Ball and Beam Apparatus
- The Ball and Beam Apparatus shows the control problems of unstable systems, for example a rocket or missile during launch, which needs active control to prevent the missile going unstable and toppling over.
- The apparatus has a steel ball which is free to roll on two parallel tensioned wires.
- The wires are on a beam that pivots at its centre.
- The system is a double integrator, so it is naturally unstable.
- It needs active feedback control using phase-advance methods.
- A servo motor controls the beam angle and sensors measure the beam angle and ball position.
- The basic control problem is to vary the beam angle to control the ball position.