Composite material mirror image fiber placement method and system

Abstract

The invention belongs to the technical field of material processing, and relates to a mirror image fiber placement method and system for a composite material. The mirror image fiber placement method of the composite material comprises the following steps: laying two fiber ribbons in a mirror image symmetry manner without using a mold, and repeating the fiber placement process for multiple times. The composite mirror image fiber placement system comprises a hardware part; the hardware part comprises a left part and a right part which are symmetrical, the right part comprises a main body plate (17), a pressure component, a shearing component, a re-conveying component, a tension component, a heat source component, a connecting piece (3) and a fiber placement tail end movement mechanism, and the pressure component, the shearing component, the re-conveying component and the tension component are sequentially arranged from front to back in the fiber moving direction; the heat source component comprises a heater (6), and the heater (6) is used for heating the ribbon (19). The performance of the composite material product is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material processing, and relates to a composite material mirror image fiber laying method and system; the application is a divisional application of application number 2024114532125, application date October 17, 2024, and name "a moldless mirror image fiber laying method and a moldless mirror image fiber laying system". BACKGROUND

[0002] In the field of material processing, fiber laying technology, as a key process for composite material manufacturing, is widely used in the production of complex components such as aircraft wings. Traditional fiber laying technology relies on pre-manufactured metal molds, which need to be customized according to the curved surface shape of the component. Not only is it time-consuming and material-consuming, but each different component also requires an independent mold, greatly limiting the flexibility and efficiency of production. In addition, the design and manufacturing process of the mold is complex and requires high technical requirements, further increasing the technical threshold and cost investment.

[0003] In the field of material processing, mirror image processing technology generally refers to using two or more sets of identical or symmetrical processing equipment to simultaneously process the two sides of the workpiece to be processed, thereby achieving accurate and symmetrical processing of the workpiece. In theory, if mirror image processing technology can be combined with fiber laying technology, two sets of identical fiber laying equipment can be used, one on each side of the workpiece to be processed, and both in a mirror-symmetrical position. The two devices can provide necessary support for each other during the fiber laying process without the need for molds, achieving moldless fiber laying. However, this idea is extremely difficult to implement because:

[0004] 1. In the fiber laying process, the curing heat is provided by the heaters on both sides, resulting in a complex and unstable heat transfer path. As the number of fiber layers increases and the structure of the intermediate layer changes, the heat transfer effect of the side heat becomes unpredictable, causing temperature fluctuations. This temperature fluctuation directly affects the curing quality of the thermoplastic resin, which may cause material performance degradation, brittle cracks, and even burning and other serious problems;

[0005] 2. If two driven pressure rollers are used to generate compaction pressure by pressing each other, due to the power source, small contact area, and high curvature characteristics of the pressure rollers, it is easy to cause a dramatic fluctuation in pressure. Unstable pressure not only affects the filling effect of the resin on the fiber gap, which may form bubbles or voids and reduce the mechanical properties of the composite material, but also may cause excessive extrusion of the resin, resulting in uneven interlayer adhesion between the fibers and weakening the interlaminar peel strength of the composite material;

[0006] 3. In the fiber laying process, mechanical arms, gantries, and other motion mechanisms are usually used. The motion accuracy and rigidity of these motion mechanisms are relatively low, much lower than that of machine tools, which increases the difficulty of pressure and temperature control during the fiber laying process.

[0007] Therefore, if the mirror image processing technology and the filament laying process are to be well combined, the problem to be solved is how to accurately control the temperature and pressure during the filament laying process.

[0008] Currently, there are some technologies for controlling temperature and pressure. For example, patent application US202117401138A discloses an in-situ monitoring method for a compaction roller in a composite filament laying process, which uses an infrared thermal imager to collect temperature data for online monitoring and feedback control. However, this patent application is for traditional mold filament laying or flat filament laying scenarios, and the compaction roller temperature profile is analyzed to infer the composite material defect situation. This method is easily disturbed by various factors and is not suitable for moldless filament laying.

[0009] In addition, existing pressure control technologies are usually based on mold compaction force prediction (for example, documents "Modeling and experimental validation of compaction pressure distribution for automated fiber placement, Composite Structures, Volume 256, 2021, 113101, ISSN0263-8223" and "Pressure distribution for automated fiber placement and design optimization of compaction rollers. Journal of Reinforced Plastics and Composites. 2019; 38(18): 860-870"). These technologies are also not suitable for moldless filament laying. SUMMARY

[0010] The purpose of the present application is to solve the problems existing in the prior art and provide a composite material mirror image filament laying method and system.

[0011] To achieve the above-mentioned purpose, the technical solutions adopted by the present application are as follows:

[0012] A moldless mirror image filament laying method does not use a mold, and lays two belts in a mirror image symmetrical manner, and repeats the filament laying process multiple times.

[0013] During the filament laying process, the real belt temperature is obtained in real time, and the temperature difference is calculated in real time. The modification value of the heater output power is calculated in real time according to the temperature difference, and the heater output power is updated in real time.

[0014] The temperature difference is the difference between the real belt temperature and the target belt temperature.

[0015] The modified value of the heater output power = kp* × T + ki* × ΣT + kd* × ΔT;

[0016] In the formula, T is the temperature difference at the current time of the current filament laying process, ΣT is the sum of all temperature differences up to the current time of the current filament laying process, and ΔT = the temperature difference at the current time of the current filament laying process - the temperature difference at the previous time of the current filament laying process; kp*, ki*, and kd* are a combination of controller parameters that meet the requirements found by continuously iterating and optimizing a reinforcement learning model through simulation in a virtual environment;

[0017] Real-time acquisition of the real tape pressure during the filament laying process and real-time calculation of the pressure difference, real-time calculation of the modified value of the laying end motion mechanism (a mechanical arm or other motion mechanism, such as a gantry or any single-axis or multi-axis motion execution mechanism) path according to the pressure difference, and real-time updating of the laying end motion mechanism path;

[0018] The pressure difference = the difference between the real tape pressure and the target tape pressure;

[0019] The modified value of the laying end motion mechanism path = kp' × P + ki' × ΣP + kd' × ΔP;

[0020] In the formula, P is the pressure difference at the current time of the current filament laying process, ΣP is the sum of all pressure differences up to the current time of the current filament laying process, and ΔP = the pressure difference at the current time of the current filament laying process - the pressure difference at the previous time of the current filament laying process; kp', ki', and kd' are a combination of controller parameters that meet the requirements found by continuously iterating and optimizing a reinforcement learning model through simulation in a virtual environment.

[0021] As a preferred technical solution:

[0022] The kp*, ki*, and kd* in the mirror image filament laying method described above are obtained through the following process:

[0023] (a) Generate a set of kp, ki, and kd;

[0024] (b) Let i = 1;

[0025] (c) Perform the same simulation as the actual process in a virtual space, and start the i-th filament laying process;

[0026] (d) Let j = 1, and let the virtual heater output power = the heater output power in the actual process;

[0027] (e) Input the virtual heater output power and the corresponding heating time into the prediction model A, and output the predicted tape temperature from the prediction model A, calculate the difference between the predicted tape temperature and the target tape temperature, and obtain the j-th temperature difference of the i-th temperature difference sequence;

[0028] Prediction model A is a trained deep learning model. During training, the heater output power and the corresponding heating time are used as the input of the deep learning model, and the ribbon temperature is used as the theoretical output of the deep learning model. The parameters of the deep learning model are continuously adjusted.

[0029] (f) Determine whether the i-th fiber placement process is completed. If not, calculate the modified value of the virtual heater output power using the following formula, update the virtual heater output power, set j = j + 1, and return to step (e); otherwise, proceed to the next step;

[0030] Modified value of virtual heater output power = kp×T+ki×ΣT+kd×ΔT;

[0031] Where T is the jth temperature difference in the i-th temperature difference sequence, ΣT is the sum of all temperature differences in the i-th temperature difference sequence, ΔT = the jth temperature difference in the i-th temperature difference sequence - the j-1th temperature difference in the i-th temperature difference sequence. When j = 1, let ΔT = 0;

[0032] (g) Score the i-th temperature difference sequence and determine whether the score of the i-th temperature difference sequence reaches the set value. If so, output the last set of kp, ki, and kd as kp*, ki*, and kd*; otherwise, proceed to the next step;

[0033] (h) Determine whether all the laying processes are completed. If not, input the last set of kp, ki, kd and the i-th temperature difference sequence into the reinforcement learning model with a reward function, which outputs a new set of kp, ki, kd, and sets i=i+1, and then returns to step (c); otherwise, report an error, inform the technician that no suitable parameters have been found, and return to step (a).

[0034] For the aforementioned patternless mirror-image fiber placement method, the process for obtaining the prediction model A is as follows:

[0035] (i) Establishing a data set;

[0036] Collect the heater output power, corresponding heating time and actual ribbon temperature in the same historical process as the current process;

[0037] At the same time, the same simulation as the actual process is performed in the virtual space to obtain the virtual heater output power and the corresponding heating time and virtual ribbon temperature;

[0038] (ii) Data augmentation: increasing the size of the dataset to obtain a training set;

[0039] (iii) Establish and train a deep learning model to obtain prediction model A.

[0040] A moldless mirror image filament laying method as described above, kp', ki', kd' are obtained through the following process:

[0041] (A) Generate a set of kp, ki, kd;

[0042] (B) Let i = 1;

[0043] (C) Perform the same simulation as the actual process in the virtual space, start the i th laying process;

[0044] (D) Let j = 1, let the virtual filament laying end motion mechanism path = the filament laying end motion mechanism path in the actual process;

[0045] (E) Input the virtual filament laying end motion mechanism path into the prediction model B, output the predicted tape pressure from it, calculate the difference between the predicted tape pressure and the target tape pressure, and get the j th pressure difference of the i th pressure difference sequence;

[0046] The prediction model B is a trained deep learning model, and when training, the filament laying end motion mechanism path is taken as the input of the deep learning model, and the tape pressure is taken as the theoretical output of the deep learning model. The parameters of the deep learning model are adjusted constantly;

[0047] (F) Determine whether the i th laying process is completed, if not, calculate the modification value of the virtual filament laying end motion mechanism path using the following formula, update the virtual filament laying end motion mechanism path, and then let j = j + 1, return to step (E); otherwise, go to the next step;

[0048] The modification value of the virtual filament laying end motion mechanism path = kp × P + ki × ΣP + kd × ΔP;

[0049] In the formula, P is the j th pressure difference of the i th pressure difference sequence, ΣP is the sum of all pressure differences of the i th pressure difference sequence, and ΔP = the j th pressure difference of the i th pressure difference sequence - the j-1 th pressure difference of the i th pressure difference sequence. When j = 1, let ΔP = 0;

[0050] (G) Score the i th pressure difference sequence, determine whether the score of the i th pressure difference sequence reaches the set value, if yes, output the last set of kp, ki, kd, and take it as kp', ki', kd'; otherwise, go to the next step;

[0051] (H) Determine whether all laying processes are completed, if not, input the last set of kp, ki, kd and the i th pressure difference sequence into the reinforcement learning model with a reward function, output a new set of kp, ki, kd from it, let i = i + 1, and return to step (C); otherwise, report an error and inform the technician that no suitable parameters are found, and return to step (A).

[0052] The acquisition process of the prediction model B is as follows:

[0053] (I) Establish a data set;

[0054] Collect the tape laying end effector path and the real tape pressure in the historical process same as the current process;

[0055] At the same time, the same simulation as the actual process is performed in the virtual space to obtain the virtual tape laying end effector path and the virtual tape pressure;

[0056] (II) Data enhancement, improve the size of the data set, and obtain a training set;

[0057] (III) Establish and train a deep learning model, that is, obtain the prediction model B.

[0058] The application also provides a moldless mirror image tape laying system, which comprises a hardware part and a control system;

[0059] The hardware part comprises symmetrical left and right parts, and the right part comprises a main plate, a pressure component, a cutting component, a re-feeding component, a tension component, a heat source component, a connecting component and a tape laying end effector;

[0060] The pressure component comprises a pressure sensor;

[0061] The heat source component comprises a heater and an infrared thermal imager, the heater is used for heating the tape, and the infrared thermal imager is used for real-time shooting of the tape laying area to obtain temperature field data of the tape;

[0062] The control system comprises a temperature stability control subsystem, a pressure stability control subsystem, a control instruction generation subsystem, a tape laying end effector control subsystem and a tape laying end function mechanism control subsystem;

[0063] The infrared thermal imager is used for real-time acquisition of the real tape temperature during the tape laying process, and the real tape temperature is sent to the temperature stability control subsystem in real time;

[0064] The temperature stability control subsystem is used for real-time calculation of a temperature difference, real-time calculation of a modification value of the heater output power according to the temperature difference, and real-time sending of the modification value of the heater output power to the control instruction generation subsystem;

[0065] The temperature difference is the difference between the real tape temperature and the target tape temperature;

[0066] The modification value of the heater output power is kp*×T+ki*×ΣT+kd*×ΔT;

[0067] In the formula, T is the temperature difference at the current time of the current fiber laying process, ΣT is the sum of all temperature differences up to the current time of the current fiber laying process, ΔT = temperature difference at the current time of the current fiber laying process - temperature difference at the last time of the current fiber laying process; kp*, ki*, and kd* are the required controller parameter combinations found by continuously iterating and optimizing the reinforcement learning model through simulation in a virtual environment;

[0068] The pressure sensor is used to obtain the real tape pressure in real time during the fiber laying process and send the real tape pressure to the pressure stabilization control subsystem in real time;

[0069] The pressure stabilization control subsystem is used to calculate the pressure difference in real time, calculate the modification value of the fiber laying end motion mechanism path according to the pressure difference in real time, and send the modification value of the fiber laying end motion mechanism path to the control instruction generation subsystem in real time;

[0070] The pressure difference = the difference between the real tape pressure and the target tape pressure;

[0071] The modification value of the fiber laying end motion mechanism path = kp' × P + ki' × ΣP + kd' × ΔP;

[0072] In the formula, P is the pressure difference at the current time of the current fiber laying process, ΣP is the sum of all pressure differences up to the current time of the current fiber laying process, ΔP = pressure difference at the current time of the current fiber laying process - pressure difference at the last time of the current fiber laying process; kp', ki', and kd' are the required controller parameter combinations found by continuously iterating and optimizing the reinforcement learning model through simulation in a virtual environment;

[0073] The control instruction generation subsystem is used to generate control instructions according to the modification value of the heater output power and the modification value of the fiber laying end motion mechanism path, and then send them to the fiber laying end function mechanism control subsystem and the fiber laying end motion mechanism control subsystem;

[0074] The fiber laying end function mechanism control subsystem is used to update the heater output power in real time after processing the control instructions;

[0075] The fiber laying end motion mechanism control subsystem is used to update the fiber laying end motion mechanism path in real time after processing the control instructions.

[0076] As a preferred technical solution:

[0077] The pressure component further comprises a pressure roller, a supporting device, a heat insulation asbestos plate and a cylinder a, the central shaft of the pressure roller is parallel to the front-back direction, the pressure roller, the supporting device, the heat insulation asbestos plate, the pressure sensor, and the cylinder a are sequentially connected from left to right, the cylinder a is fixed on the main plate and is used for pushing the pressure roller to the left to cooperate with the pressure roller on the opposite side to extrude and generate compaction pressure; the heat insulation asbestos plate can insulate the heat on the pressure roller to prevent damage to the pressure sensor;

[0078] The cutting component comprises a cylinder c and a blade, the cylinder c is used for driving the blade to cut the tape, and the cylinder c is fixed on the main plate;

[0079] The re-sending component comprises a driving wheel, a driven wheel, a motor and a cylinder b, the driving wheel and the driven wheel are vertically arranged and parallel to the left-right direction, the motor is used for driving the driving wheel to rotate, the cylinder b is used for pressing the driven wheel to the driving wheel, and the motor and the cylinder b are fixed on the main plate; before the tape is installed to start the laying, the cylinder b is not started, and the driving wheel and the driven wheel are separated, when the laying is started, the tape is installed into the channel and passes between the driving wheel and the driven wheel, the cylinder b is started, the driven wheel is pressed to the driving wheel to realize the pressing of the tape, and the motor drives the driving wheel to rotate in the laying process, and drives the driven wheel to extrude the tape together;

[0080] The tension component comprises a roll and a brake, the roll is used for winding the tape, and the roll is forced to rotate under the driving of the re-sending component in the laying process to realize the feeding of the tape, the brake is used for providing torque for the roll to maintain the stable tension of the tape feeding, so that the tape is not fed unstably under the high-speed rotation of the roll, and even falls off, and the roll and the brake are fixed on the main plate;

[0081] The heat source component further comprises a supporting plate, the heater is fixed on the main plate, and the infrared thermal imager is fixed on the main plate through the supporting plate;

[0082] The connecting piece is fixed on the main plate and connected with the tail end of the laying tail end movement mechanism.

[0083] The application further provides a composite material mirror image tape laying method, which does not use a mold and lays two tapes in a mirror image symmetrical mode.

[0084] The application further provides a composite material mirror image tape laying system, which comprises a hardware part;

[0085] The hardware part comprises symmetrical left and right parts, the right part comprises a main plate, a pressure component, a cutting component, a re-sending component, a tension component, a heat source component, a connecting piece and a laying tail end movement mechanism, and the pressure component, the cutting component, the re-sending component and the tension component are sequentially arranged from front to back along the tape laying direction;

[0086] The heat source component comprises a heater for heating the tape.

[0087] As a preferred technical solution:

[0088] The composite material mirror image fiber laying system as described above, the pressure component comprises a compression roller, a support device, a heat insulation asbestos board and a cylinder a, the central axis of the compression roller is parallel to the front-back direction, the compression roller, the support device and the heat insulation asbestos board are sequentially connected from left to right, and the cylinder a is fixed on the main body plate and used for pushing the compression roller to the left.

[0089] The composite material mirror image fiber laying system as described above, the cutting component comprises a cylinder c and a blade, the cylinder c is used for driving the blade to cut the tape, and the cylinder c is fixed on the main body plate.

[0090] The composite material mirror image fiber laying system as described above, the re-sending component comprises a driving wheel, a driven wheel, a motor and a cylinder b, the driving wheel and the driven wheel are both vertically arranged and parallel to the left-right direction, the motor is used for driving the driving wheel to rotate, the cylinder b is used for pressing the driven wheel to the driving wheel, and the motor and the cylinder b are fixed on the main body plate.

[0091] The composite material mirror image fiber laying system as described above, the tension component comprises a roll and a brake, the roll is used for winding the tape, the brake is used for providing torque for the roll to maintain stable tension of the fiber laying, and the roll and the brake are both fixed on the main body plate.

[0092] The composite material mirror image fiber laying system as described above, the heater is fixed on the main body plate.

[0093] The composite material mirror image fiber laying system as described above, the connecting piece is fixed on the main body plate and connected with the end of the fiber laying end motion mechanism.

[0094] Beneficial effects:

[0095] (1) The present application discloses a mold-free mirror image fiber laying technology, which discards the dependence on molds in traditional fiber laying technology, avoids the time and material costs required for mold manufacturing, and solves the problem that different components require different molds, so that production is more flexible and can quickly adapt to diversified component shapes, thereby significantly improving production efficiency.

[0096] (2) The present application obtains real-time tape temperature and pressure, and uses the controller parameter combination optimized by the reinforcement learning model to real-time calculate and adjust the heater output power and the fiber laying end motion mechanism path, so as to ensure the stable control of temperature and pressure in the mold-free mirror image fiber laying process, effectively avoid the problems of uneven curing or too fast caused by temperature fluctuation, material performance decline and other problems, and defects such as poor bonding performance and air bubbles caused by pressure fluctuation, thereby significantly improving the final performance of the composite material product. BRIEF DESCRIPTION OF DRAWINGS

[0097] Figure 1 Front view structural schematic diagram of hardware part of the moldless mirror image filament laying system of the present application;

[0098] Figure 2 Rear view structural schematic diagram of the left part of the hardware part of the moldless mirror image filament laying system of the present application;

[0099] Figure 3 Front view structural schematic diagram of the right part of the hardware part of the moldless mirror image filament laying system of the present application;

[0100] Figure 4 Schematic diagram of the filament tape installation process;

[0101] Figure 5 Comparison of the filament laying distance-temperature curves of the experimental group 1 and the control group 1;

[0102] Figure 6 Comparison of the filament laying distance-temperature curves of the experimental group 2 and the control group 2;

[0103] Figure 7 Comparison of the filament laying distance-temperature curves of the experimental group 3 and the control group 3;

[0104] Figure 8 Comparison of the filament laying distance-pressure curves of the experimental group 4 and the control group 4;

[0105] Figure 9 Comparison of the filament laying distance-pressure curves of the experimental group 5 and the control group 5;

[0106] Figure 10 Comparison of the filament laying distance-pressure curves of the experimental group 6 and the control group 6;

[0107] Figure 11 Full flowchart of the present application, the loop from generating system control instruction file to judging whether the filament laying is finished constitutes the filament laying process, reward calculation, model training, PID parameter (i.e. kp, ki, kd in the following) adjustment, PID parameter decision flow;

[0108] Figure 12 Logical diagram of the reward calculation, model training and PID parameter adjustment of the present application;

[0109] Wherein, 1-pressure sensor, 2-cylinder a, 3-connector, 4-tobacco roll, 5-supporting plate, 6-heater, 7-infrared thermal imager, 8-cylinder c, 9-pressing roller, 10-driving wheel, 11-cylinder b, 12-following wheel, 13-motor, 14-blade, 15-brake, 16-heat insulation asbestos plate, 17-main body plate, 19-filament tape, 20-bracket. DETAILED DESCRIPTION

[0110] The application will be further described with reference to the specific embodiments. It should be understood that these embodiments are only used to explain the application and not used to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content of the application, and these equivalent forms also fall within the scope of the appended claims.

[0111] A dieless mirror image filament laying system, as shown in Figure 1 、 Figure 2 、 Figure 3 、 Figure 11 and Figure 12 , comprises a hardware part and a control system;

[0112] As shown in Figures 1 to 3 , the hardware part comprises symmetrical left and right parts, and the right part comprises a main body plate 17, a pressure component, a shearing component, a re-feeding component, a tension component, a heat source component, a connecting piece 3 and a filament laying end movement mechanism;

[0113] As shown in Figure 1 、 Figure 3 , the pressure component comprises a pressure sensor 1, a pressure roller 9, a supporting device, a heat insulation asbestos plate 16 and a cylinder a 2; the central axis of the pressure roller 9 is parallel to the front-back direction, and the pressure roller 9, the supporting device, the heat insulation asbestos plate 16, the pressure sensor 1 and the cylinder a 2 are sequentially connected from left to right, and the cylinder a 2 is fixed on the main body plate 17 and used to push the pressure roller 9 to the left;

[0114] The shearing component comprises a cylinder c 8 and a blade 14, the cylinder c 8 is used to drive the blade 14 to shear the filament tape 19, and the cylinder c 8 is fixed on the main body plate 17;

[0115] As shown in Figure 2 、 Figure 3 , the re-feeding component comprises a driving wheel 10, a driven wheel 12, a motor 13 and a cylinder b 11, the driving wheel 10 and the driven wheel 12 are both vertically arranged and parallel to the left-right direction, the motor 13 is used to drive the driving wheel 10 to rotate, and the cylinder b 11 is used to press the driven wheel 12 to the driving wheel 10, and the motor 13 and the cylinder b 11 are fixed on the main body plate 17;

[0116] The tension component comprises a material roll 4 and a brake 15, the material roll 4 is used to wind the filament tape 19, and the brake 15 is used to provide torque for the material roll 4 to maintain stable tension force of the filament feeding, and the material roll 4 and the brake 15 are both fixed on the main body plate 17;

[0117] The heat source component includes a heater 6, an infrared thermal imager 7 and a support plate 5; the heater 6 is used for heating the tape 19; the infrared thermal imager 7 is used for real-time shooting of the tape laying area to obtain the temperature field data of the tape 19; the heater 6 is fixed on the main plate 17, and the infrared thermal imager 7 is fixed on the main plate 17 through the support plate 5;

[0118] The connecting piece 3 is fixed on the main plate 17 and connected with the end of the tape laying end movement mechanism;

[0119] The control system includes a temperature stability control subsystem, a pressure stability control subsystem, a control instruction generation subsystem, a tape laying end movement mechanism control subsystem and a tape laying end function mechanism control subsystem;

[0120] The infrared thermal imager 7 is also used for real-time acquisition of the real tape temperature during the tape laying process and real-time sending of the real tape temperature to the temperature stability control subsystem; the temperature stability control subsystem is used for real-time calculation of the temperature difference, real-time calculation of the modification value of the heater output power according to the temperature difference, and real-time sending of the modification value of the heater output power to the control instruction generation subsystem;

[0121] The temperature difference is the difference between the real tape temperature and the target tape temperature;

[0122] The modification value of the heater output power is kp*×T+ki*×ΣT+kd*×ΔT;

[0123] In the formula, T is the temperature difference at the current time of the current tape laying process, ΣT is the sum of all temperature differences up to the current time of the current tape laying process, and ΔT is the temperature difference at the current time of the current tape laying process minus the temperature difference at the previous time of the current tape laying process; kp*, ki* and kd* are obtained through the following process:

[0124] (a) generating a set of kp, ki and kd;

[0125] (b) setting i=1;

[0126] (c) performing a simulation identical to the actual process in a virtual space and starting the i th tape laying process;

[0127] (d) setting j=1 and setting the virtual heater output power equal to the heater output power in the actual process;

[0128] (e) inputting the virtual heater output power and the corresponding heating time into the prediction model A to output the predicted tape temperature, calculating the difference between the predicted tape temperature and the target tape temperature to obtain the j th temperature difference of the i th temperature difference sequence;

[0129] The acquisition process of the prediction model A is as follows:

[0130] (i) establishing a data set;

[0131] Collecting the heater output power and corresponding heating time and real tape temperature in the historical process same as the current process;

[0132] At the same time, the simulation same as the actual process is performed in the virtual space, and the virtual heater output power and corresponding heating time and virtual tape temperature are obtained;

[0133] (ii) Data enhancement, improving the size of the data set, obtaining the training set;

[0134] (iii) Establishing and training a deep learning model, i.e. obtaining the prediction model A;

[0135] (f) judging whether the i-th laying process is completed, if not, calculating the modification value of the virtual heater output power by using the following formula, updating the virtual heater output power, and returning to step (e) after j = j + 1; otherwise, going to the next step;

[0136] The modification value of the virtual heater output power = kp x T + ki x ΣT + kd x ΔT;

[0137] In the formula, T is the j-th temperature difference of the i-th temperature difference sequence, ΣT is the sum of all temperature differences of the i-th temperature difference sequence, and ΔT = the j-th temperature difference of the i-th temperature difference sequence - the j-1-th temperature difference of the i-th temperature difference sequence, when j = 1, ΔT = 0;

[0138] (g) scoring the i-th temperature difference sequence, and judging whether the score of the i-th temperature difference sequence reaches the set value, if yes, outputting the last set of kp, ki and kd as kp*, ki* and kd*, otherwise, going to the next step;

[0139] (h) judging whether all laying processes are completed, if not, inputting the last set of kp, ki and kd and the i-th temperature difference sequence into the reinforcement learning model provided with a reward function, outputting a new set of kp, ki and kd from the reinforcement learning model, and returning to step (c) after i = i + 1; otherwise, returning to step (a);

[0140] The pressure sensor 1 is used to obtain the real tape pressure in real time during the laying process, and to send the real tape pressure to the pressure stabilization control subsystem in real time; the pressure stabilization control subsystem is used to calculate the pressure difference in real time, to calculate the modification value of the laying end motion mechanism path according to the pressure difference in real time, and to send the modification value of the laying end motion mechanism path to the control instruction generation subsystem in real time;

[0141] The pressure difference = the difference between the real tape pressure and the target tape pressure;

[0142] The modification value of the filament laying end motion mechanism path = kp' x P + ki' x ∑P + kd' x ΔP;

[0143] wherein P is the pressure difference at the current time of the current filament laying process, ∑P is the sum of all pressure differences up to the current time of the current filament laying process, ΔP = the pressure difference at the current time of the current filament laying process - the pressure difference at the previous time of the current filament laying process; kp', ki', kd' are obtained through the following process:

[0144] (A) generating a set of kp, ki, kd;

[0145] (B) setting i = 1;

[0146] (C) performing a simulation identical to the actual process in a virtual space, starting the i-th filament laying process;

[0147] (D) setting j = 1, and setting the virtual filament laying end motion mechanism path = the filament laying end motion mechanism path in the actual process;

[0148] (E) inputting the virtual filament laying end motion mechanism path into the prediction model B, outputting the predicted tape pressure therefrom, calculating the difference between the predicted tape pressure and the target tape pressure to obtain the j-th pressure difference of the i-th pressure difference sequence;

[0149] The acquisition process of the prediction model B is as follows:

[0150] (I) establishing a data set;

[0151] collecting the filament laying end motion mechanism path and the real tape pressure in a historical process identical to the current process;

[0152] Meanwhile, performing a simulation identical to the actual process in a virtual space to obtain the virtual filament laying end motion mechanism path and the virtual tape pressure;

[0153] (II) data augmentation to increase the size of the data set to obtain a training set;

[0154] (III) establishing and training a deep learning model to obtain the prediction model B;

[0155] (F) determining whether the i-th filament laying process is completed, if not, calculating the modification value of the virtual filament laying end motion mechanism path using the following formula, updating the virtual filament laying end motion mechanism path, setting j = j + 1, and returning to step (E); otherwise, proceeding to the next step;

[0156] The modification value of the virtual filament laying end motion mechanism path = kp x P + ki x ∑P + kd x ΔP;

[0157] Where P is the jth pressure difference in the i-th pressure difference sequence, ΣP is the sum of all pressure differences in the i-th pressure difference sequence, ΔP = the jth pressure difference in the i-th pressure difference sequence - the j-1th pressure difference in the i-th pressure difference sequence. When j = 1, let ΔP = 0;

[0158] (G) Score the i-th pressure difference sequence and determine whether the score of the i-th pressure difference sequence reaches the set value. If yes, output the last set of kp, ki, and kd as kp', ki', and kd'; otherwise, proceed to the next step;

[0159] (H) Determine whether all the fiber placement processes are completed. If not, input the last set of kp, ki, kd and the i-th pressure difference sequence into the reinforcement learning model with a reward function, which outputs a new set of kp, ki, kd, and sets i = i + 1, and returns to step (C). Otherwise, return to step (A);

[0160] The control instruction generation subsystem is used to generate a control instruction according to the modified value of the heater output power and the modified value of the wire placement terminal motion mechanism path, and then send the control instruction to the wire placement terminal functional mechanism control subsystem and the wire placement terminal motion mechanism control subsystem;

[0161] The fiber placement terminal functional mechanism control subsystem is used to process control instructions and update the heater output power in real time;

[0162] The wire placement terminal motion mechanism control subsystem is used to process the control instructions and update the wire placement terminal motion mechanism path in real time.

[0163] The steps of placing wires using the system of the present invention will now be described using a wire placing process performed twice as an example:

[0164] (1) Ribbon installation;

[0165] like Figure 4 As shown, after the ribbon is wound on the material roll, it passes between the driving wheel and the driven wheel, passes through the blade to the pressure roller, and is fixed on the support 20, which is a vertical frame or a truss fixed to the ground. Then, the connecting piece is connected to the end of the wire placement end movement mechanism;

[0166] When the ribbon passes between the driven wheel and the driving wheel, cylinder b starts to press the ribbon between the driven wheel and the driving wheel;

[0167] When the ribbon reaches the pressing roller, cylinder a starts to push out the pressing rollers on both sides, and squeeze with the pressing rollers on the opposite side to achieve the compression of the ribbon;

[0168] (2) First laying of wire;

[0169] Firstly, the filament laying end motion mechanism starts to move along the filament laying path, at the same time, the heater starts to heat the filament tape, the infrared thermal imager starts to take the temperature field data of the filament laying area in real time, and monitors the temperature of the filament tape, the pressure sensor obtains the pressure of the filament tape in real time, the motor drives the driving wheel and the driven wheel to rotate, and drives the filament tape to advance; in this process, the temperature stable control subsystem and the pressure stable control subsystem calculate the modification value of the output power of the heater and the modification value of the path of the filament laying end motion mechanism according to the real-time data respectively, and send to the corresponding control subsystem (i.e. the filament laying end function mechanism control subsystem or the filament laying end motion mechanism control subsystem) through the control instruction generation subsystem, so as to adjust the heating power and the filament laying path in real time, and ensure that the temperature and pressure of the filament tape are kept in the target range;

[0170] Then, when the laying is about to be completed, the cylinder c is started to drive the blade to cut the filament tape, and the excess part is cut off, after cutting, the cylinder c is reset;

[0171] Finally, the reserved filament tape between the blade and the press roller is continuously laid until the first laying is completed;

[0172] (3) the second time of laying filament;

[0173] Firstly, the filament laying end motion mechanism moves to the initial position;

[0174] Then, the filament laying end motion mechanism starts to move along the filament laying path, when the laying is about to be completed, the cylinder c is started to drive the blade to cut the filament tape, and the excess part is cut off, after cutting, the cylinder c is reset;

[0175] Finally, the reserved filament tape between the blade and the press roller is continuously laid until the second laying is completed, the heater, the motor, the infrared thermal imager, the cylinder a and the cylinder b are turned off, and the connection between the connection piece and the end of the filament laying end motion mechanism is disconnected.

[0176] In order to prove that the control system in the moldless mirror image filament laying system of the application can accurately control the temperature and pressure, the following experiments are carried out to verify it:

[0177] Experiment group 1: the moldless mirror image filament laying system of the application is adopted, the target temperature of the filament tape is set to 230 DEG C, the initial speed of the filament laying end motion mechanism is set to 10 mm / s, the initial output power of the heater is set to 90 W, and the filament is laid for 300 mm;

[0178] Control group 1: basically the same as experiment group 1, the only difference is that there is no control system in the moldless mirror image filament laying system;

[0179] Experiment group 2: the moldless mirror image filament laying system of the application is adopted, the target temperature of the filament tape is set to 380 DEG C, the initial speed of the filament laying end motion mechanism is set to 50 mm / s, the initial output power of the heater is set to 210 W, and the filament is laid for 300 mm;

[0180] Control group 2: basically same as experimental group 2, the only difference is that there is no control system in the mold-free mirror image filament laying system;

[0181] Experimental group 3: the mold-free mirror image filament laying system of the application is adopted, the target tape temperature is set to 500℃, the initial speed of the filament laying end motion mechanism is 10mm / s, the initial output power of the heater is 135W, and the filament is laid for 300mm;

[0182] Control group 3: basically same as experimental group 3, the only difference is that there is no control system in the mold-free mirror image filament laying system;

[0183] Experimental group 4: the mold-free mirror image filament laying system of the application is adopted, the target tape pressure is set to 15N, the spacing of the filament laying end motion mechanism in the vertical direction is 4mm, and the filament is laid for 300mm;

[0184] Control group 4: basically same as experimental group 4, the only difference is that there is no control system in the mold-free mirror image filament laying system;

[0185] Experimental group 5: the mold-free mirror image filament laying system of the application is adopted, the target tape pressure is set to 30N, the spacing of the filament laying end motion mechanism in the vertical direction is 4mm, and the filament is laid for 300mm;

[0186] Control group 5: basically same as experimental group 5, the only difference is that there is no control system in the mold-free mirror image filament laying system;

[0187] Experimental group 6: the mold-free mirror image filament laying system of the application is adopted, the target tape pressure is set to 45N, the spacing of the filament laying end motion mechanism in the vertical direction is 4mm, and the filament is laid for 300mm;

[0188] Control group 6: basically same as experimental group 6, the only difference is that there is no control system in the mold-free mirror image filament laying system;

[0189] The comparison of the filament laying distance-temperature curves in the filament laying process of experimental group 1 and control group 1, experimental group 2 and control group 2, and experimental group 3 and control group 3 is shown in Figure 5 , Figure 6 and Figure 7 respectively, and it can be seen from Figures 5 to 7 that compared with control groups 1-3, experimental groups 1-3 can stably control the real tape temperature in the range close to the target tape temperature;

[0190] The comparison of the filament laying distance-pressure curves in the filament laying process of experimental group 4 and control group 4, experimental group 5 and control group 5, and experimental group 6 and control group 6 is shown in Figure 8 , Figure 9 and Figure 10 respectively, and it can be seen from Figures 8 to 10It can be seen that, compared with the control group 4-6, the experimental group 4-6 can stably control the real ribbon pressure in the range close to the target ribbon pressure;

[0191] The above verification process and verification results are sufficient to prove that the control system in the mold-free mirror image ribbon laying system can accurately control the temperature and pressure.

Claims

1. A composite material mirror placement method, characterized in that: Without using a mold, two ribbons are laid in a mirror-symmetrical manner and the laying process is repeated multiple times.

2. A composite material mirror placement system, characterized in that: Including hardware part; The hardware part includes a symmetrical left part and a right part, the right part includes a main plate (17), a pressure component, a shearing component, a re-feeding component, a tension component, a heat source component, a connector (3), and a wire laying end motion mechanism, the pressure component, the shearing component, the re-feeding component, and the tension component are arranged in sequence from front to back along the wire running direction; The heat source component comprises a heater (6), and the heater (6) is used to heat the ribbon (19).

3. The composite material mirror fiber placement system according to claim 2, characterized in that: The pressure component includes a pressure roller (9), a supporting device, an insulating asbestos board (16) and a cylinder a (2). The central axis of the pressure roller (9) is parallel to the front-back direction. The pressure roller (9), the supporting device and the insulating asbestos board (16) are connected in sequence from left to right. The cylinder a (2) is fixed on the main body plate (17) and is used to push the pressure roller (9) to the left.

4. The composite material mirror fiber placement system according to claim 2, characterized in that: The shearing component comprises a cylinder c (8) and a blade (14). The cylinder c (8) is used for driving the blade (14) to shear the ribbon (19). The cylinder c (8) is fixed on the main body plate (17).

5. The composite material mirror fiber placement system according to claim 2, characterized in that: The re-feeding component includes a driving wheel (10), a driven wheel (12), a motor (13) and a cylinder b (11). The driving wheel (10) and the driven wheel (12) are arranged vertically and parallel to the left and right directions. The motor (13) is used to drive the driving wheel (10) to rotate. The cylinder b (11) is used to press the driven wheel (12) onto the driving wheel (10). The motor (13) and the cylinder b (11) are fixed on the main body plate (17).

6. The composite material mirror fiber placement system according to claim 2, characterized in that: The tension component includes a material roll (4) and a brake (15). The material roll (4) is used to wind the ribbon (19). The brake (15) is used to provide torque for the material roll (4) to maintain a stable tension force for wire feeding. The material roll (4) and the brake (15) are both fixed on the main plate (17).

7. The composite material mirror fiber placement system according to claim 2, characterized in that: The heater (6) is fixed on the main body plate (17).

8. The composite material mirror fiber placement system according to claim 2, characterized in that: The connecting piece (3) is fixed on the main body plate (17) and connected to the end of the wire laying end movement mechanism.

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