Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – With indicator or control of power plant
Reexamination Certificate
1999-12-21
2001-08-14
Yuen, Henry C. (Department: 3747)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
With indicator or control of power plant
C701S114000, C701S115000, C701S102000, C073S117020
Reexamination Certificate
active
06275766
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a system and method of improving the control quality of a vehicle engine having a rotatable and positionable crankshaft by prioritizing tasks to be performed by a microprocessor preprogrammed with an inventory of foreground and background engine tasks affecting the efficiency and performance of the vehicle.
BACKGROUND ART
Vehicle engines are continuously designed with more accuracy and precision as the demand for higher efficiency and performance in vehicles increase. The accuracy and precision in engines and transmissions may be indicative of the number of parameters controlled by a vehicle's powertrain control module. Typically, the control module regulates and feeds data to engine and transmission systems of the vehicle. The operation of the control module affects some systems within the vehicle which, in turn, affects the overall efficiency and performance of the vehicle. As more engine parameters are controlled by the control module, the more engine related calculations and functions are required in order to run the vehicle in accordance with its design specifications. For example, a parameter may include determining the optimum engine air charge which involves gathering data and performing air charge calculations to establish the vehicle design specification.
The control module typically employs an operating system which is programmed to execute at least two levels of tasks, high priority and low priority tasks, based on engine speed or time. High priority tasks may be referred to as foreground tasks, and low priority tasks may be referred to as background tasks. A set of foreground tasks are executed during separate periods called foreground periods. A foreground period is a period during which the execution of a set of foreground tasks are begun and completed. Thus, the execution of a set of foreground tasks start and end during one foreground period. During a foreground period, background tasks are executed once the execution of the respective set of foreground tasks are completed.
Generally, background tasks are continuously and repeatedly executed by the control module until a piston event triggers the foreground tasks to be executed. Thus, a piston event may define the end of a previous foreground period and the beginning of a following foreground period. A cylinder or piston event may occur during one cycle of each of the pistons of the engine, such as ignition or intake. Tasks with lower priority are executed only when foreground tasks have been completed. A task may be a preprogrammed command strategy which, when accessed from memory, directs the control module to perform specific functions and subroutines in order to operate the engine at design specifications.
As engine speeds increase, piston events take place more frequently which, in turn, demand more frequent foreground tasks to be executed. The more frequently foreground tasks are executed, the more chronometric load is placed on the operating system of the control module. Chronometric load may be the measure of resources used within a control module. Thus, at increased engine speeds, more resources of the control module are used to execute high priority (or foreground) tasks and less resources are used to execute low priority (or background) tasks than at lower engine speeds. Consequently, the elapsed time between the execution of background tasks are progressively longer as engines are operated at higher speeds. Additionally, the more cylinders one engine has leads to more foreground calculations the control module employs, resulting in more severe chronometric impacts experienced.
The decrease of resources used to execute lower priority tasks at higher engine speeds may provide some systems within the vehicle to experience adverse effects. For example, transmission shifting quality of some vehicles may be lowered. The combination of (1) more frequently occurring piston events per increased engine speed, and (2) increased foreground calculations at increased engine speeds results in a relatively long background calculation time. As a result, low or fair transmission shifting quality may be experienced.
Thus, what is needed is an improvement to the operation of powertrain control modules. Particularly, an improvement is needed in reducing the chronometric load of the operating system of the control module.
Also, what is needed is a system and method for reducing the foreground tasks executed at higher speeds and reducing the rate at which the foreground tasks are executed in order to reduce the chronometric load of the control module.
DISCLOSURE OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved system and a method of improving the control quality of a vehicle engine having a rotatable crankshaft by preselecting certain foreground engine tasks to be performed by a microprocessor preprogrammed for such foreground engine tasks.
It is a further object of the present invention to provide an improved system and method of improving the control quality of a vehicle engine in order to reduce a chronometric load of an operating system of a powertrain control module.
A more specific object of this invention is a method of improving the control quality of a vehicle engine having a rotatable and positionable crankshaft by prioritizing tasks to be performed by a microprocessor preprogrammed with an inventory of foreground and background engine tasks affecting the efficiency and performance of the vehicle. The method involves sensing the speed of the crankshaft to provide a first, second, or third signal of respective low, medium, and high crankshaft speeds. The method further includes sensing the position of the crankshaft to provide a fourth signal of the crankshaft position. If the signal received indicates the crankshaft is at a predetermined position, then the method includes processing the signals to select the foreground tasks for execution. If the signal received is low crankshaft speed, then the method includes processing the signals to select a first set of the foreground tasks for execution in a first manner. If the signal received is medium crankshaft speed, then the method includes processing the signals to select a second set of the foreground tasks for execution in a second manner. If the signal received is high crankshaft speed, then the method includes processing the signals to select a third set of the foreground tasks for execution in a third manner.
Another specific object of this invention is a system for improving the control quality of a vehicle engine having a rotatable and positionable crankshaft by prioritizing tasks to be performed by a microprocessor preprogrammed with an inventory of foreground and background engine tasks affecting the efficiency and performance of the vehicle. The system includes a first mechanism for sensing the speed of the crankshaft to provide a first, second, or third signal of respective low, medium, and high crankshaft speeds. The system further includes a second mechanism for sensing the position of the crankshaft to provide a fourth signal of the crankshaft position. The system further includes a third mechanism for processing the signals. If the signal received indicates the crankshaft is at a predetermined position, then the third mechanism processes the signals to select the foreground tasks for execution. If the signal received is low crankshaft speed, then the third mechanism processes the signals to select a first set of the foreground tasks for execution in a first manner. If the signal received is medium crankshaft speed, then the third mechanism processes these signals to select a second set of the foreground tasks for execution in a second manner. If the signal received is high crankshaft speed, then the third mechanism processes the signals to select a third set of the foreground tasks for execution in a third manner.
REFERENCES:
patent: 4414946 (1983-11-01), Daumer et al.
patent: 4551803 (1985-11-01), Hosaka et al.
patent: 4562728 (1986-01-01), Timmerma
Mohr Jeffrey Raymond
Zhang Xiaoying
Drouillard Jerome R.
Ford Global Technologies Inc.
Vo Hieu T.
Yuen Henry C.
LandOfFree
System and method of reducing chronometric load does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method of reducing chronometric load, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method of reducing chronometric load will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2549896