Classical control theory

geometric representation of the complex numbers

control loop mechanism used in control engineering based on three terms (P, I and D)

process that occurs in a feedback loop which magnifies a small disturbance

graph of the frequency response of a linear system presented in logarithmic scale

mathematical term

Nyquist stability criterion in control systems

mathematical model of system that produces an output signal from any input signal subject to the constraints of linearity and time-invariance

plot

method of identifying or measuring the mathematical model of a system from measurements of the system inputs and outputs; uses statistical methods to build mathematical models of dynamical systems from measured data

graphical method for examining how the roots of a linear time-invariant system change with variation of a certain system parameter, commonly a gain within a feedback system

control law without knowledge of the state or output

a signal or function exceeding its target

Controllability is an important property of a control system and plays a crucial role in many regulation problems, such as the stabilization of unstable systems using feedback, tracking problems, obtaining optimal control strategies, or, simply prescribing an input that has a desired effect on the state.

time behavior

target value that an automatic control system, for example PID controller, will aim to reach

Observability is a measure of how well internal states of a system can be inferred from knowledge of its external outputs. In control theory, the observability and controllability of a linear system are mathematical duals.

system that provides an estimate of the internal state of a given real system, from measurements of the input and output of the real system

a specialized flow graph, a directed graph in which nodes represent system variables, and branches (edges, arcs, or arrows) represent functional connections between pairs of nodes

process in systems in which there is interaction

variable whose value is uniquely determined by the state of a dynamical system

approach to control of non-linear systems

system where the output depends only on past and current inputs

plot

linear feedback control system

in control theory, the combination of process and actuator

control system

Parameter of electronic amplifiers

error condition in a proportional–integral–derivative controller, may be limited using anti-windup

Tool in control theory