Package Name

Overview

Motion controller for Maxon EPOS4 over EtherCAT.

Keywords: EtherCAT, EPOS4, motor controller, maxon

License

The source code is released under a BSD 3-Clause license.

Author: Jonas Lauener, mail@jolau.ch

The varileg_lowlevel_controller package has been tested under ROS Kinetic and Ubuntu 16.04. This is research code, expect that it changes often and any fitness for a particular purpose is disclaimed.

Installation

Building from Source

Dependencies

• Robot Operating System (ROS) (middleware for robotics),
• openethercat_soem
• soem_interface
• varileg_msgs

Building

To build from source, clone the latest version from this repository into your catkin workspace and compile the package using

cd ~/git
git clone https://github.com/ethz-asl/ros_package_template.git
cd ~/catkin_workspace/src
ln -s ~/git/varileg_lowlevel_controller
cd ../
catkin build varileg_lowlevel_controller

Usage

Describe the quickest way to run this software, for example:

Run the main node with

roslaunch varileg_lowlevel_controller varileg_lowlevel_controller_setcap.launch

Config files

Config file folder config:

• config.yaml Set the names of the Ethernet ports. Can be found by using command ifconfig. Also defines topic names.
• joint_config.yaml Configure mapping of joints to EPOS's NodeID. Set parameters of each joint.

Launch files

• varileg_lowlevel_controller varileg_lowlevel_controller_setcap.launch: Start the main node with root rights by starting varileg_lowlevel_controller_setcap.sh and then finally varileg_lowlevel_controller.launch

  Arguments:

  • password Root password. Default: varileg.
  • motor_current Max. motor current in mA. Default: 2000.
  • frequency Frequency [Hz] of the update loop. Trajectory point have to come with same frequency. Default: 100.

• varileg_lowlevel_controller epos_example_setcap.launch: Starts a simple testing node, great for developing. Usage similiar to above.

Nodes

Subscribed Topics

• /joint_trajectory (varileg_msgs/ExtendedJointTrajectories.msg)

  Trajectory points for all joints.

Published Topics

• joint_states (varileg_msgs/ExtendedJointStates.msg)

  Current position, velocity and torque of all joints.

• device_states (varileg_msgs/ExtendedDeviceStates.msg)

  Current device states of all joints.

Services

• set_device_state (varileg_msgs/SetDeviceState.srv)

  Set the targeted device state of a joint. Will be tried to reach with the next update cycle.

• set_device_state (varileg_msgs/SetOperatingMode.srv)

  Change the operating mode of a joint. Will be tried to be changed with the next update cycle. Joint needs to be in SWITCH ON DISABLED state.

Actions

• homing/[joint_name] (varileg_msgs/Homing.action)

  Start homing of a joint. Needs to be in homing mode and enabled.