CN111723442B - Design method of rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping - Google Patents
Design method of rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping Download PDFInfo
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Abstract
The invention provides a design method of a rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping, which comprises the steps of firstly, establishing a four-degree-of-freedom machine-liquid coupling nonlinear model of rolling mill vertical vibration according to the dynamic principle of a rolling mill vibration system; then, the working roll is jumped up and down according to the vertical vibration of the rolling mill, so that the control target is set when the vertical vibration displacement of the working roll of the rolling mill approaches zero; and finally, selecting a proper Lyapunov function in combination with a nonlinear model of the vertical vibration of the rolling mill, and solving a virtual controller, an actual controller and a self-adaptive law which enable V (t) to be zero when t tends to be infinite, so as to finally obtain a design method of the controller with the preset performance for inhibiting the vertical vibration of the rolling mill. The invention establishes a rolling mill vertical vibration nonlinear model which is more in line with the actual working condition, considers the characteristic of dead zone of a servo valve and the limitation on the vibration displacement of the roller, designs a rolling mill vertical vibration suppressor, realizes the rapid active suppression of vertical vibration in the high-speed rolling process, and ensures the stability of the high-speed rolling process of a strip.
Description
Technical Field
The invention relates to the technical field of metallurgical rolling control, in particular to a design method of a rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping.
Background
When rolling extremely thin steel strip at high speed, vibration perpendicular to the rolling direction, or vertical vibration, often occurs. The vertical vibration of the rolling mill not only affects the dimensional accuracy and surface quality of the strip, but also can cause damage to rolling equipment if the vertical vibration is serious. At present, the emergency measure for solving the problem of vertical vibration of the rolling mill on site is to reduce the rolling speed, but the reduction of the rolling speed influences the production efficiency of the plate strip and cannot be used as an effective treatment measure for treating the vertical vibration of the rolling mill. Therefore, how to effectively solve the problem of vertical vibration in the high-speed process of the plate strip becomes the key point and the difficulty of field technical attack. In the past, the vibration of the rolling mill is mainly treated from the aspects of machinery and technology, such as eliminating equipment clearance, optimizing rolling rules and inhibiting the vibration of the rolling mill by measures of improving lubricating parameters of a rolling roll gap.
With the development of control technology, a reasonably designed vibration suppression controller has become a focus of attention from the viewpoint of active suppression of vibration. In practice the mill vibration system is a mechanical hydraulic coupling nonlinear system. For the nonlinear system control problem, backstepping control method can be used for processing. In addition, functions and parameters in the coupled vibration system of the rolling mill are unknown, and the self-adaptive fuzzy technology has a good effect on the unknown functions and parameters in the processing system. In addition, the roll run-out displacement and the valve core of an electro-hydraulic servo valve need to be limited in an actual rolling mill coupled vibration system, so that the dead zone problem exists. Therefore, the research on how to design the control method to ensure the effective and quick suppression of the vibration of the rolling mill has strong practical significance.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a design method of a rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping, which establishes a rolling mill vertical vibration nonlinear model more conforming to the actual working condition by considering the limitation of preset performance on the vibration displacement of a roller, realizes the rapid active suppression of vertical vibration in the high-speed rolling process and ensures the stability of the high-speed rolling process of a plate strip.
The invention provides a design method of a rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping, which comprises the following steps of firstly, establishing a nonlinear model of rolling mill vertical vibration according to the dynamic principle of a rolling mill vibration system; then, determining a control target for inhibiting the vibration of the rolling mill according to the actual working condition; and finally, designing a self-adaptive backstepping controller by combining a nonlinear model of vertical vibration of the rolling mill and a control target for inhibiting vibration of the rolling mill, wherein the specific design method of the controller comprises the following steps:
s1, collecting parameters of a mechanical-hydraulic coupling vibration system of the rolling mill and characteristic parameters of a dead zone of an electro-hydraulic servo valve;
s2, establishing a four-degree-of-freedom mechanical-hydraulic coupling nonlinear model of vertical vibration of the rolling mill according to Newton' S second theorem:
wherein z is1For the oscillating displacement of the working rolls, z2Is the work roll vibration speed, z3For the oscillatory displacement of the intermediate roll, z4Is the intermediate roll oscillation speed, z5For supporting the roll vibrational displacement, z6To the vibration speed of the support roller, z7For oscillating displacement of the cylinder, z8Is the cylinder vibration speed, z9=P1Is the pressure at the rodless cavity, miTo an equivalent mass, kiTo equivalent stiffness, ciFor equivalent damping, A1Is the area of the rodless cavity, A2Is the area of the rod cavity, ctIs the leakage coefficient, P, in the cylinder2Pressure of the rod chamber, V initial volume of the control chamber, betaeIs the bulk modulus, k, of the oilqIs a process coefficient, u is a comprehensive expression of a characteristic parameter of the dead zone of the servo valve, Fz(z1,z2) Is a function expression related to the vibration displacement and the vibration speed of the working roll;
s3, determining a target for restraining the vibration of the rolling mill;
s31, setting the vertical vibration displacement of the working roll of the rolling mill close to zero as a control target according to the fact that the vertical vibration of the rolling mill is caused by the vertical jumping of the working roll;
s32, controlling the vertical vibration attenuation rate and the maximum allowable displacement of the rolling mill within a set range, wherein the target for restraining the vibration of the rolling mill can be expressed as follows:
wherein xi is1=z1Indicating the displacement of the work rolls during vibration of the mill, mu (t) ═ mu0e-kt+μ∞,μ0,k,μ∞Is a positive real number that is specified,δandare given positive real numbers;
s4, giving a controller and a parameter adaptive law according to Lyapunov stability criterion, and designing an adaptive fuzzy vibration suppressor;
s41, selecting a proper Lyapunov function according to the four-degree-of-freedom mechanical-hydraulic coupling nonlinear model of the vertical vibration of the rolling mill established in the step S2;
s42, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is solved1(t) a vanishing virtual controller and adaptive law;
and S43, finally obtaining the design method of the preset performance controller for inhibiting the vertical vibration of the rolling mill.
Preferably, nine lyapunov functions are selected according to the nine subsystems included in step S2, and step S4 specifically includes the following steps:
s411, selecting a first Lyapunov function:
s421, deriving the Lyapunov function, and solving to make V tend to be infinite1(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,ε1and a1Is a positive parameter being designed;
s412, selecting a second Lyapunov function:
wherein xi is2=z2-α1,σ21、σ22Is a positive parameter that is being designed for,is ρ2The error of the estimation of (2) is,is theta2The estimation error of (2);
s422, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is solved2(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is ρ2Is estimated byThe value of the one or more of the one,ε22is a given normal number, σ21,τ2,l21,l22Is a positive parameter of the design and,is the vector of the fuzzy basis function of the second step,is theta2An estimated value of (d);
s413, selecting a third Lyapunov function:
wherein xi is3=z3-α2,σ32Is a positive parameter that is designed to be,is θ3The estimation error of (2);
s423, deriving the Lyapunov function, and solving to make V tend to be infinite3(t) the vanishing virtual controller and adaptation law is:
wherein, a3,l32,σ32Is a positive parameter that is being designed for,is thatThe method (2) is implemented by the following steps,is the vector of the fuzzy basis function of the third step,is θ3An estimated value of (d);
s414, selecting a fourth Lyapunov function:
wherein xi is4=z4-α3,σ41、σ42Is a positive parameter that is being designed for,is ρ4The error of the estimation of (2) is,is theta4The estimated error of (2);
s424, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution4(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,is ρ4Is determined by the estimated value of (c),ε42is a given normal number; sigma41,τ4,l41,l42Is a positive parameter of the design and,is the vector of the fuzzy basis function of the fourth step,is theta4An estimated value of (d);
s415, selecting a fifth Lyapunov function:
wherein ξ5=z5-α4,σ52Is a positive parameter that is being designed for,is θ5The estimated error of (2);
s425, deriving the Lyapunov function, and solving to enable V to be equal to zero when t is close to infinity5(t) the control law and the adaptive law of the vanishing virtual controller are:
wherein, a5,l52,σ52Is a positive parameter that is being designed for,is thatThe method (2) is implemented by the following steps,is the vector of the fuzzy basis function of the fifth step,is θ5An estimated value of (d);
s416, selecting a sixth Lyapunov function:
wherein ξ6=z6-α5,σ61、σ62Is a positive parameter that is designed to be,is ρ6The error of the estimation of (2) is,is theta6The estimated error of (2);
s426, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution6(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,is ρ6Is determined by the estimated value of (c),ε62is a given normal number; sigma61,τ6,l61,l62Is a positive parameter of the design and,is the vector of the fuzzy basis function of the sixth step,is theta6An estimated value of (d);
s417, selecting a seventh Lyapunov function:
s427, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is solved7(t) the vanishing virtual controller and adaptation law is:
wherein, a7,l72,σ72Is a positive parameter that is being designed for,is thatThe transpose of (a) is performed,is the vector of the fuzzy basis function of the seventh step,is θ7An estimated value of (d);
s418, selecting an eighth Lyapunov function:
wherein xi is8=z8-α7,σ81,σ82Is a positive parameter of the design and,is thatThe transpose of (a) is performed,
s428, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is obtained through solution8(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is ρ8Is determined by the estimated value of (c),ε82is a given normal number;
σ81,σ82,l81,l82is a positive parameter of the design and,is the vector of the fuzzy basis function of the eighth step,is θ8An estimated value of (d);
s419, selecting a ninth Lyapunov function:
wherein ξ9=z9-α8,σ91,σ92Is a positive parameter of the design and,is thatThe method (2) is implemented by the following steps, is ρ9The estimated error of (2);
s429, derivation and solving of Lyapunov functionThe solution is such that when t tends to infinity, V9(t) the actual controller and adaptation law going to zero is:
wherein the content of the first and second substances,is ρ9Is determined by the estimated value of (c),ε92is a given normal number; sigma91,σ92,l91,l92Is a positive parameter of the design and,is the fuzzy basis function vector of the ninth step,is theta9An estimate of (d).
Preferably, in step S2, m1,m2,m3,m4Equivalent mass of a working roll and a bearing, an intermediate roll and a bearing, a supporting roll and a bearing, a hydraulic cylinder and a piston rod respectively; k is a radical of1,k2,k3Equivalent rigidity between a working roll and a middle roll, between the middle roll and a supporting roll, and between the supporting roll and a hydraulic cylinder; c. C1,c2,c3The equivalent damping is respectively between the working roll and the middle roll, between the middle roll and the supporting roll, between the supporting roll and the hydraulic cylinder.
Preferably, in step S2, u is a comprehensive expression of the servo valve dead zone characteristic parameter, and the specific form thereof may be expressed as:
wherein etar、ηl、brAnd blAre all servo valve dead zone characteristic parameters.
Preferably, in step S2, kqFor process coefficients, the specific form can be expressed as:
wherein, CdIs a flow coefficient of a valve port of the servo valve; w is the area gradient of the valve port of the servo valve, rho is the density of hydraulic oil in the hydraulic cylinder, and P issFor supply pressure, PtAs oil return pressure, xvFor servo valve spool displacement, kvIs the gain factor.
Preferably, in order to ensure that the designed nine lyapunov functions are all positive, the coefficients in the nine lyapunov functions need to be designed as positive numbers according to the item in which the coefficients are located; to ensure the effectiveness of the controller, nine Lyapunov functions V are requirediThe derived results respectively satisfy the Lyapunov stabilization criterion, the coefficients in the Lyapunov functions need to be designed as positive numbers according to the item where the coefficients are located, and simultaneously, each Lyapunov function satisfies the requirement after derivationWherein c, Δ are both normal numbers; after each lyapunov function is derived, the parameters to be designed are different.
Preferably, according to the formal similarity of the neutron system in the nonlinear model created in step S2, the design parameters in the third, fifth and seventh lyapunov functions are identical, the design parameters in the second, fourth and sixth lyapunov functions are identical, and the design parameters in the eighth and ninth lyapunov functions are identical.
Compared with the prior art, the invention has the following advantages:
1. the invention establishes a vibration nonlinear model which is more in line with the reality, considers the characteristic of dead zones of servo valves, designs a vertical vibration suppressor of the rolling mill, realizes the rapid active suppression of vertical vibration in the high-speed rolling process, and ensures the stability of the high-speed rolling strip process;
2. aiming at the problem of vibration suppression control of the rolling mill, the invention considers the limitation of preset performance on the vibration displacement of the roller, designs the fuzzy self-adaptive vibration suppressor, improves the vibration attenuation performance of the rolling mill, such as vibration attenuation speed, maximum allowable vibration displacement, steady-state error and the like, and is improved compared with the traditional control method.
Drawings
FIG. 1 is a flow chart of a design method of a rolling mill sag damping controller based on adaptive fuzzy backstepping in accordance with the present invention;
FIG. 2 is a schematic diagram of hydraulic vibration of rolling mill machinery in the design method of the self-adaptive backstepping-based rolling mill vertical vibration suppression controller of the present invention;
FIG. 3 is a comparison graph of the response curves of the vibration displacement of the working rolls under the condition of no performance constraint in the design method of the self-adaptive fuzzy backstepping-based vertical vibration suppression controller of the rolling mill of the invention; and
FIG. 4 shows the effect of the vibration suppression controller on vibration suppression after the vibration suppression controller is put into use in the design method of the rolling mill vertical vibration suppression controller based on the adaptive fuzzy backstepping.
Detailed Description
The invention will be described in detail with reference to the accompanying drawings for describing the technical content, the achieved purpose and the efficacy of the invention.
A design method of a rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping is disclosed, as shown in figure 1, firstly, a nonlinear model of rolling mill vertical vibration is established according to the dynamic principle of a rolling mill vibration system; then, determining a control target for inhibiting the vibration of the rolling mill according to the actual working condition; and finally, designing a self-adaptive backstepping controller by combining a nonlinear model of vertical vibration of the rolling mill and a control target for inhibiting vibration of the rolling mill, wherein the specific design method of the controller comprises the following steps:
s1, as shown in FIG. 2, collecting parameters of the mechanical-hydraulic coupling vibration system of the rolling mill and the characteristic parameters of the electro-hydraulic servo valve dead zone, as shown in Table 1.
S2, establishing a four-degree-of-freedom mechanical-hydraulic coupling nonlinear model of the vertical vibration of the rolling mill according to Newton' S second theorem:
wherein z is1For the oscillating displacement of the working rolls, z2Is the work roll vibration speed, z3For oscillating displacement of the intermediate roll, z4Is the intermediate roll oscillation speed, z5For the vibrational displacement of the supporting roller, z6For the vibration speed of the supporting roller, z7For cylinder vibrational displacement, z8Is the cylinder oscillation speed, z9=P1Is the pressure at the rodless cavity, miTo equivalent mass, kiTo equivalent stiffness, ciFor equivalent damping, A1Is the area of the rodless cavity, A2Is the area of the rod cavity, ctIs the leakage coefficient, P, in the cylinder2Pressure of the rod chamber, V initial volume of the control chamber, betaeIs the bulk modulus, k, of the oilqIs a process coefficient, u is a comprehensive expression of the characteristic parameter of the dead zone of the servo valve, Fz(z1,z2) Is a function expression related to the vibration displacement and the vibration speed of the working roll.
S3, determining a target for restraining the vibration of the rolling mill;
s31, setting the vertical vibration displacement of the working roll of the rolling mill approaching zero as a control target according to the fact that the vertical vibration of the rolling mill is caused by the up-down run-out of the working roll;
s32, controlling the vertical vibration attenuation rate and the maximum allowable displacement of the rolling mill within a set range, wherein the target for restraining the vibration of the rolling mill can be expressed as follows:
wherein xi is1=z1Indicating the displacement of the work rolls during vibration of the mill, with μ (t) being μ0e-kt+μ∞,μ0,k,μ∞Is a positive and real number that is specified,δandare given positive real numbers.
S4, giving a controller and a parameter adaptive law according to the Lyapunov stability criterion, and designing an adaptive fuzzy vibration suppressor;
s41, selecting a proper Lyapunov function according to the four-degree-of-freedom mechanical-hydraulic coupling nonlinear model of the vertical vibration of the rolling mill established in the step S2;
s42, solving so thatAs the time t goes to infinity,the control law and the adaptive law of the virtual controller which tend to be zero;
and S43, finally obtaining the design method of the controller with the preset performance for restraining the vertical vibration of the rolling mill.
The parameters to be designed in the controller are determined according to the designed Lyapunov function, and if the designed parameters can meet the Lyapunov stability criterion, the stability of each subsystem can be ensured, namely the controller is good. Therefore, nine lyapunov functions are selected according to the nine subsystems included in step S2, and step S4 specifically includes the following detailed steps:
s411, selecting a first Lyapunov function:
s421, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is solved1(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,ε1and a1Is a positive parameter being designed;
s412, selecting a second Lyapunov function:
wherein xi is2=z2-α1,σ21、σ22Is a positive parameter that is being designed for,ρ2the error of the estimation of (2) is,is theta2The estimated error of (2);
s422, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution2(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,is ρ2Is determined by the estimated value of (c),ε22is a given normal number, σ21,τ2,l21,l22Is a positive parameter of the design and,is the vector of the fuzzy basis function of the second step,is theta2An estimated value of (d);
s413, selecting a third Lyapunov function:
wherein xi is3=z3-α2,σ32Is a positive parameter that is being designed for,is θ3The estimated error of (2);
s423, deriving the Lyapunov function, and solving to ensure that V tends to be infinite when t is close to infinity3(t) vanishing virtual controller and adaptive law:
Wherein, a3,l32,σ32Is a positive parameter that is being designed for,is thatThe method (2) is implemented by the following steps,is the fuzzy basis function vector of the third step,is theta3An estimated value of (d);
s414, selecting a fourth Lyapunov function:
wherein xi is4=z4-α3,σ41、σ42Is a positive parameter that is being designed for,is ρ4The error of the estimation of (2) is,is theta4The estimated error of (2);
s424, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution4(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is ρ4Is determined by the estimated value of (c),ε42is a given normal number; sigma41,τ4,l41,l42Is a positive parameter of the design and,is the vector of the fuzzy basis function of the fourth step,is theta4An estimated value of (d);
s415, selecting a fifth Lyapunov function:
wherein ξ5=z5-α4,σ52Is a positive parameter that is being designed for,is θ5The estimated error of (2);
s425, derivation is carried out on the Lyapunov function, and the operation is carried out so that the operation becomes trend at tAt infinite time, V5(t) the vanishingly close virtual controller and adaptive law are:
wherein, a5,l52,σ52Is a positive parameter that is being designed for,is thatThe method (2) is implemented by the following steps,is the vector of the fuzzy basis function of the fifth step,is θ5An estimated value of (d);
s416, selecting a sixth Lyapunov function:
wherein ξ6=z6-α5,σ61、σ62Is a positive parameter that is designed to be,ρ6the error of the estimation of (2) is,is theta6The estimated error of (2);
s426, derivation is conducted on the Lyapunov function, and the calculation is conducted so that t tends to be zeroIn poor times, V6(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,is ρ6Is determined by the estimated value of (c),ε62is a given normal constant. Sigma61,τ6,l61,l62Is a positive parameter of the design and,is the vector of the fuzzy basis function of the sixth step,is theta6An estimated value of (d);
s417, selecting a seventh Lyapunov function:
S427, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is solved7(t) the vanishing virtual controller and adaptation law is:
wherein, a7,l72,σ72Is a positive parameter that is designed to be,is thatThe transpose of (a) is performed,is the vector of the fuzzy basis function of the seventh step,is theta7An estimated value of (d);
s418, selecting an eighth Lyapunov function:
wherein ξ8=z8-α7,σ81,σ82Is a positive parameter of the design and,is thatThe method (2) is implemented by the following steps,
s428, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is solved8(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is ρ8Is determined by the estimated value of (c),ε82is a given normal number.
σ81,σ82,l81,l82Is a positive parameter of the design and,is the fuzzy basis function vector of the eighth step,is theta8An estimated value of (d);
s419, selecting a ninth Lyapunov function:
wherein ξ9=z9-α8,σ91,σ92Is provided withThe positive parameter of the meter is measured,is thatThe transpose of (a) is performed, is ρ9The estimation error of (2);
s429, derivation is conducted on the Lyapunov function, and when t tends to be infinite,the actual controller and adaptation law going to zero is:
wherein, the first and the second end of the pipe are connected with each other,is ρ9Is determined by the estimated value of (c),ε92is a given normal constant. Sigma91,σ92,l91,l92Is a positive parameter of the design and,is the fuzzy basis function vector of the ninth step,is theta9An estimate of (d).
In step S2, m1,m2,m3,m4Equivalent masses of a working roll and a bearing, a middle roll and a bearing, a supporting roll and a bearing, a hydraulic cylinder and a piston rod are respectively; k is a radical of1,k2,k3Equivalent rigidity between a working roll and a middle roll, between the middle roll and a supporting roll, and between the supporting roll and a hydraulic cylinder; c. C1,c2,c3The equivalent damping between the working roll and the middle roll, between the middle roll and the supporting roll, between the supporting roll and the hydraulic cylinder.
In step S2, u is a comprehensive expression of the servo valve dead band characteristic parameter, which can be expressed in a specific form as:
wherein etar、ηl、brAnd blAre all servo valve dead zone characteristic parameters.
In step S2, kqFor process coefficients, the specific form can be expressed as:
wherein, CdIs a flow coefficient of a valve port of the servo valve; w is the area gradient of the valve port of the servo valve, rho is the density of hydraulic oil in the hydraulic cylinder, and P issFor supply pressure, PtAs oil return pressure, xvFor servo valve spool displacement, kvIs the gain factor.
In order to ensure that the nine designed Lyapunov functions are all positive, the coefficients in the nine Lyapunov functions need to be designed as positive numbers according to the item where the coefficients are located; in order to ensure the effectiveness of the controller,it is necessary to make nine Lyapunov functions ViThe derived results respectively satisfy the Lyapunov stabilization criterion, the coefficients in the Lyapunov functions need to be designed as positive numbers according to the item where the coefficients are located, and simultaneously, each Lyapunov function satisfies the requirement after derivationWherein c, Δ are both normal numbers; after each lyapunov function is derived, the parameters to be designed are different.
The first Lyapunov function does not contain a nonlinear function, so that a fuzzy basis function vector is not needed; in the second to ninth lyapunov functions, a fuzzy basis function vector needs to be applied to approximate a nonlinear function.
According to the similarity in the form of the subsystem in the nonlinear model created in step S2, the design parameters in the third lyapunov function, the fifth lyapunov function, and the seventh lyapunov function are identical, the design parameters in the second lyapunov function, the fourth lyapunov function, and the sixth lyapunov function are identical, and the design parameters in the eighth lyapunov function and the ninth lyapunov function are identical.
The design method of the rolling mill vertical oscillation suppression controller based on the self-adaptive fuzzy backstepping of the invention is further described by combining the following embodiments:
s1, collecting parameters of the mechanical-hydraulic coupling vibration system of the rolling mill and the characteristic parameters of the dead zone of the electro-hydraulic servo valve, as shown in the table 1.
S2, establishing a four-degree-of-freedom mechanical-hydraulic coupling nonlinear model of vertical vibration of the rolling mill according to Newton' S second theorem:
u is a comprehensive expression of the characteristic parameter of the dead zone of the servo valve, and the specific form of the comprehensive expression can be expressed as follows:
s3, determining a target for restraining the vibration of the rolling mill;
s31, setting the vertical vibration displacement of the working roll of the rolling mill close to zero as a control target according to the fact that the vertical vibration of the rolling mill is caused by the vertical jumping of the working roll;
s32, controlling the damping rate of the vertical vibration of the rolling mill and the maximum allowable displacement within a set range, and the objective function of inhibiting the vibration of the rolling mill can be expressed as:
-2(5e-2t+0.1)<ξ1<2(5e-2t+0.1)。
s4, giving a controller and a parameter adaptive law according to Lyapunov stability criterion, and designing an adaptive fuzzy vibration suppressor;
s411, selecting a first Lyapunov function:
s421, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is solved1(t) the vanishing virtual controller and adaptation law is:
s412, selecting a second Lyapunov function:
wherein xi is2=z2-α1, Is ρ2The error of the estimation of (2) is,is theta2The estimation error of (2);
s422, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution2(t) the vanishing virtual controller and adaptation law is:
wherein the content of the first and second substances,is ρ2Is determined by the estimated value of (c), is the vector of the fuzzy basis function of the second step,is theta2An estimated value of (d);
s413, selecting a third Lyapunov function:
s423, deriving the Lyapunov function, and solving to ensure that V tends to be infinite when t is close to infinity3(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is thatThe transpose of (a) is performed,is the fuzzy basis function vector of the third step,is theta3An estimated value of (d);
s414, selecting a fourth Lyapunov function:
s424, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution4(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is ρ4Is determined by the estimated value of (c),is the vector of the fuzzy basis function of the fourth step,is theta4An estimated value of (d);
s415, selecting a fifth Lyapunov function:
s425, deriving the Lyapunov function, and solving to enable V to be equal to zero when t is close to infinity5(t) the vanishing virtual controller and adaptation law is:
wherein, the first and the second end of the pipe are connected with each other,is thatThe transpose of (a) is performed,is the fuzzy basis function vector of the fifth step,is θ5An estimated value of (d);
s416, selecting a sixth Lyapunov function:
wherein xi is6=z6-α5,Is ρ6The error of the estimation of (2) is,is theta6The estimation error of (2);
s426, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution6(t) the vanishing virtual controller and adaptation law is:
wherein, the first and the second end of the pipe are connected with each other,is ρ6Is determined by the estimated value of (c),is the fuzzy basis function vector of the sixth step,is theta6An estimated value of (d);
s417, selecting a seventh Lyapunov function:
S427, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is solved7(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is thatThe transpose of (a) is performed,is the vector of the fuzzy basis function of the seventh step,is θ7An estimated value of (d);
s418, selecting an eighth Lyapunov function:
s428, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is obtained through solution8(t) the vanishing virtual controller and adaptation law is:
wherein, the first and the second end of the pipe are connected with each other,is ρ8Is determined by the estimated value of (c),is the vector of the fuzzy basis function of the eighth step,is theta8An estimated value of (d);
s419, selecting a ninth Lyapunov function:
wherein ξ9=z9-α8,Is thatThe method (2) is implemented by the following steps,is ρ9The estimated error of (2);
s429, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution9(t) the actual controller and adaptation law going to zero is:
wherein the content of the first and second substances,is ρ9Is determined by the estimated value of (c),is the fuzzy basis function vector of the ninth step,is theta9An estimate of (d).
And S43, finally obtaining the design method of the preset performance controller for inhibiting the vertical vibration of the rolling mill.
After the designed rolling mill vibration suppression controller is applied, the response curve comparison of the rolling mill working roll vibration displacement under the control of the existence of the preset performance is shown in figure 3, and as can be seen from the figure, the vibration attenuation rate, the steady-state error and the overshoot of the rolling mill system after the vibration suppression controller designed by the method is used are obviously improved. Meanwhile, a vibration acceleration sensor is used for collecting and comparing vibration signals, and the situation of the actual site vibration alarm times after the vibration suppressor designed by the method is put into use is shown in fig. 4. As can be seen from the figure, the vibration suppressor has obvious effect on the vibration suppression of the rolling mill, and the effectiveness of the vibration suppressor on the rolling mill is shown.
TABLE 1 Rolling Mill mechanical-Hydraulic coupling vibration System parameters
The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope defined by the claims of the present invention.
Claims (5)
1. A design method of a rolling mill vertical vibration suppression controller based on self-adaptive fuzzy backstepping is characterized by firstly establishing a non-linear model of rolling mill vertical vibration according to the dynamic principle of a rolling mill vibration system; then, determining a control target for inhibiting the vibration of the rolling mill according to the actual working condition; and finally, designing an adaptive backstepping controller by combining a nonlinear model of vertical vibration of the rolling mill and a control target for inhibiting vibration of the rolling mill, wherein the specific design method of the controller comprises the following steps:
s1, collecting parameters of a mechanical-hydraulic coupling vibration system of the rolling mill and characteristic parameters of a dead zone of an electro-hydraulic servo valve;
s2, establishing a four-degree-of-freedom mechanical-hydraulic coupling nonlinear model of the vertical vibration of the rolling mill according to Newton' S second theorem:
wherein z is1For the oscillating displacement of the working rolls, z2Is the work roll vibration speed, z3For the oscillatory displacement of the intermediate roll, z4Is the intermediate roll oscillation speed, z5For supporting the roll vibrational displacement, z6For the vibration speed of the supporting roller, z7For oscillating displacement of the cylinder, z8Is the cylinder vibration speed, z9Is the pressure at the rodless cavity, m1,m2,m3,m4Equivalent mass of a working roll and a bearing, an intermediate roll and a bearing, a supporting roll and a bearing, a hydraulic cylinder and a piston rod respectively; k is a radical of formula1,k2,k3Equivalent rigidity between a working roll and a middle roll, between the middle roll and a supporting roll, and between the supporting roll and a hydraulic cylinder; c. C1,c2,c3Equivalent damping between a working roll and a middle roll, between the middle roll and a supporting roll, between the supporting roll and a hydraulic cylinder respectively; a. the1Is the area of the rodless cavity, A2Is the area of the rod cavity, ctIs the leakage coefficient, P, in the cylinder2Pressure of the rod chamber, V initial volume of the control chamber, betaeIs the bulk modulus, k, of the oilqIs a process coefficient, u is a comprehensive expression of the characteristic parameter of the dead zone of the servo valve, Fz(z1,z2) Is a function expression related to the vibration displacement and the vibration speed of the working roll;
s3, determining a target for restraining the vibration of the rolling mill;
s31, setting the vertical vibration displacement of the working roll of the rolling mill close to zero as a control target according to the fact that the vertical vibration of the rolling mill is caused by the vertical jumping of the working roll;
s32, controlling the vertical vibration attenuation rate and the maximum allowable displacement of the rolling mill within a set range, wherein the target for restraining the vibration of the rolling mill can be expressed as follows:
wherein ξ1Indicating the displacement of the work rolls during vibration of the mill, mu (t) ═ mu0e-kt+μ∞,μ0,k,μ∞Is a positive real number that is specified,δandare given positive real numbers;
s4, giving a controller and a parameter adaptive law according to the Lyapunov stability criterion, and designing an adaptive fuzzy vibration suppressor;
s41, selecting a proper Lyapunov function according to the four-degree-of-freedom mechanical-hydraulic coupling nonlinear model of the vertical vibration of the rolling mill established in the step S2;
s42, derivation is carried out on the Lyapunov function, so that when t tends to be infinite, V tends to be zeroi(t) a vanishingly close virtual controller and adaptive law;
s43, finally obtaining a design method of the controller with the preset performance for restraining the vertical vibration of the rolling mill;
selecting nine Lyapunov functions according to the nine subsystems included in the step S2, wherein the step S4 specifically comprises the following steps:
s411, selecting a first Lyapunov function:
s421, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is solved1(t) the vanishing virtual controller and adaptation law is:
wherein the content of the first and second substances,ε1and a1Is a positive parameter being designed;
s412, selecting a second Lyapunov function:
wherein xi is2=z2-α1,σ21、σ22Is a positive parameter that is designed to be, is ρ2The error of the estimation of (2) is,is theta2The estimated error of (2);
s422, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution2(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,is ρ2Is determined by the estimated value of (c),ε22is a given normal number, σ21,τ2,l21,l22Is a positive parameter of the design and,is the vector of the fuzzy basis function of the second step,is theta2An estimated value of (d);
s413, selecting a third Lyapunov function:
wherein ξ3=z3-α2,σ32Is a positive parameter that is designed to be,is theta3The estimation error of (2);
s423, deriving the Lyapunov function, and solving to make V tend to be infinite3(t) the vanishing virtual controller and adaptation law is:
wherein, a3,l32,σ32Is a positive parameter that is being designed for,is thatThe transpose of (a) is performed,is the vector of the fuzzy basis function of the third step,is theta3An estimated value of (d);
s414, selecting a fourth Lyapunov function:
wherein xi is4=z4-α3,σ41、σ42Is a positive parameter that is designed to be, is ρ4The error of the estimation of (2) is,is theta4The estimation error of (2);
s424, derivation is carried out on the Lyapunov function, and solution is carried out so thatWhen t tends to infinity, V4(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is ρ4Is determined by the estimated value of (c),ε42is a given normal number; sigma41,τ4,l41,l42Is a positive parameter of the design and,is the vector of the fuzzy basis function of the fourth step,is theta4An estimated value of (d);
s415, selecting a fifth Lyapunov function:
wherein ξ5=z5-α4,σ52Is a positive parameter that is designed to be,is theta5The estimated error of (2);
s425, deriving the Lyapunov function, and solving to ensure that V is obtained when t tends to be infinite5(t) the control law and the adaptive law of the vanishing virtual controller are:
wherein, a5,l52,σ52Is a positive parameter that is designed to be,is thatThe transpose of (a) is performed,is the vector of the fuzzy basis function of the fifth step,is θ5An estimated value of (d);
s416, selecting a sixth Lyapunov function:
wherein xi is6=z6-α5,σ61、σ62Is a positive parameter that is designed to be, is ρ6The error of the estimation of (2) is,is theta6The estimation error of (2);
s426, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution6(t) the vanishingly close virtual controller and adaptive law are:
wherein, the first and the second end of the pipe are connected with each other,is ρ6Is determined by the estimated value of (c),ε62is a given normal number; sigma61,τ6,l61,l62Is a positive parameter of the design and,is the vector of the fuzzy basis function of the sixth step,is theta6An estimated value of (d);
s417, selecting a seventh Lyapunov function:
s427, derivation of the Lyapunov function, and solving so that when t tends to be infinite, V is7(t) the vanishingly close virtual controller and adaptive law are:
wherein, a7,l72,σ72Is a positive parameter that is designed to be,is thatThe transpose of (a) is performed,is the vector of the fuzzy basis function of the seventh step,is θ7An estimated value of (d);
s418, selecting an eighth Lyapunov function:
wherein ξ8=z8-α7,σ81,σ82Is a positive parameter of the design and,is thatThe transpose of (a) is performed,is θ8The error of the estimation of (2) is,
s428, derivation is carried out on the Lyapunov function, and when t tends to be infinite, V is obtained through solution8(t) the vanishingly close virtual controller and adaptive law are:
wherein the content of the first and second substances,is ρ8Is determined by the estimated value of (c),ε82is a given normal number;
σ81,σ82,l81,l82is a positive parameter of the design and,is the fuzzy basis function vector of the eighth step,is θ8An estimated value of (d);
s419, selecting a ninth Lyapunov function:
wherein xi is9=z9-α8,σ91,σ92Is a positive parameter of the design and,is thatThe method (2) is implemented by the following steps,is θ9The error of the estimation of (2) is, is ρ9The estimated error of (2);
s429, derivation is conducted on the Lyapunov function, and when t tends to be infinite, V is obtained through solution9(t) the actual controller and adaptation law going to zero is:
wherein, the first and the second end of the pipe are connected with each other,is ρ9Is determined by the estimated value of (c),ε92is a given normal number; sigma91,σ92,l91,l92Is a positive parameter of the design and,is the fuzzy basis function vector of the ninth step,is theta9An estimate of (d).
2. The design method of the adaptive fuzzy backstepping based rolling mill droop suppression controller as claimed in claim 1, wherein in step S2, u is a comprehensive expression of the servo valve dead zone characteristic parameter, and the specific form thereof can be expressed as:
wherein eta isr、ηl、brAnd blAre all servo valve dead zone characteristic parameters.
3. The design method of the adaptive fuzzy backstepping based rolling mill droop suppression controller according to claim 1, wherein in step S2, kqThe process coefficient can be expressed in a specific form as:
wherein, CdIs a flow coefficient of a valve port of the servo valve; w is the area gradient of the valve port of the servo valve, rho is the density of hydraulic oil in the hydraulic cylinder, PsFor supply pressure, PtAs oil return pressure, xvFor servo valve spool displacement, kvIs a gain factor.
4. The design method of the vertical oscillation suppression controller of the rolling mill based on the adaptive fuzzy backstepping as claimed in claim 1, wherein in order to ensure that the nine designed lyapunov functions are all positive, according to the item where the coefficients are located, the coefficients in the nine lyapunov functions need to be respectively designed as positive numbers; to ensure the effectiveness of the controller, nine Lyapunov functions V are requirediThe derived results respectively satisfy the Lyapunov stability criterion, the coefficients in the Lyapunov functions need to be respectively designed as positive numbers according to the item where the coefficients are located, and simultaneously, each Lyapunov function after derivation satisfies the criterionWherein c, Δ are both normal numbers; after each lyapunov function is derived, the parameters to be designed are different.
5. The design method of the adaptive fuzzy backstepping based rolling mill vertical vibration suppression controller according to claim 1, wherein according to the formal similarity of the neutron system in the nonlinear model established at step S2, the design parameters in the third, fifth and seventh lyapunov functions are consistent, the design parameters in the second, fourth and sixth lyapunov functions are consistent, and the design parameters in the eighth and ninth lyapunov functions are consistent.
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
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CN110687787A (en) * | 2019-10-11 | 2020-01-14 | 浙江工业大学 | Mechanical arm system self-adaptive control method based on time-varying asymmetric obstacle Lyapunov function |
-
2020
- 2020-06-08 CN CN202010515163.9A patent/CN111723442B/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105903769A (en) * | 2016-04-14 | 2016-08-31 | 北京工业大学 | Plate-strip rolling mill roll system vibration inhibiting system and method based on hydraulic cylinder control |
CN110687787A (en) * | 2019-10-11 | 2020-01-14 | 浙江工业大学 | Mechanical arm system self-adaptive control method based on time-varying asymmetric obstacle Lyapunov function |
Non-Patent Citations (3)
Title |
---|
Adaptive backstepping control of hydraulic servo system with input saturation for rolling mill based on multi-model switching;Li YH, Fang YM, Li JX, et al;《IEEE Xplore》;20131031;全文 * |
基于模糊逻辑的液压伺服位置控制系统研究;徐兴元, 林青松, 蔡远利;《计算机仿真》;20150831;全文 * |
暂稳态性能约束下非线性下三角结构系统的控制器设计;张柳柳;《中国优秀博士学位论文全文数据库 信息科技辑》;20190115;全文 * |
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