Clutch control

Clutch Control block diagram

Role of subsystem in vehicle
The clutch control determines whether the clutch should be fully engaged, fully disengaged, or slipping–transmitting torque while the two sides of the clutch spin at different speeds.

Description of modeling approach
The state of the clutch depends on the requirements of the drivetrain.
If either:

  1. The gear is changing, for an upshift or downshift, OR
  2. No (positive) torque is required of the engine AND (the driver disengages the clutch during that situation OR the speed required of the engine is less than its idle speed)

then the clutch is disengaged.

  1. Positive torque is required of the engine AND
  2. The speed required of the engine is less than the engine launch speed AND
  3. The clutch was not fully engaged at the previous time step

then the clutch is slipping (meaning that the engine is required to operate at its launch speed).

If the clutch is neither disengaged nor slipping, then it is engaged.

If the clutch is being used in a parallel hybrid and the engine is off, the clutch is disengaged regardless of the above conditions.

Variables used in subsystem
vc_clutch_bool    vc_idle_spd    vc_launch_spd

See Appendix A.2: Input Variables

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