The best gripper [two fingers version]

To assembly this one you need:

• two servomotors dynamixel AX12-type
• usb dynamixel adapter
• 3d printer
• wires

Models and so on you can find in Internet, for example this https://hackaday.io/project/1059-adaptive-gripper

Installation

Go to you own catkin workspace

roscd && cd ../src

Get the dynamixel SDK inside package (only you have problems with already included SDK)

svn export https://github.com/ROBOTIS-GIT/DynamixelSDK.git/trunk/ros/dynamixel_sdk

Clone this repository

git clone https://github.com/be2rlab/uhvat_gripper.git

Build it

catkin build
source devel/setup.bash

Check for the rights

sudo chmod a+rw /dev/ttyUSB0

Check the pySerial library for python (required for ros driver)

pip install pyserial

How to use

1. Connect your gripper to power supply (or battery)
2. Connect the gripper to a usb2dynamixel adapter and a computer
3. Run the driver

roscore
rosrun uhvat_ros_driver driver_node.py

4. Set state

rosservice call /gripper_state "state: 0"

where

a position control

• state: 0 is a maxumum wide openning
• state: 1 is a less wide openning
• state: 2 is a more less wide openning
• state: 3 is a positions of fingers whant its touches each other

a speed (lazy force) control

• state: 4 is a low level of a closing force
• state: 5 is a middle level of closing force
• state: 6 is a high level of closing force

For more details of using see src/tests.py.

Have a fun :)