cps_rmp220_support/nodes/odom_publisher.cpp
2025-01-15 13:58:13 +01:00

95 lines
2.5 KiB
C++

#include <ros/ros.h>
#include <tf/transform_broadcaster.h>
#include <nav_msgs/Odometry.h>
double vx = 0.0; // Linear velocity
double vth = 0.0; // Angular velocity
void odomCallback(const nav_msgs::Odometry::ConstPtr& msg) {
// Extract linear and angular velocities
vx = msg->twist.twist.linear.x;
vth = msg->twist.twist.angular.z;
}
int main(int argc, char** argv) {
ros::init(argc, argv, "odometry_publisher");
ros::NodeHandle n;
// Subscriber for /odom topic
ros::Subscriber odom_sub = n.subscribe("odom", 50, odomCallback);
// Publisher for odom topic
ros::Publisher odom_pub = n.advertise<nav_msgs::Odometry>("odom_out", 50);
tf::TransformBroadcaster odom_broadcaster;
double x = 0.0;
double y = 0.0;
double th = 0.0;
ros::Time current_time, last_time;
current_time = ros::Time::now();
last_time = ros::Time::now();
ros::Rate r(50.0); // Update rate: 50 Hz
while (ros::ok()) {
ros::spinOnce(); // Check for incoming messages
current_time = ros::Time::now();
// Compute odometry based on velocities
double dt = (current_time - last_time).toSec();
double delta_x = vx * cos(th) * dt;
double delta_y = vx * sin(th) * dt;
double delta_th = vth * dt;
x += delta_x;
y += delta_y;
th += delta_th;
// Normalize the yaw angle to [-π, π]
th = fmod(th + M_PI, 2 * M_PI);
if (th < 0) th += 2 * M_PI;
th -= M_PI;
// Create quaternion from yaw
geometry_msgs::Quaternion odom_quat = tf::createQuaternionMsgFromYaw(th);
// 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 = x;
odom_trans.transform.translation.y = y;
odom_trans.transform.translation.z = 0.0;
odom_trans.transform.rotation = odom_quat;
odom_broadcaster.sendTransform(odom_trans);
// Publish the odometry message
nav_msgs::Odometry odom;
odom.header.stamp = current_time;
odom.header.frame_id = "odom";
// Set the position
odom.pose.pose.position.x = x;
odom.pose.pose.position.y = y;
odom.pose.pose.position.z = 0.0;
odom.pose.pose.orientation = odom_quat;
// Set the velocity
odom.child_frame_id = "base_link";
odom.twist.twist.linear.x = vx;
odom.twist.twist.linear.y = 0.0; // No lateral velocity
odom.twist.twist.angular.z = vth;
odom_pub.publish(odom);
last_time = current_time;
r.sleep();
}
}