CN105717873A - Automatic feeding speed control method based on template sewing machine controller - Google Patents

Abstract

A automatic feeding speed control method based on a template sewing machine controller includes the following steps that 1, a speed chart (v1,...,vm) is established by combining with the best frequency raising law of a servo motor according to a S-shaped acceleration and deceleration control algorithm, and a ladder-shaped step length table (l1,..., lm) is established according to the speed chart and movement characteristics of the motor; 2, the maximum sudden-change speeds Delta argument x and Delta argument y allowable for the motor in the directions of two shafts are determined through debugging according to the mechanical structure of a mobile platform of the automatic template sewing machine and model of the servo motor; 3, the maximum speed of every turning point of a sewing track is calculated; 4, a regression method is adopted to recalculate and determine the speed of each coordinate point (shown in the description) according to the step length table, and finally speed control is achieved. The automatic feeding speed control method can effectively solve the problems of severe shaking, poor stability, low precision and the like occurred during high-speed movement of a feeding platform of the automatic template sewing machine.

Description

A kind of self-feeding method for control speed based on template sewing machine controller

Technical field

The present invention relates to a kind of method for control speed, especially a kind of method for control speed based on template sewing machine controller self-feeding, belong to motion control field.

Background technology

Recently as China's clothing, the continuous expansion of the product industries such as bedding, shoes, leather, traditional sewing machine is eliminated gradually, and the automatic moulding plate sewing machine with automatic feeding function is subject to increasingly paying close attention to widely.

The material conveying platform of automatic moulding plate sewing machine is mainly made up of two servomotors (controlling X-axis and Y-axis respectively), moving beam, conveyer belt, form clamp, reset signal sensor.Controller is by controlling two servomotors, then is driven crossbeam to carry out self-feeding by servomotor by conveyer belt.But, yet suffer from that control accuracy is not high, shake the problems such as serious with the material conveying platform of automatic moulding plate sewing machine that servomotor is control object, become apparent from particularly in the frequent situation of high-speed motion and acceleration and deceleration.This obviously can affect the quality of automatic moulding plate sewing machine stitched products.

Summary of the invention

In order to overcome the shortcomings such as the shake that existing automatic moulding plate sewing machine material conveying platform exists under high-speed motion and acceleration and deceleration situation frequently is serious, poor stability, precision are not high, the invention provides a kind of self-feeding method for control speed based on template sewing machine controller that can effectively reduce shake, improving stability under high-speed motion and acceleration and deceleration situation frequently.

The technical solution adopted for the present invention to solve the technical problems is as follows:

A kind of self-feeding method for control speed based on template sewing machine controller, said method comprising the steps of:

1) ladder step length table is set up

First accelerometer (α is obtained according to S type acceleration/deceleration control algorithm₁,...,α_m), α represents the value of each acceleration, and subscript 1 represents the sequence of positions of each acceleration to m；Best raising frequency rule further according to servomotor sets up speedometer (v₁,...,v_m), v represents the value of each speed, and subscript 1 represents the sequence of positions of each speed to m；Kinetic characteristic in conjunction with speedometer and servomotor obtains corresponding ladder step length table (l₁,...,l_m), l represents the value of each step-length, and subscript 1 represents the sequence of positions of each step-length to m；

2) material conveying platform maximum sudden change speed on two direction of principal axis is determined

Frame for movement according to automatic moulding plate sewing machine material conveying platform and the model of servomotor by field adjustable, determine that the material conveying platform of automatic sewing machine powers on the maximum sudden change speed Δ v that function allows to run in X-axis and Y direction respectively_x、Δv_y；

3) maximal rate of the sewing each flex point of track is calculated

If the coordinate after the continuous path that automatic sewing machine material conveying platform needs run is discrete is (x_1,y₁),(x₂,y₂),...,(x_n,y_n), adjacent coordinates can form much intensive little line segment, these line segments are exactly the track that motor needs to run, and the point between adjacent segments is exactly flex point；

If changing coordinates is (x₀,y₀), now the speed on two direction of principal axis is (v_0x,v_0y), its sum velocity v₀It is θ with the angle of X-axis₀；At terminal point coordinate (x_n,y_n) sum velocity v_nDecompose two axial speed for (v_nx,v_ny)；Coordinate according to adjacent two discrete points, calculates the angle theta of n bar line segment and X-direction₁,...,θ_n, in conjunction with maximum sudden change speed Δ v_x、Δv_y, calculate the maximal rate (v obtained in sewing each coordinate flex point of track_1x,v_1y),...,(v_n-1x,v_n-1y), v_xRepresent changing coordinates flex point maximal rate in X-axis, v_yRepresenting changing coordinates flex point maximal rate in Y-axis, subscript 1 represents the sequence of positions of each coordinate flex point to n-1；

4) reverse method is used to calculate the final goal speed of the sewing each discrete point of track

Will by step 3) obtain sewing each coordinate flex point of track maximal rate (v_1x,v_1y),...,(v_n-1x,v_n-1y) as the initial target speed of each flex point on sewing track Represent the initial target speed of flex point value in the X-axis direction on sewing track,Representing the initial target speed of flex point value in the Y-axis direction on sewing track, subscript 1 represents the sequence of positions of each coordinate flex point to n-1, and the sum velocity being located at the initial target speed of n-1 point is v^ο _n-1, it is known that the sum velocity at terminal point coordinate is v_n, both are compared, if v^ο _n-1> v_n, it was shown that at the sum velocity of n point coordinates less than the sum velocity of the initial target speed at n-1 point, is reverse method due to what adopt, so when n point, will be accelerated according to ladder step length table, moves to point (x_n-1,y_n-1) time, obtaining speed now isThen sum velocity now is v^οο _n-1.If meeting v^ο _n-1> v^οο _n-1, in order to when ensureing servomotor movement velocity, it is possible to ensure its stability, then chooseFor the final goal speed (v at n-1 point_n-1x,v_n-1y)；If meeting v^ο _n-1≤v^οο _n-1, then (v is chosen^ο _n-1x,v^ο _n-1y) it is the final goal speed (v at n-1 point_n-1x,v_n-1y)；By that analogy, the final goal speed (v of all discrete points on sewing track is obtained_0x,v_0y),...,(v_nx,v_ny), v_xRepresent the final goal speed of discrete point value in the X-axis direction, v on sewing track_yRepresenting the final goal speed of discrete point value in the Y-axis direction on sewing track, subscript 0 represents the sequence of positions of various discrete point to n.

Further, described method for control speed is further comprising the steps of: in step 4) in, if current line segment is less than the length set, the length set here is designated as L_min, while revising current acceleration and deceleration, using the target velocity of next discrete point as the maximal rate in current line segment acceleration and deceleration process, if having reached this maximal rate in the motor process of this line segment, follow-up just carry out uniform motion, no longer carry out acceleration and deceleration, until moving to next discrete point.

It is an advantage of the current invention that: (1) adopts the method for control speed of ladder step length table, motor is made can quickly to obtain target velocity in acceleration and deceleration process, reduce the calculating time in acceleration and deceleration process so that the real-time of automatic sewing machine material conveying platform motion is higher；(2) in conjunction with ladder step length table, reverse method is adopted to obtain the final goal speed of middle each discrete point so that the speed of service of automatic sewing machine material conveying platform is more reasonable；(3) method for control speed of a large amount of little line segment existed in sewing track is carried out special handling so that the material conveying platform of automatic sewing machine is more steady in running；(4) control method realizes based on TMS320F2812, and aboundresources also can reduce the volume of automatic sewing machine controller.

Accompanying drawing explanation

Fig. 1 is the index speed curve chart of servomotor.

Fig. 2 is adjacent little line segment flex point velocity profile.

Detailed description of the invention

It is further described below in conjunction with accompanying drawing.

See figures.1.and.2, a kind of self-feeding method for control speed based on template sewing machine controller, comprise the following steps:

1) the rotating speed computing formula of servomotor is as follows:

$v=\frac{60}{\frac{360}{\mathrm{\θ}}{t}_s}(r/min)---\left(1\right)$

$v=\frac{1}{6}{\mathrm{\θf}}_s(r/min)---\left(2\right)$

Wherein θ represents the step angle of motor, t_sFor the pulse period, corresponding frequency is f_s, v is the rotating speed of motor, and step angle θ is a fixed constant value after choice of electrical machine is chosen, so passable according to above-mentioned formula (2), the speed of motor can be controlled by the frequency of control output pulse.Turn frequency characteristic formula of motor is as follows:

$P=\frac{2{\mathrm{\πvT}}_e}{60}\left(w\right)---\left(3\right)$

$P=\frac{2{\mathrm{\π\θf}}_s{T}_e}{360}\left(w\right)---\left(4\right)$

$T_e=\frac{360P}{2{\mathrm{\π\θf}}_s}(N\·m)---\left(5\right)$

Wherein T_eTorque during for motor movement, P is the power of motor, and owing to θ is constant, when power of motor P mono-timing, the change of torque is first quick and back slow, and namely the velocity variations of servomotor is first quick and back slow.Accelerometer (α is obtained according to S type acceleration/deceleration control algorithm₁,...,α_m), α represents the value of each acceleration, and subscript 1 represents the sequence of positions of each acceleration to m；Best raising frequency rule further according to servomotor sets up speedometer (v₁,...,v_m), v represents the value of each speed, and subscript 1 represents the sequence of positions of each speed to m, can obtain the frequency meter (f of correspondence according to formula (2)₁,...,f_m), owing to the material conveying platform of automatic sewing machine also exists inertia in acceleration and deceleration running, this can cause motor to shake in running, so the change of speed each time is required for the certain pulse step number of motor operation and adapts to, speed is more big, the pulse step number run is more many, and the kinetic characteristic in conjunction with speedometer and servomotor just can obtain pulse step step length table (l₁,...,l_m), l represents the value of each step-length, and subscript 1 represents the sequence of positions of each step-length to m.It is deposited in the memory element of controller.

2) according to the frame for movement of automatic moulding plate sewing machine material conveying platform and the model of servomotor and by field adjustable, just can determine that the maximum sudden change speed Δ v powering on two direction of principal axis function allowing_x、Δv_y。

3) read from corresponding memory element sewing track is carried out discrete after n coordinate points (x₁,y₁),(x₂,y₂),...,(x_n,y_n), it is assumed that changing coordinates is (x₀,y₀), coordinate speed on two direction of principal axis is (v_0x,v_0y), the sum velocity of motor speed on two direction of principal axis and the angle of X-axis are θ₀, terminal point coordinate (x_n,y_n) sum velocity decompose two axial speed for (v_nx,v_ny), the coordinate according to adjacent two discrete points, it is possible to the angle calculating n bar line segment and X-direction is θ₁,...,θ_n, the formula of calculating is as follows:

${\mathrm{tan\θ}}_i=\frac{y_i-y_{i-1}}{x_i-x_{i-1}}---\left(6\right)$

${\mathrm{\θ}}_i=arctan\frac{y_i-y_{i-1}}{x_i-x_{i-1}}---\left(7\right)$

As in figure 2 it is shown, the some P in the continuous line segment needing sewing_i-1、P_i、P_I+1, corresponding coordinate respectively (x_i-1,y_i-1)、(x_i,y_i)、(x_I+1,y_I+1), can calculate according to these coordinate points and obtain line segment P_i-1P_iAnd P_iP_I+1Length and the cosine value of corresponding two vectorial angle theta, computing formula is as follows:

$\cos \mathrm{\θ}=\frac{(x_i-x_{i-1})(x_{i+1}-x_i)+(y_i-y_{i-1})(y_{i+1}-y_i)}{L_i{L}_{i-1}}---\left(8\right)$

Wherein L_iRepresent line segment P_i-1P_iLength, L_i-1Represent line segment P_iP_i+1Length, it is assumed that the motor of material conveying platform is from P_i-1Move to P_iTime final speed be v_e, from P₁Move to P_i+1Starting velocity be v_s, then the known speed variable quantity at turning is:

$\mathrm{\Δ}v=\sqrt{v_e^2+v_s^2-2v_e{v}_s\·cos\mathrm{\θ}}---\left(9\right)$

Owing to motor speed can not suddenly change, it is known that:

v_e=v_s=v_i(10)

V in above-mentioned formula_iRepresent that motor movement is to putting a P_iTime speed, can obtain according to formula (9) and (10):

Δ v=2v_isin(θ/2)(11)

According to motor characteristic and mechanical inertia, it is assumed that the peak acceleration of motor is a_max, and the break-in in order to improve each motor of efficiency all completes in an interpolation axial period T, then can obtain v_iA qualifications:

$\frac{\mathrm{\&Delta;}v}{T}<a_{max}---\left(12\right)$

Can obtain in conjunction with formula (11) and (12):

$v_i\&le;\frac{a_{max}\&CenterDot;T}{2sin(\mathrm{\&theta;}/2)}---\left(13\right)$

Motor movement can be obtained to putting a P according to formula (13)_iMaximal rate, the namely maximal rate of flex point, decompose the speed of two axles for (v_ix,v_iy), namely can obtain the maximal rate (v of all flex points_1x,v_1y),...,(v_n-1x,v_n-1y), v_xRepresent changing coordinates flex point maximal rate in X-axis, v_yRepresenting changing coordinates flex point maximal rate in Y-axis, subscript 1 represents the sequence of positions of each coordinate flex point to n-1.

4) will by step 3) obtain sewing each coordinate flex point of track maximal rate (v_1x,v_1y),...,(v_n-1x,v_n-1y) as the initial target speed of each flex point on sewing track Represent the initial target speed of flex point value in the X-axis direction on sewing track,Representing the initial target speed of flex point value in the Y-axis direction on sewing track, subscript 1 represents the sequence of positions of each coordinate flex point to n-1, and the sum velocity being located at the initial target speed of n-1 point is v^ο _n-1, it is known that the sum velocity at terminal point coordinate is v_n, both are compared, if v^ο _n-1> v_n, it was shown that at the sum velocity of n point coordinates less than the sum velocity of the initial target speed at n-1 point, is reverse method due to what adopt, so when n point, will be accelerated according to ladder step length table, moves to point (x_n-1,y_n-1) time, obtaining speed now isThen sum velocity now is v^οο _n-1.If meeting v^ο _n-1> v^οο _n-1, in order to when ensureing servomotor movement velocity, it is possible to ensure its stability, then chooseFor the final goal speed (v at n-1 point_n-1x,v_n-1y)；If meeting v^ο _n-1≤v^οο _n-1, then (v is chosen^ο _n-1x,v^ο _n-1y) it is the final goal speed (v at n-1 point_n-1x,v_n-1y)；By that analogy, the final goal speed (v of all discrete points on sewing track is obtained_0x,v_0y),...,(v_nx,v_ny), v_xRepresent the final goal speed of discrete point value in the X-axis direction, v on sewing track_yRepresenting the final goal speed of discrete point value in the Y-axis direction on sewing track, subscript 0 represents the sequence of positions of various discrete point to n.

Due to a large amount of little line segment existed in sewing track, the present invention proposes for this characteristic the processing method of correspondence, reduces the shake of equipment.In step (5), if current line segment is less than L_min, in order to reduce the shake of motor, the present invention realizes by changing acceleration in motor process, by current acceleration alpha_iBecome α_i', formula is as follows:

$\begin{array}{cc}{\mathrm{\&alpha;}}_i^{\&prime;}={\mathrm{k\&alpha;}}_i+(1-k){\mathrm{\&alpha;}}_i\frac{L}{L_{min}}& (0<k<1)\end{array}---\left(14\right)$

Wherein α_iBeing the acceleration originally obtained according to S type acceleration and deceleration algorithm, k is constant coefficient.Meanwhile, using the target velocity of next discrete point as the maximal rate in current acceleration and deceleration process, if having reached this maximal rate in the motor process of this line segment, follow-up just carrying out uniform motion, no longer carrying out acceleration and deceleration, until moving to next discrete point.

Claims (2)

1. the self-feeding method for control speed based on template sewing machine controller, it is characterised in that: said method comprising the steps of:

1) ladder step length table is set up

First accelerometer (α is obtained according to S type acceleration/deceleration control algorithm₁,...,α_m), α represents the value of each acceleration, and subscript 1 represents the sequence of positions of each acceleration to m；Best raising frequency rule further according to servomotor sets up speedometer (v₁,...,v_m), v represents the value of each speed, and subscript 1 represents the sequence of positions of each speed to m；Kinetic characteristic in conjunction with speedometer and servomotor obtains corresponding ladder step length table (l₁,...,l_m), l represents the value of each step-length, and subscript 1 represents the sequence of positions of each step-length to m；

2) material conveying platform maximum sudden change speed on two direction of principal axis is determined

Frame for movement according to automatic moulding plate sewing machine material conveying platform and the model of servomotor by field adjustable, determine that the material conveying platform of automatic sewing machine powers on the maximum sudden change speed Δ v that function allows to run in X-axis and Y direction respectively_x、Δν_y；

3) maximal rate of the sewing each flex point of track is calculated

If the coordinate after the continuous path that automatic sewing machine material conveying platform needs run is discrete is (x₁,y₁),(x₂,y₂),...,(x_n,y_n), adjacent coordinates can form much intensive little line segment, these line segments are exactly the track that motor needs to run, and the point between adjacent segments is exactly flex point；

If changing coordinates is (x₀,y₀), now the speed on two direction of principal axis is (v_0x,v_0y), its sum velocity ν₀It is θ with the angle of X-axis₀；At terminal point coordinate (x_n,y_n) sum velocity v_nDecompose two axial speed for (v_nx,v_ny)；Coordinate according to adjacent two discrete points, calculates the angle theta of n bar line segment and X-direction₁,...,θ_n, in conjunction with maximum sudden change speed Δ ν_x、Δv_y, calculate the maximal rate (v obtained in sewing each coordinate flex point of track_1x,v_1y),...,(v_n-1x,v_n-1y), v_xRepresent changing coordinates flex point maximal rate in X-axis, v_yRepresenting changing coordinates flex point maximal rate in Y-axis, subscript 1 represents the sequence of positions of each coordinate flex point to n-1；

4) reverse method is used to calculate the final goal speed of the sewing each discrete point of track

Will by step 3) obtain sewing each coordinate flex point of track maximal rate (v_1x,v_1y),...,(v_n-1x,v_n-1y) as the initial target speed of each flex point on sewing track Represent the initial target speed of flex point value in the X-axis direction on sewing track,Representing the initial target speed of flex point value in the Y-axis direction on sewing track, subscript 1 represents the sequence of positions of each coordinate flex point to n-1, and the sum velocity of the initial target speed being located at n-1 point isThe known sum velocity at terminal point coordinate is v_n, both are compared, ifShow that the sum velocity at n point coordinates is less than the sum velocity of the initial target speed at n-1 point, is reverse method due to what adopt, so when n point, will be accelerated according to ladder step length table, moves to point (x_n-1,y_n-1) time, obtaining speed now isThen sum velocity now isIf meetingIn order to when ensureing servomotor movement velocity, it is possible to ensure its stability, then chooseFor the final goal speed (v at n-1 point_n-1x,v_n-1y)；If meetingThen chooseFor the final goal speed (v at n-1 point_n-1x,v_n-1y)；By that analogy, the final goal speed (v of all discrete points on sewing track is obtained_0x,v_0y),...,(v_nx,v_ny), v_xRepresent the final goal speed of discrete point value in the X-axis direction, v on sewing track_yRepresenting the final goal speed of discrete point value in the Y-axis direction on sewing track, subscript 0 represents the sequence of positions of various discrete point to n.

2. a kind of self-feeding method for control speed based on template sewing machine controller as claimed in claim 1, it is characterized in that: described method for control speed is further comprising the steps of: in step 4) in, if current line segment is less than the length set, the length set here is designated as L_min, while revising current acceleration and deceleration, using the target velocity of next discrete point as the maximal rate in current line segment acceleration and deceleration process, if having reached this maximal rate in the motor process of this line segment, follow-up just carry out uniform motion, no longer carry out acceleration and deceleration, until moving to next discrete point.