Interrelated power delivery controls – including engine control – Transmission control – Transmission controlled by engine
Patent
1994-03-18
1995-06-06
Marmor, Charles A.
Interrelated power delivery controls, including engine control
Transmission control
Transmission controlled by engine
477 98, 477121, 477156, F16H 5916
Patent
active
054217938
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an automatic transmission controller which controls at least one of the control elements of an automatic transmission such as, operating oil pressure, gear change timing, lockup range, based on a torque input to the automatic transmission which has been estimated using at least an engine intake air flow rate. This controller incorporates a correction device to correct the intake flow rate used in estimating the torque after eliminating a component of intake flow rate (referred to as flow rate friction component) which is not input to the transmission as the torque.
BACKGROUND ART
With conventional automatic transmission controllers such as disclosed in Japanese unexamined patent publication No. 3-209048 for example, the torque input to the automatic transmission is estimated from the air intake flow rate (referred to hereunder simply as flow rate) and the rotational speed of the engine. The operating oil pressure or other control element for the automatic transmission is then controlled on the basis of this estimated torque.
When the engine torque TQSEN is computed in this way using a flow rate Qa and an engine rotational speed Ne, then the torque consumed by the engine itself must be deducted.
In the controller of the above-mentioned publication, this is dealt with by determining a flow rate friction component Qfric based on the engine rotational speed Ne. The engine torque TQSEN is then obtained using the following equation, where K is a constant:
A problem arises however in that while the flow rate friction component Qfric can be determined at warm-up as shown in FIG. 9, from engine rotational speed Ne, additional temperature information is necessary for accurate determination at cool down.
The ideal temperature information in this respect is engine oil temperature. However since engine oil temperature is not used in other controls, this requires an extra sensor, thereby incurring additional costs.
Engine water temperature, oil (ATM) temperature and the like have been considered as possible alternatives. There are cases however wherein a rise in these temperatures does not show the same trend as that for engine oil temperature, so that they are somewhat lacking in accuracy as alternatives.
It is an object of the present invention, to address the above situation wherein the torque input to an automatic transmission is estimated using a flow rate corrected after eliminating a flow rate friction component, and be able to accurately correct the flow rate at the time of cool down without providing an additional sensor.
DISCLOSURE OF THE INVENTION
Therefore a controller for an automatic transmission according to the present invention comprises: a flow rate detection device for detecting an intake air flow rate of an engine; an effective flow rate computing device for computing an effective flow rate by subtracting a flow rate friction component, being a flow rate representing a component of the torque which is not input to the automatic transmission, from the detected flow rate; a torque estimation device for estimating the torque input to the automatic transmission on the basis of the computed effective flow rate; and a control device for controlling the automatic transmission on the basis of the estimated torque. The controller also incorporates any one of the following (1) through (4) constructions.
(1) A storage device for pre-storing characteristics of warm-up flow rate friction component versus engine rotational speed;
a warm-up flow rate friction component retrieval device for retrieving from the storage device, a warm-up flow rate friction component corresponding to an actual engine rotational speed;
a correction coefficient setting device for obtaining, when the automatic transmission is in a non driving range, a ratio between the actual flow rate and the warm-up flow rate friction component retrieved by the retrieval device, to thereby set a correction coefficient; and
a flow rate friction component computing device for computing a flow rate fr
REFERENCES:
patent: 4815340 (1989-03-01), Iwatsuki et al.
patent: 5107724 (1992-04-01), Takizawa
patent: 5249484 (1993-10-01), Matsuoka et al.
patent: 5292288 (1994-03-01), Kashiwabara et al.
Kwon Peter
Marmor Charles A.
Unisia Jecs Corporation
LandOfFree
Automatic transmisson controller does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automatic transmisson controller, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic transmisson controller will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-983452