KR102383249B1 - Auto braking control method and vehicle which the method is applied to - Google Patents

Abstract

The vehicle according to the present invention includes a brake system including an auto hold switch, a brake pressure sensor, and a motor, and when the auto hold switch is on, the vehicle speed is greater than or equal to a first speed, and the gear is D or N, the brake pressure and a controller configured to perform reverse hold, which is automatic braking control in the R stage, when the vehicle speed is equal to or less than the second speed and the gear is R after determining that the minimum braking pressure is less than the minimum braking pressure.

Description

Automatic braking control method and vehicle to which it is applied

The present disclosure relates to an automatic braking control method and a vehicle to which the same is applied.

The SBW (Shift-By-Wire) system enables rapid shifting to stop (P) driving (D) or DP, and automatically engages the P-stage when the door is opened and the engine is turned off in the D/R stage. It is used more conveniently than the existing SBC (by cable) type and can control safety functions in case of emergency, so it is widely applied to luxury vehicles worldwide.

However, in the case of a driver who is familiar with the existing SBC type, there is a problem that various malfunctions occur because the SBW type shift lever is not familiar.

Although there is a difference in the structure of the shift lever of the SBW system depending on the vehicle model, the reverse (R) gear may be located at the top, and the neutral (N) and driving (D) gears may be located consecutively. However, in the SBC type, shift gears are operated in the order of P-R-N-D, and when a driver familiar with the conventional SBC type operates the SBW type vehicle, the uppermost stage may be mistakenly operated as the P stage. Then, there is a problem in that the vehicle reverses and causes an accident.

By extending the auto hold function of ESC to the R stage, it is possible to secure vehicle stability and reduce driver's inconvenience, and to reduce complaints caused by the driver's inconvenience in using the SBW lever in SBW type vehicles and the vehicle to which it is applied. would like to provide

An automatic braking control method according to one aspect of the present invention includes the steps of determining whether an auto hold switch is on, determining whether a vehicle speed is equal to or greater than a first speed, determining whether a gear is D or N, and a brake pressure for stopping the vehicle Determining whether the minimum braking pressure for When it is determined that the vehicle speed is equal to or greater than the first speed and the gear is D or N, the auto-hold switch is on, the brake pressure is determined to be less than the minimum braking pressure, and then the automatic brake control method includes: Determining whether the second speed or less, determining whether the gear is R, and performing reverse hold, which is automatic braking control in the R stage, when the vehicle speed is equal to or less than the second speed and the gear is R It may further include the step of

A vehicle according to another aspect of the present invention includes a brake system including an auto hold switch, a brake pressure sensor, and a motor, and when the auto hold switch is on, a vehicle speed is greater than or equal to a first speed, and the gear is D or N , after determining that the brake pressure is less than the minimum braking pressure, when the vehicle speed is equal to or less than the second speed and the gear is R, a control unit configured to perform reverse hold, which is an automatic braking control in the R stage.

According to the embodiment, by extending the auto hold function of the ESC to the R stage, it is possible to secure the stability of the vehicle and reduce the driver's discomfort, and to reduce the dissatisfaction caused by the driver's inconvenience in using the SBW lever in the SBW type vehicle. and a vehicle to which the same is applied.

1 is a block diagram illustrating a partial configuration of a vehicle according to an embodiment of the present invention.
2 to 4 are flowcharts illustrating the operation of the control unit according to the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms.

The Auto Hold function is an additional function of ESC (electronic stability control) that maintains the vehicle's stopping state by maintaining the braking pressure of the four wheels when the vehicle is stopped. This is a convenient function that stops the vehicle by pressing the brake pedal while driving, and maintains the vehicle stop even if you take your foot off the brake pedal while the vehicle is stopped. The hold function is automatically activated when the ramp signal waiting light is stopped, and the hold function is automatically released when the accelerator pedal is pressed and the vehicle starts. An anti-skid function on a slope may be further included in the auto hold function.

The auto hold function is summarized as follows. 1) If you step on the brake pedal at the D/R/S stage and take your foot off the brake pedal after stopping the vehicle, the vehicle stop is maintained. 2) When a predetermined time (for example, 10 minutes) elapses or the driver leaves the driver's seat in the auto hold operation state, the system automatically switches to the parking brake (EPB), and the predetermined time may vary by car maker. 3) After stopping on an incline, step on the accelerator pedal to prevent the vehicle from rolling when starting. 4) Depress the accelerator pedal and automatically release the brake when the vehicle starts.

The auto hold function automatically operates the brake and releases the brake automatically with the accelerator start signal, so it is very important whether the driver is seated in the driver's seat. Therefore, the condition for entering the auto hold function is the driver's seat in the driver's seat. It may vary depending on the developer, but usually the minimum conditions for entering the auto hold function are satisfied when the driver's door is closed and the driver's seat belt is fastened. When the driver operates the Auto Hold switch under the conditions that the driver's seat is seated, the driver's door is closed, and the driver's seat belt fastening is satisfied, the HOLD lamp enters the standby state to indicate that the function is activated. In the HOLD standby state, if the HOLD condition is satisfied, the driver can recognize that the HOLD has been activated by changing the color of the lamp. Normally, the HOLD operating condition is satisfied when the brake is applied (braking pressure is generated) and the vehicle stops (vehicle speed = 0) is maintained. During HOLD operation, the moment the driver depresses the accelerator pedal and starts, the HOLD state is immediately released and converted to the HOLD standby state.

In summary, the conditions for entering the auto hold function, that is, the HOLD standby state, are: ignition on (ON), driver's door closed (CLOSE), driver's seat belt fastened (CLOSE) or brake pedal on (ON), and hood closed (CLOSE) & It may be when the condition of D/N stage is satisfied. The auto hold execution condition may be when the brake pedal ON (hydraulic pressure generation) and vehicle speed = 0 are satisfied. The conditions for entering the auto hold function may differ for each vehicle manufacturer.

Conventionally, the applied gear stages of auto hold were limited to D and N. If the auto hold function is applicable to the R stage, auto hold is applied when parking the vehicle and repeatedly driving forward/backward, so creep driving may not be possible. In addition, the inconvenience of frequently pressing the accelerator pedal to release the auto hold may occur. The contents of the gear stage applied with auto hold may differ from car manufacturer to car manufacturer. For example, there are automobile manufacturers that also implement auto hold on the R stage. However, when applied to the R stage, there is a problem that creep driving of the vehicle is impossible and inconvenience occurs to the driver.

The auto hold control method according to the embodiment and the vehicle to which the same is applied allow the auto hold function to be applied even in the R stage. Hereinafter, in order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification. In addition, since each configuration shown in the drawings is arbitrarily shown for convenience of description, the present invention is not necessarily limited to the bars shown in the drawings.

1 is a block diagram illustrating a partial configuration of a vehicle according to an embodiment of the present invention.

As shown in FIG. 1 , the vehicle 1 according to the embodiment of the present invention includes a control unit 10 , an auto hold switch 20 , a gear sensor 31 , a speed sensor 32 , and a seat belt sensor 33 . , and a brake system 40 .

The auto hold switch 20 performs a switching operation by a driver's manipulation, and information on the switching state (on or off) of the auto hold switch 20 is transmitted to the control unit 10 .

The gear sensor 31 may detect a gear state of the transmission and transmit gear information to the controller 10 . Gear information may indicate one of P, N, D, and R.

The speed sensor 32 may detect a current vehicle speed (hereinafter, referred to as vehicle speed) and transmit information about the vehicle speed to the controller 10 .

The seat belt sensor 33 may detect whether the seat belt is coupled to each seat of the vehicle, and transmit the sensed seat belt coupling information to the controller 10 .

The brake system 40 may include a brake pressure sensor 41 for sensing a braking pressure and a motor 42 for controlling the braking pressure. The brake pressure sensor 41 may transmit information on the detected braking pressure to the controller 10 . The motor 42 may be controlled by the controller 10 to control the braking pressure. For example, a pump driven by the motor 42 may increase the braking pressure by introducing brake oil into the master cylinder.

Hereinafter, the operation of the control unit will be described with reference to FIGS. 2 to 4 . The control unit 10 auto-hold

2 to 4 are flowcharts illustrating the operation of the controller according to the embodiment.

The control unit 10 determines whether the auto hold switch is on (S1). Control methods of auto hold, reverse hold 1, and reverse hold 2 may vary depending on whether the determination result in step S1 is on or off of the auto hold switch. Auto hold is an automatic braking control in gear D or N. Reverse hold 1 is automatic braking control in gear R in which the vehicle can be held only by the brake hydraulic pressure generated by the driver pressing the brake pedal without driving the motor 42 . Reverse hold 2 is an automatic braking control in gear R that allows the driver to hold the vehicle by adding additional hydraulic pressure by driving the motor 42 to the brake hydraulic pressure generated by lightening the brake pedal. Hereinafter, 'reverse hold' will be described as a generic term for 'reverse hold 1' and 'reverse hold 2'.

The control unit 10 may implement necessary control by transmitting a control signal to the brake system 40 in auto hold and reverse hold. The brake system 40 may drive the motor 42 according to a signal transmitted from the controller 10 , and may control the operation of other components (pump, brake cylinder, etc.).

First, the case where the determination result in step S1 is the auto hold switch on will be described.

The control unit 10 releases the reverse hold (S10). Reverse hold means automatic braking control in gear R. The controller 10 may reset the reverse hold control algorithm together with the reverse hold release.

The control unit 10 determines whether the vehicle speed is 10 kph or more (S11). Only when there is a driving history of 10 kph or more, the control unit 10 operates the reverse hold function. 10 kph is only a tuning parameter as an example of a criterion for determining that the vehicle is in a stopped state after driving, and the present invention is not limited thereto. In low speed driving of less than 10 kph, the control unit 10 determines that forward and reverse are repeated at low speed for parking, and does not perform unnecessary automatic braking control in the R stage.

If it is determined in step S11 that the vehicle speed is less than 10 kph, the process is repeated from step S1.

If it is determined in step S11 that the vehicle speed is greater than or equal to 10 kph, the controller 10 determines whether the gear is 'D' or 'N' (S12). When the gear starts at D or N, the control unit 10 determines whether to proceed with auto hold and reverse hold. In the case of changing from P-stage to R-stage, there is a clear intention of the driver to move the stationary vehicle to R-stage, and there is no need to perform auto-hold and reverse-hold.

As a result of the determination in step S12, if the gears are not 'D' and 'N', the process is repeated from step S1.

As a result of the determination in step S12, if the gear is 'D' or 'N', the control unit 10 determines whether P(b) is greater than or equal to P(s) (S13). P(b) is the brake pressure generated by the driver pressing the brake pedal, and P(s) is the minimum braking pressure to stop the vehicle. P(s) may be preset to several values according to hill gradient conditions, and is a tuning parameter. Whether the driver generates the brake pedal pressure with the minimum braking pressure for stopping the vehicle is an important factor in determining whether the vehicle needs to be safely stopped by additionally driving the motor.

As a result of the determination in step S13, if P(b) is equal to or greater than P(s), the controller 10 determines whether the vehicle speed V is zero (S14). If it is determined in step S14 that the vehicle speed V is zero, the controller 10 performs auto-hold (S16). If it is determined in step S14 that the vehicle speed V is not zero, step S15 is performed.

As a result of the determination in step S13, if P(b) is less than P(s), the controller 10 determines whether the vehicle speed V is 2 kph or less (S15). In an embodiment, the reverse hold may be performed only at 2 kph or less. R-speed shifting is possible at 2kph or higher, but the vehicle's kinetic energy is large and the vehicle jerks when intervening in braking control.

If it is determined in step S15 that the vehicle speed V exceeds 2 kph, the process is repeated from step S1.

As a result of the determination in step S15, if the vehicle speed V is 2 kph or less, the control unit 10 determines whether the gear is 'R' (S17).

If it is determined in step S17 that the gear is not 'R', the process is repeated from step S1.

As a result of the determination in step S17, if the gear is 'R', the control unit 10 determines whether P(b) is greater than or equal to P(s) (S18). As a result of the determination in step S18, if P(b) is greater than or equal to P(s), the control unit 10 proceeds with reverse hold 1 (S19), and if P(b) is less than P(s), the control unit 10 performs reverse hold 2 (S20).

Next, the case where the determination result in step S1 is the auto hold switch off will be described.

The control unit 10 releases the reverse hold (S20). The controller 10 may reset the reverse hold control algorithm together with the reverse hold release.

The control unit 10 determines whether the vehicle speed is 10 kph or more (S21).

If it is determined in step S21 that the vehicle speed is less than 10 kph, the process is repeated from step S1.

If it is determined in step S21 that the vehicle speed is greater than or equal to 10 kph, the controller 10 determines whether the gear is 'D' or 'N' (S22).

As a result of the determination in step S22, if the gears are not 'D' and 'N', the process is repeated from step S1.

As a result of the determination in step S22, if the gear is 'D' or 'N', the controller 10 determines whether the vehicle speed V is 2 kph or less (S23).

If it is determined in step S23 that the vehicle speed V exceeds 2 kph, the process is repeated from step S1.

As a result of the determination in step S23, if the vehicle speed V is 2 kph or less, the control unit 10 determines whether the gear is 'R' and P(b) is greater than or equal to P(s) (S24).

As a result of the determination in step S24, if the gear is not 'R', repeat from step S1.

As a result of the determination in step S24, if the gear is 'R' and P(b) is greater than or equal to P(s), the control unit 10 performs reverse hold 1 (S26).

As a result of the determination in step S24, if the gear is 'R' and P(b) is less than P(s), the control unit 10 performs reverse hold 2 (S26).

When the vehicle speed V is 2 kph or less, the control unit 10 determines whether the gear is 'R' (S17).

Steps S1, S10, S11, S20, and S21 are steps for determining the reverse hold entry condition. For example, it is a step of determining the timing of brake control intervention in a situation in which the driver of the SBW type vehicle can erroneously operate the R-stage (recognizing and operating it as the P-stage).

The remaining steps in FIG. 2 are steps of filtering the entry condition of the reverse hold. Depending on the brake pressure, reverse hold can be performed in two modes.

Next, another function, for example, switching to electronic parking brakes (EPB) or releasing reverse hold after the reverse hold operation will be described with reference to FIGS. 3 and 4 .

3, after auto-hold in step S16, it is determined whether the gear is 'R' (S31).

If it is determined in step S31 that the gear is not 'R', the control unit 10 enters the auto-hold control mode, maintains the auto-hold according to a new situation or releases the auto-hold to convert to another control mode ( S32). For example, when the EPB condition is satisfied, the controller 10 may switch from auto-hold to EPB, and may control auto-hold according to the monitoring result of other vehicle states (door, trunk, hood, etc.). The control unit 10 may check the presence or absence of a failure in the internal auto-hold control configuration, and when a failure occurs, perform a protective operation such as canceling the auto-hold and notifying the failure. In this case, not only the auto hold but also the reverse hold, the controller 10 may control the reverse hold according to the reverse hold control mode.

If it is determined in step S31 that the gear is 'R', the control unit 10 switches to reverse hold. In FIG. 3 , the control unit 10 performs reverse hold 1 ( S19 ), but the invention is not limited thereto. It is determined whether P(b) is equal to or greater than P(s), and depending on the determination result, reverse hold 1 or reverse hold 2 may be performed.

After proceeding to either one of the reverse hold 1 and the reverse hold 2 (S19 and S20), the control unit 10 determines whether the gear is 'D' (S33).

If it is determined in step S33 that the gear is 'D', the control unit 10 switches to auto hold (S16).

If it is determined in step S33 that the gear is not 'D', the control unit 10 determines whether the gear is 'N' (S34).

If it is determined in step S34 that the gear is 'N', the process is repeated from step S1. If it is determined in step S34 that the gear is not 'N', the control unit 10 enters the step of monitoring the driving state in order to control the release of the reverse hold (S35).

In step S35, the condition that the control unit 10 is automatically released in the reverse hold state other than the gear shift and the movement of the gear stage is the same as the existing auto hold release. For example, when the accelerator pedal is depressed by a predetermined % or more, the control unit 10 automatically releases the reverse hold. In addition, during the long-term operation of the reverse hold, the control unit 10 switches to the EPB in order to prevent deterioration of durability of the configuration for holding the reverse hold.

For reference, the auto-hold control configuration of the control unit 10 switches to the EPB in order to prevent deterioration of durability of the configuration for maintaining the auto-hold during long-term auto-hold operation.

As shown in FIG. 4 , after proceeding to any one of reverse hold 1 and reverse hold 2 ( S25 and S20 ), the control unit 10 determines whether the gear is 'D' ( S27 ).

If it is determined in step S27 that the gear is 'D', the control unit 10 switches to auto hold (S16).

If it is determined in step S27 that the gear is not 'D', the control unit 10 determines whether the gear is 'N' (S28).

If it is determined in step S28 that the gear is 'N', the process is repeated from step S1. If it is determined in step S28 that the gear is not 'N', the control unit 10 enters the monitoring step (S29). Monitoring step S29 is the same as step S35 described above.

According to an embodiment, it is possible to secure the stability of the vehicle and reduce the driver's discomfort by extending the function of Auto Hold of the ESC without adding a separate device by using the information that can be confirmed in the vehicle. In addition, it is possible to reduce complaints caused by the driver's inconvenience in using the SBW lever in the SBW type vehicle.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the right.

1: vehicle
10: control
20: auto hold switch
31: gear sensor
32: speed sensor
33: seat belt sensor
40: brake system
41: brake pressure sensor
42: motor

Claims (12)

determining whether the auto hold switch is on;
determining whether the vehicle speed is equal to or greater than the first speed;
determining whether the gear is D or N; and
Determining whether the brake pressure is greater than or equal to the minimum braking pressure for stopping the vehicle;
When the auto hold switch is on, when the vehicle speed is equal to or greater than the first speed and the gear is D or N, after determining that the brake pressure is less than the minimum braking pressure,
determining whether the vehicle speed is equal to or less than a second speed;
determining whether the gear is R; and
and performing reverse hold, which is automatic braking control in the R stage, when the vehicle speed is equal to or less than the second speed and the gear is R. According to claim 1,
comparing the brake pressure with the minimum brake pressure when the vehicle speed is equal to or less than a second speed and the gear is in the R stage; and
and driving a motor to increase the brake pressure when the brake pressure is less than the minimum braking pressure. According to claim 1,
After determining that the brake pressure is equal to or greater than the minimum brake pressure,
determining whether the vehicle speed is zero; and
The automatic braking control method further comprising the step of performing auto-hold for maintaining a vehicle stop state when the vehicle speed is zero. According to claim 1,
After determining that the vehicle speed is equal to or greater than the first speed and the gear is D or N under the condition that the auto hold switch is off,
determining whether the vehicle speed is equal to or less than a second speed;
determining whether the gear is R; and
and performing the reverse hold when the vehicle speed is equal to or less than the second speed and the gear is R. 5. The method of claim 4,
When the vehicle speed is equal to or less than the second speed and the gear is R,
determining whether the brake pressure is equal to or greater than the minimum brake pressure; and
and driving a motor to increase the brake pressure when the brake pressure is less than the minimum braking pressure. 5. The method of claim 1 or 4,
After the reverse hold is performed,
performing auto-hold for maintaining a vehicle stop state when the gear is D; and
and monitoring a driving state to control release of the reverse hold when the gears are not D and N. 7. The method of claim 6,
The monitoring step is
and monitoring at least one of an accelerator pedal and the reverse hold holding period. According to claim 1,
performing auto-hold for maintaining a stopped state of the vehicle when the brake pressure is equal to or greater than the minimum braking pressure and the vehicle speed is zero;
determining whether the gear is R after performing the auto hold; and
The automatic braking control method further comprising the step of performing the reverse hold when the gear is R. 9. The method of claim 8,
When the gear is not R,
The automatic braking control method further comprising the step of maintaining the auto-hold or releasing the auto-hold to switch to another control mode. auto hold switch;
a brake system including a brake pressure sensor and a motor; and
When the auto hold switch is on, when the vehicle speed is greater than or equal to the first speed and the gear is D or N, after determining that the brake pressure is less than the minimum braking pressure, the vehicle speed is less than or equal to the second speed, and the gear is R , a vehicle including a controller for performing reverse hold, which is automatic braking control in the R stage. 11. The method of claim 10,
The control unit is
Comparing the brake pressure and the minimum braking pressure when the vehicle speed is equal to or less than the second speed and the gear is R stage, and when the brake pressure is less than the minimum braking pressure, driving the motor to increase the brake pressure vehicle. 11. The method of claim 10,
The control unit is
After determining that the vehicle speed is equal to or greater than the first speed and the gear is D or N under the condition that the auto hold switch is off,
When the vehicle speed is equal to or less than the second speed and the gear is R, the vehicle performs the reverse hold.

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