KR20230039075A - Brake control apparatus and control method of brake apparatus - Google Patents

Abstract

A brake control device installed in a vehicle having a plurality of wheels comprises: a brake driving unit applying brake torque to the plurality of wheels; and a control unit electrically connected to the brake device. The control unit controls the brake device to apply the brake torque to at least one wheel by responding to a spin of at least one wheel among the plurality of wheels, reduces the brake torque applied to at least one wheel by responding to identification of hopping, and gradationally or linearly increases the brake torque applied to at least one wheel by responding to suspension of the hopping.

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. The vehicle's traction control system controls the drive torque provided to the wheels to prevent wheel spin.

In particular, 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, in the prior art, when braking and traction control is performed to improve the traction force of the vehicle, the vehicle vibrates greatly due to the periodic change in the rotational speed of the wheel. As such, the vibration of the vehicle due to the resonance of the vehicle is referred to as hopping.

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 minimizing hopping by braking traction control.

According to an aspect of the disclosed subject matter, a braking control device installed in a vehicle having a plurality of wheels includes a braking driving unit for applying braking torque to the plurality of wheels; and a controller electrically connected to the braking device, wherein the controller controls the braking device to apply braking torque to the at least one wheel in response to spin of at least one wheel among the plurality of wheels; In response to hopping being identified, the braking torque applied to the at least one wheel is reduced, and in response to the hopping being stopped, the braking torque applied to the at least one wheel is increased stepwise or linearly. can

According to an aspect of the disclosed subject matter, a control method of a braking device installed in a vehicle having a plurality of wheels includes applying a braking torque to at least one wheel in response to spin of at least one wheel among the plurality of wheels; in response to the hopping being identified, reducing the braking torque applied to the at least one wheel; In response to the stopping of the hopping, the braking torque applied to the at least one wheel may be increased stepwise or linearly.

According to one aspect of the disclosed invention, a braking control device installed in a vehicle having a plurality of wheels includes a piston pump including a cylinder and a piston; a drive motor that moves the piston to generate hydraulic pressure; and a control unit electrically connected to the drive motor, wherein the control unit adjusts the hydraulic pressure of the piston pump to apply braking torque to the at least one wheel in response to spin of at least one of the plurality of wheels. and, in response to identifying hopping, controlling the drive motor to cause the piston pump to reduce hydraulic pressure to reduce braking torque applied to the at least one wheel, wherein the hopping is In response to being stopped, the drive motor may be controlled such that the piston pump increases the hydraulic pressure to stepwise or linearly increase the braking torque applied to the at least one wheel.

According to an aspect of the disclosed invention, a braking control device capable of minimizing hopping by brake traction control and a control method of the braking device may be provided.

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 speed, hopping, and brake pressure by operation of a brake control device according to an embodiment.
5 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 (or 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.

2 shows a hydraulic circuit of a braking control device according to an embodiment.

Referring to FIG. 2, the braking control device 100 includes a brake pedal 101 that accepts a driver's braking intention, a reservoir 103 that stores a pressurized medium (eg, brake oil, etc.), and a brake pedal ( Master cylinder 104 that generates hydraulic pressure by the movement of 101, piston pump 160 that generates hydraulic pressure in response to detecting the movement of the brake pedal 101, and driving that drives the piston pump 160 and a hydraulic circuit 110 connecting the motor 150 and the master cylinder 104 and/or piston pump 160 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.

In 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. 1 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 ABS and/or ESC and/or BTCS described above.

3 shows a control block of a braking control device according to an embodiment. 4 illustrates wheel speed, hopping, and brake pressure by operation of a brake control device according to an embodiment.

As shown in FIG. 3 , the braking control device vehicle 1 includes a brake pedal sensor 130 that detects the motion of the brake pedal 101 and a wheel speed sensor 180 that detects the rotational speed of the wheel 2. ) and a motion sensor 190 for detecting the movement of the vehicle 1 are 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 provides 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 that control the drive motor 150 and the valve block 170 to provide hydraulic pressure to the wheel cylinders 44a and 44b depending on the driver's braking intention. can be saved In addition, the memory 122 provides 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 may occur while the vehicle 1 is starting or driving 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 may occur while the vehicle 1 is starting or driving on a road having a non-uniform 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 control unit 120 controls the wheel 2 based on the difference in rotational speed between the wheels (eg, the difference in rotational speed between the driving wheel and the driven wheel or the difference in rotational speed between the left wheel and the right wheel). can detect the spin of When detecting a spin of the wheel equal to or greater than the target spin, the controller 120 may control driving torque and braking torque provided to the wheel 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 provided. In particular, when detecting spin of either the left wheel or the right wheel, the controller 120 may provide braking torque to the spin-detected wheel in order to balance driving torque between the left wheel and the right wheel.

During brake traction control, the rotational speeds of the wheels 2a and 2b may change periodically. For example, when the wheel spin changes near the target spin, the braking control device 100 may periodically apply braking torque to the wheels 2a and 2b based on the comparison between the wheel spin and the target spin. Therefore, the rotation speed of the wheels 2a and 2b can be changed at a constant cycle. In addition, wheel spin occurs periodically due to the braking torque applied to the wheels 2a and 2b by the braking control device 100, and as a result, the rotational speed of the wheels 2a and 2b may periodically change.

At this time, if the period in which the rotational speeds of the wheels 2a and 2b change substantially coincides with the natural vibration period of the vehicle 1, the vehicle 1 may vibrate greatly due to resonance. This vibration of the vehicle 1 is referred to as hopping.

Such hopping is caused by an interaction between the driving system 10, the braking system 40, the suspension system, and the road surface of the vehicle 1, and continues for a short time, causing discomfort and anxiety to the driver. In particular, if the vehicle 1 vibrates at a frequency of approximately 6 to 8 Hz (hertz), the driver may sense the hopping of the vehicle 1 and may feel uneasy.

The controller 120 may identify hopping of the vehicle 1 based on the output of the wheel speed sensor 180 . If the frequency of change in the speed of the wheels 2a and 2b detected by the wheel speed sensor 180 is within a predetermined range of frequencies and the magnitude of change in the speed of the wheels 2a and 2b is greater than or equal to a predetermined amplitude, the controller ( 120) may identify hopping. For example, when the speed of the wheels 2a and 2b changes with a frequency between approximately 6 and 8 Hz (hertz) and changes with an amplitude between approximately 5 kph (km per hour) and 10 kph, the controller 120 controls the vehicle 1 ) can be identified.

For example, as shown in FIG. and based on which the spin of the wheels 2a, 2b can be identified. The controller 120 may apply braking torque to the wheels 2a and 2b in response to detecting spin of the wheels 2a and 2b. Specifically, the controller 120 may supply braking pressure to the wheel cylinders 44a and 44b at time t0 as shown in (c) of FIG. 4 . Due to the braking torque, the spin of the wheels 2a and 2b can be reduced.

Thereafter, while the spin of the wheels 2a and 2b is reduced, the rotation speeds of the wheels 2a and 2b may periodically change as shown in FIG. 4(a). The control unit 120 may detect the rotation speed of the wheels 2a and 2b that is periodically converted through the wheel speed sensor 180, and based on the periodic change in the rotation speed of the wheels 2a and 2b, the rotation speed of FIG. As shown in (b), hopping can be identified at time t1. Specifically, when the rotational speed change frequency of the wheels 2a and 2b is between about 6Hz and 8Hz and the rotational speed change amplitude is between about 5kph and 10kph, the controller 120 can identify hopping.

When hopping is identified, the control unit 120 can stop the rotational speed of the wheels 2a and 2b from changing periodically. For example, the control unit 120 may decrease or increase the braking torque applied to the wheels 2a and 2b for braking traction control. However, since the traction force of the vehicle 1 may rather decrease due to an increase in the braking torque applied to the wheels 2a and 2b, the control unit 120 may reduce the braking torque applied to the wheels 2a and 2b. there is.

In response to identifying hopping, the controller 120 may reduce the braking torque at time t1 as shown in (c) of FIG. 4 .

The controller 120 may reduce the braking torque at a predetermined ratio in response to identifying the hopping. For example, the controller 120 may apply the reduced braking torque to the wheels 2a and 2b using [Equation 1].

[Equation 1]

Here, BT_hopping represents braking torque in response to identification of hopping, BT_normal represents braking torque due to wheel spin, and α may represent a reduction factor of braking torque due to identification of hopping. α may be a real number less than “1” and greater than “0”.

In addition, the controller 120 may reduce the braking torque by a predetermined amount in response to identifying the hopping.

By reducing the braking torque applied to the wheels 2a and 2b, the frequency at which the rotational speeds of the wheels 2a and 2b oscillate can be changed. As a result, the frequency at which the rotational speed of the wheels 2a and 2b changes deviates from the natural vibration frequency of the vehicle 1, and the vibration of the vehicle 1 can be reduced.

For example, as shown in (a) of FIG. 4, after time t2, the magnitude of change in the rotation speed of the wheels 2a and 2b may decrease, and the control unit 120 may reduce As such, it can be identified that hopping is stopped at time t2.

In response to identifying that hopping is stopped, the controller 120 may gradually or linearly restore the braking torque reduced due to the detection of hopping. For example, as shown in (c) of FIG. 4 , between time t2 and time t3, the control unit 120 increases the braking torque from a value reduced due to the detection of hopping to a value corresponding to wheel spin in a stepwise or linear manner between time t2 and time t3. can be incrementally increased.

The control unit 120 may increase the braking torque stepwise or linearly using [Equation 2].

[Equation 2]

Here, BT_after_hopping represents braking torque after hopping is stopped, BT_normal represents braking torque due to wheel spin, and α may represent a braking torque reduction factor due to identification of hopping. α may be a real number less than “1” and greater than “0”. t_after_hopping may indicate a time elapsed after hopping is stopped, and t_reference may indicate a reference transition time for restoring braking torque after hopping is stopped.

According to [Equation 2], when the time t_after_hopping that has elapsed since hopping is stopped is “0”, the braking torque BT_after_hopping is BT_normal*α, and the time that has elapsed since hopping is stopped t_after_hopping reaches the reference transition time t_reference, braking Torque BT_after_hopping becomes BT_normal. In other words, the braking torque may linearly increase during the reference transition time t_reference.

In this way, by recovering the braking torque reduced due to the identification of hopping stepwise or linearly to the braking torque in response to the wheel spin, the stability of the vehicle 1 is secured and the driver feels a sense of heterogeneity with respect to the braking of the vehicle 1. this can be minimized.

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

Together with FIG. 5 , an operation 1000 of the braking control device 100 according to operating conditions is described.

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

The braking control device 100 may detect wheel spin based on the output of the wheel speed sensor 180 . If wheel spin is greater than the reference spin, the brake control device 100 may activate brake traction control.

The braking control device 100 applies braking torque to the wheels 2a and 2b according to wheel spin (1020).

While the braking traction control is activated, the braking control device 100 may apply braking torque to the wheels 2a and 2b in which the wheel spin is detected based on the difference between the target spin and the wheel spin. For example, the braking control device 100 may determine the braking torque corresponding to the wheel spin exceeding the target spin, determine the hydraulic pressure of the wheel cylinders 44a and 44b corresponding to the determined braking torque, and determine the braking torque. It is possible to determine the displacement of the piston 162 of the piston pump 160 for generating the hydraulic pressure.

The braking control device 100 may control the driving motor 150 to move the piston 162 of the piston pump 160, thereby applying braking torque to the wheels 2a and 2b.

The braking control device 100 determines whether hopping is detected (1030).

During brake traction control, the rotational speeds of the wheels 2a and 2b may change periodically. At this time, if the period in which the rotational speeds of the wheels 2a and 2b change substantially coincides with the natural vibration period of the vehicle 1, the vehicle 1 may vibrate greatly due to resonance. This vibration of the vehicle 1 is referred to as hopping.

The controller 120 may identify hopping of the vehicle 1 based on the output of the wheel speed sensor 180 . If the frequency of change in the speed of the wheels 2a and 2b detected by the wheel speed sensor 180 is within a predetermined range of frequencies and the magnitude of change in the speed of the wheels 2a and 2b is greater than or equal to a predetermined amplitude, the controller ( 120) may identify hopping.

When hopping is detected (YES in 1030), the braking control device 100 applies the reduced braking torque to the wheels 2a and 2b (1040).

If hopping is identified, the braking control device 100 may reduce the braking torque applied to the wheels 2a, 2b in order to stop the rotational speed of the wheels 2a, 2b from changing periodically. For example, the braking control device 100 may reduce the braking torque at a predetermined ratio α.

By reducing the braking torque applied to the wheels 2a and 2b, the frequency at which the rotational speed of the wheels 2a and 2b oscillates is changed, whereby the vibration of the vehicle 1 can be reduced.

If hopping is not detected (No in 1030), the braking control device 100 determines whether the time elapsed after hopping is stopped is less than the reference time (1050).

The braking control device 100 may include a counter and count the time elapsed since hopping is stopped based on the output of the counter.

The braking control device 100 compares the time counted after hopping is stopped (t_after_hopping) with a reference time (t_reference), and determines whether the counted time (t_after_hopping) after hopping is stopped is smaller than the reference time (t_reference). can be identified.

If the time elapsed after hopping is stopped is less than the reference time (YES in 1050), the braking control device 100 increases the braking torque reduced due to the detection of hopping according to the time elapsed after hopping is stopped (1060). ).

In response to identifying that hopping has stopped, the brake control device 100 may step-wise or linearly increase the brake torque reduced due to the detection of hopping. For example, the braking control device 100 may linearly increase the braking torque in proportion to the elapsed time after hopping is stopped.

The braking control device 100 may increase the braking torque so that the braking torque when the time elapsed after the hopping stops reaches the reference time reaches the braking torque due to wheel spin.

If the time elapsed after hopping is stopped is less than the reference time (No in 1050), the braking control device 100 applies braking torque due to wheel spin to the wheels 2a and 2b (1070).

When the time elapsed after hopping is stopped reaches the reference time, the braking control device 100 applies braking torque corresponding to wheel spin detected by the output of the wheel speed sensor 180 to the wheels 2a and 2b. can do.

In this way, the braking control device 100 secures the stability of the vehicle 1 and secures the vehicle 1 by recovering the braking torque reduced due to the identification of hopping stepwise or linearly to the braking torque in response to wheel spin. It is possible to minimize the sense of difference felt by the driver regarding the braking of the vehicle.

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 3
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 (11)

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,
Controlling the braking unit to apply braking torque to the at least one wheel in response to spin of at least one of the plurality of wheels;
in response to the hopping being identified, reducing the braking torque applied to the at least one wheel;
A braking control device for stepwise or linearly increasing the braking torque applied to the at least one wheel in response to the stopping of the hopping. The method of claim 1, wherein the control unit,
A brake control device that identifies the hopping based on vibration and a frequency of a change in rotational speed of the at least one wheel. The method of claim 2, wherein the control unit,
Based on the frequency of change in the rotational speed of the at least one wheel being between 6Hz (Hertz) and 8Hz and the amplitude of the change in the rotational speed of the at least one wheel being between 5kph (km per hour) and 10kph, the hopping A braking control device that identifies the The method of claim 1, wherein the control unit,
A brake control device that, in response to the hopping being identified, reduces the braking torque applied to the at least one wheel by a predetermined ratio. The method of claim 1, wherein the control unit,
In response to the hopping being stopped, the braking control device increases the braking torque reduced due to the detection of the hopping in proportion to a time elapsed after the hopping is stopped. In the control method of a braking device installed in a vehicle having a plurality of wheels,
in response to spin of at least one wheel of the plurality of wheels, apply a braking torque to the at least one wheel;
in response to the hopping being identified, reducing the braking torque applied to the at least one wheel;
and stepwise or linearly increasing the braking torque applied to the at least one wheel in response to the stopping of the hopping. The method of claim 6, wherein the braking method,
and identifying the hopping based on a frequency and vibration of a change in rotational speed of the at least one wheel. 8. The method of claim 7, wherein identifying the hopping comprises:
Based on the frequency of change in the rotational speed of the at least one wheel being between 6Hz (Hertz) and 8Hz and the amplitude of the change in the rotational speed of the at least one wheel being between 5kph (km per hour) and 10kph, the hopping A control method of a braking device further comprising identifying a. The method of claim 6, wherein reducing the braking torque comprises:
and in response to the hopping being identified, reducing the braking torque applied to the at least one wheel by a predetermined ratio. The method of claim 6, wherein increasing the braking torque comprises:
and increasing braking torque reduced due to the detection of the hopping in proportion to a time elapsed after the hopping is stopped, in response to the hopping being stopped. A braking control device installed in a vehicle having a plurality of wheels,
A piston pump comprising a cylinder and a piston;
a drive motor that moves the piston to generate hydraulic pressure; and
A control unit electrically connected to the driving motor;
The control unit,
In response to spin of at least one of the plurality of wheels, control the drive motor so that the piston pump generates hydraulic pressure to apply a braking torque to the at least one wheel;
in response to hopping being identified, controlling the drive motor to cause the piston pump to reduce hydraulic pressure to reduce braking torque applied to the at least one wheel;
responsive to the stopping of the hopping, the brake control device controls the drive motor so that the piston pump increases the hydraulic pressure to stepwise or linearly increase the braking torque applied to the at least one wheel.

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