There are three ideas to where the rider should be located in respect to the axle of the Craigway.

    1. Above the axle

    2. Below the axle

    3. Directly on the axle, technically at or negligibly distanced from it


Above the Axle

        Locating the Rider significantly above the axle point has several major flaws, but some benefits.  In many other autonomous robots where a variable weight does not come into play this works fine.  But with heavy loads of varying mass, this becomes impractical.  Under no load the robot has no problem detecting sway and compensating with quick acceleration.  Under load is another story.  The trick to to create equivalent forces to level the robot.

Below the Axle

        Locating the base of the rider below the axle would be great if the axle could be at the riders center of mass.  There would be no balancing forces required....Think about it.  Half his weight is behind the axle, half ahead.  But it's too big and bulky to create six foot diameter wheels, other than being well beyond the purpose of this project.

        Below the axle creates several large theoretical problems.  Firstly, you're unevenly splitting the mass of the rider into two different directions.  It's the largest and most difficult to compensate for of the problems.  I cannot predict how heavy or how light the lower body of a rider will be.  All mass below the axle will pull the rider back upright when tilting somewhat assisting in however a negligible amount it is.  There is still enough to create unease about how perfectly the code will be written.

Directly on level with the axle.

        If the base of the rider's feel sit level with the axle, or at a negligible distance.  The above problems won't come into play with this position of the center of gravity.  This is how I hope to set up the Craigway to operate.  This makes solving the physics behind the pbasic much simpler and less dynamic per rider.