Multi-fingered programmable grasper
The BH8-series BarrettHand™ is a multi-fingered programmable grasper with the dexterity to secure target objects of different sizes, shapes, and orientations. Even with its low weight (980 grams) and super compact (25mm) base, it is totally self-contained. Communicating by industry-standard serial communications or high-speed CANbus (USB adapters included), integration with any arm is fast and simple. The BH8-series immediately multiplies the value of any arm requiring flexible automation.
As an intelligent, highly flexible eight-axis gripper, the BarrettHand BH8–282 reconfigures itself in real time to conform securely to a wide variety of part shapes without tool-change interruptions. The grasper brings value to automation because it: reduces the required number and size of robotic workcells while boosting throughput; consolidates the hodgepodge proliferation of customized gripper-jaw shapes onto a common programmable platform; and enables incremental process improvement and accommodates frequent new-product introductions, capabilities deployed instantly via software across international networks of factories.
The BarrettHand neatly houses its own communications electronics, servo-controllers, and all four brushless motors. Of its three multi-jointed fingers, two have an extra degree of freedom with 180 degrees of lateral mobility supporting a large variety of grasp types. All joints have high-precision position encoders.
Why Buy a BarrettHand™ when Parallel-Jaw Grippers are so Cheap?
1) Each gripper must be custom designed. Grippers require specialists to design, fabricate, and debug specially-shaped finger surfaces for each part shape and for each unique part orientation.
2) Unless the host arm will perpetually perform the same task, it needs an infinitely variable supply of grippers and the ability to switch between them instantly as the part shapes and orientations change. A robot arm exchanges grippers with either a turret or a tool changer. A turret is limited to switching between 2 or 3 grippers. A tool changer can handle a large number of grippers, but at the enormous costs of wasted space from storage fixtures and badly increased cycle times.
Combined with its versatile software routines, a single BarrettHand matches the functionality of an endless set of custom grippers—yet switches part/tool shapes electronically within half a second.
The BarrettHand integrates with your application by consolidating many custom gripper tools into a single smart grasper. It is shipped as a complete turn-key system.
Barrett Technology’s full-source code and examples are included with every purchase and provide comprehensive ways of controlling the BarrettHand.
The BHControl application works under both Linux and Windows and presents an easy-to-use graphical user interface (GUI) for control of the BarrettHand. It exposes all of the functionality provided by the BarrettHand C/C++ library and the powerful yet easy-to-learn Grasper Control Language (GCL) in a graphical environment, without writing any code.
The visual control window of the BHControl application enables control of the hand interactively. The user is capable moving the fingers of the BarrettHand™ to any desired position with a mouse.
The BarrettHand C/C++ library facilities configuring and controlling the hand. The library coordinates all communications with the hand and provides functions to control the hand. The functions take advantage of the firmware's RealTime mode and Supervisory commands. The library is written for Windows and Linux.
The BarrettHand's firmware resides on the control electronics inside the hand. The firmware interprets the commands sent from the host computer and responds accordingly. The firmware has two modes: Supervisory and RealTime. The Supervisory mode allows the user to issue high-level commands, which the BarrettHand™ will execute. When the hand is finished executing the command, it returns control back to the user. The RealTime mode enables continuous control and monitoring of motor parameters, allowing real-time motion control.
PyHand allows a user to manipulate joints, read sensors, and perform hand maintenance routines.
Barrett's Perception Palm™ contains two CMOS Video Cameras, a Laser-projector, an Infrared (IR) rangefinder, and an illumination LED all within a high-impact polyurethane resin housing that is mounted directly on the palm of a BarrettHand™. The Perception Palm™ augments the contact-based localization sensors already available on the BarrettHand™ (6-axis force / torque sensor, fingertip torque sensors, and tactile sensing) with several non-contact sensors to provide valuable localization information in the critical time just before manipulation, but after base-mounted sensors may have become occluded by the manipulator itself. Gorilla Glass is used for sensor and emitter lenses, providing impact and scratch resistance, and making it perfectly safe to manipulate objects up against the surface of the palm.
Below, you can find the ROS driver for Barrett's Perception Palm™. This library is a ROS wrapper written above the open source C/C++ library for Microchip's USB-to-SPI protocol coverter. It works under Linux. This has been tested under ROS Hydro (Ubuntu 12.04) and Indigo (Ubuntu 14.04).