cps_rmp220_support/nodes/odom_publisher_fromTwist.py
2025-01-15 09:54:38 +01:00

81 lines
2.1 KiB
Python

#!/usr/bin/env python
import rospy
from nav_msgs.msg import Odometry
from geometry_msgs.msg import TransformStamped
import tf2_ros
import math
from tf.transformations import quaternion_from_euler # Import the function
# Global variables for cumulative pose
x = 0.0
y = 0.0
theta = 0.0 # Orientation in radians
def odom_callback(msg):
global x, y, theta, br
# Time interval
current_time = rospy.Time.now()
dt = (current_time - odom_callback.last_time).to_sec()
odom_callback.last_time = current_time
# Extract linear and angular velocities
linear_x = msg.twist.twist.linear.x
linear_y = msg.twist.twist.linear.y
angular_z = msg.twist.twist.angular.z
# Compute the change in position and orientation
delta_x = (linear_x * math.cos(theta) - linear_y * math.sin(theta)) * dt
delta_y = (linear_x * math.sin(theta) + linear_y * math.cos(theta)) * dt
delta_theta = angular_z * dt
# Update cumulative position and orientation
x += delta_x
y += delta_y
theta += delta_theta
# Normalize theta to the range [-pi, pi]
theta = (theta + math.pi) % (2 * math.pi) - math.pi
# Create a TransformStamped message
t = TransformStamped()
t.header.stamp = current_time
t.header.frame_id = "odom"
t.child_frame_id = "base_link"
# Set translation
t.transform.translation.x = x
t.transform.translation.y = y
t.transform.translation.z = 0.0
# Set rotation (quaternion)
q = quaternion_from_euler(0, 0, theta)
t.transform.rotation.x = q[0]
t.transform.rotation.y = q[1]
t.transform.rotation.z = q[2]
t.transform.rotation.w = q[3]
# Broadcast the transform
br.sendTransform(t)
def main():
global br
rospy.init_node("odom_to_base_link_tf_from_twist")
# Initialize TransformBroadcaster
br = tf2_ros.TransformBroadcaster()
# Initialize last time for integration
odom_callback.last_time = rospy.Time.now()
# Subscribe to the /odom topic
rospy.Subscriber("/odom", Odometry, odom_callback)
rospy.loginfo("Broadcasting /odom to /base_link transform using twist")
rospy.spin()
if __name__ == "__main__":
main()