CN1253766C

CN1253766C - Fast parameter self-setting method

Info

Publication number: CN1253766C
Application number: CN 200410017530
Authority: CN
Inventors: 蒋念平
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2004-04-08
Filing date: 2004-04-08
Publication date: 2006-04-26
Anticipated expiration: 2024-04-08
Also published as: CN1564091A

Abstract

The present invention relates to a fast parameter self-setting method which is characterized in that a control parameter of a controlled system can be rapidly determined. The method comprises the steps: setting a controlled system output in a designated goal value and dividing an area which has an upper boundary and a lower boundary and is called as a self-setting effective working area near the target value; adding an activation signal to the controlled system so as to output towards the target value, and converting the system activation to 0 before reaching the lower boundary of the set work area; adding a second activation signal after the first system output which starts to decrease; continuously applying activation signals after the system output reaches a valley point until the system output reaches an above designated increment value which takes the valley point value as a base value; and stopping data collection after the system output reaches a peak value for the second time, completing parameter tuning and finishing self-setting procedures. In the control of electric furnace devices with large inertia and large hysteresis, the method has obvious self-setting rapidity and good control effects corresponding to the setting parameters.

Description

A kind of fast parameter automatic setting method

Technical field

The present invention relates to a kind of industrial process control of being used for, the pattern-recognition of Industry Control object, the fast parameter automatic setting method that obtains especially for the controlled variable of becoming slowly in the Industry Control object, big inertia, Large-lag System.

Background technology

Control at industrial process, particularly in the control of the big inertia system that temperature etc. is become slowly, the aspect of model of controlling object will be along with the difference of object, the difference of duty and having nothing in common with each other, artificial definite controlled variable need have good understanding and enough commissioning experiences to system, how different controlling object is determined that automatically its suitable controlled variable is the common problem of Industry Control instrument industry.In the design and production of control instrument, because the instrument application surface is extremely wide, controlling object has nothing in common with each other, so generally can't pre-determine controlled variable, usually need after being used in certain controlled system of determining, instrument could determine its controlled variable targetedly.Determine controlled variable, at first need to understand the essential characteristic of controlled system.The mathematical model of system in other words.In fact relate to a pattern recognition problem.About pattern-recognition, many mature theory are arranged.But it is both unrealistic also unnecessary for many Industry Control objects to obtain system features by pattern recognition theory.Because this mode identification method needs lot of data, and operation time, the Industry Control object that becomes slowly for great majority can't effectively make in this way because recognition time is oversize.And has the feature of monotone convergence for the Industry Control object overwhelming majority of reality.On the other hand, the controll plant that PID controls for this monotone convergence on control algolithm has the characteristics low to the parameter changing sensitivity.That is to say that PID control is not very high to the degree of accuracy requirement of controlling object model.This is verified in a large amount of practical applications.So the great majority band adopts comparatively easy method from the control instrument of adjusting both at home and abroad at present.Its basic way is: by controll plant is applied excitation, and guarantee to be applied be activated at the control equilibrium point near metastable response output is arranged, and can calculate corresponding P by this excitation and corresponding output characteristics, I, D controlled variable.The automatic setting method that adopts both at home and abroad as shown in Figure 1 at present.Divide near the working point and mark one from adjusting the effective coverage, i.e. the suitable correction of system features parameter process that obtains in this zone can reflect near the system features the working point.Adopt extrinsic motivated and near the system responses of collecting work point for obtaining required characteristic information, obtain system works spot correlation feature thus and calculate controlled variable.Its process is such, at first controlled system is added a constant excitation and makes system output close to the working point, and during certain setting, system incentive becomes 0 near reaching the working point.System will continue to approach to the working point owing to inertia, and after after a while, beginning to fall after rise, when falling back to setting, system is added excitation for the second time, at this moment system will occur one from continuing to drop to the procedure body of rising, when system's output reaches this setting once more, again system incentive is put 0.The process that a rising falls after rise again will appear in system.When once fall back to this setting the time, the process of adjusting finishes.Calculate controlled variable according to image data.In the whole process of adjusting, excitation is to make system enter the working point near zone for the first time, and excitation for the second time is only the real beginning of adjusting certainly.To keep output characteristics that excitation produces relatively near the feature of working point.In the process of adjusting, the process that setting is fallen back in twice output appears whole.When system is big inertial time, this process is very long.Thereby make from the required time of adjusting very long.

Summary of the invention

When said method was not too big for the inertia of controlling object, its setting parameter required time can also be accepted.But when the inertia of controll plant was very big, the method for this setting parameter just seemed that the time is oversize.Particularly need often to change, and the bigger occasion of system parameter variations just need be carried out adjusting of parameter frequently at working state of system.Oversize setting time will reduce work efficiency.The purpose of this method adopts suitable energisation mode being to guarantee to obtain under the prerequisite of effective system characteristic information, reduces the redundant information collection.Thereby reach the purpose of accelerating parameter tuning.

This method adopts following technical proposals to parameter self-tuning, and characteristics are that method step is:

1, establishes controlled system export target value, near desired value, divide and mark a zone of being referred to as that upper and lower border is arranged from effective workspace of adjusting;

2, controlled system is added an excitation and make system's output trend desired value, before reaching the workspace lower boundary of adjusting of setting, system incentive becomes 0;

3, add pumping signal for the second time later when peak value begins to drop for the first time in system's output;

4, system output arrives and continues to keep pumping signal behind the valley point and reach when being the top designated increments value of base value with the valley point value until system's output, and system incentive becomes 0;

5, after reaching peak value for the second time, system's output finishes the process of adjusting.

The technical program and former technology relatively have the characteristics of several aspects:

1, pumping signal is short action time for the first time, as long as it is just passable to make system's output peak value enter target setting value zone.Pumping signal added later when the first time, peak value began to drop for the second time.Saved the falling time required in the former method.

2, the incentive action time is benchmark with the valley point of exporting for the second time, and keeps a rising drop ζ, to guarantee the effective actuation duration.

3, for the second time behind the peaking data acquisition promptly come to an end, and carry out controlled variable and calculate.Saved and fallen after rise the time second time required in the former method.

This method is in the control with big inertia large time delay furnace equipment, and the rapidity of adjusting certainly is apparent in view, and the control effect is also relatively good.

Description of drawings

Fig. 1 is that conventional method is from adjusting regular synoptic diagram;

Fig. 2 is that this method is from adjusting regular synoptic diagram;

Fig. 3 adjusts and the controlling recording curve certainly for conventional method;

Fig. 4 is for adjusting and the controlling recording curve certainly.

Embodiment

As shown in Figure 2, the system export target value of setting up departments is GV.Near desired value, divide and mark a zone, be referred to as from adjusting effective workspace, and to establish desired value be m to the distance on border.At first controlled system is added an excitation and make system's output close to desired value, before will arriving the border, workspace of adjusting of setting, system incentive becomes 0.System's output will continue to approach to the workspace of adjusting owing to inertia, and make system's output peak value enter the workspace of adjusting, and when outputing to peaking and falling after rise in system, again system be applied excitation, and at this moment system is owing to inertia, and output will continue to fall after rise.System's output arrives the valley point and begins and rises after a period of time.System's output continues to apply excitation reaches value top, valley point ζ until system's output designated increments after arriving the valley point.After system incentive becomes 0, system will continue to rise because of inertia, arrive peaking after a period of time.When beginning to fall after rise, system's output finishes the process of adjusting.After this, system will be with the controlled variable operation of the acquisition of adjusting certainly.Fig. 2 is the process prescription to this scheme.Among the figure, y represents system's output, and t is the time.

Fig. 3 adopts conventional automatic setting method that a big inertia large time delay furnace equipment is carried out adjusting certainly, and notes down curve with the process that setting parameter is controlled.Fig. 4 is the process record curve that adopts this method that same equipment is carried out parameter tuning and controlled by setting parameter.This subjects is an experiment baking oven, 100 ℃ of temperature of control, 10 ℃ of initial temperatures, the registering instrument chart drive speed be 2.5 lattice/hour.Conventional method about more than 2 hours from setting time, the time that controls to stationary value was at more than 1 hour.Whole about 3 and a half hours Zi 100 ℃ stable of design temperatures of the last arrival of the system of adjusting from 10 ℃ of beginnings of cold conditions environment temperature.Employing this method about more than 1 hour from setting time, the time that controls to stationary value is about half an hour.Whole about 2 hours Zi 100 ℃ stable of design temperatures of the last arrival of the system of adjusting from 10 ℃ of beginnings of cold conditions environment temperature.The The whole control time shortens greatly.Wherein most importantly from the shortening of setting time.Two kinds of methods differed from more than one hour from setting time in this example.

Claims

1, a kind of fast parameter automatic setting method is characterized in and can determines the controlled system controlled variable fast, and the step of described method is:

(1) establishes controlled system export target value, near desired value, divide and mark a zone of being referred to as that upper and lower border is arranged from effective workspace of adjusting;

(2) controlled system is added an excitation and make system's output trend desired value, before reaching the workspace lower boundary of adjusting of setting, system incentive becomes 0;

(3) add pumping signal for the second time later when peak value begins to drop for the first time in system's output;

(4) system output arrives and continues to keep pumping signal behind the valley point and reach when being the top designated increments value of base value with the valley point value until system's output, and system incentive becomes 0;

(5) after reaching peak value for the second time, system's output finishes the process of adjusting.