WO2020230495A1 - Motor control device and motor control method, and variable valve timing control device and variable valve timing control method using motor control device and motor control method - Google Patents

Abstract

The present invention addresses the problem of appropriately controlling a motor by ensuring speed calculation accuracy even when the motor is frequently switched between forward rotation and backward rotation. The present invention is provided with: a rotational angle sensor 12 that outputs a three-phase signal for detecting the rotational angle of a motor 10; and a motor control device 20 that controls a rotational speed output of the motor 10 on the basis of the three-phase signal and a command signal 21. The invention is further provided with a first period determination means 42 for determining a first period where the three-phase signal outputted from the rotational angle sensor 12 is outputted in an order of rising, falling, and rising over three phases, and a second period determination means 43 for determining a second period where the three-phase signal outputted from the rotational angle sensor 12 is outputted in an order of falling, rising, and falling over the three phases. When the output of the rotational angle sensor 12 is in the first or second period, control is performed so as to update the rotational speed output of the motor 10.

Description

Motor control device and motor control method, and variable valve timing control device and variable valve timing control method using these

The present invention relates to a motor control device and a motor control method, and a variable valve timing control device and a variable valve timing control method using these.

Internal combustion engines installed in automobiles, etc. are required to improve fuel efficiency and clean exhaust gas. As one means for that purpose, electrification of engine auxiliary equipment is being promoted. By electrifying the part that has been driven by the engine as a direct power source, it is expected that the control response will be improved and the mechanical loss such as friction will be reduced. For example, power steering, which operates by driving a hydraulic pump with the power of an engine, is being electrified, and further, electrification is being considered for parts related to engine combustion control, such as a variable valve timing device.

There are various types of motors used for electrification, but in automobiles, a DC motor is used to use a DC power supply. Conventionally, DC commutator motors that use brush commutators have been the mainstream, but with the development of power electronics in recent years, brushless DC motors are becoming widespread. The brushless DC motor detects the magnetic pole position by a rotation angle sensor such as a hall sensor or an encoder, and controls the voltage applied to the motor coil based on the detected rotation angle.
Patent Document 1 is an example of such a motor control technique.

Patent Document 1 includes a main control unit including three Hall sensors, and has a V-phase signal rise, a W signal rise, a U-phase signal fall, or a U-phase signal rise, and a W signal fall. , A technique for switching an operation mode by detecting a rise of a V-phase signal is disclosed.

Japanese Unexamined Patent Publication No. 2005-261957

When the valve timing in the engine is variably controlled by the motor, the cam attached to the rotating shaft of the motor operates to open and close the valve. The variable valve timing control device that controls the motor controls the valve opening or closing timing by changing the rotation angle of the motor corresponding to the rotation angle of the engine. While the engine is running, the motor is required to accelerate and decelerate in order to respond to the required operation, for example, fluctuations in engine torque. Therefore, depending on the conditions, the rotation direction of the motor may change from forward rotation to reverse rotation, or from reverse rotation to forward rotation. In this case, for example, when the technique described in Patent Document 1 is used for variable valve timing control, the velocity information is obtained from the pulse signal interval of the rotation angle sensor, so that the pulse signal interval is used at the switching point in the rotation direction. There will be a period when the speed does not correspond. Therefore, there may be a period in which the speed is determined to be excessive near the switching point in the rotation direction. Since it is necessary to appropriately control the motor in the variable valve timing control device, high responsiveness is required, and the gain in the upper control system is generally set high. However, when the excessive speed as described above exists, the gain cannot be increased from the viewpoint of ensuring stability, the speed calculation accuracy is lowered, and it is difficult to control the motor appropriately.

An object of the present invention is a motor control device and a motor control method capable of appropriately controlling a motor while ensuring speed calculation accuracy even when the motor frequently switches between normal rotation and reverse rotation, and a variable valve using these. It is an object of the present invention to provide a timing control device and a variable valve timing control method.

In order to achieve the above object, as an example, the present invention includes a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of the motor, and the rotation speed of the motor based on the three-phase signal and the command signal. A first period of a motor control device that controls the output, in which the three-phase signal output from the rotation angle sensor is output in the order of rising, falling, and rising over the three phases. A period determination means, a second period determination means for determining a second period in which the three-phase signal output from the rotation angle sensor is output in the order of falling, rising, and falling over the three phases. When the output of the rotation angle sensor is in the first period or the second period, it is characterized in that the rotation speed output of the motor is controlled to be updated.

The present invention is a motor control method including a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of the motor, and controls the rotation speed output of the motor based on the three-phase signal and the command signal. The period in which the three-phase signal output from the rotation angle sensor is output over the three phases in the order of rising, falling, and rising is set as the first period, and the third period output from the rotation angle sensor. When the phase signal is output over three phases in the order of falling, rising, and falling as the second period, and the output of the rotation angle sensor is in the first period or the second period, , The motor is controlled so as to update the rotation speed output of the motor.

According to the present invention, a motor control device and a motor control method capable of appropriately controlling a motor while ensuring speed calculation accuracy even when the motor frequently switches between normal rotation and reverse rotation, and a variable valve using these. A timing control device and a variable valve timing control method can be provided.

It is a block diagram which shows the motor drive system which concerns on 1st Embodiment of this invention. It is a control block diagram of the motor control device 20 which concerns on 1st Embodiment of this invention. It is a control block diagram of the motor speed estimation means 28 which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the operation of the motor speed estimation means 28 which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation of the motor speed estimation means 28 which concerns on 1st Embodiment of this invention. It is a control block diagram of the motor speed estimation means 28 which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the operation of the motor speed estimation means 28 which concerns on 2nd Embodiment of this invention. It is a control block diagram of the motor speed estimation means 28 which concerns on 3rd Embodiment of this invention. It is a figure which shows an example of the operation of the motor speed estimation means 28 which concerns on 3rd Example of this invention. It is a flowchart which shows the operation of the motor speed estimation means 28 which concerns on 3rd Embodiment of this invention. It is a figure which shows the relationship between the changing phase and the rotation direction which concerns on 3rd Example of this invention. It is sectional drawing of the variable valve timing control device which concerns on 4th Embodiment of this invention. It is a figure which shows the operation of the variable valve timing control device which concerns on 4th Embodiment of this invention. It is the schematic of the electric power steering apparatus which concerns on 5th Embodiment of this invention.

The motor control device according to the embodiment of the present invention is particularly applied to an application that requires high speed response, and the motor is a brushless DC motor. As main application examples, a variable valve timing control device that controls valve timing in an internal combustion engine engine using a motor and an electric power steering device that assists steering operation with a motor are assumed.

In the embodiment of the present invention, a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of the motor is provided, and the three-phase signal output from the rotation angle sensor rises over three phases. The first period is the period in which the signals are output in the order of falling, falling, and rising, and the three-phase signal output from the rotation angle sensor is output in the order of falling, rising, and falling over the three phases. The period is defined as the second period, and when the output of the rotation angle sensor is in the first period or the second period, the rotation speed output of the motor is controlled to be updated. In the present embodiment, the rotation speed output calculated by the rotation angle sensor pulse signal interval detection for the case where the rotation direction of the motor changes and the period until the motor rotation is settled by the configuration as described above. The case where the calculation is accurate can be selected as the rotation speed. As a result, the influence of the speed calculation error in the region where the forward rotation and the reverse rotation change and the speed unstable region due to insufficient shaft rigidity can be eliminated.

Further, in the embodiment of the present invention, a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of the motor is provided, and among the three-phase signals output from the rotation angle sensor, a specific phase The period from the time when only the signal changes two or more times to the detection of the signal change of the phase other than the specific phase is defined as the third period, and when the output of the rotation angle sensor is in the third period, the motor The rotation speed output of the motor is retained at the previous rotation speed output, and the rotation speed output of the motor is updated at the end of the third period.

Further, in the embodiment of the present invention, a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of the motor is provided, and among the three-phase signals output from the rotation angle sensor, a specific phase The period from the time when only the signal changes twice or more to the detection of the signal change of the phase other than the specific phase is defined as the third period, and when the output of the rotation angle sensor is in the third period, the motor The rotation speed output of the motor is set to 0, and the rotation speed output of the motor is updated at the end of the third period.

Further, in the embodiment of the present invention, the intake cam and the exhaust cam that open and close the intake valve and the exhaust valve, respectively, the intake cam shaft and the exhaust side cam shaft connected to the intake cam and the exhaust cam, respectively, and the intake. In variable valve timing control including an intake side electric valve timing control motor and an exhaust side electric valve timing control motor that rotationally drive the side camshaft and the exhaust side camshaft, the intake side electric valve timing control motor and the exhaust side electric The valve timing control motor is characterized by being controlled by the motor control described in the above embodiment.

In the embodiment of the present invention, the valve timing of the engine is adjusted by using the motor driven by the above-mentioned motor control device, so that the motor can secure the speed calculation accuracy even when the forward rotation and the reverse rotation are frequently switched. Appropriate control is possible, which contributes to reduced fuel consumption and cleaner exhaust.

An embodiment embodying the above embodiment will be described below.

FIG. 1 is a block diagram showing a motor drive system according to the first embodiment of the present invention. In this embodiment, an inverter for driving a three-phase motor is used as the power conversion device, and a brushless DC motor is used as the motor 10 to be controlled. The torque generated from the motor 10 is transmitted to the motor shaft 11. The motor 10 determines the timing at which a voltage is applied to each winding by the rotation angle sensor 12. As the rotation angle sensor 12, an absolute encoder, a resolver, or the like can be used, but in this figure, an example of a Hall IC will be described. The Hall IC outputs the magnetic flux direction as a digital signal. The wiring connected to the motor 10 is a three-phase wiring 13, and an AC voltage from the power conversion device 14 is applied to the wiring 13. The power conversion device 14 converts a DC voltage into an AC voltage by turning on / off the switching element 15 to create an AC voltage applied to the wiring 13.

The current detector 16 (DC current detector) measures the current flowing in or out of the power converter 14. Generally, a shunt resistor is inserted between the ground point and the negative electrode side connection terminal of the switching element 15, and the current is detected by measuring the voltage across the shunt resistor. The switching element 15 is turned ON / OFF by the gate voltage 18 created by the gate driver 17. The gate driver 17 amplifies the gate signal 19 that determines the ON / OFF timing of the switching element 15 and converts it into a voltage and a current that enable the switching element 15 to operate.

The motor control device 20 receives a command signal 21 from a higher-level control system such as an electronic control unit (ECU), and creates a gate signal 19 for operating the motor 10 so as to follow the command signal 21. The motor control device 20 uses the rotation angle sensor signal 22 and the DC current signal 23 as other inputs. The rotation angle sensor signal 22 is the output of the rotation angle sensor 12, and signals for three phases of U phase, V phase, and W phase are output. In this embodiment, these three-phase signals are defined as three-phase signals. The direct current signal 23 is the output of the current detector 16.

Next, the configuration of the motor control device 20, which is a part of the configuration of the motor drive system, will be described. FIG. 2 is a control block diagram of the motor control device 20 according to the first embodiment of the present invention. In this embodiment, the command signal 21 received by the motor control device 20 is a torque command.

The command signal 21 is input to the compensation means 24. The compensation means 24 receives the command signal 21 and the torque estimate value 25 as inputs, controls so that the deviation between the command signal 21 and the torque estimate value 25 becomes small, and outputs the torque command signal 26. Specifically, means such as PID control are used. The torque estimation means 27 estimates the torque estimation value 25 from the DC current signal 23. In the brushless DC motor that is the target of this embodiment, the generated torque is substantially proportional to the DC current, so that the torque estimation value 25 can be estimated from the DC current signal 23.

The rotation angle sensor signal 22 is input to the motor speed estimation means 28, and the motor speed estimation value 29 is output. The motor speed estimation value 29 is used for various purposes such as construction of a speed control system, correction of counter electromotive voltage, and improvement of accuracy of rotation angle, but here, for simplification, only the counter electromotive voltage estimation means 30 is shown. In the brushless DC motor (motor 10), as the rotation speed increases, the voltage that can be used for torque generation decreases due to the electromotive force inside the motor. The counter electromotive voltage estimation means 30 calculates the counter electromotive voltage estimation value 31. When the advance angle control is not performed, the counter electromotive voltage is simply proportional to the motor rotation speed.

The torque command signal 26 and the counter electromotive voltage estimated value 31 are sent to the phase voltage conversion means 32, and the phase voltage applied to each phase of the motor 10 is calculated. Since the power conversion device 14 changes the phase voltage by changing the duty ratio of switching, the duty ratio signal 33 is output here. For example, when the duty ratio is 1, a direct current voltage (VDC) is applied as the phase voltage, when the duty ratio is 0, 0 is applied, and when the duty ratio is 0.5, half of the direct current voltage (VDC / 2) is applied. Will be done. The duty ratio signal 33, the torque direction signal 34, and the rotation angle sensor signal 22 created in this manner are input to the gate signal creating means 35, and the gate signal 19 adjusted so that the motor 10 generates a desired torque is generated. Output.

Next, the configuration of the motor speed estimation means 28, which forms a part of the configuration of the motor control device 20, will be described. FIG. 3 is a control block diagram of the motor speed estimation means 28 according to the first embodiment of the present invention.

The rotation angle sensor signal 22 input to the motor speed estimation means 28 is input to the change event detecting means 41, the first period determining means 42, and the second period determining means 43. The change event detecting means 41 generates an event detecting signal 44 when the rotation angle sensor signal 22 changes. Usually, the event detection signal 44 is often mounted on the microcomputer as an interrupt activation. When the event detection signal 44 is generated, the first period determination means 42 and the second period determination means 43 store the state of the rotation angle sensor signal 22 and collate it with a preset change pattern.

There are two types of rotation angle sensor signal 22, high level and low level. The rotation angle sensor signal 22 changes from low level to high level, and the rotation angle sensor signal 22 changes from high level to low level. Is called a fall.

In this embodiment, in the first period, the rotation angle sensor signal 22 (three-phase signal) output from the rotation angle sensor 12 detects changes in rising, falling, and rising in order, and the change is U-phase. This is a pattern covering all phases (3 phases) of, V phase, and W phase.

In the second period, the rotation angle sensor signal 22 (three-phase signal) output from the rotation angle sensor 12 detects changes in falling, rising, and falling in order, and the changes are U-phase and V-phase. , It is a pattern over all phases (3 phases) of W phase. The timing diagrams of the first period and the second period will be described later in FIG.

The outputs of the first period determining means 42 and the second period determining means 43 are sent to the OR means 45, and when either the first period or the second period is satisfied, the speed calculation described later is performed.

Further, the event detection signal 44 operates the elapsed time calculation means 46. The elapsed time calculation means 46 inputs the FRC current value 48 generated from the FRC (free running counter) 47, and calculates the difference from the FRC previous value 50 recorded in the FRC previous value storage means 49. This is equivalent to the time interval of the event detection signal 44. After the calculation of the difference, the FRC current value 48 is sent to the FRC previous value storage means 49, and the FRC previous value 50 is updated. The speed calculation means 51 estimates the motor speed by calculating the reciprocal of the time interval calculated by the elapsed time calculation means 46. Since the speed calculation means 51 cannot always calculate the motor speed, the speed calculation means 51 includes an estimation speed selection means 52. For example, when the motor speed is 0 (zero), the event detection signal 44 does not occur. In such a case, it is necessary to output some motor speed estimate by another method. In this embodiment, when the motor speed cannot be calculated, the estimated speed selection means 52 selects whether to use the previous value of the speed or forcibly set the motor estimated speed to 0 (zero).

In this embodiment, when the behavior of the rotation angle sensor 12 does not correspond to both the first period determination means 42 and the second period determination means 43, the estimated speed selection means 52 uses the estimated speed selection means 52 to store the value of the speed previous value storage means 53 or The zero velocity setting means 54 is selected as the estimated velocity 55. When the behavior of the rotation angle sensor 12 corresponds to either the first period determination means 42 or the second period determination means 43, the output of the speed calculation means 51 is selected as the output of the estimated speed 55.

Next, the operation of the motor speed estimation means 28 will be described with reference to FIG. FIG. 4 is a diagram showing an example of the operation of the motor speed estimation means 28 according to the first embodiment of the present invention. For the sake of simplicity, the following is assumed.
The rotation angle sensor 12 is a Hall IC and is a digital signal output.
The elapsed time calculation means 46 acquires the time when the rotation angle sensor 12 of any phase changes.
The Hall ICs are arranged so as to be offset by 120 degrees in each phase, and an event detection signal 44 is generated every 60 degrees of the motor rotation angle.
-The motor will be a three-phase two-pole machine, and the effects of reduction gears will not be considered. As a result, the mechanical angle and the electric angle become equal, and the conversion can be omitted.
-For the motor rotation direction, clockwise is defined as forward rotation and counterclockwise rotation is defined as reverse rotation.

Further, each phase is clockwise as U phase, V phase, and W phase, and the U phase Hall IC is arranged at a position 60 degrees behind the motor coil U phase, and the V phase is located 60 degrees behind the motor coil V phase. The Hall IC is arranged, and the W-phase Hall IC is arranged at a position 60 degrees behind the W-phase of the motor coil.

In FIG. 4, 22a is a U-phase Hall IC, 22b is a V-phase Hall IC, and 22c is a W-phase Hall IC. Halls ICs 22a to 22c are arranged between the windings of the motor 10 as shown in the figure. 61a, 61b, 61c, 61d, 61e are the times at the moment when the hall ICs 22a to 22c change, and 62a, 62b, 62c, 62d, 62e are the times when the motor 10 is rotating at times 61a, 61b, 61c, 61d, 61e. is there.

The condition that the speed calculation means 51 can calculate a reliable estimated speed is that the elapsed time calculation means 46 can correctly acquire the time required for the motor 10 to rotate 60 degrees. The elapsed time calculating means 46 monitors changes in the hall ICs 22a to 22c and observes the time interval. Therefore, when the forward rotation and the reverse rotation are switched, the elapsed time calculating means 46 measures the time required for 60 degree rotation. As a result, the speed calculation means 51 outputs a speed calculation result different from the actual one.

In FIG. 4, it is assumed that the motor 10 is rotating in the positive direction until time 61a. Here, clockwise is defined as the positive direction. After the output of the W-phase hall IC 22c changes at time 61a, the motor 10 rotates in the reverse direction under the influence of an external force or the like during the period from time 61a to time 61b, and the output of the W-phase hall IC 22c changes again at time 61b. The motor 10 returns to normal rotation during the period from time 61b to time 61c, and the output of the W-phase hall IC 22c changes at time 61c. After that, the forward rotation continues at time 61d and time 61e. During the periods 61c, 61d, and 61e during which the forward rotation continues, the output rise of the W-phase hall IC22c, the output fall of the V-phase hall IC22b, and the output rise of the U-phase hall IC22a are observed. That is, by observing the rising and falling patterns of the outputs of the hall ICs 22a to 22c, it is possible to determine whether the speed calculation means 51 is operating in the forward direction or the reverse direction in a stable manner. It becomes a judgment standard.

The time interval 63 indicated by the arrow is calculated by the elapsed time calculation means 46. Further, at the speed calculation selection time 64 indicated by Δ, the estimated speed selection means 52 selects the result calculated by the speed calculation means 51.

Here, the pattern in which the outputs of the hall ICs 22a to 22c change in the order of rising, falling, and rising, and the outputs of all the hall ICs 22a to 22c change is defined as the first period. Further, the pattern in which the outputs of the hall ICs 22a to 22c change in the order of falling, rising, and falling, and the outputs of all the hall ICs 22a to 22c change is defined as the second period.

In FIG. 4, the arrow indicated by the number 65 is the first period, and the arrow indicated by the number 66 is the second period. When the brushless DC motor is normally rotating in the forward direction or the reverse direction, the first period 65 or the second period 66 is observed as long as the hall ICs 22a to 22c are normally continuously operating. When the output of the rotation angle sensor signal 22 is in the first period 65 or the second period 66, the result of the speed calculation means 51 is adopted to update the rotation speed output of the motor 10.

In FIG. 4, the speed calculation selection time 64 is displayed when the first period 65 or the second period 66 is detected. By doing so, the result of the speed calculation means 51 obtained from the time interval from time 61a to time 61b and the time interval from time 61b to time 61c for which the time required for the motor 10 to rotate 60 degrees cannot be obtained can be obtained. It is possible to determine not to adopt. Then, when the output of the rotation angle sensor signal 22 is other than the first period 65 or the second period 66, the rotation speed output of the motor 10 is held at the rotation speed output at the time of renewal.

Further, in FIG. 4, the result of the speed calculation means 51 obtained from the time interval from the time 61c to the time 61d is not adopted either. This is because when an unexpected reversal occurs during normal rotation, it is expected that a large external force is applied, and during that period, at the time interval from time 61c to time 61d due to the influence of shaft twist and backlash. There is a concern that the output accuracy of the elapsed time calculation means 46 may deteriorate. In this embodiment, since the output of the speed calculation means 51 is not adopted even in the period from the time 61c to the time 61d, it is particularly suitable for an application in which it is difficult to secure the rigidity.

It is also suitable for control systems with high gain characteristics to ensure high responsiveness. In the case of a high gain control system, if the speed estimation error is large, it is determined that the deviation from the command is also large, and a large torque is generated to try to follow. As a result, power consumption increases. In addition, although it is difficult to ensure stability, this embodiment can easily solve the problems associated with the high gain control system.

Next, the operation of the motor speed estimation means 28 will be described. FIG. 5 is a flowchart showing the operation of the motor speed estimation means 28 according to the first embodiment of the present invention.

In FIG. 5, the flowchart is started by detecting the event detection signal 44. S101 is a process of acquiring a counter, and stores the current value of FRC47 in the variable cnt. S102 is an output acquisition process for the hall ICs 22a to 22c. The acquired outputs of the Hall ICs 22a to 22c identify the changed phase by the changing phase specifying process S103. Then, the changing phase writing process S104 writes out the changing phase information to the variable phs. The variable phs can be an integer value (U phase = 1, V phase = 2, W phase = 3, etc.) or a character (U phase ='u', V phase ='V', W phase ='W' if the phase can be specified. Etc.). The counter acquisition process S101, the output acquisition process S102 of the hall ICs 22a to 22c, the changing phase specifying process S103, and the changing phase writing process S104 are executed in parallel with the event detection signal 44 as a trigger.

The counter previous value acquisition process S105 reads the counter information acquired by the previous event detection signal 44 as the variable cnt_z. S106 is a time interval acquisition process, and the difference between the variables cnt and cnt_z is calculated and stored in the variable t60. t60 means the time required for the motor 10 to rotate at an electric angle of 60 degrees. Since FRC47 is represented by a limited number of bits, it is cleared to 0 at regular intervals. Therefore, depending on the cnt acquisition timing, cnt_z> cnt may occur.

The time interval determination process S107 determines whether or not cnt_z> cnt by looking at the sign of the variable t60.
When the variable t60 is negative, the constant CMAX + 1 preset by the time interval correction process S108 is added. This gives the correct time interval. CMAX is the maximum value of FRC. For example, if the FRC is 16 bits, the CMAX is 65535. If the variable t60 is positive, the variable t60 is adopted as it is as the time interval.

S109 is a velocity calculation process, and the reciprocal of the variable t60 is multiplied by 2π (π is the pi) and divided by 6 to obtain the electric angle temporary velocity spd_tmp. Multiplying by 2π is to convert the unit system to rad / s, and dividing by 6 is to convert to the speed per rotation. S110 is the counter previous value update process, and the acquired counter information cnt is substituted into the counter previous value cnt_z. The processes from process S101 to process S110 are mainly performed by the elapsed time calculation means 46, the FRC previous value storage means 49, and the speed calculation means 51.

S111 is a phase information acquisition process, and reads the changing phase phs, the previous changing phase phs_z, and the previous last changing phase phs_z2. The variable phs is written out in the change phase writing process S104. S112 is a first period determination process, and determines whether or not the change phase phs, the previous change phase phs_z, and the previous two change phase phs_z2 correspond to the above-mentioned first period. If it does not correspond to the first period, the subsequent second period determination process S113 is performed to determine whether or not it corresponds to the above-mentioned second period. If any of the determinations in S112 and S113 is Y, the electric angular velocity spd_tmp calculated in the velocity calculation process S109 is adopted as the electric angular velocity spd.

If it is neither the first period nor the second period, the speed comparison process S115 determines whether the speed is high or low. When the constant TH is the velocity threshold value and the variable spd_tmp is larger than the velocity threshold value TH, the electric angular velocity spd is set to the electric angular velocity previous value spd_z by the velocity previous value setting process S116. When the variable spd_tmp is smaller than the velocity threshold TH, the electric angular velocity spd is set to 0 by the zero velocity setting process S117. This electric angular velocity spd is an estimated velocity 55. Here, when the output of the rotation angle sensor is other than the first period or the second period, the rotation speed output of the motor is set to 0.

S119 is a phase information update process, in which the previous change phase phs_z is substituted for the previous change phase phs_z2, and the previous change phase phs is substituted for the previous change phase phs_z. S111 to S119 are processes performed by the first period determination means 42, the second period determination means 43, the OR means 45, the estimated speed selection means 52, the speed previous value storage means 53, and the zero speed setting means 54.

According to this embodiment, since the rotation speed output of the motor is controlled to be updated when the output of the rotation angle sensor is in the first period or the second period, the motor frequently switches between normal rotation and reverse rotation. Even in this case, the speed calculation accuracy can be ensured and the motor can be appropriately controlled.

Next, the second embodiment will be described. FIG. 6 is a control block diagram of the motor speed estimation means 28 according to the second embodiment of the present invention. Since the configurations of the motor control device 20 and the motor drive system are the same as those in FIG. 1, detailed description thereof will be omitted.

The difference in FIG. 3 in the first embodiment is that the third period determination means 56 is provided instead of the first period determination means 42, the second period determination means 43, and the OR means 45. The third period is defined as the period from the time when only the signal of the specific phase of the three-phase signal changes two or more times to the detection of the change of the phase other than the specific phase.

FIG. 7 is a diagram showing an example of the operation of the motor speed estimation means 28 according to the second embodiment of the present invention. In FIG. 7, the third period is a period from time 61b to time 61d. The speed calculation selection time 64 is different from that of FIG. 4, and is also applicable at the time 61d. FIG. 4 shows that the result of the speed calculation means 51 obtained from the time interval from time 61a to time 61b and the time interval from time 61b to time 61c for which the time required for the motor 10 to rotate 60 degrees cannot be obtained is not adopted. The same is true. However, the result of the speed calculation means 51 obtained from the time interval between the time 61c and the time 61d is adopted as the speed calculation result.

During the period of time 61c and time 61d, the speed detection error is sufficiently small, for example, when sufficient rigidity is secured for the rotating shaft of the motor 10 or when a high-resolution sensor can be used. Therefore, in the case of hardware that satisfies the above conditions, the second embodiment can be used.

In the second embodiment, the speed information can be updated even at the time 61d by using the determination based on the third period, which is effective in improving the responsiveness.

Next, the speed calculation method will be explained. For the sake of simplification of the explanation, the assumptions regarding the rotation angle sensor 12 and the motor 10 used in FIG. 4 are applied as they are.

The difference between FIGS. 7 and 4 is that the execution and stop of the speed calculation are judged by the presence or absence of the third period 67. From the start of the third period 67 to immediately before the end of the third period 67, the stored value of the speed previous value storage means 53 or the zero speed setting means 54 is selected as the estimated speed 55. When the value of the zero speed setting means 54 is selected, the rotational speed output of the motor 10 becomes 0. The speed calculation means 51 continues to operate even in the third period 67, and updates the estimated speed 55 immediately after the end of the third period 67. If the third period 67 is not detected, the estimated speed 55 adopts the result of the speed calculation means 51 as usual.

The follow chart in the second embodiment is described because it only replaces the first period determination process S112 and the second period determination process S113 with the third period determination process in the flowchart of the first embodiment shown in FIG. Is omitted.

According to the second embodiment, even when the motor frequently switches between normal rotation and reverse rotation, the speed calculation accuracy can be ensured and the motor can be appropriately controlled.

Next, the third embodiment will be described. FIG. 8 is a control block diagram of the motor speed estimation means 28 according to the third embodiment of the present invention. Since the configurations of the motor control device 20 and the motor drive system are the same as those in FIG. 1, detailed description thereof will be omitted. Further, for the sake of simplification of the description, the rotation angle sensor 12 will be described below as a Hall IC.

The U phase change event generating means 71a, the V phase changing event generating means 71b, and the W phase changing event generating means 71c as the phase change event generating means of each phase monitor the change of the rotation angle signal of each layer to see if there is any change. Notify.

In FIG. 8, of the three-phase rotation angle sensor signals 22 input, the U-phase hall IC 22a output is input to the U-phase change event generating means 71a. The U-phase change event generating means 71a constantly monitors the output of the Hall IC 22a and generates an event detection signal 44 when a change is detected. When mounting with an embedded microcomputer, it is generally realized by generating an interrupt by changing the digital I / O input. If it has a sufficient processing function, it may be configured to constantly monitor by polling. The same applies to the V phase and the W phase, which includes a V phase change event generating means 71b for monitoring the Hall IC 22b output and a W phase change event generating means 71c for monitoring the Hall IC 22c output. Further, the V-phase event detection signal 44b is generated from the V-phase change event generation means 71b, and the W-phase event detection signal 44c is generated from the W-phase change event generation means 71c.

The three-phase rotation angle sensor signal 22 is input to the U-phase update permission means 72a, and determines whether to use or ignore the U-phase change event. When mounted on an embedded microcomputer, it is generally realized as a flag. In this case, the U-phase update permission means 72a operates as follows, for example.
・ If the phase that changed immediately before is V phase or W phase, set (permit) U phase update permission flag. ・ If the phase that changed immediately before is U phase, clear the U phase update permission flag. (Not permitted) In addition, in the realization, a method based on the state transition may be used without depending on the flag.

The same applies to the V phase and the W phase, and the V phase update permitting means 72b and the W phase update permitting means 72c are provided.

The U-phase event detection signal 44a operates the U-phase change time storage means 73a. The U-phase change time storage means 73a stores the FRC current value 48 (current time) obtained from the free running counter 47 when the U-phase update permission means 72a permits update as the time when the U-phase changes. When the U-phase update permitting means 72a prohibits the update, the U-phase change time storage means 73a does not operate. The same applies to the V phase and the W phase, and the V phase change time storage means 73b and the W phase change time storage means 73c are provided.

The U-phase change time storage means 73a, the V-phase change time storage means 73b, and the W-phase change time storage means 73c (phase change time storage means) store the change time of the rotation angle signal for each phase. Then, the U-phase change time storage means 73a, the V-phase change time storage means 73b, and the W-phase change time storage means 73c (phase change time storage means) are transmitted to the elapsed time calculation means 46 after the respective processing is completed, and the operation is performed. Start.

The elapsed time calculation means 46 includes a U-phase change time stored by the U-phase change time storage means 73a, a V-phase change time stored by the V-phase change time storage means 73b, and a W-phase change stored by the W-phase change time storage means 73c. Enter the time and calculate the difference between the two most recent change times. The obtained difference in change time is transmitted to the speed calculation means 51. The speed calculation means 51 calculates the speed from the difference in change time (difference between the latest two change times) of the rotation angle signals of each phase output from the phase change time storage means of each phase in the three phases. Since the difference between the two most recent change times means the occurrence interval of the event detection signal 44, the velocity information can be obtained by calculating the reciprocal.

FIG. 9 is a diagram showing an example of the operation of the motor speed estimation means 28 according to the third embodiment of the present invention. In FIG. 9, the fact that the W phase update prohibited section 68 is provided is different from FIG. 7 in the second embodiment.

At time 61a, a change in the output of the W-phase hall IC22c is observed. Since the change of the rotation angle sensor signal 22 immediately before is the U phase, the W phase update permission means 72c is in the permission state at this point, and the W phase change time storage means 73c operates. At the same time, the elapsed time calculation means 46 and the speed calculation means 51 operate. After the operation of the elapsed time calculation means 46 and the speed calculation means 51, the W phase update permission means 72c clears the W phase update permission flag, and the change of the W phase is not permitted.

At time 61b, when the motor 10 is rotated in the reverse direction due to the influence of an external force or the like, the output of the W-phase hall IC 22c changes again. However, at this point, since the W phase update permission means 72c does not allow the operation of the W phase change time storage means 73c, the change time information at the time 61b is skipped. That is, if the in-phase changes continuously before the other phases change, the change time information is ignored. At time 61c, the motor 10 returns to normal rotation, but similarly, since the W phase update permission means 72c does not allow the operation of the W phase change time storage means 73c, the change time information at time 61c is skipped. That is, in the phase change time storage means, the rotation speed output of the motor 10 is updated when the phase change event generating means detects the change in the rotation angle signal in one phase and then detects the change in the rotation angle signal in the other phase. Will be done.

At time 61d, a change in the V-phase hall IC22b is observed. At this point, the V-phase update permitting means 72c permits the operation of the V-phase change time storage means 73b, and the V-phase change time storage means 73b operates. At the same time, the elapsed time calculation means 46 and the speed calculation means 51 operate. After the operation of the elapsed time calculation means 46 and the speed calculation means 51, the V-phase update permission means 72b clears the W-phase update permission flag, and the change of the V-phase is not permitted. At the same time, the W phase update permission means 72c sets the W phase update permission flag, and is in a state of permitting the change of the W phase.

In the case of the embodiment shown in FIG. 9, just like the embodiment shown in FIG. 7, the rotation speed output of the motor can be updated at time 61d, which is effective in improving the responsiveness.

FIG. 10 is a flowchart showing the operation of the motor speed estimation means 28 according to the third embodiment of the present invention. The elapsed time calculation means 46 and the speed calculation means 51 are omitted because they are exactly the same as the processes after S106 in the flowchart shown in FIG.

In FIG. 10, since the U-phase hall IC22a, the V-phase hall IC22b, and the W-phase hall IC22c are monitored in parallel, the processing flow is branched into three after the processing is started. From the left, processing related to the U phase, processing related to the V phase, and processing related to the W phase, and the processing is the same for each phase, so the description describes the processing flow located on the leftmost side (the end is'a').

S121a is a monitoring process for the U-phase hall IC 22a, and monitors changes in the U-phase hall IC 22a by means such as interruption. If there is no change, it is continuously monitored, and if there is a change, the process proceeds to the U-phase update determination process S122a. If the U-phase update permission means 72a permits the update, the process proceeds to the next process, and if the update is prohibited, the process returns to the process S121a. Since the update determination method of the U-phase update permission means 72a is described in the explanation of FIG. 8, the description is omitted.

S123a is a pulse direction acquisition process for acquiring the changing direction of the U-phase Hall IC 22a.
Here, the variable name indicating the pulse direction is described as "pls_dir". S101a is a counter acquisition process, S105a is a counter previous value acquisition process, and the same process as the flowchart shown in FIG. 5 is performed.

S124a is an information update process, and updates the variable of the U phase change time storage means 73a. Here, the current changing phase is described as "phs", and the previous changing phase is described as "phs_z". Further, the previous value of the variable "pls_dir" described in the process S123a is described as "pls_dir_z". The variables updated here are provided to determine the rotation direction of the motor 10.

The motor control device 20 in this embodiment is intended for an application in which the forward and reverse rotations of the motor are frequently repeated, and it is often important to determine the rotation direction in the upper control system, so variables are used. There is. By the combination of these variables, the rotation direction of the motor is easily determined, for example, as shown in the table shown in FIG.

FIG. 11 is a diagram showing the relationship between the changing phase and the rotation direction according to the third embodiment of the present invention. Here, the variables “phs” and “phs_z” representing the changing phase are described as character types, and the variables “pls_dir” and “pls_dir_z” representing the pulse direction are described with the rising edge being +1 and the falling edge being -1.

In FIG. 10, the process S125a represents the process of the U-phase change time storage means 73a. The process S126 is a coupling process, and when any of the process related to the U phase, the process related to the V phase, and the process related to the W phase is completed, the branched processing flows are combined and the process proceeds to the subsequent process. Note that the motor control is designed with care so that each branch is not performed at the same time, so all consideration regarding memory contention processing and interrupt priority between each branch flow is omitted. did.

According to the third embodiment, if the in-phase changes continuously before the other phases change, the change time information is ignored, so that the motor frequently switches between normal rotation and reverse rotation. In this case as well, the speed calculation accuracy can be ensured and the motor can be appropriately controlled.

The examples of the motor control device 20 according to the present invention have been described above. The present invention is a motor control device of a type in which the time interval of the rotation angle sensor 12 is used for speed detection, and still another embodiment of the embodiment is possible. For example, the rotation angle sensor 12 is not limited to the Hall IC, and can be similarly applied to, for example, an encoder pulse signal. A general incremental encoder pulse has two phases, A phase and B phase, but it can be similarly realized by omitting the W phase in the examples shown in FIGS. 6 and 8, for example. Further, in the description of each embodiment, for the sake of simplification of the description, the speed is calculated using the time interval measured every 60 degrees of the motor rotation angle, but even if another speed detection method is used The invention can be applied. For example, from the rise of the U phase to the next rise, from the fall of the U phase to the next fall, from the rise of the V phase to the next rise, from the fall of the V phase to the next fall, from the rise of the W phase. Until the next rise, the six time interval information from the fall of the W phase to the next fall may be used. This is a method of measuring the time required for 360 rotations every 60 degrees of the motor rotation angle, and this can also be applied by changing the speed calculation means 51.

When the time interval of the output of the rotation angle sensor signal 22 is used for speed detection, the information of the rotation angle sensor signal 22 cannot be obtained when the motor is completely stopped. Therefore, strictly speaking, the speed calculation means 51 is used. Cannot be implemented. In this case, for example, when information cannot be obtained for a certain period of time or longer, it is advisable to use a coping method such as setting the speed to 0 (zero).

According to this embodiment, at the moment when the forward rotation and the reverse rotation are switched, the situation where the time interval of the rotation angle sensor signal 22 does not correspond to the rotation speed is detected and dealt with, so that the normal rotation and the reverse rotation are switched. The speed calculation error can be reduced even in the situation. Therefore, this embodiment is particularly suitable for an application in which forward rotation and reverse rotation are repeated.

Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, an example in which the motor control device described in the first to third embodiments is applied to the variable valve timing control device will be described.
FIG. 12 is a cross-sectional view of the variable valve timing control device according to the fourth embodiment of the present invention.

The engine 201 is provided with an intake side electric valve timing control device 10a and an exhaust side electric valve timing control device 10b. The crankshaft 202 of the engine is connected to a piston in the cylinder and converts the reciprocating motion of the piston into a rotary motion.

The intake cam 204a and the exhaust cam 204b are connected to the intake side cam shaft 203a and the exhaust side cam shaft 203b, respectively.

The intake side electric valve timing control device 10a has an intake side electric valve timing control motor attached to the engine 201 and an intake side phase changer attached to the intake side camshaft 203a. The intake side phase changer has a timing chain or a timing belt to transmit the rotational force of the crankshaft 202, and has a reduction mechanism (not shown) to rotate the intake side electric valve timing control motor. It is possible to decelerate and change the rotation phases of the intake side camshaft 203a and the crankshaft 202.

The exhaust side electric valve timing control device 10b has an exhaust side electric valve timing control motor attached to the engine 201 and an exhaust side phase changer attached to the exhaust side camshaft 203b. Like the intake side phase changer, the exhaust side phase changer also has a timing chain or timing belt to transmit the rotational force of the crankshaft 202, and has a reduction mechanism (not shown) on the exhaust side. The rotation of the electric valve timing control motor can be decelerated to change the rotation phases of the exhaust side camshaft 203b and the crankshaft 202.

The intake cam 204a opens the intake valve 206a by pushing the intake valve stem end 205a. When the intake cam 204a rotates to a position where the intake valve stem end 205a is not pushed, the intake valve 206a is closed by the intake valve spring 207a.
Even on the exhaust side, the exhaust cam 204b opens the exhaust valve 206b by pushing the exhaust valve stem end 205b. When the exhaust cam 204b rotates to a position where the exhaust valve stem end 205b is not pushed, the exhaust valve 206b is closed by the exhaust valve spring 207b.

The variable valve timing control device shown in FIG. 12 is a system called a rotation-synchronized type, and the intake-side camshaft 203a and the exhaust-side camshaft 203b are normally controlled to rotate in synchronization with the crankshaft 202. In the case of a 4-stroke internal combustion engine, the "synchronous state" means that the camshaft makes one rotation with respect to two rotations of the crankshaft, and the valve opening start angle and the valve opening end angle are always the same crankshaft angle. Define.

In such a variable valve timing control device, the rotation speed of the electric valve timing control motor on the intake side is increased from the synchronous state, and when the desired valve opening start angle is reached, the synchronous state is restored to accelerate the intake timing. be able to. This is called "advance angle". Further, the intake timing can be delayed by slowing down the rotation speed of the intake side electric valve timing control motor from the synchronous state and returning to the synchronous state again when the desired valve opening start angle is reached. This is called "retard". The exhaust valve can be controlled in exactly the same way.

Next, the operation of the variable valve timing control device will be described with reference to FIG. FIG. 13 is a diagram showing the operation of the variable valve timing control device according to the fourth embodiment of the present invention.

Here, the operation of returning to the re-laxing angle from the largest retarding angle (re-laxing angle) allowed by the engine, passing through the largest advancing angle (re-advancing angle) is illustrated. The horizontal axis is time. 211 is a graph of engine speed, 212 is a graph of valve phase angle, and 213 is a graph of motor speed. In this embodiment, the engine speed is assumed to be constant, and the valve phase angle 212 is set to a phase angle of 0 degrees when the camshaft angle with respect to the crankshaft angle in the normal operating state. Moreover, since the intake side and the exhaust side are exactly the same, the intake and the exhaust are not distinguished thereafter. In this embodiment, a motor that opens and closes a valve is provided at least one of intake and exhaust.

When changing from a re-delay angle to a re-advance angle, the motor speed increases once at t1 and then decreases to the synchronous speed at t2. As a result, the valve phase angle can be changed to the reclamation angle. From this state, the valve phase angle can be changed to the re-lagging angle by lowering the motor speed at t3 and increasing it to the synchronous speed again at t4. When changing from the advance side to the retard side, the motor speed is lowered from t3 to t4, but at this time, the synchronous speed determined from the engine speed and the request response up to the re-delay angle are used. In a situation where the motor rotation speed switches from normal rotation to reverse rotation. In the conventional motor speed calculation method, there is a large calculation error when switching from forward rotation to reverse rotation. In the variable valve timing control device, the upper control system often has a high gain in order to ensure high responsiveness, and therefore a calculation error may greatly deteriorate the control performance.

Therefore, in the fourth embodiment, the intake side electric valve timing control device 10a and the exhaust side electric valve timing control device 10b are controlled by the motor control devices described in the first to third embodiments from the normal rotation. Since the calculation error at the time of switching to reverse rotation can be reduced, it is possible to provide a variable valve timing control device with improved responsiveness.

Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, an example in which the motor control device described in the first to third embodiments is applied to the electric power steering device will be described. FIG. 14 is a schematic view of the electric power steering device according to the fifth embodiment of the present invention. The electric power steering device assists the steering operation by the driving force of the motor.

The steering shaft 222 is connected to the steering wheel 221. The motor 10 that is the drive source of the electric power steering device is connected to the motor shaft 11. The motor shaft 11 is connected to the steering shaft 222 by the power combining means 223, and the power of the motor 10 is combined with the steering shaft 222 by the power combining means 223. The combined power steering shaft 222 is coupled to the steering gear mechanism 224. The steering gear mechanism 224 is attached to the knuckle arm 225 and changes the direction of the wheels 226.

The electric power steering device is always in a state of receiving the resistance of the road surface. Further, since the driver repeats the adjustment in small steps so as to correct the road surface resistance by the steering wheel, the motor 10 is in a state of repeating forward rotation and reverse rotation. By applying the motor control device described in the first to third embodiments to the electric power steering device, for example, when the steering wheel 221 rotates in a direction opposite to the direction intended by the driver in off-road driving (so-called). Even in the "kicked" state), the effect of being able to realize control that reduces the torque that bounces off the driver can be obtained. Further, when electric airplanes become widespread, the same effect can be expected with electric ladder control for aircraft.

10 ... motor, 10a ... intake side electric valve timing control device, 10b ... exhaust side electric valve timing control device, 11 ... motor shaft, 12 ... rotation angle sensor, 13 ... wiring, 14 ... power conversion device, 15 ... switching element, 16 ... current detector, 17 ... gate driver, 18 ... gate voltage, 19 ... gate signal, 20 ... motor control device, 21 ... command signal, 22 ... rotation angle sensor signal, 23 ... DC current signal, 24 ... compensation means, 25 ... Torque estimation value, 26 ... Torque command signal, 27 ... Torque estimation means, 28 ... Motor speed estimation means, 29 ... Motor speed estimation value, 30 ... Countercurrent voltage estimation means, 31 ... Countercurrent voltage estimation value, 32 ... Phase voltage conversion means, 33 ... duty ratio signal, 34 ... torque direction signal, 35 ... gate signal creating means, 41 ... change event detecting means, 42 ... first period determining means, 43 ... second period determining means, 44 ... event Detection signal, 44a ... U-phase event detection signal, 44b ... V-phase event detection signal, 44c ... W-phase event detection signal, 45 ... logical sum means, 46 ... elapsed time calculation means, 47 ... free running counter, 48 ... FRC current Value, 49 ... previous value storage means, 50 ... previous value, 51 ... speed calculation means, 52 ... estimated speed selection means, 53 ... speed previous value storage means, 54 ... zero speed setting means, 55 ... estimated speed, 56 ... th 3 period determination means, 61a, 61b, 61c, 61d, 61e ... time, 63 ... time interval, 64 ... speed calculation selection time, 65 ... first period, 66 ... second period, 67 ... third period, 68 ... phase Update prohibited section, 71a ... U phase change event generating means, 71b ... V phase changing event generating means, 71c ... W phase changing event generating means, 72a ... U phase update permitting means, 72b ... V phase updating permitting means, 72c ... W Phase update permission means, 73a ... U phase change time storage means, 73b ... V phase change time storage means, 73c ... W phase change time storage means, 201 ... engine, 202 ... crank shaft, 203a ... intake side cam shaft, 203b ... Exhaust side cam shaft, 204a ... Intake cam, 204b ... Exhaust cam, 205a ... Intake valve stem end, 205b ... Exhaust valve stem end, 206a ... Intake valve, 206b ... Exhaust valve, 207a ... Intake valve spring, 207b ... Exhaust valve spring , 212 ... Valve phase angle, 221 ... Steering wheel, 222 ... Steering shaft, 223 ... Power synthesis means, 224 ... Steering gear mechanism, 225 ... Knuckle arm, 226 ... Wheel

Claims (13)

1. A motor control device including a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of a motor, and controlling the rotation speed output of the motor based on the three-phase signal and a command signal.
   A first period determining means for determining a first period in which the three-phase signal output from the rotation angle sensor is output in the order of rising, falling, and rising over the three phases.
   A second period determining means for determining a second period in which the three-phase signal output from the rotation angle sensor is output in the order of falling, rising, and falling over the three phases is provided.
   A motor control device characterized in that when the output of the rotation angle sensor is in the first period or the second period, the rotation speed output of the motor is controlled to be updated.
2. The motor control device according to claim 1.
   When the output of the rotation angle sensor is outside the first period or the second period, the motor control is provided with a speed previous value storage means for which the rotation speed output of the motor is the previous value. apparatus.
3. The motor control device according to claim 1.
   A motor control device including a zero speed setting means for setting the rotational speed output of the motor to 0 when it is in a period other than the first period or the second period.
4. A motor control device including a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of a motor, and controlling the rotation speed output of the motor based on the three-phase signal and a command signal.
   A third period for determining a third period from the time when only the signal of the specific phase changes two or more times to the detection of the signal change of the phase other than the specific phase among the three-phase signals output from the rotation angle sensor. Equipped with a period determination means
   When the output of the rotation angle sensor is in the third period, the rotation speed output of the motor is held at the previous rotation speed output, and the rotation speed output of the motor is updated at the end of the third period. A featured motor control device.
5. A motor control device including a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of a motor, and controlling the rotation speed output of the motor based on the three-phase signal and a command signal.
   A third period for determining a third period from the time when only the signal of the specific phase changes two or more times to the detection of the signal change of the phase other than the specific phase among the three-phase signals output from the rotation angle sensor. Equipped with a period determination means
   When the output of the rotation angle sensor is in the third period, the rotation speed output of the motor is set to 0, and the rotation speed output of the motor is updated at the end of the third period. ..
6. A motor control device including a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of a motor, and controlling the rotation speed output of the motor based on the three-phase signal and a command signal.
   A phase change event generating means that monitors a change in the rotation angle signal of each phase in the three phases and notifies the presence or absence of the change, a phase change time storage means that stores the change time of the rotation angle signal of the motor for each phase,
   A speed calculation means for calculating the speed from the difference in the change time of the rotation angle signal in each phase output from the phase change time storage means is provided.
   In the phase change time storage means, the rotation speed output of the motor is updated when the phase change event generating means detects a change in the rotation angle signal in one phase and then detects a change in the rotation angle signal in another phase. A motor control device characterized by being
7. An intake cam and an exhaust cam that open and close the intake valve and the exhaust valve, respectively, an intake side cam shaft and an exhaust side cam shaft connected to the intake cam and the exhaust cam, and the intake side cam shaft and the exhaust side cam shaft, respectively. In a variable valve timing control device equipped with an intake side electric valve timing control motor and an exhaust side electric valve timing control motor
   The variable valve timing control device, wherein the intake side electric valve timing control motor and the exhaust side electric valve timing control motor are controlled by the motor control device according to any one of claims 1 to 6.
8. A motor control method that includes a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of a motor, and controls the rotation speed output of the motor based on the three-phase signal and a command signal.
   The period in which the three-phase signal output from the rotation angle sensor is output over the three phases in the order of rising, falling, and rising is defined as the first period.
   The period in which the three-phase signal output from the rotation angle sensor is output over the three phases in the order of falling, rising, and falling is defined as the second period.
   A motor control method, characterized in that when the output of the rotation angle sensor is in the first period or the second period, the rotation speed output of the motor is controlled to be updated.
9. The motor control method according to claim 8.
   A motor control method, characterized in that, when the output of the rotation angle sensor is outside the first period or the second period, the rotation speed output of the motor is held at the rotation speed output at the time of renewal.
10. The motor control method according to claim 8.
    A motor control method, characterized in that the rotation speed output of the motor is set to 0 when the period is other than the first period or the second period.
11. A motor control method that includes a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of a motor, and controls the rotation speed output of the motor based on the three-phase signal and a command signal.
    Of the three-phase signals output from the rotation angle sensor, the period from the time when only the signal of the specific phase changes twice or more to the detection of the signal change of the phase other than the specific phase is defined as the third period.
    When the output of the rotation angle sensor is in the third period, the rotation speed output of the motor is held at the previous rotation speed output, and the rotation speed output of the motor is updated at the end of the third period. A featured motor control method.
12. A motor control method that includes a rotation angle sensor that outputs a three-phase signal for detecting the rotation angle of a motor, and controls the rotation speed output of the motor based on the three-phase signal and a command signal.
    Of the three-phase signals output from the rotation angle sensor, the period from the time when only the signal of the specific phase changes twice or more to the detection of the signal change of the phase other than the specific phase is defined as the third period.
    When the output of the rotation angle sensor is in the third period, the rotation speed output of the motor is set to 0, and the rotation speed output of the motor is updated at the end of the third period. ..
13. An intake cam and an exhaust cam that open and close the intake valve and the exhaust valve, respectively, an intake side cam shaft and an exhaust side cam shaft connected to the intake cam and the exhaust cam, and the intake side cam shaft and the exhaust side cam shaft, respectively. In a variable valve timing control method equipped with an intake side electric valve timing control motor and an exhaust side electric valve timing control motor
    A variable valve timing control method, wherein the intake side electric valve timing control motor and the exhaust side electric valve timing control motor are controlled by the motor control method according to any one of claims 8 to 12.

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