Rokubi mini 2.0 - Force-Torque Sensor - README

Overview

This software package will provide a driver and a ROS interface for the ethercat and serial version of the rokubi mini force-torque sensor. This is at the moment just a skeleton to connect to rokubi mini devices and support the driver development of its firmware.

Authors(s): Ilias Patsiaouras, Mike Karamousadakis

Building

Installation

Building from Source

In order to use the bota_driver package, you need to download first the following dependencies:

Dependencies

• Robot Operating System (ROS) (middleware for robotics),
• soem

Before building, you need 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 -r

Building

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

1. The catkin_tools package:

    cd catkin_workspace/src
    git clone https://gitlab.com/botasys/bota_driver.git
    cd ../
    catkin build bota_driver

1. If you don't have the catkin_tools package, you can still build from source with catkin_make:

    cd catkin_workspace/src
    git clone https://gitlab.com/botasys/bota_driver.git
    cd ../
    catkin_make --only-pkg-with-deps bota_driver
    # Don't forget to switch back to building all packages when you are done:
    # catkin_make -DCATKIN_WHITELIST_PACKAGES=""

1. Finally, you can build from source with catkin_make_isolated. The only difference is that each package will be processed sequentially:

    cd catkin_workspace/src
    git clone https://gitlab.com/botasys/bota_driver.git
    cd ../
    catkin_make_isolated --pkg bota_driver

Unit Tests

No unit tests so far.

Packages

rokubimini

The core C++ library to interface one or multiple rokubimini devices. Contains abstract interfaces to start the communication.

rokubimini_ethercat

The ethercat implementation of rokubimini.

rokubimini_serial

The serial implementation of rokubimini.

rokubimini_bus_manager

An abstract class for managing a bus.

bota_node

ROS node wrapper with some convenience functions using bota_worker.

bota_worker

High resolution and threaded version of the ROS rate class.

bota_signal_handler

Contains a static signal handling helper class.

rokubimini_msgs

Contains the definitions of the ROS messages and services used for communication over ROS.

Usage

Launching

You need to have sudo rights to the network card, or you could run the driver without using your password (and without accessing the network card with sudo credentials though), with the following command (please select the most suitable to your case):

  roslaunch rokubimini_serial  rokubimini_serial.launch
  # OR
  roslaunch rokubimini_ethercat  rokubimini_ethercat.launch

Note: The above commands should be combined with escalated privileges (e.g. su root or sudo su, if you don't have set a root password) if you work with EtherCAT devices (and you selected the corresponding launch file). If no EtherCAT device is present, the roslaunch commands with only serial devices could work 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!

Extra launch Arguments

Niceness

If you want to change the niceness of the node, consider adding the following XML element as launch_prefix:

    <arg name="launch_prefix" default="nice -n -10" />
    ...
    <node name="bus0" pkg="rokubimini_serial" type="rokubimini_serial_bus_manager_node"  output="screen" launch-prefix="$(arg launch_prefix)" required="true">

Note: If you are running the launch file as a normal user, you need to append to your /etc/security/limits.conf file the following line (change username to your username):

username - nice -20

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

GDB

For using a launch file with gdb, you need the following XML element:

  <arg name="launch_prefix_gdb" default="gdb -ex run --args" />

Configuration

In order to run your existing setup, you should modify accordingly the launch file that matches your case (serial or ethercat - found in rokubimini_[serial|ethercat]/launch directory). In these launch files, there are two kinds of parameters; parameters for each rokubimini and parameters for the bus.

The parameters for each rokubimini are the following: - name: The name of the rokubimini devices. Needed to handle multiple devices on the master side, - configuration_file: The relative path to the configuration file of the sensor - product_name: The product name of each device. - ethercat_address (EtherCAT only): The address of the EtherCAT device. EtherCAT addresses are distributed to each slave incrementally. The slave closest to the master has address 1, the second one 2 etc.

The parameters for each bus are the following: - For the ethercat bus: - ethercat_bus: The ethercat bus containing the sensor. Is the ethernet adapter name on which the sensor is connected to, as indicated in the ifconfig command output. - For the serial bus: - port: The serial port to connect to communicate with the serial sensor. - baud_rate: The baud rate used for the serial communication.

For configuring the sensor parameters, the following parameters can be set in a rokubimini_sensor.yaml file (and set in the configuration_file parameter of the launch file):

• set_reading_to_nan_on_disconnect: Sets the reading to nan when the sensor disconnects
• imu_acceleration_range: 0 = ±2g, 1 = ±4g, 2 = ±8g, 3 = ±16g
• imu_angular_rate_range: 0 = ±250°/s, 1 = ±500°/s, 2 = ±1000°/s, 3 = ±2000°/s
• imu_acceleration_filter: (cut-off Freq) 1 = 460Hz, 2 = 184Hz, 3 = 92Hz, 4 = 41Hz, 5 = 21Hz, 6 = 10Hz, 7 = 5Hz
• imu_angular_rate_filter: (cut-off Freq) 3 = 184Hz, 4 = 92Hz, 5 = 41Hz, 6 = 21Hz, 7 = 10Hz, 8 = 5Hz
• sinc_filter_size: (cut-off Freq high/low@sampling Freq) 51 = 1674/252Hz@1000Hz, 64 = 1255/189Hz@800Hz, 128 = 628/94.5hz@400Hz, 205 = 393/59.5Hz@250Hz 256 = 314/47.5Hz@200Hz, 512 = 157/23.5@100Hz
• fir_disable: false = low cut-off frequency, true = high cut-off frequency from the above result e.g. for sinc filter_size: 48 and fir_disable: 1 you get cut-off freq 1674Hz@1000Hz sample rate
• chop_enable: should be always false
• fast_enable: (only applies if fir_disable is false) True = will result in low cut-off frequency but would be still able to catch step impulses of high cut-off frequency
• calibration_matrix_active: Use the calibration matrix to compute sensor output
• temperature_compensation_active: Compensate drift due to temperature !not supported yet!
• imu_active: Chooses which IMU type is active: 0 = no imu active, 1 = internal IMU active, 2 = external IMU active (if available), 3 = both IMUs active
• coordinate_system_active: Set a user defined coordinate system
• inertia_compensation_active: Enables compensation due to inertia effect
• orientation_estimation_active: Enables orientation estimation and outputs a quaternion

Subscribed Topics

None

Published Topics

• /<bus_name>/<rokubimini_name>/ft_sensor_readings/reading (rokubimini_msgs/Reading)
• /<bus_name>/<rokubimini_name>/ft_sensor_readings/imu (sensor_msgs/Imu)
• /<bus_name>/<rokubimini_name>/ft_sensor_readings/wrench (geometry_msgs/WrenchStamped)
• /<bus_name>/<rokubimini_name>/ft_sensor_readings/temperature (sensor_msgs/Temperautre)

Services

• For Serial devices:
  • /<bus_name>/<rokubimini_name>/firmware_update (rokubimini_msgs/FirmwareUpdateSerial). Arguments:
  • file_path: The path of the firmware update file.
  • /<bus_name>/<rokubimini_name>/reset_wrench (rokubimini_msgs/ResetWrench). Arguments:
  • desired_wrench: The desired wrench to set.
• For EtherCAT devices:
  • /<bus_name>/<rokubimini_name>/firmware_update (rokubimini_msgs/FirmwareUpdateEthercat). Arguments:
  • file_name: The name of the firmware file.
  • file_path: The path of the firmware update file.
  • password: The password for authorization.
  • /<bus_name>/<rokubimini_name>/reset_wrench (rokubimini_msgs/ResetWrench). Arguments:
  • desired_wrench: The desired wrench to set.

Notes: - The <bus_name> is the name attribute in the node element, that is set in the launch file. - The <rokubimini_name> is the configuration parameter ft_sensor_x_name that is set in the launch file.

Support

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