Robot learns to brush tangly hair without inflicting pain

Teaching a robot to brush hair—especially without just powering through tangles and ripping them out of your scalp—is harder than you think. MIT roboticists and Harvard mathematicians collaborated on a computer vision system to "see" curls and tangles and come up with a gentle brushing strategy. The robot itself wields a sensor-laden brush to provide real-time force feedback to the software. From MIT News:

With rapidly growing demands on health care systems, nurses typically spend 18 to 40 percent of their time performing direct patient care tasks, oftentimes for many patients and with little time to spare. Personal care robots that brush hair could provide substantial help and relief[…]

CSAIL postdoc Josie Hughes and her team opted to represent the entangled hair as sets of entwined double helices —  think classic DNA strands. This level of granularity provided key insights into mathematical models and control systems for manipulating bundles of soft fibers, with a wide range of applications in the textile industry, animal care, and other fibrous systems. 

"By developing a model of tangled fibers, we understand from a model-based perspective how hairs must be entangled: starting from the bottom and slowly working the way up to prevent 'jamming' of the fibers," says Hughes, the lead author on a paper about RoboWig. "This is something everyone who has brushed hair has learned from experience, but is now something we can demonstrate through a model, and use to inform a robot."