JP5966976B2 - Offset learning system and offset learning method for position detection sensor - Google Patents

Description

  The present invention relates to a position detection sensor offset learning system and an offset learning method for learning a correction value for correcting an offset of a position detection sensor that detects a rotational position of a motor.

  For example, in Patent Document 1, when a position detector such as a resolver is attached at an arbitrary angular position with respect to the magnetic pole position of a servo motor, the electrical position between the position of the origin of the position detector and the magnetic pole position of the servo motor is described. An origin adjustment method that can eliminate the need for alignment is disclosed. In this origin adjustment method, the servo motor is driven at a constant rotational speed. Then, the origin position of the position detector is set as the temporary origin position, and the position data detected by the position detector is swept. A point at which the motor current value is equal to or less than a predetermined set value is regarded as a point at which the motor current is minimized, and is set as an adjusted origin position.

JP 2005-210762 A

  In the origin adjustment method of Patent Document 1 described above, it is necessary to drive the servo motor at a constant rotational speed. However, when the servo motor is attached to the device to be driven, the rotational load may vary depending on the state and type of the device. Then, when the servo motor is driven at a constant rotational speed, the value of the current flowing through the servo motor also varies. For this reason, it is difficult to perform the origin adjustment of the position detector with high accuracy when the servo motor is actually attached to the device to be driven in the origin adjustment method described in Patent Document 1. There's a problem.

  The present invention has been made in view of the above-described points, and even when the motor is attached to the device to be driven, the correction value for correcting the offset of the position detection sensor can be accurately learned. It is an object of the present invention to provide an offset learning system and an offset learning method that can be used.

In order to achieve the above object, an offset learning system for a position detection sensor according to the present invention includes:
A motor (14);
A position detection sensor (26) attached to the motor for detecting the rotational position of the motor;
A correction value for correcting the rotational position detected by the position detection sensor, and a correction value generating means (30, S190, S280) for sequentially changing the value of the generated correction value;
Driving means (30, S140, S240) for driving the motor so as to output a constant target torque based on the corrected rotational position obtained by correcting the rotational position detected by the position detection sensor with the correction value generated by the correction value generating means. When,
Counter force generation means (30, S150, S230) for generating a force that counteracts the output torque of the motor;
Each time the correction value generation means changes the correction value, the magnitude of the force generated by the counter force generation means corresponding to the output torque of the motor is detected, and the correction to be used for correcting the rotational position based on the detection result Determining means (30, S160 to S180, S250 to S270) for determining a value.

  As described above, according to the present invention, the motor is driven so as to output a constant target torque based on the corrected rotational position obtained by correcting the rotational position detected by the position detection sensor with the correction value generated by the correction value generating means. On the other hand, a force that opposes the output torque of the motor is generated by the counter force generating means. Here, the closer the corrected rotational position is to the correct rotational position, the more the motor can output a torque close to the target constant target torque. That is, even when the motor is driven to output a constant target torque, the actual motor output torque decreases as the corrected rotational position moves away from the correct rotational position, and increases as it approaches. This actual motor output torque is detected using the magnitude of the force generated by the counter force generation means corresponding to the motor output torque. That is, in the present invention, the counter force generation means is used for measuring the output torque of the motor. Therefore, based on the detection result, a correction value to be used for correcting the rotational position detected by the rotation detection sensor can be determined. The output torque of the motor is detected based on the balance and difference with the counter force generated by the counter force generating means, regardless of the influence of the load or the like by the device to be driven substantially. be able to. Therefore, even when the motor is attached to the device to be driven, it is possible to learn a correction value for correcting the rotational position error (offset error) detected by the position detection sensor with high accuracy.

The position detection sensor offset learning method according to the present invention learns the offset of the position detection sensor (26) attached to the motor (14) and detecting the rotational position of the motor,
A correction value generation step (S190, S280) for generating a correction value for correcting the rotational position detected by the position detection sensor and sequentially changing the value of the generated correction value;
A driving step (S140, S240) for driving the motor to output a constant torque based on the corrected rotational position obtained by correcting the rotational position detected by the position detection sensor with the correction value generated in the correction value generating step;
A counter force generation step (S150, S230) for generating a force against the output torque of the motor;
Each time the correction value is changed in the correction value generation step, the magnitude of the force generated in the counter force generation step corresponding to the output torque of the motor is detected, and the rotational position is corrected based on the detection result. And a determination step (S160 to S180, S250 to S270) for determining a correction value to be used.

  By executing the processing of each step as described above, as described above, even when the motor is attached to the device to be driven, the rotational position error (offset error) detected by the position detection sensor with high accuracy. ) Can be learned.

  Note that the reference numerals in the parentheses merely show an example of a correspondence relationship with a specific configuration in an embodiment described later in order to facilitate understanding of the present invention, and limit the scope of the present invention. It is not intended.

  Further, the features of the present invention other than the features described above will be apparent from the description of embodiments and the accompanying drawings described later.

1 is a block diagram illustrating a main configuration of a hybrid vehicle according to a first embodiment. It is a block diagram which shows the structure for learning a correction value in 1st Embodiment. It is the flowchart which showed the learning process of the correction value for correct | amending the offset error of the position detection sensor assembled | attached to the 1st motor performed by ECU of 1st Embodiment. It is the block diagram which showed the main structures of the hybrid vehicle based on 2nd Embodiment. It is a block diagram which shows the structure for learning a correction value in 2nd Embodiment. It is the flowchart which showed the learning process of the correction value for correct | amending the offset error of the position detection sensor assembled | attached to the 1st motor performed by ECU of 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an example of performing offset correction of a position detection sensor that detects a rotational position of an electric motor in a hybrid vehicle having an engine and an electric motor as a travel drive source of the vehicle will be described. However, the position detection sensor offset learning system according to the present invention may be used not only for the electric motor of the hybrid vehicle but also for the offset correction of the electric motor position detection sensor used for other applications.

  Generally, when the position detection sensor can detect the magnetic pole position of the motor as an absolute value, when the position detection sensor is assembled to the motor at the factory, the actual magnetic pole position of the motor and the magnetic pole position detected by the position detection sensor The offset error is measured, and a correction value for correcting the offset error is recorded in a memory such as an EEPROM. For this reason, when the position detection sensor fails, it is necessary to replace the position detection sensor, measure the offset error again, and record a correction value for correcting the offset error in the memory.

  However, after the electric motor is mounted on the vehicle, it is difficult to replace only the position detection sensor and measure the offset error of the position detection sensor. Usually, the electric motor in which the position detection sensor is assembled is replaced. Action is taken. However, when only the position detection sensor has failed, replacement of the electric motor places a burden on the user in terms of cost and is also wasteful in terms of resource saving.

  Therefore, the offset learning system according to the present embodiment learns a correction value for accurately correcting an offset error of the position detection sensor even in a state where the electric motor is mounted on the driving target vehicle (its output shaft). It is possible to record in a memory. Hereinafter, the offset learning system according to the present embodiment will be described in detail.

  First, the configuration of a hybrid vehicle to which the offset learning system according to the present embodiment is applied will be described with reference to FIG. FIG. 1 is a block diagram showing a main configuration of a hybrid vehicle. As shown in FIG. 1, the hybrid vehicle includes an engine 10 and a motor (first motor) 14 disposed on the output shaft of the engine 10 as a travel drive source. The hybrid vehicle also includes a generator (second motor) 16 that is driven to rotate by the output of the engine 10 and generates electric power.

  A power split mechanism 12 made of, for example, a planetary gear is provided between the engine 10, the electric motor 14, and the generator 16. The power split mechanism 12 divides the power generated by the engine 10 into a force for driving wheels and a force for driving the generator 16. In general, the fuel consumption rate is improved when the engine 10 is operated at a certain high load. Therefore, the rotational speed of the generator 16 is controlled so that more power than necessary is used to drive the generator 16 while maintaining the engine 10 in a high load state. Further, the power distribution ratio by the power split mechanism 12 is also controlled so that the overall energy efficiency is optimized.

  The first inverter 18 generates an AC drive signal for driving the electric motor 14 using the electric power stored in the high voltage battery 22. Further, the first inverter 18 performs regenerative braking when the vehicle is decelerated, and converts the alternating current generated by the motor 14 into a direct current when the motor 14 functions as a generator, to the high voltage battery 22. Output. Further, the second inverter 20 converts the alternating current generated by the generator 16 into a direct current when the generator 16 is driven by the engine 10, and outputs the direct current to the high voltage battery 22. The electric power generated by the generator 16 is used to charge the high voltage battery 22 or used to drive the electric motor 14. The operations of the first inverter 18 and the second inverter 20 are controlled by an ECU 30 described later.

  Of the power generated by the engine 10, the driving force distributed as the force for driving the wheels by the power split mechanism 12 is transmitted to the left and right drive wheels via the differential gear 24. Further, the output of the electric motor 14 disposed on the output shaft of the vehicle is also transmitted to the drive wheels via the differential gear 24 and used as a force for running the vehicle.

  For example, when the vehicle starts, the energy efficiency of the engine 10 deteriorates, so the engine 10 is stopped and only the output of the electric motor 14 is transmitted to the drive wheels via the differential gear 24. Further, for example, during acceleration, the power from the engine 10 and the output of the electric motor 14 are both used as forces for driving the drive wheels in order to ensure a sufficient drive force.

  Next, in the hybrid vehicle having the above-described configuration, the correction value for correcting the offset error of the position detection sensor assembled to the motor 14 is learned in a state where the motor 14 is disposed on the output shaft of the vehicle. How to do will be described.

  FIG. 2 is a configuration diagram illustrating a configuration for learning correction values. A position detection sensor 26 that detects the magnetic pole position of the motor is assembled to the first motor 14 that is an electric motor. The position detection sensor 26 can detect the magnetic pole position of the motor as an absolute value, such as a resolver or an absolute encoder. A detection signal from the position detection sensor 26 is input to the ECU 30. For example, when the position detection sensor 26 is failed and replaced, the magnetic pole position detected by the position detection sensor 26 is considered to be offset from the actual magnetic pole position of the first motor 14. In such a case, in the present embodiment, a correction value for correcting the offset error is calculated by learning. Of course, a correction value for correcting the offset error of the position detection sensor 26 may be obtained by the learning method according to the present embodiment even at the time of assembly at the factory.

  The second motor 16 that is a generator is provided with a current sensor 28 for detecting a current flowing through the second motor 16. A detection signal from the current sensor 28 is input to the ECU 30.

  When driving the vehicle, the ECU 30 controls the power distribution of the engine 10 and the load ratio of the driving force by the engine 10 and the first motor 14. Further, the ECU 30 executes a correction value learning process for correcting an offset error of the position detection sensor 26 assembled to the first motor 14. This learning process will be described with reference to the flowchart of FIG. The process shown in the flowchart of FIG. 3 is performed by the ECU 30 when an instruction to execute the learning process is given by an operator at a factory or a dealer.

  First, in step S100, a correction value for correcting an offset error is initially set to zero. In the subsequent step S110, the detection signal output from the position detection sensor 26 is read. In step S120, the rotational position (magnetic pole position) of the motor is calculated based on the detection signal read in step S110, and the corrected rotational position corrected by the correction value is obtained.

  In step S130, the engine 10 is stopped and the engine speed is set to 0 rpm. At this time, the power split mechanism 12 is in a state where the first motor 14 and the second motor 16 are directly connected. In step S140, based on the corrected rotational position calculated in step S120, the first motor 14 outputs a constant target torque, that is, with a constant drive current, via the first inverter 18. Then, the first motor 14 is driven. Further, in step S150, the second motor 16 is moved via the second inverter 20 in a direction in which a torque opposite to the direction in which the first motor 14 acts on the power split mechanism 12 is applied to the power split mechanism 12. To drive. At this time, the rotation speed of the second motor 16 is measured from a motor rotation position calculated from a detection signal from a position detection sensor (not shown). And the 2nd motor 16 is driven so that this rotation speed may turn into target rotation speed (0 rpm).

  In the subsequent step S170, the value of the current supplied to the second motor 16 via the second inverter 20 is detected based on the detection signal from the current sensor 28. Here, when the rotation speed of the second motor 16 is the target rotation speed (0 rpm), the output torques of the first motor 14 and the second motor 16 are in balance. Since the output torque of the second motor 16 and the energization current are correlated, the current value detected by the current sensor 28 can be used as an index indicating the output torque. In this way, by using the second motor 16 as a torque meter for measuring the output torque of the first motor 14, the magnitude of the torque actually output from the first motor 14 can be measured.

  In the above-described example, the target rotational speed is set to 0 rpm. In this way, there is an advantage that learning of the offset error of the position detection sensor 26 can be executed without substantially rotating the output shaft of the vehicle. However, the target rotation speed is not necessarily 0 rpm, and may be a predetermined rotation speed in any rotation direction. This is because the magnitude of the output torque of the first motor 14 can be determined if the conditions for learning the correction value for correcting the offset error are constant.

  In step S170, it is determined whether or not the current value detected in step S160 is greater than or equal to the target value. The target value is set in advance to a level at which the target torque can be regarded as being output according to the target torque to be output from the first motor 14. If it is determined in step S170 that the current value is equal to or greater than the target value, the process proceeds to step S180, and the correction value for correcting the offset error is used to calculate the corrected rotation position in step S120. Determine the correction value. On the other hand, if it is determined in step S170 that the current value is less than the target value, the correction value is changed in step S190, and the processing from step S110 is repeated.

  In addition, in order to determine the correction value for correcting the offset error, it is possible to use a method other than those described above. For example, the energization current of the second motor 16 is detected while sequentially changing the correction value, and the offset error is corrected with the correction value when the highest current value is detected among the detected current values. It may be determined as a correction value for this. Alternatively, a current value change curve corresponding to the offset error is measured in advance and stored in the ECU 30. Then, the current value is detected a plurality of times while changing the correction value. By applying the detected current value to the change curve, an offset error that maximizes the current value is obtained. The correction value for correcting this offset error is the final correction value.

  As described above, in the present embodiment, the first motor 14 is output so as to output a constant target torque based on the corrected rotational position obtained by sequentially correcting the rotational position detected by the position detection sensor 26 with the correction value to be changed. To drive. On the other hand, a torque that counters the output torque of the first motor 14 is generated by the second motor 16.

  Here, the closer the corrected rotational position is to the correct rotational position, the more the first motor 14 can output a torque close to the target constant target torque. That is, even when the first motor 14 is driven so as to output a constant target torque, the actual motor output torque decreases as the corrected rotational position moves away from the correct rotational position, and increases as it approaches. This actual motor output torque is detected by using the second motor 16 that generates a torque corresponding to the output torque of the first motor 14. Therefore, based on the detection result, a correction value to be used for correcting the rotational position detected by the position detection sensor 26 can be determined.

  Then, the output torque of the first motor 14 is balanced with the torque generated by the second motor 16 or the magnitude of the difference regardless of the influence of the load or the like by the output shaft to be driven or other devices. The output shaft rotates at a rotation speed corresponding to Therefore, the magnitude of the output torque of the first motor 14 can be detected from the state of the second motor 16. For this reason, even when the first motor 14 is attached to the output shaft to be driven, it is possible to learn a correction value for correcting the offset error of the position detection sensor 26 with high accuracy.

(Second Embodiment)
Next, a position detection sensor offset learning system according to the second embodiment will be described. Also in this embodiment, an example in which a correction value for correcting an offset error is learned for a position detection sensor attached to an electric motor of a hybrid vehicle will be described.

  FIG. 4 is a block diagram showing a main configuration of a hybrid vehicle to which the offset learning system according to the present embodiment is applied. As shown in FIG. 4, the hybrid vehicle has an engine 10 and a motor (first motor) 14 disposed on the output shaft of the engine 10 as a travel drive source. The electric motor 14 operates by receiving power supply from the high-voltage battery 22 mounted on the vehicle, and assists the driving force of the engine 10. Further, when the vehicle decelerates, the electric motor 14 generates electric power by rotational driving from the wheel side and charges the high voltage battery 22. In such a configuration, if a clutch is provided between the engine 10 and the electric motor 14 so that the engine 10 and the electric motor 14 can be disconnected, the vehicle may be driven only by the driving force of the electric motor 14. It becomes possible.

  However, in the present embodiment, unlike the first embodiment, the second motor 16 as a generator is omitted. Therefore, in this embodiment, the engine 10 is used as the torque meter of the electric motor 14 instead of the second motor 16.

  FIG. 5 is a configuration diagram showing a configuration for learning correction values in the present embodiment. A position detection sensor 26 that detects the magnetic pole position of the motor is assembled to the first motor 14 that is an electric motor. Further, the engine 10 is assembled with a rotation sensor 32 for detecting the rotational speed of the engine. Detection signals from the position detection sensor 26 and the rotation sensor 32 are input to the ECU 30.

  A correction value learning process for correcting the offset error of the position detection sensor 26 executed by the ECU 30 in the configuration described above will be described with reference to the flowchart of FIG.

  First, in step S200, a correction value for correcting an offset error is initially set to zero. In the subsequent step S210, the detection signal output from the position detection sensor 26 is read. In step S220, the rotational position (magnetic pole position) of the motor is calculated based on the detection signal read in step S210, and the corrected rotational position corrected by the correction value is obtained.

  In step S230, the engine 10 is driven at a constant rotational speed. At this time, the engine 10 outputs a constant torque. The torque output from the engine 10 is set to be larger than the torque output from the first motor 14 in step S240 described later.

  In step S240, the first motor 14 is driven through the first inverter 18 so that the first motor 14 outputs a constant target torque based on the corrected rotational position calculated in step S220. At this time, the first motor 14 is driven so that torque in the direction opposite to the direction of torque output from the engine 10 acts on the output shaft.

  In step S250, the rotation speed of the engine 10 is detected based on the detection signal of the rotation sensor 32. As described above, the first motor 14 is driven so as to output torque in the direction opposite to that of the engine 10, so that the rotational speed of the engine 10 is changed from a constant rotational speed by the output torque of the first motor 14. descend. The amount of decrease in the rotational speed changes depending on the magnitude of the output torque of the first motor 14. That is, as the torque actually output by the first motor 14 increases, the amount of decrease in the rotational speed of the engine 10 increases.

  In step S260, it is determined whether or not the rotational speed of engine 10 has decreased to a target value or less. This target value is set in advance based on the magnitude of the decrease in the engine speed when the first motor 14 outputs the target torque. If it is determined in step S260 that the engine speed is equal to or less than the target value, the process proceeds to step S270, and the correction value for correcting the offset error is used to calculate the corrected rotation position in step S220. Determine the correction value. On the other hand, if it is determined in step S260 that the engine speed is greater than the target value, the correction value is changed in step S280, and the processing from step S210 is repeated.

  Even in this case, as in the first embodiment, even when the first motor 14 is attached to the output shaft, the correction value for correcting the offset error of the position detection sensor 26 can be learned. it can. In the second embodiment, as in the first embodiment, a method other than the above can be used as a method for determining a correction value for correcting an offset error.

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

  For example, in the first embodiment described above, the example in which the correction value for correcting the offset error of the position detection sensor 26 assembled to the first motor 14 as the electric motor is learned has been described. However, even when a position detection sensor is assembled in the second motor 16 as a generator and it is necessary to learn a correction value for correcting the offset error, the present invention corrects the offset error. A correction value can be calculated. In this case, the output torque of the second motor 16 may be measured using the first motor 14 or the engine 10 as a torque meter.

  Furthermore, even when an offset error occurs in the position detection sensors of both the first motor 14 and the second motor 16, the present invention appropriately learns correction values for correcting each offset error. be able to. That is, even if an offset error has occurred in the position detection sensor of the second motor 16, the current flowing through the second motor 16 is detected while sequentially changing the correction value for the position detection sensor 26 of the first motor 14, and these are detected. This is because the magnitude of the torque actually output by the first motor 14 can be determined by comparing the magnitudes of the two motors.

10 Engine 12 Power split mechanism 14 Electric motor (first motor)
16 Generator (second motor)
18 First inverter 20 Second inverter 22 High voltage battery 24 Differential gear 26 Position detection sensor 28 Current sensor 30 ECU

Claims (12)

A motor (14);
A position detection sensor (26) attached to the motor for detecting the rotational position of the motor;
A correction value for correcting the rotational position detected by the position detection sensor, and correction value generation means (30, S190, S280) for sequentially changing the value of the generated correction value;
Drive means (30, S140) for driving the motor to output a constant target torque based on the corrected rotational position obtained by correcting the rotational position detected by the position detection sensor with the correction value generated by the correction value generating means. , S240)
Counter force generation means (30, S150, S230) for generating a force that opposes the output torque of the motor;
Each time the correction value generation means changes the correction value, the magnitude of the force generated by the counter force generation means corresponding to the output torque of the motor is detected, and the rotational position is corrected based on the detection result. An offset learning system for a position detection sensor, comprising: determination means (30, S160 to S180, S250 to S270) for determining a correction value to be used for the position detection sensor.   The motor is provided in a driving force transmission path of a vehicle, and the counter force generation means is another motor (16) connected to the driving force transmission path via a power split mechanism. The offset learning system for a position detection sensor according to claim 1.   The another motor is driven in a direction opposite to the motor so as to have a predetermined target rotational speed, thereby generating a force that opposes the output torque of the motor. The position learning sensor offset learning system according to claim 2, wherein a magnitude of a current flowing through the another motor is detected as a magnitude of a force corresponding to an output torque of the motor.   4. The position learning sensor offset learning system according to claim 3, wherein the predetermined target rotation speed is zero. The said motor is provided in the driving force transmission path | route of a vehicle, The said opposing force generation | occurrence | production means is an engine (10) connected to the driving force transmission path | route of Claim 1 characterized by the above-mentioned. Offset learning system for position detection sensors.   The engine is driven at a constant rotational speed in a direction opposite to the motor, thereby generating a force that opposes the output torque of the motor, and the determining means is configured to perform the constant rotation based on the output torque of the motor. 6. The position learning sensor offset learning system according to claim 5, wherein a decrease amount of the engine speed from the number is detected as a magnitude of a force corresponding to an output torque of the motor. An offset learning method for a position detection sensor, which is attached to a motor (14) and learns an offset of a position detection sensor (26) that detects the rotational position of the motor,
A correction value generation step (S190, S280) for generating a correction value for correcting the rotational position detected by the position detection sensor and sequentially changing the value of the correction value to be generated;
A driving step for driving the motor to output a constant torque based on the corrected rotational position obtained by correcting the rotational position detected by the position detection sensor with the correction value generated in the correction value generating step (S140, S240). When,
A counter force generation step (S150, S230) for generating a force against the output torque of the motor;
Each time the correction value is changed in the correction value generation step, the magnitude of the force generated in the counter force generation step corresponding to the output torque of the motor is detected, and the rotation is based on the detection result. And a determination step (S160 to S180, S250 to S270) for determining a correction value to be used for position correction.   The motor is provided in a driving force transmission path of a vehicle. In the counter force generation step, the output of the motor is output by another motor (16) connected to the driving force transmission path via a power split mechanism. The position learning sensor offset learning method according to claim 7, wherein a force against the torque is generated.   The another motor is driven in a direction opposite to the motor so as to have a predetermined target rotational speed, thereby generating a force that opposes the output torque of the motor. The position detection sensor offset learning method according to claim 8, wherein the magnitude of a current flowing through the another motor is detected as a magnitude of a force corresponding to an output torque of the motor.   The position detection sensor offset learning method according to claim 9, wherein the predetermined target rotation speed is zero. The motor is provided in a driving force transmission path of a vehicle. In the counter force generation step, a force that opposes the output torque of the motor is generated by the engine (10) connected to the driving force transmission path. The position learning sensor offset learning method according to claim 7, wherein the position detection sensor offset learning method is performed.   The engine is driven at a constant rotational speed in a direction opposite to that of the motor to generate a force that opposes the output torque of the motor. In the determining step, the constant rotation by the output torque of the motor is performed. 12. The position detection sensor offset learning method according to claim 11, wherein a decrease amount of the engine speed from the number is detected as a magnitude of a force corresponding to an output torque of the motor.

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