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PID and controllers
The most common controllers designed using classical control theory are PID controllers.
It should be noted that for practical PID controllers a pure differentiator is neither physically realisable or desirable due to amplification of noise and resonant modes in the system.
Such systems are often implemented as " PID controllers " ( proportional-integral-derivative controllers ).
PID controllers date to 1890s governor design .< ref name =" ben93p48 ">
* PID temperature controllers
The inverted pendulum is a classic problem in dynamics and control theory and is widely used as a benchmark for testing control algorithms ( PID controllers, neural networks, fuzzy control, genetic algorithms, etc .).
Today ’ s controllers have extensive computational capabilities and, in addition to proportional, integral, and derivative ( PID ) control, can generally perform logic and sequential control.
PID controllers are common and effective in cases such as this.
PID controllers date from the 1950s, and have been retrofitted to espresso machines since the early 2000s.
More elaborate techniques of controller design using the root locus are available in most control textbooks: for instance, lag, lead, PI, PD and PID controllers can be designed approximately with this technique.
The lab has stepper motors, amplidynes, tachogenerators, transfer function analysers, servo motors, level process work station, PID controllers, thyristors controllers, and sun tracking cum solar power generation systems.
The additional complexity of the MPC control algorithm is not generally needed to provide adequate control of simple systems, which are often controlled well by generic PID controllers.
Common dynamic characteristics that are difficult for PID controllers include large time delays and high-order dynamics.
In a chemical process, independent variables that can be adjusted by the controller are often either the setpoints of regulatory PID controllers ( pressure, flow, temperature, etc.
made available comparatively inexpensive, yet highly accurate PID controllers with an attached thermocouple probe that could be used to control a commercial rice cooker, slow cooker, electric stock pot, or similar apparatus.
* Analog PID controllers

PID and are
That is, if R is a PID, and a and b are elements of R, and d is a greatest common divisor of a and b,
The compare and compute functions are completed within the controller which may be completed electronically through a Proportional Control, PI Controller, PID Controller, Bistable, Hysteretic control or Programmable logic controller.
In a ring all of whose ideals are principal ( a principal ideal domain or PID ), this ideal will be identical with the set of multiples of some ring element d ; then this d is a greatest common divisor of a and b. But the ideal ( a, b ) can be useful even when there is no greatest common divisor of a and b. ( Indeed, Ernst Kummer used this ideal as a replacement for a gcd in his treatment of Fermat's Last Theorem, although he envisioned it as the set of multiples of some hypothetical, or ideal, ring element d, whence the ring-theoretic term.
In the United States, more than 750, 000 women are affected by PID each year, and the rate is highest with teenagers and first time mothers.
However, not all PID is caused solely by STIs ; organisms that are considered normal vaginal flora can be involved, and individual cases of PID can be due to either a single organism or a co-infection of many different species.
Principal ideal domains are thus mathematical objects which behave somewhat like the integers, with respect to divisibility: any element of a PID has a unique decomposition into prime elements ( so an analogue of the fundamental theorem of arithmetic holds ); any two elements of a PID have a greatest common divisor ( although it may not be possible to find it using the Euclidean algorithm ).
If x and y are elements of a PID without common divisors, then every element of the PID can be written in the form ax + by.
If PID and other traditional control systems are so well-developed, why bother with fuzzy control?
Especially, Gauss had looked at the case of imaginary quadratic fields: he found exactly nine values of < math > D < 0 </ math > for which the ring of integers is a PID and conjectured that there are no further values.
In fact, although Gauss also conjectured that there are infinitely many primes such that the ring of integers of is a PID, to this day we do not even know whether there are infinitely many number fields ( of arbitrary degree ) such that is a PID!
Thus these are precisely the class of domains for which Frac ( R )/ Prin ( R ) forms a group, the ideal class group Cl ( R ) of R. This group is trivial if and only if R is a PID, so can be viewed as quantifying the obstruction to a general Dedekind domain being a PID.
In particular, it asserts that all fractional ideals are principal, a statement which is false whenever is not a PID.
Control engineering in many applications produces control systems that are more complex than PID control.

PID and most
All stops have disabled access, raised paving, CCTV, a Passenger Help Point, a Passenger Information Display ( PID ), litter bins, a ticket machine, a noticeboard and lamp-posts, and most also have seats and a shelter.
PID is a vague term and can refer to viral, fungal, parasitic, though most often bacterial infections.
The most common misdiagnosis assigned to early ectopic pregnancy is PID.
A proportional – integral – derivative controller ( PID controller ) is a generic control loop feedback mechanism ( controller ) widely used in industrial control systems – a PID is the most commonly used feedback controller.
The most common extensions lead to proportional-integral-derivative control, or PID control ( pronounced pee-eye-dee ).
On control systems like the tuning of the temperature of a furnace, or perhaps the motion-control of a heavy item like a gun or camera on a moving vehicle, the derivative action of a well-tuned PID controller can allow it to reach and maintain a setpoint better than most skilled human operators could.
In computing, the process identifier ( normally referred to as the process ID or just PID ) is a number used by most operating system kernels, — such as that of UNIX, Mac OS X or Microsoft Windows — to temporarily uniquely identify a process.
In September 2010 most Cuffariani, led by Romano, left UDC to form The Populars of Italy Tomorrow ( PID ) and support the Berlusconi IV Cabinet.
Running these functions in software saved a lot of hardware ; in 1986, most drives used a separate PID controller for the spindle, and used a CPU mainly to manage the bus interface and generate positioning pulses for a stepper motor.

PID and well
By this time a procedure for determining whether the ring of all algebraic integers of a given quadratic field is a PID was well known to the quadratic form theorists.
In view of the well known and exceedingly useful structure theorem for finitely generated modules over a principal ideal domain ( PID ), it is natural to ask for a corresponding theory for finitely generated modules over a Dedekind domain.

PID and control
The PID controller is probably the most-used feedback control design.
PID is an acronym for Proportional-Integral-Derivative, referring to the three terms operating on the error signal to produce a control signal.
If u ( t ) is the control signal sent to the system, y ( t ) is the measured output and r ( t ) is the desired output, and tracking error, a PID controller has the general form
These vary from extremely general ones ( PID controller ), to others devoted to very particular classes of systems ( especially robotics or aircraft cruise control ).
* PID controller, a control concept used in automation.
PLCs may include logic for single-variable feedback analog control loop, a " proportional, integral, derivative " or " PID controller ".
A PID loop could be used to control the temperature of a manufacturing process, for example.
They include timers, arithmetic operators and comparisons, table lookups, text processing, PID control, and filtering functions.
The PID controller calculation ( algorithm ) involves three separate constant parameters, and is accordingly sometimes called three-term control: the proportional, the integral and derivative values, denoted P, I, and D. Heuristically, these values can be interpreted in terms of time: P depends on the present error, I on the accumulation of past errors, and D is a prediction of future errors, based on current rate of change.
By tuning the three parameters in the PID controller algorithm, the controller can provide control action designed for specific process requirements.
Note that the use of the PID algorithm for control does not guarantee optimal control of the system or system stability.
A PID controller will be called a PI, PD, P or I controller in the absence of the respective control actions.

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