Some recommendations and suggestions to help make the CSE Powertrain work better:
Symptom
The Simulation fails immediately upon the starting the dynamics phase.
Possible Cause
| • | The Initial conditions of the engine and clutch are not set properly. |
| • | Connections of the CSE are not consistent with the rest of the model. |
Symptom
The engine torque is either much more or much less than I was expecting.
Possible Cause
| • | The throttle scaling has not been set correctly. |
| • | The units of the torque map are not correct. |
| • | The engine map is pointing to the wrong .pwr file. |
Symptom
The Clutch torque produced is quite noisy with spikes appearing in the signal.
Possible Cause
| • | The clutch stiffness is too high; units might be incorrect. |
| • | The clutch damping is too little; heavier damping will smooth out curves. |
Symptom
The engine stalls as soon as the dynamic simulation starts.
Possible Cause
| • | The initial condition of the engine speed is below the stall speed. |
| • | The engine inertia is set to a low quantity which causes the engine to drop speed quickly. |
| • | The initial condition of the gear demand signal is incorrect. |
| • | The torque demanded by the vehicle is too high and engine is not able to support it. |
| • | The stall speed is too close to or equal to the idle speed. |
| • | The sign convention of the direction of applied output torque might be incorrect. |
| • | The sign convention of the transmission speed input is incorrect. |
Try running the anti-stall system if the clutch is disengaged or the vehicle is at neutral at initial conditions.
Symptom
The engine stalls in spite of the anti-stall flag set to 1.
Possible Cause
| • | The Engine inertia is unrealistically low. |
| • | The negative torque produced by the engine is unusually high. |
| • | The stall speed is very close to or equal to the idle speed (the engine may stall during transients). |
| • | The clutch is engaged when vehicle is in gear (the anti-stall system is only designed to prevent an idling engine from stalling). |
Try to diagnose by setting a limit on the engine speed derivative (Engine Parameter 8).
Symptom
The engine stalls at gear shifts.
Possible Cause
| • | The engine inertia is unrealistically low. |
| • | The negative torque produced by the engine is unusually high. |
Try to run the anti-stall system if you are not already doing so.
Symptom
Transients are observed at the beginning of the dynamic stage of the simulation.
Possible Cause
| • | The initial conditions are not set correctly. Specifically check the engine speed initial condition. |
| • | The throttle signal or the transmission speed signal is not hooked correctly. |
Symptom
Unexpected spikes at end of gear shifts.
Possible Cause
| • | Clutch too stiff or too little damping. |
| • | The clutch time constant is too high. |
If the clutch slip is non-zero when the clutch starts re-engaging, then reduce the clutch time constant.
