JP2011188678A - Device and method of control for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a highly accurate learning of errors in detection results detected by a sensor for detecting a motor current while driving a hybrid vehicle. <P>SOLUTION: An ECU (Electronic Control Unit) is configured to execute a program including: a step (S102) of stopping a feedback control when a torque command is constant (YES in S100); a step (S104) of deciding a tentative correction value; a step (S106) of calculating a deviation Δi(n); a step (S110) of deciding the final correction value if the present deviation Δi(n) is larger than the previous deviation Δi(n-1) (YES in S108); and a step (S112) of starting the feedback control. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to control of a vehicle equipped with an AC motor, and particularly to a technique for accurately correcting a motor current detected by a sensor when the vehicle is in a traveling state.

  Conventionally, an AC motor is mounted on a vehicle such as an electric vehicle or a hybrid vehicle as a drive source or a generator. The AC motor is supplied with DC power supplied from a high-voltage battery after being converted into three-phase AC power by an inverter.

  Such a technique is disclosed in a secondary battery control device capable of quickly and easily raising the temperature of a secondary battery disclosed in 2007-028702 (Patent Document 1). The control device for the secondary battery includes a drive circuit that drives the load upon receiving power from the secondary battery, a battery temperature acquisition unit that acquires the battery temperature of the secondary battery, and the acquired battery temperature is a predetermined value. And a control circuit that controls the drive circuit to periodically vibrate the output of the load within a predetermined output range centered on the target output value when the temperature is lower than the threshold temperature.

  According to the secondary battery control device disclosed in the above-mentioned publication, the charge / discharge current of the secondary battery is reduced by intentionally vibrating the output of the load and repeating input / output of power from the secondary battery to the load. By forcibly generating, the secondary battery can be quickly and easily heated.

JP 2007-028702 A

  By the way, the measurement value using the sensor of the alternating current supplied to the AC motor includes a detection error of the sensor. Therefore, there is a problem that the AC power supplied to the AC motor cannot be controlled with high accuracy. In particular, when the vehicle is in a running state as compared with the case where the vehicle is in a stopped state, the detection error of the sensor may change due to heat generated in the AC motor. Therefore, for example, when a predetermined value is considered as a detection error, the AC power supplied to the AC motor may not be accurately controlled. In such a case, demagnetization occurs in the AC motor, and the target torque may not be generated with high accuracy.

  In the secondary battery control device disclosed in the above-mentioned publication, the AC current detection error of the AC motor is considered as a predetermined value, and the AC power supplied to the AC motor is controlled with high accuracy. Can not do it.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a vehicle control device that accurately learns a detection error of a sensor that detects a motor current when the vehicle is running. It is to provide a vehicle control method.

  A vehicle control device according to an aspect of the present invention is a vehicle control device for a vehicle on which an AC motor is mounted. The vehicle control device includes an electric current detection unit for detecting an alternating current for driving an AC motor, and an AC detected by the current detection unit using a correction value for correcting a detection error of the current detection unit. A correction unit for correcting the actual measurement value of the current, and a feedback control unit for controlling the AC motor so that the output torque of the AC motor becomes the target torque by feedback control using the actual measurement value corrected by the correction unit. And a first condition that the vehicle is in a running state and a second condition that the amount of change in the target torque is equal to or less than the first threshold value during the first determination period during execution of feedback control is satisfied A learning unit for learning the correction value by stopping the feedback control while the vehicle is running.

  Preferably, the feedback control unit includes a first conversion unit for converting the target torque into a command value of one of the d-axis current and the q-axis current, and the actual value corrected by the correction unit as the d-axis current. And a second converter for converting into one of the current values corresponding to the command value of the q-axis current. When the learning condition is satisfied, the learning unit converts the provisional value determination unit for determining the provisional value of the correction value, the command value, and the actual value corrected using the provisional value by the second conversion unit. A calculation unit for calculating the maximum value of the absolute value of the deviation from the measured current value, and a plurality of provisional values determined as correction values by the provisional value determination unit and a plurality of maximum values calculated by the calculation unit A final determination unit for determining a provisional value corresponding to the minimum value among the plurality of maximum values as a final correction value.

  More preferably, the provisional value determination unit determines the current provisional value by adding or subtracting a predetermined value to the provisional value determined last time. The final determination unit determines, as a final correction value, a provisional value corresponding to a value that is minimal with respect to the change to the provisional value among the plurality of maximum values calculated up to this time by the calculation unit.

  More preferably, the vehicle is equipped with an internal combustion engine as a power source for generating electric power using an AC motor. In addition to the learning condition, the learning unit stops the feedback control and sets the correction value when the condition that the amount of change in the rotational speed of the internal combustion engine in the first determination period is equal to or smaller than the second threshold value is satisfied. learn.

  More preferably, the learning unit does not satisfy the second condition when the second condition is not satisfied until the second determination period elapses during the feedback control, and until the vehicle travels a distance greater than or equal to a predetermined distance. In at least one of the cases, the feedback control is stopped and the correction value is learned.

  A vehicle control method according to another aspect of the present invention is a vehicle control method for a vehicle equipped with an AC motor. This vehicle control method includes a step of detecting an alternating current for driving an alternating current motor and a step of correcting an actual value of the alternating current using a correction value for correcting a detection error when detecting the alternating current. And a step of controlling the AC motor so that the output torque of the AC motor becomes a target torque by feedback control using the actual value corrected in the step of correcting the actual value, and a step that the vehicle is in a running state. When a learning condition including one condition and a second condition that the amount of change in the target torque is equal to or less than the first threshold value during the first determination period during execution of the feedback control is satisfied, feedback is performed during traveling of the vehicle. And stopping the control to learn the correction value.

It is a figure which shows schematic structure of the vehicle by which the vehicle control apparatus which concerns on this Embodiment is mounted. It is a functional block diagram for controlling an inverter using ECU which is a control device for vehicles concerning this embodiment. It is a timing chart which shows the change of the phase current of a motor in case a detection error is not included. It is a timing chart which shows change of current command value Id_com and current value Id1 when not including detection error. It is a timing chart which shows the change of the phase current of a motor in case a detection error is included. It is a timing chart which shows change of current command value Id_com and current value Id1 in case a detection error is included. It is a functional block diagram of a learning part. FIG. 6 is a diagram (part 1) illustrating a relationship between a deviation Δi and a correction value. It is a flowchart which shows the control structure of the program performed by ECU which is the vehicle control apparatus which concerns on this Embodiment. FIG. 6 is a diagram (part 2) illustrating a relationship between a deviation Δi and a correction value. It is a timing chart which shows change of deviation deltai when a torque command value increases monotonously.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  As shown in FIG. 1, a vehicle 10 includes a boost converter 12, a battery 13, inverters 14 and 16, motor generators (hereinafter referred to as MG) 18 and 20, voltage sensors 22 and 36, and a current sensor. 24, 26, drive wheels 28, engine 30, rotation sensors 32, 34, and ECU (Electronic Control Unit) 40. In the present embodiment, vehicle 10 is described as an example of a hybrid vehicle using motor generator 20 and engine 30 as drive sources, but may be an electric vehicle using only motor generator as a drive source.

  MG 18 is coupled to engine 30. The MG 18 has a function as a generator that generates an AC voltage by the power of the engine 30 and also has a function as an electric motor that starts the engine 30.

  The MG 20 has a function as an electric motor for driving the drive wheels 28 of the vehicle 10 and also has a function as a generator that generates an AC voltage by regenerative braking. Note that regenerative braking means braking with regenerative power generation when a driver operating the vehicle 10 performs a foot brake operation, and a case where the foot pedal is not operated but the accelerator pedal is turned off during traveling. Including a case where the vehicle speed is decelerated (or acceleration is stopped) while regenerative power generation is performed.

  Each of MGs 18 and 20 is a three-phase AC motor, and includes a U-phase coil, a V-phase coil, and a W-phase coil. One end of each of U-phase coil, V-phase coil, and W-phase coil of MGs 18 and 20 is commonly connected to the midpoint.

  The power split mechanism 38 is coupled to the engine 30 and the motor generators 18 and 20 and distributes power between them. For example, a planetary gear having three rotating shafts of a sun gear, a planetary carrier, and a ring gear can be used as the power split mechanism 38, and these three rotating shafts are connected to the engine 30 and the motor generators 18 and 20, respectively.

  Boost converter 12 includes a reactor L1, NPN transistors Q1, Q2, and diodes D1, D2.

  Reactor L1 has one end connected to power supply line PL1 of battery 13, and the other end connected to an intermediate point between NPN transistor Q1 and NPN transistor Q2, that is, between the emitter of NPN transistor Q1 and the collector of NPN transistor Q2. The

  NPN transistors Q1, Q2 are connected in series between power supply line PL2 and ground line SL1. NPN transistor Q1 has a collector connected to power supply line PL2, and NPN transistor Q2 has an emitter connected to ground line SL1. In addition, diodes D1 and D2 that allow current to flow from the emitter side to the collector side are arranged between the collector and emitter of the NPN transistors Q1 and Q2, respectively.

  Each of inverters 14 and 16 includes a U-phase upper and lower arm connected to each of U-phase coils of MGs 18 and 20, a V-phase upper and lower arm connected to each of V-phase coils of MGs 18 and 20, and MGs 18 and 20. W-phase upper and lower arms connected to each of the W-phase coils. The configuration of the upper and lower arms of each phase is the boost converter except that the connection destination connected to the intermediate point of NPN transistors Q1 and Q2 is one end of each phase coil instead of one end of reactor L1. Twelve NPN transistors Q1, Q2 and diodes D1, D2 have the same configuration, and detailed description thereof will not be repeated.

  Inverter 14 supplies AC power to the U-phase coil, V-phase coil, and W-phase coil of MG 18. Inverter 16 supplies AC power to the U-phase coil, V-phase coil, and W-phase coil of MG 20. Inverters 14 and 16 are connected in parallel between power supply line PL2 and ground line SL1.

  The switching elements included in each of boost converter 12 and inverters 14 and 16 are not limited to NPN transistors, but other powers such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). You may comprise with an element.

  In the present embodiment, the battery 13 is described as a secondary battery such as nickel metal hydride or lithium ion, but a large capacity capacitor or the like may be used instead of the secondary battery. The voltage sensor 36 detects a DC voltage Vb output from the battery 13 and transmits a signal indicating the detected voltage Vb to the ECU 40.

  The rotation sensor 32 detects the rotation angle θ1 and the motor rotation number MRN1 of the MG 18, and transmits a signal indicating the detected rotation angle θ1 and the motor rotation number MRN1 to the ECU 40. The rotation sensor 34 detects the rotation angle θ2 of the MG 20 and the motor rotation number MRN2, and transmits a signal indicating the detected rotation angle θ2 and motor rotation number MRN2 to the ECU 40. For example, resolvers are used as the rotation sensors 32 and 34.

  Boost converter 12 boosts the voltage supplied from battery 13 and supplies the boosted voltage to capacitor C1. More specifically, when boosting converter 12 receives signal PWC from ECU 40, boosting converter 12 boosts the voltage according to the period during which NPN transistor Q2 is turned on by signal PWC and supplies the boosted voltage to capacitor C1.

  Further, when boosting converter 12 receives signal PWC from ECU 40, boosting converter 12 steps down the voltage supplied from inverter 14 via capacitor C <b> 1 and supplies it to battery 13.

  Capacitor C <b> 1 smoothes the DC voltage output from boost converter 12, and supplies the smoothed DC voltage to inverters 14 and 16.

  The voltage sensor 22 detects the voltage VH across the capacitor C1 (that is, the input voltage of the inverters 14 and 16; the same applies hereinafter), and transmits a signal indicating the detected voltage VH to the ECU 40.

  When the DC voltage is supplied from capacitor C1, inverter 14 converts the DC voltage into an AC voltage based on signal PWMI1 received from ECU 40, and drives MG18. The ECU 40 generates the signal PWMI1 based on the torque command value TR1 that is the target torque.

  Further, when generating power using the power of engine 30, inverter 14 converts the AC voltage generated by MG 18 into a DC voltage based on signal PWMI1 received from ECU 40, and converts the converted DC voltage to capacitor C1 and The voltage is supplied to boost converter 12 through power supply line PL2 and ground line SL1.

  Similarly, when a DC voltage is supplied from capacitor C1, inverter 16 converts dc voltage to an AC voltage based on signal PWMI2 received from ECU 40, and drives MG20. ECU 40 generates signal PWMI2 based on torque command value TR2.

  Further, inverter 16 converts the AC voltage generated by MG 20 into a DC voltage based on signal PWMI2 received from ECU 40 during regenerative braking of vehicle 10, and converts the converted DC voltage to capacitor C1, power supply line PL2, and ground line. The voltage is supplied to the boost converter 12 via SL1.

  The current sensor 24 detects motor currents (hereinafter also referred to as phase currents) Iv1 and Iw1 flowing in the V-phase coil and the W-phase coil of the MG 18, and transmits signals indicating the detected motor currents Iv1 and Iw1 to the ECU 40. Current sensor 26 detects motor currents Iv2 and Iw2 flowing through the V-phase coil and W-phase coil of MG 20, and transmits signals indicating the detected motor currents Iv2 and Iw2 to ECU 40.

  In the present embodiment, current sensor 24 detects motor currents Iv1 and Iw1 flowing in the V-phase coil and W-phase coil of MG18, and U-phase coil of MG18 based on the detected motor currents Iv1 and Iw1. However, the present invention is not limited to this. For example, current sensor 24 may detect motor currents Iu1, Iv1, and Iw1 flowing through the U-phase coil, V-phase coil, and W-phase coil of MG18.

  Similarly, in the present embodiment, current sensor 26 detects motor currents Iv2, Iw2 flowing through the V-phase coil and W-phase coil of MG 20, and based on the detected motor currents Iv2, Iw2, Although the description will be made assuming that the motor current Iu2 flowing through the U-phase coil is calculated, the present invention is not particularly limited thereto. For example, current sensor 26 may detect motor currents Iu2, Iv2, and Iw2 flowing through the U-phase coil, V-phase coil, and W-phase coil of MG20.

  ECU 40 includes torque command values TR1 and TR2 based on the operation amount of the accelerator pedal of the driver, motor rotation speeds MRN1 and MRN2 from rotation sensors 32 and 34, voltages VH and Vb from voltage sensors 22 and 36, and current. Motor currents Iv1, Iw1, Iv2, and Iw2 from sensors 24 and 26 are received.

  Based on voltage VH, torque command value TR1 and motor currents Iv1, Iw1, ECU 40 generates a signal PWMI1 for performing switching control on a plurality of NPN transistors of inverter 14 when inverter 14 drives MG18. Then, the generated signal PWMI1 is transmitted to the inverter 14.

  Based on voltage VH, torque command value TR2 and motor currents Iv2 and Iw2, ECU 40 generates signal PWMI2 for executing switching control on a plurality of NPN transistors of inverter 16 when inverter 16 drives MG20. Then, the generated signal PWMI2 is transmitted to the inverter 16.

  Further, when the inverter 14 (or the inverter 16) drives the MG 18 (or MG 20), the ECU 40 detects the voltage Vb, the voltage VH, the torque command value TR1 (or the torque command value TR2), and the motor rotational speed MRN1 (or the motor 13). Based on the motor rotational speed MRN2), a signal PWC for executing switching control for the plurality of NPN transistors Q1 and Q2 of the boost converter 12 is generated, and the generated signal PWC is transmitted to the boost converter 12.

  FIG. 2 shows a functional block diagram for controlling the inverter 14 using the ECU 40. Since control of inverter 16 using ECU 40 is substantially the same as control of inverter 14 using ECU 40, detailed description thereof will not be repeated.

  The ECU 40 includes a current command value conversion unit 410, subtracters 412 and 414, PI control units 416 and 418, a two-phase / three-phase conversion unit 420, a PWM generation unit 422, a sensor value correction unit 430, 3 A phase / two-phase conversion unit 432 and a learning unit 434 are included.

  Torque command value TR1, which is a target torque, motor rotation number MRN1 of MG 18, and voltage VH are input to current command value conversion unit 410. Current command value conversion unit 410 outputs a two-phase (d-axis and q-axis) current command for outputting the torque specified by torque command value TR1 based on torque command value TR1, motor rotational speed MRN1, and voltage VH. The values Id_com and Iq_com are generated, the generated current command value Id_com is output to the subtractor 412, and the generated current command value Iq_com is output to the subtractor 414.

  The subtractor 412 receives the current command value Id_com from the current command value conversion unit 410 and the current value Id1 from the three-phase / two-phase conversion unit 432. The subtractor 412 calculates a deviation (= Id_com−Id1) between the current command value Id_com and the current value Id1, and outputs the calculated deviation to the PI control unit 416.

  The current command value Iq_com is input from the current command value conversion unit 410 and the current value Iq1 is input from the three-phase / two-phase conversion unit 432 to the subtractor 414. The subtractor 414 calculates a deviation (= Iq_com−Iq1) between the current command value Iq_com and the current value Iq1, and outputs the calculated deviation to the PI control unit 418.

  Each of PI control units 416 and 418 calculates voltage operation amounts Vd1 and Vq1 for adjusting motor current using PI gain with respect to deviations Id_com−Id1 and Iq_com−Iq1 input from subtracters 412 and 414, respectively. Then, the calculated voltage operation amounts Vd1 and Vq1 are output to the two-phase / three-phase converter 420.

  The two-phase / three-phase conversion unit 420 performs two-phase / three-phase conversion on the voltage operation amounts Vd1 and Vq1 input from the PI control units 416 and 418 using the rotation angle θ1 received from the rotation sensor 32 and the conversion formula. Then, the voltage operation amounts Vu1, Vv1, Vw1 applied to the MG 18 are calculated. The two-phase / three-phase conversion unit 420 outputs the calculated voltage operation amounts Vu1, Vv1, and Vw1 to the PWM generation unit 422.

  The PWM generation unit 422 generates a signal PWMI1 based on the voltage manipulated variables Vu1, Vv1, Vw1, and the voltage VH, and outputs the generated signal PWMI1 to the inverter 14.

  In the inverter 14, switching control is executed in accordance with the signal PWMI 1 input from the PWM generation unit 422. Thereby, motor currents Iu1, Iv1, and Iw1 flow through the U-phase coil, V-phase coil, and W-phase coil of MG18, respectively.

  Signals indicating motor currents Iv1 and Iw1 are input from the current sensor 24 to the sensor value correction unit 430. The sensor value correction unit 430 adds correction values (hereinafter also referred to as offset correction values) ΔIv1 and ΔIw1 for correcting detection errors to the motor currents Iv1 and Iw1 that are sensor values of the current sensor 24.

  Sensor value correction unit 430 outputs motor currents Iv1 + ΔIv1, Iw1 + ΔIw1 obtained by adding offset correction values ΔIv1, ΔIw1 to three-phase / two-phase conversion unit 432.

  The motor currents Iv1 + ΔIv1, Iw1 + ΔIw1 are input from the sensor value correction unit 430 to the three-phase / two-phase conversion unit 432. The three-phase / two-phase converter 432 calculates a motor current Iu1 (= − (Iv1 + ΔIv1) − (Iw1 + ΔIw1)) based on the input motor currents Iv1 + ΔIv1, Iw1 + ΔIw1.

  The three-phase / two-phase converter 432 receives the motor currents Iu1, Iv1 + ΔIv1, Iw1 + ΔIw1 flowing in the U-phase coil, V-phase coil, and W-phase coil of the MG 18 from the rotation sensor 32 and the conversion equation. Using the three-phase / two-phase conversion, current values Id1 and Iq1 flowing in the d-axis and the q-axis are calculated.

  The three-phase / two-phase conversion unit 432 outputs the calculated current value Id1 to the subtractor 412 and outputs the calculated current value Iq1 to the subtractor 414. Since three-phase / two-phase conversion and two-phase / three-phase conversion using conversion equations are well known, detailed description thereof will not be given.

  The learning unit 434 learns a correction value for correcting the detection error of the sensor value of the current sensor 24 and outputs the correction value to the sensor value correction unit 430.

  In this way, feedback control is performed so that the current values Id1, Iq1 and the current command values Id_com, Iq_com coincide with each other.

  In the vehicle 10 having such a configuration, the measured values Iv1 and Iw1 of the alternating currents flowing through the MGs 18 and 20 using the current sensors 24 and 26 include detection errors of the current sensors 24 and 26. Therefore, the AC power supplied to the MGs 18 and 20 may not be controlled with high accuracy.

  In particular, when the vehicle 10 is in a running state as compared with the case where the vehicle 10 is in a stopped state, the detection error of the sensor may change due to heat generated in the MGs 18 and 20. Therefore, the detection error of the sensor when the vehicle 10 is in a stopped state may be different from the detection error of the sensor when the vehicle 10 is in a traveling state. Therefore, for example, when the measured value of the sensor is corrected in consideration of the detection error of the sensor when the vehicle 10 is stopped, the AC power supplied to the MGs 18 and 20 may not be controlled with high accuracy. is there. As a result, demagnetization may occur due to torque fluctuations of the MGs 18 and 20.

  For example, FIG. 3 shows the time change of the actual measurement value of the current sensor 24 when no detection error is included. 3 represents the phase current of the V-phase coil, and the horizontal axis in FIG. 3 represents time. As shown by the solid line in FIG. 3, when the detection error is not included, the current sensor 24 detects the phase current of the V-phase coil without offsetting the vibration center.

  Therefore, as shown by the solid line and the broken line in FIG. 4, when the current command value Id_com (broken line in FIG. 4) is constant, the current command value Id_com and the measured value of the current sensor 24 are converted into a three-phase / two-phase conversion. The current value Id1 (solid line in FIG. 4) substantially matches. The vertical axis in FIG. 4 indicates the current value flowing through the d axis, and the horizontal axis in FIG. 4 indicates time.

  On the other hand, FIG. 5 shows the time change of the actual measurement value of the current sensor 24 when the detection error is included. The vertical axis in FIG. 5 indicates the phase current of the V-phase coil, and the horizontal axis in FIG. 5 indicates time. As shown by the solid line in FIG. 5, when a detection error is included, the current sensor 24 detects the phase current of the V-phase coil in a state where the vibration center is offset in the positive direction.

  Therefore, as indicated by the solid line and the broken line in FIG. 6, even when the current command value Id_com (broken line in FIG. 6) is constant, the current command value Id_com and the measured value of the current sensor 24 are subjected to three-phase / two-phase conversion. It does not coincide with the current value Id1 (solid line in FIG. 6), and the current value Id1 vibrates with zero as the vibration center. As a result, the AC power supplied to the MGs 18 and 20 may not be accurately controlled.

  Therefore, in the present embodiment, the ECU 40 has the first condition that the vehicle 10 is in the traveling state and the amount of change in the target torque is equal to or less than the first threshold value during the first determination period during execution of the feedback control. When the learning condition including the second condition is satisfied, the feedback control is stopped while the vehicle 10 is traveling and the detection error is learned.

  Specifically, when the learning condition is satisfied, the ECU 40 stops the feedback control while the vehicle 10 is traveling, and determines a provisional value of a correction value (hereinafter referred to as a provisional correction value) for correcting the detection error. Then, the maximum value of the absolute value of the deviation between the current command value and the current value corrected using the provisional correction value is calculated. When a plurality of provisional correction values are determined and a plurality of maximum values are calculated, the ECU 40 determines a provisional correction value corresponding to the minimum value among the plurality of maximum values as a final correction value (hereinafter referred to as a final correction value). It is determined as Cf1. The ECU 40 corrects the actual measurement values Iv1 and Iw1 detected by the current sensor 24 using the determined final correction value Cf1.

  Similarly, the ECU 40 determines a final correction value Cf2 for the detection error of the current sensor 26, and corrects the actual measurement values Iv2 and Iw2 detected by the current sensor 26 using the verified final correction value Cf2. Therefore, detailed description thereof will not be repeated.

  Further, in the present embodiment, the ECU 40 determines the current temporary correction value C (n) by adding or subtracting a predetermined value to the previously determined temporary correction value C (n−1). . The ECU 40 determines, as the final correction value Cf1, a temporary correction value corresponding to a value that is minimal with respect to a change in the temporary correction value among a plurality of maximum values calculated so far.

  FIG. 7 shows a functional block diagram of the learning unit 434. The learning unit 434 includes a torque command determination unit 102, a feedback control stop unit 104, a provisional correction value determination unit 106, a deviation calculation unit 108, and a final correction value determination unit 110.

  In the present embodiment, the case where the present invention is applied to the control of the inverter 14 will be described, but the same applies to the case where the present invention is applied to the control of the inverter 16. Therefore, detailed description thereof will not be repeated. Further, in the present embodiment, the final correction value Cf1 may be determined by learning the detection error using the d-axis current command value Id_com and the d-axis current value Id1, or the q-axis current. The final correction value Cf1 may be determined by learning the detection error using the command value Iq_com and the q-axis current value Iq1. In the following description, a case where the d-axis current command value Id_com and the d-axis current value Id1 are used will be described as an example.

  The torque command determination unit 102 determines whether or not the torque command value (TR1) is in a substantially constant state. Specifically, the torque command determination unit 102 determines that the amount of change in the torque command value (TR1) is equal to or less than a threshold value in the first condition that the vehicle 10 is in a running state and the first determination period during feedback control. It is determined whether or not a learning condition including the second condition is satisfied. The threshold value may be a predetermined value or may be a value determined according to the traveling state of the vehicle 10. When it is determined that the learning condition is satisfied, the torque command determination unit 102 determines that the torque command value is substantially constant.

  The torque command determination unit 102 may turn on the torque command determination flag when it is determined that the torque command value is in a substantially constant state. The torque command determination unit 102 may determine that the second condition is satisfied when Id_com is in a substantially constant state (when Id_com is equal to or less than a threshold value). Further, torque command determination unit 102 determines that the first condition is satisfied, for example, when the rotation speed of drive wheel 28 or the rotation speed of MG 20 is greater than zero or greater than a predetermined speed. do it.

  The feedback control stop unit 104 stops the feedback control when the torque command determination unit 102 determines that the torque command value is substantially constant. The feedback control stop unit 104 may forcibly make the deviation between Id_com and Id1 calculated by the subtractor 412 shown in FIG. 2 zero, or forcibly input the input value of the PI control unit 416. It may be zero.

  For example, the feedback control stop unit 104 forces the deviation between Id_com and Id1 to zero by setting the current command value Id_com input from the current command value conversion unit 410 to the subtractor 412 to the same value as Id1. You may make it do.

  In the present embodiment, the feedback control stop unit 104 stops the feedback control from when the torque command determination unit 102 determines that the torque command value is in a constant state until a final correction value Cf1 described later is determined. However, the end of the period for stopping the feedback control is not limited to the time until the final correction value Cf1 is determined. For example, the feedback control stop unit 104 may stop the feedback control until a predetermined time elapses after the torque command determination unit 102 determines that the torque command value is in a constant state. The feedback control may be stopped from when the torque command determination unit 102 determines that the torque command value is in a constant state until the torque command determination unit 102 determines that the torque command value is not in a constant state. Good.

  Note that the feedback control stop unit 104 may stop the feedback control when the torque command determination flag is on, for example.

  The provisional correction value determination unit 106 determines a provisional correction value when the feedback control is stopped by the feedback control stop unit 104. If the provisional correction value is determined for the first time after the feedback control is stopped, the provisional correction value determination unit 106 determines a predetermined initial value C (0) as the provisional correction value. The temporary correction value determination unit 106 determines the temporary correction value again when the final correction value Cf1 is not determined by the final correction value determination unit 110 described later. For example, when the provisional correction value is not determined for the first time after the feedback control is stopped, the provisional correction value determination unit 106 adds a predetermined value a to the provisional correction value C (n−1) determined last time or A value obtained by subtracting a predetermined value a from the previously determined provisional correction value C (n−1) is determined as the current provisional correction value C (n).

  In the present embodiment, provisional correction value determination unit 106 determines provisional correction value C (0) (= 0), for example, for the first time after feedback control is stopped. When the final correction value Cf1 is not determined by the final correction value determination unit 110 (to be described later), the temporary correction value determination unit 106 adds a predetermined value a to the previous temporary correction value C (0) and adds the current temporary value. The correction value C (1) (= a) is determined. Thereafter, the provisional correction value determination unit 106 calculates the deviation Δi (n−1) corresponding to the previous provisional correction value C (n−1), and the final correction value Cf1 is not determined. The current provisional correction value C (n) (= C (n-1) + a) is determined by adding a predetermined value a to the previous provisional correction value C (n-1).

  The deviation calculation unit 108 is the maximum value of the absolute value of the deviation between the current command value Id_com and the current value Id1 converted by the three-phase to two-phase conversion unit 432 from the measured value corrected using the determined provisional correction value. (Hereinafter referred to as deviation Δi (n)) is calculated. The deviation calculating unit 108 calculates a deviation Δi (n) between the current command value Id_com and the current value Id1 of at least a half cycle.

  The deviation calculating unit 108 calculates, for example, a plurality of maximum values of absolute values of deviation between the current command value Id_com and the current value Id1 over a predetermined period, and the average value of the calculated plurality of maximum values. May be the deviation Δi (n).

  The final correction value determination unit 110 determines the final correction value Cf1 based on the plurality of deviations Δi (0) to deviation Δi (n) calculated by the deviation calculation unit 108. The final correction value determination unit 110 determines the temporary correction value Cmin corresponding to the minimum deviation Δi_min among the plurality of deviations Δi (0) to Δi (n) calculated by the deviation calculation unit 108 as the final correction value Cf1. . The final correction value determination unit outputs the determined final correction value Cf1 to the sensor value correction unit 430 illustrated in FIG.

  FIG. 8 shows the relationship between the correction value and the deviation Δi. As shown in FIG. 8, the deviation Δi changes so as to have a minimum value Δi_min at Cmin as the correction value increases. Therefore, the final correction value determination unit 110 determines the temporary correction value Cmin corresponding to the minimum deviation Δi_min as the final correction value Cf1.

  In the present embodiment, the provisional correction value determination unit 106 calculates zero deviation as an initial value by adding a predetermined value a to determine a provisional correction value, and the deviation calculation unit 108 calculates the deviation Δi. Repeat until the final correction value is determined. At this time, as shown in FIG. 8, the deviation Δi decreases as the provisional correction value increases, and the provisional correction value C (n) larger than the provisional correction value C (n−1) (Cmin) that becomes the minimum. When is set, it starts to increase.

  Therefore, the final correction value determination unit 110 changes the deviation Δi (n) corresponding to the current temporary correction value C (n) to the deviation Δi (n−1) corresponding to the previous temporary correction value C (n−1). On the other hand, when it increases, the deviation Δi (n−1) corresponding to the previous provisional correction value is calculated as the minimum deviation Δi_min. The temporary correction value determination unit 106 determines the temporary correction value Cmin corresponding to the calculated minimum deviation Δi_min as the final correction value Cf1.

  The final correction value determination unit 110 determines the final correction value when the deviation Δi (n) corresponding to the current temporary correction value C (n) is reduced with respect to the previous temporary correction value C (n−1). do not do.

  In the present embodiment, the torque command determination unit 102, the feedback control stop unit 104, the provisional correction value determination unit 106, the deviation calculation unit 108, and the final correction value determination unit 110 are all stored in the CPU of the ECU 40. Although it is assumed that the program functions as software, which is realized by executing the program stored in the program, it may be realized by hardware. Such a program is recorded on a storage medium and mounted on the vehicle.

  Referring to FIG. 9, a control structure of a program executed by ECU 40 that is the vehicle control device according to the present embodiment will be described.

  In step (hereinafter, step is referred to as S) 100, ECU 40 determines whether or not torque command value TR1 is in a constant state. If torque command value TR1 is in a constant state (YES in S100), the process proceeds to S102. If not (NO in S100), the process returns to S100 and waits until torque command value TR1 becomes a constant state.

  In S102, ECU 40 stops feedback control. In S104, ECU 40 adds a predetermined value a to the previous provisional correction value C (n-1) to determine the current provisional correction value C (n).

  In S106, ECU 40 calculates deviation Δi (n) based on the current provisional correction value C (n) determined. Since the method of calculating deviation Δi (n) is as described above, detailed description thereof will not be repeated.

  In S108, ECU 40 determines whether or not current deviation Δi (n) is larger than previous deviation Δi (n−1). If the current deviation Δi (n) is larger than the previous deviation Δi (n−1), the process proceeds to S110. If not (NO in S108), the process proceeds to S104.

  In S110, ECU 40 determines provisional correction value C (n-1) corresponding to previous deviation Δi (n-1) as final correction value Cf1. In S112, ECU 40 starts feedback control.

  The operation of ECU 40 that is the vehicle control device according to the present embodiment based on the above-described structure and flowchart will be described.

  For example, it is assumed that the vehicle 10 is in a traveling state and the driver keeps the amount of depression of the accelerator pedal constant. In this case, since torque command value TR1 is in a constant state (YES in S100), feedback control is stopped while vehicle 10 is traveling (S102), and learning of detection error is started.

  That is, the current temporary correction value C (n) is determined (S104), and the deviation Δi (n) is calculated based on the determined current temporary correction value C (n) (S106). If the calculated current deviation Δi (n) is equal to or smaller than the previous deviation Δi (n−1) (NO in S108), a predetermined value a is set as the current temporary correction value C (n). The next provisional correction value C (n + 1) is determined by addition (S104).

  On the other hand, when calculated current deviation Δi (n) is larger than previous deviation Δi (n−1) (YES in S108), previous provisional correction value C (n−1) is the final correction value. Cf1 is determined (S110). The ECU 40 starts feedback control using the determined final correction value Cf1 (S112).

  The ECU 40 determines final correction values Cvf1 and Cwf1 for each of the motor current of the V-phase coil and the motor current of the W-phase coil by learning the detection error described above. ECU 40 subtracts final correction values Cvf1 and Cwf1 from motor currents Iv1 and Iw1 received from current sensor 24 in sensor value correction unit 430 shown in FIG. The feedback control is executed using ΔIv1 shown in FIG. 3 is −Cvf1, and ΔIw1 is −Cwf1.

  By subtracting the final correction values Cvf1 and Cwf1 from the motor currents Iv1 and Iw1, respectively, the actual measurement value of the current sensor 24 is as shown in FIG. 3 from the waveform in which the vibration center of the actual measurement value is offset as shown in FIG. The waveform is corrected to zero as the center of vibration.

  Further, the ECU 40 executes feedback control using the determined final correction values Cvf1 and Cwf1 until the torque command value becomes constant next time, and when the torque command value becomes constant (S100) YES), the final correction values Cvf1 and Cwf1 are updated (S110).

  As described above, according to the vehicle control device of the present embodiment, when the learning condition is satisfied, the feedback control is stopped when the final correction value is determined while the vehicle is running, thereby providing feedback. The final correction value can be calculated with high accuracy by eliminating the influence of the control. Therefore, for example, even when the detection error of the current sensor changes due to the vehicle traveling for a long time, the detection error of the current sensor can be corrected appropriately. Moreover, since learning is executed when the torque command value is in a constant state, it is possible to suppress deterioration in control accuracy of current control during travel of the vehicle. Therefore, it is possible to provide a vehicle control device and a vehicle control method for accurately controlling AC power supplied to an AC motor by learning detection errors when the vehicle is running.

  Further, according to the vehicle control device of the present embodiment, it becomes possible to learn the detection error of the current sensor even while the vehicle is traveling, so the learning error learning area that was executed when the motor was stopped is expanded. be able to.

  In the present embodiment, the provisional correction value determination unit 106 has been described as determining zero as the initial value C (0) of the provisional correction value, but the initial value is not particularly limited to zero. The initial value may be a value larger than a value that can be taken as a correction value, for example.

  In this case, the temporary correction value determination unit 106 subtracts a predetermined value a from the previous temporary correction value C (n−1) when the final correction value Cf1 is not determined by the final correction value determination unit 110. The current provisional correction value C (n) (C (n) -a) may be determined.

  The operation of determining the temporary correction value Cmin corresponding to the minimum deviation Δi_min of the deviation calculation unit 108 and the final correction value determination unit 110 as the final correction value Cf1 is the same as that when the initial value is set to zero. Detailed description will not be repeated.

  Alternatively, as shown in FIG. 10, the provisional correction value determination unit 106 first determines the provisional correction value Ca, and the deviation calculation unit 108 calculates the deviation Δia based on the determined provisional correction value Ca. In addition, the provisional correction value determining unit 106 determines a value obtained by adding a predetermined value a to the provisional correction value Ca as the provisional correction value Cb, and the deviation calculating unit 108 is based on the determined provisional correction value Cb. The deviation Δib may be calculated.

  In this case, in the next calculation, the provisional correction value determination unit 106 compares the two deviations Δia and Δib, and when Δia is smaller than Δib, a value obtained by subtracting a predetermined value a from the provisional correction value Ca. Is determined as the temporary correction value Cc, and the deviation calculating unit 108 calculates the deviation Δic based on the determined temporary correction value Cc.

  When the calculated deviation Δic is larger than the deviation Δia, the final correction value determining unit 110 calculates the deviation Δia as the minimum deviation Δi_min, and as shown in FIG. 10, the calculated Δic is smaller than the deviation Δia. In this case, the current provisional correction value is calculated by subtracting a predetermined value a from the previous provisional correction value until the final correction value Cf1 is determined, and corresponds to the calculated present provisional correction value. The calculation of calculating the deviation Δi may be repeated.

  Further, the provisional correction value determining unit 106 compares the two deviations Δia and Δib, and when Δib is smaller than Δia, the provisional correction value Cc is obtained by adding a value a predetermined value to the provisional correction value Cb. The deviation calculating unit 108 calculates the deviation Δic ′ based on the determined provisional correction value Cc ′.

  When the calculated deviation Δic ′ is larger than the deviation Δib, the final correction value determining unit 110 calculates the deviation Δib as the minimum deviation Δi_min, and when the calculated Δic ′ is smaller than the deviation Δib, Until the correction value Cf1 is determined, a predetermined value a is added to the previous temporary correction value to calculate the current temporary correction value, and the deviation Δi corresponding to the calculated current temporary correction value is calculated. The calculation may be repeated.

  Furthermore, in addition to the learning condition that the torque command value is in a constant state, the ECU 40 determines that the vehicle satisfies the condition that the amount of change in the rotational speed of the engine 30 is equal to or less than a threshold value during the first determination period. The feedback control may be stopped during the traveling of 10 to learn the detection error. In this way, the final correction value can be determined with higher accuracy.

  Further, the ECU 40 stops the feedback control during the traveling of the vehicle 10 when the learning condition is not satisfied until the second determination period elapses or when the learning condition is not satisfied until the vehicle travels more than a predetermined distance. Thus, the detection error may be learned. In this way, the detection error can be corrected promptly.

  Furthermore, in the present embodiment, when the torque command value is in a constant state, the feedback control is stopped and the final correction value is determined. For example, the torque command value is monotonously increased or monotonously decreased. In this case, the final correction value Cf1 may be determined by stopping the feedback control while the vehicle is traveling.

  In this case, for example, as shown in FIG. 11, the ECU 40 calculates the maximum value of the absolute value of the deviation between Id_com and the current value Id1 in one cycle as the deviation Δi. Note that the specific method for determining final correction value Cf1 is the same as the method for determining final correction value Cf1 when the torque command value is constant, and therefore detailed description thereof will not be repeated.

  Further, the ECU 40 executes the current control by changing only the feedforward term while the feedback control at the time of determining the final correction value Cf1 is stopped.

  For example, the voltage operation amount Vd1 shown in FIG. 3 in this case is calculated by the equation Vd1 = Σvdi + vd_ff. Σvdi is an integrated value of vdi (product of gain Ki and deviation Δid) until just before feedback control is stopped. vd_ff is a feedforward term. vd_ff is calculated from the equation: vd_ff = −1 × rotational speed ω × inductance Lq × current command value Iq_com.

  Further, the voltage operation amount Vq1 shown in FIG. 3 in this case is calculated by an equation of Vq1 = ΣVqi + vq_ff. ΣVqi is an integrated value of vqi (product of gain Ki and deviation Δiq) until just before feedback control is stopped. vq_ff is a feedforward term. vq_ff is calculated from the equation: vq_ff = rotational speed ω × inductance Ld × current command value Id_com + rotational speed ω × permanent magnet motor linkage flux φ.

  Even in this case, the final correction value can be calculated with high accuracy by eliminating the influence of the feedback control.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Vehicle, 12 Boost converter, 13 Battery, 14, 16 Inverter, 18, 20 MG, 22, 36 Voltage sensor, 24, 26 Current sensor, 28 Drive wheel, 30 Engine, 32, 34 Rotation sensor, 38 Power split mechanism, 40 ECU, 102 Torque command determination unit, 104 Feedback control stop unit, 106 Temporary correction value determination unit, 108 Deviation calculation unit, 110 Final correction value determination unit, 410 Current command value conversion unit, 412, 414 Subtractor, 416, 418 PI control unit, 420 2 phase / 3 phase conversion unit, 422 PWM generation unit, 430 sensor value correction unit, 432 3 phase / 2 phase conversion unit, 434 learning unit.

Claims (6)

A vehicle control device for a vehicle equipped with an AC motor,
A current detection unit for detecting an alternating current for driving the alternating current motor;
A correction unit for correcting an actual value of the alternating current detected by the current detection unit using a correction value for correcting a detection error of the current detection unit;
A feedback control unit for controlling the AC motor so that the output torque of the AC motor becomes a target torque by feedback control using the actual measurement value corrected by the correction unit;
A learning condition includes a first condition that the vehicle is in a running state and a second condition that a change amount of the target torque is equal to or less than a first threshold value in a first determination period during execution of the feedback control. And a learning unit for learning the correction value by stopping the feedback control while the vehicle is running. The feedback control unit includes:
A first converter for converting the target torque into a command value of one of a d-axis current and a q-axis current;
A second conversion unit for converting the actual value corrected by the correction unit into one of the d-axis current and the q-axis current corresponding to the command value;
The learning unit, when the learning condition is satisfied, a provisional value determination unit for determining a provisional value of the correction value;
A calculation unit for calculating a maximum value of an absolute value of a deviation between the command value and an actual value corrected using the provisional value by the second conversion unit;
When a plurality of provisional values are determined as the correction values by the provisional value determination unit and a plurality of maximum values are calculated by the calculation unit, a provisional value corresponding to the minimum value among the plurality of maximum values is finally determined. The vehicle control device according to claim 1, further comprising a final determination unit for determining as a general correction value. The provisional value determination unit determines the provisional value of this time by adding or subtracting a predetermined value to the provisional value determined last time,
The final determination unit determines, as the final correction value, a provisional value corresponding to a value that is minimal with respect to a change to the provisional value among the plurality of maximum values calculated up to this time by the calculation unit. The vehicle control device according to claim 2. The vehicle is equipped with an internal combustion engine as a power source for generating electric power using the AC motor,
In addition to the learning condition, the learning unit stops the feedback control when a condition that the amount of change in the rotational speed of the internal combustion engine in the first determination period is equal to or less than a second threshold is satisfied. The vehicle control device according to claim 1, wherein the correction value is learned.   The learning unit satisfies the second condition when the second condition is not satisfied until the second determination period elapses during the feedback control and until the vehicle travels a distance greater than or equal to a predetermined distance. 5. The vehicle control device according to claim 1, wherein the feedback control is stopped and the correction value is learned in at least one of the cases where the correction is not performed. 6. A vehicle control method for a vehicle equipped with an AC motor,
Detecting an alternating current for driving the alternating current motor;
Correcting the measured value of the alternating current using a correction value for correcting a detection error when detecting the alternating current;
Controlling the AC motor such that the output torque of the AC motor becomes a target torque by feedback control using the actual value corrected in the step of correcting the actual value;
A learning condition includes a first condition that the vehicle is in a running state and a second condition that a change amount of the target torque is equal to or less than a first threshold value in a first determination period during execution of the feedback control. A control method for a vehicle, including a step of learning the correction value by stopping the feedback control while the vehicle is running when the vehicle is established.

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