python_client_example.md

Example Python client

A Python client example is included with this package, in order to illustrate how a client might interact with the Force Dimension node. The client is designed to be as simple as possible: it just prints the current 3D position of the robot end-effector to the ROS log, each time it receives a message on the position topic (feedback/position, by default).

In order to make it easier to run the example, a launch file has been provided. Once the ROS2 workspace has been built -- and the ROS2 environment sourced -- the example can be started with the following terminal command:

> ros2 launch force_dimension example.launch.py

If the robot is properly configured and calibrated, then this should output periodic position measurements to the terminal. The output should resemble the following (log prefixes have been removed for clarity):

All log files can be found below /path/to/logs
Default logging verbosity is set to INFO
process started with pid [123456]
process started with pid [123457]
[robot.force_dimension]: Initializing the Force Dimension interface.
[robot.force_dimension]: Force Dimension device detected: Falcon
[robot.force_dimension]: Force Dimension interface initialized.
[robot.force_dimension]: Failure getting communication refresh rate: no error
[robot.force_dimension]: Sample timer initialized: Interval (ms) = 25.000000
[robot.force_dimension]: BASELINE EFFECTOR MASS: 0.190000 kg
[robot.force_dimension]: Effector mass set to 0.190000 kg.
[robot.force_dimension]: Gravity compensation: Enabled
[robot.example_client]: position=(x: -0.00513, y: -0.00623, z: -0.058)
[robot.example_client]: position=(x: -0.00552, y: -0.00582, z: -0.0581)
[robot.example_client]: position=(x: -0.0103, y: -0.0429, z: -0.0417)
[robot.example_client]: position=(x: 0.000884, y: -0.0253, z: -0.0399)
[robot.example_client]: position=(x: -0.0242, y: -0.0266, z: -0.00622)
[robot.example_client]: position=(x: -0.00687, y: -0.0608, z: -0.00351)
[robot.example_client]: position=(x: 0.00169, y: -0.0494, z: -0.046)
[robot.example_client]: position=(x: 0.00899, y: -0.0187, z: -0.0198)
[robot.example_client]: position=(x: 0.00442, y: -0.0198, z: 0.0125)
[robot.example_client]: position=(x: -0.0272, y: -0.0291, z: 0.0606)
[robot.example_client]: position=(x: -0.0279, y: -0.0291, z: 0.0604)
[robot.example_client]: position=(x: -0.0294, y: -0.0282, z: 0.0615)
[robot.example_client]: position=(x: -0.0294, y: -0.0281, z: 0.0615)
[robot.example_client]: position=(x: -0.0294, y: -0.0281, z: 0.0615)
[robot.example_client]: position=(x: -0.0294, y: -0.0281, z: 0.0615)
[robot.example_client]: position=(x: -0.0294, y: -0.0281, z: 0.0616)
...

Moving the robot endpoint should change the reported positions. Terminate the example by striking CTRL-C.