An off-line detection method and system for an excavator

Abstract

The present invention provides an off-line detection method and system for an excavator, which can effectively solve the problems of poor accuracy and low efficiency of off-line testing, and can improve the accuracy and efficiency of off-line detection. The method includes the following steps: obtaining the identity information of the off-line excavator and the excavator detection video information; extracting the action stroke characteristic values of each component according to the excavator detection video information; the action stroke characteristic values include the lengths of the cylinders corresponding to the limits of each action stroke, the angles of the limits of each action stroke, and the time of each action; obtaining the calibrated action stroke standard values of each component; the stroke standard values include the standard lengths of the cylinders corresponding to the limits of each action stroke, the standard angles of the limits of each action stroke, and the standard time of each action; judging whether the action stroke characteristic values of each component are qualified according to the action stroke standard values of each component. If they are qualified, it is determined that the component action test of the off-line excavator is qualified; otherwise, it is determined to be unqualified, and an evaluation result is obtained.

Description

Technical Field

[0001] The present invention relates to a method and system for detecting the off-line of an excavator, belonging to the technical field of construction machinery detection. Background Art

[0002] With the continuous development of society, the degree of mechanization in the construction of infrastructure projects such as roads, bridges, and buildings has been continuously improved, and the demand for excavators has also been increasing. In order to ensure the off-line quality of the whole machine, excavator manufacturers generally conduct off-line detection on excavators at the end of the assembly line. The excavators with unqualified test results are debugged and repaired, and the qualified excavators are put on the market.

[0003] At present, the off-line detection methods of excavators are relatively traditional, and the following three common methods are as follows:

[0004] The first one is to only test whether the excavator can normally complete the specified actions without recording parameters such as movement angles and time. The main technical defect is that the performance of the excavator is simply judged subjectively by the tester.

[0005] The second one is to combine manual visual inspection and stopwatch timing to test the limit time of the single-action stroke of the excavator. Although this method has a relatively high test efficiency, the following technical defects exist: there are errors in both manual visual inspection and stopwatch timing, and it is difficult to guarantee the accuracy and consistency of the test results.

[0006] The third one is to use an external sensor to test the limit characteristic value and time of the single-action stroke of the excavator. Although this method improves the accuracy and consistency of the test results, the following technical defects exist: the test efficiency is relatively low, and the wiring needs to be reconfigured according to the measuring points for each excavator, and frequent disassembly and assembly of the sensor will take a long time. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method and system for detecting the off-line of an excavator, which can effectively solve the problems of poor accuracy and low efficiency in off-line testing, and can improve the accuracy and efficiency of off-line detection.

[0008] To achieve the above purpose, the present invention is implemented by the following technical solutions:

[0009] In the first aspect, the present invention provides a method for detecting the off-line of an excavator, including the following steps:

[0010] S1: Obtain the identity information of the off-line excavator and the excavator detection video information; the excavator detection video information includes video information of the excavator making multiple actions;

[0011] S2: Extract the action stroke characteristic values of each component from the excavator detection video information. The components include the boom, the arm, and the bucket. The action stroke characteristic values include the lengths of the cylinders corresponding to the limits of each action stroke, the angles of the limits of each action stroke, and the time of each action.

[0012] S3: Obtain the standard values of the action strokes of each calibrated component. The stroke standard values include the standard lengths of the cylinders corresponding to the limits of each action stroke, the standard angles of the limits of each action stroke, and the standard time of each action.

[0013] S4: According to the standard values of the action strokes of each component, determine whether the action stroke characteristic values of each component are qualified. If they are qualified, determine that the component action test of the offline excavator is qualified; otherwise, determine that it is unqualified to obtain the evaluation result.

[0014] Further, in step S1, the excavator detection video information includes video information of 6 actions: boom lifting, boom lowering, arm swinging out, arm swinging in, bucket swinging out, and bucket swinging in.

[0015] Further, in step S1, the method for obtaining the excavator detection video information includes:

[0016] When the excavator travels to a specified position to perform a specified action, control the high-speed camera to automatically collect the whole machine action information.

[0017] When the camera captures that the moving angle of any component exceeds the threshold δ within 3 s, determine that the component is moving, and continue to collect the subsequent information of the component.

[0018] When the camera captures that the moving angle of any component remains less than the threshold δ within 3 s, determine that the component of the excavator is not moving, stop collecting the subsequent information of the component, and delete the information that is determined not to move after capturing for 3 s.

[0019] Further, in step S2, the method for extracting the action stroke characteristic values of each component from the excavator detection video information includes:

[0020] Adsorb the target detection board on each component, capture the trajectory of the target detection board on each component under dynamic movement through the high-speed camera, and analyze to obtain the action stroke characteristic values of each component. The action stroke characteristic values include the movement angle, the cylinder displacement length, and the action time.

[0021] The target detection board includes but is not limited to reflective strips.

[0022] Further, in step S3, the calibration method for the standard values of the action strokes of each component includes:

[0023] Calibrate the length of the cylinder corresponding to the limit of each action stroke: Calibrate the limit length L of the boom cylinder according to the factory standard length1max 、L 1min , calibrate the limit length L of the boom cylinder 2max 、L 2min , calibrate the limit length L of the bucket cylinder 3max 、L 3min ;

[0024] Calibrate the angular limits of each movement stroke: The operator pushes the pilot control handle from the neutral position to the stroke limit in one go, and each component responds and gradually moves from the initial position to the stroke limit. Among them, the angular limit of the boom relative to the turntable movement is α max 、α min , the angular limit of the arm relative to the boom movement is β max 、β min , the angular limit of the bucket relative to the arm is γ max 、γ min .

[0025] Analyze the time error affected by the detection equipment: The formula for the maximum action time error is:

[0026]

[0027] In formula (7), μ is the image acquisition frequency, δ is the action judgment threshold, σ is the movement angle of this action, τ is the movement duration of this action, t i is the inherent time difference of the detection equipment in response to this action, k is the proportionality coefficient, t s is the starting time error of the detection equipment in judging a single action affected by component jitter, t f is the ending time error of the detection equipment in judging a single action affected by component jitter, t err is the calculated maximum time error of this action.

[0028] Calibrate the standard time of each action: Continuously record the time of the boom movement from the starting point to the stroke limit ten times, and the obtained average value is used as the standard time of the boom movement. Set the standard time interval of the boom movement of this model as [standard time - maximum time error, standard time + maximum time error].

[0029] Furthermore, the method for calibrating the angular limit of the boom relative to the turntable movement as α max 、α min , the angular limit of the arm relative to the boom movement as β max 、β min , and the angular limit of the bucket relative to the arm as γ max 、γ min includes:

[0030] Define point A as the hinge point between the boom and the slewing platform, point B as the hinge point between the boom and the stick, point F as the starting point of the boom cylinder, point C as the ending point of the boom cylinder, point I as the hinge point between the stick and the bucket, point D as the starting point of the stick cylinder, point H as the ending point of the stick cylinder, point J as the ending point of the bucket, point E as the starting point of the bucket cylinder, point K as the ending point of the bucket cylinder, OXYZ as the global coordinate system fixed on the slewing platform, and AX1Y1, BX2Y2, IX3Y3 as the local coordinate systems of the boom, the stick, and the bucket respectively. α, β, γ represent the angles of the boom, the stick, and the bucket relative to the upper-level component respectively, and the lengths of the three groups of cylinders of the boom, the stick, and the bucket are L1, L2, L3 respectively;

[0031] Calibrate the limit angle of the boom stroke: The position and attitude of the boom AB are determined by the length L1 of the boom cylinder FC. According to the geometric relationship between the hinge points of the boom, the relative rotation angle α of the boom with respect to the turntable can be calculated. The calculation formula is:

[0032] α = ∠CAF - ∠CAB - ∠FAX (1)

[0033] Among them, ∠FAX is a fixed value, which can be solved according to the overall machine structure parameters.

[0034] After equation (1) is sorted out by the cosine theorem, the relationship between the relative rotation angle α of the boom with respect to the turntable and the length L1 of the boom cylinder is:

[0035]

[0036] (2) In the formula, L AC is the distance between points A and C, L AF is the distance between points A and F, L1 is the length of the hydraulic cylinder, L AB is the distance between points A and B, L BC is the distance between points B and C; ∠FAX is the angle between the connection line of hinge points A and F and the horizontal axis OX, which can be solved according to the overall machine structure parameters;

[0037] Substitute the limit lengths L 1max , L 1min of the boom cylinder into the above formula respectively, and the limit position angles α max , α min of the boom movement can be obtained.

[0038] Calibrate the limit angle of the stick stroke: The main determining factor for the movement attitude of the stick BI is the length L2 of the stick cylinder DH. According to the geometric relationship between the hinge points of the stick, the relative swing angle β of the stick with respect to the boom can be obtained. The calculation formula is:

[0039] β = ∠DBH + ∠ABD + ∠HBI - π (3)

[0040] Among them, ∠ABD and ∠HBI are fixed values, which can be solved according to the overall machine structure parameters.

[0041] After equation (3) is rearranged by the cosine theorem, the relationship between the swing angle β of the stick relative to the boom and the length L2 of the boom cylinder is as follows:

[0042]

[0043] (4) In the formula, L BD is the distance between points B and D, L BH is the distance between points B and H, L2 is the length of the stick cylinder; ∠ABD is the included angle of the connecting lines of hinge points A, B, and D, and ∠HBI is the included angle of the connecting lines of hinge points H, B, and I, which can be calculated according to the overall machine structure parameters. Substitute the limit lengths L 2max and L 2min of the stick cylinder into the above formula respectively, and the limit position angles β max and β min of the stick movement can be obtained.

[0044] Calibrate the limit angle of the bucket stroke: According to the geometric relationship between the hinge points of the bucket, the swing angle γ of the bucket relative to the stick can be obtained, and the calculation formula is:

[0045] γ = ∠JIL + ∠BIN + ∠NIL - π (5)

[0046] Among them, ∠JIL and ∠BIN are fixed values, and ∠NIL = ∠KIN + ∠KIL, which can be calculated according to the overall machine structure parameters;

[0047] After equation (5) is rearranged by the cosine theorem, the relationship between the swing angle γ of the bucket relative to the stick and the length L3 of the bucket cylinder is as follows:

[0048]

[0049]

[0050] (6) In the formula, L IL is the distance between points I and L of the stick, L IN is the distance between points I and N of the stick, L EN is the distance between points E and N of the stick, L KN is the distance between points K and N of the stick, L3 is the length of the bucket cylinder; ∠ENI is the included angle of the connecting lines of hinge points E, N, and I, which can be calculated according to the overall machine structure parameters. Substitute the limit lengths L 3max and L 3min of the bucket cylinder into the above formula respectively, and the limit position angles γ max and γ min of the bucket movement can be obtained.

[0051] In a second aspect, the present invention provides an excavator off-line detection system, including station 1, station 2, identification equipment, detection equipment, and analysis equipment;

[0052] The identification device is used to collect the identity information of the excavator when the excavator is at station 1. The identity information includes the VIN barcode and vehicle number barcode of the whole machine.

[0053] The detection device is used to collect the action information of the excavator when the excavator is at station 2, and transmit the information of the judged component action and collection to the analysis device.

[0054] The analysis device is used to execute the method described in the first aspect.

[0055] Furthermore, the identification device includes a scanning device fixed at a designated position in station 1. Whenever the excavator travels to the designated area, the scanning device can automatically scan the VIN barcode or vehicle number barcode of the vehicle and store the information in the memory of the analysis device.

[0056] Furthermore, the detection device includes a high-speed camera fixed at a designated position in station 2. Whenever the excavator travels to the designated position to perform a specified action, the high-speed camera automatically collects the action information of the whole machine.

[0057] When the camera captures the moving angle of the boom exceeding the threshold δ within 3s, it is determined that the boom moves, and the subsequent information of the boom is continuously collected; when the camera captures the moving angle of the boom continuously less than the threshold δ within 3s, it is determined that the boom of the excavator does not move, and the subsequent information of the boom is stopped from being collected. The recognition conditions for the stick and bucket movements are the same as those for the boom, the moving angle threshold is the same δ, and the principle of determining whether to move and whether to continue collecting information is the same as that for the boom.

[0058] Furthermore, the system further includes a detection personnel input device;

[0059] After the analysis device obtains the confirmation information of the detection personnel through the detection personnel input device, the test is completed, and a detection report is formed and output.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] The present invention provides a method for detecting the off-line of an excavator. This method analyzes the limit angles of the boom, stick, and bucket strokes. The analysis device extracts eigenvalue by solving and collecting information to judge whether the action test result is qualified. Using this method for batch off-line detection of a certain model can save a lot of manpower and man-hours. By replacing the method of combining manual visual inspection and stopwatch timing to test the excavator's actions with this method, the accuracy and consistency of the test results can be improved. By replacing the method of using an external sensor to test the excavator's actions with this method, the test efficiency can be improved. By replacing the method of simply relying on the subjective judgment of the tester to evaluate the performance of the excavator with this method, the problems of poor accuracy and low efficiency in off-line testing can be effectively solved, and the accuracy and efficiency of off-line detection can be improved. Description of the Drawings

[0062] Figure 1 It is the flow chart for the off-line inspection of the excavator;

[0063] Figure 2 It is the flow chart for the detection equipment to collect information;

[0064] Figure 3 It is the working flow chart of the analysis equipment;

[0065] Figure 4 It is the schematic diagram for the kinematic analysis of the excavator. Specific Embodiments

[0066] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0067] Embodiment 1:

[0068] This embodiment provides a method for off-line inspection of an excavator. The implementation steps are as shown in the attached Figure 1 and include the following steps:

[0069] S1: Obtain the identity information of the off-line excavator and the excavator detection video information; the excavator detection video information contains the video information of the excavator making multiple actions.

[0070] Collect the action information of the excavator through the detection equipment, including 6 actions of boom lifting, boom lowering, stick outswing, stick in-swing, bucket outswing, and bucket in-swing. Transmit the information of the determined component action and collection to the analysis equipment, and delete the information determined not to move after 3s of capture. The implementation steps are as shown in the attached Figure 2 and are as follows:

[0071] S11: Fix a high-speed camera at a specified position in Station 2. Whenever the excavator travels to the specified position to perform the specified actions, the high-speed camera automatically collects the whole machine action information. The six actions are controlled by the driver / operator to perform on the excavator. Generally, the masters only perform once during on-site testing. If in order to reflect the test rationality, each action can also be continuously performed multiple times and the average value is taken.

[0072] S12: Set the excavator action recognition conditions to determine whether the component moves and whether to continue collecting information. When the moving angle of the boom captured by the camera exceeds the threshold within 3s, it is determined that the boom moves, and continue to collect the subsequent information of the boom; when the moving angle of the boom captured by the camera remains less than the threshold within 3s, it is determined that the boom of the excavator does not move, and stop collecting the subsequent information of the boom. The action recognition conditions for the stick and the bucket are the same as those for the boom, and the moving angle threshold is also δ. The principle of determining whether to move and whether to continue collecting information is the same as that for the boom.

[0073] The information collected and determined to be in action is transmitted to the analysis device, and the information captured for 3 seconds and determined to be inactive is deleted.

[0074] S2: Extracting the motion stroke characteristic values ​​of each component according to the excavator detection video information, the components including the boom, the dipper arm and the bucket; the motion stroke characteristic values ​​include the length of the cylinder corresponding to each motion stroke limit, the angle of each motion stroke limit and the time of each action.

[0075] Take the bucket as an example: the target detection plate is adsorbed on the bucket. The target detection plate is not limited to the reflective strip. The trajectory of the target detection plate on the bucket under dynamic motion is captured by a high-speed camera, and the motion stroke characteristic values ​​such as the bucket's motion angle, cylinder displacement length and action time are analyzed.

[0076] The specific quantified trajectory and angle can be obtained by visual inspection, image comparison, neural network extraction and other methods.

[0077] The method for extracting characteristic values ​​of the boom and arm motion stroke is the same as above.

[0078] S3: Obtain the standard stroke values ​​of the calibrated motions of each component; the standard stroke values ​​include the standard length of the oil cylinder corresponding to each motion stroke limit, the standard angle of each motion stroke limit and the standard time of each motion.

[0079] Specifically include:

[0080] S31: Calibrate the length of the cylinder corresponding to each action stroke limit. The limit values ​​of the boom cylinder, dipper cylinder and bucket cylinder have standard lengths when they leave the factory. After being installed on the excavator, calibrate the limit length L of the boom cylinder. 1max , L 1min , calibrate the limit length L of the boom cylinder 2max , L 2min , calibrate the bucket cylinder limit length L 3max , L 3min .

[0081] S32: Calibrate the angle of each action stroke limit. The operation method is that the operator pushes the pilot handle from the middle position to the stroke limit at one time, and each component responds and gradually moves from the initial position to the stroke limit. The stroke limit angle of the calibrated boom relative to the turntable is α max , α min , calibrate the limit angle of the bucket rod relative to the boom as β max , β min , calibrate the travel limit angle of the bucket relative to the bucket arm as γ max , γ min To further illustrate the calibration method, the kinematic diagram of the excavator is shown in the attached Figure 4 As shown:

[0082] S321: OXYZ is the global coordinate system fixed on the slewing platform, and AX1Y1, BX2Y2, and IX3Y3 are the local coordinate systems of the boom, stick, and bucket respectively. α, β, and γ represent the angles of the boom, stick, and bucket relative to the upper-level components (slewing platform, boom, stick), and the lengths of the three groups of cylinders of the boom, stick, and bucket are L1, L2, and L3 respectively.

[0083] S322: Calibrate the limit angle of the boom stroke. The position and attitude of the boom AB are determined by the length L1 of the boom cylinder FC. According to the geometric relationship between the hinge points of the boom, the angle α of the boom relative to the slewing platform can be calculated. The calculation formula is:

[0084] α = ∠CAF - ∠CAB - ∠FAX (1)

[0085] Among them, ∠FAX is a fixed value and can be calculated according to the overall machine structure parameters.

[0086] After equation (1) is sorted out by the cosine theorem, the relationship between the angle α of the boom relative to the slewing platform and the length L1 of the boom cylinder is:

[0087]

[0088] (2) In the formula, L AC is the distance between points A and C of the boom, L AF is the distance between points A and F of the boom, L1 is the length of the boom hydraulic cylinder, L AB is the distance between points A and B of the boom, L BC is the distance between points B and C of the boom; ∠FAX is the angle between the connection line of hinge points A and F and the horizontal axis OX, and can be calculated according to the overall machine structure parameters. Substitute the limit lengths L 1max and L 1min of the boom hydraulic cylinder into the above formula respectively, and the limit position angles α max and α min of the boom movement can be obtained.

[0089] S323: Calibrate the limit angle of the stick stroke. The calibration principle of the limit angle of the stick stroke is the same as that of the limit angle of the boom stroke. The main determinant of the movement attitude of the stick BI is the length L2 of the stick cylinder DH. According to the geometric relationship between the hinge points of the stick, the swing angle β of the stick relative to the boom can be obtained. The calculation formula is:

[0090] β = ∠DBH + ∠ABD + ∠HBI - π (3)

[0091] Among them, ∠ABD and ∠HBI are fixed values and can be calculated according to the overall machine structure parameters.

[0092] (3) After equation (3) is sorted out by the cosine theorem, the relationship between the swing angle β of the stick relative to the boom and the length L2 of the stick cylinder is:

[0093]

[0094] (4) In the formula, L BD is the distance between points B and D of the arm, L BH is the distance between points B and H of the arm, and L2 is the length of the arm cylinder; ∠ABD is the included angle of the connecting line of hinge points A, B, and D, and ∠HBI is the included angle of the connecting line of hinge points H, B, and I, which can be calculated according to the overall machine structure parameters. Substitute the limit lengths L 2max and L 2min of the arm cylinder into the above formula respectively, and the limit position angles β max and β min of the arm movement can be obtained.

[0095] S324: Calibrate the limit angle of the bucket stroke. The calibration principle of the limit angle of the bucket stroke is the same as that of the limit angle of the boom stroke. The main determining factor for the movement posture of the bucket IJ is the length L3 of the bucket cylinder EK. Similar to the kinematic analysis of the boom and arm mechanisms, according to the geometric relationship between the hinge points of the bucket, the swing angle γ of the bucket relative to the arm can be obtained, and the calculation formula is:

[0096] γ = ∠JIL + ∠BIN + ∠NIL - π (5)

[0097] Among them, ∠JIL and ∠BIN are fixed values, ∠NIL = ∠KIN + ∠KIL, which can be calculated according to the overall machine structure parameters.

[0098] After sorting out formula (5) through the cosine theorem, the relationship between the swing angle γ of the bucket relative to the arm and the length L3 of the bucket cylinder is:

[0099]

[0100] (6) In the formula, L IL is the distance between points I and L of the arm, L IN is the distance between points I and N of the arm, L EN is the distance between points E and N of the arm, L KN is the distance between points K and N of the arm, and L3 is the length of the bucket cylinder; ∠ENI is the included angle of the connecting line of hinge points E, N, and I, which can be calculated according to the overall machine structure parameters. Substitute the limit lengths L 3max and L 3min of the bucket cylinder into the above formula respectively, and the limit position angles γ max and γ min of the bucket movement can be obtained.

[0101] S33: Analyze the time error affected by the detection device. The inherent frequency of image acquisition will bring inherent errors during the analysis action. There is an inherent time difference for the detection device to respond to this action. The judgment threshold, movement angle, and movement duration of this action together constitute the relative time error. When performing a single-action test, pushing the pilot handle from the neutral position to the stroke limit at one time will cause jitter of the boom, arm, and bucket components. The component jitter will bring the judgment start time error and end time error of the detection device for a single action. The judgment start and end time errors of the detection device for a single action are both in a proportional relationship with the same coefficient to the component jitter time. The calculation formula for the maximum error of this action time is as follows:

[0102]

[0103] In formula (7), μ is the image acquisition frequency, δ is the judgment threshold of this action, σ is the movement angle of this action, τ is the movement duration of this action, t i is the inherent time difference for the detection device to respond to this action, k is the proportionality coefficient, t s is the start time error of the detection device for judging a single action affected by component jitter, t f is the end time error of the detection device for judging a single action affected by component jitter, t err is the calculated maximum error of this action time.

[0104] S34: Calibrate the standard time of each action. Continuously record the time for the boom action to move from the starting point to the stroke limit ten times, and the obtained average value is used as the standard time for the boom action. Considering that the maximum time error t err of the action was analyzed in step S3, set the standard time interval for the boom action of this model to [standard time - maximum time error, standard time + maximum time error][T1 - T 11 . The calibration method for the standard time of the arm and bucket actions is the same as that of the boom. The standard time interval for the arm action of this model is [T2 - T 22 , and the standard time interval for the bucket action of this model is [T3 - T 33 .

[0105] S4: According to the standard values of the action strokes of each component, judge whether the action stroke characteristic values of each component are qualified. If they are qualified, it is determined that the component action test of this off-line excavator is qualified; otherwise, it is determined to be unqualified, and the evaluation result is obtained.

[0106] Extract the stroke characteristic values of the boom, arm, and bucket movements, and determine whether the limit angles, cylinder lengths, and times of each movement stroke are qualified. All excavators undergoing offline inspection of this model are inspected according to the above standards. Taking the boom movement as an example, the judgment methods for the arm and bucket are the same as that for the boom. Analyze the equipment to extract the minimum limit angle and corresponding time, and the maximum limit angle and corresponding time of the boom movement. If the test results are within the set range, it is determined that the boom movement test of the offline excavator is qualified; otherwise, it is determined as unqualified.

[0107] This method further includes: after the person to be detected confirms the result and clicks OK, the system completes the test, and the analysis equipment generates a test report.

[0108] Embodiment 2:

[0109] This embodiment provides an offline inspection system for an excavator. This offline inspection system includes a whole machine identification device, a detection device, and an analysis device. The implementation steps are as shown in the appendix Figure 1 and include the following parts:

[0110] Identification device: When the excavator is at station 1, the identification device collects the identity information of the excavator, such as the VIN barcode of the whole machine, the vehicle number barcode, etc.

[0111] Detection device: When the excavator is at station 2, the detection device collects the movement information of the excavator, including 6 movements: boom lifting, boom lowering, arm swinging out, arm swinging in, bucket swinging out, and bucket swinging in. Transmit the information of the determined component movement and collection to the analysis device, and delete the information that is determined not to move after capturing for 3s.

[0112] Analysis device: Analyze the movement angles, cylinder lengths, and times of each movement of the excavator according to the information collected by the detection device. Determine whether the single movement reaches the stroke limit through the movement angle and cylinder length, calculate the stroke time, and automatically judge whether the single movement test result of the excavator is qualified. After the personnel confirm the test result, the system completes the test and generates a test report.

[0113] The specific control method of the identification device is:

[0114] S1: Fix the scanning device at a specified position in station 1. Whenever the excavator drives into the specified area, the scanning device can automatically scan the VIN barcode or vehicle number barcode of the vehicle and store the information in the offline inspection system.

[0115] The specific control method of the detection device is: When the excavator is at station 2, the detection device collects the movement information of the excavator, including 6 movements: boom lifting, boom lowering, arm swinging out, arm swinging in, bucket swinging out, and bucket swinging in. Transmit the information of the determined component movement and collection to the analysis device, and delete the information that is determined not to move after capturing for 3s. The implementation steps are as shown in the appendixFigure 2 As shown below:

[0116] S1: Fix a high-speed camera at a specified position on Station 2. Whenever the excavator travels to the specified position to perform a specified action, the high-speed camera automatically collects the action information of the whole machine.

[0117] S2: Set the action recognition conditions for the excavator to determine whether a component is moving and whether to continue collecting information. When the camera captures that the moving angle of the boom exceeds the threshold δ within 3 seconds, it is determined that the boom is moving, and the subsequent information of the boom is continuously collected; when the camera captures that the moving angle of the boom remains less than the threshold δ within 3 seconds, it is determined that the boom of the excavator is not moving, and the subsequent information collection of the boom is stopped. The action recognition conditions for the stick and bucket are the same as those for the boom, the moving angle threshold is also δ, and the principle of determining whether to move and whether to continue collecting information is the same as that for the boom.

[0118] S3: Transmit the information of the determined actions and the collected information to the analysis device, and delete the information that is determined not to move after being captured for 3 seconds.

[0119] The specific control method of the analysis device is as follows: According to the action information collected by the detection device, analyze the information of the entire action process, parse the stroke limit angles, cylinder lengths, and time of each action, extract the stroke characteristic values of the boom, stick, and bucket actions, and automatically judge whether the single-action test result of this excavator is qualified. After the personnel confirm the detection result, this system completes the test to form a detection report, and the implementation steps are as shown in the appendix Figure 3 As shown below:

[0120] S1: Calibrate the lengths of the cylinders corresponding to the stroke limits of each action. The limit values of the boom cylinder, stick cylinder, and bucket cylinder have standard lengths when leaving the factory. After being installed on the excavator, calibrate the limit length L 1max 、L 1min of the boom cylinder, calibrate the limit length L 2max 、L 2min of the stick cylinder, and calibrate the limit length L 3max 、L 3min of the bucket cylinder.

[0121] S2: Calibrate the angles of the stroke limits of each action. The operation method is that the operator pushes the pilot handle from the neutral position to the stroke limit at one time, and each component responds and gradually moves from the initial position to the stroke limit. Among them, the stroke limit angles of the boom relative to the turntable action are α max 、α min , the stroke limit angles of the stick relative to the boom action are β max 、β min , and the stroke limit angles of the bucket relative to the stick are γ max 、γ min .

[0122] To further illustrate the calibration method, the kinematic schematic diagram of the excavator is shown in the appendix Figure 4 as follows:

[0123] S21: OXYZ is the global coordinate system fixed on the slewing platform, and AX1Y1, BX2Y2, and IX3Y3 are the local coordinate systems of the boom, arm, and bucket respectively. α, β, and γ respectively represent the angles of the boom, arm, and bucket relative to the upper-level components (turntable, boom, arm), and the lengths of the three groups of cylinders of the boom, arm, and bucket are L1, L2, and L3 respectively.

[0124] S22: Calibrate the limit angle of the boom stroke. The position and attitude of the boom AB are determined by the length L1 of the boom cylinder FC. According to the geometric relationship between the hinge points of the boom, the angle α of the boom relative to the turntable can be calculated. The calculation formula is:

[0125] α = ∠CAF - ∠CAB - ∠FAX (1)

[0126] Among them, ∠FAX is a fixed value and can be calculated based on the overall machine structure parameters.

[0127] After sorting out formula (1) through the cosine theorem, the relationship between the angle α of the boom relative to the turntable and the length L1 of the boom cylinder is:

[0128]

[0129] (2) In the formula, L AC is the distance between points A and C of the boom, L AF is the distance between points A and F of the boom, L1 is the length of the boom hydraulic cylinder, L AB is the distance between points A and B of the boom, L BC is the distance between points B and C of the boom; ∠FAX is the angle between the connection line of hinge points A and F and the horizontal axis OX, and can be calculated based on the overall machine structure parameters. Substitute the limit lengths L 1max , L 1min of the boom hydraulic cylinder into the above formula respectively, and the limit position angles α max , α min of the boom movement can be obtained.

[0130] S23: Calibrate the limit angle of the arm stroke. The calibration principle of the limit angle of the arm stroke is the same as that of the limit angle of the boom stroke. The main determining factor for the movement attitude of the arm BI is the length L2 of the arm cylinder DH. According to the geometric relationship between the hinge points of the arm, the swing angle β of the arm relative to the boom can be obtained. The calculation formula is:

[0131] β = ∠DBH + ∠ABD + ∠HBI - π (3)

[0132] Among them, ∠ABD and ∠HBI are fixed values and can be calculated based on the overall machine structure parameters.

[0133] After the formula (3) is rearranged by the cosine theorem, the relationship between the swing angle β of the stick relative to the boom and the length L2 of the boom cylinder is as follows:

[0134]

[0135] In formula (4), L BD is the distance between points B and D of the stick, L BH is the distance between points B and H of the stick, and L2 is the length of the stick cylinder; ∠ABD is the included angle of the connection line of hinge points A, B, and D, and ∠HBI is the included angle of the connection line of hinge points H, B, and I, which can be calculated according to the overall machine structure parameters. Substitute the limit lengths L 2max , L 2min of the stick cylinder into the above formula respectively, and the limit position angles β max , β min of the stick movement can be obtained.

[0136] S24: Calibrate the limit angle of the bucket stroke. The calibration principle of the limit angle of the bucket stroke is the same as that of the limit angle of the boom stroke. The main determining factor for the movement posture of the bucket IJ is the length L3 of the bucket cylinder EK. Similar to the kinematic analysis of the boom and stick mechanisms, according to the geometric relationship between the hinge points of the bucket, the swing angle γ of the bucket relative to the stick can be obtained, and the calculation formula is:

[0137] γ = ∠JIL + ∠BIN + ∠NIL - π (5)

[0138] Among them, ∠JIL and ∠BIN are fixed values, ∠NIL = ∠KIN + ∠KIL, which can be calculated according to the overall machine structure parameters.

[0139] After the formula (5) is rearranged by the cosine theorem, the relationship between the swing angle γ of the bucket relative to the stick and the length L3 of the bucket cylinder is as follows:

[0140]

[0141] In formula (6), L IL is the distance between points I and L of the stick, L IN is the distance between points I and N of the stick, L EN is the distance between points E and N of the stick, L KN is the distance between points K and N of the stick, and L3 is the length of the bucket cylinder; ∠ENI is the included angle of the connection line of hinge points E, N, and I, which can be calculated according to the overall machine structure parameters. Substitute the limit lengths L 3max , L 3min of the bucket cylinder into the above formula respectively, and the limit position angles γ max , γ min of the bucket movement can be obtained.

[0142] S3: Analyze the time error affected by the detection device. The inherent frequency of image acquisition will bring inherent errors during the analysis action. There is an inherent time difference for the detection device to respond to this action. The judgment threshold, movement angle, and movement duration of this action together constitute the relative time error. When performing a single-action test, pushing the pilot handle from the neutral position to the stroke limit at one time will cause the boom, stick, and bucket components to shake. The component shake will bring the starting time error and ending time error for the detection device to judge the single action. The starting and ending time errors for the detection device to judge the single action are both in a proportional relationship with the same coefficient to the component shake time. The calculation formula for the maximum error of this action time is as follows:

[0143]

[0144] In formula (7), μ is the image acquisition frequency, δ is the judgment threshold of this action, σ is the movement angle of this action, τ is the movement duration of this action, t i is the inherent time difference for the detection device to respond to this action, k is the proportionality coefficient, t s is the starting time error for the detection device to judge the single action affected by the component shake, t f is the ending time error for the detection device to judge the single action affected by the component shake, t err is the calculated maximum error of this action time.

[0145] S4: Calibrate the standard time for each action. Continuously record the time for the boom action to move from the starting point to the stroke limit ten times, and take the obtained average value as the standard time for the boom action. Considering the maximum time error t err analyzed in step S3, set the standard time interval for the boom action of this model as [T1 - T 11 . The calibration method for the standard time of the stick and bucket actions is the same as that of the boom. The standard time interval for the stick action of this model is [T2 - T 22 , and the standard time interval for the bucket action of this model is [T3 - T 33 .

[0146] S5: Extract the stroke characteristic values of the boom, stick, and bucket actions, and judge whether the stroke limit angle, cylinder length, and time of each action are qualified. All the excavators undergoing off-line inspection of this model are inspected according to the above standards. Taking the boom action as an example for detailed elaboration, the judgment methods for the stick and bucket are the same as that of the boom. The analysis device extracts the minimum value of the stroke limit angle of the boom action and the corresponding time, as well as the maximum value and the corresponding time. If the test results are within the set interval, it is determined that the boom action test of this off-line excavator is qualified; otherwise, it is determined as unqualified.

[0147] S6: After the person to be detected confirms the result, click OK, and this system completes the test. The analysis device generates a test report.

[0148] The present invention provides an off-line detection system for an excavator. This method analyzes the stroke limit angles of the boom, arm, and bucket, and analyzes the equipment to extract characteristic values by resolving the collected information to determine whether the test result of this action is qualified. Using this method for batch off-line detection of a certain model can save a lot of manpower and man-hours. By using this method to replace the method of combining manual visual inspection and stopwatch timing to test the actions of the excavator, the accuracy and consistency of the test results can be improved. By using this method to replace the method of using external sensors to test the actions of the excavator, the test efficiency can be improved. By using this method, it can replace the evaluation of the performance of the excavator solely relying on the subjective judgment of the tester, effectively solve the problems of poor accuracy and low efficiency in off-line testing, and improve the accuracy and efficiency of off-line detection.

[0149] Key points of the concept of the present invention:

[0150] Key point 1: Analyze the stroke limit angles and cylinder lengths of the boom, arm, and bucket through the kinematics of the excavator, and calibrate the stroke limit angles and cylinder lengths of each action.

[0151] Key point 2: Calibrate the stroke limit times of the boom, arm, and bucket actions, analyze the time factors affecting the detection equipment. The inherent frequency of image acquisition will bring inherent errors when analyzing actions, there is an inherent time difference in action response, and the action judgment threshold, movement angle, and movement duration together constitute a relative time error. When testing a single action, pushing the pilot handle from the neutral position to the stroke limit at one time will cause jitter of the boom, arm, and bucket components, and the component jitter will bring errors in the detection equipment's judgment of the starting time and ending time of a single action. The errors in the detection equipment's judgment of the starting and ending times of a single action are both in a proportional relationship with the same coefficient to the component jitter time. Considering the combined influence of the above factors, set the standard time intervals for the above actions of different models.

[0152] Key point 3: Analyze the equipment to resolve the action information collected by the detection equipment, extract the stroke limit angles, cylinder lengths, and times of the above actions, and automatically judge whether the test result of a single action of the excavator is qualified. After the personnel confirm the detection result, this system completes the test and forms a detection report.

[0153] The protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention. For example: The stroke limit judgment conditions for the boom, arm, and bucket actions are not limited to the two factors of comprehensive angle and cylinder length, and also include other methods such as judging only based on the action stroke angle or only based on the cylinder length. The present invention can be applied not only to excavators, but also to other construction machinery fields such as pile drivers and loggers.

[0154] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0155] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0156] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that realizes the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0157] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for realizing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0158] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for detecting the off-line of an excavator, characterized in that, Including the following steps: S1: Obtain the identity information of the offline excavator and the excavator detection video information; the excavator detection video information includes the video information of the excavator performing multiple actions; S2: Extract the action stroke characteristic values of each component according to the excavator detection video information, where the components include the boom, the arm, and the bucket; the action stroke characteristic values include the lengths of the cylinders corresponding to the limits of each action stroke, the angles of the limits of each action stroke, and the times of each action; S3: Obtain the calibrated action stroke standard values of each component; the stroke standard values include the standard lengths of the cylinders corresponding to the limits of each action stroke, the standard angles of the limits of each action stroke, and the standard times of each action; S4: According to the action stroke standard values of each component, determine whether the action stroke characteristic values of each component are qualified. If they are qualified, determine that the component action test of the offline excavator is qualified; Otherwise, determine it as unqualified to obtain the evaluation result; The calibration method of the action stroke standard values of each component includes: Analyze the time error affected by the detection equipment: The calculation formula for the maximum action time error is: Where, μ is the image acquisition frequency, δ is the action judgment threshold, σ is the action movement angle, τ is the action movement duration, t i is the inherent time difference for the detection device to respond to this action, k is the proportionality coefficient, t s is the error in the starting time of the single action judged by the detection device affected by the component jitter, t f is the error in the ending time of the single action judged by the detection device affected by the component jitter, t err is the maximum error in the calculated action time; Calibrate the standard time of each action: Continuously record the time for the boom action to move from the starting point to the stroke limit ten times, and take the obtained average value as the standard time of the boom action. Set the standard time interval of the boom action of this model as [standard time - maximum time error, standard time + maximum time error].

2. The method for detecting the off-line of an excavator according to claim 1, characterized in that, In step S1, the excavator detection video information includes the video information of 6 actions, namely boom lifting, boom lowering, arm swinging out, arm swinging in, bucket swinging out, and bucket swinging in.

3. The method for detecting the off-line of an excavator according to claim 1, characterized in that, In step S1, the method for obtaining the excavator detection video information includes: When the excavator travels to the specified position to perform the specified actions, control the high-speed camera to automatically collect the whole machine action information; When the camera captures that the moving angle of any component exceeds the threshold δ within 3 s, determine that the component is moving, and continue to collect the subsequent information of the component; When the camera captures that the moving angle of any component remains less than the threshold δ within 3 s, determine that the component of the excavator is not moving, stop collecting the subsequent information of the component, and delete the information captured within 3 s and determined as not moving.

4. The method for detecting the off-line of an excavator according to claim 1, characterized in that, In step S2, the method for extracting the action stroke characteristic values of each component according to the excavator detection video information includes: Adsorb the target detection plate on each component, capture the trajectory of the target detection plate on each component under dynamic movement through the high-speed camera, and analyze to obtain the action stroke characteristic values of each component. The action stroke characteristic values include the movement angle, the cylinder displacement length, and the action time; The target detection plate includes but is not limited to reflective strips.

5. The method for detecting the off-line of an excavator according to claim 1, characterized in that, In step S3, the calibration method of the action stroke standard values of each component includes: Calibrate the lengths of the cylinders corresponding to the limit positions of each movement stroke: Calibrate the limit length L of the boom cylinder according to the standard length at the factory 1max 、L 1min , calibrate the limit length L of the bucket cylinder 2max 、L 2min , calibrate the limit length L of the ripper cylinder 3max 、L 3min ; Calibrate the angles of the extreme positions of each movement: The operator pushes the pilot control handle from the neutral position to the extreme position of the stroke at one time, and each component responds and gradually moves from the initial position to the extreme position of the stroke. Among them, the extreme position angle of the boom relative to the turntable movement is calibrated as α max 、α min , and the extreme position angle of the stick relative to the boom movement is calibrated as β max 、β min , and the extreme position angle of the bucket relative to the stick is calibrated as γ max 、γ min .

6. The method for detecting the off-line of an excavator according to claim 5, characterized in that, Calibrate the stroke limit angles for the boom relative to the turntable as α max and α min , calibrate the stroke limit angles for the bucket stick relative to the boom as β max and β min , calibrate the stroke limit angles for the bucket relative to the bucket stick as γ max and γ min The method includes: Define point A as the hinge point between the boom and the slewing platform, point B as the hinge point between the boom and the stick, point F as the starting point of the boom cylinder, point C as the ending point of the boom cylinder, point I as the hinge point between the stick and the bucket, point D as the starting point of the stick cylinder, point H as the ending point of the stick cylinder, point J as the ending point of the bucket, point E as the starting point of the bucket cylinder, point K as the ending point of the bucket cylinder, and OXYZ as the global coordinate system fixed on the slewing platform. AX1Y1, BX2Y2, and IX3Y3 are the local coordinate systems of the boom, stick, and bucket respectively; α, β, and γ represent the angles of the boom, stick, and bucket relative to the upper-level component. The lengths of the three groups of cylinders for the boom, stick, and bucket are L1, L2, and L3 respectively; Calibrate the limit angle of the boom stroke: The position and attitude of the boom AB are determined by the length L1 of the boom cylinder FC. According to the geometric relationship between the hinge points of the boom, the relative rotation angle α of the boom with respect to the turntable can be calculated. The calculation formula is: α = ∠CAF - ∠CAB - ∠FAX (1) Among them, ∠FAX is a fixed value, which can be solved according to the structural parameters of the whole machine; After equation (1) is sorted out by the cosine theorem, the relationship between the relative rotation angle α of the boom with respect to the turntable and the length L1 of the boom cylinder is: Wherein, L AC is the distance between points A and C, L AF is the distance between points A and F, L1 is the length of the hydraulic cylinder, L AB is the distance between points A and B, L BC is the distance between points B and C; ∠FAX is the angle between the connecting line of hinge points A and F and the horizontal axis OX, which can be calculated according to the structural parameters of the whole machine; Substitute the limit lengths L 1max and L 1min of the boom hydraulic cylinder into the above formula respectively, and the limit position angles α max and α min of the boom movement can be obtained; Calibrate the limit angle of the stick stroke: The main determining factor for the motion attitude of the stick BI is the length L2 of the stick cylinder DH. According to the geometric relationship between the hinge points of the stick, the relative swing angle β of the stick with respect to the boom can be obtained. The calculation formula is: β = ∠DBH + ∠ADB + ∠HBI - π (3) Among them, ∠ABD and ∠HBI are fixed values, which can be solved according to the structural parameters of the whole machine; After equation (3) is sorted out by the cosine theorem, the relationship between the relative swing angle β of the stick with respect to the boom and the length L2 of the stick cylinder is: In formula (4), L BD is the distance between points B and D, L BH is the distance between points B and H, and L2 is the length of the bucket cylinder; ∠ABD is the included angle of the connection line of hinge points A, B, and D, and ∠HBI is the included angle of the connection line of hinge points H, B, and I, which can be calculated according to the overall structure parameters of the machine. Substitute the limit lengths L 2max and L 2min into the above formula respectively, and the limit position angles β max and β min of the bucket movement can be obtained; Calibrate the limit angle of the bucket stroke: According to the geometric relationship between the hinge points of the bucket, the relative swing angle γ of the bucket with respect to the stick can be obtained. The calculation formula is: γ = ∠JIL + ∠BIN + ∠NIL - π (5) Among them, ∠JIL and ∠BIN are fixed values, and ∠NIL = ∠KIN + ∠KIL, which can be solved according to the structural parameters of the whole machine; After equation (5) is sorted out by the cosine theorem, the relationship between the relative swing angle γ of the bucket with respect to the stick and the length L3 of the bucket cylinder is: Wherein, L IL is the distance between two points I and L of the dipper arm, L IN is the distance between two points I and N of the dipper arm, L EN is the distance between two points E and N of the dipper arm, L KN is the distance between two points K and N of the dipper arm, L3 is the length of the bucket hydraulic cylinder; ∠ENI is the included angle of the connecting lines of hinge points E, N, and I, which can be calculated according to the overall machine structure parameters; substituting the limit lengths L 3max , L 3min into the above formula respectively, the limit position angles γ max , γ min of the bucket movement can be obtained.

7. An off-line detection system for an excavator, characterized in that, It includes Station 1, Station 2, an identification device, a detection device, and an analysis device; The identification device is used to collect the identity information of the excavator when the excavator is at Station 1. The identity information includes the VIN barcode and vehicle number barcode of the whole machine; The detection device is used to collect the action information of the excavator when the excavator is at Station 2, and transmit the information of the determined component action and collection to the analysis device; The analysis device is used to execute the method described in Claim 1.

8. The off-line detection system for an excavator according to claim 7, characterized in that, The identification device includes a scanning device fixed at a designated position in Station 1. Whenever the excavator travels to the designated area, the scanning device can automatically scan the VIN barcode or vehicle number barcode of the vehicle and store the information in the memory of the analysis device.

9. The off-line detection system for an excavator according to claim 7, characterized in that, The detection device includes a high-speed camera fixed at a designated position in Station 2. Whenever the excavator travels to the designated position to perform the specified p action, the high-speed camera automatically collects the action information of the whole machine; When the moving angle of the boom captured by the camera exceeds the threshold δ within 3 s, it is determined that the boom is moving, and the subsequent information of the boom is continuously collected; when the moving angle of the boom captured by the camera is continuously less than the threshold δ within 3 s, it is determined that the boom of the excavator is not moving, the subsequent information collection of the boom is stopped, and the video information of the boom determined not to move after 3 s of capture is deleted; When the moving angle of the stick captured by the camera exceeds the threshold δ within 3 s, it is determined that the stick is moving, and the subsequent information of the stick is continuously collected; when the moving angle of the stick captured by the camera is continuously less than the threshold δ within 3 s, it is determined that the stick of the excavator is not moving, the subsequent information collection of the stick is stopped, and the video information of the stick determined not to move after 3 s of capture is deleted; When the moving angle of the bucket captured by the camera exceeds the threshold δ within 3 s, it is determined that the bucket is moving, and the subsequent information of the bucket is continuously collected; when the moving angle of the bucket captured by the camera is continuously less than the threshold δ within 3 s, it is determined that the bucket of the excavator is not moving, the subsequent information collection of the bucket is stopped, and the video information of the bucket determined not to move after 3 s of capture is deleted.

10. The off-line detection system for an excavator according to claim 7, characterized in that, The system further includes a tester input device; After the analysis device obtains the confirmation information of the tester through the tester input device, the test is completed, and a test report is formed and output.

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