Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – With indicator or control of power plant
Patent
1998-10-15
2000-02-22
Wolfe, Willis R.
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
With indicator or control of power plant
701111, 731173, G01M 1500, G01L 300
Patent
active
060291095
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a process for estimating the torque delivered by an internal combustion engine, and more particularly to a process of this type that works based on the observation of variations in the rotation speed of the crankshaft of the engine.
The torque delivered by an internal combustion engine is an important parameter for characterizing the working condition and the performance of an engine of this type, particularly when the latter is used to power an automobile. Devices known as "torque meters" make it possible to measure the torque delivered by an engine during bench testing. It is practically impossible to install such a device in an automobile, specifically for reasons of cost. Various processes have also been proposed for estimating torque from measurements of the instantaneous engine speed delivered by a sensor that is commonly installed today in automobiles in which the engine is controlled by a computer supplied with various signals, including the one supplied by the speed sensor. For reference, it is possible to consult the 1989 publication by W. B. RIBBENS and G. RIZZONI entitled "Applications of Precise Crankshaft Position Measurements for Engine Testing, Control and Diagnosis," publication number SAE 890885 of the "Society of Automotive Engineers" of the USA. This publication describes a process comprised of performing matrix algebra on instantaneous speed measurements taken during each engine cycle, in order to deduce from the latter the absolute value of the torque for each cylinder and thus to detect any abnormal variations in this torque. These calculations are complex and require powerful computing means which are not currently possible to install in an automobile. Moreover, according to this publication, it appears that this process is only usable at low speeds (less than 3500 rpm). Other torque estimating processes are based on an observation of variations in the speed of the engine within a time "horizon" that covers several successive fuel/air mixture combustion phases in several cylinders of the engine. An abnormal combustion, such as a misfire for example, in one of the cylinders being observed, substantially disturbs the global observation made and hence the estimate obtained from it.
Also known from European patent application 532 419, filed in the name of Regie Nationale des Usines Renault SA, are a process and a device for producing a value representative of the average "gas" torque produced by each combustion of a mixture in the cylinders of an internal combustion engine, the process being comprised of generating a "primary" value representing the duration of the passage in front of a sensor of each of a plurality of reference marks disposed on a ring integral with the flywheel or the crankshaft of the engine, of operating on the primary value to produce two secondary values, respectively representing the average angular speed of the reference marks during a combustion period in the engine and the projection onto a phase reference line of the marks related to the angular combustion periods, and the alternating component of the instantaneous angular speed of the marks, and of combining these two secondary values to produce a value representing the torque sought.
This process is capable of providing a satisfactory result insofar as 1) the "combustion center", or maximum pressure in a cylinder during a combustion, remains substantially set at a fixed angular position of the crankshaft and 2) the average speed of the engine does not vary substantially in the interval between two top dead centers.
The sole figure of the appended drawing represents graphs of the variations of the pressure P in a cylinder in which a combustion occurs, and the corresponding variations in angular speed .OMEGA., between two top dead centers reached consecutively by two pistons running in two cylinders of, for example, a four-cylinder engine. Experimentally, it is observed that at high speeds, with a fuel/air mixture of normal r
REFERENCES:
patent: 4691288 (1987-09-01), Kay et al.
patent: 4697561 (1987-10-01), Citron
patent: 5377537 (1995-01-01), James
patent: 5621644 (1997-04-01), Carson et al.
patent: 5771482 (1998-06-01), Rizzoni
patent: 5878366 (1999-03-01), Schricker et al.
Rossignol Alain
Suquet Michel
Greenberg Laurence A.
Lerner Herbert L.
Siemens Automotive S.A.
Vo Hieu T.
Wolfe Willis R.
LandOfFree
Method for calculating the torque of an internal combustion engi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for calculating the torque of an internal combustion engi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for calculating the torque of an internal combustion engi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-528550