SYSTEM AND METHOD FOR PREDICTING AND CORRECTING SQUEAKING NOISES IN MOTOR VEHICLE COMPONENTS

Abstract

This document describes a system (100) for predicting and eliminating squeaking noises in components. The system (100) comprises a database (106) containing parameterized friction data (112) relating to the frictional behavior of a variety of known materials. The system (100) further comprises a device (102) configured to perform a contact simulation for a set of interacting parts connected to a component to be analyzed for squeaking noise events, based on the parameterized friction data (112). The device analyzes the changes in frictional force and frictional speed between the interacting parts, the time of the change, and the time interval between changes to determine the probability of squeaking noises occurring between the interacting parts.

Description

TECHNICAL AREA

[0001] The present invention relates generally to the field of noise analysis in vehicles. In particular, the present invention relates to a system and a method for predicting and eliminating squeaking noises in automobile or vehicle components. BACKGROUND

[0002] Squeaking noises in motor vehicles are a significant issue for both manufacturers and consumers, as they directly impact the perceived quality and comfort of the vehicle. This noise is primarily the result of a complex, non-linear phenomenon known as "stick-slip," which occurs at the interface between two interacting parts. The stick-slip phenomenon is characterized by intermittent movement between the surfaces of two contacting materials, leading to the generation of audible noise. The unpredictability and variability of this interaction make solving this problem a challenge.

[0003] Conventional methods use simulation tools to analyze the interaction between parts in order to predict the occurrence of noise, but they do not provide accurate results. These methods typically overlook important factors such as detailed surface interactions and the realistic conditions of the parts involved, including varying loads, speeds, and geometries. Consequently, they fail to capture the true dynamics of the stick-slip phenomenon, leading to unreliable predictions and inadequate solutions.

[0004] Previous efforts have been made in the field of noise simulation analysis. For example, patent document CN110263414B discloses a method for predicting an abnormal friction noise hazard point in an automotive interior system. The method comprises the steps of establishing a three-dimensional target model, defining a target surface, placing a pair of nodes in the target surface where the node pair is in contact with two components, and capturing the maximum amplitude of the relative displacement of two nodes in a node pair under vibration at a predetermined frequency.Furthermore, the method includes calculating the local stiffness value of each node pair along the relative displacement direction between the node pairs and recording the minimum abnormal acoustic displacement measured in the test of the corresponding node pair according to the selected material. In this way, based on the maximum amplitude of the relative displacement and the minimum abnormal acoustic displacement, it can be determined whether abnormal acoustic friction occurs at the location of the node pair, thus allowing the danger point for abnormal acoustics to be predicted. However, the cited reference does not offer an efficient and reliable solution to the aforementioned problem.

[0005] Therefore, there is a need for an improved and reliable solution to accurately represent the realistic interactions between the parts of a component and to improve the ability to predict the occurrence of squeaking noises with greater precision, which can enable the development of effective strategies to remedy them. OBJECTS OF INVENTION

[0006] A general objective of the present invention is to develop a solution that accurately predicts the occurrence of squeaking noises due to interactions between components or their parts, which can enable the development of effective strategies to remedy them.

[0007] One object of the present invention is to simulate the stick-slip phenomenon between interacting parts under various realistic conditions, including different loads, speeds and geometries of the interacting parts, which enables seamless analysis and improvement of the design.

[0008] One object of the present invention is to develop an effective and robust solution for reducing or eliminating squeaking noises and thereby improving vehicle quality and customer satisfaction.

[0009] One object of the present invention is to provide an improved and reliable system and method to accurately represent the realistic interactions between interacting parts and to improve the ability to predict the occurrence of squeaking noises with higher precision. SUMMARY

[0010] Aspects of the present invention relate to the technical field of noise analysis in vehicles. In particular, the present invention relates to a system and method for predicting and eliminating squeaking noises in automobile or vehicle components.

[0011] One aspect discloses a system for predicting and eliminating squeaking noises in components. The system includes a database containing parameterized friction data relating to the frictional behavior of a variety of known materials during surface interaction. This parameterized data includes the static coefficient of friction, the dynamic coefficient of friction, and the friction decay factor. The system also includes a device that communicates with the database.The computing device comprises one or more processors coupled to a memory that stores instructions which can be executed by the processors, causing the computing device to perform a contact simulation for a set of interacting parts connected to a component to be analyzed for squeaking noise events, based on the parameterized friction data, and accordingly to analyze the change in frictional force and frictional speed between the interacting parts, the time of change and the time interval between changes, in order to determine the probability of squeaking noises occurring between the interacting parts.

[0012] The device can be configured to receive CAD data of the component, where the CAD data can contain geometry and material attributes of the set of interacting parts connected to the component. The device can then generate a finite element (FE) model of the component and the corresponding parts based on the received CAD data.

[0013] Furthermore, the device can be configured to perform contact simulation on the generated FE model based on parameterized friction data to generate contact simulation data for the interacting parts. This contact simulation data includes the frictional distance, frictional velocity, frictional force, stress, and strain between the interacting parts. The device can then analyze the changes in frictional force and frictional velocity, the timing of the changes, and the time intervals between changes to determine the probability of squeaking noises occurring between the interacting parts. Moreover, the contact simulation can be performed at a predetermined time step and for a predetermined time increment, allowing the system to operate optimally and produce accurate results.

[0014] In one aspect, the device can be configured to predict the occurrence of a squeaking noise between the interacting parts when it detects the change in frictional force, the change in frictional speed, the time interval between the changes and / or the time at which the changes exceed threshold values.

[0015] Furthermore, the device can be configured so that a user can modify the CAD data associated with the interacting parts until the analyzed change in frictional force, change in frictional speed, time interval between changes and / or timing of changes in the relevant interacting parts falls below the thresholds to reduce the squeaking noise event in the component.

[0016] The device can be configured to receive friction data relating to the change in frictional force between the several known materials when the frictional speed between them changes during surface interaction, and to parameterize the received friction data to generate the parameterized data, which includes the static coefficient of friction, the dynamic coefficient of friction, and the friction decay factor, and to store them accordingly in the database.

[0017] In another aspect, a method for analyzing and solving squeaking noises in components is disclosed. The method comprises the steps of receiving parameterized friction data relating to the frictional behavior of a variety of known materials during surface interaction between them, by a computing device, wherein the parameterized data include a static coefficient of friction, a dynamic coefficient of friction, and a friction reduction factor.The procedure further includes the steps of performing a contact simulation for a set of interacting parts connected to a component to be analyzed for squeaking noise events by the computing device on the basis of the received parameterized friction data and the corresponding analysis of the change in frictional force and frictional speed between the interacting parts, the time of change and the time interval between changes, in order to determine the probability of squeaking noises occurring between the interacting parts.

[0018] The method can include the steps of receiving CAD data relating to the component, where the CAD data may contain geometry and material attributes of the set of interacting parts associated with the component, followed by the generation of a finite element (FE) model of the component and the corresponding parts based on the received CAD data. The method can further include the steps of performing contact simulation on the generated FE model based on parameterized friction data to generate contact simulation data for the interacting parts, where the contact simulation data may include friction distance, friction velocity, friction force, stress, and strain between the interacting parts.Furthermore, the method can include the steps of analyzing the changes in frictional force and frictional velocity, the timing of the changes, and the time interval between changes to determine the probability of squeaking noises occurring between the interacting parts. In addition, the contact simulation can be performed in a predetermined time step and for a predetermined time increment, enabling accurate and optimal result generation.

[0019] In one aspect, the procedure may include the steps of predicting the occurrence of a squeaking noise event between the interacting parts when the change in frictional force, the change in frictional speed, the time interval between the changes and / or the time of the changes are detected to exceed threshold values.

[0020] Furthermore, the procedure may include steps that allow a user to modify the CAD data associated with the interacting parts until the analyzed change in frictional force, change in frictional speed, time interval between changes and / or timing of changes in the relevant interacting parts fall below the thresholds to mitigate the squeaking noise event in the component.

[0021] Various objects, features, aspects and advantages of the subject matter according to the invention will become clearer from the following detailed description of preferred embodiments together with the accompanying drawing figures, in which the same numbers represent the same components. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings serve to further understand the present invention and are an integral part of this description. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. Fig. Figure 1 shows an exemplary block diagram of the proposed system for predicting and eliminating squeaking noises in components, according to an embodiment of the present invention. Fig. Figure 2 shows by way of example the steps of the proposed system for predicting and eliminating squeaking noises in components according to an embodiment of the present invention. Fig. Figure 3 shows an exemplary flowchart illustrating the operation of the proposed system according to an embodiment of the present invention. Fig. Figure 4A shows an exemplary representation of the surface interaction between two cladding parts connected to a component to be analyzed for the squeaking noise event, according to an embodiment of the present invention. Fig. Figure 4B shows an exemplary representation of an optimized design of the interacting parts of Fig. 4A with resolved squeaking noise according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] A detailed description of the embodiments of the invention illustrated in the accompanying drawings follows. The embodiments are described in sufficient detail to ensure the invention is clearly understandable. However, this level of detail is not intended to limit foreseeable variations of the embodiments; on the contrary, it is intended to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the present invention as defined by the accompanying claims.

[0024] The embodiments described here relate to a system and a method for predicting and eliminating squeaking noises in automotive or vehicle components.

[0025] With reference to Fig. 1. The proposed system 100 for predicting and correcting squeaking noises in a component is disclosed. In one embodiment, the component may be an automotive or vehicle component with multiple parts that are in surface contact and can interact with or rub against other parts, as shown in Fig. Figure 4A shows that in other embodiments, the component can also be a non-vehicle component without any restrictions. The system 100 can comprise a computing device 102 that communicates with an input device 104, a database 106, and an output device 108. The computing device 102 can comprise one or more processors 102-1 coupled to a memory 102-2 in which instructions executable by the processors 102-1 are stored, which can cause the computing device 102 to perform one or more specific operations. The computing device 102 can further comprise a finite element model (FE) module 102-3, a contact simulation module 102-4, and a parameter optimization module 102-5.

[0026] A professional should understand that different materials / part pairs can have different coefficients of friction, depending on the frictional speed between them during surface interaction. This can be illustrated using diagrams depicting the stick-slip phenomenon, which shows how the frictional force varies over time with the frictional speed and also explains how these fluctuations in frictional force can cause squeaking noises. Some existing solutions use friction data measured at a fixed frictional speed between the materials / part pairs, which can be inaccurate and inadequate, as squeaking and friction are sensitive to changes in frictional speed.

[0027] Those skilled in the art know that database 106 of the present invention (system 100) records the change in friction between the materials / part pairs when the friction speed is changed / varyed, accurately reflecting the stick-slip and squealing phenomena. This data (change in friction when the friction speed is changed / varyed) is obtained after testing the surface interaction between various known materials at different friction speeds.

[0028] Furthermore, this data (change in friction with a change in friction speed) from the test cannot be readily used for contact simulation by the computing device 102, as it can lead to convergence problems. To overcome these convergence problems, the computing device 102 according to the invention parameterizes this data. In one embodiment, the database 106 can easily store the parameterized friction data (112), which includes the static coefficient of friction, the dynamic coefficient of friction, and the friction reduction factor, and relates to the friction behavior of several known materials.In another embodiment, however, the database 106 can store the pipe friction data associated with known materials, and the computing device 102 can further receive this pipe friction data and parameterize it into parameterized friction data (112) that accurately represent the friction behavior of the interacting materials / part pairs and at the same time help with convergence problems.

[0029] Furthermore, the computing device 102 can be configured to receive CAD data (110) belonging to a component to be investigated for squeaking noises. In one embodiment, the CAD data (110) can contain the geometry (3D or 2D design) and material attributes of a set of interacting parts connected to a component to be analyzed for the occurrence of squeaking noises. In an exemplary embodiment, the material properties of the component defined in the CAD data (110) can include, among others, density, thermal conductivity, specific heat, coefficient of thermal expansion, electrical conductivity, modulus of elasticity, Poisson's ratio, yield strength, tensile strength, hardness, ductility, fatigue strength, compressive strength, shear strength, fracture toughness, optical properties, color, transparency, surface finish, and magnetic permeability.In one embodiment, the input device 104 can enable technicians or experts to create the CAD data (110) and the parameterized friction data (112) and to input them into the computing device 102 and the database 106 for further processing.

[0030] In one embodiment, the FE model module 102-3 enables the computing device 102 to create or build a finite element model (FE model) of the component and the corresponding parts based on the received CAD data (110). Furthermore, the contact simulation module 102-4 enables the computing device 102 to perform contact simulation on the generated FE model based on the parameterized friction data (112) to generate contact simulation data for the interacting parts. In an exemplary embodiment, the contact simulation data can include friction distance, friction velocity, friction force, stress, and strain between the interacting parts.

[0031] Furthermore, the computing device 102 can identify and select only the relevant data (outputs) from the generated contact simulation data for further processing and squeal noise analysis of the interacting parts. In one embodiment, the computing device 102 can select and analyze the change in frictional force, the change in frictional speed, the time interval between the changes, and the time at which the changes occur in order to analyze or determine the probability of squeal noises occurring between the interacting parts. It is advantageous that selecting only the relevant (contact simulation) data can facilitate the accurate identification of squeal noise events while simultaneously mitigating convergence problems. This further reduces the computing power required by the computing device 102 for predicting squeal noises.

[0032] In one embodiment, the computing device 102 can be configured to predict the occurrence of the squeaking noise between the surfaces of the interacting parts of the component when changes in frictional force, frictional velocity, the time interval between changes, and / or the time at which the changes exceed threshold values ​​are detected. In another embodiment, the computing device 102 can identify the specific area(s) or surface(s) of the parts that are in surface interaction and generate the squeaking noise. Furthermore, the computing device 102 can highlight these identified areas or surfaces of the interacting parts and display them via the output device 108, enabling technicians or experts to identify and resolve the squeaking noise at the respective areas or surfaces.

[0033] Accordingly, the computing device 102 can also allow users (engineers or experts) to modify the CAD data (110) associated with the interacting parts that cause the squeaking noise in the respective areas or surfaces using the input device 104, until the analyzed change in frictional force, change in frictional speed, time interval between changes, and / or timing of changes in the corresponding interacting parts falls below the threshold values, thereby reducing or eliminating the squeaking noise event in the component. In one implementation, after analyzing the simulation results, the computing device 102 can allow the engineers or experts to modify either the geometry of the parts or a friction surface of the parts to ensure that no squeaking noise occurs.

[0034] In one embodiment, the parameter optimization module 102-5 enables the computing device 102 to allow users to modify the simulation parameters associated with the contact simulation model, thus optimizing the contact simulation model for identifying squeaking noise events. In an exemplary embodiment, the simulation parameters associated with the contact simulation model may generally include boundary conditions, mesh density, contact algorithms, load conditions, solver settings, time step size, minimum time increment, maximum time increment, convergence criteria, initial conditions, and the like.

[0035] The term "time step" refers to a discrete time interval over which the contact simulation model advances the simulation. The term "time step" corresponds to the parameter that can define the range of time step sizes that the contact simulation model can use during the analysis, where the term "minimum time step" is the smallest permissible time step that the contact simulation model can use to ensure the accuracy and stability of the simulation.

[0036] In one embodiment, the computing device 102 allows users to set and execute the contact simulation for identifying squeaking noises with a predetermined (optimal) time step and for a predetermined (optimal) time increment, so that the contact simulation model can produce optimized results and accurately identify squeaking noise events. Since the optimal time step and time increment for the contact simulation model can differ for various input data (CAD data (110) and parameterized friction data (112)) provided to the contact simulation model, users can test the time step and time increment and adjust them to optimally determined values ​​until the contact simulation model delivers optimal results.

[0037] In Fig. 2. A method for analyzing, predicting, and correcting squeaking noises in components is disclosed. The method 200 may include the computing device 102, the input device 104, the database 106, and the output device 108, which are equipped with Fig. 1 are connected.

[0038] Method 200 may include step 202, in which the device receives parameterized friction (stick-slip) data relating to the frictional behavior of a variety of known materials during surface interaction, wherein the parameterized data may include the static coefficient of friction, the dynamic coefficient of friction, and the friction decay factor. Furthermore, Method 200 may include step 204, in which the device receives CAD data (110) relating to a component to be analyzed for squeaking noises, wherein the CAD data (110) may include geometric and material attributes of a set of interacting parts associated with the component.

[0039] Method 200 can further comprise step 206 of generating a finite element (FE) model of the component and the corresponding parts by the device based on the CAD data (110) received in step 204. Method 200 can further comprise step 208, in which the computing device performs a contact simulation on the generated FE model based on the parameterized friction data (112) to generate contact simulation data for the interacting parts. In one embodiment, the generated contact simulation data can include the friction distance, friction velocity, friction force, stress, and strain between the interacting parts.Furthermore, the procedure 200 may include step 210 in which the computer device analyzes the change in frictional force, the change in frictional speed, the time interval between the changes and the time at which the changes occur in order to determine the probability of squeaking noises occurring between the interacting parts.

[0040] It is understood that selecting only the relevant data (change in frictional force, change in frictional speed, the time interval between the changes and the time at which the changes occur) in step 208 from the large amount of contact simulation data generated in step 206 can facilitate the accurate identification of events where squeaking noises occur, while also mitigating any convergence problems.

[0041] In one embodiment, method 200 in step 202 can include the steps of receiving friction data (stick-slip), which relates to the change in frictional force between the several known materials when the frictional speed between them changes during surface interaction, followed by parameterizing the received friction data to generate parameterized data that includes the static coefficient of friction, the dynamic coefficient of friction, and the friction decay factor. This parameterized data can be stored in the database, which can later be used for squeaking noise prediction.

[0042] In one embodiment, the method 200 in step 210 may include the steps of predicting or determining the probability of a squealing noise event occurring between the interacting parts of the component based on the change in frictional force, the change in frictional velocity, the time interval between the changes, and / or the time of the changes. Accordingly, the squealing noise event can be identified when the change in frictional force, the change in frictional velocity, the time interval between the changes, and / or the time of the changes are detected to exceed threshold values.

[0043] Furthermore, the procedure 200 may include step 212, which allows users (technicians or experts) to modify the CAD data (110) associated with the interacting parts until the analyzed change in frictional force, change in frictional speed, time interval between changes and / or time of changes in the relevant interacting parts fall below the threshold values, thereby mitigating or resolving the squeaking noise event in the component.

[0044] In Fig. Figure 3 shows an exemplary flowchart illustrating the operation of the proposed system and procedure. As shown, in Block 302, parameterized friction (stick-slip) data 318, relating to the frictional behavior of a variety of known materials in surface interaction, can be generated using the input device and stored in the database. Furthermore, in Block 304, CAD data (110) for a component to be investigated for squeaking noises can be generated by the users using the device. The CAD data (110) can contain geometric and material attributes of a set of interacting parts associated with the component. In addition, in Block 306, a finite element (FE) model of the component and the corresponding parts can be generated by the computing device using the input device based on the CAD data (110) received in Block 304.

[0045] In block 308, the device can perform a contact simulation for the FE model generated in block 306 based on the parameterized friction data (112) from block 302 to generate contact simulation data for the interacting parts. Furthermore, test data processing 320 can be performed to obtain the required parameters. In one embodiment, the generated contact simulation data can include friction distance, friction velocity, friction force, stress, and strain between the interacting parts. Furthermore, in block 310, the device can extract (relevant) test data from the contact simulation data of block 308, including the friction force, the change in friction velocity, the time interval between changes, and the time at which the changes occur.Furthermore, the device in block 312 can perform the digital contact simulation with predefined optimal simulation parameters 322, so that the device can produce optimal and accurate results.

[0046] In block 314, the device can analyze the change in frictional force, the change in frictional speed, the time interval between the changes, and the time at which the changes occur in order to determine and identify the probability of squeaking noises occurring between the interacting parts. In block 316, the device can allow users (engineers or experts) to modify the CAD data (110) associated with the interacting parts until the squeaking noise event in the component is resolved.

[0047] With reference to Fig. 4A and Fig. 4B The component 400 to be analyzed for the squeaking noise event may consist of two trim pieces connected to a vehicle door or other vehicle component. As shown, the two trim pieces may comprise a first part 402 and a second part 404, wherein a region 406 of the first part 402 and the second part 404 may be in surface contact with each other. This region 406 may cause a squeaking noise when the contact surfaces of the first part 402 and the second part 404 rub against each other due to a gap (G) between the first part 402 and the second part 404. The computer device can highlight this identified region 404 of the interacting parts and display it via the device so that technicians or experts can identify and correct the squeaking noise in the relevant region 404.

[0048] The device can analyze the change in frictional force and frictional speed between the surfaces of the first part 402 and the second part 404, together with the time of the change and the time interval between changes, in order to identify the occurrence of squeaking noises 410 between the parts 402 and 404 in the relevant area. Accordingly, to eliminate the identified squeaking noise event in the area 406, a stopper 408 can be provided in the gap G between the first part 402 and the second part 404, as shown in Fig. 4B shown. This stopper 408 can be added to the CAD data (110) of component 400 and further analyzed to check if the squeaking noise event has been resolved.

[0049] Thus, this invention (system and method) offers an improved and reliable solution that accurately represents the realistic interactions between the parts of any component and improves the ability to predict the occurrence of squeaking noises with higher precision, which can enable the development of effective strategies to remedy them.

[0050] It is obvious to the person skilled in the art that, although various embodiments and figures of the present invention have been elaborated for the proposed system for predicting and solving squeaking noises in parts connected with vehicle components, the teachings of the present invention are equally applicable to the prediction and solution of squeaking noises in other parts and components that are not vehicle components, and that all these embodiments fall within the scope of the present invention without limitation.

[0051] In one embodiment, the input device 104 can be Fig. 1. The input device 104 may include any or a combination of a keyboard, mouse, camera, touchscreen display, and drawing pad that enables technicians or experts to create the geometry and define the material properties of the parts associated with the component in order to generate the CAD data (110) and to input the generated CAD data (110) into the computing device 102 for further processing and calculation. The input device 104 may also enable technicians or experts to update the raw friction data and / or the parameterized friction data (112), update the contact simulation parameters to optimize the contact simulation process, and modify the CAD data (110) until the squeaking noise event is mitigated or resolved. 412. Furthermore, the output device 108 may include Fig.1. Any or a combination of a display module, touchscreen display, printer or similar device that enables technicians or experts to view the geometry and defined material properties of the parts connected to the component and to further monitor the interacting surfaces of the parts where squeaking noises may occur.

[0052] Although the explanation of the invention assumes that the operation of the system is controlled by a computing device 102, it can also be assumed that the operation of the system can be controlled by a variety of computing systems, such as a computer, a server, a network server, a cloud-based environment, and the like. The computing device 102 comprises one or more processors 102-1, which are operationally coupled to a memory 102-2. The processors 102-1 can be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuits, and / or any devices that process data based on operating instructions. Among other capabilities, the processors 102-1 are configured to retrieve and execute computer-readable instructions stored in memory.The memory 102-2 can store one or more computer-readable instructions or routines that can be retrieved and executed to create or share data units via a network service. The memory 102-2 can comprise any non-volatile device, such as volatile memory like RAM or non-volatile memory like EPROM, flash memory, and the like. The computing device 102, the input device 104, the database 106, and the output device 108 can include interfaces, which may encompass a variety of interfaces for connecting the corresponding components and facilitating communication between them.

[0053] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention can be developed without deviating from the fundamental scope of the invention. The scope of the invention is defined by the following claims. The invention is not limited to the described embodiments, variants, or examples, provided that they are included to enable a person with ordinary technical knowledge to manufacture and use the invention when combined with information and knowledge available to such a person. ADVANTAGES OF THE INVENTION

[0054] The present invention offers a solution that accurately predicts the occurrence of squeaking noises due to interactions between components or their parts, which can enable the development of effective strategies to remedy them.

[0055] The present invention simulates the stick-slip phenomenon between interacting parts under various realistic conditions, including different loads, speeds and geometries of the interacting parts, enabling seamless analysis and improvement of the design.

[0056] The present invention offers an effective and robust solution for reducing or eliminating squeaking noises, thereby improving vehicle quality and customer satisfaction.

[0057] The present invention accurately represents the realistic interactions between interacting parts and improves the ability to predict the occurrence of squeaking noises with higher precision. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 110263414B

[0004]

Images