CN105929795A - Carton cutting method based on time division method cutting knife tangent following control - Google Patents

Abstract

The invention provides a carton cutting method based on time division method cutting knife tangent following control. The carton cutting method comprises the following steps that step one, an upper computer issues a PLT file to a controller; step two, the controller reads PLT file graphic information, wherein the PLT file graphic information is composed of multiple straight lines and circular curves; and step three, whether the current cutting line is a straight line or a circular curve is judged, 3.1) if the current cutting line is the straight line, cutting is performed according to the existing method; and 3.2) if the current cutting line is the circular curve, a cutting knife is rotated to a position tangent with a circular start point firstly, the start angle of the cutting knife is determined, a circular curve tangent following motion model is determined, and the feed amount of an X-axis and Y-axis knife rotation shaft of each interpolation cycle is determined by adopting a circular time division method so that tangent following of the cutting knife can be realized. According to the carton cutting method based on time division method cutting knife tangent following control, the carton cutting method can enhance control precision and has great stability.

Description

A kind of carton cutting method controlled based on time-divided method cut-off knife tangential following

Technical field

Patent of the present invention belongs to movement control technology field, especially the multijoint control cutting equipment to cut-off knife tangential following.

Background technology

Along with the development of science and technology, numerical control device has been widely used in carton, clothes, leather, waits field, and general digital control system is with the interpolation function with straight line and circular arc, it is possible to achieve the interpolation function of profile.Carton cutting machine is for cardboard cuts into specific figure, and the carton type needed for folding cardboard one-tenth after cutting, carton cutting machine belongs to cutting field.

In carton production, first according to the technology requirement of product, the mapping softwares such as CAD design the required figure that cuts, generate PLT file, host computer issue this graphic file and control motor movement to controller, controller according to cutting pattern.Cutter uses the mode of vibration at high speed, it is achieved cut cardboard.Owing to cut-off knife has certain width, and cutter is when X-axis, Y-axis are moved along graph outline, and the blade plane on cutter is tangent with figure.When insert orientation and the cut-off knife direction of motion are inconsistent, can cause cutting edge unsmooth of cardboard, the heavy wear causing cut-off knife is even ruptured, so during showing methods, the rotary shaft of cutter is controlled, with ensure the direction of blade cut with cutter during the direction of motion consistent.The control accuracy of tool motion and stability directly influence quality and the efficiency cutting cardboard.

Summary of the invention

In order to the control accuracy overcoming existing carton cutting method is relatively low, the deficiency of less stable, the present invention provided a kind of carton cutting method controlled based on time-divided method cut-off knife tangential following promoting control accuracy, having good stability.

The technical scheme used to solve above-mentioned technical problem is:

A kind of carton cutting method controlled based on time-divided method cut-off knife tangential following, comprises the following steps:

The first step, is handed down to controller by host computer by PLT file；

Second step, controller reads PLT graphic file information, and described PLT graphic file information is made up of some straight lines and circular curve；

3rd step, it is judged that current cutting is straight line or circular curve:

3.1) if when being cut into straight line, cut-off knife blade is consistent with cutter direct of travel, now X-axis and Y-axis linkage, the cut-off knife blade direction of motion is consistent, it is not necessary to rotate；When cut-off knife moves to the tie point of two straight lines, it is judged that the θ of the angle of current two straight lines, when θ angle is more than the angle set, cut-off knife is lifted, turns over θ, cutter is fallen, continue cutting；When θ angle is less than the angle set, it is not necessary to cut-off knife is lifted, directly turns over corresponding angle and continue cutting；

3.2) when cutting arc shape work piece curve, first cut-off knife is rotated to circular arc starting point to the position cut, determine the start angle of cut-off knife；If circular arcStarting point be P_A(x_a, y_a, c_a) terminal is P_B(x_b,y_b,c_b), carton cutting machine is by a P_AMove to a P_BIts X-axis, Y-axis, the rotary shaft C three-shaft linkage of cut-off knife, ensure that cut-off knife is tangent with circular arc, according to circular arc cut-off knife tangential motion model based on time-divided method, determine X-axis, Y-axis, the amount of feeding of C axle in each interpolation cycle, determine pulse period and the umber of pulse of each axle according to the step angle of current interpolation cycle and motor:

Wherein, n_xiIt is the umber of pulse of X-axis transmission, n_yiBeing the umber of pulse of Y-axis transmission, Δ x, Δ y are respectively X-axis and the amount of movement of Y-axis in the cycle, and Step is the step angle of motor.

The pulse number that the anglec of rotation of cut-off knife turns overα is the angle that cut-off knife turns over, and K is to cut rotor one to enclose required umber of pulse, then the required pulse number sent of A axle is n_ci；

The cycle of each pulse axle is according to interpolation cycle T_SDetermine with the arteries and veins number sent, it may be assumed that

The pulse period of X-axis is

The pulse period of Y-axis is

The pulse period of A axle is

Realize the tangential following of cut-off knife.

Further, described step 3.2) in, it is first determined current cut-off knife and the start angle of X-axis, mode is as follows:

If circular arcStarting point be P_A(x_a,y_a,c_a) terminal is P_B(x_b,y_b,c_b), central coordinate of circle is P₀(x₀,y₀) circular arc is inverse circular arc, wherein, initial angle c is the angle of circular arc tangential line and X-axis forward, and the parametric equation of circular curve is

Wherein, θ is that current point connects and angle formed by X-axis with the center of circle, and R is the radius of circular arc；

The computing formula of initial angle c degree is as follows:

When circular arc is inverse circular arc:

When circular arc is along circular arc:

Further, described step 3.2) in, calculating the increment in X-axis Y-axis and one interpolation cycle of cut-off knife rotary shaft C axle in an interpolation cycle, process is as follows:

When cutting arc shape work piece, in an interpolation cycle, cut-off knife is followed X-axis Y-axis and is rotated, according to step angle tangential following algorithms such as time-divided method employings, if interpolation cycle is T_sThe speed of feeding is V_s, then step-length is L=V_s·T_s；Angle delta β that rotary shaft turns over=α, the step angle α that the step-length of arc radius and each interpolation cycle is walked in determining each interpolation cycle, calculate the amount of feeding of each axle in each interpolation cycle；

When circular arc is inverse circular arc, if current interpolated point is P_i(x_i,y_i,c_i), point of arrival P after an interpolation cycle_i+1(x_i+1,y_i+1,c_i+1):

When circular arc is inverse circular arc, if current interpolated point is P_i(x_i,y_i,c_i), point of arrival P after an interpolation cycle_i+1(x_i+1,y_i+1,c_i+1):

In an interpolation cycle process, step angle corresponding to step-length is certain, obtains the size of the sine value of step angle, cosine value and step angle according to step-length L and arc radius R, and computing formula is as follows:

The technology of the present invention is contemplated that: the carton cutting equipment controlled based on time-divided method cut-off knife tangential following, described equipment includes the Mechanical course platform for cutting cardboard, for controlling to cut controller and the man-machine interaction unit of cardboard, for issuing the host computer of figure, for driving the driving means of motor；Described Mechanical course platform includes the control motor of the D axle of axle up and down of X-axis, Y-axis, the rotary shaft C axle of cutter, cutter, for cutting the cutter of cardboard, for the position sensor of position feedback；Described controller is connected respectively at host computer, man-machine interaction unit, driving means, position sensor, described driving means motor with the Mechanical course platform of controller respectively is connected, and the motor of described control platform controls the motion of tetra-axles of X, Y, C, D.

Determine the motion model of circular curve tangential following, circular arc time-divided method is used to determine the amount of feeding of X-axis Y-axis tool rotating shaft in each interpolation cycle, thus ensure blade and the orientation consistency of cut-off knife advance of cut-off knife in cutting process, ensure that cutting accuracy and the cutting efficiency of figure, reduce the abrasion of cut-off knife simultaneously.

Effective effect of the present invention is: promotes control accuracy, have good stability, the quality and the working (machining) efficiency that cut cardboard is effectively ensured.

Accompanying drawing explanation

Fig. 1 is carton cutting equipment block architecture diagram.

Fig. 2 is the structure chart of carton cutting machine controller.

Fig. 3 is that cutter rotates control schematic diagram.

Fig. 4 is straight line and straight line switching figure.

Fig. 5 is straight line and circular arc switching figure.

Fig. 6 is circular arc cut-off knife tangential following interpolation schematic diagram.

Fig. 7 is circular interpolation flow chart.

Fig. 8 is carton cutting equipment control flow chart.

Detailed description of the invention

The present invention will be further described below in conjunction with the accompanying drawings:

With reference to Fig. 1～Fig. 8, a kind of carton cutting method controlled based on time-divided method cut-off knife tangential following, the equipment realizing the method includes the Mechanical course platform for carrying paper board, for controlling cutting cardboard and performing controller and the man-machine interaction unit of cutting order, for issuing the host computer of figure, for driving the driving means of motor, described Mechanical course platform includes the control motor of each axle, for cutting the cut-off knife of cardboard, position sensor for position feedback, described host computer is connected with controller with man-machine interaction unit, described driving means motor with the Mechanical course platform of controller respectively is connected, the motor of described control platform controls the motion of each axle.The system architecture having Fig. 1 to be whole carton cutting equipment, Fig. 2 is the framework of motion controller.Fig. 8 is whole equipment master control flow chart.

The described carton cutting method controlled based on time-divided method cut-off knife tangential following, comprises the following steps:

The first step, is issued PLT file to controller by host computer；

Second step, reads PLT graphic file information, obtains by some straight lines and the coordinate information of circular curve.The control direction of each axle of cut-off knife and mode as seen from Figure 3.

3rd step, it is judged that the content that current Graphics resolves, i.e. judges that current cutting is straight line or circular curve

3.1) when resolve figure be that straight line is, cut-off knife blade direction with cut-off knife motion mode to consistent, it is that the rotary shaft C axle of cut-off knife does not rotates in cutting straight line, X-axis and Y-axis controls cut-off knife motion planar, when cut-off knife applies to the tie point of two straight lines, such as Fig. 4, it is judged that the angle Δ θ of current two straight lines of straight line, when Δ θ is more than presetting angle, cutter lifted and to turn over Δ θ angle, then cutter be fallen；When Δ θ is less than presetting angle, cutter is directly turned over Δ θ angle and continues cutting, it is not necessary to cutter is lifted.

3.2) when the figure resolved is circular arc, first have to judge the initial angle of current cut-off knife.Such as Fig. 5, it is assumed that cut-off knife is by cutting straight line P_ZP_AThen tangential circular arcWherein A is even point of contact, when cut-off knife moves to a P_ATime, be by cut-off knife rotor and circular arc to the direction cut, such as Fig. 5 midpoint P_AShown in place's arrow.

Calculating the most front cut-off knife of tangential initial angle of circular arc and the angle of X-axis, mode is as follows:

If circular arcStarting point be P_A(x_a,y_a,c_a) terminal is P_B(x_b,y_b,c_b), central coordinate of circle is P₀(x₀,y₀) circular arc is inverse circular arc.Wherein initial angle c is the angle of circular arc tangential line and X-axis forward.The parametric equation of circular curve is

Wherein, θ is that current point connects and angle formed by X-axis with the center of circle, and R is the radius of circular arc；

In circular arc cutting process, C axle to link with X-axis Y-axis so that the direction of blade is identical with the direction of circular arc tangential line, calculates the initial angle c degree of the cutter of clockwise arc and counterclockwise arc.

Calculate the increment in X-axis Y-axis and one interpolation cycle of cut-off knife rotary shaft C axle in an interpolation cycle.As shown in Figure 6, some P_iFor interpolated point current on circular arc, put P_i+1It is next interpolated point, according to step angle tangential following algorithms such as time-divided method employings, if interpolation cycle is T_sThe speed of feeding is V_s, step-length is L=V_S·T_sI.e. P in figure_iP_i+1Distance.From geometrical relationship, P in an interpolation cycle_iP_i+1, angle that cut-off knife turns over and P_iP_i+1Corresponding central angle equal delta β=α.

As a example by inverse circular arc, if current interpolated point is P_i(x_i,y_i,c_i), point of arrival P after an interpolation cycle_i+1(x_i+1,y_i+1,c_i+1)

With when should be along circular arc

In an interpolation cycle process, step angle corresponding to step-length is certain, obtains the size of the sine value of step angle, cosine value and step angle according to step-length L and arc radius R.Computing formula is as follows:

Then can obtain according to above formula, then can calculate Δ x in an interpolation cycle, the value of Δ y:

Obtain pulse number and cycle that each pulse axle in an interpolation cycle of circular arc sends:

The pulse number of X-axis is

The pulse number of Y-axis is

The pulse number of A axle is

Wherein Step is the step angle of motor, and α is the angle that cut-off knife turns over, and K is to cut rotor one to enclose required umber of pulse, and the required pulse number sent of A axle is n_ci；

The cycle of each pulse axle can be according to interpolation cycle T_SDetermine i.e. with the arteries and veins number sent:

The pulse period of X-axis is

The pulse period of Y-axis is

The pulse period of A axle is

When thus can calculate cutting arc shape work piece, the umber of pulse that each interpolation cycle cut-off knife rotating control shaft sends.Its flow chart is as shown in Figure 7.

4th step: repeat the 3rd step, until all of pattern cut point completes cutting.

Claims (3)

1. the carton cutting method controlled based on time-divided method cut-off knife tangential following, its feature It is: comprise the following steps:

The first step, is handed down to controller by host computer by PLT file；

Second step, controller reads PLT graphic file information, and described PLT graphic file is believed Breath is made up of some straight lines and circular curve；

3rd step, it is judged that current cutting is straight line or circular curve:

3.1) if when being cut into straight line, cut-off knife blade is consistent with cutter direct of travel, now X-axis and Y-axis linkage, the cut-off knife blade direction of motion is consistent, it is not necessary to rotate；Work as cut-off knife When moving to the tie point of two straight lines, it is judged that the θ of the angle of current two straight lines, when θ angle is big When the angle set, cut-off knife is lifted, turns over θ, cutter is fallen, continue cutting；When When θ angle is less than the angle set, it is not necessary to cut-off knife is lifted, directly turns over corresponding angle and continue Continuous cutting；

3.2) when cutting arc shape work piece curve, first cut-off knife is rotated to circular arc starting point to cutting Position, determines the start angle of cut-off knife；If circular arcStarting point be P_A(x_a,y_a,c_a) terminal is P_B(x_b,y_b,c_b), carton cutting machine is by a P_AMove to a P_B, its X-axis, Y-axis, the rotation of cut-off knife Rotating shaft C three-shaft linkage, it is ensured that cut-off knife is tangent with circular arc, according to circular arc based on time-divided method Cut-off knife tangential motion model, determines X-axis, Y-axis, the amount of feeding of C axle in each interpolation cycle, Step angle according to current interpolation cycle and motor determines pulse period and the umber of pulse of each axle:

$\left\{\begin{array}{c}{n}_{xi}=\frac{\mathrm{\Δ}x}{step}\\ n_{yi}=\frac{\mathrm{\Δ}y}{step}\end{array}\right.---\left(1\right)$

Wherein, n_xiIt is the umber of pulse of X-axis transmission, n_yiBeing the umber of pulse of Y-axis transmission, Δ x, Δ y divide Not being X-axis and the amount of movement of Y-axis in the cycle, Step is the step angle of motor.

The pulse number that the anglec of rotation of cut-off knife turns overα is the angle that cut-off knife turns over Degree, K is to cut rotor one to enclose required umber of pulse, then the required pulse number sent of A axle is n_ci；

The cycle of each pulse axle is according to interpolation cycle T_SDetermine with the arteries and veins number sent, it may be assumed that

The pulse period of X-axis is

The pulse period of Y-axis is

The pulse period of A axle is

Realize the tangential following of cut-off knife.

A kind of paper controlled based on time-divided method cut-off knife tangential following Case cutting method, it is characterised in that: described step 3.2) in, it is first determined current cut-off knife with The start angle of X-axis, mode is as follows:

If circular arcStarting point be P_A(x_a,y_a,c_a) terminal is P_B(x_b,y_b,c_b), central coordinate of circle is P₀(x₀,y₀) circular arc is inverse circular arc, wherein, initial angle c is the angle of circular arc tangential line and X-axis forward, The parametric equation of circular curve is

$\left\{\begin{array}{c}x=Rcos\mathrm{\θ}\\ y=Rsin\mathrm{\θ}\\ c=\mathrm{\θ}+\mathrm{\π}/2\end{array}\right.---\left(2\right)$

Wherein, θ is that current point connects and angle formed by X-axis with the center of circle, and R is the radius of circular arc；

The computing formula of initial angle c degree is as follows:

When circular arc is inverse circular arc:

$c=\left\{\begin{array}{cc}\mathrm{\&pi;}/2+\arctan \left(\frac{y_a-y_0}{x_a-x_o}\right)& x_a>x_0\\ 3\mathrm{\&pi;}/2+\arctan \left(\frac{y_a-y_0}{x_a-x_0}\right)& x_a<x_0\\ \mathrm{\&pi;}& x_a=x_0,y_a>y_0\\ 0& x_a=x_0,y_a<y_0\end{array}\right.---\left(3\right)$

When circular arc is along circular arc:

$c=\left\{\begin{array}{cc}3\mathrm{\&pi;}/2+\arctan \left(\frac{y_a-y_0}{x_a-x_0}\right)& x_a>x_0\\ \mathrm{\&pi;}/2+\arctan \left(\frac{y_a-y_0}{x_a-x_o}\right)& x_a<x_0\\ 0& x_a=x_0,y_a>y_0\\ \mathrm{\&pi;}& x_a=x_0,y_a<y_0\end{array}\right.---\left(4\right).$

A kind of based on the control of time-divided method cut-off knife tangential following Carton cutting method, it is characterised in that: described step 3.2) in, calculate an interpolation week Increment in X-axis Y-axis and one interpolation cycle of cut-off knife rotary shaft C axle in phase, process is as follows:

When cutting arc shape work piece, in an interpolation cycle, cut-off knife is followed X-axis Y-axis and is rotated Motion, according to step angle tangential following algorithms such as time-divided method employings, if interpolation cycle is T_s The speed of feeding is V_s, then step-length is L=V_s·T_s；Angle delta β that rotary shaft turns over=α, circular arc The step angle α that the step-length of radius and each interpolation cycle is walked in determining each interpolation cycle, meter Calculate the amount of feeding of each axle in each interpolation cycle；

When circular arc is inverse circular arc, if current interpolated point is P_i(x_i,y_i,c_i), through an interpolation week After date point of arrival P_i+1(x_i+1,y_i+1,c_i+1):

$\left\{\begin{array}{c}{x}_{i+1}=Rcos({\mathrm{\&theta;}}_i+\mathrm{\&alpha;})=x_{i}cos\mathrm{\&alpha;}-y_{i}sin\mathrm{\&alpha;}\\ y_{i+1}=Rsin({\mathrm{\&theta;}}_i+\mathrm{\&alpha;})=y_i\cos a+x_i\sin a\\ c_{i+1}=c_i+\mathrm{\&alpha;}\end{array}\right.---\left(5\right)$

When circular arc is inverse circular arc, if current interpolated point is P_i(x_i,y_i,c_i), through an interpolation week After date point of arrival P_i+1(x_i+1,y_i+1,c_i+1):

$\left\{\begin{array}{c}{x}_{i+1}=Rcos({\mathrm{\&theta;}}_i-\mathrm{\&alpha;})=x_{i}cos\mathrm{\&alpha;}+y_{i}sin\mathrm{\&alpha;}\\ y_{i+1}=Rsin({\mathrm{\&theta;}}_i-\mathrm{\&alpha;})=y_i\cos a-x_i\sin a\\ c_{i+1}=c_i-\mathrm{\&alpha;}\end{array}\right.---\left(6\right)$

In an interpolation cycle process, step angle corresponding to step-length is certain, according to Step-length L and arc radius R obtain the size of the sine value of step angle, cosine value and step angle, Computing formula is as follows:

$\mathrm{\&alpha;}=2\arcsin \frac{L}{2R}---\left(7\right)$

$\left\{\begin{array}{c}sin\mathrm{\&alpha;}=2sin\frac{\mathrm{\&alpha;}}{2}cos\frac{\mathrm{\&alpha;}}{2}=\frac{L\&CenterDot;\sqrt{4R^2-L^2}}{2R^2}\\ cos\mathrm{\&alpha;}=1-{\sin }^2\frac{\mathrm{\&alpha;}}{2}=\frac{2R^2-L^2}{2R^2}\end{array}\right.---\left(8\right).$