According to the author Ku ranking · ROS 21 Getting speak learning organize and refer to "ROS robotics development practices," a book.
[Note] This section may refer Ku ranking · Getting ROS say 21 Lecture 8
Experimental preparation: start small turtles emulator
- Use
$ roscorestart Ros Master - Open a new terminal, start small turtles simulator:
$ rosrun turtlesim turtlesim_node - Open a new terminal, control node start small turtles:
$ rosrun turtlesim turtle_teleop_key
Tools
$ rqt_graph: Calculation FIG visual interfaces$ rosnode: Node tool$ rosnode ping node_name: A test connection node$ rosnode list: Lists all of the current node$ rosnode info node_name: View of a node information$ rosnode machine machine_name: List the nodes running on a particular machine or machines list$ rosnode kill node_name: Kill a node$ rosnode cleanup: Clear unreachable node registration information$ rosnode help: View help information
$ rostopic: Topic Tools$ rostopic bw topic_name: View of a topic bandwidth$ rostopic delay topic_name: Delayed by a time stamp is displayed in the title topic$ rostopic echo topic_name: Displays the contents of a topic$ rostopic find topic_type: Find a type of topic$ rostopic hz topic_name: View a topic of frequency$ rostopic info topic_name: Displays information about a topic of$ rostopic list: Lists all the current topic$ rostopic pub topic_name: Publish content to a particular topic- After entering the name of the topic, double-click the TAB key to complement the default configuration, a data structure of the topic and the specific data
- For example, input
$ rostopic pub /turtle1/cmd_veldouble-click the TAB key, completion information linear velocity and angular velocity angular Twist linear data structure, respectively, and m units of radians respectively. -r rate_numberTopic issuance frequency setting, e.g., input$ rostopic pub -r 10 /turtle1/cmd_veldouble-click the TAB key completion information indicating 10 times the release per topic.
$ rostopic type topic_name: The type of viewing a topic (msg)
$ rosmsg: Message Tool$ rosmsg show message_name: View the data structure of a message$ rosmsg info message_name: Same as above,showan alias.$ rosmsg list: Lists all of the current message$ rosmsg md5 package_name: _ Unknown _$ rosmsg package package_name: List all messages in a package$ rosmsg packages message_name: List all packets containing the message
$ rosservice: Service Tools$ rosservice args: View a service parameter structure$ rosservice call sevice_name: Request a Service- After entering the service name, double-click the TAB key completion default structure
- For example, a request to generate a new service hatchlings, input
$ rosservice call /spawndouble-click the TAB key, completion information of the hatchlings are new x, y coordinates, theta angle towards, name name.
$ rosservice find service_type: Find a service by service type$ rosservice info sevice_name: View the details of a service$ rosservice list: Lists all current service request$ rosservice type sevice_name: View of a service type$ rosservice uri sevice_name: View a service where the host and port rosrpc
$ rosbag: Topics recording tool$ rosbag check: A bag is determined whether the executable file in the current system, movable$ rosbag compress: One or more compressed files bag$ rosbag decompress: Unpack a bag or more files$ rosbag decrypt: Decrypt a file or multiple bag$ rosbag encrypt: Encrypt one or more files bag$ rosbag filterContent filtering bag in:$ rosbag fix: Repair bag make it executable files in the current system$ rosbag help: View help information$ rosbag info: The contents of one or more files bag Overview$ rosbag play: Time synchronized manner one or more content playback package file$ rosbag record: A bag with the contents of the file records of the specified topic$ rosbag reindex: Re-index file one or more bag- Common commands
- Topics record:
$ rosbag record -a -O record_file_name - Recurring topic:
$ rosbag play record_file_name.bag
- Topics record:
Practical exercises
- Start ROS Simulator
$ roscore: Start Ros Master$ rosrun turtlesim turtlesim_node: Start small turtles emulator
- Control instruction
- turtle1 Draw "O"
$ rostopic pub -1 /turtle1/cmd_vel geometry_msgs/Twist '[2.0, 0.0, 0.0]' '[0.0, 0.0, 1.5708]': 90 ° arc to the left$ rostopic pub -1 /turtle1/cmd_vel geometry_msgs/Twist '[2.5, 0.0, 0.0]' '[0.0, 0.0, 0.0]': Front Line 2.5$ rostopic pub -1 /turtle1/cmd_vel geometry_msgs/Twist '[4.0, 0.0, 0.0]' '[0.0, 0.0, 3.1416]': 180 ° arc to the left$ rostopic pub -1 /turtle1/cmd_vel geometry_msgs/Twist '[2.5, 0.0, 0.0]' '[0.0, 0.0, 0.0]': Front Line 2.5$ rostopic pub -1 /turtle1/cmd_vel geometry_msgs/Twist '[2.0, 0.0, 0.0]' '[0.0, 0.0, 1.5708]': 90 ° arc to the left
- turtle2 Draw "R"
$ rosservice call /spawn 1.0 5.5 1.5708 "turtle2": Create a new tortoise turtle2, coordinates (1.0, 5.5), head towards the north$ rostopic pub -1 /turtle2/cmd_vel geometry_msgs/Twist '[5.0, 0.0, 0.0]' '[0.0, 0.0, 0.0]': Front Line 5.0$ rostopic pub -1 /turtle2/cmd_vel geometry_msgs/Twist '[0.0, 0.0, 0.0]' '[0.0, 0.0, -1.5708]': 90 ° right turn situ$ rostopic pub -1 /turtle2/cmd_vel geometry_msgs/Twist '[1.0, 0.0, 0.0]' '[0.0, 0.0, 0.0]': Front Line 1.0$ rostopic pub -1 /turtle2/cmd_vel geometry_msgs/Twist '[4.0, 0.0, 0.0]' '[0.0, 0.0, -3.1416]': 180 ° arc to the right$ rostopic pub -1 /turtle2/cmd_vel geometry_msgs/Twist '[1.0, 0.0, 0.0]' '[0.0, 0.0, 0.0]': Front Line 1.0$ rostopic pub -1 /turtle2/cmd_vel geometry_msgs/Twist '[0.0, 0.0, 0.0]' '[0.0, 0.0, 2.3562]': 135 ° turn left in situ$ rostopic pub -1 /turtle2/cmd_vel geometry_msgs/Twist '[3.5355, 0.0, 0.0]' '[0.0, 0.0, 0.0]': 3.5355 ahead
- turtle3 Draw "S"
$ rosservice call /spawn 8.0 5.5 0.0 "turtle3": Create a new tortoise turtle3, coordinates (10.0, 5.5), head towards the east$ rostopic pub -1 /turtle3/cmd_vel geometry_msgs/Twist '[1.0, 0.0, 0.0]' '[0.0, 0.0, 0.0]': Front Line 1.0$ rostopic pub -1 /turtle3/cmd_vel geometry_msgs/Twist '[4.0, 0.0, 0.0]' '[0.0, 0.0, 3.1416]': 180 ° arc to the left$ rostopic pub -1 /turtle3/cmd_vel geometry_msgs/Twist '[4.0, 0.0, 0.0]' '[0.0, 0.0, -3.1416]': 180 ° arc to the right$ rostopic pub -1 /turtle3/cmd_vel geometry_msgs/Twist '[1.0, 0.0, 0.0]' '[0.0, 0.0, 0.0]': Front Line 1.0
- turtle1 Draw "O"
