KR101650434B1

KR101650434B1 - Motor driver and the driving method thereof

Info

Publication number: KR101650434B1
Application number: KR1020150121409A
Authority: KR
Inventors: 박찬식; 이동선; 장우진
Original assignee: 충북대학교 산학협력단
Priority date: 2015-08-28
Filing date: 2015-08-28
Publication date: 2016-08-24

Abstract

The present invention provides a motor drive apparatus for driving a DC motor operated by a positive drive voltage and a negative drive voltage, comprising: a first switch element connected between a first node of the DC motor and the positive drive voltage; A second switch element connected between the second node of the direct current motor and the negative drive voltage, a third switch element connected between the second node of the direct current motor and the positive drive voltage, A fourth switching element connected between the node and the negative driving voltage, a first operation delay unit for delaying the first positive control signal for a predetermined time period and transmitting the delayed control signal to the first switching element, And a second operation delay unit for delaying the first switch element for a predetermined period of time and transmitting the delayed voltage to the third switch element. Therefore, the operation delay time between the PMOS transistor and the NMOS transistor is further increased by further forming the operation delay part in the front end of the PMOS transistor, and the operation delay time of such a switch element is secured to be one, .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a motor driving apparatus,

The present invention relates to a motor drive apparatus. And more particularly, to a motor driving apparatus having a circuit for detecting a motor driving state and a driving method thereof.

In order to control a general DC motor, direction (forward / reverse) and speed (voltage) control of the motor are required.

In order to control the direction of the motor, an H-Brigde circuit is used as shown in FIG. 1A, and P1 and N2, P2 and N1 are configured as a pair.

That is, the current flow of the motor M can be made as follows by turning on P1 and N2, and the rotation direction at this time is referred to as a clockwise direction (clock wise), and the current flow of the motor can be made as follows by turning on P2 and N1 The direction of rotation at this time is referred to as counter clock wise.

In order to control the speed (voltage) of the motor, the PWM input of each switch is used for each (forward and reverse) rotation, and the motor speed is controlled according to the duty value at this time.

However, when the H-bridge is used for motor control, the input object is controlled by the four switches P1, P2, N1, and N2, and the switch breakage phenomenon may occur due to the control sequence or the timing error.

For example, a short circuit can be formed by the switch operation delay time when the switches are switched to the switches P2 and N1 for reverse switching during forward rotation by P1 and N2.

In order to solve this problem, it is proposed to turn on the switch after a certain time delay considering the switch operation delay time after the switch is turned off during the turn-on, but this causes a delay of the motor control.

Also, as shown in FIG. 1B, when the switch is always ON due to the failure of P1, if P2 and N1 are turned on for reverse control, the current forms a short circuit through P1 and N1.

Korean Patent Registration No. 10-0704481 (Published on Apr. 10, 2007)

The present invention provides a motor drive apparatus capable of detecting and controlling a motor drive state by using an operation characteristic of the motor.

An embodiment of the present invention is directed to a motor drive apparatus for driving a DC motor operated by a positive drive voltage and a negative drive voltage, comprising: a first switch element connected between a first node of the DC motor and the positive drive voltage; A second switch element connected between the second node of the direct current motor and the negative drive voltage, a third switch element connected between the second node of the direct current motor and the positive drive voltage, A fourth switching element connected between the node and the negative driving voltage, a first operation delay unit for delaying the first positive control signal for a predetermined time period and transmitting the delayed control signal to the first switching element, And a second operation delay unit for delaying the first switch element for a predetermined period of time and transmitting the delayed voltage to the third switch element.

The first and third switch elements may be PMOS transistors, and the second and fourth switch elements may be NMOS transistors.

The first and second operation delay units may increase an operation time difference between the PMOS transistor and the NMOS transistor.

The motor driving apparatus may detect a voltage of the first node and determine an operation state of the first and third switch elements.

When the motor drive apparatus is driven in the forward direction, the first positive control signal is switched to the turn-off level, and the second switch element is turned off after the voltage of the first node drops.

Wherein the second control signal and the second negative control signal are switched to a turn-off level when the motor driving apparatus is driven in the reverse direction, and after the voltage of the first node is dropped, Can be determined.

The first operation delay unit or the second operation delay unit may include a plurality of resistors.

Wherein the first operation delay section includes a first resistor between the first positive control signal and the gate of the first switch element and a second resistor between the positive drive voltage and the gate of the first switch element, The second operation delay may comprise a third resistor between the second positive control signal and the gate of the third switch element and a fourth resistor between the positive drive voltage and the gate of the third switch element .

On the other hand, the embodiment includes a DC motor operated by a positive driving voltage and a negative driving voltage, a first switching element connected between a first node of the DC motor and the positive driving voltage, A third switch element connected between the second node of the direct current motor and the positive drive voltage; a second switch element connected between the first node of the direct current motor and the negative And a fourth switch element connected between the first switch element and the second switch element, the method comprising the steps of: delaying a first positive control signal, which is an off value in forward driving, Detecting a voltage drop at the first node within a threshold time and turning off the second switch element when a voltage drop of the first node occurs, A driving method of a driving apparatus is provided.

Checking again the first node voltage after turning off the second switch element and determining that the first switch element is operating normally if the first node voltage indicates turning off of the first switch element .

After checking the first node voltage, the level of the first positive control signal may be checked.

On the other hand, the embodiment includes a DC motor operated by a positive driving voltage and a negative driving voltage, a first switching element connected between a first node of the DC motor and the positive driving voltage, A third switch element connected between the second node of the direct current motor and the positive drive voltage; a second switch element connected between the first node of the direct current motor and the negative And a fourth switch element connected between the first switch element and the second switch element, the fourth switch element being connected between the first switch element and the second switch element, Generating a signal and delivering it to the third switch element for a predetermined time delay; detecting a voltage drop at the first node within a threshold time; If the generated and provides a driving method for a motor drive device including a step of determining that the third switching element to operate normally.

According to the present invention, the operation delay time between the PMOS transistor and the NMOS transistor is further increased by further forming the operation delay part in the front end of the PMOS transistor, and the operation delay time of such a switch element is secured, The turn-off state can be confirmed. Therefore, it is possible to protect the motor M and the element by preventing the risk that a short circuit occurs due to the direction switching drive while the PMOS transistor switching element is not completely turned off.

FIG. 1A is a circuit diagram showing the operation of the motor driving apparatus of the prior art, and FIG. 1B is a circuit diagram showing a malfunction of FIG. 1A.
2 is a circuit diagram showing an embodiment of a motor driving apparatus according to the present invention.
3 is a circuit diagram showing an example of the operation delay unit of FIG.
4 is a flowchart showing a forward driving method of the motor driving apparatus of the present invention.
5 is a waveform diagram according to the flowchart of FIG.
6 is a flowchart showing a reverse drive method of the motor drive apparatus of the present invention.
7 is a waveform diagram according to the flowchart of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between .

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

Hereinafter, a motor M driving apparatus, which is an embodiment of the present invention, will be described with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a circuit diagram showing an embodiment of a motor M driving apparatus according to the present invention, and FIG. 3 is a circuit diagram showing an example of the operation delay unit of FIG.

The motor drive apparatus of the present invention includes a motor driver including four switches between a positive drive voltage (VCC) and a negative drive voltage (VSS).

The motor driving unit includes a direct current (DC) motor M connected between the first node n1 and the second node n2 to change the direction of rotation according to the currents of both nodes n1 and n2.

In addition, the motor driving unit includes a first switching device Q1 connected between the positive driving voltage VCC and the first node n1 to perform on / off according to the first positive control signal P1.

The first switch element Q1 is a PMOS transistor which is turned on and off according to the first positive control signal P1 to transfer the positive drive voltage VCC to the first node n1.

The motor driving unit includes a second switching device Q2 connected between the negative driving voltage VSS and the second node n2 to perform ON / OFF in accordance with the second negative control signal N2.

The second switch element Q2 is an NMOS transistor which is turned on and off according to the second negative control signal N2 to transfer the negative drive voltage VSS to the second node n2.

The motor M driving unit includes a third switching device Q3 connected between the positive driving voltage VCC and the second node n2 to perform on / off according to the second positive control signal P2 .

The third switch element Q3 is a PMOS transistor which is turned on and off according to the second positive control signal P2 to transfer the positive drive voltage VCC to the second node n2.

The motor M driving part includes a fourth switching element Q4 connected between the negative driving voltage VSS and the first node n1 to perform on-off in accordance with the first negative control signal N1 .

The fourth switching element Q4 is an NMOS transistor which is turned on and off according to the first negative control signal N1 to transmit the negative driving voltage VSS to the first node n1.

The four switching elements Q1, Q2, Q3 and Q4 are connected in an H-bridge type between the two ends n1 and n2 of the DC motor M and the two driving voltages VCC and VSS.

When the motor M is driven in the clockwise direction, the motor driving apparatus turns on the first and second switch elements Q1 and Q2 to turn off the current from the first node n1 2 node n2.

On the other hand, when the motor driving apparatus is driven in the reverse direction, that is, when the motor M is driven to rotate in the counterclockwise direction, the third and fourth switch elements Q3 and Q4 are turned on to supply the current to the second node n2, To the first node n1.

At this time, the motor drive apparatus further includes the first operation delay unit 10 at the gate of the first switch element Q1.

The first operation delay unit 10 includes a circuit for delaying the first positive control signal P1 for a predetermined time and transmitting it to the gate of the first switch device Q1.

For example, the first operation delay unit 10 may be formed of a resistance column as shown in FIG. 3A.

That is, the first resistor R1 and the positive drive voltage VCC, which are connected between the first positive control signal P1 and the gate of the first switch element Q1, And a second resistor R2 connected between the gates.

At this time, the first resistor R1 and the second resistor R2 may have the same size.

In FIG. 3A, a simple resistor string is realized, but it may be formed of a resistor circuit including a plurality of resistors according to the delay time of the circuit.

It may also include an operation delay section including a switch element such as a buffer.

The motor (M) driving apparatus further includes a second operation delay unit (2) at the gate of the second switch element (Q2).

The second operation delay unit 20 includes a circuit for delaying the second positive control signal P2 for a predetermined time period and transmitting the delayed control signal P2 to the gate of the third switch element Q3.

For example, the second operation delay unit 20 may be formed of a resistance column as shown in FIG. 3B.

That is, the third resistor R3 and the positive drive voltage VCC, which are connected between the second positive control signal P2 and the gate of the third switch element Q3, And a fourth resistor R4 connected between the gates.

At this time, the third resistor R3 and the fourth resistor R4 may have the same size.

In FIG. 3B, a simple resistor string may be formed as a resistor circuit including a plurality of resistors according to the delay time of the circuit.

It may also include a delay circuit including a switching element such as a buffer.

Also, the first operation delay unit 10 and the second operation delay unit 20 may be implemented by the same circuit, but they may be implemented by different circuits.

The motor driving apparatus further includes a motor voltage detecting unit 30 that reads the voltage of the first node n1.

The motor driving apparatus may further include protection elements D1, D2, D3, and D4 that are connected in parallel with the switching elements Q1 to Q4 to prevent reverse voltages of the switching elements.

The protection elements D1, D2, D3, and D4 may be implemented as diodes, but are not limited thereto.

The motor M driving apparatus controls the first and third switching elements Q1 and Q2 within a short period of time in order to prevent a driving error of the motor M due to the signal delay of the first and third switching elements Q3, Q3) is turned off, and then the drive is switched.

Hereinafter, a driving method in forward driving will be described with reference to FIGS. 4 and 5. FIG.

4 is a flowchart showing a forward driving method of the motor (M) driving apparatus of the present invention, and Fig. 5 is a waveform diagram according to the flowchart of Fig.

The driving direction is switched in the reverse direction when the forward driving, that is, the first and second switching elements Q1 and Q2 are turned on and the current flows from the first node n1 to the second node n2, When confirming the state of the element Q1, that is, the PMOS transistor, the driving as shown in Fig. 4 is performed.

First, the motor voltage detector 30 is initialized to set the output terminal of the detector 30 to have an initial value (s100).

At this time, the initial value may be the same value as the positive driving voltage VCC.

Next, an off signal is applied to the first positive control signal P1 (s110). That is, as shown in FIG. 5, the value of the first positive control signal P1 rises to the turn-off level.

At this time, it is detected whether a voltage drop, that is, a falling edge, occurs in the value of the first node n1 that is read by the motor voltage detecting unit 30 during the critical time (s120).

At this time, the threshold time can be arbitrarily set by the user, but is longer than the sum of the turn-off time of the normal PMOS transistor and the delay time of the operation delay unit 10. [ In addition, the threshold time is shorter than the stopping time for turning off the switching element and stopping the driving of the motor M when the operation of the conventional direct current motor M is changed.

When the voltage of the first node n1 drops while the first switching element Q1 is turned off with a predetermined delay time and the polling edge fe is detected as shown in Fig. 5, the second switching element Q2 (S130). When the first and second switch elements Q1 and Q2 connected to both ends n1 and n2 of the motor M are all turned off, the motor M is not driven.

In this state, the voltage of the motor voltage detection unit 30 is checked again and it is checked whether the first switching device Q1 is turned off within the critical time (s140).

If it is confirmed that the first switch element Q1 is turned off within the threshold time period, the delay time of the first switch element Q1 and the first operation delay section 10, that is, the first positive control signal P1 The off time of the first switch element Q1 is longer than the typical delay time of the PMOS transistor at step S150.

Next, the first control signal P1 is checked again to read whether the first positive control signal P1 is an off value or an on value, and when the first positive control signal P1 is in the off state It is confirmed that the first switch element Q1 is off (s160).

If it is determined that the first positive control signal P1 is in the off state, it is determined that the first switch element Q1 operates normally (S170) and the operation of the motor M is changed.

That is, forward driving can be performed again or reverse driving can be performed.

In this way, the operation delay time 10 is further formed in the front end of the PMOS transistor so that the operation time difference between the PMOS transistor and the NMOS transistor is made larger, and the operation delay time of the first switch element Q1 is secured, So that the PMOS transistor can be sufficiently turned off within the delay time.

Therefore, it is possible to protect the motor M and the element by preventing the risk of short circuit due to conversion into reverse driving in a state where the first switch element Q1 is not completely turned off.

Hereinafter, a method of driving the third transistor in the reverse driving will be described with reference to FIGS. 6 and 7. FIG.

FIG. 6 is a flowchart showing a reverse drive method of the motor driving apparatus of the present invention, and FIG. 7 is a waveform diagram according to the flowchart of FIG.

It is possible to switch the driving direction in the forward direction in the reverse driving state, that is, in the state where the third and fourth switching elements Q3 and Q4 are turned on and the current flows from the second node n2 to the first node n1, In the case of confirming the state of the element Q3, that is, the PMOS transistor, the driving as shown in Fig. 6 is performed.

First, the motor voltage detector 30 is initialized to set the output of the detector to have an initial value (s200).

Next, an OFF signal is simultaneously applied to the second positive control signal P2 and the first negative control signal N1. That is, as shown in FIG. 7, the second control signal P2 is increased to the turn-off level and the first negative control signal N1 is decreased to the turn-off level (s210).

When the turn-off signal is simultaneously applied to the third and fourth switch elements Q3 and Q4, the operation time difference between the PMOS transistor and the NMOS transistor and the fourth switch element Q4 according to the second operation delay part 20 It is turned off first.

Next, it is detected whether or not a voltage drop, that is, a polling edge, occurs at the value of the first node n1 that is read by the motor voltage detecting unit 30 during the threshold time in accordance with the operation delay of the third switch element Q3 ).

At this time, the threshold time can be arbitrarily set by the user, but is longer than the turn-off time of the normal PMOS transistor and the delay time of the operation delay unit 20. [ In addition, the threshold time is shorter than the stopping time for turning off the switching element and stopping the driving of the motor M when the operation of the conventional direct current motor M is changed.

When the voltage of the first node n1 drops while the third switching element Q3 is turned off with a predetermined delay time and the polling edge fe is detected as shown in Fig. 7, And checks whether the third switching device Q3 is turned off within the critical time (s230).

If it is confirmed that the third switch element Q3 is turned off within the threshold time, the delay time of the third switch element Q3 and the second operation delay part 30 is larger than the typical delay time of the PMOS transistor (S240).

Next, the state of the control signal P2 of the second amount is checked again to read whether the control signal P2 of the second amount is the off value or the on value, and the second positive control signal P2 is turned off It is confirmed that the second switch element Q2 is off (s250).

If it is determined that the second positive control signal P2 is in the off state, it is determined that the second switch element Q2 is normally operated and the operation of the motor M is changed (s260).

That is, the backward driving can be performed again or the forward driving can proceed.

In this way, an operation delay time is further formed in the front end of the PMOS transistor so that the operation time difference between the PMOS transistor and the NMOS transistor is made larger, and the operation delay time of the switch element is secured to sufficiently turn off the PMOS transistor Can be achieved.

Therefore, it is possible to protect the motor M and the element by preventing the risk that a short circuit occurs due to the direction switching drive while the PMOS transistor switching element is not completely turned off.

The embodiments of the present invention described above are not only implemented by the apparatus and method but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded, The embodiments can be easily implemented by those skilled in the art from the description of the embodiments described above.

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 belongs to the scope of right.

10: first operation delay unit
20: second operation delay unit
30: Motor voltage detector

Claims

A motor drive apparatus for driving a DC motor operated by a positive drive voltage and a negative drive voltage,
A first switch element connected between a first node of the DC motor and the positive drive voltage,
A second switch element connected between the second node of the DC motor and the negative drive voltage,
A third switch element connected between the second node of the DC motor and the positive drive voltage,
A fourth switch element connected between the first node of the DC motor and the negative drive voltage,
A first operation delay unit for delaying a control signal of a first amount for a predetermined time period and transmitting the delayed control signal to the first switch element
And a second operation delay unit for delaying the second control signal for a predetermined time period and transmitting the delayed control signal to the third switch element,
Lt; / RTI >
Wherein the motor driving apparatus detects a voltage of the first node and determines an operation state of the first and third switch elements
Motor drive device.

The method according to claim 1,
Wherein the first and third switch elements are PMOS transistors and the second and fourth switch elements are NMOS transistors.

3. The method of claim 2,
Wherein the first and second operation delay units increase the operation time difference between the PMOS transistor and the NMOS transistor.

delete

The method according to claim 1,
Wherein the first control signal is switched to the turn-off level and the second switch element is turned off after the voltage of the first node drops when the motor drive device is driven in the forward direction.

The method according to claim 1,
Wherein the second control signal and the second negative control signal are switched to a turn-off level when the motor driving apparatus is driven in the reverse direction, and after the voltage of the first node is dropped, The motor driving apparatus comprising:

delete

The method according to claim 1,
Wherein the first operation delay unit comprises:
A first resistor between the first positive control signal and the gate of the first switch element and a second resistor between the positive drive voltage and the gate of the first switch element,
Wherein the second operation delay unit comprises a motor drive circuit including a third resistor between the second positive control signal and the gate of the third switch element and a fourth resistor between the positive drive voltage and the gate of the third switch element Device.

A first switch element connected between the first node of the direct current motor and the positive drive voltage, a second switch element connected between the second node of the direct current motor and the negative drive A third switch element connected between the second node of the direct current motor and the positive drive voltage, a second switch element connected between the first node of the direct current motor and the negative drive voltage, And a fourth switch element connected to the first switch element,
Delaying a first positive control signal, which is an OFF value in forward driving, for a predetermined period of time and transmitting the delayed control signal to the first switching device;
Detecting a voltage drop at the first node within a threshold time, and
And turning off the second switch element when a voltage drop of the first node occurs.

10. The method of claim 9,
Rechecking the first node voltage after turning off the second switch element, and
And determining that the first switch element operates normally if the first node voltage indicates the turn-off of the first switch element.

11. The method of claim 10,
And checking the level of the first positive control signal after checking the first node voltage.

A first switch element connected between the first node of the direct current motor and the positive drive voltage, a second switch element connected between the second node of the direct current motor and the negative drive A third switch element connected between the second node of the direct current motor and the positive drive voltage, a second switch element connected between the first node of the direct current motor and the negative drive voltage, And a fourth switch element connected to the first switch element,
Applying a first negative control signal, which is an off value in the reverse driving, to the fourth switching element, generating a second positive control signal, and delaying the control signal to the third switching element for a predetermined time,
Detecting a voltage drop at the first node within a threshold time, and
And determining that the third switch element operates normally when a voltage drop of the first node occurs.