U.S. patent number RE37,434 [Application Number 07/482,508] was granted by the patent office on 2001-11-06 for condition adaptive-type control method for internal combustion engines.
This patent grant is currently assigned to Hitachi, Ltd.. Invention is credited to Takeshi Atago, Motohisa Funabashi, Mikihiko Onari, Teruji Sekozawa.
United States Patent |
RE37,434 |
Onari , et al. |
November 6, 2001 |
Condition adaptive-type control method for internal combustion
engines
Abstract
To perform the proper control conforming to the intent of a
driver of an automotive vehicle under any condition which is
encountered by the vehicle, optimum control methods are
preliminarily classified in accordance with categories relating to
conditions of the vehicle and categories relating to intents of the
driver and the classified optimum control methods are stored in a
memory, thereby selecting one of the control methods corresponding
to the combination of the categories to which the vehicle condition
and the driver's intent detected during the running of the vehicle
belong.
Inventors: |
Onari; Mikihiko (Kokubunji,
JP), Sekozawa; Teruji (Kawasaki, JP),
Funabashi; Motohisa (Sagamihara, JP), Atago;
Takeshi (Katsuta, JP) |
Assignee: |
Hitachi, Ltd. (Tokyo,
JP)
|
Family
ID: |
14386332 |
Appl.
No.: |
07/482,508 |
Filed: |
February 21, 1990 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
046388 |
May 6, 1987 |
04853720 |
Aug 1, 1989 |
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Foreign Application Priority Data
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May 9, 1986 [JP] |
|
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61-104650 |
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Current U.S.
Class: |
701/110;
123/350 |
Current CPC
Class: |
B60K
31/0008 (20130101); B60W 10/04 (20130101); B60W
50/0097 (20130101); B60K 31/04 (20130101); B60W
10/18 (20130101); B60W 30/1819 (20130101); F02D
41/1497 (20130101); B60W 2510/0638 (20130101); B60W
2710/065 (20130101); B60W 2050/0057 (20130101); B60W
2710/0622 (20130101); B60W 2710/105 (20130101); B60W
40/09 (20130101); B60W 2540/106 (20130101); B60W
2530/00 (20130101); B60W 2540/10 (20130101); B60T
2220/02 (20130101); B60W 2540/12 (20130101); B60W
2710/0616 (20130101); B60W 2540/30 (20130101) |
Current International
Class: |
B60K
31/00 (20060101); F02D 41/14 (20060101); F02D
009/02 () |
Field of
Search: |
;364/431.07,431.04,424.01,424.02,426.01 ;123/350,352,351,395 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2151049 |
|
Jul 1985 |
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GB |
|
2151048 |
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Jul 1985 |
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GB |
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Primary Examiner: Bennet; Henry A.
Attorney, Agent or Firm: Antonelli, Terry, Stout &
Kraus, LLP
Claims
What is claimed is:
1. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having a torque
transmission mechanism, a brake pedal and an accelerator pedal,
comprising the steps of:
categorizing driver's intents and vehicle conditions, respectively,
into a plurality of categories, and preparing different engine
control methods for different combinations of said categories;
detecting a driver's intent in accordance with the state of
engagement or disengagement of said torque transmission mechanism,
the angle of said brake pedal and the angle of said accelerator
pedal;
detecting said vehicle condition from the speed of said vehicle;
and
selecting one of said engine control methods in accordance with a
combination of the categories to which said detected driver's
intent and vehicle condition belong.
2. A method according to claim 1, wherein said engine control
methods differ by the fact that they refer to different parameter
values.
3. A method according to claim 2, wherein said parameter values may
be changed according to a driver's preference.
4. A method according to claim 1, wherein said detecting step is
performed with a higher priority than other steps.
5. A method according to claim 1, wherein said selecting step
further includes a step of anticipating the occurrence of a future
phenomenon which is predicted to occur at a time when a selected
control method is employed so as to select one engine control
method in accordance with a result of said anticipating.
6. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle, comprising the
steps of:
categorizing driver's intents and vehicle conditions into six
categories and two categories, respectively, and preparing five
types of engine control methods, including an acceleration control
method, a deceleration control method, a fuel cut-off control
method, an air/fuel ratio control method and an idle speed control
method, which correspond to respective combinations of said
categories;
detecting one of said six types of driver's intents including
engaging or disengaging of a torque transmission mechanism,
braking, transition or coasting, deceleration, running and
acceleration;
detecting said vehicle condition including engine speed to
determine whether said vehicle is in a rest condition or a running
condition; and
selecting one of said six types of engine control methods in
accordance with said combination of categories to which said
detected intent and vehicle condition belong.
7. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle, comprising:
a torque servo system including first reference setup means for
setting up a first reference signal of an engine torque, torque
measuring means measuring the actual torque of said engine, first
comparing means for comparing said first reference signal with said
measured torque so as to produce a first error signal indicative of
a difference between said reference signal and said measured
torque, and torque control means for producing a torque control
signal in accordance with said first error signal;
a speed servo system including second reference setup means for
setting up a second reference signal of a vehicle speed, vehicle
speed measuring means for measuring an actual vehicle speed of said
vehicle, second comparing means for comparing said second reference
signal with said measured vehicle speed so as to produce a second
error signal indicative of a difference between said second
reference signal and said measured vehicle speed, and speed control
means for producing a speed control signal in accordance with said
second error signal;
said speed servo system including said torque servo system as a
minor servo loop for said speed servo system;
a tracking servo system including third reference setup means for
setting up a third reference signal of a distance to a forward
vehicle, distance measuring means for measuring the actual distance
to a forward vehicle, third comparing means for comparing said
third reference signal with said measured distance so as to produce
a third error signal indicative of a difference between said third
reference signal and said measured distance, and tracking control
means for producing a tracking control signal in accordance with
said third error signal;
said tracking servo system including said speed servo system as a
minor servo loop for said tracking servo system;
means for sensing an accelerator pedal angle;
means for sensing a brake pedal angle;
means for sensing engine speed;
means for detecting whether a torque transmission mechanism of said
vehicle is engaged or disengaged;
a running control selector switch for selecting one of said servo
systems;
condition discriminating means responsive to the outputs of said
accelerator pedal angle sensing means, brake pedal angle sensing
means, engine speed sensing means, torque transmission mechanism
detecting means and said selector switch for categorizing a
driver's intent and a vehicle condition in accordance with said
outputs, for determining one engine control method among different
engine control methods previously stored in said condition
discriminating unit in accordance with a combination of said
categories of said driver's intent and said vehicle condition, and
for determining one servo system among said tracking servo system,
speed servo system and said torque servo system in accordance with
said output of said running control selector switch and said first,
second and third reference signals so as to control said selected
servo system to operate in accordance with said determined engine
control method and to provide said reference signals to said
reference setup units of the selected servo system; and
engine control means for controlling fuel injection and ignition
timing of said engine in response to said torque control signal
from said torque servo system.
8. A condition adaptive-type control system according to claim 7,
wherein said different engine control methods include an
acceleration control method, a deceleration control method, a fuel
cut-off method, an air/fuel ratio control method and an idle
control method, said idle control method being operated with said
speed servo system and the other four engine control methods being
operated with said torque servo system.
9. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having a torque
transmission mechanism, a brake pedal and an accelerator pedal,
comprising the steps of:
providing a plurality of different engine control methods for said
engine, each of said different engine control methods including
parameters and being associated with a combination of one of a
plurality of vehicle conditions and one of a plurality of driver's
intents;
discriminating said driver's intent by detecting the state of
engagement or disengagement of said torque transmission mechanism,
and by sensing the angle of said brake pedal and the angle of said
accelerator pedal;
discriminating said vehicle condition by sensing the speed of said
vehicle and determining whether said vehicle is in a rest condition
or not; and
selecting one of said engine control methods in accordance with a
combination of the discriminated driver's intent and vehicle
condition.
10. A method according to claim 9, wherein said step of
discriminating said driver's intent further includes calculation of
an acceleration rate of said vehicle on the basis of the sensed
angle of said accelerator pedal.
11. A method according to claim 10, wherein said plurality of
engine control methods include an acceleration control method, a
deceleration control method, a fuel cut-off control method, an
air-fuel ratio control method and an idle speed control method, and
said step of selecting one of said engine control methods is
executed by selectively choosing one of the following steps:
(1) selecting the acceleration control method when said torque
transmission mechanism is engaged and said acceleration rate
.theta.ac is greater than a first reference value .theta.aca;
(2) selecting the deceleration control method when said torque
transmission mechanism is engaged, the vehicle speed is greater
than zero and either said acceleration rate .theta.ac is equal to
or smaller than a second reference value .theta.acd or said
acceleration pedal is released;
(3) selecting the fuel cut-off control method when said torque
transmission mechanism is engaged, said acceleration pedal is
released, and said engine speed is greater than a reference
value;
(4) selecting the air-fuel ratio control method either when said
torque transmission mechanism is engaged, said vehicle speed is
greater than zero and said acceleration rate .theta.ac is between
the first and second reference values of .theta.aca and .theta.acd,
or when said torque transmission mechanism is disengaged and said
acceleration pedal is depressed; and
(5) selecting the idle speed control method when said torque
transmission mechanism is disengaged and said acceleration pedal is
released.
12. A method according to claim 9, wherein each of said engine
control methods further includes a step of updating values of said
parameters in accordance with each combination of the engine
condition and the driver's intent.
13. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having a torque
transmission mechanism, a brake pedal and an accelerator pedal,
comprising the steps of:
programming a plurality of different engine control methods with
parameters for said engine, each of said different engine control
methods being associated with a combination of one of a plurality
of vehicle conditions and one of a plurality of driver's intents,
including braking, coasting, transient operation, decelerating,
cruising and accelerating;
discriminating the driver's intent by detecting the state of
engagement or disengagement of said torque transmission mechanism,
the angle of said brake pedal and the angle of said accelerator
pedal;
discriminating said vehicle condition by detecting engine speed and
determining whether said vehicle is in a rest condition or not;
and
selecting one of said engine control methods in accordance with a
combination of the discriminated driver's intent and vehicle
condition. .Iadd.
14. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle having a torque
transmission mechanism, a brake pedal and an accelerator pedal,
comprising:
means for categorizing driver's intents and vehicle conditions,
respectively, into a plurality of categories, and for preparing
different engine control methods for different combinations of said
categories;
means for detecting a driver's intent in accordance with the state
of said torque transmission mechanism, the angle of said brake
pedal and the angle of said accelerator pedal;
means for detecting said vehicle condition from the speed of said
vehicle; and
means for selecting one of said engine control methods in
accordance with a combination of the categories to which said
detected driver's intent and vehicle condition
belong..Iaddend..Iadd.
15. A condition adaptive-type control system according to claim 14,
further includes means for differentiating said engine control
methods in a manner that they refer to different parameter
values..Iaddend..Iadd.
16. A condition adaptive-type control system according to claim 15,
further includes means for changing said parameter values according
to a driver's preference..Iaddend..Iadd.
17. A condition adaptive-type control system according to claim 14,
further includes means for performing detecting operations of both
said detecting means prior to other means..Iaddend..Iadd.
18. A condition adaptive-type control system according to claim 14,
further includes means for anticipating the occurrence of a future
phenomenon which is predicted to occur at a time when a selected
control method is employed so as to select one engine control
method in accordance with a result of said
anticipating..Iaddend..Iadd.
19. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle comprising:
means for categorizing driver's intents and vehicle conditions into
six categories and two categories, respectively, and for preparing
five types of engine control methods, including an acceleration
control method, a deceleration control method, a fuel cut-off
control method, an air/fuel ratio control method and and idle speed
control method, which correspond to respective combinations of said
categories;
means for detecting one of said six types of driver's intents
including a torque transmission mechanism, braking, transition or
coasting, deceleration, running and acceleration;
means for detecting said vehicle condition including engine spew to
determine whether said vehicle is in a rest condition or a running
condition; and
means for selecting one of said five types of engine control
methods in accordance with said combination of categories to which
said detected intent and vehicle condition
belong..Iaddend..Iadd.
20. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle having a torque
transmission mechanism, a brake pedal and an accelerator pedal,
comprising:
means for providing a plurality of engine control methods for said
engine, each of said different engine control methods including
parameters and being associated with a combination of one of a
plurality of vehicle conditions and one of a plurality of driver's
intents;
means for discriminating said driver's intent by detecting the
state of said torque transmission mechanism, and by sensing the
angle of said brake pedal and the angle of said accelerator
pedal;
means for discriminating said vehicle condition by sensing the
speed of said vehicle and for determining whether said vehicle is
in a rest condition or not; and
means for selecting one of said engine control methods in
accordance with a combination of the discriminated driver's intent
and vehicle condition..Iaddend..Iadd.
21. A condition adaptive-type control system according to claim 20,
wherein said means for discriminating said driver's intent includes
means for calculating an acceleration rate of said vehicle on the
basis of the sensed angle of said acceleration
pedal..Iaddend..Iadd.
22. A condition adaptive-type control system according to claim 21,
wherein said plurality of engine control methods include an
acceleration control method, a deceleration control method, a fuel
cut-off control method, an air-fuel ratio control method and an
idle speed control method, and said selecting means includes:
means for selecting the acceleration control method when said
torque transmission mechanism is engaged and said acceleration rate
.theta.ac is greater than a first reference value .theta.aca;
means for selecting the deceleration control method when said
torque transmission mechanism is engaged, the vehicle speed is
greater than zero and either said acceleration rate .theta.ac is
equal to or smaller than a second reference value .theta.acd or
said acceleration pedal is released;
means for selecting the fuel cut-off control method when said
torque transmission mechanism is engaged, said acceleration pedal
is released, and said engine speed is greater than a reference
value;
means for selecting the air-fuel ratio control method either when
said torque transmission mechanism is engaged, said vehicle speed
is greater than zero and said acceleration rate .theta.ac is
between the first and second reference values of .theta.aca and
.theta.acd, or when said torque transmission mechanism is
disengaged and said acceleration pedal is depressed; and
means for selecting the idle speed control method when said torque
transmission mechanism is disengaged and said acceleration pedal is
released..Iaddend..Iadd.
23. A condition adaptive-type control system according to claim 20,
further includes means for updating values of said parameters in
each of said engine control methods in accordance with each
combination of the engine condition and the driver's
intent..Iaddend..Iadd.
24. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle having a torque
transmission mechanism, a brake pedal and an accelerator pedal,
comprising:
means for programming a plurality of engine control methods with
parameters for said engine, each of said different engine control
methods being associated with a combination of one of a plurality
of vehicle conditions and one of a plurality of driver's intents,
including braking, coasting, transient operation, decelerating,
cruising and accelerating;
means for discriminating said driver's intent by detecting the
state of said torque transmission mechanism, the angle of said
brake pedal and the angle of said accelerator pedal;
means for discriminating said vehicle condition by detecting the
engine speed and determining whether said vehicle is in a rest
condition or not; and
means for selecting one of said engine control methods in
accordance with a combination of the discriminated driver's intent
and vehicle condition..Iaddend..Iadd.
25. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle, comprising the
steps of:
categorizing driver's intents and vehicle conditions into plural
categories and plural categories, respectively, and preparing
plural types of engine control methods, including an acceleration
control method, a deceleration control method, an air/fuel ratio
control method and an idle speed control method, which correspond
to respective combinations of said categories;
detecting one of said plural types of driver's intents including
braking, transition or coasting, deceleration, running and
acceleration;
detecting said vehicle condition including engine speed to
determine whether said vehicle is in a rest condition or a running
condition; and
selecting one of said plural types of engine control methods in
accordance with said combination of categories to which said
detected intent and vehicle condition belong..Iaddend..Iadd.
26. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle comprising:
means for categorizing driver's intents and vehicle conditions into
plural categories, respectively, and for preparing plural types of
engine control methods, including an acceleration control method, a
deceleration control method, an air/fuel ratio control method and
an idle speed control method, which correspond to respective
combinations of said categories;
means for detecting one of said plural types of driver's intents
including braking, transition or coasting, deceleration, running
and acceleration;
means for detecting said vehicle condition including engine speed
to determine whether said vehicle is in a rest condition or a
running condition; and
means for selecting one of said plural types of engine control
methods in accordance with said combination of categories to which
said detected intent and vehicle condition
belong..Iaddend..Iadd.
27. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having driver
controlled elements, comprising the steps of:
detecting a driver's action in controlling said elements;
detecting a driver's preference from at least one switch set by the
driver, said one switch being a switch for setting a cruise control
for said engine;
detecting whether a distance to a forward vehicle is within a
predetermined distance or not; and
outputting a control signal for the engine in accordance with the
results of said steps, the outputted control signal being one for
changing from the cruise control to a tracking control for tracking
the forward vehicle with said predetermined distance when it is
detected by said detecting steps that said cruise control switch is
set and the distance is within said predetermined
distance..Iaddend..Iadd.
28. A condition adaptive-type control method according to claim 27,
further comprises a step of detecting a vehicle speed, and a step
of determining said predetermined distance in accordance with the
detected vehicle speed..Iaddend..Iadd.
29. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having driver
controlled elements, comprising:
means for detecting a driver's action in controlling said
elements;
means for detecting a driver's preference from at least one switch
set by the driver, said one switch being a switch for setting a
cruise control for said engine;
means for detecting whether a distance to a forward vehicle is
within a predetermined distance or not; and
means for outputting a control signal for the engine in accordance
with the detected driver's action, driver's preference and
distance, the outputted control signal being one for changing from
the cruise control to a tracking control for tracking the forward
vehicle with said predetermined distance when it is detected by
said detecting means that said cruise control switch is set and the
distance is within said predetermined distance..Iaddend..Iadd.
30. A condition adaptive-type control system according to claim 29,
further comprises means for detecting a vehicle speed, and means
for determining said predetermined distance in accordance with the
detected vehicle speed..Iaddend..Iadd.
31. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having driver
controlled elements, comprising the steps of:
categorizing driver's action and vehicle conditions, respectively,
into a plurality of categories, and preparing different engine
control methods for different combinations of said categories;
detecting said driver's action in controlling said elements;
detecting said vehicle condition from an operational parameter of
said vehicle;
selecting one of said engine control methods in accordance with a
combination of the categories to which said detected driver's
action and vehicle condition belong; and
detecting a driver's preference from at least one switch set by the
driver, wherein said categorizing step includes a step of
categorizing said driver's action, said vehicle conditions and said
driver's preference respectively, into a plurality of categories,
and a step of preparing different engine control methods for
different combinations of said categories, and said selecting step
includes a step of selecting one of said engine control methods in
accordance with a combination of the categories to which said
detected driver's action, vehicle condition and driver's preference
belong..Iaddend..Iadd.
32. A condition adaptive-type control system for in internal
combustion engine mounted on an automotive vehicle having driver
controlled elements comprising:
means for categorizing driver's action and vehicle conditions,
respectively, into a plurality of categories, and for preparing
different engine control methods for different combinations of said
categories;
means for detecting said driver's action in controlling said
elements;
means for detecting vehicle conditions from at least one
operational parameter of said vehicle; and
means for selecting one of said engine control methods in
accordance with a combination of the categories to which said
detected driver's action and vehicle condition
belong..Iaddend..Iadd.
33. A condition adaptive-type control system according to claim 31,
further comprising means for detecting a driver's preference from
at least one switch set by the driver, wherein said categorizing
means includes means for categorizing said driver's action, said
vehicle conditions and said driver's preference respectively, into
a plurality of categories, and for preparing different engine
control methods for different combinations of said categories, and
said selecting step includes a step of selecting one of said engine
control methods in accordance with a combination of the categories
to which said detected driver's action, vehicle condition and
driver's preference belong..Iaddend..Iadd.
34. A condition adaptive-type control method according to claim 36,
further comprising a step of detecting a driver's preference from
switches set by the driver, wherein said selecting step includes a
step of selecting one of said engine control methods in accordance
with said detected driver's action, vehicle condition and driver's
preference..Iaddend..Iadd.
35. A condition adaptive-type control method according to claim 34,
wherein the driver's preference detected from said switches is one
of sporty, luxury and economy modes of driving..Iaddend..Iadd.
36. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having different
engine control methods and driver controlled elements, comprising
the steps of:
detecting a driver's action in controlling said elements;
detecting a vehicle condition from an operational parameter of said
vehicle; and
selecting one of said engine control methods in accordance with
combination of said detected driver's action and vehicle
condition;
wherein said engine control methods include an acceleration control
method, a deceleration control method, a fuel cut-off control
method, an air-fuel ratio control method and an idle speed control
method; and
wherein said engine control methods are composed of the
combinations of torque servo, speed servo and tracking servo
systems..Iaddend..Iadd.
37. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having different
engine control methods and driver controlled elements, comprising
the steps of:
detecting a driver's action in controlling said elements;
detecting a vehicle condition from an operational parameter of said
vehicle;
selecting one of said engine control methods in accordance with
combination of said detected driver's action and vehicle condition;
and
detecting a driver's preference from switches set by the driver,
wherein said selecting step includes a step of selecting one of
said engine control methods in accordance with said detected
driver's action, vehicle condition and driver's preference;
wherein said engine control methods include an acceleration control
method, a deceleration control method, a fuel cut-off control
method, an air-fuel ratio control method and an idle speed control
method, and the driver's preference detected from said switches is
one of sporty, luxury and economy modes of
driving..Iaddend..Iadd.
38. A condition adaptive-type control method according to claim 37,
wherein said engine control methods are composed of the
combinations of torque servo, speed servo and tracking servo
systems selected in accordance with said detected driver's
preference..Iaddend..Iadd.
39. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle having different
engine control methods and driver controlled elements
comprising:
means for detecting a driver's action in controlling said
elements;
means for detecting a vehicle condition from an operational
parameter of said vehicle; and
means for selecting one of said engine control methods in
accordance with a combination of said detected driver's action and
vehicle condition; and
means for detecting a driver's preference from switches set by the
driver;
wherein said selecting means includes means for selecting one of
said engine control methods in accordance with said detected
driver's action, vehicle condition and driver's
preference..Iaddend..Iadd.
40. A condition adaptive-type control system according to claim 39,
wherein said engine control methods include an acceleration control
method, a deceleration control method, a fuel cut-off control
method, an air-fuel ratio control method and an idle speed control
method, and the driver's preference detected from said switches is
one of sporty, luxury and economy modes of
driving..Iaddend..Iadd.
41. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle having different
engine control methods and driver controlled elements
comprising:
means for detecting a driver's action in controlling said
elements;
means for detecting a vehicle condition from an operational
parameter of said vehicle; and
means for selecting one of said engine control methods in
accordance with a combination of said detected driver's action and
vehicle condition;
wherein said engine control methods include an acceleration control
method, a deceleration control method, a fuel cut-off control
method, an air-fuel ratio control method and an idle speed control
method; and
wherein said engine control methods are composed of the
combinations of torque servo, speed servo and tracking servo
systems..Iaddend..Iadd.
42. A condition adaptive-type control system for an internal
combustion engine mounted on an automotive vehicle having different
engine control methods and driver controlled elements
comprising:
means for detecting a driver's action in controlling said
elements;
means for detecting a vehicle condition from an operational
parameter of said vehicle;
means for selecting one of said engine control methods in
accordance with a combination of said detected driver's action and
vehicle condition; and
means for detecting a driver's preference from switches set by the
driver, wherein said selecting means includes means for selecting
one of said engine control methods in accordance with said detected
driver's action, vehicle condition and driver's preference;
wherein said engine control methods include an acceleration control
method, a deceleration control method, a fuel cut-off control
method, an air-fuel ratio control method and an idle speed control
method..Iaddend..Iadd.
43. A condition adaptive-type control system according to claim 42,
wherein the driver's preference detected from said switches is one
of sporty, luxury and economy modes of driving..Iaddend..Iadd.
44. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having different
engine control methods and driver controlled elements
comprising:
means for detecting a driver's action in controlling said
elements;
means for detecting a vehicle condition from an operational
parameter of said vehicle;
means for selecting one of said engine control methods in
accordance with a combination of said detected driver's action and
vehicle condition; and
means for detecting a driver's preference from switches set by the
driver, wherein said selecting means includes means for selecting
one of said engine control methods in accordance with said detected
driver's action, vehicle condition and driver's preference;
wherein said engine control methods include an acceleration control
method, a deceleration control method, a fuel cut-off control
method, an air-fuel ratio control method and an idle speed control
method, and the driver's preference detected from said switches is
one of sporty, luxury and economy modes of driving; and
wherein said engine control methods are composed of the
combinations of torque servo, speed servo and tracking servo
systems selected in accordance with said detected driver's
preference..Iaddend..Iadd.
45. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle having torque
servo, speed servo and tracking servo systems and reference setup
units, comprising the steps of:
setting up a first reference signal of an engine torque, measuring
the actual torque of said engine, comparing said first reference
signal with said measured torque so as to produce a first error
signal indicative of a difference between said reference signal and
said measured torque, and producing a torque control signal in
accordance with said first error signal;
setting up a second reference signal of a vehicle speed, measuring
an actual vehicle speed of said vehicle, comparing said second
reference signal with said measured vehicle speed so as to produce
a second error signal indicative of a difference between said
second reference signal and said measured vehicle speed, and
producing a speed control signal corresponding to said first error
signal in accordance with said second error signal;
setting up a third reference signal of a distance to a forward
vehicle, measuring the actual distance to a forward vehicle,
comparing said third reference signal with said measured distance
so as to produce a third error signal indicative of a difference
between said third reference signal and said measured distance, and
producing a tracking control signal corresponding to said second
error signal in accordance with said third error signal;
detecting an output of a running control selector switch for
selecting one of said servo systems;
determining one servo system among said tracking servo system,
speed servo system and said torque servo system in accordance with
said output of said running control selector switch and said first,
second and third reference signals so as to control said selected
servo system to provide said reference signals to said reference
setup units of the selected servo system; and
controlling fuel injection and/or ignition timing of said engine in
response to said torque control signal from said torque servo
system..Iaddend..Iadd.
46. A condition adaptive-type control method for an internal
combustion engine mounted on an automotive vehicle, having driver
controlled elements, torque servo, speed servo and tracking servo
systems, reference setup units, a condition discriminating unit,
and different engine control methods comprising the steps of:
setting up a first reference signal of an engine torque, measuring
the actual torque of said engine, comparing said first reference
signal with said measured torque so as to produce a first error
signal indicative of a difference between said reference signal and
said measured torque, and producing a torque control signal in
accordance with said first error signal;
setting up a second reference signal of a vehicle speed, measuring
an actual vehicle speed of said vehicle, comparing said second
reference signal with said measured vehicle speed so as to produce
a second error signal indicative of a difference between said
second reference signal and said measured vehicle speed, and
producing a speed control signal corresponding to said first error
signal in accordance with said second error signal;
setting up a third reference signal of a distance to a forward
vehicle, measuring the actual distance to a forward vehicle,
comparing said third reference signal with said measured distance
so as to produce a third error signal indicative of a difference
between said third reference signal and said measured distance, and
producing a tracking control signal corresponding to said second
error signal in accordance with said third error signal;
categorizing driver's action and vehicle conditions, respectively,
into a plurality of categories, and preparing different engine
control methods for different combinations of said categories;
detecting said driver's action in controlling said elements;
detecting said vehicle condition from an operational parameter of
said vehicle; and
detecting an output of a running control selector switch for
selecting one of said servo systems; determining one engine control
method among different engine control methods previously stored in
said condition discriminating unit in accordance with a combination
of said categories of said driver's action and said vehicle
condition, and determining one servo system among said tracking
servo system, speed servo system and said torque servo system in
accordance with said output of said running control selector switch
and said first, second and third reference signals so as to control
said selected servo system to operate in accordance with said
determined engine control method and to provide said reference
signals to said reference setup units of the selected servo system;
and
controlling fuel injection and/or ignition timing of said engine in
response to said torque control signal from said torque servo
system..Iaddend..Iadd.
47. A condition adaptive-type control method according to claim 46,
wherein said different engine control methods include an
acceleration control method, a deceleration control method, a fuel
cut-off method, an air/fuel ratio control method and an idle
control method, said idle control method being operated with said
speed servo system and the other four engine control methods being
operated with said torque servo system..Iaddend..Iadd.
48. A vehicle comprising:
first subsystem which includes means for detecting a driver's
behavior, means for detecting a vehicle condition and means for
detecting an environmental condition and for generating a signal in
accordance with the output of said detecting means; and
a second subsystem which controls the vehicle in accordance with
said signal;
wherein said environmental condition is given by a signal of a
distance between the vehicle and an obstacle and/or a preceding
vehicle detected by a distance sensor provided for the vehicle;
wherein said first subsystem includes driver's preference selector
switches and generates the signal for said second subsystem in
accordance with a signal given by one of said selector
switches..Iaddend..Iadd.
49. An adaptive control system for an automotive vehicle having
driver controlled elements comprising:
first subsystem which includes means for detecting a driver's
behavior in controlling said elements, means for detecting a
vehicle condition from an operational parameter of said vehicle and
means for detecting an environmental condition, generates a
reference signal in accordance with the output of said detecting
means; and
second subsystem which includes a feedback control, controls the
vehicle in accordance with said reference signal a feedback signal
corresponding to said control;
wherein said environmental condition is given by a signal of a
distance between the vehicle and an obstacle and/or a preceding
vehicle detected by a distance sensor provided for the vehicle;
wherein said first subsystem includes driver's preference selector
switches and generates the signal for said second subsystem in
accordance with a signal given by one of said selector
switches..Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a method for controlling a fuel
injection system and an ignition system in an internal combustion
engine, and more particularly to a control method for the internal
combustion engine of an automotive vehicle which is well suited to
meet the driver's various requirements relating to the driving of
the vehicle.
Heretofore known electronic fuel injection control systems employ a
method of intermittently supplying the fuel in an amount
corresponding to the intake air flow rate and also varying the fuel
quantity during the period of acceleration and deceleration (refer
the below-mentioned (1) and (2)). During constant speed driving,
this method can supply the engine with an amount of air and a fuel
quantity which are proportional to the load and therefore there is
no inconvenience. However, the method is disadvantageous in that
the engine cannot be controlled properly during transient
conditions, e.g., times of acceleration and deceleration.
As described above, the conventional control systems have been
unable to provide satisfactory functions to meet the highly
sophisticated and diversified requirements relating to driving
performance. On the other hand, while torque servo controls and
speed servo controls are proposed (e.g., the below-mentioned
techniques (3) and (5)) to meet sophisticated requirements, no
satisfactory consideration has been given to an overall control
ensuring proper control under all conditions which are encountered
by the vehicle.
Note that the prior art techniques relating to these types of
systems include the following, for example.
(1) IDEI: "The Engine Controls", Institute of Electrical Engineers
of Japan Journal Vol. 101, No. 12, P. 1148 (December 1981) . . .
Controls by Microcomputers; This relates to table look-up
systems.
(2) NAGAYAMA et al: Centralized Control of Engine by
Microcomputers, Systems and Controls, Vol. 24, No. 5, P. 306 (May
1980); This relates to flow charts of engine operations, fuel
injection control, ignition timing control and idling speed
control.
(3) T. TABE et al: On the Application of Modern Control Theory to
Automotive Engine Control, IECOM '85; This relates to torque
servos.
(4) JP-A-57-73836
(5) ITO: "Fuel Economy Optimalizing Control System with Compound
Control Action on Engine and Transmission", Automotive Engineering,
February 83; This relates to speed servos.
The above-mentioned conventional techniques have failed to give due
consideration in comprehensively grasping as a system the control
of the engine on a vehicle. Thus, there have been a lack of engine
control methods which could meet all the situations in which the
vehicle is to be used and the difficulty to establish the necessary
parameters for such engine control methods has been a
disadvantage.
One reason is that the conventional engine control methods are made
up of static models despite the fact that the conditions which are
encountered by a vehicle are a repetition of steady-state
operations, e.g., the constant speed running and idling operation
and the transient state operation such as acceleration and
deceleration. Moreover, the requirements for the behaviour of the
vehicle during the transient conditions have become increasingly
severe on the part of the users of the vehicles. As a result, even
if measuring devices are installed to observe the transient
conditions, their full utilization cannot be ensured by the static
model.
In the case of the conventional methods in which the static control
model is compensated for the transient conditions, a great deal of
manhours are required to materialize and adjust an engine control
method for each of different types of vehicles which are diversely
different in vehicle characteristics, measuring devices, actuators,
etc.
SUMMARY OF THE INVENTION
With a view to overcoming the foregoing deficiencies in the prior
art, it is an object of the invention to provide a method of
controlling an internal combustion engine mounted on a vehicle in
which different vehicle conditions and driver's different intents
are respectively discriminated and divided into categories so as to
select a proper one of a plurality of engine control methods
corresponding to each of various combinations of the
categories.
To adapt the dynamic characteristic of the vehicle to the
sensitivity or fancy of the driver, it is only necessary to
discriminate and classify the preferences of the driver into
certain preference modes, such as, sporty, luxury and economy modes
of driving and change the parameters of the respective control
methods to suit the corresponding modes. To realize the selection
of the engine control methods corresponding to the above
discrimination and classification, it is only necessary to develop
the software of the computer incorporated in the engine control
system in such a manner that a higher priority level is allocated
to allow execution of the condition discriminating and classifying
function in preference to the other functions.
The discrimination and classification of the vehicle's conditions
and driver's intents are performed in the following way. The
conditions of the vehicle can be detected in terms of the vehicle
speeds and vehicle speed changes. The driver indicates an intent
concerning the driving by engaging the torque transmission
mechanism (the clutch and the transmission) and depressing the
brake pedal or the accelerator pedal. In other words, the driver
indicates his intent in correspondence to the situation of the
vehicle by selectively depressing the two pedals. The intent is
represented by the angles and angular velocities of the pedals and
their time series loci. The conditions of the vehicle and the
intents of the driver can be detected in detail in accordance with
the measured values from a certain prior time up to the present
time as to the vehicle speed and its time rate of change and the
angle and angular velocity of the brake and accelerator pedals. The
angular velocity of the accelerator pedal is equivalent to the
acceleration rate .theta.ac in FIG. 4. In addition, by utilizing
these measured values, it is possible to estimate the condition of
the vehicle and the intent of the driver and predict the future
condition of the vehicle.
As regards the construction of the running controls of the vehicle,
as will be described later with reference to the illustrated
embodiments, there are a method of realizing the controls by a
cascade connection of torque servo system, speed servo system and
tracking servo system and another method of preparing the
previously mentioned various engine control methods in a parallel
manner.
The method of determining the preferences of the driver for vehicle
operation may, for example, be to provide three selector switches
respectively corresponding to the "sporty", mode placing emphasis
on drivability, "luxury" mode placing emphasis on driving
comfortability and "economy" mode placing emphasis on practicality
so that the parameters of each engine control method are changed in
response to the selection of one of the selector switches.
The computer used for realizing the abovementioned method may be of
the high type speed and the operation program may be prepared such
that the condition discrimination and the selection of the engine
control methods are effected most preferentially.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an embodiment of the
invention.
FIG. 2 is a block diagram showing another embodiment of the
invention.
FIG. 3 is a block diagram showing an exemplary construction of the
computer program used in the embodiment of FIG. 1.
FIG. 4 is a diagram showing the relation between the vehicle
conditions and the driver's intent and the respective engine
control methods.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The principle of the present invention will now be described first
with reference to FIG. 4.
FIG. 4 shows the discrimination and classification of the vehicle
conditions and driver's intent and engine control methods
corresponding to the respective categories.
The vehicle conditions are roughly divided into a rest condition
(V=0) and a running condition (V>0). The driver's intent is
discriminated on the basis of six different conditions including
the operation state of the torque transmission mechanism (clutch)
the depression of the brake pedal (breaking, .theta.br>0),
non-depression of the brake pedal (.theta.br=0) and the accelerator
pedal (coasting, .theta.ac=0) the depression of the accelerator
pedal (acceleration, the .theta.ac.gtoreq..theta.aca) the depressed
accelerator pedal (steady running,
.theta.acd<.theta.ac<.theta.aca) at rest steady running,
.theta.acd<.theta.ac<.theta.aca) and the restored accelerator
pedal (deceleration, .theta.ac.ltoreq..theta.acd).
When the torque transmission mechanism is on (engaged) and the
accelerator pedal is depressed, a control for the acceleration
requirement is performed ({character pullout} in FIG. 4). With the
vehicle running, when the accelerator pedal is released and the
brake pedal is depressed, a deceleration control is performed
({character pullout} in FIG. 4). At this time, if the idle switch
is on (which indicates that the acceleration pedal is released) and
the engine speed is excessively high, a fuel cut-off control is
performed ({character pullout} in FIG. 4).
In the running condition, if the vehicle is neither accelerated nor
decelerated, an air-fuel ratio control is performed to maintain the
air-fuel ratio at a desired value ({character pullout} in FIG.
4).
When the torque transmission mechanism is off, an idle speed
control comes into action to control the engine speed to maintain
it at a desired value ({character pullout} in FIG. 4). At this
time, if the accelerator pedal is depressed, the switching to the
previously mentioned air-fuel ratio control is effected despite the
fact that the engine is racing.
The method of discriminating and classifying the conditions of the
vehicle and the intents of the driver to select the proper engine
control method is well suited to progressively deal with the
diverse requirements of the user of the vehicle and the
introduction of new techniques which meet the requirements. To the
design and development engineer as well as persons who attend
matching of the engine control methods with the actual vehicle (the
adjustment of the parameters), this means advantages that it is
necessary to understand only the engine control methods
corresponding to the required categories, that a modification of
the computer program requires only the modification of some modules
and so on.
An embodiment of the invention will now be described with reference
to FIG. 1. The block diagram of FIG. 1 comprises a condition
discriminating unit and cascaded control systems operable in
response to the outputs of the former.
The conditions discriminating unit 1 detects the conditions of a
vehicle in terms of a vehicle speed v, engine speed N, engine
output torque T and a distance L between the vehicle and an
obstacle ahead or the preceding vehicle and it also detects the
intent of the driver in accordance with the changes in time
(dynamic changes) obtained by operating on a signal 20 indicative
of the brake pedal angle .theta..sub.br, a signal 19 indicative of
the accelerator pedal angle .theta..sub.ac and their past values.
In accordance with these detection results and the preference of
the driver, a determination is made as to which of the engine
control methods is required and the decision of the construction of
the cascade-connected running control systems, the selection of
parameters and the modification of their values are performed.
The running control systems include the torque servo system, speed
servo system and tracking servo system which are cascaded from the
inner side near to an engine 2 so as to control its speed N and
torque T.
The supply of fuel to the engine 2 is effected by a fuel injection
control system 3 and the ignition timing is controlled by an
ignition timing control system 4.
A torque control mechanism 5 determines fuel quantity and ignition
timing corresponding to a torque deviation required by the control
systems and the results are applied to the fuel injection control
system 3 and the ignition timing control system 4. While the
ignition timing control system 4 operates in accordance with the
ignition timing determined by the torque control mechanism 5 at the
low speed operation and the constant speed driving, during the
transient period the ignition timing can be controlled directly if
the condition discriminating unit 1 requires a rapid surge
preventive measure.
When the torque servo system is selected by the condition
discriminating unit 1, its reference value is applied to a torque
reference setup unit 6 from the condition discriminating unit 1.
Thus, the input to the torque control mechanism 5 represents the
difference value between the torque reference value and the
measured value of the engine torque. A torque servo system selector
switch 7 is selected in accordance with the result of the decision
in the condition discriminating unit 1. A torque measuring device 8
performs the operation of engineering value conversion and
smoothing on the measured value of the torque. Where the upstream
speed servo system is selected, the input to the torque control
mechanism 5 is the output of a speed control mechanism 9.
Where the driving involves a frequent repetition of acceleration
and deceleration, the driver demands an increase in the torque by
depressing the accelerator pedal and commands a decrease in the
torque by releasing the depression. Thus, the condition
discriminating unit 1 applies a torque desired value corresponding
to the movement of the accelerator pedal and engine speed.
Alternatively, a torque deviation may be directly applied to the
torque controlling mechanism 5.
When the condition discriminating unit 1 selects the idle speed
control (ISC) or the driver selects the constant speed driving
(cruising) control, the condition discriminating unit 1 selects a
selector switch 10 so that the vehicle speed reference value
applied to a speed reference setup unit 11 from the condition
discriminating unit 1 is compared with the actual measured vehicle
sped and the speed controlling mechanism 9 controls the vehicle
speed to approach the reference value. The actual vehicle speed is
measured by a vehicle speed measuring device 13 in which the axle
speed derived from the engine 2 through a gear 12 is corrected for
variation in the tire diameter, etc., and the resulting time series
data is smoothed out.
Even if the cruise control has been selected, when the driver
depresses the accelerator pedal, the switch 7 is turned on and the
switching to the torque servo system is effected.
Where the vehicle is provided with a sensor for measuring the
distance from an .[.obstalcle.]. .Iadd.obstacle .Iaddend.ahead, a
signal .[.17.]. from a cruising speed selector switch .[.(not
shown).]. .Iadd.17 .Iaddend.is selected so that when the distance
from the preceding vehicle is less than an allowable value, the
switching is made from the speed servo system to the tracking servo
system.
A tracking control mechanism 14 determines an increase or decrease
in the vehicle speed in accordance with the difference between the
measured value from a distance sensor 15 for measuring the distance
from an obstacle ahead and the predetermined following distance
reference value corresponding to the vehicle speed and the result
is applied to the speed control mechanism 9. The following distance
reference value is determined by the condition discriminating unit
1 and sent to a following distance reference setup unit 16. This
value is utilized for the calculation of a distance difference.
The following Table 1 shows the correspondence between the engine
control methods to be selected by the condition discriminating unit
1 and the construction of the cascade control system.
TABLE 1 Construction ENGINE Torque Speed Tracking CONTROL Servo
Servo Servo METHODS System System System Acceleration Control
.smallcircle. .DELTA. .DELTA. Deceleration Control .smallcircle.
.DELTA. .DELTA. Fuel Cut-Off Control .smallcircle. -- -- Air-Fuel
Ratio .smallcircle. .smallcircle. .smallcircle. Control Idle Speed
Control -- .smallcircle. -- Explanation .smallcircle. Great
contribution .DELTA. Moderate contribution -- Small
contribution
When the results of the condition discrimination indicates that the
acceleration or deceleration control is needed, the torque servo
system functions principally. At this time, the speed servo system
also functions if the constant speed driving is being selected and
also the tracking servo system functions if the distance sensor is
in operation. The fuel cut-off control is performed within the
range of the torque servo system. The air-fuel ratio control is
performed during the torque servo system for the purpose of
improving the fuel consumption and reducing the exhaust gas
emission. The air-fuel ratio control functions effectively even
during the constant speed driving as well as the tracking driving.
In the case of the idle speed control, the speed servo system
having the idle speed as the reference value functions.
The following Table 2 shows the results of the preference mode
selection or input signals 18 to the condition discriminating unit
1.
TABLE 2 Control System Construction Torque Speed Tracking
Preference Servo Servo Servo Node System System System Sporty
.smallcircle. -- -- Luxury .smallcircle. .smallcircle.
.smallcircle. Economy .smallcircle. .DELTA. -- .smallcircle. Great
contribution .DELTA. Moderate contribution -- Small
contribution
As will be seen from Table 2, each of the sporty, luxury and
economy modes corresponds mainly through changing of the control
parameters of the torque servo system. As regards the "luxury"
mode, coupled with the provision of the cruise control function and
the distance sensor, the speed servo system and the tracking servo
system function effectively.
In the case of the "economy" mode, while the speed servo system may
be used jointly, a control algorithm is used which ensures saving
of the fuel consumption even if the degree of the cruise control is
reduced.
FIG. 2 shows another embodiment of the invention which has the same
purposes as the embodiment of FIG. 1. FIG. 2 shows a construction
in which the proper engine control method is selected from
alternatives for the engine control methods in accordance with the
discrimination result of the condition discriminating unit 1. The
alternatives of the engine control methods include basically an
acceleration control 21, deceleration control 22, fuel cut-off
control 23, air-fuel ratio control 24 and idle speed control 25.
Each of these five engine control methods is responsive to the
results of calculations to supply a fuel quantity and an ignition
timing to a fuel injection control system 3 and an ignition timing
control system 4, respectively.
Where the acceleration control, the deceleration control or the
fuel cut-off control is selected, rapid application of the control
may have the danger of causing a surging phenomenon depending on
the condition of the vehicle and therefore a predictive calculation
is made on the basis of the vehicle condition and the selected
control method. If the occurrence of a surging phenomenon is
predicted, the air fuel-ratio control is selected or alternatively
the parameter values of the already selected engine control method
are changed.
The computer is essential for materializing the overall control
relating to the engine as shown in FIG. 1. FIG. 3 shows the
construction of the computer program.
The program shown in FIG. 3 is started at an interrupt step 31 and
then at an interrupt decision step 32 a branching is made to a
periodic interrupt step 33 or an end of A/D conversion interrupt
step 35 which takes place after an A/D conversion start step 34
initiated by the interrupt step 33. After the end of A/D conversion
interrupt step 35, the condition discrimination described in
connection with FIG. 1 is performed and the proper engine control
method is selected. In accordance with the selection result, a task
distributing step 36 calls any of the following tasks. Assigned to
a task level 0 are the ignition timing control 4, the fuel
injection control 3 and the torque control 5 for rapid response
purposes. Assigned to a task level 1 are the speed control 9, the
tracking control 14, etc. Assigned to a task level 2, et seq., are
the other programs which are allowed to respond more slowly.
From the present program construction point of view, there is a
feature that when the vehicle condition and the driver's intent are
subjected to A/D conversion and inputted, a condition
discriminating step is performed thereby rapidly responding to the
transient condition.
In accordance with the present invention, by virtue of the fact
that the condition of a vehicle and the driver's intent can be
detected rapidly from moment to moment and moreover the proper
engine control method to be used in response to the detection
results can be determined accurately, there is the effect of
improving the driving performance, ensuring effective utilization
of the engine performance, and rapidly developing engine control
methods matched to different engine performances of different
vehicles with the improved productivity of software therefor.
* * * * *