pxmlw6n2f/Gazebo_Distributed_MPI/plugins/MudPlugin.cc

349 lines
11 KiB
C++

/*
* Copyright (C) 2012 Open Source Robotics Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include <boost/algorithm/string.hpp>
#include <boost/unordered_map.hpp>
#include <boost/unordered_set.hpp>
#include "gazebo/common/Assert.hh"
#include "gazebo/physics/physics.hh"
#include "gazebo/sensors/SensorManager.hh"
#include "gazebo/sensors/ContactSensor.hh"
#include "gazebo/transport/transport.hh"
#include "plugins/MudPlugin.hh"
using namespace gazebo;
GZ_REGISTER_MODEL_PLUGIN(MudPlugin)
/////////////////////////////////////////////////
MudPlugin::MudPlugin()
: newMsg(false), newMsgWait(0), stiffness(0.0), damping(100.0),
contactSurfaceBitmask(0)
{
}
/////////////////////////////////////////////////
void MudPlugin::Load(physics::ModelPtr _model,
sdf::ElementPtr _sdf)
{
GZ_ASSERT(_model, "MudPlugin _model pointer is NULL");
this->model = _model;
this->modelName = _model->GetName();
this->sdf = _sdf;
this->world = this->model->GetWorld();
GZ_ASSERT(this->world, "MudPlugin world pointer is NULL");
this->physics = this->world->GetPhysicsEngine();
GZ_ASSERT(this->physics, "MudPlugin physics pointer is NULL");
this->link = _model->GetLink();
GZ_ASSERT(this->link, "MudPlugin link pointer is NULL");
GZ_ASSERT(_sdf, "MudPlugin _sdf pointer is NULL");
if (_sdf->HasElement("contact_sensor_name"))
{
this->contactSensorName = _sdf->Get<std::string>("contact_sensor_name");
}
else
{
gzerr << "contactSensorName not supplied, ignoring contacts\n";
}
if (_sdf->HasElement("stiffness"))
this->stiffness = _sdf->Get<double>("stiffness");
if (_sdf->HasElement("damping"))
this->damping = _sdf->Get<double>("damping");
if (_sdf->HasElement("contact_surface_bitmask"))
{
this->contactSurfaceBitmask =
_sdf->Get<unsigned int>("contact_surface_bitmask");
}
if (_sdf->HasElement("link_name"))
{
sdf::ElementPtr elem = _sdf->GetElement("link_name");
while (elem)
{
allowedLinks.push_back(elem->Get<std::string>());
links.push_back(physics::LinkPtr());
joints.push_back(physics::JointPtr());
elem = elem->GetNextElement("link_name");
}
}
GZ_ASSERT(allowedLinks.size() == links.size(),
"Length of links data structure doesn't match allowedLinks");
GZ_ASSERT(allowedLinks.size() == joints.size(),
"Length of joints data structure doesn't match allowedLinks");
}
/////////////////////////////////////////////////
void MudPlugin::Init()
{
this->node.reset(new transport::Node());
this->node->Init(this->world->GetName());
if (!this->contactSensorName.empty())
{
std::string topic = std::string("~/") + this->modelName + "/" +
this->contactSensorName;
this->contactSub =
this->node->Subscribe(topic, &MudPlugin::OnContact, this);
// create bitmask from contact sensor's collisions if it's not specified in
// the sdf
if (!this->sdf->HasElement("contact_surface_bitmask"))
{
std::string name = this->contactSensorName;
boost::replace_all(name, "/", "::");
name = this->world->GetName() + "::"+ this->modelName + "::" + name;
sensors::SensorManager *mgr = sensors::SensorManager::Instance();
// Get a pointer to the contact sensor
sensors::ContactSensorPtr sensor =
std::dynamic_pointer_cast<sensors::ContactSensor>
(mgr->GetSensor(name));
if (sensor)
{
for (unsigned int i = 0; i < sensor->GetCollisionCount(); ++i)
{
std::string colName = sensor->GetCollisionName(i);
physics::CollisionPtr colPtr =
boost::dynamic_pointer_cast<physics::Collision>(
this->world->GetEntity(colName));
if (colPtr)
{
this->contactSurfaceBitmask |=
colPtr->GetSurface()->collideWithoutContactBitmask;
}
}
}
else
{
gzerr << "Unable to GetSensor, ignoring contact_surface_bitmask\n";
}
}
}
for (unsigned int i = 0; i < this->allowedLinks.size(); ++i)
{
physics::LinkPtr allowedLink = boost::dynamic_pointer_cast<physics::Link>(
this->world->GetEntity(this->allowedLinks[i]));
if (!allowedLink)
continue;
std::vector<physics::CollisionPtr> collisions
= allowedLink->GetCollisions();
for (unsigned int j = 0; j < collisions.size(); ++j)
{
collisions[j]->GetSurface()->collideWithoutContactBitmask |=
this->contactSurfaceBitmask;
}
}
this->updateConnection = event::Events::ConnectWorldUpdateBegin(
std::bind(&MudPlugin::OnUpdate, this));
}
/////////////////////////////////////////////////
void MudPlugin::OnContact(ConstContactsPtr &_msg)
{
boost::mutex::scoped_lock lock(this->mutex);
this->newestContactsMsg = *_msg;
this->newMsg = true;
}
/////////////////////////////////////////////////
void MudPlugin::OnUpdate()
{
double dt = this->physics->GetMaxStepSize();
if (dt < 1e-6)
dt = 1e-6;
if (this->newMsg)
{
boost::mutex::scoped_lock lock(this->mutex);
unsigned int nc = this->newestContactsMsg.contact_size();
boost::unordered_set<std::string> contactLinkNames;
boost::unordered_map<std::string, unsigned int> linkNameIndices;
// If new contacts, then get the link names
if (nc)
{
// Starting with last contact message, iterate backwards
// checking each contact with a timestamp matching the last contact
// Add each link name to contactLinkNames
common::Time latestContactTime =
msgs::Convert(this->newestContactsMsg.contact(nc-1).time());
std::string targetCollName, tmpLinkName;
for (int i = nc-1; i >= 0 &&
msgs::Convert(this->newestContactsMsg.contact(i).time())
== latestContactTime; --i)
{
// Try to find name of the other collision
// If collision1() starts with this->modelName, then use collision2()
targetCollName = this->newestContactsMsg.contact(i).collision1();
if (0 == targetCollName.compare(0, this->modelName.length(),
targetCollName))
{
targetCollName = this->newestContactsMsg.contact(i).collision2();
}
tmpLinkName = targetCollName.substr(0,
targetCollName.rfind("::"));
contactLinkNames.insert(tmpLinkName);
linkNameIndices[tmpLinkName] = i;
}
}
// Iterate through the list of allowed links
std::vector<std::string>::iterator iterLinkName =
this->allowedLinks.begin();
std::vector<physics::LinkPtr>::iterator iterLink = this->links.begin();
std::vector<physics::JointPtr>::iterator iterJoint = this->joints.begin();
unsigned int countIters = 0;
// Only check the length of the first iterator since we used a GZ_ASSERT
// in the Load function to confirm the vectors have the same length
while (iterLinkName != this->allowedLinks.end())
{
// If *iterLinkName is in contactLinkNames
if (contactLinkNames.end() != contactLinkNames.find(*iterLinkName))
{
// Compute the average contact point position
math::Vector3 contactPositionAverage;
{
// Find the index to the correct contact data structure
unsigned int i = linkNameIndices[*iterLinkName];
if (i < nc)
{
unsigned int pc =
this->newestContactsMsg.contact(i).position_size();
// Add up all the contact point positions
for (unsigned int j = 0; j < pc; ++j)
{
contactPositionAverage +=
msgs::ConvertIgn(
this->newestContactsMsg.contact(i).position(j));
}
// Then divide by numer of contact points
contactPositionAverage /= static_cast<double>(pc);
}
else
{
gzerr << "Error in linkNameIndices\n";
}
}
// If joint exists
if (*iterJoint)
{
// Update the anchor position
// TODO: consider checking MaxStepSize and updating erp, cfm
(*iterJoint)->SetAnchor(0, contactPositionAverage);
}
// Otherwise, try to create a joint
else
{
// Try to get link pointer if we don't already have it
if (!(*iterLink))
{
std::string targetModelName = (*iterLinkName).substr(0,
(*iterLinkName).rfind("::"));
physics::ModelPtr targetModel =
this->world->GetModel(targetModelName);
if (targetModel)
*iterLink = targetModel->GetLink(*iterLinkName);
}
if (*iterLink)
{
// Create the joint
// gzdbg << "Creating a mud joint with " << *iterLinkName << '\n';
(*iterLink)->SetAutoDisable(false);
*iterJoint = this->physics->CreateJoint("revolute", this->model);
(*iterJoint)->Attach(this->link, *iterLink);
(*iterJoint)->Load(this->link, *iterLink,
math::Pose(contactPositionAverage, math::Quaternion()));
// Joint names must be unique
// name as mud_joint_0, mud_joint_1, etc.
{
std::stringstream jointNameStream;
jointNameStream << "mud_joint_" << countIters;
(*iterJoint)->SetName(jointNameStream.str());
}
{
double erp, cfm;
erp = this->stiffness*dt / (this->stiffness*dt + this->damping);
cfm = 1.0 / (this->stiffness*dt + this->damping);
(*iterJoint)->SetParam("erp", 0, erp);
(*iterJoint)->SetParam("cfm", 0, cfm);
(*iterJoint)->SetParam("stop_erp", 0, erp);
(*iterJoint)->SetParam("stop_cfm", 0, cfm);
}
(*iterJoint)->SetHighStop(0, 0.0);
(*iterJoint)->SetLowStop(0, 0.0);
(*iterJoint)->Init();
}
}
}
// *iterLinkName is not in contactLinkNames
else
{
// If there's an existing joint,
// then delete the joint
if (*iterJoint)
{
// gzdbg << "Destroying mud joint\n";
// reenable collision between the link pair
physics::LinkPtr parent = (*iterJoint)->GetParent();
physics::LinkPtr child = (*iterJoint)->GetChild();
if (parent)
parent->SetCollideMode("all");
if (child)
child->SetCollideMode("all");
(*iterJoint)->Detach();
(*iterJoint).reset();
}
}
// Increment
++countIters;
++iterJoint;
++iterLink;
++iterLinkName;
}
this->newMsg = false;
this->newMsgWait = 0;
}
else if (++this->newMsgWait > floor(1.0 / dt))
{
gzlog << "MudPlugin attached to " << this->modelName
<< " waited 1.0 s without contact messages\n";
this->newMsgWait = 0;
}
}