Brian Mechanism - What it is

Brian Mechanisms are a class of mechanisms that are functionally intended to convert fixed robots into compound robots so that they can be used to economically make cheap scalable robots.

Brian mechanisms have a fixed robot part and a compound robot part. The fixed robot is carried on a platform which is carried either by a set of legs or wheels. The fixed robot can be anything from a CNC to agricultural machines.

The concept is this: a fixed robot's price is reduced by making it smaller. Then a relatively cheaply priced system is used to move that fixed robot precisely over the area it is intended to work in. This forms a compound robot. The advantages of the fixed robot are inherited by the compound robot.

The compound robot moves the datum used by the fixed robot to detemine the position of its end effector. By this means the workspace of the fixed robot is moved from one place to the next adjacent area. Also provided by the compound robot is a a means of having the fixed robot being able to access the whole of that new workspace.

Difference with Walking Mechanisms and Wheels

Brian mechanisms differ from wheels and walking mechanisms in the way in which the payload is moved. In systems having wheels or legs, motion is achieved due to the following:

1. A torque T is applied by the engine to the wheel.
2. The force on the circumference of the wheel at the point of contact with the ground due to that torque T/r is less than the static Friction Fr and there is a forward reaction on the wheel which causes it to move forward as it rolls. As the wheel rolls forward, its axle is translated forward. Since the axle carries the payload, the payload is also moved forward. The same applied to walking mechanisms. The force applied to the legs on the ground cause a reaction force that move the legs and the payload forward. In brief, wheeled systems and walking mechanisms move relative to the ground.

But there is a different class of mechanisms called Brian Mechanisms which work in the following way:

1. The payload moves relative to a platform, as opposed to relative to the ground as when using wheels.
2. A system of legs/wheels are used to move, relative to the ground, the frame on which the platform moves so that the platform can have continuous motion.

This video illustrates some examples of Brian Mechanisms