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lammps/lib/poems/mixedjoint.cpp
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mixedjoint.cpp
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/*
*_________________________________________________________________________*
* POEMS: PARALLELIZABLE OPEN SOURCE EFFICIENT MULTIBODY SOFTWARE *
* DESCRIPTION: SEE READ-ME *
* FILE NAME: mixedjoint.cpp *
* AUTHORS: See Author List *
* GRANTS: See Grants List *
* COPYRIGHT: (C) 2005 by Authors as listed in Author's List *
* LICENSE: Please see License Agreement *
* DOWNLOAD: Free at www.rpi.edu/~anderk5 *
* ADMINISTRATOR: Prof. Kurt Anderson *
* Computational Dynamics Lab *
* Rensselaer Polytechnic Institute *
* 110 8th St. Troy NY 12180 *
* CONTACT: anderk5@rpi.edu *
*_________________________________________________________________________*/
#include "mixedjoint.h"
#include "point.h"
#include "matrixfun.h"
#include "body.h"
#include "fastmatrixops.h"
#include "norm.h"
#include "eulerparameters.h"
#include "matrices.h"
MixedJoint::MixedJoint(){
}
MixedJoint::~MixedJoint(){
}
JointType MixedJoint::GetType(){
return MIXEDJOINT;
}
bool MixedJoint::ReadInJointData(std::istream& in){
return true;
}
void MixedJoint::WriteOutJointData(std::ostream& out){
}
void MixedJoint::SetsP(Matrix& sPr, Vect6& temp_dofs, int i, int j){
const_sP = sPr;
dofs = temp_dofs;
numrots = i;
numtrans = j;
if (numrots < 2)
DimQandU(numrots+numtrans,numrots+numtrans);
else
DimQandU((4+numtrans),(numrots+numtrans));
cout<<"Check "<<4+numtrans<<" "<<numrots+numtrans<<" "<<i<<" "<<j<<endl;
}
void MixedJoint::ComputeLocalTransform(){
Mat3x3 ko_C_k;
EP_Transformation(q, ko_C_k);
FastMult(pk_C_ko,ko_C_k,pk_C_k);
}
Matrix MixedJoint::GetForward_sP(){
Mat6x6 temp_sP;
Matrix sP;
temp_sP.Zeros();
Mat3x3 temp0=T(pk_C_k);
for(int i=1;i<4;i++){
temp_sP(i,i)=1.0;
for(int j=1;j<4;j++){
temp_sP(3+i,3+j)=temp0(i,j);
}
}
sP = temp_sP*const_sP;
return sP;
}
Matrix MixedJoint::GetBackward_sP(){
Mat6x6 sP;
sP.Identity();
sP =-1.0*sP;
cout<<"Did I come here in "<<endl;
return sP;
}
void MixedJoint::UpdateForward_sP( Matrix& sP){
// do nothing
}
void MixedJoint::UpdateBackward_sP( Matrix& sP){
// do nothing
}
void MixedJoint::ForwardKinematics(){
if(numrots > 1)
EP_Normalize(q);
// COMMENT STEP1: CALCULATE ORIENTATIONS
ComputeForwardTransforms();
//COMMENT STEP2: CALCULATE POSITION VECTORS
Vect3 result1, result2, result3, result4;
result1.Zeros();
for (int k=0; k<3; k++){
if( dofs(3+k) != 0.0 ){
if (numrots > 1)
result1.BasicSet(k,q.BasicGet(4 + k));
else
result1.BasicSet(k,q.BasicGet(numrots + k));
}
}
FastAssign(result1,r12); // r12 in parents basis i.e. Newtonian
FastNegMult(k_C_pk,r12,r21); // r21 in body basis
FastAssign(r12,body2->r); // This is right
//COMMENT STEP3: CALCULATE QDOT
int pp = 0;
if (numrots > 1){
ColMatrix temp_u(3+numtrans);
qdot_to_u(q,temp_u,qdot);
for (int k=1;k<=6;k++){
if(dofs(k) != 0.0){
u.BasicSet(pp,temp_u.BasicGet(k-1));
pp = pp+1;
}
}
}
else u = qdot;
Vect3 WN; WN.Zeros();
int p = 0;
for (int k=0;k<3;k++){
if(dofs(k+1) != 0.0){
WN.BasicSet(k,u.BasicGet(p));
p=p+1;
}
}// WN is in body basis
Vect3 VN; VN.Zeros();
for (int k=0;k<3;k++){
if( dofs(3+k+1) != 0.0 ) {
VN.BasicSet(k,u.BasicGet(p));
p=p+1;
}
}// VN is the vector of translational velocities in Newtonian basis
FastAssign(WN,body2->omega_k);
// cout<<"Angular Velocity "<<WN<<endl;
Vect3 pk_w_k;
FastMult(body2->n_C_k,WN,pk_w_k);
FastAssign(pk_w_k,body2->omega);
//COMMENT STEP5: CALCULATE VELOCITES
FastAssign(VN,body2->v);
FastTMult(body2->n_C_k,body2->v,body2->v_k);
//CALCULATE KE
Matrix tempke;
tempke = T(body2->v)*(body2->v);
double ke = 0.0;
ke = body2->mass*tempke(1,1);
FastMult(body2->inertia,body2->omega_k,result1);
tempke= T(body2->omega_k)*result1;
ke = 0.5*ke + 0.5*tempke(1,1);
body2->KE=ke;
//COMMENT STEP6: CALCULATE STATE EXPLICIT ANGULAR ACCELERATIONS
body2->alpha_t.Zeros();
//COMMENT STEP7: CALCULATE STATE EXPLICIT ACCELERATIONS
body2->a_t.Zeros();
}
void MixedJoint::BackwardKinematics(){
cout<<"Did I come here "<<endl;
}
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