JP2003301941A - Control device for automatic transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an automatic transmission for a vehicle which can obtain appropriate decelerating force when automatically performing a down-shift before corner running of a lane. <P>SOLUTION: In a vehicle provided with the automatic transmission 14 for automatically selecting a change gear ratio γ step by step, when the automatic transmission 14 performs the down-shift on the basis of the lane information, brake is controlled by a brake control means 100 to obtain the predetermined deceleration. Since the vehicle is decelerated by not only the engine braking force to be changed step by step in response to a gear stage but also the braking force at an intermediate strength, appropriate deceleration is obtained when automatically performing the down-shift before the corner running of the lane, and the optimal deceleration curve and the appropriate car speed is accurately obtained. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission for a vehicle, which automatically downshifts the automatic transmission based on traveling road information such as a curve of a traveling road of the vehicle.

[0002]

2. Description of the Related Art In a vehicle equipped with an automatic transmission in which a gear ratio is changed stepwise, when a deceleration request point is detected based on information of a road on which the vehicle is traveling, for example, a bend (curvature) state of the road. The target vehicle speed corresponding to the deceleration request location is calculated, and if it is determined that the deceleration for making the vehicle speed of the vehicle reach the target vehicle speed is equal to or higher than a predetermined value, the automatic transmission is automatically A control device for an automatic transmission for a vehicle has been proposed in which a required deceleration is obtained by automatic downshifting according to a bend in a road by downshifting. For example, JP-A-10
That is the control device for the automatic transmission described in Japanese Patent No. 184877.

[0003]

By the way, in the above-described conventional control device for an automatic transmission for a vehicle, since the gear ratio is changed stepwise, the deceleration due to the engine braking force is also changed stepwise. Therefore, there is an inconvenience that the vehicle cannot be decelerated by a braking force having an intermediate magnitude. That is, the deceleration of the vehicle due to the engine braking force applied to achieve the proper vehicle speed for a predetermined distance ahead of the corner area of the traveling road is too large or too small, and an appropriate deceleration cannot be obtained. Comfort and drivability are reduced.

The present invention has been made in view of the above circumstances, and an object thereof is to obtain an appropriate deceleration force when an automatic downshift is performed prior to cornering on a traveling road. It is to provide a control device for an automatic transmission for a vehicle.

[0005]

In order to achieve the above object, the gist of the present invention is to provide a vehicle equipped with an automatic transmission in which a gear ratio is changed stepwise, based on information of a vehicle running path. A control device for an automatic transmission for a vehicle of a type which automatically downshifts the automatic transmission, wherein when the downshift of the automatic transmission is performed,
It is to include brake control means for executing brake control so as to obtain a predetermined deceleration.

[0006]

In this way, when the automatic transmission is downshifted, the brake control means executes the brake control so as to obtain the predetermined deceleration. Not only the engine braking force that can be changed to, but also the intermediate braking force can be used to decelerate the vehicle, and an appropriate deceleration force can be used to automatically downshift prior to cornering the road. Is obtained.

[0007]

Other Embodiments Here, preferably, the brake control means decelerates the vehicle by using any one of a hydraulic brake device, an exhaust brake device, and an electromagnetic retarder device provided in the vehicle. Is. In this way, by using any one of the hydraulic brake device, the exhaust brake device, and the electromagnetic retarder device, not only the engine braking force that is changed stepwise according to the gear stage but also the intermediate The vehicle is decelerated with a large amount of braking force.

Further, preferably, the brake control means indicates, for each gear, a plurality of types of brake strength provided in a two-dimensional diagram showing an axis showing a degree of bending of a traveling road and an axis showing a road surface gradient. The braking strength determined based on the degree of bend of the traveling road and the road surface gradient is determined from the relationship including the regions, and the braking device is executed so as to obtain the determined braking strength. In this way, the vehicle can be decelerated with the optimum amount of braking force.

[0009]

Preferred embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a diagram for briefly explaining the structure of a vehicle power transmission device to which a vehicle automatic transmission control device according to an embodiment of the present invention is applied and a control device therefor. In FIG. 1, the prime mover 10 is composed of an internal combustion engine (engine), an electric motor, or a combination thereof, but in the following, it will be described as an engine. The output of the prime mover 10 is input to the automatic transmission 14 via the torque converter 12 and transmitted to the drive wheels via a differential gear unit and an axle not shown. FIG. 2 shows the torque converter 12 and the automatic transmission 14 thereof.
It is a skeleton figure which shows the structure of.

The torque converter 12 is the engine 1
Pump impeller 18 connected to the crankshaft 16 of 0 and turbine impeller 2 connected to the input shaft 20 of the automatic transmission 14.
2, a direct coupling clutch or a lockup clutch 24 for directly coupling the pump impeller 18 and the turbine impeller 22, and a stator 28 whose one-way clutch 26 prevents rotation in one direction. .

The automatic transmission 14 includes a first transmission 30 for switching between high and low gears, and a second transmission 32 for switching between reverse gear and four forward gears. The first transmission 30 includes an HL planetary gear device 34 including a sun gear S0, a ring gear R0, and a planet gear P0 that is rotatably supported by the carrier K0 and meshed with the sun gear S0 and the ring gear R0. The clutch C0 and the one-way clutch F0 are provided between the sun gear S0 and the housing 41, and the brake B0 is provided between the sun gear S0 and the housing 41. The second transmission 32 includes a first planetary gear unit 36 including a sun gear S1, a ring gear R1, and a planet gear P1 rotatably supported by the carrier K1 and meshed with the sun gear S1 and the ring gear R1.
A second planetary gear device 38 including a sun gear S2, a ring gear R2, and a planet gear P2 rotatably supported by the carrier K2 and meshed with the sun gear S2 and the ring gear R2, and a sun gear S3 and a ring gear R.
3 and a third planetary gear unit 40 including a planetary gear P3 rotatably supported by the carrier K3 and meshed with the sun gear S3 and the ring gear R3.

In the second transmission 32, the sun gear S
1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2, and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 42. The ring gear R2 is integrally connected to the sun gear S3. A clutch C1 is provided between the ring gear R2 and the sun gear S3 and the intermediate shaft 44, and a clutch C2 is provided between the sun gear S1 and the sun gear S2 and the intermediate shaft 44. Further, a band-type brake B1 for stopping the rotation of the sun gear S1 and the sun gear S2 is provided in the housing 41. A one-way clutch F1 and a brake B2 are provided in series between the sun gear S1 and the sun gear S2 and the housing 41. The one-way clutch F1 is configured to be engaged when the sun gear S1 and the sun gear S2 try to rotate in the opposite direction to the input shaft 20. A brake B3 is provided between the carrier K1 and the housing 41, and a brake B4 and a one-way clutch F2 are provided in parallel between the ring gear R3 and the housing 41. This one-way clutch F
2 is configured to be engaged when the ring gear R3 tries to rotate in the reverse direction.

The above-mentioned automatic transmission 14 is a step-variable transmission, and, for example, according to the operation table shown in FIG. 3, one reverse gear and a gear ratio γ (= rotational speed of the input shaft 20 / rotational speed of the output shaft 42). The gear ratio γ is switched stepwise by switching to any of the five forward gears that are sequentially different. In FIG. 3, a circle indicates an engaged state, a blank indicates a released state, and a ● indicates an engaged state when engine braking is generated. For example, when the shift lever 72 (see FIG. 1) is in the "D" range, for example, when the vehicle is traveling in the fifth gear, and the vehicle is downshifted prior to the curve of the road, the clutch C0 is engaged and When the brake B0 is released, a 5 → 4 downshift is executed, and when the clutch C2 is released, a 4 → 4 downshift is performed.
Three downshifts are executed. On the contrary, in the case of up-shifting from the third gear, the clutch C2 is engaged to perform the 3 → 4 up-shifting, and the clutch C0 is released and the brake B0 is engaged. 4 → 5 upshift is executed.

The above-mentioned FIG. 1 shows an electronic control unit installed in a vehicle.
Also shown are 76 and 78. Operation amount of accelerator pedal 50
Accelerator opening θ_A(%) Is on the accelerator sensor 51
It is becoming more detectable. Accelerator pedal 50
Is depressed greatly according to the driver's required output.
And corresponds to the acceleration operation member. Engine 10 suction
A throttle actuator 54 is attached to the air pipe 52.
Basically the accelerator opening θ_AOpening angle (opening) according to
θ_TH(%) Is provided with a throttle valve 56
It Rotational speed N of the engine 10_E(R.p.m) is detected
Engine speed sensor 58 for the throttle valve
Fully closed state of 56 and its opening θ_THFor detecting
Throttle sensor with idle switch not shown, output shaft
42 rotation speed N_OUT(R.p.m) That is, the vehicle speed V is detected
Of the vehicle speed sensor 66 and the brake pedal 68 for operating
Brake switch 70 and shift lever for detecting
Operation position P of 72_SHOperation position sensor 7 for detecting
4, rotation speed N of the input shaft 20 _INThat is, the clutch C0
The rotational speed NC0 (= turbine rotational speed NT) is detected.
Input shaft rotation sensor 73 for
Engine speed N_E, Accelerator opening
θ_A, Throttle valve opening θ_TH, Vehicle speed V, brake operation
State BK, operating position PSH of shift lever 72, input shaft rotation
Signals representing the rolling speed NC0 and hydraulic oil temperature TOIL are for the engine
Supply to electronic control unit 76 or electronic control unit 78 for shifting
It is supposed to be done.

The engine electronic control unit 76 and the gear shift electronic control unit 78 shown in FIG. 1 are communicably connected to each other so that a signal necessary for one is appropriately transmitted from the other. The engine electronic control unit 76 and the shift electronic control unit 78 are a CPU, a RAM, and a RO.
M, which is a so-called microcomputer provided with an input / output interface, the CPU processes the input signal according to the program stored in the ROM in advance while utilizing the temporary storage function of the RAM, and executes various controls.

For example, the engine electronic control unit 76 is
The fuel injection valve 79 is controlled to control the fuel injection amount, the igniter 80 is controlled to control the ignition timing, and the throttle valve 56 is controlled by the throttle actuator 54 to control the traction. Further, the electronic control unit for engine 76 drives the throttle actuator 54 based on the actual accelerator pedal operation amount A _CC from the relationship not shown in the control of the throttle valve 56, and basically the accelerator pedal operation amount A _CC is As it increases, the throttle valve opening θ _TH increases. Further, the engine electronic control unit 76 executes the torque reduction control during shifting, and temporarily reduces the output of the engine 10 within the shifting period of the automatic transmission 14 in order to mitigate the shift shock.

Further, the electronic shift control device 78 uses, for example, a pre-stored shift diagram shown in FIG. 4 to determine the gear of the automatic transmission 14 based on the accelerator opening θ _A and the vehicle speed V corresponding to the actual engine load. The gear is determined, and automatic shift control is executed to control the solenoid valve of the hydraulic control circuit provided in the automatic transmission 14 so as to establish the determined gear. The solid line in FIG. 4 is the upshift line and the broken line is the downshift line. In addition to the automatic shift control, the shift electronic control unit 78 has an antenna 82 for receiving radio waves from an artificial satellite and a signal from a navigation unit 84 provided in the vehicle and an ABS / VSC electronic control unit. Navigation coordination (shift) control is executed based on a turning signal from 86 and the like. The braking device 88 is a device for applying a deceleration force or a braking force of a magnitude corresponding to a command from the electronic shift control device 78 to the vehicle for deceleration control or the like. For example, by the ABS / VSC electronic control device 86, A hydraulic wheel braking device to be controlled, an exhaust brake device for closing the exhaust pipe of the engine 10 to increase exhaust pressure to generate a braking force, and an eddy current in a magnetic field in a rotating body rotating with the wheel, It is composed of an electromagnetic retarder device that electromagnetically generates a braking force by an eddy current.

The navigation device 84 is a GPS
Using the (Global Positioning System), radio waves (GPS signals) from artificial satellites are received via the antenna 82 to sequentially calculate the current position, and the current position of the vehicle is sequentially calculated on the road stored in the map in advance. Along with the display, a radius of curvature R and a turning angle θ _S of a corner of the road around the vehicle, for example, the traveling direction of the vehicle are determined, and traveling road information such as a control signal corresponding to the road shape is output. For example, a road is stored as a series of a plurality of node points, and one node point and the node points before and after the node point have a total of 3 points.
The radius of curvature R of the corner is calculated from the node of the point, and the appropriate vehicle speed at which the vehicle can travel stably in the corner is determined from the radius of curvature R. Further, the turning angle θ _{S of the} node is determined from the tangent of a curve that smoothly connects the nodes, and for example, depending on the size of the turning angle θ _S , for example, a gentle corner (20 ° ≦
θ _S <40 °, medium corner (40 ° ≦ θ _S <95 °),
The hairpin corner (95 ° ≦ θ _S ) area is determined, and the area from a position a predetermined distance before the node to the node or a position set based on the node is set as the corner region. Here, the position before the predetermined distance from the node or the position set based on the node may be changed as appropriate depending on the type of each corner.

The navigation coordinated control stabilizes a curve on a road by, for example, increasing the deceleration force such as engine braking force and braking force prior to the curve on the traveling road to obtain an appropriate vehicle speed for entering a curve during coasting. In order to travel, for example, the shift control and the brake control are executed that is contrary to the automatic shift control in which the gear stage is determined from the shift diagram of FIG. In the normal cooperative control, for example, a radius of curvature R of a curved region located in front of the vehicle is calculated, and an appropriate vehicle speed is calculated based on the radius of curvature R based on a relationship obtained in advance for safe driving.
This relationship is determined so that the smaller the radius of curvature R, the lower the appropriate vehicle speed. Next, the deceleration curve (area) is determined from the appropriate vehicle speed and the distance to the curve area (specific node point). This deceleration curve represents a vehicle speed for decelerating to a proper vehicle speed at each point before the particular node point on the curve at a proper vehicle speed so as to travel at a proper vehicle speed. Then, the current vehicle speed is compared with the deceleration curve, and the recommended gear is determined depending on where the current vehicle speed is with respect to the deceleration curve, and the current gear is maintained (upshift prohibited) or downshift is determined. When the accelerator depressing operation or the braking operation is performed prior to the predetermined distance before the upshift or the downshift enters the curve area, the command is given priority, and the gear position is maintained while traveling in the curve area.

In this navigation coordinated control, the portion for determining whether the upshift is prohibited or the downshift is determined based on, for example, a prestored shift map (relationship) shown in FIG. _It may be directly performed based on _R and the traveling state of the vehicle. FIG. 5 shows the radius of curvature R of the curved road in front of the vehicle in order to further obtain the uphill driving force or the engine braking force at the time of downhill compared to the automatic shift control using the shift diagram of FIG. In the two-dimensional coordinates of the horizontal axis L _H and the vertical axis L _V representing the gradient θ _{R of the} traveling road surface, a downshift determination map having a plurality of types of regions corresponding to a driving operation,
A first down shift area A ₁ , a second down shift area A ₂ , a third down shift area A ₃ , a fourth down shift area A ₄ , and non-down shift areas A ₅ and A ₆ .

In the navigation cooperative control in the electronic control unit 78 for shifting, the engine braking force corresponding to the gear stage obtained after the downshift of the automatic transmission 14 is stepwise and is not necessarily the proper value. Since the vehicle speed cannot be obtained and is too high or too low, the brake control for obtaining the braking force between the graduated engine braking forces is also executed in order to accurately obtain the appropriate vehicle speed. In this brake control, from the relationship shown in, for example, FIG. 6, which is preset so as to accurately obtain an optimum deceleration curve and an appropriate vehicle speed that suppress a reduction in riding comfort and drivability (drivability), an actual road curve Radius of curvature R,
The braking device 88 is controlled so that the auxiliary braking force having a magnitude determined based on the road surface inclination θ _R and the gear is generated.

FIG. 7 is a functional block diagram for explaining the main part of the control function of the electronic shift control device 78. In FIG. 7, the shift control means 90 controls the automatic transmission 14 based on the accelerator opening θ _A and the vehicle speed V corresponding to the actual load of the engine 10 from the pre-stored shift diagram shown in FIG. 4, for example. The gear stage of the gear shift destination is determined, and the solenoid valve of the hydraulic control circuit (not shown) provided in the automatic transmission 14 is controlled so as to automatically establish the determined gear stage.

The cooperative control means 92 increases the engine braking force to stably drive the vehicle in a curved area of the road at an appropriate vehicle speed for entering a curve, to travel on an uphill road with a sufficient driving force, or to a downhill road or a corner. In order to travel safely with sufficient engine braking force when entering the vehicle, for example, from the pre-stored shift map shown in FIG. 5, the actual radius of curvature R of the road (bending information related to the turning of the road), the actual road surface The downshift, the upshift prohibition, and the upshift of the automatic transmission 14 are directly determined based on the inclination θ _R (road surface inclination information related to the road inclination) and a driving operation such as an accelerator return operation and a brake operation, The gears are switched so that the determined gear shift is performed, and from the relationship shown in FIG. 6, the radius of curvature R of the actual road curve, the road surface inclination θ _R , The braking device 88 is controlled so that an auxiliary braking force having a magnitude determined based on the gear position is generated.

For example, the cooperative control means 92 is prestored in order to specify the center position of the width of the road in the curved area of the road located in front of the vehicle in accordance with a signal from the navigation device 84, for example. A smooth curve that passes through a plurality of continuous node points is formed by a smoothing process, a radius of curvature R for each node point is determined based on the curve, and bending information including the radius of curvature R is calculated. , Throttle opening at that time θ _TH
Actual vehicle traveling road inclination i.e. gradient theta _R of based on the difference between the actual acceleration and the vehicle acceleration on a flat road in accordance with the
And a driving operation determining means 96 for determining an opening operation of the accelerator pedal 50 (an accelerator pedal depressing operation, that is, an idle switch on) and a brake pedal 68 depressing operation, that is, a brake switch on. From the pre-stored downshift map shown in FIG. 5, the radius of curvature R of the actual road (bending information relating to the bending of the road), the actual road surface inclination θ _R (information of the road surface inclination relating to the road surface inclination), and the accelerator A shift command unit 98 that directly determines a downshift of the automatic transmission 14 based on a driving operation such as a return operation or a brake operation, and gives priority to the shift determination of the shift control unit 90 to instruct the downshift or the upshift prohibition. When the downshift is instructed and executed by the shift instructing means 98,
Brake control means 100 for controlling the braking device 88 so that an auxiliary braking force having a magnitude determined based on the radius of curvature R of the actual road curve, the road surface inclination θ _R , and the gear position is generated from the relationship shown in FIG. It has and.

The relationship shown in FIG. 6 has been experimentally obtained in advance so that the vehicle can be decelerated by an optimum braking force for accurately obtaining the optimum deceleration curve and the proper vehicle speed. And a plurality of types of brake strength provided in a two-dimensional diagram showing a horizontal axis indicating a degree of curvature such as a curvature (1 / R) of a traveling road or a radius of curvature _R and a vertical axis indicating a road surface gradient θ _R. Based on the relationship shown in FIG. 6, the brake control means 100 has a relationship including regions shown for each gear, and the curvature (1 / R) or the radius of curvature R, the road surface gradient θ _R, and the shift gear position of the actual traveling road. The brake control is executed so that the brake strength determined based on the above is obtained. In the above relationship, each gear is installed so as to generate a stronger braking force as the negative road surface gradient θ _R becomes larger and the road surface curvature 1 / R becomes larger.

Further, the cooperative shift control means 92 is as follows.
It has the function of. That is, cooperative shift control means 92
Indicates that the road ahead of the vehicle is
If it is determined that the road is
For example, the downshift to the 4th gear is the 3rd gear.
Promote downshifting. In addition, the navigation device 84
If you decide to drive on a highway according to the signal from
For example, the downshift range in FIG.
To suppress downshifts by eliminating downshifts to
It In addition, according to the signal from the navigation device 84
If the left curve with a small radius of curvature is determined, the radius of curvature
Promotes downshifts compared to a large right curve. Well
Lateral acceleration detected by G sensor, left and right cars
Wheel speed difference, steering angle, navigation device 8
Judging that the vehicle is turning due to gyro signals etc.
In order to maintain stable vehicle behavior, dow
Prohibit shifting such as gear shifting. Furthermore, the coordinated shift system
The control means 92 has an engine rotation speed N._EIs 400
Predetermined value N preset to 0 to 5000 r.p.m. _E1
The vehicle speed V is determined to be 120 km /
A predetermined value V preset to about h₁Determined as above
In this case, upshifting is performed and cooperative shift control mode
Mode to the normal automatic shift control mode.

FIG. 8 is a flow chart for explaining the main part of the control operation of the electronic shift control device 78, that is, the corner cooperative control, which is repeatedly executed after the vehicle reaches a predetermined distance before entering the curve area. It is something.
8, in step (hereinafter, step is omitted) S1 corresponding to the driving operation determination means 96 and the like, a depression operation of the brake pedal 68, that is, a brake on operation, or an opening operation of the accelerator pedal 50, that is, an accelerator off operation is performed. It is judged whether or not it has been broken. This S
If the determination of 1 is denied, the process of S6 and below, which will be described later, is executed, but if the determination of 1 is affirmed, the traveling road information detecting means 94 is executed.
In S2 corresponding to, the traveling direction of the vehicle, the shape of the road in the traveling direction, the bend information including the curvature radius R of the road, and the traveling road information such as the inclination gradient θ _{R of the} traveling road are read.

Next, at S3, the gear for cooperative control determined based on the radius of curvature R and the gradient θ _R of the road from the relationship of FIG. 5 is changed to the vehicle speed V and the throttle opening θ _TH from the relationship of FIG. It is determined whether or not the gear stage is lower than the gear stage in the normal automatic shift control determined based on the above. If the determination in S3 is negative, S6, which will be described later,
The following is executed, but in the affirmative case, a downshift command is issued so that the gear position for cooperative control determined from the relationship of FIG. 5 is obtained in S4 corresponding to the shift command means 98. . When the downshift command is issued in this manner, the automatic transmission 14 is preferentially downshifted to the determined gear.

At the same time, in S5 corresponding to the brake control means 100, the curvature (1 / R) or the radius of curvature R of the actual traveling road, the road surface gradient θ _R, and the transmission gear position are stored from the relationship stored in FIG. The brake strength is determined based on the above, and the braking device 88 is controlled so as to obtain the determined brake strength. As a result, in addition to the engine braking generated by the downshift, the braking force by the braking device 88 is applied, so that the vehicle can be decelerated by the braking force of an intermediate magnitude, and the vehicle can travel before cornering on the traveling road. When the downshift is automatically performed, an appropriate deceleration force, that is, an optimum deceleration curve and an appropriate vehicle speed can be obtained with high accuracy.

Subsequently, in S6, it is determined whether or not the condition for ending the cooperative control, that is, the brake control is satisfied, for example, the depression operation of the accelerator pedal 50, that is, the accelerator-on operation is performed, and the braking operation 88 is in progress. Is judged. If the determination in S6 is negative, this routine is terminated and the above S1 and subsequent steps are repeatedly executed, but if the determination is affirmative, the braking of the vehicle by the braking device 88 is terminated in S7.

As described above, according to the present embodiment, in the vehicle provided with the automatic transmission 14 in which the gear ratio γ is changed stepwise, the automatic transmission 14 is selected based on the road information.
Is automatically downshifted, the brake control unit 100 executes the brake control so as to obtain the predetermined deceleration, so that not only the engine braking force that is changed stepwise according to the gear stage but also the Since the vehicle can be decelerated with an intermediate amount of braking force, an appropriate deceleration force can be obtained when the vehicle is automatically downshifted prior to cornering on the road, and an optimal deceleration curve and appropriate vehicle speed can be obtained. Can be obtained accurately.

Further, according to this embodiment, the brake control means 100 decelerates the vehicle by using any one of a hydraulic brake device, an exhaust brake device, and an electromagnetic retarder device provided in the vehicle. As a result, the vehicle is appropriately decelerated by not only the engine braking force that is changed stepwise according to the gear stage after the downshift, but also the braking force of an intermediate magnitude.

Further, according to the present embodiment, a plurality of types of brake strength provided in a two-dimensional diagram showing an axis showing the degree of curvature of the traveling road (for example, curvature R) and an axis showing the road surface gradient θ _R are provided. The relationship shown in FIG. 6 having the regions shown for each step is provided, and the brake control means 100 determines the relationship based on the relationship shown in FIG. 6 based on the actual degree of curvature of the road (for example, the curvature R) and the road surface gradient θ _R. Since the brake control is executed so that the obtained brake strength is obtained, the vehicle is decelerated by the braking force of the optimum magnitude.

Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other aspects.

For example, in the vehicle of the above-described embodiment, the corner in front of the vehicle is determined according to the signal from the navigation device 84 provided in the vehicle, but the road information from the road information transmission device provided in the road is determined. It is possible to determine the curve in front of the vehicle according to the above.

Further, in the above-described embodiment, the automatic transmission 14 of the stepped type is used for control from the fifth speed gear stage to the third speed gear stage. The sixth gear may be used for control from the fourth gear to the third gear or control from the sixth gear to the third gear. Further, the transmission may be a parallel shaft type transmission in which the shift speed is automatically switched by a shift actuator. Further, the vehicle may be provided with a continuously variable transmission in which a transmission belt is wound around a pair of variable pulleys having a variable effective diameter. Even with such a continuously variable transmission, the present invention can be applied to a case where a plurality of preset speed ratios are switched stepwise.

Further, in the vehicle of the above-mentioned embodiment, the engine electronic control unit 76 connected to each other via a communication line.
Although the electronic control device 78 for shifting is provided, the above-described control may be performed by the arithmetic control device provided in common, or may be performed by the electronic control device provided in the navigation device 84. .

In the cooperative control of the above-mentioned embodiment,
Since the relationship shown in FIG. 6 is used exclusively for traveling on a downhill, the relationship of the lower half thereof may be configured.

The embodiment of the present invention has been described in detail with reference to the drawings, but this is merely an embodiment,
The present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a vehicle control device including a cooperative control device according to an embodiment of the present invention.

FIG. 2 is a skeleton diagram illustrating a configuration of the automatic transmission of FIG.

FIG. 3 is a table for explaining a relationship between a combination of friction engagement devices of the automatic transmission shown in FIG. 1 and gear stages obtained thereby.

FIG. 4 is a diagram showing a pre-stored shift map used for automatic shift control in the vehicle of FIG. 1.

FIG. 5 is a diagram showing an example of a downshift map used for directly determining a downshift in cooperative control.

FIG. 6 is a diagram showing an example of a relationship used to determine the strength of the braking force applied to the engine brake so that an optimum deceleration curve and an appropriate vehicle speed can be obtained accurately in cooperative control.

FIG. 7 is a functional block diagram illustrating a main part of a cooperative control function in the electronic shift control device of FIG. 1.

8 is a diagram showing a flowchart for explaining a main part of an operation of cooperative control in the electronic shift control device of FIG.

[Explanation of symbols]

14: Automatic transmission 78: Electronic control device for shifting (control device of automatic transmission for vehicle) 88: Braking device 92: Cooperative control means 100: Brake control means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // F16H 59:66 F16H 59:66 63:12 63:12 (72) Inventor Yoshikazu Tanaka Toyota City, Aichi Prefecture Toyota Town No. 1 Toyota Motor Co., Ltd. F-term (reference) 3D046 BB17 CC02 EE01 EE03 GG06 HH02 HH05 HH07 HH17 3G065 AA09 CA00 DA04 EA05 GA10 GA11 GA29 GA31 GA41 GA43 GA46 GA49 3J552 MA02 MA12 NA01 NB01 PA32 RA05 RB21 PA34 RA06 RB21 RB21VA34 VB01Z VC01Z VC03Z VD02Z VD11Z VD14Z VE08W 5H649 BB02 BB07 HH16 JK03

Claims (3)

[Claims] 1. A vehicle equipped with an automatic transmission in which a gear ratio is changed stepwise, and a control of a vehicle automatic transmission of a type in which the automatic transmission is automatically downshifted based on information of a vehicle traveling path. An apparatus for controlling an automatic transmission for a vehicle, comprising: a brake control unit that executes a brake control so that a predetermined deceleration is obtained when a downshift of the automatic transmission is performed. 2. The vehicle automatic control system according to claim 1, wherein the brake control means decelerates the vehicle by using any one of a hydraulic brake device, an exhaust brake device, and an electromagnetic retarder device provided in the vehicle. Transmission control device. 3. The brake control means is provided with a region showing a plurality of types of brake strength for each gear step, which is provided in a two-dimensional diagram showing an axis showing a degree of bending of a traveling road and an axis showing a road surface gradient. 3. The automatic vehicular automatic shift according to claim 1, wherein the braking strength is determined based on the relationship between the actual curvature of the road and the road surface gradient, and the braking device is controlled so as to obtain the determined braking strength. Machine control device.