[Documentation] [TitleIndex] [WordIndex

  Show EOL distros: 

pr2_robot: imu_monitor | pr2_bringup | pr2_camera_synchronizer | pr2_computer_monitor | pr2_controller_configuration | pr2_ethercat | pr2_run_stop_auto_restart

Package Summary

Main loop that runs the robot.

pr2_robot: imu_monitor | pr2_bringup | pr2_camera_synchronizer | pr2_computer_monitor | pr2_controller_configuration | pr2_ethercat | pr2_run_stop_auto_restart

Package Summary

Main loop that runs the robot.

(formerly pr2_etherCAT in Groovy and earlier)

Nodes

pr2_ethercat

pr2_ethercat is the node that executes the main loop for controlling the EtherCAT devices (including all motors) on the PR2. It loads pr2_controller_manager, which in turns loads and runs controllers that act directly on the robot's motors. The ROS API detailed below is the interface for controlling pr2_ethercat itself; as a result of loading the controllers, the pr2_ethercat process offers a broader, and varying ROS API. Superuser privileges are required to run pr2_ethercat, to allow it to set its scheduling priority to run as a real-time process.

Services

pr2_ethercat/reset_motors (std_srvs/Empty) pr2_ethercat/halt_motors (std_srvs/Empty)

Permissions

Running pr2_ethercat requires the following "capabilities":

Superuser has these capabilities, but they can also be granted to another executable by setting file system attributes on the executable file. The pr2-grant program is a setuid-root program which copies pr2_ethercat to a part of the filesystem where attributes can be set (/var/tmp), and then grants the necessary capabilities to be able to run pr2_ethercaat.

Usage

Usage: ./pr2_ethercat [options]
  Available options
    -i, --interface <interface> Connect to EtherCAT devices on this interface
    -x, --xml <file|param>      Load the robot description from this file or parameter name
    -r, <param>                 Load the robot description from this parameter
    -u, --allow_unprogrammed    Allow control loop to run with unprogrammed devices
    -h, --help                  Print this message and exit

Example

pr2_ethercat is usually executed from a launch file, such as pr2_bringup/pr2.launch. Common configuration:

<node name="realtime_loop" machine="c1" launch-prefix="pr2-grant" pkg="pr2_ethercat" type="pr2_ethercat" args="-i ecat0 -x robot_description"/>

pr2-grant

pr2-grant is a utility that allows a regular user to run pr2_ethercat with appropriate capabilities. See the section in pr2_ethercat on "Permissions."

reset_motors.py

reset_motors.py is a simple command-line script that calls the pr2_ethercat/reset_motors service.

$ rosrun pr2_ethercat reset_motors.py


2019-07-13 12:59