AGV chassis rigidity detection method, detection device and AGV optimization method

Abstract

This invention discloses a method for testing the rigidity of an AGV chassis, comprising the following steps: measuring the distance from several test points on the chassis to a test platform in an unloaded state; applying a load to the center of the AGV's lifting plate to bring the AGV to a fully loaded state; measuring the distance from the same test points to the test platform in the fully loaded state and calculating the difference between the two measurements; and grouping the test points for testing according to different dimensions of chassis rigidity analysis as needed. The grouped testing includes centrally symmetrical test point groups, axisymmetric test point groups, and left and right chassis rigidity test point groups. The proposed testing method provides strong support for AGV performance optimization schemes.

Description

Technical Field

[0001] This invention relates to AGV (Automated Guided Vehicle) inspection technology, and more particularly to AGV chassis rigidity inspection methods, inspection devices, and AGV optimization methods. Background Technology

[0002] Currently, in the field of AGV research and development, the importance of measuring the rigidity of the AGV chassis is often overlooked. It is often found that even when the AGV structure and control performance are excellent, the AGV is still prone to slipping and tilting during movement. And this situation is often not completely solved by upgrading the control software and the structural layout and connection relationship. Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies by providing a method for detecting the rigidity of AGV chassis.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] A method for detecting the rigidity of an AGV chassis includes the following steps:

[0006] The distance from several test points on the chassis to the test platform is measured when the AGV is unloaded.

[0007] The load is placed at the center of the AGV trolley lifting plate, so that the AGV trolley is in a fully lifted and loaded state;

[0008] Measure the distance from the test platform to the same test point under full load, and calculate the difference between the two measurements;

[0009] As needed, the chassis rigidity is analyzed from different dimensions and the test points are grouped for testing. The grouping test includes chassis rigidity center symmetry test point grouping, chassis rigidity axis symmetry test point grouping, and left and right chassis rigidity test point grouping.

[0010] The chassis rigidity is detected by centrally symmetric test point data, the chassis axisymmetric rigidity is detected by axisymmetric test point data, and the chassis left and right rigidity is detected by left and right rigidity test point data.

[0011] As an option, when performing group detection on test points, the method for selecting test points includes:

[0012] The test points are taken from two or more inner rings in sequence, following the method of moving from the outermost ring of the chassis inwards to the inner ring.

[0013] Take several endpoints from the smallest inner circle and arrange several rays outwards with the same number of endpoints;

[0014] The measurement range is defined by the intersection area of ​​the ray with all the circles, and the test points are selected and grouped.

[0015] The test point grouping methods include:

[0016] Using the chassis centerline as a reference, the test points on both sides of the chassis center point are divided into two groups as a control group of centrally symmetrical test points;

[0017] Using the chassis axis as a reference, the test points on both sides of the chassis axis are divided into two groups as the axisymmetric rigid test point control group.

[0018] As an option, the chassis rigidity testing method further includes using a centrally symmetrical test point control group as the analysis object, calculating the average value of each group of data, and if the difference between the average values ​​of the two groups is greater than the first preset parameter, it is analyzed that the offset fixation of the lifting motor affects the central symmetry of the chassis rigidity.

[0019] As an option, the chassis rigidity testing method further includes using a centrally symmetrical test point control group as the analysis object, calculating the standard deviation of each group of data, and if the standard deviation of the two groups is greater than a second preset parameter, analyzing the data of each test point, identifying abnormal data points, performing intensive measurement on the abnormal data points, and locating the problem area.

[0020] As an option, the grouping method for the left and right chassis rigidity test points includes:

[0021] Determine the left and right areas of the chassis based on the chassis centerline; take several line segments at the edges of the left and right areas, and lay out several layers of test strips inward with the centerline as the direction, using the endpoint areas of the line segments as the measurement range of the test points; the number of test points in the left area and the right area are the same, and their positions are symmetrical along the centerline.

[0022] As an option, the chassis rigidity testing method further includes using the test point data set in the left region and the test point data set in the right region as the analysis objects, calculating the difference between the two sets of data, and solving for the mean and standard deviation of the difference data;

[0023] If the difference between the average values ​​of the two sets of data is greater than the third preset parameter, it is determined that there is a difference in the rigidity of the left and right chassis.

[0024] If the standard deviation of the two sets of data is greater than the fourth preset parameter, the change in rigidity of the left and right chassis will be inconsistent, and the side with the larger change will be less rigid.

[0025] Based on the above detection method, an optimization method for AGV vehicles is proposed. The chassis rigidity data is detected by the proposed AGV chassis rigidity detection method, and the AGV vehicle is optimized by adjusting the chassis rigidity data.

[0026] Furthermore, an AGV chassis rigidity detection device is proposed, including a measuring device for measuring the distance from the chassis to the test platform.

[0027] A further AGV chassis rigidity testing device is proposed, comprising a testing platform. To implement the AGV chassis rigidity testing method according to any one of claims 1-7, the AGV is placed on the testing platform. The testing platform includes a level, three or more adjustable feet, and an adjustable plane connected to the feet.

[0028] The beneficial effects of this invention are:

[0029] Research has found that chassis rigidity performance is related to several important parameters of the AGV (Automated Guided Vehicle). For example, the difference in rigidity between the left and right sides of the chassis is related to the grip of the left and right drive wheels, and the difference in rigidity between the front and rear of the chassis is related to the levelness of the AGV's lifting platform. This invention designs an AGV chassis rigidity detection method, providing strong support for AGV performance optimization schemes. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the AGV chassis rigidity detection method;

[0032] Figure 2 This is a schematic diagram of the grouping of rigidity test points for the AGV chassis;

[0033] Figure 3 This is a schematic diagram showing the selection of test points for the rigidity center symmetry of the AGV chassis;

[0034] Figure 4 This is a diagram illustrating the encryption selection of test points;

[0035] Figure 5 This is a schematic diagram showing the selection of test points for chassis rigidity axisymmetry.

[0036] Figure 6 This is a schematic diagram of the specific structure of the metering device. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0038] A method for testing the rigidity of an AGV chassis includes the following steps: measuring the distances from several test points on the chassis to a test platform when the AGV is unloaded; applying a load to the center of the AGV's lifting plate to bring the AGV to a fully loaded state; measuring the distances from the same test points to the test platform under full load, calculating the absolute value of the difference, and analyzing the chassis rigidity using the absolute value of the difference. (Reference) Figure 1 The disclosed structure.

[0039] As needed, the chassis rigidity is analyzed from different dimensions and the test points are grouped for testing. The grouping test includes chassis rigidity center symmetry test point grouping, chassis rigidity axis symmetry test point grouping, and left and right chassis rigidity test point grouping.

[0040] The chassis rigidity is detected by centrally symmetric test point data, the chassis axisymmetric rigidity is detected by axisymmetric test point data, and the chassis left and right rigidity is detected by left and right rigidity test point data.

[0041] Specifically, the chassis of the car is schematically divided into 10 areas, for reference. Figure 2 The front and rear chassis rigidity test points are grouped as follows: ①②③⑨⑩—④⑤⑥⑦⑧. Based on the comparative analysis of the data from these two groups of test points, the difference in rigidity between the front and rear chassis is determined, providing a reference for subsequent chassis rigidity optimization design. The study found that, as a force transmission bridge, the difference in rigidity performance between the front and rear chassis is a criterion for judging the rationality of the lifting mechanism's design. Furthermore, the rigidity of the front and rear chassis is also a significant factor affecting the levelness of the lifting platform; therefore, front and rear chassis rigidity analysis is crucial.

[0042] The left and right chassis rigidity test points were grouped into groups ③-④ and ⑧-⑨. Based on the comparative analysis of the test point data from these two control groups, the difference in rigidity between the left and right chassis was determined, providing a reference for subsequent chassis rigidity optimization design. The study found that the difference in rigidity performance between the left and right chassis is an important criterion for analyzing the difference in grip strength between the left and right drive wheels of the AGV, and also a crucial factor in analyzing the difference in torsional rigidity between the front and rear chassis.

[0043] The test points for the central symmetry of chassis rigidity are grouped as follows: ①—⑥, ②—⑦, ③—⑧, ④—⑨, ⑩—⑤. Currently, there are many chassis structures designed as centrally symmetrical. The reason for the greatest change in rigidity during operation of a centrally symmetrical chassis structure is the torsional force generated by the central symmetry of the chassis. Therefore, analyzing the rigidity performance of central symmetry facilitates the optimization of the design of the lifting motor position.

[0044] As an alternative, the overall chassis rigidity is tested. Specifically, the rigidity changes of all selected test points are compared, the maximum deformation is taken, and the standard requirements are analyzed with reference to the design standards. If they are not met, the overall chassis rigidity is improved.

[0045] As a preferred option, refer to Figure 3 When performing group testing on test points, the methods for selecting test points include:

[0046] The test points are taken from two or more inner rings in sequence, following the method of moving from the outermost ring of the chassis inwards to the inner ring.

[0047] Several endpoints are selected from the smallest inner circle, and a number of rays, the same number as the number of endpoints, are arranged outwards. The measurement range is defined by the intersections of the rays with all circles, and the test points are selected and grouped. The selection of rays includes the center line, diagonals, and rays with inflection points. Stress concentration is prone to occur at the diagonals and inflection points, and these are locations that require attention.

[0048] The test point grouping methods include: using the chassis centerline as a reference, dividing the test points on both sides of the chassis centerline into two groups as the centrally symmetric test point control group, such as ①—⑥, ②—⑦, ③—⑧, ④—⑨, ⑩—⑤ mentioned above, which are 5 control groups respectively; using the chassis axis as a reference, dividing the test points on both sides of the chassis axis as the axis of rigidity test point control group, such as the two groups of data ①②③⑨⑩—④⑤⑥⑦⑧ mentioned above, which are divided by a chassis axis as a dividing line, as one control group.

[0049] The grouping method for the left and right chassis rigidity test points includes: determining the left and right regions of the chassis based on the chassis centerline; taking several line segments at the edges of the left and right regions, and arranging several layers of pre-set test strips inward with the centerline as the direction, using the endpoint areas of the line segments as the measurement range of the test points; the number of test points in the left region and the right region are the same, and their positions are symmetrical along the centerline. As mentioned above, ③-④ and ⑧-⑨ are two control groups.

[0050] For example, the test point is determined by taking an inner ring that is recessed 50mm inward from the outer ring of the chassis. Five inner rings are selected sequentially. From the smallest inner ring, ten endpoints are chosen, emitting ten rays symmetrically. The measurement range is defined as the area within 5mm of the intersection of the rays and the ring. Figure 3 As shown, there are ten sets of data: A1-A2, B1-B2, C1-C2, D1-D2, and E1-E2. Each set of data contains six values. For example, the A1 data set contains test point data numbered A11-A16 from the outside to the inside, and the A2 data set contains test point data numbered A21-A26 from the outside to the inside. The absolute value of the difference between the two sets of data is used as the analysis object, and the difference array is △A1-△A6.

[0051] After grouping, the data is analyzed. This application proposes a preferred analysis method, which takes the centrally symmetric test point control group as the analysis object, calculates the average value of each group of data, and if the difference between the average values ​​of the two groups is greater than the first preset parameter, it is analyzed that the offset fixation of the lifting motor affects the central symmetry of the chassis rigidity.

[0052] Furthermore, as a preferred approach, the control group of centrally symmetric test points is used as the analysis object. The standard deviation of each group of data is calculated. If the standard deviation of the two groups is greater than the second preset parameter, the data of each test point is analyzed to identify abnormal data points. Abnormal data points are then subjected to intensive measurement to locate the problem area.

[0053] like Figure 6 The chassis rigidity testing method also includes using the test point data set in the left region and the test point data set in the right region as the analysis objects, calculating the difference between the two sets of data, and solving for the mean and standard deviation of the difference data;

[0054] If the difference between the average values ​​of the two sets of data is greater than the third preset parameter, it is determined that there is a difference in the rigidity of the left and right chassis.

[0055] If the standard deviation of the two sets of data is greater than the fourth preset parameter, the change in rigidity of the left and right chassis will be inconsistent, and the side with the larger change will be less rigid.

[0056] Following the example above, the difference array △A1-△A6 is analyzed to calculate its mean and standard deviation. The mean is greater than 0.5mm, indicating that the fixed offset of the lifting motor affects the central symmetry of the chassis rigidity. The offset position of the lifting motor needs adjustment to ensure the mean is less than 0.5mm. The standard deviation is greater than 0.3mm, indicating significant fluctuations in the difference data. Therefore, the difference array is observed to identify outlier data points, and the test points in the vicinity of these outlier data points are denser. Through data analysis, D23 is identified as an outlier data point. Figure 4 As shown, the measurement points in the vicinity of D23 are increased and the data is analyzed to accurately locate the problem area.

[0057] Example of selecting, grouping, and analyzing test points for left and right chassis rigidity: The rigidity data of the left and right chassis affects the grip of the AGV's drive wheels; select several line segments on the left and right edges of the chassis, and advance them parallel to the center line by 50mm, repeating this process four times to form five layers of test strips; use the endpoints of the line segments as the test center points. For example... Figure 6 As shown, there are 9 sets of comparison arrays. One set of comparison arrays, E1-E2, is selected. Array E1 contains test point data numbered E11-E15, and array E2 contains test point data numbered E21-E25. The absolute value of the difference between the two sets of data is used as the analysis object, and the difference array is △E1-△E6. The mean and standard deviation of the difference array are calculated. If the mean is greater than 0.5mm, it indicates that there is a difference in the rigidity of the left and right chassis. The side with weaker rigidity needs to be strengthened to ensure that the mean is less than 0.5mm. While ensuring that the mean is less than 0.5mm, the standard deviation should be greater than 0.3mm. If neither of these conditions is met, it indicates that the rigidity variation is inconsistent. The side with a larger variation is weaker and its structure needs to be strengthened to ensure that the standard deviation is less than 0.3mm.

[0058] Research has found that the difference in rigidity between the left and right sides has a significant impact on the grip of the AGV. Taking an AGV that is 760mm long and 550mm wide as an example, according to the tire weighing test under full load conditions, when the average value is greater than 1mm and the standard deviation is greater than 0.6mm, the difference in the weight of the drive wheel is large, which makes the AGV prone to significant deviation or even slippage when it is moving. Therefore, designing a method for comparing and detecting the rigidity of the left and right sides is crucial for the optimized design of the AGV.

[0059] The first, second, third, and fourth preset parameters disclosed in this application are all optimized parameters derived from industry standards, national standards, other enterprise standards, or laboratory data experiments. These parameters may be adjusted accordingly for different models of AGVs.

[0060] Example 2:

[0061] An AGV chassis rigidity testing device is used to measure the distance from the lower surface of the AGV chassis to a test platform. The device includes a measuring device, which includes a base 10, a ruler body 11 fixed on the base, a ruler frame 12 mounted on the ruler body, and a probe beam 13 fixed on the ruler frame. The end of the probe beam away from the ruler frame is the probe end, and the end of the probe beam connected to the ruler frame is the fixed end. An upwardly protruding probe 14 is mounted on the upper surface of the probe end. The ruler frame and the ruler body move relative to each other during measurement. When the probe beam moves to the test platform, the lower surface of the probe beam is in contact with the test platform.

[0062] The measuring device used for distance measurement employs an improved Guanglu digital height gauge, similar to the existing Guanglu digital height gauge. Figure 5 As shown in (a), traditional height gauge measuring claws can only measure the height difference by measuring the upper surface, but measuring the chassis rigidity difference requires measuring both the upper surface of the platform and the lower surface of the chassis. The improved structure is as follows. Figure 5 (b) The measuring claw of the Guanglu digital height gauge is improved into a long rod probe beam and a probe structure with the top of the probe beam protruding upwards, which facilitates the measurement of chassis rigidity.

[0063] Example 3:

[0064] An AGV chassis rigidity testing device includes a test platform on which the AGV trolley is placed to eliminate the influence of unevenness on the bottom surface. The test platform includes an adjustable plane, adjustable feet, and a level. The bottom of the adjustable plane has three or more adjustable feet, which are adjusted to level the plane. Since the changes in the AGV chassis under load and no-load conditions are minimal, to minimize the impact of the test platform's deformation on data accuracy, it is necessary to maximize the ground contact area of ​​the rubber pad and select a rubber pad material with high hardness.

[0065] As a preferred embodiment, the adjustable foot cup includes a rubber pad at the bottom, the rubber pad being compressed to 10. -3 Within the mm range. Actual measured rigid deformation of the AGV chassis ranges from 0.67mm to 3.5mm, with the chassis rigid deformation on the order of 10. 0 To reduce the impact of the test platform on the chassis rigidity, the compression of the rubber pads on the feet needs to be controlled within 10 mm. -3 The order of millimeters.

[0066] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An AGV chassis rigidity detection method, characterized in that, Includes the following steps: The distance from several test points on the chassis to the test platform is measured when the AGV is unloaded. The load is placed at the center of the AGV trolley lifting plate, so that the AGV trolley is in a fully lifted and loaded state; Measure the distance from the test platform to the same test point under full load, and calculate the difference between the two measurements; As needed, the chassis rigidity is analyzed from different dimensions and the test points are grouped for testing. The grouping test includes chassis rigidity center symmetry test point grouping, chassis rigidity axis symmetry test point grouping, and left and right chassis rigidity test point grouping. The chassis rigidity is detected by centrally symmetric test point data, the chassis axisymmetric rigidity is detected by axisymmetric test point data, and the chassis left and right rigidity is detected by left and right rigidity test point data.

2. The AGV chassis rigidity detection method according to claim 1, characterized in that, When performing group detection on test points, the method for selecting test points includes: The test points are taken from two or more inner rings in sequence, following the method of moving from the outermost ring of the chassis inwards to the inner ring. Take several endpoints from the smallest inner circle and arrange several rays outwards with the same number of endpoints; The measurement range is defined by the intersection area of ​​the ray with all the circles, and the test points are selected and grouped.

3. The AGV chassis rigidity detection method according to claim 2, characterized in that, Test point grouping methods include: Using the chassis centerline as a reference, the test points on both sides of the chassis center point are divided into two groups as a control group of centrally symmetrical test points; Using the chassis axis as a reference, the test points on both sides of the chassis axis are divided into two groups as the axisymmetric rigid test point control group.

4. The AGV chassis rigidity detection method according to claim 3, characterized in that, The chassis rigidity testing method further includes using a centrally symmetrical test point control group as the analysis object, calculating the average value of each group of data, and if the difference between the average values ​​of the two groups is greater than the first preset parameter, it is analyzed that the offset fixation of the lifting motor affects the central symmetry of the chassis rigidity.

5. The AGV chassis rigidity detection method according to claim 3, characterized in that, The chassis rigidity testing method also includes using a centrally symmetrical test point control group as the analysis object, calculating the standard deviation of each group of data, and if the standard deviation of the two groups is greater than the second preset parameter, analyzing the data of each test point, identifying abnormal data points, performing intensive measurement on the abnormal data points, and locating the problem area.

6. The AGV chassis rigidity detection method according to claim 1, characterized in that, The grouping method for the left and right chassis rigidity test points includes: Determine the left and right areas of the chassis based on the chassis centerline; take several line segments at the edges of the left and right areas, and lay out several layers of test strips inward with the centerline as the direction, using the endpoint areas of the line segments as the measurement range of the test points; the number of test points in the left area and the right area are the same, and their positions are symmetrical along the centerline.

7. The AGV chassis rigidity detection method according to claim 6, characterized in that, The chassis rigidity testing method also includes taking the test point data set in the left region and the test point data set in the right region as the analysis objects, calculating the difference between the two sets of data, and solving the mean and standard deviation of the difference data. If the difference between the average values ​​of the two sets of data is greater than the third preset parameter, it is determined that there is a difference in the rigidity of the left and right chassis. If the standard deviation of the two sets of data is greater than the fourth preset parameter, the change in rigidity of the left and right chassis will be inconsistent, and the side with the larger change will be less rigid.

8. An optimization method for an AGV (Automated Guided Vehicle), characterized in that, The AGV chassis rigidity detection method according to any one of claims 1-7 detects chassis rigidity data, and optimizes the AGV by adjusting the chassis rigidity data.

9. An AGV chassis rigidity detection device, characterized in that, The method includes a measuring device for measuring the distance from the chassis to the test platform in the AGV chassis rigidity testing method according to any one of claims 1-7.

10. An AGV chassis rigidity detection device, characterized in that, The system includes a testing platform, on which the AGV is placed in order to implement the AGV chassis rigidity testing method according to any one of claims 1-7.

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