Friday, April 5, 2013

Can open source hardware movement be used to realize low cost educational robots?

Robots are expensive! A simple robot arm costs more than ten thousand dollars. On the other hand, a state-of-the-art dish washer costs less than a thousand dollars. These two are not significantly different in terms of size or complexity, so what is the reason for such a large difference in their prices?

Most robots today get produced in relatively low volumes while popular dish washer models get produced in high volumes. This means they use different manufacturing approaches. Amortized setup and tooling costs are much lower in high volume production. High volume production lines use a high level of automation so human labor costs are reduced. Inventory costs are also much lower for products that sell in high volumes. Finally, amortized research and development costs are much lower for products that sell in high volumes. All of these factors combined together lead to higher sticker price for robots that are produced in low volumes. For obvious reasons, robots with high sales volume are relatively inexpensive (e.g., iRobot Roomba and Lego Mindstorms).

I am particularly concerned about high costs for educational robots.  Robots have emerged as wonderful teaching tools, and we ought to be using sophisticated robots in our classrooms. Unfortunately, most schools cannot afford them at current prices since we need robots that cost less than one thousand dollars. It is highly unlikely that production volumes for robots will go up dramatically over the next few years and bring costs down to below the one thousand dollar mark. We need to explore other ideas to reduce costs of educational robots.     

The open source software concept is revolutionizing the software industry. A newcomer can get started with very little initial investment and build upon the software created by others. The robotics community has embraced the open source software notion wholeheartedly.  The Open Source Robotics Foundation and Robot Operating System are leveling the field and giving an opportunity to a large number of participants to contribute to robot software development. Regardless, we still have a major problem in terms of access to the sophisticated hardware.    
The open source notion has been successfully used by the 3-D printing community in the context of hardware.  Open source hardware has led to a dramatic decrease in cost and helped in realizing low cost 3-D printers (e.g., RepRap and Fab@Home).  The robotics community is taking inspiration from this success and beginning to embrace the concept of open source hardware.   

The open source robot hardware idea calls for publishing the complete design details in an open forum. These details should include 3-D models for custom parts, instructions for making custom parts, detailed specifications for standard parts, instructions for assembling the robot, associated software for operation, and instructions for operating and maintaining the robot. 

Since people fabricate their own robots using open source design, this concept eliminates the need to pay for labor and inventory costs. People can buy components from low cost sources and reuse components from one robot design to other.  For example, a laptop can be shared across many different robots. Overall, this concept can be used to dramatically reduce the cost of acquiring a robot if one is willing to put time into building it.               

Curiously enough, the open source hardware cost model shares ideas from IKEA’s cost model that has allowed this Swedish company to sell furniture at low costs. IKEA’s model leverages three factors in reducing costs. First, it eliminates assembly costs. Second, shipping and storage costs associated with components are very small compared to shipping assembled furniture. Finally, despite offering a large variety of furniture, IKEA uses many shared components across furniture lines and is able to reduce component costs due to the economy of scale.   

Two undergraduate students in my lab, +Gregory Krummel and +Gina Knight have developed designs of two open source robots.  These designs were developed with educators and hobbyists in mind. The first one is an eight degree of freedom robot inspired by crocodile (please click here to see the video). This robot features an articulated tail, mouth, and legs, and it can demonstrate walking abilities and obstacle avoidance. The second one is a twelve degree of freedom robot that can climb stairs (please click here to see the video). Written instructions and computer-aided design (CAD) files can be found in the video descriptions. Individuals can fabricate and/or purchase their own parts from electronics suppliers and build these robots. These robots offer a new learning opportunity for those with an interest in robotics. 

Crocodile-Inspired Robot
Stair-Climbing Robot
I envision the following three different models around the open source robotics hardware movement.
  • People make custom parts on their own, purchase standard parts, and assemble the robot.
  • People buy pre-fabricated robot kits from suppliers and assemble robots.
  • People purchase preassembled robots from the suppliers based on open source design.
Once adequate numbers of open source robot designs are available, companies can use the free open source design files to fabricate parts and aggregate them with standard electronics into a kit to sell to those who do not have the equipment to make parts themselves.

The open source hardware concept is much more challenging in practice compared to open source software.  Hardware obsolescence is a major concern. Access to manufacturing equipment for making parts is also a challenge. We need to find ways to overcome these obstacles.  

Open source robotics can also promote innovation in the field of robotics. Interested individuals can begin with an open source robot design and improve parts of it. This is much easier to accomplish then designing and realizing a complete robot from scratch.  

I am looking forward to hearing from other groups that have developed open source robots. It will useful to compile a list of best practices in developing open source robot hardware.   

Can open source hardware movement be used to realize low cost educational robots? Please share your thoughts by posting comments on this post.


  1. It would be interesting to look at evolution of MakerBot (and the likes) in terms of materials (metals compared to resin) to see if robots in turn can be used to create low cost/educational robots. Open source model / marketplace for robotic components looks like a step in the right direction.

  2. In my opinion open source hardware should definitely lead to lower cost robots, and enhance innovation in robotics field. One issue could be the resulting lack of standardization of design procedures and of components.... but I guess that was the price to pay for open source software as well, and it can be overcome.

  3. "Open source robotics" holds a tremendous potential to accelerate progress in robotics and make robots ubiquitous in our society. As pointed out in the article, students are unable to access the right technology, and at the right moment, due to the high costs involved. This thereby makes it difficult to tap into their passion and high imagination capacities for creating novel robots. I see the open source approach as the best solution to this problem. There is also a wikipage now dedicated to this topic( ). I suggest that the two open source robots-crocodile and stair climber-be added to this page. When I designed and built four miniature wheeled robots (all from scratch) during my PhD, I wanted to standardize the designs, so others can replicate them for their research, but I didn't have a clue about how to proceed. Now, I realize: open source is the way to go.

  4. Interesting article. However I think we should be careful when we use the term "open source robotics". Modularity is a big problem with open source hardware. What mechanism design is optimal for one robot may not be optimal for some other robot. IKEA has done a great job in terms of creating fastener "modules" for furniture. It continues to amaze me how MOST of IKEA furniture fasteners rely on one out of three or four signature IKEA fastening methods.

    In my opinion releasing complete open source designs for a very specific robot would be of limited value. Unlike in software design (where an unfamiliar person can somewhat comprehend what functions/modules perform what tasks), it is hard for someone unfamiliar with the design process to break the hardware design into specific modules.

    The starting point for open source hardware still needs to be open source modules that can be a part of a "mechanism library" for specific tasks. These designs should be self contained on the inside for the specific task it needs to perform. (similar to functions/packages in open source software). Tweaking simple parameters such as the build material or predesignated parameters in the link geometry should be able to make these designs modular.

  5. The call for an educational robotics company with an IKEA-like business model is really interesting. Last fall, I helped organize a group 'hackathon' that took place over an entire weekend at the University of Maryland as part of a student group called Hyperion. Once we got up and running, you could see the fun that students were having and the ideas flowing through the room. Unfortunately our progress was astonishingly slow: libraries for computer vision codes had to be synced, motors only work with specific speed controllers which also only work with specific batteries, etc. The lack of interchangeability, both in software and hardware, was a huge issue for us. It would be great to see an effort from some university/group take the lead in making robotics more easily accessible for common students.

  6. Also: As far as I'm aware, DIY drones ( may be the closest to what we are talking about here, although they are focused on the hobbyist rather than the educator.

  7. A distinct benefit I see from open source hardware is variety. Uniformity can control quality and expectations, but can also limit the ability to innovate from existing designs. One type of solution for one robot may work fantastically, but put that solution it in a different environment or make the robot do another task and it can present a problem. This applies to both modules and full designs.

    This is where a student, hobbyist, or engineer can look at an open source design and consider how to complete a certain task, fit certain parameters, and improve on existing hardware. This spawns both education and innovation. Students can create a standard kit robot to learn the basics, and then truly explore robotics when they develop a different design idea and put their ideas into action. Arduino has mastered this model by having many unique platforms that support many applications by bridging software and hardware in a very affordable package. Creating a platform that can spark and support new ideas is difficult, especially for educators, and open source hardware reduces that starting barrier for robotics education, research, and home development.

  8. Thanks, SK. I agree with everything you say here. I am very interested to see how our efforts with the open source hand turn out. We are trying very hard to minimize many of those obstacles that you point out, but there are challenges, of course. We will be learning a lot in the coming months about what it takes to get people to invest the time and money to build an open source platform (even if it is much less money that purchasing it), and then being happy with the results. One particular challenge will be getting people/groups who aren’t “mechanically inclined” to be willing/able to build these platforms, as even the simplest steps can be daunting/difficult.