KR101694048B1 - Output line short detection circuit of motor driver - Google Patents

Abstract

The present invention relates to an output terminal short detection circuit of a motor driver. A first motor driver and a second motor driver for judging a B+ or ground short state before driving a motor, a first B+ short detection unit connected to the first output line of the first motor driver and a first ground short detection unit are connected to each other. And the first B+ short detection part, and a processor for determining a short state between a first output line and a second output line according to the output value of the first ground short detection part are provided. At this time, the short state is a B+ short or a ground short state. According to the present invention as described above, the short state of the output line can be known in advance so that a motor driver can be prevented from being burned.

Description

[0001] The present invention relates to a motor driver,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short-circuit detection circuit, and more particularly, to an output-terminal short-circuit detection circuit of a motor driver for detecting an output line short-circuit state of a motor driver in a processor using a motor as an actuator.

Various motor devices are employed in the vehicle. As an example, a four-wheel vehicle also has a motor for changing between two wheels and four wheels. A motor driver for driving the motor is also connected to the motor. The motor driver is connected to a microcontroller unit (MCU) for controlling a specific system (or device), and receives a control operation. That is, the motor driver drives and stops the motor in accordance with the control signal.

Before starting the motor, it is necessary to check the output terminal status of the motor driver. This is because the motor driver can be damaged if the output line of the motor driver is shorted to the B + power of the vehicle battery, or if the output line is shorted to the ground.

To prevent damage to the motor driver, a circuit has been proposed which detects the state of the output terminal of the motor driver. This is illustrated in FIG.

Referring to Fig. 1, two motor drivers 2 and 3 are connected to the motor 1. Fig.

A first sensing unit 4 and a second sensing unit 8 are connected to each line connecting the motor driver 2 (3) and the motor 1. [ A power source B + is supplied to each of the motor drivers 2 and 3. The power source is 12V for vehicle battery. The first sensing unit (or second sensing unit) 4 includes a voltage divider, a clamping unit connected to the output side of the voltage divider, and a comparator for comparing the clamped voltage with a preset reference voltage . Then, the processor 10 receives the comparison result of the comparator and judges the B + short circuit state of the line 1 or the line 2.

However, in Fig. 1, the B + short-circuit state can be sensed by the sensing units 4 and 8, but the ground short-circuit state can not be sensed. That is, even when the motor is in the short-circuited state, there is a problem that the motor drivers 2 and 3 are burned down.

Thus, the circuit of FIG. 2 and FIG. 3 has been proposed as a separate method for detecting the ground short circuit state.

As shown in the figure, in the full bridge motor drive circuit, an overcurrent sensing unit (see FIG. 2) having a sensing resistor R _SENSE on the high side is formed, or a sensing resistor R reference _sENSE), the over-current detecting unit (FIG. 3 provided), a configuration, which was determined to be above a certain voltage level when over-current comparator compares the voltage and the voltage formed in the sensing resistance (R _sENSE).

However, this also sensed only a B + short or ground short, and could not detect a single circuit configuration for B + short and ground short.

As described above, in the prior art, there is a problem that the B + short circuit state and the ground short circuit state can not be detected by only one circuit configuration. Although it is possible to detect the B + short-circuit state and the ground short-circuit state by combining the circuit configurations of FIGS. 1 to 3, the circuit configuration may be complicated.

Korean Registered Patent No. 10-1091636 (December 12, 2011. Method for Detecting Power Cable Shorting in a Motor)

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a motor driver circuit capable of detecting both a short- .

According to an aspect of the present invention for achieving the above object, there is provided a motor control apparatus comprising: a first motor driver and a second motor driver for driving a motor; A first B + short detection unit and a first ground short detection unit connected to a first output line of the first motor driver; And a processor (MCU) for determining a short-circuit state of the first output line and the second output line according to the output values of the first B + short-circuit sensing unit and the first ground short-circuit sensing unit do.

A transistor connected to the first B + short detection part and the first output line; Distribution resistances R1 and R2 connected to one end of the transistor; And a comparator for comparing the divided voltage between R1 and R2 with a preset reference voltage.

If the distribution voltage is equal to or greater than the reference voltage, the processor determines that the first output line or the second output line and the B + power supply are short-circuited.

The first short-circuit detection unit may include: a transistor that is turned on by the processor; And a capacitor charged by the processor and discharging during the turn-on operation of the transistor.

The processor (MCU) determines that the first output line or the second output line and the ground terminal are short-circuited when the capacitor is discharged.

When the capacitor is discharged, the processor receives a low state value from the first ground short detection unit.

When the first output line or the second output line and the ground terminal are short-circuited, the charge charged in the capacitor is discharged through the short-circuited portion.

The processor (MCU) simultaneously senses the B + short-circuit state of the first output line and the second output line or simultaneously detects the ground short-circuit state of the first output line and the second output line.

The output short-circuit detection circuit of the motor driver according to the present invention has the following effects.

The present invention is characterized in that a B + short-circuit detection unit and a ground short-circuit detection unit are provided in two connection lines connecting the first and second motor drivers and the motor, respectively, and the processor (MCU) receives the output value from the sensing unit, The ground short circuit state was judged.

This has the advantage of being able to sense both B + shorts and ground shorts with only a single short circuit. Therefore, when a short circuit occurs, the processor (MCU) controls the motor driver to be not driven, thereby preventing the motor driver from being burned down.

1 to 3 are diagrams of a conventional circuit for detecting an output terminal state of a motor driver.
4 is a block diagram of an output stage sensing circuit of a motor driver according to a preferred embodiment of the present invention.
FIGS. 5 and 6 are diagrams of respective circuits showing examples of sensing the B + short-circuit state and the ground short-circuit state in the circuit of FIG. 4;
FIG. 7 is a flowchart illustrating an output stage sensing method of a motor driver according to a preferred embodiment of the present invention. FIG.

The present invention is based on the basic technical idea of detecting short-circuiting by constituting a sensing unit for detecting a B + short-circuit and a ground short-circuit on both sides of a motor in a full bridge type motor drive circuit configuration.

In this embodiment, a vehicle motor driver controlled by a 4WD processor of a vehicle is described as an example, but the present invention is not limited thereto. That is, the present invention can be applied to all processors that operate a motor using a motor driver.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of an output stage sensing circuit of a motor driver according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram of an output stage sensing circuit of a motor driver according to a preferred embodiment of the present invention.

As shown in the drawing, a first motor driver 101 and a second motor driver 102, which are supplied with the 12V B + power of the vehicle battery, are configured. The outputs of the first motor driver (half bridge) 101 and the second motor driver 102 are connected in parallel by two NMOSs. The NMOS switches according to the control of the processor 105, which will be described later.

The motor 103 is connected to the first motor driver 101 and the second motor driver 102 through an output line. Here, an output line connected to the first motor driver 10 is referred to as 'line 1' and an output line connected to the second motor driver 102 is referred to as 'line 2'.

Line 1 is connected to a short-circuit detection unit. The short detection unit detects the B + short-circuit state and the ground short-circuit state, and the first B + short-circuit detection unit 111 and the first ground short-circuit detection unit 113 are connected to the line 1. The first B + short detection unit 111 detects a short circuit between the B + power source and the line 1 or the line 2, and the first ground short detection unit 113 detects a ground short between the line 1 and the line 2 .

The first B + short detection unit 111 includes an NMOS M1 connected to the node A of the line 1 and a voltage dividing resistor R1 and R2 connected to one end of the NMOS M1, And a comparator U1 connected to the node B between the distribution resistors to receive the divided voltage through the non-inverting terminal (+) and receive the reference voltage via the inverting terminal (-).

The first ground short detection unit 113 includes an NMOS M2 that is switched by the processor 105 and a capacitor C1 that is connected to one end of the NMOS M2 and is discharged according to a switching operation . Here, the charging of the capacitor C1 is charged by the processor 105, and is discharged only by the switching operation.

Resistors (R3 and R4) connected to predetermined terminals of the processor (105) are connected to one end of the capacitor (C1), and the other end is grounded. When C1_charge is set to a high state, capacitor C1 is in a charged state, and a high level value is transmitted to processor 105 via line_state2.

The processor 105 controls switching of the NMOSs of the first motor driver 101 and the second motor driver 102 and also controls the first B + short detection part 111, the first ground short detection part 111, (B +) and ground short-circuited state while controlling the elements of the transistor (113). To this end, the processor 105 is provided with a terminal for controlling the elements of the first B + short detection unit 111 and the first ground short detection unit 113.

More specifically, the control terminal of the processor 105 includes an M1_input terminal for enabling the NMOS M1, a line_state 1 terminal receiving the output of the comparator U1, M2 terminal for receiving the output of the NMOS transistor M2, a C1_charge terminal for charging the capacitor C1, and a line state 2 terminal for receiving the output value of the NMOS M2 through the resistor R4. The role of each of these terminals will be described in more detail below.

Hereinafter, the operation of the output stage sensing circuit of the motor driver will be described in detail with reference to the first B + short-circuit detection unit 111 and the first ground short-circuit detection unit 113.

≪ Operation of first B + short detection unit >

The operation of the first B + short detection unit will be described in more detail with reference to FIG.

The processor 105 turns on (turns on) the NMOS M1 via the M1_input terminal to determine the B + short-circuit condition before the motor is driven. That is, it is judged whether or not to perform the operation by judging the short-circuit state before the motor drive.

Then, the node A voltage of line 1 is distributed to the resistors R1 and R2, and the divided voltage of the node B is applied to the non-inverting terminal (+) of the comparator U1.

The comparator U1 compares the divided voltage with a reference voltage applied through the inverting terminal (-). The comparator U1 transfers the comparison result of the distribution voltage and the reference voltage to the processor 105 via the line_state 1 terminal.

The processor 105 determines the steady state when the reference voltage is greater than the distributed voltage. In the steady state, the processor 105 can drive the motor through the motor driver 101. [

On the other hand, when the distribution voltage is higher than the reference voltage (that is, in the high state), the B + power supply and the line 1 are judged to be short-circuited.

That is, when the B + power supply and the line 1 are short-circuited, the B + power is transmitted to the first B + short detection unit 111 through the line 1, and a voltage value greater than the steady state is transmitted to the node B.

As a result, the comparator U1 outputs a high state value, and the processor 105 generates a failure code indicating that the B + power supply and the line 1 are in a short-circuited state while preventing the motor driver 101 from being driven.

Due to the occurrence of the failure code, the user checks the wiring state and the like.

<Operation of first ground short detection unit>

The operation of the first ground short detection unit will be described in more detail with reference to FIG.

In the initial state, the C1 charge terminal has a high state. Therefore, the capacitor C1 maintains the charged state through the resistor R3 connected to the C1_charge terminal.

At this time, the line state 2 terminal connected to the resistor R4 is also in the high state.

When the line_state 2 terminal of the processor 105 receives the high state value from the first ground short detection unit 113, it is in a normal state. That is, the line 1 and the ground terminal are not short-circuited.

The processor 105 enables (turns on) the NMOS M2 via the M2_input terminal to judge the ground short before the motor is driven. Even when the NMOS M2 is turned on, the line_state 2 terminal is supplied with a high state value in the normal state as described above.

However, if line 1 and the ground terminal are short-circuited to each other, when the processor 105 turns on the NMOS M2 via the M2_input terminal, the charge charged in the capacitor C1 will be discharged through the shorted portion.

Thus, the voltage level of the resistor C1 becomes low, and the low state value is transferred to the line state 2 terminal.

Therefore, the processor 105 determines that the line 1 and the ground terminal are short-circuited according to the detection result of the first ground short-circuit detection unit 113, and generates a failure code to notify that the line 1 and the ground terminal are short-circuited.

Due to the occurrence of the failure code, the user checks the wiring state and the like.

7 is a flowchart illustrating an output stage sensing method of a motor driver according to a preferred embodiment of the present invention.

The process of detecting the B + short-circuit state and the ground short-circuit state according to the first B + short-circuit detection unit and the first ground short-circuit detection unit will be described in more detail with reference to FIG.

First, the processor 105 sets the M1_input terminal to the high state to turn on the NMOS M1, and sets the C1_charge terminal to the high state to charge the capacitor C1 (S100).

The processor 105 reads the value of the line_state 1 terminal connected to the output of the comparator U1 (S102).

If the read value of the line_state 1 terminal is HIGH, the processor 105 determines that the first and second lines and B + are short-circuited (S104), and accordingly outputs the fault code (B + So that the motor wiring or the controller can be checked (S106 to S108).

On the other hand, when the read value of the line_status 1 terminal of the comparator U1 is LOW, the processor 105 sets the M2_Sense terminal to the high state to turn on the NMOS M2 (S110 ).

Then, the value of the line_state 2 terminal connected to the output R4 of the first ground short detection unit 113 is read (S102).

When the read value of the line_status 2 terminal is LOW, the processor 105 determines that the first and second lines are in a short circuit state with respect to the ground GND (S114) So that the motor wiring or the controller can be checked (S116 to S108).

Due to the occurrence of the failure code, the user can check the wiring state and the like before driving the motor drivers 101 and 102, thereby preventing the motor drivers 101 and 102 from being burned down.

On the other hand, when the read value of the line_state 2 terminal is HIGH, the processor 105 determines a normal state in which no short circuit occurs in the line 1 and the line 2, and enables the motor operation (S118 To S120).

That is, in the steady state, the motor drivers 101 and 102 are in a state in which they can be driven in accordance with the control operation of the processor 105. [

On the other hand, the above-described steps are merely for convenience of description, and need not necessarily be performed in the above order. That is, the B + short circuit state of the line 1 and the second line and the ground short circuit state of the line 1 and the line 2 can not be simultaneously performed, but the ground short circuit state can be determined first and the B + short circuit state can be determined.

In this case, it is also possible to judge the ground short or the B + short-circuit state for line 2 with priority. The B + short-circuit state of the line 1 and the B + short-circuit state of the second line can be determined at the same time, and the ground short-circuit state of the line 1 and the ground short-circuit state of the line 2 can be determined at the same time.

In this embodiment, the output lines of the two motor drivers 101 and 102 connected to the motor 103 are connected to a short detection unit 111 ) 113 is constituted as a technical point.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be apparent that modifications, variations and equivalents of other embodiments are possible. Therefore, the true scope of the present invention should be determined by the technical idea of the appended claims.

101: first motor driver 102: second motor driver
103: motor 105: processor
111: first B + short detection unit 113: first ground short detection unit

Claims (8)

A first motor driver and a second motor driver for motor driving;
A first B + short detection unit and a first ground short detection unit connected to a first output line of the first motor driver; And
And a processor for determining a short-circuit state between the first output line and the second output line according to output values of the first B + short-circuit sensing unit and the first ground short-circuit sensing unit,
The first ground short detection unit may include:
A transistor that is turned on by the processor; And a capacitor charged by the processor, the capacitor discharging during a turn-on operation of the transistor. The method according to claim 1,
Wherein the first B +
A transistor coupled to the first output line;
Distribution resistances R1 and R2 connected to one end of the transistor; And
And a comparator for comparing the divided voltage between said R1 and R2 to a preset reference voltage. 3. The method of claim 2,
If the distribution voltage is greater than or equal to the reference voltage,
Wherein the processor determines that the first output line or the second output line and the B + power supply are in a short-circuited state. delete The method according to claim 1,
Wherein the processor determines that the first output line or the second output line and the ground terminal are short-circuited when the capacitor is discharged. 6. The method of claim 5,
Wherein the processor receives a low state value from the first ground short detection unit when the capacitor is discharged. 6. The method of claim 5,
Wherein when the first output line or the second output line and the ground terminal are short-circuited, the charge charged in the capacitor is discharged through the short-circuited portion. The method according to claim 1,
The processor includes an output terminal short detection circuit of a motor driver which simultaneously detects the B + short circuit state of the first output line and the second output line, or simultaneously detects a ground short circuit state of the first output line and the second output line, .

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