Comparison between Open and Closed Loop Control System

No:	Open Loop System	Closed Loop System
01	It is characterized by definite relationship between desired system output and actual system output without monitoring the actual system.	The closed loop control system is characterized by definite relation between desired system output and actual system output by monitoring the actual system. The monitored error signal will be utilized to control the system to obtain the desired output.
02	Open loop systems have moderate accuracy.	Closed loop systems have high accuracy.
03	Open loop systems are sensitive to surrounding conditions like vibrations, voltage, aging etc.	Closed loop systems are not sensitive to surrounding conditions like vibrations voltage aging etc.
04	Open loop systems have slow response to input command and changes. Therefore the system will be slow and sluggish.	The response is fast.
05	The accuracy of the open loop system depends on: a. Designed output relationship. b. The performance of the calibration over long intervals of time. c. The varying effects of environmental conditions.	The accuracy of the closed loop system depends on: a. Accuracy of the closed loop system. b. Accuracy of the comparing device. c. Accuracy of the control element and its sensitivity.
06	The advantage of open loop system is that they are simple and economical.	Advantages of closed loop system are: a. Human errors are avoided. b. High degree of accuracy efficiency is obtainable. c. Economical.