Automatic assembly guiding method and system for large gear and small gear of engine

Abstract

The invention belongs to the technical field of engine assembly, and provides an automatic assembly guiding method and system for a large gear and a small gear of an engine. Nine-point calibration is conducted through a small gear camera and a mechanical arm, and visual coordinates of the small gear camera are converted into mechanical coordinates; according to the position and the gear angle of the pinion during camera modeling, the actual position deviation and the required rotation angle of the pinion are calculated; the method comprises the following steps: calculating a required rotation angle of a bull gear according to a gear angle during camera modeling of the bull gear, converting the required rotation angle of the bull gear into a servo motor pulse, and driving the bull gear to rotate to a reference position by a servo motor; the required rotation angle of the pinion is converted into the required rotation angle of the bull gear, then the required rotation angle of the bull gear is converted into servo motor pulses, and the servo motor drives the bull gear to rotate. According to the invention, the tooth profile characteristics of the gear can be accurately identified, high-precision automatic tooth identification is realized, the assembly quality of the engine fuel injection pump is effectively improved, the production efficiency is improved, and the labor cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine assembly, and particularly relates to an automatic assembly guiding method and system for a large gear and a small gear of an engine. Background Art

[0002] In the field of engine manufacturing, gear assembly is a key process that determines the performance of core components such as fuel injection pumps. The traditional assembly process has long relied on manual or semi-automatic operation modes. Skilled workers manually operate, using a manipulator to drive the small gear (fuel injection pump gear) to rotate for tooth recognition. This process has the following problems:

[0003] 1. The efficiency of manual operation is extremely low. It often takes a long time for a skilled worker to complete tooth recognition and preliminary assembly of a set of gears. In large-scale industrial production, this severely restricts the overall production capacity of the assembly line.

[0004] 2. Manual tooth recognition is greatly affected by subjective factors and is prone to human errors. According to relevant industry statistics, the defective rate of engines caused by manual tooth recognition errors is as high as 5%-10% in some factories. This not only causes waste of raw materials and labor costs, but also may have a negative impact on the enterprise's reputation due to product quality problems.

[0005] 3. There is an error between the rotation center of the manipulator and the center of the small gear, and it is impossible to ensure stable rotation around the gear center. This leads to frequent tooth recognition failures and damage to the gears, resulting in low production yield and waste of raw materials. Summary of the Invention

[0006] The purpose of the present invention is to overcome the existing defects and provide an automatic assembly guiding method and system for a large gear and a small gear of an engine.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] An automatic assembly guiding method for a large gear and a small gear of an engine includes:

[0009] Performing nine-point calibration using a small gear camera and a manipulator to convert the visual coordinates of the small gear camera into the mechanical coordinates of the manipulator;

[0010] Calculating the actual position deviation and the required rotation angle of the small gear according to the position and gear angle during the modeling of the small gear camera;

[0011] Calculating the required rotation angle of the large gear according to the gear angle during the modeling of the large gear camera, converting the required rotation angle of the large gear into servo motor pulses, and driving the large gear to rotate to the reference position by the servo motor;

[0012] The angular difference between the current position and the reference position of the pinion is converted into the rotation angle of the gear via the gear ratio calculation formula, and then the rotation angle of the gear is converted into servo motor pulses through a secondary calculation. The servo motor drives the gear to rotate to a position that mates with the pinion.

[0013] Furthermore, the nine-point calibration is performed using the pinion camera and the manipulator, and the visual coordinates of the pinion camera are converted into the mechanical coordinates of the manipulator, including:

[0014] The manipulator is used to pick up the pinion and sequentially move it to the positions of 9 points along an S-shaped trajectory within the field of view of the pinion camera, the mechanical coordinates of the 9 points are recorded, and the pinion camera captures images of the 9 positions.

[0015] The center positions of the 9 images are found using the circle-finding tool and recorded to obtain the pixel coordinates of the 9 points.

[0016] The pixel coordinates and mechanical coordinates of the 9 points are input into the calibration tool, and the calibration is completed.

[0017] Furthermore, the actual position deviation and the required rotation angle of the pinion are calculated based on the position and gear angle during the modeling of the pinion camera, including:

[0018] The reference center of the pinion is found and recorded in the image of the pinion reference position.

[0019] The current center of the pinion is found in the image detected by the pinion camera. By calculating with the reference center, the offsets in the X and Y directions of the current pinion are obtained, and the manipulator offsets according to the offsets in the X and Y directions when installing the pinion.

[0020] In the image of the pinion reference position, the circle-finding tool is used to find the center of the pinion, the template matching tool is used to locate the pinion scale line, and with the pinion scale line as the reference, the template matching tool is used to find the outer contour of the gear where the scale line is located. The center of the pinion and the center of the outer contour of the gear where the scale line is located are fitted into a reference line.

[0021] In the image detected by the pinion camera, the circle-finding tool is used to find the center of the pinion, the template matching tool is used to locate the pinion scale line, and with the pinion scale line as the reference, the template matching tool is used to find the outer contour of the gear where the scale line is located. The center of the pinion and the center of the outer contour of the gear where the scale line is located are fitted into a detection line.

[0022] The angle calculation tool for lines is used to calculate the angle between the current detection line and the reference line to obtain the angle by which the pinion needs to rotate.

[0023] Furthermore, the required rotation angle of the gear is calculated based on the gear angle during the modeling of the gear camera, including:

[0024] Find the center of the large gear in the reference position image of the large gear, locate the engraved line of the large gear, and use the engraved line of the large gear as a positioning reference to find the outer contour of the gear where the engraved line is located. Fit the center of the large gear and the center of the outer contour of the gear where the engraved line is located into a reference line.

[0025] Find the center of the large gear in the detection image of the large gear camera, locate the engraved line of the large gear, and use the engraved line of the large gear as a positioning reference to find the outer contour of the gear where the engraved line is located. Fit the center of the large gear and the center of the outer contour of the gear where the engraved line is located into a detection line.

[0026] Calculate the angle between the current detection line and the reference line to obtain the rotation angle required for the large gear.

[0027] Furthermore, when converting the rotation angle required for the large gear into servo motor pulses, the following formula is used for calculation:

[0028]

[0029] Where CW is the servo motor pulse, R2 is the rotation angle required for the large gear, Coef is the servo motor rotation coefficient, N2 is the number of teeth of the large gear, and N3 is the number of teeth of the crankshaft gear.

[0030] Furthermore, by using the gear ratio calculation formula to convert the rotation angle required for the small gear into the rotation angle required for the large gear, and then through secondary calculation to convert the rotation angle required for the large gear into servo motor pulses, it is expressed as:

[0031]

[0032] Where CW is the servo motor pulse, R1 is the rotation angle required for the small gear, Coef is the servo motor rotation coefficient, N1 is the number of teeth of the small gear, and N3 is the number of teeth of the crankshaft gear.

[0033] Another object of the present invention is to provide an automatic assembly guiding system for the large gear and small gear of an engine, including:

[0034] A manipulator for clamping and moving the fuel injection pump.

[0035] A servo motor connected to the engine crankshaft and driving the crankshaft to rotate, and the crankshaft drives the large gear to rotate.

[0036] A large gear camera for collecting images of the large gear.

[0037] A small gear camera for collecting images of the small gear.

[0038] A vision detection module for detecting the rotation angles required for the large gear and the small gear by using the images of the large gear and the small gear.

[0039] Combined with the above technical solutions, the beneficial effects of the present invention compared with the prior art are as follows:

[0040] Through the dual-camera image acquisition and precise image processing algorithm of the present invention, the tooth profile features of the gear can be accurately identified. By converting the rotation angle of the small gear into the rotation angle required for the large gear, and then through secondary calculation, the rotation angle required for the large gear is converted into servo motor pulses, realizing high-precision automatic tooth recognition. The pure vision accuracy can reach ±0.05 mm, and the overall accuracy of the equipment can reach ±0.1 mm. It solves the problem that there is an error between the rotation center of the manipulator and the center of the small gear, and it is impossible to ensure stable rotation around the gear center, resulting in frequent tooth recognition failures and gear damage, causing low production yield and waste of raw materials, effectively improving the assembly quality of the engine fuel injection pump; the automatic tooth recognition process greatly shortens the gear assembly time, improves production efficiency, and meets the needs of large-scale production; reduces the manual operation link, reduces labor costs, and at the same time avoids the influence of human errors on the assembly quality. The present invention solves the problems of low efficiency and easy occurrence of human errors in the traditional method of using manual tooth recognition, and meets the needs of modern large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0042] Figure 1 is a flowchart of the automatic assembly guiding method for the engine large gear and small gear provided by the embodiment of the present invention;

[0043] Figure 2 is a schematic diagram of the calibration image of the small gear camera provided by the embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of the reference position image of the small gear provided by the embodiment of the present invention;

[0045] Figure 4 is a schematic diagram of the reference position image of the large gear provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The following describes the preferred embodiments of the present invention with reference to the drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0047] Embodiment 1, as Figure 1 shown, is an embodiment of the automatic assembly guiding method for the engine large gear and small gear provided by the present invention, including:

[0048] S1: Perform nine-point calibration using the pinion camera and the manipulator, and convert the visual coordinates of the pinion camera into the mechanical coordinates of the manipulator;

[0049] S2: Calculate the actual position deviation and the required rotation angle of the pinion based on the position and gear angle during the pinion camera modeling;

[0050] S3: Calculate the required rotation angle of the large gear based on the gear angle during the large gear camera modeling, convert the required rotation angle of the large gear into servo motor pulses, and the servo motor drives the large gear to rotate to the reference position;

[0051] S4: Convert the angle difference between the current position and the reference position of the pinion into the rotation angle of the large gear through the gear ratio calculation formula, and then convert the rotation angle of the large gear into servo motor pulses through secondary calculation, and the servo motor drives the large gear to rotate to the position matching the pinion.

[0052] Specifically, in step S1, the specific steps to convert the visual coordinates of the pinion camera into the mechanical coordinates of the manipulator include:

[0053] The first step: Paste the marking paper on the gear surface.

[0054] The second step: The manipulator grabs the gear and moves it to 9 point positions in sequence along an S-shaped trajectory within the camera's field of view, records the mechanical coordinates of the 9 points, and the camera records the images of the 9 points.

[0055] The third step: Use the circle-finding tool to find the center positions of the marks in the 9 images and record them to obtain the pixel coordinates of the 9 points.

[0056] The fourth step: Input the pixel coordinates and mechanical coordinates corresponding to the 9 points into the calibration tool to complete the calibration.

[0057] The correspondence between the visual coordinate system (pixels) and the mechanical coordinate system (millimeters) is as follows:

[0058] Mechanical coordinate system = rotation coefficient * image coordinate + displacement coefficient

[0059] Expressed as:

[0060]

[0061] After expansion, the following formula is obtained:

[0062]

[0063]

[0064] It can be transformed into a problem of finding the coefficients of the following system of linear equations in three variables:

[0065]

[0066]

[0067] Are respectively represented as:

[0068]

[0069] and

[0070]

[0071] Among them, , are the coordinate parameters of the mechanical coordinate system, X and Y are the coordinate parameters of the image coordinate system, R is the rotation coefficient, M is the displacement coefficient, a, b, , represent the rotation coefficient parameters when converting the image coordinate system to the mechanical coordinate system, c, are the displacement coefficient parameters when converting the image coordinate system to the mechanical coordinate system. When we have at least three sets of corresponding image coordinate points and mechanical coordinate points during the application process, substituting them into the system of linear equations with three variables can find a, b, c, , , . , are the coordinate parameters of the first set of mechanical coordinate system, , are the coordinate parameters of the second set of mechanical coordinate system, , are the coordinate parameters of the third set of mechanical coordinate system, , are the coordinate parameters of the first set of image coordinate system, , are the coordinate parameters of the second set of image coordinate system, , are the coordinate parameters of the third set of image coordinate system.

[0072] According to the above formula, at least 3 points are required to find the coefficients of the matrix transformation. However, to improve the accuracy and reduce errors, generally 9 points are selected for calculation.

[0073] Such as Figure 2 shown, it is an embodiment of the calibration image of the pinion camera, and the calibration error is 0.94 pixels. The calibration data used is as follows in the table, and a total of nine sets of data are used for calibration.

[0074] Table 1 Calibration Data

[0075] Position Uncorrected X Uncorrected Y Original Corrected X Original Corrected Y 1 1846.7 1702.8 335.4 -389.26 2 1057.55 1684 286.37 -388.76 3 256.73 1658.26 236.67 -388.46 4 278.18 859.623 236.27 -437.96 5 1086.71 889.519 286.47 -438.06 6 1883.88 916.965 336.07 -438.16 7 1909.86 275.552 336.23 -477.87 8 1109.45 238.476 286.6 -478.35 9 298.042 208.885 236.15 -478.34

[0076] Such asFigure 3 As shown, it is the reference position image of the pinion gear. In step S2, according to the position and gear angle during the pinion gear camera modeling, the actual position deviation and the required rotation angle of the pinion gear are calculated, specifically including:

[0077] The first step: Use the circle finding tool in the reference position image of the pinion gear to find the center of the pinion gear and record it.

[0078] The second step: Use the circle finding tool in the pinion gear camera detection image to find the center of the current pinion gear. By calculating with the reference center, the offsets in the X and Y directions of the current pinion gear are obtained, and the manipulator offsets according to the offsets in the X and Y directions when installing the pinion gear.

[0079] The third step: Use the circle finding tool in the reference position image of the pinion gear to find the center of the pinion gear. Use the template matching tool to locate the pinion gear scale line. Using the pinion gear scale line as a reference, use the template matching tool to find the outer contour of the gear where the scale line is located. Fit a reference line (such as Figure 3 A in) between the center of the pinion gear and the center of the outer contour of the gear where the scale line is located through the point-to-point straight line tool.

[0080] The third step: Use the circle finding tool in the pinion gear camera detection image to find the center of the pinion gear. Use the template matching tool to locate the pinion gear scale line. Using the pinion gear scale line as a reference, use the template matching tool to find the outer contour of the gear where the scale line is located. Fit a detection line (such as Figure 3 B in) between the center of the pinion gear and the center of the outer contour of the gear where the scale line is located through the point-to-point straight line tool.

[0081] The fifth step: Use the line-to-line angle calculation tool to calculate the angle between the current detection line and the reference line to obtain the required rotation angle of the pinion gear.

[0082] Such as Figure 4 As shown, it is the reference position image of the large gear. In step S3, according to the gear angle during the large gear camera modeling, the required rotation angle of the large gear is calculated, and the required rotation angle of the large gear is converted into servo motor pulses, and the servo motor drives the large gear to rotate, specifically including:

[0083] The first step: Use the circle finding tool in the reference position image of the large gear to find the center of the large gear. Use the template matching tool to locate the large gear scale line. Using the large gear scale line as a reference, use the template matching tool to find the outer contour of the gear where the scale line is located. Fit a reference line (such as Figure 4 C in) between the center of the large gear and the center of the outer contour of the gear where the scale line is located through the point-to-point straight line tool.

[0084] Step 2: Use the circle-finding tool to find the center of the large gear in the detected image of the large gear camera. Use the template matching tool to locate the engraved line of the large gear. With the engraved line of the large gear as the reference, use the template matching tool to find the outer contour of the gear where the engraved line is located. Fit a detection line by connecting the center of the large gear and the center of the outer contour of the gear where the engraved line is located through the point-to-point straight line tool (such as Figure 4 D in

[0085] ).

[0086] Step 3: Use the line-to-line angle calculation tool to calculate the angle between the current detection line and the reference line to obtain the angle that the large gear needs to rotate.

[0087] The algorithm used in this step is as follows:

[0088] Servo motor pulse = Angle that the large gear needs to rotate × Servo motor rotation coefficient × (Number of teeth of the large gear ÷ Number of teeth of the crankshaft gear)

[0089] Expressed as:

[0090]

[0091] Where, is the servo motor pulse, is the angle that the large gear needs to rotate, is the servo motor rotation coefficient, is the number of teeth of the large gear, is the number of teeth of the crankshaft gear.

[0092] In step S4, the angle difference between the current position and the reference position of the small gear is converted into the rotation angle of the large gear through the gear ratio calculation formula, and then the rotation angle of the large gear is converted into the servo motor pulse through secondary calculation, specifically including:

[0093] Step 1: Convert the angle of the small gear into the angle of the large gear through the formula.

[0094] Step 2: Convert the angle of the large gear into the rotation pulse of the servo motor through the formula.

[0095] The algorithm used in this step is as follows:

[0096] 1. Formula for converting the angle of the small gear into the angle of the large gear:

[0097] Angle that the large gear needs to rotate = Angle that the small gear needs to rotate * (Number of teeth of the small gear ÷ Number of teeth of the large gear)

[0098] Expressed as:

[0099]

[0100] 2. Formula for converting the angle of the large gear into servo motor pulses:

[0101] Servo motor pulses = Angle that the large gear needs to rotate × Servo motor rotation coefficient × (Number of teeth of the large gear ÷ Number of teeth of the crankshaft gear)

[0102] Expressed as:

[0103]

[0104] Combining and simplifying the two formulas gives:

[0105] Servo motor pulses = Angle that the small gear needs to rotate × Servo motor rotation coefficient × (Number of teeth of the small gear ÷ Number of teeth of the crankshaft gear)

[0106] Expressed as:

[0107] .

[0108] Wherein, is the angle that the small gear needs to rotate, is the angle that the large gear needs to rotate, is the number of teeth of the small gear, is the number of teeth of the large gear, is the number of teeth of the crankshaft gear, is the servo motor pulses, is the servo motor rotation coefficient.

[0109] Example 2. The present invention provides an automatic assembly guiding system for the large gear and small gear of an engine, including:

[0110] A manipulator for clamping the fuel injection pump (small gear) to the photographing position of the small gear camera for photographing processing, and substituting the small gear offset (X - direction offset, Y - direction offset) given by the small gear camera into the small gear installation position and making a position offset.

[0111] A servo motor connected to the engine crankshaft and driving the crankshaft to rotate, and the crankshaft drives the large gear to rotate;

[0112] A large gear camera for collecting images of the large gear;

[0113] A small gear camera for collecting images of the small gear;

[0114] A vision detection module for detecting the angles that the large gear and the small gear need to rotate by using the large gear image and the small gear image.

[0115] In the embodiments of the present invention, a servo motor is connected to the engine crankshaft. By driving the crankshaft to rotate, the crankshaft gear drives the large gear to rotate. Ensure that the angle of the small gear remains constant, and convert the required rotation angle of the small gear into the corresponding rotation angle of the large gear, so as to achieve the precise meshing and installation positioning of the gear system.

[0116] The working process of the automatic assembly guiding system for the engine large gear and small gear provided by the embodiments of the present invention includes:

[0117] The first step: The manipulator grabs the small gear, and the servo motor is connected to the engine crankshaft.

[0118] The second step: After the large gear camera takes a picture, the vision detection module calculates, converts the angle of the large gear into servo motor pulses, and the servo motor drives the large gear to rotate.

[0119] The third step: The manipulator grabs the fuel injection pump (small gear) to the position where the small gear camera takes pictures, the small gear camera takes pictures, and the vision detection module calculates.

[0120] The fourth step: The vision detection module calculates to convert the required rotation angle of the small gear into the angle of the large gear, and then converts the required rotation angle of the large gear into servo motor pulses, and the servo motor drives the large gear to rotate.

[0121] The fifth step: The manipulator performs tooth recognition and installation of the small gear according to the result sent by the vision detection module.

[0122] It should be understood that although the steps in the flowcharts of the embodiments of the present invention are shown in sequence according to the indication of the arrows, these steps do not necessarily need to be executed in the order indicated by the arrows. Unless there is a clear indication in the present invention, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in each embodiment may include multiple sub-steps or multiple stages. These sub-steps or stages do not necessarily need to be executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages does not necessarily need to be sequential, but can be executed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

[0123] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided by the present invention can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0124] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automatic assembly guiding method for the large gear and small gear of an engine, characterized in that The method includes: Performing nine-point calibration using a pinion camera and a manipulator, and converting the visual coordinates of the pinion camera into the mechanical coordinates of the manipulator; Calculating the actual position deviation and the required rotation angle of the pinion based on the position and gear angle during the pinion camera modeling; Calculating the required rotation angle of the large gear based on the gear angle during the large gear camera modeling, converting the required rotation angle of the large gear into servo motor pulses, and driving the large gear to rotate to the reference position by the servo motor; Converting the angle difference between the current position and the reference position of the pinion into the rotation angle of the large gear through the gear ratio calculation formula, and then converting the rotation angle of the large gear into servo motor pulses through secondary calculation, and driving the large gear to rotate to the position for mating with the pinion by the servo motor.

2. The automatic assembly guiding method for the engine large gear and small gear according to claim 1, wherein, The performing nine-point calibration using a pinion camera and a manipulator, and converting the visual coordinates of the pinion camera into the mechanical coordinates of the manipulator includes: Using the manipulator to pick up the pinion and sequentially move it to 9 point positions in the field of view of the pinion camera along an S-shaped trajectory, recording the mechanical coordinates of the 9 points, and the pinion camera collecting images of the 9 positions; Using a circle-finding tool to find the center positions of the 9 images and recording them to obtain the pixel coordinates of the 9 points; Inputting the pixel coordinates and mechanical coordinates of the 9 points into the calibration tool to complete the calibration.

3. The automatic assembly guiding method for the large gear and small gear of the engine according to claim 1, characterized in that, The calculating the actual position deviation and the required rotation angle of the pinion based on the position and gear angle during the pinion camera modeling includes: Finding and recording the reference center of the pinion in the pinion reference position image; Finding the current pinion center in the pinion camera detection image, calculating the offsets in the X and Y directions of the current pinion by calculating with the reference center, and the manipulator offsetting according to the offsets in the X and Y directions when installing the pinion; Using a circle-finding tool to find the pinion center in the pinion reference position image, using a template matching tool to locate the pinion scale line, using the template matching tool to find the gear outer contour where the scale line is located with the pinion scale line as the positioning, and fitting the pinion center and the center of the gear outer contour where the scale line is located into a reference line; Using a circle-finding tool to find the pinion center in the pinion camera detection image, using a template matching tool to locate the pinion scale line, using the template matching tool to find the gear outer contour where the scale line is located with the pinion scale line as the positioning, and fitting the pinion center and the center of the gear outer contour where the scale line is located into a detection line; Using a line-to-line angle calculation tool to calculate the angle between the current detection line and the reference line to obtain the required rotation angle of the pinion.

4. The automatic assembly guiding method for the engine large gear and small gear according to claim 1, characterized in that The calculating the required rotation angle of the large gear based on the gear angle during the large gear camera modeling includes: Finding the large gear center in the large gear reference position image, positioning the large gear scale line, using the template matching tool to find the gear outer contour where the scale line is located with the large gear scale line as the positioning, and fitting the large gear center and the center of the gear outer contour where the scale line is located into a reference line; Finding the large gear center in the large gear camera detection image, positioning the large gear scale line, finding the gear outer contour where the scale line is located with the large gear scale line as the positioning, and fitting the large gear center and the center of the gear outer contour where the scale line is located into a detection line; Calculate the angle between the current detection line and the reference line to obtain the rotation angle required for the large gear.

5. The automatic assembly guiding method for the large gear and small gear of the engine according to claim 1, characterized in that, In the conversion of the rotation angle required for the large gear into servo motor pulses, the following formula is used for calculation: ； Where CW is the servo motor pulse, R2 is the rotation angle required for the large gear, Coef is the servo motor rotation coefficient, N2 is the number of teeth of the large gear, and N3 is the number of teeth of the crankshaft gear.

6. The automatic assembly guiding method for the engine large gear and small gear according to claim 1, characterized in that, The rotation angle required for the small gear is converted into the rotation angle required for the large gear through the gear ratio calculation formula, and then the rotation angle required for the large gear is converted into servo motor pulses through secondary calculation, which is expressed as: ； Where CW is the servo motor pulse, R1 is the rotation angle required for the small gear, Coef is the servo motor rotation coefficient, N1 is the number of teeth of the small gear, and N3 is the number of teeth of the crankshaft gear.

7. An automatic assembly guiding system for the large gear and small gear of an engine, characterized in that, The system includes: A manipulator for clamping and moving the fuel injection pump. A servo motor connected to the engine crankshaft and driving the crankshaft to rotate, and the crankshaft drives the large gear to rotate. A large gear camera for collecting images of the large gear. A small gear camera for collecting images of the small gear. A vision detection module for detecting the rotation angles required for the large gear and the small gear using the large gear image and the small gear image.

Images