## What is Process Control?Edit

The manipulation of an object (actuation device) to maintain a parameter within an acceptable deviation from an ideally required condition.

There are two basic process control philosophies, feedback and feedforward control.

### Feedback ControlEdit

In feedback control, the controlled variable is measured and compared with a set-point. The deviation between the controlled variable and the set-point is the error signal. The error signal is then used to reduce the deviation of controlled variable from set-point.

#### Direct Acting ControlEdit

If the controlled variable increases as the manipulated variable increases, then direct acting control is used.

#### Reverse Acting ControlEdit

### Feedforward ControlEdit

### Advanced ControlEdit

## Mathematical ModelingEdit

## Using Mathematical ModelsEdit

## GlossaryEdit

- Actuator
- The mechanical device that cause the activation or movement of a final control element.

- Direct Synthesis

- Final Control Element
- A physical device whose activation or movement causes a change in a dynamic process. In process control, the most common final control elements are control valves.

- Frequency Domain

- Internal Model Control

- IMC-PID Tuning
- A method for PID tuning that selects tuning parameters to approximate an IMC-derived controller.

- Ladder Logic
- A semi-graphical programming language used to represent control algorithms. The language is expressed using symbols for logic devices. The arrangement of the device symbols and their connections has the appearance of a ladder.

- Laplace Transform
- An integral transformation from time domain to Laplace domain. Given a function of time , the Laplace transform is given by the following

- The use of to represent the Laplace transform of is a common convention; however, in dynamics and control it is common to use and to represent a time-domain function and its Laplace transform, respectively.

- PID Controller

- PLC
**P**rogrammable**L**ogic**C**ontroller, a microprocessor-based electronic device for implementing control algorithms.

- Time Domain

- Ziegler-Nichols Tuning