Apparatus and method for controlling brake of vehicle

Abstract

An apparatus and a method for controlling braking of a vehicle are presented. The device includes: an in-wheel motor installed in a wheel and enabling the wheel to rotate; an electromechanical brake mounted in the wheel and configured to perform braking; a vehicle speed sensor configured to measure a speed of the vehicle; and a processor configured to calculate a required braking force in response to a signal from the brake pedal application, control braking by distributing the required braking force to the electromechanical brake and the in-wheel motor, and determine a braking state and recalculate a braking torque for the in-wheel motor according to a speed of the vehicle, therefore, the in-wheel motor is controlled under the condition that the electronic mechanical brake cannot operate, so that the vehicle is stopped.

Description

Technical Field

[0001] The present disclosure relates to an apparatus and method for controlling vehicle braking, which are capable of controlling the braking of a vehicle having four independently operating wheels. Background Art

[0002] In recent years, there has been a trend toward vehicles where each vehicle has four wheels that are all independently driven and braked, and can be independently steered.

[0003] In a vehicle with four independently operated wheels, a drive device (motor), a steering device, and a brake for driving the vehicle are included in one wheel. Therefore, the wheels are driven independently and can control the direction of the vehicle.

[0004] Related technology related to a vehicle capable of independent driving and steering is disclosed in Korean Patent Application Publication No. 10-2009-0062321 (Independent driving and traveling system of in-wheel drive electric vehicle and control method thereof).

[0005] However, in cases where the vehicle is able to drive and steer independently, each wheel can be controlled independently, but this may cause problems with vehicle braking if the brakes are inoperable.

[0006] Therefore, there is a need to provide a method of braking a vehicle in the event that the brakes are inoperable. Summary of the invention

[0007] Various embodiments of the present disclosure are directed to solving the above-mentioned problems, and relate to an apparatus and method for controlling vehicle braking, which are capable of stably performing braking when a brake fails in a four-wheel drive independently controlled vehicle.

[0008] In one embodiment, in order to achieve the above-mentioned purpose, according to one aspect of the present disclosure, a device for controlling vehicle braking is provided, the device comprising: an in-wheel motor, which is installed in a wheel and enables the wheel to rotate; an electronic mechanical brake, which is installed in the wheel and is configured to perform braking; a vehicle speed sensor, which is configured to measure the speed of the vehicle; and a processor, which is configured to calculate a required braking force in response to a signal applied from a brake pedal, control braking by distributing the required braking force to the electronic mechanical brake and the in-wheel motor, and determine a braking state according to the speed of the vehicle and recalculate the braking torque of the in-wheel motor, so as to control the in-wheel motor to stop the vehicle when the electronic mechanical brake fails to operate.

[0009] In one embodiment, in the device, when the signal is input from the brake pedal, the processor may check the state of charge (SOC) of the battery. If the SOC of the battery is higher than a first set value, the processor controls the electromechanical brake to perform braking. If the SOC is at or below the first set value, the processor may distribute the required braking force to the in-wheel motor and the electromechanical brake.

[0010] In one embodiment, in the device, when the electromechanical brake fails to operate, the processor can determine whether sudden braking is required based on the signal from the brake pedal, and when the situation requiring sudden braking is reached, the processor can control the in-wheel motor so that the in-wheel motor operates at maximum braking torque.

[0011] In one embodiment, in the apparatus, when the electromechanical brake fails to operate, the processor may determine whether emergency braking is required, and when the situation requiring emergency braking is not reached, the processor may determine whether the vehicle is in a deceleration state. When the vehicle is in a deceleration state, the processor may maintain the braking torque for the in-wheel motor. When the vehicle is not in a deceleration state, the processor may recalculate the braking torque of the in-wheel motor.

[0012] In one embodiment, in the apparatus, when the speed of the vehicle is lower than a preset speed, the processor may stop braking using the in-wheel motor and may perform braking by controlling the rear wheels in a toe-in configuration.

[0013] In one embodiment, according to another aspect of the present disclosure, a method for controlling vehicle braking includes: a processor calculating a required braking force in response to a signal from a brake pedal applied to a wheel during vehicle travel; the processor controlling braking by distributing the required braking force to an electronic mechanical brake and an in-wheel motor; the processor determining a braking state based on a speed of the vehicle when the electronic mechanical brake is unable to operate; and the processor controlling the in-wheel motor by recalculating a braking torque for the in-wheel motor based on the braking state.

[0014] In one embodiment, in the method, controlling braking by the processor may include: when the signal is input from the brake pedal, after the processor checks the SOC of the battery, if the SOC of the battery is higher than a first set value, the processor uses the electronic mechanical brake to control braking; and if the SOC of the battery is at or below the first set value, the processor distributes the required braking force to the in-wheel motor and the electronic mechanical brake to control braking.

[0015] In one embodiment, in the method, determining the braking state by the processor may include: when the electronic mechanical brake fails to operate, the processor determines whether emergency braking is required based on a signal from the brake pedal; when the situation requiring emergency braking is reached, controlling the in-wheel motor by the processor so that the in-wheel motor operates at a maximum braking torque; and when the situation requiring emergency braking is not reached, determining by the processor whether the vehicle is in a deceleration state.

[0016] In one embodiment, in the method, determining by the processor whether the vehicle is in a deceleration state may include: when the vehicle is in a deceleration state, maintaining by the processor the braking torque of the in-wheel motor; and when the vehicle is not in a deceleration state, recalculating by the processor the braking torque for the in-wheel motor.

[0017] In one embodiment, the method may further include, after the processor controls the in-wheel motor: when the speed of the vehicle is lower than a preset speed, the processor stops using the out-wheel motor for braking; and the processor performs braking by controlling the rear wheels in a toe-in configuration.

[0018] The device and method for controlling vehicle braking according to an embodiment of the present disclosure can use the in-wheel motor and the steering device to perform braking in a vehicle with four wheels that are independently driven and steered. Therefore, although the brake cannot operate, the device and method can safely stop the vehicle.

[0019] The device and method for controlling vehicle braking according to the embodiment of the present disclosure can effectively perform braking according to the situation, thereby improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a view schematically showing the configuration of a four-wheel drive independent control vehicle to which an embodiment of the present disclosure is applied.

[0021] Figure 2 The present invention is a block diagram schematically showing a configuration of an apparatus for controlling vehicle braking according to a first embodiment of the present disclosure.

[0022] Figure 3 Detailed description is a flowchart showing a method for controlling vehicle braking according to a second embodiment of the present disclosure.

[0023] Figure 4 The flowchart is a flowchart showing the data flow generated when the device for controlling vehicle braking calculates the braking force in the method according to the second embodiment of the present disclosure.

[0024] Figure 5 The flowchart is a flowchart showing a data flow generated when the apparatus for controlling vehicle braking monitors a battery in the method according to the second embodiment of the present disclosure.

[0025] Figure 6 The flowchart is a flowchart showing a data flow generated when the apparatus for controlling vehicle braking distributes braking force in the method according to the second embodiment of the present disclosure.

[0026] Figure 7 The flowchart is a flowchart showing the data flow generated when the device for controlling vehicle braking distributes the braking force with the participation of the in-wheel motor in the method according to the second embodiment of the present disclosure.

[0027] Figure 8 The flowchart is a diagram showing a data flow generated when the apparatus for controlling vehicle braking determines that the brake operation is abnormal through feedback of the braking force in the method according to the second embodiment of the present disclosure.

[0028] Fig. 9 The flowchart is for illustrating a data flow generated when the apparatus for controlling vehicle braking determines emergency braking in the method according to the second embodiment of the present disclosure.

[0029] Fig.10 The flowchart is a flowchart showing a data flow generated when the apparatus for controlling vehicle braking determines a deceleration state in the method according to the second embodiment of the present disclosure.

[0030] Fig.11 The flowchart is a flowchart showing a data flow generated when the apparatus for controlling vehicle braking recalculates the in-wheel braking torque in the method according to the second embodiment of the present disclosure.

[0031] Fig.12 The flowchart is a flowchart showing a data flow generated when the apparatus for controlling vehicle braking uses the rear wheels to perform braking control in the method according to the second embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] The components described in the exemplary embodiments may be implemented by hardware components, for example, the hardware components include at least one digital signal processor (DSP), a processor, a controller, an application-specific integrated circuit (ASIC), a programmable logic element (such as a field programmable gate array, FPGA), other electronic devices or a combination thereof. At least some of the functions or processes described in the exemplary embodiments may be implemented by software, and the software may be recorded on a recording medium. The components, functions and processes described in the exemplary embodiments may be implemented by a combination of hardware and software.

[0033] The method according to the exemplary embodiment may be embodied as a program executable by a computer and may be implemented as various recording media such as a magnetic storage medium, an optical reading medium, and a digital storage medium.

[0034] The various techniques described herein may be implemented as digital electronic circuits, or as computer hardware, firmware, software, or a combination thereof. These techniques may be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, for example, in a machine-readable storage device (e.g., a computer-readable medium) or in a propagated signal, for use by a data processing device (e.g., a programmable processor, a computer, or multiple computers) to process or control the operation of a data processing device. Computer programs may be written in any form of programming language, including compiled or interpreted languages, and may be deployed in any form, including stand-alone programs or modules, components, subroutines, or other units suitable for use in a computing environment. Computer programs may be deployed to execute on a single computer or on multiple computers at a site, or distributed across multiple sites and interconnected via a communication network.

[0035] For example, processors suitable for executing computer programs include general-purpose microprocessors and special-purpose microprocessors, as well as any one or more processors of any type of digital computer. Typically, the processor will receive instructions and data from a read-only memory or a random access memory or both. The elements of a computer may include at least one processor for executing instructions and one or more storage devices for storing instructions and data. Typically, a computer will also include or be coupled to receive data from one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks), transmit data to them, or perform both on them to store data. Examples of information carriers suitable for implementing computer program instructions and data include semiconductor storage devices, for example, magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as compact disk-read only memory (CD-ROM), digital video disks (DVD), etc., and magneto-optical media such as floppy disks, as well as read-only memory (ROM), random access memory (RAM), flash memory, erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) and any other known computer readable medium. The processor and memory may be supplemented with or integrated into a dedicated logic circuit.

[0036] The processor can run an operating system (OS) and one or more software applications running on the OS. The processor device can also access, store, operate, process, and create data in response to the execution of the software. For simplicity, the description of the processor device is used as a singular; however, those skilled in the art will understand that the processor device may include multiple processing elements and / or multiple types of processing elements. For example, the processor device may include multiple processors or a processor and a controller. In addition, different processing configurations are also possible, such as parallel processors.

[0037] Additionally, non-transitory computer readable media can be any available media that can be accessed by a computer and can include both computer storage media and transmission media.

[0038] This specification includes many details of specific embodiments, but it should be understood that these details do not limit any invention or the content that can be claimed in the specification, but rather describe the features of specific exemplary embodiments. Features described in the specification in the context of various exemplary embodiments can be implemented as a combination in a single exemplary embodiment. Conversely, various features described in the specification in the context of a single exemplary embodiment can be implemented in multiple exemplary embodiments individually or in appropriate sub-combinations. In addition, features can operate in a specific combination and can be initially described as required in that combination, but in some cases, one or more features can be excluded from the required combination, and the required combination can be converted into a sub-combination or a modified form of the sub-combination.

[0039] Similarly, even if operations are described in a particular order on the accompanying drawings, they should not be construed as operations that need to be performed in a particular order or sequentially to obtain a desired result, or as all operations that need to be performed. In certain circumstances, multitasking and parallel processing can be advantageous. In addition, it should not be construed as requiring separation of the various device components in the above exemplary embodiments in all exemplary embodiments, and it should be understood that the above program components and devices can be incorporated into a single software product or can be packaged in multiple software products.

[0040] It should be understood that the exemplary embodiments disclosed herein are illustrative only and are not intended to limit the scope of the present invention. It is obvious to those skilled in the art that various modifications may be made to the exemplary embodiments without departing from the spirit and scope of the disclosed technical solution and its equivalents.

[0041] Hereinafter, with reference to the accompanying drawings, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily perform the present disclosure. However, the present disclosure can be embodied in many different forms and is not limited to the embodiments described herein.

[0042] In the following description of the embodiments of the present disclosure, detailed descriptions of known functions and configurations included herein will be omitted when it may make the subject matter of the present disclosure unclear. Parts of the drawings that are not related to the description of the present disclosure are omitted, and similar parts are represented by similar reference numerals.

[0043] In the present disclosure, components that are distinguished from each other are intended to clearly illustrate each feature. However, this does not necessarily mean that these components are independent. That is, multiple components can be integrated into one hardware or software unit, or a single component can be distributed to multiple hardware or software units. Therefore, unless otherwise stated, such integrated or distributed embodiments are also included in the scope of the present disclosure.

[0044] In the present disclosure, the components described in various embodiments are not necessarily necessary components, and some components may be optional components. Therefore, an embodiment consisting of a subset of the components described in an embodiment is also included in the scope of the present disclosure. In addition, embodiments that include other components in addition to the components described in each embodiment are also included in the scope of the present disclosure.

[0045] In the present disclosure, when a component is referred to as being "linked", "coupled" or "connected" to another component, it should be understood that not only a direct connection relationship but also an indirect connection relationship through an intermediate component may be included. In addition, when a component is referred to as "including" or "having" another component, it may mean further including the other component rather than excluding the other component, unless there is a clear description to the contrary.

[0046] In the present disclosure, the terms "first", "second", etc. are only used to distinguish one component from another component, and do not limit the order or importance of the components, etc., unless otherwise specifically stated. Therefore, within the scope of the present disclosure, a first component in an exemplary embodiment may be referred to as a second component in another embodiment, and similarly, a second component in an exemplary embodiment may be referred to as a first component.

[0047] The present disclosure will be described below with reference to the accompanying drawings.

[0048] Figure 1 1 is a view schematically showing the configuration of a four-wheel drive independent control vehicle 10 to which the embodiment of the present disclosure is applied.

[0049] like Figure 1 As shown, the vehicle 10 has four wheels 21 , 22 , 23 , 24 that are capable of independent operation.

[0050] The vehicle 10 includes a driving device (in-wheel motor) for driving, a steering device, and a braking device (brake) in each wheel. These devices drive and brake independently, and can control the direction of the vehicle 10.

[0051] The vehicle 10 can independently control the four wheels 21 to 24 , so the vehicle 10 can rotate at a suitable position or move horizontally in the axial direction.

[0052] These independent control capabilities enable vehicle 10 to provide multiple types of mobility that are distinct from existing types of mobility.

[0053] For example, Purpose-Built Vehicle (PBV), a dedicated mobility solution, has been developed as an innovative transportation solution using a variety of implementation methods with the goal of prioritizing mobility and utility over pure transportation solutions.

[0054] Figure 2 FIG. 1 is a block diagram schematically showing a configuration of an apparatus 100 for controlling vehicle braking according to a first embodiment of the present disclosure.

[0055] like Figure 2 As shown, the device 100 for controlling vehicle braking according to the present disclosure may include a memory 120, a sensor 140, an electro-mechanical brake (EMB) 171, a brake pedal 172, a battery management system (BMS) 150, an in-wheel module 160 for four wheels, and a processor 110.

[0056] The apparatus 100 for controlling vehicle braking may further include a communication unit (not shown) for communicating within the vehicle 10 and communicating with the outside. For example, the communication unit may use a Controller Area Network (CAN) communication or a Local Interconnect Network (LIN) communication to send and receive data within the vehicle 10. In addition, the communication unit may use a communication standard such as Vehicle-to-Vehicle (V2V) communication, Ethernet, WiFi, and Bluetooth to send and receive data to and from the outside.

[0057] The sensor 140 may include a vehicle speed sensor 141 and a torque sensor 142. The sensor 140 may also include a motor angle sensor, a steering angle sensor, a brake pedal sensor, a voltage sensor, a current sensor, a temperature sensor, etc., and descriptions thereof are omitted.

[0058] The vehicle speed sensor 141 detects the traveling speed of the vehicle 10 .

[0059] Torque sensor 142 measures the braking force acting on each wheel.

[0060] The battery management system (BMS) 150 controls the battery in such a manner as to charge the battery or provide the output of the battery to the processor 110 and the in-wheel module 160. In addition, the battery management system (BMS) 150 may check the state of charge (SOC) of a battery (not shown) and may detect a malfunction of the battery.

[0061] Stored in the memory 120 may be data for traveling, steering, and braking of the vehicle 10, data measured from the sensor 140, and status data of the battery. In addition, stored in the memory 120 may be data for the in-wheel module 160.

[0062] Stored in the memory 120 may be at least one of the following algorithms: a steering control algorithm, a driving control algorithm, a braking control algorithm, or a travel control algorithm.

[0063] Examples of the memory 120 may include nonvolatile memory such as random access memory (RAM), ROM, electrically erasable and programmable ROM (EEPROM), and flash memory, among other memory devices.

[0064] The electronic mechanical brake (EMB) 171 applies a braking torque to the wheel according to the braking force calculated by converting the force acting on the brake pedal 172 into an electrical signal, thereby performing braking. In addition, the electronic mechanical brake (EMB) 171 may include a button and a switch. The electronic mechanical brake (EMB) 171 may transmit the braking force to the four wheels 21 to 24 respectively based on the signal input by operating the button or the switch.

[0065] Electromechanical brakes (EMBs) 171 are provided on the four wheels 21 to 24 , respectively, and can brake the four wheels 21 - 24 independently.

[0066] The electronic mechanical brake (EMB) 171 can control the posture of the vehicle 10 by integrally controlling the functions of the anti-lock braking system (ABS), the traction control system (TCS), the brake assist system (BAS) and the electronic stability program (ESP).

[0067] When the brake pedal 172 is operated by the driver, the brake pedal 172 changes and applies a signal according to the degree of operation (pushing). The vehicle 10 operates an electromechanical brake (EMB) 171 according to the signal of the brake pedal 172, thereby reducing the speed of the vehicle 10 or stopping the vehicle 10.

[0068] The in-wheel module 160 is installed in the four wheels 21 to 24 and may include a driving device, a braking device, a suspension and a steering device. In this case, the driving device is an in-wheel motor and the braking device is an electromechanical brake (EMB).

[0069] The in-wheel module 160 drives the in-wheel motors of the four wheels 21 to 24 according to the control signal applied from the processor 110, thereby enabling the vehicle 10 to travel. The in-wheel module 160 can reduce the speed of the vehicle 10 by controlling the electromechanical brake (EMB) 171. The in-wheel module 160 can control the directions of the four wheels 21 to 24 through a steering device.

[0070] The in-wheel module 160 may brake the vehicle 10 through an electromechanical brake (EMB) 171. In addition, the in-wheel module 160 may brake the vehicle 10 by controlling an in-wheel motor, thereby generating a reverse torque.

[0071] The in-wheel module 160 includes first to fourth in-wheel modules 161 to 164 which are installed in the four wheels 21 to 24 , respectively.

[0072] The in-wheel motors are installed in the first to fourth in-wheel modules 161 to 164, respectively. Electromechanical brakes (EMBs) 171 may be installed in the first to fourth in-wheel modules 161 to 164, respectively.

[0073] The first in-wheel module 161 is installed in the left front wheel, the second in-wheel module 162 is installed in the right front wheel, the third in-wheel module 163 is installed in the left rear wheel, and the fourth in-wheel module 164 is installed in the right rear wheel.

[0074] The processor 110 may include at least one microprocessor, and may operate based on an algorithm stored in the memory 120 .

[0075] The processor 110 may determine the driving state of the vehicle 10 based on the SOC of the battery and data input from the sensor 140 .

[0076] The processor 110 calculates a required braking force according to the degree of operation of the brake pedal 172. The processor 110 performs braking by controlling the in-wheel motor and the electromechanical brake (EMB) 171, thereby enabling the vehicle 10 to reduce its speed and stop the vehicle 10.

[0077] The processor 110 calculates the required braking force according to the operation of the brake pedal 172 or the brake key (not shown). Then, the processor 110 distributes the control signal to at least one of the electronic mechanical brake (EMB) 171 and the first to fourth in-wheel modules 161 to 164, so that the control signal is applied accordingly.

[0078] Additionally, processor 110 may distribute braking force based on the speed of vehicle 10 and the SOC of the battery.

[0079] The processor 110 may check the driving state of the vehicle 10 and the SOC of the battery. Accordingly, the processor 110 may calculate the driving force and the braking force to be applied to the first to fourth in-wheel modules 161 to 164 respectively mounted on the vehicle 10 based on at least one of the limit output values ​​of the battery, and may apply the calculated driving force or braking force to the first to fourth in-wheel modules 161 to 164.

[0080] Therefore, the in-wheel motors may operate according to the respectively applied control signals, thereby applying braking force to the four wheels 21 to 24. In addition, the in-wheel motors may generate reverse torque, thereby performing braking.

[0081] During braking, the processor 110 may check whether the electromechanical brake (EMB) 171 operates normally and may detect a malfunction thereof.

[0082] In the event that the electromechanical brake (EMB) is inoperable, the processor 110 may determine whether emergency braking is required and, if necessary, control braking by redistributing braking force.

[0083] In the event that the electromechanical brake (EMB) 171 is unable to operate, the processor 110 may perform braking by generating reverse torque via the in-wheel motor.

[0084] In addition, the processor 110 may recalculate and distribute the braking force according to the state of the vehicle 10, for example, according to whether the speed of the vehicle 10 measured by the vehicle speed sensor 141 decreases or increases. Then, the processor 110 may apply a control signal to each of the first to fourth in-wheel modules 161 to 164.

[0085] In the event that the electromechanical brake (EMB) 171 fails to operate, the processor 110 may output a brake failure warning via a display (not shown), such as a dashboard.

[0086] Figure 3 Detailed description is a flowchart showing a method for controlling vehicle braking according to a second embodiment of the present disclosure.

[0087] like Figure 3 As shown, the apparatus 100 for controlling vehicle braking monitors the driving state of the vehicle 10 and the SOC of the battery. When a situation requiring braking occurs, the apparatus 100 for controlling vehicle braking controls the vehicle 10 by reducing the vehicle speed and stopping the vehicle 10.

[0088] When the vehicle 10 is traveling, the processor 110 receives vehicle speed information from the vehicle speed sensor 141 ( S310 ) and receives SOC information from the battery management system (BMS) 150 , thereby monitoring the SOC of the battery ( S320 ).

[0089] When a signal is input from the brake pedal 172 ( S330 ), the processor 110 calculates a required braking force ( S340 ).

[0090] The processor 110 disperses and distributes the braking force to the plurality of in-wheel motors and the electromechanical brake (EMB) 171 according to the required braking force ( S350 ).

[0091] The electromechanical brakes (EMB) 171 operate according to the respective allocated braking forces, thereby braking the vehicle 10. In addition, the in-wheel motors operate according to the respective allocated braking forces, and perform braking control in a manner of generating reverse torque.

[0092] In this regard, the processor 110 receives feedback from the electromechanical brake (EMB) 171 as an input, and may thereby check the status of the electromechanical brake (EMB) 171 and determine whether to brake the vehicle 10 .

[0093] The processor 110 determines whether feedback is received from the electromechanical brake (EMB) 171 (S370). In the case where the feedback is received, the processor 110 maintains braking through the electromechanical brake (EMB) 171 (S380).

[0094] In the event that no feedback is received, the processor 110 may determine that there is a problem with the electromechanical brake (EMB) 171 or that the electromechanical brake (EMB) 171 is not operable.

[0095] In the case that the electromechanical brake (EMB) 171 cannot operate, the processor 110 determines that the current situation requiring braking corresponds to emergency braking (S390).

[0096] In the case where the current situation requiring braking corresponds to emergency braking, the processor 110 controls the in-wheel motor by setting the in-wheel motor to a maximum braking torque (S400). Therefore, the in-wheel motor performs braking by generating a reverse torque to the maximum extent.

[0097] In the case where the current situation requiring braking does not correspond to emergency braking, the processor 110 determines whether the vehicle 10 is currently in a deceleration state according to the vehicle speed information input from the vehicle speed sensor 141 (S410).

[0098] In the case that the vehicle 10 is currently in a deceleration state, the processor 110 maintains the braking torque for the in-wheel motor at a current value ( S420 ).

[0099] In the case that the vehicle 10 is not currently in a deceleration state, the processor 110 recalculates the braking torque for the in-wheel motor, thereby applying a control signal to the in-wheel motor accordingly ( S430 ).

[0100] When the current speed of the vehicle 10 decreases below a preset value due to the decrease in the speed of the vehicle 10 caused by the braking control (S440), the processor 110 causes the in-wheel motor to cancel the braking and performs braking by steering the rear wheels 23 and 24 to achieve a toe state (S450).

[0101] When the electromechanical brake (EMB) 171 fails to operate, the processor 110 generates and outputs a fault warning, and controls the vehicle 10 by performing braking to stop the vehicle 10 .

[0102] The operation of the vehicle braking device 100 is described in detail as follows.

[0103] Figure 4 The flowchart is a diagram showing a data flow generated when the apparatus 100 for controlling vehicle braking calculates the braking force in the method according to the second embodiment of the present disclosure.

[0104] refer to Figure 4 , when the driver operates the brake pedal 172, the processor 110 receives the speed of the vehicle 10 (refer to S201), the braking position (operation degree) of the brake pedal 172 (refer to S202) and the vehicle data (refer to S203) as inputs, and calculates the required braking force. At this time, the vehicle data (refer to S203) includes the acceleration and mass of the vehicle 10 in the vertical direction.

[0105] The processor 110 refers to a braking force map based on vehicle speed (see S201) and brake position (see S202) in the data being input (see S204), and compares the calculated braking force with a mathematical model that varies with vehicle data (see S203) (S205).

[0106] According to the comparison result, the processor 110 calculates the maximum value MAX of the braking force according to the comparison result (S206), and finally determines the required braking force (S207).

[0107] The processor 110 sets the maximum braking force as the required braking force, thereby distributing the braking force.

[0108] Figure 5 The flowchart is a flowchart showing a data flow generated when the apparatus 100 for controlling vehicle braking monitors a battery in a method according to the second embodiment of the present disclosure.

[0109] refer to Figure 5 , the processor 110 receives the SOC from the battery management system (BMS) 150 as an input, and may determine whether to perform braking control using the in-wheel motor according to the state of the battery.

[0110] The processor 110 receives a brake signal generated by operation of the brake pedal 172 as an input ( S211 ), and receives the SOC of the battery from the battery management system (BMS) 150 as an input ( S212 ).

[0111] The processor 110 compares the SOC of the battery with a first set value γ ( S213 ).

[0112] When a brake signal is input and the SOC of the battery is higher than the first set value γ ( S214 ), the processor 110 causes the in-wheel motor to be free from brake control ( S215 ).

[0113] When the SOC of the battery is sufficient to reach or exceed the first set value γ, the processor 110 may use the electromechanical brake (EMB) 171 for braking without the involvement of the in-wheel motor.

[0114] When the SOC of the battery is lower than the first set value γ, the processor 110 performs braking control with the in-wheel motor involved ( S216 ).

[0115] The processor 110 controls braking by distributing the calculated required braking force to the in-wheel motors and the electromechanical brake (EMB) 171 .

[0116] Figure 6 A flowchart showing a data flow generated when the device 100 for controlling vehicle braking distributes braking force in a method according to the second embodiment of the present disclosure.

[0117] refer to Figure 6 , the processor 110 can control braking without using the in-wheel motor.

[0118] The processor 110 sets the electronic mechanical brake (EMB) 171 based on Figure 4 The distribution ratio of the required braking force calculated in the step 222 is the distribution ratio of the final braking force (see S221), and the braking force is distributed (S222).

[0119] Electromechanical brakes (EMBs) 171 are respectively provided in the four wheels 21 to 24 , thereby independently braking the four wheels 21 to 24 .

[0120] like Figure 6 As shown, when the SOC of the battery is at or above the first set value γ, the processor 110 does not use the in-wheel motor ( S225 ), but performs braking through the electromechanical brake (EMB) 171 .

[0121] The processor 110 distributes the braking force to the electromechanical brakes (EMBs) 171 respectively provided in the four wheels 21 to 24 according to the distribution ratio. The processor 110 applies a control signal so that each of the electromechanical brakes (EMBs) 171 performs braking independently.

[0122] Accordingly, the electromechanical brake (EMB) 171 operates according to the respective received control signals (S223), and applies predetermined braking forces to the four wheels 21 to 24, respectively, thereby performing braking (S224).

[0123] Figure 7 The flowchart is for illustrating the data flow generated when the apparatus 100 for controlling vehicle braking distributes the braking force with the participation of the in-wheel motor in the method according to the second embodiment of the present disclosure.

[0124] refer to Figure 7 , the processor 110 may control braking using the in-wheel module 160. The processor 110 may control braking by distributing braking force to the in-wheel motor and the electromechanical brake (EMB) 171.

[0125] In the case where the processor 110 uses the in-wheel motor for braking according to the SOC of the battery, the processor 110 calculates a TN (torque-RPM) map of the nominal torque of the motor based on the speed of the vehicle 10 (reference S232) and the rotation speed (RPM) of the motor (reference S233) (reference S234), and checks the possible maximum torque of the motor based on the calculated map (S235). The processor 110 converts the possible maximum torque into the braking force of the in-wheel motor.

[0126] The processor 110 compares the previously calculated required braking force (see S231 ) with the braking force (braking force of the in-wheel motor) converted from the possible maximum torque ( S236 ).

[0127] In the case where the braking force of the in-wheel motor is greater than the required braking force, the processor 110 distributes the required braking force according to the preset distribution ratio ε% (S237). The processor 110 distributes the braking force obtained by multiplying the required braking force by the preset distribution ratio ε% to the in-wheel motor. The processor 110 distributes the braking force obtained by multiplying the required braking force by (100-preset distribution ratio ε%) to the electronic mechanical brake (EMB) 171.

[0128] For example, when the distribution ratio is 60%, the processor 110 distributes 60% of the required braking force to the in-wheel motor and 40% of the required braking force to the electromechanical brake (EMB) 171, and then braking may be performed accordingly.

[0129] Since the braking of the in-wheel motor may fail, the processor 110 may distribute the required braking force to the electromechanical brake (EMB) 171 .

[0130] When the braking force of the in-wheel motor is equal to or less than the required braking force, the processor 110 may allocate a braking force corresponding to the maximum braking force of the in-wheel motor to the in-wheel motor, and may allocate a braking force obtained by subtracting the maximum braking force from the required braking force to the electronic mechanical brake (EMB) (S238).

[0131] That is, when the maximum braking force of the in-wheel motor is 70%, the processor 110 is configured to allocate 70% of the required braking force to the in-wheel motor and 30% of the required braking force to the electromechanical brake (EMB) 171, thereby performing braking accordingly.

[0132] Based on the preset distribution ratio and the distribution ratio according to the maximum braking force ( S239 ), the processor 110 switches to control inputs to the in-wheel motor and the electromechanical brake (EMB) 171 ( S241 ).

[0133] The processor 110 controls each of the electronic mechanical brakes (EMB) 171 according to the designated distribution ratio (S242). In addition, the processor 110 controls each of the in-wheel motors according to the designated distribution ratio (S243).

[0134] Figure 8 The flowchart is a diagram showing a data flow generated when the apparatus 100 for controlling vehicle braking determines that the brake operation is abnormal through feedback of the braking force in the method according to the second embodiment of the present disclosure.

[0135] refer to Figure 8 , when distributing the required braking force and controlling the electromechanical brake (EMB) 171 (S251), the processor 110 receives feedback from the electromechanical brake (EMB) 171, thereby checking the braking force (S252).

[0136] Unlike existing vehicles, the vehicle 10 capable of independently controlling four wheels does not have a hydraulic stop and connection device. Due to communication and power supply problems, the brakes may not work properly. To solve this problem, the processor 110 can verify whether the brakes work properly through feedback.

[0137] In the case where the feedback input-to-reception ratio is lower than the reference setting ratio α% (S253), or in the case where no feedback signal is received (S254), the processor 110 determines that the electromechanical brake (EMB) 171 cannot operate (S255).

[0138] When it is determined that the electromechanical brake (EMB) 171 is operating normally, the processor 110 maintains the exit control input. When it is determined that the electromechanical brake (EMB) 171 is unable to operate, the processor 110 proceeds to the next step.

[0139] Fig. 9 The flowchart is a flowchart showing a data flow generated when the apparatus 100 for controlling vehicle braking determines emergency braking in the method according to the second embodiment of the present disclosure.

[0140] refer to Fig. 9 When it is determined that the electromechanical brake (EMB) 171 cannot operate, the processor 110 determines whether emergency braking is required.

[0141] The processor 110 monitors the brake position (S261).

[0142] The processor 110 compares the braking position with the set position β. In the case where the braking position is greater than the set position β (S262), the processor 110 determines that emergency braking is required (S263).

[0143] For example, when the brake position is about 50%, normal braking is performed. However, when emergency braking is required, the brake position may be at or above 90%.

[0144] When there is an obstacle ahead while the vehicle is running, or when the traffic light turns red, the driver operates the brake to suddenly stop the vehicle 10. In addition, even in the case where the vehicle 10 is allowed to stop slowly, the driver can operate the brake pedal 172 to 90%.

[0145] Therefore, the processor 110 can determine the situation that requires emergency braking by understanding the driver's intention to perform emergency braking, so that the braking can be controlled. The processor 110 can not only determine the position (operation degree) of the brake pedal 172, but also determine the situation that requires emergency braking based on the rate of change each time.

[0146] When a situation requiring emergency braking is determined, the processor 110 controls the in-wheel motor using the current possible maximum braking torque of the in-wheel motor.

[0147] Fig.10 The flowchart is a flowchart showing a data flow generated when the apparatus 100 for controlling vehicle braking determines a deceleration state in the method according to the second embodiment of the present disclosure.

[0148] refer to Fig.10, when the electronic mechanical brake (EMB) 171 is unable to operate and the required emergency braking is not achieved, the processor 110 does not use the maximum available braking torque to control the in-wheel motor, and determines the input of the in-wheel brake after determining whether the speed of the vehicle 10 is in a deceleration state.

[0149] The processor 110 uses the longitudinal acceleration Ax to determine whether the speed of the vehicle 10 is in a deceleration state.

[0150] Based on the longitudinal acceleration Ax (S271), the processor 110 compares the longitudinal acceleration Ax with the second set value -ζ (S272). At this point, the negative (minus) longitudinal acceleration Ax represents a deceleration state, and the positive (plus) longitudinal acceleration Ax represents an acceleration state.

[0151] When the result of comparing the longitudinal acceleration Ax with the second set value -ζ is that the longitudinal acceleration Ax is lower than the second set value -ζ (S273), the processor 110 determines that the vehicle is in the deceleration process (S274) and maintains the in-wheel braking force (S275).

[0152] In a state where the electromechanical brake (EMB) 171 cannot operate, the processor 110 determines that the braking force is normally exerted by the in-wheel braking force, and maintains the in-wheel braking force.

[0153] In the case where the longitudinal acceleration Ax is higher than the second set value -ζ (S276), the processor 110 determines that the braking is insufficient (S277), and recalculates the in-wheel braking force (S280).

[0154] When the longitudinal acceleration Ax is greater than 0 (S278), the processor 110 determines that acceleration is in progress (S279) and recalculates the in-wheel braking force (S280). For example, when the braking force of the vehicle 10 is insufficient while traveling downhill, the vehicle may be in an accelerating state.

[0155] Fig.11 The flowchart is a flowchart showing a data flow generated when the apparatus for controlling vehicle braking recalculates the in-wheel braking torque in the method according to the second embodiment of the present disclosure.

[0156] refer to Fig.11 When the braking force is insufficient or the vehicle is accelerating, the processor 110 determines that the current in-wheel braking input fails to achieve braking effect and recalculates the in-wheel braking force.

[0157] The processor 110 may calculate a difference (S283) between a target speed of the vehicle 10 (refer to S281) and a current speed of the vehicle 10 (refer to S282), may perform proportional-integral (PI) control based on the difference (S284), and may recalculate the in-wheel braking torque (S285).

[0158] When the electromechanical brake (EMB) 171 is inoperable, the target speed of the vehicle 10 is zero.

[0159] The processor 110 may calculate the in-wheel braking force based on the difference between the target speed of the vehicle 10 and the current speed of the vehicle 10 , and may increase the braking force in such a manner that the vehicle 10 reduces its speed.

[0160] Fig.12 The flowchart is a flowchart showing a data flow generated when the apparatus for controlling vehicle braking uses the rear wheels 23 and 24 to perform braking control in the method according to the second embodiment of the present disclosure.

[0161] refer to Fig.12 During braking, the processor 110 monitors the vehicle speed signal input from the vehicle speed sensor 141 (S291).

[0162] In a state where the electromechanical brake (EMB) 171 is inoperable, the speed of the vehicle 10 is reduced by braking the vehicle 10 using the in-wheel motor.

[0163] When the braking reduces the speed of the vehicle 10 to below the first speed δ (S292), the processor 110 cancels the braking using the in-wheel motor (S293). At this time, the first speed may be set to about 40 km / h or less.

[0164] When the in-wheel motor generates reverse torque to perform braking, braking can be performed until the vehicle stops. However, when the in-wheel motor is not accurately controlled in the low speed range, the in-wheel braking torque may limit the behavior of the vehicle 10.

[0165] Therefore, when the vehicle 10 enters the low-speed range, the processor 110 uses the in-wheel motor to stop braking.

[0166] The processor 110 applies a control signal to the steering devices of the third and fourth in-wheel modules 163 and 164 of the rear wheels 23 and 24, so that the rear wheels 23 and 23 reach the toe state. When the rear wheels 23 and 24 reach the toe state, braking force can be generated at a low speed of the vehicle 10.

[0167] By controlling the wheel angles of the rear wheels 23 and 24 in a toe-in configuration, the processor 110 can increase the braking force and can enhance straight-line travel using the steering angles of the rear wheels 23 and 24. Thus, the processor 110 is able to stop the vehicle 10.

[0168] At this time, the processor 110 may control the four wheels 21 to 24 in a toe configuration. However, when such toe control is performed, the traveling direction of the vehicle 10 may be limitedly controlled, causing problems in avoiding obstacles. Therefore, it is preferred to control the rear wheels 23 and 24 in a toe configuration.

[0169] Therefore, the processor 110 can increase the braking force by controlling the wheel angles of the rear wheels 23 and 24 in a toe-in configuration, and can enhance straight-line travel using the steering angles of the rear wheels 23 and 24. Thus, the processor 110 can stop the vehicle 10.

[0170] When the vehicle 10 comes to a complete stop, the processor 110 completes braking (S295).

[0171] Therefore, although electronic mechanical brakes cannot operate in a vehicle that can independently control four wheels, the device and method for controlling vehicle braking according to the first and second embodiments of the present disclosure can still effectively utilize the in-wheel motor for braking and can improve the safety of the vehicle.

Claims

1. A device for controlling vehicle braking, the device comprising: An in-wheel motor, which is installed in a wheel and enables the wheel to rotate; an electromechanical brake installed in the wheel and configured to perform braking; a vehicle speed sensor configured to measure a speed of the vehicle; as well as A processor configured to calculate a required braking force in response to a signal from a brake pedal application, control braking by distributing the required braking force to the electromechanical brakes and the in-wheel motors, and determine a braking state based on a speed of the vehicle and recalculate a braking torque for the in-wheel motors to control the in-wheel motors to stop the vehicle in the event that the electromechanical brakes fail to operate.

2. The device according to claim 1, wherein: When the signal is input from the brake pedal, the processor checks the state of charge SOC of the battery, wherein if the SOC of the battery is higher than a first set value, the processor controls the electromechanical brake to perform braking, and If the SOC is at or below the first set value, the processor distributes the required braking force to the in-wheel motor and the electromechanical brake.

3. The device according to claim 1, wherein: In the event that the electromechanical brake fails to operate, the processor determines whether emergency braking is required based on a signal from the brake pedal, and when the situation requiring emergency braking is reached, the processor controls the in-wheel motor to operate the in-wheel motor at a maximum braking torque.

4. The device according to claim 1, wherein: When the electromechanical brake is inoperable, the processor determines whether emergency braking is required, and when a condition requiring emergency braking is not reached, the processor determines whether the vehicle is in a deceleration state, wherein when the vehicle is in a deceleration state, the processor maintains a braking torque for the in-wheel motor, and Wherein, when the vehicle is not in a deceleration state, the processor recalculates the braking torque for the in-wheel motor.

5. The device according to claim 1, wherein: When the speed of the vehicle is lower than a preset speed, the processor stops braking using the in-wheel motor and performs braking by controlling the rear wheels in a toe configuration.

6. A method for controlling vehicle braking, the method comprising: The processor calculates a required braking force in response to a signal from a brake pedal applied to the wheels during vehicle travel; the processor controlling braking by distributing the desired braking force to the electromechanical brakes and the in-wheel motors; the processor determining a braking state based on a speed of the vehicle when the electromechanical brake is inoperable; as well as The processor controls the in-wheel motor by recalculating a braking torque for the in-wheel motor according to the braking state.

7. The method according to claim 6, wherein: Controlling braking by the processor includes: When the signal is input from the brake pedal, after the processor checks the SOC of the battery, if the SOC of the battery is higher than a first set value, the processor controls braking using the electromechanical brake; and If the SOC of the battery is at or below a first set value, braking is controlled by the processor by distributing the required braking force to the in-wheel motor and the electromechanical brake.

8. The method according to claim 6, wherein: Determining, by the processor, the braking state comprises: In the event that the electromechanical brake fails to operate, the processor determines whether emergency braking is required based on a signal from the brake pedal; When a situation requiring emergency braking is reached, the processor controls the in-wheel motor to operate at a maximum braking torque of the in-wheel motor; and When the situation requiring emergency braking is not reached, the processor determines whether the vehicle is in a deceleration state.

9. The method according to claim 8, wherein: Determining, by the processor, whether the vehicle is in a deceleration state may include: When the vehicle is in a deceleration state, maintaining, by the processor, a braking torque for the in-wheel motor; and When the vehicle is not in a deceleration state, the processor recalculates the braking torque for the in-wheel motor.

10. The method according to claim 6, after the processor controls the in-wheel motor, further comprising: When the speed of the vehicle is lower than a preset speed, the processor stops using the braking of the in-wheel motor; as well as The processor performs braking by controlling the rear wheels in a toe configuration.

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