Hardware, Software Programs

Introducing DARwin ? the Next Evolution in Robots

Darwin’s progeny keep on evolving. The latest is DARwin OP, Dynamic Anthropomorpic Robot with Intelligence, Open Platform. This series of robots from Virginia Tech began life in 2004 and has been improving ever since. The newest version was born as a result of research labs and universities wanting to use him for education and outreach. His predecessors included versions 0 (zero) I, II, III, and IV.

DARwin OP is completely open source from software to hardware. He is PC based and can run several operating systems, from Windows to Linux. As far as programming, take your pick, including C++ and MATLAB.

Depending on your level of expertise and availability of basic machine tools, you can build or buy your own. Robotis, the commercial partner of the scholastic researchers, offers the hardware and cad assembly manuals along with fabrication manuals free on the internet for do-it-yourselfers. Robotis, a Seoul Korea company with offices in Irvine California, will be happy to sell DARwin OP to you for about $9,000 if you are lucky enough to have an educational discount, otherwise add another $3,000 or so.

The little 18 inch, 6 pound bot was introduced at IEEE?s Humanoids 2010 conference this month. His development was supported by the National Science Foundation and brought to life by the Virginia Tech?s Robotics & Mechanisms Laboratory (RoMeLa) team.

They collaborated with Purdue University and the University of Pennsylvania’s General Robotics, Automation, Sensing and Perception (GRASP) Laboratory which integrates computer science, electrical engineering, and mechanical engineering.

DARwin?s predecessors have been seen in the RoboCup competitions. RoMeLa studies robot locomotion and autonomous behaviors under the guidance of Dr. Dennis Hong. They consider mechanical design, kinematics, dynamic bipedal gaits, ZMP (zero moment point) control, vision tracking, and even complex autonomous behaviors needed for playing soccer.

DARwin OP is more steady on his feet than his predecessors

DARwin version 0 was an attempt to control a 21 DOF (degree of freedom) humanoid robot. It began with the Cycloid robot from Robotis and used the Dynamixel DX-117 motor to control its motion. DARwin I came with the same 21 degrees of freedom, 4 force sensors on each foot, a 3 axis rate gyro, a 3 axis accelerometer, and room for a computer and batteries.

His links were made from bent sheet aluminum. This earliest version was unstable and required a sequence of stances to walk and had a tendency to trip when presented with obstacles. DARwin OP has overcome the ?turtle syndrome? of landing on his tush and not being able to get up. The video with Dr. Hong, included below, shows his ease of recovery.

The on-going iteration of DARwins brings us to DARWIN III which used RX-64 motors for power and strength, and RX-28 motors for the hip?s yawing motor thereby reducing his height. A Gumstix platform instead of the previous PC/104-Plus platform further reduced the robot?s size and weight. DARwin IV used Gumstix Verdex Pro XL6P with 600MHz, operating Linux 2.6.21.

Blackfin BRF561 from Analog Devices out of Massachusetts provided 328K bytes of on-chip memory. The robot?s vision came from VT-Cam system with dual HDR (high dynamic range) cameras. He was powered by dual 7.4v 2000mAh LiPo (lithium polymer) batteries.

Dr. Dennis Hong guided DARwin OP?s development. His doctorate and master?s degrees in Mechanical Engineering were awarded by Purdue University, preceded by an B.S. from the University of Wisconsin-Madison. With a number of patents for robot locomotion mechanisms and devices for medical applications, Hong is well qualified to be the head of RoMeLa.

As a plus, he is a gourmet chef, as well as and a performing magician who also lectures on the science of magic. His hobby segway?s nicely into a Virginia Tech group being a contender in MAGIC 2010 (Multi Autonomous Ground-robotic International Challenge). The event is jointly sponsored by the Australian and US Departments of Defense. More on this interesting Challenge in a future article.