Closed-loop and open-loop systems are two different control types. Control theory is an interdisciplinary branch of engineering and mathematics that deals with the behavior of dynamical systems with inputs. Systems in which the output quantity has no effect on the processes' input quantity are open-loop control systems. Systems in which the output quantity and negative feedback affect the processes' input quantity are closed-loop control systems.
Closed-loop control systems have a closed control loop, can counteract against disturbances via negative feedback and have the potential to become unstable if the controlled variable does not fade. Open-loop control systems show an open-loop action and can only counteract against disturbances for which they have been designed to counteract. Germany's Ruhr University Bochum explains this closed-loop versus open-loop control following a simple room heating system example. An open-loop control for a room heating system has an outdoor thermostat fed to a control device. When outdoor temperatures drop to a designated level, the control device triggers the heat source to warm the indoor room temperature. If a window is opened and the room temperature drops, this disturbance goes undetected at the control device because the outdoor temperature influences the indoor room temperature. If the thermostat and control device are moved inside the room, the system becomes a closed-loop control design. The indoor room temperature is measured and determined by the set-point value of the thermostat. If a window is opened, this disturbance is detected by the controller and removed. This disturbance detection and control produce a negative feedback loop.Learn More
An open-loop system is a type of electronic control where the output of the system isn't monitored and regulated to affect the system's performance. Although simple to operate, the disadvantage is that the user has to monitor the system's output to make corrections to any error in the process.Full Answer >
The open field system was a system of agriculture in which large fields were divided into strips that were farmed by individual peasants. This form of farming predominated in Europe from the middle ages until the 1800s.Full Answer >
There are several methods that reduce the static electricity buildup in the home including adding moisture to the air through a home humidifier, adding moisture to the skin through lotions, and choosing less static-enhancing clothes. During the winter months, the drier air inside the house allows static electricity charges to build up.Full Answer >
Electricity powers a wide range of devices that cannot work with other forms of energy, but it can be dangerous. Without electricity, modern computer technology would not work. Generating electricity, however, can cause significant environmental harm.Full Answer >