A method and device for detecting the working parameters of a forklift

Abstract

A method and apparatus for detecting the working parameters of a forklift includes: 1) obtaining a top-view image of the current forklift; 2) calculating the current pixel distance A1 of a first set of labels and comparing it with the initial pixel distance A0 to determine whether a change has occurred; if so, calculating the distance H1 between the current image acquisition module and the forks according to a first proportional relationship, and proceeding to step 3); if not, calculating the final height H of the current forks as H = H0; 3) determining whether a second set of labels appears in the top-view image; if so, calculating the current pixel distance B1 of the second set of labels in the top-view image and calculating the current height change value H2 of the inner mast according to a second proportional relationship, and proceeding to step 4); if not, calculating the final height H of the current forks as H = X - H1; 4) calculating the final height H of the current forks as H = (X - H1) + H2. This invention only requires the acquired image to calculate the working parameters of the forklift, eliminating the need for sensors and reducing costs.

Description

Technical Field

[0001] This invention relates to the field of forklifts, and in particular to a method and apparatus for detecting the working parameters of a forklift. Background Technology

[0002] Forklifts are wheeled handling vehicles used for loading, unloading, stacking, short-distance transport, and heavy-duty handling of palletized goods. Also known as industrial vehicles, they belong to material handling machinery and are widely used in various sectors of the national economy, such as railway stations, ports, airports, factories, and warehouses. They are highly efficient equipment for mechanized loading, unloading, stacking, and short-distance transport.

[0003] There are many types of forklifts, but their basic structures are similar, mainly consisting of an engine, chassis, body, lifting mechanism, hydraulic system, and electrical equipment. The lifting mechanism mainly includes the mast and forks. The mast includes an inner mast and an outer mast. The outer mast is hinged to the body and can tilt relative to the body. The inner mast can be raised and lowered relative to the outer mast, and the forks can be raised and lowered relative to the inner mast.

[0004] During forklift operation, the mast and forks, as mechanical components, require various electrical sensors to monitor and provide feedback on the mast's movement. For example, angle sensors detect the mast's tilt angle, and height sensors detect parameters such as fork lifting height. However, typically, a single sensor can only detect one function and output one parameter; for instance, an angle sensor only detects angle information, and a height sensor only detects height signals. Therefore, forklifts require a combination of sensors, which creates inconvenience in installation and after-sales service, and also represents a significant cost. Summary of the Invention

[0005] The main objective of this invention is to overcome the shortcomings of existing lifting mechanisms that require multiple sensors to detect working parameters. This invention proposes a method and device for detecting the working parameters of a forklift, which only requires images captured by a camera to calculate relevant working parameters, eliminating the need for sensors, and is easy to install and low in cost.

[0006] The present invention adopts the following technical solution:

[0007] A method for detecting the working parameters of a forklift, characterized by: pre-setting a first set of labels on the upper surface of the forks and a second set of labels on the upper surface of the outer mast; and pre-determining the initial pixel distance A0 of the first set of labels and the initial pixel distance B0 of the second set of labels; the remaining steps are as follows:

[0008] 1) Set the image acquisition module to take a top-down view of the current forklift from the top of the inner mast;

[0009] 2) Calculate the current pixel distance A1 of the first group of labels in the top view image and compare it with the initial pixel distance A0 to determine whether it has changed. If it has, calculate the distance value H1 between the current image acquisition module and the fork according to the first proportional relationship, and proceed to step 3); if not, the final height value H of the current fork is the initial height H0 of the fork.

[0010] 3) Determine whether the second set of labels appears in the top view image. If yes, calculate the current pixel distance B1 of the second set of labels in the top view image, and calculate the current height change value H2 of the inner mast according to the second proportional relationship, and proceed to step 4); if no, the final height value H of the current fork is H = X - H1, where X is the initial height value of the image acquisition module.

[0011] 4) Calculate the final height value of the current fork H = (X - H1) + H2.

[0012] Preferably, in step 2), the fork height value H1 is calculated based on the first proportional relationship, as follows:

[0013] H1 = (Ha*A1) / (K1*A0)

[0014] Where K1 is a preset coefficient, and Ha is the initial distance between the image acquisition module and the fork.

[0015] Preferably, in step 3), the change value H2 of the inner gantry height is calculated according to the second proportional relationship, as follows:

[0016] H2=(Hb*B1) / (K2*B0)

[0017] Where K2 is a preset coefficient, and Hb is the initial distance between the image acquisition module and the top surface of the outer gantry.

[0018] Preferably, in step 2), the first group of labels includes two first labels, and the current pixel distance A1 is the pixel distance between the two first labels; or the first group of labels includes one first label, and the current pixel distance A1 is the number of pixels of the first label.

[0019] Preferably, in step 3), the second group of labels includes two second labels, and the current pixel distance B1 is the pixel distance between the two second labels; or the second group of labels includes one second label, and the current pixel distance A1 is the number of pixels of the second label.

[0020] Preferably, a third set of labels is pre-set on the upper surface of the connection between the vehicle body and the outer gantry, and the initial pixel distance C1 between the third set of labels and the first set of labels is pre-observed; the method also includes the step of calculating the gantry tilt: calculating the pixel distance C1 between the third set of labels and the first set of labels in the top view image, and comparing it with the initial pixel distance C0 to determine whether it has changed. If it has, the current gantry tilt angle θ is calculated according to the third proportional relationship; if not, the current gantry tilt angle θ = θ0.

[0021] Preferably, the calculation of the current gantry tilt angle θ based on the third proportional relationship is as follows:

[0022] θ=(θ0*C1) / (K3*C0)

[0023] Where θ0 is the initial value of the gantry tilt angle, and K3 is a preset coefficient.

[0024] Preferably, the third group of labels includes a third label, and the pixel distance between the third group of labels and the first group of labels refers to the pixel distance between the third label and the midpoint of the first group of labels.

[0025] A forklift operating parameter detection device, characterized in that: it includes...

[0026] The first set of labels is placed on the upper surface of the forks;

[0027] The second set of labels is placed on the upper surface of the outer gantry;

[0028] An image acquisition module, installed on the top of the inner mast, is used to acquire a top view of the forklift;

[0029] The comparison and judgment module is used to determine whether the current pixel distance A1 of the first group of labels has changed compared with the initial pixel distance A0 based on the top view image, thereby determining whether the fork has moved, and to determine whether the second group of labels appears in the top view image, thereby determining whether the inner mast has moved.

[0030] The height calculation module is used to calculate the distance H1 between the current image acquisition module and the fork according to the first proportional relationship when the fork moves; to calculate the current height change H2 of the inner mast according to the second proportional relationship when the inner mast moves; and to calculate the final height value H = (X-H1)+H2 of the current fork, where X is the initial height value of the image acquisition module.

[0031] The output module is used to output the final height value of the current forks H = X - H1 when the inner mast is not moving; and to output the final height value of the current forks H = (X - H1) + H2 when the inner mast moves.

[0032] Preferably, the system also includes a third set of labels and a tilt angle calculation module, wherein the third set of labels is disposed between the outer gantry and the vehicle body; the comparison and judgment module further includes determining whether the pixel distance C1 between the third set of labels and the first set of labels has changed from the initial pixel distance C0 based on the top view image, thereby determining whether the gantry is tilted; when the gantry tilts, the tilt angle calculation module calculates the current gantry tilt angle θ according to the third proportional relationship; the output module further includes outputting the current gantry tilt angle θ.

[0033] Preferably, the first set of labels is disposed on the top surface of the vertical section of the fork or the top surface of the fork carriage; the second set of labels is disposed on the top surface of the outer mast or the top surface of the overhead guard.

[0034] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. In this invention, by setting a first set of labels and a second set of labels on the forks and the outer mast respectively, and then collecting the top view image of the current forklift; determining whether the first set of labels and the second set of labels on the top view image have changed, and calculating the corresponding final height value of the current forks based on the determination result, the relevant working parameters can be calculated using only the images collected by the camera, without the need for sensors, making it easy to install and low in cost.

[0036] 2. In this invention, the distance between the image acquisition module and the fork and the change in the height of the inner mast are calculated based on the pixel distance in the top view image combined with the first and second proportional relationships. The calculation method is simple and accurate.

[0037] 3. In this invention, the quantity and form of the first and second sets of labels can be selected according to the actual situation, without affecting the operation of the forks and mast, and are easy to identify and judge.

[0038] 4. In this invention, by setting a third set of labels at the connection between the gantry and the vehicle body, it is determined whether the pixel distance C1 between the third set of labels and the first set of labels in the top view image changes from the initial pixel distance C0, thereby determining whether the gantry is tilted, and calculating the corresponding current gantry tilt angle based on the determination result. This method is very convenient as it does not require the use of sensors.

[0039] 5. In this invention, only an image acquisition device combined with software algorithms is needed to replace multiple sensors to detect the working parameters of the forklift. It can also be expanded with more functions as needed, and has a wide range of application scenarios and space in the intelligent mast and automatic sensing. Attached Figure Description

[0040] Figure 1 This is a flowchart of the present invention;

[0041] Figure 2A schematic diagram showing the installation of the image acquisition module;

[0042] Figure 3 This is a top view image of the present invention (with a first set of labels);

[0043] Figure 4 This is a top view image of the present invention (with a first set of labels and a second set of labels);

[0044] Figure 5 This is a top view image of the present invention (with a first set of labels and a third set of labels);

[0045] Figure 6 This is a flowchart of the gantry tilt angle detection method of the present invention;

[0046] in:

[0047] 10. Forklift, 11. First label, 20. Inner mast, 21. Image acquisition module, 30. Outer mast, 31. Second label, 32. Third label, 33. Rotary shaft.

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0049] The present invention will be further described below through specific embodiments.

[0050] In this invention, the terms "first," "second," and "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. The use of terms such as "upper," "lower," "left," "right," "front," and "rear" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings and is only for the convenience of describing the invention, not to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the scope of protection of this invention. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0051] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0052] See Figure 1A method for detecting the working parameters of a forklift, wherein a first set of tags is set on the forks 10 or fork carriage, and a second set of tags is set on the outer mast 30 or overhead guard; and the initial pixel distance A0 of the first set of tags and the initial pixel distance B0 of the second set of tags are obtained in advance.

[0053] The remaining steps of this invention are as follows:

[0054] 1) Set the image acquisition module 21 to take a top-down view of the current forklift from the top of the inner mast 20.

[0055] See Figure 2 The present invention can pre-install a camera above the top of the inner mast 20 as an image acquisition module 21 to acquire a top-down view of the forklift. This top-down view refers to an image taken from a top-down angle, and the captured image may include at least the forks 10, fork carriage, inner mast 20, outer mast 30, and overhead guard. In practical applications, the shooting angle can also be appropriately tilted, and is not limited to this.

[0056] 2) Calculate the current pixel distance A1 of the first group of labels in the top-view image and compare it with the initial pixel distance A0 to determine if there has been a change. If yes, it means the fork 10 has moved, and the distance value H1 between the current image acquisition module 21 and the fork is calculated according to the first proportional relationship, proceeding to step 3); if no, it means the fork 10 has not moved, and the final height value H of the current fork is the initial height H0 of the fork 10. This initial height H0 is the minimum height of the fork 10 from the ground when the forklift is in its initial state.

[0057] In this invention, if the first group of labels includes two first labels 11, then the current pixel distance A1 is the pixel distance between the two first labels 11; if the first group of labels includes one first label 11, then the current pixel distance A1 is the number of pixels of that first label 11. Preferably, the first group of labels includes two first labels 11, and the first label 11 is cross-shaped. See [reference needed]. Figure 3 .

[0058] In this step, the current pixel distance A1 of the first group of labels is compared with the initial pixel distance A0. This can be done by comparing whether the two are the same. If they are the same, it means that there has been no change or movement. Alternatively, the difference between the two can be compared to see if it is within a preset range. If it is, it means that there has been no change or movement.

[0059] Furthermore, the distance H1 between the current image acquisition module and the fork is calculated based on the first proportional relationship, as follows:

[0060] H1 = (Ha*A1) / (K1*A0)

[0061] Where K1 is a preset coefficient, Ha is the initial distance between the image acquisition module and the fork, Ha can be measured in advance and Ha≠0.

[0062] In this invention, the initial distance value Ha can be the distance between the fork 10 and the image acquisition module when the fork 10 is at its minimum height H0. Then, when the fork 10 is at its minimum height, the pixel distance of the first set of labels in the top view image of the forklift is taken as the initial pixel distance A0.

[0063] 3) Determine whether the second set of labels appears in the top view image. If yes, it means that the inner mast 20 has moved. Calculate the current pixel distance B1 of the second set of labels in the top view image and calculate the current height change value H2 of the inner mast 20 according to the second proportional relationship. Proceed to step 4). If no, it means that the inner mast 20 has not moved. The final height value H of the current fork 10 is H = X - H1, where X is the initial height value of the image acquisition module 21, that is, the height value of the image acquisition module 21 when the forklift is in the initial state. This value can also be equal to the height value of the top of the inner mast.

[0064] In this invention, the image acquisition module 21 can be installed on the top of the inner gantry 20, located on the bottom surface of the top and facing downwards, while the second label group is located on the top surface of the outer gantry 30. When the inner gantry 20 is not raised, the second label group will not appear in the captured top view image. Once the inner gantry 20 is raised, the second label group will appear in the captured top view image.

[0065] Wherein, if the second group of labels includes two second labels 31, then the current pixel distance B1 is the pixel distance between the two second labels 31; if the second group of labels includes one second label 31, then the current pixel distance B1 is the number of pixels of that second label 31. Preferably, the second group of labels includes two second labels 31, and the second label 31 is cross-shaped, see [reference]. Figure 4 .

[0066] Furthermore, the current height change value H2 of the inner gantry is calculated based on the second proportional relationship, as follows:

[0067] H2=(Hb*B1) / (K2*B0)

[0068] Where K2 is a preset coefficient, Hb is the initial distance between the image acquisition module and the top surface of the outer gantry, and Hb≠0.

[0069] In this invention, the initial distance between the image acquisition module and the top surface of the outer gantry can be the distance between the image acquisition module and the top surface of the outer gantry when the second set of labels first appears in the top view image captured by the image acquisition module 21 during the process of the inner gantry 20 rising relative to the outer gantry 30. At the same time, the pixel distance of the second set of labels in the top view image when the second set of labels first appears is used as the initial pixel distance B0.

[0070] 4) Calculate the final height value H of the current fork 10: H = (X - H1) + H2.

[0071] The present invention can also detect the current gantry tilt angle, the gantry including an inner gantry 20 and an outer gantry 30. Specifically: a third set of tags is pre-set on the upper surface of the connection between the vehicle body and the outer gantry 30, and the initial pixel distance C1 between the third set of tags and the first set of tags is pre-obtained.

[0072] See Figure 6 It also includes the step of calculating the current mast tilt angle, which can be performed concurrently with the step of calculating the final height value of the current fork 10 (steps 2-4), meaning there is no order of priority. The specific steps are as follows:

[0073] Calculate the pixel distance C1 between the third group of labels and the first group of labels in the top view image and compare it with the initial pixel distance C0 to determine whether it has changed. If it has, calculate the current gantry tilt angle θ according to the third proportional relationship. If not, the current gantry tilt angle θ = θ0.

[0074] The current gantry tilt angle θ is calculated based on the third proportional relationship, as follows:

[0075] θ=(θ0*C1) / (K3*C0)

[0076] Where θ0 is the initial value of the gantry tilt angle, and K3 is a preset coefficient.

[0077] Furthermore, the third group of labels includes a third label 32. The pixel distance between the third group of labels and the first group of labels refers to the pixel distance between the third label 32 and the midpoint of the first group of labels. See [link to documentation]. Figure 5 .

[0078] The initial value of the tilt angle of the mast can be the angle when the mast is not tilted. When the inner mast 20 is not tilted, the forklift top view image is collected, and the midpoint pixel distance between the third label 32 and the two second labels 31 is used as the initial pixel distance C0.

[0079] In this invention, the pixel distance between the two first labels 11, the pixel distance between the two second labels 31, and the pixel distance between the third label 32 and the midpoint of the first set of labels can be obtained by calculating the straight-line distance between the coordinates of the two pixel points, such as the Euclidean distance.

[0080] The present invention also proposes a forklift operating parameter detection device for implementing the above-mentioned forklift operating parameter detection method, which includes the following modules:

[0081] The first set of labels is placed at a suitable position on the fork 10 or fork carriage, including the top surface of the vertical or horizontal section of the fork 10, or the top surface of the fork carriage, preferably the top surface of the vertical section of the fork 10. The first set of labels may include at least one first label 11, which can be a line, pattern, or text. The line can be a straight line, the pattern can be a cross, rectangle, circle, or other polygon, and the text can be numbers, letters, or symbols, etc. The initial pixel distance A0 of the first set of labels can be set according to the number of first labels 11. If the first set of labels has one first label 11, its initial pixel distance A0 can be the initial number of pixels occupied by that first label 11. If the first set of labels has two first labels 11, its initial pixel distance A0 can be the pixel distance between the two first labels 11.

[0082] The second set of labels is placed at a suitable location on the outer gantry 30 or the top support frame, including the top surface, sides, etc., preferably on the top surface of the outer gantry 30. It may include at least one second label 31, which can be lines, patterns, or text. Lines can be straight lines, patterns can be crosses, rectangles, circles, or other polygons, and text can be numbers, letters, or symbols. The initial pixel distance B0 of the second set of labels can be set according to the number of second labels 31. If the second set of labels has one second label 31, its initial pixel distance B0 can be the initial number of pixels occupied by that second label 31. If the second set of labels has two second labels 31, its initial pixel distance B0 can be the pixel distance between the two second labels 31.

[0083] Image acquisition module 21, mounted on top of inner mast 20, is used to acquire a top view of the forklift. This image acquisition module 21 can be a camera that takes a downward-facing image of the forklift, which includes at least the forks 10, inner mast 20, and outer mast 30.

[0084] The comparison and judgment module is used to determine whether the current pixel distance A1 of the first group of labels has changed compared with the initial pixel distance A0 based on the top view image, thereby determining whether the fork 10 has moved, and to determine whether the second group of labels appears in the top view image, thereby determining whether the inner mast 20 has moved.

[0085] The height calculation module is used to calculate the distance H1 between the current image acquisition module and the fork according to the first proportional relationship when the fork 10 moves; to calculate the current height change H2 of the inner mast 20 according to the second proportional relationship when the inner mast 20 moves; and to calculate the final height value H = (X-H1)+H2 of the current fork, where X is the initial height value of the image acquisition module 21.

[0086] The output module is used to output the final height value H = X - H1 of the current fork 10 when the inner mast 20 is not moved; and to output the final height value H = (X - H1) + H2 of the current fork 10 when the inner mast 20 is moved.

[0087] The device of the present invention may further include a third set of labels and a tilt angle calculation module. The third set of labels may be set on the rotating shaft 33 of the outer mast 30, that is, the position of the third set of labels does not move with the tilt of the mast and remains stationary relative to the vehicle body.

[0088] The third set of labels may include a third label 32, which may be lines, patterns, or text. The lines may be straight lines, the patterns may be crosses, rectangles, circles, or other polygons, and the text may be numbers, letters, or symbols, etc.

[0089] The comparison and judgment module also includes determining whether the pixel distance C1 between the third group of labels and the first group of labels has changed from the initial pixel distance C0 based on the top-view image, thereby determining whether the gantry is tilted. When the gantry tilts, the tilt angle calculation module calculates the current gantry tilt angle θ according to the third proportional relationship. The output module outputs the current gantry tilt angle θ.

[0090] The detection accuracy achieved by using the method and apparatus of this invention can meet the operational requirements of forklifts, as explained below:

[0091] Taking a certain model of mast as an example, the maximum distance from the top of the mast to the upper surface of the forks is 1601mm, and the maximum distance between the inner mast 20 raised to its highest point and the outer mast is 1495mm. Therefore, the maximum distance between the camera installed on the inner mast 20 and the label affixed to the upper surface of the forks will not exceed 1.6m.

[0092] Preliminary analysis: Selecting a camera with a resolution of 1920*1080, a frame rate of 10fps, a horizontal field of view of 100°, and a vertical field of view of 40°, according to the parameters provided by the manufacturer, at a distance of 0.4 meters, the actual field of view that the camera can see is 0.95m*0.33m; at a distance of 1.6 meters, the actual field of view that the camera can see is 3.80m*1.34m.

[0093] Theoretical calculations show that: (1) at a distance of 0.4m from the camera, the accuracy in the X direction is 95cm ÷ 1920 = 0.05cm; the accuracy in the Y direction is 33cm ÷ 1080 = 0.03cm; (2) at a distance of 1.6m from the camera, the accuracy in the X direction is 380cm ÷ 1920 = 0.20cm; the accuracy in the Y direction is 134cm ÷ 1080 = 0.12cm.

[0094] Affix "+" labels to the forks as the first label group. Each first label is 5cm x 5cm in size. Combining this with the calculated accuracy in the X and Y directions, we can obtain:

[0095] (1) At a distance of 0.4m from the camera, the recognition accuracy error of the first tag in the X direction is 0.05cm ÷ 5cm = 1%; the recognition accuracy error of the first tag in the Y direction is 0.03cm ÷ 5cm = 0.6%.

[0096] (2) At a distance of 1.6m from the camera, the recognition accuracy error of the first tag in the X direction is 0.20cm ÷ 5cm = 4%; the recognition accuracy error of the first tag in the Y direction is 0.12cm ÷ 5cm = 2.4%.

[0097] The camera's altitude and angle measurement algorithms are based on the magnification / reduction / offset of the "+" labels in the field of view of two consecutive photos. Therefore, the theoretical error accuracy can be taken as the sum of the squares of the errors in the X and Y directions. Thus, the label position recognition error = √(x... 2 +y 2 Therefore, we can conclude that the theoretical minimum error should be 1.17% at a distance of 0.4m from the camera, and 4.66% at a distance of 1.6m. That is, with the same 1m increase in height, the theoretical measurement error is approximately ±1cm at a distance of 0.4m from the camera, and approximately ±5cm at a distance of 1.6m. The principle for calculating the accuracy error of the tilt angle is similar.

[0098] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A method for detecting the operating parameters of a forklift, characterized in that: A first set of labels is pre-set on the forks or fork carriage, and a second set of labels is pre-set on the outer mast or overhead guard; the initial pixel distance A0 of the first set of labels and the initial pixel distance B0 of the second set of labels are obtained in advance; the remaining steps are as follows: 1) Set the image acquisition module to take a top-down view of the forklift from the top of the inner mast; 2) Calculate the current pixel distance A1 of the first group of labels in the top view image and compare it with the initial pixel distance A0 to determine whether it has changed. If it has, calculate the distance value H1 between the current image acquisition module and the fork according to the first proportional relationship and proceed to step 3); if not, the final height value H of the current fork is the initial height H0 of the fork. 3) Determine whether the second set of labels appears in the top view image. If yes, calculate the current pixel distance B1 of the second set of labels in the top view image, and calculate the current height change value H2 of the inner mast according to the second proportional relationship, and proceed to step 4); if no, the final height value H of the current fork is H=X-H1, where X is the initial height value of the image acquisition module. 4) Calculate the final height value of the current fork: H = (X - H1) + H2; A third set of labels is pre-set on the upper surface of the connection between the vehicle body and the outer gantry, and the initial pixel distance C0 between the third set of labels and the first set of labels is obtained in advance; the method also includes the step of calculating the gantry tilt: calculate the pixel distance C1 between the third set of labels and the first set of labels in the top view image, and compare it with the initial pixel distance C0 to determine whether it has changed. If it has, the current gantry tilt angle θ is calculated according to the third proportional relationship. If not, the current gantry tilt angle θ = θ0, where θ0 is the initial value of the gantry tilt angle.

2. The method for detecting the working parameters of a forklift as described in claim 1, characterized in that: In step 2), the fork height value H1 is calculated based on the first proportional relationship, as follows: H1 = (Ha*A1) / (K1*A0); Where K1 is a preset coefficient, and Ha is the initial distance between the image acquisition module and the fork.

3. The method for detecting the working parameters of a forklift as described in claim 1, characterized in that: In step 3), the change in inner gantry height H2 is calculated based on the second proportional relationship, as follows: H2=(Hb*B1) / (K2*B0); Where K2 is a preset coefficient, and Hb is the initial distance between the image acquisition module and the top surface of the outer gantry.

4. The method for detecting the working parameters of a forklift as described in claim 1, characterized in that: In step 2), the first group of labels includes two first labels, and the current pixel distance A1 is the pixel distance between the two first labels; or the first group of labels includes one first label, and the current pixel distance A1 is the number of pixels of the first label.

5. The method for detecting the working parameters of a forklift as described in claim 1, characterized in that: In step 3), the second group of labels includes two second labels, and the current pixel distance B1 is the pixel distance between the two second labels; or the second group of labels includes one second label, and the current pixel distance B1 is the number of pixels of the second label.

6. The method for detecting the working parameters of a forklift as described in claim 1, characterized in that: The current gantry tilt angle θ is calculated based on the third proportional relationship, as follows: θ = (θ0 * C1) / (K3 * C0); Wherein, K3 is a preset coefficient.

7. The method for detecting the working parameters of a forklift as described in claim 1, characterized in that: The third group of labels includes a third label, and the pixel distance between the third group of labels and the first group of labels refers to the pixel distance between the third label and the midpoint of the first group of labels.

8. A forklift operating parameter detection device, characterized in that: include The first set of labels is placed on the forks or fork carriage; The second set of labels is placed on the outer gantry or roof support frame; The image acquisition module, installed on the top of the inner mast, is used to acquire a top view of the forklift. The comparison and judgment module is used to determine whether the current pixel distance A1 of the first group of labels has changed compared with the initial pixel distance A0 based on the top view image, thereby determining whether the fork has moved, and to determine whether the second group of labels appears in the top view image, thereby determining whether the inner mast has moved. The height calculation module is used to calculate the distance H1 between the current image acquisition module and the forks according to the first proportional relationship when the forks move; and to calculate the current height change H2 of the inner mast according to the second proportional relationship when the inner mast moves. And calculate the final height value of the current fork H = (X - H1) + H2, where X is the initial height value of the image acquisition module; The output module is used to output the final height value of the current fork H=X-H1 when the inner mast is not moving; and to output the final height value of the current fork H=(X-H1)+H2 when the inner mast moves. It also includes a third set of labels and a tilt angle calculation module, the third set of labels being set between the outer gantry and the vehicle body; the comparison and judgment module further includes determining whether the pixel distance C1 between the third set of labels and the first set of labels has changed from the initial pixel distance C0 based on the top view image, thereby determining whether the gantry is tilted; when the gantry tilts, the tilt angle calculation module calculates the current gantry tilt angle θ according to the third proportional relationship; the output module further includes outputting the current gantry tilt angle θ.

9. The forklift operating parameter detection device as described in claim 8, characterized in that: The first set of labels is set on the top surface of the vertical section of the fork or the top surface of the fork carriage; the second set of labels is set on the top surface of the outer mast or the top surface of the overhead guard.

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