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.