ros多个小乌龟_ros turtlesim 控制小乌龟

运行小乌龟

roscore

rosrun turtlesim turtlesim_node

rosrun turtlesim turtle_teleop_key

可以使用方向键控制乌龟，上下代表前后移动，左右调整方向

节点详细信息

rosnode info /turtlesim

Node [/turtlesim]

Publications:

* /rosout [rosgraph_msgs/Log]

* /turtle1/color_sensor [turtlesim/Color]

* /turtle1/pose [turtlesim/Pose]

Subscriptions:

* /turtle1/cmd_vel [geometry_msgs/Twist]

Services:

* /clear

* /kill

* /reset

* /spawn

* /turtle1/set_pen

* /turtle1/teleport_absolute

* /turtle1/teleport_relative

* /turtlesim/get_loggers

* /turtlesim/set_logger_level

contacting node http://ace-VirtualBox:35435/ ...

Pid: 3624

Connections:

* topic: /rosout

* to: /rosout

* direction: outbound

* transport: TCPROS

* topic: /turtle1/cmd_vel

* to: /teleop_turtle (http://ace-VirtualBox:42445/)

* direction: inbound

* transport: TCPROS

图形化消息订阅情况

rosrun rqt_graph rqt_graph

查看所有topic

rostopic list

查看速度变化消息，分别为前后左右

rostopic echo /turtle1/cmd_vel

命令行发布消息，以一秒钟十次的频率发送消息，小乌龟会自己画圆

rostopic pub -r 10 /turtle1/cmd_vel geometry_msgs/Twist "linear:

x: 2.0

y: 0.0

z: 0.0

angular:

x: 0.0

y: 0.0

z: 2.0

"

服务列表

rosservice list

查看服务

rosservice info /spawn

调用服务，创建一只新乌龟，注意冒号之后有一个空格然后才是数据，否则报错！！！！！！！！！！

rosservice call /spawn "

x: 10.0

y: 20.0

theta: 0.0

name: 'ace3'

"

Python 控制小乌龟，不用在指定目录下创建文件，随意写就行

服务参数为Empty，所以直接调用

即可，不用传递一个Empty的对象

# coding:utf-8

from geometry_msgs.msg import Twist, Vector3

from std_srvs.srv import Empty

print(Empty)

import rospy

def talker():

pub = rospy.Publisher("turtle1/cmd_vel", Twist, queue_size=10)

rospy.init_node("move", anonymous=True)

rate = rospy.Rate(10)

rospy.wait_for_service("clear")

client = rospy.ServiceProxy("clear", Empty)

cnt = 0

while not rospy.is_shutdown():

speed = Vector3(2, 0, 0)

angular = Vector3(0, 0, 2)

twist = Twist(speed, angular)

pub.publish(twist)

# print(twist)

if not cnt % 20:

print('clear')

resp = client.call()

rate.sleep()

cnt += 1

if __name__ == "__main__":

talker()

小乌龟会画圆，过一段时间会将轨迹清空