Barrett Hand

ROS packages to control the Barrett Hand. Supported models: BH8-280 and BH8-282

Table of Contents

1. Quick start with real Barrett
2. Prerequisites
   1. 1. Essentials
   2. 2. Peak-CAN driver
   3. 3. pcan_python
3. Troubleshooting
   1. Error openning port /dev/pcanusb32
4. Collections
   1. bhand_controller
   2. rqt_bhand
   3. barrett_hand_description
   4. barrett_hand_sim

Quick start with real Barrett

1. Prepare prerequisites

2. Catkin build

3. Connect to hand

   roslaunch bhand_controller bhand_controller.launch

4. Testing through ROS services

   1. rosservice call /bhand_node/actions "action: 1" : INIT_HAND
   2. rosservice call /bhand_node/actions "action: 6" : CLOSE_HALF_GRASP
   3. rosservice call /bhand_node/actions "action: 3" : OPEN_GRASP

Prerequisites

For Python3, please check the Barret manual from the RISE Notion.

1. Essentials

sudo apt-get install swig libelf-dev libpopt-dev

2. Peak-CAN driver

The PEAK driver is included in the Linux kernel, but there is a problem that some packages cannot be built. Therefore, it is recommended to overwrite and install the PEAK driver according to the following install guide.

1. Download peak-linux-driver-8.x from here. Scroll down and you will find the 'Download PCAN Driver Package' button.
2. Build and install

   tar -xzf peak-linux-driver-X.Y.Z.tar.gz
   cd peak-linux-driver-X.Y.Z
   make clean
   make NET=NO_NETDEV_SUPPORT
   sudo make install

3. Load PCAN driver w/o reboot and check the result. Example:

   $ sudo modprobe pcan
   $ pcaninfo
   PCAN driver version: 8.15.2
   PCAN-Basic version: 4.6.2.36
   
     * pcanusb32: "PCAN_USBBUS1" (0x051), PCAN-USB #1, devid=0x00 (/sys/class/pcan/pcanusb32)

3. pcan_python

The pcan_python is a Python 2.x wrapper for the Peak-CAN driver. We need to build this for Python 3.x.

1. Git clone git clone https://github.com/RobotnikAutomation/pcan_python.git

2. Fix some files. The below are examples for python3.8.

   1. Line 11 of Makefile: INC = -I/usr/include/python3.8 -I/usr/include
   2. Line 01 of setup.py: #!/usr/bin/env python3

3. Change the code style and build

   sudo apt install python3-dev
   cd pcan_python
   2to3 -w -n .
   make

4. Modify lines 12 to 15 of pcan_python/pcan_module.py(generated file) as follows:

   # if __package__ or "." in __name__:
   #     from . import _pcan_module
   # else:
   #     import _pcan_module
   import _pcan_module

5. Install

   sudo make install

6. Add /usr/lib to PYTHONPATH

   export PYTHONPATH=/usr/lib:$PYTHONPATH

Troubleshooting

Error openning port /dev/pcanusb32

Check your pcan with:

sudo modprobe pcan
pcaninfo

If you couldn't solve the issue with sudo modprobe pcan (or pcan_usb), then reinstall the driver:

cd peak-linux-driver-X.Y.Z
make clean
make NET=NO_NETDEV_SUPPORT
sudo make install

Collections

bhand_controller

• ROS controller based on the Barrett pyHand library to command and read the state of the hand.
• bhand_controller is forked from RobotnikAutomation/barrett_hand (kinetic-devel)

rqt_bhand

• RQT plugin to control and monitor the hand
• rqt_bhand is forked from RobotnikAutomation/barrett_hand (kinetic-devel)

barrett_hand_description

• Barrett Hand description (urdf and meshes)
• barrett_hand_description is forked from RobotnikAutomation/barrett_hand_common (kinetic-devel)

barrett_hand_sim

• Barrett hand simulation package for ROS

• barrett_hand_sim is forked from RobotnikAutomation/barrett_hand_sim (kinetic-devel)

• Launch the Gazebo simulation:

  roslaunch barrett_hand_gazebo barrett_hand.launch

• How to switch to available hand models:

  • Edit file barrett_hand_description/robots/bh_alone.urdf.xacro and change the name of the included file (bh282.urdf.xacro or bh280.urdf.xacro)

• Publish topics to control the hand:

  rostopic pub /bh_j11_position_controller/command std_msgs/Float64 'desired_angle'

• Controller list:

  • bh_j11_position_controller -> spread DoF
  • bh_j12_position_controller -> finger 1 grasp
  • bh_j22_position_controller -> finger 2 grasp
  • bh_j32_position_controller -> finger 3 grasp