SINGAPORE -It can take some people hours hunched over packs of screws and manuals to assemble an IKEA chair. But a new made-in-Singapore robot can do it in less than 10 minutes.
Designed by a team from the School of Mechanical and Aerospace Engineering at Nanyang Technological University (NTU), it comprises a 3D camera and two arms equipped with grippers to pick up objects.
"For a robot, putting together an IKEA chair with such precision is more complex than it looks," said assistant professor Pham Quang Cuong, one of three team members.
"The job of assembly, which may come naturally to humans, has to be broken down into different steps, such as identifying where the different chair parts are, the force required to grip the parts, and making sure the robotic arms move without colliding."
The robot is designed to mimic the human function of assembling objects - the 'eyes' through a 3D camera and 'arms' through industrial robotic arms capable of six-axis motion. Each arm is equipped with parallel grippers.
The robot starts the assembly process by taking 3D photos of the parts laid out on the floor to generate a map of the estimated positions of each part. This is to replicate, as much as possible, the cluttered environment after humans unbox and prepare the parts.
Mounted on the wrists are force sensors that determine how strongly the 'fingers' are gripping and how powerfully they push objects.
This allows the robot to precisely and consistently detect holes by sliding the wooden plug on the surfaces of the work pieces, and perform tight insertions.
The NTU team, including research fellow Dr Francisco Suárez-Ruiz and alumnus Mr Zhou Xian, also developed their own algorithms to programme the robot for two-handed motion that is fast and collision-free.
It was especially challenging for the robot to grip the pieces tightly and perform tasks such as inserting wooden plugs, said assistant professor Pham. He explained that industrial robots designed to be precise at positioning are usually bad at regulating forces.
The robot put together IKEA's Stefan chair in eight minutes and 55 seconds. Prior to the assembly, it required 11 minutes and 21 seconds to independently plan the motion pathways and three seconds to locate the parts.
All the components that make up the robot are easily available and relatively low in cost.
The three years of research behind this invention was supported by grants from the Ministry of Education, NTU's innovation and enterprise arm NTUitive, and the Singapore-MIT Alliance for Research & Technology.
The team is also working with companies to also apply this form of robotic manipulation to a range of industries, such as the aircraft manufacturing industry.
