KR20170095003A - Regenerative Braking System of Vehicle And Driving Method Thereof - Google Patents

Abstract

The present invention relates to a regenerative braking system of a vehicle capable of increasing the amount of regenerative braking energy recovered by detecting the braking will of a driver to perform regenerative braking, and a driving method thereof. The regenerative braking system of a vehicle according to an embodiment of the present invention includes a proximity sensor disposed on a brake pedal and detecting the contact and proximity of the foot of a driver or within a predetermined distance; a control part for determining whether there is the deceleration will of the driver based on the detection signal of the proximity sensor, and determining whether to perform the regenerative braking when there is the deceleration will; and a regenerative braking driving part for performing the regenerative braking under the control of the control part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative braking system for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a regenerative braking system for a vehicle, and more particularly, to a regenerative braking system for a vehicle and a driving method thereof, capable of increasing the amount of regenerative braking energy recovered by sensing regenerative braking by sensing a braking force of a driver .

An eco-friendly automobile includes a fuel cell vehicle, an electric vehicle, a plug-in electric vehicle, and a hybrid vehicle, and includes a motor for generating a driving force. Among such environment-friendly vehicles, a hybrid vehicle means that a vehicle is driven by efficiently combining two or more kinds of power sources. In most cases, an engine that burns fuel (fossil fuel such as gasoline) Means a vehicle driven by an electric motor that obtains a rotational force by battery power.

In addition to hybrid vehicles, regenerative braking technology is applied to improve fuel efficiency in vehicles that use power generation control. This regenerative braking technique uses a part of the braking force for power generation at the time of braking of the vehicle and charges the battery with the generated electric energy. Thus, by using a part of the kinetic energy due to the running speed of the automobile as energy required for driving the generator, kinetic energy reduction (reduction in running speed) and electric energy generation are simultaneously realized. The regeneration braking control can extend the mileage of the vehicle to improve fuel economy and reduce the emission of noxious exhaust gas.

As one example, although a technique has been proposed in which regenerative braking control is performed when the driver does not step on the accelerator pedal, there is a limitation in improving fuel economy. As another example, Korean Patent Laid-Open Publication No. 10-2014-0068552 discloses a regenerative braking control device for an electric vehicle that controls regenerative braking according to the position of a deceleration pedal. However, regenerative braking is performed only when the deceleration pedal is depressed, so that there is a limitation in improving fuel economy.

Korean Patent Publication No. 10-2014-0068552 (Regenerative braking control device of electric vehicle using deceleration pedal position information and method thereof)

SUMMARY OF THE INVENTION The present invention provides a regenerative braking system for a vehicle that can increase the amount of regenerative braking energy recovered and a method of driving the same.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

According to an aspect of the present invention, there is provided a regenerative braking system for a vehicle, comprising: a proximity sensor which is disposed on a brake pedal and detects proximity of a foot of a driver or within a predetermined distance; And a regenerative braking driver for performing regenerative braking under the control of the control unit. The regenerative braking drive unit may include a regenerative braking unit that regenerates the regenerative braking based on the regenerative braking.

The control unit of the regenerative braking system of the vehicle according to the embodiment of the present invention, The proximity sensor is a proximity sensor of a capacitive type or a proximity switch of a capacitive type and detects when the driver's foot touches or approaches within a certain distance and generates the detection signal.

The controller of the vehicle regenerative braking system according to an embodiment of the present invention further determines a vehicle speed, an engine speed, a battery charging state, and an elcelerator position to determine execution of regenerative braking, The execution of the regenerative braking is determined when the engine speed, the battery charging state, and the elcelator position satisfy a reference value.

The control unit of the regenerative braking system of the vehicle according to the embodiment of the present invention calculates the first regenerative braking amount based on the vehicle weight, the vehicle speed, and the vehicle reference deceleration. Then, the second regenerative braking amount is calculated based on the vehicle speed, the vehicle reference speed, the engine speed, the engine idle RPM, the battery charging state, and the battery reference charging state. The regenerative braking amount is finally determined by reflecting the first regenerative braking amount and the second regenerating braking amount.

The control unit of the regenerative braking system of the vehicle according to the embodiment of the present invention independently drives the driving of the hydraulic brake of the vehicle and the regenerative braking.

According to another aspect of the present invention, there is provided a method of driving a regenerative braking system for a vehicle, the method comprising the steps of: detecting, based on a detection signal output from a proximity sensor disposed on a brake pedal, Determining whether to decelerate the driver based on the detection signal of the proximity sensor, determining the regenerative braking if the deceleration of the driver is determined, and determining the regenerative braking amount, And performing regenerative braking based on the regenerative braking amount.

In the method of driving a regenerative braking system for a vehicle according to an embodiment of the present invention, in the step of determining the regenerative braking, a regenerative braking is determined by further checking the vehicle speed, engine speed, battery charging state and elcelerator position of the vehicle , Determines the regenerative braking when the vehicle speed of the vehicle, the engine speed, the battery charging state, and the elcelerator position satisfy a reference value.

The method of driving a regenerative braking system for a vehicle according to an embodiment of the present invention includes the steps of: calculating a first regenerative braking amount based on a vehicle weight, a vehicle speed, and a vehicle reference deceleration; Calculating a second regenerative braking amount based on a vehicle speed, a vehicle reference speed, an engine speed, an engine idle RPM, a battery charging state, and a battery reference charging state; and a step of calculating a second regenerative braking amount, And finally determining the regenerative braking amount.

The regenerative braking system and the driving method of the vehicle according to the embodiment of the present invention can increase the amount of regenerative braking energy recovery by sensing the braking will of the driver and performing regenerative braking.

The regenerative braking system and the driving method of the vehicle according to the embodiment of the present invention can increase the recovery rate of the regenerative braking energy to improve the fuel consumption and reduce the exhaust gas emissions.

In addition, other features and advantages of the present invention may be newly understood through embodiments of the present invention.

1 is a view showing a regenerative braking system for a vehicle according to an embodiment of the present invention.
2 is a view showing charging of a battery with electric energy developed through regenerative braking.
3 is a diagram showing a driving method of a regenerative braking system for a vehicle according to an embodiment of the present invention.
4 is a diagram showing a method for confirming a vehicle condition.
5 is a diagram showing how the regenerative braking amount is determined by the vehicle condition.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

If any part is referred to as being "on" another part, it may be directly on the other part or may be accompanied by another part therebetween. In contrast, when a section is referred to as being "directly above" another section, no other section is involved.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

Terms indicating relative space such as "below "," above ", and the like may be used to more easily describe the relationship to other portions of a portion shown in the figures. These terms are intended to include other meanings or acts of the apparatus in use, as well as intended meanings in the drawings. For example, when inverting a device in the figures, certain portions that are described as being "below" other portions are described as being "above " other portions. Thus, an exemplary term "below" includes both up and down directions. The device can be rotated by 90 degrees or rotated at different angles, and terms indicating relative space are interpreted accordingly.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

The regenerative braking system of the vehicle according to the embodiment of the present invention can be applied to both hybrid vehicles and electric vehicles. In the case of a hybrid vehicle, it is possible to increase the energy recovery rate by performing only the regenerative braking when determining the braking will. In addition, in the case of an electric vehicle, regenerative braking is performed only when it is determined that the vehicle is to be braked. In the case where there is no determination as to whether or not the vehicle can be braked, energy waste can be reduced by driving the vehicle.

FIG. 1 is a view showing a regenerative braking system for a vehicle according to an embodiment of the present invention, and FIG. 2 is a view showing charging a battery with electric energy generated through regenerative braking.

1 and 2, a regenerative braking system for a vehicle according to an embodiment of the present invention includes a brake pedal 50, a proximity sensor 60, a control unit 70, and a regenerative braking drive unit 80.

The regenerative braking drive unit 80 includes an energy conversion unit 20 for converting the kinetic energy of the vehicle wheel 10 into electric energy and a regenerative braking unit 80 for rectifying the electric energy input from the energy conversion unit 20, 40).

The regenerative braking system of the vehicle according to the embodiment of the present invention according to the embodiment of the present invention allows the regenerative braking to be performed when the driver approaches or comes into contact with the pedal without stepping on the brake pedal 50. [ To this end, a proximity sensor 60 is disposed on the brake pedal 50. [ The proximity sensor 60 and the control unit 70 are used to determine the driver's braking intent. When it is determined that there is a braking intention, regenerative braking is performed. At this time, the regenerative braking amount is determined according to the current vehicle condition.

The proximity sensor 60 has a cylindrical or square shape and is disposed on the brake pedal 50. The proximity sensor 60 detects when the driver's foot touches or approaches a predetermined distance (about 10 mm), and outputs the detection signal (electric signal) based on the detection result. The detection signal output from the proximity sensor 60 is supplied to the control unit 70. [

Here, as the proximity sensor 60, a proximity sensor of a capacitance type or a proximity switch of a capacitance type may be applied. The proximity sensor 60 detects not only the driver's foot touches the brake pedal 50 but also when the driver's foot approaches within a certain distance, and generates a detection signal.

For example, the proximity sensor 60 detects a change in capacitance due to movement and separation of charges in an object existing in an electric field, and detects contact and approach of an insulator (dielectric) such as plastic, glass, ceramics or wood . In addition, the proximity sensor 60 can detect contact and access of liquids such as water, oil, and drugs.

If a mechanical switch is used, it is possible to determine the deceleration will without operating the hydraulic brake by depressing a very minute section using the dead zone of the brake. However, it is difficult to depress the dead zone only by human senses. It can not be guaranteed that the hydraulic brake does not work in all situations. As a result, regenerative braking is performed only when the brake pedal 50 is depressed, resulting in loss of regenerable energy.

By disposing the proximity sensor 60 on the brake pedal 50 as in the present invention, it is possible to determine whether the driver is decelerating while the brake pedal 50 is not stepped on. The proximity sensor 60 may detect only a nearby object such as automatically turning off the screen so that a touch can not be made when the smartphone is in a call. As a result, the hydraulic brake and regenerative braking can be driven completely independently.

The control unit 70 determines the deceleration of the driver based on the detection signal input from the proximity sensor 60. [ The driver's deceleration will be determined when the foot is placed on the brake pedal 50 in a state in which the brake pedal 50 is not pressed. The proximity sensor 60 is disposed on the brake pedal 500. When the driver's foot contacts the proximity sensor 60 or approaches within a certain distance, the proximity sensor 60 detects a change in capacitance. So that the driver's deceleration will can be determined.

In addition, the control unit 70 determines whether or not the current state of the vehicle (vehicle speed, engine speed, battery state of charge (SOC), accelerator position, etc.) Based on which the execution of regenerative braking and the amount of regenerative braking are determined. Here, hydraulic braking (brake) and regenerative braking are independently driven.

For example, if the driver's foot is detected as being in contact with or close to the brake pedal 50 in the proximity sensor 60 and the driver is determined to be decelerated, the regenerative braking is not performed if the current system condition does not satisfy the reference value Do not. That is, the regenerative braking is performed only when the vehicle speed, the engine speed, the battery SOC, and the position of the accelerator satisfy the reference value, so that the regenerative braking that is not intended by the driver is not performed.

The control unit 70 determines the regenerative braking amount when the vehicle speed, the engine speed, the battery SOC, and the position of the accelerator satisfy the reference values. The control unit 70 determines the regenerative braking amount and drives the regenerative braking unit 80 based on the regenerative braking amount to perform regenerative braking.

FIG. 3 is a diagram showing a driving method of a regenerative braking system for a vehicle according to an embodiment of the present invention, and FIG. 4 is a diagram showing a method for confirming a vehicle condition.

3, a detection signal input from the proximity sensor 60 disposed on the brake pedal 50 is input to the control unit 70. Based on the detection signal inputted, the driver's feet are depressed by a brake pedal (50). That is, it is determined whether there is a driver's deceleration intention (S10).

Then, as shown in FIG. 4, the system conditions (vehicle speed, engine speed, battery state of charge (SOC), accelerator position, etc.) of the vehicle are checked (S20).

Specifically, it is confirmed whether the reference value of the vehicle speed is satisfied (S21).

If it is determined in S21 that the vehicle speed satisfies the reference value, it is confirmed whether the engine speed satisfies the reference value (S22).

As a result of the check in S22, if the engine speed satisfies the reference value, it is confirmed whether the battery SOC satisfies the reference value (battery reference SOC) (S23).

As a result of S23, if the battery SOC satisfies the reference value, it is confirmed whether the elcelerator position satisfies the reference value using the elcelater position sensor (S24).

As a result of the determination in S21, S22, S23, and S24, the regenerative braking is performed when all the reference values are satisfied. However, the present invention is not limited thereto, As a result of the determination in S21, S22, S23, and S24, the regenerative braking may be performed even when the two conditions or the three conditions satisfy the reference value.

5 is a diagram showing how the regenerative braking amount is determined by the vehicle condition.

Referring to FIG. 5, when the execution of the regenerative braking is determined, the regenerative braking amount is determined based on the system condition of the vehicle (S30).

More specifically, the first regenerative braking amount is calculated based on the vehicle weight, the vehicle speed, and the vehicle reference deceleration. Then, the second regenerative braking amount is calculated based on the vehicle speed, the vehicle reference speed, the engine speed, the engine idle RPM, the battery SOC, and the battery reference SOC. The regenerative braking amount is finally determined by reflecting the first regenerative braking amount and the second regenerating braking amount.

Subsequently, the control unit 70 drives the regenerative braking drive unit 80 based on the determined regenerative braking amount to perform regenerative braking.

Then, it is checked whether the starting of the vehicle is off (S50). If the vehicle is in the ON state, the regenerative braking is continuously performed while the vehicle is running. On the other hand, when the vehicle is in the off state, the regenerative braking is stopped.

The regenerative braking system and the driving method of the vehicle according to the embodiment of the present invention can increase the amount of regenerative braking energy recovery by sensing the braking will of the driver and performing regenerative braking.

Further, the regenerative braking system and the driving method of the vehicle according to the embodiment of the present invention can increase the amount of regenerative braking energy recovered, thereby improving the fuel consumption and reducing the exhaust gas emissions.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. .

10: Wheel
20: energy conversion section
30: Inverter
40: Battery
50: Brake pedal
60: Proximity sensor
70:
80: Regenerative braking drive

Claims (8)

A proximity sensor disposed on the brake pedal for detecting that the driver's foot is in contact with or within a predetermined distance;
A controller for determining whether to decelerate the driver based on the detection signal of the proximity sensor and determining execution of the regenerative braking if the deceleration is determined; And
And a regenerative braking drive unit for regenerating braking under the control of the control unit. The apparatus of claim 1,
Wherein the proximity sensor is a proximity sensor of a capacitive type or a proximity switch of a capacitive type and detects when the driver's foot touches or approaches within a certain distance and generates the detection signal. The apparatus of claim 1,
Further determining the vehicle speed, engine speed, battery charge status and elcelerator position to determine the performance of the regenerative braking,
And determines execution of regenerative braking when the vehicle speed, the engine speed, the battery charge state, and the elcelerator position of the vehicle satisfy a reference value. The apparatus of claim 1,
The first regenerative braking amount is calculated based on the vehicle weight, the vehicle speed, and the vehicle reference deceleration,
The second regenerative braking amount is calculated based on the vehicle speed, the vehicle reference speed, the engine speed, the engine idle RPM, the battery charging state, and the battery reference charging state,
And the regenerative braking amount is finally determined by reflecting the first regenerative braking amount and the second regenerating braking amount. The apparatus of claim 1,
And regenerative braking of the hydraulic brake of the vehicle. Detecting that the driver's foot is in contact with the brake pedal or approaching within a predetermined distance based on the detection signal output from the proximity sensor disposed on the brake pedal;
Determining a deceleration of the driver based on a detection signal of the proximity sensor;
Determining a regenerative braking if the driver's deceleration is determined, and determining a regenerative braking amount; And
And performing regenerative braking on the basis of the regenerative braking amount. 7. The method according to claim 6, wherein in the step of determining the regenerative braking,
The regenerative braking is determined by further checking the vehicle speed, the engine speed, the battery charge status, and the elcelerator position,
And determines the regenerative braking when the vehicle speed, the engine speed, the battery charging state, and the elcelerator position of the vehicle satisfy a reference value. 7. The method according to claim 6, wherein, in the step of determining the regenerative braking amount,
Calculating a first regenerative braking amount based on the vehicle weight, the vehicle speed, and the vehicle reference deceleration;
Calculating a second regenerative braking amount based on the vehicle speed, the vehicle reference speed, the engine speed, the engine idle RPM, the battery charging state, and the battery reference charging state; And
And determining a final regenerative braking amount by reflecting the first regenerative braking amount and the second regenerative braking amount.

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