Motor Control Device

Abstract

To provide a motor control device which can at all times correct positional deviation occurring in a rotation sensor.SOLUTION: A blower motor control device halts electric conduction to a motor when the revolution speed of a rotor reaches a learning revolution speed to acquire a correction amount to correct positional deviation of the rotor and a Hall element as a learning value using an induction voltage generated on a motor coil and a detection signal from a rotation sensor (S33, S34). The blower motor control device stores the learning value into a ROM (S35, S36). Until the revolution speed reaches the learning revolution speed, the blower motor control device corrects the positional deviation using the learning value of the previous time which is the learning value read from the ROM, so as to perform electric conduction control of the motor (S32). When the revolution speed reaches the learning revolution speed and after the learning value is acquired in a learning part, the blower motor control device corrects the positional deviation using the latest learning value acquired in the learning part, so as to perform the electric conduction control of the motor (S32).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a motor control device. [Background technology]

[0002] An example of a motor control device is a brushless motor control device disclosed in Patent Document 1.

[0003] The brushless motor control device stops energization of all phases of the stator coil after a predetermined rotation of the rotor and when the rotor is in a lower speed range than steady rotation, to set an inertial rotation period of the rotor. The brushless motor control device detects an induced voltage of at least one phase of the stator coil during the inertial rotation period of the rotor. The brushless motor control device detects a phase difference between the induced voltage obtained during the inertial rotation period of the rotor and a detection signal from a rotation sensor that detects the rotational position of the rotor, and detects an angular deviation of the rotation sensor used to correct the energization timing based on the phase difference. The brushless motor control device then corrects the energization timing in response to an angle deviation that may occur in the rotation sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5144337 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the brushless motor control device detects the deviation angle by detecting the induced voltage during the inertial rotation period in the low rotation speed range. Therefore, the brushless motor control device does not detect the deviation angle until the low rotation speed range is reached. This causes a problem in that there is a period during which the brushless motor control device cannot make correction.

[0006] One disclosed object is to provide a motor control device that can constantly correct positional deviations that occur in a rotation sensor. [Means for solving the problem]

[0007] The motor control device disclosed herein comprises: The rotational position of the rotor in the motor is acquired based on a detection signal from the rotation sensor, and the current supply to the motor is controlled according to the rotational position. a learning unit (S33, S34) that stops energization of the motor when the rotation speed of the rotor reaches a learning rotation speed, and acquires a correction amount for correcting a positional deviation between the rotor and the rotation sensor as a learning value using an induced voltage generated in a coil of the motor and a detection signal from the rotation sensor; A storage unit (S35, S36) that stores the learning value in a non-volatile memory; The motor control unit (S32) corrects the position deviation using the previous learning value read from the non-volatile memory and controls the energization of the motor until the rotation speed reaches the learning rotation speed, and after the rotation speed reaches the learning rotation speed and the learning value is acquired by the learning unit, corrects the position deviation using the latest learning value acquired by the learning unit and controls the energization of the motor.

[0008] In this way, the motor control device stores the learning value in the non-volatile memory, and therefore the motor control device can make corrections using the learning value stored in the non-volatile memory until the rotation speed reaches the learned rotation speed.

[0009] Furthermore, the motor control device acquires the learning value when the rotation speed reaches the learning rotation speed, and therefore, after acquiring the learning value, the motor control device can make corrections using the latest learning value.

[0010] The aspects disclosed in this specification adopt different technical means to achieve their respective objectives. The claims and the parenthetical symbols described in this section are illustrative of the corresponding relationship with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the following detailed description and the attached drawings. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram showing a schematic configuration of a blower motor control device according to an embodiment; [Diagram 2] 4 is a flowchart showing a processing operation of a blower motor control device in the embodiment. [Diagram 3] 4 is a flowchart showing a processing operation during motor operation of the blower motor control device in the embodiment. [Figure 4] 4 is a flowchart showing a processing operation during normal energization of the blower motor control device in the embodiment. [Diagram 5] 6 is a time chart in the case where the rotation speed at power-on does not exceed the learning speed in the embodiment. [Figure 6] 6 is a time chart in the case where the rotation speed exceeds the learning speed when the power is turned on in the embodiment. [Figure 7] 11 is a time chart in the case where a learning process is not performed in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0013] In this embodiment, as an example, the motor control device of the present disclosure is applied to a blower motor control device 100 for a vehicle. The blower motor control device 100 controls a so-called blower motor used to blow air in an in-vehicle air conditioner. Therefore, the motor 30 in the following description indicates a blower motor. However, the motor control device of the present disclosure may also control a motor other than a blower motor. The motor control device of the present disclosure can also be applied to a device that controls an electric fan motor.

[0014] The blower motor control device 100 includes at least a microcomputer 10. However, in the present embodiment, as an example, a configuration including circuit elements such as an inverter circuit 20, a Hall element 41, a comparator 42, a voltage dividing circuit 50, a current sensor 60, a choke coil 71, and a reverse connection prevention FET 72 in addition to the microcomputer 10 is adopted. The microcomputer 10 can also be said to correspond to a motor control device.

[0015] The blower motor control device 100 is electrically connected to the motor 30, the battery 200, and the air conditioner ECU 300. The blower motor control device 100 may be configured integrally with the motor 30. A structure in which the blower motor control device 100 and the motor 30 are integrated may also be called a motor unit. In the motor unit, for example, the motor 30 is attached to a case that houses the blower motor control device 100. However, the blower motor control device 100 is not limited to this, and may be provided separately from the motor 30.

[0016] <Inverter circuit> The inverter circuit 20 switches the power supplied to the coil of the stator 31 of the motor 30. For example, the inverter FETs 21A and 21D switch the power supplied to the U-phase coil 31U, the inverter FETs 21B and 21E switch the power supplied to the V-phase coil 31V, and the inverter FETs 21C and 21F switch the power supplied to the W-phase coil 31W.

[0017] The drains of the inverter FETs 21A, 21B, and 21C are connected to the positive electrode of the vehicle-mounted battery 200 via a noise-removing choke coil 71. The sources of the inverter FETs 21D, 21E, and 21F are connected to the negative electrode of the battery 200 via a reverse connection prevention FET 72. The inverter circuit 20 corresponds to a drive unit.

[0018] <Motor> 1, the motor 30 includes a stator 31 and a rotor magnet 32. In addition to these, the motor 30 also includes a rotor, a shaft, a fan, etc. The motor 30 is a brushless three-phase motor.

[0019] Stator 31 is an electromagnet with coils 31U, 31V, and 31W wound around a core member, and constitutes three phases: U phase, V phase, and W phase. Each of the U phase, V phase, and W phase of stator 31 generates a rotating magnetic field by switching the polarity of the magnetic field generated by the electromagnet under the control of blower motor control device 100.

[0020] The rotor magnet 32 ​​is provided inside the rotor. The rotor magnet 32 ​​rotates the rotor by reacting to the rotating magnetic field generated by the stator 31. The rotor is provided with a shaft. The shaft rotates integrally with the rotor. The shaft is provided with a fan such as a so-called sirocco fan. The in-vehicle air conditioner is able to blow air by the fan rotating together with the shaft.

[0021] <Detection section> The Hall element 41 has a Hall sensor corresponding to each phase. The Hall element 41 detects the magnetic field of the rotor magnet 32, which is provided coaxially with the shaft, as a magnetic field indicating the rotational position of the rotor. The Hall element 41 outputs the detected detection signal (output signal) to the microcomputer 10. The Hall element 41 corresponds to a rotation sensor.

[0022] The comparator 42 has a negative input terminal connected to the neutral points of the phase coils 31U, 31V, 31W, and a positive input terminal connected to one end of the U-phase coil 31U. The comparator 42 receives the phase voltage of the U-phase coil 31U (a composite voltage of the drive voltage and the induced voltage). The comparator 42 outputs a signal corresponding to the induced voltage among the phase voltages of the U-phase coil 31U. For this reason, the comparator 42 can be said to be a circuit component for detecting the induced voltage.

[0023] The voltage dividing circuit 50 has a thermistor 51A and a resistor 51B. The resistance value of the thermistor 51A changes according to the temperature of the circuit board, so that the voltage of the signal output from the voltage dividing circuit 50 changes according to the temperature of the board. The current sensor 60 has a shunt resistor 60A and an amplifier 60B that amplifies the potential difference across the shunt resistor 60A.

[0024] <Microcomputer> The microcomputer 10 is mounted on a substrate together with the above circuit elements. The microcomputer 10 is a microcomputer including a CPU 11, a volatile memory 12, a non-volatile memory 13, an input / output interface, and a bus connecting these. The microcomputer 10 is electrically connected to the inverter circuit 20, the Hall element 41, the comparator 42, the voltage divider circuit 50, the current sensor 60, the battery 200, and the air conditioner ECU 300.

[0025] The CPU 11 executes a program stored in the non-volatile memory 13 to perform calculations using data stored in the volatile memory 12 and signals acquired through the input / output interface. The microcomputer 10 performs processing operations as the CPU 11 executes the program.

[0026] The non-volatile memory 13 stores various programs executed by the CPU 11. The non-volatile memory 13 also stores therein in a rewritable manner learned values, which will be described later.

[0027] The CPU 11 uses a part of the volatile memory 12 as a learning flag. The learning flag is set to a value indicating whether or not a learning value has been stored in the nonvolatile memory 13. For example, the CPU 11 sets the learning flag to 1 when the learning value has been stored in the nonvolatile memory 13, and sets the learning flag to 0 when the learning value has not been stored in the nonvolatile memory 13. The learning flag also becomes 0 when the power supply to the microcomputer 10 is stopped. That is, the microcomputer 10 sets the learning flag to 1 when the learning value is acquired and stored in the nonvolatile memory 13 from the start of the supply of the operating power (power-on) until the stop of the supply of the operating power (power-off). For this reason, the learning flag can be said to be information indicating whether or not a learning value has been stored in the nonvolatile memory 13 from power-on to power-off. In other words, the learning flag is information indicating whether or not a learning process has been executed from power-on to power-off. Therefore, even if a learning value has been stored in the nonvolatile memory 13, the learning flag becomes 0 when the power supply is stopped.

[0028] The value of the learning flag, 1, can be regarded as information indicating that the learning value has been stored in the non-volatile memory 13. The value of the learning flag, 0, can be regarded as information indicating that the learning value has not been stored in the non-volatile memory 13. Furthermore, the information indicating that the learning value has been stored in the non-volatile memory 13 can also be regarded as information indicating that the storage of the learning value in the non-volatile memory 13 has been completed. On the other hand, the information indicating that the learning value has not been stored in the non-volatile memory 13 can also be regarded as information indicating that the storage of the learning value in the non-volatile memory 13 has not been completed.

[0029] However, the present disclosure is not limited to this. The CPU 11 may store in the volatile memory 12 information indicating that the learning value has been stored in the non-volatile memory 13 and information indicating that the learning value has not been stored in the non-volatile memory 13. The learning value and the learning process will be described in detail later.

[0030] The microcomputer 10 obtains the rotation speed and position (rotational position) of the rotor based on the magnetic field (detection signal) detected by the Hall element 41. The microcomputer 10 obtains a signal corresponding to the induced voltage of the U-phase coil 31U output from the comparator 42. The rotation speed and rotational position of the rotor can also be said to be the rotation speed and rotational position of the motor 30.

[0031] The microcomputer 10 may calculate the temperature of the substrate based on a change in the voltage of the signal output from the voltage dividing circuit 50. In this embodiment, for convenience, the signal output from the voltage dividing circuit 50 is a signal based on the detection result of thermistor 51A. In this embodiment, the substrate temperature calculated based on the detection result of thermistor 51A is the substrate temperature detected by thermistor 51A. The microcomputer 10 may calculate the current value of the inverter circuit 20 based on the signal output from the amplifier 60B.

[0032] The microcomputer 10 receives a control signal including a rotation speed command value from an air conditioner EU300 that controls the air conditioner in response to a switch operation of the air conditioner. There are various cases in which the switch of the air conditioner is operated. The operation of reducing the rotation speed of the motor 30 (rotor) includes an operation of reducing the air volume of the air conditioner and an operation of increasing the set temperature of the air conditioner. For example, when a switch operation is performed to reduce the air volume of the air conditioner and an operation to increase the set temperature of the air conditioner, the air conditioner ECU 300 outputs a command to the microcomputer 10 to reduce the rotation speed of the motor 30. The air conditioner ECU 300 can also be considered as a higher-level ECU. Therefore, the control signal can also be considered as a higher-level command.

[0033] Furthermore, the microcomputer 10 calculates a duty ratio of PWM control related to the control of switching of the inverter circuit 20 based on, for example, a control signal from the air conditioner ECU 300 and the rotation speed and rotation position of the rotor based on a signal from the Hall element 41. PWM is an abbreviation of Pulse Width Modulation. The microcomputer 10 controls the switching of the inverter circuit 20 so as to generate a voltage of the duty ratio. In this way, the microcomputer 10 controls the energization of the motor 30 via the inverter circuit 20. Note that the blower motor control device 100 may include a driver circuit between the microcomputer 10 and the inverter circuit 20. In this case, the microcomputer 10 controls the switching of the inverter circuit 20 via the driver circuit.

[0034] Incidentally, the non-volatile memory 13 can be said to have programs including various functions. Therefore, the microcomputer 10 can execute various functions by executing the programs. The microcomputer 10 can be expressed by each function. In other words, the microcomputer 10 has a correction unit 11a as a functional block.

[0035] The rotor (rotor magnet 32) and the Hall element 41 are misaligned due to mounting errors when mounting the Hall element 41 and characteristic variations caused by aging deterioration of the Hall element 41. The correction unit 11a corrects the positional deviation between the rotor and the Hall element 41. The correction unit 11a obtains a correction amount (electrical angle) for correcting the positional deviation as a learned value.

[0036] For example, the correction unit 11a stops the supply of electricity to the motor 30 when the rotor reaches the learning speed. The correction unit 11a turns off all of the inverter FETs 21A to 21F to stop the supply of electricity to the coils 31U, 31V, and 31W of each phase. This is to make the phase voltage of the U-phase coil 31U input to the comparator 42 only the induced voltage. In other words, the induced voltages generated in the coils 31U, 31V, and 31W of each phase reflect the actual magnetic pole position of the rotor and indicate the ideal position of each Hall sensor. Therefore, the induced voltages are generated in the coils 31U, 31V, and 31W of each phase by the inertial rotation after the rotor is rotated at a predetermined rotation speed, and the induced voltage of the U-phase coil 31U is used among them. The learning speed corresponds to the learning rotation speed.

[0037] Then, when the power supply to the motor 30 is stopped, the correction unit 11a acquires (detects) the induced voltages generated in the U-phase coil 31U, the V-phase coil 31V, and the W-phase coil 31W of the motor 30. In this embodiment, as an example, the induced voltage of the U-phase coil 31U is acquired. The correction unit 11a acquires a learning value by using the induced voltage and the detection signal from the Hall element 41. The correction unit 11a also corrects the position deviation based on the acquired learning value.

[0038] The method of acquiring and correcting the learning value may be, for example, the method described in Japanese Patent No. 5144337. However, the method of acquiring and correcting the learning value is not limited to this, and any method may be used as long as it stops the power supply to the motor 30 when the rotation speed of the rotor reaches the learning speed, and acquires the learning value using the induced voltage and the detection signal from the Hall element 41.

[0039] The learning speed is a reference value for determining whether or not to stop the supply of electricity to the motor 30. If the supply of electricity to the motor 30 is stopped while the motor 30 is rotating at high speed, abnormal noise or the like may be generated, which may cause a user to feel uncomfortable. Therefore, the learning speed is preferably set to a low-speed rotation range in the middle of the increase in the rotation speed at the start of the motor 30. In other words, it is preferable for the correction unit 11a to cut off the supply of electricity to the motor 30 when the rotation speed is low, where the torque ripple is small with a low current and abnormal noise or the like is unlikely to occur.

[0040] The process of acquiring the learning value may be called a learning process. The process of correcting the positional deviation may be called a correction process. The correction unit 11a may be provided separately from the microcomputer 10.

[0041] <Processing Operation> Here, the processing operation of the blower motor control device 100 will be described with reference to Figs. 2 to 7. Figs. 2 to 4 are flowcharts showing the processing mainly executed by the microcomputer 10. The microcomputer 10 starts the processing shown in the flowchart of Fig. 2 when the power is turned on. In other words, the microcomputer 10 starts up when operating power is supplied to the microcomputer 10, and starts the processing shown in the flowchart of Fig. 2. The microcomputer 10 also performs the processing shown in the flowchart of Fig. 2 until the power is turned off.

[0042] In step S10, an initial value setting process is performed. The microcomputer 10 sets the learning value acquired in the previous learning process (previous learning value) as the learning value to be used in the current correction process (used learning value). The learning value to be used in the correction process varies depending on the rotation speed and the memory status of the learning value. For this reason, the used learning value set in step S10 can be considered a provisional learning value.

[0043] The microcomputer 10 reads out the previous learning value from the non-volatile memory 13. Then, the microcomputer 10 stores the read out previous learning value in the volatile memory 12 or the like for use in the current correction process.

[0044] In step S20, main processing is performed. As the main processing, the microcomputer 10 drives (operates) or stops the driving of the motor 30 in response to a control signal from the air conditioner ECU 300. As part of the main processing, the microcomputer 10 starts the processing shown in the flowchart of Fig. 3. More specifically, the microcomputer 10 operates the motor 30 in response to a higher-level command indicating the operation of the motor 30, which is received as a control signal from the air conditioner ECU 300.

[0045] Here, the motor operation process of the microcomputer 10 will be described with reference to Fig. 3. The flowchart in Fig. 3 can be regarded as the process in the correction unit 11a.

[0046] In step S31, it is determined whether the learning flag is "completed." Based on the value of the learning flag, the microcomputer 10 determines whether the storage of the learning value in the non-volatile memory 13 is completed between power-on and power-off. In other words, based on the value of the learning flag, the microcomputer 10 determines whether the learning process has been performed between the current power-on and power-off.

[0047] When the value of the learning flag is 1, the microcomputer 10 determines that the storage of the learning value in the non-volatile memory 13 is complete, and proceeds to step S32. When the value of the learning flag is 0, the microcomputer 10 determines that the storage of the learning value in the non-volatile memory 13 is incomplete, and proceeds to step S33.

[0048] As will be described later, in step S33, a learning process is performed. Therefore, the microcomputer 10 acquires a learning value only when the learning value has not been acquired. This allows the microcomputer 10 to reduce the number of times the non-volatile memory 13 is written to or erased.

[0049] However, the present disclosure may not include a learning flag. In other words, the present disclosure may not include a learning flag when it is not necessary to determine whether or not a learning process has been performed from when the power is turned on until when the power is turned off. For example, the present disclosure may not include a learning flag and a process for determining the value of the learning flag (step S31) when a learning process is performed every time the motor 30 is driven from a stopped state. In this case, the microcomputer 10 can always perform a correction process using the latest learning value.

[0050] In step S33, a learning energization process is performed (learning section). In order to obtain a learning value, the microcomputer 10 controls energization of the motor 30 to obtain the learning value. Step S33 is a process for obtaining the latest learning value. The microcomputer 10 obtains the learning value by using the induced voltage and the detection signal from the Hall element 41.

[0051] The learning process will now be described with reference to Fig. 5, Fig. 6, and Fig. 7. In Fig. 5 to Fig. 7, timing t1 is the timing at which power is turned on. Timing t2 is the start timing of a higher-level command from the air conditioner ECU 300 that indicates the operation of the motor 30. The dashed and dotted lines indicate the higher-level command. The solid lines indicate the rotation speed of the motor 30.

[0052] In the example of FIG. 5, there is a period after timing t1 where the rotation speed does not reach the learning speed. Then, the microcomputer 10 performs learning processing from timing t3, when the rotation speed reaches the learning speed, to timing t4. The non-volatile memory 13 stores the previous learning value even during the period from timing t1 to t4. Therefore, the microcomputer 10 can perform correction processing using the learning value even during the period from timing t1 to t4. Therefore, until the rotation speed reaches the learning speed, the microcomputer 10 performs correction processing using the previous learning value read from the non-volatile memory 13, and controls the supply of electricity to the motor 30.

[0053] Furthermore, in the blower motor control device 100, the motor 30 is subjected to a high load, for example, when the vehicle is traveling at high speed with the windows open.

[0054] In such a situation, as shown in Fig. 6, the motor is started from a state in which the rotation speed exceeds the learning speed. In other words, the microcomputer 10 operates differently from the higher-level command (command rotation speed) to decelerate the rotation speed toward the learning speed. Even in this case, the microcomputer 10 can perform correction processing using the learning value even during the period from timing t1 to t4.

[0055] As shown in Fig. 7, when the motor is started from a state in which the rotation speed exceeds the learning speed, the microcomputer 10 can avoid deceleration and accelerate the motor in accordance with a higher-level command. In this case, the learning process is not performed because the rotation speed does not reach the learning speed. However, the microcomputer 10 can perform correction using the previous learning value read from the non-volatile memory 13 and control the energization of the motor 30.

[0056] In step S34, it is determined whether the learning value is within a range (learning section). The microcomputer 10 determines whether the learning value acquired in step S33 is within a predefined range. That is, the microcomputer 10 compares the learning value acquired in step S33 with an upper limit value and a lower limit value that define the range. Note that the range here is a possible range for the learning value, that is, an assumable range. Also, the range here can be said to be a range in which the power supply to the motor 30 can be considered to be within a normal range when correction is performed based on the learning value. The range corresponds to the specified range. In this way, the microcomputer 10 determines whether the learning value acquired in step S33 can be used for correction.

[0057] If the microcomputer 10 determines in step S33 that the learned value is within the range, the microcomputer 10 proceeds to step S35. In other words, if the microcomputer 10 determines that the learned value is within the range, the microcomputer 10 assumes that the learned value obtained in step S33 can be used for correction, and proceeds to step S35.

[0058] On the other hand, if the microcomputer 10 does not determine that the learned value acquired in step S33 is within the range, the microcomputer 10 proceeds to step S38. In other words, if the microcomputer 10 does not determine that the learned value acquired in step S33 is within the range, the microcomputer 10 assumes that the learned value acquired in step S33 cannot be used for correction, and proceeds to step S38.

[0059] In step S38, the learning flag is set to incomplete. That is, the microcomputer 10 sets the learning flag to 0. In this way, when the microcomputer 10 determines that the learning value acquired in step S33 is out of range, the microcomputer 10 proceeds to step S32 without storing the learning value in the non-volatile memory 13. However, the present disclosure is not limited to this, and steps S34 and S38 may be omitted.

[0060] However, the present disclosure is not limited to this. For example, if the determination in step S34 is NO, the microcomputer 10 may adopt a default value as the learning value used for correction. Then, the microcomputer 10 proceeds to step S36 without proceeding to step S38. Therefore, in step S36, the microcomputer 10 stores the default value as the learning value in the non-volatile memory 13. In this case, step S38 may be omitted.

[0061] In step S35, the learning value is set as the current learning value (storage unit). Then, in step S36, it is stored in the non-volatile memory 13 (storage unit). The microcomputer 10 adopts the learning value acquired in step S33 (current learning value) as the learning value to be used for correction. Then, the microcomputer 10 stores the current learning value in the non-volatile memory 13. That is, the microcomputer 10 overwrites and updates the learning value set in step S10 with the current learning value. It can also be said that the microcomputer 10 stores the current learning value in the non-volatile memory 13 in place of the learning value set in step S10. The current learning value can also be said to be the latest learning value.

[0062] In this embodiment, only when the determination in step S34 is YES, the current learned value is stored in the non-volatile memory 13. That is, the microcomputer 10 stores only learned values ​​within the range in the non-volatile memory 13. This makes it possible for the microcomputer 10 to prevent the storage of inappropriate learned values. It can also be said that the microcomputer 10 can prevent the supply of abnormal current to the motor 30.

[0063] In step S37, the learning flag is set to "completed." That is, the microcomputer 10 sets the learning flag to "1." In this way, when the microcomputer 10 determines that the learning value acquired in step S33 is within the range, the microcomputer 10 stores the learning value in the non-volatile memory 13 and proceeds to step S32. Note that, when step S34 is omitted, the microcomputer 10 stores the learning value acquired in step S33 in the non-volatile memory 13 and proceeds to step S32.

[0064] In step S32, normal energization processing is performed (energization control section). As shown in FIG. 4, the microcomputer 10 performs normal energization processing. That is, the microcomputer 10 performs correction processing using the learning value (S40). At this time, the microcomputer 10 can perform correction processing using the latest learning value. Then, the microcomputer 10 performs energization processing to the motor 30 via the inverter circuit 20 in response to a control signal from the air conditioner ECU 300 (S41). In this way, after the rotation speed reaches the learning speed and the learning value is acquired, the microcomputer 10 can correct the position deviation using the latest learning value and control energization of the motor 30. For example, after timing t4 in FIG. 5, the microcomputer 10 corrects the position deviation using the latest learning value and controls energization of the motor 30.

[0065] <Effects> In this way, the blower motor control device 100 stores the learning value in the nonvolatile memory 13. Therefore, the motor control device can make corrections using the learning value stored in the nonvolatile memory 13 until the rotation speed reaches the learning speed. Furthermore, the blower motor control device 100 acquires the learning value when the rotation speed reaches the learning speed. Therefore, after acquiring the learning value, the blower motor control device 100 can make corrections using the latest learning value. In this way, the blower motor control device 100 can constantly correct position deviations occurring in the Hall element 41.

[0066] Therefore, the blower motor control device 100 can constantly suppress deterioration in quietness and motor performance of the motor 30 that may occur due to misalignment. In other words, the blower motor control device 100 can constantly ensure quietness and motor performance of the motor 30 even if misalignment occurs.

[0067] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also encompasses various modifications and modifications within the equivalent range. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one element, or less than one element are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0068] 10...microcomputer, 11...CPU, 11a...correction unit, 12...volatile memory, 13...non-volatile memory, 20...inverter circuit, 21A to 21F...inverter FET, 30...motor, 31...stator, 31U, 31V, 31W...coil, 32...rotor magnet, 40...hall element, 50...voltage divider circuit, 51A...thermistor, 51B...resistor, 60...current sensor, 60A...shunt resistor, 60B...amplifier, 71...choke coil, 72...reverse polarity prevention FET, 100...blower motor control device, 200...battery, 300...air conditioner ECU

Claims

1. A rotational position of a rotor in a motor is acquired based on a detection signal from a rotation sensor, and current supply to the motor is controlled in accordance with the rotational position. a learning unit (S33, S34) that stops energization of the motor when the rotation speed of the rotor reaches a learning rotation speed, and acquires a correction amount for correcting a positional deviation between the rotor and the rotation sensor as a learning value using an induced voltage generated in a coil of the motor and the detection signal from the rotation sensor; A storage unit (S35, S36) that stores the learning value in a non-volatile memory; and an energization control unit (S32) that corrects the position deviation using the previous learning value read from the non-volatile memory and controls energization of the motor until the rotation speed reaches the learning rotation speed, and after the rotation speed reaches the learning rotation speed and the learning value has been acquired by the learning unit, corrects the position deviation using the latest learning value acquired by the learning unit and controls energization of the motor.

2. The motor control device according to claim 1 , wherein the learning unit acquires the learning value only when the learning value has not been acquired.

3. 3. The motor control device according to claim 1, wherein the storage unit stores only the learned values ​​within a specified range in the non-volatile memory as storage targets.

4. 4. The motor control device according to claim 1, wherein the learning unit does not acquire the learned value unless the rotation speed falls below a learning rotation speed after starting the energization control.

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