KR20230039072A - Brake control apparatus and control method of brake apparatus - Google Patents

Abstract

The present invention relates to a brake control apparatus and a control method of a brake apparatus. The brake control apparatus installed at a vehicle with a plurality of wheels comprises: a braking unit which applies a braking torque to the plurality of wheels; and a control unit electrically connected to the braking unit. The control unit reduces a driving torque for driving the wheels based on an increase in spin of the plurality of wheels, and applies the braking torque to at least one of the plurality of wheels while controlling the driving torque. Also, the control unit may increase the driving torque for driving the wheels based on a change in the spin of the plurality of wheels. Provided are the brake control apparatus capable of identifying a high coefficient of friction on a road, and the control method of the brake apparatus.

Description

Brake control device and control method of the brake device {BRAKE CONTROL APPARATUS AND CONTROL METHOD OF BRAKE APPARATUS}

The disclosed invention relates to a braking control device and a control method of the braking device, and more particularly, to a braking control device including a traction control system (TCS) and a control method of the braking device.

A braking device for performing braking is necessarily installed in a vehicle, and a braking control device for controlling the braking device in various ways has been proposed for the safety of drivers and passengers.

Recently, a traction control system (TCS) for improving traction power has been provided in vehicles. Traction control controls the drive torque provided to the wheels to prevent wheel spin (or slip).

A brake traction control system (BTCS) for improving vehicle traction is provided in a vehicle braking control device. The braking traction control may control the braking torque of the wheel in order to prevent the left-right asymmetrical spin of the wheel due to the non-uniform friction coefficient (split mu) of the road surface.

However, the conventional traction control still applies a low driving torque to the wheels even after the vehicle enters a road with a high friction coefficient, and as a result, the vehicle may not be able to quickly get out of a low friction road such as an icy road.

For the above reasons, one aspect of the disclosed invention is to provide a braking control device and a control method of the braking device capable of identifying a high friction coefficient of a road while a traction control system is activated.

According to one aspect of the disclosed invention, a braking control device installed in a vehicle having a plurality of wheels includes a braking unit for applying braking torque to the plurality of wheels; and a control unit electrically connected to the braking unit, wherein the control unit reduces drive torque for driving the wheels based on a comparison between spins of the plurality of wheels and target spins, and reduces the drive torque. Braking torque may be applied to any one of the plurality of wheels, and driving torque for driving the wheel may be increased based on a change in spin of another wheel positioned opposite to the one wheel.

According to one aspect of the disclosed invention, a control method of a braking device installed in a vehicle having a plurality of wheels includes reducing drive torque for driving the wheels based on a comparison between spins of the plurality of wheels and a target spin; applying a braking torque to any one of the plurality of wheels while reducing the driving torque; and increasing the drive torque based on a change in spin of another wheel positioned opposite the one wheel.

According to an aspect of the disclosed invention, a braking control device installed in a vehicle having a plurality of wheels and a plurality of wheel cylinders corresponding to each of the plurality of wheels is configured to apply braking torque to the plurality of wheels, A piston pump that supplies hydraulic pressure to the cylinder; a drive motor that drives the piston pump; a passage extending from the piston pump to the wheel cylinder; at least one valve opening the passage; and a control unit electrically connected to the drive motor and the at least one valve, wherein the control unit identifies spin of the plurality of wheels based on outputs of wheel speed sensors installed in the plurality of wheels, and Controls an engine control module of the vehicle to reduce drive torque for driving the plurality of wheels based on a comparison between a wheel and a target spin, and at least one wheel of the plurality of wheels while reducing the drive torque. An engine of the vehicle to control the drive motor and the at least one valve to apply a braking torque, and to increase the drive torque based on a change in the spin of another wheel located opposite the one wheel. Control module can be controlled.

According to one aspect of the disclosed invention, it is possible to provide a braking control device capable of identifying a high friction coefficient of a road while a traction control system is activated and a control method of the braking device.

Thereby, the braking control device and the control method of the braking device can enable the vehicle to quickly move away from a low friction coefficient road such as an icy road while the traction control system is activated.

1 shows a drive system and a braking system included in a vehicle according to one embodiment.
2 shows a hydraulic circuit of a braking control device according to an embodiment.
3 shows a control block of a braking control device according to an embodiment.
4 illustrates wheel spin on a road with a low friction coefficient of a vehicle according to an exemplary embodiment.
5 illustrates wheel spin on a road with a high friction coefficient of a vehicle according to an exemplary embodiment.
6 illustrates changes in driving torque, braking torque, and target spin of a vehicle according to an exemplary embodiment.
7 illustrates the operation of a braking control device according to an embodiment.

Like reference numbers designate like elements throughout the specification. This specification does not describe all elements of the embodiments, and general content or overlapping content between the embodiments in the technical field to which the disclosed invention belongs is omitted. The term 'unit, module, member, or block' used in the specification may be implemented as software or hardware, and according to embodiments, a plurality of 'units, modules, members, or blocks' may be implemented as one component, It is also possible that one 'part, module, member, block' includes a plurality of components.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case of being directly connected but also the case of being indirectly connected, and indirect connection includes being connected through a wireless communication network. do.

In addition, when a certain component is said to "include", this means that it may further include other components without excluding other components unless otherwise stated.

Throughout the specification, when a member is said to be located “on” another member, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members.

Terms such as first and second are used to distinguish one component from another, and the components are not limited by the aforementioned terms.

Expressions in the singular number include plural expressions unless the context clearly dictates otherwise.

In each step, the identification code is used for convenience of description, and the identification code does not explain the order of each step, and each step may be performed in a different order from the specified order unless a specific order is clearly described in context. there is.

Hereinafter, the working principle and embodiments of the disclosed invention will be described with reference to the accompanying drawings.

1 shows a drive system and a braking system included in a vehicle according to one embodiment.

The vehicle 1 includes a body forming its exterior and accommodating a driver and/or luggage, a chassis including constituent parts of the vehicle 1 other than the body, and a body through which the vehicle 1 can move. It includes a wheel (2) that rotates to

Referring to FIG. 1 , a vehicle 1 includes a driving system 10 and a braking system 40 .

The driving system 10 generates driving torque for driving the vehicle 1 and includes an engine 11, an engine control module 12, and a transmission 21.

The engine 11 includes a cylinder and a piston, and can generate driving torque for driving the vehicle 1 . The transmission 21 includes a plurality of gears and can transmit the driving torque generated by the engine 11 to the wheels. In particular, the transmission 21 includes a differential gear that allows the left wheel and the right wheel to rotate at different rotational speeds by the drive torque of the engine 11 .

The engine control module 12 is an electronic control unit for controlling revolution per minute (rpm) and/or driving torque of the engine 11 in response to the driver's will to accelerate through the accelerator pedal 11a. Unit, ECU).

The braking system 40 generates braking torque for stopping the vehicle 1 and includes a braking device 41 and an electronic brake control module (EBCM) 100 .

As shown in FIG. 1 , the braking device 41 may include a brake caliper 42 installed on the wheel 2 of the vehicle 1 . The brake caliper 42 includes a pair of brake pads provided on both sides of the brake disk 43 connected to the wheel 2 . The brake caliper 42 may press the brake disc 43 from both sides of the brake disc 43 by fluid pressure or mechanical pressure. Due to the friction between the brake pad of the brake caliper 42 and the brake disc 43, rotation of the brake disc 43 and the wheel 2 may be stopped.

In addition, the brake caliper 42 receives a pressurized medium (eg, brake oil) from the brake control device 100, and the brake pads are connected to the brake disc by the pressure of the pressurized medium (hereinafter referred to as "hydraulic pressure"). It may include wheel cylinders 44a, 44b (see FIG. 2), which are brought into contact.

A wheel speed sensor 180 for detecting the rotational speed of the wheel 2 is provided on the brake control device wheel 2 .

The braking control device 100 may include a hydraulic circuit for supplying hydraulic pressure to wheel cylinders in response to a driver's braking intention through the brake pedal 101 and an electronic control unit for controlling the hydraulic circuit.

The brake control device 100 may control the hydraulic pressure supplied to the wheel cylinder of the brake device 41 to temporarily release the brake of the wheel in response to the slip of the wheel 2 during braking of the vehicle 1 ( Anti-lock Braking Systems (ABS).

The brake control device 100 supplies wheel cylinders of the brake device 42 to selectively brake the wheels 2 in response to oversteering and/or understeering during steering of the vehicle 1. The hydraulic pressure can be controlled (Electronic stability control, ESC).

Also, the braking control device 100 may control the rotation of the wheel in response to the spin of the wheel 2 when the vehicle 1 is driven. For example, in response to the spin of the wheel 2 sensed when the vehicle 1 starts, the brake control device 100 applies the brake device 42 to a wheel cylinder to temporarily brake the wheel 2. The hydraulic pressure supplied can be controlled. In response to the spin of the wheel 2 detected while the vehicle 1 is running, the braking control device 100 may control the engine control module 12 to reduce the torque of the engine 11, and also the wheel It is possible to control the hydraulic pressure supplied to the wheel cylinder of the braking device 42 so as to temporarily brake (2).

The driving system 10 and the braking system 40 may communicate with each other through an in-vehicle communication network. For example, electrical components transmit data through Ethernet, MOST (Media Oriented Systems Transport), Flexray, CAN (Controller Area Network), LIN (Local Interconnect Network), etc. can give and take

For example, the engine control module 12 may transmit the number of revolutions of the engine 11, the driving torque of the engine 11, the displacement of the accelerator pedal 11a, and the like through a communication network.

The braking control device 100 receives data including the number of revolutions of the engine 11, the driving torque of the engine 11, the displacement of the accelerator pedal 11a, the gear position of the transmission 21, etc. through a communication network, and , it is possible to control the braking device 41 based on the received data.

Brake control device Fig. 2 shows a hydraulic circuit of a brake control device according to an embodiment.

Referring to FIG. 2 , a brake pedal 101 that accepts a driver's will to brake is provided in the braking control device vehicle 1 . The brake control device 100 includes a reservoir 103 for storing pressurized medium (eg, brake oil, etc.), a master cylinder 104 for generating hydraulic pressure by movement of the brake pedal 101, and a brake pedal ( A piston pump 160 that generates hydraulic pressure in response to sensing the movement of the 101), a drive motor 150 that drives the piston pump 160, a master cylinder 104, and/or a piston pump 160 and a hydraulic circuit 110 connecting to the wheel cylinders 44a and 44b.

The piston pump 160 includes a cylinder 161 and a piston 162, and the inner space of the cylinder 161 is divided into a first pressure chamber 161a and a second pressure chamber 161b by the piston 162. It can be.

The piston pump 160 may generate hydraulic pressure by moving the piston 162 in response to the movement of the brake pedal 101 . A brake pedal sensor 130 detecting movement of the brake pedal 101 may be provided, and the piston 162 of the piston pump 160 may move based on an output of the brake pedal sensor 130 .

The driving motor 150 may generate rotational force for moving the piston 162 . The rotational force of the drive motor 150 is converted into reciprocating force through a power transmission unit (eg, a plurality of gears), and the piston 162 can move reciprocally by the reciprocating force converted by the power transmission unit.

The hydraulic circuit 110 hydraulically connects the piston pump 160 to the wheel cylinders 44a and 44b, and transfers or blocks hydraulic pressure generated from the piston pump 160 to the wheel cylinders 44a and 44b.

The hydraulic circuit 110 includes a main flow path 111 connecting the piston pump 160 to the wheel cylinders 44a and 44b, and on the main flow path 111, a hydraulic control unit 117 and inlet valves ( 113a, 113b) and outlet valves 114a, 114b are provided.

The hydraulic control unit 117 may be hydraulically connected to the first pressure chamber 161a and the second pressure chamber 161b of the piston pump 160 and may include a plurality of valves. The hydraulic pressure control unit 117 may guide the hydraulic pressure generated by the piston pump 160 to the wheel cylinders 44a and 44b. For example, the hydraulic pressure control unit 117 may guide the hydraulic pressure generated in the first pressure chamber 161a to the wheel cylinders 44a and 44b while the piston 162 moves forward, and the piston 162 During the backward movement, the hydraulic pressure generated in the second pressure chamber 161b may be guided to the wheel cylinders 44a and 44b.

Downstream of the hydraulic control unit 117, the main flow path 111 is branched into a first main flow path 111a and a second main unit 111b, and the first main flow path 111a is connected to the first wheel 2a and the second main unit 111b. It extends to the associated first wheel cylinder 44a, and the second main passage 111b extends to the second wheel shield 44b associated with the second wheel 2b. Here, the first wheel 2a and the second wheel 2b may be wheels provided on the left and right sides of the vehicle 1, respectively. For example, the first wheel 2a may be a left front wheel or a left rear wheel, and the second wheel 2b may be a right front wheel or a right rear wheel.

Inlet valves 113a and 113b and outlet valves 114a and 114b may be provided in the first main flow path 111a and the second main unit 111b, respectively.

The inlet valves 113a and 113b are disposed on the main flow passages 111a and 111b connecting the piston pump 160 and the wheel cylinders 44a and 44b. A first inlet valve 113a may be provided in the first main flow path 111a, and a second inlet valve 113b may be provided in the second main unit 111b. The inlet valves 113a and 113b may allow or block hydraulic pressure transmitted from the piston pump 160 to the wheel cylinders 44a and 44b. The inlet valves 113a and 113b may be normally open solenoid valves.

The outlet valves 114a and 114b are disposed on a flow path connecting the wheel cylinders 44a and 44b with the reservoir 103. A first outlet valve 114a is provided on a flow path connecting the first wheel cylinder 44a to the reservoir 103, and a second outlet valve 114a is provided on a flow path connecting the second wheel cylinder 44b to the reservoir 103. A valve 114b is provided. The outlet valves 114a and 114b may allow or block the hydraulic pressure of the wheel cylinders 44a and 44b from being discharged to the reservoir 103 . The outlet valves 114a and 114b may be normally closed solenoid valves.

The hydraulic circuit 110 further includes an auxiliary oil passage 112 connecting the master cylinder 104 to the wheel cylinder 44a and a cut valve 118 provided on the auxiliary oil passage 112 .

The cut valve 118 can prevent the hydraulic pressure of the master cylinder 104 from being provided to the wheel cylinder 44a. In other words, the cut valve 118 may block the hydraulic pressure of the master cylinder 104 and allow the hydraulic pressure of the piston pump 160 to be provided to the wheel cylinder 44a.

When the piston pump 160 fails or is out of control, the cut valve 118 can be opened, allowing hydraulic pressure from the master cylinder 104 to be provided to the wheel cylinders. there is. The cut valve 118 may be a normally open solenoid valve that is normally open to allow connection between the piston pump 160 and the wheel cylinders 44a and 44b when power is lost.

The hydraulic circuit 110 further includes check valves installed at appropriate flow path positions to prevent reverse flow of brake oil. The valves included in the brake control device 100, such as the inlet valves 113a and 113b, the outlet valves 114a and 114b, the hydraulic control unit 117, the cut valve 118, and the check valve, integrally form a valve block. can form

The braking control device 100 may further include a pressure sensor 140 that measures the hydraulic pressure of the hydraulic circuit 110 .

When the driver steps on the brake pedal 101, the piston pump 160 may supply hydraulic pressure to the wheel cylinders 44a and 44b through the hydraulic control unit 117 and the inlet valves 113a and 113b.

In addition, the brake control device 100 may generate and control hydraulic pressure for realizing the above-described ABS and/or ESC and/or BTCS.

3 shows a control block of a braking control device according to an embodiment. 4 illustrates wheel spin on a road with a low friction coefficient of a vehicle according to an exemplary embodiment. 5 illustrates wheel spin on a road with a high friction coefficient of a vehicle according to an exemplary embodiment.

As shown in FIG. 3, the braking control device vehicle 1 includes a brake pedal sensor 130 for detecting the movement of the brake pedal 101 and a wheel speed sensor 180 for detecting the rotational speed of the wheel 2. And, a motion sensor 190 for detecting the movement of the vehicle 1 is provided. The brake control device 100 includes a pressure sensor 140 that detects the pressure in the hydraulic circuit 110, a piston pump 160 that generates hydraulic pressure to be supplied to the wheel cylinders 44a and 44b, and a piston pump 160. ), a valve block 170 that opens or closes a flow path for guiding the hydraulic pressure generated by the piston pump 160 to the wheel cylinders 44a and 44b, and a braking control device 100 ) Includes a control unit 120 that controls the operation of.

The brake pedal sensor 130 may detect a moving distance and/or a moving speed of the brake pedal 101 according to the driver's braking intention, and an electrical output signal depending on the detected moving distance and/or moving speed ( pedal signal) may be provided to the control unit 120 . The controller 120 may determine the driver's will to brake based on the pedal signal of the brake pedal sensor 130 .

The pressure sensor 140 is provided on the hydraulic circuit 110 that supplies hydraulic pressure to the wheel cylinders 44a and 44b, and can sense the hydraulic pressure of the pressurized medium on the hydraulic circuit 110. The pressure sensor 140 may provide an electrical output signal (pressure signal) depending on the detected hydraulic pressure to the control unit 120 . The controller 120 may determine the hydraulic pressure generated by the master cylinder 104 and/or the piston pump 160 depending on the pressure signal of the pressure sensor 140 .

The location and number of pressure sensors 140 are not limited. For example, the pressure sensor 140 may be provided at a position capable of detecting hydraulic pressure generated by the master cylinder 104 and/or the piston pump 160 . In addition, a sufficient pressure sensor 140 capable of sensing the hydraulic pressure generated by the master cylinder 104 and/or the piston pump 160 may be provided.

The wheel speed sensor 180 may detect the rotational speed of the wheel 2 provided in the vehicle 1 . The wheel speed sensor 180 is installed on each of a plurality of wheels (eg, four wheels) and can detect the rotational speed of each of the plurality of wheels. For example, the wheel 2 of the vehicle 1 may be provided with a sawtooth ring having a plurality of metal poles formed on its outer circumferential surface, and the wheel speed sensor 180 includes a bar-shaped permanent magnet and a coil winding the permanent magnet. can include The wheel speed sensor 180 is provided around the toothed ring so that the pole (N pole or S pole) of the permanent magnet faces the toothed ring of the wheel 2 . The rotation of the sawtooth-shaped ring by the rotation of the wheel 2 causes a change in the magnetic field around the permanent magnet, and the coil of the wheel speed sensor 180 generates an electrical signal (AC signal) corresponding to the change in the magnetic field around the permanent magnet. may be transmitted to the control unit 120. The controller 120 may identify the rotational speed of the wheel 2 based on the electrical signal of the wheel speed sensor 180 .

The motion sensor 190 may detect motion of the vehicle 1 including linear acceleration and rotational acceleration of the vehicle 1, and provide an electrical signal corresponding to the motion of the vehicle 1 to the control unit 120. . For example, the motion sensor 190 may detect vertical acceleration, longitudinal acceleration, and lateral acceleration of the vehicle 1 based on a change in gravitational acceleration acting on the vehicle 1 . In addition, the motion sensor 190 may detect a yaw rate, a roll rate, and a pitch rate of the vehicle 1 using rotational inertia or Coriolis force.

The piston pump 160 may generate hydraulic pressure by receiving rotational force from the drive motor 150 . The piston pump 160 includes, for example, a cylinder 161 and a piston 162, and may generate hydraulic pressure by moving the piston 162 by rotation of the driving motor 150.

The driving motor 150 may generate rotational force in response to a driving signal from the control unit 120 . Rotational force generated by the drive motor 150 may be provided to the piston pump 160 . The drive motor 150 may include, for example, a brushless direct current motor (BLDC Motor), a permanent magnet synchronous motor (PMSM), a DC motor, or an induction motor.

The valve block 170 may include a plurality of valves of the braking control device 100 . For example, the valve block 170 may include the inlet valves 113a and 113b, the outlet valves 114a and 114b, the hydraulic control unit 117 and the cut valve 118 shown in FIG. 2 . .

The valve block 170 may open or close a flow path included in the hydraulic circuit 110 in response to a control signal (an open signal or a close signal) of the control unit 120 . For example, as shown in FIG. 2 , the valve block 170 provides a flow path for guiding hydraulic pressure from the master cylinder 104 to the wheel cylinders 44a and 44b, or transfers hydraulic pressure from the piston pump 160 to the wheel cylinders. A passage leading to (44a, 44b) can be provided.

The controller 120 includes an output signal (pedal signal) of the brake pedal sensor 130, an output signal (pressure signal) of the pressure sensor 140, an output signal (wheel speed signal) of the wheel speed sensor 180, and a motion sensor ( The driving motor 150 and the valve block 170 may be controlled based on the output signal (motion signal) of 190 . In addition, the control unit 120 may obtain data related to driving of the vehicle 1 from the engine control module 12 through a vehicle communication network, and based on the data related to driving of the vehicle 1, the driving motor 150 ) and the valve block 170 can be controlled.

The controller 120 may include a plurality of semiconductor elements and may be variously called an ECU (Electronic Control Unit). The controller 120 includes a CAN transceiver 123, a memory 122, and a processor 121. The CAN transceiver 123, the memory 122, and the processor 121 may be implemented as separate semiconductor devices or as a single semiconductor device. The controller 120 may include a plurality of processors and/or a plurality of memories.

The CAN transceiver 123 may receive data related to driving of the vehicle 1 from the engine control module 12 through a vehicle communication network. For example, the can transceiver 123 may receive data including the displacement of the accelerator pedal 11a and the driving torque of the engine 11 from the engine control module 12, and the received data may be converted to the processor 121 ) can be passed on.

The memory 122 may store/store programs and data for braking the vehicle 1 depending on the driver's braking intention. For example, the memory 122 stores/stores programs and data for controlling the drive motor 150 and the valve block 170 to supply hydraulic pressure to the wheel cylinders 44a and 44b depending on the driver's will to brake. can be saved In addition, the memory 122 supplies the hydraulic pressure to the wheel cylinders 44a and 44b depending on the displacement of the accelerator pedal 11a and/or the drive torque of the engine 11, so that the drive motor 150 and the valve block ( 170) may be stored/stored.

The memory 122 may provide programs and data to the processor 121 and may store temporary data generated during an arithmetic operation of the processor 121 .

The memory 122 includes volatile memories such as Static Random Access Memory (S-RAM) and Dynamic Random Access Memory (D-RAM), Read Only Memory (ROM), and EpiROM (EPROM). Erasable Programmable Read Only Memory (EPROM) and non-volatile memory such as flash memory may be included. The memory 122 may include one semiconductor device or a plurality of semiconductor devices.

The processor 121 may provide control signals to the driving motor 150 and the valve block 170 according to programs and data provided from the memory 122 . For example, the processor 121 may provide a driving signal for generating hydraulic pressure to the driving motor 150, and may provide an opening/closing signal for guiding the hydraulic pressure from the piston pump 160 to the wheel cylinders 44a and 44b. It can be provided to the valve block 170.

The processor 121 may include an arithmetic circuit, a memory circuit, and a control circuit. The processor 121 may include one semiconductor device or a plurality of semiconductors. Also, the processor 121 may include one core or a plurality of cores in one semiconductor device. This processor 121 may be called variously, such as MPU (Micro Processing Unit).

As such, the controller 120 may control the drive motor 150 and/or the valve block 170 to brake the vehicle 1 depending on the output signal output from the brake pedal sensor 130 .

Wheel spin (slip) may occur while the brake control device vehicle 1 starts or travels on a road having a low friction coefficient. For example, spin may occur in a driving wheel (a wheel driven by a driving system), and the vehicle 1 may slip without moving forward due to the wheel spin.

In addition, wheel spin (slip) may occur while the vehicle 1 starts or runs on a road having an uneven friction coefficient (split-mu). For example, spin can occur on either the left drive wheel or the right drive wheel. When a wheel spins, the driving torque of the engine 11 may be biased and provided to the spinned wheel due to the differential gear. As a result, the vehicle 1 may slip on the road without being able to move forward.

The brake control device 100 may control wheel spin to improve traction (force for the vehicle to move) on a road surface with a low friction coefficient or a road surface with an uneven friction coefficient.

The controller 120 may detect spin of the wheel 2 based on a difference in rotational speed between the wheels (eg, a difference in rotational speed between a driving wheel and a driven wheel). When the spin of the wheel that exceeds the target spin is detected, the controller 120 can control the driving torque and the braking torque so that the spin of the wheel is smaller than the target spin. For example, the control unit 120 may provide the engine control module 12 with a message for reducing the driving torque of the engine 11, and brake the corresponding wheel to reduce the rotational speed of the wheel at which spin is detected. Torque can be applied as braking torque. For example, when detecting the spin of the first wheel 44a, the control unit 120 adjusts the spin-sensed first wheel 44a to balance the drive torque between the first wheel 44a and the second wheel 44b. It is possible to control the braking control device 100 to apply the braking torque to the braking torque.

In addition, the controller 120 detects that the vehicle 1 enters a road with a high friction coefficient while driving on a road with a low friction coefficient, and in response to this, the driving torque of the engine 11 or It is possible to control the engine control module 12 to increase the driving torque.

For example, the control unit 120 may activate the traction control and reduce the driving torque or driving torque of the engine 11 while the vehicle 1 is driving on a road with a low friction coefficient, the engine control module 12 can control. As a result, the spin of the wheels 2a and 2b is reduced, and the traction force of the vehicle 1, that is, the force by which the vehicle 1 moves forward can be increased.

While the traction control is activated, the control unit 120 may periodically apply braking torque to one of the wheels 2a and 2b and monitor spin of the other of the wheels 2a and 2b. As the rotational speed of one wheel decreases, the driving torque supplied to the other wheel by the differential gear may increase. At this time, if the vehicle 1 is still driving on a road with a low friction coefficient, spin may increase on the other wheel (the wheel to which braking torque is not supplied). On the other hand, when the vehicle 1 is driving on a road with a high friction coefficient, the spin of the other wheel does not increase and a certain level of spin can be maintained.

The controller 120 may determine that the vehicle 1 is driving on a road having a high friction coefficient when an increase in wheel spin (spin of another wheel) is not detected. The controller 120 may control the engine control module 12 to increase the driving torque or driving torque of the engine 11 in order to increase the traction force of the vehicle 1 .

Specifically, the controller 120 may activate traction control based on spin of the wheels 2a and 2b. The control unit 120 determines whether or not the wheels 2a and 2b spin based on the difference in rotational speed between the wheels 2a and 2b (eg, the difference between the rotational speed of the driving wheel and the rotational speed of the driven wheel). can identify. The controller 120 may control the engine control module 12 to reduce driving torque or driving torque of the engine 11 in response to detecting spin of the wheels 2a and 2b.

The controller 120 may apply braking torque to any one of the wheels 2a and 2b based on the yaw rate of the vehicle 1 . The controller 120 may obtain a yaw rate of the vehicle 1 from the motion sensor 190 and may identify a rotation direction of the vehicle 1 based on the yaw rate. The control unit 120 may apply braking torque to a wheel opposite to the rotational direction of the vehicle 1 . For example, when rotation of the vehicle 1 in the right direction is identified, the control unit 120 may apply braking torque to the left first wheel 2a. In addition, when rotation of the vehicle 1 in the left direction is identified, the control unit 120 may apply braking torque to the second wheel 2b on the right side. This prevents the driving of the vehicle 1 from becoming unstable due to the operation for estimating the friction coefficient of the road surface.

After applying the braking torque to any one of the wheels 2a and 2b, the control unit 120 may monitor the spin of the other one of the wheels 2a and 2b. For example, after applying the braking torque to the left wheel, the controller 120 monitors the spin of the right wheel, and after applying the braking torque to the right wheel, the controller 120 monitors the spin of the left wheel. can monitor

When an increase in the spin of the other wheel is detected, the controller 120 may maintain traction control as it is. For example, the controller 120 may control the braking control device 100 to apply the braking torque T_brake to the first wheel 2a as shown in (a) of FIG. 4 . By the braking torque applied to the first wheel 2a, the rotational speed of the first wheel 2a is reduced, and the difference between the rotational speed of the first wheel 2a and the rotational speed of the second wheel 2b occurs. Due to the difference between the rotational speed of the first wheel 2a and the rotational speed between the second wheels 2b, the driving torque transmitted to the first wheel 2a decreases and the driving torque transmitted to the second wheel 2b decreases. Torque can be increased. Due to the increase in driving torque transmitted to the second wheel 2b, spin may occur in the second wheel 2b. At this time, when the vehicle 1 drives on a road surface having a low friction coefficient, spin on the second wheel 2b may rapidly increase as shown in (b) of FIG. 4 . In other words, the wheel spin of the second wheel 2b may be greater than the reference spin. When the wheel spin of the second wheel 2b is greater than the reference spin, the controller 120 may determine that the vehicle 1 is driving on a road surface having a low friction coefficient and maintain traction control as it is.

On the other hand, if an increase in the spin of the other wheel is not detected, the control unit 120 operates the engine control module 12 to increase the drive torque or drive torque of the engine 11 to improve the traction of the vehicle 1. can control. For example, the controller 120 may apply the braking torque T_brake to the first wheel 2a as shown in (a) of FIG. 5 . Due to the braking torque T_brake applied to the first wheel 2a, the driving torque transmitted to the first wheel 2a may decrease and the driving torque transmitted to the second wheel 2b may increase. Due to the increase in driving torque transmitted to the second wheel 2b, spin may occur in the second wheel 2b. At this time, when the vehicle 1 drives on a road surface having a high friction coefficient, as shown in FIG. 5(b), spin occurs in the second wheel 2b, but the spin of the second wheel 2b increases. Otherwise, the spin of the second wheel 2b may be maintained or reduced. In other words, the wheel spin of the second wheel 2b may be smaller than the reference spin. If the wheel spin of the second wheel 2b is not greater than the reference spin, the control unit 120 determines that the vehicle 1 is driving on a road surface having a high friction coefficient, and the driving torque of the engine 11 by traction control. Alternatively, the engine control module 12 may be controlled to increase driving torque.

As such, the controller 120 may identify whether or not the vehicle 1 enters a road having a high friction coefficient while the vehicle 1 is driving on a road having a low friction coefficient, and the vehicle 1 has a low friction coefficient. If entering a high road is identified, the engine control module 12 may be controlled to increase driving torque or driving torque of the engine 11 to improve traction of the vehicle 1 .

6 illustrates changes in driving torque, braking torque, and target spin of a vehicle according to an exemplary embodiment.

Together with FIG. 6 , the operation of the braking control device 100 according to the lapse of time is described.

As shown in (a) of FIG. 6 , the vehicle 1 can drive on the road (Low-μ) having a low friction coefficient at time t0.

While the vehicle 1 is running, the braking control device 100 determines the speeds WS1 and WS2 of the wheels 2a and 2b (where the wheel speed is the speed obtained by converting the angular speed of the wheel into a linear speed based on the radius of the wheel). ) can be sensed, and the spin of the wheels 2a, 2b can be identified based on the speeds of the wheels 2a, 2b. For example, the braking control device 100 determines a difference between the speed of the vehicle 1 (here, the speed of the vehicle may be based on the speed of the driven wheels) and the speeds WS1 and WS2 of the wheels 2a and 2b. Based on the difference, the spin of the wheels 2a and 2b can be identified.

As shown in (b) of FIG. 6 , the braking control device 100 can identify the spin of the wheels 2a and 2b at time t0.

As shown in (c) of FIG. 6 , the braking control device 100 may activate the traction control (TCS) in response to the spin of the wheels 2a and 2b.

According to the control of the traction control (TCS), the braking control device 100 may determine a target spin for limiting the spin of the wheel as shown in (f) of FIG. 6 . The target spin may be experimentally or empirically set for stable driving of the vehicle 1 . The target spin may vary according to weather or road conditions. The target spin can be varied according to the driver's choice.

By setting the target spin, the braking control device 100 may control the engine control module 12 to adjust the driving torque or driving torque of the engine 11 as shown in FIG. 6(g). For example, when the spin of the wheels 2a and 2b is greater than the target spin, the braking control device 100 may control the engine control module 12 to reduce the driving torque or driving torque of the engine 11 .

While the traction control is activated, the brake control device 100 may periodically activate the brake traction control (BTCS). As shown in (d) of FIG. 6 , the brake control device 100 may activate the brake traction control (BTCS) at time t1.

According to the control of the brake traction control (BTCS), the braking control device 100 may apply braking torque to any one of the wheels 2a and 2b. As shown in (e) of FIG. 6 , the braking control device 100 may apply the braking torque T_brake to the first wheel 2a at time t1 .

As shown in (b) of FIG. 6 , when the spin of the other wheel increases, the braking control device 100 determines that the vehicle 1 is driving on a road surface having a low friction coefficient, and at time t2 It is possible to remove the braking torque applied to any one wheel. In addition, in response to the spin of the wheel exceeding the target spin, the braking control device 100 reduces the drive torque or drive torque of the engine 11 at time t2 as shown in FIG. The control module 12 can be controlled.

Thereafter, while the traction control is activated, the brake control device 100 may reactivate the brake traction control (BTCS) periodically. As shown in (d) of FIG. 6 , the brake control device 100 may activate the brake traction control (BTCS) at time t3.

According to the control of the brake traction control (BTCS), the braking control device 100 may apply braking torque to any one of the wheels 2a and 2b. As shown in (e) of FIG. 6 , the braking control device 100 may apply the braking torque T_brake to the first wheel 2a at time t3.

As shown in (b) of FIG. 6, if the spin of the other wheel does not increase, the braking control device 100 determines that the vehicle 1 is driving on a road surface having a high friction coefficient, At time t4, the braking torque applied to any one wheel may be removed. In addition, in response to the vehicle 1 traveling on a road surface having a high friction coefficient, the braking control device 100 may increase the target spin at time t4 as shown in (f) of FIG. 6 . In response to increasing the target spin, the braking control device 100 may control the engine control module 12 to increase the drive torque or drive torque of the engine 11 as shown in FIG. 6(g). there is.

As a result, the vehicle 1 driving on a road surface with a high friction coefficient can increase the driving torque of the engine 11 and accelerate within a short time after leaving the road surface with a low friction coefficient.

7 illustrates the operation of a braking control device according to an embodiment.

Together with FIG. 7 , an operation 1000 of the braking control device 100 according to operating conditions is described.

The brake control device 100 activates traction control (1010).

The brake control device 100 may detect wheel spin based on the speeds of the wheels 2a and 2b. If the wheel spin is greater than the reference spin, the braking control device 100 may activate traction control. While the traction control is activated, the drive torque or drive torque of the engine 11 is controlled based on the difference between the target spin and the wheel spin.

The braking control device 100 determines whether the moving acceleration of the vehicle 1 is smaller than the reference acceleration (1020).

The braking control device 100 may determine the moving acceleration of the vehicle 1 based on the output of the motion sensor 190 or the output of the wheel speed sensor 180 . The braking control device 100 may compare the moving acceleration of the vehicle 1 with a reference acceleration and identify whether the moving acceleration of the vehicle 1 is smaller than the reference acceleration.

Here, the reference acceleration represents the acceleration of the vehicle 1 corresponding to the driving torque of the engine 11 when the vehicle 1 runs on a road surface having a high friction coefficient, and may be experimentally or empirically set.

If the moving acceleration of the vehicle 1 is not smaller than the reference acceleration (No in 1020), the braking control device 100 maintains the target spin (1025).

If the moving acceleration of the vehicle 1 is greater than or equal to the reference acceleration, since the vehicle 1 is already traveling with sufficient acceleration, the braking control device 100 determines whether the vehicle 1 has entered a road surface having a high friction coefficient. There is no need to identify. Thus, the braking control device 100 maintains the target spin.

If the moving acceleration of the vehicle 1 is less than the reference acceleration (No in 1020), the braking control device 100 determines whether the spin of the wheels 2a and 2b is less than the first reference spin (1030).

The braking control device 100 compares the spin of the wheels 2a and 2b with a first reference spin in order to evaluate the driving stability of the vehicle 1 prior to the operation for estimating the friction coefficient of the road, and the wheel 2a, It can be identified whether the spin of 2b) is less than the first reference spin. Here, the first reference spin may be experimentally or empirically set.

If the spins of the wheels 2a and 2b are not smaller than the first reference spin (No in 1030), the braking control device 100 maintains the target spin (1025).

If the spin of the wheels 2a and 2b is greater than or equal to the first reference spin, the driving stability of the vehicle 1 may be reduced by the operation for estimating the friction coefficient of the road, so the braking control device 100 sets the target Spin can be maintained.

If the spin of the wheels 2a and 2b is smaller than the first reference spin (YES in 1030), the braking control device 100 determines whether the vehicle 1 is rotating in the right direction (1040).

The braking control device 100 may identify the rotation direction of the vehicle 1 based on the yaw rate output from the motion sensor 190 .

When the vehicle 1 rotates in the right direction (YES in 1040), the braking control device 100 applies braking torque to the left wheel (1050).

In order to prevent the driving of the vehicle 1 from becoming unstable due to the operation for estimating the friction coefficient of the road surface, the braking control device 100 applies braking torque to a wheel on the opposite side to the rotational direction of the vehicle 1. can Specifically, the braking control device 100 may supply a hydraulic pressure of approximately 10 bar to a wheel cylinder of a wheel opposite to the rotational direction of the vehicle 1 .

If the vehicle 1 does not rotate in the right direction (No in 1040), the braking control device 100 applies braking torque to the right wheel (1050).

The braking control device 100 may determine rotation in the left direction and may apply braking torque to a wheel opposite to the rotational direction of the vehicle 1 . Specifically, the braking control device 100 may supply a hydraulic pressure of approximately 10 bar to a wheel cylinder of a wheel opposite to the rotational direction of the vehicle 1 .

The braking control device 100 determines whether the reference time has elapsed after applying the braking torque to the wheel (1060), and if the reference time has not elapsed (No in 1060), determines whether the reference time has elapsed. Judge again.

The braking control device 100 may monitor a change in wheel spin for a reference time period after applying the braking torque to the wheel. Here, the reference time may be experimentally or empirically set.

The braking control device 100 determines whether the spin of the wheels 2a and 2b is smaller than the second reference spin (1070).

The braking control device 100 may estimate a change in the coefficient of friction of the road surface on which the vehicle 1 travels based on whether the spin of the wheels 2a and 2b is smaller than the second reference spin. For example, when wheel spin rapidly increases after partial braking, the braking control device 100 may identify that the vehicle 1 is driving on a road surface having a low friction coefficient. Also, if wheel spin does not increase or gradually increases after partial braking, the braking control device 100 may identify that the vehicle 1 is driving on a road surface having a high friction coefficient.

The braking control device 100 may determine whether the spin of the wheels 2a and 2b is less than the second reference spin in order to identify whether the spin of the wheel rapidly increases after partial braking. Here, the second reference spin may be set experimentally or empirically.

If the spin of the wheels 2a and 2b is not smaller than the second reference spin (No in 1070), the braking control device 100 maintains the target spin (1025).

When the spin of the wheels 2a and 2b is greater than or equal to the second reference spin, the braking control device 100 may identify that the vehicle 1 is running on a road surface having a low coefficient of friction. Accordingly, in order to prevent wheel spin, the braking control device 100 may maintain the target spin.

If the spins of the wheels 2a and 2b are smaller than the second reference spin (YES in 1070), the braking control device 100 increases the target spin (1080).

When the spins of the wheels 2a and 2b are smaller than the second reference spin, the braking control device 100 may identify that the vehicle 1 is running on a road surface having a high friction coefficient. Therefore, in order to improve the driving performance of the vehicle 1, the braking control device 100 may control the engine control module 12 to increase the target spin and increase the driving torque or driving torque of the engine 11. there is.

Accordingly, the braking control device 100 may allow the vehicle 1 to quickly move away from a road with a low coefficient of friction, such as an icy road. The brake control device 100 may cause the vehicle 1 to accelerate rapidly after leaving the road with a low friction coefficient.

Meanwhile, the disclosed embodiments may be implemented in the form of a recording medium storing instructions executable by a computer. Instructions may be stored in the form of program codes, and when executed by a processor, create program modules to perform operations of the disclosed embodiments. The recording medium may be implemented as a computer-readable recording medium.

As above, the disclosed embodiments have been described with reference to the accompanying drawings. Those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in a form different from the disclosed embodiments without changing the technical spirit or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

1: vehicle 2: wheel
10: drive system 10a: accelerator pedal
11: engine 12: engine control module
21: transmission 40: braking system
41: braking device 42: brake caliper
43: brake disc 44a, 44b: wheel cylinder
100: brake control device 101: brake pedal
103: reservoir 104: master cylinder
110: hydraulic circuit 111: main flow path
112: auxiliary flow path 113a, 113b: inlet valve
114a, 114b: outlet valve 117: hydraulic control unit
118: cut valve 120: control unit
121: processor 122: memory
123: can transceiver 130: brake pedal sensor
140: pressure sensor 150: drive motor
160: piston pump 161: cylinder
162: piston 170: valve block
180: wheel speed sensor 190: motion sensor

Claims (17)

A braking control device installed in a vehicle having a plurality of wheels,
a braking unit that applies braking torque to the plurality of wheels; and
A control unit electrically connected to the braking unit;
The control unit,
reducing drive torque for driving the plurality of wheels based on a comparison between spin of the plurality of wheels and a target spin;
Applying braking torque to any one of the plurality of wheels while reducing the driving torque;
A braking control device for increasing the driving torque based on a change in spin of another wheel positioned opposite to the one wheel. The method of claim 1, wherein the control unit,
Identifying the direction of rotation of the vehicle based on the output of a motion sensor installed in the vehicle;
Selecting one of the wheels based on the rotation direction of the vehicle;
A braking control device for applying braking torque to any one of the wheels. The method of claim 2, wherein the control unit,
A braking control device that increases the driving torque based on a change in spin of another wheel positioned opposite to the one wheel in response to a elapse of a reference time after applying the braking torque to the one wheel. . The method of claim 3, wherein the control unit,
The braking control device for maintaining the target spin when the spin of the other wheel is equal to or greater than the reference spin. The method of claim 3, wherein the control unit,
A braking control device for increasing the target spin when the spin of the other wheel is less than the reference spin. The method of claim 5, wherein the control unit,
A braking control device that increases the driving torque based on a comparison between the increased target spin and the spin of the plurality of wheels. The method of claim 1, wherein the control unit,
Identifying rotational speeds of the plurality of wheels based on outputs of wheel speed sensors installed in the vehicle;
A braking control device that identifies spins of the plurality of wheels based on rotational speeds of the plurality of wheels. In the control method of a braking device installed in a vehicle having a plurality of wheels,
reduce drive torque for driving the wheels based on a comparison between the spin of the plurality of wheels and a target spin;
applying a braking torque to any one of the plurality of wheels while reducing the driving torque;
and increasing the driving torque based on a change in spin of another wheel positioned opposite to the one wheel. The method of claim 8, wherein applying the braking torque to any one wheel,
identifying a rotational direction of the vehicle based on an output of a motion sensor installed in the vehicle;
select the one wheel based on the rotational direction of the vehicle;
A method of braking a vehicle comprising applying braking torque to any one of the wheels. 10. The method of claim 9, wherein increasing the driving torque,
In response to the elapse of a reference time after applying the braking torque to the one wheel, increasing the driving torque based on a change in spin of another wheel located opposite the one wheel Control method of brake system. The method of claim 10, wherein the control method,
and maintaining the target spin when the spin of the other wheel is equal to or greater than the reference spin. The method of claim 10, wherein the control method,
and increasing the target spin when the spin of the other wheel is less than the reference spin. The method of claim 12, wherein the control method,
and increasing the drive torque based on a comparison between the increased target spin and spins of the plurality of wheels. The method of claim 8, wherein the control method,
identifying rotational speeds of the plurality of wheels based on outputs of wheel speed sensors installed in the vehicle;
The method of controlling a braking device further comprising identifying spins of the plurality of wheels based on rotational speeds of the plurality of wheels. A braking control device installed in a vehicle having a plurality of wheels and a plurality of wheel cylinders corresponding to each of the plurality of wheels,
a piston pump supplying hydraulic pressure to the plurality of wheel cylinders to apply braking torque to the plurality of wheels;
a drive motor that drives the piston pump;
a passage extending from the piston pump to the wheel cylinder;
at least one valve opening the passage; and
A control unit electrically connected to the driving motor and the at least one valve,
The control unit,
Identify spins of the plurality of wheels based on outputs of wheel speed sensors installed in the plurality of wheels;
Control an engine control module of the vehicle to reduce a driving torque for driving the plurality of wheels based on a comparison between spin of the plurality of wheels and a target spin;
Controlling the driving motor and the at least one valve to apply braking torque to any one of the plurality of wheels while reducing the driving torque;
A braking control device for controlling an engine control module of the vehicle to increase the drive torque based on a change in spin of another wheel positioned opposite to the one wheel. The method of claim 15, wherein the control unit,
A braking control device for increasing the target spin when the spin of another wheel positioned opposite to the one wheel is less than the reference spin in response to the elapse of a reference time after applying the braking torque to the one wheel. . The method of claim 15, wherein the control unit,
A braking control device that maintains the target spin when the spin of another wheel positioned opposite to the one wheel is equal to or greater than the reference spin in response to the elapse of a reference time after applying the braking torque to the at least one wheel. .

Images