CN105388764A - Electro-hydraulic servo PID control method and system based on dynamic matrix feed-forward prediction - Google Patents

Abstract

The invention provides an electro-hydraulic servo PID control method and system based on dynamic matrix feed-forward prediction. The method comprises carrying out optimization on input quantity of an electro-hydraulic servo system through combination of a DMC feed-forward controller and a PID negative feedback controller, and comprises the following specific steps: establishing the DMC feed-forward controller; optimizing the performance index of the electro-hydraulic servo system through the DMC feed-forward controller, and carrying out rolling optimization on control input value of the electro-hydraulic servo system; establishing the PID negative feedback controller, and obtaining the control input value of the optimized electro-hydraulic servo system; and obtaining a head optimized control input value of the electro-hydraulic servo system according to the control input value of the electro-hydraulic servo system obtained by the DMC feed-forward controller through rolling optimization and the optimized control input value of the electro-hydraulic servo system obtained by the PID negative feedback controller. Through the electro-hydraulic servo PID control method and system, the problems of object-independent mathematic model and interference of outside world can be solved.

Description

Based on electro-hydraulic servo PID control method and the system of dynamic matrix feed forward prediction

Technical field

The present invention relates to PID control technology field, more specifically, relate to a kind of electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction and system.

Background technology

At present, electrohydraulic servo system is widely used in the industrial sectors such as Aeronautics and Astronautics, weapon, big machinery, metallurgy.The effect of electrohydraulic servo-controlling system be according to setting parameter in advance by the state modulator of system load in certain scope, prevent load from breaking down, thus the precision of electrohydraulic servo system with determine that the parameter that load runs well is closely related.Along with the development of modern industry, the performance of electrohydraulic servo system is had higher requirement, require that system has stronger adaptive faculty to rugged surroundings simultaneously.

Electrohydraulic servo system is typical mechanical electronic hydraulic coupled system, it is characterized in that non-linear, uncertain, time variation, external interference and cross-couplings interference, Hydrauservo System is also subject to, as the impact of multiple " soft " parameter factors such as oil viscosity, temperature, field working conditions, therefore setting up the accurate mathematical model of system and there is certain difficulty in addition.Current electrohydraulic servo system uses PID (Proportion ratio, Integration integration, Differentiation differential) to control usually, PID control principle is simple, be easy to adjust, easy to use and adjusting function index is not very sensitive for the change slightly of controll plant.But just can reach gratifying effect under the prerequisite that PID controller is only well adjusted in parameter.In order to meet the requirement of electrohydraulic servo system control performance, just need to seek a kind of new control strategy controlling to combine with PID.Smith Prediction Control method can make regulator advancement, thus balances out the impact that time lag characteristic causes, and reduces overshoot, improves the stability of system, accelerates adjustment process, improves the rapidity of system; But Smith Prediction Control has two main shortcomings: the robustness that (1) changes along with plant characteristic can not be guaranteed; (2) when there is external interference, can not well be overcome.

Therefore, for solving the problem, need to provide a kind of new electro-hydraulic servo PID control technology.

Summary of the invention

In view of the above problems, the object of this invention is to provide a kind of electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction and system, to solve the mathematical model and the extraneous interference problem brought that do not rely on object.

The invention provides a kind of electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction, comprising: being combined by DMC feedforward controller and PID negative feedback control device is optimized electrohydraulic servo system input quantity, and concrete steps are as follows:

Set up described DMC feedforward controller;

The performance index of electrohydraulic servo system are optimized by described DMC feedforward controller, and the control inputs value of electrohydraulic servo system described in rolling optimization;

Set up described PID negative feedback control device, obtain the control inputs value optimizing described electrohydraulic servo system; Wherein, the parameter of described PID negative feedback control device is adjusted;

The control inputs value of rolling optimization of described electrohydraulic servo system obtained according to described DMC feedforward controller and the control inputs value of the optimization according to the described electrohydraulic servo system of described PID negative feedback control device acquisition, obtain the control inputs value of the total optimization of described electrohydraulic servo system.

The present invention also provides the another kind of electro-hydraulic servo PID control system based on dynamic matrix feed forward prediction, comprising:

DMC feedforward controller sets up unit, for setting up described DMC feedforward controller;

Performance index optimize unit, for being optimized the performance index of electrohydraulic servo system by described DMC feedforward controller;

Control inputs value rolling optimization unit, for the control inputs value by electrohydraulic servo system described in described DMC feedforward controller rolling optimization;

Unit set up by PID negative feedback control device, for setting up described PID negative feedback control device, obtains the control inputs value optimizing described electrohydraulic servo system;

The parameter tuning unit of PID negative feedback control device, for adjusting to the parameter of described PID negative feedback control device;

The control inputs value acquiring unit of total optimization, for the control inputs value of the rolling optimization of described electrohydraulic servo system that obtains according to described DMC feedforward controller and the control inputs value of the optimization of described electrohydraulic servo system obtained according to described PID negative feedback control device, obtain the control inputs value of the total optimization of described electrohydraulic servo system.

From technical scheme above, the invention provides the electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction and system, adopt the PID controller based on feedforward DMC (dynamic matrix control) to carry out control design case and analysis to electrohydraulic servo system.DMC algorithm adopts the unit-step response coefficient of object to set up forecast model, does not rely on the mathematical models of object, can utilize the control output sequence in less time domain, be realized the optimization of current time control inputs amount by rolling optimization.On the other hand, DMC algorithm, by introducing regularization term in optimality criterion, the interference that can effectively suppress the external world to bring, makes whole electrohydraulic servo system have good rapidity, Stability and veracity.

In order to realize above-mentioned and relevant object, will describe in detail and the feature particularly pointed out in the claims after one or more aspect of the present invention comprises.Explanation below and accompanying drawing describe some illustrative aspects of the present invention in detail.But what these aspects indicated is only some modes that can use in the various modes of principle of the present invention.In addition, the present invention is intended to comprise all these aspects and their equivalent.

Accompanying drawing explanation

By reference to the content below in conjunction with the description of the drawings and claims, and understand more comprehensively along with to of the present invention, other object of the present invention and result will be understood and easy to understand more.In the accompanying drawings:

Fig. 1 is the electro-hydraulic servo PID control method schematic flow sheet based on dynamic matrix feed forward prediction according to the embodiment of the present invention;

Fig. 2 is the control structure block diagram of the electrohydraulic servo system according to the embodiment of the present invention;

Fig. 3 is the electro-hydraulic servo PID Control system architecture block diagram based on dynamic matrix feed forward prediction according to the embodiment of the present invention.

Label identical in all of the figs indicates similar or corresponding feature or function.

Embodiment

In the following description, for purposes of illustration, in order to provide the complete understanding to one or more embodiment, many details have been set forth.But, clearly, also these embodiments can be realized when there is no these details.

The robustness along with plant characteristic change for aforementioned proposition can not be guaranteed, and when there is external interference, the problem such as well can not to be overcome, the present invention proposes a kind of electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction and system, the present invention adopts the PID controller based on feedforward DMC to carry out control design case and analysis to electrohydraulic servo system, to solve the problem.

Below with reference to accompanying drawing, specific embodiments of the invention are described in detail.

In order to the electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction provided by the invention is described, Fig. 1 show according to the embodiment of the present invention in the electro-hydraulic servo PID control method flow process of dynamic matrix feed forward prediction.

As shown in Figure 1, the electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction provided by the invention comprises: being combined by DMC feedforward controller and PID negative feedback control device is optimized electrohydraulic servo system input quantity, and concrete steps are as follows:

S110: set up DMC feedforward controller;

S120: the performance index being optimized electrohydraulic servo system by DMC feedforward controller, and the control inputs value of rolling optimization electrohydraulic servo system;

S130: set up PID negative feedback control device, obtains the control inputs value optimizing electrohydraulic servo system; Wherein, the parameter of PID negative feedback control device is adjusted;

S140: the control inputs value of rolling optimization of electrohydraulic servo system obtained according to DMC feedforward controller and the control inputs value of the optimization according to the electrohydraulic servo system of PID negative feedback control device acquisition, obtain the control inputs value of the total optimization of electrohydraulic servo system.

In the present invention, the PID controller based on feedforward DMC is adopted to carry out control design case and analysis to electrohydraulic servo system, wherein, DMC (dynamic matrix control) is the predictive control algorithm of a kind of advanced person, DMC algorithm adopts the unit-step response coefficient of object to set up forecast model, do not rely on the mathematical models of object, the control output sequence in less time domain can be utilized, realized the optimization of current time control inputs amount by rolling optimization.

That is, in the present invention, DMC, as the feedforward controller of system, combines with PID negative feedback control device and optimizes input value in electrohydraulic servo system in advance.

In step s 110, set up DMC feedforward controller, namely set up the forecast model of DMC algorithm.

DMC algorithm adopts the unit-step response coefficient of object to set up forecast model, after the input end of electrohydraulic servo system adds a unit step signal, is respectively a in the dynamic step-response coefficients in each sampling time _i=a (iT), i=1,2 ..., N, N are the time domain length of model;

According to ratio and the sumproperties of linear system, from the k moment, M input control increment Delta u (k+j) is applied to system, j=0,1, after M-1, then system the prediction in a following p moment export equal not apply any controlling increment time system output with independent apply that this M the system that input control increment causes export superpose, that is:

y _M(k+1|k)＝y ₀(k+1|k)+a ₁Δu(k)(1a)

y _M(k+2|k)＝y ₀(k+2|k)+a ₂Δu(k)+a ₁Δu(k+1)(1b)

.

.

.

Y _m(k+P|k)=y ₀(k+P|k)+a _pΔ u (k)+... + a _p-M+1Δ u (k+M-1) (1c) is write formula (1a) to (1c) as vector form:

Y _M(k+1)＝Y ₀(k+1)+AΔU(k)(2)

Wherein, Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^t, P is rolling optimization time domain length, and M is for controlling time domain length (M≤P≤N), and A is the P × Metzler matrix be made up of step-response coefficients, as follows:

In step s 12, optimized the performance index of electrohydraulic servo system by DMC feedforward controller, and the input quantity of rolling optimization electrohydraulic servo system, the namely input of optimality criterion and rolling optimization controller.

Wherein, DMC adopts rolling optimization objective function, the following controlling increment sequence controlled in time domain M of selection, make the prediction output valve of system under its effect in following optimization time domain P as far as possible close to desired output, optimal control law is determined by following quadratic performance index:

$\min J\left(k\right)=\underset{i=1}{\overset{P}{\Σ}}{q}_i{\[y_r(k+i)-y_M(k+i|k)\]}^2+\underset{j=1}{\overset{M}{\Σ}}{r}_j{\mathrm{\Δu}}^2(k+j-1)---\left(4\right)$

Wherein, q _iand r _jfor weight coefficient, represent the suppression to tracking error and controlled quentity controlled variable change respectively;

The form of formula (4) one-tenth vector is:

$\min J\left(k\right)=\left|\right|Y_r(k+1)-Y_M(k+1)|{|}_Q^2+|\left|\mathrm{\Δ}U\left(k\right)\right|{|}_R^2---\left(5\right)$

Wherein, Y _r(k+1)=[y _r(k+1) ..., y _r(k+P)] ^tfor the desired output of following P sampling instant system; Q is error coefficient matrix, and R is control matrix, is expressed as:

Q＝diag[q ₁,q ₂,...,q _P]，R＝diag[r ₁,r ₂,...,r _M]

Formula (2) is brought in formula (5), makes dJ (k)/d Δ U (k)=0, obtain optimal control law as follows:

ΔU(k)＝(A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](6)

What formula (6) provided is Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^toptimum solution, and instant controlling increment Δ u (k) is wherein formed working control by described DMC feedforward controller acts on object:

u(k)＝u(k-1)+Δu(k)(7)

Wherein, in formula (7),

Δu(k)＝[1,0,…,0](A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](8)

In above-mentioned steps S130, set up PID negative feedback control device.

The present invention adopts incremental timestamp device to carry out On-line Control to electrohydraulic servo system, and its control law can be described as following form:

u _PID(k)＝u _PID(k-1)+K _p(e(k)-e(k-1))+K _ie(k)

(9)

+K _d(e(k)-2e(k-1)+e(k-2))

Wherein, K _p, K _iand K _dbe respectively scale-up factor, integration time constant and derivative time constant; The true output valve that e (k) is etching system during k and the difference of given expectation value.

In the process setting up PID negative feedback control device, need to adjust to the parameter of PID controller.Wherein, the PID controller parameter implication of adjusting is indeed through adjustment K _p, K _iand K _dthree parameters, make the characteristics match of controller characteristic and controlled device, meet the control effects that control system will reach.For the industrial stokehold of purely retarded, the industrial setting method of conventional pid parameter is: stability boundaris (aritical ratio band method).Wherein, its sight line is when system closed loop, removes integration and differentiation effect, allows system produce continuous oscillation under the effect of pure proportioner, utilizes critical gain K now _pwith critical concussion cycle T, the experimental formula as shown in the table proposed according to Ziegler and Nichols and correct type, 1 three parameters obtaining PID of tabling look-up.

Table 1 aritical ratio band method parameter tuning formula

As known from the above, combined by feedforward DMC algorithm and PID negative feedback control device, set up the control structure of the electrohydraulic servo system according to the embodiment of the present invention as shown in Figure 2, so, the optimal control input value that etching system is total when k is

u _sum(k)＝u _PID(k)+u(k)(10)

Wherein, u _pIDk control law that () obtains for PID negative feedback control device; The control law that u (k) obtains for DMC feedforward controller.

Corresponding with said method, the present invention also provides a kind of electro-hydraulic servo PID control system based on dynamic matrix feed forward prediction, and Fig. 3 shows the electro-hydraulic servo PID control system logical organization based on dynamic matrix feed forward prediction according to the embodiment of the present invention.

As shown in Figure 3, a kind of electro-hydraulic servo PID control system 300 based on dynamic matrix feed forward prediction provided by the invention comprises: DMC feedforward controller sets up unit 310, performance index optimize unit 320, control inputs value rolling optimization unit 330, PID negative feedback control device set up unit 340, the parameter tuning unit 350 of PID negative feedback control device and the control inputs value acquiring unit 360 of total optimization.

Wherein, DMC feedforward controller sets up unit 310 for setting up DMC feedforward controller;

Performance index optimize unit 320 for being optimized the performance index of electrohydraulic servo system by DMC feedforward controller;

Control inputs value rolling optimization unit 330 is for the control inputs value by DMC feedforward controller rolling optimization electrohydraulic servo system;

PID negative feedback control device sets up unit 340 for setting up PID negative feedback control device, obtains the control inputs value optimizing electrohydraulic servo system;

The parameter tuning unit 350 of PID negative feedback control device is for adjusting to the parameter of PID negative feedback control device;

The control inputs value acquiring unit 360 of total optimization, for the control inputs value of the rolling optimization of electrohydraulic servo system that obtains according to DMC feedforward controller and the control inputs value of the optimization of electrohydraulic servo system obtained according to PID negative feedback control device, obtains the control inputs value of the total optimization of electrohydraulic servo system.

Wherein, DMC feedforward controller sets up unit 310 in the process setting up described DMC feedforward controller, DMC algorithm adopts the unit-step response coefficient of object to set up forecast model, after the input end of electrohydraulic servo system adds a unit step signal, at the dynamic step-response coefficients a in each sampling time _i=a (iT), i=1,2 ..., N, N are the time domain length of model;

According to ratio and the sumproperties of linear system, from the k moment, M input control increment Delta u (k+j) is applied to system, j=0,1, after M-1, then system the prediction in a following p moment export equal not apply any controlling increment time system output with independent apply that this M the system that input control increment causes export superpose, that is:

y _M(k+1|k)＝y ₀(k+1|k)+a ₁Δu(k)(1a)

y _M(k+2|k)＝y ₀(k+2|k)+a ₂Δu(k)+a ₁Δu(k+1)(1b)

.

.

.

Y _m(k+P|k)=y ₀(k+P|k)+a _pΔ u (k)+... + a _p-M+1Δ u (k+M-1) (1c) is write formula (1a) to (1c) as vector form:

Y _M(k+1)＝Y ₀(k+1)+AΔU(k)(2)

Wherein, Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^t, P is rolling optimization time domain length, and M is for controlling time domain length (M≤P≤N), and A is the P × Metzler matrix be made up of step-response coefficients, as follows:

Wherein, performance index optimize unit 320 and control inputs value rolling optimization unit 330 in the performance index being optimized electrohydraulic servo system by DMC feedforward controller, and in the process of input quantity optimizing electrohydraulic servo system,

DMC feedforward controller rolling optimization objective function, select the following controlling increment sequence controlled in time domain M, make the prediction output valve of system under its effect in following optimization time domain P as far as possible close to desired output, optimal control law is determined by following quadratic performance index:

$\min J\left(k\right)=\underset{i=1}{\overset{P}{\Σ}}{q}_i{\[y_r(k+i)-y_M(k+i|k)\]}^2+\underset{j=1}{\overset{M}{\Σ}}{r}_j{\mathrm{\Δu}}^2(k+j-1)---\left(4\right)$

Wherein, q _iand r _jfor weight coefficient, represent the suppression to tracking error and controlled quentity controlled variable change respectively;

The form of formula (4) one-tenth vector is:

$\min J\left(k\right)=\left|\right|Y_r(k+1)-Y_M(k+1)|{|}_Q^2+|\left|\mathrm{\Δ}U\left(k\right)\right|{|}_R^2---\left(5\right)$

Wherein, Y _r(k+1)=[y _r(k+1) ..., y _r(k+P)] ^tfor the desired output of following P sampling instant system; Q is error coefficient matrix, and R is control matrix, is expressed as:

Q＝diag[q ₁,q ₂,...,q _P]，R＝diag[r ₁,r ₂,...,r _M]

Formula (2) is brought in formula (5), makes dJ (k)/d Δ U (k)=0, obtain optimal control law as follows:

ΔU(k)＝(A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](6)

What formula (6) provided is Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^toptimum solution, and instant controlling increment Δ u (k) is wherein formed working control by described DMC feedforward controller acts on object:

u(k)＝u(k-1)+Δu(k)(7)

Wherein, in formula (7),

Δu(k)＝[1,0,…,0](A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](8)

Wherein, PID negative feedback control device sets up unit 340 in the process setting up PID negative feedback control device, and PID controller carries out On-line Control to electrohydraulic servo system, and its control law is:

u _PID(k)＝u _PID(k-1)+K _p(e(k)-e(k-1))+K _ie(k)

(9)

+K _d(e(k)-2e(k-1)+e(k-2))

Wherein, K _p, K _iand K _dbe respectively scale-up factor, integration time constant and derivative time constant;

The true output valve that e (k) is etching system during k and the difference of given expectation value.

Wherein, the control inputs value acquiring unit 360 of total optimization is in the process of control inputs value obtaining the total optimization of electrohydraulic servo system, and DMC feedforward controller and PID negative feedback control device combine, and the control inputs value of the optimization that etching system is total when K is:

u _sum(k)＝u _PID(k)+u(k)(10)

Wherein, u _pIDk control law that () obtains for PID negative feedback control device; The control law that u (k) obtains for DMC feedforward controller.

Can be found out by above-mentioned embodiment, electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction provided by the invention and system, DMC algorithm adopts the unit-step response coefficient of object to set up forecast model, do not rely on the mathematical models of object, the control output sequence in less time domain can be utilized, realized the optimization of current time control inputs amount by rolling optimization.On the other hand, DMC algorithm, by introducing regularization term in optimality criterion, the interference that can effectively suppress the external world to bring, makes whole electrohydraulic servo system have good rapidity, Stability and veracity.

The electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction and system that propose according to the present invention is described in an illustrative manner above with reference to accompanying drawing.But, it will be appreciated by those skilled in the art that the electro-hydraulic servo PID control method based on dynamic matrix feed forward prediction and system that the invention described above is proposed, various improvement can also be made on the basis not departing from content of the present invention.Therefore, protection scope of the present invention should be determined by the content of appending claims.

Claims (10)

1. based on an electro-hydraulic servo PID control method for dynamic matrix feed forward prediction, comprising: being combined by DMC feedforward controller and PID negative feedback control device is optimized electrohydraulic servo system input quantity, and concrete steps are as follows:

Set up described DMC feedforward controller;

The performance index of electrohydraulic servo system are optimized by described DMC feedforward controller, and the control inputs value of electrohydraulic servo system described in rolling optimization;

Set up described PID negative feedback control device, obtain the control inputs value optimizing described electrohydraulic servo system; Wherein, the parameter of described PID negative feedback control device is adjusted;

The control inputs value of rolling optimization of described electrohydraulic servo system obtained according to described DMC feedforward controller and the control inputs value of the optimization according to the described electrohydraulic servo system of described PID negative feedback control device acquisition, obtain the control inputs value of the total optimization of described electrohydraulic servo system.

2. as claimed in claim 1 based on the electro-hydraulic servo PID control method of dynamic matrix feed forward prediction, wherein, in the process setting up described DMC feedforward controller,

DMC algorithm adopts the unit-step response coefficient of object to carry out the foundation of forecast model, after the input end of described electrohydraulic servo system adds unit step signal, is respectively a in the dynamic step-response coefficients in each sampling time _i=a (iT), i=1,2 ..., N, N are the time domain length of model;

According to ratio and the sumproperties of linear system, from the k moment, M input control increment Delta u (k+j) is applied to system, j=0,1, after M-1, then system the prediction in a following p moment export equal not apply any controlling increment time system output with independent apply that this M the system that input control increment causes export superpose, that is:

y _M(k+1|k)＝y ₀(k+1|k)+a ₁Δu(k)(1a)

y _M(k+2|k)＝y ₀(k+2|k)+a ₂Δu(k)+a ₁Δu(k+1)(1b)

·

·

·

y _M(k+P|k)＝y ₀(k+P|k)+a _PΔu(k)+…+a _P-M+1Δu(k+M-1)(1c)

Being write formula (1a) to (1c) as vector form is:

Y _M(k+1)＝Y ₀(k+1)+AΔU(k)(2)

Wherein, Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^t, P is rolling optimization time domain length, and M is for controlling time domain length (M≤P≤N), and A is the P × Metzler matrix be made up of step-response coefficients, as follows:

。

3. as claimed in claim 1 based on the electro-hydraulic servo PID control method of dynamic matrix feed forward prediction, wherein, the performance index of electrohydraulic servo system are being optimized by described DMC feedforward controller, and in the process of the input quantity of electrohydraulic servo system described in rolling optimization

Described DMC feedforward controller rolling optimization objective function, select the following controlling increment sequence controlled in time domain M, make the prediction output valve of system under its effect in following optimization time domain P as far as possible close to desired output, optimal control law is determined by following quadratic performance index:

Wherein, q _iand r _jfor weight coefficient, represent the suppression to tracking error and controlled quentity controlled variable change respectively;

The form of formula (4) one-tenth vector is:

Wherein, Y _r(k+1)=[y _r(k+1) ..., y _r(k+P)] ^tfor the desired output of following P sampling instant system; Q is error coefficient matrix, and R is control matrix, is expressed as:

Q＝diag[q ₁,q ₂,...,q _P]，R＝diag[r ₁,r ₂,...,r _M]

Formula (2) is brought in formula (5), makes dJ (k)/d Δ U (k)=0, obtain optimal control law as follows:

ΔU(k)＝(A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](6)

What formula (6) provided is Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^toptimum solution, and instant controlling increment Δ u (k) is wherein formed working control by described DMC feedforward controller acts on object:

u(k)＝u(k-1)+Δu(k)(7)

Wherein, in formula (7),

Δu(k)＝[1,0,…,0](A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](8)。

4. as claimed in claim 1 based on the electro-hydraulic servo PID control method of dynamic matrix feed forward prediction, wherein, in the process setting up described PID negative feedback control device,

Described PID controller carries out On-line Control to electrohydraulic servo system, and its control law is:

Wherein, K _p, K _iand K _dbe respectively scale-up factor, integration time constant and derivative time constant;

The true output valve that e (k) is etching system during k and the difference of given expectation value.

5. as claimed in claim 1 based on the electro-hydraulic servo PID control method of dynamic matrix feed forward prediction, wherein, in the process obtaining the total control inputs value of described electrohydraulic servo system,

Described DMC feedforward controller and PID negative feedback control device combine, and the optimal control input value that etching system is total when K is:

u _sum(k)＝u _PID(k)+u(k)(10)

Wherein, u _pIDk control law that () obtains for PID negative feedback control device; The control law that u (k) obtains for DMC feedforward controller.

6., based on an electro-hydraulic servo PID control system for dynamic matrix feed forward prediction, comprising:

DMC feedforward controller sets up unit, for setting up described DMC feedforward controller;

Performance index optimize unit, for being optimized the performance index of electrohydraulic servo system by described DMC feedforward controller;

Control inputs value rolling optimization unit, for the control inputs value by electrohydraulic servo system described in described DMC feedforward controller rolling optimization;

Unit set up by PID negative feedback control device, for setting up described PID negative feedback control device, obtains the control inputs value optimizing described electrohydraulic servo system;

The parameter tuning unit of PID negative feedback control device, for adjusting to the parameter of described PID negative feedback control device;

The control inputs value acquiring unit of total optimization, for the control inputs value of the rolling optimization of described electrohydraulic servo system that obtains according to described DMC feedforward controller and the control inputs value of the optimization of described electrohydraulic servo system obtained according to described PID negative feedback control device, obtain the control inputs value of the total optimization of described electrohydraulic servo system.

7., as claimed in claim 6 based on the electro-hydraulic servo PID control system of dynamic matrix feed forward prediction, wherein, described DMC feedforward controller sets up unit in the process setting up described DMC feedforward controller,

DMC algorithm adopts the unit-step response coefficient of object to carry out the foundation of forecast model, after the input end of described electrohydraulic servo system adds unit step signal, is respectively a in the dynamic step-response coefficients in each sampling time _i=a (iT), i=1,2 ..., N, N are the time domain length of model;

According to ratio and the sumproperties of linear system, from the k moment, M input control increment Delta u (k+j) is applied to system, j=0,1, after M-1, then system the prediction in a following p moment export equal not apply any controlling increment time system output with independent apply that this M the system that input control increment causes export superpose, that is:

y _M(k+1|k)＝y ₀(k+1|k)+a ₁Δu(k)(1a)

y _M(k+2|k)＝y ₀(k+2|k)+a ₂Δu(k)+a ₁Δu(k+1)(1b)

·

·

·

y _M(k+P|k)＝y ₀(k+P|k)+a _PΔu(k)+…+a _P-M+1Δu(k+M-1)(1c)

Being write formula (1a) to (1c) as vector form is:

Y _M(k+1)＝Y ₀(k+1)+AΔU(k)(2)

Wherein, Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^t, P is rolling optimization time domain length, and M is for controlling time domain length (M≤P≤N), and A is the P × Metzler matrix be made up of step-response coefficients, as follows:

。

8. as claimed in claim 6 based on the electro-hydraulic servo PID control system of dynamic matrix feed forward prediction, wherein, described performance index optimization unit and described control inputs value rolling optimization unit are in the performance index being optimized electrohydraulic servo system by described DMC feedforward controller, and in the process of input quantity optimizing described electrohydraulic servo system

Described DMC feedforward controller rolling optimization objective function, select the following controlling increment sequence controlled in time domain M, make the prediction output valve of system under its effect in following optimization time domain P as far as possible close to desired output, optimal control law is determined by following quadratic performance index:

Wherein, q _iand r _jfor weight coefficient, represent the suppression to tracking error and controlled quentity controlled variable change respectively;

The form of formula (4) one-tenth vector is:

Wherein, Y _r(k+1)=[y _r(k+1) ..., y _r(k+P)] ^tfor the desired output of following P sampling instant system; Q is error coefficient matrix, and R is control matrix, is expressed as:

Q＝diag[q ₁,q ₂,...,q _P]，R＝diag[r ₁,r ₂,...,r _M]

Formula (2) is brought in formula (5), makes dJ (k)/d Δ U (k)=0, obtain optimal control law as follows:

ΔU(k)＝(A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](6)

What formula (6) provided is Δ U (k)=[Δ u (k), Δ u (k+1) ..., Δ u (k+M-1)] ^toptimum solution, and instant controlling increment Δ u (k) is wherein formed working control by described DMC feedforward controller acts on object:

u(k)＝u(k-1)+Δu(k)(7)

Wherein, in formula (7),

Δu(k)＝[1,0,…,0](A ^TQA+R) ^-1A ^TQ[Y _r(k+1)-Y ₀(k+1)](8)。

9., as claimed in claim 6 based on the electro-hydraulic servo PID control system of dynamic matrix feed forward prediction, wherein, described PID negative feedback control device is set up described in unit in the process setting up described PID negative feedback control device,

Described PID controller carries out On-line Control to electrohydraulic servo system, and its control law is:

Wherein, K _p, K _iand K _dbe respectively scale-up factor, integration time constant and derivative time constant;

The true output valve that e (k) is etching system during k and the difference of given expectation value.

10. as claimed in claim 6 based on the electro-hydraulic servo PID control system of dynamic matrix feed forward prediction, wherein, the control inputs value acquiring unit of described optimization always in the process of control inputs value obtaining the total optimization of described electrohydraulic servo system,

Described DMC feedforward controller and PID negative feedback control device combine, and the control inputs value of the optimization that etching system is total when K is:

u _sum(k)＝u _PID(k)+u(k)(10)

Wherein, u _pIDk control law that () obtains for PID negative feedback control device; The control law that u (k) obtains for DMC feedforward controller.