This simple motorized kneeless walker travels with a gyroscopically driven shuffling stride. The onboard motor just spins the flywheel and forces it to nutate (nod up and down). Reactive gyroscopic torques acting on the rapidly spinning flywheel and the chassis do the rest.
https://www.youtube.com/watch?v=3KCg2zI0kfIAs you can see at 0:47, net travel without the spinning flywheel and its large axial moment of inertia is nil. That's because the forward steps are actually gyroscopic precessions induced by the flywheel's forced nutations.
Operation couldn't be simpler:
o Use full power to get decent travel speed.
o Reverse the motor to reverse the direction of travel.
o Pull gently on the "leash" to steer.
Noted roboticist John Jameson introduced the first "Walking Gyro" in 1981. The concept soon made its way into at least 2 commercially successful walking robot toys, and a number of DIY versions have popped up on YouTube in recent years...
https://www.youtube.com/watch?v=8qM3Bao3zJQhttps://www.youtube.com/watch?v=HJPlPwwR8Ak.
This is the only LEGO version I know of. Its feet don't lift completely off the ground, but even a shuffling gait took a tremendous amount of fiddling with flywheels, spin transmission ratios, and most of all, the feet! The foot disks used in most walking gyros failed miserably, as did nearly every other foot design I tried. The bird feet shown here emerged after hours of trial and error. And they work only when
pigeon-toed, as shown.
Photos and write-up
here.