- #1
Chimaera987
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- TL;DR Summary
- Hi, I’m making a vehicle simulator and I'm unsure how to calculate the inertia of the drivetrain.
Hi, I’m making a vehicle simulator and I’m not entirely sure if my inertia calculations are right or are completely wrong. What I currently have now is something like this:
1. Engine:
if 4WD:
5. Differential:
Like in the case of the tranfercase, do I split the input inertia based on the left/right torque distribution in the differential? Do I include the left wheel side inertia in the right wheel side inertia calculation?
7. Wheel:
1. Engine:
- engine_Out_Inertia = engine_Inertia; this should contain the inertia of the engine and all of it’s auxiliaries, the flywheel and the clutch parts connected to it
- clutch_In_Inertia = engine_Out_Inertia
- clutch_Out_Inertia = clutch_Inertia; the clutch plate rotates with the gearbox, I guess it also could be included in transmission_Inertia, then this would be 0
- clutch_Out_Inertia = clutch_In_Inertia + clutch_Inertia
- clutch_Out_Inertia = clutch_In_Inertia * clucthLocking +clutch_Inertia; where clucthLocking is a 0-1 value where 0 is clutch is disengaged and 1 is locked? Or should I transfer all of the engine_Inertia once the clutch is engaged??
- tranmsmission_In_Inertia = clucth_Out_Inertia
- transmission_Out_Inertia = (tranmsmission_In_Inertia + transmission_Inertia) * gearRatio^2
- transfercase_In_Inertia = transmission_Out_Inertia
- transfercase_Out_Inertia_FrontAxle = transfercaseFront_Inertia ; front axle is disconnected, so only the inertia of the front driveshaft has to be taken into account?
- transfercase_Out_Inertia_ RearAxle = (transfercase_In_Inertia +transfercaseRear_Inertia) * gearRatio^2
if 4WD:
- transfercase_Out_Inertia_FrontAxle = (transfercase_In_Inertia +transfercaseFront_Inertia) * gearRatio^2
- transfercase_Out_Inertia_ RearAxle = (transfercase_In_Inertia +transfercaseRear_Inertia) * gearRatio^2
- transfercase_Out_Inertia_RearAxle = (transfercase_In_Inertia + transfercaseRear_Inertia + FrontRight_Wheel_Inertia + FrontLeft_Wheel_Inertia) * gearRatio^2
5. Differential:
Like in the case of the tranfercase, do I split the input inertia based on the left/right torque distribution in the differential? Do I include the left wheel side inertia in the right wheel side inertia calculation?
- Rear_Differential_In_Inertia = transfercase_Out_Inertia_RearAxle
- Rear_Differential_Out_Inertia_Left = (Rear_Differential_In_Inertia +differential_inertia) * finalDrive^2
- Rear_Differential_Out_Inertia_Right = (Rear_Differential_In_Inertia +differential_inertia) * finalDrive^2
- Rear_Axle_Out_Inertia_LeftWheel = (Rear_Differential_Out_Inertia_Left + halfshaftLeft_Inertia)
- Rear_Axle_Out_Inertia_RightWheel = (Rear_Differential_Out_Inertia_Right + halfshaftRight_Inertia)
7. Wheel:
- Right_Wheel_Inertia = Rear_Axle_Out_Inertia_RightWheel +wheelAssembly_Inertia + brakeDisc_Inertia