KR20230137616A - Method and apparatus for controlling transition from auto vehicle hold function to electronic parking brake function, and vehicle having the same - Google Patents

Abstract

The present invention relates to a method and device for controlling the transition from an automatic vehicle hold function to an electronic parking brake function, and a vehicle equipped with the same. The control method according to an embodiment of the present invention is a vehicle control method that switches the braking force function so that the Electronic Parking Brake (EPB) function operates after the Auto Vehicle Hold (AVH) function operates, comprising: determining whether the braking force of the EPB function is less than a reference value at a time when the driver is expected to get off during the transition to the EPB function; and generating a warning notification signal when the braking force of the EPB function is less than the reference value.

Description

Method and device for controlling the transition from an automatic vehicle hold function to an electronic parking brake function, and a vehicle equipped therewith

The present invention relates to a transition control technology from the automatic vehicle hold function to the electronic parking brake function, and more specifically, to the electronic parking brake (EPB) function after operation of the automatic vehicle hold (AVH) function. This is about a technology to prepare for a situation in which braking force cannot be formed while switching the braking force function to operate.

There are cases where the Electronic Parking Brake (EPB) system and Automatic Vehicle Hold (AVH) system are applied together to a vehicle. At this time, EPB is controlled electronically, unlike the wire method, and is a device that automatically applies the brakes when the vehicle is stopped and then automatically releases the brakes when the driver steps on the accelerator pedal to start.

In addition, AVH is a device for realizing waiting at a signal or easy stopping in a complex city center or on an incline where stopping occurs frequently. In particular, the AVH is connected to the EPB unit (UNIT) by an electrical signal. Unlike the EPB, which operates the brake by hydraulic pressure, it is connected to the ESC (Electronic Stability Control) unit (UNIT) by an electrical signal and operates the brake through a pneumatic actuator. I order it.

In other words, the AVH function is an additional function of ESC that automatically holds hydraulic pressure when the driver presses the brake pedal while the AVH activation switch is turned on and the vehicle stops, thereby maintaining braking force even when the driver releases the brake pedal. Accordingly, when the AVH function is activated, the stopped state of the vehicle can be maintained through hydraulic pressure even if the driver does not press the brake pedal when the vehicle is stopped.

In particular, the AVH function is activated and automatically switches to EPB when a certain period of time is exceeded after the hydraulic hold function is activated. Hereinafter, this function is referred to as the “EPB conversion function”. That is, when a large amount of power consumption is expected due to prolonged operation of the AVH function, the vehicle can be maintained in a stopped state by operating the EPB switching function.

Meanwhile, there are cases where the driver of a vehicle to which the EPB switching function is applied leaves the vehicle while the vehicle is stopped (i.e., exit is realized). However, if braking force cannot be established during automatic conversion to EPB (e.g., related hardware failure, etc.), an accident may occur as a vehicle without a driver is pushed on a slope (e.g., a hill, etc.).

However, the above-described content merely provides background information on the present invention and does not correspond to previously disclosed technology.

In order to solve the problems of the prior art as described above, the present invention provides a technology to prepare for a situation in which braking force cannot be formed during the switching of the braking force function so that the EPB function operates after the AVH function is activated in a vehicle to which the EPB switching function is applied. The purpose is to provide.

However, the problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The control method according to an embodiment of the present invention to solve the above problem is to apply a braking force function so that the Electronic Parking Brake (EPB) function operates after the Auto Vehicle Hold (AVH) function operates. A method of controlling a vehicle in transition, comprising: determining whether a braking force of the EPB function is set to be less than a reference value at a time when a driver is expected to get off while switching to the EPB function; and generating a warning notification signal when the braking force of the EPB function is less than the reference value.

The expected time of getting off may occur at a time after the driver's intention to get off is recognized.

The expected time of getting off may be generated during the period between when the driver's intention to get off is recognized and the pre-stored expected stay time of the driver before getting off.

The act of willingness to get off may include unfastening the driver's seat belt or opening the driver's seat door.

The expected disembarkation time may occur during a time when the hydraulic pressure of the AVH function that maintains the vehicle at a stop is applied.

The braking force of the EPB function can be determined based on the difference between the EPB current applied in relation to the EPB function and the no-load current.

The control device according to an embodiment of the present invention is a control device that switches the braking force function so that the Electronic Parking Brake (EPB) function operates after the Auto Vehicle Hold (AVH) function is activated in the vehicle, a memory storing a reference value for braking force of the EPB function; and a processor that performs control using information stored in the memory.

The processor determines whether the braking force of the EPB function is less than the reference value at the expected time when the driver gets off during the transition to the EPB function, and then, when the braking force of the EPB function is less than the reference value, the processor determines whether the braking force of the EPB function is less than the reference value. A warning notification signal can be generated.

The processor may use the time between the recognition of the driver's intention to get off and the pre-stored expected stay time of the driver before getting off as the expected time of getting off.

The processor may use the time during which the hydraulic pressure of the AVH function, which maintains the vehicle stopped, is applied, as the expected time of getting off.

The processor may determine the braking force of the EPB function based on the difference between the EPB current applied in relation to the EPB function and the no-load current.

A vehicle according to an embodiment of the present invention includes a first control device that controls an Auto Vehicle Hold (AVH) function; and a second control device that controls an electronic parking brake (EPB) function.

The second ECU determines whether the braking force of the EPB function is lower than the reference value at the expected time of the driver's exit during switching of the braking force function so that the EPB function operates after the AVH function is activated, and then operates the EPB function. If the braking force is less than the reference value, a warning signal may be generated.

A vehicle according to another embodiment of the present invention is a vehicle that includes an integrated control device that integrates and controls an Auto Vehicle Hold (AVH) function and an Electronic Parking Brake (EPB) function, The integrated control device determines whether the braking force of the EPB function is lower than the reference value at the expected time of the driver's exit during switching of the braking force function so that the EPB function operates after the AVH function is activated, and then determines whether the braking force of the EPB function is lower than the reference value. If it falls below the above-mentioned reference value, it generates a warning notification signal.

The present invention configured as described above can prepare for a situation in which braking force cannot be formed during the switching of the braking force function so that the EPB function operates after the AVH function is activated in a vehicle to which the EPB switching function is applied, thereby preventing vehicle accidents in advance. There is an advantage to doing this.

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

1 is a block diagram of a device according to an embodiment of the present invention.
Figure 2 shows a flowchart of a control method according to an embodiment of the present invention.
Figure 3 shows a more detailed flowchart of a control method according to an embodiment of the present invention.
Figure 4 shows a time-dependent diagram of hydraulic pressure, EPB current and braking force when the EPB switching function is operating normally.
Figure 5 shows a time-dependent diagram of hydraulic pressure, EPB current, and braking force when the EPB switching function operates abnormally.
Figure 6 shows a time-dependent diagram of hydraulic pressure, EPB current and braking force for the EPB switching function to prepare for abnormal operation.

The above purpose and means of the present invention and the resulting effects will become clearer through the following detailed description in conjunction with the accompanying drawings, and thus the technical idea of the present invention will be easily understood by those skilled in the art. It will be possible to implement it. Additionally, in describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

The terminology used herein is for describing embodiments and is not intended to limit the invention. In this specification, singular forms also include plural forms, as appropriate, unless specifically stated otherwise in the context. In this specification, terms such as “comprise,” “provide,” “provide,” or “have” do not exclude the presence or addition of one or more other components other than the mentioned components.

In this specification, terms such as “or” and “at least one” may represent one of words listed together, or a combination of two or more. For example, “A or B”, “at least one of A and B” may include only A or B, or both A and B.

In this specification, descriptions under "for example" and the like may not exactly match the information presented, such as the cited characteristics, variables, or values, and may be subject to tolerances, measurement errors, limits of measurement accuracy and other commonly known factors. Effects such as modifications, including, should not limit the embodiments of the invention according to various embodiments of the present invention.

In this specification, when a component is described as being 'connected' or 'connected' to another component, it may be directly connected or connected to the other component, but other components may exist in between. It must be understood that it may be possible. On the other hand, when a component is mentioned as being 'directly connected' or 'directly connected' to another component, it should be understood that there are no other components in between.

In this specification, when a component is described as being ‘on’ or ‘in contact with’ another component, it may be in direct contact with or connected to the other component, but there may be another component in between. It must be understood that it can be done. On the other hand, if a component is described as being 'right above' or 'in direct contact' with another component, it can be understood that there is no other component in the middle. Other expressions that describe the relationship between components, such as 'between' and 'directly between', can be interpreted similarly.

In this specification, terms such as 'first' and 'second' may be used to describe various components, but the components should not be limited by the above terms. Additionally, the above term should not be interpreted as limiting the order of each component, but may be used for the purpose of distinguishing one component from another component. For example, a 'first component' may be named a 'second component', and similarly, a 'second component' may also be named a 'first component'.

Unless otherwise defined, all terms used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

1 is a block diagram of a device according to an embodiment of the present invention.

The device according to an embodiment of the present invention (hereinafter referred to as “this device”) is a device applied to a vehicle and is a device for controlling the braking force of the vehicle. As shown in FIG. 1, it is connected through an interface. It includes a plurality of electronic control units (ECUs) 10 and 20 that perform control functions by transmitting and receiving various electrical signals such as control signals and status signals.

At this time, the first control device (i.e., first ECU) 10 is a device for controlling the Auto Vehicle Hold (AVH) function and may be a device for controlling an Electronic Stability Control (ESC) system. . At this time, the ESC system is a device for optimally controlling the driving posture of the vehicle, and is a next-generation device of the Anti-Lock Brake System (ABS) that prevents the wheels from locking during braking. This ESC system can enhance driving stability on dry roads, rainy roads, gravel roads, snowy roads, etc. by momentarily controlling each of the four wheels independently to maintain stability when the vehicle is about to skid.

In particular, the first ECU 10 can control the performance of the AVH function. That is, the first ECU 10 can control the operation of the AVH function by operating the brake through a pneumatic actuator using an electrical signal.

In other words, the AVH function may be an additional function of the ESC system that automatically holds hydraulic pressure when the driver presses the brake pedal while the AVH activation switch is turned on and the vehicle stops, thereby maintaining braking force even when the driver releases the brake pedal. Accordingly, when the AVH function is activated, the stopped state of the vehicle can be maintained through hydraulic pressure even if the driver does not press the brake pedal when the vehicle is stopped.

The first ECU 10 may include a processor (not shown) and a memory (not shown). That is, the memory can store programs for processing or controlling the processor and various data for controlling braking force, such as controlling the AVH function.

Additionally, the second control device (i.e., second ECU) 20 is a device for controlling an electronic parking brake (EPB) function and may be a device for controlling the EPB system. At this time, the EPB system is a device that electronically controls the operation of the parking brake. Even if the driver does not manually apply the parking brake, the EPB system operates automatically when the vehicle is stopped or there is a risk of the vehicle rolling backward when starting up a hill. This allows the car to be maintained in a parked or stopped state.

In particular, when the AVH function is activated and a certain time period is exceeded after the hydraulic hold function is activated, the EPB switching function is activated, which automatically switches to the EPB function. That is, when a large amount of power consumption is expected due to prolonged operation of the AVH function, the second ECU 20 controls the EPB switching function to operate, thereby maintaining the vehicle's stationary state.

The second ECU 20 may include a processor (not shown) and a memory (not shown). That is, the memory can store programs for processor processing or control and various data for controlling braking force, such as control of the EPB function and EPB switching function.

However, in the present invention, the ESC system and EPB system may be integrated into one system. In this case, one integrated control device (i.e., integrated ECU) in which the first and second ECUs 10 and 20 are integrated may perform each control function of the first and second ECUs 10 and 20.

The integrated ECU may include a processor (not shown) and memory (not shown). That is, the memory can store programs for processor processing or control and various data for controlling braking force, such as control of AVH functions, EPB functions, and EPB switching functions.

For example, the memory included in the first ECU 10, the second ECU 20, or the integrated ECU is not only volatile memory such as S-RAM and D-RAM, but also flash memory and ROM. It may include non-volatile memory such as Read Only Memory (ROM) and Erasable Programmable Read Only Memory (EPROM).

Hereinafter, a method of controlling the EPB switching function for the case where the first ECU 10 and the second ECU 20 are respectively provided will be described. However, this control method can be applied even when an integrated ECU is provided. In this case, control performed by the first and second ECUs 10 and 20 may be performed by the integrated ECU.

Figure 2 shows a flowchart of a control method according to an embodiment of the present invention, and Figure 3 shows a more detailed flowchart of a control method according to an embodiment of the present invention.

The control method (hereinafter referred to as “this control method”) according to an embodiment of the present invention is performed by the second ECU 20 and is a method for controlling the performance of the EPB switching function. That is, this control method can be performed while switching the braking force function to operate the EPB function after the AVH function is activated.

As shown in FIG. 2, this control method determines whether the braking force of the EPB function satisfies the reference value (i.e., is formed below the reference value) at the expected time of the driver's exit during the transition to the EPB function. A step (S210) of generating a warning notification signal when the braking force of the EPB function does not satisfy the reference value (i.e., less than the reference value) (S220), and a step of generating a warning notification signal when the braking force of the EPB function does not meet the reference value (S220). A step (S230) of performing the EPB function may be included when the value is satisfied (that is, when the value is greater than or equal to the reference value).

Specifically, this control method may include S201 to S205, S221, S222, and S231, as shown in FIG. 3. That is, S210 may include S211 to S215, S220 may include S221 and S222, and S231 may include S231.

First, in S211, the second ECU 20 determines whether the AVH function is operating. For example, the second ECU 20 can determine whether the AVH function is operating using a status signal related to the operation of the AVH function transmitted from the first ECU 10, etc. As a result of S211, if the AVH function is operating, S212 is performed, and if the AVH function is not operating, it is terminated.

In S212, the second ECU 20 determines whether the driver's defective action occurs. At this time, the driver's act of willingness to get off is an action the driver takes before getting off the vehicle. For example, the act of willing to get off may include unfastening the driver's seat belt or opening the driver's seat door.

In other words, the second ECU 20 can recognize (grasp) whether such a defective volitional act occurs using a sensor signal from a sensor related to the corresponding abort volitional act. For example, the second ECU 20 can recognize the act of getting off the driver's seat related to unfastening the seat belt using a sensor signal from the driver's seat seat belt wearing detection sensor, and uses a sensor signal from the driver's seat door opening/closing detection sensor to Using this, it is possible to recognize the act of willingness to get off related to opening the driver's seat door. However, these sensor signals can be transmitted from the sensor through a communication interface, or through a communication interface with the first ECU 10 or another ECU that received the sensor signal.

As a result of S212, if the occurrence of an act of will to get off is recognized, S213 is performed, and if the occurrence of an act of will to get off is not recognized, the process returns to S211.

Figure 4 shows a time-dependent diagram of hydraulic pressure, EPB current and braking force when the EPB switching function is operating normally. Additionally, Figure 5 shows a time-dependent diagram of hydraulic pressure, EPB current, and braking force when the EPB switching function operates abnormally.

In S213, the second ECU 20 controls the braking force function to be switched from the AVH function to the EPB function. That is, the second ECU 20 performs an EPB switching function while communicating with the first ECU 10. That is, according to the communication, as shown in FIGS. 4 and 5, the first ECU 10, which was operating the AVH function by operating the brake of the ESC system, operates the hydraulic pressure for a certain period of time to operate the AVH function. (i.e., hydraulic pressure holding time) and then gradually decrease. In addition, according to the communication, the second ECU 20 applies the driving current (i.e., EPB current) of the EPB motor to operate the brake of the EPB system within the hydraulic maintenance time at a value greater than the no-load current of the EPB motor. By doing so, the EPB function is activated, and thus the EPB switching function can be performed.

Referring to FIG. 4, when the EPB switching function operates normally, the hydraulic pressure of the brake of the ESC system is maintained above a certain level and a current greater than the no-load current of the EPB motor is generated within the time when the AVH function is operating (i.e., hydraulic pressure maintenance time). An EBP current of value is applied. Accordingly, as the EPB function operates normally, a fastening force sufficient to maintain the vehicle in a stopped state is created by the brakes of the EPB system.

However, referring to FIG. 5, when the EPB switching function operates abnormally due to a hardware failure of the EPB system, an EBP current greater than the no-load current of the EPB motor is not applied within the hydraulic maintenance time. Accordingly, as the EPB function operates abnormally, the brakes of the EPB system do not generate enough fastening force to maintain the vehicle in a stopped state, and as a result, the vehicle becomes movable. If the driver disembarks in this state, an accident may occur as the vehicle without the driver is pushed off an inclined area (e.g., a hill, etc.).

Figure 6 shows a time-dependent diagram of hydraulic pressure, EPB current and braking force for the EPB switching function to prepare for abnormal operation.

To solve this problem, as shown in FIG. 6, the present invention determines whether the braking force of the EPB function satisfies the reference value at the expected time when the driver gets off during the transition to the EPB function. For this purpose, determination steps according to S214 and S215 are additionally performed.

In S214, the second ECU 20 determines whether the expected unloading point has been reached. At this time, the expected time of getting off is the time after it is recognized that the act of willingness to get off has occurred, and is the time when the driver is expected to actually realize getting off. Accordingly, the expected time of getting off is generated during the period between when the driver's intention to get off is recognized as having occurred and the driver's expected stay before getting off.

At this time, the expected residence time before getting off is the time the driver stayed in the vehicle from the time he started his will to get off to the time he actually realized getting off, and is derived through experiment, and the data for that time is already stored in the memory of the second ECU. It can be. If the EPB switching function operates abnormally as shown in FIG. 5, an accident can be prevented only if a warning notification, which will be described later, is delivered to the driver during the expected stay time before getting off (i.e., while the driver is still in the vehicle). .

For example, the expected residence time before getting off may be 1 to 3 seconds. In other words, the driver can actually get off within 1 to 3 seconds from the time he or she begins to intend to get off, such as unfastening the driver's seat belt or opening the driver's seat door.

In particular, so that it can be determined whether the EPB function operates normally while the vehicle is maintained at a stop, the expected time of disembarkation occurs during the time when the hydraulic pressure of the AVH function that maintains the vehicle at a stop is applied (i.e., hydraulic pressure maintenance time). It may be desirable to be

As a result of S214, if the expected disembarkation point has been reached, S215 is performed. If the expected disembarkation point has not been reached, the process returns to S213.

In S215, the second ECU 20 determines whether the delta current D exceeds a certain amount. That is, the second ECU 20 can determine whether the braking force of the EPB function is operating normally based on the delta current (D). At this time, delta current (D) is a current value that can determine whether the braking force of the EPB function is operating normally, and corresponds to the difference between the EPB current and the no-load current.

In other words, EPB current and no-load current are currents related to the operation of the EPB function. Specifically, in the EPB system, in order to operate the motor of the EPB actuator (i.e., EPB motor) to operate the EPB function, an EPB current greater than the no-load current of the EPB motor must be supplied. If the EPB current less than that is supplied, the EPB motor does not operate even if the EPB current is applied to the EPB motor. Therefore, the delta current (D), which corresponds to the difference between the EPB current and the no-load current, must be a positive value for the EPB motor to operate. In particular, the delta current (D) must exceed a certain value (i.e., reference value) for the vehicle to operate. A braking force sufficient to maintain a stationary state can be generated.

As a result of S215, if the delta current exceeds the reference value, S221 is performed, and if the delta current does not exceed the reference value, S231 is performed.

In S221, the EPB function operates normally under the control of the second ECU 20. In other words, the EPB motor can operate normally according to the EPB current and provide enough braking force of the EPB function to maintain the vehicle in a stopped state, and as a result, engagement of the EPB brake can be completed.

On the other hand, in S231, the second ECU 20 suspects a failure of hardware, etc. of the EPB system (for example, a broken gear of the brake of the EPB system, etc.). Accordingly, in S231, the second ECU 20 generates a warning notification signal. For example, a signal to activate a warning notification, such as a warning light or a warning alarm sound, can be generated and transmitted to the device that performs the warning notification or the ECU that controls the device.

The present invention, configured as described above, can prepare for a situation in which braking force cannot be formed during the switching of the braking force function so that the EPB function operates after the AVH function is activated in a vehicle to which the EPB switching function is applied, thereby preventing vehicle accidents in advance. There is an advantage to having it.

In the detailed description of the present invention, specific embodiments have been described, but of course, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, but should be defined by the claims described below and equivalents to these claims.

10: 1st ECU 20: 2nd ECU

Claims (13)

A vehicle control method for switching the braking force function so that the Electronic Parking Brake (EPB) function operates after the Auto Vehicle Hold (AVH) function operates, comprising:
determining whether the braking force of the EPB function is less than a reference value at a time when the driver is expected to get off during the transition to the EPB function; and
generating a warning notification signal when the braking force of the EPB function is less than the reference value;
A control method comprising:
According to paragraph 1,
A control method in which the expected time of getting off is generated at a time after the driver's intention to get off is recognized.
According to paragraph 1,
The expected disembarkation time is a control method in which the expected disembarkation time occurs during a period between the recognition of the driver's intention to disembark and the pre-stored expected stay time of the driver before disembarkation.
According to paragraph 2 or 3,
A control method wherein the act of willing to get off includes unfastening the seat belt of the driver's seat or opening the door of the driver's seat.
According to paragraph 2 or 3,
A control method in which the expected disembarkation time occurs during a time when the hydraulic pressure of the AVH function that maintains the vehicle at a stop is applied.
According to paragraph 1,
A control method in which the braking force of the EPB function is determined based on the difference between the EPB current applied in relation to the EPB function and the no-load current.
A control device that switches the braking force function so that the Electronic Parking Brake (EPB) function operates after the Auto Vehicle Hold (AVH) function is activated in the vehicle,
a memory storing a reference value for braking force of the EPB function; and
It includes a processor that performs control using information stored in the memory,
The processor,
After determining whether the braking force of the EPB function is less than the reference value at the expected time of the driver's exit during the transition to the EPB function, a warning is issued if the braking force of the EPB function is less than the reference value. A control device that generates a signal.
In clause 7,
The processor is a control device that uses a time period between the recognition of the driver's intention to get off and the pre-stored expected stay time of the driver before getting off as the expected time of getting off.
According to clause 8,
The control device wherein the act of willingness to get off includes unfastening the seat belt of the driver's seat or opening the door of the driver's seat.
According to clause 8,
The processor is a control device that uses a time during which the hydraulic pressure of the AVH function, which maintains the vehicle stopped, is applied, as the expected time of getting off.
In clause 7,
The processor is a control device that determines the braking force of the EPB function based on the difference between the EPB current applied in relation to the EPB function and the no-load current.
A first control device for controlling an Auto Vehicle Hold (AVH) function; and
It includes a second control device that controls the Electronic Parking Brake (EPB) function,
The second ECU determines whether the braking force of the EPB function is lower than the reference value at the expected time of the driver's exit during switching of the braking force function so that the EPB function operates after the AVH function is activated, and then operates the EPB function. A vehicle that generates a warning notification signal when the braking force is formed below the above reference value.
A vehicle that includes an integrated control device that integrates and controls the Auto Vehicle Hold (AVH) function and the Electronic Parking Brake (EPB) function,
The integrated control device determines whether the braking force of the EPB function is set to be less than a reference value at the expected time of the driver's exit during switching of the braking force function so that the EPB function operates after the AVH function is activated, and then operates the EPB function. A vehicle that generates a warning notification signal when the braking force is formed below the above reference value.