Call me a sceptic but the guy's too late. Honda have been using the exact same concept in their electric power steering for some years. They use an electric motor to control the speed of the ring gear* to vary the ratio applied through the Sun and Planetary gears. * If you find the words 'ring gear' amusing, it's correct name is 'annulus' lol.
There's nothing revolutionary about it. It's the same as a car with an open diff running on a jack with the drive wheels both off the ground. If the tailshaft speed remains constant and you slow or stop one side the other side increases speed. Drive one side faster with an electric motor and the opposite side slows or stops.
It took the guy 20 years of his life to work that out?