Nonlinear System Control (25pts)
Given the following inverted pendulum. Modeled as a point mass of negligible size connected to a massless rod. With a motor connected at the base, providing a moment torque.
A
mm
M
With m = 3 kg. l = 500 cm
a. 10% Derive the equations of motion of the system. Then linearize and derive the transfer function of the system, relating torque to angular position.
M(s)
b. 30% Using the transfer function, design a PID controller to achieve the following specifications:
- T = 1s
- ωg = 2 rad/s
c. 30% Simulate the system with your controller, on the nonlinear model (numerical integration), and test it by using it as a regulator for each of the following initial conditions:
- θ = 30°
- θ = 60°
- θ = 90°
- θ = 145.180°
Plot all the responses on the same subplot. Plot the torque applied for each case in a different subplot.
d. 30% In practice, you are bounded by the actuation effort. Repeat the simulation in part c with the saturation limit. Discuss how you would change your PID gains after you've added this saturation limit.