bullet3/examples/MultiBody/InvertedPendulumPDControl.cpp
Erwin Coumans b23cb1dd2c pybullet.createCollisionShape, createVisualShape, createMultiBody, programmatic creation using ProgrammaticUrdfInterface
(still preliminary, not ready for commit yet, see examples\pybullet\examples\createSphereMultiBodies.py)
2017-06-03 10:57:56 -07:00

466 lines
14 KiB
C++

#include "InvertedPendulumPDControl.h"
#include "BulletDynamics/Featherstone/btMultiBodyLinkCollider.h"
#include "BulletDynamics/Featherstone/btMultiBodyJointFeedback.h"
#include "../CommonInterfaces/CommonMultiBodyBase.h"
#include "../Utils/b3ResourcePath.h"
#include "../CommonInterfaces/CommonParameterInterface.h"
static btScalar radius(0.2);
static btScalar kp = 100;
static btScalar kd = 20;
static btScalar maxForce = 100;
struct InvertedPendulumPDControl : public CommonMultiBodyBase
{
btMultiBody* m_multiBody;
btAlignedObjectArray<btMultiBodyJointFeedback*> m_jointFeedbacks;
bool m_once;
int m_frameCount;
public:
InvertedPendulumPDControl(struct GUIHelperInterface* helper);
virtual ~InvertedPendulumPDControl();
virtual void initPhysics();
virtual void stepSimulation(float deltaTime);
virtual void resetCamera()
{
float dist = 5;
float pitch = -21;
float yaw = 270;
float targetPos[3]={-1.34,1.4,3.44};
m_guiHelper->resetCamera(dist,yaw,pitch,targetPos[0],targetPos[1],targetPos[2]);
}
};
InvertedPendulumPDControl::InvertedPendulumPDControl(struct GUIHelperInterface* helper)
:CommonMultiBodyBase(helper),
m_once(true),
m_frameCount(0)
{
}
InvertedPendulumPDControl::~InvertedPendulumPDControl()
{
}
///this is a temporary global, until we determine if we need the option or not
extern bool gJointFeedbackInWorldSpace;
extern bool gJointFeedbackInJointFrame;
btMultiBody* createInvertedPendulumMultiBody(btMultiBodyDynamicsWorld* world, GUIHelperInterface* guiHelper, const btTransform& baseWorldTrans, bool fixedBase)
{
btVector4 colors[4] =
{
btVector4(1,0,0,1),
btVector4(0,1,0,1),
btVector4(0,1,1,1),
btVector4(1,1,0,1),
};
int curColor = 0;
bool damping = false;
bool gyro = false;
int numLinks = 2;
bool spherical = false; //set it ot false -to use 1DoF hinges instead of 3DoF sphericals
bool canSleep = false;
bool selfCollide = false;
btVector3 linkHalfExtents(0.05, 0.37, 0.1);
btVector3 baseHalfExtents(0.04, 0.35, 0.08);
//mbC->forceMultiDof(); //if !spherical, you can comment this line to check the 1DoF algorithm
//init the base
btVector3 baseInertiaDiag(0.f, 0.f, 0.f);
float baseMass = fixedBase ? 0.f : 10.f;
if(baseMass)
{
//btCollisionShape *shape = new btSphereShape(baseHalfExtents[0]);// btBoxShape(btVector3(baseHalfExtents[0], baseHalfExtents[1], baseHalfExtents[2]));
btCollisionShape *shape = new btBoxShape(btVector3(baseHalfExtents[0], baseHalfExtents[1], baseHalfExtents[2]));
shape->calculateLocalInertia(baseMass, baseInertiaDiag);
delete shape;
}
btMultiBody *pMultiBody = new btMultiBody(numLinks, 0, baseInertiaDiag, fixedBase, canSleep);
pMultiBody->setBaseWorldTransform(baseWorldTrans);
btVector3 vel(0, 0, 0);
// pMultiBody->setBaseVel(vel);
//init the links
btVector3 hingeJointAxis(1, 0, 0);
//y-axis assumed up
btVector3 parentComToCurrentCom(0, -linkHalfExtents[1] * 2.f, 0); //par body's COM to cur body's COM offset
btVector3 currentPivotToCurrentCom(0, -linkHalfExtents[1], 0); //cur body's COM to cur body's PIV offset
btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; //par body's COM to cur body's PIV offset
//////
btScalar q0 = 1.f * SIMD_PI/ 180.f;
btQuaternion quat0(btVector3(1, 0, 0).normalized(), q0);
quat0.normalize();
/////
for(int i = 0; i < numLinks; ++i)
{
float linkMass = 1.f;
//if (i==3 || i==2)
// linkMass= 1000;
btVector3 linkInertiaDiag(0.f, 0.f, 0.f);
btCollisionShape* shape = 0;
if (i==0)
{
shape = new btBoxShape(btVector3(linkHalfExtents[0], linkHalfExtents[1], linkHalfExtents[2]));//
} else
{
shape = new btSphereShape(radius);
}
shape->calculateLocalInertia(linkMass, linkInertiaDiag);
delete shape;
if(!spherical)
{
//pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), hingeJointAxis, parentComToCurrentPivot, currentPivotToCurrentCom, false);
if (i==0)
{
pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1,
btQuaternion(0.f, 0.f, 0.f, 1.f),
hingeJointAxis,
parentComToCurrentPivot,
currentPivotToCurrentCom, false);
} else
{
btVector3 parentComToCurrentCom(0, -radius * 2.f, 0); //par body's COM to cur body's COM offset
btVector3 currentPivotToCurrentCom(0, -radius, 0); //cur body's COM to cur body's PIV offset
btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; //par body's COM to cur body's PIV offset
pMultiBody->setupFixed(i, linkMass, linkInertiaDiag, i - 1,
btQuaternion(0.f, 0.f, 0.f, 1.f),
parentComToCurrentPivot,
currentPivotToCurrentCom);
}
//pMultiBody->setupFixed(i,linkMass,linkInertiaDiag,i-1,btQuaternion(0,0,0,1),parentComToCurrentPivot,currentPivotToCurrentCom,false);
}
else
{
//pMultiBody->setupPlanar(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f)/*quat0*/, btVector3(1, 0, 0), parentComToCurrentPivot*2, false);
pMultiBody->setupSpherical(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), parentComToCurrentPivot, currentPivotToCurrentCom, false);
}
}
pMultiBody->finalizeMultiDof();
///
world->addMultiBody(pMultiBody);
btMultiBody* mbC = pMultiBody;
mbC->setCanSleep(canSleep);
mbC->setHasSelfCollision(selfCollide);
mbC->setUseGyroTerm(gyro);
//
if(!damping)
{
mbC->setLinearDamping(0.f);
mbC->setAngularDamping(0.f);
}else
{ mbC->setLinearDamping(0.1f);
mbC->setAngularDamping(0.9f);
}
//
//////////////////////////////////////////////
if(numLinks > 0)
{
btScalar q0 = 180.f * SIMD_PI/ 180.f;
if(!spherical)
{
mbC->setJointPosMultiDof(0, &q0);
}
else
{
btQuaternion quat0(btVector3(1, 1, 0).normalized(), q0);
quat0.normalize();
mbC->setJointPosMultiDof(0, quat0);
}
}
///
btAlignedObjectArray<btQuaternion> world_to_local;
world_to_local.resize(pMultiBody->getNumLinks() + 1);
btAlignedObjectArray<btVector3> local_origin;
local_origin.resize(pMultiBody->getNumLinks() + 1);
world_to_local[0] = pMultiBody->getWorldToBaseRot();
local_origin[0] = pMultiBody->getBasePos();
// double friction = 1;
{
// float pos[4]={local_origin[0].x(),local_origin[0].y(),local_origin[0].z(),1};
// float quat[4]={-world_to_local[0].x(),-world_to_local[0].y(),-world_to_local[0].z(),world_to_local[0].w()};
if (1)
{
btCollisionShape* shape = new btBoxShape(btVector3(baseHalfExtents[0],baseHalfExtents[1],baseHalfExtents[2]));//new btSphereShape(baseHalfExtents[0]);
guiHelper->createCollisionShapeGraphicsObject(shape);
btMultiBodyLinkCollider* col= new btMultiBodyLinkCollider(pMultiBody, -1);
col->setCollisionShape(shape);
btTransform tr;
tr.setIdentity();
//if we don't set the initial pose of the btCollisionObject, the simulator will do this
//when syncing the btMultiBody link transforms to the btMultiBodyLinkCollider
tr.setOrigin(local_origin[0]);
btQuaternion orn(btVector3(0,0,1),0.25*3.1415926538);
tr.setRotation(orn);
col->setWorldTransform(tr);
bool isDynamic = (baseMass > 0 && !fixedBase);
int collisionFilterGroup = isDynamic? int(btBroadphaseProxy::DefaultFilter) : int(btBroadphaseProxy::StaticFilter);
int collisionFilterMask = isDynamic? int(btBroadphaseProxy::AllFilter) : int(btBroadphaseProxy::AllFilter ^ btBroadphaseProxy::StaticFilter);
world->addCollisionObject(col,collisionFilterGroup,collisionFilterMask);//, 2,1+2);
btVector4 color(0.0,0.0,0.5,1);
guiHelper->createCollisionObjectGraphicsObject(col,color);
// col->setFriction(friction);
pMultiBody->setBaseCollider(col);
}
}
for (int i=0; i < pMultiBody->getNumLinks(); ++i)
{
const int parent = pMultiBody->getParent(i);
world_to_local[i+1] = pMultiBody->getParentToLocalRot(i) * world_to_local[parent+1];
local_origin[i+1] = local_origin[parent+1] + (quatRotate(world_to_local[i+1].inverse() , pMultiBody->getRVector(i)));
}
for (int i=0; i < pMultiBody->getNumLinks(); ++i)
{
btVector3 posr = local_origin[i+1];
// float pos[4]={posr.x(),posr.y(),posr.z(),1};
float quat[4]={-world_to_local[i+1].x(),-world_to_local[i+1].y(),-world_to_local[i+1].z(),world_to_local[i+1].w()};
btCollisionShape* shape =0;
if (i==0)
{
shape = new btBoxShape(btVector3(linkHalfExtents[0],linkHalfExtents[1],linkHalfExtents[2]));//btSphereShape(linkHalfExtents[0]);
} else
{
shape = new btSphereShape(radius);
}
guiHelper->createCollisionShapeGraphicsObject(shape);
btMultiBodyLinkCollider* col = new btMultiBodyLinkCollider(pMultiBody, i);
col->setCollisionShape(shape);
btTransform tr;
tr.setIdentity();
tr.setOrigin(posr);
tr.setRotation(btQuaternion(quat[0],quat[1],quat[2],quat[3]));
col->setWorldTransform(tr);
// col->setFriction(friction);
bool isDynamic = 1;//(linkMass > 0);
int collisionFilterGroup = isDynamic? int(btBroadphaseProxy::DefaultFilter) : int(btBroadphaseProxy::StaticFilter);
int collisionFilterMask = isDynamic? int(btBroadphaseProxy::AllFilter) : int(btBroadphaseProxy::AllFilter ^ btBroadphaseProxy::StaticFilter);
//if (i==0||i>numLinks-2)
{
world->addCollisionObject(col,collisionFilterGroup,collisionFilterMask);//,2,1+2);
btVector4 color = colors[curColor];
curColor++;
curColor&=3;
guiHelper->createCollisionObjectGraphicsObject(col,color);
pMultiBody->getLink(i).m_collider=col;
}
}
return pMultiBody;
}
void InvertedPendulumPDControl::initPhysics()
{
{
SliderParams slider("Kp",&kp);
slider.m_minVal=-200;
slider.m_maxVal=200;
m_guiHelper->getParameterInterface()->registerSliderFloatParameter(slider);
}
{
SliderParams slider("Kd",&kd);
slider.m_minVal=-50;
slider.m_maxVal=50;
m_guiHelper->getParameterInterface()->registerSliderFloatParameter(slider);
}
{
SliderParams slider("max force",&maxForce);
slider.m_minVal=0;
slider.m_maxVal=100;
m_guiHelper->getParameterInterface()->registerSliderFloatParameter(slider);
}
int upAxis = 1;
gJointFeedbackInWorldSpace = true;
gJointFeedbackInJointFrame = true;
m_guiHelper->setUpAxis(upAxis);
this->createEmptyDynamicsWorld();
m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
m_dynamicsWorld->getDebugDrawer()->setDebugMode(
//btIDebugDraw::DBG_DrawConstraints
+btIDebugDraw::DBG_DrawWireframe
+btIDebugDraw::DBG_DrawContactPoints
+btIDebugDraw::DBG_DrawAabb
);//+btIDebugDraw::DBG_DrawConstraintLimits);
m_dynamicsWorld->setGravity(btVector3(0,-10,0));
btTransform baseWorldTrans;
baseWorldTrans.setIdentity();
baseWorldTrans.setOrigin(btVector3(1,2,3));
m_multiBody = createInvertedPendulumMultiBody(m_dynamicsWorld, m_guiHelper, baseWorldTrans, true);
//for (int i=pMultiBody->getNumLinks()-1;i>=0;i--)//
for (int i=0;i<m_multiBody->getNumLinks();i++)
{
btMultiBodyJointFeedback* fb = new btMultiBodyJointFeedback();
m_multiBody->getLink(i).m_jointFeedback = fb;
m_jointFeedbacks.push_back(fb);
//break;
}
}
char fileName[1024];
static btAlignedObjectArray<btScalar> qDesiredArray;
void InvertedPendulumPDControl::stepSimulation(float deltaTime)
{
static btScalar offset = -0.1*SIMD_PI;
m_frameCount++;
if ((m_frameCount&0xff)==0 )
{
offset = -offset;
}
btScalar target= SIMD_PI+offset;
qDesiredArray.resize(0);
qDesiredArray.resize(m_multiBody->getNumLinks(),target);
for (int joint = 0; joint<m_multiBody->getNumLinks();joint++)
{
int dof1 = 0;
btScalar qActual = m_multiBody->getJointPosMultiDof(joint)[dof1];
btScalar qdActual = m_multiBody->getJointVelMultiDof(joint)[dof1];
btScalar positionError = (qDesiredArray[joint]-qActual);
double desiredVelocity = 0;
btScalar velocityError = (desiredVelocity-qdActual);
btScalar force = kp * positionError + kd*velocityError;
btClamp(force,-maxForce,maxForce);
m_multiBody->addJointTorque(joint, force);
}
if (m_frameCount==100)
{
const char* gPngFileName = "pendulum";
if (gPngFileName)
{
//printf("gPngFileName=%s\n",gPngFileName);
sprintf(fileName,"%s%d.png",gPngFileName,m_frameCount);
b3Printf("Made screenshot %s",fileName);
this->m_guiHelper->getAppInterface()->dumpNextFrameToPng(fileName);
}
}
m_dynamicsWorld->stepSimulation(1./60.,0);//240,0);
static int count = 0;
if ((count& 0x0f)==0)
{
#if 0
for (int i=0;i<m_jointFeedbacks.size();i++)
{
b3Printf("F_reaction[%i] linear:%f,%f,%f, angular:%f,%f,%f",
i,
m_jointFeedbacks[i]->m_reactionForces.m_topVec[0],
m_jointFeedbacks[i]->m_reactionForces.m_topVec[1],
m_jointFeedbacks[i]->m_reactionForces.m_topVec[2],
m_jointFeedbacks[i]->m_reactionForces.m_bottomVec[0],
m_jointFeedbacks[i]->m_reactionForces.m_bottomVec[1],
m_jointFeedbacks[i]->m_reactionForces.m_bottomVec[2]
);
}
#endif
}
count++;
/*
b3Printf("base angvel = %f,%f,%f",m_multiBody->getBaseOmega()[0],
m_multiBody->getBaseOmega()[1],
m_multiBody->getBaseOmega()[2]
);
*/
// btScalar jointVel =m_multiBody->getJointVel(0);
// b3Printf("child angvel = %f",jointVel);
}
class CommonExampleInterface* InvertedPendulumPDControlCreateFunc(struct CommonExampleOptions& options)
{
return new InvertedPendulumPDControl(options.m_guiHelper);
}