Drive Torque Application

Adams Car Package > Adams Car > Appendix > Solver Routines > Drive Torque Application

Drive Torque Application

In Adams Car the torque required to drive a vehicle is applied through a user written VTORQUE subroutine. In order to maintain the vehicle velocity at the user specified value, this routine accesses the necessary torque from Proportional-Integral Traction Controller (seeTraction Controller (PI) ). Based on the presence of a simple power train model, the torques are applied either at the wheel/spindle location or at the halfshaft/subframe location. For models without a powertrain, the torques are applied at the wheel and reacted on the subframe. The VTORQUE statement for such a model should be as follows:

VTORQUE/id, I = imrk, JFLOAT = jmrk, RM = rmrk
, FUN=USER (1105, itire, difid, pwr_lmt )

where:

id	=	Vtorque statement id
imrk	=	Marker on wheel at which the torque is applied
jmrk	=	Floating marker at which the reaction torque is applied
rmrk	=	Reference marker in whose coordinate system the torque is applied
itire	=	Tire id corresponding to the VTORQUE statement

difid	=	(Optional) Id of the differential equation balancing the longitudinal reaction force on the body to ground inline jprim

pwr_lmt	=	(Optional) Limiting horsepower. The simulation will be terminated if the power requirement exeeds the user specified value

Adams Car comes with an option to model simple powertrains which consists of only halfshaft parts. The torque required to drive the vehicle is determined from a torque-speed spline and is applied at the halfshafts. The VTORQUE statement for such a model should be as follows:

VTORQUE/id, I = imrk, JFLOAT = jmrk, RM = rmrk
, FUN=USER (1105, itire, difid, thrid, spdid, splid, trarat, sclfac, revlim, gearrat)

where:

id	=	Vtorque statement id
imrk	=	Marker on wheel at which the torque is applied
jmrk	=	Floating marker at which the reaction torque is applied
rmrk	=	Reference marker in whose coordinate system the torque is applied
itire	=	Tire id corresponding to the VTORQUE statement

difid	=	Id of the differential equation balancing the longitudinal reaction force on the body to ground inline jprim

thrid	=	Variable id to determine throttle position

spdid	=	Variable id to determine engine speed. The engine speed is determined from the average wheel rotational velocities and trasmission ratio

splid	=	Torque-speed spline id

trarat	=	Transmission ratio

sclfac	=	(Optional) Scale factor for unit conversion of torque (default is N-mm)

revlim	=	(Optional) Revolution limiter for engine speed

gearrat	=	(Optional) Gear ratio variable id. If variable representing gearrat is present then trarat is overwritten by the value of gearrat