Accessing Data From The Hand

There are four main ways to access data from the hand:

Example: accessing joint state data

  • Using the graphical user interface to view the joint state data in the Data Visualizer.

  • Using the Command line interface to view the joint state data in the topic /joint_state

  • Using SrHandCommander methods of:

    • current_state = hand_commander.get_current_state()

    • joints_position = hand_commander.get_joints_position()

    • joints_velocity = hand_commander.get_joints_velocity()

  • Using ROS Python subscriber or ROS CPP subscriber

Recording ROS Bags

A rosbag or bag is a file format in ROS for storing ROS message data. These bags are often created by subscribing to one or more ROS topics, and storing the received message data in an efficient file structure.

The different ways to record and playback ROS bags can be found here

Example: Recording and playing a ROS Bag of joint states

To record a ROS Bag of the /joint_states topic for 1 minute and name it joint_state_bag.bag. The command-line tool can be used:

rosbag record --duration=1m joint_state_bag.bag /joint_states

To find information about the rosbag joint_state_bag.bag:

rosbag info joint_state_bag.bag

To play back this ROS Bag:

rosbag play joint_state_bag.bag

The rosbag command-line has many options of how to record and playback various topics that are published, these can be found here.

Copying data out of the dexterous hand container

docker cp is a way to copy files/folders between a container and the local filesystem. An extended description can be found here.

Coping FROM the container TO the file system:

docker cp [OPTIONS] CONTAINER:SRC_PATH DEST_PATH

Copying FROM the file system TO the container:

docker cp [OPTIONS] DEST_PATH CONTAINER:SRC_PATH

Some of the [OPTIONS] include:

Name, shorthand

Description

–archive , -a

Archive mode (copy all uid/gid information)

–follow-link , -L

Always follow symbol link in SRC_PATH