KR20130138011A - Control method of reducing speed using electric booster brake device and control device thereof - Google Patents

Abstract

The present invention relates to a deceleration control method of an electric booster brake device, the method comprising the steps of: calculating target deceleration of a vehicle through a measurement value input from a sensor unit; determining brake torque of the vehicle based on the target deceleration and acceleration of the vehicle; and generating brake in the vehicle by applying pressure to a master cylinder by driving a motor according to the brake torque. According to the present invention, by performing deceleration control for smart cruise control (SCC) and downhill brake control (DBC) through an electric booster, it is possible to improve responsibility by reducing hydraulic value operation noise generated during the deceleration control. [Reference numerals] (AA) Start;(BB) No;(CC) Yes;(DD) End;(S10) Calculate target deceleration through a measurement value of a sensor unit;(S22) Correct the target deceleration and an acceleration error of a vehicle;(S24) Operate hydraulic brake according to an error;(S26) Determining brake torque corresponding to the hydraulic brake;(S32) Is brake pressure generated in the vehicle?;(S34) Add torque corresponding to the brake pressure;(S40) Drive a motor according to the brake torque;(S50) Brake the vehicle by applying pressure to a master cylinder

Description

Control method of deceleration using electric booster braking device and control device therefor {CONTROL METHOD OF REDUCING SPEED USING ELECTRIC BOOSTER BRAKE DEVICE AND CONTROL DEVICE THEREOF}

The present invention relates to a deceleration control method using the electric booster braking device and a control device thereof, and more particularly, by performing the deceleration control for the SCC (Smart Cruise Control) and DBC (Downhill Brake Control) through the electric booster The present invention relates to a deceleration control method using an electric booster braking device that improves responsiveness and reduces hydraulic valve noise compared to an existing electronic stability control (ESC), and a control device thereof.

The electric booster braking device is an active braking device that can cooperatively control the regenerative braking of a hybrid vehicle using a motor-based booster.

In the electric booster braking system, when the driver presses the brake pedal, pressure is generated in the sub master cylinder, and an open / close signal is applied to the solenoid valve. Due to this open / close signal, the Normal Close valve connected to the pedal simulator is opened, and the Normal Open valve connected to the main master cylinder is closed.

Therefore, the pressure generated in the sub master cylinder is transmitted to the pedal simulator through the open valve to push the piston. This causes the driver to feel pedal effort by the rubber and spring reaction forces inside the pedal simulator.

The ECU (Electronic Control Unit, ECU) calculates the braking pressure requirement based on the stroke detected by the pedal stroke measuring sensor and the pressure detected by the sub master cylinder pressure measuring sensor, and drives the motor according to the calculated braking pressure request. To form pressure.

Conventionally, Smart Cruise Control (SCC) and Downhill Brake Contol (DBC) are in charge of ESC (Electronic Stability Control, ESC), so that when the vehicle needs deceleration, the hydraulic pressure is applied to each wheel. And deceleration control was performed by this hydraulic pressure.

However, when the hydraulic pressure was applied to the wheels of the vehicle through the ESC, the brake oil had to be moved by opening the hydraulic valves without generating pressure in the master cylinder.

Therefore, when the hydraulic control through the ESC, the valve operation noise occurs, the problem that the responsiveness to the deceleration control is not good.

Prior art related to the present invention is Republic of Korea Patent Publication No. 10-2012-0030623 (2012.03.29. Publication, the name of the invention: hydraulic braking system).

The present invention was devised to improve the above-described problem, and by performing the deceleration control for the SCC (Smart Cruise Control) and DBC (Downhill Brake Control) through an electric booster, responsiveness compared to the existing Electronic Stability Control (ESC) It is an object of the present invention to provide a deceleration control method using the electric booster braking device which improves and reduces the hydraulic valve noise, and a control device thereof.

Deceleration control method using an electric booster braking device according to an aspect of the present invention comprises the steps of calculating the target deceleration of the vehicle through the measurement value received from the sensor unit; Determining a braking torque of the vehicle based on the target deceleration and the acceleration of the vehicle; And applying braking pressure to the master cylinder by driving the motor according to the braking torque.

According to an aspect of the present invention, before driving a motor according to the braking torque, it is determined whether a braking pressure is generated by a driver in the vehicle, and when the braking pressure is generated by the driver, a torque corresponding to the braking pressure is added to the braking torque. It further comprises.

In the present invention, the determining of the braking torque of the vehicle may include determining the braking torque of the vehicle, correcting the error so that the vehicle follows the target deceleration according to an error between the target deceleration and the acceleration of the vehicle; Calculating a braking hydraulic pressure necessary for braking the vehicle according to the error; And determining a corresponding braking torque to generate the braking hydraulic pressure.

In the present invention, the braking torque is determined in consideration of the minimum braking torque in consideration of safety, the braking torque required for deceleration on a flat surface and the inclination of the road where the vehicle is located.

The present invention is characterized in that the motor is driven such that the braking torque is increased at a constant rate of change until the braking torque is reached when the motor is driven according to the braking torque.

Deceleration control device using an electric booster braking device according to another aspect of the present invention includes a sensor unit for measuring the driving state of the vehicle; A control unit which determines a torque required for braking the vehicle based on the measured value input from the sensor unit; And a braking unit configured to generate braking to the vehicle under control of the controller, wherein the controller calculates a target deceleration of the vehicle based on the measured value input from the sensor unit, and calculates the vehicle through the target deceleration and the acceleration of the vehicle. Determines the braking torque of the vehicle, and if the braking pressure is generated by the driver, the torque corresponding to the braking pressure is added to the braking torque, and the motor is driven according to the braking torque to apply pressure to the master cylinder to brake the vehicle. It characterized in that to generate.

In the present invention, the sensor unit vehicle speed measuring sensor for measuring the speed of the vehicle; An acceleration measurement sensor measuring acceleration of the vehicle; Radar to measure distance from other cars; And it characterized in that it comprises a pedal stroke measuring sensor for measuring the stroke of the pedal.

In the present invention, the control unit corrects the error so that the vehicle follows the target deceleration according to the error of the target deceleration and the acceleration of the vehicle, and calculates the braking hydraulic pressure required for braking the vehicle according to the error to correspond to the braking hydraulic pressure. The torque to be determined is characterized in that the braking torque.

In the present invention, the controller determines the braking torque in consideration of the minimum braking torque in consideration of safety, the braking torque required for deceleration on a flat surface, and the inclination of the road where the vehicle is located.

In the present invention, the control unit is further characterized in that it determines whether the braking pressure is generated by the driver by receiving the measurement value of the pedal stroke measuring sensor.

In the present invention, the control unit drives the motor such that the braking torque is increased at a constant rate of change until the braking torque is reached when the motor is driven according to the braking torque.

According to the present invention, by performing the deceleration control for the SCC (Smart Cruise Control) and DBC (Downhill Brake Control) through the electric booster, the hydraulic valve generated during the deceleration control through the existing electronic stability control (ESC) Responsiveness can be improved by reducing operating noise.

In addition, the present invention can be easily implemented by setting only the control logic using devices provided in the existing vehicle without additional hardware.

1 is a functional block diagram of a deceleration control device using an electric booster braking device according to an embodiment of the present invention.
2 is a flowchart illustrating an implementation process of a deceleration control method using an electric booster braking device according to an embodiment of the present invention.
3 is a graph showing braking torque, current, and duty ratio of a motor formed in a motor according to a deceleration control method using an electric booster braking apparatus according to an embodiment of the present invention.

In the following description, a deceleration control method using an electric booster braking device and a control device thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or convention of a user or an operator. Therefore, definitions of these terms should be made based on the contents throughout the specification.

1 is a functional block diagram of a deceleration control device using an electric booster braking device according to an embodiment of the present invention.

Referring to FIG. 1, a deceleration control device using an electric booster braking device includes a sensor unit 10, a control unit 20, and a braking unit 30.

The sensor unit 10 includes various sensors for measuring the driving state of the vehicle. In the present embodiment, the vehicle speed measuring sensor 12, the acceleration measuring sensor 14, the radar 16, and the pedal stroke measuring sensor 18 are described. ).

The vehicle speed measurement sensor 12 is a sensor for measuring the speed of the vehicle. In the present embodiment, the vehicle speed measurement sensor measures the speed of the vehicle in order to calculate the target deceleration of the vehicle, and the measured value is transmitted to the controller 20. Here, the target deceleration of the vehicle refers to the amount of reduction in the speed per unit time of the target vehicle during the operation of the SCC (Smart Cruise Control) or DBC (Downhill Brake Control).

Acceleration measurement sensor 14 is a sensor for measuring the acceleration of the vehicle, in this embodiment measures the acceleration of the vehicle in order to calculate the braking hydraulic pressure required according to the error of the target deceleration of the vehicle, the measured value is the control unit 20 Is delivered.

Radar 16 is a device for measuring the distance between the target using the reflection of the radio wave, in this embodiment to measure the distance between the vehicle and the target to calculate the target deceleration of the vehicle, the measured value is the control unit 20 Is delivered.

The pedal stroke measurement sensor 18 is a sensor for detecting the braking intention by the driver. In this embodiment, when the pressure is applied to the pedal by the driver, the pedal stroke measurement sensor 18 measures the stroke of the pedal and the measured value is transmitted to the controller 20.

The control unit 20 receives various measurement values of the sensor unit 10, calculates a target deceleration required for the vehicle, determines a braking hydraulic pressure of the vehicle according to an error between the target deceleration and the acceleration of the vehicle, and corresponds to a motor. The motor 33 is driven in accordance with the braking torque of 33 and the torque corresponding to the braking pressure input to the vehicle.

A detailed process of determining the braking torque for driving the motor 33 in the control unit 20 will be described later.

In this embodiment, by driving the motor 33, pressure is applied to the master cylinder 34 to reduce the hydraulic valve noise and improve the responsiveness of the deceleration control.

The brake unit 30 is a device for generating a brake on the vehicle, and includes an electric booster 32, a master cylinder 34, and a brake caliper 36.

The electric booster 32 is an active braking device that enables cooperative control during regenerative braking of a hybrid vehicle using an electric motor-based booster. In this embodiment, the electric booster 32 includes a motor 33.

The electric booster 32 drives the motor 33 under the control of the controller 30 to apply pressure to the master cylinder 34, and brake oil is injected into the brake caliper 36 due to the increase in pressure of the master cylinder 34. do.

The master cylinder 34 stores the brake oil therein, and when the pressure is increased by the operation of the motor 33, the master cylinder 34 injects the brake oil into the brake caliper 36.

The brake caliper 36 performs braking by rubbing the brake pad (not shown) and the rotating disk (not shown) using the pressure generated by the injection of the brake oil.

2 is a flowchart illustrating an implementation process of a deceleration control method using an electric booster braking apparatus according to an embodiment of the present invention, and FIG. 3 is a deceleration using an electric booster braking apparatus according to an embodiment of the present invention. It is a graph showing the braking torque, current, and duty ratio of the motor formed in the motor according to the control method.

Referring to FIGS. 2 and 3, a deceleration control method using an electric booster braking device according to an embodiment of the present invention will be described. First, the control unit 20 uses the measured value measured from the sensor unit 10 to target a vehicle. Calculate the deceleration (S10).

In the SCC operation, the target deceleration of the vehicle is calculated based on the speed of the vehicle and the distance between the vehicle in front of the vehicle, so that the controller 20 measures the speed of the vehicle measured by the vehicle speed sensor 12 and the radar 16. Calculate the target deceleration by receiving the distance from the previous vehicle.

That is, the target deceleration is calculated to control how much the speed of the vehicle measured by the vehicle speed measurement sensor 12 is controlled according to the distance from the front vehicle measured by the radar 16.

In addition, during the DBC operation, since the target deceleration of the vehicle is calculated based on the speed of the vehicle and the inclination angle of the road where the vehicle is located, the control unit 20 measures the measured value measured by the vehicle speed measurement sensor 12 and the acceleration measurement sensor 14. Calculate by inputting

In this embodiment, the target deceleration is calculated in consideration of the inclination angle of the road where the vehicle is located, and the inclination angle is calculated through the speed and acceleration of the vehicle.

Next, the controller 20 determines the braking torque of the vehicle based on the calculated target deceleration and the acceleration of the vehicle (S20). The determining of the braking torque of the vehicle may include an error correction step (S22) of performing a Proportional Integral Derivative (PID) control so that the vehicle follows the target deceleration according to the error of the target deceleration of the vehicle and the actual acceleration of the vehicle. Calculating a braking hydraulic pressure necessary for braking the vehicle according to the step S24 and determining a braking torque corresponding to the braking hydraulic pressure S26.

In step S26 of determining the braking torque corresponding to the braking hydraulic pressure, the control unit 20 determines the braking torque in consideration of the minimum braking torque considering safety, the braking torque required for deceleration on a flat surface, and the inclination of the road where the vehicle is located. .

와 같은 식으로 계산될 수 있다. 이 때,

은 제동토크,

는 안전을 고려한 최소 토크,

은 평지에서 감속에 소요되는 토크 및 θ는 차량이 위치한 도로의 경사각을 의미한다. 단 차량이 오르막길에 위치했을 때 θ는 양의 값을 갖고, 차량이 내리막길에 위치했을 때 θ는 음의 값을 갖는 것으로 한다.According to this embodiment, the braking torque is

It can be calculated as At this time,

Silver braking torque,

Is the minimum torque for safety considerations,

Is the torque required for deceleration on the flat and θ means the inclination angle of the road on which the vehicle is located. However, it is assumed that θ has a positive value when the vehicle is located uphill and θ has a negative value when the vehicle is located downhill.

) 이외에 안전을 고려한 최소 토크(

)가 추가된다. 또한 차량이 위치한 도로의 경사각을 고려하므로, 차량이 오르막길을 주행하면서 감속도 제어 시에는 차량이 위치한 도로의 경사각이 0°에서 90°로 변할수록 제동토크가 감소하도록 결정되고, 내리막길을 주행하면서 감속도 제어 시에는 차량이 위치한 도로의 경사각이 0°에서 -90°로 변할수록 제동토크가 증가하도록 결정된다.According to this formula, the braking torque is the torque

In addition to), the minimum torque for safety considerations (

) Is added. In addition, since the inclination angle of the road where the vehicle is located is considered, when the vehicle travels uphill and the deceleration control is performed, the braking torque is decreased as the inclination angle of the road where the vehicle is located changes from 0 ° to 90 °, and while driving downhill In the deceleration control, the braking torque is increased as the inclination angle of the road where the vehicle is located changes from 0 ° to -90 °.

In addition, the controller 20 determines whether a torque corresponding to the braking pressure generated by the driver is required as well as the braking torque through the measured value input from the sensor unit 10 (S30). Whether or not the torque corresponding to the braking pressure generated by the driver is required is determined in step S32 of whether the braking pressure is generated by the driver and adding a torque corresponding to the braking pressure when the braking pressure is generated by the driver to the braking torque. Step S34 is included.

That is, if the braking pressure is not generated by the driver, the braking torque for driving the motor 33 is maintained at the braking torque determined in the step S20 of determining the braking torque of the vehicle, but when the braking pressure is generated by the driver, the braking torque is maintained. Since the torque corresponding to the pressure is added to the braking torque, the braking torque for driving the motor 33 is increased.

At this time, whether the braking pressure generated by the driver in the vehicle is determined through the pedal stroke measured by the pedal stroke measuring sensor 18.

The controller 20 drives the motor 33 according to the braking torque determined by the measured value input from the sensor unit 10 and the torque corresponding to the braking pressure generated by the driver (S40), and drives the motor 33. In accordance with the pressure applied to the master cylinder 34 generates a braking (S50).

In this case, referring to FIG. 3, the braking torque, the current, and the duty ratio of the motor formed in the motor according to the deceleration control method using the electric booster braking device according to an embodiment of the present invention will be described. According to the present invention, a graph showing braking torque formed in the motor, (b) is a graph showing the current applied to the motor according to the braking torque, and (c) is a graph showing the duty ratio of the motor according to the current applied to the motor.

In order to minimize the heterogeneity of the driver due to the occurrence of braking during the control to reach the target deceleration, as shown in (a), the control unit 20 controls the motor 33 to increase the braking torque at a constant rate of change until the desired braking torque is reached. Drive it.

Therefore, the current is applied to the motor 33 at a constant rate of change until the target current capable of generating the desired braking torque is reached as shown in (b), and the motor at a constant rate of change until the target current is reached as shown in (c). The duty ratio of (33) also changes.

According to the present embodiment, by performing the deceleration control for the SCC and DBC through the electric booster 32, the hydraulic valve operating noise generated during the deceleration control through the existing electronic stability control (ESC) to reduce the response Can improve the sex.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, I will understand. Accordingly, the true scope of the present invention should be determined by the following claims.

10: sensor unit 12: vehicle speed measuring sensor
14: Accelerometer 16: Radar
18: pedal stroke measuring sensor 20: control unit
30: braking part 32: electric booster
33: motor 34: master cylinder
36: brake caliper

Claims (11)

Calculating a target deceleration of the vehicle based on the measured value input from the sensor unit;
Determining a braking torque of the vehicle based on the target deceleration and the acceleration of the vehicle; And
Generating a brake on the vehicle by applying pressure to the master cylinder by driving the motor according to the braking torque;
Deceleration control method using an electric booster braking device comprising a.
The method of claim 1,
Before driving the motor according to the braking torque, determining whether a braking pressure is generated by the driver and adding a torque corresponding to the braking pressure to the braking torque when the braking pressure is generated by the driver. Deceleration control method using an electric booster braking device, characterized in that.
The method of claim 1,
The determining of the braking torque of the vehicle may include correcting the error so that the vehicle follows the target deceleration according to an error between the target deceleration and the acceleration of the vehicle;
Calculating a braking hydraulic pressure necessary for braking the vehicle according to the error; And
Determining a corresponding braking torque to generate the braking hydraulic pressure
Deceleration control method using an electric booster braking device comprising a.
3. The method of claim 2,
The braking torque is a deceleration control method using the electric booster braking device, characterized in that the minimum braking torque in consideration of safety, the braking torque required for deceleration on the flat surface and the inclination of the road in which the vehicle is located.
The method of claim 1,
And driving the motor such that the braking torque is increased at a constant rate of change until the braking torque is reached when the motor is driven according to the braking torque.
Sensor unit for measuring the driving state of the vehicle;
A control unit which determines a torque required for braking the vehicle based on the measured value input from the sensor unit; And
A braking unit for generating braking to the vehicle under control of the controller,
The controller calculates a target deceleration of the vehicle based on the measured value input from the sensor unit, determines the braking torque of the vehicle based on the target deceleration and the acceleration of the vehicle, and when the braking pressure is generated by the driver, A deceleration control apparatus using an electric booster braking device, wherein a torque corresponding to a braking pressure is added to the braking torque, and a braking is generated by applying a pressure to a master cylinder by driving a motor according to the braking torque.
The method according to claim 6,
The sensor unit vehicle speed measuring sensor for measuring the speed of the vehicle;
An acceleration measurement sensor measuring acceleration of the vehicle;
Radar to measure distance from other cars; And
Pedal stroke sensor to measure the stroke of the pedal
Deceleration control device of the electric booster braking device comprising a.
The method according to claim 6,
The control unit corrects the error so that the vehicle follows the target deceleration according to the error between the target deceleration and the acceleration of the vehicle, and calculates a braking hydraulic pressure necessary for braking the vehicle according to the error to obtain a torque corresponding to the braking hydraulic pressure. Deceleration control device using an electric booster braking device characterized in that determined by the braking torque.
The method of claim 8,
The control unit is a deceleration control device using the electric booster braking device, characterized in that for determining the braking torque in consideration of the minimum braking torque in consideration of safety, the braking torque required for deceleration on the flat surface and the inclination of the road in which the vehicle is located.
8. The method of claim 7,
The control unit is a deceleration control device using an electric booster braking device characterized in that further determining whether the braking pressure is generated by the driver based on the measurement value received from the pedal stroke measuring sensor.
The method according to claim 6,
And the control unit drives the motor so that the braking torque is increased at a constant rate of change until the braking torque is reached when the motor is driven according to the braking torque.

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