Engine control (conventional vehicle)

Engine Control Block Diagram

Role of subsystem in vehicle
The engine control determines whether the engine should be on or off and at what speed the engine crankshaft should be turning.  The command signals it generates are used by the engine to determine fuel use, torque delivered, and actual crankshaft speed.

Description of modeling approach
There are two largely separate issues handled by the engine control:  engine state (on/off) and speed command.

The engine is on if the key is on (vc_key_on) and the clutch is not disengaged (meaning that torque is required) or if it is disengaged and the engine idles rather than shutting down, as determined by vc_idle_bool.  It is shut off if the ignition key is off, as determined by vc_key_on.  And it will not shut down, even if the engine is commanded not to idle, when transmission is shifting.

The speed command is identical to the speed required at the clutch input unless the vehicle is about to launch:  if the clutch is disengaged and the vehicle is not moving and it must be moving one second in the future, the engine will spin up to vc_launch_spd.  Also, the engine will spin at no less than vc_idle_spd if it is on.

Variables used in subsystem
vc_idle_bool    vc_idle_spd    vc_key_on    vc_launch_spd

See Appendix A.2: Input Variables

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