Stepping motor control method, device and equipment for coating die head

Abstract

The invention provides a stepping motor control method, device and equipment for a coating die head, and relates to the technical field of coating control, and the method comprises the steps: obtaining a first coating control parameter sent by an upper computer, a state parameter of a stepping motor at the current moment, and a two-phase current of the stepping motor in a two-phase static coordinate system; determining a control reference amount based on a deviation between the state parameter and the configured position control amount; according to the state parameters and the control reference quantity, converting the two-phase current under the two-phase static coordinate system to obtain two-phase voltage of the stepping motor under the two-phase static coordinate system; generating a second coating control parameter according to the two-phase voltage of the stepping motor under the two-phase static coordinate system; and based on the first coating control parameter and the second coating control parameter, a stepping motor of the coating die head is controlled to move at the next moment. According to the application, the upper computer is used for simultaneously controlling the stepping motor control system of the plurality of coating die heads through the CAN bus, so that the space utilization rate and the control precision of the stepping motors of the coating die heads are improved.

Description

Technical Field

[0001] The present application relates to the field of coating control technology, and in particular to a stepper motor control method, device and equipment for a coating die head. Background Art

[0002] Slot extrusion coating is a high-precision coating technology. Its working principle is to transfer the slurry to the substrate by squeezing it out along the slit of the coated wood at a certain flow rate. Compared with other coating methods, it has many advantages, such as fast coating speed, high coating efficiency, and uniform moisture thickness. Adding closed-loop control to the coating system can prevent pollutants from entering during the coating process, increase the slurry utilization rate, keep the slurry uniformly coated, and adjust different slurry viscosities and solid contents.

[0003] The existing coating die head is composed of an upper die head, a lower die head, a flow regulating mechanism and a gasket sandwiched therein. The height of the gasket can determine the thickness of the coated slurry. During the coating process, due to the influence of the slurry's own temperature and viscosity, the coating effect thickness will be uneven. Therefore, it is necessary to introduce a CAN bus-based stepper motor closed-loop control system.

[0004] At present, the slurry thickness is mainly controlled by adjusting the height of the gasket to adjust the coating gap through the open-loop stepper motor set on the coating die head. However, the open-loop stepper motor adjustment has the characteristics of poor responsiveness, low precision, low torque, etc., which easily leads to the inability to accurately position and adjust, the adjustment time is too long and requires manual judgment, the adjustment error is large, and the adjustment is often not in place or excessive, resulting in uneven coating thickness and poor coating quality, which is not conducive to automated production; and the coating die head adjustment mechanism based on the open-loop stepper motor does not introduce position calibration, and cannot better form feedback on the current position of the stepper motor to improve the accuracy of adjustment; nor does it introduce a closed-loop control system, and cannot control the three loops of the motor position loop, speed loop, and torque loop in series. When introducing different load changes, it cannot adapt to the changing slurry, which will make the open-loop stepper motor prone to step loss and torque inertia reduction.

[0005] The existing coating die head motor control cannot achieve one-to-many high-response communication, so the motor cannot quickly receive instructions from the operating end, affecting the adjustment accuracy. Summary of the invention

[0006] The purpose of the embodiments of the present application is to provide a stepper motor control method, device and equipment for a coating die head, so as to solve the above-mentioned problems existing in the prior art, and to use a host computer to simultaneously control the stepper motor control systems of multiple coating die heads through a CAN bus, thereby improving space utilization and control accuracy of the stepper motor of the coating die head.

[0007] In a first aspect, a stepper motor control method for a coating die head is provided, which is applied to a stepper motor control system corresponding to each coating die head, and multiple stepper motor control systems are connected to a host computer through a CAN bus; the stepper motor control system is used to control the movement of the stepper motor of the corresponding coating die head; the method may include:

[0008] Acquire the first coating control parameter sent by the host computer, as well as the state parameters of the stepper motor at the current moment and the two-phase current in the two-phase stationary coordinate system;

[0009] Determining a control reference amount based on a deviation between the state parameter and a configured position control amount;

[0010] According to the state parameter and the control reference, the two-phase current in the two-phase stationary coordinate system is converted to obtain the two-phase voltage of the stepper motor in the two-phase stationary coordinate system;

[0011] generating a second coating control parameter according to the two-phase voltage of the stepping motor in a two-phase stationary coordinate system;

[0012] Based on the first coating control parameter and the second coating control parameter, the stepping motor of the coating die head is controlled to move at the next moment.

[0013] In an optional implementation, the state parameters include: displacement, rotation speed and electrical angle;

[0014] The displacement is acquired by using a pre-calibrated displacement sensor;

[0015] The rotation speed and electrical angle are calculated based on the angle value of the stepper motor measured by the angle sensor.

[0016] In an optional implementation, determining a control reference amount based on a deviation between the state parameter and a configured position control amount includes:

[0017] Performing PID operation on the displacement and the position control amount to obtain a speed reference;

[0018] A PID operation is performed on the rotation speed and the speed reference to obtain a control reference.

[0019] In an optional implementation, converting the two-phase current in the two-phase stationary coordinate system according to the state parameter and the control reference to obtain the two-phase voltage of the stepper motor in the two-phase stationary coordinate system includes:

[0020] Converting the two-phase currents in the two-phase stationary coordinate system to obtain converted two-phase currents;

[0021] Based on the converted two-phase current and the electrical angle, obtaining the two-phase current of the stepper motor in a synchronous rotating coordinate system;

[0022] Based on the control reference and the two-phase current of the stepper motor in the synchronous rotating coordinate system, the two-phase voltage of the stepper motor in the two-phase stationary coordinate system.

[0023] In an optional implementation, the two-phase current of the stepper motor in the synchronous rotating coordinate system includes: a direct-axis current and a quadrature-axis current;

[0024] Based on the control reference and the two-phase current of the stepper motor in the synchronous rotating coordinate system, determining the two-phase voltage of the stepper motor in the two-phase stationary coordinate system includes:

[0025] Inputting the direct-axis current into a pre-built PI proportional-integral controller to obtain a direct-axis voltage;

[0026] Inputting the control reference and the quadrature-axis current into the PI proportional-integral controller to obtain the quadrature-axis voltage;

[0027] The direct-axis voltage and the quadrature-axis voltage are subjected to an inverse Park transformation to obtain two-phase voltages of the stepper motor in a two-phase stationary coordinate system.

[0028] In an optional implementation, generating a second coating control parameter according to the two-phase voltage of the stepper motor in a two-phase stationary coordinate system includes:

[0029] Converting the two-phase voltage of the stepper motor in a two-phase stationary coordinate system to obtain a pulse signal;

[0030] Processing the pulse signal using a two-phase inverter to generate a PWM signal;

[0031] Based on the PWM signal, a second coating control parameter is generated.

[0032] In an optional implementation, an adjustment block is provided in the coating die head; the stepping motor is used to control the movement of the adjustment block;

[0033] The displacement sensor calibration method comprises:

[0034] Transmitting the configured intermittent displacement command to the stepper motor via the CAN bus to control the movement of the adjustment block;

[0035] For any moment after the stepper motor receives the intermittent displacement command, a first displacement amount and a second displacement amount at the moment are obtained; wherein the first displacement amount is obtained by reading the detection value of the displacement sensor; and the second displacement amount is obtained by reading the detection value of the calibration sensor pre-set on the adjustment block;

[0036] Taking the difference between the first displacement and the second displacement as the displacement deviation of the displacement sensor at the moment;

[0037] Fitting the displacement deviation of the displacement sensor at each moment to obtain a linear function of the displacement deviation;

[0038] The displacement deviation linear function is used to calibrate the detection value of the displacement sensor to obtain a calibrated displacement sensor.

[0039] In a second aspect, a stepper motor control device for a coating die head is provided, and the device may include:

[0040] An acquisition unit is used to acquire the first coating control parameter sent by the host computer, as well as the state parameters of the stepper motor at the current moment and the two-phase current in the two-phase stationary coordinate system; the host computer is connected to multiple stepper motor control systems through a CAN bus; each stepper motor control system corresponds to a coating die head; the stepper motor control system is used to control the movement of the stepper motor of the coating die head;

[0041] a determining unit, configured to determine a control reference amount based on a deviation between the state parameter and a configured position control amount;

[0042] A conversion unit, configured to convert the two-phase current in the two-phase stationary coordinate system according to the state parameter and the control reference, so as to obtain the two-phase voltage of the stepping motor in the two-phase stationary coordinate system;

[0043] A generating unit, used for generating a second coating control parameter according to a two-phase voltage of the stepping motor in a two-phase stationary coordinate system;

[0044] A control unit is used to control the movement of the stepper motor of the coating die head at a next moment based on the first coating control parameter and the second coating control parameter.

[0045] In a third aspect, an electronic device is provided, the electronic device comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0046] Memory, used to store computer programs;

[0047] The processor is used to implement any method step described in the first aspect when executing the program stored in the memory.

[0048] In a fourth aspect, a computer-readable storage medium is provided, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, any method step described in the first aspect is implemented.

[0049] This application utilizes a host computer to send and receive commands for a pair of multiple stepper motor control systems based on the CAN bus protocol. A set of command protocols can be used to adjust the different spacing of the single motor actions of the entire coating die head, which is conducive to the application of coating conditions of different widths and thicknesses and reduces the use of repeated wiring and cables, optimizes the lines, reduces wiring costs, and improves space utilization.

[0050] The present application utilizes a pre-calibrated displacement sensor to collect the displacement of the stepper motor, performs compensation according to different situations, and improves the linear relationship of the displacement; it can reduce the error generated during assembly of the mechanical structure and improve the closed-loop position accuracy of the stepper motor of the coating die head.

[0051] This application adopts a stepper motor vector control algorithm, which obtains the phase current and electrical angle in real time, performs inverse Park transformation and PI adjustment controller, calculates the voltage required at the next moment and then combines it with the SVPWM algorithm; it can not only reduce the coating die structure space and improve space utilization, but also greatly improve the various performance of the motor, so that the uniformity of the coating slurry is guaranteed to a certain extent; it can also improve the utilization rate of the torque generated by the current magnetic field, thereby improving the responsiveness of the stepper motor, increasing the torque, and the adjustment error can reach ±1um, thereby improving the coating production efficiency and the uniformity of the coating thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 A coating control system architecture diagram provided in an embodiment of the present application;

[0054] Figure 2 A flow chart of a stepper motor control method for a coating die head provided in an embodiment of the present application;

[0055] Figure 3 A schematic diagram of a stepper motor control of a coating die head provided in an embodiment of the present application;

[0056] Figure 4 A schematic diagram of the structure of a stepper motor control device for a coating die head provided in an embodiment of the present application;

[0057] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] The stepper motor control method of the coating die head provided in the embodiment of the present application can be applied to Figure 1 In the coating control system architecture shown, the coating control system includes a host computer and multiple stepper motor control systems; each stepper motor control system corresponds to a coating die head; multiple stepper motor control systems are connected to the host computer via a CAN bus;

[0060] The host computer is used to generate the first coating control parameter of each coating die head based on the target coating parameters of different coating die heads;

[0061] A stepper motor control system is arranged on a driving board; it is used to control the movement of the stepper motor of the corresponding coating die head; the stepper motor control system includes: a main control chip and a stepper motor drive component; the stepper motor drive component includes a displacement unit, a temperature unit and a speed unit; the displacement unit is used to receive a detection signal from a displacement sensor arranged on the stepper motor; the speed unit is used to receive a detection signal from an angle sensor arranged on the stepper motor.

[0062] In the embodiments of the present application, the target coating parameters of different coating dies may be the same or different; when the target coating parameters of different coating dies are different, that is, different coating dies of the same coating device have different coating parameters during the coating process; the host computer receives and sends commands for a pair of multiple stepper motor control systems based on the CAN bus protocol, and a set of command protocols can be used to adjust the different spacing of the single motor action of the entire coating die, which can be used for coating conditions of different widths and thicknesses and reduce repeated wiring, thereby improving space utilization.

[0063] In the embodiment of the present application, each coating die head is provided with a stepper motor, which is used to control the movement of the adjustment block on the coating die head; the stepper motor is provided with an angle sensor connected to the drive board, and the angle sensor is used to read the angle value of the stepper motor.

[0064] In one embodiment of the present application, the model of the main control chip can be STM32G431; the model of the angle sensor can be the magnetic encoder MTC6835 chip.

[0065] In one embodiment of the present application, the magnetic encoder MTC6835 chip is placed directly below the central shaft of the stepper motor. A circular magnet is attached to the bottom of the central shaft of the stepper motor. The magnetic field changes when the stepper motor rotates, and the ABZ encoder signal is output to the STM32G431 main control chip.

[0066] In one embodiment of the present application, the displacement sensor is a calibrated LVDT-L9001-2.5W displacement sensor.

[0067] The preferred embodiments of the present application are described below in conjunction with the drawings in the specification. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In addition, the embodiments and features in the embodiments of the present application may be combined with each other if there is no conflict.

[0068] Figure 2 The following is a schematic flow chart of a stepper motor control method for a coating die head provided in an embodiment of the present application. Figure 2 As shown, the method may include:

[0069] Step S210, obtaining the first coating control parameter sent by the host computer, as well as the state parameters of the stepper motor at the current moment and the two-phase current in the two-phase stationary coordinate system; determining the control reference quantity based on the deviation between the state parameters and the configured position control quantity.

[0070] In the embodiment of the present application, the first coating control parameter is generated by the host computer based on the target coating parameters of different coating dies.

[0071] In an embodiment of the present application, the state parameters of the stepper motor at the current moment include: displacement, rotational speed and electrical angle; specifically, the displacement is collected using a pre-calibrated displacement sensor; the rotational speed and electrical angle are calculated based on the stepper motor angle value measured by the angle sensor.

[0072] In practical applications, since the displacement sensor itself has certain errors and cannot meet the accuracy requirements of the coating process, the displacement sensor must be calibrated and then used to measure the displacement to obtain accurate displacement, thereby improving the accuracy of the position closed-loop adjustment.

[0073] In an embodiment of the present application, a method for calibrating a displacement sensor includes:

[0074] The intermittent displacement command configured by CAN bus transmission is sent to the stepper motor to control the movement of the adjustment block; for any moment after the stepper motor receives the intermittent displacement command, the first displacement amount and the second displacement amount at the moment are obtained; the difference between the first displacement amount and the second displacement amount is used as the displacement deviation amount of the displacement sensor at the moment; the displacement deviation amount of the displacement sensor at each moment is fitted to obtain a displacement deviation linear function; the displacement deviation linear function is used to correct the detection value of the displacement sensor to obtain a calibrated displacement sensor.

[0075] In the embodiment of the present application, after calibration, the displacement sensor displacement deviation linear function and corresponding compensation parameters are stored in the main control chip, thereby compensating the real-time data of the displacement sensor.

[0076] In the embodiment of the present application, the first displacement is obtained by reading the detection value of the displacement sensor; the second displacement is obtained by reading the detection value of the calibration sensor pre-set on the adjustment block.

[0077] In the embodiment of the present application, the calibration sensor uses a displacement sensor with higher accuracy than the displacement sensor; specifically, the displacement sensor can use an LVDT-L9001-2.5W displacement sensor; the calibration sensor can use a GT2-H12K displacement sensor.

[0078] In practical applications, the angle value of the stepper motor measured by the angle sensor is actually the mechanical angle, while the electrical angle is an angle related to the electrical characteristics of the stepper motor. Therefore, the result measured by the angle sensor cannot be directly applied to the control of the stepper motor. The electrical angle and speed need to be calculated based on the mechanical angle. Specifically, electrical angle = mechanical angle * number of pole pairs of the stepper motor; speed = change in mechanical angle per unit time / time interval.

[0079] The stepper motor control method of the coating die head of the present application converts the control problem of the stepper motor into controlling the two-phase rotating current; the two-phase current of the stepper motor in the two-phase stationary coordinate system at the current moment can be obtained by phase current sampling and collection; the two-phase current of the stepper motor in the two-phase stationary coordinate system at the current moment is the two-phase current Iα and Iβ in the α-β coordinate system of the stepper motor.

[0080] In the embodiment of the present application, the control reference quantity is determined based on the deviation between the state parameter and the configured position control quantity, including:

[0081] The displacement and position control quantity are subjected to PID operation to obtain the speed reference quantity; the rotation speed and speed reference quantity are subjected to PID operation to obtain the control reference quantity.

[0082] In the embodiment of the present application, a plurality of PI proportional-integral controllers arranged on a main control chip may be used to perform PID calculations.

[0083] Step S220: convert the two-phase current in the two-phase stationary coordinate system according to the state parameter and the control reference quantity to obtain the two-phase voltage of the stepper motor in the two-phase stationary coordinate system.

[0084] In the embodiment of the present application, the two-phase current in the two-phase stationary coordinate system is converted according to the state parameter and the control reference quantity to obtain the two-phase voltage of the stepper motor in the two-phase stationary coordinate system, including:

[0085] The two-phase current in the two-phase stationary coordinate system is converted to obtain the converted two-phase current; based on the converted two-phase current and the electrical angle, the two-phase current of the stepper motor in the synchronous rotating coordinate system is obtained; based on the control reference and the two-phase current of the stepper motor in the synchronous rotating coordinate system, the two-phase voltage of the stepper motor in the two-phase stationary coordinate system is obtained.

[0086] In an embodiment of the present application, a method for determining two-phase currents of a stepper motor in a synchronous rotating coordinate system includes:

[0087] The two-phase current in the two-phase stationary coordinate system is subjected to Park transformation to obtain the converted two-phase current; the converted two-phase current is combined with the electrical angle to obtain the two-phase current Id (i.e., direct-axis current) and Iq (i.e., quadrature-axis current) of the stepper motor in the synchronous rotating coordinate system (i.e., dq coordinate system).

[0088] In the embodiment of the present application, based on the control reference and the two-phase current of the stepper motor in the synchronous rotating coordinate system, the two-phase voltage of the stepper motor in the two-phase stationary coordinate system includes:

[0089] In an embodiment of the present application, based on a control reference and two-phase currents of the stepper motor in a synchronous rotating coordinate system, determining the two-phase voltage of the stepper motor in a two-phase stationary coordinate system includes:

[0090] The direct-axis current Id is input into a pre-built PI proportional-integral controller to obtain the direct-axis voltage; the control reference and the quadrature-axis current Iq are input into the PI proportional-integral controller to obtain the quadrature-axis voltage; the direct-axis voltage and the quadrature-axis voltage are subjected to inverse Park transformation to obtain the two-phase voltages of the stepper motor in a two-phase stationary coordinate system.

[0091] Step S230, generating a second coating control parameter according to the two-phase voltage of the stepper motor in the two-phase stationary coordinate system; and controlling the movement of the stepper motor of the coating die head at the next moment based on the first coating control parameter and the second coating control parameter.

[0092] In the embodiment of the present application, the second coating control parameter is generated according to the two-phase voltage of the stepper motor in the two-phase stationary coordinate system, including:

[0093] The two-phase voltage of the stepper motor in the two-phase stationary coordinate system is converted to obtain a pulse signal; the pulse signal is processed by a two-phase inverter to generate a PWM signal; and the second coating control parameter is generated based on the PWM signal.

[0094] In the embodiment of the present application, the SVPWM algorithm can be used to convert the two-phase voltage of the stepper motor in a two-phase stationary coordinate system to obtain a pulse signal.

[0095] In an embodiment of the present application, before generating a PWM signal, it is necessary to calculate the duty cycle of the PWM signal based on the amplitude of the pulse signal; based on the duty cycle of the PWM signal, a PWM signal is generated, and the PWM signal is applied to the drive circuit of the stepper motor to control the movement of the stepper motor.

[0096] In one embodiment of the present application, Figure 3 As shown, the stepper motor control method of the coating die head of the present application can adopt the following steps:

[0097] The displacement sensor on the stepper motor collects the current displacement and the set position control value, and performs PID calculation through the PI proportional integral controller to output the speed reference value; according to the mechanical angle value collected by the angle sensor on the stepper motor, the current speed and electrical angle θ of the stepper motor are calculated;

[0098] The current speed and the calculated speed reference value are processed by a PI proportional integral controller to perform PID operation and output an Iq reference value;

[0099] Phase current sampling collects the two-phase currents Iα and Iβ in the α-β coordinate system (i.e., the two-phase stationary coordinate system) of the stepper motor; Iα and Iβ are converted into two-phase currents Id and Iq in the two-phase rotating coordinate system (i.e., the dq coordinate system) by Park transformation combined with the electrical angle θ;

[0100] The current Id is controlled by a PI proportional integral controller ( Figure 3 The voltage Ud in the dq coordinate system is calculated by the middle circle X); the voltage Uq in the dq coordinate system is obtained by combining the Iq reference value with the current Iq for PID operation;

[0101] The calculated two-phase voltages Ud and Uq in the dq coordinate system are converted into two-phase voltages Uα and Uβ in the α-β coordinate system by inverse Park transformation, and the two-phase voltages Uα and Uβ in the α-β coordinate system are converted into pulses by the SVPWM algorithm, and then a PWM signal with a certain duty cycle is generated through a two-phase inverter to generate the required voltage value for controlling the stepper motor.

[0102] Corresponding to the above method, the present application embodiment also provides a stepper motor control device for a coating die head, such as Figure 4 As shown, the stepper motor control device of the coating die head includes:

[0103] The acquisition unit 410 is used to acquire the first coating control parameter sent by the host computer, as well as the state parameters of the stepper motor at the current moment and the two-phase current in the two-phase stationary coordinate system; the host computer is connected to multiple stepper motor control systems through a CAN bus; each stepper motor control system corresponds to a coating die head; the stepper motor control system is used to control the movement of the stepper motor of the coating die head;

[0104] A determination unit 420, configured to determine a control reference amount based on a deviation between the state parameter and a configured position control amount;

[0105] The conversion unit 430 is used to convert the two-phase current in the two-phase stationary coordinate system according to the state parameter and the control reference quantity to obtain the two-phase voltage of the stepping motor in the two-phase stationary coordinate system;

[0106] A generating unit 440, configured to generate a second coating control parameter according to a two-phase voltage of the stepping motor in a two-phase stationary coordinate system;

[0107] The control unit 450 is used to control the movement of the stepper motor of the coating die head at the next moment based on the first coating control parameter and the second coating control parameter.

[0108] The functions of each functional unit of the stepper motor control device of the coating die head provided in the above embodiments of the present application can be realized through the above-mentioned method steps. Therefore, the specific working process and beneficial effects of each unit in the stepper motor control device of the coating die head provided in the embodiments of the present application will not be repeated here.

[0109] The present application also provides an electronic device, such as Figure 5 As shown, it includes a processor 510 , a communication interface 520 , a memory 530 and a communication bus 540 , wherein the processor 510 , the communication interface 520 , and the memory 530 communicate with each other via the communication bus 540 .

[0110] A memory 530, for storing computer programs;

[0111] The processor 510 is used to execute the program stored in the memory 530 to implement the following steps:

[0112] Obtain the first coating control parameter sent by the host computer, as well as the state parameters of the stepper motor at the current moment and the two-phase current in the two-phase stationary coordinate system; the host computer is connected to multiple stepper motor control systems through a CAN bus; each stepper motor control system corresponds to a coating die head; the stepper motor control system is used to control the movement of the stepper motor of the coating die head;

[0113] Determine a control reference quantity based on the deviation between the state parameter and the configured position control quantity;

[0114] According to the state parameters and the control reference, the two-phase currents in the two-phase stationary coordinate system are converted to obtain the two-phase voltages of the stepper motor in the two-phase stationary coordinate system;

[0115] generating a second coating control parameter according to the two-phase voltage of the stepping motor in the two-phase stationary coordinate system;

[0116] Based on the first coating control parameter and the second coating control parameter, the stepping motor of the coating die head is controlled to move at the next moment.

[0117] The communication bus mentioned above can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0118] The communication interface is used for communication between the above electronic device and other devices.

[0119] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0120] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0121] The implementation methods and beneficial effects of the components of the electronic device in the above embodiments to solve the problems can be seen in Figure 2The various steps in the illustrated embodiment are implemented, therefore, the specific working process and beneficial effects of the electronic device provided by the embodiment of the present application are not repeated here.

[0122] In another embodiment provided in the present application, a computer-readable storage medium is provided, in which instructions are stored. When the computer-readable storage medium is run on a computer, the computer executes the stepper motor control method for the coating die head of any of the above embodiments.

[0123] In another embodiment provided in the present application, a computer program product including instructions is also provided, which, when executed on a computer, enables the computer to execute the stepper motor control method for a coating die head of any of the above embodiments.

[0124] Those skilled in the art will appreciate that the embodiments in the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt a complete hardware embodiment, a complete software embodiment, or a form of an embodiment combining software and hardware. Moreover, the present application may adopt a form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0125] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0126] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0127] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0128] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present application.

[0129] Obviously, those skilled in the art can make various changes and modifications to the embodiments in the present application without departing from the spirit and scope of the embodiments in the present application. Thus, if these modifications and variations of the embodiments in the present application fall within the scope of the claims and their equivalents in the embodiments of the present application, the embodiments of the present application are also intended to include these modifications and variations.

Claims

1. A stepper motor control method for a coating die head, characterized in that: Applied to the stepper motor control system corresponding to each coating die head, multiple stepper motor control systems are connected to the host computer through a CAN bus; the stepper motor control system is used to control the movement of the stepper motor of the corresponding coating die head; the method includes: Acquire the first coating control parameter sent by the host computer, as well as the state parameters of the stepper motor at the current moment and the two-phase current in the two-phase stationary coordinate system; Determining a control reference amount based on a deviation between the state parameter and a configured position control amount; According to the state parameter and the control reference, the two-phase current in the two-phase stationary coordinate system is converted to obtain the two-phase voltage of the stepper motor in the two-phase stationary coordinate system; generating a second coating control parameter according to the two-phase voltage of the stepping motor in a two-phase stationary coordinate system; Based on the first coating control parameter and the second coating control parameter, the stepping motor of the coating die head is controlled to move at the next moment.

2. The method according to claim 1, characterized in that The state parameters include: displacement, rotation speed and electrical angle; The displacement is acquired by using a pre-calibrated displacement sensor; The rotation speed and electrical angle are calculated based on the angle value of the stepper motor measured by the angle sensor.

3. The method according to claim 2, characterized in that Determining a control reference amount based on a deviation between the state parameter and a configured position control amount includes: Performing PID operation on the displacement and the position control amount to obtain a speed reference; A PID operation is performed on the rotation speed and the speed reference to obtain a control reference.

4. The method according to claim 2, characterized in that According to the state parameter and the control reference, the two-phase current in the two-phase stationary coordinate system is converted to obtain the two-phase voltage of the stepper motor in the two-phase stationary coordinate system, including: Converting the two-phase currents in the two-phase stationary coordinate system to obtain converted two-phase currents; Based on the converted two-phase current and the electrical angle, obtaining the two-phase current of the stepper motor in a synchronous rotating coordinate system; Based on the control reference and the two-phase current of the stepper motor in the synchronous rotating coordinate system, the two-phase voltage of the stepper motor in the two-phase stationary coordinate system.

5. The method according to claim 4, characterized in that The two-phase current of the stepper motor in the synchronous rotating coordinate system includes: direct-axis current and quadrature-axis current; Based on the control reference and the two-phase current of the stepper motor in the synchronous rotating coordinate system, determining the two-phase voltage of the stepper motor in the two-phase stationary coordinate system includes: Inputting the direct-axis current into a pre-built PI proportional-integral controller to obtain a direct-axis voltage; Inputting the control reference and the quadrature-axis current into the PI proportional-integral controller to obtain the quadrature-axis voltage; The direct-axis voltage and the quadrature-axis voltage are subjected to an inverse Park transformation to obtain two-phase voltages of the stepper motor in a two-phase stationary coordinate system.

6. The method according to claim 1, characterized in that Generating a second coating control parameter according to the two-phase voltage of the stepper motor in a two-phase stationary coordinate system includes: Converting the two-phase voltage of the stepper motor in a two-phase stationary coordinate system to obtain a pulse signal; Processing the pulse signal using a two-phase inverter to generate a PWM signal; Based on the PWM signal, a second coating control parameter is generated.

7. The method according to claim 2, characterized in that The coating die head is provided with an adjustment block; the stepping motor is used to control the movement of the adjustment block; The displacement sensor calibration method comprises: Transmitting the configured intermittent displacement command to the stepper motor via the CAN bus to control the movement of the adjustment block; For any moment after the stepper motor receives the intermittent displacement command, a first displacement amount and a second displacement amount at the moment are obtained; wherein the first displacement amount is obtained by reading the detection value of the displacement sensor; and the second displacement amount is obtained by reading the detection value of the calibration sensor pre-set on the adjustment block; Taking the difference between the first displacement and the second displacement as the displacement deviation of the displacement sensor at the moment; Fitting the displacement deviation of the displacement sensor at each moment to obtain a linear function of the displacement deviation; The displacement deviation linear function is used to calibrate the detection value of the displacement sensor to obtain a calibrated displacement sensor.

8. A stepper motor control device for a coating die head, characterized in that: The device comprises: An acquisition unit is used to acquire the first coating control parameter sent by the host computer, as well as the state parameters of the stepper motor at the current moment and the two-phase current in the two-phase stationary coordinate system; the host computer is connected to multiple stepper motor control systems through a CAN bus; each stepper motor control system corresponds to a coating die head; the stepper motor control system is used to control the movement of the stepper motor of the coating die head; a determining unit, configured to determine a control reference amount based on a deviation between the state parameter and a configured position control amount; A conversion unit, configured to convert the two-phase current in the two-phase stationary coordinate system according to the state parameter and the control reference, so as to obtain the two-phase voltage of the stepping motor in the two-phase stationary coordinate system; A generating unit, used for generating a second coating control parameter according to a two-phase voltage of the stepping motor in a two-phase stationary coordinate system; A control unit is used to control the movement of the stepper motor of the coating die head at a next moment based on the first coating control parameter and the second coating control parameter.

9. An electronic device, characterized in that: The electronic device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory, used to store computer programs; A processor, for implementing any of the methods described in claims 1-7 when executing a program stored in a memory.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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