darwin_odom_alg_node.cpp

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#include "darwin_odom_alg_node.h"

DarwinOdomAlgNode::DarwinOdomAlgNode(void) :
  algorithm_base::IriBaseAlgorithm<DarwinOdomAlgorithm>()
{
  //init class attributes if necessary
  this->loop_rate_ = 100;//in [Hz]

  this->public_node_handle_.param<std::string>("tf_prefix",    this->tf_prefix_,    "");
  this->public_node_handle_.param<std::string>("odom_id",      this->odom_id_,      "odom" );
  this->public_node_handle_.param<std::string>("base_link_id", this->base_link_id_, "base_link" );
  this->public_node_handle_.param<bool>       ("publish_tf",   this->publish_tf_,   true  );

  // push down frame ids if necessary
  if( this->tf_prefix_.size()!=0 )
  {
    this->odom_id_      = this->tf_prefix_ + "/" + this->odom_id_;
    this->base_link_id_ = this->tf_prefix_ + "/" + this->base_link_id_;
  }

  // [init publishers]
  this->odom_publisher_ = this->public_node_handle_.advertise<nav_msgs::Odometry>("odom", 100);
  
  // [init subscribers]
  this->darwin_imu_subscriber_ = this->public_node_handle_.subscribe("darwin_imu", 100, &DarwinOdomAlgNode::darwin_imu_callback, this);
  
  // [init services]
  
  // [init clients]
  
  // [init action servers]
  
  // [init action clients]
}

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

void DarwinOdomAlgNode::mainNodeThread(void)
{
  ros::Time current_time = ros::Time::now();
  geometry_msgs::TransformStamped odom_trans_msg;
  static ros::Time last_time = ros::Time::now();
  static double yaw_angle=0.0,pitch_angle=0.0,roll_angle=0.0;
  //compute differencial
  double dt = (current_time - last_time).toSec();

  // compute the orientation angles
  this->darwin_imu_mutex_.enter(); 
  yaw_angle+=this->status.angular_velocity.z*dt;
  pitch_angle+=this->status.angular_velocity.y*dt;
  roll_angle+=this->status.angular_velocity.x*dt;

  //since all odometry is 6DOF we'll need a quaternion created from yaw
  geometry_msgs::Quaternion odom_quat = tf::createQuaternionMsgFromRollPitchYaw(roll_angle,pitch_angle,yaw_angle);

  //update transform message
  transform_.translation.x += twist_.twist.linear.x*dt;
  transform_.translation.y += twist_.twist.linear.y*dt;
  transform_.translation.z += twist_.twist.linear.z*dt;
  transform_.rotation       = odom_quat;

  //update pose
  pose_.pose.position.x += twist_.twist.linear.x*dt;
  pose_.pose.position.y += twist_.twist.linear.y*dt;
  pose_.pose.position.z += twist_.twist.linear.z*dt;
  pose_.pose.orientation = odom_quat;

  //update twist
  twist_.twist.linear.x  += this->status.linear_acceleration.x*dt;
  twist_.twist.linear.y  += this->status.linear_acceleration.y*dt;
  twist_.twist.linear.z  += this->status.linear_acceleration.z*dt;
  twist_.twist.angular.x = this->status.angular_velocity.x;
  twist_.twist.angular.y = this->status.angular_velocity.y;
  twist_.twist.angular.z = this->status.angular_velocity.z;
  this->darwin_imu_mutex_.exit(); 

  //update last time
  last_time = current_time;

  //send the transform
  if(this->publish_tf_)
  {
    //first, we'll publish the transform over tf
    odom_trans_msg.header.stamp    = current_time;
    odom_trans_msg.header.frame_id = this->odom_id_;
    odom_trans_msg.child_frame_id  = this->base_link_id_;
    odom_trans_msg.transform       = this->transform_;

    this->odom_broadcaster_.sendTransform(odom_trans_msg);
  }

  //next, we'll publish the odometry message over ROS
  this->Odometry_msg_.header.stamp     = current_time;
  this->Odometry_msg_.header.frame_id  = this->odom_id_;
  this->Odometry_msg_.child_frame_id   = this->base_link_id_;
  this->Odometry_msg_.pose             = this->pose_;
  this->Odometry_msg_.twist            = this->twist_;

  // [publish messages]
  this->odom_publisher_.publish(this->Odometry_msg_);

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

/*  [subscriber callbacks] */
void DarwinOdomAlgNode::darwin_imu_callback(const sensor_msgs::Imu::ConstPtr& msg) 
{ 
  ROS_INFO("DarwinOdomAlgNode::darwin_imu_callback: New Message Received"); 

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

  //std::cout << msg->data << std::endl; 
  this->status=*msg;

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

/*  [service callbacks] */

/*  [action callbacks] */

/*  [action requests] */

void DarwinOdomAlgNode::node_config_update(Config &config, uint32_t level)
{
  this->alg_.lock();

  this->alg_.unlock();
}

void DarwinOdomAlgNode::addNodeDiagnostics(void)
{
}

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