segway_rmp200_odom_alg_node.cpp

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#include "segway_rmp200_odom_alg_node.h"

SegwayRmp200OdomAlgNode::SegwayRmp200OdomAlgNode(void) :
  algorithm_base::IriBaseAlgorithm<SegwayRmp200OdomAlgorithm>()
{
  //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<std::string>("base_footprint_id", this->base_footprint_id_, "base_footprint" );
  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_;
    this->base_footprint_id_ = this->tf_prefix_ + "/" + this->base_footprint_id_;
  }

  // [init publishers]
  this->odom_publisher_ = this->public_node_handle_.advertise<nav_msgs::Odometry>("odom", 100);
  
  // [init subscribers]
  this->segway_status_subscriber_ = this->public_node_handle_.subscribe("segway_status", 100, &SegwayRmp200OdomAlgNode::segway_status_callback, this);
  
  // [init services]
  
  // [init clients]
  
  // [init action servers]
  
  // [init action clients]
}

SegwayRmp200OdomAlgNode::~SegwayRmp200OdomAlgNode(void)
{
  // [free dynamic memory]
}

void SegwayRmp200OdomAlgNode::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 accum_th=0;

  //compute differencial
  double dt = (current_time - last_time).toSec();
  this->segway_status_mutex_.enter(); 
  accum_th = this->status.yaw_displacement;

  //get current translational velocity and component velocities
  double vT  = (this->status.left_wheel_velocity + this->status.right_wheel_velocity)/2;
  double vx  = vT*cos(accum_th);
  double vy  = vT*sin(accum_th);

  //update position
  double delta_x  = vx*dt;
  double delta_y  = vy*dt;

  // [fill msg structures]
  //since all odometry is 6DOF we'll need a quaternion created from yaw
  geometry_msgs::Quaternion odom_quat = tf::createQuaternionMsgFromYaw(accum_th);
  geometry_msgs::Quaternion odom_quat_pitch = tf::createQuaternionMsgFromRollPitchYaw(0.0,this->status.pitch_angle,0.0);

  //update transform message
  this->transform_.translation.x += delta_x;
  this->transform_.translation.y += delta_y;
  this->transform_.translation.z += 0.0;
  this->transform_.rotation       = odom_quat;
  
  //update transform pitch message
  this->transform_pitch_.translation.x = 0.0;
  this->transform_pitch_.translation.y = 0.0;
  this->transform_pitch_.translation.z = 0.23;
  this->transform_pitch_.rotation       = odom_quat_pitch;

  //update pose
  this->pose_.pose.position.x += delta_x;
  this->pose_.pose.position.y += delta_y;
  this->pose_.pose.position.z += 0.0;
  this->pose_.pose.orientation = odom_quat;

  //update twist
  this->twist_.twist.linear.x  = vT;
  this->twist_.twist.linear.y  = 0.0;
  this->twist_.twist.linear.z  = 0.0;
  this->twist_.twist.angular.x = this->status.roll_rate;
  this->twist_.twist.angular.y = this->status.pitch_rate;
  this->twist_.twist.angular.z = -this->status.yaw_rate;
  this->segway_status_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_footprint_id_;
    odom_trans_msg.transform       = this->transform_;
    this->odom_broadcaster_.sendTransform(odom_trans_msg);
    
    odom_trans_msg.header.stamp    = current_time;
    odom_trans_msg.header.frame_id = this->base_footprint_id_;
    odom_trans_msg.child_frame_id  = this->base_link_id_;
    odom_trans_msg.transform       = this->transform_pitch_;
    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_footprint_id_;
  this->Odometry_msg_.pose             = this->pose_;
  this->Odometry_msg_.twist            = this->twist_;

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

  //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 SegwayRmp200OdomAlgNode::segway_status_callback(const iri_segway_rmp_msgs::SegwayRMP200Status::ConstPtr& msg) 
{ 
  //ROS_INFO("SegwayRmp200OdomAlgNode::segway_status_callback: New Message Received"); 

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

  //std::cout << msg->data << std::endl; 
  this->status.pitch_angle=msg->pitch_angle;
  this->status.pitch_rate=msg->pitch_rate;
  this->status.roll_angle=msg->roll_angle;
  this->status.roll_rate=msg->roll_rate;
  this->status.left_wheel_velocity=msg->left_wheel_velocity;
  this->status.right_wheel_velocity=msg->right_wheel_velocity;
  this->status.yaw_rate=msg->yaw_rate;
  this->status.uptime=msg->uptime;
  this->status.left_wheel_displacement=msg->left_wheel_displacement;
  this->status.right_wheel_displacement=msg->right_wheel_displacement;
  this->status.forward_displacement=msg->forward_displacement;
  this->status.yaw_displacement=msg->yaw_displacement;
  this->status.left_motor_torque=msg->left_motor_torque;
  this->status.right_motor_torque=msg->right_motor_torque;
  this->status.operation_mode=msg->operation_mode;
  this->status.gain_schedule=msg->gain_schedule;
  this->status.ui_battery=msg->ui_battery;
  this->status.powerbase_battery=msg->powerbase_battery;

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

/*  [service callbacks] */

/*  [action callbacks] */

/*  [action requests] */

void SegwayRmp200OdomAlgNode::node_config_update(Config &config, uint32_t level)
{
  this->alg_.lock();

  this->alg_.unlock();
}

void SegwayRmp200OdomAlgNode::addNodeDiagnostics(void)
{
}

/* main function */
int main(int argc,char *argv[])
{
  return algorithm_base::main<SegwayRmp200OdomAlgNode>(argc, argv, "segway_rmp200_odom_alg_node");
}