JP2002005279A - Variable speed control device of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make proper a variable change gear of an automatic transmission and to cancel an poor acceleration caused by suppressing shifting down and a slowing of switching to a higher speed stage caused by suppressing shifting up. SOLUTION: By judging whether or not a lateral acceleration not less than a determined value by reading the lateral acceleration is produced (S1, S2) when the lateral acceleration not less than the determined value is produced, a car speed V is read and a time when the lateral acceleration is continuously produced is integrated (S3, S4). On the basis of the value of the lateral acceleration and the integrated value of the time when the lateral acceleration is continuously produced, and by judging whether or not in the forbidden region of gear change stage suppression control by referring to a judge map of each car speed region or not (S5, S6) when in non forbidden region of gear change stage suppression control, the gear change stage suppression control is allowed the gear change stage suppression control to realize the gear change stage suppression control fixing the automatic transmission at a fixed gear change stage (S7, S8). When in the forbidden region of the gear change stage suppression control, the gear change stage suppression control is cancelled to realize a regular gear change control (S9 to S11).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission that appropriately executes a shift speed suppression control for fixing a shift speed of the automatic transmission to support a driving operation.

[0002]

2. Description of the Related Art In general, an automatic transmission mounted on a vehicle such as an automobile automatically switches gears according to an operation range based on a throttle opening and a vehicle speed. However, road conditions where an uphill road or a continuous corner continues. In some cases, the driver may select the gear position and drive the vehicle. For this reason, in the shift control of the automatic transmission, a function for assisting the driver's driving operation has been added to the normal shift speed change based on the throttle opening and the vehicle speed.

For example, Japanese Unexamined Patent Publication No. 11-51175 discloses a shift stage suppression control for limiting the shift stage when the turning lateral acceleration is equal to or higher than a reference value, that is, fixing a so-called shift stage. Due to the suppression control, the downshift is not performed during corner turning, and the running feeling can be improved.

[0004]

However, in the conventional shift speed suppression control, the shift restriction is determined based on the magnitude of the lateral acceleration. Therefore, the lateral acceleration exceeding the specified value such as a ramp approach on a highway continues. The downshift suppression control works in a road situation that occurs for a long time, and there is a problem that even if the driver enters the straight road from the approach road and steps on the accelerator to accelerate, the intended acceleration can not be obtained . Also, when merging with the main expressway,
There is a contradiction that the upshift to the high-speed stage is delayed due to the influence of the shift stage suppression control, and the driving feeling is rather deteriorated due to the generation of noise or the like. Further, in a system in which corner control is performed based on road information from a navigation device as in the prior art, the device is not only expensive, but cannot be adopted in a vehicle without a navigation device for extracting information.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made to optimize gear position suppression control for fixing the gear position of an automatic transmission, thereby reducing poor acceleration due to downshifting and suppressing high speed due to upshifting. It is an object of the present invention to provide a shift control device for an automatic transmission that can eliminate a delay in switching.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, an invention according to a first aspect of the present invention is a shift control for an automatic transmission which performs a shift stage suppression control for fixing a shift stage of an automatic transmission under predetermined operating conditions. A device for determining permission / prohibition of the gear position suppression control based on a lateral acceleration generated during traveling and a time during which the lateral acceleration continues, and the lateral acceleration equal to or more than a predetermined value continues for a predetermined time. In the event that a shift occurs, means for inhibiting execution of the above-mentioned gear position suppression control is provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the inhibition region of the gear position suppression control is expanded with an increase in vehicle speed.

That is, according to the present invention, the shift speed suppression control for fixing the shift speed of the automatic transmission is enabled / disabled based on the lateral acceleration generated during traveling and the time during which the lateral acceleration continues. Judge prohibition. When the lateral acceleration equal to or more than the predetermined value is continuously generated for the predetermined time, the execution of the gear position suppression control is prohibited, and the acceleration shift failure due to the suppression of the downshift and the delay in switching to the high speed stage due to the suppression of the upshift are suppressed. To eliminate. At this time, as described in claim 2, it is desirable that the inhibition region of the gear position suppression control be expanded with an increase in the vehicle speed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 relate to an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a shift control system, FIG. 2 is a flowchart of a shift control routine, FIG. 3 is an explanatory diagram of a normal shift map, and FIG. It is an explanatory view of a step suppression control cancellation judgment map.

FIG. 1 schematically shows a shift control system for an automatic transmission (AT) 2 connected to an engine 1. In this shift control system, an electronic control unit (T / M_ECU) 3 that controls the automatic transmission 2 includes a throttle opening sensor 4,
A vehicle speed sensor 5 and a lateral acceleration (lateral G) sensor 6 are connected, and the T / M_ECU 3 performs a shift control based on these signals.

That is, the T / M_ECU 3 automatically shifts up / down the gear position based on the throttle opening Th detected by the throttle opening sensor 4 and the vehicle speed V detected by the vehicle speed sensor 5 during normal driving.
Shift down and perform shift control. Further, under predetermined driving conditions, for example, when the lateral G sensor 6 detects a lateral G exceeding a specified value during cornering, shift up or down is prohibited and the gear is fixed to a fixed gear (shift hold). The gear shift control is executed to support the driver's driving operation.

In the shift speed suppression control, in a situation where the lateral G continuously occurs, the execution of the shift speed suppression control is prohibited, thereby preventing the deterioration of the drivability due to the shift hold. Hereinafter, a process of determining whether to permit or prohibit the gear position suppression control and selectively performing the normal gear position control and the gear position suppression control will be described with reference to the flowchart shown in FIG.

In the shift control routine of FIG. 2, first, in step S1, the lateral G detected by the lateral G sensor 6 is read, and in step S2, it is determined whether or not a lateral G equal to or more than a predetermined value has occurred. If the lateral G is smaller than the predetermined value, the routine jumps to step S11 to execute the normal shift control with reference to the normal shift map of FIG. 3 based on the throttle opening Th and the vehicle speed V. This normal shift control
This is a well-known control. For example, as shown by a solid line in FIG.
2nd gear, 2 → 3rd gear, 3 → 4th gear automatically upshift,
As shown by the dashed line, hysteresis is provided,
Shift down automatically from 2nd gear to 2nd gear.

On the other hand, if it is determined in step S2 that a lateral G equal to or greater than the predetermined value has occurred, the process proceeds to step S2.
2 to step S3, and the vehicle speed V from the vehicle speed sensor 5
Is read, and in step S4, the time during which the lateral G equal to or more than the predetermined value continuously occurs is integrated. Then, in step S5, the value of the lateral G and the integrated value of the time during which the lateral G continues to occur Σ
Referring to the shift speed suppression control cancellation determination map shown in FIG. 4 based on T, it is determined in step S6 whether or not the current region is a shift range suppression control prohibition region.

The shift speed suppression control cancellation determination map is as follows:
In this embodiment, the vehicle is divided and provided for each vehicle speed region.
Using the characteristic maps shown in FIGS. 4A, 4B, and 4C, permission / prohibition of the gear position suppression control is determined. In the map for each vehicle speed range, the permission range and the prohibition range of the gear position suppression control that can avoid the deterioration of the drivability due to the gear position suppression include the value of the lateral G and the integrated time ΔT during which the lateral G continues. Is determined by simulation or experiment based on the above, and it is determined with reference to the map whether the current region is in the permitted region or the prohibited region of the speed reduction control.

In the map for each vehicle speed region, the region in which the lateral G is relatively large and the integrated time ΔT is large in the vehicle speed region is set as the prohibited region of the gear position suppression control, and the prohibited region is enlarged as the speed shifts from the low speed region to the high speed region. In a high-speed range where the influence of the shift hold by the gear position suppression control is large, the feeling of incongruity due to poor acceleration due to downshift suppression and delay in upshifting is eliminated. Note that the shift stage suppression control cancellation determination map may be configured as a three-dimensional map of the vehicle speed V, the lateral G, and the accumulated time ΔT.

If the current region is not the prohibited region of the gear position suppression control, the process proceeds from step S6 to step S7.
The control proceeds to step S8 to permit the gear position suppression control, and in step S8, executes the gear position suppression control to fix the automatic transmission 2 at a constant gear position. On the other hand, if the current region is a prohibited region of the gear position suppression control, the process proceeds from step S6 to step S9 to cancel the gear position suppression control, clear the integrated time ΔT in step S10, and then, in step S11, The normal shift control based on the normal shift map shown in FIG. 3 is continued.

That is, in cornering on a general road or a curved road, the occurrence of the high lateral G is short, and under such running conditions, the gear position suppression control is executed to assist the driver's driving operation. On the other hand, in a road situation in which the high lateral G continuously occurs for a long time on a ramp approach road of an expressway or the like, the shift stage suppression control is prohibited, and the shift operation according to the accelerator operation of the driver is enabled. As a result, when merging with the main road on the expressway, etc., smooth merging is enabled by quick acceleration by downshifting, and noise is suppressed by suppressing the generation of noise by upshifting to the high speed stage immediately after merging. The deterioration of the ring can be prevented, and the fuel consumption can be reduced.

[0019]

As described above, according to the present invention, the gear position suppression control for fixing the gear position of the automatic transmission is optimized, and the shift to the high speed gear is suppressed by suppressing the downshift and the shift-up. It is possible to eliminate the delay of the switching and to enable the shift according to the driver's accelerator operation, thereby contributing to an improvement in driving feeling and an improvement in fuel efficiency.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a shift control system.

FIG. 2 is a flowchart of a shift control routine.

FIG. 3 is an explanatory diagram of a normal shift map.

FIG. 4 is an explanatory diagram of a shift stage suppression control cancellation determination map.

[Explanation of symbols]

 2 automatic transmission 3 electronic control unit 6 lateral acceleration sensor G acceleration V vehicle speed ΣT integrated time

Claims (2)

[Claims] 1. A shift control device for an automatic transmission for performing a shift speed suppression control for fixing a shift speed of an automatic transmission under a predetermined driving condition, wherein the lateral acceleration generated during traveling and the lateral acceleration are maintained. And determining whether to permit or prohibit the gear position suppression control based on the time to perform. If lateral acceleration equal to or greater than a predetermined value is continuously generated for a predetermined time, a means for prohibiting execution of the gear position suppression control is determined. A shift control device for an automatic transmission, comprising: 2. The shift control device for an automatic transmission according to claim 1, wherein the inhibition region of the shift speed suppression control is expanded as the vehicle speed increases.