2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Singapore engineers taught two robotic manipulators to assemble an IKEA chair from a set of original parts. They independently take parts, insert dowels into them and connect them into a single structure, the developers say in Science Robotics magazine.
Assembling furniture from ready-made kits with detailed instructions can seem relatively easy. But robots need to have an accurate positioning system in order to correctly position the parts, force sensors in order not to break them, as well as have several other skills and know the exact assembly sequence. As a result, there is little development in this area and most of them can only perform one of the basic operations. For example, in 2015, engineers at Nanyang Technological University, led by Quang-Cuong Pham, taught robots to insert a wooden dowel into a groove in furniture.
Now they have refined this system and taught robots all the necessary skills to assemble a chair frame from a set of parts. As in previous work, the researchers used two off-the-shelf robotic arms with grippers at the end and six-axis force sensors. A 3D camera is installed in front of the robots to help them “see” details and synchronize their movements. It overlays the part models on the scanned space and determines the position of the real parts.
Since the robot has a high, but not perfect positioning accuracy, the engineers have developed an interesting way to find the dowel slot. After the dowel touches the surface of the part, the robot starts to move it in a spiral until the moment when the part practically ceases to resist - this means that the dowel is over the groove. The robot then simply inserts the dowel before the resistance of the part reaches a predetermined threshold.
Dowel groove search method by touch
The developers have created a motion planning system that allows robots to perform actions together, for example, one of them holds a part, and the other takes a dowel and inserts it into a groove. In addition, it helps them not to collide, despite the fact that their areas of movement overlap. Engineers demonstrated the work of robots using the example of a wooden chair from IKEA. It took the robots a little over twenty minutes to assemble a chair from a set of parts (most of the time was spent not directly on the movements, but on their planning):
Some people prefer to assemble furniture not from ready-made sets, but from raw materials according to their project. Engineers at the Massachusetts Institute of Technology have created for such people a system of several robots that can independently cut furniture parts from raw materials. After that, all that remains is to assemble them on their own or to entrust this to robots like those created by Singaporean researchers.