JP2020088928A - Electronic control device - Google Patents

Abstract

To precisely control the position of a target to be driven, by detecting deterioration in the operation accuracy of a motor.SOLUTION: An electronic control device (20) controls a vehicle control system including a motor (11) that moves an output shaft, a rotation sensor (13) that detects the motor rotation angle of the motor, and position sensors (18, 19) each of which outputs a sensor value according to the absolute position of the output shaft. The electronic control device includes a motor control unit (24) that controls the motor such that the output shaft is restored to an initial position immediately before termination of the system, a first measuring unit (21) that measures, on the basis of the motor rotation angle obtained by the rotation sensor, an output-shaft position measurement value the origin of which is set at a start-up position of a system start-up time, and a second measuring unit (22) that measures, on the basis of the sensor values obtained by the position sensors, an output-shaft position measurement value the origin of which is set at the initial position.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electronic control device.

A general motor electronic control device controls a drive target to a target position while detecting a motor rotation speed and a motor rotation angle with a rotation sensor. In this case, the motor rotation angle is determined from the difference between the current position of the drive target and the target position, and the drive target is moved to the target position by rotating the motor by the motor rotation angle. The electronic control device can grasp the drive status of the motor in real time by the rotation sensor, and performs feedback control as necessary. This feedback control is generally known as motor position control, and is described in, for example, Patent Document 1.

JP, 2016-193645, A

In controlling the position of the motor, the relative rotation distance of the drive target from the origin can be calculated based on the current motor rotation angle, with the motor rotation angle at system startup as the origin. Although the relative movement distance can always be calculated from the motor rotation angle, the absolute position from the initial position which is the position reference of the drive target cannot be detected. For this reason, if the drive target is displaced after the system is terminated, or if a memory abnormality or an erroneous detection of the rotation sensor occurs during the system operation, there is a problem that the operation accuracy of the motor deteriorates.

The present invention solves the above problems, and an object of the present invention is to provide an electronic control device capable of detecting deterioration of operation accuracy of a motor and accurately controlling the position of a drive target.

An electronic control device according to an aspect of the present invention includes a motor that moves a drive target, a rotation sensor that detects a motor rotation angle of the motor, and a position sensor that outputs a sensor value according to an absolute position of the drive target. An electronic control unit for controlling a system including: a motor control unit that controls the motor so as to return the drive target to an initial position immediately before the system ends; and a system start-up based on a motor rotation angle of the rotation sensor. A first measuring unit that measures the position measurement value of the driven object with the starting position at the time as the origin, and the position measurement value of the driven object with the initial position as the origin based on the sensor value of the position sensor. And a second measurement unit.

According to the present invention, since the drive target is returned to the initial position immediately before the system is terminated, it is measured from the origin of the position measurement value of the drive target measured from the motor rotation angle and the sensor value of the position sensor at the next system startup. The origin of the position measurement value of the drive target matches. Therefore, from the deviation between the position measurement value of the drive target measured from the motor rotation angle with respect to the origin and the position measurement value of the drive target measured from the sensor value of the position sensor, the position deviation of the drive target after the system is terminated. It is also possible to detect the deterioration of the motor operation accuracy due to a memory abnormality during system operation, an erroneous detection of the rotation sensor, or the like. Further features related to the present invention will be apparent from the description of the present specification and the accompanying drawings. Further, problems, configurations and effects other than those described above will be clarified by the following description of the embodiments.

The block diagram of the vehicle control system which concerns on this embodiment. The control block diagram of the electronic control unit concerning this embodiment. The hardware block diagram of the electronic control unit which concerns on this embodiment. Explanatory drawing of the position control of the output shaft which concerns on this embodiment. Explanatory drawing of the position control of the output shaft which concerns on this embodiment. The flowchart of the monitoring process of the motor which concerns on this embodiment. 6 is a flowchart of a motor control process when the system according to the present embodiment ends. 5 is a flowchart of a motor control process at system startup according to the present embodiment. 6 is a flowchart of position correction processing at system startup according to the present embodiment. 6 is a flowchart of position correction processing during system operation according to the present embodiment.

Hereinafter, the vehicle control system 10 including the electronic control device 20 according to the present embodiment will be described. FIG. 1 is a configuration diagram of a vehicle control system 10 according to the present embodiment. In addition, in the present embodiment, a configuration in which the electronic control device 20 of the present disclosure is applied to the vehicle control system 10 will be described, but it is possible to apply the configuration to another system in which the position of a drive target is changed by rotation of the motor 11. is there. Although described in detail later, the electronic control unit 20 of the present embodiment has a function of monitoring the operating state of the motor 11 during system operation and a function of returning the drive target to the initial position when the system is activated. ..

As shown in FIG. 1, the vehicle control system 10 uses a rack-and-pinion mechanism to convert the rotation of the motor 11 into the reciprocating movement of the output shaft 17, which is a drive target. A pinion gear 15 is connected to a rotating shaft of the motor 11 via a speed reducer 14, and an output shaft 17 is fixed to the pinion gear 15. The rack gear 16 meshing with the pinion gear 15 is fixed on the base 12, and the rotation of the pinion gear 15 causes the base 12 to reciprocate, that is, the output shaft 17 to move relative to the rack gear 16. The motor 11 is provided with a rotation sensor 13 that detects a motor rotation angle. A pair of position sensors 18 and 19 for detecting the position of the output shaft 17 on the rack gear 16 are fixed on the base 12.

Further, the vehicle control system 10 is provided with an electronic control device 20 that controls driving of the motor 11 by using a three-phase current or the like. The rotation sensor 13 is connected to the electronic control unit 20, the motor rotation angle is input from the rotation sensor 13 to the electronic control unit 20 in real time, and the rotation state of the motor 11 is monitored by the electronic control unit 20. As the rotation sensor 13, for example, a resolver or an encoder is used. The electronic control unit 20 determines the motor rotation angle from the deviation between the starting position of the output shaft 17 on the rack gear 16 and the target position, and rotates the motor 11 by the motor rotation angle to move the output shaft 17 to the target position on the rack gear 16. Have moved relative to.

The electronic control unit 20 has various information such as the gear ratio of the speed reducer 14, the number of teeth of the pinion gear 15, the pitch of the rack gear 16, and the like, and measures the moving distance from the starting position of the output shaft 17 by the motor rotation angle. ing. In this case, the pinion rotation angle of the pinion gear 15 is obtained from the motor rotation angle by the following equation (1), and the movement distance from the starting position of the output shaft 17 is measured from the pinion rotation angle by the following equation (2).
Pinion rotation angle = reduction gear ratio × motor rotation angle (1)
Moving distance = (number of teeth of pinion gear x pinion rotation angle/360) x pitch of rack gear (2)

However, the moving distance of the output shaft 17 measured from the motor rotation angle is a relative moving distance from the starting position of the output shaft 17 when the system is started. If the starting position at system startup changes, the absolute position based on the initial position of the output shaft 17 cannot be recognized from the motor rotation angle. Therefore, when the system ends, the output shaft 17 is returned to the initial position serving as the position reference, and then the power is turned off. The absolute position of the output shaft 17 can be measured from the motor rotation angle by matching the starting position of the output shaft 17 when the system is started up with the initial position. As a result, it is not necessary to search for the initial position of the output shaft 17 when the system is activated, and the system startup time can be shortened.

Further, a pair of position sensors 18 and 19 fixed to the base 12 are connected to the electronic control unit 20, and the sensor values corresponding to the absolute position of the output shaft 17 are transmitted from the position sensors 18 and 19 to the electronic control unit 20. Is being output in real time. As the position sensors 18 and 19, for example, distance sensors that detect the distance from the sensor surface to the output shaft 17 as a sensor value are used. The electronic control unit 20 measures the absolute position of the output shaft 17 with the initial position as the origin, based on the distance from the sensor surface to the output shaft 17. Although it is possible to measure the absolute position of the output shaft 17 with a single position sensor, the measurement accuracy is improved by measuring the absolute position of the output shaft 17 with the position sensors 18 and 19 that are separated in the moving direction of the output shaft 17. ing.

Since the absolute position based on the initial position of the output shaft 17 can be measured using the pair of position sensors 18 and 19, instead of controlling the position of the output shaft 17 using the motor rotation angle, the position sensors 18 and 19 are used. A configuration is conceivable in which the position of the output shaft 17 is controlled by using. Position measurement using the position sensors 18 and 19 causes a resolution error and a measurement delay error due to the sampling timing with respect to the actual position of the output shaft 17 during movement. Since the position measurement using the position sensors 18 and 19 always has a measurement delay with respect to the actual position of the output shaft 17, the position control of the output shaft 17 is performed by the motor rotation angle in the transient state during the movement of the output shaft 17. Should.

However, in the position control using the motor rotation angle, if a memory abnormality such as a so-called RAM or an erroneous detection of the rotation sensor 13 occurs during system operation, the position of the output shaft 17 measured from the motor rotation angle is measured. The value (hereinafter referred to as the position measurement value) deviates from the actual position. Further, even if the system is terminated after returning the output shaft 17 to the initial position, if the output shaft 17 is moved by an unintended external force after the system is terminated, the activation position of the output shaft 17 at the time of system activation deviates from the initial position. .. The position control using the motor rotation angle can reduce the measurement delay with respect to the actual position of the output shaft 17, but may deteriorate the operation accuracy of the motor 11.

Therefore, in the position control of the output shaft 17 of the present embodiment, there is a deviation between the position measurement value of the output shaft 17 measured from the motor rotation angle and the position measurement value of the output shaft 17 measured from the sensor values of the position sensors 18 and 19. Are watching. From the difference in the position measurement values when the actual position of the output shaft 17 is measured by the two types of measuring methods, the deterioration of the operation accuracy of the motor 11 due to a defect such as a memory abnormality during system operation is detected. Further, the output shaft 17 is returned to the initial position immediately before the end of the system, and the position of the output shaft 17 is stored in the memory as the next initial position. As a result, even if the output shaft 17 is moved after the system is finished and the starting position is displaced from the initial position, the output shaft 17 can be returned to the initial position read from the memory when the system is started.

The device configuration of the electronic control device 20 will be described with reference to FIGS. 2 and 3. FIG. 2 is a control block diagram of the electronic control unit 20 according to the present embodiment. FIG. 3 is a hardware configuration diagram of the electronic control unit 20 according to the present embodiment.

As shown in FIG. 2, the electronic control device 20 monitors the operating state of the motor 11, and includes a first measuring unit 21, a second measuring unit 22, and a state monitoring unit 23. The first measuring unit 21 measures the position measurement value of the output shaft 17 (see FIG. 1) whose origin is the starting position at system startup, based on the motor rotation angle of the rotation sensor 13. The moving distance from the starting position is obtained from the motor rotation angle, and the position of the output shaft 17 on the rack gear 16 (see FIG. 1) is measured from the moving distance. The second measuring unit 22 measures the position measurement value of the output shaft 17 whose origin is the initial position based on the sensor values of the position sensors 18 and 19. The position of the output shaft 17 on the rack gear 16 is measured from the sensor value according to the absolute position of the output shaft 17.

The state monitoring unit 23 compares the position measurement value of the output shaft 17 measured by the first measurement unit 21 and the position measurement value of the output shaft 17 measured by the second measurement unit 22 during system operation. The operation accuracy of the motor 11 is monitored. When the deviation of these position measurement values is out of the allowable range for a certain period or longer, the state monitoring unit 23 determines that the motor 11 is abnormal because a memory abnormality or the like occurs during the system operation. If the deviation of the position measurement value is within the allowable range, or if the deviation of the position measurement value is out of the allowable range does not continue for a certain period of time, the status monitoring unit 23 determines that the malfunction of the system is not occurring. Is determined to be normal.

Further, the electronic control unit 20 controls the motor 11 so as to match the output shaft 17 to the initial position when the system is started, and includes a motor control unit 24, a first storage area 25, and a second storage area 26. , And a diagnosis unit 27. The motor control unit 24 controls the motor 11 so as to return the output shaft 17 to the initial position immediately before the system ends. Further, the motor control unit 24 controls the motor 11 so as to correct the deviation between the starting position and the initial position of the output shaft 17 at the time of system startup, so that the output shaft 17 moved by an unintended external force or the like after the system ends. It has returned to its original initial position.

The first storage area 25 stores the initial position measurement value of the output shaft 17 returned to the initial position when the system is terminated. Since the initial position measurement value is stored in the first storage area 25 each time the system is terminated, the secular change such as backlash can be reflected in the initial position by the latest initial position measurement value. The second storage area 26 stores the initial position measurement value of the output shaft 17 adjusted to the initial position during system assembly. The initial position measurement value of the second storage area 26 is used as a preliminary initial position measurement value when the initial position measurement value cannot be read from the first storage area 25. The second storage area 26 uses an area of the memory that is not rewritten to avoid damage to electronic information.

The diagnostic unit 27 diagnoses the storage state of the initial position measurement value in the first storage area 25 when the system is activated. For example, the diagnosis unit 27 uses an error detection function such as a checksum to diagnose the storage state of the initial position measurement value based on the damage of the initial position measurement value or the defective writing in the first storage area 25. When the diagnosis result of the diagnosis unit 27 is normal, the initial position measurement value at the time of the previous system termination is read from the first storage area 25 and used for the position correction of the output shaft 17 by the motor control unit 24. It When the diagnosis result of the diagnosis unit 27 is abnormal, the initial position measurement value at the time of system assembly is read from the second storage area 26 and used for the position correction of the output shaft 17 by the motor control unit 24.

That is, when the storage state of the initial position measurement value in the first storage area 25 is normal, the motor control unit 24 sets the start position measurement value of the output shaft 17 measured by the second measurement unit 22 at the time of system startup. The motor 11 is controlled so as to correct the deviation from the initial position measurement value stored in the first storage area 25. When the storage state of the initial position measurement value in the first storage area 25 is abnormal, the motor control unit 24 determines the start position measurement value of the output shaft 17 measured by the second measurement unit 22 during system startup and the second The motor 11 is controlled so as to correct the deviation from the initial position measurement value stored in the storage area 26 of FIG. Therefore, even if the initial position measurement value cannot be read from the first storage area 25, the motor 11 can be controlled by reading the initial position measurement value from the second storage area 26.

As shown in FIG. 3, a microcomputer 30 is mounted on the electronic control unit 20. Each unit of the electronic control unit 20 is realized by hardware such as a processor 31, a memory 32, and an integrated circuit (not shown) provided in the microcomputer 30. As the processor 31, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), or the like is used. As the memory 32, a RAM (Random Access Memory) 35, an EEPROM (Electrically Erasable Programmable Read Only Memory) 36, and a ROM (Read Only Memory) 37 are provided. The EEPROM 36 may be one outside the microcomputer 30.

The RAM 35 temporarily stores information such as a motor rotation angle during system operation. Various types of information are written in the EEPROM 36 when the system is terminated, and various types of information are read from the EEPROM 36 when the system is started. In the EEPROM 36, the initial position measurement value of the output shaft 17 measured from the sensor values of the position sensors 18 and 19 is written when the system ends. The correctness of the write data of the EEPROM 36 is checked by an error detection function such as a checksum. For example, if the power supply is lost during writing to the EEPROM 36, the checksum cannot confirm the correctness, and the electronic information is diagnosed as damaged.

Programs and the like are written in the ROM 37. Since various information is not written in the ROM 37 at system startup and system termination, electronic information is not damaged unlike the EEPROM 36. Utilizing the characteristics of the ROM 37, the initial position measurement value of the output shaft 17 adjusted to the initial position during system assembly is written. In this way, the EEPROM 36 functions as the first storage area 25, and the ROM 37 functions as the second storage area 26. The EEPROM 36 may function as the second storage area 26. In this case, the area of the EEPROM 36 to be written when the system ends is used as the first storage area 25, and the area of the EEPROM 36 that is not rewritten after the system is shipped is used as the second storage area 26.

An outline of position control of the output shaft 17 by the electronic control unit 20 will be described with reference to FIGS. 4 and 5. 4 and 5 are explanatory views of the position control of the output shaft 17 according to the present embodiment. 4 and 5, a time chart of the actual position of the output shaft 17, a time chart of the position measurement value of the output shaft 17 measured by the first measuring unit 21, and a measurement by the second measuring unit 22. The time chart of the position measurement value of the output shaft 17 is shown.

FIG. 4 shows a state where the starting position and the initial position of the output shaft 17 match. When the vehicle control system 10 is activated, the output shaft 17 is moved by the rotation of the motor 11. The rotation sensor 13 detects the motor rotation angle in accordance with the movement of the output shaft 17, and the first measurement unit 21 measures the position measurement value of the output shaft 17 according to the motor rotation angle. Further, the sensor values are output from the position sensors 18 and 19 in accordance with the movement of the output shaft 17, and the position measurement value of the output shaft 17 corresponding to the sensor values of the position sensors 18 and 19 is measured by the second measuring unit 22. To be done. The position measurement value of the output shaft 17 measured by the first and second measuring units 21 and 22 follows the change in the actual position of the output shaft 17.

The first measurement unit 21 measures the position measurement value of the output shaft 17 whose origin is the starting position, and the second measurement unit 22 measures the position measurement value of the output shaft 17 whose origin is the initial position. In FIG. 4, the initial position and the starting position always match. Since there is a measurement delay in the first and second measuring units 21 and 22, the position measurement value of the output shaft 17 is measured by the first and second measuring units 21 and 22 after the actual position of the output shaft 17. To be done. Since the output shaft 17 starts moving after the rotation of the motor 11 is transmitted to the output shaft 17, the second measuring unit 22 for measuring the position of the output shaft 17 has a larger measurement delay than the first measuring unit 21. .. Therefore, during system operation, the motor 11 is controlled using the motor rotation angle with a small measurement delay.

Immediately before the end of the system, the motor controller 24 controls the motor 11 to return the output shaft 17 to the initial position. In this case, the output shaft 17 is moved toward the same initial position as the initial start-up at the time when the system end instruction is issued from the electronic control unit 20 to the motor 11, and the power is turned off after the output shaft 17 is stopped at the initial position. Be done. As a result, the output shaft 17 can be moved from the same initial position at the next startup as at the initial startup. Here, “immediately before the system is terminated” is the time when the system termination instruction is issued before the system termination. Further, when the system ends, the output shaft 17 returns to the initial position and stops after the system ends. The period from the system termination instruction to the system termination is secured for a period sufficient to return the output shaft 17 to the initial position.

After the system ends, the position measurement value of the output shaft 17 cannot be measured by the first and second measuring units 21 and 22, and the actual position of the output shaft 17 cannot be recognized until the system is activated. In the example of FIG. 4, since the output shaft 17 is not moved by an unintended external force or the like after the system ends, after the system is started, the output shaft 17 is moved with the same initial position as the initial start as the origin. In this way, when the starting position of the output shaft 17 and the initial position match at the time of system startup, the initial position is set as the origin and the output shaft 17 is accurately position-controlled based on the motor rotation angle with less measurement delay. can do.

FIG. 5 shows a state in which the starting position of the output shaft 17 is moved from the initial position by an unintended external force or the like after the system ends. After the system is finished, the position measurement value of the output shaft 17 cannot be measured by the first and second measuring units 21 and 22 as described above. Even if the output shaft 17 is moved after the system ends, the moving distance of the output shaft 17 is not reflected in the motor rotation angle at the time of system startup. Therefore, when the system is started up, the first measuring unit 21 measures the same initial position as that at the previous start up as the initial position measurement value of the output shaft 17. In this state, the origin of the first measuring unit 21 does not reach the initial position, so that the position of the output shaft 17 cannot be controlled based on the motor rotation angle.

On the other hand, since the position sensors 18 and 19 output the sensor value according to the absolute position of the output shaft 17, even if the output shaft 17 is moved after the system is finished, it is output by the second measuring unit 22 when the system is started. A position measurement of the shaft 17 can be measured. Therefore, by using the position measurement value of the output shaft 17 measured by the second measuring unit 22, it is possible to correct the position deviation of the output shaft 17 that occurs after the system ends. In the position correction of the output shaft 17, the motor 11 is configured to return the output shaft 17 from the starting position to the initial position based on the initial position measured value of the output shaft 17 stored at the end of the system and the starting position measured value measured at the system startup. Is controlled.

In this case, the motor required to return the output shaft 17 from the starting position to the initial position based on the deviation between the measured initial position value of the output shaft 17 at the system end and the measured starting position value of the output shaft 17 at the system start-up. The rotation angle is calculated. The motor control unit 24 drives the motor 11 by a motor rotation angle corresponding to the deviation, and the starting position of the output shaft 17 is returned to the initial position. Since the position measurement value of the output shaft 17 measured by the first measuring unit 21 follows this movement of position correction, the position measurement value of the first measuring unit 21 is returned when the output shaft 17 is returned to the initial position. Is cleared to zero. Instead of clearing the position measurement value of the first measuring unit 21 to zero, the motor rotation angle from the starting position to the initial position may be held as an offset.

In this way, when the output shaft 17 is moved from the initial position to the starting position after the system ends, the output shaft 17 can be returned from the starting position to the initial position when the system is started. Therefore, the position of the output shaft 17 can be accurately controlled by using the motor rotation angle with a small measurement delay with the initial position as the origin. In addition, when data damage or the like occurs in the initial position measurement value at the end of the system, the position of the output shaft 17 is corrected using the initial position measurement value set when the system is assembled.

Further, during the operation of the system, the information about the motor rotation angle in the RAM may be damaged or the rotation sensor 13 may be erroneously detected. The erroneous detection of the rotation sensor 13 is shown by a dashed line in FIG. In the present embodiment, the deviation between the position measurement value of the output shaft 17 measured by the first measurement unit 21 and the position measurement value of the output shaft 17 measured by the second measurement unit 22 is monitored during system operation. ing. As a result, the operation accuracy of the motor 11 deteriorates due to the deviation between the position measurement value of the output shaft 17 measured from the motor rotation angle and the position measurement value of the output shaft 17 measured from the sensor values of the position sensors 18 and 19. To be detected. In this way, the deterioration of the operating accuracy of the motor 11 is monitored not only when the system is started but also when the system is operating.

The motor monitoring process will be described with reference to FIG. FIG. 6 is a flowchart of the motor monitoring process according to the present embodiment.

As shown in FIG. 6, the electronic control unit 20 measures the position measurement value of the output shaft 17 based on the motor rotation angle of the rotation sensor 13, and the output shaft 17 of the output shaft 17 based on the sensor values of the position sensors 18 and 19. The position measurement value is measured (step S01). Next, the electronic control unit 20 calculates the deviation between the position measurement value of the output shaft 17 measured from the motor rotation angle and the position measurement value of the output shaft 17 measured from the sensor values of the position sensors 18 and 19 (step S02). ). In this case, the electronic control unit 20 calculates the deviation in consideration of the delay element between the position measurement value measured from the motor rotation angle and the position measurement value measured from the sensor values of the position sensors 18 and 19.

Next, the electronic control unit 20 determines whether or not the deviation of the position measurement value is outside the first allowable range (step S03). When the deviation of the position measurement value falls within the first allowable range (NO in step S03), the electronic control unit 20 determines that the motor 11 is normal because there is no malfunction during system operation (step S04). On the other hand, when the deviation of the position measurement value is outside the first allowable range (YES in step S03), the electronic control unit 20 continues to keep the position measurement value deviation outside the first allowable range for a certain period. It is determined whether or not there is (step S05).

If the deviation of the position measurement value is out of the first permissible range and does not continue for a certain period (NO in step S05), the electronic control unit 20 determines that the motor 11 is normal because of a temporary failure during system operation. It is determined that there is (step S04). If the deviation of the position measurement value deviates from the first allowable range for a certain period of time (YES in step S05), the electronic control unit 20 determines that a malfunction such as a memory abnormality has occurred during the system operation, and the motor 11 It is determined to be abnormal (step S06). As the first allowable range, a value experimentally, empirically, or theoretically obtained from past data or the like is used.

In this way, due to the difference between the position measurement value of the output shaft 17 measured from the motor rotation angle and the position measurement value of the output shaft 17 measured from the sensor values of the position sensors 18 and 19, memory abnormality during the system operation, rotation Deterioration of motor operation accuracy due to erroneous detection of sensors is monitored.

With reference to FIG. 7, a motor control process at the time of ending the system will be described. FIG. 7 is a flowchart of the motor control process at the time of ending the system according to this embodiment.

As shown in FIG. 7, the electronic control unit 20 sets the initial position measurement value to the target value immediately before the system ends, and drives the motor 11 while measuring the position measurement value of the output shaft 17 (step S11). Next, the electronic control unit 20 determines whether or not the measured position measurement value of the output shaft 17 matches the initial position measurement value (step S12), and the position measurement value of the output shaft 17 becomes the initial position measurement value. The processes of steps S11 and S12 are repeated until they match. As a result, the output shaft 17 is returned to the initial position immediately before the system ends. The position measurement value of the output shaft 17 may be measured from the sensor values of the position sensors 18 and 19 or may be measured from the motor rotation angle.

When the output shaft 17 is returned to the initial position (YES in step S12), the electronic control unit 20 reads the sensor values of the position sensors 18 and 19 and measures the position measurement value of the output shaft 17 according to the sensor value. (Step S13). Next, the electronic control unit 20 stores the position measurement value of the output shaft 17 corresponding to the sensor values of the position sensors 18 and 19 in the first storage area 25 as the next initial position measurement value (step S14). The sensor values of the position sensors 18 and 19 may be stored in the first storage area 25 as the initial position measurement values of the output shaft 17. In this way, when the system ends, the position measurement value of the output shaft 17 returned to the initial position by the motor 11 is stored in the first storage area 25 as the next initial position measurement value.

With reference to FIG. 8, a motor control process at system startup will be described. FIG. 8 is a flowchart of the motor control process at system startup according to this embodiment. The output shaft 17 is positioned at an ideal initial position when the system is assembled, and the position measurement value of the output shaft 17 is stored in the second storage area 26 as the initial position measurement value. The second storage area 26 may store the sensor values of the position sensors 18 and 19 as initial position measurement values during system assembly.

As shown in FIG. 8, the electronic control unit 20 measures the starting position measurement value of the output shaft 17 from the sensor values of the position sensors 18 and 19 at the time of system startup (step S21). Next, the electronic control unit 20 diagnoses the storage state of the initial position measurement value in the first storage area 25 (step S22). When the storage state of the initial position measurement value in the first storage area 25 is normal (YES in step S22), the electronic control unit 20 reads the initial position measurement value at the time of the last system shutdown from the first storage area 25 ( Step S23). When the storage state of the initial position measurement value in the first storage area 25 is abnormal (NO in step S22), the electronic control unit 20 reads the initial position measurement value at the time of system assembly from the second storage area 26 (step S24). ).

Next, the electronic control unit 20 allows the deviation of the measured value of the starting position of the output shaft 17 measured at system startup from the measured value of the initial position read from the first storage area 25 or the second storage area 26 to the second allowable value. It is determined whether it is out of the range (step S25). When the deviation of the position measurement value is out of the second allowable range (YES in step S25), the electronic control unit 20 determines that the deviation between the starting position measurement value of the output shaft 17 and the initial position measurement value has occurred, and performs the position correction process. Is executed (step S26). On the other hand, when the deviation of the position measurement value falls within the second permissible range (NO in step S25), the electronic control unit 20 determines that there is no deviation between the starting position and the initial position of the output shaft 17, and performs the position correction process. Shift to normal control without executing. As the second allowable range, a value experimentally, empirically or theoretically obtained from past data or the like is used.

In this way, when the initial position measurement value at the time of the previous system termination cannot be read from the first storage area 25, the initial position measurement value at the time of system assembly can be read from the second storage area 26. Is becoming In addition, the first storage area 25 stores the position of the output shaft 17 returned to the initial position at the time of the previous system termination as the initial position measurement value, so that the position based on the initial position reflecting the secular change is set as the reference. A correction process can be performed. Further, since the second storage area 26 is not rewritten, it is possible to avoid damage to the initial position measurement value at the time of system assembly.

Further, in the motor control process at system startup, the processes of steps S22 and S24 may be omitted and the initial position measurement value stored in the first storage area 25 may be always read. Further, in the motor control process at system startup, the processes of steps S22 and S23 may be omitted and the initial position measurement value stored in the second storage area 26 may be always read.

The position correction process when the system is started up will be described with reference to FIG. 9. FIG. 9 is a flowchart of the position correction process at system startup according to this embodiment.

As shown in FIG. 9, the electronic control unit 20 uses the deviation between the measured start position value of the output shaft 17 measured at system startup and the measured initial position value read from the first storage area 25 or the second storage area 26. The target motor rotation angle is calculated (step S31). Next, the electronic control unit 20 detects the motor rotation angle by the rotation sensor 13 and drives the motor 11 so that the motor rotation angle detected by the rotation sensor 13 approaches the target rotation angle (step S32). Next, the electronic control unit 20 determines whether or not the motor rotation angle matches the target motor rotation angle (step S33), and the processes of steps S32 and S33 are performed until the motor rotation angle matches the target motor rotation angle. repeat.

When the motor rotation angle matches the target motor rotation angle (YES in step S33), the electronic control unit 20 clears the motor rotation angle to zero (step S34). This is because the motor rotation angle is relative angle information with the motor rotation angle at system startup as the origin, as described above. By clearing the motor rotation angle to zero, the electronic control unit 20 can recognize the motor rotation angle at the time of zero clear as the origin. It is also possible to hold the target motor rotation angle as an offset without performing zero clear.

In this way, even if the output shaft 17 is moved after the system is terminated and the output shaft 17 is displaced from the initial position, the initial position measurement value of the output shaft 17 at the system termination and the output shaft at the system startup are output. The output shaft 17 is moved by an amount corresponding to the deviation of the measured start position value of 17, and the output shaft 17 is returned to the initial position when the system is started. Therefore, it is possible to accurately control the position of the drive target by the motor rotation angle with the initial position as the origin after the system is activated.

In the present embodiment, the output axis position correction processing at the time of system startup has been described, but the output axis position correction processing during normal operation can also be performed. The motor control unit 24 measures the moving distance of the output shaft 17 measured from the motor rotation angle during the system operation by the second measuring unit 22 from the initial position measurement value stored in the second storage area 26. The motor 11 may be controlled so as to match the moving distance of the output shaft 17 up to the position measurement value. Hereinafter, the position correction process during the system operation will be described with reference to FIG. FIG. 10 is a flowchart of position correction processing during system operation according to this embodiment.

As shown in FIG. 10, the electronic control unit 20 measures the moving distance from the motor rotation angle during the system operation, and also measures the moving distance from the sensor values of the position sensors 18 and 19 (step S41). In this case, the moving distance of the output shaft 17 is measured from the motor rotation angle detected by the rotation sensor 13. Further, the moving distance of the output shaft 17 is measured from the initial position measurement value at the time of system assembly stored in the second storage area 26 and the position measurement value of the output shaft 17 measured by the second measuring unit 22. Next, the electronic control unit 20 calculates the deviation between the moving distance measured from the motor rotation angle and the moving distance based on the initial position at the time of system assembly (step S42).

Next, the electronic control unit 20 determines whether or not the deviation of the moving distance is outside the third allowable range (step S43). If the deviation of the movement distance is outside the third allowable range (YES in step S43), the electronic control unit (motor control unit) 20 determines that a malfunction has occurred during system operation, and the motor rotation angle corresponds to the deviation of the movement distance. Is offset (step S44). On the other hand, when the deviation of the moving distance falls within the third allowable range (NO in step S43), it is determined that the motor 11 is normal and that there is no malfunction during the system operation, and the normal processing is performed.

In this way, by comparing the moving distance based on the motor rotation angle and the moving distance from the sensor values of the position sensors 18 and 19 during the system operation, the position correction processing can be performed even during the system operation. By performing the position correction process during the system operation, the initial position can be quickly specified even when the motor rotation angle is lost during the system operation due to a momentary power failure or memory abnormality during the system operation.

As described above, in the electronic control unit 20 of the present embodiment, the output shaft 17 is returned to the initial position immediately before the system is terminated. Therefore, at the next system startup, the position measurement value of the output shaft 17 measured from the motor rotation angle The origin coincides with the origin of the position measurement value of the output shaft 17 measured from the sensor values of the position sensors 18 and 19. Therefore, from the deviation between the position measurement value of the output shaft 17 measured from the motor rotation angle based on the origin and the position measurement value of the output shaft 17 measured from the sensor values of the position sensors 18 and 19, the system operation is being performed. Deterioration of motor operation accuracy due to memory abnormality, erroneous detection of rotation sensor, etc. is detected. Even if the output shaft 17 is moved after the system is finished, the output shaft 17 is returned to the initial position when the system is started. The position can be well controlled.

In each of the above-described embodiments, the output shaft 17 of the vehicle control system 10 is illustrated as the drive target, but the drive target of the motor 11 is not particularly limited.

As described above, the electronic control unit 20 described in the present embodiment is configured to operate the motor 11 that moves the drive target (output shaft 17), the rotation sensor 13 that detects the motor rotation angle of the motor 11, and the drive target (output shaft 17). ), which is an electronic control unit 20 for controlling a system (vehicle control system 10) including position sensors 18 and 19 that output sensor values according to the absolute position of the drive target (output shaft 17). ) To a motor control unit 24 for controlling the motor 11 to return to the initial position, and the position measurement value of the drive target (output shaft 17) whose origin is the starting position at the time of system startup based on the motor rotation angle of the rotation sensor 13. And a second measuring unit 22 for measuring the position measurement value of the drive target (output shaft 17) whose initial position is the origin based on the sensor values of the position sensors 18, 19. Is equipped with.

According to this configuration, the position measurement value of the drive target (output shaft 17) measured from the motor rotation angle and the position measurement value of the drive target (output shaft 17) measured from the sensor values of the position sensors 18 and 19 From the deviation, it is possible to monitor the deterioration of the operation accuracy of the motor due to the memory abnormality during the system operation, the false detection of the rotation sensor, and the like.

The electronic control unit 20 according to the present embodiment includes a first storage area 25 for storing the initial position measurement value of the drive target (output shaft 17) returned to the initial position when the system is terminated, and the motor control unit 24 , A motor for correcting the deviation between the measured start position value of the drive target (output shaft 17) measured by the second measurement unit 22 when the system is started and the initial position measured value stored in the first storage area 25. Control 11

According to this configuration, even if the drive target (output shaft 17) is moved after the system is finished and the starting position is displaced from the initial position, the initial position measurement value at the system ending and the starting position at the system starting are set. The drive target (output shaft 17) is moved by an amount corresponding to the deviation of the measured value, and the drive target (output shaft 17) is returned to the initial position when the system is started. Therefore, it is possible to accurately control the position of the drive target (output shaft 17) with the motor rotation angle with the initial position as the origin after the system is started. By storing the position of the driven object (output shaft 17) returned to the initial position at the time of the previous system termination as the initial position measurement value, it is possible to reflect the secular change due to backlash or the like in the initial position.

The electronic control unit 20 according to the present embodiment includes a second storage area 26 that stores the initial position measurement value of the drive target (output shaft 17) adjusted to the initial position during system assembly, and the motor control unit 24 includes , A motor for correcting the deviation between the measured start position value of the drive target (output shaft 17) measured by the second measurement unit 22 when the system is started and the initial position measured value stored in the second storage area 26. Control 11

According to this configuration, even if the drive target (output shaft 17) is moved after the system is finished and the starting position is displaced from the initial position, the initial position measurement value at the system ending and the starting position at the system starting are set. The drive target (output shaft 17) is moved by an amount corresponding to the deviation of the measured value, and the drive target (output shaft 17) is returned to the initial position when the system is started. Therefore, it is possible to accurately control the position of the drive target (output shaft 17) with the motor rotation angle with the initial position as the origin after the system is started. The initial position adjusted during system assembly can be used as the initial position measurement.

In the electronic control unit 20 according to the present embodiment, a diagnostic unit 27 that diagnoses the storage state of the initial position measurement value of the first storage area 25 at the time of system startup is provided, and when the diagnostic result of the diagnostic unit 27 is normal, The motor control unit 24 shifts the start position measurement value of the drive target (output shaft 17) measured by the second measurement unit 22 at the time of system startup from the initial position measurement value stored in the first storage area 25. When the motor 11 is controlled to be corrected and the diagnosis result of the diagnosis unit 27 is abnormal, the motor control unit 24 starts the drive target (output shaft 17) measured by the second measurement unit 22 at the time of system startup. The motor 11 is controlled so as to correct the deviation between the position measurement value and the initial position measurement value stored in the second storage area 26.

According to this configuration, even if the initial position measurement value cannot be read from the first storage area 25, the motor 11 can be controlled by reading the initial position measurement value from the second storage area 26.

In the electronic control device 20 according to the present embodiment, the motor control unit 24 stores the moving distance of the drive target (output shaft 17) measured from the motor rotation angle during system operation in the second storage area 26. The motor 11 is controlled so as to match the moving distance of the drive target (output shaft 17) from the initial position measurement value to the position measurement value measured by the second measuring unit 22.

With this configuration, it is possible to quickly specify the initial position even when the motor rotation angle is lost during system operation due to a momentary power failure or memory abnormality during system operation.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It is something that can be changed. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Furthermore, it is possible to add/delete/replace other configurations with respect to a part of the configurations of the respective embodiments.

10 Vehicle control system (system)
11 Motor 13 Rotation Sensor 17 Output Shaft (Drive Target)
18 Position Sensor 19 Position Sensor 20 Electronic Control Device (Motor Control Unit)
21 1st measurement part 22 2nd measurement part 24 Motor control part 25 1st storage area 26 2nd storage area 27 Diagnostic part

Claims (5)

An electronic control device for controlling a system including a motor for moving a drive target, a rotation sensor for detecting a motor rotation angle of the motor, and a position sensor for outputting a sensor value according to an absolute position of the drive target. There
A motor control unit that controls the motor so as to return the drive target to the initial position immediately before the system ends;
A first measuring unit that measures a position measurement value of the driven object with the starting position at system startup as the origin, based on the motor rotation angle of the rotation sensor;
An electronic control device comprising: a second measurement unit that measures a position measurement value of the driven object with an initial position as an origin based on a sensor value of the position sensor. A first storage area for storing the initial position measurement value of the driven object returned to the initial position when the system ends;
The motor control unit corrects the deviation between the measured starting position of the driven object measured by the second measuring unit and the initial position measured value stored in the first storage area when the system is started. The electronic control device according to claim 1, which controls the motor. A second storage area storing the initial position measurement value of the driven object adjusted to the initial position when the system is assembled,
The motor control unit corrects the deviation between the measured start position value of the drive target measured by the second measurement unit and the initial position measurement value stored in the second storage area when the system is started. The electronic control device according to claim 2, which controls the motor. A diagnostic unit for diagnosing the storage state of the initial position measurement value of the first storage area at system startup,
When the diagnosis result of the diagnosis unit is normal, the motor control unit stores the start position measurement value of the drive target measured by the second measurement unit at system startup and the first storage area. Control the motor to correct the deviation from the initial position measurement value,
When the diagnosis result of the diagnosis unit is abnormal, the motor control unit stores the start position measurement value of the drive target measured by the second measurement unit at the time of system startup and the second storage area. The electronic control device according to claim 3, wherein the motor is controlled so as to correct the deviation from the initial position measurement value. The motor control unit measures the moving distance of the driven object measured from the motor rotation angle during system operation by the second measurement unit from the initial position measurement value stored in the second storage area. The electronic control device according to claim 4, wherein the motor is controlled so as to match a movement distance of the drive target up to a position measurement value.

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