KR20110108919A - Method for regenerative braking and regenerative braking employing the same - Google Patents

Abstract

The present invention relates to a regenerative braking device and a regenerative braking method using the same, in particular, calculating a target braking force based on a brake signal generated by manipulating the brake, and front wheel friction until the difference between the target braking force and the maximum regenerative braking force is reached. A regenerative braking apparatus for selectively performing braking and rear wheel friction braking and a regenerative braking method using the same.

Description

Regenerative braking device and regenerative braking method using same {METHOD FOR REGENERATIVE BRAKING AND REGENERATIVE BRAKING EMPLOYING THE SAME}

The present invention relates to a regenerative braking device and a regenerative braking method using the same, in particular, calculating a target braking force based on a brake signal generated by manipulating the brake, and front wheel friction until the difference between the target braking force and the maximum regenerative braking force is reached. A regenerative braking apparatus for selectively performing braking and rear wheel friction braking and a regenerative braking method using the same.

Due to the depletion of fossil fuels and the deepening of environmental pollution, research on renewable energy that can replace or reduce fossil fuels is ongoing.

For example, four-wheeled vehicles, ie automobiles, use alternative power sources in addition to traditional internal combustion engines as power sources for automobiles to reduce environmental pollution by exhaust gas and to cope with limited petroleum resources. Attempts are being made.

Specifically, there are a hybrid electric vehicle (HEV) and an electric vehicle (EV). In the case of HEV and EV, it is a vehicle which improved fuel efficiency by mixing internal combustion engine and an electric motor efficiently and driving them efficiently.

HEVs and EVs use a portion of the braking force for power generation during braking to use the generated electrical energy to charge the battery. That is, by using a part of the kinetic energy due to the driving speed of the vehicle as the energy required for driving the generator, the reduction of the kinetic energy (that is, the reduction of the running speed) and the generation of the electric energy are simultaneously implemented. This method of braking is called regenerative braking.

However, when the regenerative braking is to be used, it is disadvantageous to perform braking after determining the state of charge of the battery, the driving speed of the vehicle, the temperature state of the battery and the driving motor, and the like. If braking is performed when the target braking force is not met, the driving motor or the battery may be damaged.

As another example, in the case of a two-wheeled vehicle, that is, an electric bicycle, a product equipped with a regenerative charging function capable of charging a battery by switching a driving motor to a generator while driving has been released. However, the bicycle not only has a lower driving safety than a vehicle, but also requires the driver's skilled operation and is designed to directly distribute the front and rear wheel braking force during braking.

Therefore, when the regenerative braking is to be performed on the electric bicycle, the energy recovery rate according to the regenerative charging is also important, but it is important to safely distribute the front and rear wheel braking force during braking and to brake safely.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and calculates a target braking force based on a brake signal generated by manipulating the brake, and performs front wheel friction braking and rear wheel friction braking until the difference between the target braking force and the maximum regenerative braking force is reached. It is an object of the present invention to provide a regenerative braking apparatus and a regenerative braking method using the same.

The regenerative braking method according to the present invention includes the steps of: (a) generating a brake signal corresponding to the operation of the brake; (b) calculating a target braking force based on the brake signal; (c) calculating regenerative braking force to perform regenerative braking; (d) if the maximum regenerative braking force is less than the target braking force, performing rear wheel friction braking while increasing the rear wheel friction braking force until reaching a first value; (e) when the rear wheel friction braking force reaches the first value, performing front wheel friction braking while increasing the front wheel friction braking force until the second value is reached; And (f) step (d) until the accumulated rear wheel braking force and the front wheel friction braking force by performing steps (d) and (e) reach a difference between the maximum regenerative braking force and the target braking force. And repeating step (e).

Step (c) according to the present invention includes the steps of: (c-1) sensing the temperature and charge state of the battery and the temperature and rotational speed of the motor; (c-2) calculating the maximum regenerative braking force based on the sensed temperature and state of charge of the battery and the temperature and rotation speed of the motor; And (c-3) performing the regenerative braking.

In the present invention, in the case where the maximum regenerative braking force is obtained from the rear wheel, each of the steps (d) to (f) includes the rear wheel friction braking coefficient and the front wheel friction braking coefficient obtained from Equations 1 and 2, respectively. And performing the rear wheel friction braking and the front wheel friction braking until the first value and the second value are reached.

[Equation 1]

[Equation 2]

Further, in the present invention, when the maximum regenerative braking force is obtained from the front wheels, the steps (d) to (f) are each of the rear wheel friction braking coefficients and the front wheel friction braking obtained from Equations 3 and 4, respectively. Preferably performing the rear wheel friction braking and the front wheel friction braking until a coefficient reaches the first value and the second value.

&Quot; (3) "

&Quot; (4) "

Preferably, the first value and the second value may be 40% and 60%, respectively.

The regenerative braking device according to the present invention includes a brake; A front wheel friction braking module for generating a front wheel friction braking force; A rear wheel friction braking module for generating a rear wheel friction braking force; And control means for calculating a target braking force based on the brake signal generated corresponding to the operation of the brake, and controlling the front wheel friction braking module and the rear wheel friction braking module, wherein the control means includes the rear wheel friction braking and Selectively performing the rear wheel friction braking and the front wheel friction braking until the rear wheel friction braking force and the front wheel friction braking force accumulated by performing the front wheel friction braking reach a difference between the maximum regenerative braking force and the target braking force. do.

The control means according to the present invention includes a sensor unit for generating a status signal by sensing the temperature and charge state of the battery and the temperature and the number of rotation of the motor; And an MCU configured to calculate the target braking force and the maximum regenerative braking force, respectively, based on the brake signal and the state signal.

Further, when the maximum regenerative braking force is smaller than the target braking force, the control means performs the rear wheel friction braking until the rear wheel friction braking force reaches a first value, and the rear wheel friction braking force reaches the first value. The front wheel friction braking may be performed until the front wheel friction braking force reaches a second value, and the first value and the second value may be 40% and 60%, respectively.

The brake according to the invention, the brake lever; A permanent magnet attached to the brake lever; And a hall sensor configured to generate the brake signal by sensing a magnetic field that is changed by the permanent magnet.

The regenerative braking apparatus according to the present invention calculates a target braking force based on a brake signal generated by operating a brake, and when braking is started, performs regenerative braking to maximize the energy recovery rate and reaches a difference between the target braking force and the maximum regenerative braking force. There is an advantage that the braking can be safely performed by selectively performing the front wheel friction braking and the rear wheel friction braking.

1 is a flowchart illustrating a regenerative braking method using a regenerative braking apparatus according to the present invention.
Figure 2 is a block diagram showing a regenerative braking apparatus according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention;

The regenerative braking method using the regenerative braking apparatus according to the present invention is a method performed by a driver, for example, to perform braking of a vehicle in motion. Therefore, the regenerative braking method using the regenerative braking apparatus according to the present invention described below is a process performed after the driver operates the brake for braking the vehicle.

1 is a flowchart illustrating a regenerative braking method using a regenerative braking apparatus according to the present invention.

Referring to FIG. 1, a brake signal corresponding to an operation of the brake is generated (S100).

For example, the brake signal is generated in proportion to the operational displacement of the brake operated by the driver. That is, if the brake is operated harder, the operation displacement of the brake is increased, and thus a larger brake signal is generated. If the brake is operated smaller, the brake operation signal is smaller.

Next, a target braking force is calculated based on the brake signal (S110). The control means receives the brake signal from the brake and calculates the target braking force. Specifically, since the brake signal is generated in proportion to the operating displacement of the brake, the brake signal can be the basis for calculating the target braking force required for braking the vehicle.

Next, the maximum possible regenerative braking force is calculated and regenerative braking is performed (S120). The control means generates a status signal by sensing the temperature and charge state of the battery and the temperature and rotation speed of the motor. The control means may calculate the maximum regenerative braking force that can be generated from the vehicle from the state signal.

When the brake is operated by the driver and braking is started, the motor generates counter electromotive force. That is, the control means controls the motor to perform regenerative braking, and controls to charge the battery by DC / DC conversion of back EMF generated from the motor during regenerative braking. The regenerative braking force is generated by the front wheels when the motor drives the front wheels, and the regenerative braking force is generated by the rear wheels when the motor drives the rear wheels.

Next, the control means compares the maximum regenerative braking force and the target braking force calculated in the step S120 (S130).

If the maximum regenerative braking force is greater than or equal to the target braking force, the vehicle can be braked only by regenerative braking, and the control means controls the motor to brake the vehicle only by the regenerative braking performed in step S120.

However, if the maximum regenerative braking force is less than the target braking force, the braking of the vehicle is impossible by the regenerative braking alone, so that the control means controls the rear wheel friction braking module and the front wheel friction braking module to perform rear wheel friction braking and rear wheel friction braking.

Specifically, the control means controls the rear wheel friction braking module to perform rear wheel friction braking (S140).

Next, the control means compares the sum of the rear wheel friction braking force generated by performing the rear wheel friction braking in step S140 and the maximum regenerative braking force calculated in step S120 and the target braking force (S150).

If the sum of the rear wheel friction braking force and the maximum regenerative braking force is greater than or equal to the target braking force, the vehicle may be braked only by the rear wheel friction braking and the regenerative braking. Thus, the control means performs the rear wheel friction braking to brake the vehicle.

However, if the sum of the rear wheel friction braking force and the maximum regenerative braking force is less than the target braking force, the control means obtains the rear wheel friction braking coefficient from Equation 1 or Equation 3 below.

The rear wheel friction braking coefficient serves as a criterion for determining whether to switch from rear wheel friction braking to front wheel friction braking.

Specifically, the control means obtains the rear wheel friction braking coefficient from Equation 1 or 3 below and compares the rear wheel friction braking coefficient with the first value (S160). Preferably, the first value may be 30-50%, more preferably 40%.

[Equation 1]

&Quot; (3) "

Preferably, Equation 1 is to calculate the rear wheel friction braking coefficient when the maximum regenerative braking force is generated in the rear wheel, Equation 3 is to calculate the rear wheel friction braking coefficient when the maximum regenerative braking force is generated in the front wheel To find.

If the rear wheel friction braking coefficient is smaller than the first value, the control means increases the rear wheel friction braking force (S165).

That is, the control means controls the rear wheel friction braking module to perform the rear wheel friction braking with the increased rear wheel friction braking force (S140), and compares the sum of the accumulated rear wheel friction braking force and the maximum regenerative braking force with the target braking force. (S150).

When the sum of the accumulated rear wheel friction braking force and the maximum regenerative braking force is greater than or equal to the target braking force, the control means performs the rear wheel friction braking to brake the vehicle.

However, when the sum of the accumulated rear wheel friction braking force and the maximum regenerative braking force is smaller than the target braking force, the control means obtains the rear wheel friction braking coefficient based on Equation 1 or 3 below from the accumulated rear wheel friction braking force. It calculates and compares the rear wheel friction braking coefficient and the first value (S160).

If the rear wheel friction braking coefficient is greater than or equal to the first value, the control means stops the rear wheel friction braking and performs front wheel friction braking, and if the rear wheel friction braking coefficient is less than the first value, the rear wheel friction braking The process, that is, the steps S140 to S165 are repeated until the coefficient reaches the first value. That is, the reference for switching from the rear wheel friction braking to the front wheel friction braking is the rear wheel friction braking coefficient.

In addition, the control means controls to charge the battery by DC / DC conversion of the counter electromotive force generated in the motor during the rear wheel friction braking.

If the rear wheel friction braking coefficient is greater than or equal to the first value, the control means stops the rear wheel friction braking and performs front wheel friction braking (S170).

The control means includes a sum of the front wheel friction braking force generated by performing the front wheel friction braking in step S170, the rear wheel friction braking force accumulated by performing the rear wheel friction braking in step S140, and the maximum regenerative braking force calculated in step S120. The target braking force is compared (S180).

If the sum of the front wheel friction braking force, the accumulated rear wheel friction braking force and the maximum regenerative braking force is greater than or equal to the target braking force, the front wheel friction braking, the rear wheel friction braking and the regenerative braking may be performed by the vehicle. Thus, the control means performs the front wheel friction braking to brake the vehicle.

However, if the sum of the front wheel friction braking force, the accumulated rear wheel friction braking force and the maximum regenerative braking force is smaller than the target braking force, the control means obtains the front wheel friction braking coefficient from the following equation (2) or (4).

The front wheel friction braking coefficient is a criterion for determining whether to switch from front wheel friction braking to rear wheel friction braking.

Specifically, the control means obtains the front wheel friction braking coefficient from Equation 2 or 4 below and compares the front wheel friction braking coefficient with a second value (S190). Preferably, the second value may be 50 to 70%, more preferably 60%.

[Equation 2]

&Quot; (4) "

Preferably, Equation 2 is to calculate the front wheel friction braking coefficient when the maximum regenerative braking force is generated in the rear wheel, Equation 4 is to calculate the front wheel friction braking coefficient when the maximum regenerative braking force is generated in the front wheel To find.

When the front wheel friction braking coefficient is smaller than the second value, the control means increases the front wheel friction braking force (S195).

That is, the control means controls the front wheel friction braking module to perform the front wheel friction braking with the increased front wheel friction braking force (S170), and the accumulated front wheel friction braking force, the accumulated rear wheel friction braking force, and the maximum regenerative braking force. Is compared with the target braking force (S180).

When the sum of the accumulated front wheel friction braking force, the accumulated rear wheel friction braking force and the maximum regenerative braking force is greater than or equal to the target braking force, the control means performs the front wheel friction braking to brake the vehicle.

However, when the sum of the accumulated front wheel friction braking force, the accumulated rear wheel friction braking force, and the maximum regenerative braking force is smaller than the target braking force, the control means is based on Equation 2 or 4 from the accumulated front wheel friction braking force. The front wheel friction braking coefficient is obtained, the front wheel friction braking coefficient is obtained, and the front wheel friction braking coefficient is compared with the second value (S190).

If the front wheel friction braking coefficient is greater than or equal to the second value, the control means stops the front wheel friction braking and returns to step S140 to perform rear wheel friction braking, wherein the front wheel friction braking coefficient is greater than the second value. If small, the process, that is, steps S170 to S190 are repeated until the front wheel friction braking coefficient reaches the second value. That is, the criterion for switching from the front wheel friction braking to the rear wheel friction braking is the front wheel friction braking coefficient.

Further, the control means controls to charge the battery by DC / DC conversion of the counter electromotive force generated in the motor during the front wheel friction braking.

Hereinafter, a process of performing the rear wheel friction braking and the front wheel friction braking while inserting a numerical value directly into an equation for convenience of understanding will be described with reference to FIG. 1. It is assumed that the maximum regenerative braking force is generated in the rear wheel, the rear wheel regenerative braking force generated in the rear wheel is 1, the target braking force is 10, and the rear wheel friction braking force and the front wheel friction braking force are constantly increased by one. At this time, it is assumed that there is no change in the regenerative braking force generated in the rear wheel during rear wheel friction braking and front wheel friction braking.

The control means performs the rear wheel friction braking to generate the rear wheel friction braking force by one (S140).

When the sum of the generated rear wheel friction braking force and the rear wheel regenerative braking force is compared with the target braking force (S150), the sum (2) of the rear wheel friction braking force (1) and the rear wheel regenerative braking force (1) generated is smaller than the target braking force (10). Therefore, according to Equation 1, the rear wheel friction braking coefficient can be obtained as follows.

When the rear wheel friction braking coefficient is compared with the first value (S160), the rear wheel friction braking coefficient is 100%, which is greater than the first value of 40%, and the control means stops the rear wheel friction braking and performs front wheel friction braking. To perform.

The control means performs the front wheel friction braking to generate the front wheel friction braking force by one (S170).

When the sum of the generated front wheel friction braking force, the generated rear wheel friction braking force and the rear wheel regenerative braking force is compared with the target braking force (S180), the generated front wheel friction braking force (1), the generated rear wheel friction braking force (1) and the rear wheel regenerative braking force (1) Since the sum 3 is smaller than the target braking force 10, the front wheel friction braking coefficient can be obtained as follows.

Comparing the front wheel friction braking coefficient with the second value (S190), the front wheel friction braking coefficient is 33.3%, which is less than the second value, 60%, so that the control means increases the front wheel friction braking force to 2 (S195). ) Front wheel friction braking is performed (S170).

Comparing the accumulated front wheel friction braking force, the generated rear wheel friction braking force and the rear wheel regenerative braking force with the target braking force (S180), the accumulated front wheel friction braking force (3), the generated rear wheel friction braking force (1) and the rear wheel regenerative braking force ( Since the sum 5 of 1) is smaller than the target braking force 10, the front wheel friction braking coefficient can be obtained as follows.

When the front wheel friction braking coefficient is compared with the second value (S190), the front wheel friction braking coefficient is 60%, which is the same as the second value 60%, and the control means stops the front wheel friction braking, and again the rear wheel friction braking. Do this.

The control means generates the rear wheel friction braking force by performing the rear wheel friction braking (S140).

When the sum of the accumulated rear wheel friction braking force, the accumulated front wheel friction braking force and the rear wheel regenerative braking force is compared with the target braking force (S180), the accumulated rear wheel friction braking force (2), the accumulated front wheel friction braking force (3) and the rear wheel regeneration Since the sum 6 of the braking forces 1 is smaller than the target braking force 10, the rear wheel friction braking coefficient can be obtained as follows.

When the rear wheel friction braking coefficient is compared with the first value (S160), the rear wheel friction braking coefficient is 50%, which is greater than the first value of 40%, so that the control means stops the rear wheel friction braking and performs front wheel friction braking. To perform.

The control means performs the front wheel friction braking to generate the front wheel friction braking force by two (S170).

When the sum of the accumulated front wheel friction braking force, the accumulated rear wheel friction braking force and the rear wheel regenerative braking force is compared with the target braking force (S180), the accumulated front wheel friction braking force (5), the accumulated rear wheel friction braking force (2) and the rear wheel regeneration Since the sum 8 of the braking forces 1 is smaller than the target braking force 10, the front wheel friction braking coefficient can be obtained as follows.

When the front wheel friction braking coefficient is compared with the second value (S190), the front wheel friction braking coefficient is 62.5%, which is greater than the second value, 60%, so that the control means stops the front wheel friction braking, and again the rear wheel friction braking. Do this.

The control means performs the rear wheel friction braking to generate the rear wheel friction braking force by one (S140).

Comparing the sum of the accumulated rear wheel friction braking force, the accumulated front wheel friction braking force and the rear wheel regenerative braking force with the target braking force (S180), the accumulated rear wheel friction braking force (3), the accumulated front wheel friction braking force (5) and the rear wheel regeneration Since the sum 9 of the braking force 1 is smaller than the target braking force 10, the rear wheel friction braking coefficient can be obtained as follows.

When the rear wheel friction braking coefficient is compared with the first value (S160), the rear wheel friction braking coefficient is 44.4%, which is greater than the first value of 40%, and the control means stops the rear wheel friction braking and performs front wheel friction braking. To perform.

The control means performs the front wheel friction braking to generate the front wheel friction braking force by two (S170).

When the sum of the accumulated front wheel friction braking force, the accumulated rear wheel friction braking force and the rear wheel regenerative braking force is compared with the target braking force (S180), the accumulated front wheel friction braking force (7), the accumulated rear wheel friction braking force (3) and the rear wheel regeneration Since the sum 11 of the braking force 1 is greater than the target braking force 10, the control means performs braking of the vehicle by front wheel friction braking.

Hereinafter, the regenerative braking apparatus according to the present invention will be described in detail.

2 is a block diagram showing a regenerative braking apparatus according to the present invention.

As shown in FIG. 2, the regenerative braking apparatus according to the present invention includes a brake 100, a front wheel friction braking module 200, a rear wheel friction braking module 300, and a control means 400.

The brake 100 may be mounted on the regenerative braking device according to the present invention, such as a hybrid electric vehicle (HEV), an electric vehicle (EV), or the like, and more preferably, may be attached to the electric motorcycle. The brake 100 controls the braking of the vehicle by the driver's operation.

Preferably, the brake 100 may include a brake lever (not shown), a permanent magnet (not shown), and a hall sensor (not shown).

The position of the permanent magnet attached to the brake lever is changed according to the operation of the brake lever, and the hall sensor detects a magnetic field changed by the movement of the permanent magnet to generate a brake signal.

Specifically, when the brake lever is operated by the driver, the hall sensor generates the brake signal by detecting a magnetic field that changes according to the position of the permanent magnet. The brake signal is the basis for calculating the target braking force required for the vehicle to brake.

For example, when the driver manipulates the brake 100 strongly, a larger target braking force is required than when the driver 100 operates weakly. In this case, the brake 100 may generate a brake signal corresponding to a larger target braking force.

The front wheel friction braking module 200 and the rear wheel friction braking module 300 generate the front wheel friction braking force and the rear wheel friction braking force, respectively, under the control of the control means 400.

The front wheel friction braking module 200 and the rear wheel friction braking module 300 will be described in detail together with the control means 400.

The control means 400 calculates the target braking force based on the brake signal generated in response to the operation of the brake 100, and controls the front wheel friction braking module 200 and the rear wheel friction braking module 300.

The control means 400 includes a sensor unit 410 and the MCU 430.

The sensor unit 410 generates a state signal by detecting a temperature and a charging state of the battery and a temperature and a rotation speed of the motor. The state signal generated by the sensor unit 410 is the basis for calculating the maximum regenerative braking force that can be generated from the vehicle.

The MCU 430 calculates the maximum regenerative braking force based on the state signal received from the sensor unit 410. In addition, the MCU 430 calculates the target braking force based on the brake signal corresponding to the operation of the brake 100.

The MCU 430 selectively performs regenerative braking, front wheel friction braking, and rear wheel friction braking by comparing the calculated maximum regenerative braking force, the front wheel friction braking force, and the rear wheel friction braking force with each other.

Hereinafter, the case where the control means 400 selectively performs the regenerative braking, the front wheel friction braking and the rear wheel friction braking will be described in detail.

When the driver starts braking by manipulating the brake 100, each of the brake 100 and the sensor unit 410 generates the brake signal and the status signal and transmits the brake signal to the MCU 430. The MCU 430 calculates the target braking force and the maximum regenerative braking force based on the brake signal and the state signal.

At this time, the motor generates a counter electromotive force at the same time that braking is started.

That is, the MCU 430 controls the motor to perform regenerative braking, and controls to charge the battery by DC / DC conversion of the counter electromotive force generated by the motor during regenerative braking. At this time, the regenerative braking force is generated by the front wheel when the motor drives the front wheel, and the regenerative braking force is generated by the rear wheel when the motor drives the rear wheel.

When the calculated maximum regenerative braking force is greater than the target braking force, the vehicle can be braked only by regenerative braking, so the MCU 430 controls the motor to brake the vehicle only by the regenerative braking.

However, when the maximum regenerative braking force is smaller than the target braking force, the braking of the vehicle cannot be performed by the regenerative braking alone, so the regenerative braking and the friction braking should be performed in parallel.

Specifically, the MCU 430 performs rear wheel friction braking when the maximum regenerative braking force is smaller than the target braking force.

When the sum of the rear wheel friction braking force and the maximum regenerative braking force generated by the rear wheel friction braking is less than the target braking force, the rear wheel friction braking force is increased as described in step S160 of FIG. 1 to perform rear wheel friction braking. By repeating this process, the MCU 430 may obtain the rear wheel friction braking coefficient which is a reference for switching from the rear wheel friction braking to the front wheel friction braking from the accumulated rear wheel friction braking force.

The rear wheel friction braking coefficient may be calculated from Equation 1 or Equation 3 below, wherein Equation 1 calculates the rear wheel friction braking coefficient when the maximum regenerative braking force is generated in the rear wheel, and Equation 3 is the maximum regenerative braking force. The rear wheel friction braking coefficient is obtained when generated at this front wheel.

[Equation 1]

&Quot; (3) "

The MCU 430 obtains the rear wheel friction braking coefficient from Equation 1 or Equation 3, and compares the rear wheel friction braking coefficient with a first value and if the rear wheel friction braking coefficient is smaller than the first value, the rear wheel friction braking force. To increase the rear wheel friction braking. Preferably, the first value may be 30-50%, more preferably 40%.

In addition, the MCU 430 controls to charge the battery by DC / DC conversion of the counter electromotive force generated by the motor during the rear wheel friction braking.

If the rear wheel friction braking coefficient is greater than or equal to the first value, the MCU 430 stops the rear wheel friction braking and performs front wheel friction braking.

Specifically, when the sum of the front wheel friction braking force generated by the front wheel friction braking and the rear wheel friction braking force accumulated by performing the rear wheel friction braking and the maximum regenerative braking force is smaller than the target braking force, as described in step S190 of FIG. 1. Likewise, front wheel friction braking is performed by increasing the front wheel friction braking force. By repeating this process, the MCU 430 may obtain the front wheel friction braking coefficient which is a reference for converting the front wheel friction braking to the rear wheel friction braking from the accumulated front wheel friction braking force.

The front wheel friction braking coefficient may be calculated from Equation 2 or Equation 4 below, and Equation 2 calculates the rear wheel friction braking coefficient when the maximum regenerative braking force is generated in the rear wheel, and Equation 4 is the maximum regenerative braking force. The rear wheel friction braking coefficient is obtained when generated at this front wheel.

[Equation 2]

&Quot; (4) "

The MCU 430 obtains the front wheel friction braking coefficient from Equation 2 or Equation 4, and compares the front wheel friction braking coefficient with a second value, and if the front wheel friction braking coefficient is smaller than the second value, the front wheel friction braking force. To increase the front wheel friction braking. Preferably, the second value may be 50 to 70%, more preferably 60%.

In addition, the MCU 430 controls to charge the battery by DC / DC conversion of the counter electromotive force generated by the motor during the front wheel friction braking.

When the front wheel friction braking coefficient is greater than or equal to the second value, the MCU 430 stops the front wheel friction braking and performs the rear wheel friction braking.

That is, the MCU 430 may switch from the rear wheel friction braking to the front wheel friction braking or the front wheel friction braking to the rear wheel friction braking based on the rear wheel friction braking coefficient and the front wheel friction braking coefficient.

According to the present invention, the case where the vehicle is an electric two-wheeled vehicle has been described as an example, but is not limited thereto.

Although the configuration of the present invention has been described in detail, these are merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. This will be possible.

Therefore, the embodiments disclosed in the present specification are intended to illustrate rather than limit the present invention, and the scope and spirit of the present invention are not limited by these embodiments. It is intended that the scope of the invention be interpreted by the following claims, and that all descriptions within the scope equivalent thereto will be construed as being included in the scope of the present invention.

100: brake 200: front wheel friction braking module
300: rear wheel friction braking module 400: control means
410: sensor unit 430: MCU

Claims (10)

(a) generating a brake signal corresponding to the operation of the brake;
(b) calculating a target braking force based on the brake signal;
(c) calculating regenerative braking force to perform regenerative braking;
(d) if the maximum regenerative braking force is less than the target braking force, performing rear wheel friction braking while increasing the rear wheel friction braking force until reaching a first value;
(e) when the rear wheel friction braking force reaches the first value, performing front wheel friction braking while increasing the front wheel friction braking force until the second value is reached; And
(f) performing the steps (d) and (e) until the accumulated rear wheel braking force and the front wheel friction braking force reach a difference between the maximum regenerative braking force and the target braking force; Repeating step (e)
Regenerative braking method comprising a. The method of claim 1,
In step (c),
(c-1) detecting the temperature and the charging state of the battery and the temperature and the rotation speed of the motor;
(c-2) calculating the maximum regenerative braking force based on the sensed temperature and state of charge of the battery and the temperature and rotation speed of the motor; And
(c-3) regenerative braking method comprising the step of performing the regenerative braking. The method of claim 1,
When the maximum regenerative braking force is obtained from the rear wheels, the steps (d) to (f) each include the rear wheel friction braking coefficient and the front wheel friction braking coefficient obtained from Equation 1 and Equation 2 below, respectively. And performing the rear wheel friction braking and the front wheel friction braking until the second value is reached.
[Equation 1]

[Equation 2]

The method of claim 3,
In the case where the maximum regenerative braking force is obtained from the front wheel, the steps (d) to (f) each include the rear wheel friction braking coefficient and the front wheel friction braking coefficient obtained from Equation 3 and Equation 4 below, respectively. And performing the rear wheel friction braking and the front wheel friction braking until the second value is reached.
[Equation 3]

[Equation 4]

The method of claim 4, wherein
The first and second values are regenerative braking method, characterized in that 40% and 60%, respectively. brake;
A front wheel friction braking module for generating a front wheel friction braking force;
A rear wheel friction braking module for generating a rear wheel friction braking force; And
Control means for calculating a target braking force based on the brake signal generated in response to the operation of the brake and controlling the front wheel friction braking module and the rear wheel friction braking module
Including,
The control means performs the rear wheel friction braking and the front wheel friction braking until the rear wheel friction braking force and the front wheel friction braking force reach the difference between the maximum regenerative braking force and the target braking force. A regenerative braking device, characterized in that selectively performing braking. The method of claim 6,
Wherein,
A sensor unit configured to generate a state signal by sensing a temperature and a charge state of the battery and a temperature and a rotation speed of the motor; And
And an MCU for calculating the target braking force and the maximum regenerative braking force, respectively, based on the brake signal and the state signal. The method of claim 6,
If the maximum regenerative braking force is less than the target braking force, the control means performs the rear wheel friction braking until the rear wheel friction braking force reaches a first value, and when the rear wheel friction braking force reaches the first value, And the front wheel friction braking until the front wheel friction braking force reaches a second value. The method of claim 8,
And said first value and said second value are 40% and 60%, respectively. The method of claim 6,
The brake is,
Brake lever;
A permanent magnet attached to the brake lever; And
And a hall sensor configured to generate a brake signal by detecting a magnetic field that is changed by the permanent magnet.

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