CN101905820A - Pneumatic slip shaft-based winding tension and rotation speed control method - Google Patents

Abstract

The invention relates to a pneumatic slip shaft-based winding tension and rotation speed control method. The conventional control method lacks dynamic compensation control of an acceleration and deceleration dynamic process, compensation control of winding inertia and coordinate control of the rotation speed of a slip shaft, and therefore, causes serious heating and short service life of the slip shaft. The method comprises: firstly, computing a winding radius and the rotation speed n of the pneumatic slip shaft according to the width and winding length of a strip; secondly, computing a dynamic acceleration of the transport of the strip and the input air pressure of the pneumatic slip shaft; and finally, inputting the obtained input air pressure signal to the pneumatic slip shaft and the rotation speed signal of the pneumatic slip shaft into a slip shaft transmission motor driver to realize the coordinate control of the winding tension and rotation speed. When the method of the invention is used, the smooth control of the static and dynamic winding tension and the compensation control of the winding inertia can be realized, the slip power consumption of the pneumatic slip shaft is reduced, and thus, the life of the pneumatic slip shaft is improved greatly.

Description

Winding tension and method for controlling number of revolution based on Pneumatic slip shaft

Technical field

The invention belongs to the automation of industry field, relate to a kind of control method that is used for the band cutting machine based on the winding tension and the rotating speed of Pneumatic slip shaft.

Background technology

Pneumatic slip shaft is novel coiling parts crucial in the modern all kinds of band cutting machine, it is mainly by axis body, axial leather bag, hairfelt, parts such as friction slip ring group assembly from inside to outside, Pneumatic slip shaft is by electric motor drive, be input to the air pressure of leather bag in the Pneumatic slip shaft by adjusting, friction force between change differential slip ring and hairfelt is to realize being wound on the some Tension Control of coiling around thing on the same Pneumatic slip shaft, strap tension between respectively coiling may be inhomogeneous because of thickness of strip, the initial different problem of the inconsistent elasticity of respectively reeling that causes of coil diameter is then carried out cushioning balance by differential slip ring, that is: the rotating speed of coaxial each differential slip ring may be different, can normally move to guarantee that polydisc independent of each other is reeled on the same slip shaft.The Winding Tension Controlling method of Pneumatic slip shaft commonly used all adopts the method for air inlet air pressure linear increase with the increase of coil diameter of Pneumatic slip shaft at present, and its main shortcoming is: the one, lifting quick-action attitude process is not carried out dynamic compensation control; The 2nd, coiling inertia is not compensated control; The 3rd, the rotating speed of slip shaft is not carried out co-operative control and cause that the slip shaft heating is serious, the life-span is short.Thereby be difficult to adapt to production occasions such as the control of High Performance coiling, busy shift, also be difficult to prolong the work life of Pneumatic slip shaft, the maintenance cost of reduction production facilities.

Summary of the invention

The objective of the invention is at the deficiencies in the prior art, designed a kind of have quiet, dynamic tension steadily control with reduce the Pneumatic slip shaft heating, improve the control method in its life-span.

The inventive method may further comprise the steps:

Step a is according to thickness of strip and coiling length computation winding radius R (unit: m);

Step b calculates Pneumatic slip shaft rotation speed n (unit: r/s);

Step c calculates that band carries dynamically adds (subtracting) speed

(unit: m/s ²);

Steps d is calculated the input air pressure P (unit: MPa) of Pneumatic slip shaft;

Step e is input to Pneumatic slip shaft with the input air pressure P signal that obtains, and Pneumatic slip shaft rotation speed n signal is input to slip shaft driving motor actuator, thereby realizes the co-operative control of winding tension and rotating speed.

Winding radius R described in the step a, and thickness of strip h (unit: m) and the coiling length L (unit: possess m) functional relation R=r (h, L), represent by following formula:

$R=\sqrt{R_0^2+\frac{\mathrm{hL}}{\mathrm{\π}}}---\left(1\right)$

Wherein, R ₀Be initial winding radius, be known quantity.Along with the growth of time, the coiling length L also increases, and winding radius R also increases; L can obtain by meter long pass sensor.

Calculating Pneumatic slip shaft rotation speed n described in the step b, be the linear velocity V that carries according to band (unit: m/s), parameter such as winding radius R calculates, computing formula is as follows:

$n=\frac{k_{n}V}{2\mathrm{\πR}}+\mathrm{\Δn}---\left(2\right)$

Wherein, k _nBe slip ratio, Δ n is initial slippage rotating speed, and V and Δ n set by the user.

The described calculating band of step c is carried dynamically adds (subtracting) speed

Be the linear velocity V according to this collection, the linear velocity V that gathered last time ^-And the pitch time T of twice data acquisition (that is: in the sampling period, unit: s) calculate, computing formula is as follows:

$\frac{\mathrm{dV}}{\mathrm{dt}}=\frac{V-V^{-}}{T}---\left(3\right)$

The input air pressure P of the calculating Pneumatic slip shaft described in the steps d (unit: MPa), and winding tension setting value F (unit: N), possess between winding radius R, the coiling tapering z functional relation P=p (F, R z), are represented by following formula:

$P=k_p[(1-z\frac{R-R_0}{R_m-R_0})\mathrm{FR}+0.02k_n\mathrm{B\γ}{R}^3\frac{\mathrm{dV}}{\mathrm{dt}}+0.01k_n^2\mathrm{B\γhR}{V}^2]+P_0---\left(4\right)$

Wherein, k _pBe the air pressure-moment coefficient (that is: the model specification by specific Pneumatic slip shaft determines) of Pneumatic slip shaft characteristic decision, γ is a strip density (unit: kg/m ³), h be thickness (unit: m), P ₀For initial gas pressure (unit: MPa), B be band on the every Pneumatic slip shaft overall width (unit: m), R ₀, R _mBe respectively initial winding radius and maximum winding radius (unit: m), k _nBe slip ratio, z, R ₀, R _mSet by the user.

The input air pressure P signal with obtaining described in the step e is input to Pneumatic slip shaft, it is will be with the air pressure result of calculation P of steps d by air pressure function unit (as: electricity-gas apportioning valve) that Pneumatic slip shaft rotation speed n signal is input to slip shaft driving motor actuator, be input to the control that realizes in the Pneumatic slip shaft winding tension, the rotation speed n signal that step b is obtained is input to motor driver (as: frequency converter), the rotating speed of control Pneumatic slip shaft drive motor.

The beneficial effect that the present invention has:

(1) do not need to change the hardware configuration of control system;

(2) quiet, the steady control of dynamic winding tension and the compensate control of coiling inertia have been realized;

(3) rotating speed of Pneumatic slip shaft has been carried out the co-operative control that changes with coil diameter, thereby reduced the life-span that the slippage power consumption of Pneumatic slip shaft has improved Pneumatic slip shaft greatly.

The present invention has solved the defective that prior art exists fully, and realizes easily simple.

The specific embodiment

Winding tension and method for controlling number of revolution concrete steps based on Pneumatic slip shaft are:

Step a is according to thickness of strip and coiling length computation winding radius R (unit: m);

Step b calculates Pneumatic slip shaft rotation speed n (unit: r/s);

Step c calculates that band carries dynamically adds (subtracting) speed

(unit: m/s ²);

Steps d is calculated the input air pressure P (unit: MPa) of Pneumatic slip shaft;

Step e is input to Pneumatic slip shaft with the input air pressure P signal that obtains, and Pneumatic slip shaft rotation speed n signal is input to slip shaft driving motor actuator, thereby realizes the co-operative control of winding tension and rotating speed.

Winding radius R described in the step a, and thickness of strip h (unit: m) and the coiling length L (unit: possess m) functional relation R=r (h, L), represent by following formula:

$R=\sqrt{R_0^2+\frac{\mathrm{hL}}{\mathrm{\π}}}---\left(1\right)$

Wherein, R _OBe initial winding radius, be known quantity.Along with the growth of time, the coiling length L also increases, and winding radius R also increases; L can obtain by meter long pass sensor.

Calculating Pneumatic slip shaft rotation speed n described in the step b, be the linear velocity V that carries according to band (unit: m/s), parameter such as winding radius R calculates, computing formula is as follows:

$n=\frac{k_{n}V}{2\mathrm{\πR}}+\mathrm{\Δn}---\left(2\right)$

Wherein, k _nBe slip ratio, Δ n is initial slippage rotating speed, and V and Δ n set by the user.

The described calculating band of step c is carried dynamically adds (subtracting) speed Be the linear velocity V according to this collection, the linear velocity V that gathered last time ^-And the pitch time T of twice data acquisition (that is: in the sampling period, unit: s) calculate, computing formula is as follows:

$\frac{\mathrm{dV}}{\mathrm{dt}}=\frac{V-V^{-}}{T}---\left(3\right)$

The input air pressure P of the calculating Pneumatic slip shaft described in the steps d (unit: MPa), and winding tension setting value F (unit: N), possess between winding radius R, the coiling tapering z functional relation P=p (F, R z), are represented by following formula:

$P=k_p[(1-z\frac{R-R_0}{R_m-R_0})\mathrm{FR}+0.02k_n\mathrm{B\γ}{R}^3\frac{\mathrm{dV}}{\mathrm{dt}}+0.01k_n^2\mathrm{B\γhR}{V}^2]+P_0---\left(4\right)$

Wherein, k _pBe the air pressure-moment coefficient (that is: the model specification by specific Pneumatic slip shaft determines) of Pneumatic slip shaft characteristic decision, γ is a strip density (unit: kg/m ³), h be thickness (unit: m), P ₀For initial gas pressure (unit: MPa), B be band on the every Pneumatic slip shaft overall width (unit: m), R ₀, R _mBe respectively initial winding radius and maximum winding radius (unit: m), V be linear velocity (unit: m/s), k _nBe slip ratio, z, R ₀, R _mSet by the user.

The input air pressure P signal with obtaining described in the step e is input to Pneumatic slip shaft, it is will be with the air pressure result of calculation P of step (d) by air pressure function unit (as: electricity-gas apportioning valve) that Pneumatic slip shaft rotation speed n signal is input to slip shaft driving motor actuator, be input to the control that realizes in the Pneumatic slip shaft winding tension, the rotation speed n signal that step (b) is obtained is input to motor driver (as: frequency converter), the rotating speed of control Pneumatic slip shaft drive motor.

Automation control system according to the initial tension value F that is provided with in the man machine operation interface and taper value z (span: 0.1～0.9), maximum, minimum radius value R _mWith R ₀, slip ratio k _n(span: 1.1～1.5), initial slippage rotating speed Δ n, the band parameter (comprising: strip density γ, thickness h, strip width B), and the real-time winding radius R that calculates acquisition after testing, calculate the air inlet atmospheric pressure value of cooresponding Pneumatic slip shaft and the tachometer value of Pneumatic slip shaft, and then the control incoming signal (0～10V) that sends by the D/A module of regulating control in the automation control system or PLC system, convert thereof into 0～100% specified air pressure through electric pneumatic converter (as: electricity-gas apportioning valve) and be input to Pneumatic slip shaft, realize Winding Tension Controlling; And the control incoming signal that the speed control signal of Pneumatic slip shaft is sent by the D/A module of regulating control in the automation control system or RLC system is realized the co-operative control of speed through the drive motor of motor driver (as: frequency converter) control Pneumatic slip shaft.

Claims (1)

1. based on the winding tension and the method for controlling number of revolution of Pneumatic slip shaft, it is characterized in that this method comprises the steps:

Step a. calculates winding radius R according to thickness of strip h and coiling length L,

R wherein ₀Be initial winding radius, L can obtain by meter long pass sensor;

Step b. calculates the Pneumatic slip shaft rotation speed n, K wherein _nBe slip ratio, Δ n is initial slippage rotating speed, and V and Δ n set by the user;

Step c is calculated the dynamic acceleration that band is carried

Wherein V is the linear velocity of this collection, V ^-Be the linear velocity that gathered last time, T is the pitch time of twice data acquisition;

Steps d. calculate the input air pressure P of Pneumatic slip shaft,

$P=k_p[(1-z\frac{R-R_0}{R_m-R_0})\mathrm{FR}+0.02k_n\mathrm{B\γ}{R}^3\frac{\mathrm{dV}}{\mathrm{dt}}+0.01k_n^2\mathrm{B\γhR}{V}^2]+P_0;$

K wherein _pBe the air pressure-moment coefficient of Pneumatic slip shaft characteristic decision, z is the coiling tapering, R ₀, R _mBe respectively initial winding radius and maximum winding radius, F is the winding tension setting value, and B is the overall width of band on the every Pneumatic slip shaft, and γ is a strip density, P ₀Be initial gas pressure;

Step e. is input to Pneumatic slip shaft with the input air pressure P signal that steps d obtains, and realizes the control to winding tension; Step b is obtained Pneumatic slip shaft rotation speed n signal be input to slip shaft driving motor actuator, realize the control of rotating speed.