CN113687630A

CN113687630A - Control system of medical catheter knitting machine

Info

Publication number: CN113687630A
Application number: CN202010423160.2A
Authority: CN
Inventors: 李龙
Original assignee: GUIDAOJIAOTONG POLYTECHNIC INSTITUTE
Current assignee: GUIDAOJIAOTONG POLYTECHNIC INSTITUTE
Priority date: 2020-05-19
Filing date: 2020-05-19
Publication date: 2021-11-23

Abstract

The invention discloses a control system of a medical catheter braiding machine, which comprises an air switch, an alternating current contactor unit, a switch power supply, a button unit, a sensor unit, a PLC (programmable logic controller), a touch screen, a servo driver and a servo driver wiring terminal table. The touch screen and the button unit are arranged on a control panel at the upper part of the knitting machine, and the rest parts are arranged in an electric control cabinet at the lower part of the knitting machine. The control system can realize the weaving function of the steel wire mesh in the medical interventional catheter. The touch screen can be set with a woven shape of diamond full load or diamond half load, the system can store 9 process formulas, each process formula can support 24 woven sections at most, each woven section can be independently set with PPI, the PPI means the number of diamond grids woven in each inch, and the larger the PPI value is, the denser the woven grids are. The system can be set in a continuous operation mode or a discrete operation mode, and the requirements of different production working conditions are met. The PPI precision can reach +/-1, and the segment length size precision can reach 0.01 inch.

Description

Control system of medical catheter knitting machine

Technical Field

The invention belongs to the field of production control of medical consumables, belongs to the field of servo control, and particularly relates to a precise control system for weaving a medical catheter steel wire mesh by relying on a PLC (programmable logic controller), a touch screen, a servo driver and a servo motor.

Background

With the improvement of medical technology, the use of catheters is increasing, and some medical institutions and scientific research institutes develop the catheters and also have partial patents on the catheters. However, in terms of production, the medical catheters produced are limited to low-grade catheters such as infusion sets and catheters. The method has no capability of producing high-quality and high-performance catheters. Even some manufacturers can process the product, and the quality and the performance of the product can not meet the requirements. The domestic catheter is generally a catheter without a metal wire mesh, and cannot meet the requirements of an interventional catheter in the aspects of torsion resistance, elasticity and hardness. The main reason is that the diameter of the interventional catheter is small, the processing difficulty is large, the traditional braiding machine adopts a technical route controlled by a frequency converter, the control precision cannot meet the requirement, only steel wire meshes of cables and the like can be produced, and the steel wire meshes of the interventional medical catheter cannot be braided.

Disclosure of Invention

Aiming at the defects of the existing braiding machine, a technical route of a medical catheter braiding machine based on a PLC, a touch screen, a servo driver and a servo motor is provided. The stainless steel wire mesh is woven on the mandrel, and the woven stainless steel wire mesh is added into the medical catheter, so that the technical parameters of torsion resistance, elasticity and hardness of the medical catheter are improved. The knitting machine may be provided with 9 process recipes, each recipe may store 24 knitted sections, and the PPI of each knitted section may be set independently. The PPI precision can reach +/-1, and the length dimension precision of each section of the woven mesh can reach 0.01 inch.

In order to achieve the purpose, the technical scheme of the invention is as follows: the system comprises an air switch, an alternating current contactor unit, a switching power supply, a button unit, a sensor unit, a PLC, a touch screen, a servo driver 1, a servo driver 2, a servo driver wiring terminal table 1 and a servo driver wiring terminal table 2. The touch screen and the button unit are arranged on a control panel at the upper part of the knitting machine, and the rest parts are arranged in an electric control cabinet at the lower part of the knitting machine. The control system can realize the weaving function of the steel wire meshes in various medical catheters. The touch screen can be set with a woven shape of diamond full load or diamond half load, the system can store 9 process formulas, each process formula can support 24 woven sections at most, each woven section can be independently set with PPI, the PPI means the number of diamond grids woven in each inch, and the larger the PPI value is, the denser the woven grids are. The system can be set in a continuous operation mode or a discrete operation mode, and the requirements of different production working conditions are met. The PPI precision can reach +/-1, and the segment length size precision can reach 0.01 inch. The formula set on the touch screen is stored in a power-off holding register of the PLC, so that the formula can be stored for a long time after being set. The PPI control of the mesh grid is controlled by the power frequency output by the servo driver 1 and the servo driver 2, the pulling speed required by the set PPI and the set shuttle disk speed is calculated in real time in the PLC, and the calculated pulse frequency is output by Y0 and Y1 to control the output of the servo driver so as to control the speed of the servo motor. The shuttle shaft controlled by the servo driver 1 is responsible for weaving the metal wire, the pulling shaft controlled by the servo driver 2 is responsible for moving the metal wire mesh in the horizontal direction, and the moving speed of the pulling shaft determines the size of the PPI, namely: the faster the pulling shaft is running, the larger the woven wire mesh and the smaller the PPI. The PPI can therefore be controlled by controlling the speed of the pulling shaft relative to the shuttle shaft. The length control of each section of wire mesh is realized by reading the running length data of each section stored in a formula by a PLC to calculate the corresponding pulse output number, and the section weaving length of the woven mesh is only controlled by the high-speed pulse output by a Y1 port of the PLC, namely the section length is completely controlled by the running distance of the pulling shaft. Other weaving technical parameters of the metal wire mesh are designed by a PLC internal program according to a program flow chart.

The invention has the advantages that:

the medical catheter braiding machine control system is compact in structure, the electric control cabinet is compact in size, and the length, the width and the depth are 600 x 550 x 240 mm. The selected PLC and servo driver have excellent performance and low cost. The system has a visual operation interface, 9 process formulas can be set on the touch screen, process parameters of different types of products can be stored conveniently, and production efficiency is improved. Each process formula supports at most 24 braided sections with different lengths, each braided section can be independently provided with PPI, and whether each braided section is suspended after being finished and whether transition is needed between the two braided sections can be set. The machine mode can be selected to be a knitting machine or a winding machine on the touch screen, and the operation mode can be selected to be continuous operation or discrete operation. The positions of the shuttle disk shaft and the pulling shaft can be manually adjusted on the touch screen, and the parameters of the servo driver can also be manually adjusted on the touch screen. The PPI precision of the woven and formed metal wire mesh can reach +/-1, the length dimension error of each woven section is 0.01 inch, and the woven and formed metal wire mesh can meet the weaving requirements of various types of metal wire meshes for catheters.

Drawings

Fig. 1 is a block diagram of the control system of the medical catheter braiding machine according to the present invention, and the components are shown in the figure.

Fig. 2 is a mechanical schematic diagram of a medical catheter braiding machine.

Fig. 3 is a flow chart of a main program of a control system of the knitting machine.

Figure 4 is a flow diagram of an operator level subroutine in a knitting machine control system.

Fig. 5 is a flow chart of a knitting machine operation control subroutine in the knitting machine control system.

Detailed Description

As shown in fig. 1, a control system of a medical catheter braiding machine includes an air switch, an ac contactor unit, a switching power supply, a button unit, a sensor unit, a PLC, a touch panel, a servo driver 1, a servo driver 2, a servo driver terminal block 1, and a servo driver terminal block 2.

As shown in fig. 2, the button unit and the touch screen are mounted on the control panel in a screw fixing manner. The air switch, the alternating current contactor unit, the switching power supply, the PLC servo driver 1, the servo driver 2, the servo driver wiring terminal table 1 and the servo driver wiring terminal table 2 are all installed in an electric control cabinet of a control system of the knitting machine in a guide rail installation mode. The work flow of the whole system is as follows: and opening the change-over switch in the button unit to the direction of opening the puller, penetrating the spindle out of the hole in the shuttle disc shaft until the spindle penetrates through the puller, and opening the change-over switch in the button unit to the direction of closing the puller. And (3) manually winding the 16 weaving wires on the shuttle disk on a mandrel, and fixing the 16 weaving wires by using an adhesive tape. The type, the knitting mode, the operation mode, the number of sections, the length of each section, PPI of each section, whether section end pause is needed or not, whether transition between sections is needed or not and the like are set on the touch screen. After necessary parameters required by the operation of the knitting machine are set, the green starting button on the button unit is pressed twice, the knitting machine can be started to operate, and the knitting machine is automatically stopped after the knitting machine operates to the set length required by the technological parameters, so that one-time knitting is completed. The length of the segment set on the touch screen and the PPI and other parameter formulas of each segment are stored in a power-off holding register of the PLC, so that the formulas can be stored for a long time after being set. The PPI control of the mesh grid is controlled by the power frequency output by the servo driver 1 and the servo driver 2, the pulling shaft speed required by the set PPI and the set shuttle disk shaft speed is calculated in real time in the PLC, and the calculated pulse frequency is output by Y0 and Y1 to control the output of the servo driver so as to control the speed of the servo motor. The shuttle disc shaft controlled by the servo driver 1 is responsible for knitting the knitting wire, the pulling shaft controlled by the servo driver 2 is responsible for moving the wire mesh in the horizontal direction, and the moving speed of the pulling shaft determines the size of the PPI, namely: the faster the pulling shaft is running, the larger the braided wire mesh and the smaller the PPI. The PPI can therefore be controlled by controlling the speed of the pulling shaft relative to the shuttle shaft. The length control of each section of wire mesh is realized by reading the running length data of each section stored in a formula by a PLC to calculate the corresponding pulse output number, and the section weaving length of the woven mesh is only controlled by the high-speed pulse output by a Y1 port of the PLC, namely the section length is completely controlled by the running distance of the pulling shaft. Other weaving technical parameters of the metal wire mesh are designed by a PLC internal program according to a program flow chart. The PLC program flow chart is shown in fig. 3 to 5.

As shown in fig. 3, it is a flow chart of the main program of the control system of the knitting machine. And inputting an account number and a password on the touch screen, and judging whether the current login level is an operator level, a maintainer level or an engineer level by the PLC program according to the login level transmitted by the touch screen. And then the control program moves to enter the corresponding subprogram.

As shown in fig. 4, is an operator level subroutine flowchart. After entering the operator level subprogram, firstly judging a page pointer of the touch screen, if the page pointer is currently positioned in an equipment adjusting interface, judging whether jog signals of a shuttle disk and a pulling shaft exist, and if the jog signals exist, operating according to the jog signals. The jog speed of the shuttle disk is 1.5r/s, and the jog speeds of the pulling shaft in the forward direction and the pulling shaft in the backward direction are both 1.0 r/s. If there is a return signal, the routine returns to the beginning of the subroutine. If the touch screen page is located on the formula loading page, the selected formula and the formula number can be stored in the memory of the PLC when the loading signal is available. Then judging whether the touch screen is in an operation control page, if so, continuously judging whether input signals of a start button, an emergency stop button and a pause button exist, and if so, stopping all output; if the pause signal blocks the existing output, jumping to an empty program, if the pause signal disappears, returning to a breakpoint before pause, and continuing to execute the unfinished program. If only the starting signal is effective, the position 1 of the state mark is prepared, whether the starting signal exists again within 5 seconds is judged, and if the starting signal exists, the knitting machine operation control subprogram is entered; if there is no more start signal, then the timeout flag position 1 will be started.

As shown in fig. 5, a flow chart of the knitting machine operation control subroutine is shown. After entering the knitting machine operation control subprogram, reading the currently loaded formula, the shuttle disk operation speed set value and the current knitting section, and when the program is executed for the first time, the current knitting section n is 1, namely knitting is started from the first knitting section. And then, calculating a pulse frequency value required by the shuttle disc shaft, calculating a pulse frequency value of an nth pulling shaft according to the PPI of the current section, and calculating the number of pulses which are output by the PLC output end corresponding to the current pulling shaft according to the length value of the nth section. Then, the high-speed pulse outputs of Y0 and Y1 of the PLC are enabled, and the corresponding servo driver activation signals are enabled, thereby controlling the knitting machine to start knitting the wire mesh for medical catheters. And in each scanning period, judging whether the Y1 pulse output is finished, if the Y1 pulse output is not finished, continuing the output, if the pulse output is finished, judging whether the end of the segment needs to be paused, and if the pause is needed, calling an idle program to keep paused. And under the pause state, judging whether a starting signal exists or not, if so, automatically increasing the current section n of the weaving section, and repeating the above process to start weaving the next section. In the suspend state, if there is no start signal, the current state is maintained. If the last section does not need to be paused, judging whether the current weaving section is the last weaving section, if not, continuously judging whether the transition is needed between the last section and the initial section of the next section, and if the transition is not needed, directly starting to weave the next section. If a transition is required, the PPI of the transition segment is first calculated from the PPIs of the current and next segments, and the algorithm is the average of the two. And calculating the pulse number required to be output by Y1 in the transition process and the corresponding pulse output frequency according to the transition length in the formula, and then enabling the pulse output of Y0 and Y1 and a starting signal of a servo driver. And judging whether the output of the pulse train is finished or not in the output process of the Y1, if not, outputting the pulse train, and if so, increasing the current weaving section n and starting to weave the next section. In the last decision condition, if the current knitting section is judged to be the last knitting section, then it is judged whether the current knitting machine operation mode is the continuous operation mode, if so, the current knitting section n is assigned to 1, and the knitting is resumed from the first section. If it is determined that the knitting machine operation mode is not the continuous mode, i.e. the knitting machine is operating in the discrete operation mode, it is continuously determined whether the knitting machine is in the loop mode or the length mode in the discrete mode. If the pattern is the loop pattern, then judging whether the current loop is the last loop, if so, ending the whole knitting process. If not the last turn, the number of turns is increased by 1, n is assigned to 1, and the next turn is knitted starting from the first segment. If the length mode is adopted, whether the current running total length is larger than or equal to the running length set value is judged, and if the running total length is larger than or equal to the running length set value, the whole weaving process is ended. If not, n is assigned to 1 and weaving continues from the first segment.

And the maintenance level subprogram can create and store a formula and check the input and output states of the PLC on the basis of the operator subprogram.

And the engineer level subprogram can delete the formula and create the formula of a newly developed product on the basis of the maintainer level subprogram, and can check all state feedback values.

Claims

1. A control system of a medical catheter braiding machine is characterized in that: the system comprises an air switch, an alternating current contactor unit, a switching power supply, a button unit, a sensor unit, a PLC, a touch screen, a servo driver and a servo driver wiring terminal table, wherein the touch screen and the button unit are arranged on a control panel at the upper part of a knitting machine, the rest parts of the touch screen and the button unit are arranged in an electric control cabinet at the lower part of the knitting machine, the control system can realize the knitting function of a steel wire mesh in various medical catheters, the knitting shape of the touch screen can be set to be rhombic full load or rhombic half load, the system can store 9 process formulas, at most 24 knitting sections can be supported by each process formula, each knitting section can be independently provided with the PPI, the PPI meaning is the number of rhombic meshes knitted in each inch, the larger the PPI value is, the denser the system can be provided with a continuous operation mode or a discrete operation mode, the requirements of different production working conditions are met, and the PPI precision can reach +/-1, the segment length dimensional accuracy can be up to 0.01 inch.

2. The medical catheter braiding machine control system of claim 1, wherein: the air switch is arranged in an electric control cabinet, is a main switch for supplying power to the whole control system, is supplied with alternating-current 220V power frequency electricity, can realize short-circuit protection, overcurrent protection and overload protection, and has the following types: C65N-C20-3P,20A, the manufacturer is Meilanylang.

3. The medical catheter braiding machine control system of claim 1, wherein: the ac contactor unit includes two ac contactors KM1 and KM2, KM1 is responsible for power supply control of the servo driver 1, KM2 is responsible for power supply control of the servo driver 2, and the types of the ac contactor unit are as follows: LC1-D0601M5N, manufacturer TEL.

4. The medical catheter braiding machine control system of claim 1, wherein: the button unit comprises 5 buttons and 1 selector switch, wherein the 5 buttons are respectively a green start button, a red stop button, a yellow inching button, a black pause button and a red emergency stop button, the switches are 3 reset self-reset selector switches, and the green start button has the functions of: according to the first time, the system is in a preparation state, and the system is started and operated according to the second time, and the type is as follows: XB4-BA31, GN, 1NO, the function of the red stop button is: the button system is pressed down to decelerate and stop, the process is finished, and the model is as follows: XB4-BA42, RD, 1NC, the function of the yellow jog button is: the button is pressed, the shuttle disk and the pulling shaft run at a low speed, the shuttle disk and the pulling shaft are respectively dragged by servo motors driven by a servo driver 1 and a servo driver 2, the running speed is 1.5 revolutions per second, the button is released, the system stops, and the black pause button has the functions of: the first time the button is pressed, the system is in a pause state, 2 servo motors stop running, the second time the button is pressed, the system resumes running, the 2 servo motors continue running according to the established speed and the unfinished running distance before pause, and the red scram button has the functions of: pressing the button stops all output, all equipment stops running, releasing the button, pressing the start button again can start the system running, and the function of the selection switch is as follows: and opening the puller to the left position, and closing the puller to the right position.

5. The medical catheter braiding machine control system of claim 1, wherein: the sensor unit comprises 1 safety door switch detector and 1 broken wire detection switch, and the functions of the safety door switch detector are as follows: the emergency exit is closed, and its normally open contact is closed, gives PLC with this signal transmission, judges the basis that the emergency exit has closed as PLC, and disconnected silk detection switch's function is: the stainless steel wire for weaving is broken, the normally open contact is closed, the signal is transmitted to the PLC and used as the basis for judging the wire breakage of the PLC, and then the system is stopped.

6. The medical catheter braiding machine control system of claim 1, wherein: the types of the PLC are as follows: FX3GA-40MT-CM, with 24 inputs, 16 outputs, functions as: the control core of the whole knitting machine system is characterized in that a button unit and a sensor unit are connected as input ends of the control core of the whole knitting machine system and used as command signal sources, a state indicator lamp is connected as output ends, a pulse signal input end of a servo driver, a starting signal end and a reset signal end of the servo driver, a high-speed output pulse signal at a Y0 end controls the output frequency and the walking distance of a servo motor 1 driven by the servo driver 1, a high-speed output pulse signal at a Y1 end controls the output frequency and the walking distance of a servo motor 2 driven by the servo driver 2, a control program is stored in a PLC, and a control program flow chart is shown in fig. 3 to fig. 5.

7. The medical catheter braiding machine control system of claim 1, wherein: the touch screen is GS 2107-WTWD in size of 7 inches, is arranged on a control panel at the upper part of the knitting machine, and is mainly used for inputting formula parameters, selecting the type and the working mode of the knitting machine, monitoring the running state and the like.

8. The medical catheter braiding machine control system of claim 1, wherein: the servo driver comprises two servo drivers, namely a servo driver 1 and a servo driver 2, wherein the types of the servo driver 1 and the servo driver 2 are as follows: MR-JE-40A, the servo driver 1 is used for receiving the high-speed pulse sent by the output Y0 of the PLC, controlling the servo motor 1 to rotate at a preset speed and angle according to the frequency and the number of the high-speed pulse to complete the rotation of the shuttle disk, the servo driver 2 is used for receiving the high-speed pulse sent by the output Y1 of the PLC and controlling the servo motor 2 to rotate at a preset speed and angle according to the frequency and the number of the high-speed pulse to complete the movement of the pulling shaft when working in a position control mode, and the servo driver 2 is used for receiving 10000 pulses to control the servo motor 2 to rotate at a circle when working in the position control mode.

9. The medical catheter braiding machine control system of claim 1, wherein: the servo driver wiring terminal block comprises 2 wiring terminal blocks which are respectively a servo driver wiring terminal block 1 and a servo driver wiring terminal block 2, the main function of the servo driver wiring terminal block 1 is to lead out a wiring terminal of CN1 of the servo driver 1, one part of the led-out wiring terminal is connected with the input of a PLC, the other part of the led-out wiring terminal is connected with the output of the PLC, the main function of the servo driver wiring terminal block 2 is to lead out a wiring terminal of CN1 of the servo driver 2, one part of the led-out wiring terminal is connected with the input of the PLC, and the other part of the led-out wiring terminal is connected with the output of the PLC.

10. The medical catheter braiding machine control system of claim 1, wherein: the switching power supply is characterized in that the model is as follows: G2/S-150-24/6.5A, the manufacturer is Taiwan Ming latitude, and the product is used as an input driving power supply of a PLC, a 24V output driving power supply of the PLC and a 24V power supply of a touch screen.