U.S. patent application number 12/232721 was filed with the patent office on 2009-02-12 for abnormality determination device and abnormality determination method of vehicle.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Hiroatsu Endo, Kazuo Kawaguchi.
Application Number | 20090038387 12/232721 |
Document ID | / |
Family ID | 38282398 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090038387 |
Kind Code |
A1 |
Endo; Hiroatsu ; et
al. |
February 12, 2009 |
Abnormality determination device and abnormality determination
method of vehicle
Abstract
An abnormality determination device and an abnormality
determination method of a vehicle that includes a stepped type
automatic transmission capable of forming a plurality of speed
change steps are provided. The presence/absence of an abnormality
of an element related to formation of a predetermined speed change
step is determined in a state of the vehicle where the
predetermined speed change step is formed. Information about the
abnormality determined to be present is then stored. If the
information about the abnormality is stored when the vehicle is to
newly start to run, the predetermined speed change step where the
abnormality stored occurred is established, and the
presence/absence of the abnormality of the element related to the
formation of the predetermined speed change step is
re-determined.
Inventors: |
Endo; Hiroatsu; (Nagoya-shi,
JP) ; Kawaguchi; Kazuo; (Kasugai-shi, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
TOYOTA-SHI
JP
|
Family ID: |
38282398 |
Appl. No.: |
12/232721 |
Filed: |
September 23, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11653401 |
Jan 16, 2007 |
7426854 |
|
|
12232721 |
|
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|
Current U.S.
Class: |
73/118.01 |
Current CPC
Class: |
B60W 20/50 20130101;
F16H 61/12 20130101; F16H 2061/1208 20130101; F16H 2061/1224
20130101; F16H 2037/0873 20130101; F16H 3/728 20130101; F16H 61/686
20130101 |
Class at
Publication: |
73/118.01 |
International
Class: |
G01M 13/02 20060101
G01M013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2006 |
JP |
2006-021830 |
Claims
1. An abnormality determination device of a vehicle that includes a
stepped type automatic transmission capable of forming a plurality
of speed change steps, comprising: an abnormality determiner that
determines presence/absence of an abnormality of an element related
to formation of a predetermined speed change step in a state of the
vehicle where the predetermined speed change step is formed; a
storage device that stores information about the abnormality
determined to be present by the abnormality determiner; and a
controller that establishes, if the information about the
abnormality is stored in the storage device when the vehicle is to
newly start to run, the predetermined speed change step where the
abnormality stored occurred, in order to cause re-determination of
the presence/absence of the abnormality of the element related to
the formation of the predetermined speed change step.
2. The abnormality determination device of the vehicle according to
claim 1, wherein the stepped type automatic transmission is capable
of forming one or more speed change steps on a low speed step side,
and one or more speed change steps on a high speed step side, and
wherein if the information about the abnormality stored in the
storage device is information about an element related to the
formation of a speed change step on the high speed step side, the
controller forms the speed change step on the high speed step side
and causes the abnormality determiner to re-determine the
presence/absence of the abnormality of the element related to the
formation of the speed change step on the high speed step side when
the vehicle is to newly start to run.
3. The abnormality determination device of the vehicle according to
claim 2, wherein the vehicle is a hybrid vehicle, and wherein the
controller causes the stepped type automatic transmission to be in
the speed change step on the high speed step side in response to an
activating operation of the hybrid vehicle and prior to setting of
a ready-to-run state of the vehicle.
4. The abnormality determination device of the vehicle according to
claim 2, wherein the speed change steps on the low speed step side
consist of only one low speed step, and the speed change steps on
the high speed step side consist of only one high speed step, and
wherein if the information about the abnormality stored in the
storage device is information about the element related to the
formation of the high speed step, the controller forms the high
speed step and causes the abnormality determiner to re-determine
the presence/absence of the abnormality of the element related to
the formation of the high speed step when the vehicle is to newly
start to run.
5. The abnormality determination device of the vehicle according to
claim 4, wherein the vehicle is a hybrid vehicle, and wherein the
controller causes the stepped type automatic transmission to be in
the high speed step in response to the activating operation of the
hybrid vehicle and prior to the setting of the ready-to-run state
of the vehicle.
6. An abnormality determination method of a vehicle that includes a
stepped type automatic transmission capable of forming a plurality
of speed change steps, comprising: determining presence/absence of
an abnormality of an element related to formation of a
predetermined speed change step in a state of the vehicle where the
predetermined speed change step is formed; storing information
about the abnormality determined to be present; and establishing,
if the information about the abnormality is stored when the vehicle
is to newly start to run, the predetermined speed change step where
the abnormality stored occurred, and re-determining the
presence/absence of the abnormality of the element related to the
formation of the predetermined speed change step.
7. The abnormality determination method of the vehicle according to
claim 6, wherein the stepped type automatic transmission is capable
of forming one or more speed change steps on a low speed step side,
and one or more speed change steps on a high speed step side, and
wherein if the stored information about the abnormality is
information about an element related to the formation of a speed
change step on the high speed step side, the speed change step on
the high speed step side is formed and the presence/absence of the
abnormality of the element related to the formation of the speed
change step on the high speed step side is re-determined when the
vehicle is to newly start to run.
8. The abnormality determination method of the vehicle according to
claim 7, wherein the vehicle is a hybrid vehicle, and wherein the
stepped type automatic transmission is caused to be in the speed
change step on the high speed step side in response to an
activating operation of the hybrid vehicle and prior to setting of
a ready-to-run state of the vehicle.
9. The abnormality determination method of the vehicle according to
claim 7, wherein the speed change steps on the low speed step side
consist of only one low speed step, and the speed change steps on
the high speed step side consist of only one high speed step, and
wherein if the stored information about the abnormality is
information about the element related to the formation of the high
speed step, the high speed step is formed and the presence/absence
of the abnormality of the element related to the formation of the
high speed step is re-determined when the vehicle is to newly start
to run.
10. The abnormality determination method of the vehicle according
to claim 9, wherein the vehicle is a hybrid vehicle, and wherein
the stepped type automatic transmission is caused to be in the high
speed step in response to the activating operation of the hybrid
vehicle and prior to the setting of the ready-to-run state of the
vehicle.
Description
[0001] This is a Continuation Application of application Ser. No.
11/653,401 filed Jan. 16, 2007, the entire disclosure of the prior
application is hereby incorporated by reference herein in its
entirety.
INCORPORATION BY REFERENCE
[0002] The disclosure of Japanese Patent Applications No.
2006-021830 filed on Jan. 31, 2006, including the specification,
drawings and abstract is incorporated herein by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention relates to an abnormality determination device
and an abnormality determination method of a vehicle equipped with
a stepped type automatic transmission. More particularly, the
invention relates to a technology that performs abnormality
determination regarding elements that are related to formation of a
predetermined speed change step.
[0005] 2. Description of the Related Art
[0006] In a vehicle equipped with a stepped type automatic
transmission capable of forming a plurality of speed change steps,
a known abnormality determination device determines whether or not
the stepped type automatic transmission can normally form a speed
change step.
[0007] For example, Japanese Patent Application Publication No.
JP-A-2001-50382 describes a failure detection device in conjunction
with a planetary gear type automatic transmission in which the
switching among the speed change steps is performed by controlling
the fastening (engagement) and release of a plurality of engagement
devices. This failure detection device of the automatic
transmission includes abnormality determination means for
intentionally outputting a signal that causes the fastening of an
engagement device that normally must not be fastened for a gear
step, that is, an engagement device other than the engagement
devices selected as a combination of devices to be fastened for the
gear step, and for determining whether a fail-safe device that
prevents interlock (simultaneous engagement) of the automatic
transmission is reliably operating on the basis of whether or not
pressure has been transmitted to the engagement device that
normally must not be fastened.
[0008] Incidentally, in general, as for abnormalities due to valve
sticking (valve fixation) of a fail-safe valve, a control valve,
etc., or abnormalities of a detection switch that detects the
pressure transmitted to engagement devices, etc., the abnormality
determination needs to be performed in a state where a speed change
step has actually been formed, or in a state where a command to
form a speed change step has been output as shown in Japanese
Patent Application Publication No. JP-A-2001-50382.
[0009] Then, in the case where there is an abnormality, such as the
valve sticking or the like, which cannot be detected unless a speed
change step has actually been formed, the shift to the speed change
step having the abnormality may possibly be performed despite the
abnormality thereof; thus, there is a possibility of deterioration
of the drivability. Particularly, a high speed-side speed change
step, which is less frequently used than a low speed-side speed
change step, usually requires a relatively long time for the
abnormality determination and the normality return determination,
thus leading to a possibility of even greater deterioration of the
drivability.
SUMMARY OF THE INVENTION
[0010] In light of the aforementioned problem, there are provided
an abnormality determination device and an abnormality
determination method of a vehicle equipped with a stepped type
automatic transmission capable of forming a plurality of speed
change step which both improve the drivability by appropriately
determining the occurrence of an abnormality that cannot be
detected unless a speed change step has actually been formed.
[0011] Accordingly, an abnormality determination device of a
vehicle that includes a stepped type automatic transmission capable
of forming a plurality of speed change steps is provided. This
determination device includes the following devices:
[0012] an abnormality determiner that determines presence/absence
of an abnormality of an element related to formation of a
predetermined speed change step in a state of the vehicle where the
predetermined speed change step is formed;
[0013] a storage device that stores information about the
abnormality determined to be present by the abnormality determiner;
and
[0014] a controller that establishes, if the information about the
abnormality is stored in the storage means when the vehicle is to
newly start to run, the predetermined speed change step where the
abnormality stored occurred, in order to cause re-determination of
the presence/absence of the abnormality of the element related to
the formation of the predetermined speed change step.
[0015] According to another aspect of the invention, an abnormality
determination method of a vehicle that includes a stepped type
automatic transmission capable of forming a plurality of speed
change steps is provided. This determination method includes:
[0016] determining presence/absence of an abnormality of an element
related to formation of a predetermined speed change step in a
state of the vehicle where the predetermined speed change step is
formed;
[0017] storing information about the abnormality determined to be
present; and
[0018] establishing, if the information about the abnormality is
stored when the vehicle is to newly start to run, the predetermined
speed change step where the abnormality stored occurred, and
re-determining the presence/absence of the abnormality of the
element related to the formation of the predetermined speed change
step.
[0019] According to the abnormality determination device and the
abnormality determination method of the vehicle described above, if
the information about an abnormality of an element related to the
formation of a predetermined speed change step which was determined
to be present by the abnormality determiner is stored in the
storage device when the vehicle is to newly start to run, the
predetermined speed change step is established by the controller in
order to cause re-determination of the presence/absence of the
abnormality of the element related to the formation of the
predetermined speed change step. Therefore, the occurrence of the
abnormality that cannot be detected unless the predetermined speed
change step has actually been established can be determined before
the vehicle runs on the predetermined speed change step. Hence, for
example, if the abnormality exists, the fail-safe operation of
prohibiting the shift to the predetermined speed change step or the
like can be performed. On the other hand, if normality has
returned, the shift to the predetermined speed change step is
allowed. Thus, the drivability can be improved.
[0020] In a suitable construction, the automatic transmission is
constructed of any of various planetary gear type multi-step
transmissions having speed change steps of, for example, forward
four steps, forward five steps, forward six steps or more, in which
one of a plurality of gear steps is selectively achieved as the
rotating elements of a plurality of sets of planetary gear devices
are selectively engaged, or a hybrid drive device has a
configuration in which the automatic transmission includes a
differential mechanism constructed of, for example, a planetary
gear device, which distributes the motive power from an engine to a
first electric motor and to an output shaft, and a second electric
motor provided on the output shaft of the differential mechanism,
and that mechanically transmits a major part of the motive power
from the engine to the driving wheels and electrically transmits
the remainder part of the motive power from the engine through the
use of an electric path from the first electric motor to the second
electric motor so that the speed change ratio is electrically
altered, wherein the second electric motor is operatively linked to
the output shaft via the above-described planetary gear type
multi-step transmission, or the like.
[0021] Furthermore, in a suitable construction, the installed
posture of the transmission relative to the vehicle may be a
transversely mounted type in which the axis of the transmission is
in the direction of width of the vehicle as in FF (front engine,
front wheel drive) vehicles and the like, or a longitudinally
mounted type in which the axis of the transmission is in the
longitudinal direction of the vehicle as in FR (front engine, rear
wheel drive) vehicles and the like.
[0022] In a suitable construction, as for the aforementioned
friction engagement devices, hydraulic friction engagement devices
that are engaged by hydraulic actuators, including a multi-plate
type or single-plate clutches or brakes, belt-type brakes, etc.,
are widely used. The oil pump that supplies working oil for
engaging the hydraulic type friction engagement devices may be, for
example, a pump that is driven by a motive power source for running
the vehicle to eject the working oil, or may also be a pump that is
driven by a dedicated electric motor that is disposed separately
from the vehicle-running motive power source. Besides, the clutches
or brakes may also be electromagnetic engage devices, for example,
electromagnetic clutches, magnetic particle clutches, etc., besides
hydraulic type friction engagement devices.
[0023] Also, in a suitable construction, it is appropriate if the
drive power source, such as the engine, that is, an internal
combustion engine such as a gasoline engine, a diesel engine, etc.,
an electric motor, etc., and the automatic transmission are
operatively interlinked. For example, a pulsation absorption damper
(vibration damping device), a direct-couple clutch, a
damper-equipped direct-couple clutch, a fluid transfer device,
etc., may be disposed between therebetween. The drive power source
and the input shaft of the automatic transmission may also be
always linked. As for the fluid transfer device, a lockup
clutch-equipped torque converter, a fluid coupling, etc., are
widely used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The features, advantages thereof, and technical and
industrial significance of this invention will be better understood
by reading the following detailed description of preferred
embodiments of the invention, when considered in connection with
the accompanying drawings, in which:
[0025] FIG. 1 is a diagram illustrating a hybrid drive device to
which a first embodiment as an example of the invention is applied,
and is also a block diagram illustrating portions of a control
system that is provided in the vehicle for controlling the hybrid
drive device and the like;
[0026] FIG. 2 is an alignment chart showing a relative relationship
in rotation speed among the rotating elements of a single-pinion
type planetary gear device that functions as a torque
combining-distributing mechanism;
[0027] FIG. 3 is an alignment chart representing an
interrelationship among the rotating elements of Ravigneaux type
planetary gear mechanism that constitutes a transmission;
[0028] FIG. 4 shows a shift-purpose hydraulic control circuit for
automatically controlling the shift of the transmission by engaging
and releasing a first brake and a second brake;
[0029] FIG. 5 is a diagram showing a valve characteristic of a
normally closed type first linear solenoid valve that establishes
an open valve (communicated) state between the input port and the
output port during a non-electrified state;
[0030] FIG. 6 is a diagram showing a valve characteristic of a
normally open type second linear solenoid valve that establishes a
closed valve (shut-off) state between the input port and the output
port during a non-electrified state;
[0031] FIG. 7 is a table illustrating operations of a hydraulic
control circuit;
[0032] FIG. 8 is a functional block diagram illustrating portions
of control functions of electronic control devices shown in FIG.
1;
[0033] FIG. 9 is a shift chart that is used in a shift control of
the transmission performed by the electronic control devices shown
in FIG. 1;
[0034] FIG. 10 is a flowchart illustrating portions of the control
operation of the electronic control devices shown in FIG. 1, that
is, an abnormality determination routine for performing abnormality
determination regarding a high speed step, and is a subroutine
corresponding to an abnormality determination routine that is
executed in a flowchart shown in FIG. 11; and
[0035] FIG. 11 is the flowchart illustrating portions of the
control operation of the electronic control devices shown in FIG.
1, that is, a control operation for abnormality determination
regarding the high speed step which is one of system checks that is
executed at the time of start of vehicle run.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] In the following description and the accompanying drawings,
the present invention will be described in more detail with
reference to exemplary embodiments.
[0037] FIG. 1 is a diagram illustrating a hybrid drive device 10 to
which a first embodiment as an example of the invention is applied.
Referring to FIG. 1, in the hybrid drive device 10, torque of a
first drive source 12 that is a main drive source is transmitted to
an output shaft 14 that functions as an output member, and the
torque is transmitted from the output shaft 14 to a pair of left
and right driving wheels 18 via a differential gear device 16 in a
vehicle. Besides, in the hybrid drive device 10, a second drive
source 20 capable of selectively executing a power running control
of outputting the drive power for running the vehicle or a
regenerative control for recovering energy is provided. The second
drive source 20 is linked to the output shaft 14 via a transmission
22. Therefore, the capacity of torque transmitted from the second
drive source 20 to the output shaft 14 is increased or decreased in
accordance with the speed change ratio .gamma.s (=the rotation
speed of the MG2/the rotation speed of the output shaft 14) that is
set by the transmission 22.
[0038] The transmission 22 is constructed so as to establish a
plurality of steps whose speed change ratios .gamma.s is greater
than or equal to "1". Therefore, at the time of power running when
torque is output from the second drive source 20, the torque can be
increased by the transmission 22 while being transmitted to the
output shaft 14. Hence, the second drive source 20 is constructed
with a further reduced capacity or in a further reduced size. Due
to this, for example, in the case where the rotation speed of the
output shaft 14 increases in association with high vehicle speed,
the speed change ratio .gamma.s is dropped to drop the rotation
speed of the second drive source 20, in order to maintain a good
state of the operation efficiency of the second drive source 20. In
the case where the rotation speed of the output shaft 14 drops, the
speed change ratio .gamma.s is increased.
[0039] As for the shifting of the transmission 22, the torque
capacity of the transmission 22 drops or inertial torque associated
with change in the rotation speed occurs, in which case the torque
of the output shaft 14, that is, the output shaft torque, is
affected. Therefore, in the hybrid drive device 10, on the occasion
of shifting by the transmission 22, a control is performed such
that the torque of the first drive source 12 is corrected so as to
prevent or restrain the torque fluctuation of the output shaft
14.
[0040] The first drive source 12 is constructed mainly of an engine
24, a MG1 (hereinafter, referred to as "MG1"), and a planetary gear
device 26 provided for combining or distributing torque between the
engine 24 and the MG1. The engine 24 is a publicly known internal
combustion engine that outputs power by burning fuel, such as a
gasoline engine, a diesel engine, etc. The engine 24 is constructed
so that states of operation thereof, such as a the throttle opening
degree, the intake air amount, the fuel supply amount, the ignition
timing, etc., are electrically controlled by an engine-controlling
electronic control device (E-ECU) 28 that is made up mainly of a
microcomputer. The electronic control device 28 is supplied with
detection signals from an accelerator operation amount sensor AS
that detects the operation amount of an accelerator pedal 27, a
brake sensor BS for detecting operation of a brake pedal 29,
etc.
[0041] The MG1 is, for example, a synchronous electric motor, and
is constructed to selectively perform the function as an electric
motor of generating drive torque and the function as an electric
power generator. The MG1 is connected to an electricity storage
device 32, such as a battery, a capacitor, etc., via an inverter
30. Then, the inverter 30 is controlled by a
motor-generator-controlling electronic control device (MG-ECU) 34
made up mainly of a microcomputer so that the output torque of the
MG1 or the regenerative torque is adjusted or set. The electronic
control device 34 is supplied with detection signals from an
operation position sensor SS that detects the operation position of
a shift lever 35, and the like.
[0042] The planetary gear device 26 is a single-pinion type
planetary gear mechanism that includes three rotating elements: a
sun gear S0, a ring gear R0 disposed concentrically with the sun
gear S0, and a carrier C0 that supports pinions P0 meshing with the
sun gear S0 and the ring gear R0, in such a manner that the pinions
P0 are rotatable about their own axes and also revolvable. The
planetary gear device 26 causes known differential effect. The
planetary gear device 26 is provided concentrically with the engine
24 and the transmission 22. Since the planetary gear device 26 and
the transmission 22 are constructed substantially symmetrically
about a center line, the half portions thereof below the center
line are omitted in FIG. 1.
[0043] In this embodiment, a crankshaft 36 of the engine 24 is
linked to the carrier C0 of the planetary gear device 26 via a
damper 38. The sun gear S0 is linked to the MG1, and the output
shaft 14 is linked to the ring gear R0. The carrier C0 functions as
an input element, and the sun gear S0 functions as a reaction force
element, and the ring gear R0 functions as an output element.
[0044] Relative relationships among the rotating elements of the
single-pinion type planetary gear device 26 that functions as a
torque combining-distributing mechanism are shown by an alignment
chart in FIG. 2. In the alignment chart, a vertical axis S, a
vertical axis C, and a vertical axis R represent the rotation speed
of the sun gear S0, the rotation speed of the carrier C0, and the
rotation speed of the ring gear R0, respectively. The intervals
between the vertical axis S, the vertical axis C, and the vertical
axis R are set so that when the interval between the vertical axis
S and the vertical axis C is 1, the interval between the vertical
axis C and the vertical axis R becomes p (the number of teeth Zs of
the sun gear S0/the number of teeth Zr of the ring gear R0).
[0045] In the planetary gear device 26, when a reaction torque from
the MG1 is input to the sun gear S0 while the output torque of
engine 24 is input to the carrier C0, a torque greater than the
torque input from the engine 24 appears on the ring gear R0 that is
the output element, so that the MG1 functions as an electric power
generator. While the rotation speed of the ring gear R0 (output
shaft rotation speed) NO is constant, the rotation speed NE of the
engine 24 can be continuously (steplessly) changed by changing the
rotation speed of the MG1 upward or downward. The dashed line in
FIG. 2 shows a state where the rotation speed NE of the engine 24
drops when the rotation speed of the MG1 is lowered from the value
shown by a solid line. That is, a control of setting the rotation
speed NE of the engine 24 at, for example, a rotation speed that
provides the best fuel economy, can be executed by controlling the
MG1. This type of hybrid system is termed mechanical distribution
system or split type.
[0046] Referring back to FIG. 1, the transmission 22 of the
embodiment is constructed of one set of a Ravigneaux type planetary
gear mechanism. Specifically, in the transmission 22, a first sun
gear S1 and a second sun gear S2 are provided, and short pinions P1
mesh with the first sun gear S1. The short pinions P1 also mesh
with long pinions P2 whose axial length is longer than that of the
short pinions P1. The long pinions P2 mesh with a ring gear R1 that
is disposed concentrically with the sun gears S1, S2. The pinions
P1, P2 are supported by a common carrier C1 so as to be rotatable
about their own axes and also revolvable. Besides, the second sun
gear S2 meshes with the long pinions P2.
[0047] The second drive source 20 is constructed of a second
motor-generator (hereinafter, referred to as "MG2") that is an
electric motor or an electric power generator that is controlled by
the motor-generator-controlling electronic control device (MG-ECU)
34 via an inverter 40 so that the assist-purpose output torque or
the regenerative torque is adjusted or set. The MG2 is linked to
the second sun gear S2, and the carrier C1 is linked to the output
shaft 14. The first sun gear S1 and the ring gear R1, together with
the pinions P1, P2, construct a mechanism that corresponds to a
double-pinion type planetary gear device. The second sun gear S2
and the ring gear R1, together with the long pinions P2, construct
a mechanism that corresponds to a single-pinion type planetary gear
device.
[0048] The transmission 22 is also provided with a first brake B1
that is provided between the first sun gear S1 and a transmission
housing 42 for selectively fixing the first sun gear S1, and a
second brake B2 that is provided between the ring gear R1 and the
transmission housing 42 for selectively fixing the ring gear R1.
These brakes B1, B2 are so-called friction engagement devices that
produce braking force by friction force. As the brakes, it is
possible to adopt multi-plate type engagement devices or band-type
engagement devices. Then, each of the brakes B1, B2 is constructed
so that the torque capacity thereof continuously changes in
accordance with the engagement pressure that is generated by a
hydraulic actuator or the like.
[0049] In the transmission 22 constructed as described above, when
the second sun gear S2 functions as an input element and the
carrier C1 functions as an output element and the first brake B1 is
engaged, a high speed step H whose speed change ratio .gamma.sh is
greater than "1" is achieved. If the second brake B2 is engaged
instead of the first brake B1 in a similar situation, a low speed
step L whose speed change ratio .gamma.sl is greater than the speed
change ratio .gamma.sh of the high speed step H is set. The
shifting between the speed change steps H and L is executed on the
basis of states of run of the vehicle such as the vehicle speed,
the required drive power (or the accelerator operation amount),
etc. More concretely, speed change step regions are determined
beforehand as a map (shift chart), and a control is performed such
as to set either one of the speed change steps in accordance with
the detected vehicle driving state. A shift-controlling electronic
control device (T-ECU) 44 made up mainly of a microcomputer for
performing the control is provided.
[0050] The electronic control device 44 is supplied with detection
signals from an oil temperature sensor TS for detecting the
temperature of the working oil, a hydraulic switch SW1 for
detecting the engagement oil pressure of the first brake B1, a
hydraulic switch SW2 for detecting the engagement oil pressure of
the second brake B2, a hydraulic switch SW3 for detecting the line
pressure PL, etc.
[0051] FIG. 3 shows an alignment chart that has four vertical axes,
that is, a vertical axis S1, a vertical axis R1, a vertical axis
C1, and a vertical axis S2, in order to represent relative
relationships between the rotating elements of the Ravigneaux type
planetary gear mechanism that constitutes the transmission 22. The
vertical axis S1, the vertical axis R1, the vertical axis C1, and
the vertical axis S2 show the rotation speed of the first sun gear
S1, the rotation speed of the ring gear R1, the rotation speed of
the carrier C1, and the rotation speed of the second sun gear S2,
respectively.
[0052] In the transmission 22 constructed as described above, when
the ring gear R1 is fixed by the second brake B2, the low speed
step L is set, and the assist torque that the MG2 outputs is
amplified in accordance with the corresponding speed change ratio
.gamma.sl, and is thus applied to the output shaft 14. On the other
hand, when the first sun gear S1 is fixed by the first brake B1,
the high speed step H having the speed change ratio .gamma.sh that
is smaller than the speed change ratio .gamma.hl of the low speed
step L is set. Since the speed change ratio of the high speed step
H is also larger than "1", the assist torque that the MG2 outputs
is amplified in accordance with the speed change ratio .gamma.sh,
and is applied to the output shaft 14.
[0053] Incidentally, although the torque applied to the output
shaft 14 during a state where one of the speed change steps L, H is
steadily set is a torque obtained by increasing the output torque
of the MG2 in accordance with the corresponding speed change ratio,
the torque during a shift transitional state of the transmission 22
is a torque that is affected by the torque capacity at the brake B1
or B2, the inertia torque associated with the rotation speed
change, etc. Besides, the torque applied to the output shaft 14
becomes positive torque during a driving state of the MG2, and
becomes negative torque during a driven state of the MG2.
[0054] FIG. 4 shows a shift-purpose hydraulic control circuit 50
for automatically controlling the shifting of the transmission 22
by engaging and releasing the brakes B1, B2. The hydraulic control
circuit 50 includes, as oil pressure sources, a mechanical type
hydraulic pump 46 that is operatively linked to the crankshaft 36
of the engine 24 and therefore is rotationally driven by the engine
24, and an electric type hydraulic pump 48 that includes an
electric motor 48a and a pump 48b that is rotationally driven by
the electric motor 48a. The mechanical type hydraulic pump 46 and
the electric type hydraulic pump 48 suck the working oil that is
refluxed to an oil pan (not shown), via a strainer 52, or suck the
working oil that is directly refluxed via a reflux oil passageway
53, and pumps the working oil to a line pressure oil passageway 54.
An oil temperature sensor TS for detecting the oil temperature of
the refluxed working oil is provided on a valve body 51 that
partially forms the hydraulic control circuit 50, but may also be
connected to a different site.
[0055] A line pressure regulating valve 56 is a relief-type
pressure regulating valve, and includes a spool valve element 60
that opens and closes between a supply port 56a connected to the
line pressure oil passageway 54 and a discharge port 56b connected
to a drain oil passageway 58, a control oil chamber 68 which houses
a spring 62 that generates thrust in the closing direction of the
spool valve element 60 and which receives a module pressure PM from
a module pressure oil passageway 66 via an electromagnetic
open-close valve 64 when the set pressure of the line pressure PL
is altered to a higher level, and a feedback oil chamber 70
connected to the line pressure oil passageway 54 which generates
thrust in the opening direction of the spool valve element 60. The
line pressure regulating valve 56 outputs a constant line pressure
PL that is one of a low pressure and a high pressure. The line
pressure oil passageway 54 is provided with a hydraulic switch SW3
that is in an off-state when the line pressure PL is at the high
pressure-side value, and that is in an on-state when the line
pressure PL is at the low pressure-side value or lower. Since the
operation of the hydraulic switch SW3 is switched depending of the
high or low level of the line pressure PL, it is possible to
determine the presence/absence of an abnormality of the line
pressure regulating valve 56 as well as the presence/absence of an
abnormality of the line pressure PL.
[0056] A module pressure regulating valve 72 outputs to the module
pressure oil passageway 66 a constant module pressure PM that is
set lower than the low pressure-side line pressure PL, using the
line pressure PL as a basic pressure, regardless of fluctuations of
the line pressure PL. A first linear solenoid valve SLB1 for
controlling the first brake B1 and a second linear solenoid valve
SLB2 for controlling the second brake B2, using the module pressure
PM as a basic pressure, output control pressures PC1 and PC2 in
accordance with drive currents ISOL1 and ISOL2 that are command
values from the electronic control device 44.
[0057] The first linear solenoid valve SLB1 has a normally open
type valve characteristic of establishing an open valve
(communicated) state between the input port and the output port
during the non-electrified state. As shown in FIG. 5, as the drive
current ISOL1 increases, the output control pressure PC1 is
dropped. As shown in FIG. 5, the valve characteristic of the first
linear solenoid valve SLB1 is provided with a dead band A in which
the output control pressure PC1 does not drop until the drive
current ISOL1 exceeds a predetermined value Ia. The second linear
solenoid valve SLB2 has a normally closed type valve characteristic
of establishing a closed (shut-off) state between the input port
and the output port during the non-electrified state. As shown in
FIG. 6, as the drive current ISOL2 increases, the output control
pressure PC2 is increased. As shown in FIG. 6, the valve
characteristic of the second linear solenoid valve SLB2 is provided
with a dead band B in which the output control pressure PC2 does
not increase until the drive current ISOL2 exceeds a predetermined
value Ib.
[0058] A B1 control valve 76 includes a spool valve element 78 that
opens and closes between an input port 76a connected to the line
pressure oil passageway 54 and an output port 76b that outputs a B1
engagement oil pressure PB1, a control oil chamber 80 that receives
the control pressure PC1 from the first linear solenoid valve SLB1
in order to urge the spool valve element 78 in the opening
direction, and a feedback oil chamber 84 which houses a spring 82
that urges the spool valve element 78 in the closing direction and
which receives the B1 engagement oil pressure PB1 that is the
output pressure. The B1 control valve 76, using the line pressure
PL in the line pressure oil passageway 54 as a basic pressure,
outputs the B1 engagement oil pressure PB1 whose magnitude is in
accordance with the control pressure PC1 from the first linear
solenoid valve SLB1, and supplies it to the brake B1 through a B1
apply control valve 86 that functions as an interlock valve.
[0059] A B2 control valve 90 includes a spool valve element 92 that
opens and closes between an input port 90a connected to the line
pressure oil passageway 54 and an output port 90b that outputs a B2
engagement oil pressure PB2, a control oil chamber 94 that receives
the control pressure PC2 from the second linear solenoid valve SLB2
in order to urge the spool valve element 92 in the opening
direction, and a feedback oil chamber 98 which houses a spring 96
that urges the spool valve element 92 in the closing direction and
which receives the B2 engagement oil pressure PB2 that is the
output pressure. The B2 control valve 90, using the line pressure
PL in the line pressure oil passageway 54 as a basic pressure,
outputs the B2 engagement oil pressure PB2 whose magnitude is in
accordance with the control pressure PC2 from the second linear
solenoid valve SLB2, and supplies it to the brake B2 through a B2
apply control valve 100 that functions as an interlock valve.
[0060] The B1 apply control valve 86 includes a spool valve element
102 which opens and closes an input port 86a that receives the B1
engagement oil pressure PB1 output from the B1 control valve 76 and
an output port 86b connected to the first brake B1, an oil chamber
104 that receives the module pressure PM in order to urge the spool
valve element 102 in the opening direction, and an oil chamber 108
which houses a spring 106 that urges the spool valve element 102 in
the closing direction and which receives the B2 engagement oil
pressure PB2 output from the B2 control valve 90. The B1 apply
control valve 86 is held in the open valve state until it is
supplied with the B2 engagement oil pressure PB2 for engaging the
second brake B2. When the B2 engagement oil pressure PB2 is
supplied, the B1 apply control valve 86 is switched to the closed
valve state, so that the engagement of the first brake B 1 is
prevented.
[0061] The B1 apply control valve 86 is provided with a pair of
ports 110a and 110b that are closed when the spool valve element
102 is in the open valve position (position as indicated on the
right side of a center line shown in FIG. 4), and that are opened
when the spool valve element 102 is in the valve closed position
(position as indicated on the left side of the center line shown in
FIG. 4). The hydraulic switch SW2 for detecting the B2 engagement
oil pressure PB2 is connected to the port 110a, and the second
brake B2 is directly connected to the other port 110b. The
hydraulic switch SW2 assumes an on-state when the B2 engagement oil
pressure PB2 becomes a high-pressure state that is set beforehand,
and is switched to an off-state when the B2 engagement oil pressure
PB2 reaches or goes below a low-pressure state that is set
beforehand. Since the hydraulic switch SW2 is connected to the
second brake B2 via the B1 apply control valve 86, it is possible
to determine the presence/absence of an abnormality of the first
linear solenoid valve SLB1, the B1 control valve 76, the B1 apply
control valve 86, etc., that constitute the hydraulic system of the
first brake B1, as well as the presence/absence of an abnormality
of the B2 engagement oil pressure PB2.
[0062] The B2 apply control valve 100, similar to the B1 apply
control valve 86, includes a spool valve element 112 that opens and
closes between an input port 100a that receives the B2 engagement
oil pressure PB2 output from the B2 control valve 90 and an output
port 100b connected to the second brake B2, an oil chamber 114 that
receives the module pressure PM in order to urge the spool valve
element 112 in the opening direction, and an oil chamber 118 which
houses a spring 116 that urges the spool valve element 112 in the
closing direction and which receives the B1 engagement oil pressure
PB1 output from the B1 control valve 76. The B2 apply control valve
100 is held in the open valve state until it is supplied with the
B1 engagement oil pressure PB1 for engaging the first brake B1.
When the B1 engagement oil pressure PB1 is supplied, the B2 apply
control valve 100 is switched to the closed valve state, so that
the engagement of the second brake B2 is prevented.
[0063] The B2 apply control valve 100 is also provided with a pair
of parts 120a and 120b that are closed when the spool valve element
112 is in the open valve position (position as indicated on the
right side of a center line shown in FIG. 4), and that are opened
when the spool valve element 112 is in the valve closed position
(position as indicated on the left side of the center line shown in
FIG. 4). The hydraulic switch SW1 for detecting the B1 engagement
oil pressure PB1 is connected to the port 120a, and the first brake
B1 is directly connected to the other port 120b. The hydraulic
switch SW1 assumes an on-state when the B1 engagement oil pressure
PB1 becomes a high-pressure state that is set beforehand, and is
switched to an off-state when the B1 engagement oil pressure PB1
reaches or goes below a low-pressure state that is set beforehand.
Since the hydraulic switch SW1 is connected to the first brake B1
via the B2 apply control valve 100, it is possible to determine the
presence/absence of an abnormality of the second linear solenoid
valve SLB2, the B2 control valve 90, the B2 apply control valve
100, etc., that constitute the hydraulic system of the second brake
B2, as well as the presence/absence of an abnormality of the B1
engagement oil pressure PB1.
[0064] FIG. 7 is a table illustrating operations of the hydraulic
control circuit 50 constructed as described above. In FIG. 7,
symbol ".largecircle." shows the excited state or the engaged
state, and symbol ".times." shows the non-excited state or the
released state. That is, by putting both the first linear solenoid
valve SLB1 and the second linear solenoid valve SLB2 into the
excited state, the first brake B1 is put into the released state
and the second brake B2 is put into the engaged state, so that the
low speed step L (i.e., the first speed gear step) of the
transmission 22 is achieved. By putting both the first linear
solenoid valve SLB1 and the second linear solenoid valve SLB2 into
the non-excited state, the first brake B1 is put into the engaged
state and the second brake B2 is put into the released state, so
that the high speed step H (i.e., the second speed gear step) of
the transmission 22 is achieved.
[0065] FIG. 8 is a functional block diagram illustrating portions
of control functions of the electronic control devices 28, 34 and
44. In FIG. 8, for example, when the control is activated as the
power switch is operated during a state where the brake pedal is
operated after the key has been inserted into the key slot, a
hybrid drive control device 130 calculates a driver's requested
output on the basis of the accelerator operation amount, and causes
the engine 24 and/or the MG2 to generate the requested output so as
to bring about an operation with good fuel economy and low emission
gas amount. For example, the run mode is switched in accordance
with the state of run of the vehicle, among a motor run mode in
which the engine 24 is stopped and the MG2 is solely used as drive
source, a run mode in which the vehicle is run by using the MG2 as
a drive source while electric power is generated from the motive
power of the engine 24, and an engine run mode in which the vehicle
is run by mechanically transmitting the motive power of the engine
24 to the driving wheels 18.
[0066] The hybrid drive control device 130 controls the rotation
speed of the engine 24 via the MG1 so that the engine 24 operates
on an optimal fuel economy curve, even when the engine 24 is
driven. Besides, in the case where the MG2 is driven to perform the
torque assist, the hybrid control device 130 sets the transmission
22 to the low speed step L to increase the torque applied to the
output shaft 14 during a state of low vehicle speed. During a state
of increased vehicle speed, the hybrid control device 130 sets the
transmission 22 to the high speed step H to relatively drop the
rotation speed of the MG2 and therefore reduce the loss. Thus, the
torque assist with good efficiency is executed. Furthermore, during
the coasting run, the inertia energy that the vehicle has is used
to rotationally drive the MG1 or the MG2, so that the energy is
regenerated as electric power that is in turn stored into the
electricity storage device 32.
[0067] A shift control device 132 determines a speed change step of
the transmission 22 on the basis of the speed V and the drive power
P of the vehicle from a pre-stored shift chart, for example, as
shown in FIG. 9, and outputs the drive currents ISOL1 and ISOL2,
i.e., the command values, to the hydraulic control circuit 50 to
control the engagement and release of the first brake B1 and the
second brake B2 so that the switch to the determined speed change
step is automatically performed.
[0068] In the case where the calculated driver's requested output
is greater than a pre-set output criterion value, or in the case
where the transmission 22 is performing a shift, that is, is in a
shift transition state, or the like, a line pressure control device
134 switches the set pressure of the line pressure PL from a low
pressure state to a high pressure state by switching the
electromagnetic open-close valve 64 from the closed state to the
open state to supply the module pressure PM into the oil chamber 68
of the line pressure regulating valve 56 and to therefore increase
the thrust on the spool valve element 60 in the closing direction
by a predetermined value.
[0069] In the state of the vehicle in which either one of the speed
change steps L, H is formed, an abnormality determination device
136 determines the presence/absence of an abnormality of elements
related to the formation of that speed change step L, H on the
basis of, for example, a predetermined rule.
[0070] The elements related to the formation of the speed change
steps L, H include the line pressure regulating valve 56 that
regulates the line pressure PL that serves as the basic pressure
of, for example, the B1 engagement oil pressure PB1, the B2
engagement oil pressure PB2, etc., the first linear solenoid valve
SLB1, the B1 control valve 76, the B1 apply control valve 86, etc.
that constitute the hydraulic system of the first brake B1, the
second linear solenoid valve SLB2, the B2 control valve 90, the B2
apply control valve 100, etc. that constitute the hydraulic system
of the second brake B2, the hydraulic switch SW1 for detecting the
B1 engagement oil pressure PB1, the hydraulic switch SW2 for
detecting the B2 engagement oil pressure PB2, the hydraulic switch
SW3 for detecting the line pressure PL, etc. As for the abnormality
of these elements, the valve sticking or the like is assumed with
regard to the aforementioned valves. With regard to the hydraulic
switches SW1, SW2, SW3, the abnormality in the switching operation
between the on-state and the off-state thereof or the like is
assumed. With regard to the linear solenoid valves SLB1, SLB2, such
abnormalities as a break, shortcircuit, etc. are assumed.
[0071] Thus, the presence/absence of an abnormality of the
aforementioned individual valves can be determined by detecting the
states of operation of the hydraulic switches SW1, SW2, SW3, and
the presence/absence of an abnormality of the individual switches
SW1, SW2, SW3 themselves can also be determined. For example, in
the case where the speed change step is switched to the low speed
step L, the normal state includes the off-state of the switch SW1
corresponding to the pre-set low pressure state of the B1
engagement oil pressure PB1 or a state below the pre-set low
pressure state, the on-state of the switch SW2 corresponding to the
pre-set high pressure state of the B2 engagement oil pressure PB2,
and the on-state of the switch SW3 that detects the high pressure
state, that is, the set pressure of the line pressure PL for the
shift transition time. Besides, when the speed change step is
switched to the high speed step H, the normal state includes the
on-state of the switch SW1 corresponding to the pre-set high
pressure state of the B1 engagement oil pressure PB1, the off-state
of the switch SW2 corresponding to the pre-set low pressure state
of the B2 engagement oil pressure PB2 or a state below the pre-set
low pressure state, and the on-state of the switch SW3 that detects
the high pressure state, that is, the set pressure of the line
pressure PL for the shift transition time.
[0072] The abnormality determination device 136, for example, when
the low speed step L has been established, determines whether or
not the switch SW1 is in the off-state, and whether or not the
switch SW2 is in the on-state, and whether or not the switch SW3 is
in the on-state, on the basis of a rule determined beforehand. If
it is determined that the switch SW1 is in the off-state, and the
switch SW2 is in the on-state, and the switch SW3 is in the
on-state, the abnormality determination device 136 sets up a
low-speed step normality determination flag FLG as a low-speed step
determination flag FL. On the other hand, if the abnormality
determination device 136 makes any one of the following: a
determination that the switch SW1 is in the on-state; a
determination that the switch SW2 is in the off-state; and a
determination that the switch SW3 is in the off-state, the
abnormality determination device 136 sets up a low-speed step
abnormality determination flag FLE as a low-speed step
determination flag FL.
[0073] For example, when the high speed step H has been
established, the abnormality determination device 136 determines
whether or not the switch SW1 is in the on-state, and whether or
not the switch SW2 is in the off-state, and whether or not the
switch SW3 is in the on-state, on the basis of a rule determined
beforehand. If it is determined that the switch SW1 is in the
on-state, and the switch SW2 is in the off-state, and the switch
SW3 is in the on-state, the abnormality determination device 136
sets up a high-speed step normality determination flag FHG as a
high-speed step determination flag FH. On the other hand, if the
abnormality determination device 136 makes any one of the
following: a determination that the switch SW1 is in the off-state;
a determination that the switch SW2 is in the on-state; and a
determination that the switch SW3 is in the off-state, the
abnormality determination device 136 sets up a high-speed step
abnormality determination flag FHE as the high-speed step
determination flag FH.
[0074] A storage device 138 stores information about the
abnormality determined to be present by the abnormality
determination device 136. For example, the storage device 138
stores the low-speed step determination flag FL and the high-speed
step determination flag FH while serially rewriting them to the
determination flags F that are set up by the abnormality
determination device 136.
[0075] A speed change step determination device 140 determines
whether or not the shift of the transmission 22 to the high speed
step H has been performed, for example, on the basis of whether or
not the command values of the drive currents ISOL1 and ISOL2 for
obtaining the high speed step H via the shift control device 132
have been output to the hydraulic control circuit 50. Also, the
speed change step determination device 140 determines whether or
not the shift of the transmission 22 to the low speed step L has
been performed, for example, on the basis of whether or not the
commands of the drive currents ISOL1 and ISOL2 for obtaining the
low speed step L via the shift control device 132 have been output
to the hydraulic control circuit 50.
[0076] The fail-safe process device 142 performs the abnormality
determination on the basis of the determination flag F set up by
the abnormality determination device 136, and accordingly executes
a fail-safe process.
[0077] For example, the fail-safe process device 142 determines the
low-speed step determination flag FL that has been set up by the
abnormality determination device 136. Then, if the low-speed step
abnormality determination flag FLE has been set up as the low-speed
step determination flag FL, the fail-safe process device 142
outputs to the shift control device 132 a command to prohibit the
shift to the low speed step L as a fail-safe process. On the other
hand, if the low-speed step normality determination flag FLG has
been set up as the low-speed step determination flag FL, the
fail-safe process device 142 does not output to the shift control
device 132 the command to prohibit the shift to the low speed step
L as a normal-time process.
[0078] Also, the fail-safe process device 142 determines the
high-speed step determination flag FH that has been set up by the
abnormality determination device 136. Then, if the high-speed step
abnormality determination flag FHE has been set up as the
high-speed step determination flag FH, the fail-safe process device
142 outputs to the shift control device 132 a command to prohibit
the shift to the high speed step H as a fail-safe process. On the
other hand, if the high-speed step normality determination flag FHG
has been set up as the high-speed step determination flag FH, the
fail-safe process device 142 does not output to the shift control
device 132 the command to prohibit the shift to the high speed step
H, as a normal-time process.
[0079] Thus, the determination as to the abnormality regarding the
formation of each of the speed change steps L, H is carried out by
actual performance of the shift to the speed change step, and if
the abnormality determination is made, the fail-safe operation is
then executed. From another viewpoint, the abnormalities of valves,
such as the B1 apply control valve 86 and the like, cannot be
detected without actual formation of any speed change step.
Therefore, in order for the fail-safe operation to be executed at
the time of abnormality determination, there is a need to perform
the shift to each speed change step L, H and perform the
abnormality determination. Therefore, even if an abnormality has
occurred regarding a speed change step, the shift to that speed
change step may be performed once, and there is possibility of
deterioration of the drivability. Particularly, the high speed step
H, which is less frequently used than the low speed step L, usually
requires a relatively long time for the abnormality determination
and the normality return determination, and there is a possibility
of even greater deterioration of the drivability.
[0080] Hence, in order that the occurrence of an abnormality that
cannot be detected unless a speed change step has actually been
formed will be determined before the vehicle runs on that speed
change step, a re-determination-purpose speed change step
establishment device 144, if information about an abnormality is
stored in the storage device 138 when the vehicle is to newly start
to run, establishes the speed change step where the abnormality
stored in the storage device 138 occurred, in order to cause the
abnormality determination device 136 to re-determine the
presence/absence of an abnormality of an element related to the
formation of the speed change step. Due to this, for example, in
the case where the abnormality is determined to be present, a
fail-safe operation of, for example, prohibiting the shift to that
speed change step, can be performed before the vehicle runs on the
speed change step. On the other hand, in the case where the
abnormality is not determined to be present but normality has
returned, the shift to that speed change step can be performed.
Thus, the drivability can be improved.
[0081] Hereinafter, the control operation of the
re-determination-purpose speed change step establishment device 144
will be concretely described. Incidentally, the following
description will be made in conjunction with the case of the high
speed step H where there particularly is a possibility of
deterioration of the drivability, as for example, and the
description in conjunction with the case of the low speed step L
will be omitted. Of course, what will be described below applies to
the low speed step L as well.
[0082] A vehicle run start determination device 146 determines
whether or not a new vehicle run starting operation has been
performed, that is, whether or not a user's operation for starting
to run the vehicle has been performed, for example, on the basis of
whether or not a power switch ST_ON has been operated during a
state where the brake pedal is operated after the on-operation with
the key inserted in a key slot has been performed. It is to be
noted herein that the vehicle run starting operation includes the
activating operation of the control device, and the starting of a
system check of a control device or the like for obtaining a
ready-to-run state READY-ON (e.g., the abnormality determination by
the abnormality determination device 136), and does not mean the
launch of the vehicle from the stopped state, as in the case of a
signal stop or the like. However, by subsequently operating the
shift lever 35 to a run position and operating the accelerator, a
new vehicle run, that is, a new trip, is started. This trip is
ended by, for example, the off-operation of the key, the
re-depression of the power switch ST_ON, etc.
[0083] If it is determined by the vehicle run start determination
device 146 that the user's operation for starting to run the
vehicle has been performed, the previous-trip abnormality
determination device 148 determines whether or not the information
about the abnormality of the high speed step (second gear step) H
determined to be present by the abnormality determination device
136 is stored, that is, whether or not the abnormality of the high
speed step H occurred during the previous trip, that is, during the
run preceding the present new start of vehicle run, on the basis of
whether or not the high-speed step abnormality determination flag
FHE is stored as the high-speed step determination flag FH in the
storage device 138.
[0084] At the time of a new start of vehicle run where it is
determined by the vehicle run start determination device 146 that
the user's operation for starting to run the vehicle has been
performed, if it is determined by the previous-trip abnormality
determination device 148 that the information about the abnormality
of the high speed step (second gear step) H is stored, the
re-determination-purpose speed change step establishment device 144
causes the shift control device 132 to establish the high speed
step H in order to cause the abnormality determination device 136
to perform re-determine the presence/absence of the abnormality of
an element related to the formation of the high speed step H.
[0085] The fail-safe process device 142, in addition to the
foregoing function, performs the abnormality determination on the
basis of the high-speed step determination flag FH that has been
set up again and thus updated by the abnormality determination
device 136, and accordingly executes the fail-safe process.
[0086] The shift control device 132, in addition to the foregoing
function, performs an operation for putting the vehicle into a
ready-to-run state by setting up the low speed step L after the
fail-safe process is performed by the fail-safe process device 142.
Besides, even in the case where, at the time of a new start of
vehicle run, it is determined by the previous-trip abnormality
determination device 148 that the information about the abnormality
of the high speed step H is not stored, the shift control device
132 performs an operation for putting the vehicle into the
ready-to-run state by setting up the low speed step L.
[0087] In this manner, the re-determination-purpose speed change
step establishment device 144, in response to the activating
operation of the vehicle and prior to the setting of the
ready-to-run state, forms the high speed step H and causes the
re-determination of the presence/absence of an abnormality of an
element related to the formation of the high speed step H.
[0088] In this embodiment, the abnormality determination device
136, the storage device 138, the re-determination-purpose speed
change step establishment device 144, the previous-trip abnormality
determination device 148, etc., correspond to an abnormality
determination device.
[0089] FIG. 10 is a flowchart illustrating portions of the control
functions of the electronic control devices 28, 34 and 44, that is,
an abnormality determination routine for performing the abnormality
determination regarding the high speed step H. This routine is
repeatedly executed in a very short cycle time of, for example,
about several msec to several ten msec.
[0090] Firstly, in step (hereinafter, "step" will be omitted) S1
corresponding to the speed change step determination device 140, it
is determined whether or not the shift of the transmission 22 to
the high speed step H (second gear step) has been performed, for
example, on the basis of whether or not the command values of the
drive currents ISOL1 and ISOL2 for obtaining the high speed step H
have been output to the hydraulic control circuit 50.
[0091] If a negative judgment is made in S1, this routine is ended.
If an affirmative judgment is made in S1, it is then determined
whether or not the switch SW1 is in the on-state, in S2
corresponding to the abnormality determination device 136. If an
affirmative judgment is made in S2, it is then determined whether
or not the switch SW2 is in the off-state, in S3 corresponding to
the abnormality determination device 136. If an affirmative
judgment is made in S3, it is then determined whether or not the
switch SW3 is in the on-state, in S4 corresponding to the
abnormality determination device 136.
[0092] If an affirmative judgment is made in S4, the high-speed
step normality determination flag FHG is set up as the high-speed
step determination flag FH in S5 corresponding to the abnormality
determination device 136. On the other hand, if a negative judgment
is made in any one of S2 to S4, the high-speed step abnormality
determination flag FHE is set up as the high-speed step
determination flag FH in S6 corresponding to the abnormality
determination device 136.
[0093] Subsequently to S5 or S6, in S7 corresponding to the storage
device 138, the high-speed step determination flag FH is stored
while it is being rewritten to the determination flag F set up in
S5 or S6.
[0094] Furthermore, subsequently to S5 or S6, in a step (not shown)
corresponding to the fail-safe process device 142, the command to
prohibit the shift to the high speed step H is output if the
high-speed step abnormality determination flag FHE has been set up
as the high-speed step determination flag FH. Then, if it is
determined that there is an abnormality regarding the high speed
step H, the vehicle is run only on the low speed step L from then
on. On the other hand, if the high-speed step normality
determination flag FHG has been set up as the high-speed step
determination flag FH, the command to prohibit the shift to the
high speed step H is not output. Then, if it is determined that the
high speed step H is normal, the switch between the low speed step
L and the high speed step H is performed, for example, from a shift
chart shown in FIG. 9 on the basis of the state of the vehicle,
from then on.
[0095] FIG. 11 is a flowchart illustrating portions of the control
functions of the electronic control devices 28, 34 and 44, that is,
a control operation for performing the abnormality determination
regarding the high speed step H which is a system check that is
executed at the time of start of vehicle run. This routine is
repeatedly executed in a very short cycle time of, for example,
about several msec to several ten msec. The abnormality
determination routine of FIG. 10 is a subroutine that corresponds
to the abnormality determination routine executed in the flowchart
of FIG. 11.
[0096] Firstly in step S11 corresponding to the vehicle run start
determination device 146, it is determined whether or not a user's
operation for starting to run the vehicle has been performed, for
example, on the basis of whether or not the power switch ST_ON has
been operated in a state where the brake pedal is operated after
the key has been inserted into the key slot.
[0097] If a negative judgment is made in S11, this routine is
ended. However, if an affirmative judgment is made in S11, the
process proceeds to S12 corresponding to the previous-trip
abnormality determination device 148. In S12, it is determined
whether or not an abnormality regarding the high speed step H
occurred during the previous trip, for example, on the basis of
whether or not the high-speed step abnormality determination flag
FHE is stored as the high-speed step determination flag FH in S7 in
FIG. 10.
[0098] If an affirmative judgment is made in S12, the process
proceeds to S13 corresponding to the re-determination-purpose speed
change step establishment device 144. In S13, the high speed step H
is established in order that the presence/absence of an abnormality
of an element related to the formation of the high speed step H
will be re-determined in the abnormality determination routine of
FIG. 13.
[0099] Subsequently, in S14 corresponding to the abnormality
determination routine shown in FIG. 10, the abnormality of the
element related to the formation of the high speed step H is
determined to be present, and the high-speed step determination
flag FH is newly set up and thus updated.
[0100] Subsequently, in S15 corresponding to the fail-safe process
device 142, the abnormality determination is performed on the basis
of the high-speed step determination flag FH updated in S14.
[0101] If the high-speed step abnormality determination flag FHE is
set up as the high-speed step determination flag FH in S14 and an
affirmative judgment is made in S14, the command to prohibit the
shift to the high speed step H is output as a fail-safe process in
S16 corresponding to the fail-safe process device 142. Thus, the
shift to the high speed step H is prohibited beforehand, without
the need to actually perform the shift to the high speed step H
during the running of the vehicle.
[0102] If the high-speed step normality determination flag FHG has
been set up as the high-speed step determination flag FH in S14 and
a negative judgment is made in S15, the command to prohibit the
shift to the high speed step H is not output, as a normal-time
process, in S17 corresponding to the fail-safe process device 142.
Therefore, the shift to the high speed step H is allowed during the
running of the vehicle.
[0103] In the case where a negative judgment is made in S12, or
subsequently to S16 or S17, an operation for putting the vehicle
into the ready-to-run state by setting up the low speed step L (1st
speed gear step) in S18 corresponding to the shift control device
132.
[0104] As described above, according to the embodiment, if the
information about an abnormality of an element related to the
formation of the high speed step H which was determined to be
present by the abnormality determination device 136 is stored in
the storage device 138 when the vehicle is to newly start to run,
the high speed step H is established by the
re-determination-purpose speed change step establishment device 144
in order to cause the re-determination of the presence/absence of
the abnormality of the element related to the formation of the high
speed step H. Therefore, the occurrence of the abnormality that
cannot be detected unless the high speed step H has actually been
established can be determined before the vehicle runs on the high
speed step H. Therefore, for example, if the abnormality exists,
the fail-safe operation of prohibiting the shift to the high speed
step H can be performed. On the other hand, if normality has
returned, the shift to the high speed step H is allowed. Thus, the
drivability can be improved.
[0105] Furthermore, the frequency of the abnormality determination
being performed regarding the high speed step H, which is less
frequently used, becomes higher, so that the drivability can be
further improved.
[0106] Furthermore, in response to the activating operation of the
vehicle and prior to the setting of the ready-to-run state, the
transmission 22 is caused to be in the high speed step H by the
re-determination-purpose speed change step establishment device
144. Therefore, there is a need to set up the high speed step H and
perform the abnormality determination again beforehand only in the
case where the information about the abnormality is stored. That
is, it is no longer necessary to set up the high speed step H and
perform the abnormality determination every time the vehicle is to
newly start to run. Therefore, the low speed step L can be promptly
set up, and the time required before the vehicle is put into the
ready-to-run state is shortened, and the drivability can be
improved.
[0107] While the embodiment of the invention has been described in
detail with reference to the drawings, the invention is also
applicable in other manners.
[0108] For example, although in the foregoing embodiment, the
transmission 22 is a two-step automatic transmission (speed
reducer) having the low speed step L and the high speed step H
which is provided between the MG2 and the output shaft 14 so that
the torque the MG2 outputs is increased and then applied to the
output shaft 14, the transmission 22 is not restrictive, that is,
the invention is also applicable if a different type of
transmission is employed. For example, the invention is also
applicable if a well-known planetary gear type stepped (multi-step)
transmission that transmits the output of the engine 24 to the
driving wheels 18 is employed.
[0109] Furthermore, although in the foregoing embodiment, the
abnormality determination device 136 performs the abnormality
determination regarding the speed change steps L, H in accordance
with the on/off-states of the switches SW1, SW2, SW3, this
determination method is not restrictive, but other determination
methods may also be used. For example, the abnormality
determination regarding the speed change steps L, H may be
performed by performing the abnormality determination regarding a
break or shortcircuit of each of the first linear solenoid valve
SLB1 and the second linear solenoid valve SLB2 on the basis of
detection signals supplied from well-known IC type abnormality
detection sensors such as a break detection sensor, a shortcircuit
detection sensor, etc.
[0110] While the invention has been described with reference to
exemplary embodiments thereof, it is to be understood that the
invention is not limited to the exemplary embodiments or
constructions. To the contrary, the invention is intended to cover
various modifications and equivalent arrangements. In addition,
while the various elements of the exemplary embodiments are shown
in various combinations and configurations, which are exemplary,
other combinations and configurations, including more, less or only
a single element, are also within the spirit and scope of the
invention.
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