Self-adaptive parameter control method and device for stamping die of longitudinal beam of automobile body

Abstract

The invention relates to the technical field of automobile stamping control, and discloses a self-adaptive parameter control method and device for an automobile body longitudinal beam stamping die. The method comprises the following steps: collecting process data during initial stamping, converting the process data into a plate forming curve, and dividing process stages to obtain parameter deviation degrees of the stages; and a process stability index is obtained by combining plate characteristic data, so that the parameter adjustment amount of each process stage is determined, and the parameters of the corresponding execution mechanism are regulated and controlled. Parameter deviation of each process stage is dynamically captured, targeted adjustment of parameters is achieved by combining plate characteristics and process stability, die parameters can adapt to dynamic changes in the stamping process in real time, the adaptability and the forming effect of the stamping process are effectively improved, and the production efficiency is improved. And a new parameter control thought is provided for high-quality stamping of the automobile body longitudinal beam.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile stamping control, in particular to a self-adaptive parameter control method and device for automobile body longitudinal beam stamping die. BACKGROUND

[0002] The automobile body longitudinal beam is a core component supporting the body structure, with complex shape and high bearing requirement. The stamping forming process is extremely sensitive to die parameters. In current production practice, the parameter control of automobile body longitudinal beam stamping die mostly adopts the preset initial parameter mode, that is, the key parameters such as stamping pressure, speed, stroke are set according to theoretical calculation or historical experience, and remain fixed throughout the stamping process. This mode seems to simplify the operation process, but ignores many dynamic factors in actual production, resulting in unstable stamping quality.

[0003] The fluctuation of sheet properties is an important factor affecting the stamping quality. Different batches of sheet metal often have slight differences in thickness, hardness, ductility, etc. Even the same batch of sheet metal may have fluctuations in local properties due to uneven rolling process. When the die is stamped according to fixed initial parameters, these property differences will directly cause deviations between actual forming effect and expectation. For example, sheet metal with slightly lower ductility is prone to cracking in the drawing process, while sheet metal with higher hardness may have excessive springback in the bending process.

[0004] The demand for parameters varies significantly at different stages of the stamping process. The stamping of automobile body longitudinal beam usually includes drawing, bending, punching, trimming and other continuous processes. Each process has different forming mechanisms and different requirements for die actuator parameters. The drawing process requires precise control of blank holder force to avoid wrinkling or cracking, the bending process has specific requirements for die radius and punch pressure, and the punching process relies on the matching of punch speed and die gap. The traditional fixed parameter mode cannot distinguish these process differences, and uniform parameter setting will inevitably cause over-adjustment or under-adjustment in some processes.

[0005] Existing parameter adjustment methods mostly rely on human experience, lacking scientificity and real-time performance. When defects occur, operators often adjust parameters through trial and error, which not only prolongs the production cycle, but also may exacerbate the defects due to incorrect adjustment direction. Even if some production lines introduce data acquisition devices, they mostly stay at the level of simple data recording, without combining real-time process data with process stage characteristics and sheet properties, and cannot form effective parameter adjustment basis.

[0006] The cumulative effect of parameter deviation further deteriorates the stamping quality. The parameter deviation of the previous process is transmitted to the subsequent process, causing the defect to be continuously enlarged. For example, the blank holder force deviation of the drawing process can cause the local thickness of the plate to be uneven, thereby causing the stress distribution to be unbalanced in the bending process, and finally causing the longitudinal beam size precision to be out of the allowable range. The traditional control method cannot quantify and correct the parameter deviation of each process stage, and it is difficult to break this cumulative effect.

[0007] These problems collectively result in a high scrap rate and low production efficiency in the stamping production of automobile body longitudinal beams, which cannot meet the requirements of modern automobile manufacturing for high precision and high stability. How to realize dynamic adaptation of the mold parameters has become a difficult problem to be solved in the current stamping field. SUMMARY

[0008] The purpose of the present application is to provide a self-adaptive parameter control method and device for an automobile body longitudinal beam stamping die to solve the problems raised in the background art.

[0009] To achieve the above-mentioned purpose, the present application provides a self-adaptive parameter control method for an automobile body longitudinal beam stamping die, which comprises: The automobile body longitudinal beam stamping die stamps the plate according to the initial control parameters, and starts collecting process data of the stamping area in the stamping die; The collected process data is converted into the plate forming curve of the stamping area, the plate forming curve is divided into process stages, and the plate forming curve segments of the stamping area at different stamping process stages are obtained. The parameter deviation degree of each stamping process stage is determined through the corresponding plate forming curve segment; The plate characteristic data of the automobile body longitudinal beam stamping die is obtained, the process stability index when the stamping die stamps the plate according to the initial control parameters is obtained based on the plate characteristic data, and the parameter adjustment amount of each stamping process stage is determined according to the process stability index and the corresponding parameter deviation degree; The execution mechanism parameters of each stamping process stage in the automobile body longitudinal beam stamping die are regulated and controlled according to the corresponding parameter adjustment amount.

[0010] Preferably, the initial control parameters are set according to the thickness and material of the plate processed by the automobile body longitudinal beam stamping die.

[0011] Preferably, the process data of the stamping area in the stamping die is collected by a displacement sensor and a force sensor.

[0012] Preferably, the collected process data is converted into the plate forming curve of the stamping area by training the collected process data through a neural network model, and then the plate forming curve of the stamping area is obtained.

[0013] Preferably, the process division of the sheet forming curve is according to the pre-set stamping process stage.

[0014] Preferably, the parameter deviation degree of each stamping process stage is determined by the corresponding sheet forming curve segment, and specifically includes: For each stamping process stage, the sheet forming curve segment of the stamping process stage is obtained; The target parameter value corresponding to the stamping process stage in the initial control parameter is obtained; The model prediction value of the sheet forming curve segment is determined; Based on the model prediction value and the target parameter value, the parameter deviation rate of each sheet forming data point in the sheet forming curve segment is determined; The parameter deviation degree of the stamping process stage is determined by all the parameter deviation rates, and the parameter deviation degree of each stamping process stage is obtained.

[0015] Preferably, the sheet property data of the automobile body longitudinal beam stamping die is obtained by using a multi-sensor fusion technology.

[0016] Preferably, the parameter adjustment amount of each stamping process stage is determined according to the process stability index and the corresponding parameter deviation degree, and specifically includes: For each stamping process stage, the target parameter value corresponding to the stamping process stage in the initial control parameter is obtained; Based on the target parameter value, the process stability index and the parameter deviation degree of the stamping process stage, the parameter adjustment amount of the stamping process stage is determined, and the parameter adjustment amount of each stamping process stage is obtained.

[0017] Preferably, the execution mechanism parameters of each stamping process stage in the automobile body longitudinal beam stamping die are regulated and controlled according to the corresponding parameter adjustment amount, and specifically includes: For each stamping process stage in the automobile body longitudinal beam stamping die, the final execution parameter of the stamping process stage is determined according to the target parameter value corresponding to the stamping process stage in the initial control parameter and the parameter adjustment amount of the stamping process stage, and the regulation and control of the execution mechanism parameters of each stamping process stage in the automobile body longitudinal beam stamping die is completed.

[0018] Preferably, the present application also includes an automobile body longitudinal beam stamping die self-adaptive parameter control device for executing the above-mentioned automobile body longitudinal beam stamping die self-adaptive parameter control method, and the control device includes: The parameter initialization module is used to control the automobile body longitudinal beam stamping die to stamp the sheet according to the initial control parameter, and start the process data collection of the stamping area in the stamping die. a deviation determination module configured to convert the collected process data into a sheet forming curve of the stamping area, divide the sheet forming curve into sheet forming curve segments corresponding to different stamping process stages, and determine the parameter deviation degree of each stamping process stage according to the corresponding sheet forming curve segment; an adjustment amount determination module configured to obtain sheet property data of the automobile body side rail stamping die, obtain a process stability index of the stamping die when stamping the sheet according to the initial control parameters based on the sheet property data, and determine the parameter adjustment amount of each stamping process stage according to the process stability index and the corresponding parameter deviation degree; an execution control module configured to control the execution mechanism parameters of each stamping process stage in the automobile body side rail stamping die according to the corresponding parameter adjustment amount.

[0019] Compared with the prior art, the automobile body side rail stamping die self-adaptive parameter control method has the following advantages: The automobile body side rail stamping die self-adaptive parameter control method provided by the application effectively makes up for the shortcomings of the traditional parameter control mode through dynamic sensing and accurate control of the stamping process. The core value lies in deeply fusing real-time process data, process stage characteristics and sheet properties to form a closed-loop parameter adjustment mechanism, so that the die parameters can be dynamically adapted to the changes in the stamping process.

[0020] In terms of the pertinence of parameter adjustment, the method can accurately locate the parameter deviation of each stamping process stage through process division of the sheet forming curve. The forming mechanisms of different process stages are different, and the forms and influence degrees of parameter deviations are also different. For example, the parameter deviation in the drawing stage may be manifested as sheet wrinkling or cracking, while the deviation in the bending stage may be manifested as angle over tolerance. By decomposing the forming curve into curve segments corresponding to each process, the parameter deviation degree of each stage can be quantified, avoiding the drawbacks of the traditional method of adjusting the overall deviation, so that each parameter adjustment can directly hit the core problem of the process.

[0021] The process stability index is calculated in combination with the sheet property data, providing a scientific basis for parameter adjustment. The thickness, hardness, ductility and other properties of the sheet directly determine its deformation ability in the stamping process. The same initial parameters will produce completely different effects on sheets with different properties. The process stability index can quantify the matching degree of the initial parameters and the current sheet properties. When the index is low, it means that the adaptability of the initial parameters and the sheet properties is poor, and a larger adjustment is needed. When the index is high, the parameter adjustment can be kept within a small range. This adjustment logic based on sheet properties avoids the problem of disconnection between parameter setting and actual sheet performance.

[0022] The method realizes the dynamicity and real-time of parameter adjustment. The traditional mold parameter control is mostly pre-set, unchanged in the whole process, which cannot cope with the sudden process fluctuation in the stamping process. The method can find the parameter deviation in time at each process stage by collecting the process data of the stamping area in real time, and quickly calculate the adjustment amount according to the deviation degree and the process stability index, and then control the execution mechanism parameter. The dynamic adjustment mechanism can correct the deviation as soon as it appears, avoid the accumulation and amplification of the deviation, and reduce the forming defects caused by parameter mismatch.

[0023] For different types of plates, the method has good adaptability. In automobile production, the body longitudinal beam may use high-strength steel, aluminum alloy and other materials, and the stamping characteristics of different materials are significantly different. The traditional parameter control needs to re-set the initial parameters for different materials, which is tedious and prone to error. The method can automatically adapt to the characteristics of different materials by obtaining the process stability index through the plate characteristic data, without the need for manual parameter re-setting, reducing the dependence on the experience of the operator, and improving the adaptability of the mold to multi-species plates.

[0024] In actual production, the method can reduce waste and improve production continuity. Since the parameter adjustment is more accurate and timely, the defects such as wrinkling, cracking and size out-of-tolerance in the plate forming process are greatly reduced, and the waste rate is reduced. At the same time, it avoids the production interruption caused by frequent shutdown to adjust the parameters, shortens the production cycle, and improves the overall production efficiency. This optimization from the parameter control level does not need to make large-scale modifications to the mold structure, is easy to popularize and apply in existing production lines, and has strong practical value. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The working principle diagram of the automobile body longitudinal beam stamping die self-adaptive parameter control method described in the application; Figure 2 The working principle diagram of the process data acquisition; Figure 3 The working principle diagram of the plate forming curve generation; Figure 4 The working principle diagram of the parameter deviation degree determination. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0027] Please refer toFigure 1 The application provides a self-adaptive parameter control method and device for a stamping die of an automobile body longitudinal beam. The stamping die of the automobile body longitudinal beam stamps a plate according to initial control parameters, and starts to collect process data of a stamping area in the stamping die. In this step, the initial control parameters are set in advance based on design requirements of the automobile body longitudinal beam and basic attributes of the plate, and are used to guide actions of each actuator of the stamping die. Meanwhile, the started data collection process needs to cover key positions of the stamping area, so as to ensure that the obtained data can comprehensively reflect state changes of the plate in the stamping process.

[0028] The collected process data is converted into a plate forming curve of the stamping area, the plate forming curve is divided into process procedures, plate forming curve segments of the stamping area in different stamping process stages are obtained, and parameter deviation degrees of each stamping process stage are determined through corresponding plate forming curve segments. In the conversion process, the process data needs to be preprocessed to remove outliers and noises, so as to ensure the accuracy of the plate forming curve. The process division needs to combine the working process of the stamping die, divide the continuous plate forming curve into curve segments corresponding to each stamping process stage, and then calculate the parameter deviation degrees by analyzing differences between each curve segment and a target state.

[0029] Plate characteristic data of the stamping die of the automobile body longitudinal beam is obtained, a process stability index of the stamping die when stamping the plate according to the initial control parameters is obtained based on the plate characteristic data, and parameter adjustment amounts of each stamping process stage are determined according to the process stability index and the corresponding parameter deviation degrees. The plate characteristic data includes information such as mechanical properties and chemical composition of the plate, which will affect the stability of the stamping process. The process stability index is a quantitative evaluation of the stability degree of the stamping process, and the parameter adjustment amounts of each process stage can be comprehensively judged by combining the parameter deviation degrees.

[0030] The parameters of actuators in each stamping process stage of the stamping die of the automobile body longitudinal beam are regulated according to the corresponding parameter adjustment amounts. The calculated parameter adjustment amounts are sent to control systems of the actuators, and the action parameters such as pressure, speed, displacement, etc. of the actuators are adjusted in real time, so that the stamping process can always be kept in an ideal state, thereby ensuring the forming quality of the automobile body longitudinal beam.

[0031] Embodiment 1: please refer to Figure 2The setting of the initial control parameters is based on the thickness and material of the plate processed by the automobile body longitudinal beam stamping die. The deformation difficulty and the required energy of plates of different thicknesses are obviously different during stamping. For example, when the plate thickness is larger, its own stiffness is higher, and a larger impact force is needed to make it have the expected plastic deformation, so when setting the pressure parameter in the initial control parameter, the pressure parameter needs to be increased accordingly with the increase of the thickness. For plates of different materials, such as high-strength alloy steel and ordinary low-carbon steel, the mechanical properties are significantly different, high-strength alloy steel has higher yield strength and tensile strength, and higher pressure and slower stamping speed are needed during stamping to avoid cracks in the plate, so the speed parameter in the initial control parameter needs to be adjusted according to the different materials. In specific operation, the technician will first obtain the thickness data of the plate, which can be accurately obtained through pre-measurement tools, and at the same time, the material type of the plate is determined, and then the recommended parameter range for different thicknesses and materials in the die design manual is referred to, and the specific values of the initial control parameters, including the pressure, speed, and holding time of each process stage, are determined according to the forming requirements of the longitudinal beam of the vehicle in actual production.

[0032] The process data acquisition of the stamping area in the stamping die is realized by displacement sensors and force sensors. The installation position of the displacement sensor is carefully selected, and is usually distributed at the edge of the upper die, the positioning block of the lower die, and the key nodes of the plate feeding path. The displacement sensors at the edges of the upper die and the lower die are used to monitor the displacement change of the die closing and opening during stamping, and to record the movement distance of the die in the vertical direction in real time. These data can reflect the depth of the plate pressed by the die. The displacement sensors on the plate feeding path are used to capture the position change of the plate in the horizontal direction, to ensure the accurate positioning of the plate in each process stage. The installation position of the force sensor is concentrated in the core stress area of the die, such as the end of the piston rod of the stamping cylinder, the contact surface between the die cavity and the plate, etc. The force sensor at the end of the stamping cylinder mainly collects the pressure output during stamping, which directly acts on the plate, and its change is closely related to the deformation degree of the plate. The force sensor on the contact surface of the die cavity is used to detect the contact force between the plate and the die, and the distribution and size of the force can reflect the stress state of each part of the plate during forming, to avoid damage to the plate caused by excessive local stress.

[0033] The displacement sensor and the force sensor will work continuously when collecting data according to the set sampling interval. The length of the sampling interval is determined according to the speed of the stamping process. For the rapid stamping stage, the sampling interval is set to milliseconds to ensure the continuity and accuracy of the data. For the slow pressure maintaining stage, the sampling interval can be appropriately extended, but it still needs to ensure that the subtle changes of pressure and displacement can be captured. The collected raw data includes displacement value, force value and corresponding timestamp. These data are sent to the control system of the mold in real time through a dedicated data transmission line. The control system will preliminarily arrange the data, remove obvious interference signals, and then store them in the data buffer area for subsequent processing. In the data transmission process, an anti-interference transmission protocol is used to prevent data loss or distortion during transmission and ensure that the generated sheet forming curve can truly reflect the actual forming process of the sheet. All sensors are calibrated before installation to ensure that their measurement accuracy meets the process requirements. The calibration process includes zero point calibration and range calibration. The output value of the sensor is verified and adjusted by a standard gauge to control the measurement error within the allowable range.

[0034] Example 2: see Figure 3 When converting the collected process data into the sheet forming curve of the stamping area, the collected process data need to be trained by a neural network model to obtain the sheet forming curve. The collected process data are comprehensively preprocessed. In this process, the data are first screened to eliminate those obviously out of the normal range. These data may be abnormal values caused by instantaneous sensor failure or external electromagnetic interference. The screened data are smoothed by the moving average method to eliminate high-frequency noise in the data, making the data curve smoother and more able to reflect the true trend of sheet forming. After data preprocessing, different types of process data are normalized to convert the data of displacement, force and other physical quantities to the numerical interval of [0, 1], avoiding the influence of large data magnitude difference on the training effect of the model.

[0035] A neural network model for training is constructed. The model adopts a three-layer structure, including an input layer, a hidden layer, and an output layer. The number of neurons in the input layer is consistent with the dimension of the pre-processed process data, and each neuron corresponds to the time series data of a process parameter. The hidden layer contains multiple neurons, the specific number of which is adjusted according to the complexity of the process data. The input data is nonlinearly converted by an activation function to extract deep features in the data. The neurons in the output layer correspond to key feature points of the sheet forming curve, such as forming positions at different times, curvature, and other parameters. In the model training stage, a large number of qualified process data accumulated in the past production process and the corresponding sheet forming curves are selected as training samples. The sample data is divided into a training set and a validation set. The training set is used for iterative optimization of model parameters, and the validation set is used to evaluate the generalization ability of the model. During training, the weights of the model are continuously adjusted to gradually reduce the error between the model output and the actual forming curve until the error is within a reasonable range. The trained neural network model can quickly generate a corresponding sheet forming curve based on newly collected process data. The curve can fully present the morphological changes of the sheet from the initial state to the final forming process.

[0036] The sheet forming curve is divided into process stages according to pre-set stamping process stages. The pre-set stamping process stages are based on the structural characteristics and forming process requirements of the automobile body longitudinal beam, covering various links from sheet feeding into the mold to final forming. Each process stage has a clear process purpose and operation characteristics. For example, the first process stage is the pre-positioning stage, mainly through the positioning device to fix the sheet at the specified position of the mold. At this time, the sheet has not been deformed significantly, and the corresponding forming curve is relatively flat. The second process stage is the preliminary forming stage. The mold starts to apply pressure to the sheet, and the edge of the sheet begins to bend. The slope of the forming curve gradually increases. The third process stage is the deep forming stage. The sheet undergoes large-scale plastic deformation under the action of the mold, forming the basic outline of the longitudinal beam, and the curve slope reaches the maximum value. The fourth process stage is the shaping stage. The shape of the sheet is more accurate through fine-tuning of the pressure, and the curve tends to be smooth. The last process stage is the demolding stage. The mold gradually separates, and the sheet completes the forming, and the curve returns to the initial level.

[0037] In the specific division, according to the time range and characteristic parameters of each process stage, the starting point and ending point of each stage are determined on the sheet forming curve. For example, the ending point of the positioning stage corresponds to the moment when the mold starts to apply pressure, at which time the force value collected by the force sensor starts to rise from zero, and on the forming curve, the position where the curve slope starts to change from zero; the ending point of the preliminary forming stage corresponds to the moment when the edge of the sheet starts to fully contact with the mold cavity, at which time the displacement of the displacement sensor reaches the preset threshold, and the curve slope changes for the first time. In this way, the continuous sheet forming curve is accurately divided into curve segments corresponding to each process stage, and each curve segment reflects the sheet forming condition of a process stage, providing a clear data basis for the calculation of the parameter deviation degree of each stage. After the division, each curve segment is marked with the corresponding process stage, which facilitates subsequent data processing and parameter adjustment.

[0038] Example 3: Please refer to Figure 4 When determining the parameter deviation degree of each stamping process stage through the corresponding sheet forming curve segment, the following procedures need to be followed. For each stamping process stage, the sheet forming curve segment corresponding to the stage is obtained. The sheet forming curve segment is the curve part obtained after process division, which corresponds completely to the stamping process stage and contains all the data points related to sheet forming in this stage. These data points are composed of time, displacement, force and other parameters, which completely record the deformation process of the sheet in this process stage.

[0039] The target parameter value corresponding to the initial control parameter of the stamping process stage is obtained. The target parameter value is set in advance according to the design standard and process requirement of the longitudinal beam, which covers the standard values of key parameters such as displacement, force and speed that should be reached in this process stage. For example, in the plastic deformation stage, the target parameter value may include the stamping depth and the corresponding pressure value at a specific time, which are the benchmarks to ensure that the sheet can be formed according to the design requirements.

[0040] The model prediction value of the sheet forming curve segment is determined. The model prediction value is calculated through a pre-set mathematical model, which is based on the theory of material mechanics and stamping forming and can simulate the sheet forming parameters of this process stage in an ideal state according to the initial control parameters and sheet characteristic data. The calculation of the model prediction value needs to input the initial conditions of this process stage, such as the initial position of the sheet and the initial pressure of the mold, and after multiple iterative operations, the prediction parameter value corresponding to each data point of the curve segment is output.

[0041] Based on the model prediction value and the target parameter value, the parameter deviation rate of each sheet forming data point in the sheet forming curve segment is determined. The parameter deviation rate is used to measure the deviation degree of the actual forming state of a single data point from the target state, and its calculation formula is:

[0042] wherein, represents the parameter deviation rate of the kth sheet forming data point, represents the model prediction value of the kth sheet forming data point, represents the target parameter value corresponding to the kth sheet forming data point.

[0043] In the calculation process, it is necessary to ensure that the model prediction value and the target parameter value of each data point are consistent in physical meaning, for example, both are displacement values or both are force values, to avoid calculation errors of the parameter deviation rate due to mismatching of parameter types. For each data point, the difference between the model prediction value and the target parameter value is obtained, and then the difference is divided by the target parameter value and multiplied by 100%. If the result is positive, it means that the model prediction value is higher than the target parameter value; if it is negative, it means that the model prediction value is lower than the target parameter value.

[0044] The parameter deviation degree of the stamping process stage is determined by all the parameter deviation rates. The parameter deviation degree is a comprehensive evaluation of the deviation of the entire process stage, and the importance of each data point in the process stage needs to be considered in the calculation. For data points that have a greater impact on forming quality, such as peak pressure points in the plastic deformation stage, higher weights are given; for data points that have a smaller impact, such as end-of-draw stage data points, lower weights are given. The weight values are pre-set according to the process manual and historical experience and stored in the control system. In specific operation, the parameter deviation rate of each data point is multiplied by the corresponding weight, and then all the products are added to obtain the parameter deviation degree of the process stage. For example, a process stage contains 100 data points, and the sum of the parameter deviation rates of each data point multiplied by the respective weights is the parameter deviation degree of the stage. The numerical value of the parameter deviation degree reflects the overall deviation degree of the entire process stage, and the larger the numerical value, the greater the difference between the actual forming state and the target state of the process stage, and the more significant the parameter adjustment needed.

[0045] In practical application, the above steps need to be performed for each stamping process stage to obtain the parameter deviation degree of each stage. These parameter deviation degrees will serve as an important basis for subsequent determination of parameter adjustment amount and provide precise quantitative indicators for adaptive parameter control of stamping dies. At the same time, in the calculation process, all intermediate results need to be stored in real time to facilitate tracing and analysis in subsequent processes, ensuring that the calculation of each link can be verified and reproduced.

[0046] In the process of acquiring sheet material characteristic data for an automobile body longitudinal beam stamping die using multi-sensor fusion technology, multiple types of sensors need to be deployed to cover different characteristic parameters of the sheet material. On the conveying path before the sheet material enters the stamping die, a laser thickness measurement sensor is installed. This sensor irradiates the surface of the sheet material with a laser beam and calculates the thickness data of the sheet material by using the time difference of laser reflection. It can continuously measure the thickness at different positions during the conveying process of the sheet material, ensuring that the overall thickness distribution of the sheet material is obtained. Downstream of the laser thickness measurement sensor, a spectral sensor is set up. This sensor irradiates the surface of the sheet material with light of a specific wavelength and collects spectral information of the reflected light. According to the spectral characteristics, it analyzes the chemical composition of the sheet material, such as the content of alloy elements such as carbon and manganese, to determine the material type of the sheet material. At the entrance of the stamping die, an infrared temperature sensor is installed to monitor the temperature of the sheet material entering the die in real time. This temperature data will affect the plasticity and forming performance of the sheet material and is an important part of the sheet material characteristic data. In addition, a surface roughness sensor is installed on the side of the stamping die. Through contact or non-contact measurement methods, it obtains the roughness parameters of the sheet material surface. This parameter is related to the friction coefficient of the sheet material during the stamping process and will affect the forming effect.

[0047] The data collected by these different types of sensors is processed through a multi-sensor fusion algorithm. First, the data from each sensor is time-synchronized to ensure that all data corresponds to the same time point or the same sheet material position, avoiding fusion errors caused by inconsistent data timing. Then, consistency verification is performed on the data. Related data collected by different sensors are compared, such as combining the thickness data measured by the laser thickness measurement sensor with the material data analyzed by the spectral sensor to determine if there is any contradiction. If the data from a certain sensor deviates significantly from the data from other sensors, it is marked as unreliable data and is corrected. Finally, through a data fusion model, the data from various sensors is integrated into a unified sheet material characteristic data set. This data set contains comprehensive information such as thickness, material composition, temperature, and surface roughness, providing a complete data basis for subsequent calculation of the process stability index.

[0048] When determining the parameter adjustment amount for each stamping process stage according to the process stability index and the corresponding parameter deviation degree, it needs to be calculated separately for each stamping process stage. First, the target parameter values set in the initial control parameters for this process stage are extracted. These target parameter values include stamping pressure, die displacement, stamping speed, etc., and are the ideal parameter levels that should be achieved in this process stage. Then, the process stability index calculated based on the sheet material characteristic data is called. This index quantifies the stability of the current stamping process by analyzing parameters such as thickness uniformity, material consistency, and temperature stability. The numerical range of the index is set according to historical data, covering various states from highly stable to unstable.

[0049] When calculating the parameter adjustment amount, the relationship among the target parameter value, the process stability index and the parameter deviation degree should be considered comprehensively. When the process stability index is high, it indicates that the current process state is stable, and the parameter adjustment amount is mainly determined according to the parameter deviation degree. The greater the deviation degree, the greater the adjustment amount, so as to ensure that the actual parameter is close to the target parameter value. When the process stability index is low, it indicates that the process has a large fluctuation. At this time, even if the parameter deviation degree is small, the adjustment amount should also be appropriately increased to cope with the possible unstable factors. In specific operation, a basic adjustment ratio is determined according to the process stability index. The ratio decreases as the index increases and increases as the index decreases. At the same time, a deviation adjustment coefficient is determined according to the parameter deviation degree. The coefficient increases as the deviation degree increases. The basic adjustment ratio is multiplied by the deviation adjustment coefficient to obtain a comprehensive adjustment coefficient. Then, the target parameter value is multiplied by the comprehensive adjustment coefficient to obtain the parameter adjustment amount of the process stage. The parameter adjustment amount calculated in this way can not only compensate for the deviation between the actual parameter and the target parameter, but also adapt to the stable state of the process, so as to ensure that the adjusted parameter meets the forming requirements and maintains the stable operation of the process. After the parameter adjustment amount of each stamping process stage is calculated, it is stored in the adjustment amount database, waiting to be sent to the actuator for parameter control.

[0050] When the actuators in the stamping die for automobile body longitudinal beam are controlled according to the corresponding parameter adjustment amount, operation should be carried out for each stamping process stage. First, the target parameter values recorded in the initial control parameters of the stamping process stage are extracted. These target parameter values cover various running indexes that the actuators should reach in the process stage, such as the output pressure of the stamping cylinder, the die closing speed, the extension stroke of the positioning pin, etc., which are all set in advance according to the design standards and forming process requirements of the longitudinal beam. At the same time, the parameter adjustment amount calculated for the process stage is obtained. The adjustment amount is determined comprehensively based on the process stability index and the parameter deviation degree, and reflects the adjustment range required to make the actual parameter close to the target parameter value.

[0051] When determining the final execution parameter, the target parameter value and the parameter adjustment amount should be operated. If the parameter deviation degree is positive, it indicates that the actual collected process data corresponds to a parameter higher than the target parameter value. At this time, the parameter adjustment amount should be subtracted from the target parameter value to obtain the final execution parameter. If the parameter deviation degree is negative, it indicates that the actual parameter is lower than the target parameter value. Then, the parameter adjustment amount should be added to the target parameter value to obtain the final execution parameter. This operation process should be automatically completed in the control system of the die, and the operation result is stored in the parameter record table of the process stage in real time, so as to facilitate subsequent tracing and checking.

[0052] After the final execution parameter is determined, the control system sends the parameter command to the corresponding execution mechanism controller through the internal data bus. Different execution mechanisms are equipped with special controllers that can receive and analyze parameter commands and then drive the mechanism to complete parameter adjustment. For example, for a hydraulic punching cylinder responsible for providing punching power, after its controller receives the final pressure parameter, it will change the flow and pressure of hydraulic oil by adjusting the opening degree of the proportional valve in the hydraulic system. When the pressure needs to be increased, the proportional valve opening degree increases, more hydraulic oil enters the rodless cavity of the punching cylinder, pushing the piston down, and the output pressure rises to the value corresponding to the final execution parameter. When the pressure needs to be reduced, the proportional valve opening degree decreases, the hydraulic oil flow decreases, and the output pressure decreases accordingly. In this process, the pressure sensor installed on the punching cylinder will feedback the actual pressure value in real time, and the controller will compare the actual value with the final execution parameter. If there is a deviation, the proportional valve opening degree will continue to be adjusted until the actual pressure stabilizes within the range of the final execution parameter.

[0053] For the feeding mechanism responsible for plate conveying, its execution parameters are mainly feeding speed and feeding position. After receiving the final execution parameter, the motor controller of the feeding mechanism will adjust the speed and rotation angle of the servo motor. If the feeding speed needs to be increased, the motor controller increases the output frequency, the servo motor speed increases, and through the gear transmission mechanism, the feeding roller speed is accelerated, so that the plate conveying speed is increased. If the feeding position needs to be adjusted, the motor controller accurately controls the rotation angle of the motor, and through the ball screw, the rotary motion is converted into linear motion to push the feeding platform to move to the specified position. The encoder on the feeding mechanism will record the number of motor rotation and angle in real time, calculate the actual feeding speed and position, and feedback to the controller to ensure consistency with the final execution parameter.

[0054] For the positioning device of the mold, its execution parameters are the extension length of the positioning pin and the clamping force. The extension length of the positioning pin determines the initial positioning accuracy of the plate. After the controller receives the final execution parameter, it adjusts the gas pressure or oil pressure in the positioning cylinder to push the positioning pin to extend or retract to reach the set length. The displacement sensor installed at the end of the positioning pin will monitor its actual extension length. If there is a deviation from the final execution parameter, the controller will adjust the on-off time of the gas valve or liquid valve for compensation. The adjustment of the clamping force is realized by changing the pressure of the clamping cylinder. The controller adjusts the set value of the pressure relay according to the final execution parameter to stabilize the output force of the clamping cylinder within the required range, ensuring that the plate does not move during the punching process.

[0055] During the whole regulation process, the control system will monitor the parameter adjustment process of all actuators in real time, and the adjustment state, actual parameter value and adjustment time of each actuator will be recorded in the system log. If an actuator does not reach the final execution parameter within the specified time, the control system will issue a warning signal to prompt the operator to check, ensuring that the execution parameter of each stamping process stage can accurately operate according to the final execution parameter, thereby realizing precise control of the automobile body longitudinal beam stamping process.

[0056] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0057] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, alternatives, and variations can be made in the embodiments without departing from the spirit and scope of the present application as defined by the appended claims and their equivalents.

Claims

1. An adaptive parameter control method for an automobile body side rail stamping die, characterized by, The control method comprises the following steps: The automobile body longitudinal beam stamping die stamps the plate according to the initial control parameters, and the process data of the stamping area in the stamping die is collected; The collected process data is converted into the plate forming curve of the stamping area, the plate forming curve is divided into processes, the plate forming curve segments of the stamping area at different stamping process stages are obtained, and the parameter deviation degree of each stamping process stage is determined through the corresponding plate forming curve segment; The plate characteristic data of the automobile body longitudinal beam stamping die is obtained, the process stability index of the stamping die when stamping the plate according to the initial control parameters is obtained based on the plate characteristic data, and the parameter adjustment amount of each stamping process stage is determined according to the process stability index and the corresponding parameter deviation degree; The execution mechanism parameters of each stamping process stage in the automobile body longitudinal beam stamping die are regulated and controlled according to the corresponding parameter adjustment amount.

2. The method of claim 1, wherein the method further comprises: The initial control parameters are set according to the thickness and material of the plate processed by the automobile body longitudinal beam stamping die.

3. The method of claim 1, wherein the method further comprises: The process data of the stamping area in the stamping die is collected by a displacement sensor and a force sensor.

4. The method of claim 1, wherein the method further comprises: The collected process data is converted into the plate forming curve of the stamping area by training a neural network model on the collected process data to obtain the plate forming curve of the stamping area.

5. The method of claim 1, wherein the method further comprises: The plate forming curve is divided into processes according to the pre-set stamping process stages.

6. The method of claim 1, wherein, The parameter deviation degree of each stamping process stage is determined through the corresponding plate forming curve segment, which specifically comprises: For each stamping process stage, the plate forming curve segment of the stamping process stage is obtained; The target parameter value corresponding to the stamping process stage in the initial control parameters is obtained; The model prediction value of the plate forming curve segment is determined; The parameter deviation rate of each plate forming data point in the plate forming curve segment is determined based on the model prediction value and the target parameter value; The parameter deviation degree of the stamping process stage is determined by all the parameter deviation rates, and the parameter deviation degree of each stamping process stage is obtained.

7. The adaptive parameter control method for automobile body longitudinal beam stamping die as described in claim 1, characterized in that, The plate characteristic data of the automobile body longitudinal beam stamping die is obtained using a multi-sensor fusion technology.

8. The adaptive parameter control method for automobile body longitudinal beam stamping die as described in claim 1, characterized in that, The parameter adjustment amount of each stamping process stage is determined according to the process stability index and the corresponding parameter deviation degree, which specifically comprises: For each stamping process stage, the target parameter value corresponding to the stamping process stage in the initial control parameters is obtained; The parameter adjustment amount of the stamping process stage is determined based on the target parameter value, the process stability index and the parameter deviation degree of the stamping process stage, and the parameter adjustment amount of each stamping process stage is obtained.

9. The adaptive parameter control method for automobile body longitudinal beam stamping die as described in claim 1, characterized in that, The execution mechanism parameters of each stamping process stage in the automobile body longitudinal beam stamping die are regulated and controlled according to the corresponding parameter adjustment amount, which specifically comprises: For each stamping process stage in the automobile body longitudinal beam stamping die, the final execution parameter of the stamping process stage is determined according to the corresponding target parameter value of the stamping process stage in the initial control parameter and the parameter adjustment amount of the stamping process stage, and then the execution mechanism parameter of each stamping process stage in the automobile body longitudinal beam stamping die is regulated and controlled.

10. An apparatus for adaptive parameter control of an automobile body side rail stamping die for performing the method of any one of claims 1 to 9, characterized by, The control device comprises: A parameter initialization module is configured to control the automobile body longitudinal beam stamping die to stamp the plate according to the initial control parameter, and start collecting the process data of the stamping area in the stamping die. A deviation determination module is configured to convert the collected process data into the plate forming curve of the stamping area, divide the plate forming curve into different plate forming curve segments according to different stamping process stages, and determine the parameter deviation of each stamping process stage according to the corresponding plate forming curve segment. An adjustment amount determination module is configured to obtain the plate characteristic data of the automobile body longitudinal beam stamping die, obtain the process stability index of the stamping die when stamping the plate according to the initial control parameter based on the plate characteristic data, and determine the parameter adjustment amount of each stamping process stage according to the process stability index and the corresponding parameter deviation. An execution regulation module is configured to regulate and control the execution mechanism parameter of each stamping process stage in the automobile body longitudinal beam stamping die according to the corresponding parameter adjustment amount.

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