JP3588818B2 - Power train control device during turning of vehicle - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an automatic transmission and an engine whose output is determined by a throttle actuator capable of controlling the opening degree of a throttle valve even in response to information other than the operation of an accelerator pedal by a driver, such as an electronically controlled throttle. The present invention relates to a power train control device for a vehicle equipped with a power train when turning.
[0002]
[Prior art]
Regardless of whether the transmission is a stepped transmission or a continuously variable transmission, the automatic transmission calculates a gear ratio suitable for the current operating state from a combination of the engine operating load and the vehicle speed, and the gear ratio is achieved. A configuration for electronically performing shift control is being used frequently. In the case of such an electronically controlled automatic transmission, it is relatively easy to change the gear ratio. For example, as described in Japanese Patent Application Laid-Open No. 60-169330, a downshift is performed in a shift pattern during turning of the vehicle. It is possible to control the vehicle so that the vehicle can be decelerated by the engine brake to make the vehicle turn safely and to improve the acceleration performance at the time of re-acceleration. is there.
[0003]
[Problems to be solved by the invention]
However, such a change in the gear ratio inevitably causes a sudden change in the wheel driving force, and since this change in driving force occurs abruptly irrespective of the driver's operation of the accelerator pedal, it is necessary to start smooth turning. It makes it difficult and also makes the driver feel uncomfortable.
[0004]
The present invention is equipped with an engine equipped with a throttle actuator capable of controlling the opening of the throttle valve independently of the accelerator pedal operation by the driver as required, that is, according to information other than the accelerator pedal operation by the driver. In the case of a vehicle that performs the above, the object is to solve this problem by realizing this idea from the viewpoint that the abrupt change in the wheel driving force can be offset by correcting the throttle valve opening.
[0005]
[Means for Solving the Problems]
For this purpose, the power train control device during turning according to the first invention has a concept as shown in FIG.
An engine whose output is determined by a throttle actuator capable of controlling the opening of the throttle valve even in response to information other than the accelerator pedal operation by the driver;
In a vehicle including a power train including an automatic transmission that selects a gear ratio based on operation of the accelerator pedal and vehicle speed,
Turning traveling detection means for detecting turning traveling of the vehicle,
While the turning traveling detecting means detects that the turning traveling is being performed, the speed ratio by the automatic transmission is changed to a speed ratio lower than the speed ratio selected by the operation of the accelerator pedal and the vehicle speed. Change means;
The difference between the output torque of the automatic transmission based on the speed ratio selected by the operation of the accelerator pedal and the vehicle speed and the output torque of the automatic transmission based on the speed ratio selected by the turning speed change means is reduced. And a throttle opening correcting means for correcting the opening of the throttle valve.
[0006]
Further, in the power train control device of the second invention, the turning speed change ratio changing means of the first invention is characterized in that the change ratio of the speed ratio becomes smaller as the vehicle speed increases. .
[0007]
Further, in the power train control device of the third invention, the turning ratio change means for turning in the first invention may be such that the change amount of the speed ratio increases as the yaw rate generated in the vehicle during turning increases. It is characterized by having done.
[0008]
[Action]
In the first invention, the output of the engine is controlled by a throttle actuator capable of controlling the opening of the throttle valve even in response to information other than the operation of the accelerator pedal by the driver, and the vehicle is powered by the engine and the automatic transmission. It is driven by power from the train.
[0009]
Here, the turning ratio change means for turning travel changes the speed ratio by the automatic transmission to a speed lower than the speed ratio selected by the operation of the accelerator pedal and the vehicle speed while the turning travel detecting means detects the turning travel of the vehicle . Change to gear ratio. Such a change in the gear ratio increases the response gain of the engine to the driver's operation, so that deceleration of the vehicle by the engine brake is ensured so that turning can be performed safely, and acceleration performance at the time of subsequent re-acceleration can be improved. it can.
[0010]
On the other hand, the throttle opening correction means adjusts the output torque of the automatic transmission based on the gear ratio selected by the operation of the accelerator pedal and the vehicle speed so that the change in the transmission output torque caused by the change in the gear ratio is reduced. The throttle opening is corrected so that the difference between the transmission output torque and the transmission ratio based on the speed ratio selected by the turning speed change means is reduced. Therefore, it is possible to mitigate a situation in which a change in the vehicle driving force occurs abruptly regardless of the driver's accelerator pedal operation, even when the gear ratio is changed for the above purpose during turning. may become cornering is hardly started smoothly, it is possible to avoid the driver you or uncomfortable.
[0011]
In the second aspect of the invention, the turning speed change ratio changing means reduces the change amount of the speed ratio to a lower speed side as the vehicle speed increases. In this case, the change amount of the speed ratio appropriately matches the turning traveling condition, and is always appropriate without any excess or shortage, so that the above operation and effect can be more reliably achieved.
[0012]
In the third invention, the turning speed change ratio changing means increases the speed ratio change amount to the lower speed side as the yaw rate acting on the vehicle during turning operation increases. In this case as well, the change amount of the speed ratio appropriately matches the turning traveling condition, becomes appropriate without any excess and deficiency at all times, and the above operation and effect can be more reliably achieved.
[0013]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a system diagram illustrating a power train control device during vehicle turning according to the present invention. In the figure, reference numeral 1 denotes an engine whose output is controlled by an electronically controlled throttle, and 2 denotes an automatic transmission such as a continuously variable transmission, for example, and a vehicle power train is provided by tandem coupling of the engine 1 and the automatic transmission 2. Is composed.
[0014]
The engine 1 is controlled by the engine controller 3 via a system 4 such as a fuel injection amount, an ignition timing, an exhaust gas recirculation amount, and the like. The degree (throttle opening) is controlled, and the engine output control is performed. In this engine output control, the engine controller 3 basically responds to a signal from a potentiometer 7 for detecting a depression amount AC of an accelerator pedal 6 operated by a driver, and adjusts a throttle opening through a throttle actuator 5. For example, it is assumed that the opening is set to correspond to the depression amount AC of the accelerator pedal 6 in accordance with the characteristics shown in FIG. At this time, the throttle opening sensor 10 detects the actual throttle opening and feeds it back.
[0015]
The automatic transmission 2 may be a stepped automatic transmission, but here, it is a continuously variable transmission, and a stepping motor 9 responds to a shift command from a transmission controller 8 to select a speed ratio corresponding to the shift command. It is assumed that the speed is changed to the state in which Here, the transmission controller 8 basically responds to the signal from the potentiometer 7 for detecting the depression amount AC of the accelerator pedal 6 and the signal from the vehicle speed sensor 11 for detecting the vehicle speed V, and the accelerator opening AC and A gear ratio matching the driving state is calculated from the combination of the vehicle speeds V, and a corresponding gear shift command is output to the step motor 9.
[0016]
In addition to the normal engine control described above, the engine controller 3 performs a throttle opening control in addition to a signal from the potentiometer 7 for a gear ratio change control and a throttle opening correction control during turning when the present invention is aimed at. The signal from the throttle opening sensor 10 for detecting the degree TH, the signal from the vehicle speed sensor 11 for detecting the vehicle speed V, and the signal from the yaw rate sensor 12 for detecting the yaw rate Φ acting on the vehicle are separately input. It is assumed that the control program shown in FIG. 3 is executed based on the input information.
[0017]
In FIG. 3, first, in step 21 it reads the input information described above, then the following as at step 22, a suitable target gear ratio in the operating state to set the gamma _S. In this setting, the program shown in FIG. 4 is executed to perform the setting. First, in step 31, the target turbine speed (target transmission) is calculated based on the accelerator pedal depression amount AC and the vehicle speed V based on the map shown in FIG. prompted rpm) N _TS, then the target turbine rotational speed N _TS at step 32, calculates a target speed ratio gamma _S is divided by the transmission output rotation speed can be seen from the vehicle speed V (k / V) .
[0018]
In the next step 23 in FIG. 3, to find a target throttle opening degree TH _S corresponding to the accelerator pedal depression amount AC based on the map of FIG.
[0019]
Next, in step 24 corresponding to the turning traveling detecting means, it is determined whether or not the vehicle is turning, based on whether or not the yaw rate Φ is generated. In this determination, instead of using the yaw rate Φ, the steering angle of the steering wheel is detected, and it can be determined whether or not the vehicle is turning based on whether or not the steering angle has occurred.
[0020]
If it is not in turning, above the target throttle opening degree TH _S is output to the throttle actuator 5 at step 25, thereby the throttle opening TH to form with the target value TH _S, returns control to step 21. Therefore, if the vehicle is not turning, the throttle opening TH is controlled as usual in accordance with the accelerator pedal depression amount AC, that is, as determined in step 23, and the shift control of the automatic transmission is performed by the transmission controller 8 as described above. Let the control you do.
[0021]
If it is determined in step 24 that the vehicle is turning, the target speed ratio γ _S set in step 22 is corrected by Δγ toward the low speed side in step 26 corresponding to turning speed change means to change γ _S to γ. Update to _S = γ _S + Δγ. Then, in the next step 27, the change of the gear ratio is instructed to the transmission controller 8. At this time, the transmission controller 8 in preference to the normal shift control described above, changing the gear ratio to a lower speed side to the updated target speed ratio gamma _S is achieved. Such a change of the gear ratio to a lower speed side can ensure that the vehicle is decelerated by the engine brake, perform the turning safely, and improve the acceleration performance in the subsequent reacceleration.
[0022]
It is convenient to set the change amount Δγ of the speed ratio to the low speed side to a constant value which is approximately equivalent to the engine brake required for turning and the acceleration performance required thereafter, but preferably as shown in FIG. In addition, the higher the vehicle speed V, the smaller the change amount Δγ of the speed ratio to the lower speed side, and as shown in FIG. 9, the larger the yaw rate Φ acting on the vehicle during turning, the lower the speed ratio to the lower speed side. It is preferable to increase the change amount Δγ. In this case, the change ratio Δγ of the gear ratio accurately matches the turning traveling condition, becomes appropriate without any excess or deficiency at all times, and ensures that the vehicle is decelerated by an appropriate engine brake so that the turning traveling can be performed. In addition to the safe operation, the operation and effect of improving the acceleration performance during the subsequent reacceleration can be more reliably achieved.
[0023]
Step 28 following FIG. 3 corresponds to a throttle opening correction means. In this step, the subroutine shown in FIG. 5 is executed to prevent a change in the wheel driving force from being caused by the change in the gear ratio. obtains a correction throttle opening TH _c, this is set to the target throttle opening degree TH _S. Therefore, in step 41 of FIG. 5, when the gear ratio (final reduction ratio) of the final drive gear is γ _F , the wheel turning radius is R, the target speed ratio is γ _S , and the turbine torque is _Tt , the wheel driving force F Is calculated by F = γ _F × R × γ _S × T _t . Here, although γ _F , R, and γ _S are already known, the turbine torque T _t is the turbine torque T _t corresponding to the turbine speed N _TS based on the performance diagram of the torque converter in FIG. A map search shall be performed.
[0024]
In step 42 of FIG. 5, the corrected target turbine torque T _t ′ for keeping the wheel drive torque F unchanged also by the aforementioned change γ _S + Δγ of the speed ratio to the low speed side is T _t ′ = F / [γ _F × R × (γ _S + Δγ)]. Next, at step 43, the turbine speed N _TS ′ that changes according to the change γ _S + Δγ of the speed ratio to the lower speed side is calculated by N _TS ′ = [(γ _S + Δγ) × V] / k. Then, in step 44, based on the corrected target turbine torque T _t ′ and the turbine speed N _TS ′, a point X corresponding to the combination is obtained based on the torque converter performance diagram of FIG. Interpolation calculation based on the distances L ₁ and L ₂ to the throttle opening TH = 10% performance line and the throttle opening TH = 20% performance line, TH _C = 10 + [L ₁ / (L ₁ + L ₂ )] × 10 obtains a corrected throttle opening degree TH _C. The corrected throttle opening TH _C represents a throttle opening for keeping the wheel drive torque F calculated as described above unchanged even by changing the gear ratio to a lower speed side γ _S + Δγ, and this is the target throttle opening TH _S Set to.
[0025]
In step 25 in FIG. 3, the throttle opening of the engine 1 is set to THC by outputting the target throttle opening THS set to the corrected throttle opening THC to the throttle actuator 5. By the way, since the corrected throttle opening THC is such that the wheel drive torque F is kept unchanged even by the change γS + Δγ of the gear ratio to the lower speed side as described above, this is performed for the above-mentioned purpose at the time of cornering. Even if the gear ratio is changed, it is possible to eliminate a situation in which a change in the wheel drive torque occurs suddenly regardless of the driver's operation of the accelerator pedal, making it difficult to start turning smoothly or making the driver feel uncomfortable. It is possible to avoid remembering.
[0026]
In the above example, the engine controller 3 determines that the vehicle is turning and determines whether to change the gear ratio or to correct the throttle opening. When the automatic transmission and the automatic transmission are comprehensively controlled by one common controller, the change of the gear ratio and the correction of the throttle opening are determined by the single common controller.
[0027]
【The invention's effect】
Thus, the power train control device at the time of turning traveling according to the first invention is as described in claim 1.
Since the speed ratio by the automatic transmission during turning is changed to a speed ratio lower than the speed ratio selected by the operation of the accelerator pedal and the vehicle speed ,
This makes it possible to ensure that the vehicle is decelerated by the engine brake during cornering and to carry out the cornering safely, and to improve the acceleration performance at the time of subsequent reacceleration.
[0028]
At the same time, the output torque of the automatic transmission based on the gear ratio selected by the operation of the accelerator pedal and the vehicle speed, and the transmission output torque generated by the change of the gear ratio by the gear ratio selected by the turning traveling speed change means . Since the throttle opening is modified to reduce the change,
Even when the gear ratio is changed for the above-mentioned purpose during cornering, it is possible to mitigate a situation in which a change in the transmission output torque occurs suddenly irrespective of the driver's operation of the accelerator pedal. This makes it possible to prevent the traveling from starting smoothly and to prevent the driver from feeling uncomfortable.
[0029]
According to a second aspect of the present invention, there is provided a power train control device during turning traveling,
Because the change ratio of the gear ratio to the low speed side is made smaller as the vehicle speed increases,
The change amount of the gear ratio appropriately matches the turning traveling condition, becomes appropriate without any excess or shortage, and the above-described operation and effect can be more reliably achieved.
[0030]
According to a third aspect of the present invention, there is provided a power train control device during turning traveling according to a third aspect of the present invention.
Because the larger the yaw rate acting on the vehicle during turning is, the larger the change amount of the speed ratio to the low speed side is,
In this case as well, the change amount of the speed ratio appropriately matches the turning traveling condition, becomes appropriate without any excess and deficiency at all times, and the above operation and effect can be more reliably achieved.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a power train control device for turning a vehicle according to the present invention.
FIG. 2 is a control system diagram of a vehicle power train showing an embodiment of a power train control device according to the present invention.
FIG. 3 is a flowchart showing a power train control program to be executed by the engine controller during turning in the example.
FIG. 4 is a flowchart showing a subroutine for calculating a target gear ratio in the same program.
FIG. 5 is a flowchart showing a subroutine for calculating a corrected throttle opening in the same program.
FIG. 6 is a change characteristic diagram of a target turbine speed used for calculating a target speed ratio.
FIG. 7 is a relationship diagram of a target throttle opening with respect to an accelerator pedal depression amount.
FIG. 8 is a change characteristic diagram of a speed ratio correction amount useful for the purpose of the present invention.
FIG. 9 is another change characteristic diagram of a speed ratio correction amount useful for the purpose of the present invention.
FIG. 10 is a performance diagram of a torque converter.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 electronically controlled engine with throttle 2 continuously variable transmission 3 engine controller 5 throttle actuator 6 accelerator pedal 7 potentiometer 8 transmission controller 9 step motor 10 throttle opening sensor 11 vehicle speed sensor 12 yaw rate sensor

Claims (3)

An engine whose output is determined by a throttle actuator capable of controlling the opening of the throttle valve even in response to information other than the accelerator pedal operation by the driver;
In a vehicle including a power train including an automatic transmission that selects a gear ratio based on operation of the accelerator pedal and vehicle speed,
Turning traveling detection means for detecting turning traveling of the vehicle,
While the turning traveling detecting means detects that the turning traveling is being performed, the speed ratio for the turning traveling that changes the speed ratio by the automatic transmission to a speed ratio lower than the speed ratio selected by the operation of the accelerator pedal and the vehicle speed. Change means;
The difference between the output torque of the automatic transmission based on the speed ratio selected by the operation of the accelerator pedal and the vehicle speed and the output torque of the automatic transmission based on the speed ratio selected by the turning speed change means is reduced. A power train control device during turning of a vehicle, comprising: throttle opening correction means for correcting the opening of a throttle valve. 2. The power train control device according to claim 1, wherein the turning speed change ratio changing means is configured to reduce the speed ratio change amount as the vehicle speed increases. 2. The power of the vehicle during turning according to claim 1, wherein the turning speed change ratio changing means is configured to increase the speed ratio changing amount as the yaw rate generated in the vehicle during turning increases. Train control device.

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