public ChLinkMotorRotationTorque()
{
this.c_rz = false;
SetupLinkMask();
m_func = new ChFunction_Const(0.0);
}
// This can be used, at each time step, to compute the actual value of torque
// transmitted to the wheels, according to gas throttle / speed / gear value.
// The following is a very simplified model (the torque curve of the motor is linear
// and no latency or inertial or clutch effects in gear train are considered.)
double ComputeWheelTorque()
{
// Assume clutch is never used. Given the kinematics of differential,
// the speed of the engine transmission shaft is the average of the two wheel speeds,
// multiplied the conic gear transmission ratio inversed:
double shaftspeed = (1.0 / this.conic_tau) * 0.5 *
(this.link_engineL.Get_mot_rot_dt() + this.link_engineR.Get_mot_rot_dt());
// The motorspeed is the shaft speed multiplied by gear ratio inversed:
double motorspeed = (1.0 / this.gear_tau) * shaftspeed;
// The torque depends on speed-torque curve of the motor: here we assume a
// very simplified model a bit like in DC motors:
double motortorque = max_motor_torque - motorspeed * (max_motor_torque / max_motor_speed);
// Motor torque is linearly modulated by throttle gas value:
motortorque = motortorque * this.throttle;
// The torque at motor shaft:
double shafttorque = motortorque * (1.0 / this.gear_tau);
// The torque at wheels - for each wheel, given the differential transmission,
// it is half of the shaft torque (multiplied the conic gear transmission ratio)
double singlewheeltorque = 0.5 * shafttorque * (1.0 / this.conic_tau);
// Set the wheel torque in both 'engine' links, connecting the wheels to the truss;
ChFunction_Const mfun1 = (ChFunction_Const)link_engineL.Get_tor_funct();
ChFunction_Const mfun2 = (ChFunction_Const)link_engineR.Get_tor_funct();
//if (mfun == link_engineL as )
mfun1.Set_yconst(singlewheeltorque);
mfun2.Set_yconst(singlewheeltorque);
// if (mfun = (ChFunction_Const)(link_engineR.Get_tor_funct()))
// mfun.Set_yconst(singlewheeltorque);
// debug:print infos on screen:
// GetLog() << "motor torque="<< motortorque<< " speed=" << motorspeed << " wheel torqe=" << singlewheeltorque
// <<"\n";
// If needed, return also the value of wheel torque:
return(singlewheeltorque);
}
public ChLinkMotorRotationSpeed()
{
variable.GetMass()[0, 0] = 1.0;
variable.GetInvMass()[0, 0] = 1.0;
m_func = new ChFunction_Const(1.0);
rot_offset = 0;
aux_dt = 0; // used for integrating speed, = rot
aux_dtdt = 0;
avoid_angle_drift = true;
}
public ChLinkMotorLinearSpeed()
{
variable.GetMass()[0, 0] = 1.0;
variable.GetInvMass()[0, 0] = 1.0;
m_func = new ChFunction_Const(1.0);
pos_offset = 0;
aux_dt = 0; // used for integrating speed, = pos
aux_dtdt = 0;
avoid_position_drift = true;
}
public ChLinkMotor()
{
m_func = new ChFunction_Const(0); // defaults to no motion.
}
public ChFunction_Const(ChFunction_Const other)
{
C = other.C;
}
