KR102569824B1 - Apparatus and method for protecting a vehicle - Google Patents

Abstract

The present invention relates to a vehicle protection device and method for preventing burnout of peripheral circuits due to sudden motor stop when an MDPS failure occurs.
A vehicle protection device according to an embodiment of the present invention includes a relay for conducting or blocking battery power for driving motor driven power steering (MDPS) on a high current path, and a three-phase motor by receiving a pulse width modulation (PWM) signal. When recognizing the failure of the motor driver for applying drive current to the U, V, and W phases of the motor driver and the MDPS, the duty-adjusted PWM signal is output to the motor driver, and the current signal fed back from the 3-phase motor for a predetermined period of time. It includes an electrical control unit (MCU) that outputs a control signal to block the relay according to the monitoring result of the.

Description

Vehicle protection device and method {APPARATUS AND METHOD FOR PROTECTING A VEHICLE}

The present invention relates to a vehicle protection device and method for preventing burnout of peripheral circuits due to sudden motor stop when an MDPS failure occurs.

In general, in order to facilitate rotation of a steering wheel, a steering apparatus of a vehicle uses a power pump that uses oil flow when the engine is driven to rotate the steering wheel, so that power steering is performed hydraulically.

Recently, motor driven power steering (MDPS) (hereinafter referred to as MDPS) has been applied to the steering system of a vehicle. This MDPS uses the rotation of a motor rather than the flow of oil caused by the rotation of an engine. This allows the steering wheel to be easily rotated, thereby reducing the load on the engine and thus improving fuel efficiency.

When such a MDPS failure situation occurs, the current flowing in the electrical control unit (ECU) and the motor that controls the operation of the MDPS is abruptly cut off by blocking the high current pass due to the relay blocking, resulting in inrush current In addition, there is a high possibility that internal elements of the ECU may be damaged due to counter-electromotive voltage caused by sudden motor stop.

The foregoing background art is technical information that the inventor possessed for derivation of the present invention or acquired during the derivation process of the present invention, and cannot necessarily be said to be known art disclosed to the general public prior to filing the present invention.

Korean Patent Publication No. 2013-0107683

The present invention has been made to solve the above problems and / or limitations, and an object of the present invention according to one aspect is to burn out ECU internal elements due to inrush current and reverse electromotive voltage due to sudden motor stop when an MDPS failure occurs. is to prevent

A vehicle protection device according to an embodiment of the present invention includes a relay that conducts or blocks battery power for driving motor driven power steering (MDPS) on a high current path; a motor driver for receiving a pulse width modulation (PWM) signal and applying driving current to U, V, and W phases of the three-phase motor; and when recognizing the occurrence of a failure of the MDPS, outputting a duty-adjusted PWM signal to the motor driving unit and outputting a control signal for shutting off the relay according to a monitoring result of a current signal fed back from the 3-phase motor for a predetermined time. It may include; an electrical control unit (MCU) to.

The device may include: a first current sensor connected between the motor driving unit and the connecting end of the U phase of the three-phase motor, sensing a first current output from the U phase of the three-phase motor and feeding back to the MCU; and a second current sensor connected between the motor driving unit and the connection terminal of phase V of the three-phase motor, sensing a second current output from phase V of the three-phase motor and feeding back the second current to the MCU. there is.

The MCU may recognize the occurrence of a failure at a level at which the MDPS stops.

The MCU may output the PWM signal whose duty is adjusted to 1/2 to the motor driver.

The MCU may enter the MDPS into a manual mode after blocking the relay.

A vehicle protection method according to an embodiment of the present invention includes recognizing, by an MCU, a failure of an MDPS; outputting, by the MCU, a PWM signal with an adjusted duty to a motor driving unit that receives a PWM signal and applies driving current to U, V, and W phases of the three-phase motor; monitoring, by the MCU, a current signal fed back from the three-phase motor for a predetermined period of time; and blocking, by the MCU, a relay that conducts or blocks battery power for driving the MDPS on a high current path according to a monitoring result of a current signal fed back from the 3-phase motor.

The monitoring may include monitoring a first current signal output from the U phase of the 3-phase motor and sensed and fed back by a first current sensor connected between the motor driver and the connection end of the U-phase of the 3-phase motor. doing; and monitoring a second current signal output from the V phase of the 3-phase motor and sensed and fed back by a second current sensor connected between the motor driver and the connection terminal of the V-phase of the 3-phase motor. can do.

The recognizing may include recognizing occurrence of a failure at a level at which the MDPS stops.

The outputting may include outputting the PWM signal whose duty is adjusted to 1/2 to the motor driving unit.

The method may further include, by the MCU, entering the MDPS into a manual mode after blocking the relay.

In addition to this, other methods for implementing the present invention, other systems, and computer programs for executing the methods may be further provided.

Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

According to embodiments, when an MDPS failure occurs, by using PWM duty control for controlling a motor to prevent ECU internal device burnout, additional failures can be prevented and accordingly A/S costs can be reduced.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a diagram schematically illustrating a vehicle protection device according to an embodiment of the present invention.
2 is a flowchart illustrating a vehicle protection method according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will become clear with reference to the detailed description of embodiments in conjunction with the accompanying drawings. However, it should be understood that the present invention is not limited to the embodiments presented below, but may be implemented in a variety of different forms, and includes all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. . The embodiments presented below are provided to complete the disclosure of the present invention and to fully inform those skilled in the art of the scope of the invention to which the present invention belongs. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded. Terms such as first and second may be used to describe various components, but components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same or corresponding components are assigned the same reference numerals, and overlapping descriptions thereof are omitted. I'm going to do it.

1 is a diagram schematically illustrating a vehicle protection device according to an embodiment of the present invention. Referring to FIG. 1 , the vehicle protection device 1 may include a three-phase motor 100, a battery 200, a first current sensor 300, a second current sensor 400, and an ECU 500. there is. In this embodiment, the ECU 500 may include a relay 510, an MCU 520, a pre-driver 530, and a motor driving unit 540.

The three-phase motor 100 may generate a power source of the MDPS by receiving current applied from the ECU 500 to each of the U, V, and W phases and rotationally driving the steering wheel (not shown).

The battery 200 may supply power for driving the MDPS, for example, 12V. The battery 200 includes a nickel-cadmium battery, a lead acid battery, a nickel metal hydride battery (NiMH), a lithium ion battery, and a lithium polymer battery. A rechargeable secondary battery such as a battery) may be included, but is not limited thereto.

The first current sensor 300 is a U-phase current sensor, connected between the motor driving unit 540 and the U-phase connecting end of the 3-phase motor 100, and the current flowing in the U-phase of the 3-phase motor 100 (below). Corresponding to the first current of the claims) may be sensed, converted into a voltage, and then fed back to the MCU 520.

The second current sensor 400 is a V-phase current sensor, and is connected between the motor driving unit 540 and the V-phase connecting terminal of the 3-phase motor 100, and the current flowing in the V-phase of the 3-phase motor 100 ( Corresponding to the second current of the following claims) may be sensed, converted into a voltage, and then fed back to the MCU 520.

The ECU 500 may control the entire operation of the vehicle protection device 1, and may operate to prevent burnout of internal elements of the ECU due to inrush current and reverse electromotive voltage due to sudden motor stop when an MDPS failure occurs. The ECU 500 may include a relay 510, an MCU 520, a pre-driver 530, and a motor driving unit 540.

The relay 510 serves as a switch that conducts or blocks the high current path 511 by receiving a command from the MCU 520. Here, the high current path 511 refers to a path formed between the relay 510 and the motor driving unit 540 to drive the three-phase motor 100 with power supplied from the battery 200 when the relay 510 is conducting. can include

The MCU 520 is responsible for central calculation of the MDPS and control of the motor driving unit 540, detects a failure mode when a failure situation occurs, and may issue a command to conduct or block the relay 510. Here, the MCU 520 may receive signals from blocks related to the MDPS, other than the illustrated blocks, and determine whether a normal signal is received to determine the MDPS failure. In addition, a fault master list database (not shown) may be provided therein. The fault level is stored in the fault master list database, and the fault level can be detected by comparing the received signal with the fault master list database. In this embodiment, when the MCU 520 detects a manual fault, Fault Level S or Fault Level A, as a serious fault in which the MDPS is stopped, it may perform a protective operation to prevent burnout.

In addition, the MCU 520 recognizes the sensing voltages of the first current sensor 300 and the second current sensor 400, checks whether the current flowing through the three-phase motor 100 is different from the command current, and issues a feedback command. .

The pre-driver 530 may operate the motor driving unit 540 according to a PWM control signal from the MCU 520 .

The motor driver 540 may receive the PWM signal of the pre-driver 530 to control the current flowing in the U, V, and W phases of the three-phase motor 100 . The motor driver 540 is composed of at least six FET (Field Effect Transistor) switching elements (not shown), is connected to phase U, V, and W, and receives a PWM signal from the pre-driver 530 to By being driven, driving current may be applied to U, V, and W phases of the three-phase motor 100, respectively.

Hereinafter, an operation of the MCU 520 will be described in detail. When a failure occurs in the MDPS, the MCU 520 can recognize this and detect a failure fault level. As a result of detecting the fault fault level, if the fault fault level is detected as a serious fault such that the MDPS stops, such as S or A, the MCU 520 sets the PWM duty of the FET switching element of each phase to the pre-driver 530 to 50% (1 /2) can be passed. Here, when the PWM duty is 50% (1/2), the current flowing through the 3-phase motor 100 becomes 0, so the most stable state is based on the situation in which the PWM signal is formed from the hardware point of view of the ECU 500 of the MDPS. It can be. The pre-driver 530 may control the FET switching element of each phase included in the motor driving unit 540 according to a command of the MCU 520 . The FET switching element of each phase included in the motor driving unit 540 operates at a PWM duty of 50% (1/2), and the current flowing through the three-phase motor 100 may be zero. The U-phase and V-phase currents of the three-phase motor 100 may be sensed by the first current sensor 300 and the second current sensor 400, converted into a voltage value of 2.5V, and fed back to the MCU 520. there is. When the reference phase current of the current sensors 300 and 400 applied to the current MDPS is 0, it can be converted into a voltage of 2.5V and fed back to the MCU 520. The MCU 520 may monitor that the first current and the second current from the first current sensor 300 and the second current sensor 400 become 0A (2.5V) for 3 periods. Since 1 period of PWM control of the FET switching element is 1/20KHz (50 μs), the MCU 520 can monitor for 150 μs from the first 0 current sensing point. It can be a standby time controlled by zero current. The MCU 520 monitors for 3 periods, and when all three-phase FET switching elements become 0 current, it can issue a cut-off command to the relay 510. When the relay 510 is blocked, the MCU 520 may enter the MDPS into manual mode in a 0 current state.

In the case of cutting off the current immediately upon occurrence of an MDPS failure situation, the prior art, which did not have time to separately protect circuit elements, could cause secondary failure conditions by causing permanent element burnout in addition to the existing cause of failure. The embodiment can prevent additional failure by fundamentally blocking secondary damage, which can also be advantageous in terms of a quantitative effect of reducing A/S costs for field claims.

2 is a flowchart illustrating a vehicle protection method according to an embodiment of the present invention. In the following description, descriptions of overlapping portions with those of FIG. 1 will be omitted.

Referring to FIG. 2 , in step S210, the MCU 520 recognizes when a failure occurs in the MDPS.

In step S220, the MCU 520 detects a failure fault level of the MDPS. A fault master list database in which MDPS fault levels according to fault signals are stored is provided inside the MCU 520, and the fault level can be detected by comparing the abnormal signal received by the MCU 520 with the fault master list database. .

In step S230, if the fault fault level is detected as a serious fault such that the MDPS stops, such as S or A, the MCU 520 sends the pre-driver 530 the PWM of each phase FET switching element included in the motor driving unit 540 The command is transmitted so that the duty is 50% (1/2). Here, when the PWM duty is 50% (1/2), the current flowing through the 3-phase motor 100 becomes 0, so the most stable state is based on the situation in which the PWM signal is formed from the hardware point of view of the ECU 500 of the MDPS. It can be.

In step S240, the pre-driver 530 outputs a PWM signal whose duty is adjusted to 50% (1/2) to the FET switching element of each phase included in the motor driving unit 540 according to the command of the MCU 520. With this operation, the current flowing through the three-phase motor 100 may be zero.

In step S250, the U-phase and V-phase currents of the three-phase motor 100 are sensed by the first current sensor 300 and the second current sensor 400, respectively, and converted to a voltage value of 2.5V, and then the MCU 520 ) is fed back. When the reference phase current of the current sensors 300 and 400 applied to the current MDPS is 0, it can be converted into a voltage of 2.5V and fed back to the MCU 520.

In step S260, the MCU 520 monitors that the first current and the second current from the first current sensor 300 and the second current sensor 400 become 0A (2.5V) for 3 periods. 1 period of FET switching element PWM control is 1/20KHz (50㎲), so MCU 520 can monitor for 150㎲ from the first 0 current sensing point, and monitoring for 3 periods is all 3-phase FET switching elements It can be a standby time controlled by zero current.

In step S270, the MCU 520 determines whether all three-phase FET switching elements become 0 current as a result of monitoring for 3 periods.

In step S280, the MCU 520 issues a blocking command to the relay only when all three-phase FET switching elements become 0 current as a result of monitoring for 3 periods.

In step S290, when the relay 510 is cut off, the MCU 520 enters the MDPS into manual mode in a 0 current state.

Embodiments according to the present invention described above may be implemented in the form of a computer program that can be executed on a computer through various components, and such a computer program may be recorded on a computer-readable medium. At this time, the medium is a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, an optical recording medium such as a CD-ROM and a DVD, a magneto-optical medium such as a floptical disk, and a ROM hardware devices specially configured to store and execute program instructions, such as RAM, flash memory, and the like.

Meanwhile, the computer program may be specially designed and configured for the present invention, or may be known and usable to those skilled in the art of computer software. An example of a computer program may include not only machine language code generated by a compiler but also high-level language code that can be executed by a computer using an interpreter or the like.

In the specification of the present invention (particularly in the claims), the use of the term "above" and similar indicating terms may correspond to both singular and plural. In addition, when a range is described in the present invention, it includes an invention in which individual values belonging to the range are applied (unless there is a description to the contrary), and each individual value constituting the range is described in the detailed description of the invention Same as

The steps constituting the method according to the present invention may be performed in any suitable order unless an order is explicitly stated or stated to the contrary. The present invention is not necessarily limited according to the order of description of the steps. The use of all examples or exemplary terms (eg, etc.) in the present invention is simply to explain the present invention in detail, and the scope of the present invention is limited due to the examples or exemplary terms unless limited by the claims. it is not going to be In addition, those skilled in the art can appreciate that various modifications, combinations and changes can be made according to design conditions and factors within the scope of the appended claims or equivalents thereof.

Therefore, the spirit of the present invention should not be limited to the above-described embodiments and should not be determined, and all scopes equivalent to or equivalently changed from the claims as well as the claims described below are within the scope of the spirit of the present invention. will be said to belong to

1: Vehicle protection device
100: 3-phase motor
200: battery
300: first current sensor
400: second current sensor
500: ECU
510: relay
520: MCU
530: free driver
540: motor drive unit

Claims (10)

A relay that conducts or blocks battery power for driving MDPS (motor driven power steering) on a high current path;
a motor driver for receiving a pulse width modulation (PWM) signal and applying driving current to U, V, and W phases of the three-phase motor; and
When recognizing the occurrence of a failure of the MDPS, outputting a duty-adjusted PWM signal to the motor driving unit, and outputting a control signal for blocking the relay according to the monitoring result of the current signal fed back from the 3-phase motor for a predetermined time Including; electrical control unit (MCU);
The MCU outputs a PWM signal with the duty adjusted to 1/2 to the motor driving unit so that the current flowing through the three-phase motor becomes zero. According to claim 1,
a first current sensor connected between the motor driver and a connection end of the U phase of the 3-phase motor, sensing a first current output from the U-phase of the 3-phase motor and feeding back the first current to the MCU; and
A second current sensor connected between the motor driving unit and the connection terminal of the V phase of the 3-phase motor, sensing a second current output from the V phase of the 3-phase motor and feeding back the second current to the MCU; further comprising a vehicle protection device. The method of claim 1, wherein the MCU,
A vehicle protection device that recognizes the occurrence of a failure at a level at which the MDPS stops. delete The method of claim 1, wherein the MCU,
A vehicle protection device for entering the MDPS into a manual mode after blocking the relay. Recognizing, by the MCU, a failure of the MDPS;
outputting, by the MCU, a PWM signal with an adjusted duty to a motor driving unit that receives a PWM signal and applies driving current to U, V, and W phases of the three-phase motor;
monitoring, by the MCU, a current signal fed back from the three-phase motor for a predetermined period of time; and
Blocking, by the MCU, a relay that conducts or blocks battery power for driving the MDPS on a high current path according to a monitoring result of a current signal fed back from the three-phase motor;
The outputting step is
and outputting a PWM signal with the duty cycle adjusted to 1/2 to the motor driver so that the current flowing through the three-phase motor becomes zero. The method of claim 6, wherein the monitoring step,
monitoring a first current signal output from the U-phase of the 3-phase motor and sensed and fed back by a first current sensor connected between the motor driving unit and a connection terminal of the U-phase of the 3-phase motor; and
Monitoring a second current signal output from the V phase of the three-phase motor and sensed and fed back by a second current sensor connected between the motor driver and the connection terminal of the V phase of the three-phase motor; , How to protect your vehicle. The method of claim 6, wherein the recognizing step,
Recognizing the occurrence of a failure at a level at which the MDPS stops; including, vehicle protection method. delete According to claim 6,
The vehicle protection method further comprising: entering the MDPS into a manual mode after blocking the relay by the MCU.

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