Quantcast OPEN-LOOP CONTROL SYSTEM

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
2-2 system and the complexity of the system are directly related to the requirements of the system's application. Control systems are broadly classified as either CLOSED-LOOP or OPEN-LOOP. Closed-loop control systems are the type most commonly used in the Navy because they respond and move the loads they are controlling quicker and with greater accuracy than open-loop systems. The reason for quicker response and greater accuracy is that an automatic feedback system informs the input that the desired movement has taken place. Upon receipt of this feedback information, the system stops the motor, and motion of the load ceases until another movement is ordered by the input. This is similar to the system that controls heat in many homes. The thermostat (input) calls for heat. The furnace (output) produces heat and distributes it. Some of the heat is "fed back" to the thermostat. When this "feedback" raises the temperature of the room to that of the thermostat setting, the thermostat responds by shutting the system down until heat is again required. In such a system, the feedback path, input to output and back to input, forms what is called a "closed loop." This is a term you will hear and use often in discussions of control systems. Because closed-loop control systems are automatic in nature, they are further classified by the function they serve (e.g., controlling the position, the velocity, or the acceleration of the load being driven). An open-loop control system is controlled directly, and only, by an input signal, without the benefit of feedback. The basic units of this system are an amplifier and a motor. The amplifier receives a low- level input signal and amplifies it enough to drive the motor to perform the desired job. Open-loop control systems are not as commonly used as closed-loop control systems because they are less accurate. OPEN-LOOP CONTROL SYSTEM As we stated previously, an open-loop control system is controlled directly, and only, by an input signal. The basic units of this type consist only of an amplifier and a motor. The amplifier receives a low- level input signal and amplifies it enough to drive the motor to perform the desired job. The open-loop control system is shown in basic block diagram form in figure 2-1. With this system, the input is a signal that is fed to the amplifier. The output of the amplifier is proportional to the amplitude of the input signal. The phase (ac system) and polarity (dc system) of the input signal determines the direction that the motor shaft will turn. After amplification, the input signal is fed to the motor, which moves the output shaft (load) in the direction that corresponds with the input signal. The motor will not stop driving the output shaft until the input signal is reduced to zero or removed. This system usually requires an operator who controls speed and direction of movement of the output by varying the input. The operator could be controlling the input by either a mechanical or an electrical linkage. Figure 2-1.—Open-loop control system basic block diagram.


Electrical News
Power Week: Popular Gaming Consoles' Energy Use Compared
Just in time for the holidays, engineers at the Electric...
eetimes.com
Make This Engineering Museum a Reality
Help turn the first house to have a telephone into...
eetimes.com
Industrial IoT Framework Near
The Industrial Internet Consortium plans to finish a reference architecture...
eetimes.com
Sony's Debuts Smartglasses Module
Following up on prototypes demonstrated earlier this year, Sony has...
eetimes.com
MIT Discovers Superconductor Law
The Massachusetts Institute of Technology has discovered a law governing...
eetimes.com
Top Robot Stories of 2014
Robots have fascinated us for centuries, but now we are...
eetimes.com
ESIstream vs. JESD204B for Ultra-High-Speed Chip-Chip Communications
The open ESIstream protocol has less encoding overhead and higher...
eetimes.com
Vote for the Engineer of the Year
Finalists announced, survey below. The award, sponsored by National Instruments,...
eetimes.com
Want a Voltera Desktop PCB Printer?
Who amongst us wouldn't want the ability to create PCBs...
eetimes.com
11 Views of IEDM
This week's International Electron Devices Meeting inspired new hope for...
eetimes.com
AMD Gives RF Mico Exec Ops Job
AMD has hired James A. Clifford as its senior vice...
eetimes.com
Infineon & UMC Extend Manufacturing Pact Into Auto ICs
German chipmaker will partner with Taiwanese foundry to manufacture power...
eetimes.com
EEVblog #693 – AVO Transistor Analyser Teardown
Dave tears down a 1962 vintage AVO Transistor Analyser. Service...
eevblog.com
Apps Layer Translation Coming in 2015, Says Silicon Labs
Plenty of people and companies in the technology world tend...
eetimes.com
Top 10 Industrial Control DesignLine Stories in 2014
It's time for a quick recap of the Industrial Control...
eetimes.com
I Want a Zano Autonomous, Intelligent, Swarming Nano-Drone
The promise of the ZANO is that even a drongo...
eetimes.com
How New-Gen MCUs Handle Security in Cars
The incessant evolution of communication networks inside vehicles is quickly...
eetimes.com
IBM Says PCM Non-Volatility Not Essential
At IEDM 2014, IBM claims that for PCM, non-volatility/data-retention is...
eetimes.com
DesignCon Revs High-Speed Engine
DesignCon promises a smorgasbord of sessions on high-speed interconnect engineering...
eetimes.com
G.fast Now on Fast Track
Chip vendors are gung-ho about G.fast, the standard that promises...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +