Method and system for efficient engine torque control

Abstract

The present invention relates to methods and systems for efficient engine torque control. Methods and systems are provided for adjusting engine torque in response to changes in desired engine torque. In one example, a method may include, in response to increasing the desired engine torque, monotonically decreasing the alternator torque from a second level to a first level when fuel is not being injected into the engine cylinder, and in response to the alternator torque reaching A first level, alternator torque is gradually increased from the first level to a second level while initiating engine combustion, and then the alternator torque is monotonically decreased from the second level to the first level. In this manner, the method may include adjusting a load exerted on the engine by an alternator mechanically coupled to the engine both during cylinder combustion and during non-fueling conditions.

Description

technical field [0001] The present application relates to methods and systems for controlling torque of an internal combustion engine while optimizing fuel economy. Background technique [0002] A speed and torque control system for an internal combustion engine varies throttle position and fuel injection amount to increase or decrease engine torque to a desired torque. Thus, during engine operating conditions in which the actual delivered engine torque is greater than the operator requested engine torque, the throttle may be adjusted to reduce airflow to the engine. Therefore, fuel injection can be reduced. Because the throttle is coupled to the air intake valves of multiple cylinders through the intake manifold, there is a lag time before a change in throttle position results in a change in engine torque. Since adjusting throttle position does not provide an immediate change in engine torque, spark timing is retarded to provide a faster response time. In the description...

AI Technical Summary

Problems solved by technology

However, when the driver requested engine torque increases above a threshold, i.e. where fuel injection is turned back on, the increase in engine torque caused by fuel injection may be greater than the driver requested increase in engine torque

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