Search results
Results From The WOW.Com Content Network
Many PID loops control a mechanical device (for example, a valve). Mechanical maintenance can be a major cost and wear leads to control degradation in the form of either stiction or backlash in the mechanical response to an input signal. The rate of mechanical wear is mainly a function of how often a device is activated to make a change.
A Piping and Instrumentation Diagram (P&ID or PID) is a detailed diagram in the process industry which shows process equipment together with the instrumentation and control devices. It is also called as mechanical flow diagram (MFD).
In the context of PID controller, the setpoint represents the reference or goal for the controlled process variable. It serves as the benchmark against which the actual process variable (PV) is continuously compared.
Physical Interface Device, a class of a USB device; PID controller (proportional-integral-derivative controller), a control concept used in automation; Piping and instrumentation diagram (P&ID), a diagram in the process industry which shows the piping of the process flow etc. Principal ideal domain, an algebraic structure
For this reason, closed loop controllers are also called feedback controllers. [ 3 ] The definition of a closed loop control system according to the British Standards Institution is "a control system possessing monitoring feedback, the deviation signal formed as a result of this feedback being used to control the action of a final control ...
A programmable logic controller (PLC, for smaller, less complex processes) or a distributed control system (DCS, for large-scale or geographically dispersed processes) analyzes this sensor data transmitted to it, compares it to predefined setpoints using a set of instructions or a mathematical model called the control algorithm and then, in ...
A photoionization detector or PID is a type of gas detector. Typical photoionization detectors measure volatile organic compounds and other gases in concentrations from sub parts per billion to 10 000 parts per million (ppm). The photoionization detector is an efficient and inexpensive detector for many gas and vapor analytes.
The usual objective of control theory is to control a system, often called the plant, so its output follows a desired control signal, called the reference, which may be a fixed or changing value. To do this a controller is designed, which monitors the output and compares it with the reference.