Patent Publication Number: US-2020300620-A1

Title: System and method for automatically checking seat dimension accuracy and computer-readable recording medium recorded with program for the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Application No. 10-2019-0032310 filed on Mar. 21, 2019, the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a system and a method for automatically checking seat dimension accuracy for a vehicle and a computer-readable recording medium recorded with a program for the same, and more particularly, to a system and a method for automatically checking seat dimension accuracy for a vehicle and a computer-readable recording medium recorded with a program for the same, which can automatically check whether an actually produced seat has been accurately produced to match predesigned seat dimensions. 
     Description of Related Art 
     As is well-known, a seat for a vehicle is configured to include a seat cushion for seating, a seat back for leaning the back thereon, and a head rest for supporting a neck and a head, and such a seat has been produced with different sizes and shapes by vehicle types. 
     A seat producing process is briefly divided into designing a seat, producing the seat to match the designed dimensions and shape in an actual producing process, and checking the quality of the produced seat. 
     Furthermore, in checking the quality of the seat, seat dimension accuracy checking is performed to check whether the actually produced seat has been produced to match the designed dimensions and shape. 
     The seat dimension accuracy checking is performed to include obtaining seat design data from seat design data (e.g., CAD data), obtaining seat measurement data through measurement of the dimensions of an actually produced seat, comparing the seat design data with the seat measurement data, and preparing a quality check report in accordance with the result of the comparison. 
     However, the seat dimension accuracy checking in the related art has problems that there exist errors on the checking types of respective operators who perform the seat dimension accuracy checking, and thus the accuracy deteriorates in checking the seat dimension accuracy and the quality. 
     Furthermore, since the seat dimension accuracy checking in the related art is manually performed by the operator, it takes for too much time to perform the checking, and thus workability of the seat quality checking is greatly lowered. 
     The information included in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and may not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY 
     Various aspects of the present invention are directed to providing a system and a method for checking seat dimension accuracy for a vehicle and a computer-readable recording medium recorded with a program for the same, which can automatically check whether an actually produced seat has been accurately produced to match designed seat dimensions through automatic comparison of seat design data with scan data of the actually produced seat, and can automatically generate a checking result report. 
     In one aspect of the present invention for achieving the object, a system for automatically checking seat dimension accuracy for a vehicle may include a storage unit configured to store therein seat design data at a time of designing an actually produced seat and seat scan data obtained by scanning the actually produced seat; a controller configured to determine whether the actually produced seat has been produced to match predesigned dimensions using the seat design data and the seat scan data stored in the storage unit; and an output unit configured to automatically output a result of determination by the controller in a specific form. 
     In another aspect of the present invention for achieving the object, a method for automatically checking seat dimension accuracy for a vehicle may include storing, in a storage unit, seat design data at a time of designing an actually produced seat and seat scan data obtained by scanning the actually produced seat; determining, by a controller connected to the storage unit, whether the actually produced seat has been produced to match predesigned dimensions using the seat design data and the seat scan data stored in the storage unit; and automatically outputting, by an output unit connected to the controller, the result of determination by the controller in a specific form. 
     In yet another aspect of the present invention for achieving the object, a recording medium recorded with a program for executing a method for automatically checking seat dimension accuracy for a vehicle, including storing, in a storage unit, seat design data at a time of designing an actually produced seat and seat scan data obtained by scanning the actually produced seat; determining, by a controller connected to the storage unit, whether the actually produced seat has been produced to match predesigned dimensions using the seat design data and the seat scan data stored in the storage unit; and automatically outputting, by an output unit connected to the controller, the result of determination by the controller in a specific form. 
     Through the above, various aspects of the present invention provide the following effects. 
     First, it is possible to automatically check whether the actually produced seat has been accurately produced to match the designed seat dimensions through automatic comparison of the seat design data with the scan data of the actually produced seat, and thus it is possible to improve the accuracy of the seat dimension accuracy checking. 
     Second, since the seat dimension accuracy checking is automatically performed, it is possible to greatly reduce the checking time in comparison with the existing manual checking (e.g., the existing manual checking time of two hours may be reduced to about one minute). 
     Third, because of the automation and time reduction of the seat dimension accuracy checking, it is possible to improve workability and accuracy in comparison with the existing manual work. 
     Fourth, since the seat dimension accuracy checking data and the checking result report after the checking are automatically constructed as a database, it is advantageous to search for and utilize the checking data thereafter. 
     Other aspects and exemplary embodiments of the disclosure are discussed infra. 
     It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger vehicles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and may include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. 
     The above and other features of the disclosure are discussed infra. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating the configuration of a system for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention; 
         FIG. 2  is a flowchart illustrating a method for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention; 
         FIG. 3  is a flowchart illustrating a subdivided seat dimension accuracy process of a system for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention; 
         FIG. 4  is an image diagram showing an execution screen of an input unit and a matching unit in a system for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention; 
         FIG. 5  is an image diagram showing an execution screen of a measurement unit and an analysis unit in a system for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention; 
         FIG. 6  is an image diagram showing an execution screen of an output unit in a system for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention; and 
         FIG. 7 ,  FIG. 8 ,  FIG. 9 ,  FIG. 10 ,  FIG. 11 ,  FIG. 12 ,  FIG. 13  and  FIG. 14  are diagrams explaining respective subdivided processes of a seat matching step of  FIG. 6 . 
     
    
    
     It may be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the present invention. The specific design features of the present invention as included herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particularly intended application and use environment. 
     In the figures, reference numbers refer to the same or equivalent portions of the present invention throughout the several figures of the drawing. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the present invention(s) will be described in conjunction with exemplary embodiments of the present invention, it will be understood that the present description is not intended to limit the present invention(s) to those exemplary embodiments. On the other hand, the present invention(s) is/are intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the present invention as defined by the appended claims. 
     In the whole description, it will be understood that when a component is referred to as being “comprising” any component, it does not exclude other components, but can further comprises the other components unless otherwise specified. 
     Hereinafter, a preferable embodiment of the present invention will be described with reference to the accompanying drawings. 
     Referring to  FIG. 1 , a system for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention includes a storage unit  110 , a controller  120 , and an output unit  130 , and the controller  120  is configured to include an input loading unit  122 , a seat matching unit  124 , a measurement unit  126 , and an analysis unit  128 . 
     Furthermore, a three-dimensional (3D) scanner  200  and an external device (e.g., smart device)  210  are connected to the storage unit  110  through a communication unit  140 , so that data may be transmitted between them. 
     In the storage unit  110 , seat design data (e.g., a CAD file which is a seat design drawing file) at the time of designing and seat scan data (e.g., a seat scan file) obtained by scanning an actually produced seat are stored. 
     That is, the seat scan data obtained by scanning the actually produced seat using the 3D scanner  200  is inputted to and stored in the storage unit  110  through the communication unit  140 , and the seat design data is inputted from the external device  210  to the storage unit  110  through the communication unit  140 , and is stored in the storage unit  110 . 
     The controller  120  is configured to determine whether the actually produced seat has been produced to match predesigned dimensions using the seat design data and the seat scan data stored in the storage unit  110 , and is configured to include the input loading unit  122 , the seat matching unit  124 , the measurement unit  126 , and the analysis unit  128 . 
     The input loading unit  122  loads the seat design data and the seat scan data stored in the storage unit  110  to display the stored data, and includes certain information input windows and menus for seat matching. 
     The seat matching unit  124  loads the seat design data and the seat scan data stored in the storage unit  110 , and performs the matching by comparing dimensions and shapes of the seat design data and the seat scan data with each other or making the dimensions and shapes of the seat design data and the seat scan data overlap each other. 
     For example, the seat matching unit  124  converts the seat design data and the seat scan data into 3D seat shapes, and automatically matches two converted 3D seat models with each other using coordinates of external points and hinge points of the seat design data and the seat scan data. 
     If a main section of the seat is selected in a matching state in which the two 3D seat models, that is, the 3D seat design data and seat scan data, overlap each other, the measurement unit  130  determines reference points (e.g., the highest point, the lowest point, and an inflection point) for a cutting plane of the selected section, and automatically measures the dimension values (e.g., bolster height and seat width) of the seat design data and the seat scan data on the cutting plane of the section at the same time. 
     The analysis unit  140  analyzes, through comparison, the dimension difference between the dimensions measured by the measurement unit, that is, the dimension difference between the seat design data and the seat scan data, and if the dimension difference is within an error range, the analysis unit  140  makes a pass decision for the dimension accuracy, whereas if the dimension difference deviates from the error range, the analysis unit  140  makes a fail decision for the dimension accuracy. 
     The output unit  150  automatically generates a specific result report file (e.g., PPT) including comparison analysis data and the pass/fail decision results. 
     Hereinafter, a method for automatically checking seat dimension accuracy, which is performed based on the above-described configuration, according to an exemplary embodiment of the present invention will be described. 
       FIG. 2  is a flowchart illustrating a method for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention. 
     First, seat design data (e.g., a CAD file which is a seat design drawing file) at the time of designing is inputted from the external device  210  through the communication unit  140 , and is stored in the storage unit  110 . Furthermore, seat scan data (e.g., a seat scan file) obtained by scanning the actually produced seat using the 3D scanner  200  is inputted from the 3D scanner  200  through the communication unit  140 , and is stored in the storage unit  110 . 
     As such, a program for executing the method for automatically checking the seat dimension accuracy is executed after a computer including a recording medium for executing the method for automatically checking the seat dimension accuracy is booted, and then the seat design data (e.g., the seat design drawing (CAD file)) and the seat scan data (e.g., the seat scan file) stored in the storage unit  110  are loaded through the input loading unit  122  (S 101 ). 
     As such, certain information for seat matching (e.g., angles among hip-point, torso, and thigh during seating) is selected and inputted using a menu input window of the input unit  122  (S 102 ). 
     Next, if the seat design data (e.g., the seat design drawing (CAD file)) and the seat scan data (e.g., the seat scan file) are loaded and displayed on a display, seat matching using a specific algorithm is performed by the seat matching unit  120  to check whether the seat design data and the seat scan data coincide with each other (S 103 ). 
     For reference, if a seat model in accordance with the seat design data (e.g., the seat design drawing (CAD file)) and a seat model in accordance with the seat scan data (e.g., the seat scan file) are loaded and then displayed on the display in an overlapping manner through the seat matching, as shown in  FIG. 4 , the seat model in accordance with the seat design data is displayed as a dotted portion, and the seat model in accordance with the seat scan data is displayed as a grey portion. 
     Here, the seat matching will be described in detail. 
     Accompanying  FIG. 3  is a flowchart illustrating subdivided processes of a seat matching step in a method for checking seat dimension accuracy for a vehicle according to an exemplary embodiment of the present invention, and  FIGS. 7 to 14  are diagrams explaining respective subdivided processes of a seat matching step. 
     If a specific algorithm is executed by the seat matching unit  120 , a 3D seat model in accordance with the seat scan data (e.g., seat scan file) is first divided into a seat cushion and a seat back (S 103 - 1 ). 
     The reason why the 3D seat model in accordance with the seat scan data (e.g., seat scan file) may include the seat cushion and the seat back is to compare the dimensions of the seat cushion and the seat back with the dimensions of the seat cushion and the seat back of the seat design data, respectively. 
     For this, dividing the 3D modeling seat in accordance with the seat scan data into the seat cushion and the seat back is performed in the order of: 
     Extracting a center profile (refer to a dotted line of  FIG. 7 ) of the seat cushion and the seat back on the basis of a hip-point of the 3D seat model in accordance with the seat scan data (e.g., seat scan file) as shown in  FIG. 7 ; 
     Creating a seat side portion curve (refer to a solid line of  FIG. 8 ) by connecting points of the extracted center profile with one another through curve fitting of the respective points; 
     Determining a curvature of each fine section on the generated seat side portion curve; 
     Determining a point at which the curvature is changed most greatly as a separation reference point (refer to a separation reference point indicated in  FIG. 9 ) at which the seat back and the seat cushion meet each other; 
     Defining a cutting plane by connecting the separation reference point with the hip-point inputted by a user; and 
     Dividing the seat cushion and the seat back from each other on the basis of the cutting plane, and discriminating the seat cushion and the seat back from each other with different colors (refer to color discrimination example of  FIG. 10 ) on the basis of a division boundary portion of the seat cushion and the seat back. 
     As such, if the 3D seat model in accordance with the seat scan data is divided into the seat cushion and the seat back, analogizing a rotation axis of the divided seat is performed (S 103 - 2 ). 
     The reason why to analogize the rotation axis of the divided seat is to utilize the rotation axis in a process of adjusting an angle between the divided seat cushion and seat back. 
     For this, analogizing the rotation axis of the divided seat is performed in the order of: 
     Determining a transformation matrix (=translation+rotation matrix) for respectively aligning the separated seat cushion and seat back using an iterative closest point (ICP) method which is a kind of 3D object matching algorithm; 
     Extracting only the rotation matrix of the seat back from the determined transformation matrix; and 
     Determining an eigenvector from the rotation matrix of the extracted seat back, and defining an axis that passes through a position of the eigenvector and is in parallel to a side-direction axis (Y axis), and thus, as shown in  FIG. 11 , the rotation axis on which the seat back is rotatable against the seat cushion is determined. 
     Accordingly, it is possible to transform the position of the rotation axis as determined above into relative coordinates (AX, AZ) on the basis of the hip-point as shown in  FIG. 12 , and thus the angle adjustment utilization with respect to the seat model in accordance with the seat scan data may be easily performed. 
     Next, to match the seat model in accordance with the seat scan data and the seat model in accordance with the seat design data with each other, equally adjusting seat angles is performed to make the angle between the seat back and the seat cushion of the seat model in accordance with the seat scan data and the angle between the seat back and the seat cushion of the seat model in accordance with the seat design data equal to each other (S 103 - 3 ). 
     For this, equally adjusting the seat angles is performed in the order of: 
     Refer to  FIG. 13 , Extracting four or more feature points from the center profile of the seat model in accordance with the seat scan data and the seat model in accordance with the seat design data (e.g., extracting two feature points from the seat back and extracting two feature points from the seat cushion) and extracting a straight line connecting the feature points (refer to dotted line in the  FIG. 12 ); 
     Determining, from the extracted straight line, the angle between the seat back and the seat cushion of the seat model in accordance with the seat scan data and the angle between the seat back and the seat cushion of the seat model in accordance with the seat design data; 
     If there occurs a difference between the angle between the seat back and the seat cushion of the seat model in accordance with the seat scan data and the angle between the seat back and the seat cushion of the seat model in accordance with the seat design data, adjusting the angle between the seat back and the seat cushion of the seat model in accordance with the seat scan data to match the angle between the seat back and the seat cushion of the seat model in accordance with the seat design data. 
     In the case of adjusting the angle between the seat back and the seat cushion of the seat model in accordance with the seat scan data, the seat back and the seat cushion are separated from each other as described above at operation S 103 - 1  and the rotation axis is determined as described above at operation S 103 - 2 , and thus by rotating only the seat back of the seat model in accordance with the seat scan data about the rotation axis, the angle between the seat back and the seat cushion of the seat model in accordance with the seat scan data coincides with the angle between the seat back and the seat cushion of the seat model in accordance with the seat design data. 
     Next, primary seat matching is performed to primarily match the seat model in accordance with the seat scan data with the seat model in accordance with the seat design data (S 103 - 4 ). 
     Although the seat back and the seat cushion of the seat model in accordance with the seat scan data are separated from each other as described above at operation S 103 - 1  and the rotation axis is determined as described above at operation S 103 - 2 , the primary seat matching step is performed to match the non-separated seat model with the seat model in accordance with the seat design data as making the seat models overlap each other. 
     That is, the primary seat matching includes deriving the seat model in accordance with the seat scan data as a transformation matrix using the ICP algorithm and aligning the seat model in accordance with the seat scan data to overlap the seat model in accordance with the seat design data as it is. 
     After the primary seat matching, precise seat matching is performed to precisely match the seat model in accordance with the seat scan data with the seat model in accordance with the seat design data (S 103 - 5 ). 
     After the primary seat matching is performed, the precise seat matching is performed to adjust the angle between the seat cushion and the seat back of the seat model in accordance with the seat scan data about the rotation axis determined at operation S 103 - 2  to match the angle between the seat cushion and the seat back of the seat model in accordance with the seat design data, and thus the matching accuracy between the seat model in accordance with the seat scan data and the seat model in accordance with the seat design data may be heightened. 
     Preferably, by repeatedly performing operations S 103 - 1  to S 103 - 5  forming the seat matching step several times until the dimension difference between the seat model in accordance with the seat scan data and the seat model in accordance with the seat design data converges, the seat matching is completed. 
     Next, if the seat section of the target of checking is set in a state in which the seat model in accordance with the seat scan data and the seat model in accordance with the seat design data match each other (S 104 ), reference points (a bolster projection point, the highest seat point, the lowest seat point, and a seat inflection point) included in the seat section are extracted (S 105 ). 
     As such, as shown in  FIG. 5 , the corresponding cross-sectional shape in accordance with the seat section setting is displayed on a display screen, and in  FIG. 5 , a thick line indicates the cross-sectional shape of the seat model in accordance with the seat design data, and a thin line indicates the cross-sectional shape of the seat model in accordance with the seat scan data. 
     In the instant case, the measurement unit  130  determines the reference points (e.g., the highest point, the lowest point, and the inflection point) for the cutting plane of the selected section based on the specific algorithm, and automatically measures the dimension values (e.g., bolster height and seat width) of the seat design data and the seat scan data on the cutting plane of the section at the same time (S 106 ). 
     The analysis unit  140  analyzes, through comparison, the dimension difference between the seat design data and the seat scan data (e.g., bolster height difference and seat width difference) based on the specific algorithm (S 107 ), and if the dimension difference is within the error range (e.g., about 5 mm or less) as the result of the comparison analysis, the analysis unit  140  makes the pass decision for the dimension accuracy, whereas if the dimension difference deviates from the error range (e.g., about 5 mm or more), the analysis unit  140  makes the fail decision for the seat dimension accuracy (S 107  and S 108 ). 
     In the instant case, the dimension checking result of the analysis unit  140  is visualized and displayed by a color map as shown as an image on the upper right side thereof (S 109 ). 
     Finally, a report is automatically generated such that the final results of the dimension checking executed by the analysis unit  140  are automatically written on a specific report form (e.g., PPT file) as shown in  FIG. 6  through the specific algorithm (S 110 ). 
     According to an exemplary embodiment of the present invention as described above, it may be automatically verified whether the actually produced seat has been accurately produced to match the designed seat dimensions through automatic comparison of the seat design data with the scan data of the actually produced seat, and thus the accuracy of the seat dimension checking may be improved and the checking time may be greatly reduced in comparison with the conventional manual checking. 
     For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner”, “outer”, “up”, “down”, “upwards”, “downwards”, “front”, “rear”, “back”, “inside”, “outside”, “inwardly”, “outwardly”, “internal”, “external”, “inner”, “outer”, “forwards”, and “backwards” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. It will be further understood that the term “connect” or its derivatives refer both to direct and indirect connection. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described to explain certain principles of the present invention and their practical application, to enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the present invention be defined by the Claims appended hereto and their equivalents.