发布者/订阅者ROS Python

Question

晚上好，我需要创建一个发布者，在从我以前的acuisite包中读取pointcloud2后发送它们。这是为了模拟实时执行。

在rqt_graph中，所有内容似乎都连接正确，但pub和sub似乎根本无法通信。

这是我的出版商：

#!/usr/bin/env python
import rospy
from sensor_msgs.msg import PointCloud2
import std_msgs.msg
import sensor_msgs.point_cloud2 as pcl2
import rosbag
def talker(msg):
pub = rospy.Publisher('chatter', PointCloud2)
rospy.init_node('talker', anonymous=True)
rate = rospy.Rate(1) #hz
rospy.loginfo(msg)
pub.publish(msg)
rate.sleep()

if __name__ == '__main__':
bag = rosbag.Bag('bag2.bag')

for msg in bag.read_messages(topics=['/d435/depth/color/points']):
talker(msg)

这是我的订户：

#!/usr/bin/env python
import rospy
from sensor_msgs.msg import PointCloud2
import std_msgs.msg
import sensor_msgs.point_cloud2 as pcl2
def callback(data):
#rospy.loginfo(rospy.get_caller_id() + "I heard %s", data.data)
print("ptCloud received")
ptc = Point
def listener():
rospy.init_node('listener', anonymous=True)
rospy.Subscriber("chatter", PointCloud2, callback)
rospy.spin()
if __name__ == '__main__':
listener()

有人能帮我吗？使用尝试字符串

from std_msgs.msg import String

通信起了作用，但点云没有。我是ROS的新手，帮帮我！

Answer 1

在讲话者一侧，您正在多次调用rospy.init_node。节点初始化应该只进行一次。使用Python"；类"；你可以这样解决问题：

#!/usr/bin/env python
import rospy
from sensor_msgs.msg import PointCloud2
import std_msgs.msg
import sensor_msgs.point_cloud2 as pcl2
import rosbag
class Talker():
def __init__(self, bag_file):
self.pub = rospy.Publisher('chatter', PointCloud2)
self.rate = rospy.Rate(1) #hz
self.bag_file = bag_file
def Talk(self):
for msg in self.bag_file.read_messages(topics=['/d435/depth/color/points']):
self.pub.publish(msg)
self.rate.sleep()
if __name__ == '__main__':
rospy.init_node('talker', anonymous=True)
bag = rosbag.Bag('bag2.bag')
talker = Talker(bag)
talker.Talk()

Answer 2

它就是这样工作的！

def Talk(self):
for topic, msg, t in self.bag_file.read_messages(topics=['/d435/depth/color/points']):

self.pub.publish(msg)  
self.rate.sleep()