KR102612239B1 - Motor Controlling Apparatus And The Method Thereof - Google Patents

Abstract

The present invention relates to a motor control device and method that detects simultaneous failure of a plurality of amplifiers and allows countermeasures against the occurrence of failure.
A motor control device according to an embodiment of the present invention includes a current sensor that detects the current supplied by the motor driver to the motor, a battery that supplies power to the motor driver, and a voltage detector that detects the voltage output by the current sensor. and a reference data generator configured to convert the output voltage of the battery into first reference data, convert the positive output voltage of the motor into second reference data, and convert the negative output voltage of the motor into third reference data. , and a control unit that determines the generation of back electromotive force of the motor based on the first to third reference data and controls driving of the motor based on the determination result of the back electromotive force of the motor.

Description

Motor Controlling Apparatus And The Method Thereof}

The present invention relates to a motor control device and method, and more specifically, to a motor control device and method that detects simultaneous failure of a plurality of amplifiers (common mode failure detection) and responds to the failure.

The electric steering system, which has become widespread as a vehicle steering device, comprehensively judges the driver's intention and driving situation using torque, vehicle speed, and steering angle, generates steering assistance force, and then transmits it to the steering column, rack bar, etc., making it easy and safe. Let it drive.

This electric steering device includes an Electronic Control Unit (ECU), which analyzes electrical signals transmitted from various external sensors and controls the motor using various logic. In general, the ECU calculates the driving current to drive the motor using the steering torque detected through a torque sensor in the MCU (Micro Controller Unit) contained within it, and calculates it using two or more switches and a battery. Supply the generated driving current to the motor. At this time, the current flowing in the motor is detected by connecting a current sensor between the switch and the battery motor. IC devices such as Hall sensors can be used as a means of detecting motor current, but there are problems such as increased manufacturing costs and decreased accuracy of current detection due to failure. Therefore, a means of detecting motor current using a shunt resistance is mainly used.

A motor control device that can detect a failure of an amplifier or offset circuit through detection of motor current using a shunt resistor has been proposed. However, although it is possible to detect whether one amplifier is broken, there is a problem that it is not possible to detect when multiple amplifiers are broken at the same time (common mode failure).

Japanese Patent Publication 2003-107112A (2003. 09. 28)

The present invention is intended to solve the problems described above, and its technical task is to provide a motor control device and method that detects the simultaneous failure of multiple amplifiers (common mode failure detection) and responds to the failure. .

In addition to the technical problems of the present invention mentioned above, other features and advantages of the present invention are described below, or can be clearly understood by those skilled in the art from such description and description.

A motor control device according to an embodiment of the present invention for achieving the purpose described above includes a current sensor that detects the current supplied by the motor drive unit to the motor, a battery that supplies power to the motor drive unit, and the current sensor outputs a voltage detector for detecting the voltage, converting the output voltage of the battery into first reference data, converting the positive output voltage of the motor into second reference data, and converting the negative output voltage of the motor into third reference data. It includes a reference data generating unit that converts, and a control unit that determines the generation of back electromotive force of the motor based on the first to third reference data, and controls driving of the motor based on the determination result of the back electromotive force of the motor. do.

The voltage detection unit of the motor control device according to an embodiment of the present invention includes a first amplification unit and a second amplification unit that amplifies and outputs the voltage output by the current sensor, and the first amplification unit and the second amplification unit. It includes a first offset unit and a second offset unit that are respectively connected to and output an offset voltage.

The control unit of the motor control device according to an embodiment of the present invention includes a determination unit that determines whether the output voltage of the first offset unit and the output voltage of the second offset unit are within a set offset voltage range.

The reference data generator of the motor control device according to an embodiment of the present invention converts the output voltage of the battery into first reference data, converts the positive output voltage of the motor into second reference data, and converts the positive output voltage of the motor into second reference data. The output voltage is converted into third reference data.

The determination unit of the motor control device according to an embodiment of the present invention determines the absolute value of the difference value between the second reference data and the third reference data and the size of the first reference data using Equation 1 below. Compare.

[Equation 1]

1st reference data < |2nd reference data - 3rd reference data|

If the conditions of Equation 1 are satisfied, it is determined that back electromotive force has been generated in the motor. Conversely, if the conditions of Equation 1 are not satisfied, it is determined that back electromotive force is not generated in the motor.

The determination unit of the motor control device according to an embodiment of the present invention is configured to operate in a common mode (AMP1 < offset1) when the output of the first offset unit is greater than the output of the first amplifier (AMP1 < offset1) in a state in which no back electromotive force is generated in the motor. common mode) It is determined that a failure has occurred.

The determination unit of the motor control device according to an embodiment of the present invention operates in a common mode ( common mode) It is determined that a failure has occurred.

If a common mode failure occurs, the control unit of the motor control device according to an embodiment of the present invention immediately stops driving the motor and displays a warning sound or a separate warning light to indicate the inability of EPS (electric power steering). .

The control unit of the motor control device according to an embodiment of the present invention operates when the output of the first offset unit is greater than the output of the first amplifier (AMP1 < offset1) and the output of the second offset unit is greater than the output of the second amplifier. A motor control device that includes a counter that increases the number of failure occurrence counts when (AMP2 < offset2), and determines a common mode failure when the failure occurrence count is greater than or equal to a threshold value.

The motor control device and method according to an embodiment of the present invention can detect that a plurality of amplifiers fail at the same time (common mode failure detection) and enable response to the occurrence of the failure.

In addition, other features and advantages of the present invention may be newly understood through embodiments of the present invention.

1 is a diagram showing a motor control device according to an embodiment of the present invention.
FIG. 2 is a diagram showing the control unit shown in FIG. 1.
Figure 3 is a diagram showing a motor control method according to an embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts that are not relevant to the description are omitted, and identical or similar components are assigned the same reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected," but also the case where it is "electrically connected" with another element in between. . Additionally, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

When a part is referred to as being “on” another part, it may be directly on top of the other part or it may be accompanied by another part in between. In contrast, when a part is said to be "directly above" another part, it does not entail any other parts in between.

Terms such as first, second, and third are used to describe, but are not limited to, various parts, components, regions, layers, and/or sections. These terms are used only to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, the first part, component, region, layer or section described below may be referred to as the second part, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is only intended to refer to specific embodiments and is not intended to limit the invention. As used herein, singular forms include plural forms unless phrases clearly indicate the contrary. As used in the specification, the meaning of "comprising" refers to specifying a particular characteristic, area, integer, step, operation, element and/or ingredient, and the presence or presence of another characteristic, area, integer, step, operation, element and/or ingredient. This does not exclude addition.

Terms indicating relative space, such as “below” and “above,” can be used to more easily describe the relationship of one part shown in the drawing to another part. These terms are intended to include other meanings or operations of the device in use along with the meaning intended in the drawings. For example, if the device in the drawing is turned over, some parts described as being “below” other parts will be described as being “above” other parts. Accordingly, the exemplary term “down” includes both upward and downward directions. The device can be rotated 90° or at other angles, and terms indicating relative space are interpreted accordingly.

Although not defined differently, all terms including technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted as having meanings consistent with related technical literature and currently disclosed content, and are not interpreted in ideal or very formal meanings unless defined.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

FIG. 1 is a diagram showing a motor control device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the control unit shown in FIG. 1.

Referring to Figures 1 and 2, a motor control device according to an embodiment of the present invention includes a voltage detection unit 100 and a control unit 200. Here, the voltage detection unit 100 includes a first offset unit 110, a second offset unit 120, an amplification unit 130, and a current sensor 140. In addition, the control unit 200 includes a plurality of analog-to-digital converters (211 to 217: ADC), a determination unit 220, a storage unit 230, a first current calculation unit 240, a second current calculation unit 250, It includes a relay command generation unit 260 and a relay control unit 270. In addition, the control unit 200 includes a counter to distinguish between a common mode failure and the occurrence of a temporary minor signal error or abnormal signal, and uses the counter to count when it is determined that a failure has occurred. Increase by 1.

The control unit 200 controls the motor driving unit 160 to supply driving current to the motor 150 based on the output voltage of the voltage detection unit 100. Hereinafter, the analog-to-digital converter is referred to as an 'ADC (analog-digital converter)'. Let's name it.

The relay 190 is turned on or turned off based on a relay control signal (RCS) input from the control unit 200, and when turned on, the driving current supplied from the battery 170 is supplied to the motor driving unit 160. When the relay 190 is turned off, the supply of driving current to the motor driver 160 is blocked.

The motor driver 160 supplies driving current to the motor 150. The motor driving unit 160 converts the driving current supplied from the battery 170 into a motor driving current and supplies it to the motor 150. At this time, the motor drive unit 160 generates a drive current corresponding to the drive current value calculated by the control unit 200 and supplies it to the motor 150.

Here, the motor driver 160 includes four FETs (A, B, C, and D), and can drive the motor 150 by switching the FETs. That is, the motor driver 160 is configured as an H-bridge circuit and can drive the motor 150 by switching the FET using PWM (Pulse Width Modulation).

The regulator 180 converts the voltage supplied from the battery 170 to be suitable for driving the amplification unit 130 and the control unit 200, and transmits the converted voltage to the amplification unit 130 and the control unit 200, respectively. supply.

The current sensor 140 senses the current flowing in the motor 150. The current sensor 140 detects a shunt voltage when the shunt current output by the motor driver 160 is applied, and a shunt resistance may be applied. Accordingly, the current sensor 140 detects the shunt voltage applied by the load current of the motor driving unit 160.

The amplifier 130 includes a first amplifier (132, AMP 1) and a second amplifier (134, AMP 2). In Figure 1, the amplifier 130 is shown as being composed of two channels including two amplifiers 132 and 134, but it may also be composed of three channels or more.

The first offset unit 110 outputs a first offset voltage, and the second offset unit 120 outputs a second offset voltage. The first offset unit 110 is connected to the first amplifier 132, and the second offset unit 120 is connected to the second amplifier 134. The first offset voltage output from the first offset unit 110 is supplied to the first amplifier 132 and the control unit 200. And, the second offset voltage output from the second offset unit 120 is supplied to the second amplifier 134 and the control unit 200.

The first amplifier 132 amplifies the shunt voltage output from the current sensor 140 and the first offset voltage output from the first offset unit 110, and then outputs them to the control unit 200.

The second amplifier 134 amplifies the shunt voltage output from the current sensor 140 and the second offset voltage output from the second offset unit 120 and outputs them to the control unit 200.

The control unit 200 controls the motor driving unit 160 so that the driving current is supplied to the motor 150, and adjusts the driving current based on the motor current detected by the voltage detection unit.

As shown in FIG. 2, the control unit 200 is a device in charge of main control in the ECU, and is used to adjust the drive current using the detected motor current and to ensure that the adjusted drive current is supplied to the motor 150. It may include a storage unit that stores data and software that performs control, and a micro controller unit (MUC) that executes the software.

The control unit 200 includes an ADC unit 210, a determination unit 220, a storage unit 230, a first current calculation unit 240, a second current calculation unit 250, a relay command generation unit 260, and a relay. Includes a control unit 270. The ADC unit 210 includes first to seventh ADCs 211 to 217.

The storage unit 230 stores a first reference voltage and a second reference voltage to check whether the first offset voltage of the first offset unit 110 and the second offset voltage of the second offset unit 120 are normally output. do.

The first ADC 211 included in the control unit 200 converts the first offset voltage output from the first offset unit 110 into a first digital signal (V1) to be used in the determination unit 220 and the storage unit 230. and supplied to the first current calculation unit 240.

The second ADC 212 included in the control unit 200 converts the second offset voltage output from the second offset unit 120 into a second digital signal V2 to be used in the storage unit 230 and the first current calculation unit. Supplied to (240).

The second ADC 212 and third ADC 213 included in the control unit 200 convert the voltage output from the first amplifier 132 into a third digital signal V3 and send it to the first current calculation unit 240. supply.

The fourth ADC 214 included in the control unit 200 converts the voltage output from the second amplifier 134 into a fourth digital signal V4 and supplies it to the first current calculation unit 240.

The first current calculation unit 240 receives the output of the first ADC 211, the output of the second ADC 212, the output of the third ADC 213, and the output of the fourth ADC 214, and then 1 The output of the ADC (211) is converted into the output current of the first offset unit (110). Additionally, the output of the second ADC 212 is converted into an output current of the second offset unit 120. Additionally, the output of the third ADC (213) is converted into the output current of the first amplifier (132). Additionally, the output of the fourth ADC 214 is converted into the output current of the second amplifier 134.

Additionally, the first current calculation unit 240 may calculate the difference between the output current of the first offset unit 110 and the output current of the first amplifier 132 as the first shunt current. Additionally, the difference between the output current of the second offset unit 120 and the output current of the second amplifier 134 can be calculated as the second shunt current.

Accordingly, the first current calculation unit 240 can measure the current flowing through the current sensor, that is, the shunt current, using each converted output current. The shunt current may be a first shunt current that is the difference between the output current of the first offset unit 110 and the output current of the first amplifier 132. Additionally, the shunt current may be a second shunt current that is the difference between the output current of the second offset unit 120 and the output current of the second amplifier 134. In the present invention, either the first shunt current or the second shunt current can be used as the shunt current.

As an example, the control unit 200 stops the operation of the first offset unit 110 when the first offset voltage output from the first offset unit 110 is outside the allowable range. At this time, the second shunt current calculated based on the difference between the output current of the second offset unit 120 and the output current of the second amplifier 134 can be used as the cent current of the motor control device.

The determination unit 220 determines whether the first offset voltage and the second offset voltage, including the tolerance, are normally output. For example, if the first reference voltage and the second reference voltage are each 1 [V], and the set tolerance is around 10%, the first offset voltage and the second offset voltage are effective within 0.9 to 1.1 [V]. It can work.

The determination unit 220 uses the first and second reference voltages stored in the storage unit 230 to determine the first offset voltage output from the first offset unit 110 and the second offset voltage output from the second offset unit 120. It is determined whether the second offset voltage is valid. In FIG. 2, the storage unit 230 is shown as an independent configuration, but the determination unit 220 stores the first reference voltage and the second reference voltage therein to determine whether the first offset voltage and the second offset voltage are valid. It may be possible.

If the first offset unit 110 outputs an offset voltage that is outside the allowable range of the first reference voltage, it may be determined that the first offset unit 110 is broken. At this time, if the output voltage of the second offset unit 120 does not exceed the allowable range, the operation of the first offset unit 110 may be stopped and the second offset unit 120 may continue to operate.

Conversely, if the second offset unit 120 outputs an offset voltage that is outside the allowable range of the second reference voltage, it may be determined that the first offset unit 110 is broken. At this time, if the output voltage of the first offset unit 110 does not exceed the allowable range, the operation of the second offset unit 120 may be stopped and the first offset unit 110 may continue to operate.

Here, the determination unit 220 may determine whether the difference between the output voltage of the first amplifier 132 and the output voltage of the second amplifier 134 is within the set amplification voltage difference range. That is, the set amplification voltage difference is a standard for determining whether the first amplifier 132 and the second amplifier 134 output normal voltages, and in this case, the set amplification voltage difference is the difference between the first amplifier 132 and the second amplifier 134. It can indicate the standard of the allowable error range for the output voltage difference. Therefore, if the set amplification voltage difference is 1 [V] and the set tolerance is around 10%, the difference between the output voltage of the first amplifier 132 and the output voltage of the second amplifier 134 is within 0.9 to 1.1 [V]. can operate effectively.

If the output voltage difference between the first amplifier 132 and the second amplifier 134 outputs a voltage that is outside the set amplification voltage difference range, either the first amplifier 132 or the second amplifier 134 is considered to be faulty. You can judge. In this case, as described above, if it is determined that the first offset unit 110 is broken, the first amplifier 132 can be considered to be broken, so the operation of the first amplifier 132 is stopped and the second amplifier 134 ) can continue to operate.

As another example, the control unit 200 stops the operation of the second offset unit 120 when the second offset voltage output from the second offset unit 120 is outside the allowable range. At this time, the first shunt current calculated based on the difference between the output current of the first offset unit 110 and the output current of the first amplifier 132 can be used as the cent current of the motor control device.

If the output voltage difference between the first amplifier 132 and the second amplifier 134 outputs a voltage that is outside the set amplification voltage difference range, either the first amplifier 132 or the second amplifier 134 is considered to be faulty. You can judge. In this case, if it is determined that the second offset unit 120 is broken, the second amplifier 134 can be considered to be broken, so the operation of the second amplifier 134 is stopped and the first amplifier 132 is continued to operate. You can do it. Therefore, when only one amplifier was included, it was not possible to determine if the amplifier was broken. However, according to the embodiment of the present invention including two amplifiers, the output voltage of the first amplifier 132 and the second amplifier 134 By determining whether the difference in output voltage is within the set amplification voltage difference range, it can be determined whether the first offset unit 110 and the second offset unit 120 are operating normally. Additionally, it can be determined whether the first amplifier 132 and the second amplifier 134 operate normally. Additionally, if one of the first amplifier 132 and the second amplifier 134 fails, the motor 150 and the control unit 200 can operate normally using the normally operating amplifier.

As a way to detect that the first offset unit 110 and the second offset unit 120 are broken at the same time or to detect that two amplifiers are broken at the same time, two 1-channel amplifiers can be applied, but in this case, the manufacturing Other problems may arise that increase costs. In particular, the prior art was unable to determine which amplifier was defective when the output of the first amplifier (AMP1 out) and the output of the second amplifier (AMP2 out) were the same or similar.

When applying the amplification unit 130 including a two-channel amplifier, the motor control device according to an embodiment of the present invention uses the reference data generation unit 150 to generate the first offset unit 110 and the second offset unit 120. ) can be detected even if they fail at the same time (common mode failure). Additionally, even if the first amplifier 132 and the second amplifier 134 fail at the same time, this can be detected.

The second ADC 154 of the reference data generator 150 converts the voltage (MOT V+) of the positive terminal of the motor 150 into second reference data, and the control unit 200 determines the converted second reference data. It is supplied as part 220.

The third ADC 156 of the reference data generator 150 converts the voltage (MOT V-) of the negative terminal of the motor 150 into third reference data, and uses the converted third reference data as the third reference data of the control unit 200. It is supplied to the judgment unit 220.

The fifth ADC 215 converts the voltage (MOT V-) of the negative (-) terminal of the motor 150 into first reference data and supplies the first reference data to the determination unit 220.

The sixth ADC 216 converts the voltage (MOT V+) of the positive (+) terminal of the motor 150 into second reference data and supplies the second reference data to the determination unit 220.

The seventh ADC 217 converts the output voltage of the battery 170 into third reference data and supplies the third reference data to the determination unit 220.

The determination unit 220 is based on the first reference data supplied from the fifth ADC (215), the second reference data supplied from the sixth ADC (216), and the third reference data supplied from the seventh ADC (217). It is determined whether the first offset unit 110 and the second offset unit 120 fail at the same time. In addition, the determination unit 220 determines the first reference data supplied from the fifth ADC 215, the second reference data supplied from the sixth ADC 216, and the third reference data supplied from the seventh ADC 217. Based on this, it is determined whether the first amplifier 132 and the second amplifier 134 failed at the same time.

When the output voltages of the first offset unit 110 and the second offset unit 120 are set to 1V, if the output values of the first amplifier 132 and the second amplifier 134 are floating, the first amplifier The output values of 132 and the second amplifier 134 are the same or similar within an error range. Therefore, a common mode failure in which the first offset unit 110 and the second offset unit 120 fail at the same time cannot be detected. Additionally, a common mode failure in which the first amplifier 132 and the second amplifier 134 fail at the same time cannot be detected.

Specifically, the output of the first offset unit 110 is greater than the output of the first amplifier 132 (AMP1 < offset1) or the output of the second offset unit 120 is greater than the output of the second amplifier 134. (AMP2 < offset2) may occur. Since back electromotive voltage may be generated due to the high-speed operation of the motor 150, a common mode failure cannot be detected in the above case.

In the present invention, the determination unit 220 converts the first reference data supplied from the fifth ADC 215 and the second reference data supplied from the sixth ADC 216 into the third reference data supplied from the seventh ADC 217. By comparing with , the presence or absence of back electromotive force of the motor 150 is determined. Thereafter, in a state where there is no back electromotive force of the motor 150, the output of the first offset unit 110 is greater than the output of the first amplifier 132 (AMP1 < offset1) or is greater than the output of the second amplifier 134. 2 When the output of the offset unit 120 is large (AMP2 < offset2), it is determined that a common mode failure has occurred.

The determination unit 220 uses the output voltage of the battery 170, the voltage of the positive (+) terminal of the motor 150 (MOT V+), and the voltage of the negative (-) terminal of the motor 150 (MOT V-). Thus, the presence or absence of back electromotive force of the motor 150 is determined.

Specifically, the output voltage of the battery 170, that is, the magnitude of the first reference data and the output voltage (MOT V+, MOT V-) of the motor 150 are compared. At this time, as shown in Equation 1 below, the output voltage of the battery 170, that is, the third reference data, and the positive (+) output (first reference data) and negative (-) output (first reference data) of the motor 150 2 Compare the size of the absolute value (|(MOT+) - (MOT-)|) of the difference between the reference data).

[Equation 1]

Third reference data < |First reference data - Second reference data|

If the condition of Equation 1 is satisfied, the output voltage of the motor 150 is greater than the output voltage of the battery 170. In this case, the determination unit 220 determines that a back electromotive force has occurred in the motor 150. You can.

Conversely, if the condition of Equation 1 is not satisfied, the output voltage of the battery 170 and the output voltage of the motor 150 are the same, or the output voltage of the battery 170 is greater than the output voltage of the motor 150. , In this case, the determination unit 220 may determine that no back electromotive force is generated in the motor 150.

The determination unit 220 operates in a common mode when the output of the first offset unit 110 is greater than the output of the first amplifier 132 (AMP1 < offset1) while no back electromotive force is generated in the motor 150. mode) It is determined that a failure has occurred.

In addition, the determination unit 220 operates in the common mode when the output of the second offset unit 120 is greater than the output of the second amplifier 134 (AMP2 < offset2) in a state in which no back electromotive force is generated in the motor 150. (common mode) It is determined that a failure has occurred.

When it is determined that a common mode failure has occurred, the relay command generator 260 generates a relay off command to immediately stop driving the motor 150. The relay off command generated by the relay command generation unit 260 is supplied to the relay control unit 270. The relay control unit 270 turns off the relay according to the input relay off command to block the output voltage of the battery 170 from being supplied to the motor driving unit 160. In addition, the control unit 200 may display a warning sound or turn on a separate warning light to indicate that the EPS (electric power steering) cannot be operated so that the driver can recognize the EPS (electric power steering) inability.

In the description referring to FIG. 2 , it was explained that the first current calculation unit 240 and the second current calculation unit 250 are each independently constructed. However, it is not limited to this, and the first current calculation unit 240 and the second current calculation unit 250 may be integrated and applied as one configuration.

Figure 3 is a diagram showing a motor control method according to an embodiment of the present invention.

Referring to FIG. 3, in order to detect a common mode failure, the output voltage of the motor 150 and the output voltage of the battery 170 are compared to determine whether back electromotive force is generated in the motor 150 (S10). .

The determination unit 220 determines the voltage of the negative (-) terminal of the motor 150 supplied from the fifth ADC 215 (first reference data) and the positive voltage of the motor 150 supplied from the sixth ADC 216. It is determined whether back electromotive force has been generated in the motor 150 using the voltage of the (+) terminal (second reference data) and the voltage of the battery 170 (third reference data) supplied from the seventh ADC 217. At this time, the absolute value of the difference between the voltage of the negative (-) terminal of the motor 150 and the voltage of the positive (+) terminal of the motor 150 (|first reference data - second reference data| = |motor voltage|) Calculate Afterwards, it is determined whether the battery voltage is greater than the absolute value of the motor voltage.

If the battery voltage is greater than the absolute value of the motor voltage, it is determined that no back electromotive force is generated in the motor 150. Conversely, if the absolute value of the battery voltage and the motor voltage are the same, or if the battery voltage is smaller than the absolute value of the motor voltage, it is determined that back electromotive force has occurred in the motor 150.

Specifically, the output voltage of the battery 170, that is, the magnitude of the third reference data and the output voltage of the motor 150 (|first reference data - second reference data|) are compared. At this time, as shown in Equation 1 above, the output voltage of the battery 170, that is, the third reference data, and the absolute value of the difference between the positive (+) output and the negative (-) output of the motor 150 (|(MOT+ ) - Compare the sizes of (MOT-)|).

If the conditions of Equation 1 are satisfied, the output voltage of the motor 150 is greater than the output voltage of the battery 170, and in this case, it can be determined that back electromotive force has been generated in the motor 150.

Conversely, if the condition of Equation 1 is not satisfied, the output voltage of the battery 170 and the output voltage of the motor 150 are the same, or the output voltage of the battery 170 is greater than the output voltage of the motor 150, In this case, it can be determined that no back electromotive force is generated in the motor 150.

Next, when no back electromotive force is generated in the motor 150, the determination unit 220 determines whether the output of the first offset unit 110 is greater than the output of the first amplifier 132 (AMP1 < offset1) (S20) ). Additionally, the determination unit 220 determines whether the output of the second offset unit 120 is greater than the output of the second amplifier 134 (AMP2 < offset2) (S20).

As a result of the determination in S20, if the output of the first amplifier 132 and the output of the first offset unit 110 are the same, or if the output of the first amplifier 132 is greater than the output of the first offset unit 110, The determination unit 220 determines that it is not a common mode failure. Then, the failure occurrence count addition number is set to 0 so that the failure occurrence count does not increase (S30).

Likewise, as a result of the determination in S20, the output of the second amplifier 134 and the output of the second offset unit 120 are the same, or the output of the second amplifier 142 is equal to the output of the second offset unit 120. If it is greater than this, the determination unit 220 determines that it is not a common mode failure. Then, the failure occurrence count addition number is set to 0 so that the failure occurrence count does not increase (S30).

Here, a failure occurrence count was applied to increase the accuracy of common mode failure determination, and the normal operation of the EPS is not judged as a common mode failure due to a temporary minor signal error or abnormal signal occurrence. Avoid doing so. That is, when the failure occurrence count satisfies a certain standard value, the failure occurrence count is applied so that a common mode failure is determined.

Subsequently, as a result of the determination in S20, when back electromotive force is not generated in the motor 150, the determination unit 220 determines that the output of the first offset unit 110 is greater than the output of the first amplifier 132 (AMP1 < offset1). In this case, the failure occurrence count is increased (S40). At this time, the failure occurrence count addition number can be set to 1.

Likewise, as a result of the determination in S20, when back electromotive force is not generated in the motor 150, the determination unit 220 determines that the output of the second offset unit 120 is greater than the output of the second amplifier 134 (AMP1 < In the case of offset1), the failure occurrence count is increased (S40). At this time, the failure occurrence count addition number can be set to 1.

Next, it is determined whether the failure occurrence count is greater than or equal to the threshold value (fail count >= threshold) (S50).

As a result of S50's determination, if the failure occurrence count is less than the threshold, it is determined that it is not a common mode failure, and EPS operation is performed normally.

Meanwhile, as a result of the determination of S50, if the failure occurrence count is greater than or equal to the threshold value (fail count >= threshold), it is determined that a common mode failure has occurred. Thereafter, the control unit 200 turns off the relay 190 through the relay control signal (RCS) to block the driving voltage from being supplied to the motor 150. Through this, the operation of the motor 150 is immediately stopped (off). In addition, so that the driver can recognize the EPS inability, a warning sound or a separate warning light can be turned on to indicate that the EPS cannot operate (S60).

The motor control device and method according to an embodiment of the present invention can detect that a plurality of amplifiers fail at the same time (common mode failure detection) and enable response to the occurrence of the failure.

Those skilled in the art to which the present invention pertains should understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features, and that the embodiments described above are illustrative in all respects and not restrictive. Just do it. The scope of the present invention is indicated by the claims described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. .

100: voltage detection unit 110: first offset unit
120: second offset unit 130: amplification unit
132: first amplifier 134: second amplifier
140: current sensor 150: motor
160: motor driving unit 170: battery
180: regulator 190: relay
200: Control unit 210: ADC unit
211: first ADC 212: second ADC
213: 3rd ADC 214: 4th ADC
215: 5th ADC 216: 6th ADC
217: 7th ADC 220: Judgment unit
230: storage unit 240: first current calculation unit
250: second current calculation unit 260: relay command generation unit
270: relay control unit

Claims (9)

A current sensor that detects the current supplied by the motor drive unit to the motor;
a battery that supplies power to the motor drive unit;
a voltage detection unit that detects the voltage output by the current sensor;
a reference data generator converting the output voltage of the battery into first reference data, converting the positive output voltage of the motor into second reference data, and converting the negative output voltage of the motor into third reference data; and
A control unit that determines the generation of back electromotive force of the motor based on the first to third reference data and controls driving of the motor based on the determination result of the back electromotive force of the motor,
The voltage detector,
an amplification unit including a first amplifier and a second amplifier that amplifies and outputs the voltage output from the current sensor; and
It includes a first offset unit and a second offset unit respectively connected to the first amplifier and the second amplifier to output an offset voltage,
The control unit,
Determine whether the difference between the output voltage of the first amplifier and the output voltage of the second amplifier is within a set amplification voltage difference range, and based on the determination result of the output voltage, the first offset unit and the second offset unit A motor control device including a determination unit that determines whether the operation is normal. delete The method of claim 1, wherein the determination unit,
A motor control device that determines whether the output voltage of the first offset unit and the output voltage of the second offset unit are within a set offset voltage range. The method of claim 3, wherein the reference data generator,
Converting the output voltage of the battery into first reference data,
Converting the positive output voltage of the motor into second reference data,
A motor control device that converts the negative output voltage of the motor into third reference data. The method of claim 4, wherein the determination unit,
Using Equation 1 below, compare the absolute value of the difference between the second and third reference data and the size of the first reference data,
(Equation 1)
1st reference data < |2nd reference data - 3rd reference data|
A motor control device that determines that back electromotive force has been generated in the motor if the conditions of Equation 1 are satisfied, and conversely, if the conditions of Equation 1 are not satisfied, it is determined that back electromotive force has not been generated in the motor. The method of claim 5, wherein the determination unit,
A motor control device that determines that a common mode failure has occurred when the output of the first offset unit is greater than the output of the first amplifier (AMP1 < offset1) while no back electromotive force is generated in the motor. The method of claim 5, wherein the determination unit,
A motor control device that determines that a common mode failure has occurred when the output of the second offset unit is greater than the output of the second amplifier (AMP2 < offset2) while no back electromotive force is generated in the motor. The method of claim 6 or 7, wherein the control unit,
A motor control device that immediately stops driving the motor when a common mode failure occurs and displays a warning sound or a separate warning light to indicate the inability of EPS (electric power steering). The method of claim 6 or 7, wherein the control unit,
When the output of the first offset unit is greater than the output of the first amplifier (AMP1 < offset1) and the output of the second offset unit is greater than the output of the second amplifier (AMP2 < offset2), the number of additions to the failure occurrence count is increased. Contains a counter,
A motor control device that determines a common mode failure when the failure occurrence count is greater than or equal to a threshold value.

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