The open loop system is also known as "no feedback system". Symmetry of "closed loop system (feedback system)". The system's input affects the output of output instead of output. Because there is no closed feedback loop in which the closed feedback loop is formed, it is as disconnected. Since the output does not impose an impact on the input, the open loop system does not respond to the output deviation and the disturbance, and only specifically responds to the set value. For example, a clock is a open system because it does not observe it on time or not, it will not adjust itself. There are few open-loop systems in the socio-economic system. In the initial stage of system dynamics model debugging, the designer can cancel the feedback loop so that the system is an open-loop system to simplify the problem, easy to debug.
Open loop control, also known as "open loop control system" refers to a control system that is not affected by the input signal of the system in a control system. That is, the results of the control result are not referred to in the current controlled system.
The open loop control means that only the control device and the controlled object are only in the control process without reverse contact. Therefore, the output of the open-loop control system does not affect the control of the system. Some automation devices for the various departments of the national economy, such as vending machines, automatic washing machines, product automatic production lines, automatic lathes, etc., are generally open-loop control systems.
Since the opening control is characterized, the control device is only one-way controlled by a given input signal, and does not measure the controlled amount and reverse affects the control, which does not have a correction due to disturbance The ability caused by deviating the amount of control from the desired value.
In open loop control, for each input signal of the system, there must be a fixed working state and a system output amount. Since the anti-disturbance capacity of open loop control is poor, there is a limitation in use.
