CN103439881A - PID parameter setting method adjustable in control process adjusting time - Google Patents

Abstract

The invention relates to a PID parameter setting method adjustable in control process adjusting time. The method comprises the following steps: identifying the controlled process of a current known type so as to obtain the model parameter of the controlled process; selecting types of PID controllers according to control requirements; finding out a corresponding PID parameter setting calculation formula from a PID controller parameter computation sheet based on multi-capacity inertia standard transfer functions and adjusting time according to the type of the controlled process and the types of the PID controllers, utilizing the formula to calculate the parameter of the PID controllers according to the model parameter of the controlled process, and controlling all the PID controllers according to the parameter calculation result. Compared with the prior art, the parameter setting method is suitable for control systems which require slow reaction and are little in overshoot, and has the advantages of being strong in stability, high in robustness and adjustable in system adjusting time.

Description

Control procedure is adjusted adjustable pid parameter setting method of time

Technical field

The present invention relates to a kind of pid parameter setting method, especially relate to a kind of control procedure and adjust adjustable pid parameter setting method of time.

Background technology

The PID controller is most widely used industrial control unit (ICU) in the world.The invention of PID controller can trace back to 1939 United States Patent (USP), and it is to be declared by the Kao Lunde of Britain (Albert Callender) and Stevenson (Allan Stevenson).The purpose of PID controller is: guarantee the stability of whole control system, suppress the impact of external disturbance and the performance of optimization system, put and requiring as much as possible the simple, understandable of operation before this, and the very wide scope of application is arranged as much as possible.Therefore, the technological means based on advanced, we are the thereof using PID control method better, with efficiency and the production cost that improves better industry spot.

The performance of PID control system depends primarily on adjusting of PID controller parameter.Therefore, the parameter tuning technology of PID controller becomes the key of PID controller implementation success.Since the J.G.Ziegler of nineteen forty-two Tayor company and N.B.Nichols propose Ziegler--Nichols, adjust after criterion (being called for short the Z-N Tuning), just not more not influential PID controller parameter setting method occurs again.But, the adjustment time of the PID control system of adjusting with the Z-N Tuning is fixed, nonadjustable.This control system that can adjust with the need for the adjustment time that requires control system just is not suitable for.

Summary of the invention

Purpose of the present invention is exactly to provide a kind of PID of raising stability of control system and robustness, control procedure applied widely to adjust adjustable pid parameter setting method of time in order to overcome the defect that above-mentioned prior art exists.

Purpose of the present invention can be achieved through the following technical solutions:

A kind of control procedure is adjusted adjustable pid parameter setting method of time, and the method comprises the following steps:

1) controlled process of current known type is carried out to identification, obtain the controlled process model parameter;

2) require selected PID controller type according to controlling;

3) according to controlled process type, PID controller type from based on finding the corresponding pid parameter computing formula of adjusting many appearances inertia standard transport function and the PID controller parameter reckoner of the time of adjustment, utilize this formula to calculate the PID controller parameter according to the controlled process model parameter, and according to each PID controller of calculation of parameter output control.

Described based on many appearances inertia standard transport function and adjust the PID controller parameter reckoner of time and be specially:

In table, G _c(s) be the transport function expression formula of PID controller, G ₀(s) mean the transport function expression formula of controlled process, K, T, τ are respectively amplification coefficient, time constant and the pure delay time of controlled process, K _p, T _i, T _dbe respectively scale-up factor, integration time constant and the derivative time constant of PID controller, t _sfor control procedure is adjusted the time.

Described based on many appearances inertia standard transport function and adjust the PID controller parameter reckoner of time and be stored in data-carrier store.

The type of described controlled process includes the self-equilibrating process and, without the self-equilibrating process, described have the expression formula of self-equilibrating process to be:

the described expression formula without the self-equilibrating process is:

Described PID controller type comprises proportional controller, pi controller, proportional plus derivative controller and ratio infinitesimal analysis controller.

Compared with prior art, the present invention has the following advantages:

1) the present invention is based on inertia (MCP) standard transport functions and the standard transport function systems held more and carry out pid parameter with the relation of the time of adjustment and adjust, the PID control system after the inventive method is adjusted has the advantages that stability is strong, robustness is high and reduce the actuator wearing and tearing;

2) the inventive method is applied widely, and is applicable to those and requires the control system that the adjustment time can adjust with the need.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in detail.The present embodiment be take technical solution of the present invention and is implemented as prerequisite, provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

A kind of control procedure is adjusted adjustable pid parameter setting method of time, and the method is applicable to require the slow and control system that overshoot is little of reaction and has that stability is strong, robustness is high and system is adjusted adjustable characteristics of time.What in the method, adopt is stored in data-carrier store based on many appearances inertia standard transport function and the PID controller parameter of adjusting the time reckoner of adjusting, reusable.

The described PID controller parameter reckoner of adjusting is as shown in table 1, this reckoner is first according to inertia (MCP) the standard transport functions of holding more, to derive fundamental formular according to the standard transport function design method of controller and then according to MCP standard transport function system and the relation of the time of adjustment, add the adjustment time and draw, corresponding controllers parameter (K _p, T _i, T _d) totally 16 of the computing formula of adjusting.Compare many 2 formula for the PD controller with Z-N method formula.The PD controller is applied very extensive in Industry Control.

Table 1

In table 1, G _c(s) be the transport function expression formula of PID controller, G ₀(s) mean the transport function expression formula of controlled process, K, T, τ are respectively amplification coefficient, time constant and the pure delay time of controlled process, K _p, T _i, T _dbe respectively scale-up factor, integration time constant and the derivative time constant of PID controller, t _sfor control procedure is adjusted the time.

The method specifically comprises the following steps:

1) controlled process of current known type is carried out to identification, obtain the controlled process model parameter.The method that the described parameter to current controlled process is carried out the identification employing comprises the step response test method, add a step signal at the controlled process input end and then at output terminal, measure the step response data of process, then try to achieve the controlled process parameter with step response diagram modeling.

The type of described controlled process includes the self-equilibrating process and, without the self-equilibrating process, described have the expression formula of self-equilibrating process to be:

the described expression formula without the self-equilibrating process is:

2) choose required PID controller type according to setting, the PID controller type comprises proportional controller (P:G _c(s)=K _p), pi controller

proportional plus derivative controller (PD:G _c(s)=K _p(1+T _dand ratio infinitesimal analysis controller s))

3) from adjusting reckoner, finds the PID controller parameter the corresponding pid parameter computing formula of adjusting according to controlled process type, PID controller type, utilize this formula to calculate the PID controller parameter according to the controlled process model parameter, and according to each PID controller of calculation of parameter output control.

Suppose that certain controlled process can be described by formula (1), and learn, each controls parameter K=3, T=1, τ=0.1.If select the PID controller to be described by formula (2), and to establish the adjustment time be t _s=1, but in deck watch 1 corresponding formula calculate corresponding PID controller parameter suc as formula shown in (3), formula (4) and formula (5).

$G_0\left(s\right)=\frac{3}{s+1}{e}^{-0.1s}---\left(1\right)$

$G_c\left(s\right)=K_p(1+\frac{1}{T_{i}s}+T_{d}s)---\left(2\right)$

$k_p=\frac{1}{K}(\frac{3\mathrm{T\τ}}{{\left(0.158t_s\right)}^2}-1)=\frac{1}{3}(\frac{3\×0.1}{{(0.158\×1)}^2}-1)=3.6724---\left(3\right)$

$T_i=0.474t_s-\frac{{\left(0.158t_s\right)}^3}{\mathrm{T\τ}}=0.474-\frac{{\left(0.158\right)}^3}{0.1}=0.43456---\left(4\right)$

$T_d=(\frac{3\mathrm{T\τ}}{0.158t_s}-T-\mathrm{\τ})/(\frac{3\mathrm{T\τ}}{{\left(0.158t_s\right)}^2}-1)=(\frac{3\×0.1}{0.158}-1.1)/(\frac{0.3}{{\left(0.158\right)}^2}-1)=0.072498---\left(5\right)$

。

Claims (5)

1. a control procedure is adjusted adjustable pid parameter setting method of time, it is characterized in that, the method comprises the following steps:

1) controlled process of current known type is carried out to identification, obtain the controlled process model parameter;

2) require selected PID controller type according to controlling;

3) according to controlled process type, PID controller type from based on finding the corresponding pid parameter computing formula of adjusting many appearances inertia standard transport function and the PID controller parameter reckoner of the time of adjustment, utilize this formula to calculate the PID controller parameter according to the controlled process model parameter, and according to each PID controller of calculation of parameter output control.

2. a kind of control procedure according to claim 1 is adjusted adjustable pid parameter setting method of time, it is characterized in that, describedly based on many appearances inertia standard transport function and the PID controller parameter reckoner of the time of adjustment, is specially:

In table, G _c(s) be the transport function expression formula of PID controller, G ₀(s) mean the transport function expression formula of controlled process, K, T, τ are respectively amplification coefficient, time constant and the pure delay time of controlled process, K _p, T _i, T _dbe respectively scale-up factor, integration time constant and the derivative time constant of PID controller, t _sfor control procedure is adjusted the time.

3. a kind of control procedure according to claim 2 is adjusted adjustable pid parameter setting method of time, it is characterized in that, describedly based on many appearances inertia standard transport function and the PID controller parameter reckoner of the time of adjustment, is stored in data-carrier store.

4. a kind of control procedure according to claim 2 is adjusted adjustable pid parameter setting method of time, it is characterized in that, the type of described controlled process includes the self-equilibrating process and, without the self-equilibrating process, described have the expression formula of self-equilibrating process to be:

the described expression formula without the self-equilibrating process is: $G_0\left(s\right)=\frac{K}{s}{e}^{-\mathrm{\τs}}.$

5. a kind of control procedure according to claim 2 is adjusted adjustable pid parameter setting method of time, it is characterized in that, described PID controller type comprises proportional controller, pi controller, proportional plus derivative controller and ratio infinitesimal analysis controller.