calculate constant values before first pivoting of dynamic states

[Jens Frenkel]

The example PlanarMechanicsForTesting.Examples.SingleTrackWithEngine.mos fails with the following error message

 0.00000e+000  0.00000e+000  0.00000e+000 

 0.00000e+000 -9.00000e-001  0.00000e+000 

idealWheelRear.v_long

idealWheelFront.v_long

bodyRear.w

assert            | assert  | Error, singular Jacobian for dynamic state selection at time 0.000000

The selected states are equivalent to dymola and the problem is after analyzing the jacobian for pivoting that the constant parts of the initial system are not calculated before pivoting.

In detail the start value revolute.phi_start of revolute is not propagedet to bodyRear.frame_a.phi and as an result the jacobimatrix is numerical singular in the fist row

bodyFront.w.DERStateSetJac1.dummyVarStateSetJac1  = 0,0,1
6/6 (1): bodyFront.w.DERStateSetJac1.dummyVarStateSetJac1 = bodyRear.w.DERStateSetJac1.bodyRear.w
$DER.trail.R[2,1].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,-1
8/8 (1): -$DER.trail.R[2,1].DERStateSetJac1.dummyVarStateSetJac1 = bodyFront.w.DERStateSetJac1.dummyVarStateSetJac1 * cos(bodyFront.frame_a.phi)
$DER.trail.R[2,2].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,0
7/7 (1): $DER.trail.R[2,2].DERStateSetJac1.dummyVarStateSetJac1 = (-bodyFront.w.DERStateSetJac1.dummyVarStateSetJac1) * sin(bodyFront.frame_a.phi)
$DER.trail.r0[1].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,0.1
10/10 (1): $DER.trail.r0[1].DERStateSetJac1.dummyVarStateSetJac1 = $DER.trail.R[2,2].DERStateSetJac1.dummyVarStateSetJac1 * trail.r[1] + (-$DER.trail.R[2,1].DERStateSetJac1.dummyVarStateSetJac1) * trail.r[2]
$DER.chassis.R[2,1].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,1
4/4 (1): -$DER.chassis.R[2,1].DERStateSetJac1.dummyVarStateSetJac1 = bodyRear.w.DERStateSetJac1.bodyRear.w * cos(bodyRear.frame_a.phi)
idealWheelFront.v[1].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,0
2/2 (1): idealWheelFront.v[1].DERStateSetJac1.dummyVarStateSetJac1 = idealWheelFront.e0[1] * idealWheelFront.v_long.DERStateSetJac1.idealWheelFront.v_long
$DER.revolute.cylinder.rvisobj[1].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,0.1
11/11 (1): $DER.revolute.cylinder.rvisobj[1].DERStateSetJac1.dummyVarStateSetJac1 + $DER.trail.r0[1].DERStateSetJac1.dummyVarStateSetJac1 = idealWheelFront.v[1].DERStateSetJac1.dummyVarStateSetJac1
$DER.chassis.R[2,2].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,0
1/1 (1): $DER.chassis.R[2,2].DERStateSetJac1.dummyVarStateSetJac1 = (-bodyRear.w.DERStateSetJac1.bodyRear.w) * sin(bodyRear.frame_a.phi)
$DER.chassis.r0[1].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,1
5/5 (1): $DER.chassis.r0[1].DERStateSetJac1.dummyVarStateSetJac1 = $DER.chassis.R[2,2].DERStateSetJac1.dummyVarStateSetJac1 * chassis.r[1] + (-$DER.chassis.R[2,1].DERStateSetJac1.dummyVarStateSetJac1) * chassis.r[2]
bodyRear.v[1].DERStateSetJac1.dummyVarStateSetJac1 = 0,0,0
12/12 (1): bodyRear.v[1].DERStateSetJac1.dummyVarStateSetJac1 + $DER.chassis.r0[1].DERStateSetJac1.dummyVarStateSetJac1 = $DER.revolute.cylinder.rvisobj[1].DERStateSetJac1.dummyVarStateSetJac1
$STATESET1.J[1].DERStateSetJac1.dummyVarStateSetJac1 
13/13 (1): $STATESET1.J[1].DERStateSetJac1.dummyVarStateSetJac1 = bodyRear.v[1].DERStateSetJac1.dummyVarStateSetJac1 - idealWheelRear.e0[1] * idealWheelRear.v_long.DERStateSetJac1.idealWheelRear.v_long

A simple solution coult be to calculate all constants (for example simplify the initial system and use the simplified parts) before the first pivoting is done. This would also increase the initialization process because actually all bound parameters are calculated twice. Once in boundparameter function and the second one in initialEquations.

[Jens Frenkel]

• partial solved in r14800 by disable error message about singulare jacobin for the first call of pivoting and usage of default selection

[Martin Sjölund]

Postponed until 1.9.1

[Martin Sjölund]

This ticket was not closed for 1.9.1, which has now been released. It was batch modified for milestone 1.9.2 (but maybe an empty milestone was more appropriate; feel free to change it).

[Lennart Ochel]

This is fixed in the meantime.