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
Development Kit Targets Motion Control Design
TI's DesignDRIVE gives motion control developers a sandbox in which...
eetimes.com
New Tool Automates Register Verification Process for FPGA, SoC & IP Designs
Registers are one of the first aspects of the design...
eetimes.com
How the Apple Watch Can Collect Patient Data
A project in southern New Jersey is using Apple Watches...
eetimes.com
Intel, Altera, Moore...and Drinks
The on-again, off-again Intel/Altera acquisition was the talk of a...
eetimes.com
Huawei's Everything-Connected Game Plan
As Chinese Internet companies like Tencent, Alibaba and Xiaomi bulldoze...
eetimes.com
Samsung Ramps 10nm in 2016
Samsung said its 10nm FinFET process node will be in...
eetimes.com
Friday Quiz: Losses in Power Devices
Power devices such as MOSFETs and IGBTs can waste power...
eetimes.com
HP Strikes China Deal, Sales Slump
The same day it reported declining quarterly results, Hewlett-Packard announced...
eetimes.com
Robot Revolution Initiative Launches in Japan
Seeking to lead the "robot revolution," Japan has initiated development...
eetimes.com
Quarter-Sized, Magnetically Stackable Modules for Students and Makers
mCookies are small, powerful, Arduino-compatible modules for makers, designers, engineers,...
eetimes.com
Apple Watch Lacks Pulse, Says Startup
Bloom Technologies aims to pave the way toward medical-grade wearables...
eetimes.com
Mao Zedong & Little Red Internet
Linking Internet leaders like Jack Ma with Chairman Mao...
eetimes.com
Self-Driving Cars Without Passengers
Forschungszentrum Informatik (FZI) is aiming for self-driving cars that you...
eetimes.com
Apple Watch, Android Wear Updates Begin
The first update for the Apple Watch makes performance improvements...
eetimes.com
Crowdfunding Gives IoT a Boost
Wearable startups are getting more attention these days -- from...
eetimes.com
Software Secure? Good! But What About the Hardware (FPGAs & SoCs)?
The Prospect Hardware Security Design and Analysis Toolkit from Tortuga...
eetimes.com
DesignCon 2016 Welcomes Abstracts
DesignCon fans, the time has come! If your work concerns...
eetimes.com
Moore's Law: What Broke the Model
In a sense Moore's Law, or at least many of...
eetimes.com
ITU Targets 5G Wireline Standards
I have lost count of the number of standards efforts,...
eetimes.com
Raspberry Pi 2: 10 Unusual & Interesting Projects
Raspberry Pi Foundation's newest board the RPi 2 is gaining...
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 +