ROS2 - CANopen - EPOS4: Setup Guide

Topic:

The attached document (and provided links) contain step-by-step instructions for integrating maxon EPOS4 controllers into a ROS2 system environment (-> ROS = Robot Operating System: https://www.ros.org). The software package ros2_canopen (https://rosindustrial.github.io/ros2_canopen/manual/rolling/index.html) is used for CANopen data exchange in between the ROS2 master and EPOS4.

Target Audience:

The attached document and all shared information is written for users who have some base knowledge of CANopen (https://www.can-cia.org/can-knowledge/canopen) and ROS2 (https://docs.ros.org/en/rolling). It contains all the necessary links to extend your knowledge on the topic, but it mainly focuses on specificities related to the EPOS4 and ros2_canopen setup.

Use Cases:

ROS2 is suitable for applications where it is beneficial to have modular architecture and support for distributed systems in robotics and automation. It officially runs on the Ubuntu Linux distribution.

With the help of the attached document and the examples in the maxon_epos4_ros2 package, users have a practical guide for setting up a motion control system in ROS2 that connects to EPOS4 motor controllers via CAN bus. The goal is to enable motor control directly from the ROS2 environment.

Restriction:

The code examples contained in the maxon_epos4_ros2 package describe simple use cases, which can be easily extended to more controllers for a specific application. At this point the example supports the drive operation mode “Profile Position Mode” (PPM), “Profile Velocity Mode” (PVM), “Cyclic Synchronous Position Mode” (CSP) and “Cyclic Synchronous Velocity Mode” (CSV).
 

Setup your system, test, and adapt the code to your needs

Initial action steps:

All following steps are described in detail in the attached manual:

1. Setup the EPOS4
2. Setup the ROS2 environment
3. Setup the CAN driver and SocketCAN
4. Setup the ros2_canopen package
5. Install and run the “maxon_epos4_ros2” examples

Important:

Always take care to use the mentioned Ubuntu and ROS2 versions and links!
ROS and ROS2 is quite sensitive and sometimes just has a low compatibility if different ROS2 and Linux versions are mixed up!

Tested Hardware:

• NVIDIA Jetson Orin Nano
• Raspberry Pi 5 and CAN-HAT
• "EPOS4 Compact 24/1.5 CAN" (P/N: 546714) with firmware version 0x170 or higher
  All other EPOS4 product types with a CAN interface can also be used. Motor and control parameters present in the examples have to be adapted depending on the EPOS4 product type, motor and sensor in use. 

Main important link: maxon's EPOS2 + ROS2 package

This link holds the required maxon_epos4_ros2 example code package:
-> https://github.com/MattMax319/maxon_epos4_ros2

and note the attached document!

Cross references:

Add-on Support Center documents:

• EPOS4 / IDX: Important steps during initial commissioning
• CAN bus topology and bus termination
• CANopen basics and links
• EPOS / IDX: Export of the *.eds resp. *.esi file (Electronic Data Sheet)
• EPOS / IDX: Export of parameter configuration in a *.dcf file
• EPOS4 / IDX: CSP or CSV Mode -> Relevance of "Interpolation Time Period Value"?
• Information about ROS (not ROS2): Using the EPOS4 by a ROS system environment?!

3rd party links:

• Official website of ROS - Robot Operating System
• ROS2 CANopen: Stack 
• ROS2 CANopen: User Guide
• ROS2 CANopen: Github project and source code
• ROS2 Documentation
• ROS2 Installation

maxon "EPOS4 - ROS2 Setup Guide":

see attached below!