U.S. patent application number 09/788418 was filed with the patent office on 2001-09-13 for controller for automatic transmission.
Invention is credited to Iwase, Masakatsu, Kusafuka, Muneo, Unoki, Masamichi.
Application Number | 20010021891 09/788418 |
Document ID | / |
Family ID | 18567897 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010021891 |
Kind Code |
A1 |
Kusafuka, Muneo ; et
al. |
September 13, 2001 |
Controller for automatic transmission
Abstract
An automatic transmission controller is capable of compensating
for both driver type and tendencies of a driver in temporary
acceleration, such as in passing. The automatic transmission
controller executes a driver type judging subroutine for judging
the overall acceleration habits of the driver and classifying the
driver as one of a plurality of driver types by monitoring the
driving behavior for a predetermined time. The controller also
executes a temporary acceleration inclination judging routine for
judging the habits of the driver in temporary acceleration by
monitoring driving behavior for a period of time shorter than the
predetermined time, and executes shift control routines for
controlling and changing the shift timing based on the judged
driver type and the inclination in temporary acceleration. The
controller controls shift timing, taking into account both the
driver type and the inclination in temporary acceleration, such as
passing.
Inventors: |
Kusafuka, Muneo; (Anjo-shi,
JP) ; Unoki, Masamichi; (Anjo-shi, JP) ;
Iwase, Masakatsu; (Anjo-shi, JP) |
Correspondence
Address: |
LORUSSO & LOUD
3137 Mount Vernon Avenue
Alexandria
VA
22305
US
|
Family ID: |
18567897 |
Appl. No.: |
09/788418 |
Filed: |
February 21, 2001 |
Current U.S.
Class: |
701/57 ; 477/121;
701/55 |
Current CPC
Class: |
F16H 59/48 20130101;
Y10T 74/19251 20150115; F16H 2059/183 20130101; F16H 59/18
20130101; F16H 2061/0081 20130101; F16H 61/0213 20130101; B60W
2050/0057 20130101; F16H 2059/003 20130101; F16H 59/24 20130101;
B60W 40/09 20130101 |
Class at
Publication: |
701/57 ; 701/55;
477/121 |
International
Class: |
F16H 059/24; F16H
059/18; F16H 059/48 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2000 |
JP |
2000-45287 |
Claims
What is claimed is:
1. An automatic transmission controller capable of changing shift
timing of a transmission in accordance with acceleration behavior
of a driver, comprising: driver type judging means for judging a
driver type in accordance with the acceleration of the driver, as
one of a plurality of driver types, by monitoring the driving
behavior of the driver over a predetermined period of time;
temporary acceleration inclination judging means for judging the
temporary inclination of the driver in temporary acceleration by
monitoring said driving behavior for a time shorter than said
predetermined period of time; and shift control means for
controlling and changing said shift timing based on the driver type
judged by said driver type judging means and the temporary
inclination judged by said temporary acceleration inclination
judging means.
2. The automatic transmission controller according to claim 1,
wherein said temporary acceleration inclination judging means
judges that the driver has the temporary inclination when the speed
of accelerator depression exceeds a predetermined value.
3. The automatic transmission controller according to claim 2,
wherein said temporary acceleration inclination judging means
judges that the driver has the temporary inclination when the speed
of accelerator depression exceeds a predetermined value.
4. The automatic transmission controller according to claim 1,
wherein said shift control means changes the shift timing for a
driver type based on the temporary inclination judged by said
temporary acceleration inclination judging means.
5. The automatic transmission controller according to claim 4,
wherein said shift timing for each driver type is stored as a shift
map wherein accelerator opening is one parameter and said shift
control means computes a compensation value for the accelerator
opening based on said temporary inclination, computes a shift map
retrieving accelerator opening by adding said compensation value to
the actual accelerator opening and changes the shift timing by
retrieving said shift map based on the computed shift map
retrieving accelerator opening.
6. The automatic transmission controller according to claim 5,
wherein said driver type judging means judges the driver type as
one of at least into two driver types, including a high
acceleration inclination type and low acceleration inclination type
and said shift control means limits said accelerator opening
compensation as the judged driver type goes from the low
acceleration inclination type toward the high acceleration
inclination type.
7. The automatic transmission controller according to claim 5,
wherein said driver type judging means judges the driver type as
one of at least into two driver types, including a high
acceleration inclination type and low acceleration inclination type
and said shift control means raises the maximum value of said
accelerator opening compensation as the judged driver type goes
from the high acceleration inclination type toward the low
acceleration inclination type.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] Our copending application (Attorney Docket No. AW-C050)
having the same title and filed on even date herewith discloses and
claims related subject matter.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an automatic transmission
controller which is capable of making a judgment emphasizing
acceleration using two criteria judged at different times.
[0004] 2. Related Art Statement
[0005] One known controller monitors the driving habits of a driver
for a predetermined time to judge the type of the driver and to
change the shift timing, initially set to a standard, to the timing
intended by the driver based on that judgment.
[0006] However, with such a system it is necessary to monitor the
driving habits of the driver for a relatively long time, e.g.,
about 30 seconds, to judge the type of the driver. That is, when a
driver who stresses acceleration temporarily experiences a control
scheme tailored to a driver who stresses fuel consumption, for
example, the driver feels a sense of incompatibility because the
driver has been judged to stress fuel consumption even though the
driver actually stresses acceleration.
[0007] Further, such a system is unable to accommodate a temporary
emphasis on acceleration, such as in passing, due to the driver
type being judged over a relatively longer time. That is, when a
driver who has been judged to be the type who normally stresses
fuel consumption passes a car, there arises the problem that the
driver is unable to make the intended acceleration because the
shift timing is selectively changed toward the low-speed side based
on determination of driver type through the monitoring of the
driver for a relatively long time and the up-shift is made sooner,
without sufficient acceleration.
[0008] Accordingly, the present invention has as its object
provision of an automatic transmission controller which is capable
of adequately accommodating a temporary emphasis on acceleration,
such as in passing, even when the control shift timing is in
accordance with a determination of driver type.
SUMMARY OF THE INVENTION
[0009] According to a first aspect, the present invention provides
an automatic transmission controller capable of changing shift
timing of a transmission in accordance with acceleration
inclination of a driver. The transmission controller includes
driver type judging means for judging the overall inclination of a
driver in acceleration as one of a plurality of driver types by
monitoring the driving behavior for a predetermined time, e.g.,
around 30 seconds; temporary acceleration inclination judging means
for judging inclination of the driver in temporary acceleration by
monitoring the driving behavior for a time shorter than the
predetermined time; and shift control means for controlling and
changing the shift timing based on the driver type judged by the
driver type judging means and the temporary acceleration
inclination judged by the temporary acceleration inclination
judging means. Thus, it becomes possible to control the shift
timing in a highly advanced manner taking into consideration both
the overall inclination in acceleration and the inclination in
temporary acceleration for an individual.
[0010] The terminology "acceleration inclination" as used herein
means behavior of a given driver in accelerating, as monitored over
some period of time. It can also be characterized as a behavior
pattern, habit or tendency.
[0011] According to a second aspect of the invention, the temporary
acceleration inclination judging means judges whether or not the
driver intends a temporary acceleration by judging whether or not
the accelerator has been quickly applied. Thus, it becomes easier
to detect the true inclination of the driver in acceleration and
the possibility of erroneous detection is reduced.
[0012] According to a third aspect of the invention, the temporary
acceleration inclination judging means in accordance with the
second aspect, judges that the driver intends a temporary
acceleration when the speed of accelerator depression exceeds a
predetermined value.
[0013] According to a fourth aspect of the invention, the shift
control means in accordance with the first aspect, changes the
shift timing in a manner taking into account the driver type based
on a temporary acceleration judged by the temporary acceleration
inclination judging means. Thus, it is possible to appropriately
adjust for inclination in temporary acceleration, such as in
passing, in addition to the change in shift timing per driver
type.
[0014] According to a fifth aspect of the invention, shift timing
for each driver type is stored in as a shift map (see the economy
mode map ECONOMY in FIG. 13, medium mode map MEDIUM in FIG. 14 and
sport mode map SPORT in FIG. 15, for example) wherein accelerator
opening is plotted against vehicle speed. The shift control means
computes compensation of the accelerator opening (CP) based on the
inclination of temporary acceleration, computes a shift map
retrieving accelerator opening wherein the compensation is added to
the actual accelerator opening (AC) of the driver and changes the
shift timing in accordance with the shift map retrieved based on
the computed shift map retrieving accelerator opening. Because the
change of the shift timing to be made in connection with temporary
acceleration may be made by using the same shift map as that
prepared for each driver type, by computing the shift map
retrieving accelerator opening, the control is simplified.
[0015] According to a sixth aspect-of the invention, the driver
type judging means judges that the driver type is one of at least
into two driver types, including a high acceleration inclination
type ("sport type", for example) and a low acceleration inclination
type ("economy type", for example) and the shift control means
limits the accelerator opening compensation (CP) as the driver type
becomes closer to the higher acceleration inclination type. This
makes it possible to prevent a situation wherein the shift timing
(sport mode shift map SPORT) originally set at the high-speed side
is shifted further to the high-speed side by a sudden accelerator
operation and no upshift is made, when a driver of the driver type
who stresses acceleration (the sport type driver) tries to pass.
Thus, a smooth shift operation is provided. Alternatively,
according to a seventh aspect of the invention, the driver type
judging means raises the maximum value (*G) of the accelerator
opening compensation as the driver type becomes closer to the low
acceleration inclination type. Thus, it becomes possible to
downshift and upshift according to the inclination in temporary
acceleration and to allow the driver to accelerate appropriately as
intended, because a large shift map retrieving accelerator opening
is set even when the driver is the type who stresses economy of
fuel consumption, for whom the shift timing has been shifted to the
lower speed side, tries to pass.
[0016] The above and other advantages of the invention will become
more apparent from a reading of the following description and the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a block diagram illustrating one embodiment of an
automatic transmission controller in accordance with the present
invention;
[0018] FIG. 2 is a flowchart of one example of a shift control
program in accordance with the present invention;
[0019] FIG. 3 is a flowchart of a driver type judging subroutine
("SUB1") in FIG. 2;
[0020] FIG. 4 shows the details of a fuzzy inference routine (S4 in
FIG. 3);
[0021] FIG. 5 is a diagram showing one example of the membership
function in the fuzzy inference routine;
[0022] FIG. 6 is a diagram showing examples of output of arithmetic
operations by the fuzzy inference routine;
[0023] FIG. 7 is a diagram showing other examples of output of
arithmetic operations by the fuzzy inference routine;
[0024] FIG. 8 is a flowchart of an accelerator operation judging
subroutine ("SUB2" in FIG. 2);
[0025] FIG. 9 is a flowchart of a map retrieving accelerator
opening compensating subroutine ("SUB3" in FIG. 2);
[0026] FIGS. 10(a) and 10(b) are tables of accelerator opening
compensation factors and accelerator opening compensation
guards;
[0027] FIG. 11 is a flowchart of a shift map judging subroutine
("SUB 4" in FIG. 2);
[0028] FIG. 12 shows one example of a timing chart as used in
judging accelerator operation and in judging driver type;
[0029] FIG. 13 is a graph which is one example of an economy mode
map used in the subroutine of FIG. 11;
[0030] FIG. 14 is a graph which is one example of a medium mode map
used in the subroutine of FIG. 11; and
[0031] FIG. 15 is a graph which is one example of a sport mode map
used in the subroutine of FIG. 11.
INCORPORATION BY REFERENCE
[0032] The teachings of Japanese Application No. 2000-45287, filed
Feb. 23, 2000 are incorporated herein in their entirety, inclusive
of the specification, claims and drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] As shown in FIG. 1, a vehicle 1 such as a car has an engine
2 which is connected to a transmission 3 via a torque converter 4.
The transmission 3 is provided with a speed sensor 7 which detects
the rotary speed of the output shaft of the transmission 3 and the
engine 2 is provided with a throttle opening sensor 10.
[0034] The vehicle speed sensor 7 and the throttle opening sensor
10 are connected to an electronic control unit (ECU) 9 for
controlling the transmission 3. The electronic control unit 9
comprises an accelerator ("quick, step-on") judging section 12, a
driver type judging section 17, shift determining means 20, and
shift output means 21.
[0035] In the vehicle 1 as described above, the rotation of the
engine 2 is transmitted to the transmission 3 via the torque
converter 4 and is decelerated by the transmission 3 for transfer
to the wheels via an axle (not shown), i.e., to the vehicle drive
wheels. The electronic control unit 9 controls the transmission 3
to change the speed of rotation input from the engine 2 in
accordance to a predetermined shift map so that the optimum driving
force can be obtained at the wheels and, in doing so, it also
controls the transmission 3 in a manner appropriate to the driving
style of the driver, i.e., in accordance with the driver type, the
degree of accelerator depression by the driver and the like. The
details of this control will be described below.
[0036] While running the vehicle 1, the electronic control unit 9
reads a shift control program SCP, such as shown in FIG. 2, from a
memory (not shown) to execute the program in a predetermined cycle
and to control the transmission 3 based on that program.
[0037] As shown in FIG. 2, the shift control program SCP determines
the overall habits (tendencies) of acceleration of the driver
currently driving the vehicle by monitoring the driving behavior
for a predetermined time. This monitoring is by the driver type
judging section 17 of the electronic control unit 9 in Step S1.
That is, it determines whether the driver is a sports type driver
who prefers sporty driving, an economy type driver who prefers
economical driving or a medium type driver who is between them.
[0038] That is, the driver type judging section 17 executes a
driver type judging subroutine SUB1, such as shown in FIG. 3. The
driver type judging section 17 first calculates average vehicle
speed, within a predetermined time of about 30 seconds, from the
output of the vehicle speed sensor 7 in Step S1 and calculates a
time during which the accelerator is operated with a high degree of
opening within the predetermined time from the output of the
throttle opening sensor 10 in Step S2. It also calculates an
average value for speeds of accelerator depression within the
predetermined time in StepS3. Then, based on the results of those
calculations, it determines the driver type utilizing a fuzzy
inference routine based on fuzzy inference and outputs points
within a range from 0 as the lower limit to 100 as the upper
limit.
[0039] Referring to FIGS. 4 and 5, by way of example, when the
average vehicle speed in Step S1 is 30 km, the accelerator
high-opening time in Step S2 is 5 seconds and the average
accelerator speed of depression in Step S3 is 10%/second, as shown
in Example 1 in FIG. 4, the fuzzy rule (1) is applied and the
membership function is applied as shown in FIG. 6, thus outputting
0 as a fuzzy output. When the average vehicle speed in Step S1 is
60 km, the accelerator high-opening time in Step S2 is 15 seconds
and the average speed of depression of the accelerator pedal in
Step S3 is 35%/second as shown in Example 2 in FIG. 4, the fuzzy
rules (4) and (9) are applied and the membership function is
applied as shown in FIG. 7, thus outputting 50 as a fuzzy
output.
[0040] When the fuzzy output point is more than A in Step S5, the
driver type judging subroutine SUB1 judges that the driver is a
sport type driver in Step S6. When the point of the fuzzy output is
less than A in Step S5, the driver type judging subroutine SUB1
judges whether or not the driver is a sport type (initial value is
economy type) in Step S7. When the driver has been judged to be the
sport type and the point of the fuzzy output is less than B (<A)
in Step S8, the driver type judging subroutine SUB1 judges that the
driver is the medium type driver in Step S9 to prevent the
designation of type of driver from changing immediately from the
sport type to the economy type and to realize smooth control of the
shift. When the point of the fuzzy output is more than B (<A) in
Step S8, the judgment of the sport type is maintained.
[0041] When the driver has not been judged to be the sport type in
Step S7, the process goes to Step S10 to judge whether or not the
driver has been judged to be the medium type. When the driver has
been judged to be the medium type, the process advances to Step S11
to judge whether or not the driver is the economy type in Step S11.
Then the driver is judged to be the economy type in Step S12 when
the point of the fuzzy output is less than C (<B) or the
judgment of medium type is retained when the point of the fuzzy
output is more than C (<B). When the type of the driver is not
the medium type in Step S10, i.e., the driver is the economy type,
it is judged whether or not the point of the fuzzy output is more
than D (B>D>C) in Step S13. When the point is D or more
(B>D>C), the process proceeds to Step S9 to judge that the
driver is the medium type or retains the judgment of economy type
when the point is less than D (B>D>C).
[0042] The thresholds between A and B and B and C for changing
judgement between the sport type, medium type and economy type are
set with hysteresis in that the threshold in the direction of
changing the judgment from the sport type to the medium and economy
types and in the opposite direction thereof are different to
prevent the judgment from frequently changing around the
thresholds. Also, the medium type positioned between the sport type
and the economy type may be subdivided further into several
types.
[0043] When the driver type has been determined in Step S0 in FIG.
2, the electronic control unit 9 judges whether or not the driver
has a tendency in temporary acceleration in Step S14 in addition to
the judgment of the overall tendency (habit) in acceleration in
Step S0. This judging operation is carried out by monitoring the
behavior of the driver over a time shorter than the time required
for judging the driver type by the driver type judging section 17.
That is, the electronic control unit 9 commands the accelerator
rapid depression ("quick step-on") judging section 12 to execute an
accelerator rapid depression judging subroutine SUB2 in Step S14.
Then, the accelerator rapid depression judging section SUB2
calculates accelerator depression speed, at each moment while the
vehicle is running, from the output of the throttle opening sensor
10 in Step S15 and judges whether or not the accelerator depression
speed exceeds a predetermined value in Step S16. When the
accelerator depression speed exceeds the predetermined value and is
what can be characterized as rapid acceleration, the process
advances to Step S17 to turn on a rapid acceleration ("quick
step-on") flag. Then, it is judged whether or not a predetermined
time has elapsed since the rapid acceleration flag has been turned
on in Step S18.
[0044] When the predetermined time has elapsed since the time when
the rapid acceleration flag was turned on, the rapid acceleration
flag is turned from ON to OFF in Step S19 because it is not
necessary to compensate the accelerator opening (as described
later) to reflect the tendency of the driver in temporary
acceleration. When the predetermined time has not elapsed since
when rapid acceleration flag was turned on in Step S18, it is
judged whether or not the vehicle speed has increased by more than
predetermined amount A Km/h from the point of time when the rapid
acceleration flag was turned on in Step S20. When the vehicle speed
has been already increased by more than the predetermined amount A
Km/h from the vehicle speed at the point of time when the rapid
acceleration flag was turned on, the rapid acceleration flag is
turned from ON to OFF in Step S19 because the purpose of
acceleration has been achieved to a certain degree and it has
become unnecessary to compensate the accelerator opening.
[0045] When the vehicle speed has not increased by the
predetermined amount A Km/h from the vehicle speed at the point of
time when the rapid acceleration flag was turned on, it is judged
whether or not the engine 2 is idling in Step S21. When the engine
2 is in the idling condition, the rapid acceleration flag is turned
from ON to OFF in Step S19 because it has become unnecessary to
accelerate the speed. When the engine 2 is not in the idling
condition, i.e., when the predetermined time has not yet elapsed
since the rapid acceleration flag was turned on, the predetermined
speed A Km/h has not yet increased from the vehicle speed at the
point of time when the quick step-on flag was turned on and the
engine 2 is not in the idling condition, the rapid acceleration
flag is retained in the ON condition by judging that the request
for temporary acceleration is maintained and the control for rapid
acceleration is required.
[0046] Next, the shift control program SCP proceeds to Step S22 in
the main routine of FIG. 2 and commands the shift determining means
20 of the electronic control unit 9 to execute the map retrieving
accelerator opening compensating subroutine SUB3. The map
retrieving accelerator opening compensating subroutine SUB3 judges
whether or not the rapid acceleration flag is ON in Step S23 in
FIG. 9. When the rapid acceleration flag is not ON, i.e., OFF, the
map retrieving accelerator opening compensating subroutine SUB3
advances to Step S24 where it judges that the driver has no intent
to temporarily accelerate and sets the accelerator opening output
from the throttle opening sensor 10 as the retrieved shift map
accelerator opening as it is.
[0047] When the rapid acceleration flag is ON in Step S23, the map
retrieving accelerator opening compensating subroutine SUB3
proceeds to Step S240 where it computes a compensation for the
actual accelerator opening based on the following expression:
Compensation=Accelerator Depression Speed (%/25 msec.).times.*K
[0048] wherein *K is an Accelerator Opening Compensation Factor
[0049] The accelerator opening compensation factor *K is set so
that the greater the shift step, the greater the value and the
compensation becomes as shown in FIG. 10a.
[0050] When the compensation is found, the process proceeds to Step
S25 to judge whether or not the compensation is greater than an
accelerator opening compensation guard *G which has been set as the
maximum value for the compensation. When the compensation is
greater than the accelerator opening compensation guard *G, the
compensation is made equal to *G in Step S26. The accelerator
opening compensation guard *G is set so that the closer the driver
type is to the sport type, as opposed to the economy type, i.e.,
the stronger the overall tendency to accelerate, the smaller it
becomes. The closer the driver type is to the economy type, the
larger the maximum allowable compensation becomes.
[0051] When the compensation is not greater than the accelerator
opening compensation guard *G in Step S25 or the compensation is
set at the upper limit value of the accelerator opening
compensation guard *G in Step S26, the process proceeds to Step S27
to set the retrieved shift map accelerator opening at a value
obtained by adding the above-mentioned compensation to the actual
accelerator opening which is an output from the throttle opening
sensor 10.
[0052] When the shift map accelerator opening has been thus
computed and determined in Step S24 or 27, the shift control
program SCP proceeds to Step S27 in FIG. 2 so that the shift
determination means 20 executes a shift map determination
subroutine SUB4 as shown in FIG. 11. The shift map determination
subroutine SUB4 judges whether or not the driver type judged by the
driver type judging subroutine SUB1 in Step S1 is the sport type in
Step S28. When the driver is the sport type, the process proceeds
to Step S29 to select a sport mode map SPORT from among three types
of running mode maps, i.e., from among an economy mode map ECONOMY
in FIG. 13, a medium mode map MEDIUM in FIG. 14 and a sport mode
map SPORT in FIG. 15.
[0053] As is apparent from the maps, the vehicle speed and the
accelerator opening are set as parameters in the economy mode map
ECONOMY in FIG. 13, the medium mode map MEDIUM in FIG. 14 and the
sport mode map SPORT in FIG. 15, and upshift lines and downshift
lines are shifted further to the high-speed side as the type
advances from the economy mode map ECONOMY to the medium mode map
MEDIUM and then to the sport mode map SPORT. These maps are
arranged such that the downshift is carried out at low accelerator
opening and the lower speed side gear step is selected as the type
advances from the economy mode map ECONOMY to the medium mode map
MEDIUM and then to the sport mode map SPORT at the same vehicle
speed. Further, for the same accelerator opening, the upshift is
shifted further to the higher-speed side as the type advances from
the economy mode map ECONOMY to the medium mode map MEDIUM and then
to the sport mode map SPORT. That is, the upshift line is set for a
"sporty" style so that the lower speed side gear step may be
readily selected.
[0054] When the driver type judged by the driver type judging
subroutine SUB1 in Step S1 is not the sport type in Step S28, the
process goes to Step S30 to judge whether or not the driver type is
the medium type. When the driver type is the medium type, the
process proceeds to Step S31 to select the medium mode map MEDIUM
in FIG. 14.
[0055] When the driver type is judged not to be the medium type in
Step S30, i.e., judged to be the economy type, the process goes to
Step S32 to select the economy mode map ECONOMY in FIG. 13.
[0056] When the shift map to be used in shifting and the
accelerator opening for retrieving the shift map are thus decided
by the shift control program SCP, the electronic control unit 9
executes a shift operation in the transmission 3 by the shift
output means 21 based on the shift map and the shift map retrieving
accelerator opening thus decided. When the accelerator opening is
used to retrieve the shift map, the map is retrieved using a value
for accelerator opening greater than the actual accelerator
opening, regardless of the shift map to be used, i.e., the economy
mode map ECONOMY, the medium mode map MEDIUM or the sport mode map
SPORT, when the rapid acceleration flag is ON, i.e., when the
inclination for temporary acceleration is set by passing or the
like. Each shift map is retrieved according to a shift map
retrieving accelerator opening to which the compensation found in
Step S24 is added in Step S27 in FIG. 9. Accordingly, the downshift
and upshift lines are shifted to the high-speed side for all driver
types and, as a result, the timing is changed to the acceleration
oriented shift timing.
[0057] The accelerator opening compensation guard *G, which is the
upper limit value in computing the compensation of the map
retrieving accelerator opening by the compensating subroutine SUB3,
is set such that it becomes greater as the driver type advances
from the sport type to the economy type and a greater compensation
may be added for rapid (temporary) acceleration, so that the map is
retrieved in accordance with the value for accelerator opening as
increased for the inclination in temporary acceleration. The shift
timing is accordingly shifted far to the high-speed side and
sufficient acceleration may be obtained even if the downshift and
upshift lines of the economy mode map ECONOMY have been shifted
more to the lower-speed side than in the sport mode map SPORT.
[0058] When a passing operation has been completed and the driver
no longer intends acceleration, the rapid acceleration ("quick
step-on") flag is turned off in Step S14 in FIG. 1, so that the
accelerator opening from the throttle opening sensor 10 is used as
is, as the shift map retrieving accelerator opening, in determining
the shift map corresponding to the driver type judged by the shift
map determination subroutine SUB4 in Step S24 in FIG. 9.
Accordingly, because the shift operation is carried out according
to the shift map corresponding to the driver type determined by the
driver type judging SUB1, based on the long term monitoring, the
driver can return to normal driving operation without feeling any
sense of discomfort.
[0059] FIG. 12 shows examples in which the present invention is
applied to actual driving conditions. Suppose that a driver, who
has been judged to be the economy type by the driver type judging
section 17, steps on the accelerator quickly, for the need of
passing or the like at point of time T1 while driving in fourth
speed. Then, the rapid acceleration flag is turned on by the rapid
acceleration judging section 12, the economy mode map ECONOMY shown
in FIG. 13 is retrieved using a value for the shift map retrieving
accelerator opening to which the compensation corresponding to the
economy type driver is added, by the map retrieving accelerator
opening compensating routine SUB3 of the shift discriminating means
20, and the shift timing is determined for the value obtained by
adding the compensation to the actual accelerator opening detected
from the throttle opening sensor 10.
[0060] Because the accelerator opening on the map moves from point
P1 to point P2 in FIG. 13, for example, such that the compensation
CP is added to the actual accelerator opening AC detected by the
throttle opening sensor 10, in determining the shift timing from
the economy mode map ECONOMY, the downshift is carried out and the
acceleration inclination of the driver may be reflected
appropriately, even though the downshift is not in accordance with
the actual accelerator opening AC detected from the throttle
opening sensor 10.
[0061] Thus, the gear stage is downshifted from fourth to third and
the rapid acceleration flag is turned from ON to OFF at the point
of time T2 in FIG. 12, the addition of the compensation CP to the
accelerator opening is eliminated as shown in Step S24 in FIG. 9,
so that the economy mode map ECONOMY is retrieved by the actual
accelerator opening AC detected by the throttle opening sensor 10,
control returns to the normal economy type shift map and the
driving mode returns to the economy type mode.
[0062] Meanwhile, although the fuzzy inference routine of Step S4
in the driver type judging routine SUB1 in FIG. 3 computes the type
of the driver continuously as fuzzy output FOT, the driving style
is judged per time interval T, e.g., 30 seconds, to judge the
overall driving style of the driver and its result is maintained
until the next time period T elapses as described before.
Accordingly, the judgment of the driver type as the fuzzy output
FOT is made, not only according to whether or not a rapid
acceleration has been made, but also according to a plurality of
parameters such as average vehicle speed, accelerator high opening
time, average rapid depression speed and the like which indicate
the driving behavior of the driver as shown in FIG. 4. Thereby, the
driver type is changed from the economy type to the medium type at
the point of time T3 in FIG. 12, for example.
[0063] When the driver type is changed from the economy type to the
medium type, the shift map used in judging the shift timing is
changed from the economy mode map ECONOMY to the medium mode map
MEDIUM and the shift timing thereafter is carried out based on the
medium mode map MEDIUM. When the rapid acceleration flag is turned
on due to rapid accelerator depression or the like, even when the
normal shift operation is carried out by the medium mode map
MEDIUM, the retrieval by the shift map retrieving accelerator
opening is carried out in the same manner as described above to
correspond to the acceleration tendency of the driver by adding the
compensation CP to the accelerator opening AC based on the medium
mode map MEDIUM.
[0064] The invention may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The present embodiments are therefore to be considered in
all respects as illustrative and not restrictive, the scope of the
invention being indicated by the appended claims rather than by the
foregoing description, and all changes which come within the
meaning and range of equivalency of the claims are therefore
intended to be embraced therein.
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