Vehicle and method of limiting powertrain emissions

Abstract

A vehicle having a drivetrain including an electric motor, an internal combustion engine, and a turbocharger and a method of limiting powertrain emissions are disclosed. The vehicle further includes a controller configured to apply a variable filter to the engine torque command in response to driver demand. The filter affects commands for rates of increase above a predetermined threshold such that corresponding rates of increase of both engine torque and turbocharger speed are limited to rates each less than a maximum available level to reduce a surge in engine output emissions. Additionally the controller issues commands for motor torque such that the total driveline torque meets driver demand.

Description

technical field [0001] The present invention relates to hybrid vehicles, and more particularly to powertrain control systems. Background technique [0002] Known hybrid vehicles utilize a drivetrain with an internal combustion engine cooperating with an electric machine. Dual power sources allow the use of smaller, more efficient engines. However, engine transients that result in lower fuel efficiency and increased engine emissions may still occur in response to certain inputs. One such input is a sudden change in the power or torque demand of the engine. [0003] One or more additional turbochargers coupled to the engine exhibit different response settings to rapid changes in demanded drivetrain output. There is often a delay from the time power is demanded to the time the driver becomes aware of turbocharger assistance. Contents of the invention [0004] A vehicle is provided having a powertrain that includes an electric motor, an internal combustion engine, and a tu...

AI Technical Summary

Problems solved by technology

There is often a delay from the time power is demanded to the time the driver becomes aware of turbo assist

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