CN103105867A - Computer liquid level control system - Google Patents
Computer liquid level control system Download PDFInfo
- Publication number
- CN103105867A CN103105867A CN 201110385029 CN201110385029A CN103105867A CN 103105867 A CN103105867 A CN 103105867A CN 201110385029 CN201110385029 CN 201110385029 CN 201110385029 A CN201110385029 A CN 201110385029A CN 103105867 A CN103105867 A CN 103105867A
- Authority
- CN
- China
- Prior art keywords
- converter
- control
- control system
- liquid level
- level control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Feedback Control In General (AREA)
Abstract
The invention discloses a computer liquid level control system. The computer liquid level control system is mainly composed of a pressure transmitter, an electric control valve, an analog-digital (A/D) converter, a digital-analog (D/A) converter, a controller and an upper computer, wherein the pressure transmitter and the electric control valve are respectively connected with a controlled member, the A/D converter is connected with the pressure transmitter, the D/A converter is connected with the electric control valve, the controller is connected with the A/D converter and the D/A converter, and the upper computer is connected with the controller. The computer liquid level control system can restrain effect of external disturbance, ensures stability of a process, truly reproduces the condition of an actual industrial site, and enables process steady state and dynamic state working conditions to be optimal.
Description
Technical field
The present invention relates to a kind of computing machine tank level control system.
Background technology
Control theory has experienced classical control theory, two developing stage of modern control theory, has entered now Nonlinear Intelligent control theory developing period.The problem that solves from control theory and opinion, a lot of great, basic problems as controllability, observability, stability etc., have all been set up fairly perfect theoretical system in tradition control.Use traditional control theory and substantially can satisfy the needs in engineering and various other fields.But along with the development of industry and modern science and technology, in every field, automatic control system is also more and more higher to the requirement of control accuracy, response speed, system stability and adaptive faculty.Since the eighties in last century, the quick update of robot calculator and the high-speed development of computing technique have promoted carrying out in a deep going way of control theory research, and have entered one section new course.Along with developing rapidly of control theory, many advanced persons' control algolithm has appearred.But the various controllers take PID as principle are still basic control unit indispensable in process control.So far, pid control algorithm worldwide is used in the industrial process more than 80%, and the PID control technology has obtained good development, and the researcher has proposed many Control System Design methods and parameter adjustment is theoretical.This is because PID control has simple in structure, easy realization, controls the characteristics such as effective, and the pid algorithm principle is simple and clear, the parameter explicit physical meaning, and the theoretical analysis system is complete, by vast control engineering teacher is familiar with.
Liquid level is one of control parameter that often runs in industrial process production, required control object is carried out accurate liquid level control, and is related to the quality of product, is the major issue that ensures production effect and safety.Thereby the control of liquid level has important practical significance and application prospect widely.
Tank level control system is the system take liquid level as controlled parameter, and its every field in industry is related to widely.In industrial processes, having a lot of places to carry out liquid level to control object controls, make liquid level remain on accurately given numerical value, as in building material industry, glass furnace liquid level stable to the serviceable life of kiln and the quality of product playing vital effect.Also have in commercial production, especially also can often run into liquid level control problem in oil, chemical industry and metallurgical production.Therefore, required control object being carried out accurate liquid level control, be related to the realization of controlling target, is the major issue that ensures production effect and safety.
Nineteen thirty-nine, Taylor Instrument Company and Foxboro Instrument Company produce the pneumatic controller that has pid control function fully.People generally believe that PID should be referred to as Based Intelligent Control, because it is based on production operation personnel's control experience.The inventor thinks by observation, and controller should resemble and go to control a skilled operator, reduces until the error that occurs in the elimination system.Control three subject matters that have that face at PID at that time: (1) seeks a kind of straightforward procedure, regulates parameters for three that can calculate the PID controller.(2) judge whether production run is controlled.(3) operation of PID controller does not rely on the mechanical organ of complicated rapid wear.Theoretical research mainly concentrates on the first two problem, nineteen forty-two, gives part and solves.Second Problem is the controllability of system.The 3rd problem is due to the develop rapidly of the industrial revolution, and the PID controller of today uses electronic component and microprocessor substantially, has given the solution of almost Perfect.
The PID controller remains most widely used industrial control unit (ICU) now as the practical the earliest controller history of existing nearly 70 years.Trace it to its cause, be because the PID controller has following principal feature: (1) PID controller is easily understood, and does not need accurate especially system model in use.(2) usability is flexible, only needs to set three parameters and gets final product.Under many circumstances, whole three unit might not be needed, one to two unit wherein can be got.(3) pid parameter is more easily adjusted, and namely pid parameter can in time be adjusted according to the dynamic perfromance of process.If the dynamic perfromance of process changes, for example may be caused by the variation of load that system dynamic characteristic changes, pid parameter just can be adjusted again.And the step input response curve is the PID control most important foundation of effect and standard.It is generally acknowledged that it is the most serious interference that step is disturbed, as long as feedback control system can return to set-point in setting time under this type of disturbs, system meets the demands substantially.
The realization that PID controls is the basis that is established as with actual control system.Therefore, after just deciding the PID controller parameter, should first select suitable control hardware according to needs and the cost performance of actual control system, form actual control system.
The structures that hold liquid level control systems more, to consider generally the factor of four aspects:
(1) suppress the impact of external disturbance.The primary and foremost purpose of control system is to eliminate outside impact on producing, and namely introduces control system, makes process produce as far as possible little variation, the harmful effect that production is caused to eliminate external disturbance.The control system design purpose is with as far as possible little cost, strives for best control effect.
(2) guarantee the stability of process.Making whole system stable is the most basic purpose of controlling.Be stable for the production run self character, under the effect of externally disturbing, process need not to control to disturb and just can reach stable.Under this occasion, the purpose of control just suppresses the impact of interference, keeps predetermined working condition.Yet, be unsettled for the production run self character, control purpose except the impact that suppresses to disturb, also must make process keep stable.
(3) want the situation at true reappearance actual industrial scene.The starting points of holding the liquid level control system design allow the operator can know condition and the situation at understanding manufacture scene exactly.Like this, when the operator has really arrived the production scene, just can be calm control.Therefore, also to design according to the characteristics of the on-the-spot liquid level control system of actual industrial.
(4) make Steady-state process and dynamic operation condition optimum.Make process satisfy production target and safety index is two basic purposes of production run.After reaching these two purposes, next target is exactly how to make factory obtain more economic benefit.Change if affect the operating conditions of production run, just need to go to change process condition, the target of optimal control that Here it is by economic goal maximum or the minimum mode of cost.
Summary of the invention
The object of the invention is to overcome the shortcoming and defect of above-mentioned prior art, a kind of computing machine tank level control system is provided, this computing machine tank level control system can suppress the impact of external disturbance, guarantee the stability of process, the situation at true reappearance actual industrial scene makes Steady-state process and dynamic operation condition optimum.
Purpose of the present invention is achieved through the following technical solutions: the computing machine tank level control system, mainly by the pressure unit that is connected respectively with control object and electric control valve, the A/D converter that is connected with pressure unit, the D/A converter that is connected with electric control valve, the controller that all is connected with A/D converter and D/A converter and the host computer that is connected with controller consist of.
Be connected with the RS232 interface by the RS485 interface between described controller and host computer.
Described controller is intelligence instrument.
Described Intelligent Instrument is AI-818 type Intelligent Instrument.
Described host computer is computing machine.
In sum, the invention has the beneficial effects as follows: can suppress the impact of external disturbance, guarantee the stability of process, the situation at true reappearance actual industrial scene makes Steady-state process and dynamic operation condition optimum.
Description of drawings
Fig. 1 is structural representation of the present invention.
Embodiment
Below in conjunction with embodiment, the present invention is described in further detail, but embodiments of the present invention are not limited only to this.
Embodiment:
As shown in Figure 1, the computing machine tank level control system that the present invention relates to, main mainly by the pressure unit that is connected respectively with control object and electric control valve, the A/D converter that is connected with pressure unit, the D/A converter that is connected with electric control valve, the controller that all is connected with A/D converter and D/A converter and the host computer that is connected with controller consist of.
Be connected with the RS232 interface by the RS485 interface between described controller and host computer.
Described controller is intelligence instrument.
Described Intelligent Instrument is AI-818 type Intelligent Instrument.
Described host computer is computing machine.
Computing machine is used for moving ForceControl software, acts on by the access to serial ports the control that intelligence instrument is realized high water tank.Computing machine is a personnel operation and control maintenance platform in whole experiment, intuitively shows liquid level by the man-machine interface in the power control, and expert's form and history report are stored data for consulting and analyzing.
AI-818 type instrument is the PID control type, is output as 4～20mADC signal.AI-818 type instrument is passed through RS485 serial communication protocol and host computer communication, thereby realizes the Real Time Monitoring of system.
Electric control valve has that precision is high, advanced technology, volume is little, lightweight, expulsive force is large, function is strong, control module and electric operator is integrated, reliability is high, the advantage such as easy to operate, control signal is 4～20mA DC or 1～5V DC, the valve position signal of output 4～20mA DC uses and proofreaies and correct very convenient.
Pressure unit adopts industrial diffused silicon pressure transmitter, contains the stainless steel isolation diaphragm, adopts simultaneously Signal Isolation Technology, and compensation is followed in drift to sensor temperature.Pressure unit is used for the liquid level of three water tanks is detected, and transmitter is two-wire system, therefore need be connected in series the 24V direct supply when working.
The course of work of the present invention is: at first, pressure unit detects the liquid level in control object, and the signal that detects is sent to A/D converter; A/D converter is sent to AI-818 type Intelligent Instrument after signal is changed; AI-818 type Intelligent Instrument passes the signal to host computer; After host computer carried out computational analysis to signal, the output steering order was to AI-818 type Intelligent Instrument; AI-818 type Intelligent Instrument passes the signal to D/A converter; D/A converter is sent to electric control valve after signal is changed; Electric control valve is controlled the aperture of magnetic force driving pump, and then control object is controlled as actuator.
The above is only preferred embodiment of the present invention, is not the present invention is done any pro forma restriction, and every foundation technical spirit of the present invention, any simple modification, equivalent variations that above embodiment is done are within all falling into protection scope of the present invention.
Claims (5)
1. computing machine tank level control system, it is characterized in that, mainly by the pressure unit that is connected respectively with control object and electric control valve, the A/D converter that is connected with pressure unit, the D/A converter that is connected with electric control valve, the controller that all is connected with A/D converter and D/A converter and the host computer that is connected with controller consist of.
2. computing machine tank level control system according to claim 1, is characterized in that, is connected with the RS232 interface by the RS485 interface between described controller and host computer.
3. computing machine tank level control system according to claim 1, is characterized in that, described controller is intelligence instrument.
4. computing machine tank level control system according to claim 3, is characterized in that, described Intelligent Instrument is AI-818 type Intelligent Instrument.
5. computing machine tank level control system according to claim 1, is characterized in that, described host computer is computing machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110385029 CN103105867A (en) | 2011-11-14 | 2011-11-14 | Computer liquid level control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110385029 CN103105867A (en) | 2011-11-14 | 2011-11-14 | Computer liquid level control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103105867A true CN103105867A (en) | 2013-05-15 |
Family
ID=48313803
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110385029 Pending CN103105867A (en) | 2011-11-14 | 2011-11-14 | Computer liquid level control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103105867A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106094905A (en) * | 2016-07-24 | 2016-11-09 | 哈尔滨理工大学 | Four hold high water tank control system |
-
2011
- 2011-11-14 CN CN 201110385029 patent/CN103105867A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106094905A (en) * | 2016-07-24 | 2016-11-09 | 哈尔滨理工大学 | Four hold high water tank control system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110702361A (en) | Flow field accurate control system and control method of direct-current temporary-impulse type transonic wind tunnel | |
| CN103195975B (en) | Method for controlling piezoelectric valve positioner capable of changing PWM (pulse-width modulation) duty ratio | |
| CN202208972U (en) | Multi-point synchronization jacking device | |
| CN106292290B (en) | A kind of calm rolling optimization control method of wheeled mobile robot point | |
| CN102536935A (en) | Hydraulic synchronous control device and method | |
| Meng et al. | Liquid level control of four-tank system based on active disturbance rejection technology | |
| CN104374560B (en) | Gas lift valve test system | |
| CN202165088U (en) | Automatic guide control mechanism of pipe jacking machine | |
| CN103105860A (en) | Computer liquid level control system and control method of computer liquid level | |
| CN105329788A (en) | Uniform velocity amplitude-varying control method for jib crane | |
| CN103105867A (en) | Computer liquid level control system | |
| CN103105869A (en) | Three-tank single-loop liquid level system | |
| CN103105866A (en) | Control method based on computer liquid level control system | |
| CN108132596B (en) | Design method of differential advanced generalized intelligent internal model set PID controller | |
| CN103105870A (en) | Three-tank single-loop liquid level system and control method thereof | |
| CN103105864A (en) | Control method of double-holding single-circuit liquid level system | |
| CN103105868A (en) | Control method based on dual-container cascade-stage liquid level system | |
| CN103105871A (en) | Double-holding cascade stage liquid level system | |
| CN103105863A (en) | Double-tank cascade liquid level system based on piping and instrument diagram (PID) controller and control method thereof | |
| CN103105861A (en) | Double-tank cascade liquid level control method based on piping and instrument (PID) controller | |
| CN103105873A (en) | Control method applied to three-container single-circuit liquid level system | |
| CN103105865A (en) | Double-holding single-circuit liquid level system | |
| CN103291689A (en) | Method for controlling loading pressure of tested valve based on hydraulic test bench | |
| CN103105862A (en) | Double-tank cascade liquid level system based on piping and instrument diagram (PID) controller | |
| CN103105874A (en) | Double-holding single-circuit liquid level system and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20130515 |