Tutorial: PID control without the math

PID stands for "Proportional, Integral, Derivative". It is a mathematical way of describing a closed loop control method that is very widely used throughout the process industries. Closed loop control is about controlling, for example, a temperature by measuring it and then applying a correction by adjusting the amount of heat being Closed loop control in-principle diagram provided. PID is only one possible form of closed loop control, but it is very popular because it can be very effective.

I've often been asked if SPLat "has" PID control. My answer has always been something like "Well, yes, you can do PID with SPLat because it has floating point." However, to implement a PID system from scratch can be a daunting task.

We realise that many of our users are not controls experts or PID experts. In the main, your expertise lies in other areas like machine design or product development. That's why we work so hard to make the stuff we regard as our fields of expertise as accessible as possible to others.

To help you implement PID controls within SPLat we have developed a complete PID toolset. This consists of a tutorial, a software modeling and simulation tool and various support materials. The whole toolset is completely free.

Tutorial

The PID tutorial assumes no prior knowledge of closed loop control, and avoids the mathematics. Nevertheless it seeks to give you a good understanding, rather than just have you take things on blind trust. It is important that you have some understanding so you can handle problems that arise in an informed manner.

PIDassist program

PIDassist is a Windows program that provides multiple functions:

A data logger that lets a SPLat controller be used to measure and record the process you are seeking to control.
A process simulator
A simulated SPLat controller
An automatic SPLat code generator

PIDassist can be downloaded free from the downloads section of our website.

Support materials

The package includes a number of spreadsheets that are used while determining the characteristics of your target process. These are included in the PIDassist download. There are also several SPLat programs that help you during various stages of your development.