U.S. patent application number 09/727798 was filed with the patent office on 2001-06-14 for vehicle speed control system using wireless communications and method for controlling the same.
Invention is credited to Jeon, Yong-Won.
Application Number | 20010003808 09/727798 |
Document ID | / |
Family ID | 19625609 |
Filed Date | 2001-06-14 |
United States Patent
Application |
20010003808 |
Kind Code |
A1 |
Jeon, Yong-Won |
June 14, 2001 |
Vehicle speed control system using wireless communications and
method for controlling the same
Abstract
Disclosed a vehicle speed control system using wireless
communications, the system including a driving state detecting unit
for detecting a driving state and outputting corresponding signals;
a transmitter/receiver for outputting low-strength signals; an
electronic control unit for receiving the signals of the
transmitter/receiver and establishing an ISA mode if necessary,
determining if a present driving state corresponds to a first
driving state, determining if the driver has performed deceleration
operations and performing control into the first driving state if
needed; an engine control unit for outputting signals for control
of the throttle valve opening; a throttle valve electronic control
unit for outputting electrical signals to a throttle valve to
control the same; and a display for displaying a present mode and a
vehicle state. A method for controlling the system comprises the
steps of receiving signals from an RF transmitter/receiver to
determine if a vehicle is in a first driving state; establishing an
ISA mode and performing display of the ISA mode; determining a
present driving state for comparison with the first driving state
and performing display to inform the driver of the result of the
comparison; determining if the driver has performed a deceleration
operation if the present driving state does not correspond to the
first driving state; disengaging the ISA mode and enabling full
control of the vehicle by the driver if the present driving state
corresponds to the first driving state or if the driver has
performed a deceleration operation; and controlling an engine
control unit via CAN communications if the driver has not performed
a deceleration operation.
Inventors: |
Jeon, Yong-Won;
(Hwaseong-kun, KR) |
Correspondence
Address: |
CHRISTIE, PARKER & HALE, LLP
350 WEST COLORADO BOULEVARD
SUITE 500
PASADENA
CA
91105
US
|
Family ID: |
19625609 |
Appl. No.: |
09/727798 |
Filed: |
November 30, 2000 |
Current U.S.
Class: |
701/93 ;
340/905 |
Current CPC
Class: |
B60W 30/18145 20130101;
G01S 2013/9316 20200101; B60W 2050/143 20130101; B60W 2540/18
20130101; G01S 13/931 20130101; B60W 2540/20 20130101; G01S
2013/9322 20200101; G01S 2013/9318 20200101; G01S 2013/932
20200101; G01S 2013/93185 20200101; B60K 31/0058 20130101; G01S
2013/9321 20130101; B60W 2540/12 20130101; B60W 2710/0605 20130101;
G01S 2013/9319 20200101; B60W 2050/0045 20130101 |
Class at
Publication: |
701/93 ;
340/905 |
International
Class: |
B60K 031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 1999 |
KR |
99-57402 |
Claims
What is claimed is:
1. A vehicle speed control system using wireless communications
comprising: a driving state detecting unit for detecting steering
angle, vehicle speed, throttle valve opening, brake operation, and
turn signal operation, and outputting corresponding signals; a
transmitter/receiver for outputting low-strength signals containing
information of a speed limit and a range of the speed limit; an
electronic control unit for receiving the signals of the
transmitter/receiver and establishing an ISA mode if necessary,
determining if a present driving state corresponds to a first
driving state using the signals of the driving state detecting
unit, determining if the driver has performed deceleration
operations, and performing control into the first driving state if
needed; an engine control unit for outputting signals for control
of the throttle valve opening according to control signals of the
electronic control unit; a throttle valve electronic control unit
for receiving the signals output from the engine control unit and
outputting electrical signals to a throttle valve to control an
opening degree of the throttle valve; and a display for displaying
a present mode and a vehicle state according to the control signals
of the electronic control unit.
2. The vehicle speed control system of claim 1 wherein the
transmitter/receiver is provided adjacent to a specific lane, and
the low-strength signals of the transmitter/receiver are such that
vehicles traveling on the opposite lane do not receive the
signals.
3. The vehicle speed control system of claim 1 wherein the
electronic control unit determines if the present driving state
corresponds to the first driving state after establishing the ISA
mode, enables full control of the vehicle by the driver if the
present driving state corresponds to the first driving state, and
control the display to output a warning message if the present
driving state does not correspond to the first driving state.
4. The vehicle speed control system of claim 3 wherein the
electronic control unit determines if the driver has performed a
deceleration operation during a predetermined interval after output
of the warning message, enables full control of the vehicle by the
driver if the driver has performed a deceleration operation, and
performing control into the first driving state if the driver has
not performed a deceleration operation.
5. A method for controlling a vehicle control system using wireless
communications comprising the steps of: receiving signals from an
RF transmitter/receiver to determine if a vehicle is in a first
driving state in a speed limit zone; establishing an ISA mode for
control into the first driving state and performing display to
alert the driver of such control; determining a present driving
state, comparing the present driving state with the first driving
state, determining if the present driving state corresponds to the
first driving state, and performing display to inform the driver of
the result of the comparison; determining if the driver has
performed a deceleration operation if the present driving state
does not correspond to the first driving state; disengaging the ISA
mode and enabling full control of the vehicle by the driver if the
present driving state corresponds to the first driving state or it
the driver has performed a deceleration operation; and controlling
an engine control unit via CAN communications if the driver has not
performed a deceleration operation, engine control being performed
such that a throttle valve is controlled to reduce the speed of the
vehicle.
6. The method of claim 6 wherein the step of determining if the
driver has performed a deceleration operation comprises the steps
of: (a) determining if the driver has depressed a brake,
determining if the driver has released an accelerator pedal, or if
the a throttle valve opening is less than a predetermined throttle
valve opening; (b) determining if the driver has operated a turn
signal if one of the conditions of step (a) is not satisfied; (c)
determining if a steering angle is greater than or equal to
30.degree.if the driver has not operated a turn signal; (d)
maintaining the ISA mode if the steering angle is less than
30.degree.; (e) disengaging the ISA if any of the conditions of
steps (a), (b) and (c) are satisfied.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an operational control
system for vehicles, and more particularly, to a vehicle speed
control system using wireless communications and a method for
controlling the same.
[0003] 2. Description of the Related Art
[0004] There are two main types of prior vehicle speed control
systems. One uses a GPS (Global Positioning System), while the
other uses RF (radio frequency) communications. In the vehicle
speed control system using a GPS, after the position of a vehicle
is determined, speed limit information corresponding to vehicle
position is used to possibly alert the driver or control the
vehicle. With the system using RF communications, the vehicle is
controlled in areas where RF signals are received. Both these
systems are still undergoing testing in Europe, Japan and other
countries.
[0005] A drawback of the system utilizing the GPS is that road
information of a uniform setting is used. That is, changes in road
conditions are not taken into account. With the system in which RF
communications are used, on the other hand, vehicle control is
realized according to pre-installed road information, and each RF
transmitter is controlled such that vehicle control is performed to
match changing weather and road conditions.
[0006] However, a serious drawback of the system utilizing RF
communications is that the system is limited to use in only areas
where RF signals are received. Accordingly, a strong output is
required by the RF transmitters, and, as a result, the same
information may be transmitted to more than just the targeted
vehicle. That is, unwanted control of a vehicle travelling in the
opposite lane may result. Vehicle speed control is particularly
problematic in areas where there are curves in the road.
SUMMARY OF THE INVENTION
[0007] The present invention has been made in an effort to solve
the above problems.
[0008] It is an object of the present invention to provide a
vehicle speed control system using wireless communications and a
method for controlling the same in which vehicle control is
possible with only a small output by a RF transmitter, and in which
unanticipated vehicle control is prevented.
[0009] To achieve the above object, the present invention provides
a vehicle speed control system using wireless communications and a
method for controlling the same. The system comprises a driving
state detecting unit for detecting steering angle, vehicle speed,
throttle valve opening, brake operation, and turn signal operation,
and outputting corresponding signals; a transmitter/receiver for
outputting low-strength signals containing information of a speed
limit and a range of the speed limit; an electronic control unit
for receiving the signals of the transmitter/receiver and
establishing an ISA mode if necessary, determining if a present
driving state corresponds to a first driving state using the
signals of the driving state detecting unit, determining if the
driver has performed deceleration operations, and performing
control into the first driving state if needed; an engine control
unit for outputting signals for control of the throttle valve
opening according to control signals of the electronic control
unit; a throttle valve electronic control unit for receiving the
signals output from the engine control unit and outputting
electrical signals to a throttle valve to control an opening degree
of the throttle valve; and a display for displaying a present mode
and a vehicle state according to the control signals of the
electronic control unit.
[0010] According to a feature of the present invention, the
transmitter/receiver is provided adjacent to a specific lane, and
the low-strength signals of the transmitter/receiver are such that
vehicles traveling on the opposite lane do not receive the
signals.
[0011] According to another feature of the present invention, the
electronic control unit determines if the present driving state
corresponds to the first driving state after establishing the ISA
mode, enables full control of the vehicle by the driver if the
present driving state corresponds to the first driving state, and
control the display to output a warning message if the present
driving state does not correspond to the first driving state.
[0012] According to yet another feature of the present invention,
the electronic control unit determines if the driver has performed
a deceleration operation during a predetermined interval after
output of the warning message, enables full control of the vehicle
by the driver if the driver has performed a deceleration operation,
and performing control into the first driving state if the driver
has not performed a deceleration operation.
[0013] The method for controlling the vehicle control system using
wireless communications comprising the steps of receiving signals
from an RF transmitter/receiver to determine if a vehicle is in a
first driving state in a speed limit zone; establishing an ISA mode
for control into the first driving state and performing display to
alert the driver of such control; determining a present driving
state, comparing the present driving state with the first driving
state, determining if the present driving state corresponds to the
first driving state, and performing display to inform the driver of
the result of the comparison; determining if the driver has
performed a deceleration operation if the present driving state
does not correspond to the first driving state; disengaging the ISA
mode and enabling full control of the vehicle by the driver if the
present driving state corresponds to the first driving state or if
the driver has performed a deceleration operation; and controlling
an engine control unit via CAN communications if the driver has not
performed a deceleration operation, engine control being performed
such that a throttle valve is controlled to reduce the speed of the
vehicle.
[0014] According to a feature of the present invention, the step of
determining if the driver has performed a deceleration operation
comprises the steps of (a) determining if the driver has depressed
a brake, determining if the driver has released an accelerator
pedal, or if the a throttle valve opening is less than a
predetermined throttle valve opening; (b) determining if the driver
has operated a turn signal if one of the conditions of step (a) is
not satisfied; (c) determining if a steering angle is greater than
or equal to 30.degree.if the driver has not operated a turn signal;
(d) maintaining the ISA mode if the steering angle is less than
30.degree.; (e) disengaging the ISA if any of the conditions of
steps (a), (b) and (c) are satisfied.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate an embodiment of
the invention, and, together with the description, serve to explain
the principles of the invention:
[0016] FIG. 1 is a block diagram of a vehicle speed control system
using wireless communications according to a preferred embodiment
of the present invention;
[0017] FIG. 2 is a flow chart of a method for controlling the
vehicle speed control system using wireless communications of FIG.
1 according to a preferred embodiment of the present invention;
and
[0018] FIG. 3 is a flow chart of a process for determining when the
driver has performed deceleration operations.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Preferred embodiments of the present invention will now be
described in detail with reference to the accompanying
drawings.
[0020] FIG. 1 shows a block diagram of a vehicle speed control
system using wireless communications according to a preferred
embodiment of the present invention.
[0021] As shown in the drawing, the vehicle speed control system
includes a steering angle sensor 100, a vehicle speed sensor 200, a
throttle valve position sensor 300, a brake sensor 400, left turn
signal sensor 500, a right turn signal sensor 600, an RF
transmitter/receiver 700, an ECU 800, a display 900, a sound output
unit 1000, warning light driver 1100, a CAN communications
interface 1200, an EMS 1300, an ETC (electronic throttle valve
controller) 1400, and a throttle valve 1500.
[0022] The steering angle sensor 100 detects the operation of a
steering wheel (i.e., the degree to which the steering wheel has
been rotated by the driver), and outputs corresponding electrical
signals to the ECU 800. The vehicle speed sensor 200 detects a
present vehicle speed and outputs corresponding electrical signals
to the ECU 800. The throttle valve position sensor 300 detects an
opening degree of a throttle valve and outputs corresponding
electrical signals to the ECU 800. The brake sensor 400 detects
driver operation of a brake pedal and outputs corresponding
electrical signals to the ECU 800. The left turn signal sensor 500
and the right turn signal sensor 600 detect the operation of a turn
signal and output corresponding electrical signals to the ECU
800.
[0023] The RF transmitter/receiver 700 is installed at a specific
location adjacent to a road, and outputs a signal including a
message for controlling a vehicle at a predetermined speed and for
a set distance. The RF transmitter/receiver 700 outputs a weak
signal such that vehicles travelling in an opposite lane do not
receive the signal. At this time, since the output of the RF
transmitter/receiver 700 is weak such that the entire speed limit
zone is not covered, information of a range of the speed limit zone
is included in the signal.
[0024] The RF transmitter/receiver 700 receives control signals
from a control center, the control signals varying operational and
output messages of the RF transmitter/receiver 700. It is also
possible for the RF transmitter/receiver 700 to receive signals
from vehicles such that the control center is alerted of changes in
road conditions such as those caused by a change in weather and the
occurrence of an accident.
[0025] The ECU 800 determines the present driving state of the
vehicle from the signals received from the various sensors 100 -
600 and from the RF transmitter/receiver 700. From the signals
output by the RF transmitter/receiver 700, the presence of a first
driving state zone is determined. The ECU 800 compares two driving
states to determine if the driver has performed deceleration
operations to thereby determine if forced control into the first
driving state is required. If such control is needed, corresponding
control signals are output by the ECU 800.
[0026] The display 900 is realized through an LED (light emitting
diode) and a VFD (vacuum fluorescent display). However, it is
possible to use other display elements such as an LCD (liquid
crystal display). The display 900 enables the driver to check the
present driving state controlled by the ECU 800, as well as a mode
set up the by ECU 800. The sound output unit 1000 alerts the driver
when the present driving state does not correspond to the first
driving state. The warning light driver 1100 operates a warning
light according to control by the ECU 800 when the vehicle is
forced into the first driving state. The CAN communications
interface 1200 receives control signals from the ECU 800 and
transmits the control signals to the EMS 1300 via CAN
communications. After receiving the control signals from ECU 800
via the CAN communications interface 1200, the EMS 1300 outputs
control signals for control the opening degree of the throttle
valve 1500. The ETC 1400 outputs electrical signals to the throttle
valve 1500 according to the control signals output by the EMS 1300
to control throttle valve opening.
[0027] FIG. 2 shows a flow chart of a method for controlling the
vehicle speed control system using wireless communications
described above.
[0028] After the vehicle is started, the ECU 800 initializes an
operational program in step S100, after which the ECU 800 receives
the signals output by the sensors 100 through 600 to determine the
present driving state of the vehicle in step S200. That is, the ECU
800 determines the present vehicle speed and throttle valve opening
from the signals output by the vehicle speed sensor 200 and the
throttle valve position sensor 300, respectively. Also, the ECU
determines the driving direction of the vehicle and whether the
brake is depressed from the signals output by the steering angle
sensor 100, the brake sensor 400, and the left and right turn
signal sensors 500 and 600.
[0029] Subsequently, the ECU 800 performs a self-diagnosis using
the signals input from the various sensors 100 through 600, and
signals received from other sensors corresponding to engine rpm and
turbine rpm in step S300. That is, the ECU 800 determines if there
is any malfunction, and if there is, performs the necessary
control. Accordingly, a stable driving state is realized.
[0030] If the vehicle enters a special speed limit zone, that is an
area where there is a substantial curve in the road, an area where
weather conditions require slower driving, or a school zone area,
signals transmitted by the RF transmitter/receiver 700 are received
by the vehicle in step S400. The ECU 800 then processes the signals
of the RF transmitter/receiver 700 to determine if control into the
first driving state is needed in step S500. The first driving state
refers to the driving state needed when driving through a special
speed limit zone.
[0031] In the above, since weak signals are output by the RF
transmitter/receiver 700, the entire special speed limit zone can
not be covered. Accordingly, information of the range of the
special speed limit zone is included in the signals. Hence, the ECU
800 determines from the signals of the RF transmitter/receiver 700
both the requirement for control into the first driving state and
the range of the special speed limit zone.
[0032] Next, the ECU 800 establishes an ISA mode for controlling
the driving state of the vehicle into the first driving state in
step S600. After completing this step, the ECU 800 drives the
display 900 to inform the driver that the ISA mode has been
established in step S700. That is, the display 900 illuminates the
LED to inform the driver of the establishment of the ISA mode.
Next, through the VFD, the display 900 informs the driver of road
information such as the speed limit, whether the vehicle is
speeding, and the reason for the special speed limit zone (curves
in the road, fog area, school zone, etc.) in step S800.
[0033] After driving the display 900 as in the above, the ECU 800
checks whether the present driving state corresponds to the first
driving state to determine if the ISA mode needs to be established,
and, finally, to determine if a warning mode needs to be
established in step S900. Here, the comparison of the present
driving state with the first driving state is performed to
determine whether the present driving state already corresponds to
the first driving state such that further control is not required.
If the present driving state corresponds to the first driving
state, the ECU 800 disengages the ISA mode in step S1800 such that
the vehicle is driven according to driver operation in step S1900.
Following this step, the ECU 800 continues to receive signals from
the sensors 100 - 600 to monitor the present driving state.
However, if the present driving state does not correspond to the
first driving state after entering a special speed limit zone, the
ISA mode is established and the following operations are
performed.
[0034] In particular, in the case where the present driving state
does not correspond to the first driving state in step S900, the
ECU 800 drives the sound output unit 1000 such that the driver is
alerted by a sound warning message that the vehicle has entered a
special speed limit zone and also that the present driving state
does not correspond to the first driving state in step S1000. The
duration of the output by the sound output unit 1000 can be varied
by the manufacturer.
[0035] Next, the ECU 800 initiates a response time delay for a
predetermined time during which no control is performed in step
S1100. This allows the driver some time to react to the sound
warning message. After the response time delay, the ECU 800
determines if the driver has performed deceleration operations in
step S1200. That is, using the output of the brake sensor 400, the
steering angle sensor 100, and the left and right turn signal
sensors 500 and 600, the ECU 800 initiates the procedure outlined
in FIG. 3 to determine if the driver has performed deceleration
operations. Here, deceleration operations refer to those actions
taken by the driver resulting in the vehicle being driven in the
first driving state such that forced control is unneeded.
[0036] With reference to FIG. 3, the ECU 800 first determines if a
brake signal has been output by the brake sensor 400, or if an idle
signal has been output by an idle switch (not shown), or through
the signals output by the throttle valve position sensor 300 if a
throttle valve opening is at or below a lower critical value in
step S1210. That is, it is determined respectively if the brake
pedal has been depressed, or if the accelerator pedal has been
released, or if the accelerator pedal is depressed only slightly,
which are all indicative of deceleration operations by the driver.
If it is determined one or more of the conditions of step S1210 are
satisfied, the ECU 800 disengages the ISA mode in step S1250.
[0037] However, if none of the conditions of step S1210 are
satisfied, the ECU 800 determines if the left turn signal sensor
500 or the right turn signal sensor 600 has output a signal in step
S1220. Here, input by the left or right turn signal sensors 500 and
600 is regarded as the driver's intention to move from the present
lane to a slow speed lane. If a signal from the left or right turn
signals 500 and 600 is received, the ECU 800 then disengages the
ISA mode in step S1250.
[0038] If no signal is received from the left turn signal sensor
500 or the right turn signal sensor 600, the ECU 800 then
determines if a steering angle is greater than 30.degree.in step
S1230. That is, from the signals output from the steering angle
sensor 100, the ECU 800 determines if the steering wheel has been
rotated by the driver more than 30.degree.in either direction. Such
operation of the steering wheel is also regarded as the driver's
intention to a slow speed lane. This step is performed in addition
to step S1220 since it is possible for the driver to change lanes
without the use of turn signals.
[0039] If the condition of step S1230 is not satisfied, the ISA
mode is maintained in step S1300 of FIG. 2. In more detail, if none
of the conditions outlined in FIG. 3 are satisfied, it is
determined that the driver has not performed any deceleration
operations such that it is necessary to maintain the establishment
of the ISA mode. Next, the ECU 800 outputs a drive signal to the
warning light driver 1100 such that the warning light is
illuminated in step S1400.
[0040] The above is followed by actual forced control into the
first drive state (i.e., implementation of the ISA mode). That is,
the ECU 800 does not directly perform control to reduce throttle
valve opening, but instead outputs a throttle valve opening control
signal to the EMS 1300 via the CAN communications interface 1200 in
step S1500. After receiving the throttle valve opening control
signal, the EMS 1300 outputs a control signal to the ETC 1400,
which, in turn, outputs a drive signal to the throttle valve 1500
such that the throttle valve opening is reduced to less than the
predetermined lower critical value in step S1600. Accordingly,
vehicle speed is reduced to correspond to the first driving
state.
[0041] In step S1200, if the ECU 800 determines the driver has
performed deceleration operations, the ECU 800 disengages the ISA
mode in step S1800 such that the vehicle is driven according to
driver operation in step S1900.
[0042] There are many advantages to the vehicle speed control
system using wireless communications and method for controlling the
same of the present invention described above: it is acceptable for
the output of the RF transmitter/receiver to be weak, thereby
preventing non-targeted vehicles (i.e., vehicles travelling in the
opposite lane) from receiving control; smooth control is performed
as a result of vehicle speed control by the ECU; and driver
deceleration operations are detected such that unwanted control is
not performed.
[0043] Although preferred embodiments of the present invention have
been described in detail hereinabove, it should be clearly
understood that many variations and/or modifications of the basic
inventive concepts herein taught which may appear to those skilled
in the present art will still fall within the spirit and scope of
the present invention, as defined in the appended claims.
* * * * *