Internal-combustion engines – Engine speed regulator – Open loop condition responsive
Reexamination Certificate
1999-08-26
2001-08-21
Solis, Erick (Department: 3747)
Internal-combustion engines
Engine speed regulator
Open loop condition responsive
Reexamination Certificate
active
06276333
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to engine controlling technique, and more specifically to system and/or process for controlling a throttle valve opening degree.
A Japanese Patent Kokai Publication No. 4(1992)-101037 shows an engine control system for determining a target throttle opening degree based on a target engine torque calculated in accordance with an accelerator opening degree.
SUMMARY OF THE INVENTION
When the relation between the throttle valve opening degree and engine torque is not linear as shown in
FIG. 15
, minute fluctuation in the target torque in a large throttle opening range can cause an excessive response of the throttle valve opening degree, resulting in unwanted torque fluctuation. This is due to such a curvilinear characteristic that, in the small throttle opening range in which the throttle opening is relatively small, a change induced in the throttle opening degree by a change in the engine torque is relatively small, and the ratio of the responsive change in the throttle opening degree to the change in the engine torque becomes greater in the large opening range.
It is an object of the present invention to provide apparatus and/or method for preventing excessive response in a throttle valve opening degree to minute changes in an input parameter such as a target torque.
According to the present invention, an engine control apparatus comprises: an actuator for controlling an actual throttle opening degree in response to a throttle control signal, independently of accelerator operation; an accelerator input device (such as items 7 and 12) for producing an accelerator signal representing an accelerator opening degree varying from a minimum degree to a maximum degree corresponding to a throttle opening degree of a fully open throttle valve position; a target quantity calculating section for calculating a target torque representative quantity representative of a target torque in accordance with the accelerator opening degree represented by the accelerator signal; a first target opening determining section for calculating a first mode target throttle opening degree in accordance with the target torque representative quantity; an output section for determining a desired target throttle opening degree in accordance with the first mode target throttle opening degree and for producing the throttle control signal in accordance with the desired target throttle opening degree to reduce a deviation of the actual throttle opening degree from the desired target throttle opening degree; a discriminating section for monitoring the target torque representative quantity to examine whether a predetermined condition is satisfied, and a modifying section for modifying the control characteristic when the predetermined condition is satisfied. According to one aspect of the present invention, the discriminating section is arranged to judge a first condition to be satisfied when the target torque representative quantity is equal to or greater than a threshold representative quantity, and the accelerator opening degree is equal to or greater than a threshold opening degree; and the modifying section is in the form of a second determining section for determining a second mode target throttle opening degree in accordance with the accelerator opening degree when the first condition is satisfied, and for substituting the second mode target throttle opening degree, as the desired target throttle opening degree, for the first mode target throttle opening degree when the first condition is satisfied. According to another aspect of the invention, the discriminating section judges a predetermined second condition to exist when the target torque representative quantity is equal to or greater than a threshold representative quantity, and the accelerator opening degree is smaller than a threshold degree; and the modifying section includes a limiting section for limiting the target torque representative quantity to the threshold representative quantity.
The target torque representative quantity is a quantity representative of the target torque, such as the target torque per se, the ratio of the target torque to a maximum torque and an intake air flow ratio.
According to still another aspect of the present invention, an engine control apparatus comprises: means for calculating a target torque representative quantity; controlling means for determining a control input in accordance with the target torque representative quantity, for determining a control output representing a desired target throttle opening degree from the control input according to a predetermined nonlinear characteristic of the control output with respect to the control input, for producing a throttle control signal in accordance with the control output; condition discriminating means for producing a condition signal when the target torque representative quantity is equal to or greater than the threshold representative quantity; and constraining means for constraining said controlling means to determine the control output in accordance with one of the accelerator opening degree and the threshold representative quantity, independently of the target torque representative quantity when the condition signal is present.
An engine control process according to one aspect of the invention comprises: calculating a target torque representative quantity; preparing a control input in accordance with the target torque representative quantity; determining a control output representing a desired target throttle opening degree from the control input according to a predetermined characteristic; producing a throttle control signal in accordance with the control output; comparing the target torque representative quantity with a threshold representative quantity to produce a condition signal when the target torque representative quantity is equal to or greater than the threshold quantity; and constraining one of the control input and the control output so that the control output is determined independently of the target torque representative quantity when the condition signal is present.
REFERENCES:
patent: 5150680 (1992-09-01), Nishimura
patent: 5623905 (1997-04-01), Kau et al.
patent: 5775293 (1998-07-01), Kresse
patent: 5899830 (1999-05-01), Tabata
patent: 5983861 (1999-11-01), Nishio et al.
patent: 5992384 (1999-11-01), Bauer et al.
patent: 6058349 (2000-05-01), Kikori et al.
patent: 35 04 195 (1985-09-01), None
patent: 41 02 910 (1991-08-01), None
patent: 43 33 896 (1995-04-01), None
patent: 0 189 190 (1986-07-01), None
patent: 3-140664 (1991-06-01), None
patent: 4-101037 (1992-04-01), None
patent: 5-231225 (1993-09-01), None
patent: 9-287513 (1997-11-01), None
Iwano Hiroshi
Kazama Isamu
Ooba Hiraku
Foley & Lardner
Nissan Motor Co,. Ltd.
Solis Erick
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