CN201848985U - Control system for die opening-closing motor and ejection motor of full-automatic injection molding machine - Google Patents

Abstract

The utility model discloses a control system for a die opening-closing motor and an ejection motor of a full-automatic injection molding machine. The control system comprises a computer controller, a PLC (programmable logic controller), a die opening-closing ejection driver, a die opening-closing motor and an ejection motor that are mutually connected. The control system provided by the utility model meets the control requirements for die-closing force, speed and position, ensures that a formed die is reliably locked, and realizes the opening-closing actions of the die, and the products are accurately and stably ejected from the die; and by adopting the designed DSP (digital signal processor)-based driver, the stable reliability of the system under high load condition is guaranteed, and the compensation for disturbance is simultaneously improved at the same time.

Description

Control system of mold opening and closing motor and ejection motor of all-electric injection molding machine

technical field

The utility model relates to the field of electric injection molding machines, in particular to a control system and a control method for a mold opening and closing motor and an ejection motor of an electric injection molding machine. the

Background technique

During the injection process of the all-electric injection molding machine, the mold clamping device is a component that ensures the reliable closing of the molding mold and realizes the opening and closing of the mold and the ejection of the product. During injection molding, since the molten material entering the mold cavity still has a certain pressure, the mold clamping devices of many injection molding machines do not have enough clamping force at present, and the mold is opened under the pressure of the molten material, resulting in product overflow or Decrease the precision of the product. the

In addition, at present, many mold clamping motor drive systems still cannot meet the speed requirements when the mold is opened and closed, neither shortening the no-load travel time nor considering the buffering requirements of the mold opening and closing process, resulting in damage to the mold and parts. The productivity of the machine is low, and the machine is subject to strong vibration and impact noise. the

In addition, many molds cannot meet the requirements of the space position when installing and taking out the product, so that the mold clamping device cannot meet the control requirements of the mold clamping force, speed, and position. The bearing capacity is low, the structure is not compact, and the movement performance is poor. The magnification ratio is relatively small, and it is easy to cause mold swelling during the injection process. the

Many ejection devices do not have sufficient and uniform ejection force, controllable ejection times, ejection speed, nor sufficient adjustable ejection stroke, resulting in products that cannot be accurately and smoothly ejected from in-mold products. the

Utility model content

The purpose of this utility model is to overcome the shortcomings and deficiencies of the prior art, to provide a control system and control method for the opening and closing motor and ejection motor of an all-electric injection molding machine, to ensure the reliable closing of the forming mold and to realize the opening and closing action of the mold And the products are ejected from the mold accurately and smoothly. the

The purpose of this utility model is achieved through the following technical solutions: a control system for the opening and closing motor and the ejection motor of an all-electric injection molding machine, which is connected with the opening and closing motor and the ejection motor, and is characterized in that it includes a computer controller, PLC controller and opening and closing mold and ejection driver; Described computer controller and PLC controller are respectively connected with opening and closing mold and ejection driver signal by CAN network, and described opening and closing mold and ejection driver are connected with opening and closing respectively Die motor and ejector motor connection. the

In order to better realize the utility model, the mold opening and closing and the ejection driver are composed of a servo controller, an IPM power drive board, a current sensor, a code disc and a switching power supply; the servo controller is connected to an external circuit signal; The IPM power drive board is connected to the servo controller and the servo motor; the current sensor is connected to the IPM power drive board, the servo motor and the servo controller; the code disc is connected to the servo motor and the servo controller; the switching power supply is connected to the IPM power module , a current sensor, a code disc and a servo controller; the servo motor refers to a mold opening and closing motor and an ejection motor. the

The servo controller in the mold opening and closing and ejection driver refers to a digital signal processing chip TMS320F2833X, which includes a system initialization program module, a timer underflow interrupt service program module, and an orthogonal encoder interrupt processing module; the chip TMS320F2833X One of the output ports is connected to the injection molding machine computer controller and the emulator through its own CAN bus communication module and JTAG interface, and the other output port is connected to the IPM power driver board and the Servo motor, the servo motor is connected to the analog-to-digital conversion module ADC of the chip through the current sensor, and the quadrature encoder unit QEP of the chip is also connected to the servo motor through the code disc; the servo motor refers to the mold opening and closing motor and the top out of the motor. the

The above-mentioned control method of the mold opening and closing motor and the ejection motor control system of the all-electric injection molding machine is characterized in that it includes the following steps:

The first step is to use the double toggle mold clamping mechanism of the five hinged molds and the crank slider ejector mechanism, and determine the mold clamping device and the jacking mechanism according to the mold moving speed characteristics and force characteristics of the double toggle mechanism during the mold opening and closing process. The ball screw, mold opening and closing motor, and ejection motor selected for the ejection device;

The second step is to control the mold opening and closing motor and ejection motor according to the load characteristics and process requirements of the opening and closing motor and the ejection motor, and set up perfect mold protection measures, including:

(1) During the mold closing process, the mold is first clamped quickly with low pressure, and when the movable platen is close to the fixed platen, it is automatically switched to low-speed mold clamping, and after confirming that there is no foreign matter in the mold cavity, it is switched to high pressure again to close the mold; During the mold closing process, in order to prevent the mold material from overflowing, a large mold clamping force needs to be applied, and the mold opening and closing motor adopts torque control during this process;

(2) During the mold opening process, it is first necessary to ensure that the cooling mold cavity surface of the injection molded part is away from the position of the guide post, then the movable template moves at a constant speed to open the mold quickly, and the movable template stops slowly when it is close to the starting position of the movable template;

(3) Adjust the ejection speed by adjusting the speed of the ejection motor to ensure accurate and smooth ejection of the product in the mold. the

In order to better realize the above method, the ball screw, mold opening and closing motor, and ejection motor for determining the mold clamping device and the ejector device in the first step refer to: The translational working condition of the clamping mechanism determines the ball screw shaft diameter, lead, screw length, screw shaft diameter and accuracy level; ② comprehensively consider the required clamping force, mold moving speed, stroke ratio, ball screw The mold opening and closing motor and the ejector motor are selected according to the gear ratio of the lever lead and the belt drive. the

Determining that there is no foreign matter in the mold cavity in the second step (1) refers to setting a detection interval at a position close to the fixed template, and determining whether there is any obstacle by detecting whether the change of the load current of the mold opening and closing motor exceeds the limit. thing. the

In the second step (2), ensuring that the cooling mold cavity surface of the injection molded part is separated from the guide post refers to setting the position as the position when the guide post is in contact with the mold on the fixed side. the

The mold clamping process in the second step (1) includes:

①. Move from the mold opening end position to the mold clamping speed change position, which is called the first stage of mold clamping speed;

②. Moving from the mold clamping speed change position to the mold protection position, it is called the mold clamping speed as 2 stages, which is high-speed and low-pressure movement;

③. Moving from the mold protection position to the mold contact position is called the mold clamping speed 3 section, which is the mold protection zone. If the current sensor detects that the mold clamping current in this section is greater than the normal current curve, it is considered that there is residual plastic on the end surface of the mold not taken out, the mold clamping process stops and the mold is opened immediately;

④. Move from the mold protection area to the mold and tighten it, and apply the maximum pressure to lock the mold. the

The mold-moving speed of described second step mold opening and mold-closing process obtains by following method:

I. Moving template stroke

According to the structural analysis, the moving stroke S _m of the movable formwork can be characterized by the displacement of point B of the hinge support:

${\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="B"\; filenames="HSA00000220247200011.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="L\; A\; B"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">L</figure-callout></span><figure-callout\; id="1"\; label="L\; A\; B"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; A</span>}{}_{}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

是在终锁位置铰A、B的中心连线。 In formula (1)

It is the connecting line between the centers of hinges A and B at the final lock position.

${\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="L"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">L</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="L"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">L</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="L"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">L</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

Elbow length ratio λ=L ₁ /L ₂ , according to the law of sine

Therefore $S_m=L_1(1-\cos {\mathrm{\&alpha;}}_1+\frac{\sqrt{1-{\mathrm{\&lambda;}}^2{\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2{\mathrm{\&alpha;}}_1}}{\mathrm{\&lambda;}})---\left(4\right)$

${\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; cos</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="L"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">L</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

II. Piston rod stroke S _g and stroke ratio K _S

The stroke of the piston rod is the term used for the hydraulic mold clamping device. In the motor-driven mold clamping device, S _g represents the stroke of the crosshead, which is characterized by the movement of the hinge E on the crosshead:

The ratio of template stroke to crosshead stroke is called stroke ratio K _S ＝S _M /S _g (9)

K _S reflects the ratio of mold moving speed to crosshead moving speed, and also reflects the energy consumption of the machine;

III, mold moving speed V _m and speed variation coefficient K _V

The mold moving speed of the toggle mold clamping mechanism is controllable. If the friction loss is ignored, according to the principle of energy conservation, the power input to the mold clamping mechanism should be equal to the output power.

P _B · V _B = P _M · V _M (10)

So the moving speed of the template can be obtained

The control principle of the present utility model is as follows:

As shown in Figure 1 and Figure 2-1, the mold moving speed characteristics of the opening and closing process of the double toggle mechanism are:

1. Travel template stroke S _m

式中 

是在终锁位置铰A、B的中心连线。 

In the formula

It is the connecting line between the centers of hinges A and B at the final lock position.

肘长比λ＝L₁/L₂，根据正弦定律 

可得 

Elbow length ratio λ=L ₁ /L ₂ , according to the law of sine

Available

由此可知肘杆机构的行程是S_m是随肘长比λ和α₁的增大而增加的。然而后连杆L₁的尺寸受后模板的外形尺寸制约，一般有L₁＜L_AA/2，L_AA为后模板两支铰的中心距。而α₁的大小则会影响到机构能否实现自锁。 in:

It can be seen that the stroke of the toggle mechanism is _Sm , which increases with the increase of the elbow length ratio λ and _α1 . However, the size of the rear connecting rod L ₁ is restricted by the external dimensions of the rear formwork, generally L ₁ < L _AA /2, where L _AA is the center distance between the two hinges of the rear formwork. The size of _α1 will affect whether the mechanism can realize self-locking.

2. Piston rod stroke S _g and stroke ratio K _S

In the motor-driven mold clamping device, S _g represents the stroke of the crosshead, which is characterized by the movement of the hinge E on the crosshead:

模板行程与十字头行程之比称为行程比K_S＝S_M/S_g，K_S反映了移模速度和十字头移动速度的比值，而且也反映了机台的能量消耗。实践证明K_S在1～3之间，小型机取大值，大型机取小值，过大的K_S值会引起冲击现象。 in:

The ratio of template stroke to crosshead stroke is called stroke ratio K _S =S _M /S _g , and K _S reflects the ratio of mold moving speed to crosshead moving speed, and also reflects the energy consumption of the machine. Practice has proved that K _S is between 1 and 3, the small computer takes a large value, and the mainframe takes a small value, and an excessively large K _S value will cause a shock phenomenon.

3. Die-moving speed V _m and speed variation coefficient K _V

The mold-moving speed of the toggle-type clamping mechanism generally refers to its average mold-moving speed. If the friction loss is neglected, according to the principle of energy conservation, the power input to the mold clamping mechanism should be equal to the output power, that is, P _B · V _B = P _M · V _M , so the moving speed of the template is:

From the above formula, we can know the characteristics of the toggle mechanism's smooth speed change during the mold moving process. the

The force-increasing characteristics of the mold opening and closing process of the double toggle mechanism are:

1. Multiplier M

故有 

根据虚位移原理P_Ods_g-P_mds_m＝0，则连杆机构的增力倍数 Assuming crosshead thrust P _O and mold clamping force P _m , it can be seen from the above motion analysis that the moving speed of the crosshead is V _g = _VE , and the moving speed of the moving template is V _m =V _B , because

Therefore there

According to the principle of virtual displacement P _O ds _g -P _m ds _m = 0, then the force multiplier of the link mechanism

In the formula

2. Self-locking and normal movement conditions of the mechanism

可知连杆机构的自锁条件是 

连杆机构的正常运动条件是 

Depend on

It can be seen that the self-locking condition of the linkage mechanism is

The normal motion condition of the linkage mechanism is

3. The deformation force of the toggle mechanism during the mold locking process

Let ΔS be the total deformation of the system, then have

ΔS=ΔL _p +AL _k -f ₁ -f ₂ =L _k -L _p =L ₁ (cosα-cosα _L )+L ₂ (cosβ-cosβ _L )

In the formula: L _P , ΔL _P ——the length and tensile deformation of the tie rod;

L _K , ΔL _K - the total free length and compression deformation of the compression part;

f ₁ , f ₂ ——the bending deflection of the rear formwork and the front formwork;

αL, βL——the critical angle of mode locking;

According to Hooke's law, the deformation force of the clamping mechanism is:

P _C ＝C[L ₁ (cosα-cosα _L )+L ₂ (cosβ-cosβ _L )], when the mold is tightened and the connecting rods L ₁ and L ₂ are in a straight line, α=0°, β=0 °, the deformation force reaches the maximum value, that is, P _cm =c[l ₁ (1-cosα _L )+l ₂ (1-cosβ _L )], where C is the total stiffness of the system.

4. Crosshead thrust P _O

According to the requirements of process production, during the mold tightening process, the mold clamping force P _m generated by the crosshead thrust P _O (equivalent to the hydraulic cylinder thrust in the hydraulic model) should be greater than or equal to the mechanism deformation force P _C

The double toggle mechanism has the characteristic of force magnification, and the force magnification M represents the relationship between the movement force P _m of the mechanism and the crosshead thrust P _O during the mold clamping process. The change curve of the force magnification ratio of the double-toggle five-hinge mold clamping mechanism during the entire mold clamping process is shown in Figure 2-3a. The deformation force P _C changes with the α angle in a quadratic parabola law, while the mold removal force P _m has a hyperbolic relationship with α as shown in the figure. In the process of the mechanism overcoming the deformation resistance and finally realizing the mold clamping force, the driving force of the motor transmission mechanism acting on the crosshead is amplified by the double toggle mechanism to obtain the mold moving force P _m , which changes with the enlargement ratio of the mechanism, as shown in the figure As shown in 2-3b, the mold can be closed smoothly only when P _m is guaranteed to be greater than the deformation force P _C of the mechanism during the mold closing process, as shown in the tangent situation in Figure 2-3b. In fact, due to reasons such as friction and processing accuracy, the mold shifting force is usually higher than P _m1 to close the mold. Therefore, P _m1 has become the key reference basis for calculating the rated torque of the motor in our motor selection.

Fuzzy adaptive position control In the all-electric injection molding machine, the rapid movement of the template and frequent opening and closing of the mold cause the motor to switch between forward and reverse in a few seconds, and mechanical transmission such as a screw type lead screw will produce In addition, the mold protection also needs to detect the torque and current at a narrow position near 1.5mm before locking, so the position control is very important. the

5. Design of current loop controller

The function of the current loop in the system is mainly to control the output torque, the purpose is to achieve a fast dynamic response, and to ensure that there is no overshoot or the smaller the overshoot during the transition process of the current when the load is suddenly added. For this reason, we correct the current loop into an I-type system, and the open-loop transfer function is

The current loop adopts PI control, and the block diagram is shown in Figure 8. the

所以 

In order to make the zero point of the controller cancel the relatively large time constant of the motor control object, let τ _i =T _m , then T=T _s ,

so

In order to make the overshoot less than 5%, the desirable damping ratio ξ=0.707, KT=0.5, then K=1/2T, according to formula (13)

K _i and τ _i can be obtained by substituting the values, where the motor parameters are: rated speed N, rated torque T, rotor inertia J, winding resistance R, mechanical time constant T _m , electrical time constant T _s , inductance L _q , the torque constant K _t ;

6. Design of speed loop controller

The transfer function of the current loop is $W\left(\mathrm{the\; s}\right)=\frac{1}{\frac{T}{K}{\mathrm{the\; <figure-callout\; id="2"\; label="s"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">s</figure-callout>}}^2+\frac{\mathrm{the\; s}}{K}+1}---\left(14\right)$

Considering that the cut-off frequency of the speed loop is generally low, the transfer function of the current loop can be approximately reduced to

On the basis of the above-mentioned current regulation link, the schematic block diagram of the speed loop using the PI controller is shown in Figure 9: the speed loop is corrected to a typical type II system, and the PI speed controller is used, and the open-loop transfer function is

${\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}\mathrm{<span\; class="notranslate">\; J</span>}{\mathrm{<span\; class="notranslate">\; the\; s</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Ts</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span>$

According to the typical type II system design reference formula τ _n = h·2T

${\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; J</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; T</span>}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}$

Taking h=5, we can obtain τ _n , K _n

7. Design of fuzzy adaptive position controller

The position loop is located in the outermost loop of the closed-loop control system, and its function is to ensure the static accuracy of the moving position of the moving template. In the all-electric injection molding machine, the rapid movement of the template and frequent mold opening and closing cause the motor to switch between forward and reverse in a few seconds, plus the cumulative error caused by mechanical transmission such as screw type lead screw. , In addition, the mold protection also needs to detect the torque and current at a narrow position near 1.5mm before locking, so the position control is very important. the

The design of the fuzzy adaptive controller is to establish an adaptive mechanism based on the fuzzy theory. It does not require the establishment of an accurate mathematical model for the reference model and the controlled object, but only needs to simulate an experienced control worker according to the fuzzy information of the system. The fuzzy conditional statement writes the control rules, and its control function can be realized. In addition, the fuzzy algorithm is relatively simple, which is convenient for real-time control on the DSP. Its principle block diagram is shown below. the

The design of the fuzzy position controller includes the following steps:

(1) Fuzzification of precise quantities

The model of the position control object is described by a second-order transfer function:

${\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}{{\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="2"\; label="s"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">s</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&xi;s</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&omega;</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 17</span>}<span\; class="notranslate">\; )</span>$

输出控制变量ΔK为速度环的给定信号。它们三者的实际变化范围称为这些变量的基本论域。对位置误差e、误差变化率 

和控制变量ΔK的定义如下：位置误差e的精确值分为14级，其基变量的模糊集的论域定义为： The fuzzy controller is designed as a two-input single-output system, and the input variables are position error e and error change rate

The output control variable ΔK is the given signal of the speed loop. The actual variation range of the three of them is called the basic discourse domain of these variables. For position error e, error change rate

And the definition of the control variable ΔK is as follows: the precise value of the position error e is divided into 14 levels, and the domain of the fuzzy set of the basic variable is defined as:

{-6, -5, -4, -3, -2, -1, -0, +0, 1, 2, 3, 4, 5, 6};

Correspondingly, the fuzzy language subset of the error e is defined as 8 files, which correspond from "positive large" to "negative large" in turn:

{PL PM PS PO NO NS NM NL} 

error rate of change The level of is divided into 13 levels, and the domain of its basic variable fuzzy set is defined as:

{-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6};

的模糊语言子集定义为7档： error rate of change

The fuzzy language subset is defined as 7 files:

{PL PM PS O NS NM NL} 

基变量模糊集的论域定义为： The definition of the control variable ΔK is similar to

The domain of discourse of the basic variable fuzzy set is defined as:

{-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6};

The fuzzy language subset of the control variable ΔK is defined as:

{PL PM PS O NS NM NL} 

则是前者对时间t的导数，最大的输出量为电机的最高转速2000转/分。从测量反馈回来的误差和误差变化率的精确值，变换到基变量模糊集中的某一个成员，这需要一个量化比例因子或者换算表。同样地输出的控制量ΔK也有一个从基变量模糊论域成员到精确量的比例因子。实际程序中换算的公式如式18、19所示，换算表1说明具体换算的情况。 In our motor mold clamping system, the position error e is the difference between the displacement converted from the number of pulses fed back by the quadrature encoder and the measured value of the electronic ruler, and the rate of change of the position error

It is the derivative of the former to time t, and the maximum output is the maximum speed of the motor at 2000 rpm. The precise value of the error and the rate of change of the error returned from the measurement feedback is transformed into a member of the basic variable fuzzy set, which requires a quantization scale factor or conversion table. Similarly, the output control quantity ΔK also has a proportional factor from the basic variable fuzzy domain member to the precise quantity. The conversion formula in the actual program is shown in formulas 18 and 19, and the conversion table 1 illustrates the specific conversion situation.

n _i =k _e ·e (or ) (18)

ΔK=k _ΔK ·n _i (19)

Table 1 Quantification table of fuzzy basic variables

给出： Then it is necessary to determine the membership degree of the elements in the domain of discourse of the basic variable to the variables of the fuzzy language subset, which is called the process of linguisticization. The linguistic process of the position error variable e is determined by the fuzzy relation matrix

gives:

输出控制量ΔK的语言化过程由模糊关系矩阵 

和 给出： same error rate of change

The verbalization process of the output control quantity ΔK is defined by the fuzzy relationship matrix

and gives:

论域上的模糊集为 

语言论域上的模糊集为 

则把测量进行Fuzzy语言化的过程可以用矩阵的内积表示为： Let the fuzzy set on e domain be The fuzzy set on the domain of language discourse is

The fuzzy set on the domain of discourse is

The fuzzy set on the domain of language discourse is

Then the process of fuzzy linguisticizing the measurement can be expressed by the inner product of the matrix as:

和 

分别是 

和 的转置矩阵。 

and

respectively

and The transpose matrix.

在Fuzzy语言论域上的模糊集为 

则把控制量ΔK数量化的过程可以表示为： When determining the output control quantity ΔK, quantification is the inverse transformation of Fuzzy language, and the fuzzy set on the universe of ΔK is

The fuzzy set on the domain of fuzzy language discourse is

Then the process of quantifying the control quantity ΔK can be expressed as:

(2) Design fuzzy rules

The selection of fuzzy rules is the core of designing fuzzy controllers. Fuzzy control rules are essentially a collection of fuzzy conditional statements obtained by summarizing the operator's practical experience in the control process (ie manual control strategy). Operators should carefully investigate and study, and conduct repeated experiments to make the fuzzy rules objectively reflect the laws of the control object, so as to reduce the human influence and make it meet the control requirements. And pay attention to the integrity, compatibility and interference of the rules. Table 2 is the control rule for output ΔK based on experience. the

Table 2 Control rules for ΔK

These rules achieve a good control effect in practice. These rules can be used to solve the linguistic value of the control quantity through fuzzy algorithm. Each table is composed of 56 statements, and the meaning of the statement represented by the point (i, j) in the table is:

and 

then  if

and

then

(3) Fuzzy Judgment

The output of the fuzzy controller above is a fuzzy set, and the controlled process can only accept one control quantity, which requires a precise control quantity to be determined from the output fuzzy set, that is, to design a fuzzy set to an ordinary set The mapping of is called a judgment. We use the median method (mean judgment method). The above calculation is carried out off-line, the correction value table is obtained through calculation, and the realization of model reference fuzzy adaptive control in DSP is realized by querying the correction table 3. the

Table 3 Fuzzy control correction query table of ΔK

The mold clamping mechanism is equipped with perfect mold protection measures. The cycle of injection molding is generally marked by one mold closing action, the starting position is ①, and the tightness is ⑧. During the mold clamping process, the mold clamping is performed quickly at low pressure first. When the movable platen is close to the fixed platen, it is automatically switched to low speed mold clamping. After confirming that there is no foreign matter in the cavity, it is switched to high pressure again to close the mold. During the mold clamping process, in order to prevent the mold from expanding or the material overflowing, it is necessary to apply a large mold clamping force, and the servo motor adopts torque control in this process. the

Clamping action decomposition:

1. Moving from the mold opening end position ① to the mold closing speed change position ④ is called the mold clamping speed segment 1 (where ① to ② are the displacements of the moving platen at the moment of overcoming the static friction drive, and ③ to ④ are the mold clamping speed segment 1). the

2. The mold clamping speed change position ④ moves to the mold protection position ⑥, which is called the mold clamping speed is 2 sections, which is high-speed and low-pressure movement. the

3. The mold protection position ⑥ moves to the mold contact position ⑦, which is called the mold clamping speed of 3 stages or the mold protection area. The mold position ⑥ moves to the mold contact position ⑦ by the mold protection force. If the driver detects that there is residual plastic on the end surface of the mold Not taken out, the clamping process stops and the mold is opened immediately. the

4. Insert the mold guide post into the fixed mold position ⑦ and move to the mold closing ⑧, and the servo motor applies the maximum pressure to lock the mold. the

In the locked state, the current position of the mold opening and closing shaft is ⑧. the

Mold opening action setting:

The first step, mold opening ⑧ to ⑨ is to ensure that the cooling mold cavity surface of the injection molded part is away from the guide post when the mold is opened. the

The second step, ⑨ and ⑩ is to open the mold quickly, and move at a constant speed according to the panel setting value. (11) to ① is to open the mold and stop at a slow speed, which is about 10mm smaller than the value of ① to ②. the

The third step, the position of ⑧ to ⑨ is set to the position when the guide post of the mold contacts the mold on the fixed side. the

The setting values of step 4, ⑦ to ⑧ and ⑧ to ⑨ should be the same. the

In addition, perfect mold protection measures are also required. Usually injection molds are precise and complex in structure. If there are products or residues in the mold, or if the position of the insert is not placed correctly when the insert is used, the mold will be closed according to the setting, which will damage the mold. In the all-electric injection molding machine, the mold protection is to set a detection interval near the position of the fixed mold, the motor pushes the template close to the fixed mold at a low speed and low torque, and at the same time detects whether the change of the motor load current exceeds the limit to ensure that there is no obstacle thing. the

The function of the product ejection device is to ensure that the products in the mold are ejected accurately and smoothly. Therefore, the ejector device should have sufficient and uniform ejection force, controllable ejection times, ejection speed, and sufficient adjustable ejection stroke. In this example, a ball screw ejection mechanism is used, and the ejection speed is adjusted by adjusting the motor speed. The structure of this ejection mechanism is simple, and the ejection is stable. the

The mold opening and closing motor ejector motor control device of the all-electric injection molding machine has the following characteristics: 1. The mold opening and closing mechanism adopts a five-piece hinged mold double-clamp mold clamping mechanism; 2. The ejector device of the all-electric injection machine adopts a ball screw 3. Perfect mold protection measures; 4. The servo driver is designed with PI current loop controller, PI speed loop controller, and fuzzy adaptive position controller; 5. The servo motor control program based on DSP adopts the field orientation (FOC ) control algorithm. the

Compared with the prior art, the utility model has the following advantages and effects:

1. The control system of the utility model introduces a fuzzy adaptive intelligent controller, which has high dynamic performance and static performance; the algorithm is simple, easy to analyze and generate, and is suitable for real-time control; it is suitable for various parameter changes, disturbances and uncertainties. It is not sensitive to interference and has good system robustness; it is combined with traditional control strategies (such as PID control) and has complementary advantages. the

2. The driver used in the control system of this utility model meets the control technology required by the nonlinear motion law of mold opening and closing, and various control strategies such as self-learning control, sliding mode variable structure control, and robust self-adaptive control improve the self-tuning of system parameters. Ability to ensure the stability and reliability of the system under high load conditions, while improving the compensation of disturbances. the

3. The control system of the utility model is used for control, and the stress load of the motor is eliminated, so that the ejection process completely eliminates the sudden phenomenon of stress release of the plastic product cavity and ensures the normal operation of the ejection process. the

4. The utility model adopts the combination of the TMS320F2833X microprocessor controller chip and the high-power intelligent module IPM power drive board, which meets the control requirements of the clamping force, speed and position, and adopts the control method of the utility model to realize It not only optimizes the opening and closing time of the mold, but also has a perfect mold protection function, which ensures the reliable closing of the forming mold, the realization of the opening and closing action of the mold and the accurate and stable ejection of the product from the mold. the

Description of drawings

Figure 1 is a schematic diagram of the structure of the motor mold clamping mechanism used in the all-electric injection molding machine:

Among them: 1-adjusting template; 2-toggle mechanism; 3-moving template; 4-fixed template; 5-opening and closing mold motor; 6-ejection motor; 7-ball screw; Rod; 10-fixed mold;

Figure 2-1 is the motion diagram of the double toggle mechanism used in the all-electric injection molding machine;

Figure 2-2a is the speed characteristic diagram of the double toggle mechanism used in the all-electric injection molding machine;

Figure 2-2b is the pressure characteristic diagram of the double toggle mechanism used in the all-electric injection molding machine;

Fig. 2-3a The change curve of the force amplification ratio of the double toggle five hinge mold clamping mechanism used in the all-electric injection molding machine during the entire mold clamping process;

Figure 2-3b is the magnification ratio curve of the double toggle mechanism force used in the all-electric injection molding machine;

Fig. 3 is a structural block diagram of the control system of the mold opening and closing motor of the all-electric injection molding machine of the present invention;

Fig. 4 is the schematic diagram of current, speed, position three closed-loop control methods that the control system of the present invention adopts;

Fig. 5 is the internal connection block diagram of the servo driver in the control system of the present utility model;

Fig. 6 is the connection diagram of the servo controller and the external circuit in the control system of the present utility model;

Fig. 7 is the FOC algorithm control block diagram that the control system of the present invention adopts;

Fig. 8 is the current loop control block diagram that the control system of the present invention adopts;

Fig. 9 is the speed loop control block diagram that the control system of the present invention adopts;

Fig. 10 is a block diagram of fuzzy adaptive control adopted by the control system of the present invention. the

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described. However, the embodiments of the present invention are not limited thereto. the

As shown in Figure 1, the mold clamping mechanism adopted by the all-electric injection molding machine includes three parts: the five hinged mold double toggle mold clamping mechanism, the crank slider ejector device and the control system, among which the five hinged mold double toggle The mold clamping mechanism is composed of mold opening and closing motor, adjusting platen, toggle mechanism, moving platen, moving mold, fixed mold, ejector motor, ball screw, guide rod, fixed platen, crank slider ejector is composed of ejector motor , ball screw, ejector rod, top plate, toothed pulley, belt, and movable template; one end of the mold opening and closing motor is connected to the adjusting template, the ball screw and the crosshead of the toggle mechanism, and the other end of the adjusting template is connected to the ball The screw rod is connected with the guide rod at the same time, the guide rod is also connected with the movable template and the fixed template, the movable template is connected with the toggle mechanism and the ejector rod is fixedly connected with the movable mold, and the other end of the ball screw is connected with the ejector The ejector motor, the top plate are connected to the toothed pulley, the toothed pulley drives the belt and drives the ball screw to rotate, the other end of the top plate is connected to the ejector rod, the other end of the fixed template is connected to the fixed mold, and the control system is connected to control the mold opening and closing motor and ejection motor. the

The cycle of injection molding is generally marked by one mold closing action, the starting position is ①, and the tightness is ⑧. During the mold clamping process, the mold clamping is performed quickly at low pressure first. When the movable platen is close to the fixed platen, it is automatically switched to low speed mold clamping. After confirming that there is no foreign matter in the cavity, it is switched to high pressure again to close the mold. During the mold clamping process, in order to prevent the mold from expanding or the material overflowing, it is necessary to apply a large mold clamping force, and the servo motor adopts torque control in this process. the

In addition, perfect mold protection measures are also required. Usually injection molds are precise and complex in structure. If there are products or residues in the mold, or if the position of the insert is not placed correctly when the insert is used, the mold will be closed according to the setting, which will damage the mold. In the all-electric injection molding machine, the mold protection is to set a detection interval near the position of the fixed mold, the motor pushes the template close to the fixed mold at a low speed and low torque, and at the same time detects whether the change of the motor load current exceeds the limit to ensure that there is no obstacle thing. the

The function of the product ejection device is to ensure that the products in the mold are ejected accurately and smoothly. Therefore, the ejector device should have sufficient and uniform ejection force, controllable ejection times, ejection speed, and sufficient adjustable ejection stroke. In this example, a ball screw ejection mechanism is used, and the ejection speed is adjusted by adjusting the motor speed. The structure of this ejection mechanism is simple, and the ejection is stable. the

As shown in Figure 2-1, it is the schematic diagram of the movement of the double toggle mold clamping mechanism of five hinged molds at a certain position. Its working principle is that the servo motor drives the ball screw to connect with the crosshead of the toggle mechanism, and the motor passes through The ball screw drives the crosshead to move, and the crosshead cooperates with the toggle mechanism to convert the rotary motion into linear motion in the direction of mold opening and closing. The principle of the mold closing process is: when the motor rotates forward, the mold transfer screw drives the toggle mechanism to push the template forward. When the parting surfaces of the molds are in contact, the toggle mechanism has not yet formed a line arrangement, and the movable template is subjected to deformation resistance. At this time, the rotating speed of the motor decreases and the torque increases, so that the force acting on the die-moving screw increases continuously, until it is enough to overcome the deformation stress, and the toggles are arranged in a straight line. The elastic deformation of the clamping mechanism realizes the pre-tightening of the mold, and the pre-tightening force is the clamping force. When the mold is opened, the motor reverses, and under the action of the force of the mold-moving screw, the line arrangement of the toggle is pulled down and twisted, and the movable platen is forced to separate from the fixed platen and return to the initial position before closing the mold, thereby realizing mold opening. the

During the mold closing process, the speed of the moving template is required to change according to the law of "slow-fast-slow". In the initial stage, the mold moving speed should be as slow as possible to reduce the impact of the system; during the operation, the mold moving speed should be as high as possible, so as to reduce the working cycle time and improve work efficiency; when approaching the end of the stroke, the moving speed of the movable template can be unlimited Close to O, so as to prevent the mold from being impacted by the clamping system and prolong its service life. When the mechanism moves to a certain position before the end point, the mold just hits, and the mechanism continues to move, forcing the parts of the mold clamping device to undergo elastic deformation, thereby generating a compressive force (ie, clamping force) on the mold to prevent the mold from being injected into the high-pressure melt. The cavity of the mold is opened when the body is formed. the

In Figure 2-1, the clamping servo motor pushes the crosshead, the moving platen moves forward, and L ₁ L ₂ straightens. in:

1. From the stroke S _m of the driven template, it can be seen that the stroke S _m of the toggle mechanism increases with the increase of the elbow length ratio λ and α ₁ . However, the size of the rear connecting rod L ₁ is restricted by the external dimensions of the rear formwork, generally L ₁ < L _AA /2, where L _AA is the center distance between the two hinges of the rear formwork. The size of _α1 will affect whether the mechanism can realize self-locking.

2. Piston rod stroke S _g and stroke ratio K _S

Practice has proved that K _S is between 1 and 3, the small computer takes a large value, and the mainframe takes a small value, and an excessively large K _S value will cause a shock phenomenon.

Figure 2-2a shows the speed characteristic diagram of the double toggle mechanism. As shown in Figure 2-2a and b, the mold-moving speed of the toggle-type mold clamping mechanism generally refers to its average mold-moving speed. If the friction loss is neglected, according to the principle of energy conservation, it can be known that the toggle mechanism has the characteristics of smooth speed change during the mold moving process. the

The double toggle mechanism has the characteristic of force magnification, and the force magnification M represents the relationship between the movement force P _m of the mechanism and the crosshead thrust P _O during the mold clamping process. The change curve of the force magnification ratio of the double-toggle five-hinge mold clamping mechanism during the entire mold clamping process is shown in Figure 2-3a.

The deformation force P _C changes with the α angle in a quadratic parabola law, while the mold removal force P _m has a hyperbolic relationship with α as shown in the figure. In the process of the mechanism overcoming the deformation resistance and finally realizing the mold clamping force, the driving force of the motor transmission mechanism acting on the crosshead is amplified by the double toggle mechanism to obtain the mold moving force P _m , which changes with the enlargement ratio of the mechanism, as shown in the figure As shown in 2-3b, the mold can be closed smoothly only when P _m is guaranteed to be greater than the deformation force P _C of the mechanism during the mold closing process, as shown in the tangent situation in Figure 2-3b. In fact, due to reasons such as friction and processing accuracy, the mold shifting force is usually higher than P _m1 to close the mold. Therefore, P _m1 has become the key reference basis for calculating the rated torque of the motor in our motor selection.

According to the load characteristics of the mold opening and closing motor and the ejection motor, the control system of the mold opening and closing motor and ejection motor of the all-electric injection molding machine as shown in Figure 3 is adopted, including a computer controller, a PLC controller, and the mold opening and closing and ejection drivers ;The computer controller and PLC controller control the mold opening and closing and ejection drive through the CAN network connection, and the opening and closing and ejection driver are connected to control the opening and closing motor and the ejection motor. The computer of the injection molding machine is AMDGeodeLX800. The functions of the mold opening and closing motor ejector motor control system are: the mold opening and closing motor and the ejection motor are controlled by the DSP servo driver to complete the mold opening and closing control and ejection control of the electric injection molding machine. The mold opening and closing motor and the ejection motor realize the intelligent control of the motor through the three closed-loop control of current, speed and position shown in Figure 4, and the high-speed CAN bus is used to realize the communication between the upper controller and the lower servo control system. the

In Fig. 4, the fuzzy self-adaptive control can be seen from the link of electric mold locking. The PI current loop of the motor control part serves to control the mold clamping force and limit the maximum current; the PI speed loop is responsible for controlling the mold moving speed and eliminating the speed fluctuation; The self-adaptive position ring is at the outermost, responsible for the start and stop positioning of the moving template, and its function is to ensure the static accuracy of the moving position of the moving template. In the all-electric injection molding machine, the rapid movement of the template and frequent opening and closing of the mold lead to the need for a forward and reverse switching of the motor in a few seconds, coupled with the cumulative error generated by the mechanical transmission such as screw type lead screw, etc., In addition, the mold protection also needs to detect the torque and current at a narrow position near 1.5mm before locking, so the position control is very important. the

The design of the fuzzy adaptive controller is to establish an adaptive mechanism based on the fuzzy theory. It does not require the establishment of an accurate mathematical model for the reference model and the controlled object, but only needs to simulate an experienced control worker according to the fuzzy information of the system. The fuzzy conditional statement writes the control rules, and its control function can be realized. In addition, the fuzzy algorithm is relatively simple, which is convenient for real-time control on the DSP. the

The mechanical structure of the mold clamping device determines the force and motion characteristics of the electric mold clamping object, and the control requirements of the injection molding process for the opening and closing of the mold are a bridge connecting mechanical motion and control theory. The utility model combines the mechanism characteristics and process requirements of the mold clamping device with the control theory of the servo motor, extracts a plurality of physical quantities closely related to the double toggle mold clamping mechanism and the motor drive for analysis and calculation, and designs the fuzzy control in detail device. the

In the utility model, the structure of the mold opening and closing and the ejection driver is shown in Figure 5, which is composed of a servo controller, an IPM power drive board, a current sensor, a code disc, and a switching power supply, and is electrically connected with the servo motor, wherein the servo motor In the utility model, it refers to the mold opening and closing motor and the ejector motor; the IPM power drive board is connected to the servo controller and the servo motor, the current sensor is connected to the IPM power drive board, the servo motor and the servo controller, and the code disc is connected to the servo motor and the servo motor. The controller and the switching power supply are connected to the IPM power module, current sensor, code disc and servo controller. Among them, the servo controller takes TMS320F2833X as the core, and is mainly responsible for the processing of feedback signals such as current, encoder, and alarm, the operation of motor control algorithms, the display of running status, and the realization of communication with the host computer; the power drive circuit uses IPM power The drive board is the core, and the main circuit of the power drive circuit adopts AC-DC-AC rectification and inverter circuit; the power circuit adopts switching power supply, and the multi-channel power supply obtained by transformation is supplied to the control board, and the grid of the power module controls the power supply, sensors, cooling fans, etc. use. the

As shown in Fig. 6, the hardware structural diagram of the servo controller of the mold opening and closing ejector of the utility model, the servo controller of the mold opening and closing and the ejection driver refers to the DSP control composed of the digital signal processing chip TMS320F2833X and its peripheral modules device, wherein the peripheral module includes: SCI peripheral interface, CAN bus communication module, JTAG interface, event manager EVA/B, ADC conversion module, quadrature encoder unit QEP; the chip TMS320F2833X controller one output through its The peripheral modules CAN and JTAG are respectively connected to the injection molding machine computer and the emulator, and the other output terminal is connected to the IPM module and the mold opening and closing motor in turn through the event manager EVA/B. Set the module ADC conversion module, quadrature encoder unit QEP, the ejection motor is also connected to the DSP controller through the event manager EVA/B, and the ejection motor is also connected to the peripheral module ADC of the DSP through the current sensor and the code disc Transformation module, quadrature encoder unit QEP. The servo controller of the utility model takes the TMS320F2833X chip as the core control circuit, connects the emulator and the servo motor alarm to output the positioning completion signal, connects the online monitoring through the SCI, connects the injection molding machine computer with the CAN bus, and generates the pulse through the event manager EVA/B The wide modulation signal PWM is sent to the intelligent module IPM to control the mold opening and closing motor and the ejection motor. At the same time, the opening and closing motor and the ejection motor feed back the current to the ADC through the current sensor and process it through the Clarke/Park transformation. The quadrature encoder unit QEP obtains the speed and direction information of the motor rotor based on the captured encoder signal. The servo controller of the utility model uses the MS320F2833X chip as the core control circuit, adopts the field oriented algorithm (FOC), and realizes the control of the current, speed and position of the opening and closing motor and the ejector motor.

The servo motor control program based on DSP implements a modular design according to the division of functions, including four parts, which are composed of the system initialization program module, the timer underflow interrupt service program, and the quadrature encoder interrupt processing module. The major modules are composed of multiple functionally subdivided sub-modules. The system initialization module completes the power-on self-test of the system, initializes the chip-level registers, and initializes the parameters of the servo control module. The external interrupt processing module handles the interrupt of the quadrature encoder level jump caused by the rotation of the motor. Its function is to obtain the relative position information of the rotor and calculate the speed increment. This module is an important part of the realization of the magnetic field orientation algorithm. The timer underflow interrupt service routine is the most complex and computationally intensive software module in the entire program, and the core calculations in the field-oriented algorithm are all completed here. The ZLG7290 program module is the software for managing human-computer interaction, which is responsible for displaying the operating status of the system, setting parameters and processing key events. the

The first thing after entering the main program is to block all PWM channels and make them into a high-impedance state, so that the gate state of the IPM power tube is pulled up by the pull-up resistor in the hardware circuit, that is, it is in the cut-off state. Although the PWM channel of the DSP is the I/O port of the input function by default after power-on, it will not turn on the power transistor of the IPM module in theory, but in order to avoid accidentally modifying the state of the PWM channel during the initialization process, it is It is necessary to reliably block the PWM channel. Then check whether the main circuit is normal (whether there is undervoltage, power module protection, etc.), and initialize the registers at the chip level, including SCSR, WatchDog, MCRA, IMR, IFR, etc. Then it is the initialization of the operating parameters of the servo system, such as the operating mode, the maximum allowable speed, the maximum allowable torque, and the clearing of the speed counter. After everything is normal, the nixie tube displays the first running option, the program starts and interrupts, and waits for the speed command or key. the

As shown in Fig. 7, it is a control block diagram of the field-oriented algorithm (FOC) of the present invention, the program of the field-oriented algorithm (FOC) implements a modular design, and the modules used are shown in Table 4. the

Table 4 Magnetic Field Oriented Algorithm Program Module

Each magnetic field orientation calculation is completed in sequence: stator rotor position detection, current detection, CLARKE and PARK coordinate transformation, speed loop PI adjustment, q-axis current PI adjustment, PARK inverse transformation, SVPWM generation and other steps. The event that triggers each FOC calculation is the underflow interrupt of DSP timer 1. The interrupt period is 67us, and the corresponding PWM carrier frequency is 15KHz. All calculations of the FOC algorithm are completed in the underflow interrupt program of timer 1. the

The field oriented control algorithm is discussed based on the voltage space vector theory. We decouple and correct the control variables through coordinate transformation and fuzzy and PI regulators to obtain the output quantities u _α and u _β based on the two-phase stationary coordinate system. When it needs to be modulated by DSP according to the voltage space vector theory, the PWM output acts on the grid of the power tube, which is the last link in the entire FOC calculation.

可见得到任意幅值和相位的空间矢量的关键是不断计算和更新T1、T2和T0的值。根据三角形的正弦定理有 

解得 

上 述是基于abc三相坐标系讨论的，当把UOUT、UX和UX+60投影到2相平面直角坐标系αβ中时，式 

变换成： According to formula

It can be seen that the key to obtain the space vector of arbitrary amplitude and phase is to constantly calculate and update the values of T1, T2 and T0. According to the law of sines of triangles, we have

Solutions have to

The above discussion is based on the abc three-phase coordinate system. When UOUT, UX and UX+60 are projected into the two-phase plane Cartesian coordinate system αβ, the formula

into:

$\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ {\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="t"\; filenames="HSA00000220247200011.png,HSA00000220247200012.png"\; state="\{\{state\}\}">t</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; PWM</span>}}{\left[\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; X\&alpha;</span>}}& {\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \&PlusMinus;</span>\mathrm{<span\; class="notranslate">\; 60</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}\\ {\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; X\&beta;</span>}}& {\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \&PlusMinus;</span>\mathrm{<span\; class="notranslate">\; 60</span>}\mathrm{<span\; class="notranslate">\; \&beta;</span>}}\end{array}\right]}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; OUT\&alpha;</span>}}\\ {\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; OUT\&beta;</span>}}\end{array}\right]<span\; class="notranslate">\; .</span>$

是可以离线预先计算好，然后分扇区存储成表，在实际的计算中查表就可得到。则t1和t2就可以通过式 

计算确定了。根据TPWM＝t1+t2+t0，可确定零矢量的作用时间t0＝TPWM-(t1+t2)。 Among them, once the carrier frequency of PWM is determined, Tpwm is selected in advance, and U _OUTα and U _OUTβ are the output quantities u _α and u _β of the PARK inverse transformation in the penultimate link of the FOC algorithm. And the six non-zero basic space voltage vectors are known, so the inverse matrix

It can be pre-calculated off-line, and then stored in a table by sector, which can be obtained by looking up the table in actual calculation. Then t1 and t2 can pass the formula

Calculation OK. According to TPWM=t1+t2+t0, the action time t0=TPWM-(t1+t2) of the zero vector can be determined.

Originally, for a motor without a rotor position detection device, such as an asynchronous motor, to apply SVPWM to modulate the output voltage, it is necessary to calculate the sector where UOUT is located through U _OUTα and U _OUTβ , and then to know which pair of UX and UX±60 inverses to choose from the look-up table. array to calculate. However, in the permanent magnet synchronous servo motor with rotor position feedback, you can directly know which sector the current UOUT is located in. Adding a zero vector is to follow the principle of minimizing the switching times of the power tube. There are two different ways to insert zero vectors, one is to insert zero vectors in a concentrated manner, and the other is to divide the zero vector action time into several parts and insert multiple points into one PWM cycle, but the sum of action time It is still t0. The former is good for reducing the switching times of the power tube, while the latter is good for smoothing the changing speed of flux linkage and suppressing torque ripple.

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications and substitutions made without departing from the spirit and principle of the present utility model , combination, and simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present utility model. the

Claims (3)

1. A mold opening and closing motor and ejection motor control system of an all-electric injection molding machine, connected with the mold opening and closing motor and the ejection motor, characterized in that it includes a computer controller, a PLC controller, mold opening and closing, and ejection Driver; the computer controller and the PLC controller are respectively connected to the opening and closing mold and the ejection driver signal through the CAN network, and the opening and closing mold and the ejection driver are respectively connected to the opening and closing motor and the ejection motor. 2. The mold opening and closing motor and ejection motor control system of an all-electric injection molding machine according to claim 1, wherein the mold opening and closing and ejection drivers are composed of a servo controller, an IPM power drive board, and a current sensor , a code disc and a switching power supply; the servo controller is connected to an external circuit signal; the IPM power drive board is connected to the servo controller and the servo motor; the current sensor is connected to the IPM power drive board, the servo motor and the servo controller; The code disc is connected to a servo motor and a servo controller; the switching power supply is connected to an IPM power module, a current sensor, a code disc and a servo controller; the servo motor refers to a mold opening and closing motor and an ejection motor. 3. The mold opening and closing motor and ejection motor control system of an all-electric injection molding machine according to claim 2, wherein the servo controller in the mold opening and ejection driver refers to a digital signal processing chip TMS320F2833X ; One output end of the chip TMS320F2833X is connected to the computer controller of the injection molding machine and the emulator through its own CAN bus communication module and JTAG interface, and the other output end is connected to the IPM power driver in turn through its own event manager. Plate and servo motor, the servo motor is connected to the analog-to-digital conversion module ADC of the chip through the current sensor, and the quadrature encoder unit QEP of the chip is also connected to the servo motor through the code disc; the servo motor refers to the mold opening and closing motor and ejection motor. the

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