U.S. patent application number 15/350480 was filed with the patent office on 2018-02-01 for method of controlling coasting of vehicle.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Jae Hoon CHO, Jin Woo CHO, Tae Hyuck KIM.
Application Number | 20180029599 15/350480 |
Document ID | / |
Family ID | 61012085 |
Filed Date | 2018-02-01 |
United States Patent
Application |
20180029599 |
Kind Code |
A1 |
KIM; Tae Hyuck ; et
al. |
February 1, 2018 |
METHOD OF CONTROLLING COASTING OF VEHICLE
Abstract
A method of controlling coasting of a vehicle, may include a
preparing step of measuring an interval between an objective
vehicle and a foregoing vehicle traveling ahead of the objective
vehicle. A starting step of calculating a distance moved by
coasting for a first predetermined time from a current speed of the
objective vehicle and of starting coasting when the calculated
movement distance is larger than the interval measured in the
preparing step. An ending step of calculating a distance moved by
coasting for a second predetermined time from the current speed of
the objective vehicle after coasting is started in the starting
step, and of giving an instruction to end coasting when the
calculated movement is larger than the interval measured in the
preparing step, in which the time T1 is longer than the time
T2.
Inventors: |
KIM; Tae Hyuck; (Seoul,
KR) ; CHO; Jin Woo; (Uiwang-si, KR) ; CHO; Jae
Hoon; (Suwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
|
Family ID: |
61012085 |
Appl. No.: |
15/350480 |
Filed: |
November 14, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60W 2530/18 20130101;
B60W 2554/801 20200201; B60W 2552/15 20200201; Y02T 10/76 20130101;
Y02T 10/60 20130101; B60W 50/14 20130101; B60W 2540/10 20130101;
B60W 30/18072 20130101; B60W 2540/12 20130101 |
International
Class: |
B60W 30/18 20060101
B60W030/18; B60W 50/14 20060101 B60W050/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2016 |
KR |
10-2016-0097129 |
Claims
1. A method of controlling coasting of a vehicle, the method
comprising: a preparing step of measuring an interval between an
objective vehicle and a foregoing vehicle traveling ahead of the
objective vehicle; a starting step of determining a distance moved
by coasting during a first predetermined time from a current speed
of the objective vehicle and of starting coasting when the
determined distance moved is larger than the interval measured in
the preparing step; and an ending step of determining a distance
moved by coasting during a second predetermined time from the
current speed of the objective vehicle after coasting is started in
the starting step, and of giving an instruction to end coasting
when the determined distance moved is larger than the interval
measured in the preparing step, wherein the first predetermined
time is longer than the second predetermined time.
2. The method of claim 1, wherein the preparing step includes a
measuring process of measuring a relative speed and an interval
between the objective vehicle and the foregoing vehicle and a
determination process of determining whether to perform the
starting step based on data obtained in the measuring process, and
in the determination process, the measuring process is performed
again when the relative speed measured in the measuring process is
0 or more, and the starting step is performed when the relative
speed is less than 0.
3. The method of claim 2, wherein the measuring process further
measures a slope of a road on which the objective vehicle travels,
and in the determination process, the road is determined to be one
of an uphill road, a downhill road, and a level road based on the
measured slope, the measuring process is performed again when the
road is determined to be an uphill road, and the starting step is
performed when the road is determined to be a downhill road or a
level road.
4. The method of claim 1, wherein the starting step includes: a
first comparing process of comparing a distance moved by coasting
during the first predetermined time with the interval measured in
the preparing step; an instructing process of informing a driver
that it is time to start coasting when the distance moved by
coasting during the first predetermined time is larger than the
measured interval; a checking process of detecting input values
from an accelerator pedal and a brake pedal after the instructing
process; and a coasting-starting process of informing the driver
that coasting has started when there is no input value from the
accelerator pedal or the brake pedal in the checking process.
5. The method of claim 4, wherein when the distance moved by
coasting during the first predetermined time, determined in the
first comparing process, is smaller than the measured interval, the
preparing step is performed again.
6. The method of claim 4, wherein the preparing step is performed
again when there are input values from the accelerator pedal and
the brake pedal in the checking process.
7. The method of claim 6, wherein the starting step further
includes a reset process of discontinuing an alarm generated in the
instructing process or the coasting-starting process before
performing the preparing step again, when there are input values
from the accelerator pedal and the brake pedal in the checking
process.
8. The method of claim 4, wherein the ending step includes, a
second comparing process of comparing a determined distance moved
by coasting for a the second predetermined time with the interval
measured in the preparing step; and a coasting-ending process of
informing the driver that it is time to end coasting when the
determined distance moved by coasting during the second
predetermined time is larger than the measured interval.
9. The method of claim 8, wherein when the distance moved by
coasting during the second predetermined time, determined in the
second comparing process, is smaller than the measured interval,
the checking step is performed again.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Korean Patent
Application No. 10-2016-0097129, filed Jul. 29, 2016, the entire
contents of which is incorporated herein for all purposes by this
reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a method of controlling
coasting of a vehicle, and more particularly to a method of
controlling coasting of a vehicle, whereby the method determines
the start and end points of coasting.
Description of Related Art
[0003] A smart cruise control (hereafter, referred to as `SCC`)
system automatically controls a vehicle so that the vehicle
maintains an appropriate distance from a vehicle ahead even without
specific operation by a driver. According to the SCC system, a
radar unit is mounted at the front of a vehicle and measures the
distance and relative speed etc. with respect to a foregoing
vehicle.
[0004] Meanwhile, a technology that controls a vehicle to coast in
order to improve fuel efficiency using such an SCC radar has been
developed. Coasting means that a vehicle keeps moving using only
inertia without additional acceleration in consideration of the
distance from a foregoing vehicle or traffic signals.
[0005] Repeating excessive acceleration and braking consumes more
fuel, so fuel efficiency is reduced, but coasting allows for stable
traveling without unnecessary acceleration. However, many
conditions including the distance from a foregoing vehicle and the
vehicle speed should be considered, so it is difficult for a driver
to determine the start and end points of coasting using only
his/her judgment.
[0006] In the related art, a control method of determining points
of entering and exiting a coasting mode and informing a driver of
the points has been proposed. However, the coasting mode was too
frequently turned on/off, or the turning-on/off points vary greatly
depending on the situation, which is confusing for drivers.
[0007] Accordingly, there is a need for a new method of controlling
coasting that is predictable to a driver and is not frequently
turned on/off.
[0008] The information disclosed in this Background of the
Invention section is only for enhancement of understanding of the
general background of the invention and should not be taken as an
acknowledgement or any form of suggestion that this information
forms the prior art already known to a person skilled in the
art.
BRIEF SUMMARY
[0009] Various aspects of the present invention are directed to
providing a method of controlling coasting of a vehicle, whereby
the method can improve fuel efficiency by providing a coasting
signal to a driver at an appropriate point.
[0010] In an aspect of the present invention, there is provided a
method of controlling coasting of a vehicle, the method including:
a preparing step of measuring an interval between an objective
vehicle and a foregoing vehicle traveling ahead of the objective
vehicle; a starting step of calculating a distance moved by
coasting for a predetermined time T1 on the basis of a current
speed of the objective vehicle and of starting coasting when the
calculated movement distance is larger than the interval measured
in the preparing step; and an ending step of calculating a distance
moved by coasting for a predetermined time T2 on the basis of the
current speed of the objective vehicle after coasting is started in
the starting step, and of giving an instruction to end coasting
when the calculated movement is larger than the interval measured
in the preparing step, in which the time T1 is longer than the time
T2.
[0011] The preparing step may include a measuring process of
measuring a relative speed and an interval between the objective
vehicle and the foregoing vehicle and a determination process of
determining necessary conditions for coasting; and in the
determination process, the measuring process may be performed again
when the relative speed measured in the measuring process is 0 or
more, and the starting step may be performed when the relative
speed is less than 0.
[0012] The measuring process may further measure a slope of a road
on which the objective vehicle is traveling, and in the
determination process, the road may be determined to be any one of
an uphill road, a downhill road, and a level road on the basis of
the measured slope, the measuring process may be performed again
when the road is determined to be an uphill road, and the starting
step may be performed when the road is determined to be a downhill
road or a level road.
[0013] The starting step may include: a first comparing process of
comparing a distance moved by coasting for the time T1 with the
interval measured in the preparing step; an instructing process of
informing a driver that it is time to start coasting when the
distance moved by coasting during the time T1 is larger than the
measured interval; a checking process of detecting input values by
an accelerator pedal and a brake pedal after the instructing
process; and a coasting-starting process of informing the driver
that coasting has started when there is no input value from the
accelerator pedal or the brake pedal in the checking process.
[0014] When the distance moved by coasting for the time T1,
calculated in the first comparing process, is smaller than the
measured interval, the preparing step may be performed again.
[0015] The preparing step may be performed again when there are
input values from the accelerator pedal and the brake pedal in the
checking process.
[0016] The starting step may further include a reset process of
removing an alarm generated in the instructing process or the
coasting-starting process before performing the preparing step
again, when there are input values from the accelerator pedal and
the brake pedal in the checking process.
[0017] The ending step may include: a second comparing process of
comparing a calculated distance moved by coasting during a
predetermined time T2 with the interval measured in the preparing
step; and a coasting-ending process of informing a driver that it
is time to end coasting, when the calculated distance moved by
coasting during the time T is larger than the measured
interval.
[0018] When the distance moved by coasting during the time T2,
calculated in the second comparing process, is smaller than the
measured interval, the checking step may be performed again.
[0019] The method of controlling coasting of a vehicle of the
present invention has the following effects.
[0020] First, a driver can intuitively understand the coasting
start and end points, so the convenience of the driver can be
improved.
[0021] Second, it is possible to contribute to improving the fuel
efficiency of a vehicle by prompting to perform coasting.
[0022] The methods and apparatuses of the present invention have
other features and advantages which will be apparent from or are
set forth in more detail in the accompanying drawings, which are
incorporated herein, and the following Detailed Description, which
together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a graph showing a speed change and a movement
distance for a predetermined time from T1 to T2 of a coasting
vehicle.
[0024] FIG. 2 is a flowchart according to an embodiment of the
present invention.
[0025] FIG. 3 is a view showing the configuration according to an
embodiment of the present invention.
[0026] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various features illustrative of the basic
principles of the invention. The specific design features of the
present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0027] In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0028] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that the present description is
not intended to limit the invention(s) to those exemplary
embodiments. On the contrary, the invention(s) is/are intended to
cover not only the exemplary embodiments, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
[0029] Terminologies stated herein are used only for describing
specific embodiments without limiting the present invention. The
singular terms used herein include plural terms unless phrases
express opposite meanings clearly.
[0030] Though not differently defined, all the terms, including
technical terms and scientific terms used hereafter, have the same
meanings as those that those skilled in the art generally
understand The terms defined in dictionaries should be construed as
having meanings corresponding to the related prior art documents
and those stated herein and should not be construed as being ideal
or official, if not defined.
[0031] Hereinafter, a method of controlling coasting of a vehicle
according to an exemplary embodiments exemplary embodiment of the
present invention is described with reference to the accompanying
drawings.
[0032] As shown in FIGS. 1 to 3, the present invention broadly
includes a preparing step S100, a starting step S200, and an ending
step S300.
[0033] The steps are briefly respectively described hereafter. The
preparing step S100 collects and determines various items of
information for starting coasting. When predetermined conditions
are satisfied, coasting is started, but when the conditions are not
satisfied, the preparing step S100 is repeated and the current
state is maintained.
[0034] When the conditions are satisfied in the preparing step
S100, the starting step S200 is started, and a driver is prompted
to start coasting.
[0035] After coasting is started in the starting step S200, when
predetermined conditions are satisfied, the driver is instructed to
stop coasting in the ending step S300.
[0036] The subject of `determining` and `instructing` in the steps
is a controller 100 in a vehicle, for example, an ECU. The subject
of determination and instruction to be described hereafter is the
same.
[0037] Hereafter, the steps are described in more detail on the
basis of the relationship between a vehicle to which the present
invention is applied (hereafter, referred to as a `objective
vehicle`) and another vehicle traveling ahead of the objective
vehicle (hereafter, referred to as a `foregoing vehicle`).
[0038] First, the preparing step S100 includes a measuring process
S110 for continuously measuring the interval and relative speed
between an objective vehicle and a foregoing vehicle and the state
of a road surface, particularly, the slope of a road, and a
determination process S120 for determining whether to start the
starting step S200 or repeat the measuring process S110 on the
basis of the data obtained in the measuring process S110.
[0039] In the measuring process S110, the device and method for
measuring the interval and relative speed between an objective
vehicle and a foregoing vehicle are not specifically limited, but a
distance-measuring unit 210 such as the SCC radar may be used.
[0040] A gyroscope in a vehicle, or a slope-measuring unit 220,
such as a navigation system, providing the shapes of road surfaces
may be used to measure the slope of roads. Accordingly, when a
measured slope is in a predetermined range, for example,
-10.degree. .about.+10.degree., the road can be determined to be a
level road, when the slope is larger than this range, the road can
be determined to be an uphill road, and when the slope is smaller
than the range, the road can be determined to be a downhill
road.
[0041] The determination process S120 performs the following
determination using the data collected through the measuring
process S110.
[0042] First, when the relative speed between an objective vehicle
and a foregoing vehicle is 0 or more, that is, when the speeds of
an objective vehicle and a foregoing vehicle are the same or the
speed of the foregoing vehicle is higher, the measuring process
S110 is performed without performing the starting step S200.
[0043] Since the speed of a vehicle that is coasting gradually
decreases, when an objective vehicle starts coasting with the speed
of foregoing vehicle being higher than or the same as the speed of
the objective vehicle, the interval between the objective vehicle
and the foregoing vehicle will gradually increase.
[0044] It is preferable for the interval between vehicles to be
maintained while the vehicles are traveling, so when the relative
speed between an objective vehicle and a foregoing vehicle is 0, it
is preferable to supply additional power in order to maintain or
increase the speed without starting to coast.
[0045] Further, when an objective vehicle is moving or when the
road that an objective vehicle is about to enter is an uphill road,
the measuring process S110 is repeated without performing the
starting step S200.
[0046] Power must be continuously supplied to travel up an uphill
road, but coasting is performed without power, and thus it is
impossible to coast up an uphill road. Accordingly, when an object
vehicle is traveling on an uphill road or an object vehicle is
expected to enter an uphill road while coasting, it is preferable
not to start coasting.
[0047] That is, when the relative speed between an objective
vehicle and a foregoing vehicle is 0 or more or a road is uphill,
the measuring process S110 is repeated without performing the
starting step S200.
[0048] On the other hand, when the relative speed between an
objective vehicle and a foregoing vehicle is 0 or less and a road
is flat or downhill, the starting step S200 is performed.
[0049] The starting step S200 includes, a first comparing process
S210 of comparing the distance (D1+D2) that an objective vehicle
runs after a predetermined time T1 from the current time with the
interval between the objective vehicle and a foregoing vehicle,
when the objective vehicle starts coasting at the current speed. an
instructing process S220 of informing the driver of the starting
point of coasting when the distance (D1+D2) is determined to be
larger than the interval between the objective vehicle and the
foregoing vehicle in the first comparing process S210. a checking
process S230 of checking whether the driver has released an
accelerator pedal 320 and a brake pedal 310 by detecting input
values. A coasting-starting process S240 of informing the driver
that coasting has been started when it is determined that the
driver has released the accelerator pedal 320 and the brake pedal
310.
[0050] The first comparing process 210 is performed in accordance
with a coasting reduction graph according to the current speed of
an objective vehicle, but the graph is not limited to that shown in
FIG. 1 and may be changed in various ways, depending on the kind of
vehicle.
[0051] As shown in the figure, a reference point Tn is determined
on the basis of the current speed Vn of an objective vehicle. A
movement distance from the reference point Tn to a point T1 is
defined as the area (D1+D2) under the graph between the reference
point Tn and the point T1.
[0052] The calculated movement distance (D1+D2) and the interval
between the objective vehicle and the foregoing vehicle are
compared, and when the movement distance (D1+D2) is larger, the
instructing process S220 is performed.
[0053] The instructing process S220 is a process of informing a
driver that it is time to start coasting, and it may be achieved,
for example, by showing a notice that instructs the driver to take
his/her feet off the accelerator pedal and the brake pedal for
coasting on a dashboard 400, turning on a coasting instruction lamp
410 such as an icon, or generating a voice message.
[0054] In the checking process S230, it is checked whether the
driver has recognized that it is time to start coasting and has
released the accelerator pedal 320 and the brake pedal 310.
[0055] In order to check the above, for example, it is possible to
detect input values from the accelerator pedal and the brake pedal
using an accelerator position sensor (APS) and a brake position
sensor (BPS) and to check whether the driver is operating the
accelerator pedal or the brake pedal.
[0056] When it is determined that the driver has released the
accelerator pedal and the brake pedal, it is possible to inform the
driver that coasting has been started by turning on the coasting
lamp 420, showing the start of coasting, on the dashboard or
generating a voice in the coasting-starting process S240.
[0057] When the conditions described above are not satisfied in the
processes of the starting step S200, the preparing step is
performed again.
[0058] In detail, when the movement distance (D1+D2) calculated in
the first comparing process S210 is smaller than the current
interval between the objective vehicle and the foregoing vehicle or
when the operation of the accelerator pedal or the brake pedal is
found in the checking process S230, the process returns to the
preparing step S100 and repeats the steps.
[0059] The method may further include a reset process S250 that
discontinues the alarm that instructs a driver to start coasting or
informs the driver of coasting, when operation of the accelerator
pedal or the brake pedal is found in the checking process S230,
after which the process returns to the preparing step S100.
[0060] In the reset process S250, for example, the coasting
instruction lamp 410, for prompting for coasting, or the coasting
lamp 420, showing that the vehicle is coasting, may be turned off.
The driver can clearly recognize that coasting is stopped through
the reset process S250.
[0061] The ending step S300 includes a second comparing process
S310 and a coasting-ending process S320.
[0062] The second comparing process S310 is similar to the first
comparing process S210. However, the movement distance (D1+D2)
during the time T1 is compared with the interval between an
objective vehicle and a foregoing vehicle in the first comparing
process S210, but the movement distance during the time T2 is
compared with the interval between an objective vehicle and a
foregoing vehicle in the second comparing process S310. The time T2
should be set shorter than the time T1.
[0063] When the movement distance D2 calculated in the second
comparing process S310 is larger than the interval between the
objective vehicle and the foregoing vehicle, the coasting-ending
process S320 is performed, but when the movement distance D2
calculated in the second comparing process S310 is smaller than the
interval between the objective vehicle and the foregoing vehicle,
the checking process S230 is performed again.
[0064] The coasting-ending process S320 instructs the driver to
operate the accelerator pedal or the brake pedal by indicating that
it is time to end coasting. Accordingly, the driver recognizes that
it is time to operate the accelerator pedal and the brake pedal in
his/her judgment.
[0065] In order to give those instructions to a driver, it may be
possible to turn off the coasting lamp 420 or generate a voice.
[0066] The determination of the point of ending coasting through
the second comparing process S310 serves to end coasting before the
objective vehicle approaches the foregoing vehicle and potentially
collides with the foregoing vehicle. This will be described
below.
[0067] The times T1 and T2 are not specifically limited, but for
example, the time T1 may be 9.about.11 seconds and the time T2 may
be 4.about.6 seconds.
[0068] A detailed example of operation of the present invention
under various situations is described hereafter.
[0069] In the preparing step S100, whether to perform the starting
step S200 is determined in consideration of the relative speed and
interval between an objective vehicle and a foregoing vehicle and
the slope of a road etc. Although the coasting start and end points
are determined by continuously considering the relative speed of an
objective vehicle and a foregoing vehicle in the related art, these
points are considered only for starting coasting and are not
considered for ending coasting in an exemplary embodiment of the
present invention.
[0070] In the starting step S200, when the total distance (D1+D2)
moved by coasting during the time T1 from the current speed Vn,
which is the start speed of the objective vehicle, is longer than
the interval between the objective vehicle and the foregoing
vehicle, the driver is instructed to start coasting.
[0071] In other words, when the time the objective vehicle takes to
reach the current position of the foregoing vehicle after starting
coasting is shorter than the time T1, an instruction for coasting
is given.
[0072] According to an exemplary embodiment of the present
invention, after coasting is started, when a driver operates the
accelerator pedal or the brake pedal or when the total movement
distance D2 by coasting for the time T2 is larger than the interval
between an objective vehicle and a foregoing vehicle, that is, when
the time the objective vehicle takes to reach the current position
of the foregoing vehicle after starting coasting is shorter than
the time T2, coasting is ended in the ending step S300.
[0073] Although coasting is repeatedly started and ended in
consideration of the speed relative to a foregoing vehicle before
and after coasting in the related art, the relative speed is not
considered after coasting is started in an exemplary embodiment of
the present invention, so an unnecessary signal for ending coasting
is not generated during coasting.
[0074] According to an exemplary embodiment of the present
invention, the condition for ending coasting is only the case when
the interval between an objective vehicle and a foregoing vehicle
is smaller than the total movement distance D2 during the time T2,
that is, the case when the objective vehicle approaches the
foregoing vehicle and risks causing a collision, so that a driver
receiving an ending signal can prevent a collision by operating the
brake pedal.
[0075] On the other hand, when the foregoing vehicle accelerates
and the interval between the objective vehicle and the foregoing
vehicle increases while the objective vehicle is coasting, coasting
is not automatically ended, but the driver can end coasting by
recognizing that the foregoing vehicle has moved ahead and
operating the accelerator pedal.
[0076] According to the method of the present invention, a driver
can intuitively understand the coasting start and end points and
unnecessary repetition of coasting is minimized, so confusion and
fatigue of the driver can be minimized.
[0077] Although exemplary embodiments of the present invention have
been described above with reference to the accompanying drawings,
those skilled in the art will understand that the present invention
may be implemented in various ways without changing the necessary
features or the spirit of the prevent invention.
[0078] Therefore, it should be understood that the exemplary
embodiments are not limiting but illustrative in all aspects. The
scope of the present invention is defined not by the specification,
but by the following claims, and all changes and modifications
obtained from the meaning and range of claims and equivalent
concepts should be construed as being included in the scope of the
present invention.
[0079] For convenience in explanation and accurate definition in
the appended claims, the terms "upper", "lower", "inner", "outer",
"up", "down", "upper", "lower", "upwards", "downwards", "front",
"rear", "back", "inside", "outside", "inwardly", "outwardly",
"interior", "exterior", "inner", "outer", "forwards", and
"backwards" are used to describe features of the exemplary
embodiments with reference to the positions of such features as
displayed in the figures.
[0080] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
* * * * *