JP3784741B2 - Motor device that outputs device abnormality signal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor device that detects a device abnormality and outputs a device abnormality signal when the device abnormality occurs.
[0002]
[Prior art]
In the electric power steering device, an assist torque is applied to the steering device by a motor. Since the assist torque is applied, the steering force that a person needs to apply for steering is reduced. In order to make the steering feeling felt by humans natural, it is required to accurately adjust the motor torque to the intended torque.
In order to accurately adjust the motor torque, a motor in which the current value applied to the motor is proportional to the motor torque is used, and a motor drive circuit in which the motor is connected to a power source and a switch element is often used. This motor drive circuit is used in combination with a motor controller. The motor controller performs feedback control of the switch element by comparing a current value (motor current value) flowing through the motor drive circuit with a command value of the motor current. That is, if the motor current value is smaller than the motor current command value, the on-period of the switch element is lengthened to increase the motor current value. If the motor current value is larger than the motor current command value, the ON period of the switch element is shortened to decrease the motor current value. The motor current value is subjected to PMW control or duty ratio control by a switch element, and is adjusted to increase or decrease so as to coincide with the motor current command value. As a result, the motor torque is adjusted to the intended torque.
[0003]
Unfortunately, a motor device that uses a motor may become abnormal. If abnormal, the motor torque is not adjusted to the intended one. Therefore, there is a need for a technique for monitoring the occurrence of an abnormality in an apparatus using a motor and outputting an apparatus abnormality signal when the apparatus abnormality occurs.
[0004]
In order to monitor whether or not an abnormality has occurred in the motor device, it is necessary to monitor a physical quantity indicating the state of the motor device such as a current value, voltage value, rotation angle, and torque of the motor. If the motor current value, voltage value, or torque deviates greatly from the intended one, it is abnormal. It is abnormal even if the rotation angle of the motor deviates greatly from the intended rotation angle. The occurrence of an abnormal phenomenon can be monitored by detecting and comparing the physical quantity.
[0005]
By monitoring a physical quantity indicating the state of the motor device, it is possible to instantaneously determine whether the motor device is normal or abnormal. However, when using a motor controller that performs feedback control of the duty ratio of the switch element by comparing the measured motor current value and the motor current command value, the device is normal due to the inertia of the motor and the feedback tracking delay. Even so, the detected physical quantity may become abnormal. If the judgment criterion for instantaneous abnormality is relaxed so as not to erroneously determine that this is an apparatus abnormality, the apparatus abnormality is no longer detected as an abnormality.
Therefore, a technique for determining whether or not an abnormality has occurred in a motor device based on whether or not an instantaneous abnormality signal continues for a certain time or more has become widespread. The abnormal state of the physical quantity detected when the device is normal is mainly due to the tracking delay within the allowable range, and it is resolved in a short time. It is possible to monitor that an abnormality has occurred in the device.
[0006]
In the prior art, in order to realize the above, an instantaneous abnormal signal generator that detects a physical quantity indicating the state of the motor device to determine an instantaneous abnormal state and generates an instantaneous abnormal signal during the abnormal state; When a momentary abnormal signal is input during timing, the timing device starts timing, the instantaneous abnormality signal counter that accumulates the input time of the instantaneous abnormality signal, and the device abnormality signal when the cumulative number of instantaneous abnormality signal counters reaches a predetermined number. Means for outputting. When the cumulative number of instantaneous abnormality signal counters reaches a predetermined number, it is determined that the motor device is abnormal. If the cumulative number of instantaneous abnormality signal counters when the time counted by the timing device reaches a predetermined time is less than the predetermined number, the cumulative number of instantaneous abnormal signal counters is cleared to zero.
If the motor device is normal, even if an instantaneous abnormality signal is output continuously due to a delay in tracking, etc., the continuous time is short, and the instantaneous abnormality signal counter when the time measured by the timing device reaches a predetermined time The cumulative number should be less than the predetermined number.
[0007]
FIG. 4 illustrates an example of a change in the cumulative number of abnormal signal counters according to the prior art. 4 (a) and 4 (b), timing A indicates the timing at which an instantaneous abnormality signal is input while the timing device is not counting. When an instantaneous abnormality signal is input at timing A, the cumulative number of instantaneous abnormality signal counters starts to increase. There are two types of methods for counting the duration of instantaneous abnormal signals. FIG. 4 illustrates the case where the instantaneous abnormal signal continues to take the abnormal signal continuously while the instantaneous abnormal state is determined. In this case, the level of the instantaneous abnormal signal is determined at a predetermined short time interval. The number of times that abnormal signals are continuously determined is accumulated. Conversely, when the instantaneous abnormality signal generator outputs normal or abnormal determination results at short time intervals, the number of times that the instantaneous abnormality signal generator continuously outputs instantaneous abnormality signals is accumulated. The cumulative number of instantaneous abnormality signal counters increases after timing A regardless of which method is used. Z1 in FIG. 4 is a predetermined time compared with the time measuring device, and the instantaneous abnormality signal counter continues to accumulate during the predetermined time. There may be a period during which the instantaneous abnormality signal is not temporarily input during the predetermined time Z1. In this case, the cumulative number of instantaneous abnormality signal counters is maintained and is not cleared to zero. Z3 in FIG. 4 indicates a predetermined number to be compared with the cumulative number of instantaneous abnormality signal counters. Assume that a device abnormality has occurred when the cumulative number of instantaneous abnormal signal counters reaches a predetermined number Z3. In FIG. 4A, it is determined that the apparatus is abnormal at timing G, and in FIG. 4B, it is determined that the apparatus is abnormal at timing H. If the motor device is normal, even if instantaneous abnormal signals often occur due to follow-up delay or the like, the cumulative number of instantaneous abnormal signal counters does not reach the predetermined number Z3 within the predetermined time Z1, At the end of the predetermined time Z1, the cumulative number of instantaneous abnormality signal counters is cleared to zero.
[0008]
[Problems to be solved by the invention]
According to the study by the present inventors, it has been found that according to the above technique, even when the apparatus is not abnormal, it is determined that the apparatus is abnormal. Even if the motor apparatus is normal, the instantaneous abnormality signal illustrated in FIG. 4B may be input. If the apparatus abnormality occurs at the timing H, the apparatus abnormality occurs although the apparatus abnormality does not occur. It has been understood that.
An object of the present invention is to prevent as much as possible misjudgment seen in the prior art.
[0009]
Means for Solving the Problem, Action, and Effect The motor device of the present invention is a motor device that is less likely to erroneously generate a device abnormality signal, a motor controller that controls driving of the motor, a power source, and a switch A motor drive circuit that drives the motor based on a command from the motor controller, and a physical quantity that indicates the state of the motor device, such as the motor current value, voltage value, rotation angle, and torque, is detected. And a device for generating an instantaneous abnormality signal by determining an instantaneous abnormal state and a device abnormality signal generating device for inputting an instantaneous abnormality signal and generating a device abnormality signal when the device is abnormal. The apparatus abnormality signal generator includes a first timing device that starts timing when an instantaneous abnormality signal is input during non-timekeeping, and an instantaneous abnormality signal that accumulates the input time of the instantaneous abnormality signal input during timing of the first timing device. counter and a second timing device for measuring the instantaneous abnormal signal between time to the instantaneous abnormal signal input from the stop of the next instantaneous abnormal signal is input, counting time measured by the first timing device is first 1 If the cumulative number of instantaneous abnormal signal counters does not reach the predetermined number when the predetermined time is reached, the cumulative number of instantaneous abnormal signal counters is cleared to zero and the time measured and the time between the instantaneous abnormal signals are cleared to zero. means for stopping the apparatus and timing of the second timing device, the inter-timed instantaneous abnormal signal time second timing device is cleared to zero the cumulative number of instantaneous abnormal signal counter becomes a second predetermined time And means for stopping the counting of the first timing device and a second timing device to zero clear the measured time and the instantaneous abnormal signal between time also, apparatus abnormality signal when a cumulative number of instantaneous abnormal signal counter reaches a predetermined number Is provided.
[0010]
In the apparatus, by the second timing device is inputted instantaneous abnormal signal for measuring the time from the stop until you enter the next instantaneous abnormal signal. If the next instantaneous abnormality signal is not input even after the second predetermined time has elapsed, the cumulative number of instantaneous abnormality signal counters is cleared to zero.
By adding the above-described abnormality determination procedure through the research of the present inventors, it is possible to significantly reduce the erroneous determination that occurred in the prior art, that is, the erroneous determination that determines that the motor device is abnormal even if the motor device is normal. Was confirmed. For example, the transition of the instantaneous abnormality signal in FIG. 4A is seen when the apparatus is abnormal, whereas the transition of the instantaneous abnormality signal in FIG. 4B is seen even when the apparatus is normal. It is necessary that the apparatus is abnormal for (a) and not abnormal for (b). In the prior art, both (a) and (b) cause an apparatus abnormality. According to the present invention, when the second timing device keeps time and a predetermined condition is satisfied, the device abnormality signal is output in (a) and not output in (b) in order to clear the cumulative number of instantaneous abnormality signal counters to zero.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
(Mode 1) When the time counted by the first time measuring device has passed a predetermined time, the cumulative number of instantaneous abnormality signal counters is cleared to zero.
(Mode 2) The motor is a motor that applies assist torque to the steering device, and prohibits application of assist torque when the motor device is abnormal.
[0012]
【Example】
An embodiment embodying the present invention will be described with reference to FIGS. FIG. 1 shows a motor device of the embodiment and a device configuration for detecting a device abnormality of the motor device, FIG. 2 shows a processing procedure, and FIG. 3 is a diagram for explaining a processing process or a device abnormality signal output process. .
The motor device of this embodiment includes a motor drive circuit, a motor controller, an instantaneous abnormality signal generator, and a device abnormality signal generator. In the motor drive circuit, a DC power source, a switch element, and a motor are connected, and the duty ratio is adjusted by PWM control of the switch element. The motor current value, that is, the motor torque is increased or decreased by the duty ratio of the switch element. In order to measure the motor current value flowing through the motor drive circuit, an ammeter is added to the motor drive circuit. The duty ratio of the switch element is adjusted by the motor controller. The motor controller inputs a motor current command value and an actual motor current value measured by an ammeter. If the motor current command value is larger than the actual motor current value, the motor controller increases the duty ratio to increase the actual motor current value. If the motor current command value is smaller than the actual motor current value, the duty ratio is shortened to decrease the actual motor current value. The motor controller matches the actual motor current value with the motor current command value by feedback control of the duty ratio.
[0013]
The instantaneous abnormality signal generator is equipped with a device that detects a physical quantity representing the state of the motor device, in this case, the current value, voltage value, rotation angle, torque, etc. of the motor. These detection devices are repeated at short intervals. Detect physical quantities. The physical quantity repeatedly detected at short time intervals is compared with the normal value at that time, and the normality / abnormality of the motor device at each moment is determined. For example, the motor rotation angle command value is compared with the actual motor rotation angle, and if the two deviate by a certain width or more, it is assumed that the motor device is abnormal at that moment. The motor has inertia, moves the load, and a follow-up delay occurs even if the motor device is normal. Even if the motor device is normal, if a follow-up delay occurs, the instantaneous state is abnormal. The instantaneous abnormality signal stores the determination result at the previous moment until the physical quantity is detected again after a short time and the normal abnormality at the next moment is determined. An example of the instantaneous abnormality signal is shown at reference numeral 10 in FIG. Even during one pulse, for example, a pulse that becomes abnormal at time A and becomes normal at time B, instantaneous abnormality determination is repeatedly performed at short time intervals, and each time the determination result is continuous from time A to time B. This is an example of abnormalities.
[0014]
The instantaneous abnormality signal is input to the apparatus abnormality signal generator. The apparatus abnormality signal generator is an apparatus that inputs an instantaneous abnormality signal and outputs an apparatus abnormality signal when the apparatus is abnormal, and includes a first timing device, a second timing device, an instantaneous abnormality signal counter, a zero clear unit, a device abnormality signal output unit, It has.
The first timing device starts timing when an instantaneous abnormality signal is input during non-timekeeping. In the case of FIG. 1, since the instantaneous abnormality signal becomes abnormal at time A, time measurement is started. The time measured is C1. The second timing device measures the time between the instantaneous abnormal signals after the instantaneous abnormal signal is input until the next instantaneous abnormal signal is input. In the case of FIG. 1, since the instantaneous abnormality signal becomes normal at time B, time measurement is started, and time measurement is continued until time C at which the instantaneous abnormality signal is input next. The time measured is C2. The instantaneous abnormality signal counter accumulates the input time of the instantaneous abnormality signal input during the time counting of the first time measuring device. The input time of the instantaneous abnormality signal is equal to the time when the instantaneous abnormality signal is abnormal. In the case of FIG. 1, the cumulative number of instantaneous abnormality signal counters increases in proportion to the elapsed time from time A to B, and is maintained at a constant value from time B to C. Let C3 be the cumulative number of instantaneous abnormality signal counters. The zero clear means clears the cumulative number C3 of the instantaneous abnormality signal counter to zero when the time C2 between the instantaneous abnormality signals measured by the second timing device becomes equal to or longer than the second predetermined time Z2. The means for outputting the device abnormality signal outputs the device abnormality signal when the cumulative number C3 of the instantaneous abnormality signal counter reaches the predetermined number Z3.
[0015]
FIG. 2 shows a processing procedure executed by the apparatus abnormality signal generator. This process is repeatedly executed at short intervals during operation of the motor device.
In step S2, it is determined whether or not the first timing device is timing. During non-time measurement, the process proceeds to step S4. In step S4, it is determined whether the instantaneous abnormality signal at that time is normal or abnormal. If it is normal, the current process is terminated. If the first time measuring device is not timed and the instantaneous abnormal signal is normal, the substantial processing is not executed, and an event to be described later is awaited.
[0016]
If the instantaneous abnormality signal is abnormally reversed while the first timing device is not counting, the first timing device starts timing (steps S4 and S6). Further, the cumulative number C3 of the instantaneous abnormality signal counter is incremented by 1 (step S8, which results in 1), and the time keeping time C2 of the second time measuring device is cleared to zero (step S10).
If the first time measuring device is measuring time, the time measurement is continued (step S12). Thereafter, it is determined whether the instantaneous abnormality signal is normal or abnormal. If there is an abnormality, the cumulative number C3 of the instantaneous abnormality signal counter is incremented by 1 (step S8), and the time keeping time C2 of the second time measuring device is cleared to zero (step S10). If the instantaneous abnormality signal becomes abnormal, the time keeping time C2 of the second time measuring device is always cleared to zero.
If the instantaneous abnormality signal is normal, the time is counted by the second timing device (step S16). The second time measuring device is always cleared to zero while the instantaneous abnormality signal is abnormal (step S10), and the time measured in step S16 is an elapsed time from the timing when the instantaneous abnormality signal is normally inverted. The second timing device keeps timing until the instantaneous abnormality signal is abnormally inverted, and is cleared to zero when the instantaneous abnormality signal is abnormally inverted.
[0017]
The timing time C2 of the second timing device is compared with the second predetermined time Z2 in step S18. If the second predetermined time Z2 or longer, that is, if the instantaneous abnormal signal is continuous for Z2 hours or longer, the cumulative number C3 of the instantaneous abnormal signal counter is cleared to zero (step S20). Furthermore, the time keeping time C1 of the first time measuring device is cleared to zero, and the first time measuring device stops measuring time (step S22). While the time keeping time C2 of the second time measuring device is less than the second predetermined time Z2, in order to skip step S20 and step S22, the instantaneous abnormality signal counter continues accumulation, and the first time measuring device continues time keeping.
[0018]
The cumulative number C3 of the instantaneous abnormality signal counter is compared with the predetermined number Z3 in step S24. While the predetermined number Z3 is not reached, the time C1 timed by the first time measuring device is compared with the first predetermined time Z1 (step S28). When the time C1 timed by the first time measuring device becomes equal to or greater than the first predetermined time Z1, the time measuring time C1 of the first time measuring device, the time measuring time C2 of the second time measuring device and the cumulative number C3 of the instantaneous abnormality signal counter are cleared to zero. The first timing device and the second timing device stop timing.
As a result of this processing, before the cumulative number C3 of the instantaneous abnormality signal counter reaches the predetermined number Z3 (NO in step 24), if the time C1 counted by the first time measuring device becomes equal to or longer than the first predetermined time Z1, The device stops timing.
On the other hand, when the cumulative number C3 of the instantaneous abnormality signal counter is equal to or greater than the predetermined number Z3, the process proceeds to step S26 and a signal indicating that an abnormality has occurred in the motor device is output. It should be noted that the cumulative number C3 of instantaneous abnormal signal counters compared in step S24 is the cumulative number C3 of instantaneous abnormal signal counters cleared to zero in step S20 when the condition of step S18 is satisfied. .
[0019]
Processing realized by the above processing will be described with reference to FIG.
When the time C1 counted by the first time measuring device before the cumulative number C3 of the instantaneous abnormality signal counter reaches the predetermined number Z3 during execution of the immediately preceding device abnormality determination process, the first time measuring device is reached. Has stopped timing.
While the first timing device is not counting and the instantaneous signal is normal, the cumulative number C3 of the instantaneous abnormal signal counter is zero (see before timing A in FIG. 3). If the instantaneous abnormality signal is abnormally inverted while the first time measuring device is not measuring time, the first time measuring device starts counting time (step S6), as illustrated in timing A of FIG. The number C3 starts to increase (step S8). The cumulative number C3 of the instantaneous abnormality signal counter does not increase if the instantaneous abnormality signal is normal even when the first timing device is measuring (step S18 is skipped from step S14 to step S18). If the instantaneous abnormality signal is repeatedly inverted between normal and abnormal in the meantime, the total time during which the instantaneous abnormality signal is abnormal appears in the cumulative number C3 of the instantaneous abnormality signal counter. On the other hand, the first time measuring device keeps timing regardless of whether the instantaneous abnormality signal is normal or abnormal.
The time C1 timed by the first time measuring device before the cumulative number C3 of the instantaneous abnormality signal counter reaches the predetermined number Z3 is equal to or more than the first predetermined time Z1 because the abnormal state of the instantaneous abnormal signal within the first predetermined time Z1 In this case, it can be determined that there is no abnormality in the motor device. In this case, all of the first timing device, the second timing device, and the instantaneous abnormality signal counter are initialized and prepared for the next processing (step S30).
The cumulative number C3 of the instantaneous abnormality signal counter reaches the predetermined number Z3 before the time C1 timed by the first time measuring device becomes equal to or greater than the first predetermined time Z1. This is a case where the total time of the state is equal to or greater than the predetermined number Z3. In this case, it is determined that an abnormal phenomenon has occurred continuously and an abnormality has occurred in the motor device (step S26).
[0020]
However, in this embodiment, if the instantaneous abnormality signal is continuous for the second predetermined time (Z2) or longer, the cumulative number C3 of the instantaneous abnormality signal counter is cleared to zero (steps S18 and S20).
In FIG. 3A, since the instantaneous abnormal signal is abnormally inverted within the second predetermined time Z2 after the instantaneous abnormal signal is normally inverted, step S18 is not YES, and the cumulative number of instantaneous abnormal signal counters. C3 is not cleared to zero. For this reason, it is determined that an abnormality has occurred in the motor device because the total time of the abnormal state of the instantaneous abnormality signal within the first predetermined time Z1 is equal to or greater than the predetermined number Z3 (step S26). On the other hand, in FIG. 3B, since the normal state continues continuously for the second predetermined time Z2 or more from the timing D at which the instantaneous abnormality signal is normally inverted, and then the abnormality is inverted, When the predetermined time Z2 has elapsed, the cumulative number C3 of the instantaneous abnormality signal counter is cleared to zero. For this reason, the cumulative number C3 of the instantaneous abnormality signal counter does not reach the predetermined number Z3, and step S24 does not become YES. The device is not considered abnormal.
[0021]
In the case shown in FIG. 3A, the instantaneous abnormal signal is intermittently inverted between normal and abnormal at regular intervals, and it cannot be assumed that there is no failure in the apparatus. Since the instantaneous abnormality continues intermittently, there is a high possibility that the apparatus is abnormal.
As shown in FIG. 3B, if the device is continuously normal for the second predetermined time Z2 or more after the timing D, it can be assumed that there is no failure in the apparatus. There is a high possibility that the instantaneous abnormal phenomenon that occurs irregularly is caused by a follow-up delay or the like that may occur in a normal motor device. In this case, in order to clear to zero in step S20, step S24 does not become YES, and the apparatus is not abnormal.
In the prior art, since there is no second timing device and naturally there is no zero clear means in step S20, the device is abnormal as illustrated in FIG. 4B. According to the conventional apparatus abnormality determination apparatus, as shown in FIG. 4, the instantaneous abnormality signal continues to be accumulated within the first predetermined time Z1. In the meantime, the instantaneous abnormal signal continues to accumulate even if it is normal for the second predetermined time or longer. If the accumulated time of the instantaneous abnormality signal accumulated within the first predetermined time Z1 reaches a predetermined number, a device abnormality signal is output. In the conventional apparatus abnormality determination device, the apparatus abnormality may not be correctly determined.
In this embodiment, as shown in FIG. 3 (b), the time between the instantaneous abnormal signal and the next instantaneous abnormal signal is measured, and when the second predetermined time is detected, the motor device returns to normal. Since the possibility is high, the cumulative number of instantaneous abnormal signal counts is cleared to zero. In the case of FIG. 3B, the cumulative number of instantaneous abnormal signal counts starts to be accumulated again from zero at timing E. If the motor apparatus is normal, the cumulative number C3 of the instantaneous abnormality signal counter does not reach the predetermined number Z3 within the first predetermined time Z1, and the apparatus abnormality signal is not output. If a failure actually occurs in the apparatus, an instantaneous abnormality signal as shown in FIG. 3A is input, so that the apparatus abnormality signal can be output when the apparatus is abnormal.
[0022]
Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a hardware configuration of a motor device according to an embodiment.
FIG. 2 is a diagram showing a device abnormality signal determination processing procedure of the motor device according to the present embodiment.
FIG. 3 is a diagram for explaining a device abnormality determination process;
FIG. 4 is a diagram for explaining a conventional device abnormality determination process;

Claims (1)

A motor controller that controls driving of the motor, a power source, a switch element, and a motor are connected, and a motor driving circuit that drives the motor based on a command from the motor controller, and a current value, a voltage value, and a rotation angle of the motor A device that detects a physical quantity indicating the state of a motor device such as torque and torque to determine an instantaneous abnormal state and generates an instantaneous abnormal signal, and a device abnormality that inputs an instantaneous abnormal signal and generates a device abnormal signal when the device is abnormal A signal generating device, the device abnormal signal generating device comprising: a first time measuring device that starts timing when an instantaneous abnormal signal is input during non-timekeeping; and an input of the instantaneous abnormal signal input during timekeeping of the first time measuring device. an instantaneous abnormal signal counter for accumulating the time, second counting instrumentation for measuring the instantaneous abnormal signal between time until the next instantaneous abnormal signal input of instantaneous abnormal signal has stopped is inputted When the measured time with the timed measurement time in the first timing device cumulative number of instantaneous abnormal signal counter upon reaching the first predetermined time is cleared to zero the cumulative number of instantaneous abnormal signal counter and when it is less than a predetermined number And a means for stopping the time of the first time measuring device and the second time measuring device by clearing the time between the instantaneous time abnormal signals to zero, and an instantaneous time when the time between the instantaneous time abnormal signals measured by the second time measuring device exceeds a second predetermined time. Means for clearing the accumulated number of abnormal signal counters to zero, and clearing the timed time and the time between instantaneous abnormal signal zeros to stop the time counting of the first time measuring device and the second time measuring device, and the cumulative number of instantaneous abnormal signal counters is predetermined. And a means for outputting a device abnormality signal when the number is reached.

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