How to publish topics at different rates using while loop?
I'd like to fix the hz for one topic control to control of the robot at 30 HZ.
I am using object detection in my work, the hz of the video's topic /usb_cam/image_raw is between 15 and 25.
Note: I'd like to using while loop in my work.
When I run this code, the hz above 100 for control topic, it is not 30 as I wanted. I am using the command : rostopic hz /control to measure of hz.
How to fix it at 30 hz?
Please help me.
Thanks in advince!
Full the code:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import division
from __future__ import absolute_import
import rospy
import cv2
from std_msgs.msg import String, Float32MultiArray, Bool, Float32
from cv_bridge import CvBridge, CvBridgeError
from sensor_msgs.msg import Image, PointCloud2
class Detector:
def __init__(self):
self.pubtracking = rospy.Publisher('control', Float32MultiArray, queue_size=1)
rospy.Timer(rospy.Duration(1 / 30), self.control)
self._bridge = CvBridge()
# rospy.Subscriber("/camera/rgb/image_color", Image, self.image_callback)
# rospy.Subscriber("/camera/rgb/image_raw", Image, self.image_callback)
rospy.Subscriber("/usb_cam/image_raw", Image, self.image_callback)
# rospy.Subscriber('/camera/depth/points', PointCloud2, self.pc_callback)
# rospy.Subscriber('stopback', Bool, self.shutdownlistener)
self._current_image = None
self._current_pc = None
# self.array = 0
self.error_v = 0
self.error_w = 0
def image_callback(self, image):
self._current_image = image
def run(self):
global error_v, error_w, array
while not rospy.is_shutdown():
if self._current_image is not None:
try:
scene = self._bridge.imgmsg_to_cv2(self._current_image, "bgr8")
self.error_v = 2
self.error_w = 1
# hello_str = [error_v, error_w]
# array = Float32MultiArray(data=hello_str)
self.control()
cv2.imshow("image", scene)
key = cv2.waitKey(1)
except CvBridgeError as e:
print(e)
def control(self, event=None):
# error_v = 2
# error_w = 1
hello_str = [self.error_v, self.error_w]
print hello_str
array = Float32MultiArray(data=hello_str)
self.pubtracking.publish(array)
# rospy.Timer(rospy.Duration(1 / 30), self.control)
# rospy.spin()
if __name__ == '__main__':
rospy.init_node('dodo_detector_ros', log_level=rospy.INFO)
try:
tr = Detector()
tr.run()
# rospy.spin()
# tr.control()
except KeyboardInterrupt:
rospy.loginfo('Shutting down')
I need it works like this code but using while loop, I don't know if it is possible or not in ROS?
Here I put hs = 50
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import division
from __future__ import absolute_import
import rospy
import cv2
from std_msgs.msg import String, Float32MultiArray, Bool, Float32
from cv_bridge import CvBridge, CvBridgeError
from sensor_msgs.msg import Image, PointCloud2
class Detector:
def __init__(self):
self.pubtracking = rospy.Publisher('control', Float32MultiArray, queue_size=1)
rospy.Timer(rospy.Duration(1 / 50), self.control)
self._bridge = CvBridge()
# rospy.Subscriber("/camera/rgb/image_color", Image, self.image_callback)
# rospy.Subscriber("/camera/rgb/image_raw", Image, self.image_callback)
rospy.Subscriber("/usb_cam/image_raw", Image, self.image_callback)
# rospy.Subscriber('/camera/depth/points', PointCloud2, self.pc_callback)
# rospy.Subscriber('stopback', Bool, self.shutdownlistener)
self._current_image = None
self._current_pc = None
# self.array = 0
self.error_v = 0
self.error_w = 0
def image_callback(self, image):
self._current_image = image
# def run(self):
global error_v, error_w, array
# rate = rospy.Rate(30)
# while not rospy.is_shutdown():
if self._current_image is not None ...add a comment
