Method for checking a positioning device

Abstract

A method for checking the dimensional accuracy of transportable positioning devices (P) for producing motor vehicles, wherein the positioning devices (P) each have a support (1, 3, 5, 7) in order to enable a body component (K) of a motor vehicle to be manufactured to be positioned geometrically accurately on the positioning device (P), and wherein the positioning devices (P) are moved together with the body components (K) positioned on them respectively in a motor vehicle production flow for the production of motor vehicles, characterized in that predefined measuring points (M) on the body components (K) respectively positioned on the positioning devices (P) are measured in position in the workstations and / or in in-line measuring stations specially provided for detecting measuring values during the motor vehicle production flow, wherein the dimensional accuracy of the transportable positioning devices (P) is determined by evaluating the measuring points (M) by a control unit.

Description

Technical Field

[0001] The present invention relates to a method for checking the dimensional accuracy of a transportable or movable positioning device used in the production of motor vehicles. Background Technology

[0002] In the automotive manufacturing industry, it is known to precisely position relatively large and rigid components, especially body parts, in multiple workstations, so that these components can be further processed or fitted to ultimately produce motor vehicles or motor vehicle parts. Some manufacturers use positioning devices fixedly mounted in workstations to support or house body components. More recently, it has become known to use transportable positioning devices, which, on the one hand, can precisely house components, especially body components, and on the other hand, can be transported—particularly through suitable transfer technologies—from one workstation to the next, along with the components positioned on the positioning device. Such positioning devices are also known as "geo-skids." The positioning devices themselves can be precisely positioned in the corresponding workstations using transfer technologies. This ensures that the components to be manufactured, or the body to be manufactured, can be repeatedly and identically positioned in the vehicle coordinate system for all manufacturing processes in different workstations or machining rooms.

[0003] Therefore, the positioning device forms a geometrically oriented connection between the transmission technology and the product to be manufactured, and can also produce a variety of different products or vehicle types in a closed manufacturing process.

[0004] Typically, these movable positioning devices or geometric skids are periodically inspected at a separate measuring station or measuring room outside the production cycle. For this purpose, the positioning devices are transported from the vehicle body construction process (i.e., from the motor vehicle production flow) at prescribed intervals to the measuring room, where they are inspected, calibrated, and re-inspected using 3D coordinate measuring equipment for verification before being reintroduced into the production process. Here, the positioning device is directly measured or the measuring points on the positioning device are directly inspected. This verification of the dimensional accuracy of the positioning device can be performed, for example, approximately 1 to 4 times per year. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for inspecting the dimensional accuracy of transportable positioning devices used in the production of motor vehicles, thereby requiring almost no additional time in the mass production of motor vehicles, while still allowing for the reliable elimination of defective positioning devices, thus enabling the method as a whole to achieve efficient and dimensionally stable mass production of motor vehicles.

[0006] The technical problem is solved by a method for checking the dimensional accuracy of transportable positioning devices for the production of motor vehicles, wherein the positioning devices each have supports (Aufnahme or pillars) so that the body components of the motor vehicle to be manufactured can be geometrically and accurately positioned on the positioning devices, and wherein the positioning devices, together with the body components respectively positioned on the positioning devices, are moved to different workstations in the motor vehicle production flow for the production of motor vehicles, wherein during the motor vehicle production flow, predefined measurement points on the corresponding body components positioned on the positioning devices are measured at the workstations and / or at inline-measuring stations (specifically set up in the motor vehicle production flow for detecting measurement values), wherein the dimensional accuracy of the transportable positioning devices is determined by evaluating the measurement points by a control unit.

[0007] According to the invention, the position of a transportable positioning device is indirectly measured by measuring the position of a measuring point on the transported vehicle body component, preferably in three dimensions, i.e., the 3D coordinates of a predefined measuring point on the transported component. These measurements are performed during normal vehicle production flow, i.e., during the normal operation of the positioning device and the vehicle body component. According to the invention, the control unit is designed to infer possible errors in the positioning device, i.e., its dimensional accuracy, and particularly dimensional accuracy exceeding specified tolerances, from the measuring points, and especially from the deviations of the measuring points from preset standard values. Such defective positioning devices can then be rejected, for example, at a separate measuring or control station outside of normal vehicle production flow, and, for example, corrected or eliminated.

[0008] Because measurements are taken during the continuous production run of vehicle manufacturing, verification and maintenance or elimination of potentially unsuitable positioning devices can be achieved with minimal time loss and, consequently, with exceptional efficiency. Therefore, measurements are performed at in-line measurement stations or workstations within the production flow. In-line measurements can be performed at workstations and / or at in-line measurement stations specifically designed for detecting measured values ​​within the production flow. Thus, stations in the production flow typically equipped with high-precision measuring devices for detecting measurement point M, intended for process monitoring purposes, are used to indirectly measure positioning devices. This evaluation of the dimensional accuracy of the positioning device should be distinguished from the preferred additional evaluation of the dimensional accuracy of the same measuring point within the vehicle body frame itself.

[0009] Preferably, predefined measurement points and measuring equipment are already standardly used for process control of body components or for checking the dimensional accuracy of the body components themselves, thus eliminating the need for additional measurement points and equipment to check the dimensional accuracy of transportable positioning devices or geometric skids. Preferably, no additional measurements are performed to check the dimensional accuracy of movable positioning devices or geometric skids, or no additional measurement time is required that could slow down the production process. Existing measurement points / data necessary for checking the body components themselves are evaluated accordingly to draw conclusions regarding the dimensional accuracy of the positioning devices (i.e., geometric skids).

[0010] Preferably, the positioning device is identified in the control unit—thus each device has a unique ID or explicit identifier. Preferably, during multiple vehicle production flows, at multiple workstations and / or in-line measurement stations or measurement rooms specifically designed for detecting measurement values, predefined measurement points on body components correspondingly positioned on the same identified positioning device are measured, wherein the dimensional accuracy of the corresponding identified transportable positioning device is determined by evaluating the measurement points of the same identified positioning device in multiple vehicle production flows by the control unit. Therefore, it is preferable to track individual identified positioning devices in multiple vehicle production flows, i.e., in multiple flows or production cycles. From the performance of measurement values ​​or measurement deviations in multiple different carried body components, it can be easily inferred which deviations are based on the properties of the changed, transported body components and which deviations are based on the properties of the identified geometric skids used. In this way, not only can the influence of individual components or component batches be advantageously eliminated, but also other external influences such as vibration, light, pollution, etc., can be eliminated.

[0011] Preferably, predetermined measurement points on each vehicle body component positioned on the positioning device are grouped into one or more predefined measurement point groups by a control unit for evaluating the measurement points, wherein performance-related measurement points are grouped into separate measurement point groups. All measurement points are grouped into one or more measurement point groups so that more precise conclusions about possible error groups or error types can be drawn from these measurement point groups. For example, these measurement point groups could be: the x-position of the component, the y-position of the rear of the component, etc. Grouping these preferably existing or used measurement points into measurement point groups and their algorithm-based evaluation is an "additional expense" according to the invention, because the detection of measurement points and their measured values ​​is carried out from the beginning as specified or implemented according to standards for monitoring the dimensional accuracy of the vehicle body components themselves.

[0012] The names x, y, and z refer to a common vehicle coordinate system. Thus, direction x extends longitudinally, direction y extends laterally orthogonal to direction x, and direction z extends vertically to the component and / or vehicle.

[0013] Preferably, the predefined measurement points are divided into exactly seven measurement point groups, specifically one x measurement point group, two y measurement point groups (preferably in the front and rear of the x direction) and four z measurement point groups (preferably left front and right front and left rear and right rear).

[0014] Preferably, each set of measuring points corresponds to exactly one support of the positioning device, wherein the positional deviation from the set of measuring points is determined by the control unit to achieve dimensional accuracy at the corresponding support. Multiple sets of measuring points can be assigned to one support.

[0015] Particularly preferably, each positioning device has exactly four supports so that the body components of the motor vehicle to be manufactured can be geometrically precisely positioned on the positioning device.

[0016] The four supports are preferably constructed by an xyz support (i.e., a support that determines the position in the x, y, and z directions), a yz support that determines the position in the y and z directions, and two z supports that determine the position only in the z direction (i.e., the vertical direction).

[0017] Preferably, each positioning device, in addition to the retainer, has an additional support point to prevent the vehicle body component positioned on the positioning device from loosening. Therefore, these support points support the carried component in the z-direction but are not used for precise positioning of the component. Attached Figure Description

[0018] The present invention will now be described with reference to the accompanying drawings and through embodiments.

[0019] Figure 1 A flowchart of a motor vehicle manufacturing process using the method of the present invention is shown.

[0020] Figure 2 The steps of determining the dimensional accuracy of a transportable positioning device by evaluating measurement points through a control unit are illustrated schematically in the method according to the invention.

[0021] Figure 3 This diagram shows the geometric orientation of the vehicle body component (upper part) via the positioning device (below) and the supports used.

[0022] Figure 4 A schematic diagram showing a set of measurement points on a vehicle body component.

[0023] Figure 5 This diagram illustrates how measurement points are assigned to groups of measurement points on the vehicle body components. Detailed Implementation

[0024] Figure 1 A flowchart of a motor vehicle manufacturing process using the method of the present invention is shown.

[0025] The attached diagram uses labels to indicate the various steps in the flowchart:

[0026] 1-1 Loading Station: The movement of the body-in-white or production begins by placing the positioning device P into the loading station.

[0027] 1-2 Manufacturing Operation of Body Component K in the Body-in-White Plant

[0028] 1-3 The possible measurement values ​​of the measurement value M are collected during the nth run by the in-line station or in-line measurement station, that is, the component measurement data of the vehicle body component K are obtained.

[0029] Reading bits 1-4 (RFID, etc.)

[0030] Decision-making steps 1-5 – Elimination? (Elimination station)

[0031] J is

[0032] No

[0033] 1-5b refers to the measurement technology / calibration of the empty geometry skid P.

[0034] 1-6 Interface Measurement System

[0035] 1-7 Database of measurement data M used for calculating the algorithm

[0036] 1-8 Continuous Counter (Calculates geometric slide flow / measurement cycle)

[0037] Calculation algorithm for 1-9 (program code) — see Figure 2

[0038] 1-10 Measurement data 1-7, M visualized through calculation algorithm 1-9 for calculation / bias / evaluation

[0039] 1-11 Decision Steps – Is the geometric sled P significantly correlated with the loop from the nth run?

[0040] 1-12 MES Production System

[0041] 1-13, e.g., 5: Decision-making steps – Discharge? (Discharge station) – The geometric sled P can be transported from the flow to the defined stopping position.

[0042] In one cycle of motor vehicle production, the geometric skid P (i.e., the transportable positioning device P) is transported through the production equipment, and the significant defining features of the components or component groups transported on it (= the significant measurement points of the corresponding measurement point group) are measured by the measurement system as measurement points M in each cycle.

[0043] The production flow begins at step 1, introducing a geometric sled into the production equipment. Here, the geometric sled assembles components, which later undergo processing, such as welding, together in manufacturing run or machining run 2. During and / or at the end of manufacturing run 2, it is possible that at least once, measurement data at step 3 is generated for each flow, and this data is transferred to database 7 via interface 6. Furthermore, database 7 also stores data such as the number of flows at step 8. Additionally, a calculation algorithm 9 runs in the control unit, which evaluates and calculates the geometric properties of the geometric sled P from the acquired measurement data M, determining whether it adheres to a specified allowable maximum deviation relative to the defined flow and measurement cycles (see...). Figure 2 (The functional algorithm in the text).

[0044] If a deviation is detected in inspection 9, a message is generated, such as via SMS, email, or similar, and sent to the designated distributor via production system 12. Within this system, a process is also initiated that causes the involved positioning device P to be pre-tagged and identified, for example, via RFID upon reaching the defined read position 4, and then conveyed to its stopping position in the next discharge station 13. The geometric skid / positioning device P is then reintroduced into the system, for example, without manual release. This process, through algorithm 9 and the geometric deviations learned therein, ensures that no degraded or defective products are produced in the production plant.

[0045] Figure 2 The diagram schematically illustrates the steps of a method for determining the dimensional accuracy of a movable positioning device P by evaluating a measurement point M through a control unit, i.e., more accurately according to the method and... Figure 1 The algorithm in step 9 is performed.

[0046] The reference numerals in the attached figures indicate:

[0047] 2-20 is used for each measurement point group.

[0048] 2-21 is used for each geometry skid ID and data point.

[0049] 2-1 start

[0050] 2-2 Calculation of Sudden Changes

[0051] 2-3 Correct the average value to zero

[0052] 2-4 Calculation of the covariance matrix

[0053] 2-5 Calculate the optimal displacement

[0054] 2-6 Displacement grouped according to geometric skid ID

[0055] 2-7 Calculation of sudden changes in optimal displacement

[0056] 2-8 Calculation of average value and standard calibration since the last mutation

[0057] 2-9 Calculate the probability value outside of, for example, ±0.2 mm tolerance.

[0058] 2-10 Calculate the probability that at least one feature of each geometric skid exceeds the tolerance.

[0059] 2-11 Visualization of the time series of optimal displacement and average value

[0060] 2-12 Classification of geometric sleds according to the probability of exceeding tolerance

[0061] End of 2-13

[0062] The algorithm identifies NIO (abnormal) geometric skids, or Geo-Skid positioning devices P, from in-line measurement data of continuously detected vehicle body measurement points. To do this, it first checks for sudden changes caused by manual intervention in the measurements of all measurement points M. Each segment with a constant average value is corrected, resulting in a data sequence with a total average of zero. Since the error of the geometric skid P always affects multiple features simultaneously, the measurement points M are grouped together, and these groups change together due to the defect. Therefore, if the displacement in the x-direction originates from the defective geometric skid P, the displacement in the x-direction can be observed at all measurement points M. This is because orientation is achieved only at a single point. If that measurement point is incorrect, the entire body-in-white (body component K) is displaced. In the y-direction, the front and rear are oriented separately. Therefore, the error is either displayed in front of all points or behind all points. The same applies in the z-direction, but here it is adjusted at all four vertices, so the error is displayed as left front, right front, left rear, or right rear, but is always common to all features. For each of these seven regions, relevant points were defined and grouped into measurement point sets. For each set, the characteristics of the "normal" data points were estimated from the data using the so-called Mahalanobis distance.

[0063] For measurements in the y and z directions, the distance between the support point, the point of action, and the measurement point M also plays a crucial role. When using a geometric sled P to support the component, it moves at different points to ensure proper orientation. The point of action is the point of application set within the support, and undesirable displacements can occur at this point. The support point A is the point around which the component rotates during setup. It changes with the point of action. Each set of measurement points has exactly one point of action, but can have multiple support points A; the evaluation of the set of measurement points results in a deviation at a particular point of action. Not all measurement points M are exactly aligned with the point of action and the support point A. As an approximation, the measurement point M is projected onto the line connecting the nearest point of action and the support point A. If the measurement point M is closer to the support point A than the point of action, only a smaller displacement of the point of action at the measurement point can be observed. Conversely, if the measurement point M is farther from the support point A than the point of action, the displacement factor considered is given by the levers between the points.

[0064] Then, all features in each group are moved together until the data points appear as normal as possible. This displacement provides an estimate of how much the geometric skid P affects the measurement.

[0065] By observing the same geometric skid P in multiple runs with different body shapes K, it can be determined whether the systematic deviation in the measurement data is actually caused by the geometric skid P. If similar displacements in the same direction are determined in multiple runs, the defect of the geometric skid P is obvious. To quantify this, abrupt changes are looked for in the results, ultimately forming the average displacement since the last jump. This is suitable as an estimate of the actual displacement of the geometric skid P. Finally, for each geometric skid P, the probability of a deviation greater than ±0.20 mm is calculated (depending on the tolerance specification of the standard used, e.g., ±0.20 mm).

[0066] The results are output to the console, for example, as text. The geometric sled P is sorted according to the probability of exceeding the tolerance in at least one group of measurement points. Additionally, the best estimate of the deviation for each group of measurement points with a standard deviation is displayed, along with a comparison of the number of measurements used for the estimate since the last change point to the total number of measurements in the dataset used.

[0067] During automatic elimination, probability values ​​are invoked for decision-making. For this purpose, limit values ​​and a minimum number of measurements are defined (e.g., an 80% probability that the deviation exceeds ±0.20 after at least 20 measurements). If this condition is met, then... Figure 1 Steps 1-11 are the decision-making steps.

[0068] Figure 3 A schematic diagram showing the geometric orientation of the vehicle body component (upper part) via the positioning device (lower part) and the supports used.

[0069] The view of the positioning device P (bottom) shows four supports 1, 3, 5, and 7, through which the components (in this case, the vehicle chassis) are oriented on the geometric skid P, namely 1, 3, 5, and 7.

[0070] Correspondingly, there are openings 2, 4, 6 and 8 on the upper part of the body component K.

[0071] In addition to the four support points 1, 3, 5, and 7, other support points A in the z-direction are provided on the geometric skid P and component K.

[0072] For example, regarding the measurement point group "x": the orientation of component K along the x-direction on the geometric skid P is achieved through the main support xyz on the left front of the geometric skid P (i.e., responsible for positioning in the x, y and z directions) and the circular hole 2 in component K.

[0073] If the geometric skid P has a dimensional deviation in the x direction, the entire component K will be affected—visible on, for example, all 57 x-measurement features M on the component.

[0074] Measurement point group y front and y rear: y orientation in the front is the same as along the x-direction through the support xyz on the left front of the geometric skid P. If there is a dimensional deviation of the geometric skid P in the y-direction of the front region, the component K will be affected in the front region—for example, visible in the front of the 26 y-measurement features M.

[0075] Opposite to the x-direction of action, the y-direction is further oriented in the rear region through the yz support 3 on the geometric skid P and the elongated holes in the chassis assembly 4. Therefore, the dimensional deviation of the rear of the geometric skid P in the y-direction only affects the rear region of component K and is visible in the rear of the 11 y-measurement features M.

[0076] Measurement point groups z-left front, z-right front, z-left rear, and z-right rear: The same principle applies to the z-direction of action.

[0077] Component K is oriented via all four supports on the geometric skid P, namely 1, 3, 5, and 7, and the corresponding holes on component K, namely 2, 4, 6, and 8. 6 is an elongated hole, and 8 is a clamping hole without a fixing device.

[0078] If a z-deviation exists at the front left of the geometric sled P, it is visible in all 12 z-measurement features M at the front left. This front left deviation is caused by support 1 on the geometric sled P, and this deviation has no causal relationship with the z-features of the components in the other 3 z-measurement point groups, as they are oriented by 3, 5, and 7. The same principle applies to the other 3 supports.

[0079] Regarding the function of the supports and the support body: Component K is geometrically oriented on the geometric skid P via the supports. There are four types of supports (1, 3, 5, 7) used to determine the position, namely the 3-2-1 support scheme, as shown below. Figure 3 As shown. The component is placed only on the additional 6 z-supports A, so it will not tilt—but there is no geometric orientation there. Only supports 1, 3, 5, and 7 are geometrically related to the set of measurement points. Figure 3 The diagram shows a view of support A, which, in addition to supports 1, 3, 5, and 7 related to positioning, involves geometric skid P in contact with member K.

[0080] Figure 4 A schematic diagram showing a group of seven measurement points on a vehicle body component.

[0081] The measurement point group appears only on component K. Together, they constitute the composition, or summary, of the measurement feature / measurement point M. They behave identically because they are influenced in the same way by a common orientation (i.e., the corresponding supports on the geometric sled). The measurement feature M is given by the measurement plan and cycle time. Based on their direction of action and position on component K, they are assigned to the correct measurement point group for algorithmic calculation.

[0082] The measurement plan / measurement point plan preferably depends only on the body component K or on which measurement points are needed for process control / serial monitoring of the body component K or to check the dimensional accuracy of the body component itself. Only on the basis of these given measurement points can existing measurement points be assigned to measurement point groups, or assigned to corresponding measurement point groups according to the influence of their positions on various spatial directions.

[0083] Figure 4 Display: The black frame for all measurement points M in measurement point group x includes—for example, 57 measurement points M in this case. Dashed lines divide measurement points M into a front y region containing 26 measurement points M and a rear y region containing 11 measurement points M. Two intersecting dotted lines separate measurement points M into a front left z region (12 measurement points), a front right z region (12 measurement points), a rear left z region (6 measurement points), and a rear right z region (6 measurement points).

[0084] Multiple or all individual measurement points M can be assigned to multiple regions or groups of measurement points.

[0085] Example of measurement point group x: The main support at the left front will affect all 57 x-features (measurement points M) on the entire component because the orientation in the x-direction is only performed at the front.

[0086] Example of measurement point group y-front and rear: The main support at the left front affects 26 front y-features M. The support at the left rear affects 11 rear y-features M.

[0087] Example of a measurement point group for the left front: The main support at the left front affects 12 left front z-features M. The same principle also applies to the other 3 measurement point groups in the z-direction of action.

[0088] Figure 5 This is a schematic diagram of assigning measurement point M to a group of measurement points on the vehicle body component K (i.e., the rear end).

[0089] Figure 5 The small illustration in the upper left corner shows Figure 4 The rear end position of the body components ( Figure 5 (Bottom right)

[0090] In the case of the tail end, 7 measurement points M are measured, of which 7 measurement points M involve the x direction, 2 measurement points M involve the y direction, and 2 measurement points M involve the z direction.

[0091] These measurement points M (measurement features) are assigned as follows:

[0092] Seven x-measurement features are used to measure the x-point group.

[0093] Two y-measurement features are used for the rear measurement point group y

[0094] One z-measurement feature is used for the right rear measurement point group z.

[0095] One z-measurement feature is used for the left rear measurement point group z.

[0096] Therefore, one measurement point group corresponds to one region. There are a total of seven measurement point groups (1x, 2y, 4z), where the measurement features M related to the performance of product K are grouped. For each measurement point group, there are multiple measurement points M. Taking a car tailgate as an example (…). Figure 5 ), 7 x-features (= x measurement points M) are assigned to the total measurement point group x( on the entire vehicle body K). Figure 4 The framed area in the image shows that all 57 x-features M in product K are relevant regardless of their position if the device has displacement in x. Two y-features M are associated with the tailgate component and are assigned only to the rear y-measurement point group. Figure 4 The dotted lines at the rear are not related to the y-feature (measurement point) of the front area of ​​the vehicle body (due to the compensation properties of the distance from the rear support and the stiffness of the vehicle body).

[0097] The two sets of y-measurement points (front and rear y-measurement points) are divided into the front and rear regions of (artificial) component K, such as... Figure 4 As shown by the dashed line in the image.

[0098] Since component K is supported on the device on both the right and left rear sides, a deviation on one side does not necessarily imply a deviation on the other side. Following the same logic, the z-features are grouped into side-by-side and front / rear measurement point groups, because the relevant feature M can be summarized into four regions. These four z-measurement point groups are divided into the front and rear regions of component K, as well as the left and right regions, as shown from... Figure 4 As can be seen from the two dotted lines in the image.

[0099] Why is a group of exactly seven measurement points advantageous? These regions address the question, "What is the minimum number of groups / regions that generate the most information?" When the 3-2-1 support and clamping scheme is applied here, there are exactly seven measurement points for the self-supporting vehicle body K and the measurement points M defined on component K. If, for example, additional x-regions are defined, these regions will not provide any additional information because all x-features M behave identically on the vehicle body K. Conversely, if the two y-regions are reduced to a single y-region, relevant information will be lost because the front and rear y-features are not correlated and therefore must be separated.

[0100] List of reference numerals

[0101] Support point A

[0102] K body components

[0103] M measurement point

[0104] P-positioning device or geometric sled

[0105] Positioning directions of X, Y, and Z on the support

[0106] J is

[0107] No

[0108] 1. Support on the positioning device

[0109] 2. Support openings on body components

[0110] 3. Support on the positioning device

[0111] 4. Support openings on body components

[0112] 5. Support on the positioning device

[0113] 6. Support openings on body components

[0114] 7. Support on the positioning device

[0115] 8. Support openings on body components

[0116] 1-1 Loading Station

[0117] Manufacturing operations / processing in processing stations 1-2

[0118] 1-3 Measurement value collection, component measurement data inspection

[0119] Read bits 1-4

[0120] Decision-making steps 1-5 - Elimination?

[0121] 1-5b refers to measurement techniques / correction discharge

[0122] 1-6 Interface Measurement System

[0123] Database M of 1-7 Measurement Data

[0124] 1-8 Continuous Counter

[0125] 1-9 Calculation Algorithm

[0126] 1-10 Visualization

[0127] 1-11 Decision Steps - Geometric Sled Significance?

[0128] 1-12 MES Production System

[0129] 1-13 Decision-making steps - Elimination?

[0130] 2-1 start

[0131] 2-2 Calculation of Sudden Changes

[0132] 2-3 Correct the average value to zero

[0133] 2-4 Calculation of the covariance matrix

[0134] 2-5 Calculate the optimal displacement

[0135] 2-6 Displacement grouped according to geometric skid ID

[0136] 2-7 Calculation of sudden changes in optimal displacement

[0137] 2-8 Calculation of average value and standard calibration since the last mutation

[0138] 2-9 Calculate the probability value outside of, for example, ±0.2 mm tolerance.

[0139] 2-10 Calculate the probability that at least one feature of each geometric skid exceeds the tolerance.

[0140] 2-11 Visualization of the time series of optimal displacement and average value

[0141] 2-12 Classification of geometric skids according to power exceeding tolerance

[0142] End of 2-13

[0143] 2-20 is used for each measurement point group.

[0144] 2-21 is used for each geometric skid ID (identified positioning device) and data point.

Claims

1. A method for inspecting the dimensional accuracy of a transportable positioning device (P) used in the production of motor vehicles, wherein, The positioning device (P) has multiple supports (1, 3, 5, 7) to enable the body components (K) of the motor vehicle to be manufactured to be geometrically precisely positioned on each positioning device (P). The multiple supports, based on the vehicle coordinate system, include an xyz support for determining the position in the x, y, and z directions, a yz support for determining the position in the y and z directions, and a z support for determining the position in the z direction. The positioning device (P), together with the body components (K) respectively positioned on it, is moved to different workstations in the motor vehicle production flow for use in motor vehicle production. During the motor vehicle production flow, predefined measurement points (M) on the body components (K) corresponding to each transportable positioning device (P) are measured as measurement data at the workstations and / or at in-line measurement stations specifically set up in the motor vehicle production flow for detecting measurement values. The dimensional accuracy of each transportable positioning device (P) is determined by evaluating the measurement points (M) by a control unit.

2. The method according to claim 1, characterized in that, The predefined measurement point (M) on the corresponding body component (K) positioned on the positioning device (P) is measured so that the dimensional accuracy of the transportable positioning device (P) is determined by evaluating the measurement point (M) by the control unit. The predefined measurement point is only used to check the body component (K) itself, that is, the measurement point (M) used to determine the dimensional accuracy of the body component (K).

3. The method according to claim 1 or 2, characterized in that, The positioning device (P) is identified in the control unit, and during multiple vehicle production flows in the workstation, the position of a predefined measurement point on a body component (K) that is correspondingly positioned on the same identified positioning device (P) is measured, wherein the dimensional accuracy of the identified transportable positioning device (P) is determined by the control unit evaluating the measurement point (M) for the same identified positioning device (P) during multiple vehicle production flows.

4. The method according to claim 1, characterized in that, Predefined measurement points (M) on the body component (K) positioned on the positioning device (P) are assigned by the control unit to one or more predetermined measurement point groups for evaluating the measurement points (M), wherein the performance-related measurement points (M) are assigned to a measurement point group respectively.

5. The method according to claim 4, characterized in that, The predefined measurement points (M) are divided into exactly seven groups of measurement points: one x group, two y groups, and four z groups.

6. The method according to claim 4 or 5, characterized in that, Each set of measuring points is corresponding to exactly one support (1, 3, 5, 7) of the positioning device (P), wherein the dimensional accuracy at the corresponding support (1, 3, 5, 7) is determined by the control unit from the positional deviation in the set of measuring points.

7. The method according to claim 1, characterized in that, Each positioning device (P) has exactly four supports (1, 3, 5, 7) so that the body components (K) of the motor vehicle to be manufactured can be geometrically precisely positioned on the positioning device (P).

8. The method according to claim 7, characterized in that, The four supports (1, 3, 5, 7) are formed by one xyz support, one yz support, and two z supports.

9. The method according to claim 1, characterized in that, In addition to the supports (1, 3, 5, 7), the positioning device (P) has an additional support point (A) to prevent the body component (K) positioned on the positioning device (P) from loosening.

Images