kinton_arm_tag_tracker_alg_node.cpp

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#include "kinton_arm_tag_tracker_alg_node.h"

using namespace KDL;
using namespace Eigen;
using namespace std;

KintonArmTagTrackerAlgNode::KintonArmTagTrackerAlgNode(void) :
  algorithm_base::IriBaseAlgorithm<KintonArmTagTrackerAlgorithm>()
{
  //init class attributes if necessary
  this->loop_rate_ = 2;//in [Hz]

  this->time_ = ros::Time::now();

  this->cam_vel_ = MatrixXd::Zero(6,1);

  this->num_joints_ = 0;
  this->cam_vel_ok_ = false;

  this->T_endeff_ = Matrix4d::Zero();
  this->T_endeff_.block(0,0,3,3) = Matrix3d::Identity();
  this->T_endeff_(3,3) = 1.0;

  ros::NodeHandle nh;
 
  string tip_name, root_name;
  string xml_string;
  Tree tree;   
  string urdf_xml,full_urdf_xml;
  nh.param("urdf_xml",urdf_xml,string("robot_description"));
  nh.searchParam(urdf_xml,full_urdf_xml);      
  ROS_DEBUG("Reading xml file from parameter server\n");
  if (!nh.getParam(full_urdf_xml, xml_string)){
    ROS_ERROR("Could not load the xml from parameter server: %s\n", urdf_xml.c_str());
  }
  if (!nh.getParam("root_name", root_name)){
    ROS_ERROR("No root name found on parameter server");
  }
  if (!nh.getParam("tip_name", tip_name)){
    ROS_ERROR("No tip name found on parameter server");
  }
  if (!kdl_parser::treeFromString(xml_string, tree)){
    ROS_ERROR("Could not initialize tree object");
  }
  if (!tree.getChain(root_name, tip_name, this->kdl_chain_)){
    ROS_ERROR("Could not initialize kdl_chain object");
  }

  // [init publishers]
  this->output_publisher_ = this->public_node_handle_.advertise<sensor_msgs::JointState>("output", 10);
  
  // [init subscribers]
  this->input_subscriber_ = this->public_node_handle_.subscribe("input", 10, &KintonArmTagTrackerAlgNode::input_callback, this);
  
  // [init services]
  
  // [init clients]
  
  // [init action servers]
  
  // [init action clients]
}

KintonArmTagTrackerAlgNode::~KintonArmTagTrackerAlgNode(void)
{
  // [free dynamic memory]
}

void KintonArmTagTrackerAlgNode::mainNodeThread(void)
{

  // Initialize arm and time
  if (this->init_)
  {
    this->time_last_=this->time_;
    init_arm();
    this->init_=false;
  }

  this->dt_=(this->time_-this->time_last_).toSec(); 

  if (this->cam_vel_ok_ && this->activate_){
    // Get current end-effector transform to get positions of the robot
    this->alg_.lock();          
    this->tag_tracker_.tag_tracker(this->cam_vel_,this->kdl_chain_,this->dt_,this->q_);
    this->alg_.unlock();   
  }
  else 
  {
    this->init_ = true; 
  }

  // [fill msg structures]
  //this->JointState_msg_.data = my_var;

  // fill arm joints message
  for (int s=0; s<this->num_joints_; ++s){
    this->JointState_msg_.position[s]=this->q_(s,0);
    this->JointState_msg_.velocity[s]=0.0;
    this->JointState_msg_.effort[s]=10;
  }    

  this->time_last_ = this->time_;

  // [fill msg structures]
  //this->JointState_msg_.data = my_var;
  
  // [fill srv structure and make request to the server]
  
  // [fill action structure and make request to the action server]

  // [publish messages]
  this->output_publisher_.publish(this->JointState_msg_);
}

/*  [subscriber callbacks] */
void KintonArmTagTrackerAlgNode::input_callback(const geometry_msgs::TwistWithCovariance::ConstPtr& msg) 
{ 
  //ROS_INFO("KintonArmTagTrackerAlgNode::input_callback: New Message Received"); 

  //use appropiate mutex to shared variables if necessary 
  //this->alg_.lock(); 
  this->input_mutex_.enter(); 

  this->cam_vel_ = MatrixXd::Zero(6,1);

  if (msg->covariance[0]<1000 && this->activate_)
  {
    //To drive the quadrotor, the twist on x and y will be achieved by pitch and roll movements respectively
    //thus both linear velocities should be exchanged
    this->cam_vel_(0,0) = msg->twist.linear.x;
    this->cam_vel_(1,0) = msg->twist.linear.y;
    this->cam_vel_(2,0) = msg->twist.linear.z;
    this->cam_vel_(3,0) = msg->twist.angular.x;
    this->cam_vel_(4,0) = msg->twist.angular.y;
    this->cam_vel_(5,0) = msg->twist.angular.z;

    this->cam_vel_ok_ = true;
  }
  else
  {
    this->cam_vel_ok_ = false;
  } 

  this->time_ = ros::Time::now();

  //std::cout << msg->data << std::endl; 

  //unlock previously blocked shared variables 
  //this->alg_.unlock(); 
  this->input_mutex_.exit(); 
}

void KintonArmTagTrackerAlgNode::init_arm()
{

    this->num_joints_=5;
    this->JointState_msg_.header.stamp=ros::Time::now();
    this->JointState_msg_.header.frame_id="";
    this->JointState_msg_.name.resize(this->num_joints_);
    this->JointState_msg_.position.resize(this->num_joints_);
    this->JointState_msg_.velocity.resize(this->num_joints_);
    this->JointState_msg_.effort.resize(this->num_joints_);
    this->JointState_msg_.name[0]="joint1";
    this->JointState_msg_.name[1]="joint2";
    this->JointState_msg_.name[2]="joint3";
    this->JointState_msg_.name[3]="joint4";
    this->JointState_msg_.name[4]="joint5";
    this->q_ = MatrixXd::Zero(this->num_joints_,1);
    this->q_ << 90, 160, 180, 20, 90;
}


/*  [service callbacks] */

/*  [action callbacks] */

/*  [action requests] */

void KintonArmTagTrackerAlgNode::node_config_update(Config &config, uint32_t level)
{
  this->alg_.lock();
  this->activate_=config.activate;
  this->alg_.unlock();
}

void KintonArmTagTrackerAlgNode::addNodeDiagnostics(void)
{
}

/* main function */
int main(int argc,char *argv[])
{
  return algorithm_base::main<KintonArmTagTrackerAlgNode>(argc, argv, "kinton_arm_tag_tracker_alg_node");
}