The Man Behind the Robot That Built an IKEA Chair: Francisco Suárez-Ruiz, NTU Singapore.

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INTERVIEW: NTU’s Francisco Suárez-Ruiz talks about the recent IKEA-chair assembly project, the important role of Robotiq’s 2-finger grippers, human-robot collaboration, and his team’s future plans.

Francisco Suárez-Ruiz (R) and Pham Quang Cuong (L) show off the robot-assembled IKEA chair. Image: Nanyang Technological University, Singapore

Francisco Suárez-Ruiz has been all over the news recently.

The Colombian-born roboticist and research fellow at the CRI Group, Nanyang Technological University (NTU), Singapore led a team that built a robotic system capable of assembling an IKEA chair.

And from Wired and CNN to Reuters and beyond, the global press rejoiced.

The system comprises a 3D camera and two robotic arms equipped with Robotiq 2-finger adaptive grippers, supported by coded algorithms built on four different open-source libraries. [OpenRAVE | OpenCV | ROS | PCL]

In total, the assembly process took 20 min 19 s (3s for localization, 11min21s for motion planning, and 8min55s for execution).

Suárez-Ruiz (whose research interests include robot arm manipulation, path planning, grasping and computer vision for robotics), kindly agreed to be interviewed about the IKEA project, the important role of Robotiq’s 2-finger grippers, human-robot collaboration, and his team’s future plans.

Congratulations on the success of your project and the global media coverage.

S-R: Thanks. We were expecting some interest but the media coverage has been massive and it has exceeded our expectations by far.

Using off-the-shelf components makes an interesting statement, inasmuch as it shows that existing technology can be used to accomplish surprising new tasks. What were your reasons for taking this approach?

S-R: We wanted to develop capabilities that can be deployed elsewhere in the industry and by using off-the-shelf components we show the manufacturing industry, who tend to be skeptical, that it’s possible.

What criteria did you have in mind when choosing a gripper?

S-R: When selecting the gripper, we were looking at opening and force ranges as well as available interfaces with open-source tools such as ROS.

One additional factor was that I had some experience using
Robotiq’s 3-finger gripper during my PhD. [More details can be found in this paper:
Grasp Mapping Between a 3-Finger Haptic Device and a Robotic Hand.]

I like the combination between active and underactuated DoFs which results in a versatile gripper that is easy to control.

That previous experience gave us confidence that we were going to succeed in this project.

Why did you choose the 2 finger gripper for the recent IKEA-assembly project?

S-R: The fact that the 2-finger gripper has only 1 DoF forced us to simplify the grasping problem as much as possible.

I imagine that enabled you to eliminate a lot of unnecessary math and computation?

S-R: Yes. It simplified the requirements of the grasp planning component.

What was the integration process between the gripper and the robot arm like?

S-R: Integration was very easy. We just had to manufacture one coupling plate to attach the gripper to the F/T sensor.

On the software side, all our devices use Ethernet, with different protocols, which in the case of the Robotiq gripper is Modbus/TCP-IP, so the integration with our software architecture was easy as well.

(French language)

Robotiq: What role, if any, would you foresee for humans in systems like the IKEA-assembling bot? Imagine the same system (or a cell) using a human and a robot to achieve the same end. What difference would that have made to outcomes do you think (e.g. task completion times) and how might you have divided up the labour differently?

S-R: Because we work with traditional industrial robots rather than cobots, there was no role for humans in the system we developed. With industrial robots the role of humans is limited for safety reasons.

If the robots were collaborative, I would imagine some human-robot collaboration to assemble the chair faster.

Regarding dividing tasks between human and robots we are not experts in that subject, but I can imagine some collaboration in the form of handing over pieces, the human doing the screwing or things like that.

Robotiq: If you were tasked with designing and deploying a manufacturing cell with high production requirements and quality standards for assembly of IKEA chairs, would you use the current system or a human-robot collaborative design?

S-R: Under those requirements, I think a collaborative system would make more sense. Such a system would definitely help in terms of task completion times and flexibility of the system. With the new developments in AI, I think the difficult parts, such as ‘reading’ human intentions, are closer to being solved, so, I would expect human-robot collaboration to grow even more over the years.

Robotiq: What’s next for this project?

S-R: For now, the team is exploring the possibility of using AI to help the robot figure out the sequence of instructions from a manual. This is something we are just starting to explore.

We have also already started working with other exciting applications such as handling, drilling, glue dispensing, and inspection where several of the capabilities developed to assemble the IKEA chair can be applied.

Robotiq: So, do you have commercialization plans for the technology?

S-R: The team has been working on commercialization of the technology for the past year. We are currently focusing our efforts on industrial applications that are pain-points in existing production lines, particularly in the high-mix low-volume sector.

Robotiq: Thanks again for speaking with us. It’s great to see our grippers being used in exciting research work like yours.

S-R: Thanks for having me.

Further Reading:
Can robots assemble an IKEA chair?,” Science Robotics: Volume 3, Issue 17, April 2018