PID


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PID

PID

(1) (Process IDentifier) A temporary number assigned by the operating system to a process or service.

(2) (Proportional-Integral-Derivative) The most common control methodology in process control. It is a continuous feedback loop that keeps the process flowing normally by taking corrective action whenever there is any deviation from the desired value ("setpoint") of the process variable (rate of flow, temperature, voltage, etc.). An "error" occurs when an operator manually changes the setpoint or when an event (valve opened, closed, etc.) or a disturbance changes the load, thus causing a change in the process variable.

The PID controller receives signals from sensors and computes corrective action to the actuators from a computation based on the error (proportional), the sum of all previous errors (integral) and the rate of change of the error (derivative). See PAC.


Inputs from a PID
The large white boxes are Opto 22 SNAP PACs, which are programmable automation controllers that are processing the PID loops in Chevron's research facility in Richmond, Virginia. The wires come from thermocouples that sense pipe temperature in a laboratory test that analyzes the best way to break down crude oil. The PACs determine when to raise and lower the temperature, and the three modules with the black sockets send digital signals to the heaters (cables not connected in this image). (Image courtesy of Opto 22, www.opto22.com)
References in periodicals archive ?
To determine the association of Pelvic inflammatory Disease (PID) and Intra Uterine Contraceptive Device (IUCD) in women coming to the Out Patient departments of tertiary care settings in Rawalpindi.
Psychological impact and quality of life in primer immunodeficiencies: Taking into account the studies on children and adolescents with PID, it is seen that psychosocial characteristics and HR-QOL are related and have been evaluated together in the literature (Table I).
PID employees have contradictory accounts of the incident.
He said as per his information, no human or material loss occurred in the incident and the record and archives of PID are completely safe as fire could not reach those areas.
Earlier, Principal Information Officer, Shafqat Jalil briefed the Minister in detail about the working and functioning of media centres established at PID Islamabad and PID regional offices in Karachi, Hyderabad, Multan, Lahore, Faisalabad, Peshawar, D.I.
In this work, the fuzzy/PID compound controller makes use of the nonlinear mapping of applied fuzzy logic to establish the angle position error parameters e and ec, as well as three PID parameters.
Up to now, there always exist some debates about the mechanism of PID, and there are also no effective measures to prevent PID.
That same day, Adalah filed a request demanding the PID open an investigation into the killing.
Digital controller is a combination of three features proportional 'P', integral 'I', derivative 'D' controller, which forms the new controller called PID controller.
Abstract: In this paper, a fuzzy PID controller is proposed for angular position control of a nonlinear propeller pendulum system.