Design and Build Methods for a Variable Radius Wheel Mechanism

One of the main concerns regarding robotic mobility is its ability to traverse different types of terrain. As we know from our own experiences driving and riding wheeled vehicles, different types of wheels are better for different applications. In the same vein, giving robots wheels of variable radius can change the torque needed to traverse the terrain, the speed of the vehicle, and the way the vehicle handles the roughness of the terrain. In our prior research of basic modes of mobility, we were able to identify a method for creating a variable radius wheel mechanism. This paper will focus on the mechanical manipulation needed to actuate the mechanism as well as several different ways to implement it. In application, one mechanism can be the sole mobility source for a robot or a few can be chained together to create a more conventional system. This mechanism can be used to give us more versatility in our application scope as well as provide us with more control over the vertical motion of the Center of Mass of a robotic vehicle.