Hi all,
I've some codes below to connect to gazebo (turtlebot);
>> rosinit('http://192.168.2.87:11311')
Initializing global node /matlab_global_node_77319 with NodeURI http://192.168.2.126:62581/
>> rosnode list
/gazebo
/laserscan_nodelet_manager
/matlab_global_node_77319
/mobile_base_nodelet_manager
/robot_state_publisher
/rosout
>> rostopic list
/camera/depth/camera_info
/camera/depth/image_raw
/camera/depth/points
/camera/parameter_descriptions
/camera/parameter_updates
/camera/rgb/camera_info
/camera/rgb/image_raw
/camera/rgb/image_raw/compressed
/camera/rgb/image_raw/compressed/parameter_descriptions
/camera/rgb/image_raw/compressed/parameter_updates
/clock
/gazebo/link_states
/gazebo/model_states
/gazebo/parameter_descriptions
/gazebo/parameter_updates
/gazebo/set_link_state
/gazebo/set_model_state
/joint_states
/mobile_base/commands/motor_power
/mobile_base/commands/reset_odometry
/mobile_base/commands/velocity
/mobile_base/events/bumper
/mobile_base/events/cliff
/mobile_base/sensors/imu_data
/odom
/rosout
/rosout_agg
/tf
>> rosnode info /matlab_global_node_77319
Node: [/matlab_global_node_77319]
URI: [http://192.168.2.126:62581/]
Publications (1 Active Topics):
* /rosout
Subscriptions (1 Active Topics):
* /clock
When I tried to create a publisher for a topic as below (using ‘rospublisher’), it works:
>> robot = rospublisher('/mobile_base/commands/velocity')
robot =
Publisher with properties:
TopicName: '/mobile_base/commands/velocity'
IsLatching: 1
NumSubscribers: 0
MessageType: 'geometry_msgs/Twist'
As shown below, the topic is added to the publishers list:
>> rosnode info /matlab_global_node_77319
Node: [/matlab_global_node_77319]
URI: [http://192.168.2.126:62581/]
Publications (3 Active Topics):
* /mobile_base/commands/velocity
* /odom
* /rosout
Subscriptions (1 Active Topics):
* /clock
Services (0 Active):
Now, I add a new node:
>> node_1 = robotics.ros.Node('node_1', 'http://192.168.2.87:11311');
>> rosnode info node_1
Node: [/node_1]
URI: [http://192.168.2.126:62966/]
Publications (1 Active Topics):
* /rosout
Subscriptions (1 Active Topics):
* /clock
Services (0 Active):
And add the same topic to publish but using another code (robotics.ros.publisher). It works too, as shown below:
>> robotics.ros.Publisher(node_1,'/mobile_base/commands/velocity');
>> rosnode info node_1
Node: [/node_1]
URI: [http://192.168.2.126:62966/]
Publications (2 Active Topics):
* /mobile_base/commands/velocity
* /rosout
Subscriptions (1 Active Topics):
* /clock
Services (0 Active):
However, now when I tried to use (robotics.ros.publisher) on the first node (/matlab_global_node_77319), it doesn’t work:
>> tPub = robotics.ros.Publisher(matlab_global_node_77319,'/mobile_base/commands/motor_power');
Undefined function or variable
'matlab_global_node_77319'.
>> tPub = robotics.ros.Publisher(matlab_global_node_77319,'/mobile_base/commands/motor_power','kobuki_msgs/MotorPower');
Undefined function or variable
'matlab_global_node_77319'.
>> tPub = robotics.ros.Publisher(/matlab_global_node_77319,'/mobile_base/commands/motor_power','kobuki_msgs/MotorPower');
tPub = robotics.ros.Publisher(/matlab_global_node_77319,'/mobile_base/commands/motor_power','kobuki_msgs/MotorPower');
|
Error: Unexpected MATLAB operator.
However, if I used the same code on the new node, and publish a new topic, it works:
>> robotics.ros.Publisher(node_1,'/mobile_base/commands/motor_power')
ans =
Publisher with properties:
TopicName: '/mobile_base/commands/motor...'
IsLatching: 1
NumSubscribers: 1
MessageType: 'kobuki_msgs/MotorPower'
>> rosnode info /node_1
Node: [/node_1]
URI: [http://192.168.2.126:62966/]
Publications (2 Active Topics):
* /mobile_base/commands/motor_power
* /rosout
Subscriptions (1 Active Topics):
* /clock
Services (0 Active):
How do I publish a topic for a node that already exist?
