A new collaborative dual arm robot named YuMi uses a unique mechatronic design and innovative motion control to eliminate the need for barriers, cages, and software safety zones. In developing the new design concept, aimed at making automation technically and economically feasible for small parts assembly, the goal was to automate cells that can coexist with both manual work cells nearby and implement an inherently safe environment when interacting with human workers.
Unique Mechatronic Design
YuMi’s design is based on a revolutionary integration of motion control software, speed-limited hardware, reduced weight, a compact frame, and 14-axis agility. Lightweight, padded magnesium arms can cease operation in milliseconds if necessary, in the event of an unexpected collision, for example, while cameras embedded in its integrated hands monitor the immediate environment. The combined effect is to ensure the safety of human coworkers on production lines and in fabricating cells.
“YuMi is designed not to hurt people, even when contact occurs,” Nicolas De Keijser, Assembly and Test Business Line Manager for the Robotics Business Unit at ABB Inc., told Design News .
“The soft padded dual arms and the lightweight design contribute to the overall safety of the robot’s co-workers. The design of the robot makes humans feel safe and comfortable.”
“Put simply, in the unlikely event of a safety failure, the physical robot including its grippers is incapable of causing harm,” De Keijser said. “Moderate robot speeds also allow time for human reaction to avoid collision.”
YuMi is what ABB claims is the world’s first inherently safe, collaborative, industrial robot. Its inherently safe design has been classified as a global certification by UL.
Focused on Small Parts Assembly
Dual arm technology used in the design of the robot offers many advantages for assembly applications. It enables flexible fixturing within an assembly cell, as one arm can be used as fixture while the other manipulates the part, and also allows for guiding of flexible parts. Another key is that YuMi enables high throughput in a collaborative manner with its small footprint, speed, and precision/accuracy to thread a needle.
The robot’s inherently safe design is intended to eliminate the need for fencing, caging, or other barriers, and its servo gripper hands can easily locate and then direct the grippers to pick parts. Real-time algorithms set a collision-free path for each arm, customized for the required task. Padding protects coworkers by absorbing force if, in the unlikely event, contact is made.
“If the robot encounters an unexpected object, the slightest contact with a human coworker for example, YuMi can rapidly diagnose the change in its environment and, if necessary, register the overload, shutting down the motion within milliseconds to prevent injury,” De Keijser said.
If YuMi senses an unexpected impact, such as a collision with a coworker, it can “pause” a motion in progress within milliseconds, and the motion can easily be restarted again. Additionally, the robot can rapidly diagnose changes in its environment and, if necessary, register the overload, shutting down its motion within milliseconds to prevent injury. When this is combined with the floating padding, safety