Using your favorite continuous-time modeling software (such as
LabVIEW, Simulink, or Ptolemy II), construct a model of the
helicopter control system shown in Figure 2.4. Choose some
reasonable parameters and plot the actual angular velocity as a
function of time, assuming that the desired angular veloc- ity is
zero, ψ(t) = 0, and that the top-rotor torque is non-zero, Tt(t) =
bu(t). Give your plot for several values of K and discuss how the
behavior varies with K.
Modify the model of part (a) to replace the Controller of
Figure 2.4 (the sim- ple scale-by-K actor) with the alternative
controller shown in Figure 2.6. This
2. CONTINUOUS DYNAMICS
K1 K2
Figure 2.6: A PI controller for the helicopter.
alternative controller is called a proportional-integrator
(PI) controller. It has two parameter K1 and K2. Experiment with
the values of these parame- ters, give some plots of the behavior
with the same inputs as in part (a), and discuss the behavior of
this controller in contrast to the o