Getting started using Bota FT sensors with FR3 arms

• Firstly, you will need the BOTA driver. Install it and read the instructions for the driver, as well as the Bota Demo repo instructions (below)
• Modifications to the franka_ros package are also required, see here
• This repo contains slightly modified launch files (with '_fr3' added to the file names) which will set up the driver to measure the wrist wrench for an FR3 arm
• 'Fake' gravity compensation is done using the orientation of the robot wrist link. The mass/COM properties used for compensation are stored in config/gravity_comp_*.yaml. Calibration has been done for the empty sensor and the Franka Hand, using the procedure from the force_torque_tools package, see here. You can use that package to calibrate a different gripper (change loaded config here)
• The static bias in the configs has not been set, as it is recommended to set this manually after launching the sensor/robot using the ResetWrench action (orient the sensor vertically and set all to zero except the known gripper weight in Z axis).

The rest of the instructions below are from the upstream Bota Demo repo.

BOTA Demo - README

Overview

This software package provides a demo with examples for running the BOTA driver.

Author(s): Lefteris Kotsonis, Ilias Patsiaouras, Mike Karamousadakis

Installation

Cloning the package

Clone the package with:

git clone https://gitlab.com/botasys/bota_demo.git

Building from Source

In order to use the bota_demo package, you need to clone/download the following source dependencies:

Source Dependencies

• force_torque_tools

After cloning the package and before building, you need also to make sure that all the binary dependencies are installed. To do so, run in a terminal:

cd catkin_workspace/ && rosdep update && rosdep install --from-path src --ignore-src -y

Building

Compile the package using the catkin_tools package:

cd catkin_workspace
catkin build bota_demo

Usage

Launching

Run the launch file which is related with your product, you can find your product name on the product label.

Serial

The roslaunch commands with only serial devices works without root privileges provided that the user is in the dialout group. This can be done with:

sudo usermod -a -G dialout username

Please log off and log in again for the changes to take effect!

To run the sensor you can use the following command as an example:

roslaunch bota_demo BFT_ROKA_SER_M8.launch

EtherCAT

The EtherCAT device driver is using SOEM which requires access to certain network capabilities as it is using raw sockets, and as such any executable linking against SOEM needs to be run with certain privileges. Typically, you would run any SOEM executables with sudo or as root. This is impractical for any ROS system, and as such there exists a tool called ethercat_grant that helps with that.

If you followed the installation instructions for the bota_driver, ethercat_grant is already installed. Alternatively, you can install it with

sudo apt install ros-<DISTRO>-ethercat-grant

and add the following launch prefix to the node tag of the rokubimini_ethercat_bus_manager_node in your launch file:

launch-prefix="ethercat_grant"

Note: This launch prefix is already added to all the launch files in this repo.

To run the sensor you can use the following command as an example:

roslaunch bota_demo BFT_ROKA_ECAT_M8.launch

For more complicated examples have a look at BFT_SENS_ECAT_M8_realsense.launch to see how to combine our sensor with a realsense camera.

(Alternative:) EtherCAT without launch prefix

Instead of using the ethercat_grant launch prefix, the above command to interface with your EtherCAT sensor can also be combined with escalated privileges (e.g. su root or sudo su, if you don't have set a root password).

Support

For any queries or problems found with the software provided, please contact us at sw-support@botasys.com