current_state_monitor.cpp

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/* Author: Ioan Sucan */

#include <moveit/planning_scene_monitor/current_state_monitor.h>
#include <tf_conversions/tf_eigen.h>
#include <limits>

planning_scene_monitor::CurrentStateMonitor::CurrentStateMonitor(const robot_model::RobotModelConstPtr &robot_model, const boost::shared_ptr<tf::Transformer> &tf)
  : tf_(tf)
  , robot_model_(robot_model)
  , robot_state_(robot_model)
  , state_monitor_started_(false)
  , error_(std::numeric_limits<float>::epsilon())
{
  robot_state_.setToDefaultValues();
}

planning_scene_monitor::CurrentStateMonitor::~CurrentStateMonitor()
{
  stopStateMonitor();
}

robot_state::RobotStatePtr planning_scene_monitor::CurrentStateMonitor::getCurrentState() const
{
  boost::mutex::scoped_lock slock(state_update_lock_);
  robot_state::RobotState *result = new robot_state::RobotState(robot_state_);
  return robot_state::RobotStatePtr(result);
}

ros::Time planning_scene_monitor::CurrentStateMonitor::getCurrentStateTime() const
{
  boost::mutex::scoped_lock slock(state_update_lock_);
  return current_state_time_;
}

std::pair<robot_state::RobotStatePtr, ros::Time> planning_scene_monitor::CurrentStateMonitor::getCurrentStateAndTime() const
{
  boost::mutex::scoped_lock slock(state_update_lock_);
  robot_state::RobotState *result = new robot_state::RobotState(robot_state_);
  return std::make_pair(robot_state::RobotStatePtr(result), current_state_time_);
}

std::map<std::string, double> planning_scene_monitor::CurrentStateMonitor::getCurrentStateValues() const
{
  std::map<std::string, double> m;
  boost::mutex::scoped_lock slock(state_update_lock_);
  const double *pos = robot_state_.getVariablePositions();
  const std::vector<std::string> &names = robot_state_.getVariableNames();
  for (std::size_t i = 0 ; i < names.size() ; ++i)
    m[names[i]] = pos[i];
  return m;
}

void planning_scene_monitor::CurrentStateMonitor::setToCurrentState(robot_state::RobotState &upd) const
{
  boost::mutex::scoped_lock slock(state_update_lock_);
  const double *pos = robot_state_.getVariablePositions();
  upd.setVariablePositions(pos);
}

void planning_scene_monitor::CurrentStateMonitor::addUpdateCallback(const JointStateUpdateCallback &fn)
{
  if (fn)
    update_callbacks_.push_back(fn);
}

void planning_scene_monitor::CurrentStateMonitor::clearUpdateCallbacks()
{
  update_callbacks_.clear();
}

void planning_scene_monitor::CurrentStateMonitor::startStateMonitor(const std::string &joint_states_topic)
{
  if (!state_monitor_started_ && robot_model_)
  {
    joint_time_.clear();
    if (joint_states_topic.empty())
      ROS_ERROR("The joint states topic cannot be an empty string");
    else
      joint_state_subscriber_ = nh_.subscribe(joint_states_topic, 25, &CurrentStateMonitor::jointStateCallback, this);
    state_monitor_started_ = true;
    monitor_start_time_ = ros::Time::now();
    ROS_DEBUG("Listening to joint states on topic '%s'", nh_.resolveName(joint_states_topic).c_str());
  }
}

bool planning_scene_monitor::CurrentStateMonitor::isActive() const
{
  return state_monitor_started_;
}

void planning_scene_monitor::CurrentStateMonitor::stopStateMonitor()
{
  if (state_monitor_started_)
  {
    joint_state_subscriber_.shutdown();
    ROS_DEBUG("No longer listening o joint states");
    state_monitor_started_ = false;
  }
}

std::string planning_scene_monitor::CurrentStateMonitor::getMonitoredTopic() const
{
  if (joint_state_subscriber_)
    return joint_state_subscriber_.getTopic();
  else
    return "";
}

bool planning_scene_monitor::CurrentStateMonitor::isPassiveDOF(const std::string &dof) const
{
  if (robot_model_->hasJointModel(dof))
  {
    if (robot_model_->getJointModel(dof)->isPassive())
      return true;
  }
  else
  {
    // check if this DOF is part of a multi-dof passive joint
    std::size_t slash = dof.find_last_of("/");
    if (slash != std::string::npos)
    {
      std::string joint_name = dof.substr(0, slash);
      if (robot_model_->hasJointModel(joint_name))
        if (robot_model_->getJointModel(joint_name)->isPassive())
          return true;
    }
  }
  return false;
}

bool planning_scene_monitor::CurrentStateMonitor::haveCompleteState() const
{
  bool result = true;
  const std::vector<std::string> &dof = robot_model_->getVariableNames();
  boost::mutex::scoped_lock slock(state_update_lock_);
  for (std::size_t i = 0 ; i < dof.size() ; ++i)
    if (joint_time_.find(dof[i]) == joint_time_.end())
    {
      if (!isPassiveDOF(dof[i]))
      {
        ROS_DEBUG("Joint variable '%s' has never been updated", dof[i].c_str());
        result = false;
      }
    }
  return result;
}

bool planning_scene_monitor::CurrentStateMonitor::haveCompleteState(std::vector<std::string> &missing_states) const
{
  bool result = true;
  const std::vector<std::string> &dof = robot_model_->getVariableNames();
  boost::mutex::scoped_lock slock(state_update_lock_);
  for (std::size_t i = 0 ; i < dof.size() ; ++i)
    if (joint_time_.find(dof[i]) == joint_time_.end())
      if (!isPassiveDOF(dof[i]))
      {
        missing_states.push_back(dof[i]);
        result = false;
      }
  return result;
}

bool planning_scene_monitor::CurrentStateMonitor::haveCompleteState(const ros::Duration &age) const
{
  bool result = true;
  const std::vector<std::string> &dof = robot_model_->getVariableNames();
  ros::Time now = ros::Time::now();
  ros::Time old = now - age;
  boost::mutex::scoped_lock slock(state_update_lock_);
  for (std::size_t i = 0 ; i < dof.size() ; ++i)
  {
    if (isPassiveDOF(dof[i]))
      continue;
    std::map<std::string, ros::Time>::const_iterator it = joint_time_.find(dof[i]);
    if (it == joint_time_.end())
    {
      ROS_DEBUG("Joint variable '%s' has never been updated", dof[i].c_str());
      result = false;
    }
    else
      if (it->second < old)
      {
        ROS_DEBUG("Joint variable '%s' was last updated %0.3lf seconds ago (older than the allowed %0.3lf seconds)",
                  dof[i].c_str(), (now - it->second).toSec(), age.toSec());
        result = false;
      }
  }
  return result;
}

bool planning_scene_monitor::CurrentStateMonitor::haveCompleteState(const ros::Duration &age,
                                                                    std::vector<std::string> &missing_states) const
{
  bool result = true;
  const std::vector<std::string> &dof = robot_model_->getVariableNames();
  ros::Time now = ros::Time::now();
  ros::Time old = now - age;
  boost::mutex::scoped_lock slock(state_update_lock_);
  for (std::size_t i = 0 ; i < dof.size() ; ++i)
  {
    if (isPassiveDOF(dof[i]))
      continue;
    std::map<std::string, ros::Time>::const_iterator it = joint_time_.find(dof[i]);
    if (it == joint_time_.end())
    {
      ROS_DEBUG("Joint variable '%s' has never been updated", dof[i].c_str());
      missing_states.push_back(dof[i]);
      result = false;
    }
    else
      if (it->second < old)
      {
        ROS_DEBUG("Joint variable '%s' was last updated %0.3lf seconds ago (older than the allowed %0.3lf seconds)",
                  dof[i].c_str(), (now - it->second).toSec(), age.toSec());
        missing_states.push_back(dof[i]);
        result = false;
      }
  }
  return result;
}

bool planning_scene_monitor::CurrentStateMonitor::waitForCurrentState(double wait_time) const
{
  double slept_time = 0.0;
  double sleep_step_s = std::min(0.05, wait_time / 10.0);
  ros::Duration sleep_step(sleep_step_s);
  while (!haveCompleteState() && slept_time < wait_time)
  {
    sleep_step.sleep();
    slept_time += sleep_step_s;
  }
  return haveCompleteState();
}

bool planning_scene_monitor::CurrentStateMonitor::waitForCurrentState(const std::string &group, double wait_time) const
{
  if (waitForCurrentState(wait_time))
    return true;
  bool ok = true;

  // check to see if we have a fully known state for the joints we want to record
  std::vector<std::string> missing_joints;
  if (!haveCompleteState(missing_joints))
  {
    const robot_model::JointModelGroup *jmg = robot_model_->getJointModelGroup(group);
    if (jmg)
    {
      std::set<std::string> mj;
      mj.insert(missing_joints.begin(), missing_joints.end());
      const std::vector<std::string> &names= jmg->getJointModelNames();
      bool ok = true;
      for (std::size_t i = 0 ; ok && i < names.size() ; ++i)
        if (mj.find(names[i]) != mj.end())
          ok = false;
    }
    else
      ok = false;
  }
  return ok;
}

void planning_scene_monitor::CurrentStateMonitor::jointStateCallback(const sensor_msgs::JointStateConstPtr &joint_state)
{
  if (joint_state->name.size() != joint_state->position.size())
  {
    ROS_ERROR_THROTTLE(1, "State monitor received invalid joint state (number of joint names does not match number of positions)");
    return;
  }
  bool update = false;
  
  {    
    boost::mutex::scoped_lock _(state_update_lock_);
    // read the received values, and update their time stamps
    std::size_t n = joint_state->name.size();
    current_state_time_ = joint_state->header.stamp;
    for (std::size_t i = 0 ; i < n ; ++i)
    {
      const robot_model::JointModel* jm = robot_model_->getJointModel(joint_state->name[i]);
      if (!jm)
        continue;
      // ignore fixed joints, multi-dof joints (they should not even be in the message)
      if (jm->getVariableCount() != 1)
        continue;

      joint_time_[joint_state->name[i]] = joint_state->header.stamp;

      if (robot_state_.getJointPositions(jm)[0] != joint_state->position[i])
      {
        update = true;
        robot_state_.setJointPositions(jm, &(joint_state->position[i]));
        
        // continuous joints wrap, so we don't modify them (even if they are outside bounds!)
        if (jm->getType() == robot_model::JointModel::REVOLUTE)
          if (static_cast<const robot_model::RevoluteJointModel*>(jm)->isContinuous())
            continue;
        
        const robot_model::VariableBounds &b = jm->getVariableBounds()[0]; // only one variable in the joint, so we get its bounds
        
        // if the read variable is 'almost' within bounds (up to error_ difference), then consider it to be within bounds
        if (joint_state->position[i] < b.min_position_ && joint_state->position[i] >= b.min_position_ - error_)
          robot_state_.setJointPositions(jm, &b.min_position_);
        else
          if (joint_state->position[i] > b.max_position_ && joint_state->position[i] <= b.max_position_ + error_)
            robot_state_.setJointPositions(jm, &b.max_position_);
      }
    }
    
    // read root transform, if needed
    if (tf_ && (robot_model_->getRootJoint()->getType() == robot_model::JointModel::PLANAR ||
                robot_model_->getRootJoint()->getType() == robot_model::JointModel::FLOATING))
    {
      const std::string &child_frame = robot_model_->getRootLink()->getName();
      const std::string &parent_frame = robot_model_->getModelFrame();
      
      std::string err;
      ros::Time tm;
      tf::StampedTransform transf;
      bool ok = false;
      if (tf_->getLatestCommonTime(parent_frame, child_frame, tm, &err) == tf::NO_ERROR)
      {
        try
        {
          tf_->lookupTransform(parent_frame, child_frame, tm, transf);
          ok = true;
        }
        catch(tf::TransformException& ex)
        {
          ROS_ERROR_THROTTLE(1, "Unable to lookup transform from %s to %s.  Exception: %s", parent_frame.c_str(), child_frame.c_str(), ex.what());
        }
      }
      else
        ROS_DEBUG_THROTTLE(1, "Unable to lookup transform from %s to %s: no common time.", parent_frame.c_str(), child_frame.c_str());
      if (ok && last_tf_update_ != tm)
      {
        update = true;
        last_tf_update_ = tm;
        const std::vector<std::string> &vars = robot_model_->getRootJoint()->getVariableNames();
        for (std::size_t j = 0; j < vars.size() ; ++j)
          joint_time_[vars[j]] = tm;
        Eigen::Affine3d eigen_transf;
        tf::transformTFToEigen(transf, eigen_transf);
        robot_state_.setJointPositions(robot_model_->getRootJoint(), eigen_transf);        
      }
    }
  }
  
  // callbacks, if needed
  if (update)
    for (std::size_t i = 0 ; i < update_callbacks_.size() ; ++i)
      update_callbacks_[i](joint_state);
}