Overview

The O.R.B. (orb)  is a self-propelled, self-contained, rolling sphere. It is uniquely capable of rolling forwards and backwards at varying speed as well as turning while in motion.

Forward motion is achieved by shifting the ball’s center of mass out of equilibrium by means of  a motor-driven shaft spanning the diameter of the sphere, causing the ball to continuously ‘fall’ forward. Turning is similarly accomplished by shifting a pendulum mass to one side, causing the ball to lean, and change its direction.

The control program for The O.R.B. functions by converting radio control (RC) signals into DC motor actions.  Our  RC receiver sends a 60 Hz Pulse Width Modulated (PWM) signal with a low duty cycle. A programmable microprocessor characterizes these signals and sends usable PWM commands to the two H-bridge amplifiers. Thus we can control the drive and steering motors through a full range of motion.  

An encoder coupled to the steering motor is used by a proportional control algorithm to position the pendulum.

The O.R.B. is powered by a self contained 12 Volt rechargeable battery system.  A second, independent battery system provides power to the microprocessor.  The weight of these batteries combined with the steering motor provide weight to our shifting pendulum system.