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Robotis DARwIn-OP Raises The Bar

Open Source PC-Based Humanoid To Boost Research, Education And Outreach

DARwIn (Dynamic Anthropomorphic Robot with Intelligence) is a family of fully autonomous humanoid robots capable of bipedal walking and performing human like motions. Developed at the Robotics & Mechanisms Laboratory (RoMeLa) at Virginia Tech, DARwIn is a research platform for studying robot locomotion and autonomous behaviors and also the base platform for Virginia Techs and the University of Pennsylvanias entry to the RoboCup competition. We have published previously on the DARwin humanoid seriesan earlier version of this robot was our January/February 2010 cover.

We caught up with Professor Dennis Hong, director of RoMeLa (Robotics & Mechanisms Laboratory) at Virginia Tech and asked him to describe the latest iteration of this awesome humanoid. As always, Dennis spoke quickly and articulately, delivering a massive amount of information in a short amount of time with the greatest of ease, something his students love him for, and his enthusiasm is contagious. Heres the inside scoop! Tom Atwood

The name DARwIn stands for Dynamic Anthropomorphic Robot with Intelligence, and OP stands for open platform. This research project is funded by National Science Foundation (NSF) grant No. CNS-0958406, and ROBOTIS will be building and selling commercial versions of DARwIn-OP. The DARwIn project, overall, is a collaboration between Virginia Techs RoMeLa laboratory, Purdue University, University of Pennsylvania and ROBOTIS.

The DARwIn series of humanoid robots started in 2004 and has evolved through four generations. It was the very first humanoid platform from the USA to qualify for competition at RoboCup and has been on at least three magazine covers. About two years ago, we started to receive a growing number of requests from research laboratories and universities who wanted to use this kind of research humanoid platform for research, education and outreach activities. Based on this growing interest, we wrote an NSF research and development proposal that was approved and funded, and this then became a serious R&D project for RoMeLa and our partners. Ultimately, the humanoid robotics research and educational community across our nation and world are sure to grow, owing to this fantastic new platform.

OPEN SOURCE, OPEN PLATFORM

The best thing about the DARwIn-OP is that it is truly open source software and open source hardware. That is, it is PCbased and you can use Windows, Linux or whatever operating system you desire and whatever programming language you prefer. For example, you can use LabVIEW, MATLAB, C++ or any other PC compatible language. Support for ROS is planned. In fact, you can attach your USB mouse, keyboard, and HDMI monitor directly to DARwIn-OP and use them to program it!

Based upon early comments from ROBOTIS, the MSRP of DARwIn-OP may land at roughly $12,000 USD, and with an educational discount, it may be priced closer to $9,600 (these are not final prices; for final pricing, please contact ROBOTIS). A RoboCup discount may also be in the offing, but nothing has been announced as we go to press.

ALL FREE ONLINE

As for hardware, all of the CAD files, plans, assembly manuals and the fabrication manuals will be made available online for free. Although we designed the basic platform, nobody owns the design. You dont have to buy this robot from ROBOTIS! You can build your own, if you have the basic machine tools and off the shelf components. Or, you can buy portions of the robot from ROBOTIS, say some of the machined parts, and build the rest. You could buy all of the components for the frame and the electronics and servos, and then make your own body plates. Its entirely up to you. We encourage people to hack it and share their innovations online as well.

Thats one of the best aspects of this robot, but another cool thing is that we designed it as a research platform so that it has enough torque and raw power, enough payload carrying capacity, such that you can add different sensors and different types of computing platforms and be confident it will be up to the task. You can add additional camera gear, a laser range-finder or other components to it to make your very own custom platform for research and education.

The project really benefited from collaboration. Virginia Tech handled the design of the mechanical hardware and ROBOTIS redesigned parts to make it mass-producible so that it can be sold commercially. UPenn led on the software design and Purdue helped define important specifications.

The result is the first table-top humanoid robot that can run and jump off the ground! Ive personally seen it jump up and down, and we have designed in the capability to run using a gait that will at times have both feet off the ground. It comes with a high performance Zigbee radio, as well. I personally have not seen a higher performing humanoid robot in this class, and the team is very proud of our baby, the DARwIn- OP!

NEXT-GEN TECHNOLOGY

For computer science researchers, this is intended to be the next generation humanoid platform. Not only is it modular and quickly repairable if it falls and something breaks, but it has great leading-edge technology. A 1.6GHz Atom chip enables it to handle computationally intense vision algorithms and a variety of complex autonomous behaviors. It also has a microcontroller designed for serious research (see specifications chart). Moreover, it uses new Dynamixel RX-28M metal-gear servos with magnetic encoders instead of potentiometers, which increases resolution by four times! It uses a PID controller that is modifiablethe user can modify the gain.

Its onboard LiPo battery gives it an average run time of about 30 minutes. A higher capacity battery is in the works that will extend its operational duration to an average of about 45 minutes. It has a really good inertial measurement unit (IMU), a device that monitors orientation, angular rotation, velocity and gravitational forces. The IMU includes three accelerometers and three rate gyros that enable it to actively adjust its stance and position. If it falls down, it knows exactly what to do, and it gets up very quickly.

It comes with a really nice HD camera on its head and can recognize objects. Optional force sensors on its feetthats four per foot, eight total, open up many avenues for locomotion research. The off the shelf version does not have a hand or gripper, but ROBOTIS is considering hand kits and any number of experimenters will hack it and add their own.

We at Virginia Tech led the R&D on this project in partnership with ROBOTIS, but we have no commercial involvement at all and are not making any money out of this project. When will it be available? ROBOTIS will start selling DARwIn-OP in late January 2011. Fabrication information is planned to be release by summer 2011 or sooner.

HIGH PERFORMANCE & OPEN PLATFORM VERSIONS

There are actually two DARwIn versions in the latest lineup: the DARwIn-HP, which stands for High Performance and the DARwIn- OP, for Open Platform as noted. Virginia Tech is building the HP and OP versions and giving them to over a dozen universities (see Partnering University table). Nine DARwIn-HP units and 26 DARwIn- OP units are to be given out in this program. Both are being distributed through our NSF grant. We in the robotics community are very excited about this. This NSF funded program will enable our partners, the participating universities and our students to take next steps in humanoid robotics research that will help advance our nations leadership in robotics technologies.

If the DARwIn family of robots increases the number of students majoring in computer science and engineering, even as it helps us design humanoid robots that better embody the capabilities of human beings, then all of our goals will be met. Together, we are creating a truly exciting enabling infrastructure for humanoid research, education and outreach.

SPECIFICATIONS

ROBOT: DARwIn-OP (Dynamic Anthropomorphic Robot with IntelligenceOpen Platform)

HEIGHT: 455mm (17.9 in.)

WEIGHT: 2.8KGS (6.3 lbs)

DEFAULT WALKING SPEED: 24.0cm/sec (9.5 in/sec) DEFAULT

GAIT SPEED: 0.25 sec/step

DEFAULT STAND-UP SPEED: (modifiable)

FACING DOWN: 2.8 sec

FACING UP: 3.9 sec

ONBOARD PC: 1.6GHz Intel Atom Z530 with 4GB flash SSD

COMMUNICATIONS: 5 LEDs, 2 RGB LEDs, 6 external I/O Ports, 8 external ADC ports, 2 Mbps serial bus; 4.5 Mbps Dynamixel servo bus,

MANAGEMENT CONTROLLER (CM-730): ARM CortexM3 STM32F103RE 72MHz

DOF: 20

STABILIZATION: 3-axis gyro; 3-axis accelerometer

POWER: Standby mode for energy conservation, charger and external power adapter; external power can be applied while removing battery

BATTERY: LiPo with 30 minute duration

COMPATIBILITY: Accepts legacy, current and future peripherals

DYNAMIXEL RX-28M SERVOS NUMBER OF SERVOS: 20, 6 per leg, 3 per arm, 2 for neck (plus a spare)

1 Maxon RE-Max customized DC motor

2 Durable metal gears, 193:1 reduction ratio

3 Up to 4.5 Mbps Buffered TTL interface

4 User programmable PID Gain

5 Auto-adaptable feed forward control

6 Dynamixel 1.0 and 2.0 protocols

7 Up to 4096 resolution non-contact feedback

PERIPHERALS

1 15bit full color LEDs on head

2 USB HD 2MP camera & mic

3 Wi-Fi 802.11 b/g/n

4 USB mic, speaker, audio line in and line out

5 HDMI Video Port, 2X USB Port

6 Speaker 8ohm 1W

7 Mini SD socket, Ethernet port, power switch

OPTIONAL ACCESSORIES

1 4 FSR pressure sensors for each foot

2 Gripper Arm, 4DOF

3 Yaw joint appended Gripper Arm 5DOF

4 2 mics for stereo sensing

ONGOING OPEN-SOURCE OPEN-PLATFORM UPDATES:

MECHANICS: Dimensions, kinematics, dynamics, CAD

ELECTRONICS: Controllers, sub B/Ds, schematics, parts

SOFTWARE: Development environment, Framework, Source Code

MANAGEMENT: Assembly diagrams, maintenance guide

COMMUNITY: User-developed code, application and mod examples

COMMENTS: The DARwIn-OP is an affordable, miniature humanoid robot platform with advanced computational power, sophisticated sensors, high payload capacity and dynamic motion ability designed to enable many exciting research and education activities. It features a high-speed bus, simple wiring, a wide-angle HD camera mounted in its head and a self maintenance kit with instructions, among its many well thought out elements. It has the power and speed to run and jumpa first in this category; and has a modifiable default gait speed of 0.25 sec/step. Specifications are intended to evolve: regularly check http://sourceforge.net/projects/darwinop for updates. The robot is the outcome of a joint collaboration between Virginia Tech, Purdue, University of Pennsylvania and ROBOTIS.

PARTNERING UNIVERSITIES… UNIVERSITY LEAD EDUCATORS

Colby College . . . . . . . . . . . .Bruce Maxwell

Drexel University . . . . . . . . .Ani Hseih, Youngmoo Kim

Georgia Tech . . . . . . . . . . . .Ayanna Howard

Michigan State University . .Joyce Chai

Ohio University . . . . . . . . . . .Robert Williams

Ohio State University . . . . . .David Orin ,Yuan Zheng

Northwestern University . . .Kevin M. Lynch

Purdue University: . . . . . . . . .C. S. George Lee, Cheng-Kok Koh, Yung-Hsiang Lu

Sweet Briar College . . . . . . .Dorsa Sandagol, Scott Pierce

University of Minnesota . . . .Nikolaos Papanikolopoulos

University of Notre Dame . .James Schmiedeler

University of Pennsylvania . .Daniel Lee

Virginia Tech . . . . . . . . . . . .Dennis Hong


Links

DARwIn-OP Updates (RoMeLa), www.romela.org/main/DARwIn_OP

DARwIn-OP Opensource Software & Evolving Specs, http://sourceforge.net/projects/darwinop

ROBOTIS, www.robotis.com

RoMeLa (Robotics & Mechanisms Laboratory), www.romela.org

Words by Denis Hong