BionicSoftHand Python Libraries

IMPORTANT NOTICES ⚠️

⚠️ If you open the case of the BionicSoftHand there is the possibility that you get in touch with the 300V piezo electronics! Avoid touching anything inside the case!

⚠️ The BionicSoftHand 2.0 works best with a pressure of 5.5 bars (650000 PSI)! If you go higher the hand can be damaged!

⚠️ The BionicSoftHand 2.0 is a prototype and not a series product.

SHORTCUTS

• Install Instructions
  • Manual Installation
  • Automatic Installation
• BionicSoftHand Setup
  • Mount the hand
  • First connection
  • Debug LEDs
  • Control the hand
    
    

PURPOSE

These libraries implement the necessary messages and core functionalities to communicate with the BionicSoftHand

INSTALL INSTRUCTIONS

HELPER SCRIPTS

There are some helper scripts here to setup your environment.

MANUAL INSTALL

• Download or clone the necessary repositories
  • PID Control
  • DHCP
  • Bionic Message Tools
  • BionicSoftHand Python Libraries
• And install one by one on your computer. To do this change into the root directory of each cloned repository and enter the following command. This executes the setup.py file and installes the libraries locally on your computer. The point in the end means to use the current directory.
  • pip3 install .

AUTOMATIC INSTALL

The automatic install is only available for the BionicSoftHand with ROS

Linux:

bash <(wget -qO- https://raw.githubusercontent.com/Schwimo/linux_config/master/scripts/setup_phand.bash)

BIONIC SOFT HAND 2.0 SETUP

The BionicSoftHand is a pneumatic gripper with 12 independent controllable chambers.

MOUNT THE HAND

POWER SUPPLY

The BionicSoftHand needs a 24V power supply. Alternatively you can connect a 48V power source. Refer to your support team for more information.

AIR SUPPLY

There are two tube connectors on the bottom side of the hand. Next to it are small letters engraved. Connect the exhaust tube to the E and the supply tube to the B. Not more than 5 bars!

ETHERNET CONNECTION

Connect the ethernet cable with your local network. If you have no DHCP activated the default IP address of the hand will be 192.168.4.34 make sure that you are in the same subnet.

FIRST CONNECTION

If you want to try out the connection between your computer and the BionicSoftHand, execute the python script test_phand_connection.py under the "scripts" folder.

This script prints out if the connection was successful or notes any problems.

DEBUG LEDS

There are three LEDs on the mainboard of the BionicSoftHand. One is glowing blue as soon as the power supply is activated.
The other two are used as debug indication and are located next to each other. LED 1 (outer) LED 2 (inner)

STARTUP ROUTINE if everything is connected correctly

1. LED 1: Red on
2. LED 1: Red off
3. LED 1: Green on
4. LED 1: Green off

LED 2: Indicates the connection state of the BionicSoftHand

• Blinking Green: Not connected
• Blinking Blue: Connected
• Nothing or not blinking: Problem

LED 1: Indicates an error of the BionicSoftHand

• Blue on: Not able to send data
• Red on: Can't set the valves
• Green on: Problem reading out the sensors

Control the Hand

The phand.py script provides several functions to communicate with the BionicSoftHand. For example if you want to move the fingers, use the function "set_pressure_data" and pass an array with 12 float values between 100000.0 (1Bar or 100000 PSI) and 600000.0. Each index of the array corresponds to a different actor. The mapping is in the table below.

• Valve control: There are 24 valves inside the hand, 12 supply valves and 12 exhaust valves. The mapping for each supply or exhaust valve is shown in the table below. The first index is always the supply valve and the second one in the brackets is used for the exhaust valve.
• Pressure control: If the pressure control mode is active (default), send 12 pressure values to the hand where the index below is mapped to each actor.
• Position control: Not implemented yet

Index	Corresponding actor	Description
0 (12)	Thumb side	Rotate the thumb left / right
1 (13)	Thumb lower	Open / close the lower part of the thumb
2 (14)	Counter pressure	The counter pressure is used for the wrist cylinders, the index side and the thumb rotation as restoring spring
3 (15)	Thumb upper	Open / close the upper part of the thumb
4 (16)	Index finger upper	Open / close the upper part of the index finger
5 (17)	Wrist left	Move the left wrist cylinder up / down
6 (18)	Index finger lower	Open / close the lower part of the index finger
7 (19)	Wrist right	Move the right wrist cylinder up / down
8 (20)	Middle finger	Open / close the middle finger
9 (21)	Index side	Move the index finger left / right
10 (22)	Ring finger	Open / close the ring finger
11 (23)	Pinky	Open / close the pinky

LICENSE

The Festo BionicSoftHand python libraries are published under the GNU GPL v3.0 License.