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onbody.cpp
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Wed, Jul 10, 15:15

onbody.cpp

/*
*_________________________________________________________________________*
* POEMS: PARALLELIZABLE OPEN SOURCE EFFICIENT MULTIBODY SOFTWARE *
* DESCRIPTION: SEE READ-ME *
* FILE NAME: onbody.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 "onbody.h"
#include "body.h"
#include "inertialframe.h"
#include "joint.h"
#include "onfunctions.h"
#include "virtualmatrix.h"
#include "matrixfun.h"
#include <iostream>
#include "norm.h"
#include "eulerparameters.h"
using namespace std;
OnBody::OnBody(){
system_body = 0;
system_joint = 0;
parent = 0;
// these terms have zeros which are NEVER overwritten
sI.Zeros();
sSC.Zeros();
}
OnBody::~OnBody(){
children.DeleteValues();
}
int OnBody::RecursiveSetup (InertialFrame* basebody){
int ID = 0;
system_body = basebody;
// record that the traversal algorithm has been here
if( system_body->GetID() ) return 0;
ID++;
system_body->SetID(ID);
// setup inertial frame
SetupInertialFrame();
Joint* joint;
OnBody* child;
int tempID;
// loop through children calling the recursive setup function
ListElement<Joint>* ele = system_body->joints.GetHeadElement();
while(ele){
joint = ele->value;
child = new OnBody;
tempID = child->RecursiveSetup(ID,this,joint);
if( tempID ){
children.Append(child);
ID = tempID;
}
else delete child;
ele = ele->next;
}
return ID;
}
int OnBody::RecursiveSetup(int ID, OnBody* parentbody, Joint* sys_joint){
// initialize the topology and system analogs
parent = parentbody;
system_joint = sys_joint;
system_body = system_joint->OtherBody(parentbody->system_body);
// record that the traversal algorithm has been here
if( system_body->GetID() ) return 0;
ID++;
// perform the local setup operations
Setup();
Joint* joint;
OnBody* child;
int tempID;
// loop through children calling the recursive setup function
ListElement<Joint>* ele = system_body->joints.GetHeadElement();
while(ele){
joint = ele->value;
if(joint != sys_joint){
child = new OnBody;
tempID = child->RecursiveSetup(ID,this,joint);
if( tempID ){
children.Append(child);
ID = tempID;
}
else delete child;
}
ele = ele->next;
}
return ID;
}
void OnBody::SetupInertialFrame(){
// error check
if(system_body->GetType() != INERTIALFRAME){
cerr << "ERROR: attempting to setup inertial frame for non-inertial body" << endl;
exit(1);
}
// setup gravity
Vect3 neg_gravity = -((InertialFrame*) system_body)->GetGravity();
sAhat.Zeros();
Set6DLinearVector(sAhat,neg_gravity);
}
void OnBody::Setup(){
// get the direction of the joint
if( system_joint->GetBody2() == system_body ) joint_dir = FORWARD;
else joint_dir = BACKWARD;
// set the function pointers for the joint direction
if( joint_dir == FORWARD ){
kinfun = &Joint::ForwardKinematics;
updatesP = &Joint::UpdateForward_sP;
gamma = system_joint->GetR12();
pk_C_k = system_joint->Get_pkCk();
} else {
kinfun = &Joint::BackwardKinematics;
updatesP = &Joint::UpdateBackward_sP;
gamma = system_joint->GetR21();
pk_C_k = system_joint->Get_kCpk();
}
// initialize variables and dimensions
// sI
OnPopulateSI(system_body->inertia, system_body->mass, sI);
// sP
if( joint_dir == FORWARD )
sP = system_joint->GetForward_sP();
else
sP = system_joint->GetBackward_sP();
// dimension these quantities
sM = T(sP)*sP;
sMinv = sM;
sPsMinv = sP;
sIhatsP = sP;
// get the state and state derivative column matrix pointers
q = system_joint->GetQ();
u = system_joint->GetU();
qdot = system_joint->GetQdot();
udot = system_joint->GetUdot();
qdotdot = system_joint->GetQdotdot();
}
void OnBody::RecursiveKinematics(){
OnBody* child;
// Perform local kinematics recursively outward
ListElement<OnBody>* ele = children.GetHeadElement();
while(ele){
child = ele->value;
child->LocalKinematics();
child->RecursiveKinematics();
Mat3x3 result=*child->pk_C_k;
ele = ele->next;
}
}
void OnBody::RecursiveTriangularization(){
OnBody* child;
// Perform local triangularization recursively inward
ListElement<OnBody>* ele = children.GetHeadElement();
while(ele){
child = ele->value;
child->RecursiveTriangularization();
//child->LocalTriangularization();
ele = ele->next;
}
}
void OnBody::RecursiveForwardSubstitution(){
OnBody* child;
// Perform local forward substitution recursively outward
ListElement<OnBody>* ele = children.GetHeadElement();
while(ele){
child = ele->value;
// child->LocalForwardSubstitution();
child->RecursiveForwardSubstitution();
ele = ele->next;
}
}
void OnBody::LocalKinematics(){
// do the directional kinematics
(system_joint->*kinfun)();
(system_joint->*updatesP)( sP );
OnPopulateSC( *gamma, *pk_C_k, sSC );
}
Mat3x3 OnBody::GetN_C_K(){
Mat3x3 nck=system_body->n_C_k;
return nck;
}
int OnBody::GetBodyID(){
int ID=system_body->GetID();
return ID;
}
Vect3 OnBody::LocalCart(){
(system_joint->*kinfun)();
Vect3 RR=system_body->r;
return RR;
}
void OnBody::LocalTriangularization(Vect3& Torque, Vect3& Force){
Vect3 Iw,wIw,Ialpha,wIwIalpha,ma,Bforce,Bforce_ma,Btorque,Btorque_wIwIalpha;
Iw.Zeros();wIw.Zeros();wIwIalpha.Zeros();ma.Zeros();
Bforce.Zeros();Bforce_ma.Zeros();Btorque.Zeros();Btorque_wIwIalpha.Zeros();
FastMult(system_body->inertia,system_body->omega_k,Iw);
FastCross(Iw,system_body->omega_k,wIw);
FastMult(system_body->inertia, system_body->alpha_t, Ialpha);
FastSubt(wIw,Ialpha,wIwIalpha);
FastMult(-system_body->mass,system_body->a_t,ma);
Mat3x3 k_C_n=T(system_body->n_C_k);
Bforce=k_C_n*Force;
Btorque=k_C_n*Torque;
FastAdd(Bforce,ma,Bforce_ma);
FastAdd(Btorque,wIwIalpha,Btorque_wIwIalpha);
OnPopulateSVect(Btorque_wIwIalpha,Bforce_ma,sF);
sIhat = sI;
sFhat = sF;
Mat6x6 sPsMinvsPT;
Mat6x6 sIhatsPsMsPT;
Mat6x6 sUsIhatsPsMsPT;
Mat6x6 sTsIhat;
Mat6x6 sTsIhatsSCT;
Vect6 sTsFhat;
Mat6x6 sU;
sU.Identity();
OnBody* child;
ListElement<OnBody>* ele = children.GetHeadElement();
while(ele){
child = ele->value;
FastMultT(child->sIhatsP,child->sPsMinv,sIhatsPsMsPT);
FastSubt(sU,sIhatsPsMsPT,sUsIhatsPsMsPT);
FastMult(child->sSC,sUsIhatsPsMsPT,child->sT);
FastMult(child->sT,child->sIhat,sTsIhat);
FastMultT(sTsIhat,child->sSC,sTsIhatsSCT);
FastAdd(sIhat,sTsIhatsSCT,sIhat);
FastMult(child->sT,child->sFhat,sTsFhat);
FastAdd(sFhat,sTsFhat,sFhat);
ele = ele->next;
}
FastMult(sIhat,sP,sIhatsP);
FastTMult(sP,sIhatsP,sM);
sMinv=SymInverse(sM);
FastMult(sP,sMinv,sPsMinv);
}
void OnBody::LocalForwardSubstitution(){
Vect6 sSCTsAhat;
Vect6 sIhatsSCTsAhat;
Vect6 sFsIhatsSCTsAhat;
Vect6 sPudot;
int type = system_joint->GetType();
if(type == 1){
FastTMult(sSC,parent->sAhat,sSCTsAhat);
FastMult(sIhat,sSCTsAhat,sIhatsSCTsAhat);
FastSubt(sFhat,sIhatsSCTsAhat,sFsIhatsSCTsAhat);
FastTMult(sPsMinv,sFsIhatsSCTsAhat,*udot);
ColMatrix result1=*udot;
ColMatrix result2=*qdot;
ColMatrix result3=*q;
int num=result1.GetNumRows();
ColMatrix result4(num+1);
result4.Zeros();
EPdotdot_udot(result1, result2, result3, result4);
FastAssign(result4, *qdotdot);
FastMult(sP,*udot,sPudot);
FastAdd(sSCTsAhat,sPudot,sAhat);
}
else if (type == 4){
FastTMult(sSC,parent->sAhat,sSCTsAhat);
FastMult(sIhat,sSCTsAhat,sIhatsSCTsAhat);
FastSubt(sFhat,sIhatsSCTsAhat,sFsIhatsSCTsAhat);
FastTMult(sPsMinv,sFsIhatsSCTsAhat,*udot);
ColMatrix result1=*udot;
ColMatrix result2=*qdot;
ColMatrix result3=*q;
int num=result1.GetNumRows();
ColMatrix result4(num+1);
result4.Zeros();
EPdotdot_udot(result1, result2, result3, result4);
FastAssign(result4, *qdotdot);
FastMult(sP,*udot,sPudot);
FastAdd(sSCTsAhat,sPudot,sAhat);
}
else if (type == 5){
FastTMult(sSC,parent->sAhat,sSCTsAhat);
FastMult(sIhat,sSCTsAhat,sIhatsSCTsAhat);
FastSubt(sFhat,sIhatsSCTsAhat,sFsIhatsSCTsAhat);
FastTMult(sPsMinv,sFsIhatsSCTsAhat,*udot);
ColMatrix temp_u = *udot;
ColMatrix result1(3);
result1(1)=0.0;
result1(2)=temp_u(1);
result1(3)=temp_u(2);
ColMatrix result2=*qdot;
ColMatrix result3=*q;
int num=result1.GetNumRows();
ColMatrix result4(num+1);
result4.Zeros();
EPdotdot_udot(result1, result2, result3, result4);
FastAssign(result4, *qdotdot);
FastMult(sP,*udot,sPudot);
FastAdd(sSCTsAhat,sPudot,sAhat);
}
else if (type == 6){
FastTMult(sSC,parent->sAhat,sSCTsAhat);
FastMult(sIhat,sSCTsAhat,sIhatsSCTsAhat);
FastSubt(sFhat,sIhatsSCTsAhat,sFsIhatsSCTsAhat);
FastTMult(sPsMinv,sFsIhatsSCTsAhat,*udot);
ColMatrix temp_u = *udot;
int tt = temp_u.GetNumRows() + 1;
ColMatrix result1(tt);
result1(1)=0.0;
for (int k =2; k<=tt; k++){
result1(k)=temp_u(k-1);
}
ColMatrix result2=*qdot;
ColMatrix result3=*q;
int num=result1.GetNumRows();
ColMatrix result4(num+1);
result4.Zeros();
EPdotdot_udot(result1, result2, result3, result4);
FastAssign(result4, *qdotdot);
FastMult(sP,*udot,sPudot);
FastAdd(sSCTsAhat,sPudot,sAhat);
}
else{
cout<<"Joint type not recognized in onbody.cpp LocalForwardSubsitution() "<<type<<endl;
exit(-1);
}
CalculateAcceleration();
}
void OnBody::CalculateAcceleration(){
}

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