Control system is used in industry to enhance production ,efficiency and safety. They are mainly used in the agricultural sector, chemical plants, pulp and paper mills, and industrial manufacturing quality control. Control systems exist in almost every system such as boiler control and power plant operation ,environmental control, water and sewerage treatment plants.
Control systems are widely used in industrial processes such as in boiler control systems for monitoring the heating and power plant system. In pipeline monitoring and water distribution systems and much more. Control system has various parts: sensor, controller and actuator. A valve is often a part of a pneumatic control system. proportional flow control valve is widely used in such systems.
Types of Control System
There are two types of control loop systems: open loop control system and closed loop control .
Open Loop Control
Open Loop control system is also known as non-feedback system as the output system is not fed back to input of the system. In an open loop system the output has no control on the action of a system. Final result is not affected by input of a system.
Close Loop Control
A feedback control system is also called a close control system . Unlike an open control system , this system sends output signals back to the input system. The control function is based on output results. a proportional flow control valve is a type of valve used to control the fluid.
Close Loop Control Applications
- Thermostat Heater
A thermostat heater can be used to warm up the water or surrounding atmosphere. A thermostat detects change in temperature and maintains heater temperature. It is a system with a closed loop. Here the controller is the thermostat.
- Sunseeker solar system
It is a closed loop control system which detects sun rays using LDR to sense sunlight. A microcontroller uses LDR voltage and sends a signal to the motor which rotates the solar panel towards the sun.
- Voltage Stabilizer
It stables the supply or input voltage in case of fluctuation. An electronic circuit is used as a controller which measures the fluctuation in voltage and reduces or increases the voltage according to the situation.
- Missile Launcher
A computer controller system is used to detect the position of a plane using a radar tracking unit.
- Auto Engine
In an automobile engine, a tachometer is a controller that provides a voltage proportional to the speed of the shaft. An error voltage is calculated by input signal minus output signal. It is then used to control the speed of a vehicle.
Open Loop Control Applications
- Traffic control system
In the traffic control system , each signal is settled with a specific time slot. It has to be green or red for a specific time. It is independent of a traffic flow. It is not linked with output of a system ie. traffic flow. It operates according to its allocated time. a proportional flow control valve is a type of valve used in a control system to control the flow of liquid.
- Washing Machine
Washing machine is an open system. A washing machine washes, rinses and dry clothes. The user sets a timer and operates. It has nothing to do with cleanliness, dryness or quality of clothes washed.
- Volume on Stereo system
Volume has to be set manually irrespective of output volume required. Usually open systems are manual ones that can not be automated.
- Electric Lamp
Lamp works by switching on or off. If the switch is on it provides light. Lighting does not depend on the temperature of the lamp or the ambience needed in the room. It is an open loop control system.
- Bread Toaster
A bread toaster works by heating the bread at a given timer set in it. A bread can burn if it exceeds. But it can not detect the burning of bread and does not stop working. It continues to operate in accordance with the instructions.Hence it is an open loop system.
Open-loop systems have fixed inputs and lack self-regulation and adaptation. Closed-loop systems, on the other hand, include feedback mechanisms that allow for self-correction and stability. Closed-loop systems beat open-loop systems in dynamic situations, increasing accuracy and performance. It is critical to understand these paradigms in order to build efficient processes. a proportional flow control valve is a type of valve often used in control system application at industry level.
