Higher Colleges of TechnologyMCE 4603 – Control SystemsLab 8Introduction:In this lab we will introduce a simple, yet versatile, feedback compensator structure: the Proportional-Integral-Derivative(PID) controller. The PID controller is widely employed because it is very understandable and because it is quite effective.One attraction of the PID controller is that all engineers understand conceptually differentiation and integration, so theycan implement the control system even without a deep understanding of control theory. Further, even though thecompensator is simple, it is quite sophisticated in that it captures the history of the system (through integration) andanticipates the future behavior of the system (through differentiation). We will discuss the effect of each of the PIDparameters on the dynamics of a closed-loop system and will demonstrate how to use a PID controller to improve asystem's performance.The Characteristics of the P, I, and D TermsIncreasing the proportional gain () has the effect of proportionally increasing the control signal for the same level oferror. The fact that the controller will "push" harder for a given level of error tends to cause the closed-loop system to reactmore quickly, but also to overshoot more. Another effect of increasingis that it tends to reduce, but not eliminate,thesteady-state error.
