Mechanical and system design of Egg shape robot

In this paper, we want to build a small robot (about 40 cm height) that has the shape of an egg. The robot has no external actuators; instead it is actuated by a heavy fast rotating gyro (flywheel, symmetric rotor) in a hollow sphere that is located in the middle of the egg. The outside structure of the egg robot and the gyro are connected by using a gimbal, which is a similar structure as a control moment gyroscope in spacecraft. The joints of the gimbal can be actuated. In this way, the orientation of axis for the gyro in relation to the egg can be changed. Since the inertia of the axis of the fast rotating gyro is large in relation to the outside structure, a relative rotation of the axis against the outside structure results in a motion of the egg by inertia principle. In this way, we can use this principle for controlling the robot to move forward, turn around and stand up.