Chosing PID as controlling method

What is PID? and why I choose PID as the controlling metdod?


The word PID is composed by the first letters from the terms Proportional, Integral and Derivative. The Proportional, Integral, and Derivative terms are summed to calculate the output of the PID. Here is the diagram to get a first (just a first) idea how this system works:

PID controllers are a family of controllers.  PID controllers are sold in large quantities and are often the solution of choice when a controller is needed to close the loop.  The reason PID controllers are so popular is that using PID gives the designer a larger number of options and those options mean that there are more possibilities for changing the dynamics of the system in a way that helps the designer.  If the designer works it right s/he can get the advantages of several effects.  In particular, starting with a proportional controller, and adding integral and derivative terms to the control the designer can take advantage of the following effects.

• An integral controller gives zero SSE for a step input.
• A derivative control terms often produces faster response.

        A PID controller operates on the error in a feedback system and does the following:

• A PID controller calculates a term proportional to the error - the P term.
• A PID controller calculates a term proportional to the integral of the error - the I term.
• A PID controller calculates a term proportional to the derivative of the error - the D term.
• The three terms - the P, I and D terms, are added together to produce a control signal that is applied to the system being controlled.