FreeIO.org is currently running a poll to determine what sort of free hardware project the community would most like to see developed. At present the poll is leaning heavily towards robots. So I thought it would be worthwhile to do a quick survey of existing free/open hardware robot projects to see what there is to work with and improve on. There are a lot of FLOSS (Free/Libre Open Source Software) robotics projects out there too but this article will focus on hardware projects that are under free hardware licenses. See the FreeIO.org “about page” to learn more about the concepts of free / open hardware.

I’ve attempted to list the projects roughly in chronological order by the project’s creation date. To qualify for this list, a project needs several attributes: 1) it must be a complete mobile robot, not just part of a robot such as a manipulator arm 2) the hardware design documents (e.g. CAD files, schematics, etc) must be available under a free license (i.e. a license that protects the user’s basic freedoms – licenses with commercial-use restrictions are NOT free/open licenses, 3) at least one working robot must have been developed and demonstrated. Projects that are in the planning stages didn’t make the list as we’d like to see well-proven designs that have been well-tested in the real world.

Read on for the full list of free/open hardware robot designs!

Update 30 Jan 2013 : Added the veter project

: Added the veter project Update 6 Feb 2013: Added the ArcBotics Hexy project

Sea Perch ROV

Date: 1997

Hardware License: CC BY v3.0

Software License: n/a

The Sea Perch ROV started out as a project description in the spiral-bound book Build Your Own Underwater Robot and Other Wet Projects by Harry Bohm and Vickie Jensen. Later, Professor Thomas Consi of MIT discovered the Sea Perch design and incorporated it into his Ocean Engineering Program curriculum. The MIT project took the original idea and turned it into a simpler and cheaper ROV. MIT also developed parts lists and build manual for the CC-licensed project. MIT’s project was partially funded by the Office of Naval Research, who helped adopt the Sea Perch design as part of a partnership with the Society of Naval Architects and Marine Engineers (SNAME). Through that program the design was developed into a kit and a contest managed by the Association of Unmanned Vehicle Systems International Foundation. Over 50,000 students have participated so far, perhaps making this most widespread free hardware design for a robot ever created. For more information see the ONR Sea Perch website.

The Sea Perch is a Remotely Operated Vehicle (ROV) rather than a true autonomous robot but the open design can be (and has been) modified to be fully autonomous by the user if desired. Sea Perch kits are available for $143 USD.

Open PINO Platform Humanoid Robot

Date: 1999

Hardware License: GNU FDL

Software License: GNU GPL

The Open PINO project was an attempt by Japanese research organizations to establish a freely licensed, standardized humanoid robot platform suitable for research and collaboration. The project started in 1999, with prototypes shown as early as 2000. The robot was 72 cm tall, had 26 degrees of freedom, and weighed 4.6 kg (more specs). It could dynamically balance and walk. The control software was based on genetic algorithms. The chassis, boards, and software were released under GPL or GFDL licenses. The project description contained this description:

Open PINO Platform is the project to accelerate the research and development of humanoid robots by providing the technical information of PINO open to the public. Everyone can use PINO as a base of the research and development, in other words, to foster PINO to be more sophisticated humanoid robot. We hope PINO to play the similar role as LINUX, for humanoid robot development. Please join us to foster PINO!

In 2001, a Japanese company, ZMP, Inc., developed a kit version of the PINO robot and also offered a plastic exterior shell that was not freely licensed. While the robot made headlines for a while, the high cost of the kit combined with the high complexity of reproducing the mechanical and board designs prevented widespread acceptance of the robot. Costs to build a PINO could run as high as $30,000 USD. In 2004, ZMP released a PINO version 2 but the license status is unknown. The version 2 kit sold for around $45,000 USD.

It appears there is no longer active development on PINO project. Most of the websites that originally hosted the designs are gone and the designs do not appear to be available online any longer. The ERATO Kitano Symbiotic Systems website is still operating and has what appears to be a link to the designs but it is password protected. The login used on the original PINO site to access the designs was user: “pino” and password: “open-pino” but these do seem to work on the Kitano site. I would be interested in obtaining the PINO design documents from anyone who has them in order to make them available to the community once more.

iCub

Date: 2004

Hardware license: GNU FDL

Software license: GNU GPL

The iCub is a 1 meter tall humanoid robot platform developed by the RobotCub Consortium, a group of EU Universities. The goals were identical to the PINO project but the iCub has met with much more success, perhaps because of the large number of research institutions that are participating in the project. The robot’s hardware, firmware, and high-level software are all under free licenses; in most cases the GNU FDL and GPL. The RobotCub Wiki is a good source of information on the iCub robot design. As of 2010, over 8.5 million euro has been spent on development of the iCub. The robot has 53 motors, providing two times the degrees of freedom available in the PINO humanoid. Not surprisingly, the iCub is also much more costly to build than the PINO. Assembled units are sold at cost by the Italian Institute of Technology. Cost per unit is $200,000 euros (about $266,000 USD). Development work continues and the iCub v2.0 is now in development. The v2 robot will likely cost about 25% more than the v1.

e-puck Robot

Date: 2004

Hardware license: e-puck Robot Open Hardware License

Software license: e-puck Library License

The e-puck project of the Ecole Polytechnique Fédérale de Lausanne as collaboration between the Autonomous Systems Lab, the Swarm-Intelligent Systems group and the Laboratory of Intelligent Systems. The goal is create a free/open miniature mobile robot for educational use that has a simple design, is flexible, user-friendly, and inexpensive. The e-puck is a differential drive robot with a variety of sensors. Many hundreds of e-puck robots have been produced and tested. The design has gone through several releases with improvements from previous versions. Inexpensive, in this case, means 950 CHF ($1050 USD) per robot for assembled units. No kits are available but all design documents are available on the project website.

Both the hardware and software are released under one-off licenses. They appear to meet the guidelines of the Free Software Foundation and Open Source Hardware Foundation closely enough to qualify as free/open. However, it’s unknown whether they are compatible with standard licenses so creating derived works that integrate these designs with others under conventional licenses may be problematic.

Jasmine Swarmrobot

Date: 2005

Hardware license: GNU GPL

Software license: GNU GPL

The Jasmine Swarmbot project maintains the design for a small (less than 3cm cube) robot optimized for swarm-related research. Their goal is maintain a per-robot cost of 100 euros ($133 USD) or less. The robots have differential drive, have a variety of sensors, and robot-to-robot communication. The robots have been widely used in research projects, in some case in swarms of over 100 robots. The design is robust and stable. The Jasmine robot was original developed at the University of Stuttgart but the design is now maintained independently. No kits or assembled robots seem to be available.

SERB

Date: 2008

Hardware license: CC BY-SA v3.0

Software license: CC BY-SA v3.0 (see note below)

SERB (arduino-based SErvo RoBot) was a completely free/open hardware and software robot design created in 2008 by Oomlout, a UK company that developed DIY Arduino-based projects and kits. The robot consisted of laser-cut acrylic combined with two RC servos, an open hardware Arduino microcontroller, and assorted off-the-shelf hardware. The result was a differential drive robot with whisker sensors for impact detection. For a while, kits were available from Oomlout and other online DIY stores. Interest in the design has declined and kits are no longer available. The design is not under active development any longer.

Software license note: The software for this project is licensed under a CC license, which is not a recommended practice since CC licenses don’t adequately handle the legalities of object code vs source code. The FSF and the Creative Commons guidelines discourage the use of CC licenses for software. Software licensed in this way is not GPL compatible and generally cannot be mixed with conventionally licensed FLOSS software and would need to be re-licensed or replaced before it could be combined with free or open source software for use in a larger project. Never use a CC license for software!

veter

Date: 2010

Hardware license: GNU GPL

Software license: GNU GPL

A small team of robotics enthusiasts in Germany have been hard at work on a project called veter for several years. The first public release was made in 2010 and the group has continued to revise and improve the robot. The hardware and software and released under the GNU GPL license and available from a git repository. The latest version of the robot is a differential drive tracked robot. It uses a combination of off-the-shelf parts, 3D printed parts, and open source boards like the BeagleBoard-xm. The robot is equipped with ultra-sonic rangers, stereo video, compass, GPS, and other sensors. The robot can communicate via WiFi. It can operate autonomously or can be controlled by a human operator from a navigational interface that includes real-time streaming video. The software for autonomous navigation is well-developed and utilizes PID control as well as a Kalman filter and particle filter for position estimation. No assembled units or kits are currently available but the website suggests that a kit is under consideration and might be available in the future. For more information see the main veter website or the veter blog.

AMIGO

Date: 2011

Hardware license: CERN OHL v1.1

Software license: Various

AMIGO is a service and care robot that is a project of the CST group at Eindhoven University of Technology. The name stands for Autonomous Mate for IntelliGent Operations. The robot is roughly a humanoid torso mounted on a rolling platform. It stands about 135 cm tall and weighs around 80 kg. It uses three PC type motherboards and other off the shelf hardware including ethernet routers and switches. Vision is based on a Microsoft Kinect. The robot has two arms with grippers. The software includes Ubuntu GNU/Linux, ROS, and custom code in C++, Python, JAVA and Lisp. The cost of the prototype is unknown but at the time the design was open sourced, the researchers noted that such robot typically cost as much as 400,000 euros but “our aim is that within a few years you’ll be able to build the successor to our AMIGO for 10,000 euro”. It’s unknown whether anyone has used the designs to build more AMIGO robots. No kits or assembled robots are available for purchase at this time.

Ikimo Robot Platform

Date: 2011

Hardware license: CC BY-SA v3.0

Software license: CC BY-SA v3.0 (see note below)

The Ikimo robot is a 4 wheeled chassis that uses skid-steering. The design include both the robot’s chassis and the Atmel-based microcontroller. Drive motors may be either RC servos or DC motors. It appears there are no motor encoders or other sensors in the design. A full parts kit is available for $135 USD.

Software license note: The software for this project is licensed under a CC license, which is not a recommended practice since CC licenses don’t adequately handle the legalities of object code vs source code. The FSF and the Creative Commons guidelines discourage the use of CC licenses for software. Software licensed in this way is not GPL compatible and generally cannot be mixed with conventionally licensed FLOSS software and would need to be re-licensed or replaced before it could be combined with free or open source software for use in a larger project. Never use a CC license for software!

Mini-Skybot

Date: 2011

Hardware: CC BY SA v3.0

Software: GNU GPL

Mini-Skybot is a differential drive robot with two RC servo-driven wheels and a castor. The robot lacks motor encoders and has only a single sensor: an ultrasonic range finder. The robot is designed to be 3D-printable and uses open source mechanics and electronics. Of particular note about the Mini-Skybot is that it was designed using only open source tools. The design was created for educational use. The primary goals were minimal expense and a simple design useful for teaching students programming. The design was a collaboration between the Carlos III University of Madrid Robotics Lab and Universidad Autónoma de Madrid.

The Mini-Skybot Wiki provides access to the hardware design files and software as well as step-by-step assembly instructions with photos. No kits or assembled units are available at this time. The project is still active and a Miniskybot v2 prototype is being developed.

Thymio II Project

Date: 2011

Hardware license: CC BY SA v3.0

Software license: GNU LGPL

Thymio II is an improved version of an earlier robot, not surprisingly called Thymio. The robot was developed as a collaboration between Ecole Polytechnique Fédérale de Lausanne (EPFL) and the Ecole Cantonale d’Art de Lausanne. Goals of the project include minimal cost and wide distribution. Thymio II is a small, differential drive robot with a variety of behaviors. It can be programmed using a visual programming language. Assembled robot can be purchased for $200 USD. Hardware design files including CAD files and schematics can be found on the Thymio II website. No kits are available at this time.

Tiny Wanderer

Date: 2011

Hardware license: GNU GPL

Software license: GNU GPL

The Tiny Wanderer robot is the result of a year-long series of DIY robot workshops at the Dallas Personal Robotics Group that took users through the process of building an entire robot from scratch. This includes designing and building a PCB for an Atmel AVR based microcontroller, laser-cutting a robot chassis, and combining the parts into a small, differential drive robot with several sensors for light detection, edge detection and line following. The Tiny Wanderer robot made the rounds of Instructables, MAKE magazine, and many robots were built in a variety of material including acrylic and wood. A full kit of parts is available through Maker SHED for $179. All design files, schematics, and source code are available for download. Design files for laser cut and scoll saw versions are provided.

Aracna Open Source Quadruped Platform

Date: 2012

Hardware license: GNU GPL

Software license: GNU GPL

The Aracna Open Source Quadruped Platform is a project of Cornell Creative Machines Lab. The design intentionally uses non-intuitive motor commands for locomotion in order to create a challenge for new gait learning algorithms, developed through evolutionary algorithms. The design uses a combination of off-the-shelf and 3D printed parts. One unique design characteristic is that unlike other legged robots, the legs do not contain any servos. All servos are located in the body and are connected to leg joints through mechanical linkages. A paper is available that provide more technical detail on the design, Aracna: An Open-Source Quadruped Platform For Evolutionary Robotics (PDF format). Component costs are estimated to be $1400 USD. At this time no kits or assemble units are available for sale.

ArcBotics Hexy

Date: 2012

Hardware license: CC BY-SA v3.0

Software license: MIT

The ArcBotics Hexy is a hexapod robot. The design was funded by a kickstarter campaign in 2012. The robot uses 19 RC servos, three for each of the six legs, plus one for a sonar-equipped sensor array. The design aims at being low-cost and the designers claim a completed Hexy costs only 1/10 the price of proprietary hexapod kits. Structural components are laser cut acrylic. The controller, known as the Servotor32, is also an open source design. Software and hardware design files available on github for those who wish to build from sratch. A complete Hexy kit is available for $250 USD. A fully assembled Hexy robot is available for $500 USD.

OpenROV

Date: 2012

Hardware license: CC BY-SA v3.0

Software license: CC BY-SA v3.0 (see note below)

The OpenROV project has developed a hardware design for an ROV capable reaching depths of 100 meters. You can build the design yourself from scratch using the design files provided by the project, or you can buy kits or completely assembled ROVs. The design relies on the BeagleBone microcontroller, itself a partially free hardware design.

Software license note: The software for this project is licensed under a CC license, which is not a recommended practice since CC licenses don’t adequately handle the legalities of object code vs source code. The FSF and the Creative Commons guidelines discourage the use of CC licenses for software. Software licensed in this way is not GPL compatible and generally cannot be mixed with conventionally licensed FLOSS software and would need to be re-licensed or replaced before it could be combined with free or open source software for use in a larger project. Never use a CC license for software!

OpenROV Meets the OpenWATER from Gerty on Vimeo.

Open Hardware Mobile Manipulator (OHMM)

Date: 2012

Hardware license: CC BY SA v3.0

Software license: GNU GPL

The Open Hardware Mobile Manipulator project was started by the Geometric and Physical Computing group at Northeastern University College of Computer and Information Science. The group set out to design a small mobile robot with a manipulator arm for educational use. A design goal was to use off-the-shelf hardware and software as much as possible. Pololu Orangutan SVP and Pandaboard microcontrollers are used. There are no custom PCBs. CAD files are provided for a creating a variety of 3D printed and laser cut components. Once all the parts are available, the only tools needed to assemble them are pliers and screwdriver. Custom software was developed which integrates a number of existing free software robotics libraries such as OpenCV, JavaCV, and libfreenect. Current work is underway to develop an ROS interface. The total build cost is estimated at $1730 USD. No kits or assembled robots are available at this time.

Other Open Hardware Robots?

It’s almost certain I missed some projects, so post a comment if you know of others. I’ll revise the article as needed to include any I missed. However, there were several robots widely touted to be open hardware or free hardware which I evaluated for this article but declined to include. In most cases the robots were either under licenses which were too restrictive to qualify as free/open or lacked any license at all. In one case I was unable to even find any hardware design files to evaluate. If you are associated with any of the following projects and can point me to updated information regarding the copyright and license status of your project by posting a comment with links, I’ll take another look.

ArcBotics Hexy – claims to be open source but design files lack any explicit copyright or license information. Without it they must be assumed to be “all rights reserved” and not available under a free/open license.

CMU Chiara Robot – claims to be “open” but no hardware design files, license, or any evidence of this being an open hardware design could be found.

DARwIn-OP Humanoid Robot – claims to be “open” but most design files lack any explicit copyrights at all and some have a copyright plus a non-commercial use license, so are too restrictive to be considered free/open.

Maryland Robotics Center Open Source Robotic Crocodile – claims to be open source but design files and source code files lack any explicit copyright or license information. Without it they must be assumed to be “all rights reserved” and not available under a free/open license.

NimbRo-OP Humanoid Robot – claims to be “open” but hardware license has a non-commercial use clause, making it too restrictive to qualify as free/open.

Open Q.bo – claims to be “open” but no hardware design files, license, or any evidence of this being an open hardware design could be found.