KR100653876B1 - Electronic hydraulic brake for ACC - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking control device, and more particularly to an adaptive travel control system that can be easily added on to an existing braking device.

In the conventional ACC system, a large motor, a hydraulic pump, and an accumulator are configured to generate a hydraulic force, and the cost of equipment increases according to the capacity, and the braking operation is caused by the pulsation of the hydraulic pressure generated by using a large hydraulic pump. It causes vibration and noise in performance, and it is necessary to configure a plurality of directional electronic control valves to perform pulse width modulation control, which causes a problem of using a relatively expensive linear valve. In addition, in the ACC system, only partial braking, ie, low-pressure automatic braking, is performed in the ACC system, which causes a problem of installation space and resource waste in the large-capacity motor and hydraulic pump accumulator.

Accordingly, the present invention is to solve the above-described problems, the object of the present invention is compatible with the existing brake system, low price operation control braking device that can supply a suitable braking control pressure to the adaptive driving control system To implement

Adaptive Drive Control System

Description

Electronic hydraulic brake for ACC of adaptive drive control system

1 is a hydraulic circuit diagram for showing the configuration of a conventional ACC system.

2 is a hydraulic circuit diagram for showing the configuration of the present invention ACC system.

Figure 3 is a block diagram for showing the configuration of a control unit applied to the present invention ACC system.

4 is a view for showing a hydraulic change process by the operation of the piston of the present invention,

Figure 4a shows the operation of the piston for pressurization.

Figure 4b is a view showing the operation of the piston for decompression.

* Description of the symbols for the main parts of the drawings *

10: angle sensor 20: object detection sensor

30: wheel speed sensor 40: cut valve

50: chamber 60: cylinder

70: cylinder 80: motor

90: wheel cylinder 100: control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking control device, and more particularly to an adaptive travel control system that can be easily added on to an existing braking device.

In general, an adaptive cruise control (ACC) system is a system that constantly drives a vehicle at a set speed without a driver using an accelerator pedal. That is, when the driver sets the autonomous driving mode while driving the vehicle at a predetermined speed, the system keeps the speed set in the autonomous driving mode even when the driver does not operate the deceleration or accelerator pedal.

The brake system used in the current vehicle is a hydraulic system including a booster system, and ABS, TCS and VDC systems are widely used to enable the driver to operate the vehicle easily, comfortably and safely. However, the ACC system has special functions such as a collision avoidance function, a vehicle amount guidance function, and a parking assist function, and a braking device having a function of easily integrating many systems is required to perform such a complex and many functions.

According to these demands, a lot of researches have been conducted on the brake system of the electronic hydraulic brake (EHB), which can realize all functions such as the existing hydraulic brake system (CBS), ABS, TCS and VDC. It is becoming.

On the other hand, in recent years, when there is a car ahead while driving, an improved ACC system has been implemented to automatically control the speed in consideration of the distance between the front car and the own vehicle. In other words, if there is no car ahead, acceleration and deceleration are properly controlled to maintain the speed set by the user in advance, and if there is a car ahead, the speed based on the distance or own vehicle speed set in advance by the sensor data is considered. To decelerate appropriately.

A conventional ACC system is shown in Figure 1,

The first brake line 101 is connected to both the left front wheel and the right rear wheel brake cylinder 102, and the second brake line 103 is a brake line connected to both the right front wheel and the left rear wheel brake cylinder 102.

The master cylinder 200 has two positions connected to the brake pedal 201, so that the actuation of the brake pedal 201 pressurizes the brake fluid by the movement of the piston in the master cylinder 200, and thus the first and the first The brake fluid is pressurized to the wheel brake cylinder 102 via the two brake lines 101 and 103. At this time, the first brake outlet port of the master cylinder 200 is connected to the first brake line 101 at the connection point a through the first brake fluid supply line 202 and the second of the master cylinder 200. The brake outlet port is connected to the second brake line 103 at the connection point b via the second brake fluid supply line 202 ′. The distribution valve 203 is disposed between the first brake line 101 and the second brake line 103 and receives the brake hydraulic pressure from the master cylinder 200 or the hydraulic pumps 206 and 206 '. Each of the wheel brake cylinders 102 is provided via the 101 or second brake line 103.

The first hydraulic shutoff valve 204 is disposed in the first brake fluid supply line 202, and the second hydraulic shutoff valve 204 ′ is disposed in the second brake fluid supply line 202 ′. At this time, between the inlet side and the outlet side of the first hydraulic shutoff valve 204 and the second hydraulic shutoff valve 204 ', the check valves 205 and 205' do not flow back to the master cylinder side. ), And each of the two hydraulic shutoff valves 202 and 202 'is composed of an electronic normal open (NO) directional control valve, and according to the control signal of the controller 107, the master cylinder 200 side and the hydraulic circuit Separate the side.

The hydraulic pumps 206 and 206 'are arranged in the hydraulic line 207, the outlet port of which is connected to the accumulator 208 through the hydraulic line 207, and the inlet ports of the hydraulic pumps 206 and 206' are It is connected to the pass hydraulic line (209). In addition, the outlet ports of the hydraulic pumps 109 and 109 'are connected to the hydraulic line 210 at the connection point c through the hydraulic line 207.

The hydraulic pumps 206 and 206 'supply the pumped brake fluid to the brake lines 101 and 103 regardless of the master cylinder pressure generated by the pressure of the brake pedal 201 by the control signal of the controller 107. . At this time, the check valve 206a is disposed on the inlet side and the outlet side of the hydraulic pump 206 so that the brake fluid does not flow back, and the check valve 206'a is also provided on the inlet side and the outlet side of the hydraulic control pump 206 '. Is placed.

A bypass line 212 for bypassing the brake fluid to the brake fluid reservoir 211 is connected to the connection point d of the hydraulic line 210 for supplying the pumped brake fluid to the wheel brake cylinder side. 212 is connected to the hydraulic line 209 and the connection point (e). The first directional control valve 213 and the second directional control valve 214 are disposed between the connection point d and the connection point c, and the third directional control valve 215 is connected to the connection point d. Disposed between points (e).

The first and third directional control valves 213 and 215 are constituted by a normal open (NO) electronic directional control valve so that a gentle pressure increase / decrease is achieved by the pulse width modulation signal of the controller 107. The control valve 214 is composed of an electronic normal closed (NC) directional control valve. The opening and closing positions of each of the directional control valves 213, 214, and 215 can be controlled in response to a control signal generated from the controller.

The conventional ACC system configured as described above drives the first, second and third directional control valves 213, 214, and 215 by a high frequency pulse width modulated signal when the brake pressure increases according to the automatic control of the controller. It is achieved by increasing the brake hydraulic pressure and performing the operation opposite to the above when the brake pressure is decreased. In addition, the accumulator 208 and the hydraulic pumps 206 and 206 'are configured to form the hydraulic pressure.

However, in the conventional ACC system as described above, a large-capacity motor, a hydraulic pump, and an accumulator are configured to generate a hydraulic force, and the cost of equipment cost increases according to the capacity, and hydraulic pulsation generated by using a large-capacity hydraulic pump. Due to the phenomenon, vibration and noise are generated when the braking operation is performed, and a plurality of directional electronic control valves must be configured to perform pulse width modulation control, thereby causing a problem of using a relatively expensive linear valve.

In addition, in the ACC system, only partial braking, ie, low-pressure automatic braking, is performed in the ACC system, which causes problems of installation space and resource waste in the large-capacity motor and hydraulic pump accumulator.

Accordingly, the present invention is to solve the above-described problems, the object of the present invention is compatible with the existing brake system, low price operation control braking device that can supply a suitable braking control pressure to the adaptive driving control system To implement

The present invention for achieving the above object is a vehicle braking control device, the blocking means for blocking the hydraulic pressure on the master cylinder side during automatic braking control by the ACC system, and configured on the flow path to the wheel cylinder side Storage means for temporary storage, braking pressure control means for providing a braking pressure to the wheel cylinder side by applying pressure to the hydraulic pressure stored in the storage means, and a control unit for controlling the braking pressure control means.

The blocking means is characterized in that the cut valve.

The storage means is configured on the flow path to the wheel cylinder side is characterized in that it comprises a chamber for temporarily storing the hydraulic pressure, and a cylinder for guiding the pressure to the pressure stored in the chamber.

The braking pressure control means detects a piston which is inserted into a cylinder of the storage means to apply pressure to the hydraulic pressure in an up and down motion, a motor connected to the lower side of the piston to provide a vertical driving force to the piston, and a rotation angle of the motor. It consists of an angle sensor for                     

The control unit receives acceleration and deceleration of the vehicle by receiving the speed signal and the front object detection signal transmitted from each wheel speed sensor and the object detection sensor, and the motor according to the determination result of the acceleration and deceleration determination device. A forward / reverse rotation instruction indicating forward rotation or reverse rotation, a rotation angle / pressure comparison table in which a pressure change amount proportional to the rotation angle of the motor is stored in the motor controller, and the acceleration / deceleration judgment device outputs the A motor controller for outputting a signal for controlling the motor rotational speed of the braking pressure control means using data of the rotation angle / pressure comparison table according to the acceleration / deceleration degree, and a pulse by inputting a motor control signal of the motor controller It consists of a PWM signal generator for generating a modulation width signal.

Hereinafter, the configuration and detailed operation of the present invention will be described with reference to the accompanying drawings.

First, referring to the hydraulic circuit diagram of FIG.

Cut valve 40 for cutting off the hydraulic pressure on the master cylinder side during automatic control of the ACC system, a chamber 50 configured on the flow path to the wheel cylinder 90 side to temporarily store the hydraulic pressure, and the chamber 50 A cylinder (60) for guiding the pressure to the hydraulic pressure stored in the cylinder), a piston (70) inserted into the cylinder (60) to apply pressure to the hydraulic pressure in a vertical motion, and a lower side of the piston (70). A motor 80 that is connected to provide a vertical driving force to the piston 70, an angle sensor 10 for detecting a rotation angle of the motor 80, and a braking pressure by controlling the rotation angle of the motor 80. It is composed of a control unit 100 for controlling.                     

The cylinder 60 has a female thread 62 formed at a predetermined setting position to allow the piston 70 to be coupled to move upward and downward, and a locking step 61 for restricting the upward movement of the piston 70 to the upper side thereof. ) Is configured.

The piston 70 has a male screw thread 71 formed at a position corresponding to the female screw thread 62 of the cylinder 60, and an insertion hole (3) is inserted into the piston 70 to insert the driving shaft of the motor 80. 72).

The control unit 100 receives the speed signal and the front object detection signal transmitted from each of the wheel speed sensor 30 and the object detection sensor 20 and the acceleration / deceleration determination unit 11 that determines acceleration / deceleration of the vehicle. In accordance with the determination result of the acceleration / deceleration determination unit 11, the forward and reverse rotation indicators 12 for instructing forward or reverse rotation of the motor 80, and the motor controller 13 to the rotation angle of the motor 80. The rotation angle / pressure comparison table 14 in which the proportional change in pressure is stored in advance and the acceleration / deceleration degree of the vehicle output from the acceleration / deceleration judging device 11 are used. The motor controller 13 outputs a signal for controlling the motor rotation speed of the motor 80 by using data, and the pulse for driving the motor 80 by inputting the motor control signal of the motor controller 13. And a PWM signal generator 15 for generating a modulation width signal.

The cut valve 40 is a normal open valve NO.

Detailed operation of the present invention configured as described above will be described as follows.

In the braking operation by the user, that is, in the normal state, the piston 70 is retracted as much as possible, and the cut valve 40 is opened to perform the normal state operation.                     

When the ACC operation mode is executed by the user, the controller 100 closes the cut valve 40 by applying an off signal to the cut valve 40 to block the flow path to the master cylinder side.

Thereafter, a braking operation is performed to maintain the speed selected or set by the user. The acceleration / deceleration determination unit 11 of the controller 100 is input from each of the wheel speed sensor 30 and the object detection sensor 20. The acceleration and deceleration of the vehicle is determined by inputting the sensing signal.

That is, when the speed signal higher than the speed set by the user is input, or when the distance with the front vehicle is within the predetermined distance, the acceleration / deceleration determination unit 11 outputs the deceleration control signal. When the deceleration control signal is output from the acceleration / deceleration determination unit 11, the forward and reverse rotation indicator 12 inputs the output signal indicating the forward or reverse rotation of the motor 80. In the present invention, the motor 80 Will be described as an example in which the piston 70 rises when the forward rotation rotates and the piston 70 descends when the rotation reverses.

More specifically, as shown in FIG. 2, a female thread 62 is formed at a predetermined setting position of the cylinder 60, and the arm is located at a predetermined setting position of the piston 70 inserted into the cylinder 60. A male thread 71 corresponding to the thread 62 is configured to show a shape in which the piston 70 is screwed to the cylinder 60 so as to vertically flow. An insertion hole 72 is formed at the bottom of the piston 70 to insert the drive shaft of the motor 80. As the motor 80 rotates, the piston 70 is formed with a thread 62 formed in the cylinder 60. Follow the up and down movement will be performed.                     

When the deceleration control signal is input from the acceleration / deceleration determiner 11, the forward rotation indicator 12 outputs the forward rotation signal of the motor 80, and the motor controller 13 may control the wheel speed sensor 30 and the object. The target pressure value is set in consideration of the speed detected by the detection sensor 20 and the distance to the vehicle ahead, and the rotation angle of the motor 80 is adjusted by applying the set target pressure value to the rotation angle / pressure comparison table 14. It will output the signal to control. When the target rotation angle is selected using the rotation angle / pressure comparison table 14, the PWM signal generator of the controller 100 is controlled by a proportional control method with reference to the rotation angle of the motor 80 detected by the angle sensor 10. Reference numeral 15 denotes a pulse width modulated signal.

Thereafter, the motor 80 gradually rotates forward by inputting a pulse width modulation signal output from the PWM signal generator 15, thereby raising the piston 70 as shown in FIG. 4A. As the piston 70 rises, the hydraulic pressure stored in the chamber 50 is applied to the wheel cylinder 90 to increase the braking pressure.

On the contrary, when the speed signal lower than the speed set by the user is input or the distance from the front vehicle is further than the preset distance, the acceleration / deceleration judging 11 outputs the acceleration control signal. When the acceleration control signal is output from the acceleration / deceleration determination unit 11, the forward and reverse rotation indicator 12 inputs the reverse rotation signal of the motor 80.

When the acceleration control signal is input from the acceleration / deceleration determiner 11, the forward rotation indicator 12 outputs the reverse rotation signal of the motor 80, and the motor controller 13 may control the wheel speed sensor 30 and the object. The target pressure value is set in consideration of the speed detected by the detection sensor 20 and the distance to the vehicle ahead, and the rotation angle of the motor 80 is adjusted by applying the set target pressure value to the rotation angle / pressure comparison table 14. It will output the signal to control. When the target rotation angle is selected using the rotation angle / pressure comparison table 14, the PWM signal generator of the controller 100 is controlled by a proportional control method with reference to the rotation angle of the motor 80 detected by the angle sensor 10. Reference numeral 15 denotes a pulse width modulated signal.

Thereafter, the motor 80 slowly rotates by inputting a pulse width modulation signal output from the PWM signal generator 15 to lower the piston 70 as shown in FIG. 4B. As the piston 70 descends, the hydraulic pressure stored in the chamber 50 is applied from the wheel cylinder 90 side to the chamber 50 side to lower the braking pressure, and the vehicle accelerates the speed.

As described above, in the present invention, when the ACC operation mode is started by the ACC system, the flow path to the master cylinder is blocked, and the braking control of the vehicle is performed by pressurizing or reducing the hydraulic pressure stored in the chamber by the vertical movement of the cylinder by the rotation of the motor. By doing this, the configuration is simpler than the conventional one, and thus, the cost is low and the control logic is simple, so that the burden on the design and the compatibility are excellent.

Claims (6)

In the adaptive driving control system for performing a braking control of the vehicle based on the movement information of the vehicle input from the sensors for detecting the movement information of the vehicle and the sensing data of the sensor for detecting the front object, Blocking means for interrupting the hydraulic pressure on the master cylinder side during automatic braking control by the adaptive driving control system, a storage means configured on the flow path to the wheel cylinder side for temporarily storing the hydraulic pressure, and the hydraulic pressure stored in the storage means. A brake control device for an adaptive drive control system, characterized in that the brake pressure control means for providing a brake pressure to the wheel cylinder side by adding or subtracting pressure, and a control unit for controlling the braking pressure control means. The method of claim 1, The storage means is configured on the flow path to the wheel cylinder side adaptive driving control system characterized in that it comprises a chamber for temporarily storing the hydraulic pressure, and a cylinder for guiding the pressure to the pressure stored in the chamber Hydraulic brake control device. The method of claim 1, The braking pressure control means detects a piston which is inserted into a cylinder of the storage means to apply pressure to the hydraulic pressure in an up and down motion, a motor connected to the lower side of the piston to provide a vertical driving force to the piston, and a rotation angle of the motor. Hydraulic brake control device of the adaptive driving control system, characterized in that consisting of an angle sensor for. The method of claim 1, The control unit receives an acceleration and deceleration of the vehicle by receiving the movement information and the front object detection signal of the vehicle from the sensor, and instructs forward or reverse rotation of the motor according to the determination result of the acceleration and deceleration determination unit. A rotation angle / pressure comparison table in which a forward / reverse rotation indicator, a pressure change amount proportional to the rotation angle of the motor is stored in the motor controller, and the acceleration / deceleration degree of the vehicle output from the acceleration / deceleration judging device A motor controller for outputting a signal for controlling the motor rotational speed of the braking pressure control means using data of the angle / pressure comparison table, and a PWM signal for inputting a motor control signal of the motor controller to generate a pulse modulation width signal Hydraulic brake control device of the adaptive running control system, characterized in that the generator. The method of claim 1, The shutoff means is a hydraulic braking control device of an adaptive running control system, characterized in that the normal open valve for blocking the flow path to the master cylinder side by the blocking control signal of the control unit when the adaptive running control system. The method of claim 2 or 3, A female thread is formed at a predetermined setting position of the cylinder, and a male thread corresponding to the female thread is configured at a predetermined setting position of the piston inserted into the cylinder, and the piston is screwed to allow the cylinder to flow up and down. Hydraulic brake control device of adaptive travel control system.

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