阅读说明：本技术 用于制动车辆的设备和方法 (Device and method for braking a vehicle ) 是由 郑夏珉 于 2021-05-31 设计创作，主要内容包括：本公开的至少一个实施例提供了一种用于制动车辆的设备和方法,该设备包括：多个机电制动(EMB)系统,其被分别安装用于多个车轮并且被配置为分别对多个车轮生成制动力；驾驶信息检测单元,其用于测量车辆的驾驶信息；电子动力转向(EPS)系统,其沿与在车辆中生成的制动扭矩相反的方向生成转向扭矩；以及电子控制单元(ECU),其控制机电制动系统和电子动力转向系统,其中,电子控制单元被配置为在确定多个机电制动系统中的一个或一些机电制动系统发生故障时,通过使用电子动力转向系统来控制车辆,并且电子动力转向系统被配置为根据包括车轮速度的驾驶信息生成转向扭矩。(At least one embodiment of the present disclosure provides an apparatus and method for braking a vehicle, the apparatus including: a plurality of electromechanical brake (EMB) systems installed for a plurality of wheels, respectively, and configured to generate braking forces to the plurality of wheels, respectively; a driving information detecting unit for measuring driving information of the vehicle; an Electric Power Steering (EPS) system that generates a steering torque in a direction opposite to a braking torque generated in a vehicle; and an Electronic Control Unit (ECU) that controls the electromechanical braking systems and the electric power steering system, wherein the electronic control unit is configured to control the vehicle by using the electric power steering system when it is determined that one or some of the plurality of electromechanical braking systems is malfunctioning, and the electric power steering system is configured to generate a steering torque according to driving information including wheel speeds.)

1. An apparatus for braking a vehicle, comprising:

a plurality of electromechanical brake systems mounted for a plurality of wheels of the vehicle, respectively, and configured to generate braking forces for the plurality of wheels, respectively;

a driving information detection unit configured to measure driving information of the vehicle;

an electric power steering system configured to generate a steering torque in a direction opposite to a braking torque generated in the vehicle; and

an electronic control unit configured to control the plurality of electromechanical braking systems and the electric power steering system,

wherein the electronic control unit is configured to control the vehicle by using the electric power steering system upon determining that one or some of the plurality of electromechanical brake systems is malfunctioning, and

the electronic power steering system is configured to generate the steering torque according to the driving information including a wheel speed.

2. The apparatus of claim 1, wherein the electronic control unit is configured to control the electromechanical braking system for braking a right wheel of the plurality of wheels to generate a left steering torque when it is determined that all electromechanical braking systems for braking a left wheel of the plurality of wheels are malfunctioning.

3. The apparatus of claim 1, wherein the electronic control unit is configured to control the electromechanical braking system for braking a left wheel of the plurality of wheels to generate the right steering torque upon determining that all electromechanical braking systems for braking a right wheel of the plurality of wheels are malfunctioning.

4. The apparatus of claim 1, wherein the electronic control unit is configured to control the electronic power steering system and the remaining normal electromechanical braking systems to control the vehicle not to rotate upon determining that any one of the plurality of electromechanical braking systems is malfunctioning relative to the remaining normal electromechanical braking systems.

5. The apparatus according to claim 1, wherein the driving information detecting unit includes:

a plurality of wheel speed sensors are provided,

wherein the electronic power steering system is further configured to generate the steering torque by using one or more normal wheel speed sensors when one or some of the plurality of wheel speed sensors fail.

6. The apparatus according to claim 5, wherein the driving information detecting unit further includes:

a steering angle sensor for detecting a steering angle of the vehicle,

wherein the electronic control unit is further configured to determine whether the rotation of the vehicle is reduced by using the steering angle detected by the steering angle sensor.

7. The apparatus of claim 6, wherein the electronic control unit is configured to control the electronic power steering system to additionally generate the steering torque when it is determined that the rotation of the vehicle is not decreasing.

8. A method of braking a vehicle, comprising:

determining whether the electromechanical braking system is malfunctioning;

upon determining that the electromechanical braking system is malfunctioning, generating wheel speed information by measuring wheel speed using one or more wheel speed sensors and transmitting the wheel speed information to an electronic power steering system by using on-board communications; and is

Generating a steering torque for preventing the vehicle from rotating during braking based on the wheel speed information by using the electric power steering system.

9. The method of claim 8, further comprising:

measuring a steering angle by using a steering angle sensor; and is

Determining whether the steering torque is additionally generated in the vehicle by using the steering angle.

Technical Field

In some embodiments, the present disclosure relates to an apparatus and method for vehicle braking.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

A braking apparatus for a vehicle is provided for decelerating or stopping the vehicle as needed in a traveling state. The brake apparatus generates a braking force by using a frictional force. A brake apparatus using hydraulic pressure includes a master cylinder, an Electronic Control Unit (ECU), an Electronic Power Steering (EPS) system, and wheel brakes.

Even when a failure occurs in one wheel brake, a typical brake apparatus can brake a vehicle by using the remaining three wheel brakes. When the vehicle fails at the two-sided wheel brakes (one wheel brake on each side, e.g., one left-sided wheel brake and its right-sided wheel brake), the vehicle can be braked without undesired rotation by using the complete wheel brake.

However, when both wheel brakes on the same left or right side fail, the braking performance becomes very weak. For example, when it is assumed that both wheel brakes braking the front left wheel and the rear left wheel are down, braking performed with two opposite full wheel brakes may cause uncontrolled rotation of the vehicle.

A conventional braking apparatus using a single yaw rate sensor is used to control a vehicle to prevent rotation by using an electronic power steering system or the like in response to when a yaw rate value is determined to be greater than or equal to a reference value, for example, when a braking torque is generated due to braking of the vehicle. However, the conventional arrangement using a sensor solely responsible for handling the braking torque caused by the braking of the vehicle cannot solve the problem of the rotation torque once the sensor fails, which needs to be solved to ensure redundancy for braking stability or fail-safe braking.

Disclosure of Invention

According to at least one embodiment, the present disclosure provides an apparatus for braking a vehicle, the apparatus comprising: a plurality of electro-mechanical brake (EMB) systems, a driving information detection unit, an Electronic Power Steering (EPS) system, and an Electronic Control Unit (ECU). A plurality of electromechanical braking (EMB) systems are respectively mounted for a plurality of wheels of a vehicle and configured to respectively generate braking forces to the plurality of wheels. The driving information detection unit is configured to measure driving information of the vehicle. An Electric Power Steering (EPS) system is configured to generate a steering torque in a direction opposite to a braking torque generated in a vehicle. An Electronic Control Unit (ECU) is configured to control the electromechanical braking system and the electric power steering system. Here, the electronic control unit is configured to control the vehicle by using the electronic power steering system when it is determined that one or some of the plurality of electromechanical brake systems is malfunctioning, and the electronic power steering system is configured to generate the steering torque according to driving information including the wheel speed.

Drawings

Fig. 1 is a block diagram of a braking apparatus according to at least one embodiment of the present disclosure.

Fig. 2 is a diagram showing simultaneous occurrence of a failure in an electromechanical braking (EMB) system for braking the front right wheel FR and an EMB system for braking the rear right wheel RR.

Fig. 3 is a diagram illustrating simultaneous failures in the EMB system for braking the front left wheel FL and the EMB system for braking the rear left wheel RL.

Fig. 4 is a diagram showing a failure occurring in the EMB system for braking the left front wheel FL.

Fig. 5 is a flow chart of a steering control process according to at least one embodiment of the present disclosure.

Fig. 6 is a table of adjustment values for steering torque generated by an Electronic Power Steering (EPS) system according to at least one embodiment of the present disclosure.

Detailed Description

The present disclosure, in at least one embodiment, attempts to safely brake a vehicle without rotation by using an Electronic Power Steering (EPS) system based on a wheel speed sensor even when a failure occurs simultaneously in two wheel brakes (e.g., a front left wheel brake and a rear left wheel brake) on the same left or right side.

In addition, the present disclosure, in at least one embodiment, seeks to counter unnecessary vehicle rotation involved in vehicle braking based on multiple wheel speed sensors to address the issue of rotation or rotational torque even in the event of failure of some of the sensors, thereby ensuring redundancy to braking stability or fail-safe braking.

Some exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings. In the following description, although elements are shown in different drawings, the same reference numerals preferably denote the same elements. Moreover, in the following description of some embodiments, a detailed description of known functions and configurations incorporated herein will be omitted for clarity and conciseness.

Additionally, the alphanumeric codes (such as first, second, i), ii), a), b), etc. in the numbered components are used only for the purpose of distinguishing one component from the other, but do not imply (impry) or (negest) the substance, order or sequence of the components. Throughout the specification, when an element "includes" or "includes" an element, the element is intended to further include other elements, but not to exclude the element, unless specifically described to the contrary.

Fig. 1 is a block diagram of a braking apparatus 100 according to at least one embodiment of the present disclosure.

As shown in fig. 1, the brake apparatus 100 includes all or some of a driving information detection unit 110, an Electronic Control Unit (ECU)120, an Electronic Power Steering (EPS) system 130, and at least one or more electromechanical brake (EMB) systems 140.

The driving information detection unit includes wheel speed sensors 111, 112, 113, 114 and a steering angle sensor 115.

Wheel speed sensors 111, 112, 113, 114 are mounted on the wheels for measuring wheel speed information of the vehicle. The measured wheel speed information is transmitted to the electronic control unit 120.

The vehicle is equipped with four wheel speed sensors 111, 112, 113, 114 corresponding to respective wheels. The conventional brake apparatus has only one yaw rate sensor for controlling the braking torque generated due to braking of the vehicle. In contrast, some embodiments of the present disclosure include four wheel speed sensors 111, 112, 113, 114 for controlling braking torque generated due to braking of the vehicle.

Meanwhile, the brake apparatus 100 according to some embodiments allows the electronic control unit 120 employing a plurality of wheel speed sensors to provide fail-safe control by deploying other complete wheel speed sensors (e.g., 112, 113, and 114) even in the event of a failure in braking torque due to braking of the vehicle in any one wheel speed sensor (e.g., 111), thereby achieving excellent redundancy for braking stability or fail-safe braking.

The steering angle sensor 115 detects steering information of the vehicle and transmits it to the electronic control unit 120. Here, the steering information may include a steering angle and a steering direction. The steering angle sensor 115 is mounted on a lower portion of the steering wheel. The steering angle sensor 115 detects whether the wheels are steered as much as the EPS system 130 steers the wheels.

The electronic control unit 120 includes a braking force calculation unit 122, a failure/normal determination unit 124, and a steering state determination unit 126.

The braking force calculation unit 122 calculates a braking force required to brake the vehicle.

The fault/normal determination unit 124 determines whether a fault occurs in the EMB system 140. In order to determine whether a fault occurs in the EMB system 140, the fault/normal determination unit 124 uses wheel speed information measured by the wheel speed sensors 111, 112, 113, and 114. Even when the electronic control unit 120 operates the EMB system 140 to generate braking force, the rotation speed of the wheels is not reduced if a failure occurs in the EMB system 140. Accordingly, the fault/normal determination unit 124 may determine whether the EMB system 140 is faulty by determining whether the rotation speed of the wheel is reduced based on the wheel speed information.

The steering state determination unit 126 determines whether the steering angle has reached a target value requested by the electronic control unit 120 when the electronic control unit 120 steers the wheels by using the EPS system 130. The steering state determination unit 126 determines the steering state of the vehicle using the steering angle information measured by the steering angle sensor 115.

The electronic control unit 120 receives wheel speed information and steering angle information from the wheel speed sensors 111, 112, 113, 114 and the steering angle sensor 115. Then, the electronic control unit 120 transmits the wheel speed information to the EPS system 130. When transmitting the wheel speed information, the electronic control unit 120 uses on-vehicle communication, for example, Controller Area Network (CAN) communication.

The EPS system 130 generates steering torque for controlling rotation (e.g., rotation due to braking torque) generated during braking of the vehicle. Here, the braking torque refers to a torque that causes the vehicle to rotate in one direction due to a speed difference between corresponding wheels during braking of the vehicle when some EMB systems 140 fail. Meanwhile, the steering torque is a torque generated by the EPS system 130, and refers to a torque that acts in the opposite direction to a braking torque generated during braking of the vehicle to prevent the vehicle from rotating.

Specifically, the EPS system 130 operates to control the rotation due to the braking torque by generating the steering torque in the direction opposite to the rotation so that the vector sum of the braking torque and the steering torque is zero. When the sum of these vectors reaches 0, the vehicle does not rotate, and straightness can be ensured.

The EPS system 130 generates steering torque sufficient to prevent the vehicle from rotating using wheel speed information including wheel speeds measured by the wheel speed sensors 111, 112, 113, 114. The wheel speed information is received from the electronic control unit 120 by using on-vehicle communication (for example, CAN communication).

The EPS system 130 generates a pre-adjusted steering torque from the wheel speed information measured by the wheel speed sensors 111, 112, 113, 114. The pre-adjusted steering torque may be referred to fig. 6. As shown in fig. 6, as the wheel speeds measured by the wheel speed sensors 111, 112, 113, 114 increase, the pre-adjusted steering torque also increases. This is because, as the wheel speed increases, the rotational torque generated during braking of the vehicle increases, and therefore, the required value of the steering torque also increases, resisting the braking torque due to braking.

The EPS system 130 steers the front and/or rear wheels of the vehicle. The EPS system 130 includes both a method of steering only the front wheels and a method of steering not only the front wheels but also the rear wheels.

The EMB system 140 is installed corresponding to each wheel. Each EMB system 140 is independently controlled and generates a braking force on each wheel according to a braking request of the electronic control unit 120.

Fig. 2 is a diagram showing simultaneous occurrence of a failure in the EMB system for braking the front right wheel FR and the EMB system for braking the rear right wheel RR.

As shown in fig. 2, shaded EMB systems 140 indicate a fault occurring therein, while unshaded EMB systems 140 indicate their normal operating state.

When both EMB systems 140 braking the right wheels FR and RR of the vehicle fail, the vehicle rotates to the left during braking. This is because even if the electronic control unit 120 controls the four EMB systems 140 to generate braking force, the right EMB system 140 braking the right wheels FR and RR does not operate in its failure state, but the left EMB system 140 is activated to brake only the left wheels FL and RL. Therefore, the left wheels FL and RL are slowed down due to the transmission of the braking force by their EMB systems 140, but the speeds of the right wheels FR and RR remain the same without receiving the transmission of the braking force from the EMB systems 140. Then, the right wheels FR and RR, which roll faster with respect to the left wheels FL and RL, rotate the vehicle to the left. In this way, as the vehicle brakes, torque is generated to rotate the vehicle to the left.

The electronic control unit 120 prevents the vehicle from rotating leftward by the EPS system 130 by generating a steering torque in a direction opposite to a braking torque due to braking of the vehicle. The electronic control unit 120 transmits the wheel speed information received from the wheel speed sensors 111, 112, 113, 114 to the EPS system 130 by using in-vehicle communication (for example, CAN communication).

The EPS system 130 receiving the transmitted wheel speed information generates a right steering torque. Here, the steering torque is the same in magnitude as the braking torque, but opposite in direction.

The magnitude of the braking torque is determined based on the transmitted wheel speed information. For example, as shown in fig. 6, when the wheel speed reference value of the wheel speed sensors 111, 112, 113, 114 is 1, the magnitude of the braking torque due to braking is 100kgf · m. Therefore, the EPS system 13 generates a steering torque of 100kgf · m. Here, the wheel speed reference value will be described in detail in fig. 5.

Finally, when both EMB systems 140 for braking the right wheels FR and RR fail, the braking force generated in the vehicle rotates the vehicle to the left, resulting in a left braking torque due to braking. This is arranged to generate a right steering torque by the EPS system. Therefore, the coexistence of the braking torque due to the braking of the vehicle and the applied steering torque cancel each other out, thereby nullifying the rotational torque acting on the vehicle, and therefore the vehicle does not rotate and remains straight.

However, when the vehicle is still rotating even in a situation where the EPS system 130 generates a steering torque to control the vehicle to rotate, the EPS system 130 needs to generate an additional steering torque.

The electronic control unit 120 determines whether to further generate the steering torque based on the steering angle information measured by the steering angle sensor 115. The determination process is as follows.

The steering angle sensor 115 measures the steering angle of the vehicle and transmits it to the electronic control unit 120. The electronic control unit 120 determines whether the received steering angle is within a preset tolerance.

When the comparison of the measured steering angle with the preset tolerance determines that the steering angle measured by the steering angle sensor 115 is within the preset tolerance, for example, even if rotation occurs, the electronic control unit 120 does not generate further steering torque when no significant accident for braking safety occurs.

On the other hand, when the comparison of the measured steering angle with the preset tolerance determines that the steering angle measured by the steering angle sensor 115 is equal to or greater than the preset tolerance, for example, when only the generated steering torque cannot control the rotation of the vehicle, the electronic control unit 120 generates additional steering torque.

The braking process of the brake apparatus 100 is terminated when the generated additional steering torque stops the vehicle from rotating and completes its braking.

Fig. 3 is a diagram illustrating simultaneous failures in the EMB system for braking the front left wheel FL and the EMB system for braking the rear left wheel RL.

As shown in fig. 3, shaded EMB systems 140 indicate a fault occurring therein, while unshaded EMB systems 140 indicate their normal operating state.

FIG. 3 illustrates an example embodiment in which the vehicle rotates in opposition to the vehicle of FIG. 2. Specifically, fig. 2 shows the vehicle rotating to the left, while fig. 3 shows the vehicle rotating to the right.

In contrast to the situation of fig. 2, fig. 3 shows a failed EMB system 140, where only the failed side is switched but the other sides remain intact, and therefore further description will be omitted.

Fig. 4 is a diagram showing a failure occurring in the EMB system for braking the left front wheel FL.

As shown in fig. 4, shaded EMB system 140 indicates a fault occurring therein, while unshaded EMB system 140 indicates its normal operating state.

When the EMB system 140 for braking the left front wheel FL malfunctions, the vehicle rotates to the right during braking. The electronic control unit 120 prevents the vehicle from rotating rightward by generating a steering torque in a direction opposite to a torque due to braking of the vehicle by using the EPS system 130. Here, the EPS system 130 generates a pre-adjusted steering torque according to the wheel speed information.

Fig. 5 is a flow chart of a steering control process according to at least one embodiment of the present disclosure.

As shown in fig. 5, the driving information detecting unit 110 detects the driving information of the vehicle and transmits it to the electronic control unit 120 (S510). For example, the transmission of the driving information includes measuring the wheel speed using the wheel speed sensors 111, 112, 113, and 114 and transmitting it to the electronic control unit 120.

The electronic control unit 120 determines whether the EMB system 140 is malfunctioning based on the received driving information (S520). For example, when the wheel speed is not reduced even after the EMB system 140 is controlled, the electronic control unit 120 may determine that the EMB system 140 is malfunctioning.

Upon determining that there is no fault in the EMB system 140, the electronic control unit 120 ends the algorithm.

On the other hand, when it is determined that the EMB system 140 is out of order, the electronic control unit 120 determines whether the vehicle is rotating (S530). For example, the electronic control unit 120 may determine that the vehicle is actually rotating when a comparison is made between the wheel speeds and the speed difference is determined to be equal to or greater than a predetermined value or a sudden change in the steering angle is determined.

Upon determining that no vehicle is present, the electronic control unit 120 ends the algorithm.

However, when it is determined that the vehicle is rotating, for example, when the EMB system 140 braking the left wheels FL and RL is malfunctioning, the EPS system 130 generates steering torque for controlling the plurality of wheels to prevent the vehicle from rotating (S540). The steering torque generated at this time is a steering torque adjusted in advance in accordance with the wheel speed information measured by the wheel speed sensors 111, 112, 113 and 114. Meanwhile, the steering torque generated by the EPS system 130 is in the opposite direction to the braking torque due to braking of the vehicle. Therefore, the vector sum of the braking torque and the steering torque is reduced, which consequently reduces the magnitude of the rotational torque acting on the vehicle to zero.

The electronic control unit 120 determines whether the rotation of the vehicle is reduced by using the steering angle measured by the steering angle sensor (S550). For example, the electronic control unit 120 determines whether the measured steering angle is within a preset tolerance (e.g., a set value).

When it is determined that the magnitude of the measured steering angle exceeds a preset tolerance, the electronic control unit 120 controllably enables the EPS system 130 to further generate a steering torque for preventing the vehicle from rotating. In other words, the electronic control unit 120 returns to step S540 to generate more steering torque.

On the other hand, when it is determined that the magnitude of the measured steering angle is equal to or within the preset tolerance, the electronic control unit 120 ends the algorithm.

Fig. 6 is a table of adjustment values for steering torque generated by an EPS system according to at least one embodiment of the present disclosure.

For example, the wheel speed reference value of fig. 6 refers to a wheel speed that is adjusted in advance. For example, after the pre-adjustment, the wheel speed reference value 1 is 30km/h, the wheel speed reference value 2 is 40km/h, the wheel speed reference value 3 is 50km/h, and the like.

The braking torque due to braking in fig. 6 refers to a torque generated when the electronic control unit 120 brakes the vehicle. For example, when the wheel speed reference value is 1(30km/h), a braking torque of 100kgf · m is generated as the electronic control unit 120 controls the EMB system 140.

The steering torque of the EPS of fig. 6 refers to a pre-adjusted steering torque. For example, when the wheel speed reference value is 1, the magnitude of the steering torque is adjusted to 100kgf · m, and when the wheel speed reference value is 2, the magnitude of the steering torque is adjusted to 200kgf · m.

The vehicle rotation torque of fig. 6 refers to the vector sum of the braking torque and the steering torque. For example, when the wheel speed reference value is 1(30km/h), the vector sum of the braking torque and the steering torque is 0.

As shown in fig. 6 in particular, as the wheel speeds measured by the wheel speed sensors 111, 112, 113, 114 increase, the braking torque due to the braking of the vehicle increases. This occurs because the greater the wheel speed, the greater the vehicle speed, and the greater the vehicle speed, the greater the wheel speed difference between the left and right wheels during braking (when some EMB systems are determined to be faulty). In other words, an increase in the wheel speed difference between the left and right wheels increases the magnitude of the braking torque applied to the vehicle due to braking.

Therefore, the EPS system 130 needs to generate a large steering torque to offset the braking torque caused by braking. Here, the EPS system 130 generates a pre-adjusted steering torque for the wheel speed.

As described above, according to at least one embodiment of the present disclosure, an electronic control unit safely brakes a vehicle using an Electronic Power Steering (EPS) system based on wheel speed sensors, without rotating even when a failure occurs simultaneously in two wheel brakes (e.g., a front left wheel brake and a rear left wheel brake) of the same left or right side.

Further, the present disclosure may, in at least one embodiment, process braking torque caused by braking of the vehicle based on a plurality of wheel speed sensors, rather than using a single responsible sensor to process braking torque caused by braking of the vehicle, thereby ensuring redundancy for vehicle stability or fail-safe braking even in the event of failure of some sensors.

Although the exemplary embodiments of the present disclosure have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as claimed. Accordingly, exemplary embodiments of the present disclosure have been described for the sake of brevity and clarity. The scope of the technical idea of the present embodiment is not limited by the illustration. Accordingly, it will be appreciated by those of ordinary skill in the art that the scope of the claimed invention is not limited by the embodiments explicitly described above, but by the claims and their equivalents.

Reference mark

110: driving information detection unit

120: electronic control unit

130: electronic Power Steering (EPS) system

140: electromechanical braking (EMB) system

FR, FL, RR, RL: a plurality of wheels.