The ball and beam system consists of a long beam which can be tilted by a servo or electric motor together with a ball
rolling back and forth on top of the beam.
It is a popular textbook example in
control theory
Control theory is a field of mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or algorithm governing the application of system inputs to drive the system to a ...
.
The significance of the ball and beam system is that it is a simple system which is open-loop
unstable
In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds. Not all systems that are not stable are unstable; systems can also be mar ...
.
Even if the beam is restricted to be very nearly horizontal, without active
feedback, it will swing to one side or the
other, and the ball will roll off the end of the beam. To stabilize the ball, a
control system which
measures the position of the ball and adjusts the beam accordingly must be used.
In two dimensions, the ball and beam system becomes the ball and plate system, where a ball rolls on top of
a plate whose inclination can be adjusted by tilting it forwards, backwards, leftwards, or rightwards.
External links
Ball & Beam with various controls strategiesBall and Beam 1: basicsBall and Beam with comprehensive dynamics and movies{{tech-stub
Control engineering