NONLINEAR CONTROLLER COMPARISON ON A BENCHMARK ...

Chapter 2
Plant Speci cations and Model
2.1 Hardware Set-up and Speci cations
The various control strategies studied in this thesis are implemented on the
same experimental testbed, which consists of a Flexible Beam System (FBS) that
was purchased from Quanser Consulting Inc. A picture of the FBS upon which the
control experiments were conducted is shown in Figure 2.1.
It consists of a thin metal beam that is clamped at one end while free at the
other. The free end is equipped with a voltage controlled DC motor that rotates a
rigid beam structure this structure acts as a proof mass, and it's rotation is the only
actuation mechanism in the system. The object of the control is to actuate this proof
mass in such away that its motion will damp an initial vibration in the exible beam.
The whole system consists of four parts:
1) A exible beam,
2) A proof mass structure consisting of two rigid beams and a cross beam,
3) A DC motor and an encoder,
4) A base plate instrumented with a strain gauge.
The exible beam is 44 cm in length, while the rigid beams that form the proof
mass are 28.5 cm in length. The rst mode sti ness of the system is experimentally
derived by measuring the natural frequency, anditsvalue is approximately 30 N . The
m
mass of the cross bar that acted as the proof mass is .05 kg, with the inertia of the
rigid beams connecting the cross bar to the motor is found to be :0039Kgm 2 . The DC
motor has an external gear ratio of 70 to 1, an electrical resistance of 2.6 ohms, and a
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