for converting analog detection signals output from the Hall elements 51 and 52 into digital sensor signals. Therefore, two digital sensor signals generated by the rotation angle sensor 50 are input to the driver 30. The Hall elements 51 and 52 and the AD converter constitute the first sensor element and the second sensor element described in the claims.

  As shown in FIG. 2, the Hall elements 51 and 52 are located above the permanent magnet 212 of the rotor 210. As described above, the magnetic flux (magnetic signal) generated by the permanent magnet 212 changes periodically every time the rotor 210 rotates 90 ° in mechanical angle (360 ° in electrical angle). Therefore, every time the rotor 210 rotates 360 ° in electrical angle, the magnetic flux passing through the two Hall elements 51 and 52 also periodically changes. When the rotor 210 is rotated by 180 ° in terms of electrical angle, the direction of the magnetic flux passing through the two Hall elements 51 and 52 is reversed.

  As shown in FIG. 2, the two Hall elements 51 and 52 are provided around the axis of the rotor 210 at a mechanical angle of 30 ° (an electrical angle of 120 °). As a result, the magnetic flux of the permanent magnet 212 that passes through the two Hall elements 51 and 52 is shifted by 120 ° in electrical angle, and the phases of the detection signals output from the two Hall elements 51 and 52 are also shifted by 120 °. As shown in FIG. 2, the U-phase Hall element 51 has a mechanical angle of 7.5 ° (electrical angle of 30 °) with respect to the U-phase stator coil 224 closest to itself. In the reverse direction). Similarly, the V-phase Hall element 52 is arranged on the reverse side in the forward rotation direction of the rotor 210 with respect to the V-phase stator coil 225 closest to itself in a mechanical angle of 7.5 ° (electrical angle of 30 °). . In the following, the rotation angle is expressed in electrical angle unless otherwise specified.

  Next, detection of the rotation angle by the driver 30 will be described. The driver 30 receives the U-phase sensor signal of the U-phase hall element 51 and the V-phase sensor signal of the V-phase hall element 52 as sensor signals. As shown in FIG. 6, the signal levels of the U-phase sensor signal and the V-phase sensor signal fluctuate between a Hi level and a Lo level at a cycle of 180 °. And 120 degrees out of phase with each other. When the Hi level is 1, the Lo level is 0, and the above two sensor signals are expressed as 00, 01, for example, when the rotor 210 is rotating forward, the sensor signal changes in order of 00, 10, 11, 01. . As shown in FIG. 4, the sensor signal becomes 00, 11 while the rotor 210 rotates 60 °, and the sensor signal becomes 10, 01 when the rotor 210 rotates 120 °.

  More specifically, the sensor signal is 00 when the rotation angle is 0 ° -60 °, and the sensor signal is 10 when the rotation angle is 60 ° -180 °. Similarly, the sensor signal is 11 when the rotation angle is 180 ° -240 °, and the sensor signal is 01 when the rotation angle is 240 ° -360 °. Therefore, the time when the sensor signal becomes 00 is the time when the motor 200 rotates from 0 ° to 60 °, and the time when the sensor signal becomes 11 is the time when the motor 200 rotates from 180 ° to 240 °.

  Unless the rotation speed of the motor 200 changes transiently, the motor 200 rotates at a constant speed. Accordingly, it can be considered that the time for which the motor 200 rotates in increments of 60 ° is substantially equal.

  Therefore, the driver 30 measures the time when the sensor signal becomes 00, 11, and estimates the rotation angle of the motor 200 based on the measurement time and the signal level of the sensor signal. In order to estimate this rotation angle, the driver 30 detects the fluctuation timing (the falling edge and the rising edge of the pulse) of the signal level of the sensor signal.

  When the signal level of the V-phase sensor signal switches from the Hi level to the Lo level and the sensor signal changes from 01 to 00, the driver 30 determines that the rotation angle is 0 ° -60 ° and measures the time. start. This timing corresponds to time t1 as shown in FIG. The driver 30 measures a time (T1) from the time t1 to a time t2 when the signal level of the U-phase sensor signal is switched from the Lo level to the Hi level and the sensor signal becomes 00 to 10.

  Next, the driver 30 estimates that the rotation angle is 60 ° -120 ° from the time t2 when the sensor signal becomes 10 to the time t3 when the measurement time T1 has elapsed.

  The driver 30 still estimates that the sensor signal remains 10, but the rotation angle is 120 ° to 180 ° from time t3 to time t4 when the measurement time T1 has elapsed.

  As shown in FIG. 6, when the signal level of the V-phase sensor signal is switched from the Lo level to the Hi level at time t4 and the sensor signal is changed from 10 to 11, the driver 30 has a rotation angle of 180 ° to 240 °. And start measuring time. The driver 30 measures the time from time t4 to time t5 when the signal level of the U-phase sensor signal switches from the Hi level to the Lo level and the sensor signal becomes 11 to 01. As shown in FIG. 6, the command signal does not fluctuate between time t1 and time t8, and the target rotational speed does not fluctuate. For this reason, the actual rotational speed does not change, and the motor 200 can be regarded as rotating at a constant speed. Therefore, the time measured at this time is equal to the measurement time T1.

  The driver 30 estimates that the rotation angle is 240 ° -300 ° from the time t5 when the sensor signal becomes 01 to the time t6 when the measurement time T1 elapses.

  The driver 30 still estimates that the sensor signal remains 01, but the rotation angle is 300 ° to 360 ° from time t6 to time t7 when the measurement time T1 has elapsed.

  As described above, the driver 30 calculates the rotation angles 0 ° -60 °, 180 ° -240 °, and other rotation angles 60 ° -120 °, 120 ° -180 °, 240 ° -300 °, Estimate 300 ° -360 °. The driver 30 calculates and estimates the rotation angle as described above, and outputs control signals I to VI corresponding to the rotation angle to the inverter 40 as shown in FIG. By doing so, the driver 30 generates rotational torque in the motor 200 and controls the phase difference.

  However, it is assumed that the sensor signal is switched from 10 to 11 when the rotation time is estimated to be 120 ° to 180 ° without the measurement time having elapsed. In this case, the driver 30 determines that the rotation angle is 180 ° to 240 ° even if the measurement time has not elapsed. On the contrary, it is assumed that the sensor signal is 10 although the measurement time has elapsed. In this case, the driver 30 estimates that the rotation angle is 120 ° -180 ° even if the measurement time has elapsed. Therefore, switching from the control signal III to the control signal IV is performed when the sensor signal is switched from 10 to 11.

  Similarly, it is assumed that the sensor signal is switched from 01 to 00 when the rotation time is estimated to be 300 ° to 360 ° without the measurement time having elapsed. In this case, the driver 30 determines that the rotation angle is 0 ° -60 ° even if the measurement time has not elapsed. On the contrary, it is assumed that the sensor signal is 01 even though the measurement time has elapsed. In this case, the driver 30 estimates that the rotation angle is 300 ° -360 ° even if the measurement time has elapsed. Therefore, switching from the control signal VI to the control signal I is performed when the sensor signal is switched from 01 to 00. The determination and estimation of the rotation angle described above are the same even when the rotor 210 is reversely rotated.

  FIG. 6 shows a W-phase sensor signal as a reference, and also shows a reference control signal output based on three sensor signals. As shown in the figure, when there is no change in the command signal, there is no difference between the reference control signal and the control signal that the driver 30 actually outputs to the inverter 40. However, when the target rotational speed changes as shown in FIG. 6, the rotational speed of the motor 200 changes accordingly. In this case, as shown in FIG. 6, there is a difference δ between the reference control signal and the control signal, but this difference δ can be reduced as follows.

  The driver 30 temporarily stores the target rotational speed included in the command signal input as needed, and stores the latest target rotational speed (current target rotational speed) and the stored target rotational speed (past target rotational speed). And compare. The driver 30 calculates a difference value obtained by subtracting the past target rotational speed from the current target rotational speed as a change amount. When the difference value is positive, the target rotation number tends to increase, so that the pulse width of the sensor signal is expected to be reduced. On the other hand, when the difference value is negative, the target rotational speed tends to decrease as shown in FIG. 6, so that the pulse width of the sensor signal is expected to increase.

  Therefore, the driver 30 calculates the correction coefficient α based on the difference value. The correction coefficient α is a value smaller than 1 when the difference value is positive, and a value larger than 1 when the difference value is negative. The deviation width of the correction coefficient α from 1 is proportional to the absolute value of the difference value. The driver 30 multiplies the measurement time by the correction coefficient α. By doing so, even if the target rotation speed changes at time t8 as shown in FIG. 6, the measurement time T1 is corrected to T1 × α, and thereby the time estimated to be a rotation angle of 60 ° -120 °. Becomes longer and the difference δ becomes smaller. Thereby, the output time of the control signal II is suppressed from being shortened, and the control of the motor 200 is suppressed from becoming unstable.

  In this way, the driver 30 corrects the measurement time T1, but when the sensor signal changes from 10 to 11 at time t10 as shown in FIG. 6, the time is measured. Then, the driver 30 estimates the rotation angle based on the new measurement time T2. Thus, the measurement time is corrected and the output time of the control signal is corrected when the sensor signal is 10,01.

  Note that, unlike FIG. 6, even when the target rotational speed changes transiently and continuously, the driver 30 calculates the correction coefficient α each time, thereby correcting the measurement time. However, if the change in the target rotational speed is so small that the control of the motor 200 is not affected, the driver 30 fixes the correction coefficient α to 1 and does not correct the measurement time.

  Next, starting of the stopped motor 200 will be described. When starting the motor 200, the driver 30 first detects the signal level of the sensor signal. When the sensor signal when the motor 200 is stopped is 00, the driver 30 outputs the control signal I and measures the time until the sensor signal switches from 00 to 10. Then, after the sensor signal is switched from 00 to 10, the control signals II and III are sequentially output based on the measurement time. By doing so, the motor 200 is started. When the motor 200 starts to rotate, the driver 30 detects the rotation angle as described above, and outputs the control signals I to VI corresponding thereto to the inverter 40.

  Similarly, when the sensor signal when the motor 200 is stopped is 11, the driver 30 outputs the control signal IV and measures the time until the sensor signal switches from 11 to 01. Then, after the sensor signal is switched from 11 to 01, the control signals V and VI are sequentially output based on the measurement time. By doing so, the motor 200 is started. When the motor 200 starts to rotate, the driver 30 detects the rotation angle as described above, and outputs the control signals I to VI corresponding thereto to the inverter 40.

  On the other hand, when the sensor signal when the motor 200 is stopped is 10 or 01, the driver 30 outputs a control signal on the reverse side with respect to the forward rotation direction of the rotor 210. That is, when the control signal is 10, the rotation angle indicates 60 ° -180 °. In this case, the driver 30 outputs the control signal II corresponding to the reverse rotation angle 60 ° -120 °. The rotation angle when the control signal is 01 indicates 240 ° -360 °. In this case, the driver 30 outputs the control signal V corresponding to the reverse rotation angle 240 ° -300 °. This is because the total amount of rotational torque generated in the rotor 210 is larger when a control signal corresponding to the reverse rotation angle with respect to the forward rotation direction is output as shown below.

  In FIG. 7, the rotational torque generated in the rotor 210 by outputting the control signal I is indicated by a solid line. This rotational torque is represented by the sum of the magnet torque and the reluctance torque indicated by the broken line and the alternate long and short dash line in FIG. Magnet torque is generated in the permanent magnet 212 of the rotor 210, and reluctance torque is generated in the iron core 211 of the rotor 210. The magnet torque is shifted by 90 ° with respect to the reluctance torque, and the phase is ½ times. The magnet torque has a larger amplitude than the reluctance torque.

  As described above, the U-phase Hall element 51 is disposed on the reverse side by 30 ° with respect to the normal rotation direction with respect to the U-phase stator coil 224 closest to itself. The V-phase hall element 52 is disposed on the reverse side of 30 ° with respect to the normal rotation direction with respect to the V-phase stator coil 225 closest to itself. Therefore, as shown in FIG. 7, the rotation angle detected by the sensor signal is advanced by 30 ° with respect to the rotation torque generated in the rotor 210. As a result, the rotational torque gradually increases from zero to a peak value as the rotational angle advances from -60 ° to 60 °, and decreases rapidly from the peak value as the rotational angle goes from 60 ° to 120 °. And become zero. Of this rotational torque, the rotational angle from 0 ° to 60 ° is actually generated in the rotor 210. In FIG. 7, the total amount of rotational torque generated by the control signal I until the rotational angle changes from 0 ° to 60 ° is indicated by hatching.

  In FIG. 8, the rotational torque generated in the rotor 210 by the control signal II is indicated by a solid line, and the rotational torque generated in the rotor 210 by the control signal III is indicated by a broken line. The total rotation torque generated until the rotation angle changes from 60 ° to 180 ° by the control signal II and the rotation angle from 60 ° to 180 ° by the control signal III. The total amount of rotational torque generated between them is indicated by hatching. As is apparent from FIG. 8, when the rotation angle changes from 60 ° to 180 ° (when the sensor signal is 10), the rotational torque generated by the control signal II is generated by the control signal III. The total amount becomes larger than the rotational torque. Therefore, as described above, when the control signal is 10, the driver 30 outputs the control signal II. This is the same when the rotation angle changes from 240 ° to 360 ° (when the control signal is 01). The driver 30 outputs the control signal V when the control signal is 01 as described above. As a result, the driver 30 starts rotating the motor 200 by generating a rotational torque.

  When the sensor signal is changed from 10 to 11 as a result of outputting the control signal II when the sensor signal is 10, as described above, the driver 30 outputs the control signal IV. On the other hand, if the sensor signal does not change from 10 even after a predetermined time has elapsed, the driver 30 regards the motor 200 as rotated by 60 ° and outputs the control signal III. By doing so, the motor 200 is started. When the motor 200 starts to rotate, the driver 30 detects the rotation angle as described above, and outputs the control signals I to VI corresponding thereto to the inverter 40.

  Similarly, when the sensor signal changes from 01 to 00 as a result of outputting the control signal V when the sensor signal is 01, the driver 30 outputs the control signal I. In contrast, if the sensor signal does not change from 01 even after a predetermined time has elapsed, the driver 30 regards the motor 200 as rotated by 60 ° and outputs the control signal VI. By doing so, the motor 200 is started. When the motor 200 starts to rotate, the driver 30 detects the rotation angle as described above, and outputs the control signals I to VI corresponding thereto to the inverter 40.

  Next, rotation angle estimation processing by the driver 30 will be described with reference to FIGS. 9 and 10. First, in step S10, the driver 30 determines whether the sensor signal is 00 or 11. If the sensor signal is 00 or 11, the driver 30 proceeds to step S20. On the other hand, if the sensor signal is not 00 or 11 (the sensor signal is 10 or 01), the driver 30 repeats step S10 and waits until the sensor signal becomes 00 or 11. .

  In step S20, the driver 30 determines whether or not the sensor signal is 00. If the sensor signal is 00, the driver 30 proceeds to step S30. On the other hand, if the sensor signal is not 00 (the sensor signal is 11), the driver 30 proceeds to step S40.

  In step S30, the driver 30 measures the time during which the sensor signal outputs 00. On the other hand, when proceeding to step S40, the driver 30 measures the time during which the sensor signal is 11 output. When the time is measured, the driver 30 proceeds to step S50.

  In step S50, the driver 30 corrects the time (measurement time) measured in step S30 or step S40. Then, the driver 30 proceeds to step S60. Step S50 will be described in detail later with reference to FIG.

  In step S60, the driver 30 estimates the rotation angle based on the sensor signal and the measurement time corrected in step S50. Then, the estimation process ends.

  For example, when the rotor 210 is rotating forward and the sensor signal is 00, the driver 30 measures time in step S30. When the sensor signal subsequently changes from 00 to 10, the driver 30 estimates that the rotation angle is 60 ° -120 ° until the measurement time elapses therefrom. Further, the driver 30 estimates that the rotation angle is 120 ° -180 ° until the measurement time further elapses.

  As described above, it is assumed that the sensor signal is switched from 10 to 11 when the rotation time is estimated to be 120 ° to 180 ° without the measurement time elapses. In this case, the driver 30 determines that the rotation angle is 180 ° to 240 ° even if the measurement time has not elapsed. On the contrary, it is assumed that the sensor signal is 10 although the measurement time has elapsed. In this case, the driver 30 estimates that the rotation angle is 120 ° -180 ° even if the measurement time has elapsed.

  To further illustrate, when the rotor 210 is rotating forward and the sensor signal is 11, the driver 30 measures time in step S40. When the sensor signal subsequently changes from 11 to 01, the driver 30 estimates that the rotation angle is 240 ° -300 ° until the measurement time elapses. Then, the driver 30 estimates that the rotation angle is 300 ° -360 ° until the measurement time elapses thereafter.

  Although this is also described above, it is assumed that the sensor signal is switched from 01 to 00 when the rotation time is estimated to be 300 ° to 360 ° without ending the measurement time. In this case, the driver 30 determines that the rotation angle is 0 ° -60 ° even if the measurement time has not elapsed. On the contrary, it is assumed that the sensor signal is 01 even though the measurement time has elapsed. In this case, the driver 30 estimates that the rotation angle is 300 ° -360 ° even if the measurement time has elapsed.

  Next, the rotation angle correction processing by the driver 30 will be described with reference to FIG. First, in step S110, the driver 30 calculates a difference value obtained by subtracting the past target rotational speed from the current target rotational speed. Then, the driver 30 determines whether or not the absolute value of the difference value is larger than a predetermined value. If the absolute value of the difference value is larger than the predetermined value, the driver 30 considers that the target rotational speed has changed and proceeds to step S120. On the other hand, if the difference value is smaller than the predetermined value, the driver 30 regards that the target rotational speed has not changed and proceeds to step S130.

  In step S120, the driver 30 calculates a correction coefficient α based on the difference value. The correction coefficient α is a value smaller than 1 when the difference value is positive, and a value larger than 1 when the difference value is negative. On the other hand, when the process proceeds to step S130, the driver 30 fixes the correction coefficient α = 1. Then, the driver 30 proceeds to step S140.

  In step S140, the driver 30 multiplies the measurement time by the correction coefficient α. By doing so, the driver 30 corrects the measurement time. Of course, when the correction coefficient α is 1, even if this correction coefficient α is multiplied by the measurement time, the measurement time is not substantially corrected.

  Next, the starting process of the motor 200 by the driver 30 will be described based on FIG. First, in step S210, the driver 30 determines whether or not the sensor signal when the motor 200 is stopped is 00 or 11. If the sensor signal is 00 or 11, the driver 30 proceeds to step S220. On the other hand, if the sensor signal is not 00 or 11, (the sensor signal is 10 or 01), the driver 30 proceeds to step S230.

  In step S220, the driver 30 determines whether or not the sensor signal is 00. If the sensor signal is 00, the driver 30 proceeds to step S240. On the other hand, if the sensor signal is not 00 (the sensor signal is 11), the driver 30 proceeds to step S250.

  In step S240, the driver 30 outputs the control signal I and ends the starting process. At this time, the driver 30 measures the time when the sensor signal is 00, performs the processing shown in FIGS. 9 and 10, and rotates the motor 200 stably.

  In step S250, the driver 30 outputs the control signal IV and ends the starting process. At this time, the driver 30 measures the time when the sensor signal is 11, performs the processing shown in FIGS. 9 and 10, and stably rotates the motor 200.

  Back in the flow, when it is determined in step S210 that the sensor signal is 10 or 01 and the process proceeds to step S230, the driver 30 determines whether or not the sensor signal when the motor 200 is stopped is 01. To do. If the sensor signal is 01, the driver 30 proceeds to step S260. On the other hand, if the sensor signal is not 01 (the sensor signal is 10), the driver 30 proceeds to step S270.

  In step S260, the driver 30 outputs a control signal V. By doing so, the driver 30 generates rotational torque in the rotor 210 and starts rotating the rotor 210. After this, the driver 30 proceeds to step S280.

  In step S280, the driver 30 determines whether the sensor signal has become 00 as a result of the rotation of the rotor 210. If the sensor signal is 00, the driver 30 proceeds to step S290. On the other hand, if the sensor signal is not 00 but is still 01, the driver 30 proceeds to step S300.

  In step S290, the driver 30 outputs the control signal I and ends the starting process. At this time, the driver 30 measures the time when the sensor signal is 00, performs the processing shown in FIGS. 9 and 10, and rotates the motor 200 stably.

  In step S300, the driver 30 considers that the motor 200 has rotated by 60 °, outputs the control signal VI, and ends the starting process. Thereafter, when the sensor signal indicates 00, the driver 30 outputs the control signal I and performs the processes shown in FIGS. 9 and 10 to rotate the motor 200 stably. Although not shown, when the sensor signal does not change to 00, the driver 30 executes the start process shown in FIG. 11 once again.

  Going back a little, the driver 30 outputs a control signal II when determining that the sensor signal is 10 in step S230 and proceeding to step S270. By doing so, the driver 30 generates rotational torque in the rotor 210 and starts rotating the rotor 210. Thereafter, the driver 30 proceeds to step S310.

  In step S310, the driver 30 determines whether the sensor signal becomes 11 as a result of the rotation of the rotor 210. If the sensor signal is 11, the driver 30 proceeds to step S320. On the other hand, if the sensor signal is still 10 instead of 11, the driver 30 proceeds to step S330.

  In step S320, the driver 30 outputs the control signal IV and ends the starting process. At this time, the driver 30 measures the time when the sensor signal is 11, performs the processing shown in FIGS. 9 and 10, and stably rotates the motor 200.

  In step S330, the driver 30 regards the motor 200 as being rotated by 60 °, outputs the control signal III, and ends the starting process. Thereafter, when the sensor signal indicates 11, the driver 30 outputs the control signal IV and performs the processing shown in FIGS. 9 and 10 to rotate the motor 200 stably. Although not shown, when the sensor signal does not change to 11, the driver 30 executes the starting process shown in FIG. 11 once again.

  Next, functions and effects of the motor control device 100 according to the present embodiment will be described. As described above, even if the number of Hall elements 51 and 52 is two, the rotation angle of the motor 200 can be detected.

  If the absolute value of the difference value between the current target rotational speed and the past target rotational speed is higher than a predetermined value, the driver 30 corrects the measurement time based on the difference value. Thereby, even if the time until the motor 200 rotates from 60 ° to 120 ° becomes longer than the time when the motor 200 rotates from 0 ° to 60 ° because the target rotational speed has decreased, for example, 60 ° -120 ° It is possible to suppress the estimation of the rotation angle. Similarly, it is suppressed that the estimation of the rotation angle of 120 ° -180 °, 240 ° -300 °, 300 ° -360 ° is shifted.

  As described above, when the sensor signal is 10, the total amount of the rotational torque generated by the control signal II is larger than the rotational torque generated by the control signal III. Therefore, the driver 30 outputs the control signal II when the control signal is 10 when the motor 200 is stopped. When the sensor signal is 01, the total amount of the rotational torque generated by the control signal V is larger than the rotational torque generated by the control signal VI. Therefore, the driver 30 outputs the control signal V when the control signal is 01 when the motor 200 is stopped. Thus, the motor 200 is more efficient than the configuration in which the control signal III is output when the control signal is 10 when the motor 200 is stopped or the control signal V is output when the control signal is 01. It can start well.

  Thus, even if the number of Hall elements 51 and 52 is two, the motor 200 can be started based on two sensor signals. Therefore, for example, it is not necessary to forcibly move the rotor 210 to the initial position in order to start the motor 200 or to store the initial position of the rotor 210 in advance.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, an example in which the motor control device 100 controls the motor 200 provided in the valve timing conversion unit 310 is shown. However, the motor 200 to be controlled by the motor control device 100 is not limited to the above example.

  In the present embodiment, an example in which the target rotational speed is input from the engine ECU 10 to the driver unit 20 has been shown. However, the electronic control device that outputs the target rotational speed to the driver unit 20 is not limited to the above example, and for example, a configuration in which the target rotational speed is input from the hybrid ECU to the driver unit 20 may be employed.

  In this embodiment, the rotation angle sensor 50 has shown the example which has Hall elements 51 and 52 as a sensor element. However, any sensor element can be used as long as it is a magnetoelectric conversion element that converts a magnetic signal into an electric signal.

  In this embodiment, the rotation angle sensor 50 has shown the example which has the U-phase Hall element 51 corresponding to the U-phase stator coil 224, and the V-phase Hall element 52 corresponding to the V-phase stator coil 225. However, the two sensor elements included in the rotation angle sensor 50 are not limited to the above example, and may be two sensor elements corresponding to any two of the three stator coils 224 to 226.

  In the present embodiment, an example is shown in which time is measured when the sensor signal is both 00 and 11, and the rotation angle is estimated based on the measurement time. However, only the time when the sensor signal is 00 or 11 may be measured, and the rotation angle may be estimated based on the measurement time.

  In this embodiment, the example which correct | amends measurement time based on the variation | change_quantity of target rotation speed was shown. However, the measurement time need not be corrected.

  In the present embodiment, the control signal is changed from I to VI when the motor 200 is rotated forward, but no particular mention is made of the change of the control signal when the motor 200 is rotated backward. When the motor 200 is reversely rotated, the control signal is sequentially changed from VI to I, contrary to the normal rotation.

  In this embodiment, when starting the stopped motor 200, the example which rotates the motor 200 forward was shown. However, the motor 200 may be reversed when starting. In this case, the control signal VI is output in step S260 shown in FIG. 11, and it is determined whether or not the sensor signal is 11 in S280. In step S290, the control signal IV is output. In step S300, the control signal V is output. In step S270, the control signal III is output, and in step S310, it is determined whether or not the sensor signal is 00. In step S320, the control signal I is output. In step S300, the control signal II is output. Finally, after steps S240, S250, S290, S300, S320, and S330, the sensor signals are measured at 00 and 11, and the control signals are sequentially output to VI to I based on the measurement time and the sensor signals. Then, the motor 200 is reversely rotated.

  As described above, when the motor 200 is reversely rotated at the time of starting, the U-phase Hall element 51 may be disposed on the traveling side in the forward rotation direction by 30 ° with respect to the U-phase stator coil 224 closest to itself. Similarly, the V-phase hall element 52 may be arranged on the traveling side in the forward rotation direction by 30 ° with respect to the closest V-phase stator coil 225.

DESCRIPTION OF SYMBOLS 10 ... Engine ECU, 20 ... Driver unit, driver 30, Inverter 40, 51 ... 1st Hall element, 52 ... 2nd Hall element, 200 ... Motor, 300 ... Internal combustion engine, 310 ... Valve timing conversion part

Claims (4)

A first sensor element (51) and a second sensor element (52) for converting a periodic magnetic signal generated by the rotation of the motor (200) into a digital signal;
A driver unit (20) for controlling the motor based on each of the first sensor signal output from the first sensor element and the second sensor signal output from the second sensor element;
The first sensor element and the second sensor element are disposed 120 ° apart from each other in the electrical angle of the magnetic signal in the rotation direction of the motor,
The driver unit measures time when the signal levels of the first sensor signal and the second sensor signal are the same, and the measurement time and the signal levels of the first sensor signal and the second sensor signal, respectively. The motor control apparatus which estimates the rotation angle of the said motor based on.   The driver unit controls the motor so that an actual rotational speed of the motor reaches a target rotational speed input from an electronic control device (10) of the vehicle, and measures the measurement time after measuring the target time. The motor control device according to claim 1, wherein when the rotational speed changes, a correction coefficient is calculated based on the change amount, and the measurement time is corrected by multiplying the measurement time by the correction coefficient. The motor includes an embedded magnet type rotor (210) to which an output shaft is fixed, and a plurality of stators that generate a rotating torque in which a magnet torque and a reluctance torque are combined in the embedded magnet type rotor when an electric current flows. A permanent magnet synchronous motor having a stator (220) having coils (224 to 226);
The driver unit generates the control signal for controlling the inverter based on the estimated rotation angle, while estimating the rotation angle of the inverter (40) for passing current to the stator coil and the motor, A driver (30) for outputting the control signal to the inverter;
The plurality of stator coils include a first stator coil (224) and a second stator coil (225) that are sequentially spaced 120 degrees each in the electrical angle of the magnetic signal in the rotation direction of the embedded magnet type rotor. ), There is a third stator coil (226),
The first sensor element is arranged to be shifted from the first stator coil by 30 ° in the electrical angle on the reverse side with respect to the rotational direction,
The second sensor element is disposed at a position shifted by 30 ° from the second stator coil in the backward direction with respect to the rotation direction by the electrical angle.
The driver is
Each time the rotation angle changes by 60 ° in the electrical angle, the control signal is changed so that the embedded magnet rotor rotates.
When starting the stopped motor,
When the signal level of each of the first sensor signal and the second sensor signal is the same, the control signal in an angle range of 60 ° corresponding to the signal level of the first sensor signal and the second sensor signal Produces
When the signal levels of the first sensor signal and the second sensor signal are different, an angle range of 120 ° corresponding to the signal levels of the first sensor signal and the second sensor signal is set to 60 ° and 60 °. Generating the control signal corresponding to an angle range of 60 ° on the reverse side with respect to the rotation direction of the motor when equally divided into two
Thereafter, in order to rotate the motor in the rotation direction, each time the rotation angle changes by 60 degrees in the electrical angle according to the variation of the signal level of each of the first sensor signal and the second sensor signal, The motor control device according to claim 1, wherein the control signal is changed so that the embedded magnet type rotor rotates. The output shaft of the motor is connected to the crankshaft (330) and the camshaft (320) via a valve timing converter (310),
The motor control device according to claim 1, wherein the driver unit adjusts a phase of the camshaft with respect to the crankshaft by controlling rotation of the motor.

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