robchair_node.cpp

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* Author: Gonçalo Cabrita on 28/05/2012
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#include <ros/ros.h>
#include <tf/transform_broadcaster.h>
#include <nav_msgs/Odometry.h>                  // odom
#include <geometry_msgs/Twist.h>                // cmd_vel

#include "RobChair.h"

RobChair robot;

void cmdVelReceived(const geometry_msgs::Twist::ConstPtr& cmd_vel)
{
    robot.setVelocities(cmd_vel->linear.x, cmd_vel->angular.z);
}


int main(int argc, char** argv)
{
        ros::init(argc, argv, "robchair_node");

        ROS_INFO("RobChair for ROS");

    ros::NodeHandle n;
        ros::NodeHandle pn("~");
        
        tf::TransformBroadcaster odom_broadcaster;
        
        ros::Publisher odom_pub = n.advertise<nav_msgs::Odometry>("/odom", 50);
        ros::Subscriber cmd_vel_sub = n.subscribe<geometry_msgs::Twist>("/cmd_vel", 10, cmdVelReceived);
    
    ros::Publisher tx_pub = n.advertise<can_msgs::CANFrame>("/can_bus_tx", 10);
    ros::Subscriber rx_sub = n.subscribe<can_msgs::CANFrame>("/can_bus_rx", 10, &RobChair::receivedCANFrame, &robot);
    
    // PI parameters...
    // If we defined Kp and Ki set them
    double kp, ki;
        if(pn.getParam("kp", kp) && pn.getParam("ki", ki))
    {
        ROS_INFO("RobChair -- Setting new PI gains.");
        robot.initializeRobChair(&tx_pub, kp, ki);
    }
    // Otherwise go with default values
    else
    {
        robot.initializeRobChair(&tx_pub);
    }
    
        ros::Time current_time;
        
        ros::Rate r(50.0);
        while(n.ok())
        {
        current_time = ros::Time::now();
        
        float odom_x = robot.getPositionX();
        float odom_y = robot.getPositionY();
        float odom_yaw = robot.getYaw();
                
                // Since all odometry is 6DOF we'll need a quaternion created from yaw
                geometry_msgs::Quaternion odom_quat = tf::createQuaternionMsgFromYaw(odom_yaw);
                
                // First, we'll publish the transform over tf
                geometry_msgs::TransformStamped odom_trans;
                odom_trans.header.stamp = current_time;
                odom_trans.header.frame_id = "/odom";
                odom_trans.child_frame_id = "/base_link";
                
                odom_trans.transform.translation.x = odom_x;
                odom_trans.transform.translation.y = odom_y;
                odom_trans.transform.rotation = odom_quat;
                
                // Send the transform
                odom_broadcaster.sendTransform(odom_trans);
                
                // Next, we'll publish the odometry message over ROS
                nav_msgs::Odometry odom;
                odom.header.stamp = current_time;
                odom.header.frame_id = "/odom";
                
                // Set the position
                odom.pose.pose.position.x = odom_x;
                odom.pose.pose.position.y = odom_y;
                odom.pose.pose.orientation = odom_quat;
                
                // Set the velocity
                odom.child_frame_id = "/base_link";
                odom.twist.twist.linear.x = robot.getLinearVelocity();
                odom.twist.twist.angular.z = robot.getAngularVelocity();
                
                // Publish the message
                odom_pub.publish(odom);

                ros::spinOnce();
                r.sleep();
        }
        
        return 0;
}

// EOF