KR102440601B1 - System and method for stop control of vehicle - Google Patents

Abstract

A vehicle stop control system and method are disclosed.
According to an embodiment of the present invention, there is provided a vehicle stop control system in which an electronic parking brake (EPB) is omitted, comprising: a driving information detector configured to detect driving information measured by various sensors according to driving of the vehicle; Adaptive cruise control (ACC) that controls to maintain a certain distance according to the speed of the vehicle in front measured by the camera of the vehicle in front; a vehicle attitude control device (ESC) for stabilizing the attitude of the vehicle by individually applying hydraulic braking force to the four wheels according to the attitude behavior of the vehicle; And when the front vehicle stops while the ACC function is in operation, hydraulic braking force is applied to the 4 wheels through the ESC to stop the vehicle, and after a certain time elapses, the stop maintenance control is performed with hydraulic braking force that operates some valves of less than 4 wheels. and a vehicle control unit for rotationally controlling the valves that are in operation and the remaining idle valves.

Description

Vehicle stop control system and method

The present invention relates to a vehicle stop control system and method thereof, and more particularly, to a vehicle stop control system and method for supporting vehicle stop maintenance control by omitting and replacing the conventional electronic parking brake (EPB) will be.

In general, vehicles are equipped with adaptive cruise control (ACC) and auto hold (AVH) functions to improve driver convenience.

ACC, also called Advanced Smart Cruise Control (ASCC), is a system that maintains a distance from the vehicle in front using a radar/camera mounted on the front of the vehicle and automatically stops the vehicle when stopped.

AVH is a system that automatically operates when waiting for a signal or stopping on a slope as an automatic vehicle stop maintenance function, and prevents the vehicle from rolling backwards when starting.

In order to perform the functions of ACC and AVH, an electronic parking brake (EPB) is commonly used to keep the vehicle stopped.

For example, FIG. 1 is a conceptual diagram for explaining the vehicle stop control of the conventional ACC function.

1, when the front vehicle stops while the ACC function is operating in a conventional vehicle, the vehicle is stopped by generating 4 wheel braking hydraulic pressure through the control of the electronic stability control (ESC). make it (S1).

At this time, since the durability problem of the ESC may occur if the vehicle has been stopped for a long time, release the braking hydraulic pressure of the ESC and switch to the EPB braking to maintain a more stable stop (S2) to maintain the stopped state (P) (S3).

Similarly, while the AVH function is operating, if the vehicle stops by pressing the brake pedal, and then takes the foot off the brake pedal, and a predetermined stop time increases, the system automatically switches to EPB.

For this reason, EPB is applied as an essential option for ACC or AVH applied vehicles.

However, since EPB must always be applied as an essential option to ACC or AVH applied vehicles, there is a problem in that the manufacturing cost of the vehicle increases.

Matters described in this background section are prepared to promote understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

The embodiment of the present invention omits the conventional EPB (Electronic Parking Brake) and rotationally controls the ESC braking hydraulic pressure according to the stopped vehicle state to an arbitrary less than four wheel hydraulic pressure, thereby maintaining the vehicle's vehicle stop and the valve's durability problem. An object of the present invention is to provide a vehicle stop control system and method for overcoming the

According to an aspect of the present invention, there is provided a vehicle stop control system in which an electronic parking brake (EPB) is omitted, comprising: a driving information detector configured to detect driving information measured by various sensors according to driving of the vehicle; Adaptive cruise control (ACC) that controls to maintain a certain distance according to the speed of the vehicle in front measured by the camera of the vehicle in front; a vehicle attitude control device (ESC) for stabilizing the attitude of the vehicle by individually applying hydraulic braking force to the four wheels according to the attitude behavior of the vehicle; And when the front vehicle stops while the ACC function is in operation, hydraulic braking force is applied to the 4 wheels through the ESC to stop the vehicle, and after a certain time elapses, the stop maintenance control is performed with hydraulic braking force that operates some valves of less than 4 wheels. and a vehicle control unit for rotationally controlling the valves in operation and the remaining idle valves.

In addition, the vehicle control unit may perform the stop maintenance control by rotating the valve at which the valve temperature according to the hydraulic braking time reaches the endurance temperature with the idle valve.

In addition, the vehicle controller may calculate a required braking force of the vehicle in consideration of a vehicle stop gradient, and determine the stop maintenance control in any one of the two-wheel braking mode and the three-wheel braking mode according to the magnitude of the required braking force.

Also, the vehicle control unit may calculate the required braking force under the worst weight condition based on a vehicle stopping gradient and a total weight (GVW) of vehicle specifications.

In addition, the vehicle control unit operates the two-wheel valve when the magnitude of the required braking force is less than a reference braking force that is the sum of the hydraulic braking force of the two rear wheels, and performs the stop maintenance control in the three-wheel braking mode when the magnitude of the required braking force is greater than or equal to the reference braking force.

In addition, the vehicle control unit may differentiate and set the hydraulic pressure level of each valve used in the two-wheel braking mode or the three-wheel braking mode.

In addition, the vehicle control unit may calculate each valve temperature based on the holding time of each valve in operation and the magnitude of the brake hydraulic pressure.

In addition, the vehicle control unit may calculate a time for which the valve temperature of each valve to which the hydraulic pressure is set differently reaches the endurance temperature specification.

In addition, the vehicle control unit may determine the valve endurance temperature specification by adjusting the hydraulic pressure of each wheel so that a stopping braking force in consideration of a weight according to the brake specification of each wheel with respect to the braking force required according to the stopping inclination of the vehicle is generated.

On the other hand, the stopping control method of a vehicle in which the electronic parking brake (EPB) is omitted is a) When the front vehicle stops while the adaptive cruise control (ACC) function is operating, hydraulic braking force is applied to the four wheels through the vehicle attitude control device (ESC). stopping the vehicle; b) when a predetermined stop time elapses, performing stop maintenance control using hydraulic braking force that operates some valves of less than 4 wheels, and waiting the remaining valves in an idle state; c) calculating a valve temperature based on the hydraulic braking time of each valve in operation and the magnitude of the braking hydraulic pressure; and d) maintaining the vehicle stop state by rotating the valve at which the valve temperature reaches the endurance temperature and the valve in the idle state.

Also, step b) may include calculating the required braking force of the vehicle in consideration of the weight of the vehicle and the stopping gradient.

In addition, the step b) may include performing stop maintenance control in the two-wheel braking mode when the magnitude of the braking force required for maintaining the vehicle stop is less than the reference braking force obtained by adding the hydraulic braking force of the two wheels; Alternatively, when the magnitude of the required braking force exceeds the reference braking force, the method may include performing stop maintenance control in a three-wheel braking mode.

Also, step b) may include differentiating and setting the hydraulic pressure level of each valve used in the two-wheel braking mode or the three-wheel braking mode.

In addition, the step b) includes adjusting the hydraulic pressure of each wheel to generate a stopping braking force in consideration of the weight according to the brake specification of each wheel with respect to the required braking force, and determining the endurance temperature specification for each valve accordingly. can do.

In addition, the step c) may include calculating a valve temperature based on the holding time of each valve in operation and the magnitude of the brake hydraulic pressure; and calculating a valve temperature rise estimation graph of each valve according to time, and calculating a maximum time for the valve temperature of each valve to reach the endurance temperature from the graph.

In addition, in step c), the estimated time for the valve temperature to reach the endurance temperature is calculated in advance in consideration of the calorific value according to the hydraulic pressure of each valve, and the hydraulic release and the idle valve of the valve reaching the endurance temperature in consideration of the margin It may include the step of determining the hydraulic operation time of the.

In addition, in step d), when any one of the valve temperatures calculated according to the vehicle stop time reaches the endurance temperature, the hydraulic pressure of the idle valve according to the rotation event is operated, and the hydraulic pressure of the valve that has reached the endurance temperature is released. and switching to the idle state.

In addition, after step d), a step of changing to a two-wheel or three-wheel braking mode according to a result of comparing the reference braking force, which is the sum of the hydraulic braking forces of the valves reconfigured according to the rotation, and the braking force required to keep the vehicle stopped may further include.

Meanwhile, according to another aspect of the present invention, there is provided a method for controlling a vehicle stop in which an electronic parking brake (EPB) is omitted, the method comprising: a) stopping the vehicle while an automatic vehicle hold (AVH) function is operating; b) when a predetermined stop time elapses, performing stop maintenance control using hydraulic braking force that operates some valves of less than 4 wheels of the vehicle attitude control device (ESC), and waiting the remaining valves in an idle state; c) calculating a heating temperature based on the hydraulic braking time of each valve in operation and the magnitude of the braking hydraulic pressure; and d) maintaining the vehicle stop state by rotating the valve at which the heating temperature reaches the endurance temperature and the valve in the idle state.

According to an embodiment of the present invention, by providing vehicle stop maintenance control using ESC, manufacturing cost can be reduced by omitting the EPB mounted as an essential option for applying convenient functions such as ACC to a conventional vehicle.

In addition, the cost burden caused by the deletion of the EPB is reduced, and convenience functions can be applied to vehicle types, thereby improving product competitiveness and customer satisfaction.

In addition, by performing vehicle stop maintenance control that rotates hydraulic braking force with some wheel combinations of less than 4 wheels, durability of the hydraulic valve can be secured and stable stop maintenance control can be performed.

1 is a conceptual diagram for explaining a vehicle stop control of a conventional ACC function.
2 schematically shows the configuration of a vehicle stop control system according to an embodiment of the present invention.
3 shows the configuration of an ESC according to an embodiment of the present invention.
4 is a flowchart schematically illustrating a vehicle stop control method according to an embodiment of the present invention.
5 is a view for explaining a method of selecting a vehicle stop maintenance control mode according to a required braking force of a vehicle according to an embodiment of the present invention.
6 is a graph showing the time to reach the endurance temperature of the valve according to the hydraulic pressure according to an embodiment of the present invention.
7 is a graph for explaining a rotation method of a hydraulic valve according to an embodiment of the present invention.
8 is a conceptual diagram of various situations requiring vehicle stop maintenance, such as an AVH function, in a conventional vehicle.
Also, FIG. 9 is a flowchart illustrating a vehicle stop control method during AVH operation according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, terms such as “…unit”, “…group”, and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software. have.

Throughout the specification, terms such as first or second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one element from other elements, for example, without departing from the scope of the present invention, a first element may be called a second element, and similarly The second component may also be referred to as the first component.

Vehicles, automobiles, or other similar terms used throughout this specification refer to sports utility vehicles (SUVs), buses, trucks, passenger cars including various commercial vehicles, hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, and hydrogen fueled vehicles. and other alternative fuel (eg, fuel obtained from resources other than petroleum) vehicles.

Now, a vehicle stop control system and method according to an embodiment of the present invention will be described in detail with reference to the drawings.

2 schematically shows the configuration of a vehicle stop control system according to an embodiment of the present invention.

2 , the vehicle stop control system 100 according to an embodiment of the present invention includes a driving information detector 110 , an Adaptive Cruise Control/Advanced Smart Cruise Control (ACC) 120 , and an Electronic Stability Control (ESC). , 130 ), a cluster 140 , and a vehicle control unit 150 .

The stop control system 100 is characterized in that it deletes the configuration of an electronic parking brake (EPB) used for maintaining a vehicle stop in the related art, and performs stop maintenance control using the ESC 130 by replacing it.

The driving information detecting unit 110 detects driving information measured by various sensors according to the driving of the vehicle.

The driving information detection unit 110 includes a wheel speed sensor, a steering angle sensor, a yaw sensor, a G sensor for measuring lateral/longitudinal acceleration, an engine information sensor, a shift stage sensor, an accelerator pedal (APS) sensor, and a brake (BPS). ) detects driving information according to vehicle operation, including the operating state of the sensor and electric load, and provides it to the vehicle control unit 150 .

The ACC 120 controls the speed of the vehicle to maintain a predetermined distance according to the vehicle speed of the vehicle in front through a camera/radar (not shown).

In addition, when the vehicle ahead stops, the ACC 120 stops the vehicle and accelerates the vehicle when the vehicle ahead starts.

The ESC 130 analyzes the driving information of the wheel speed sensor, the steering angle sensor, the yaw rate and the lateral acceleration sensor (G), and applies hydraulic braking force to the four wheels individually according to the unstable posture behavior of the vehicle to adjust the posture of the vehicle. Stabilize.

3 shows the configuration of an ESC according to an embodiment of the present invention.

3, the ESC 130 according to the embodiment of the present invention controls the hydraulic braking force of the FL valve FL_V and the front right wheel FR for controlling the hydraulic braking force of the front left wheel FL of the vehicle. It includes an FR valve (FR_V) for regulating, a RL valve (RL_V) for regulating the hydraulic braking force of the rear left wheel (RL), and an RR valve (RR_V) regulating the hydraulic braking force of the rear right wheel (RR).

The cluster 140 displays the driving state of the vehicle, and visually displays the ACC function operation state and the vehicle stop maintenance state according to the brake operation.

The vehicle control unit 150 controls the overall operation for performing stop maintenance control of the vehicle by omitting and replacing the EPB conventionally mounted on the vehicle.

The vehicle control unit 150 may be configured as a controller of the ESC 130 , and further may be configured as a higher level controller that controls overall operations for convenience functions such as ACC, auto hold, and posture control of the vehicle.

When the vehicle in front stops while the ACC 120 is in operation, the vehicle controller 150 applies hydraulic braking force to all four wheels of the ESC 130 to stop the vehicle.

Thereafter, when a predetermined time elapses in a state in which the vehicle is stopped, the vehicle controller 150 controls the vehicle stop maintenance using hydraulic braking force using some valves of less than four wheels, and leaves at least one remaining valve in an idle state. Then, the valve that reaches the endurance temperature according to the heat generation temperature according to the hydraulic braking time is rotated as the idle valve to alternately perform stop maintenance control.

If the vehicle is stopped at a place where the incline is not large after the vehicle has stopped, it is possible to maintain the vehicle stop even if only the 2 rear wheels (RL, RR) generate hydraulic pressure. It is possible to keep the vehicle stopped sufficiently by generating wheel hydraulic pressure.

For example, when explaining why a vehicle can be stopped with only two wheel hydraulic pressure, the parking brake is designed to park the vehicle by fixing the two rear wheels of the vehicle when designing the brake system of the vehicle. The rear brake size is determined so that the vehicle can be parked even on a 20% slope of the GVW condition of the specifications. And in the case of the front wheel brake, a larger size brake is applied than the rear wheel considering the load transfer to the front wheel during braking.

That is, if the hydraulic pressure of the two rear wheels is used so that the two rear wheels are eventually fixed, parking or stopping is possible even in the GVW state of the vehicle. At this time, if the vehicle is stopped by using the front brake instead of the rear wheel, the vehicle can be maintained much more advantageously than the two rear wheel hydraulic control in the case of the front wheel with a large brake size under the same hydraulic conditions.

When controlling the hydraulic pressure of the front brake, which has a larger size compared to the rear wheel, it is possible to maintain a vehicle stop with less hydraulic pressure than when controlling the rear wheel.

The vehicle control unit 150 calculates the required braking force (necessary parking force, Br) of the vehicle in consideration of the vehicle weight and the stopping gradient, and stops any one of the two-wheel braking mode and the three-wheel braking mode according to the magnitude of the required braking force. maintenance control can be determined.

For example, the vehicle controller 150 operates the two-wheel valve to apply the hydraulic braking force when the magnitude of the required braking force Br required to maintain the vehicle stop is less than the reference braking force that is the sum of the hydraulic braking force of the two-wheel valve of the rear wheel. Carry out stop maintenance control.

On the other hand, when the magnitude of the required braking force Br is greater than the reference braking force that is the sum of the hydraulic braking forces of the two-wheel valves of the rear wheels, the vehicle controller 150 operates the three-wheel valve to apply the hydraulic braking force. can do.

That is, the vehicle control unit 150 performs the two-wheel mode stop maintenance control that can sufficiently cover the low required braking force Br due to the small stopping gradient of the vehicle, and the required braking force Br is increased due to the large vehicle stopping slope. If it is high, 3 wheel braking mode stop maintenance control can be performed.

On the other hand, when the vehicle control unit 150 performs the stop maintenance control in the two-wheel braking mode or the three-wheel braking mode, by calculating the calorific value compared to the endurance temperature of each valve according to the stop time, the rotation control is performed while alternately controlling the position of the wheel at which hydraulic pressure is generated. .

For example, in the case of 3-wheel braking mode, if the hydraulic pressure of the RL valve (RL_V), RR valve (RR_V), and FR valve (FR_V) is initially operated, the RR valve (RR_V) , FR valve (FR_V) and FL valve (FL_V) are switched to hydraulic operation. Next, the hydraulic operation of FR valve (FR_V), FL valve (FL_V), and RL valve (RL_V) is switched, and then the hydraulic operation of FL valve (FL_V), RL valve (RL_V), RR valve (RR_V) is performed. Rotation control can be continued by alternating each valve.

Through this stop maintenance control, heat generation due to the concentration of hydraulic pressure in any one valve is prevented, thereby securing the durability of the valve.

In addition, when the vehicle control unit 150 switches to the stop maintenance control of the two-wheel or three-wheel braking mode according to the stopping gradient of the vehicle after a certain period of time has elapsed in the four-wheel hydraulic braking state, the two-wheel or three-wheel braking mode is applied. Control is performed by differentially setting the hydraulic pressure of each valve used.

Here, if the hydraulic pressure of each valve is not different and the braking hydraulic pressure is generated at the same hydraulic pressure level for the same time, the rising temperature of each valve is the same and the release point (endurance temperature) is reached at the same time, so rotation control is difficult.

So, when 2 wheels or 3 wheels are in the braking mode, the hydraulic pressure of each valve is set differently to differentiate the rising temperature of the hydraulic valve in the ESC 130 that is responsible for the hydraulic pressure to each wheel, thereby making the hydraulic release order and releasing the valve in order. and to allow rotation (switching) with the idle valve.

As such, the vehicle control unit 150 differentiates the hydraulic pressure of each valve used in the two-wheel or three-wheel braking mode to vary the time for the heating temperature of each valve to reach the endurance temperature specification, thereby reducing the valve rotation period of the ESC 130. It can be set up and operated alternately.

The vehicle control unit 150 monitors the change of the slope condition signal from the G sensor in the event of a rattle of the vehicle in the process of switching through the overlap when the wheel hydraulic operation is switched. In order to maintain control more safely, the vehicle inclination condition can be checked from the G-sensor once again, and then stop maintenance control can be performed.

Meanwhile, a vehicle stop control method for maintaining a vehicle stop while the ACC function is operating according to an embodiment of the present invention based on the configuration of the vehicle stop control system described above will be described with reference to FIG. 3 below. However, since the detailed configuration described above can be integrated into the vehicle stop control system for each function, the subject of the vehicle stop control method will be described as the stop control system.

4 is a flowchart schematically illustrating a vehicle stop control method according to an embodiment of the present invention.

4 , the vehicle stop control system 100 according to an embodiment of the present invention operates in a state in which the ACC function of the vehicle is activated (S101; Yes) and when the vehicle is stopped (S102; Yes), the weight of the vehicle The required braking force (Br) of the vehicle is calculated in consideration of the stop gradient and the stopping gradient (S103).

At this time, the stop control system 100 may determine the operating state of the ACC 120 and confirm that the vehicle is stopped as the vehicle speed detected through the driving information detection unit 110 is 0, and the ACC function is not operating. or (S101; No), if the vehicle speed is not 0 (S102; No), it returns to the start step and waits for vehicle stop control.

The vehicle stop control system 100 performs stop maintenance control in the two-wheel braking mode when the magnitude of the required braking force Br required to keep the vehicle stopped is less than the reference braking force that is the sum of the hydraulic braking forces of the two wheels (S104; Yes) ( S105).

On the other hand, when the magnitude of the required braking force Br exceeds the two-wheel reference braking force (S104; No), the vehicle stop control system 100 performs the vehicle stop maintenance control in the three-wheel braking mode (S106).

Here, a method of selecting the vehicle stop maintenance control mode according to the required braking force of the vehicle will be described in more detail with reference to FIG. 7 .

5 is a view for explaining a method of selecting a vehicle stop maintenance control mode according to a required braking force of a vehicle according to an embodiment of the present invention.

Referring to FIG. 5 , the vehicle stop control system 100 may calculate the required braking force Br in consideration of the weight W and the inclination θ of the vehicle while the vehicle is stopped on the slope.

At this time, the valve temperature specification (spec) according to the vehicle's stopping inclination condition is determined by the valve temperature condition of each wheel (T), the hydraulic pressure assigned to each valve (B), and the hydraulic pressure generated at each wheel (D) in the previous cycle situation. Based on the braking torque and braking force, it is determined whether to park with the two-wheel braking force or the three-wheel braking force according to the magnitude of the required braking force Br according to the vehicle stopping gradient condition.

In this case, the vehicle stopping gradient may be determined using the longitudinal G sensor value detected by the driving information detection unit 110 .

The stopping braking force corresponding to the required braking force Br may be calculated as the sum of braking forces generated through the braking hydraulic pressure of each wheel.

In addition, the vehicle weight (W) is calculated by calculating the total weight (GVW) value of the vehicle specifications to maintain a stopped state in the worst condition.

The stop control system 100 adjusts the hydraulic pressure of each wheel to generate a stopping braking force in consideration of the weight according to the brake specifications of each wheel with respect to the required braking force Br according to the two-wheel braking mode or the three-wheel braking mode for each vehicle inclination. It is possible to determine the endurance temperature spec for each valve according to the mapping.

On the other hand, the vehicle stop control system 100 performs the vehicle stop maintenance control by braking the two rear wheels RL and RR in the two-wheel braking mode (S105). At this time, the vehicle stop control system 100 maps the hydraulic pressure levels of the RL valves RL_V and RR valves RR_V of the two idle wheels to different levels (eg, RL_V > RR_V). In addition, the remaining FR valves (FR_V) and FL valves (FL_V) are idle valves for rotation standby.

Alternatively, the vehicle stop control system 100 performs vehicle stop maintenance control by braking two rear wheels and one front wheel (RL, RR, FR) in the three-wheel braking mode (S106). At this time, the stop control system 100 maps the hydraulic levels of the RL valve (RL_V), the RR valve (RR_V), and the FR valve (FR_V) to differential levels differently (eg, RL_V > RR_V > FR_V). In addition, the remaining FL valves FL_V are idle valves for rotation standby.

The vehicle stop control system 100 estimates and calculates the hydraulic valve temperature F based on the hold time of each hydraulic valve used in the braking mode and the magnitude of the braking hydraulic pressure (S107).

The vehicle stop control system 100 calculates a graph for estimating the rise of the hydraulic valve temperature (F) of each valve over time (S108), and in the graph, calculates the maximum time for the temperature generated by each hydraulic valve to reach the valve endurance temperature do (S109).

For example, FIG. 6 is a graph showing the time to reach the endurance temperature of the valve for each hydraulic size according to an embodiment of the present invention.

Referring to FIG. 6 attached, the magnitude of the hydraulic pressure is P1 > P2 > P3 > ... > In the case of decreasing in the order of Pn, the time for the valve temperature (T) to reach the endurance temperature is t1 < t2 < t3 < … < t4 shows that it increases in order.

Therefore, the vehicle control unit 150 differentially controls the hydraulic pressure of each valve that is simultaneously operated on 2 wheels or 3 wheels, and sets the time for the heat generation temperature of each valve to reach the valve endurance temperature differently.

The vehicle control unit 150 calculates in advance the expected time according to the control hydraulic pressure of t1, t2, t3, etc. of each valve, and considers the margin, and releases the hydraulic pressure of the valve reaching the endurance temperature and the hydraulic operation time of the additional valve (that is, the switching time/rotation time of the hydraulic valve) can be determined.

For example, in step S109, it is assumed that the endurance temperature reaching time of each hydraulic valve is set to RL_V: t1, RR_V: t2, FR_V: t3, and FL_V: t4, respectively.

The stop control system 100 counts the vehicle stop maintenance control time, and when the stop maintenance time reaches the time t1 (S110; Yes), an idle valve and a first valve rotation event are generated. At this time, the valve temperature of RL_V, in which the hydraulic pressure level is set to the greatest P1, may reach the time t1 to generate a rotation event.

The stop control system 100 operates the hydraulic pressure of the idle valve FL_V according to the rotation event (S111), and releases the hydraulic pressure of RL_V in which the hydraulic pressure level P1 is set to the largest (S112).

At this time, as above, during the rotation process of operating the idle valve to issue hydraulic pressure to the wheel and releasing the existing valve, the vehicle rattles due to unintended noise or vibration (NVH) caused by the operation of the pump of the ESC 130. can be

Therefore, a method for solving the pump NVH problem during rotation will be specifically described.

7 is a graph for explaining a rotation method of a hydraulic valve according to an embodiment of the present invention.

7, the stop control system 100 according to an embodiment of the present invention controls with a sufficient switching time (Ct) of a predetermined time in the conversion process of releasing and operating the hydraulic pressure of each valve of the rotation target.

When the minimum required hydraulic pressure value is determined by calculating the required braking force according to the vehicle's stopping inclination, the vehicle control unit 150 sets the oil pressure in consideration of the margin according to the vehicle tuning, and considers the sufficient switching time according to the expected rise time of the valve temperature. The pump noise problem can be solved by allowing the hydraulic release and hydraulic pressure generation of the two valves to overlap each other at the time when the hydraulic pressure is switched.

However, if the vehicle rattles in the process of switching through the overlap concept during the hydraulic valve rotation, the required braking force can be recalculated by checking the vehicle inclination condition from the G-sensor once again to maintain safer control. have.

Thereafter, the stop control system 100 may perform the stop induction control by rotating the hydraulic valve by repeating steps S104 to S112 until the vehicle is accelerated.

At this time, the vehicle stop control system 100 compares the magnitude of the required braking force Br of the vehicle with the reference braking force that is the sum of the hydraulic braking force of the two-wheel valve reconstructed according to the hydraulic valve rotation for each rotation of the hydraulic valve, and according to the result. It may be determined to change to the two-wheel or three-wheel braking mode (S113). This is because there is a difference between the braking force of the front wheel and the braking force of the rear wheel, and thus the reference braking force may be changed according to a combination of 2 wheels or 3 wheels.

That is, since the braking force of the rear wheels is smaller than that of the front wheels, it is preferable to set the reference braking force to the sum of the hydraulic braking forces of the two rear wheels. One of the reasons for first braking using the wheel is to prevent a reduction in the reference braking force during rotation with the front wheel.

Thereafter, when the vehicle speed is accelerated to exceed 5 kph (S117; Yes), the vehicle stop control system 100 cancels the vehicle stop maintenance control and returns to step S101.

As such, according to an embodiment of the present invention, by providing vehicle stop maintenance control using ESC, manufacturing cost can be reduced by omitting the EPB mounted as an essential option for applying convenient functions such as ACC to a conventional vehicle.

In addition, since the cost burden due to the deletion of EPB is reduced, convenience functions can be applied to vehicle types, thereby improving product competitiveness and customer satisfaction.

In addition, by performing vehicle stop maintenance control that rotates hydraulic braking force with some wheel combinations of less than 4 wheels, durability of the hydraulic valve can be secured and stable stop maintenance control can be performed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various other modifications are possible.

In the above-described embodiment of the present invention, the vehicle stop maintenance control applied to the ACC function has been mainly described, but the embodiment of the present invention is not limited thereto, and the vehicle stops without applying the EPB device even in various vehicle stopping situations such as the AVH (Automatic Vehicle Hold) function. maintenance control can be performed.

For example, FIG. 8 is a conceptual diagram illustrating various situations in which vehicle stop maintenance such as an automatic vehicle hold (AVH) function is required in a conventional vehicle.

Also, FIG. 9 is a flowchart illustrating a vehicle stop control method when AVH is operated according to another embodiment of the present invention.

First, referring to the accompanying FIG. 8 , in a conventional vehicle, if the vehicle is stopped after stepping on the brake pedal and the vehicle is released, the vehicle stops, and various stop maintenance control is required, such as a signal waiting situation or prevention of back rolling on a slope. There is this.

In particular, the parking brake using the EPB was applied when the vehicle stopped for a certain period of time or the driver left the driver's seat while the AVH (=AUTO HOLD) function was activated. For this, the EPB had to be applied as an essential option.

However, referring to FIG. 9 , in the stop control system 100 according to an embodiment of the present invention, when the AVH function of the vehicle is activated (S101; Yes) and the vehicle is stopped by the brake operation (S102; Yes), the vehicle's The required braking force Br of the vehicle is calculated in consideration of the weight and the stopping gradient (S203).

Thereafter, similarly to the flow of FIG. 4 , the stop control system 100 maintains the vehicle stop by rotating the hydraulic braking force using some valves less than 4 wheels according to the magnitude of the required braking force Br required to maintain the vehicle stop. control can be performed.

Accordingly, the AVH function can be additionally applied to the vehicle without applying the conventional EPB, and there is an advantage in that the vehicle stop maintenance control can be performed in various stop situations.

The embodiment of the present invention is not implemented only through the apparatus and/or method described above, but a program for realizing a function corresponding to the configuration of the embodiment of the present invention, a recording medium in which the program is recorded, etc. Also, such an implementation can be easily implemented by an expert in the technical field to which the present invention pertains from the description of the above-described embodiment.

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 improved forms of the present invention are also provided by those skilled in the art using the basic concept of the present invention as defined in the following claims. is within the scope of the right.

100: stop control system 110: driving information detection unit
120: ACC 130: ESC
140: cluster 150: vehicle control unit
FL: Front left wheel FR: Front right wheel
RL: Rear left wheel RR: Rear right wheel
FL_V: FL valve FR_V: FR valve
RL_V: RL valve RR_V: RR valve

Claims (19)

In the vehicle stop control system in which the electronic parking brake (EPB) is omitted,
a driving information detection unit configured to detect driving information measured by various sensors according to the driving of the vehicle;
adaptive cruise control (ACC) for controlling to maintain a predetermined distance according to the speed of the vehicle in front measured by the camera of the vehicle;
a vehicle attitude control device (ESC) for stabilizing the attitude of the vehicle by individually applying hydraulic braking force through valves mounted on each of the four wheels according to the attitude behavior of the vehicle; and
If the vehicle in front stops while the ACC function is in operation, hydraulic braking force is applied to the 4 wheels through the ESC to stop the vehicle. a vehicle control unit that performs stop maintenance control and rotationally controls the operating valve and the remaining idle valves;
A vehicle stop control system comprising: According to claim 1,
The vehicle control unit
A vehicle stop control system for performing stop maintenance control by rotationally controlling the operating valve at which the valve temperature according to hydraulic braking time reaches the endurance temperature with the idle valve. The method of claim 1
The vehicle control unit
A vehicle stop control system that calculates a required braking force of a vehicle in consideration of a vehicle weight and a stop gradient, and determines a stop maintenance control in any one of a two-wheel braking mode and a three-wheel braking mode according to the magnitude of the required braking force. delete 4. The method of claim 3,
The vehicle control unit
If the required braking force is less than the reference braking force that is the sum of the hydraulic braking forces of the two rear wheels, the vehicle stop control system performs the two-wheel braking mode stop maintenance control and if the reference braking force is greater than the reference braking force, the vehicle stop control system performs the three-wheel braking mode stop maintenance control . According to claim 1,
The vehicle control unit
A vehicle stop control system that differentiates and sets the hydraulic pressure of each valve used in the 2-wheel braking mode or 3-wheel braking mode. According to claim 1,
The vehicle control unit
A vehicle stop control system that calculates each valve temperature based on the size of the brake hydraulic pressure and the holding time of each valve in operation. 8. The method of claim 7,
The vehicle control unit
A vehicle stop control system that calculates the time it takes for the valve temperature of each valve to reach the endurance temperature specification with different hydraulic sizes. 9. The method of claim 8,
The vehicle control unit
A vehicle stop control system for determining the valve endurance temperature specification by adjusting the hydraulic pressure level of each wheel to generate a stopping braking force in consideration of a weight according to the brake specification of each wheel with respect to the braking force required according to the stopping gradient of the vehicle. In the method for controlling a vehicle stop in which the electronic parking brake (EPB) is omitted,
a) stopping the vehicle by applying hydraulic braking force to the four wheels through the vehicle attitude control device (ESC) when the vehicle in front stops while the adaptive cruise control (ACC) function is operating;
b) when a predetermined stop time elapses, performing stop maintenance control using hydraulic braking force that operates valves mounted on any 3 or 2 wheels among the valves mounted on each of the 4 wheels, and waiting the remaining valves in an idle state;
c) calculating a valve temperature based on the hydraulic braking time of each valve in operation and the magnitude of the braking hydraulic pressure; and
d) maintaining a vehicle stop state by rotating a valve at which the valve temperature reaches an endurance temperature and a valve in the idle state;
A vehicle stop control method comprising a. 11. The method of claim 10,
Step b) is,
A method for controlling a vehicle stop, comprising the step of calculating a required braking force of the vehicle in consideration of the weight of the vehicle and the stopping gradient. 12. The method of claim 10 or 11,
Step b) is,
performing stop maintenance control in a two-wheel braking mode when the amount of braking force required to maintain a stop of the vehicle is less than a reference braking force that is a sum of hydraulic braking forces of two wheels; or
and performing stop maintenance control in a three-wheel braking mode when the magnitude of the required braking force is equal to or greater than the reference braking force. 13. The method of claim 12,
Step b) is,
and differentiating and setting the hydraulic pressure level of each valve used in the two-wheel braking mode or the three-wheel braking mode. 13. The method of claim 12,
Step b) is,
and determining an endurance temperature specification for each valve by adjusting the hydraulic pressure of each wheel to generate a stopping braking force in consideration of a weight according to a brake specification of each wheel with respect to the required braking force. 11. The method of claim 10,
Step c) is,
calculating a valve temperature based on a holding time of each valve in operation and a magnitude of a brake hydraulic pressure; and
A vehicle stop control method comprising: calculating a valve temperature rise estimation graph of each valve according to time, and calculating a maximum time for the valve temperature of each valve to reach an endurance temperature from the graph. 11. The method of claim 10,
Step c) is,
In consideration of the calorific value according to the hydraulic size of each valve, the estimated time for the valve temperature to reach the endurance temperature is calculated in advance, and the hydraulic pressure release time of the valve reaching the endurance temperature and the hydraulic operation time of the idle valve are determined in consideration of the margin. A method for controlling a vehicle stop, comprising the steps of: 11. The method of claim 10,
Step d) is,
When any one valve temperature calculated according to the vehicle's stopping time reaches the endurance temperature, the hydraulic pressure of the idle valve is operated according to the rotation control, and the hydraulic pressure of the valve that has reached the endurance temperature is released to switch to the idle state. A method for controlling a vehicle stop, including: 11. The method of claim 10,
After step d),
and changing to a two-wheel or three-wheel braking mode according to a result of comparing a reference braking force, which is the sum of hydraulic braking forces of the valves reconfigured according to the rotation control, and a braking force required to maintain the vehicle stop. Way. In the method for controlling a vehicle stop in which the electronic parking brake (EPB) is omitted,
a) stopping the vehicle while the AVH (Automatic Vehicle Hold) function is operating;
b) When a certain stop time has elapsed, stop maintenance control is performed by hydraulic braking force that operates the valves installed on any 3 or 2 wheels of the valves mounted on each of the 4 wheels of the vehicle attitude control device (ESC), and the remaining valves are idle. waiting in a state;
c) calculating the heating temperature based on the hydraulic braking time of each valve in operation and the magnitude of the braking hydraulic pressure; and
d) maintaining a vehicle stop state by rotating a valve at which the heating temperature reaches an endurance temperature and a valve in the idle state;
A vehicle stop control method comprising:

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