This is an unofficial fork of SimLab's allegro hand ros package.

It improves significantly upon the SimLab version by providing a catkin-ized version, simplifies the launch file structure, updates the package/node names to have a more consistent structure, improves the build process by creating a common driver, introduces an AllegroNode C++ class that reduces the amount of duplicated code.

It also provides the BHand library directly in this package (including both 32-bit and 64-bit versions, though 32-bit systems will need to update the symlink manually).

At this point no effort has been made to be backwards compatible. Some of the non-compatible changes between the two version are:

• Put all of the controllers into one package (allegro_hand_controllers) and made each controller a different node (allegro_node_XXXX): grasp, pd, velsat.
• Single launch file with arguments instead of multiple launch files with repeated code.
• Both the parameter and description files are now ROS packages, so that rospack find works with them.
• These packages will likely not work with pre-hydro versions (only tested on indigo so far, please let me know if this works on other distributions).
• Added a torque controller (from @nisommer).

There is now a single file, allegro_hand.launch that starts the hand. It takes many arguments, but at a minimum you must specify the handedness:

roslaunch allegro_hand_controllers allegro_hand.launch HAND:=right

Optional (recommended) arguments:

      NUM:=0|1|...
      ZEROS:=/path/to/zeros_file.yaml
      CONTROLLER:=grasp|pd|velsat|torque
      RESPAWN:=true|false   Respawn controller if it dies.
      KEYBOARD:=true|false  (default is true)
      AUTO_CAN:=true|false  (default is true)
      CAN_DEVICE:=/dev/pcanusb1 | /dev/pcanusbNNN  (ls -l /dev/pcan* to see open CAN devices)
      VISUALIZE:=true|false  (Launch rviz)

Note on AUTO_CAN: There is a nice script detect_pcan.py which automatically finds an open /dev/pcanusb file. If instead you specify the can device manually (CAN_DEVICE:=/dev/pcanusbN), make sure you also specify AUTO_CAN:=false. Obviously, automatic detection cannot work with two hands.

The second launch file is for visualization, it is included in allegro_hand.launch if VISUALIZE:=true. Otherwise, it can be useful to run it separately (with VISUALIZE:=false), for example if you want to start rviz separately (and keep it running):

roslaunch allegro_hand_controllers allegro_viz.launch HAND:=right

Note that you should also specify the hand NUM parameter in the viz launch if the hand number is not zero.

• allegro_hand Metapackage.
• allegro_hand_driver Driver for talking with the allegro hand.
• allegro_hand_controllers Different nodes that actually control the hand. The AllegroNode class handles all the generic driver comms, each class then implements computeDesiredTorque differently (and can have various topic subscribers):
  • grasp: Apply various pre-defined grasps, including gravity compensation.
  • pd: Joint space control: save and hold positions.
  • velsat: velocity saturation joint space control (supposedly experimental)
  • torque: Direct torque control.
• allegro_hand_description xacro descriptions for the kinematics of the hand, rviz configuration and meshes.
• allegro_hand_keyboard Node that sends the commanded grasps. All commands are available with the grasp controller, only some are available with the other controllers.
• allegro_hand_parameters All necessary parameters for loading the hand:
  • gains_pd.yaml: Controller gains for PD controller.
  • gains_velSat.yaml: Controller gains and parameters for velocity saturation controller.
  • initial_position.yaml: Home position for the hand.
  • zero.yaml: Offset and servo directions for each of the 16 joints, and some meta information about the hand.
  • zero_files/ Zero files for all hands.
• bhand Library files for the predefined grasps, available in 32 and 64 bit versions. 64 bit by default, update symlink for 32 bit.

Note on polling (from SimLabs): The preferred sampling method is utilizing the Hand's own real time clock running @ 333Hz by polling the CAN communication (polling = true, default). In fact, ROS's interrupt/sleep combination might cause instability in CAN communication resulting unstable hand motions.

• Allegro Hand wiki.
• ROS wiki for original package.

When running more than one hand using ROS, you must specify the number of the hand when launching.

roslaunch allegro_hand.launch HAND:=right ZEROS:=parameters/zero0.yaml NUM:=0 CAN_DEVICE:=/dev/pcan0 AUTO_CAN:=false

roslaunch allegro_hand.launch HAND:=left  ZEROS:=parameters/zero1.yaml NUM:=1 CAN_DEVICE:=/dev/pcan1 AUTO_CAN:=false

While all parameters defining the hand's motor/encoder directions and offsets fall under the enumerated "allegroHand_#" namespaces, the parameter "robot_description" defining the kinematic structure and joint limits remains global. When launching a second hand, this parameter is overwritten. I have yet to find a way to have a separate enumerated "robot_decription" parameter for each hand. If you have any info on this, please advise.

Before using the hand, you must install the pcan drivers. This assumes you have a peak-systems pcan to usb adapter.

1. Install these packages

   sudo apt-get install libpopt-dev ros-indigo-libpcan

2. Download latest drivers: http://www.peak-system.com/fileadmin/media/linux/index.htm#download

Install the drivers:

make clean; make NET=NO_NETDEV_SUPPORT
sudo make install
sudo /sbin/modprobe pcan

Test that the interface is installed properly with:

 cat /proc/pcan

You should see some stuff streaming.

When the hand is connected, you should see pcanusb0 or pcanusb1 in the list of available interfaces:

ls -l /dev/pcan*

If you do not see any available files, you may need to run:

sudo ./driver/pcan_make_devices 2

from the downloaded pcan folder: this theoretically creates the devices files if the system has not done it automatically.