I have been studying the videos of the SafePath wheelchair "alpha trials." Most seem to have been in a shopping center that has a Sears store. I am AMAZED at how smooth the avoids are! GOSY has some real MAGIC in their GeckoMotorController software. I read on GOSY's website that it runs in compiled C on a 40mHz 8 bit banger. No OS there since this is a tight closed loop system. I particularly like the "constant energy" acceleration capability and the "no lurch" de-acceleration ramp downward. Very, very smart! Just a subtlety, but for a differential drive robot to go in a straight line is non-trivial. That is because no two wheels are identical. (Of course we know that is why we must balance our car tires to get a wheel vibration free ride.) So GOSY no doubt has an excellent way of calibrating their motor controller PID's such that going straight is easy for the robot. At every level of GOSY's tech, I see sound engineering solutions and/or a BRILLIANT invention that is WORLD CLASS.