Nonlinear controlNonlinear control theory is the area of control theory which deals with systems that are nonlinear, time-variant, or both. Control theory is an interdisciplinary branch of engineering and mathematics that is concerned with the behavior of dynamical systems with inputs, and how to modify the output by changes in the input using feedback, feedforward, or signal filtering. The system to be controlled is called the "plant".
Perceptual control theoryPerceptual control theory (PCT) is a model of behavior based on the properties of negative feedback control loops. A control loop maintains a sensed variable at or near a reference value by means of the effects of its outputs upon that variable, as mediated by physical properties of the environment. In engineering control theory, reference values are set by a user outside the system. An example is a thermostat. In a living organism, reference values for controlled perceptual variables are endogenously maintained.
Positive feedbackPositive feedback (exacerbating feedback, self-reinforcing feedback) is a process that occurs in a feedback loop which exacerbates the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in the magnitude of the perturbation. That is, A produces more of B which in turn produces more of A. In contrast, a system in which the results of a change act to reduce or counteract it has negative feedback. Both concepts play an important role in science and engineering, including biology, chemistry, and cybernetics.
Step responseThe step response of a system in a given initial state consists of the time evolution of its outputs when its control inputs are Heaviside step functions. In electronic engineering and control theory, step response is the time behaviour of the outputs of a general system when its inputs change from zero to one in a very short time. The concept can be extended to the abstract mathematical notion of a dynamical system using an evolution parameter.
Open-loop gainThe open-loop gain of an electronic amplifier is the gain obtained when no overall feedback is used in the circuit. The open-loop gain of many electronic amplifiers is exceedingly high (by design) – an ideal operational amplifier (op-amp) has infinite open-loop gain. Typically an op-amp may have a maximal open-loop gain of around , or 100 dB. An op-amp with a large open-loop gain offers high precision when used as an inverting amplifier.
Root locus analysisIn control theory and stability theory, root locus analysis is a graphical method for examining how the roots of a system change with variation of a certain system parameter, commonly a gain within a feedback system. This is a technique used as a stability criterion in the field of classical control theory developed by Walter R. Evans which can determine stability of the system. The root locus plots the poles of the closed loop transfer function in the complex s-plane as a function of a gain parameter (see pole–zero plot).
GameCube controllerThe GameCube controller is the standard game controller for the GameCube home video game console, manufactured by Nintendo and launched in 2001. As the successor to the Nintendo 64 controller, it is the progression of Nintendo's controller design in numerous ways. The contentious M-shaped design of its predecessor was replaced with a more conventional handlebar style controller shape; a second analog stick was added, replacing the C buttons with a C stick and the X and Y face buttons, last seen on the Super Nintendo controller, were reintroduced; the shoulder buttons were changed to hybrid analog triggers.
Loop gainIn electronics and control system theory, loop gain is the sum of the gain, expressed as a ratio or in decibels, around a feedback loop. Feedback loops are widely used in electronics in amplifiers and oscillators, and more generally in both electronic and nonelectronic industrial control systems to control industrial plant and equipment. The concept is also used in biology. In a feedback loop, the output of a device, process or plant is sampled and applied to alter the input, to better control the output.
Game controllerA game controller, gaming controller, or simply controller, is an input device or input/output device used with video games or entertainment systems to provide input to a video game. Input devices that have been classified as game controllers include keyboards, mouses, gamepads, and joysticks, as well as special purpose devices, such as steering wheels for driving games and light guns for shooting games. Controllers designs have evolved to include directional pads, multiple buttons, analog sticks, joysticks, motion detection, touch screens and a plethora of other features.
PlantPlants are eukaryotes, predominantly photosynthetic, that form the kingdom Plantae. Many are multicellular. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi. All current definitions exclude the fungi and some of the algae. By one definition, plants form the clade Viridiplantae (Latin for "green plants") which consists of the green algae and the embryophytes or land plants. The latter include hornworts, liverworts, mosses, lycophytes, ferns, conifers and other gymnosperms, and flowering plants.
Motion controllerIn video games and entertainment systems, a motion controller is a type of game controller that uses accelerometers or other sensors to track motion and provide input. Motion controllers using accelerometers are used as controllers for video games, which was made more popular since 2006 by the Wii Remote controller for Nintendo's Wii console, which uses accelerometers to detect its approximate orientation and acceleration, and serves an image sensor, so it can be used as a pointing device.
Nintendo 64 controllerThe Nintendo 64 controller (model number: NUS-005) is the standard game controller for the Nintendo 64 home video game console. Manufactured and released by Nintendo on June 23, 1996, in Japan, in September 29, 1996 in North America, and March 1, 1997 in Europe, it is the successor to the Super Nintendo controller and is designed in an "M" shape and features 10 buttons, one analog "Control Stick" and a directional pad. The controller was designed by Nintendo R&D3, under direction to try new ideas that would break from typical game controllers.
