KR101986847B1 - Electronic Parking brake and control method applying the same - Google Patents

Abstract

An electronic parking brake apparatus and a control method applied thereto are provided. The electronic parking brake apparatus can provide an electronic parking brake apparatus for generating a steering control signal by using information of an inflation speed and a lateral acceleration and transmitting the steering control signal to an electric power steering control unit and a control method applied thereto, It is possible to perform cooperative control of the EPB-MDPS for reducing spin generation in the emergency dynamic control state. This makes it possible to reduce the possibility of occurrence of spin even in the SRU emergency dynamic control state of the EBP device.

Description

[0001] The present invention relates to an electronic parking brake apparatus and an electronic parking brake apparatus,

The present invention relates to an electronic parking brake device and a control method applied thereto, and more particularly, to an electronic parking brake device capable of cooperative control with a steering device and a control method applied thereto.

  Most of the current parking brake systems have a key role in stabilizing the car by applying braking force when parking the vehicle by pressing the parking brake pedal by the driver (by foot) or by pulling the lever (by hand). However, the EPB (Electronic Parking Brake) system is a progressive control system that is designed to operate or release the parking brake automatically in conjunction with the manual operation mode of the driver and the HECU, engine ECU, and TCU by simple switch operation and to ensure braking stability in emergency situations. Parking brake system. Although the EPB system applied to enhance the convenience and safety of a vehicle has a high degree of freedom of installation on a vehicle, recently, the EPB system is integrated with a brake caliper to further enhance the mounting capability of the EPB.

In this way, the caliper-integrated type EPB mounts an actuator composed of a motor and a multi-stage gear box for amplifying the motor's power, on the caliper of both rear wheels, so that the braking force can be applied by restricting the brake disk by the electric power. These actuators are controlled via a wire bundle from an EPB ECU attached to a separate internal position in the vehicle and the user's willingness to apply the parking braking force is obtained from the operation of an EPB switch directly connected to the ECU.

From the above-described structure, the caliper-integrated type EPB has the same static braking force as that of the conventional parking brake system, but also emergency braking (Dynamic Braking) function. The dynamic braking function can be classified into three functions as described below. Functions for optimal dynamic braking are realized according to the failure situation of each required sensor.

Electric Controlled Deceleration (ECD)

- While the vehicle is running, the foreign body is placed under the brake pedal. EPB is commanded to ESC by continuously applying the EPB switch in the Apply direction when the main brake is normal but the braking force can not be generated.

- ESC should be normal (Function can not be implemented in case of ABS specification)

RWU (Rear Wheel Unlocker)

- In case the main braking force can not be generated due to the failure of the main brake during driving, the EPB switch is continuously applied in the Apply direction to generate the braking force through the operation of the EPB actuator

- The rear wheel equipped with the EPB actuator is slip-controlled from the EPB, and the reference wheel is obtained from the front wheel. → The optimal dynamic braking

- All two rear wheel speed sensors are normal, and one or more front wheel speed sensors are normal.

SRU (Slow Ramp Up)

- In case the normal braking force can not be generated during driving, the EPB switch is continuously applied in the Apply direction to generate the braking force through the operation of the EPB actuator

- All or some of the wheel sensors fail to operate with the slip control disabled via the wheel

- Gradually apply high braking power to both rear wheel discs without wheel information

- Using the signal from the acceleration sensor to check the vehicle behavior, it is determined whether the vehicle is braked by the EPB and is decelerating.

- Failure of the wheel speed sensor, acceleration sensor should not be malfunctioning.

To summarize these, ECD is implemented from ESC in case EPB, ESC, and peripheral sensor are all normal, and inevitably braking with EPB switch is needed, such as when a foreign object under brake pedal is inserted. RWU and SRU are functions implemented in EPB, and RWU has a difference in slip control for preventing spin from wheel information.

The number of cases in which the user causes EPB dynamic braking is infinite, but the case where the fault is most frequent in the actual field is a failure of the wheel speed sensor mounted on the exposed position outside the vehicle with four independent sensor structures. As a result, the dynamic braking of the EPB is most frequently performed by the SRU, which is a non-slip control by driving the EPB actuator. Since SRU can cause both braking force imbalance due to the non-slip control characteristic, sudden spin occurs in the emergency braking, so that the vehicle is braked abnormally, and in case of high speed, it may lead to a serious accident.

  In the case of a typical main brake failure, the user pulls the EPB switch in the Apply direction to stop the vehicle for which braking control is disabled. However, in an emergency situation, the user is perplexed and has a low perceived ability and is likely to reflexively continue to pull the EPB Apply switch. This is the correct stopping method for RWU control as a spin prevention function, but as mentioned above, SRU maximizes vehicle spin. The correct functioning of the SRU is to steer the steering wheel to the opposite side where the spin occurs while repeatedly applying the EPB switch in an emergency and stopping the vehicle by applying steady braking force. This can be seen in the same concept as a conventional parking brake system that pulls the parking brake lever in an emergency and slowly brakes it.

The factors of SRU spin generation mentioned in the above explanation can be classified as in-vehicle. As external factors, there is an imbalance between the road surface and the tire. Internal factors include the deviation of both motor driver elements on the ECU, the resistance difference between the ECU-actuator wiring resistance and the motor winding, the deviation of the gear, .

Among the factors classified as inner - outer, the largest factor of spin generation is the unevenness of the road surface. This is a fundamental problem that can not be overcome by various controls in SRU emergency braking situations, which are the wheel brake pawl and the main brake pedal.

The most significant of the internal factors is the imbalance of both motor currents as shown in the actuator operating force-current waveform at the SRU above. In the EPB logic, both motors are controlled by the same force, but from the internal factors described above, the currents flowing to both motors have large deviations and eventually the difference in operating force occurs when these currents are applied to each motor. To overcome these disadvantages caused by open loop control, current control method is used but it also has control error.

It is an object of the present invention to provide an electronic parking brake device for generating and transmitting a steering control signal to an electric power steering control unit by using information of an end closing speed and a lateral acceleration, And a control method applied thereto.

According to an aspect of the present invention, there is provided an electronic parking brake comprising a longitudinal acceleration sensor for sensing an longitudinal acceleration of the vehicle in a longitudinal direction and a transverse acceleration sensor for sensing lateral acceleration in a lateral direction of the vehicle, A receiver for receiving information and lateral acceleration information; And an electronic parking brake controller which generates and transmits a steering control signal to the electric power steering controller using the received end closing speed information and the lateral acceleration information.

The electronic parking brake control unit calculates the spin direction and the spin amount of the vehicle by using the sensed closing speed information and the lateral acceleration and generates the steering control signal using the calculated spin direction and the spin amount of the vehicle You may.

The electronic parking brake control section generates the steering control signal and outputs the steering control signal to the electric power steering control section when the main brake is in a failure state and some or all of the wheel speed sensors are in a failure state and the electronic parking brake switch is kept in a locked state It can also be delivered.

The electronic parking brake control unit may detect whether an obstacle exists in a specific area near the vehicle, and may generate the steering control signal and transmit the steering control signal to the electric power steering control unit when the obstacle is not detected.

According to another aspect of the present invention, there is provided an electric power steering apparatus control method comprising the steps of: receiving closing rate information from an closing rate sensor for sensing a closing rate in a front-back direction of a vehicle; Receiving lateral acceleration information from a lateral acceleration sensor that senses a lateral acceleration in a lateral direction of the vehicle; Generating a steering control signal using the longitudinal acceleration information and the lateral acceleration information; And transmitting the steering control signal to the electric power steering control unit.

The steering control signal generating step may include calculating the spin direction and the spin amount of the vehicle using the sensed closing speed information and the lateral acceleration, and calculating the steering control signal using the spin direction and the spin amount of the vehicle .

When the main brake is in a failure state and some or all of the wheel speed sensors are in a failure state and the electronic parking brake switch is kept in a locked state, the steering control signal transmission step generates the steering control signal, .

The method of claim 1, further comprising the step of: detecting whether an obstacle is present in a specific area near the vehicle, wherein the steering control signal transmission step generates the steering control signal when the obstacle does not exist, To the steering control unit.

According to various embodiments of the present invention, it is possible to provide an electronic parking brake device that generates and transmits a steering control signal to the electric power steering control unit by using the information of the closing speed and the lateral acceleration, and a control method applied thereto, The apparatus 100 can perform the cooperative control of the EPB-MDPS to lower the spin generation in the SRU emergency dynamic control state. This makes it possible to reduce the possibility of occurrence of spin even in the SRU emergency dynamic control state of the EBP device.

1 is a view showing a structure of an electronic parking brake (EPB) apparatus included in a vehicle according to an embodiment of the present invention;
2 is a flow chart provided to illustrate a method of controlling an electronic parking brake (EPB) device, in accordance with an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 is a diagram showing a structure of an electronic parking brake (EPB) apparatus included in a vehicle according to an embodiment of the present invention.

1, the EPB apparatus 100 includes a receiving unit 110, an EPB switch 120, an actuator 130, a cluster 140, and an EPB control unit 150.

The receiving unit 110 receives information on the rotational speed of the four wheels of the vehicle from the wheel speed sensor 111. [ The receiving unit 110 receives the closing rate information and the lateral acceleration information from the longitudinal acceleration sensor 113 for detecting the longitudinal acceleration of the vehicle in the longitudinal direction of the vehicle and the lateral acceleration sensor 115 for sensing the transverse acceleration in the lateral direction of the vehicle do. The receiving unit 110 transmits the received various information to the EPB control unit 150.

The EPB switch 120 switches the EPB device 100 to either the Apply state, the Release state, or the Neutral state according to the user's operation.

The actuator 130 restrains the brake disk to apply the braking force to the parking brake under the control of the EPB controller 150. [ That is, when the actuator 130 restrains the brake disk, a braking force is generated.

The cluster 140 informs the driver of the occurrence of emergency braking through a warning lamp or a buzzer.

The EPB control unit (electronic parking brake control unit) 150 controls the overall operation of the EPB apparatus 100. [ Specifically, the EPB controller 150 generates a steering control signal using the received end closing speed information and the lateral acceleration information, and transmits the generated steering control signal to the motor driven power steering (MDPS) controller 160.

Specifically, the EPB control unit 150 calculates the spin direction and the spin amount of the vehicle by using the sensed closing speed information and the lateral acceleration. Thus, the EPB controller 150 can check whether the vehicle is in an abnormal rotation state or in a spin state. When the vehicle is in the spin state, the EPB control unit 150 generates the steering control signal using the calculated spin direction and spin amount of the vehicle. Such a steering control signal is a signal for controlling the MDPS apparatus to suppress spin by being steered in the direction opposite to the spin direction of the vehicle. When the vehicle is in a spin state, the driver is often confused and unable to properly steer the vehicle. Therefore, the EPB control unit 150 controls the steering control signal so as to be steered in the opposite direction of the spin direction .

The EPB control unit 150 generates a steering control signal when the spin generation condition that is equal to or greater than a predetermined full-angle speed and a lateral acceleration is satisfied using the received data, which can be considered as follows.

Steering control angle = A (closing speed) + B (lateral acceleration) + C

Where A is the ramp rate constant, B is the lateral acceleration constant, and C is the constant of the steering command constant. This is determined through tuning in the actual vehicle state, taking into consideration the requirements such as the MDPS setting value and the like. In addition, the equation for obtaining the steering control angle may vary depending on factors such as the performance of the acceleration sensor.

The EPB control unit 150 generates a steering control signal when the main brake is in a fault state and some or all of the wheel speed sensors are in a fault state and the electronic parking brake switch is in the SRU (Slow Ramp Up) state, To the control unit 160. Here, the SRU state is a state in which the EPB emergency braking function Dynamic Breaking function is activated. The EPB apparatus 100 is operated in the SRU state when the electronic parking brake switch is kept in the locked state while the main brake is in a failure state and some or all of the wheel speed sensors are in a failure state.

In addition, the EPB controller 150 may detect whether an obstacle exists in a specific area near the vehicle, and may generate the steering control signal and transmit the steering control signal to the MDPS controller 160 when the obstacle is not detected. If an obstacle appears on the front of the vehicle, the steering effort of the user to avoid obstacles is more important than the steering to prevent the emergency braking spin. Accordingly, the EPB controller 150 determines whether or not an obstacle is present by using an ultrasonic sensor attached to a bumper used in a parking guide system (PGS) logic, and if the obstacle is detected, So that the vehicle does not transmit the steering control signal so as to be steered. The EPB control unit 150 can receive the data of the ultrasonic sensor through the CAN (Controller Area Network) from the BCM (Body Chasis Module) in which the PGS is implemented.

MDPS is a steering device, which is a device mounted on a steering shaft to amplify and transmit the steering force of a user. It has an ECU (Electronic Control Unit) for various control purposes like other electric parts, and uses CAN to exchange data with other electric parts. In addition, other electrical components can issue steering commands to MDPS under special circumstances.

By using this point, the EPB apparatus 100 having the above-described structure performs cooperative control for transferring the steering control signal to the MDPS controller 160 in the SRU state, which is the non-slip control in the emergency state in question, The vehicle can be prevented from spinning to achieve greater stability.

 In order to reduce the risk of spin generation, if the user is a user who is skilled in driving, he or she will try to stabilize the behavior of the vehicle due to spin generation by operating the steering wheel in a direction opposite to that in which the spin occurs. However, this is a steering technology that is difficult to be used in an emergency situation. It is very likely that an ordinary user will attempt emergency braking without steering in reverse direction.

However, the EPB apparatus 100 having the above-described structure according to an embodiment of the present invention uses an EBP-MDPS Cooperative control is implemented and stability is enhanced.

Hereinafter, a control method of the electronic parking brake apparatus will be described with reference to FIG. 2 is a flow chart provided to illustrate a control method of an electronic parking brake (EPB) apparatus 100, in accordance with an embodiment of the present invention.

First, the EPB apparatus 100 operates in the SRU state as a dynamic braking function during emergency braking (S210). Specifically, the EPB apparatus 100 operates in the SRU (Slow Ramp Up) state when the main brake is in a failure state and some or all of the wheel speed sensors 111 are in a failure state and the EPB switch 120 is kept in a locked state .

Then, the EPB apparatus 100 generates a notification sound notifying the emergency braking through the cluster 140 (S220). This informs the EPB apparatus 100 that it is in the emergency braking state.

Thereafter, the EPB apparatus 100 checks whether the MDPS controller 160, the closing acceleration sensor 113, and the lateral acceleration sensor 115 are in a normal state or in a fault state (S230). The MDPS controller 160, the closing acceleration sensor 113, and the lateral acceleration sensor 115 must be in a normal state.

Then, the EPB apparatus 100 operates the parking brake in accordance with the operation of locking the EPB switch 120 by the driver (S240). Specifically, the EPB apparatus 100 actuates the parking brake by applying the braking force to the parking brake disk by the actuator 130.

The EPB apparatus 100 senses the closing speed and the lateral acceleration (S250). In step S260, the EPB apparatus 100 determines whether a spin is generated by satisfying a spin generation condition that is equal to or greater than a predetermined full-angle speed and a lateral acceleration using the received information of the closing speed and the lateral acceleration.

If the spin has occurred (S260-Y), the EPB apparatus 100 generates the steering control signal using the received information of the closing speed and the lateral acceleration (S265). Then, the EPB apparatus 100 detects whether an obstacle exists around the vehicle (S270).

If there is an obstacle (S270-Y), the EPB apparatus 100 does not generate a steering control signal and directly returns to step S240. On the other hand, if there is no obstacle (S270-N), the EPB apparatus 100 transmits the steering control signal to the MDPS controller 160 (S275), and then returns to the step S240.

On the other hand, if the vehicle is not in the spin state (S260-N), the EPB apparatus 100 determines whether the vehicle is in a stop state (S280). The EPB apparatus 100 judges that the vehicle is in a stopped state when the closing speed value is kept at 0 for a certain period of time.

If the vehicle is not in the stop state (S280-N), the EPB apparatus 100 returns to step S240. On the other hand, if the vehicle is stopped (S280-Y), the EPB apparatus 100 switches the mode to the static apply mode (S290).

Through the above process, the EPB apparatus 100 can perform cooperative control of the EPB-MDPS to lower the spin generation in the SRU emergency dynamic control state.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

100: EPB control device 110: Receiver
120: EPB switch 130: Actuator
140: Cluster 150: EPB control unit
160: MDPS controller

Claims (8)

A receiving unit for receiving the closing rate information and the lateral acceleration information from a longitudinal acceleration sensor for detecting a longitudinal acceleration of the vehicle in the longitudinal direction of the vehicle and a lateral acceleration sensor for sensing lateral acceleration of the vehicle in the lateral direction; And
And an electronic parking brake controller for generating and transmitting a steering control signal to the electric power steering control unit using the received end closing speed information and the lateral acceleration information,
The electronic parking brake control unit may include:
Wherein the controller checks whether the vehicle is in a normal state before receiving the information from the acceleration sensor and the lateral acceleration sensor,
The electronic parking brake control unit may include:
Calculating a spin direction and a spin amount of the vehicle by using the sensed closing speed information and the lateral acceleration when the acceleration sensor and the lateral acceleration sensor are in a normal state and calculating the spin direction and the spin amount of the vehicle based on the calculated spin rate and the spin amount, Generates a steering control signal,
The electronic parking brake control unit may include:
When the steering control signal is generated, whether or not an obstacle exists in a specific area near the vehicle before the steering control signal is transmitted,
The electronic parking brake control unit may include:
When the main brake is in a failure state and some or all of the wheel speed sensors are in a failure state and the electronic parking brake switch is kept in a locked state, the generated steering control signal is transmitted to the electric power steering control unit,
Wherein the control unit detects whether an obstacle exists in a specific area near the vehicle and transmits the generated steering control signal to the electric power steering control unit only when it is detected that no obstacle is present.
delete delete delete Receiving the closing rate information from an closing rate sensor that detects a closing rate of the vehicle in the front-rear direction;
Receiving lateral acceleration information from a lateral acceleration sensor that senses a lateral acceleration in a lateral direction of the vehicle;
Generating a steering control signal using the longitudinal acceleration information and the lateral acceleration information; And
And transmitting the steering control signal to the electric power steering control unit,
Checking whether the vehicle is in a steady state before receiving information from the closing rate sensor and the lateral acceleration sensor; And
When the steering control signal is generated, detecting whether an obstacle is present in a specific area near the vehicle through the ultrasonic sensor of the parking guide system in which the electronic parking brake controller is separately provided before the steering control signal is transmitted; Further included,
The steering control signal generation step includes:
Calculates a spin direction and a spin amount of the vehicle by using the sensed value-added speed information and the lateral acceleration, generates the steering control signal by using the calculated spin direction and spin amount of the vehicle,
The steering control signal transmission step includes:
When the main brake is in a failure state and some or all of the wheel speed sensors are in a failure state and the electronic parking brake switch is kept in a locked state, the generated steering control signal is transmitted to the electric power steering control section, And transmits the generated steering control signal to the electric power steering control unit only when it is detected.
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