Sunflower wheel position control method, system and equipment for yarn forming

Abstract

The invention discloses a sunflower wheel position control method, system and equipment for yarn forming, and belongs to the technical field of multi-motor synchronous control. According to the position control method for the sunflower wheel for yarn forming, the position control of the sunflower wheel for yarn forming is realized by constructing the first direction position given model, the first motor driving model, the second direction position given model, the multi-motor driving model and the position synchronous compensation model; therefore, the error of synchronous control of the positions of the two sunflower wheels can be effectively reduced, the synchronous control precision and the response speed are improved, the form of the ripple structure can be accurately controlled, and the scheme is scientific, reasonable and feasible. Furthermore, compared with an existing manual adjusting mode, the multi-model control method has the advantages that the corrugation forming quality and the flexible production capacity of the hollow fiber membrane (yarn) can be effectively improved, and therefore the high-quality formed fiber membrane can be obtained.

Description

Technical Field

[0001] The present invention relates to a method, system and device for controlling the position of a sunflower wheel for yarn forming, belonging to the technical field of multi-motor synchronous control. Background Art

[0002] A hollow fiber membrane (yarn) with a corrugated structure on its surface can provide a larger effective filtration area, improve fluid flow characteristics, and significantly enhance the overall performance of the membrane. These advantages have made the hollow fiber membrane more and more widely used in medical dialysis, air purification and other aspects.

[0003] The corrugated structure on the surface of the fiber membrane can be generated by a variety of processes, such as die forming, hot pressing technology, chemical etching, laser etching, etc. Among them, the hot pressing technology has become an important way to produce hollow fiber membranes because of its strong material adaptability, high efficiency and suitability for large-scale production. In order to better adapt to different application scenarios of the hollow fiber membrane, the morphology of the corrugations can be adjusted when forming the corrugated structure by hot pressing. Among them, sunflower wheel forming is a commonly used adjustment method at present, including the adjustment of the corrugation frequency of two sunflower wheels in the X direction and the adjustment of the corrugation amplitude in the Y direction.

[0004] However, at present, traditional sunflower wheel hot pressing forming equipment generally adopts the method of multi-motor independent drive for control. The adjustment of the corrugation frequency of the sunflower wheel in the X direction and the adjustment of the corrugation amplitude in the Y direction are manually controlled separately, and the adjustment of the corrugation amplitude in the Y direction can only be carried out when the equipment is on standby. This manual adjustment method limits the quality of corrugation forming and the flexible production capacity.

[0005] The information disclosed in this background art is only used to understand the background of the inventive concept of the present invention, so it may include information that does not constitute the prior art. Summary of the Invention

[0006] Aiming at the above problems or one of the above problems, the first object of the present invention is to provide a method for controlling the position of a sunflower wheel for yarn forming. By constructing a first-direction position given model, a first-motor drive model, a second-direction position given model, a multi-motor drive model, and a position synchronization compensation model, the position control of the sunflower wheel for yarn forming is realized, so that the error of the position synchronization control of the two sunflower wheels can be effectively reduced, the synchronization control accuracy and response speed can be improved, and further the morphology of the corrugated structure can be accurately controlled. The scheme is scientific, reasonable and practical.

[0007] In view of the above problems or one of the above problems, the second object of the present invention is to provide a method, a system and a device for controlling the position of sunflower wheels for yarn forming, which can accurately control the distance between the two sunflower wheels in real time so as to improve the production efficiency of the corrugated structure; and can greatly reduce the synchronization error of the two motors; when receiving disturbances, it can recover synchronization faster; when starting with load, it can reach the target speed faster; thus having stronger robustness.

[0008] In view of the above problems or one of the above problems, the third object of the present invention is to provide a method, a system and a device for controlling the position of sunflower wheels for yarn forming. By using the multi-model control method, compared with the existing manual adjustment method, it can effectively improve the automation level of adjustment in both X and Y directions and the position synchronization accuracy of the two sunflower wheels in the X direction. Therefore, it can effectively improve the quality of corrugated forming of hollow fiber membranes (yarns) and the flexible production capacity, and thus can obtain high-quality formed fiber membranes.

[0009] To achieve one of the above objects, the first technical solution of the present invention is:

[0010] A method for controlling the position of sunflower wheels for yarn forming, comprising the following steps:

[0011] Step 1, through a pre-constructed first-direction position given model, set the Y-direction position given θ y according to the required yarn corrugated shape, and based on the Y-direction position given θ y , obtain the Y-direction position difference control information for controlling the Y-direction distance between the two sunflower wheels;

[0012] Step 2, adopt a pre-constructed first-motor drive model, based on the Y-direction position difference control information, obtain the first-motor drive signal in the Y direction, and then obtain the actual position θ 1 of the first motor after operation;

[0013] Step 3, use a pre-constructed second-direction position given model, set the first X-direction position given θ x1 and the second X-direction position given θ x2 according to the required yarn corrugated shape; and according to the first X-direction position given θ x1 and the second X-direction position given θ x2 , as well as the actual position θ 1 of the first motor after operation, obtain the X-direction position difference control information for controlling the X-direction distance between the two sunflower wheels;

[0014] Step 4, adopt a pre-constructed multi-motor drive model, based on the X-direction position difference control information, obtain the second-motor drive signal and the third-motor drive signal in the X direction, and then obtain the actual position θ 2 of the second motor and the actual position θ3 ;

[0015] Step Five, according to the pre-constructed position synchronization compensation model, based on the actual position θ of the second motor 2 and the actual position θ of the third motor 3 , and based on the required yarn corrugated shape, obtain the synchronous feedback compensation information as the feedback signals of the second motor and the third motor, so as to realize the position control of the yarn-forming sunflower wheel.

[0016] Through continuous exploration and experiments, the present invention realizes the position control of the yarn-forming sunflower wheel by constructing the first-direction position given model, the first-motor drive model, the second-direction position given model, the multi-motor drive model, and the position synchronization compensation model. Thus, the error of the position synchronization control of the two sunflower wheels can be effectively reduced, the synchronization control accuracy and response speed can be improved, and furthermore, the shape of the corrugated structure can be accurately controlled. The solution is scientific, reasonable, and feasible.

[0017] Furthermore, the method of the present invention can accurately control the distance between the two sunflower wheels in real time, thereby improving the production efficiency of the corrugated structure; and can greatly reduce the synchronization error of the two motors; when receiving disturbances, it can recover synchronization faster; when starting with load, it can reach the target speed faster; thus, it has stronger robustness.

[0018] Moreover, the multi-model control method of the present invention can effectively improve the automation level of the adjustment in the X and Y directions and the position synchronization accuracy of the two sunflower wheels in the X direction compared with the existing manual adjustment method. Therefore, it can effectively improve the quality of the corrugation forming of the hollow fiber membrane (yarn) and the flexible production capacity, and thus high-quality formed fiber membranes can be obtained.

[0019] As a preferred technical measure:

[0020] Step One, through the pre-constructed first-direction position given model, according to the required yarn corrugated shape, set the Y-direction position given θ y , and based on the Y-direction position given θ y , the method for obtaining the Y-direction position difference control information for controlling the Y-direction distance between the two sunflower wheels is as follows:

[0021] According to the required yarn corrugated shape, set a reasonable Y-direction position given. The yarn corrugated shape is a sine curve type, which is formed on the surface of the yarn by thermoforming;

[0022] The three-phase currents i a , i b and i c in the three-phase coordinate system of the first motor are obtained by the method of collecting current signals through two Hall current sensors, and input it into the Clarke transformation module. The transformation formula of the Clarke transformation module is:

[0023]

[0024] Where the phase current i c is calculated by the formula i a +i b +i c =0;

[0025] The output of the Clarke transformation module is the actual current i α and i β in the stationary two-phase coordinate system, which serves as the input to the Park transformation module; i α and i β and the actual angular position θ 1 of the first motor are input into the Park transformation module to obtain the actual direct-axis current i d and the actual quadrature-axis current i q in the synchronous rotating coordinate system. The Park transformation formula is:

[0026]

[0027] The actual quadrature and direct-axis currents i q and i d in the synchronous rotating coordinate system output by the Park transformation module and the output quadrature and direct-axis currents and of the MTPA module are subtracted and used as the input to the current loop PI regulator;

[0028] The actual position θ 1 of the first motor collected by the encoder and the given θ y of the Y-direction position are input into the subtractor to obtain the angular position error θ y -θ 1 , which is used as the input to the position loop P regulator; the output of the position loop P regulator is the given speed ω 1ref ; then the given speed and the actual speed ω 1 of the motor obtained by differentiating the actual angular position of the motor are input into the subtractor to obtain the speed error ω 1ref -ω 1 as the input to the speed loop PI regulator; the output of the speed loop PI regulator is the given electromagnetic torque to form the Y-direction position difference control information for controlling the Y-direction spacing between the two sunflower wheels, which is used as the input to the MTPA module.

[0029] As a preferred technical measure:

[0030] Step 2: Using the pre - constructed first - motor drive model, based on the Y - direction position - gap control information, obtain the first - motor drive signal in the Y direction, and acquire the actual position θ after the first motor operates. 1 The method is as follows:

[0031] Input the Y - direction position - gap control information into the MTPA module;

[0032] The MTPA module outputs the given quadrature - axis current and the actual quadrature - axis current i q After passing through a subtractor, obtain the error between the given quadrature - axis current and the actual quadrature - axis current, and input it into the quadrature - axis current PI controller. After calculation, obtain the given quadrature - axis voltage

[0033] The MTPA module outputs the given direct - axis current and the actual direct - axis current i d After passing through a subtractor, obtain the error between the given direct - axis current and the actual direct - axis current, and input it into the direct - axis current PI controller. After calculation, obtain the given direct - axis voltage The formula is as follows:

[0034]

[0035] Among them, K piq is the proportional coefficient of the quadrature - axis current PI controller; K Iiq is the integral coefficient of the quadrature - axis current PI controller; K pid is the proportional coefficient of the direct - axis current PI controller; K Iid is the integral coefficient of the direct - axis current PI controller; the given quadrature - axis voltage and the given direct - axis voltage are input into the IPark transformation module together;

[0036] The given quadrature - axis voltage The given direct - axis voltage and the actual electrical angle θ 1 After being transformed by the IPark transformation module, they become the given voltages and in the stationary two - phase coordinate system and are input into the space - vector pulse - width modulation module. The voltage given values and in the stationary two - phase coordinate system pass through the space - vector pulse - width modulation module to obtain six - way PWM signals as the input for controlling the three - phase inverter;

[0037] The three-phase inverter performs switching operations on six switching tubes according to six input PWM signals, outputs three-phase voltages, thereby obtaining the first motor drive signal in the Y direction, and inputs the first motor drive signal in the Y direction into the first motor to drive the first motor, and obtains the actual position θ after the first motor runs through the encoder. 1 。

[0038] As a preferred technical measure:

[0039] Step 3: Use the pre-constructed second-direction position given model to set the first position given θ in the X direction according to the required yarn ripple shape x1 and the second position given θ x2 ; and according to the first position given θ in the X direction x1 and the second position given θ x2 , as well as the actual position θ after the first motor runs 1 , the method for obtaining the X-direction position gap control information for controlling the X-direction spacing between the two sunflower wheels is as follows:

[0040] When the first motor runs to the given position, according to the required yarn ripple shape, use the trajectory planning and position synchronization control module to obtain the first position given θ in the X direction x1 and the second position given θ x2 , and input them into the second motor and the third motor respectively;

[0041] The second motor inputs the actual position θ of the second motor collected by the encoder 2 and the first position given θ input in the X direction x1 into the subtractor to obtain the angular position error θ x1 -θ 2 , as the X-direction position gap control information for controlling the X-direction spacing between the two sunflower wheels, and use it as the input of the position loop P regulator.

[0042] As a preferred technical measure:

[0043] Step 4: Adopt the pre-constructed second motor drive model, based on the X-direction position gap control information, obtain the second motor drive signal and the third motor drive signal in the X direction, and obtain the actual position θ of the second motor 2 and the actual position θ of the third motor 3 The method is as follows:

[0044] Based on the X-direction position gap control information, through the same process as the first motor, obtain the second motor drive signal and the third motor drive signal in the X direction, and obtain the actual position θ of the second motor through the encoder 2 and the actual position θ of the third motor 3 。

[0045] As a preferred technical measure:

[0046] Step five, according to the pre-constructed position synchronization compensation model, based on the actual position θ of the second motor 2 and the actual position θ of the third motor 3 , and based on the required yarn corrugation shape, the method for obtaining the synchronous feedback compensation information as the feedback signals of the second motor and the third motor is as follows:

[0047] After the collected current signal undergoes Clark transformation and Park transformation, the Park transformation module outputs the actual direct-axis and quadrature-axis currents i q and i d which are subtracted from the direct-axis and quadrature-axis current references output by the MTPA module and , and at the same time, the direct-axis and quadrature-axis currents are output to the load torque identification module;

[0048] The load torque identification module calculates the actual rotational speed ω m received through the differentiator with the actual direct-axis and quadrature-axis currents i q and i d to perform operations, and finally obtains the identified load torque The identified load torque of the second motor calculated by the load torque identification module is used as the input for position synchronization control;

[0049] For the third motor, it is the same as the second motor, and finally the identified load torque is output to the synchronization compensation module;

[0050] The actual position θ of the second motor feedback by the encoder 2 and the actual position θ of the third motor 3 as well as the identified load torques and the identified load torque output by the two-position servo system are input to the position synchronization control module. After calculation, the synchronization control module outputs the synchronous feedback compensation current two and the synchronous feedback compensation current three as the synchronous feedback compensation information, and inputs them into the second motor and the third motor to ensure the synchronous operation of the two sunflower wheel shafts.

[0051] As a preferred technical measure:

[0052] The method for outputting the synchronous feedback compensation current two and the synchronous feedback compensation current three is as follows:

[0053] The voltage equation of the permanent magnet synchronous motor in the synchronous rotating coordinate system d-q axis is:

[0054]

[0055] The torque equation of a permanent magnet synchronous motor in the d-q coordinate axes is as follows:

[0056]

[0057] Where, T e is the electromagnetic torque; P n is the number of pole pairs of the motor rotor;

[0058] For a surface-mounted permanent magnet synchronous motor, L d = L q , so the torque equation is simplified to:

[0059]

[0060] The kinematic equation of a permanent magnet synchronous motor is as follows:

[0061]

[0062] Define the state variables as:

[0063]

[0064] Write the state equations according to the torque equation and kinematic equation of the permanent magnet synchronous motor:

[0065]

[0066] Select the integral sliding mode surface s of the system as:

[0067] s = c 1 x 1 + c 2 x 2 (10)

[0068] Select the exponential reaching law and replace the sign function with the saturation function to obtain the sign function replacement formula, which is shown as follows:

[0069]

[0070] From the state equations and the sign function replacement formula, the expression of the sliding mode feedback compensation current is obtained as:

[0071]

[0072] To make the system meet the stability requirements, select the Lyapunov function as:

[0073]

[0074] Deriving the derivative of the above formula gives:

[0075]

[0076] According to Lyapunov's second theorem, the designed sliding mode controller must satisfy to make the system meet the stability conditions; where ε and k are both constants greater than 0; therefore, regardless of the sign of s, s and its derivative have different signs, that is When the condition of reaching the sliding mode surface is satisfied, the system enters the sliding mode;

[0077] The calculated sliding mode feedback compensation current outputs the synchronous feedback compensation current two after passing through gains k1 and k2 and the synchronous feedback compensation current three

[0078] To achieve one of the above purposes, the second technical solution of the present invention is:

[0079] A sunflower wheel position control system for yarn forming, including a Y-direction position servo system and an X-direction two-axis position synchronous servo system;

[0080] The Y-direction position servo system includes a trajectory planning and position synchronization control module based on PLC, a first position servo system, a first motor and an encoder 1;

[0081] The X-direction two-axis position synchronous servo system includes a second position servo system, a third position servo system, a second motor, a third motor, two reducers and two sunflower wheels;

[0082] The output of the trajectory planning and position synchronization control module based on PLC is respectively connected to the inputs of the three position servo systems for giving position servo commands;

[0083] The output of the first position servo system is connected to the input of the first motor. The first motor is connected to the first reducer through a coupling, and the reducer is connected to the lead screw, forming the Y-direction position servo system;

[0084] The output of the second position servo system is connected to the input of the second motor. The second motor is connected to the second reducer through a coupling, and the second reducer is connected to the first sunflower wheel through a coupling, forming a sunflower wheel shaft;

[0085] The third position servo system, the third motor, the third reducer and the second sunflower wheel form another sunflower wheel shaft in the same way;

[0086] The two sunflower wheel shafts are connected through the lead screw and the first reducer to form the X-direction two-axis position synchronous servo system.

[0087] To achieve one of the above objects, the third technical solution of the present invention is as follows:

[0088] A sun wheel position control method for yarn forming, which is applied to the above-mentioned sun wheel position control system for yarn forming, and includes the following:

[0089] The trajectory planning and position synchronization control module based on PLC first gives the position set value θ y as the input of the first position servo system;

[0090] The input θ y is subtracted from the motor angular position θ 1 fed back by the encoder and then input into the position loop P regulator. After calculation, the set rotational speed ω 1ref is output and subtracted from the motor rotational speed ω 1 and then input into the speed loop PI regulator;

[0091] The PI regulator outputs the set electromagnetic torque

[0092] The MTPA module finds the optimal dq-axis currents by using the look-up table method and and subtracts them from the collected dq-axis currents after Clark transformation and Park transformation respectively and inputs them into the current loop PI regulator;

[0093] The current loop PI regulator outputs the set dq-axis voltages and and then outputs the two-phase coordinate system voltages and through the Ipark transformation module to the space vector pulse width modulation SVPWM module. After calculation, six-way PWM signals are output to control the three-phase inverter for voltage output, thereby driving the permanent magnet synchronous motor;

[0094] The permanent magnet synchronous motor drives the two sun wheel shafts to slowly approach or move away through the speed reducer and the lead screw. When the position feedback of the first motor is equal to the position set value, that is, θ 1 = θ y the rotor of the first motor reaches the given position and stops working;

[0095] The trajectory planning and position synchronization control module based on PLC outputs the same position set values θ x1 and θ x2 to the second motor and the third motor;

[0096] The input position set value θ x1 is subtracted from the encoder position feedback θ 2After taking the difference, it is input into the second motor, and after passing through the position loop and speed loop, the given electromagnetic torque is output After passing through the MTPA module, the optimal dq-axis given current is obtained using the look-up table method and

[0097] The given q-axis current is synchronized with the feedback synchronous q-axis current received from the PLC-based trajectory planning and position synchronization control module And the collected q-axis current i obtained through Clark transformation and Park transformation q At the same time, take the difference between the given d-axis current and the collected d-axis current i obtained through Clark transformation and Park transformation d Take the difference and input it into the current loop PI regulator;

[0098] After passing through the inverse Park transformation module and the space vector pulse width modulation module, six-way PWM signals are output to control the three-phase inverter to output three-phase voltages to control the motor;

[0099] The collected dq-axis current after Park transformation is input into the load torque identification module. At the same time, the rotor position collected by the encoder is calculated through a differentiator to obtain the rotational speed ω m Is also input into the load torque identification module, and the estimated load torque is output after calculation

[0100] The control process of the third motor is exactly the same as that of the second motor;

[0101] The second position servo system and the third position servo system calculate the estimated load torque and Input into the position synchronization control module for calculation, and the feedback synchronous q-axis current is obtained and input into the second position servo system and the third position servo system for compensation to ensure the synchronous operation of the two sunflower wheel shafts.

[0102] To achieve one of the above purposes, the fourth technical solution of the present invention is:

[0103] An electronic device, which includes:

[0104] One or more processors;

[0105] A storage device for storing one or more programs;

[0106] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned sunflower wheel position control method for yarn forming.

[0107] Compared with the prior art solution, the present invention has the following beneficial effects:

[0108] Through continuous exploration and experiments, the present invention realizes the position control of the yarn-forming sunflower wheels by constructing a first-direction position setting model, a first motor drive model, a second-direction position setting model, a multi-motor drive model, and a position synchronization compensation model. Thus, the error of the position synchronization control of the two sunflower wheels can be effectively reduced, the synchronization control accuracy and response speed can be improved, and then the shape of the corrugated structure can be accurately controlled. The solution is scientific, reasonable, and practical.

[0109] Furthermore, compared with the existing manual adjustment method, the multi-model control method of the present invention can effectively improve the automation level of the adjustment in the X and Y directions and the position synchronization accuracy of the two sunflower wheels in the X direction. Therefore, the quality of the corrugation forming of the hollow fiber membrane (yarn) and the flexible production capacity can be effectively improved, and thus a high-quality formed fiber membrane can be obtained.

[0110] Moreover, the position servo system and method in the present invention can, compared with the existing sunflower wheel production equipment, accurately control the distance between the two sunflower wheels in real time to improve the production efficiency of the corrugated structure; at the same time, it can greatly reduce the synchronization error of the two motors; when receiving a disturbance, it can recover synchronization faster; when starting with a load, it can reach the target speed faster; and it has stronger robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] Figure 1 is a schematic diagram of the present invention using sunflower wheels to form yarn;

[0112] Among them, Figure 1 the left side in Figure 1 is a working schematic diagram of the sunflower wheel, and

[0113] Figure 2 the right side in

[0114] Figure 3 is Figure 2 a control structure block diagram of the position servo system 1 in

[0115] Figure 4 is Figure 2 a control structure block diagram of the position servo system 2 in

[0116] Figure 5 is Figure 2 a control structure block diagram of the position servo system 3 in

[0117] Figure 6 is Figure 2 a control structure block diagram of the position synchronization control in DETAILED DESCRIPTION OF THE INVENTION

[0118] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0119] On the contrary, the present invention covers any alternatives, modifications, equivalent methods and solutions made to the essence and scope of the present invention as defined by the claims. Further, in order to enable the public to better understand the present invention, some specific details are described in detail in the following detailed description of the present invention. Those skilled in the art can fully understand the present invention without the description of these details.

[0120] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0121] The first specific embodiment of the sunflower wheel position control method for yarn forming of the present invention:

[0122] A sunflower wheel position control method for yarn forming, comprising the following steps:

[0123] Step 1, through a pre-constructed first-direction position given model, set the Y-direction position given θ according to the required yarn ripple shape y , and based on the Y-direction position given θ y , obtain the Y-direction position difference control information for controlling the Y-direction spacing between the two sunflower wheels;

[0124] Step 2, adopt a pre-constructed first motor drive model, based on the Y-direction position difference control information, obtain the first motor drive signal in the Y-direction, and then obtain the actual position θ after the first motor runs 1 ;

[0125] Step 3, use a pre-constructed second-direction position given model, set the first position given θ in the X-direction and the second position given θ in the X-direction according to the required yarn ripple shape x1 and the second position given θ x2 ; and according to the first position given θ x1 and the second position given θ x2 , as well as the actual position θ after the first motor runs 1 , obtain the X-direction position difference control information for controlling the X-direction spacing between the two sunflower wheels;

[0126] Step 4: Using the pre-constructed multi-motor drive model, based on the X-direction position gap control information, obtain the second motor drive signal and the third motor drive signal in the X direction, and then obtain the actual position θ of the second motor 2 and the actual position θ of the third motor 3 ;

[0127] Step 5: According to the pre-constructed position synchronization compensation model, based on the actual position θ of the second motor 2 and the actual position θ of the third motor 3 , and based on the required yarn corrugation shape, obtain the synchronous feedback compensation information as the feedback signals of the second motor and the third motor to achieve the position control of the yarn-forming sunflower wheel.

[0128] Therefore, by applying the method of the present invention, the error of the position synchronization control of the two sunflower wheels can be effectively reduced, the synchronization control accuracy and response speed can be improved, and the shape of the corrugated structure can be accurately controlled.

[0129] Meanwhile, by applying the method of the present invention, the distance between the two sunflower wheels can be accurately controlled in real time, thereby improving the production efficiency of the corrugated structure; and the position synchronization control method of the present invention can greatly reduce the synchronization error between the two motors; when receiving disturbances, it can recover synchronization faster; when starting with load, it can reach the target speed faster; and it has stronger robustness.

[0130] As Figures 2 - 5 shown, a specific embodiment of the sunflower wheel position control system for yarn forming according to the present invention:

[0131] A sunflower wheel position control system for yarn forming, comprising a PLC-based trajectory planning and position synchronization control module; a Y-direction position servo system composed of a position servo system 1, a motor 1 and an encoder 1; an X-direction two-axis position synchronization servo system composed of a position servo system 2, a position servo system 3, a motor 2, a motor 3, two reducers and two sunflower wheels. The connection relationship is as follows:

[0132] The output of the PLC-based trajectory planning and position synchronization control module is respectively connected to the inputs of the three position servo systems for giving position servo commands; the output of the position servo system 1 is connected to the input of the motor 1, the motor 1 is connected to the reducer 1 through a coupling, and the reducer is connected to the lead screw to form a Y-direction position servo system; the output of the position servo system 2 is connected to the input of the motor 2, the motor 2 is connected to the reducer 2 through a coupling, and the reducer 2 is connected to the sunflower wheel 1 through a coupling to form one sunflower wheel shaft; the position servo system 3, the motor 3, the reducer 3 and the sunflower wheel 2 form another sunflower wheel shaft in the same way, and the two sunflower wheel shafts are connected through a lead screw and the reducer 1 to form an X-direction two-axis position synchronization servo system. The cross-sectional view of the two sunflower wheels during operation is asFigure 1 As shown on the left, the yarn passes through the middle of the two wheels, and a corrugated structure is formed on the surface by thermoforming. The shape of the generated corrugations is as Figure 1 shown on the right, roughly presenting the shape of a sine curve. When the distance between the two wheels decreases, the Y-direction spacing Y of the corrugations 1 -Y 0 increases; conversely, when the distance between the two wheels increases, the Y-direction spacing of the corrugations decreases. When the rotational speed of the two wheels increases, the X-direction spacing X of the corrugations 1 -X 0 decreases; when the rotational speed of the two wheels decreases, the X-direction spacing of the corrugations increases.

[0133] The second specific embodiment of the sunflower wheel position control method for yarn forming in the present invention:

[0134] A sunflower wheel position control method for yarn forming, using the above-mentioned sunflower wheel position servo system for yarn forming, the control method is as follows:

[0135] The trajectory planning and position synchronization control module based on PLC first gives the position setpoint θ y as the input of the position servo system 1. The structural block diagram of the position servo system 1 is as Figure 5 shown. The input θ y is subtracted from the motor angular position θ 1 fed back by the encoder and then input into the position loop P regulator. After calculation, the given rotational speed ω 1ref is output and subtracted from the motor rotational speed ω 1 and input into the speed loop PI regulator; the PI regulator outputs the given electromagnetic torque after operation The MTPA module finds the optimal dq-axis currents and using the look-up table method according to the given electromagnetic torque, and subtracts them from the collected dq-axis currents after Clark transformation and Park transformation respectively and inputs them into the current loop PI regulator; the current loop PI regulator outputs the given dq-axis voltages and after operation, and then outputs the two-phase coordinate system voltages and to the space vector pulse width modulation (SVPWM) module through the Ipark transformation module. After operation, six-way PWM signals are output to control the three-phase inverter for voltage output, thereby driving the permanent magnet synchronous motor (PMSM). After passing through the speed reducer, the motor controls the two sunflower wheel shafts to slowly approach or move away through the lead screw. When the position feedback of motor 1 is equal to the position setpoint, that is, θ 1 = θ y , the rotor of motor 1 reaches the given position and stops working.

[0136] The trajectory planning and position synchronization control module based on PLC outputs the same position command θ x1 and θ x2 to position servo system 2 and position servo system 3. The control block diagrams of the two position servo systems are as shown in Figure 4 、 Figure 5 The control method is not very different from that of position servo system 1. The input position command θ x1 and the encoder position feedback θ 2 are subtracted and then input into position servo system 2. After passing through the position loop and speed loop, the given electromagnetic torque is output After passing through the MTPA module, the optimal dq-axis given currents are obtained using the look-up table method and The given q-axis current is synchronized with the feedback q-axis current received from the trajectory planning and position synchronization control module based on PLC and the sampled q-axis current i obtained through Clark transformation and Park transformation q are subtracted simultaneously. The given d-axis current and the sampled d-axis current i obtained through Clark transformation and Park transformation d are subtracted and input into the current loop PI regulator. After passing through the inverse Park transformation module and the space vector pulse width modulation module, six-way PWM signals are output to control the three-phase inverter to output three-phase voltages to control the motor. The sampled dq-axis currents after Park transformation are input into the load torque identification module. At the same time, the rotor position collected by the encoder is calculated through a differentiator to obtain the rotational speed ω m is also input into the load torque identification module, and the estimated load torque is output after calculation Position servo system 3 is exactly the same as position servo system 2, as shown in Figure 5 The estimated load torques and calculated by position servo system 2 and position servo system 3 are input into the position synchronization control module for calculation, and the feedback synchronized q-axis current is obtained and input into position servo system 2 and position servo system 3 for compensation. The calculation principle block diagram of the feedback synchronized q-axis current is as shown in Figure 6 shown.

[0137] The third specific embodiment of the sunflower wheel position control method for yarn forming in the present invention:

[0138] A sunflower wheel position control method for yarn forming, including the following:

[0139] Step 1: Perform position command and current acquisition, which specifically includes the following:

[0140] Set a reasonable Y - direction position given according to the required ripple shape, and input it into the position servo system 1 by the trajectory planning and position synchronization control module based on PLC. The three - phase currents \(i\) a 、\(i\) b and \(i\) c of the permanent - magnet synchronous motor 1 are obtained by the method of collecting current signals through two Hall current sensors, and are input into the Clarke transformation module. The transformation formula of the Clarke transformation module is:

[0141]

[0142] In the formula, the phase current \(i\) c is calculated by the formula \(i\) a +\(i\) b +\(i\) c =0. The output of the Clarke transformation module is the actual currents \(i\) α and \(i\) β in the stationary two - phase coordinate system, which are used as the input of the Park transformation module. The aforementioned \(i\) α and \(i\) β and the actual angular position \(\theta\) 1 of the permanent - magnet synchronous motor are input into the Park transformation module to obtain the actual direct - axis current \(i\) d and the actual quadrature - axis current \(i\) q in the synchronous rotating coordinate system. The Park transformation formula is:

[0143]

[0144] The actual direct - axis and quadrature - axis currents \(i\) q and \(i\) d in the synchronous rotating coordinate system output by the Park transformation module and the output direct - axis and quadrature - axis currents and of the MTPA module are subtracted and used as the input of the current - loop PI regulator.

[0145] Step 2: Calculate the position and speed errors, which specifically includes the following content:

[0146] The actual position \(\theta\) 1 of the permanent - magnet synchronous motor collected by the encoder and the Y - direction position given \(\theta\) y input in Step 1 are input into the subtractor to obtain the angular - position error \(\theta\) y -\(\theta\) 1 , which is used as the input of the position - loop P regulator. The output of the position - loop P regulator is the given speed \(\omega\) 1ref . Then, the given speed and the actual speed \(\omega\) 1 of the motor obtained by differentiating the actual angular position of the motor are input into the subtractor to obtain the speed error \(\omega\) 1ref -\(\omega\)1 As the input of the speed loop PI regulator. The output of the speed loop PI regulator is the electromagnetic torque command. Take it as the input of the MTPA module.

[0147] Step 3: Conduct current and voltage regulation and motor drive, which specifically includes the following:

[0148] The current loop PI controller module includes a quadrature axis current PI controller and a direct axis current PI controller. The MTPA module outputs the commanded quadrature axis current and the actual quadrature axis current i q After passing through a subtractor, the error between the commanded quadrature axis current and the actual quadrature axis current is obtained and input to the quadrature axis current PI controller. After calculation, the commanded quadrature axis voltage is obtained.

[0149] The MTPA module outputs the commanded direct axis current and the actual direct axis current i d After passing through a subtractor, the error between the commanded direct axis current and the actual direct axis current is obtained and input to the direct axis current PI controller. After calculation, the commanded direct axis voltage is obtained. The formula is as follows:

[0150]

[0151] where, K piq is the proportional coefficient of the quadrature axis current PI controller; K Iiq is the integral coefficient of the quadrature axis current PI controller; K pid is the proportional coefficient of the direct axis current PI controller; K Iid is the integral coefficient of the direct axis current PI controller. The commanded quadrature axis voltage and the commanded direct axis voltage are input to the IPark transformation module together. The commanded quadrature axis voltage The commanded direct axis voltage and the actual electrical angle θ 1 are transformed by the IPark transformation module into the commanded voltages and in the stationary two-phase coordinate system and input to the space vector pulse width modulation module. The voltage command values and in the stationary two-phase coordinate system pass through the space vector pulse width modulation module to obtain six PWM signals as the input for controlling the three-phase inverter; the three-phase inverter performs switching actions on six switching tubes according to the six input PWM signals and outputs three-phase voltages to the permanent magnet synchronous motor to achieve the drive of the permanent magnet synchronous motor.

[0152] Step 4: Conduct position synchronization and load torque identification, which specifically includes the following:

[0153] After the motor 1 runs to the given position, the trajectory planning and position synchronization control module based on the PLC will input the given X-direction position θ x1 and θ x2 into the position servo system 2 and the position servo system 3 respectively. The position servo system 2 will input the actual position θ of the permanent magnet synchronous motor collected by the encoder 2 and the input X-direction position set value θ x1 into the subtractor to obtain the angular position error θ x1 -θ 2 , and use it as the input of the position loop P regulator. Subsequently, through the same process as the position servo system 1, the motor 2 is driven to operate. The position servo system 3 is the same as the position servo system 2. After the current signal collected by the position servo system 2 undergoes Clark transformation and Park transformation, the Park transformation module outputs the actual direct-axis and quadrature-axis currents i q and i d which are subtracted from the direct-axis and quadrature-axis current set values output by the MTPA module and , and at the same time, the direct-axis and quadrature-axis currents are output to the load torque identification module. The load torque identification module will calculate the actual rotational speed ω m (Since the load torque identification module is not the main inventive content of this patent, the principle of the load torque identification module will not be elaborated here too much) received by the differentiator and the actual direct-axis and quadrature-axis currents i q and i d are operated on, and finally the identified load torque The identified load torque of the position servo system 2 calculated by the load torque identification module is used as the input of the position synchronization control. The position servo system 3 is the same as the position servo system 2, and finally the identified load torque is output to the synchronous compensation module.

[0154] Step 5: Perform position synchronization compensation, which specifically includes the following:

[0155] The actual positions θ 2 and θ 3 of the motors 2 and 3 fed back by the encoder and the estimated load torques and output by the two position servo systems are input into the position synchronization control module. After calculation, the synchronization control module outputs the synchronous feedback compensation currents and as the inputs of the position servo system 2 and the position servo system 3. The specific principle of its implementation is as follows:

[0156] The voltage equation of the permanent magnet synchronous motor in the synchronous rotating coordinate system d-q axis is:

[0157]

[0158] The torque equation of the permanent magnet synchronous motor in the d-q coordinate axes is as follows:

[0159]

[0160] Wherein, T e is the electromagnetic torque; P n is the number of pole pairs of the motor rotor. For the surface-mounted permanent magnet synchronous motor, L d = L q , so equation (5) can be simplified to:

[0161]

[0162] The kinematic equation of the permanent magnet synchronous motor is as follows:

[0163]

[0164] Define the state variables as:

[0165]

[0166] Write the state equation set according to the torque equation and kinematic equation of the permanent magnet synchronous motor:

[0167]

[0168] Select the integral sliding mode surface s of the system as:

[0169] s = c 1 x 1 + c 2 x 2 (10)

[0170] Select the exponential reaching law and replace the sign function with the saturation function, as shown in the following formula:

[0171]

[0172] From equations (9) and (11), the expression of the sliding mode feedback compensation current can be obtained as:

[0173]

[0174] In order to make the system meet the stability requirements, select the Lyapunov function as:

[0175]

[0176] Take the derivative of the above formula to get:

[0177]

[0178] According to the second Lyapunov theorem, the designed sliding mode controller must satisfy so that the system can meet the stability condition. In the formula, both ε and k are constants greater than 0. Therefore, regardless of the sign of s, s and its derivative have different signs, that is meeting the condition of reaching the sliding mode surface, the system can enter the sliding mode.

[0179] The calculated sliding mode feedback compensation current outputs the synchronous feedback compensation current after passing through gains k1 and k2 and to the position servo system 2 and the position servo system 3 to ensure the synchronous operation of the two sunflower wheel shafts.

[0180] Therefore, the method of the present invention can effectively reduce the error of the position synchronization control of the two sunflower wheels, improve the synchronization control accuracy and response speed, and provide a high-precision corrugated X and Y direction control system for accurately controlling the shape of the corrugated structure.

[0181] Furthermore, the position servo system and method in the present invention can, compared with the existing sunflower wheel production equipment, accurately control the distance between the two sunflower wheels in real time so as to improve the production efficiency of the corrugated structure; and the position synchronization control method of the present invention can greatly reduce the synchronization error of the two motors; when receiving disturbances, it can recover synchronization faster; it can reach the target speed faster when starting with load; and it has stronger robustness.

[0182] An equipment embodiment applying the method of the present invention:

[0183] An electronic device, which includes:

[0184] One or more processors;

[0185] A storage device for storing one or more programs;

[0186] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned sunflower wheel position control method for yarn forming.

[0187] A computer medium embodiment applying the method of the present invention:

[0188] A computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the above-mentioned sunflower wheel position control method for yarn forming.

[0189] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, optical storage, etc.) containing computer-usable program code.

[0190] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices produce means for implementing the functions specified in one Figure 1 one flow or multiple flows or / and blocks Figure 1 or multiple blocks.

[0191] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including instruction means that implement the functions specified in one Figure 1 one flow or multiple flows or / and blocks Figure 1 or multiple blocks.

[0192] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 one flow or multiple flows or / and blocks Figure 1 or multiple blocks.

[0193] The model in the present application is an object that constitutes an objective description of the morphological structure by means of physical or virtual representations. The object is not equal to an object, is not limited to physical and virtual, and can be a data processing function, a software program, a processing mode, a usage method, an operation mode, a workflow, an application process, electronic hardware, a circuit module, a processing system, a system imitation, or a simulation object.

[0194] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still modify or equivalently replace the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A sunflower wheel position control method for yarn forming, characterized in that: The following steps are involved: Step 1: Using the pre-built first direction position given model, set the Y direction position given θ according to the required yarn corrugation shape. y , and θ is given based on the Y direction position y , obtain the Y direction position difference control information for controlling the Y direction spacing between the two sunflower wheels; Step 2, using the pre-built first motor driving model, based on the Y direction position difference control information, obtain the first motor driving signal in the Y direction, and then obtain the actual position θ1 after the first motor is running; Step 3: Use the pre-built second direction position given model to set the X direction position given as θ according to the required yarn corrugation shape. x1 and position given by θ x2 ; and a θ is given according to the position x1 and position given by θ x2 , and the actual position θ1 of the first motor after operation, to obtain the X-direction position difference control information for controlling the X-direction spacing between the two sunflower wheels; Step 4, using a pre-built multi-motor drive model, based on the X-direction position difference control information, obtain the second motor drive signal and the third motor drive signal in the X-direction, and then obtain the actual position θ2 of the second motor and the actual position θ3 of the third motor; Step five, according to the pre-constructed position synchronization compensation model, according to the actual position θ2 of the second motor and the actual position θ3 of the third motor, and based on the required yarn corrugation shape, obtain the synchronization feedback compensation information as the feedback signal of the second motor and the third motor to realize the position control of the yarn forming sunflower wheel.

2. A method for controlling the position of a sunflower wheel for yarn forming according to claim 1, characterized in that: Step 1: Using the pre-built first direction position given model, set the Y direction position given θ according to the required yarn corrugation shape. y , and θ is given based on the Y direction position y , the method for obtaining the Y direction position difference control information for controlling the Y direction spacing between the two sunflower wheels is as follows: According to the required yarn corrugation shape, a reasonable Y-direction position is set, and the yarn corrugation shape is a sine curve type, which is formed on the yarn surface by thermoforming; The three-phase current i of the first motor in the three-phase coordinate system is obtained by collecting current signals with two Hall current sensors. a 、i b and i c , and input into the Clarke transformation module. The transformation formula of the Clarke transformation module is: Where phase current i c It is through formula i a +i b +i c =0 calculated; The output of the Clarke transformation module is the actual current i in the stationary two-phase coordinate system. α and i β , as the input of the Park transformation module; i α and i β The actual angular position θ1 of the first motor is input into the Park transformation module to obtain the actual direct axis current i in the synchronous rotating coordinate system. d and the actual quadrature axis current i q , the Park transformation formula is: The actual AC and DC axis current i in the synchronous rotating coordinate system output by the Park transformation module q and i d The output AC and DC current of the MTPA module and After making the difference, it is used as the input of the current loop PI regulator; The actual position θ1 of the first motor acquired by the encoder is compared with the given position θ in the Y direction. y Input into the subtractor to get the angular position error θ y -θ1, and use it as the input of the position loop P regulator; the output of the position loop P regulator is the given speed ω 1ref ; Then the actual motor speed ω1 obtained by the derivation of the given point speed and the actual angular position of the motor is input into the subtractor to obtain the speed error ω 1ref -ω1 is used as the input of the speed loop PI regulator; the output of the speed loop PI regulator is the electromagnetic torque given The Y-direction position difference control information for controlling the Y-direction spacing between the two sunflower wheels is formed and used as the input of the MTPA module.

3. A sunflower wheel position control method for yarn forming as claimed in claim 2, characterized in that: Step 2: Using the pre-built first motor driving model, based on the Y direction position difference control information, the first motor driving signal in the Y direction is obtained, and the actual position θ1 after the first motor is running is obtained as follows: Input the Y-direction position gap control information into the MTPA module; MTPA module outputs a given quadrature axis current The actual quadrature axis current i q The error between the given quadrature axis current and the actual quadrature axis current is obtained by the subtractor, and then input into the quadrature axis current PI controller for calculation to obtain the given quadrature axis voltage. MTPA module outputs a given direct axis current The actual direct axis current i d The error between the given direct-axis current and the actual direct-axis current is obtained by the subtractor, and then input into the direct-axis current PI controller for calculation to obtain the given direct-axis voltage. The formula is as follows: Among them, K piq is the proportional coefficient of the quadrature axis current PI controller; K Iiq is the integral coefficient of the quadrature axis current PI controller; K pid is the proportional coefficient of the direct-axis current PI controller; K Iid is the integral coefficient of the direct axis current PI controller; given the quadrature axis voltage and a given direct axis voltage Input them into IPark transformation module together; Given quadrature axis voltage Given direct axis voltage The actual electrical angle θ1 is transformed into a given voltage in a stationary two-phase coordinate system by the IPark transformation module and And input to the space vector pulse width modulation module, the voltage given value in the static two-phase coordinate system and Through the space vector pulse width modulation module, six PWM signals are obtained as inputs for controlling the three-phase inverter; The three-phase inverter switches the six switching tubes according to the six input PWM signals and outputs a three-phase voltage, that is, obtaining the first motor drive signal in the Y direction, and inputs the first motor drive signal in the Y direction into the first motor to realize the driving of the first motor, and obtains the actual position θ1 of the first motor after operation through the encoder.

4. A method for controlling the position of a sunflower wheel for yarn forming according to claim 1, characterized in that: Step 3: Use the pre-built second direction position given model to set the X direction position given as θ according to the required yarn corrugation shape. x1 and position given by θ x2 ; and give a θ according to the position in the X direction x1 and position given by θ x2 , and the actual position θ1 after the first motor is running, the method for obtaining the X-direction position difference control information for controlling the X-direction spacing between the two sunflower wheels is as follows: When the first motor runs to a given position, according to the required yarn corrugation shape, the trajectory planning and position synchronization control module is used to obtain the X-direction position given value θ x1 and position given by θ x2 , and are input into the second motor and the third motor respectively; The second motor sets the actual position θ2 of the second motor acquired by the encoder to the position in the input X direction by θ x1 Input into the subtractor to get the angular position error θ x1 -θ2, as the X-direction position difference control information for controlling the X-direction spacing between the two sunflower wheels, and is used as the input of the position loop P regulator.

5. A method for controlling the position of a sunflower wheel for yarn forming according to claim 1, characterized in that: Step 4: Using the pre-built second motor drive model, based on the X-direction position difference control information, the second motor drive signal and the third motor drive signal in the X-direction are obtained, and the actual position θ2 of the second motor and the actual position θ3 of the third motor are obtained as follows: Based on the X-direction position difference control information, the second motor drive signal and the third motor drive signal in the X-direction are obtained through the same process as the first motor, and the actual position θ2 of the second motor and the actual position θ3 of the third motor are obtained through the encoder.

6. A method for controlling the position of a sunflower wheel for yarn forming according to claim 1, characterized in that: Step 5: According to the pre-constructed position synchronization compensation model, according to the actual position θ2 of the second motor and the actual position θ3 of the third motor, and based on the required yarn corrugation shape, the method of obtaining the synchronization feedback compensation information as the feedback signal of the second motor and the third motor is as follows: After the collected current signal is transformed by Clark and Park, the Park transformation module outputs the actual AC and DC axis current i q and i d The AC and DC axis currents output by the MTPA module are given and Subtract the two and output the AC and DC axis currents to the load torque identification module at the same time; The load torque identification module receives the actual speed ω calculated by the derivative m The actual AC and DC current i q and i d Perform calculations to obtain the identified load torque The load torque identification module calculates the identified load torque of the second motor. As input for position synchronization control; The third motor is similar to the second motor, and the final output is the identified load torque To the synchronous compensation module; The actual position θ2 of the second motor and the actual position θ3 of the third motor fed back by the encoder, as well as the identified load torque output by the two-position servo system and load torque identification Input position synchronization control module, after calculation, the synchronization control module outputs synchronization feedback compensation current 2 and synchronous feedback compensation current three As synchronous feedback compensation information, it is input into the second motor and the third motor to ensure the synchronous operation of the two sunflower wheel shafts.

7. A method for controlling the position of a sunflower wheel for yarn forming as claimed in claim 6, characterized in that: Output synchronous feedback compensation current 2 and synchronous feedback compensation current three The method is as follows: The voltage equation of the permanent magnet synchronous motor under the dq axis of the synchronous rotating coordinate system is: The torque equation of the permanent magnet synchronous motor under the dq coordinate axis is: Where, T e is the electromagnetic torque; P n is the number of motor rotor pole pairs; For surface mounted permanent magnet synchronous motor L d =L q , so the torque equation is simplified to: The kinematic equation of a permanent magnet synchronous motor is as follows: Define the state variables as: According to the torque equation and kinematic equation of the permanent magnet synchronous motor, the state equation group is written as follows: The integral sliding surface s of the selected system is: s=c1x1+c2x2 (10) Select the exponential approach law and replace the sign function with the saturation function to obtain the sign function replacement formula, which is shown in the following formula: By replacing the formula with the state equation group and the symbolic function, the expression of the sliding mode feedback compensation current is obtained as follows: In order to make the system meet the stability requirements, the Lyapunov function is selected as: Derivative of the above formula: According to Lyapunov's second theorem, the designed sliding mode controller must satisfy In order for the system to meet the stability condition; in the formula, ε and k are both constants greater than 0; therefore, regardless of whether s is positive or negative, s and its derivative have opposite signs, that is, When the conditions for reaching the sliding surface are met, the system enters the sliding mode; The calculated sliding mode feedback compensation current is output as synchronous feedback compensation current 2 after passing through gains k1 and k2. and synchronous feedback compensation current three 8. A sunflower wheel position control system for yarn forming, characterized in that: Including Y-direction position servo system and X-direction dual-axis position synchronous servo system; The Y-direction position servo system includes a PLC-based trajectory planning and position synchronization control module, a first position servo system, a first motor and an encoder 1; The X-direction dual-axis position synchronous servo system includes a second position servo system, a third position servo system, a second motor, a third motor, two reducers and two sunflower wheels; The output of the PLC-based trajectory planning and position synchronization control module is connected to the input of the three position servo systems respectively to give position servo instructions; The output of the first position servo system is connected to the input of the first motor, the first motor is connected to the first reducer through a coupling, the reducer is connected to the lead screw, forming a Y-direction position servo system; The output of the second position servo system is connected to the input of the second motor, the second motor is connected to the second reducer through a coupling, and the second reducer is connected to the sunflower wheel through a coupling to form a sunflower wheel shaft; The third position servo system, the third motor, the third reducer and the second sunflower wheel form another sunflower wheel shaft in the same manner; The two sunflower wheel shafts are connected to the first reducer through a lead screw to form an X-direction dual-axis position synchronous servo system.

9. A method for controlling the position of a sunflower wheel for yarn forming, characterized in that: A sunflower wheel position control system for yarn forming as claimed in claim 8, comprising the following contents: The trajectory planning and position synchronization control module based on PLC first gives the position given θ y as an input to the first position servo system; Input θ y The difference between the motor angular position θ1 fed back by the encoder is input into the position loop P regulator, and the given speed ω is output after calculation. 1ref The difference between the motor speed ω1 and the speed loop PI regulator is input; The PI regulator outputs the given electromagnetic torque after calculation MTPA module according to the given electromagnetic torque Use the lookup table method to find the optimal dq axis current and The difference between the collected dq axis current after Clark transformation and Park transformation is input into the current loop PI regulator; The current loop PI regulator outputs a given dq axis voltage after calculation and Then the Ipark conversion module outputs the two-phase coordinate system voltage and To the space vector pulse width modulation (SVPWM) module, after calculation, six PWM signals are output to control the three-phase inverter to output voltage, thereby driving the permanent magnet synchronous motor. After the permanent magnet synchronous motor passes through the reducer, the two sunflower wheel shafts are controlled by the lead screw to slowly approach or move away. When the position feedback of the first motor is equal to the position setting, that is, θ1 = θ y When , the rotor of the first motor reaches a given position and stops working; The trajectory planning and position synchronization control module based on PLC outputs the same position given θ x1 and θ x2 to the second motor and the third motor; Input position given θ x1 The difference between the encoder position feedback θ2 is input into the second motor, and the given electromagnetic torque is output after passing through the position loop and speed loop. The optimal dq axis given current is obtained by using the lookup table method through the MTPA module and The given q-axis current is synchronized with the feedback received from the PLC-based trajectory planning and position synchronization control module And the collected q-axis current i obtained by Clark transformation and Park transformation q At the same time, the difference is made between the given d-axis current and the collected d-axis current i obtained by Clark transformation and Park transformation. d Make a difference and input it into the current loop PI regulator; After the inverse Park transformation module and the space vector pulse width modulation module output six PWM signals to control the three-phase inverter to output three-phase voltage to control the motor; The collected dq axis current after Park transformation is input into the load torque identification module. At the same time, the rotor position collected by the encoder is calculated by the derivative to obtain the speed ω m It is also input into the load moment identification module, and the estimated load moment is output after calculation. The control process of the third motor is exactly the same as that of the second motor; The second position servo system and the third position servo system calculate the estimated load torque and The current is input into the position synchronization control module for calculation, and the feedback synchronization q-axis current is input into the second position servo system and the third position servo system for compensation to ensure the synchronous operation of the two sunflower wheel shafts.

10. An electronic device, characterized in that: It includes: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement a sunflower wheel position control method for yarn molding as described in any one of claims 1-7.

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