JP7379894B2 - motor control device - Google Patents

Description

The present invention relates to a motor control device that controls driving of a motor.

If vehicle users and maintenance personnel can understand the timing of failures for each device installed in a vehicle, they will be able to replace or repair the relevant devices before the failure is confirmed, thereby preventing on-road failures. can be prevented. In order to meet such demands, techniques for detecting signs of failure in various devices mounted on a vehicle have been considered (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2011-189788

For example, when considering detecting signs of failure in a motor that functions as a drive source for a fuel pump that supplies fuel to an internal combustion engine as a device installed in a vehicle, conventional technology has the following issues. there were. That is, in the prior art, signs of failure are not detected in consideration of the operating states of the motor and fuel pump. Therefore, in the prior art, the parameters for detection vary greatly depending on the control state of the motor or the fuel pump, and there is a risk that erroneous detection may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a motor control device that can accurately detect signs of failure related to a motor to be controlled.

A motor control device according to a first aspect of the present invention controls driving of a motor, and includes a control state acquisition section (10), a parameter acquisition section (11), and a symptom determination section (13, 25). The control state acquisition unit acquires the control state of the motor. The parameter acquisition unit acquires parameters necessary for determining signs of abnormality in the motor and/or the load of the motor, among various parameters obtained when the motor is driven. The parameters acquired by the parameter acquisition unit include the power supply voltage of the motor control device, the power supply current of the motor control device, the rotation speed of the motor, the load voltage that is the voltage of the load, and the load current that is the current of the load.

As described above, such parameters may vary greatly depending on the control state of the motor. However, in the above configuration, the symptom determination section takes into account the characteristics of the control state acquired by the control state acquisition section and determines whether one or both of the motor and load is abnormal based on the parameters acquired by the parameter acquisition section. It is designed to judge symptoms. Specifically, the symptom determination unit uses data accumulated in a data accumulation unit (7) that accumulates data in which the control status acquired by the control status acquisition unit and the parameters acquired by the parameter acquisition unit are associated. Analyze regularly and determine signs based on the analysis results. Therefore, according to the above configuration, an excellent effect can be obtained in that signs of failure related to the motor can be detected with high accuracy regardless of the control state of the motor.

A diagram schematically showing the configuration of a motor control device according to the first embodiment A diagram showing the fluctuation status of various parameters for each control state regarding various symptom modes according to the first embodiment. Timing chart for explaining the control state of the motor according to the first embodiment A diagram schematically showing a specific example of processing by the control unit according to the first embodiment A diagram schematically showing a specific example of processing by the symptom determination unit according to the first embodiment Timing chart for explaining specific example 1 of sign determination according to the first embodiment Timing chart part 1 for explaining specific example 2 of sign determination according to the first embodiment Timing chart part 2 for explaining specific example 2 of sign determination according to the first embodiment Timing chart part 3 for explaining specific example 2 of sign determination according to the first embodiment FIG. 3 is a diagram for explaining specific example 3 of predictive sign determination according to the first embodiment, and is a diagram schematically showing a waveform of an induced voltage. FIG. 3 is a diagram for explaining specific example 3 of the sign determination according to the first embodiment, and is a diagram showing the slope of the induced voltage in a normal state and in a deterioration state. A diagram schematically showing the configuration of a motor control device according to a second embodiment Timing chart for explaining the first application example of symptom determination according to the second embodiment Timing chart for explaining the second application example of symptom determination according to the second embodiment Timing chart for explaining the third application example of symptom determination according to the second embodiment

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. Note that in each embodiment, substantially the same configurations are denoted by the same reference numerals, and description thereof will be omitted.
(First embodiment)
The first embodiment will be described below with reference to FIGS. 1 to 11.

As shown in FIG. 1, a motor control device 1 according to the present embodiment is mounted on a vehicle, and controls the drive of a motor 2 that is also mounted on the vehicle. The motor 2 functions as a drive source for a fuel pump 3 that supplies fuel to the internal combustion engine, and is, for example, a three-phase brushless motor. The electronic control device 4 is also installed in the vehicle, and determines target values such as the fuel flow rate and fuel pressure required for the internal combustion engine based on the amount of depression of the vehicle's accelerator pedal, the speed of the vehicle, etc. Calculate. Note that in this specification, the electronic control unit may be referred to as an ECU.

The ECU 4 achieves operation in an optimal engine state by integrally controlling the motor control device 1 and various actuators such as injectors based on the calculation results of such target values. The motor control device 1 communicates with the ECU 4 and controls the drive of the motor 2 based on commands given from the ECU 4. The motor control device 1 includes a drive circuit 5, a control section 6, a data storage section 7, a determination section 8, and the like. The motor control device 1 operates by receiving power supply voltage +B applied from the outside via terminals P1 and P2.

The drive circuit 5 is configured to include, for example, a three-phase inverter circuit, and based on the control signal Sa given from the control unit 6, a three-phase drive signal for driving the motor 2, specifically a U-phase, Generate V-phase and W-phase drive signals. The three-phase drive signals generated by the drive circuit 5 are applied to each terminal of the motor 2 via terminals P3, P4, and P5, respectively, thereby driving the motor 2. The drive circuit 5 has a function of detecting the current flowing through the motor 2, that is, the load current. The drive circuit 5 outputs a detection signal Sb representing the detected value of the load current to the control section 6.

The control section 6 includes a drive control section 9, a control state acquisition section 10, a parameter acquisition section 11, and a data transmission section 12. In this case, the drive control unit 9 drives the motor 2 without a sensor. Therefore, the drive control unit 9 acquires the induced voltages induced in the coils of each phase of the motor 2, and detects the rotational position, rotational speed, etc. of the rotor of the motor 2 based on the induced voltages. Note that in this specification, the rotational speed may be referred to as the number of rotations. The drive control section 9 generates a control signal Sa and outputs it to the drive circuit 5 based on the command signal Sc given from the ECU 4, the various detected values described above, and the like.

The control state acquisition section 10 acquires the control state of the motor 2 based on the control signal Sa generated by the drive control section 9 and the like. The control states of the motor 2 mainly include a stopped state, an accelerated state, a constant speed state (steady state), a decelerated state, and the like. In this specification, when the control state of the motor 2 is in a stopped state, it is referred to as "stopped", when it is in an accelerated state, it is referred to as "accelerated", and when it is in a constant speed state (steady state), it is referred to as "low speed" (steady state). A state of deceleration is sometimes referred to as a time of deceleration.

The parameter acquisition unit 11 acquires, among various parameters obtained when the motor 2 is driven, those necessary for determining a sign of abnormality in one or both of the motor 2 and the fuel pump 3 that is a load of the motor 2. . The parameters acquired by the parameter acquisition unit 11 include, for example, power supply voltage, power supply current, fuel pump rotation speed, motor 2 rotation speed, load voltage (applied voltage), load current, reflux time, induced voltage, acceleration time, and Examples include deceleration time. The parameter acquisition unit 11 acquires each of the above parameters based on various data and signals exchanged within the control unit 6, the various detected values described above, various detected values provided from an external sensor (not shown), etc. do.

The data transmitter 12 associates the data representing the control state acquired by the control state acquirer 10 with the data representing the parameters acquired by the parameter acquirer 11, that is, associates the control state and the parameter. The data Da is transmitted to the data storage section 7. The data Da is, for example, data representing the load current during acceleration, data representing the load current during steady state, data representing the applied voltage during acceleration, and data representing the applied voltage during steady state. The data storage unit 7 stores data Da given from the control unit 6.

The determination unit 8 includes a symptom determination unit 13 and an abnormality determination unit 14. The symptom determination unit 13 periodically analyzes the data accumulated in the data storage unit 7, and determines a symptom of an abnormality in one or both of the motor 2 and the fuel pump 3 based on the analysis results. That is, the symptom determination section 13 determines the above-described symptom of the abnormality based on the parameters acquired by the parameter acquisition section 11, taking into consideration the characteristics of the control state acquired by the control state acquisition section 10.

The "signs of abnormality" referred to herein include not only those associated with deterioration of the motor 2 or the fuel pump 3, but also those associated with changes in the characteristics of the motor 2 or the fuel pump 3. Note that in this specification, a sign of an abnormality may be referred to as a sign. In this case, the symptom determination unit 13 is configured to individually set a determination threshold value for each control state according to its characteristics. Then, the symptom determining unit 13 determines a sign by comparing the determination threshold value corresponding to the control state acquired by the control state acquiring unit 10 and the parameter acquired by the parameter acquiring unit 11.

In addition, when determining a sign of an abnormality in which the difference between the determination threshold value and the parameter increases in a specific control state compared to other control states, the symptom determination unit 13 determines whether the control state of the motor 2 is in the specific control state. A sign can be determined based on the parameters acquired by the parameter acquisition unit 11 at a certain time. The sign determination unit 13 executes a sign notification process for notifying the user of the vehicle of the result of such a sign determination. The predictive warning process can be performed by the motor control device 1 alone, or can be performed by the motor control device 1 and the ECU 4 in cooperation.

The abnormality determination unit 14 determines whether the motor 2 is abnormal. Examples of abnormalities in the motor 2 include overvoltage, overcurrent, short circuits in wiring, terminals, etc., motor lock, and abnormal rotation speed (high rotation, low rotation). The abnormality determination unit 14 determines these abnormalities based on the various detected values described above. When some kind of abnormality is detected as a result of the abnormality determination, the abnormality determination section 14 notifies the control section 6 of the abnormality by outputting a detection signal Sd representing that fact. When the drive control section 9 of the control section 6 receives the detection signal Sd, it generates and outputs a control signal Sa for safely stopping the motor 2.

That is, in the present embodiment, the drive control section 9 has a function as a restriction processing section that executes a process for imposing restrictions on the drive of the motor 2 based on the determination result by the abnormality determination section 14. Note that the process to limit the drive of the motor 2 is not limited to the process of stopping the drive of the motor 2, but may also be a process of suppressing the drive (rotation speed, etc.) of the motor 2, or a process to limit the drive of the motor 2. It is also possible to perform processing such as not starting the program. Through such operations of the abnormality determination section 14 and the drive control section 9, a protection function for protecting the motor control device 1 and the motor 2 is realized. In this case, the protective functions include protection from the various abnormalities described above, ie, overvoltage protection, overcurrent protection, short circuit protection, motor lock protection, high rotation protection, low rotation protection, and the like.

There are various signs as mentioned above. A typical example of these predictive modes is as shown in FIG. 2, for example. That is, the predictive mode is roughly divided into those related to the fuel pump 3 and those related to the motor 2. Predictive modes related to the fuel pump 3 include "pump chamber foreign matter" where foreign matter enters the pump chamber, "impeller swelling/warping" where the impeller swells or warps, "pump chamber wear" where the pump chamber wears out, and vapor lock. Examples include "vapor lock," which occurs.

Pump chamber foreign matter is divided into "pump chamber foreign matter (one shot)" and "pump chamber foreign matter (accumulation)" depending on the size of the foreign matter that has entered. Further, vapor locks are classified into "vapor locks (low flow rate)" and "vapor locks (high flow rate)" depending on the level of flow rate. On the other hand, the predictive modes related to motor 2 include ``magnetic swelling'' where the magnet swells, ``core corrosion'' where the core corrodes, ``magnetic corrosion'' where the magnet corrodes, ``bearing corrosion'' where the bearing corrodes, and bearing wear. Examples include "bearing wear → bearing lock," where the bearing locks.

For each of these predictive modes, which parameters fluctuate and how, what kind of control conditions do these fluctuations appear under, and what kind of control conditions do the fluctuations become noticeable in? , etc. are as shown in FIG. In addition, in FIG. 2, the data serving as the detection mechanism corresponds to the various parameters described above, and the breakdown thereof includes motor parameters and control data. In this case, the motor parameters represent actual values and the control data represent output or detected values. In addition, in the control state column, a circle mark means that parameter fluctuations appear during that control state, and a double circle mark means that parameter fluctuations appear significantly during that control state. are doing.

For example, in the case of "impeller swelling/warping", the rotational speed decreases, load torque, power supply current, load voltage, load current, and reflux time increase, causing a delay in acceleration time and shortening deceleration time. The above-mentioned fluctuations in "impeller swelling/warpage" appear not only during steady state but also during acceleration and deceleration. In the case of "magnetic corrosion," the rotational speed and induced voltage decrease, load torque, power supply current, load voltage, load current, and reflux time increase, causing a delay in acceleration time and shortening deceleration time. The above-mentioned fluctuations in "magnetic corrosion" appear not only during steady state but also during acceleration and deceleration.

In the case of "pump chamber wear", the rotational speed increases, the load torque, power supply current, load voltage, load current and reflux time decrease, the acceleration time is shortened, and the deceleration time is delayed. The above fluctuations in "pump chamber wear" are noticeable during acceleration, steady state, and deceleration. In the case of "vapor lock", the rotational speed increases, load torque, power supply current, load voltage, load current and reflux time decrease, acceleration time is shortened, and deceleration time is delayed. The above fluctuations in "vapor lock" appear prominently during acceleration, steady state, and deceleration.

As shown in Figure 2, for example, there are various predictive modes in which the load current increases, but it is important to consider the fluctuation status of other parameters, the data change time, and in which control state the fluctuation appears prominently. If you take this into account, you can identify the predictive mode. Furthermore, as shown in FIG. 2, there are only three predictive modes in which fluctuations in induced voltage occur: "magnet swelling," "core corrosion," and "magnet corrosion," all of which are related to motor 2. . Therefore, when a fluctuation occurs in the induced voltage, it can be reliably determined that it is a symptom mode related to the motor 2. In this way, it is possible to roughly determine which predictive mode the mode is based on the fluctuation status of each parameter and in which control state the fluctuation appears conspicuously.

Next, the operation of the above configuration will be explained with reference to FIGS. 3 to 11.
[1] Control state of motor 2 As shown in FIG. 3, the drive control unit 9 controls the drive of the motor 2 at the time when the power to the motor control device 1 is turned on from off, that is, at the time t1 when the power is turned on. start (start). At time t1, the target value of the rotation speed of the motor 2 is set to a desired value, and accordingly, the load current, the actual rotation speed of the motor 2, and the applied voltage start to increase. These values continue to increase during the period from time t1 to time t2. The period from time t1 to time t2 corresponds to an acceleration state (at the time of acceleration).

When the actual rotation speed of the motor 2 reaches the target value at time t2, the load current, rotation speed, and applied voltage are maintained at constant values for a period from then until time t3. The period from time t2 to time t3 corresponds to a constant speed state (low speed). Thereafter, at time t3, the target value of the rotation speed of the motor 2 is set to zero, and accordingly, the load current, the actual rotation speed of the motor 2, and the applied voltage begin to decrease.

These values continue to decrease during the period from time t3 to time t4. The period from time t3 to time t4 corresponds to a deceleration state (during deceleration). When the actual rotation speed of the motor 2 becomes zero at time t4, the load current, the rotation speed, and the applied voltage are maintained at zero thereafter. The period after such time t4 corresponds to a stopped state (at the time of stopping).

[2] Processing by the control unit 6 The flow of processing executed by the control unit 6 is as shown in FIG. 4, for example. Note that the control unit 6 is configured to repeatedly execute such processing at a predetermined timing. As shown in FIG. 4, in step S110, the control state of the motor 2 is determined. In step S120, various parameters are acquired. In step S130, data Da in which the control state determined in step S110 and the parameter acquired in step S120 are associated is generated and output.

[3] Processing by the symptom determining unit 13 The flow of processing executed by the symptom determining unit 13 is as shown in FIG. 5, for example. Note that the symptom determination unit 13 is configured to repeatedly execute such processing at predetermined timing. As shown in FIG. 5, in step S210, the data stored in the data storage section 7 is analyzed.

In step S220, a determination threshold is set based on the analysis result in step S210. Specifically, in step S220, a determination threshold value is individually set for each parameter according to its characteristics for each control state. In step S230, a sign is determined for each parameter by comparing it with the determination threshold set in step S220. In step S240, the result of the sign determination is announced (notified) to the outside.

[4] Specific example 1 of predictive sign determination
Specific example 1 is a predictive mode in which an increase in load current, an increase in applied voltage, and a delay in acceleration time occur, that is, "pump chamber foreign matter (accumulation),""impellerswelling/warping,""magnetcorrosion," and "bearing corrosion." ” etc. As shown in Fig. 6, when the motor 2 and fuel pump 3 are deteriorated due to foreign objects, warping, etc., the load current tends to increase during acceleration compared to normal times when such deterioration does not occur. There is. Furthermore, when the engine is deteriorated, the acceleration time, which is the time required for the rotational speed to reach a desired value due to acceleration, is delayed compared to when the engine is normal, and the applied voltage during normal operation is increased. Note that in FIGS. 6 to 9, parameters (load current, rotation speed, and applied voltage) during deterioration are shown by dashed-dotted lines, and parameters during normal conditions are shown by solid lines.

However, even when the motor 2 is deteriorated, once the motor 2 starts rotating smoothly, foreign objects are removed and warpage is removed. In this case, even during deterioration, the load current in steady state may not be significantly different from that in steady state, and it may become difficult to determine the sign based on the load current. Further, even when the motor 2 is deteriorated, the voltage applied to the motor 2 during acceleration is not significantly different from that during normal operation. Therefore, in specific example 1, with respect to the load current, a sign determination is performed using only the data during acceleration, and with respect to the applied voltage, a sign determination is performed using only the data during steady state.

For example, the value of the load current detected when the system including the motor control device 1 is started for the first time is used as a criterion for determining an increase in the load current. This is because such a value is considered to be a value similar to a value in a normal state where no deterioration or the like occurs. A determination threshold is set based on such a value, and a sign determination is performed based on whether the value of the load current during acceleration exceeds the determination threshold. Note that the same applies to the criteria used when determining an increase in the applied voltage. The value of the load current and the value of the applied voltage may change depending on the environment such as the type of fuel. In this embodiment, in order to prevent erroneous determinations caused by such changes, as described above, the sign determination is performed based on a relative criterion.

[5] Specific example 2 of predictive sign determination
Specific example 2 corresponds to a symptom mode in which a decrease in load current, a decrease in applied voltage, and a shortening of acceleration time occur, such as "vapor lock" and "pump chamber wear." As shown in FIG. 7 and the like, when the motor 2 and the fuel pump 3 are idling, when the motor 2 and the fuel pump 3 are idling, the load current tends to decrease compared to the normal state when such deterioration does not occur. Note that during deterioration, the load current during acceleration tends to decrease compared to when it is normal, but during acceleration (startup), as shown in Figure 8, the idling state shifts to a state in which the idling is eliminated. There is a possibility that this may occur, and it is difficult to judge the sign based on the drop in load current during acceleration.

The reason why the idling state shifts to the state in which the idling is eliminated during acceleration is as follows. That is, when the piping or tank connected to the fuel pump 3 is empty, the fuel pump 3 and the motor 2 operate in the same manner as when they are idling at the time of startup, that is, at the time of acceleration. Therefore, during acceleration, the load becomes light until the inside of the pipe is filled with liquid fuel, and as a result, the load current and applied voltage exhibit lower values than in normal times. Thereafter, as fuel is supplied and filled inside the piping, etc., the load becomes heavier, and as a result, the load current and applied voltage come to show the same values as in normal times. For this reason, during acceleration, there is a possibility that the idling state, more precisely, a state similar to the idling state, shifts to a state in which the idling is eliminated.

As described above, in the second specific example, the sign determination is performed using only steady state data regarding the load current and applied voltage. For example, as shown in FIG. 7, in a case where the idling state continues to occur from the beginning, the load current and applied voltage at the time of deterioration show lower values than during normal times during acceleration and steady state, and Acceleration time is shortened compared to normal. Therefore, in such a case, the predictive mode can be correctly determined based on the load current, applied voltage, etc. during steady state.

In addition, as shown in Figure 8, in the case where a slipping state (or similar state) occurs initially, but the slipping state disappears during acceleration, the load current and applied voltage at the time of deterioration are Although it sometimes shows a lower value than normal, during normal times it shows the same value as normal. Therefore, even in such a case, the predictive mode can be correctly determined based on the load current, applied voltage, etc. during steady state.

In addition, as shown in Figure 9, in the case where no idling occurs at the beginning but idling occurs in the middle of steady state, the load current and applied voltage at the time of deterioration change from the time of acceleration to the middle of steady state. shows the same value as during normal conditions, but from the middle of steady conditions it shows lower values compared to normal times. Therefore, even in such a case, the predictive mode can be correctly determined based on the load current, applied voltage, etc. during steady state.

[5] Specific example 3 of predictive sign determination
Specific example 3 corresponds to a symptom mode in which a drop in induced voltage occurs, ie, "core corrosion", "magnet corrosion", etc., and will be explained with reference to FIGS. 10 and 11. Note that FIG. 10 shows an example of the waveform of the induced voltage when the three-phase motor 2 is energized at 120 degrees. Further, in FIG. 10, the waveform during normal operation is shown by a solid line, and the waveform at a portion different from that during normal operation during deterioration is shown by a broken line.

As shown in FIG. 10, during deterioration where core corrosion, magnet corrosion, etc. have occurred, there are locations where the slope (rate of change) of the induced voltage is smaller than in normal times when such deterioration does not occur. Therefore, as shown in FIG. 11, the slope of the induced voltage during deterioration shows a smaller value than when normal. Therefore, in the third specific example, the predictive sign determination is performed based on the slope of the induced voltage.

According to this embodiment described above, the following effects can be obtained.
The motor control device 1 of the present embodiment includes a control state acquisition unit 10 that acquires the control state of the motor 2, and a control state acquisition unit 10 for determining the deterioration of the motor 2 and the fuel pump 3 among various parameters obtained when the motor 2 is driven. It includes a parameter acquisition unit 11 that acquires necessary information, and a symptom determination unit 13. As described above, various parameters may vary greatly depending on the control state of the motor 2. Therefore, in the present embodiment, the symptom determination unit 13 considers the characteristics of the control state acquired by the control state acquisition unit 10 and determines whether the motor 2 and the fuel pump 3 It is designed to determine signs of abnormality in one or both of the two. Therefore, according to this embodiment, regardless of the control state of the motor 2, an excellent effect can be obtained in that signs of failure related to the motor 2 can be detected with high accuracy.

The symptom determination unit 13 sets a determination threshold value for each control state individually according to its characteristics, and sets the determination threshold value corresponding to the control state acquired by the control state acquisition unit 10 and the determination threshold value acquired by the parameter acquisition unit 11. Symptoms are determined by comparing the parameters. As described above, variations in various parameters may vary depending on the control state of the motor 2. Therefore, if the judgment threshold is set individually for each control state and signs are judged as described above, it becomes possible to appropriately capture the fluctuations in parameters for each control state, and as a result, the accuracy of sign judgment becomes This has the effect of improving.

When determining a symptom in which the difference between the determination threshold value and the parameter increases in a specific control state with respect to other control states, the symptom determination unit 13 determines whether the parameter is Symptoms are determined based on the parameters acquired by the acquisition unit 11. For example, in specific example 1, a sign of an abnormality is determined in which the load current during acceleration tends to increase compared to normal times. That is, in specific example 1, the time of acceleration corresponds to a specific control state, and the determination target is a sign of an abnormality in which the difference between the determination threshold value and the load current increases during acceleration compared to other control states. In specific example 1, the symptoms are determined based on the load current during acceleration.

Further, in the first specific example, a sign of an abnormality is determined in which the applied voltage in a steady state tends to increase compared to a normal state. That is, in specific example 1, the steady state corresponds to a specific control state, and the determination target is a sign of an abnormality in which the difference between the determination threshold value and the applied voltage increases in the steady state with respect to other control states. In specific example 1, symptoms are determined based on the applied voltage during steady state. In this way, when a sign of an abnormality occurs, the difference between the parameter and the judgment threshold increases, making it less likely that false judgments will occur, and as a result, the accuracy of predictive sign judgment will be further improved. It will be done.

For example, in Specific Example 2, a sign of an abnormality is determined in which the load current and applied voltage during steady state tend to decrease compared to normal times. In other words, in specific example 2, the steady state corresponds to a specific control state, and the determination target is a sign of an abnormality in which the difference between the judgment threshold and the load current and applied voltage increases in the steady state with respect to other control states. There is. In specific example 2, symptoms are determined based on the load current and applied voltage during steady state. In this way, when a sign of an abnormality occurs, the difference between the parameter and the judgment threshold increases, making it less likely that false judgments will occur, and as a result, the accuracy of predictive sign judgment will be further improved. It will be done.

The motor control device 1 of this embodiment includes an abnormality determining section 14 that determines whether the motor 2 is abnormal. The drive control unit 9 included in the motor control device 1 functions as a stop processing unit that executes processing for stopping the drive of the motor 2 based on the determination result by the abnormality determination unit 14. According to such a configuration, when an abnormality occurs in the motor 2 and, by extension, in the fuel pump 3, the drive of the motor 2 can be safely stopped, and as a result, the various protection functions described above are realized. can do.

(Second embodiment)
The second embodiment will be described below with reference to FIGS. 12 to 15.
As shown in FIG. 12, the motor control device 21 of the present embodiment differs from the motor control device 1 of the first embodiment in that it includes a control section 22 instead of the control section 6, and a control section 22 is provided instead of the determination section 8. The difference is that a determination section 23 is provided. The control unit 22 includes a mode switching unit 24 in addition to the configuration included in the control unit 6.

The mode switching unit 24 performs switching between a normal mode and a determination mode, which are two modes related to control of driving of the motor 2 by the drive control unit 9. The normal mode is a mode in which the drive control unit 9 controls the drive of the motor 2 according to the command signal Sc, which is a control command given from the external ECU 2. The determination mode is a mode in which the drive control unit 9 controls the drive of the motor 2 so that at least one of the various parameters acquired by the parameter acquisition unit 11 has a value different from the value in the normal mode. . Note that examples of parameters that are set to values different from those in the normal mode include rotational speed, load current, and applied voltage.

The mode switching unit 24 can be configured to switch to the determination mode based on a switching signal given from the outside, such as a switching command transmitted from the ECU 2, for example. Furthermore, the mode switching unit 24 can be configured to switch to the determination mode at a predetermined switching timing. The above-mentioned switching timing may be any timing that makes it easy to determine the symptoms, and may be, for example, any time after power is turned on to the motor control device 21, after the state of the vehicle has stabilized, and at any time during normal operation.

The determining unit 23 differs from the determining unit 8 in that it includes a symptom determining unit 25 instead of the symptom determining unit 13. The symptom determining section 25 has the same basic function as the symptom determining section 13. However, the symptom determination section 25 is designed to perform symptom determination during a period in which the mode switching section 24 switches to the determination mode.

Next, a specific application of symptom determination using the above configuration will be described.
[1] First Application Example As shown in FIG. 13, in the first application example, switching to the determination mode is performed at time ta in the middle of the steady state. Note that in FIGS. 13 and 14, parameters (load current and applied voltage) at the time of deterioration are shown by dotted lines, and parameters at normal times are shown by solid lines. In this case, when switching to the determination mode, the target value of the rotation speed is set to a value higher than the steady value, and accordingly, the load current, the actual rotation speed of the motor 2, and the applied voltage start to increase.

Thereafter, when the actual rotation speed of the motor 2 reaches a target value higher than the steady value, that state is maintained for a predetermined period. Then, at time tb when the predetermined period has elapsed, the target value of the rotation speed of the motor 2 is reset to the steady value. The symptom determination unit 25 determines the symptom based on various parameters obtained during the period Ta between the time ta and the time tb when the determination mode is thus set. In this manner, in the first application example, the rotational speed is forcibly increased in the steady state of the motor 2, and signs of deterioration or the like are detected at points where the amount of change is high.

[2] Second Application Example As shown in FIG. 14, in the second application example, like the first application example, switching to the determination mode is performed at time ta in the middle of the steady state. In this case, when switching to the determination mode, the target value of the rotation speed is set to a value lower than the steady value, and accordingly, the load current, the actual rotation speed of the motor 2, and the applied voltage start to decrease.

Thereafter, when the actual rotation speed of the motor 2 reaches a target value lower than the steady value, that state is maintained for a predetermined period. Then, at time tb when the predetermined period has elapsed, the target value of the rotation speed of the motor 2 is reset to the steady value. The symptom determination unit 25 determines the symptom based on various parameters obtained during the period Ta between the time ta and the time tb when the determination mode is thus set. In this manner, in the second application example, the rotational speed is forcibly reduced in the steady state of the motor 2, and signs of deterioration or the like are detected at points where the amount of change is high.

[3] Third Application Example As shown in FIG. 15, in the third application example, the switching to the determination mode is performed at a time tc before the time t1 when driving of the motor 2 is started, that is, before starting. It has become. Note that it is also possible to switch to the determination mode after the time t4 when the drive of the motor 2 is stopped, that is, at the time of transition to stop. In this case, when the mode is switched to the determination mode, the target value of the rotation speed is set to a value lower than the steady value. Note that in this case, the target value of the rotation speed may be set to a value higher than the steady value.

Along with this, the load current, the actual rotational speed of the motor 2, and the applied voltage begin to decrease. Thereafter, when the actual rotation speed of the motor 2 reaches a target value lower than the steady value, that state is maintained for a predetermined period. Then, at time point td when the predetermined period has elapsed, the target value of the rotation speed of the motor 2 is set to zero. The symptom determination unit 25 determines the symptom based on various parameters obtained during the period Tb between the time tc and the time td when the determination mode is thus set. In this way, in the third application example, a predetermined operation is executed at an arbitrary timing before the motor 2 starts or after it stops, and signs of deterioration or the like are detected.

As explained above, this embodiment also provides the same effects as the first embodiment. Further, in the present embodiment, after the mode switching unit 24 switches to a determination mode in which the driving of the motor 2 is controlled so that at least one of the parameters has a value different from the value in the normal mode, the symptom determining unit Symptom determination based on 25 is performed. Therefore, according to the present embodiment, as explained in the first application example and the second application example, for example, the rotation speed is forcibly increased or decreased, and signs of deterioration etc. are detected at a point where the amount of change is high. As a result, the accuracy of symptom determination can be improved.

When increasing the number of rotations as in the first application example, the greater the amount of increase, the higher the accuracy of symptom determination, but the amount of increase in number of rotations should only be increased within the limits of the specifications of the device, etc. I can't. On the other hand, when lowering the rotation speed as in the second application example, the rotation speed can be reduced by a large amount without being subject to such restrictions, so depending on the operating conditions of the motor 2, etc. The accuracy of symptom determination is higher in the second application example than in the application example. As described above, since the first application example and the second application example each have their own merits, the motor control device 21 can be used by switching between these two application examples depending on the operating conditions of the motor 2, etc. It is better to make it .

Note that if the rotation speed is forcibly increased or decreased during normal driving of the motor 2, the characteristics may be affected. Furthermore, there may be cases in which it is difficult to forcibly increase or decrease the rotational speed during normal driving of the motor 2. According to the third application example of the present embodiment, even in such a case, the symptom can be determined by switching to the determination mode at any timing before starting or stopping the motor 2. The accuracy of judgment can be improved.

In addition, in the first application example and the second application example of the present embodiment, after the motor control device 21 is powered on, after the state of the vehicle is stabilized, and in the middle of the steady state, the time ta is used as the timing for switching to the determination mode. There is. Note that whether the vehicle condition has stabilized can be determined from the muffler, oil temperature, etc. In this way, since the condition of the vehicle is stable and the rotational speed of the motor 2 is stable, variations in the judgment of symptoms are less likely to occur, and as a result, the possibility of erroneous judgments is kept low. Judgment accuracy can be improved.

(Other embodiments)
Note that the present invention is not limited to the embodiments described above and illustrated in the drawings, and can be modified, combined, or expanded as desired without departing from the spirit thereof.
The numerical values shown in each of the above embodiments are merely examples, and the present invention is not limited thereto.
The present invention is applicable not only to the motor control devices 1 and 21 that control the drive of the motor 2 functioning as a drive source of the fuel pump 3, but also to motor control devices in general that control the drive of various motors.

The symptom determination units 13 and 25 may also consider at least one piece of environmental information related to the motor 2 to determine the symptom. Various types of environmental information include air temperature, fuel temperature, fuel pressure, engine speed, engine injection amount, fuel type, fuel amount, engine status (idling, F/C, etc.). In addition, examples of the determination taking environmental information into consideration include changing the determination threshold according to the environmental information. In this way, it becomes possible to perform symptom determination with higher accuracy by assuming the load acting on the motor 2 and the fuel pump 3, changes, etc.

Although the present disclosure has been described based on examples, it is understood that the present disclosure is not limited to the examples or structures. The present disclosure also includes various modifications and equivalent modifications. In addition, various combinations and configurations, as well as other combinations and configurations that include only one, more, or fewer elements, are within the scope and scope of the present disclosure.

DESCRIPTION OF SYMBOLS 1, 21... Motor control device, 2... Motor, 3... Fuel pump, 9... Drive control part, 10... Control state acquisition part, 11... Parameter acquisition part, 13, 25... Symptom determination part, 14... Abnormality determination part, 24...Mode switching section.

Claims (9)

A motor control device that controls driving of a motor,
a control state acquisition unit (10) that acquires a control state of the motor;
a parameter acquisition unit (11) that acquires, among various parameters obtained when driving the motor, those necessary for determining a sign of abnormality in one or both of the motor and the load of the motor;
A sign for determining a sign of an abnormality in one or both of the motor and the load based on the parameters acquired by the parameter acquisition unit, taking into consideration the characteristics of the control state acquired by the control status acquisition unit. A determination unit (13, 25);
Equipped with
The parameters acquired by the parameter acquisition unit include the power supply voltage of the motor control device, the power supply current of the motor control device, the rotation speed of the motor, the load voltage that is the voltage of the load, and the load that is the current of the load. Contains current ,
The symptom determination section stores data accumulated in a data accumulation section (7) that accumulates data in which the control state acquired by the control state acquisition section and the parameter acquired by the parameter acquisition section are associated. A motor control device that periodically analyzes and determines the symptoms based on the analysis results . The symptom determination unit includes:
A determination threshold is individually set for each control state according to its characteristics,
The motor control device according to claim 1, wherein the symptom is determined by comparing the determination threshold corresponding to the control state acquired by the control state acquisition unit and the parameter acquired by the parameter acquisition unit. . The symptom determination unit includes:
When determining the sign that the difference between the determination threshold value and the parameter increases in a specific control state with respect to other control states, when the control state of the motor is the specific control state, The motor control device according to claim 2, wherein the symptom is determined based on the parameter acquired by the parameter acquisition unit. moreover,
an abnormality determining unit (14) that determines whether the motor is abnormal;
a restriction processing unit (9) that executes a process for imposing a restriction on driving of the motor based on a determination result by the abnormality determination unit;
The motor control device according to any one of claims 1 to 3, comprising: Furthermore, a normal mode in which the drive of the motor is controlled according to a control command given from the outside, and a determination mode in which the drive of the motor is controlled so that at least one of the parameters has a value different from the value in the normal mode. and a mode switching unit (24) for switching between the
The motor control device according to any one of claims 1 to 4, wherein the symptom determining section (25) determines the symptom during a period in which the mode switching section switches to the determination mode. The motor control device according to claim 5, wherein the mode switching section switches to the determination mode based on a switching signal given from the outside. The motor control device according to claim 5, wherein the mode switching unit switches to the determination mode at a predetermined switching timing. The motor control device according to any one of claims 1 to 7, wherein the symptom determining section determines the symptom in consideration of at least one piece of information out of various environmental information related to the motor. The motor control device according to any one of claims 1 to 8, wherein the motor functions as a drive source for a fuel pump that supplies fuel to an internal combustion engine.

Images