Controls

Controls refer to the mechanisms, devices, or interfaces that govern the behavior of a system, device, or process. The concept appears across engineering, computing, and everyday technology, where humans or automated agents influence outcomes through inputs and feedback.

In control engineering, a control system typically includes a plant (the object being controlled), a controller that processes input signals, and actuators and sensors that apply and measure actions. A central distinction is between open-loop control, where inputs are fixed regardless of output, and closed-loop (feedback) control, where the system measures its output and adjusts inputs to reduce error. Design goals include stability, responsiveness, robustness, and accuracy.

User interfaces also rely on controls. UI controls are the elements that allow users to manipulate software or hardware, such as physical buttons, switches, knobs, sliders, and on-screen controls. Control usability emphasizes consistency, discoverability, and accessibility.

Remote and industrial controls cover devices and systems that regulate operation remotely or at scale. Examples include remote controllers for consumer electronics, programmable logic controllers (PLCs), and supervisory control and data acquisition (SCADA) systems, which coordinate sensors, actuators, alarms, and safety interlocks. Redundancy and fail-safe design are common concerns.

In computing and video games, controls describe the input mappings that translate user actions into outcomes. Control schemes affect ergonomics, precision, and inclusivity for users with different abilities.

Overall, controls are central to automation, safety, and user experience, shaping how systems respond to inputs and how people interact with technology.