The universe linked to exoskeletons is made up of a thousand different nuances. There are devices that increase performance, others that support the back, still others dedicated to people with disabilities. Finally, others add functions to functions, multiplying the possibility of carrying out actions.
This is the case of "redundant" devices. Having two arms is comfortable and natural, but the opportunities increase considerably if we have four. There is a limit, however, and it is currently represented by the user interface, which is often complicated to use. It would be better to say "was", given that today there are the robotic arms of the Co-Limbs project.
The key factor: intuitiveness
An international group of engineers from Japan and France have created a pair of wearable robotic arms that allow the user to interact with objects. Development will be presented at the SIGGRAPH Asia 2019 conference.
The interface is the strong point: even users who interact with this system for the first time can use it immediately. They make simple movements and complex tasks in a very wide range of possible applications. Here is a video showing some of them.
Co-Limbs' robotic arms are placed on the user's back. A controller is positioned on each of them, at wrist height, to be able to guide the movements (both hands and fingers). The fingers can move separately, clench into a fist or open.
How does Co-Limbs work?
The device works with objects in two stages: first the arms 'catch' an object, then they begin to manipulate it with the user's help. The applications can be different, all useful:
Support for lifting heavy objects: it is the 'classic' use of an exoskeleton. The arms can exert force (equal or greater than that of a user) halving or eliminating the effort of lifting or holding a lifted object. In the demonstration, a researcher grabs a tray with robotic arms and then moves the contents with his hands.
Programming of actions: the arms can be programmed by “recording” a specific action and then repeating it at will. In the video a researcher lets himself be "blown" with a fan after having appropriately recorded the movement on Co-Limbs. It's just an example, even a rather frivolous one, but it gives you the idea.