PID Experiment for ECP's Feedback Control Workstations Figure 1. Step and Sine Sweep Tests Correlate Transient and Frequency Response Behavior Figure 2. Unique Trajectory and Data Plotting Functions Reveal Classic Bode Magnitude Figure 3. Addition of Integral Action Yields Characteristic Shapes T his experiment covers many fundamental principles and is an excellent introduction to control systems applications.
Students first implement proportional, rate, and integral gains individually.
The step responses are measured and the effect of damping ratio on rise time and overshoot is observed. The students examine the two data sets and correlate the time and frequency response behaviors. The underdamped resonance corresponds to the step oscillation. Reduced bandwidth with increased damping correlates to the slower step rise time. The sine sweep data plotted in Figure 1 uses linear time and amplitude scaling.