Locomotive cylinder head cross arm guide rod installation accuracy detection system and method

Abstract

The present invention provides a system and method for detecting the installation accuracy of a cross arm guide rod of a locomotive cylinder head. The present invention includes a positioning detection platform, an image acquisition system, a main control system and a driving device, wherein the driving device is connected to the image acquisition system, and the main control system is respectively connected to the image acquisition system and the driving device, the positioning detection platform is used to place the cross arm guide rod of the cylinder head to be detected, the driving device is used to drive the image acquisition component to move to the top of the cross arm guide rod of the cylinder head to be detected under the control of the main control system, the image acquisition system is used to capture the original image and transmit the original image to the main control system, the main control system is used to pre-process and extract features of the image, and judge whether the deflection angle of the keyway of the cross arm guide rod exceeds the qualified range based on the preset standard. Through the detection system, the present invention realizes automated detection based on a computer and an image acquisition component, improves the inspection efficiency, and greatly reduces the false detection rate; at the same time, the automated detection method reduces the labor cost.

Description

Technical Field

[0001] The invention relates to the technical field of installation of a cross arm guide rod of a locomotive cylinder cover, and in particular to a system and method for detecting the installation accuracy of a cross arm guide rod of a locomotive cylinder cover. Background Art

[0002] In the early stage of engine technology development, dual-valve technology (single-inlet, single-row) was generally used. At this stage, the opening and closing of the valves were generally directly controlled by rocker arms (connecting rods), and each rocker arm (connecting rod) could only control one valve. With the development of science and technology, the continuous progress of engine technology, and the requirements of environmental protection, multi-valve technology (multi-inlet, multi-row) has emerged. The emergence of multi-valve technology requires the rocker arm to be able to control two (or more) valves of the same name at the same time in terms of structure. At this time, the valve cross arm appeared. The valve cross arm is a part that connects two (or more) valve stems of the same name and connects to the rocker arm, so that the rocker arm can operate two or more valves with the help of the valve cross arm.

[0003] like Figure 1 As shown in the figure, the valve cross arm used on the Dongfeng 4 locomotive engine connects two valves of the same name, and the valve guide rod is installed at the corresponding position on the cylinder head. A positioning guide hole is also set at the center of the valve cross arm. A cross arm guide rod is installed on the cylinder head. The cross arm guide rod plays a guiding and positioning role for the valve cross arm; the cross arm guide rod is fixedly installed on the cylinder head by interference connection. A guide key is set along the axial direction in the positioning guide hole of the valve cross arm, and a keyway matching the guide key is set on the corresponding cross arm guide rod. The rotation of the valve cross arm is limited by the joint action of the guide key and the keyway. During the assembly of the engine, the installation accuracy of the cross arm guide rod and the valve guide on both sides should ensure that the valve and the valve cross arm can move smoothly up and down in a straight line. Since the cross arm guide rod, the valve guide and the cylinder head are connected by interference, it is necessary to detect the position of the cross arm guide rod keyway to ensure the smooth operation of the valve cross arm and the valve after the valve guide and the cross arm guide rod are installed. At the same time, the keyway of the cross arm guide rod is installed too offset, which affects the smoothness of the valve cross arm and the valve linear movement. Therefore, it is necessary to detect the slot position of the installed cross arm guide rod.

[0004] At present, in order to meet the above requirements, a customized cross arm guide rod and valve guide installation tool is usually used for inspection on the engine assembly line, such as Figure 1As shown. The tool is customized according to the engine model and is strictly based on the optimal theoretical installation position of the cross arm guide rod and the valve guides on both sides. The guide sleeve (with a guide key inside the sleeve) corresponding to the cross arm guide rod and the guide column corresponding to the valve guide are set on the tool. The valve guide and cross arm guide rod are installed on the cylinder head using the tool, and then the position of the cross arm guide rod keyway is checked with the tool. During the inspection, the guide sleeve and guide column of the tool are connected with the corresponding cross arm guide rod and the two valve sleeves, and then the worker shakes the tool by hand to feel whether the installation of the cross arm guide rod meets the requirements.

[0005] The prior art has the following disadvantages:

[0006] 1. The detection method provided by the prior art requires workers to use detection tools for manual inspection, which has low operating efficiency.

[0007] 2. The installation tools used are heavy, and long-term work can easily cause worker fatigue, thus affecting the test results.

[0008] 3. When using existing technology for testing, the test results have no quantitative standards and can only rely on the workers' hand feeling. The test results of this method are often more dependent on the individual skills and experience of workers, and there is a high probability of accidental false detection (false detection, that is, detecting unqualified products as qualified products). Summary of the invention

[0009] In view of the above technical problems, a system and method for detecting the installation accuracy of a cross arm guide rod of a locomotive cylinder head is provided. The technical means adopted by the present invention are as follows:

[0010] A locomotive cylinder head cross arm guide rod installation accuracy detection system comprises a positioning detection platform, an image acquisition system, a main control system and a driving device, wherein the driving device is connected to the image acquisition system, and the main control system is respectively connected to the image acquisition system and the driving device, the positioning detection platform is used to place the cylinder head cross arm guide rod to be detected, the driving device is used to drive the image acquisition component to move to the top of the cross arm guide rod of the cylinder head to be detected under the control of the main control system, the image acquisition system is used to capture the original image and transmit the original image to the main control system, the main control system is used to pre-process and extract features of the image, and judge whether the deflection angle of the cross arm guide rod keyway exceeds the qualified range based on the preset standard.

[0011] Furthermore, the image acquisition system is fixedly installed on the driving device, and the image acquisition system includes an industrial camera and an industrial lens, a bracket and a light source installed on the industrial camera; one end of the bracket is fixedly connected to the driving device, and the light source is installed on the other end. A photo-taking hole is reserved at the end of the bracket where the light source is installed, and the industrial camera is fixed on the inner side of the bracket. The industrial lens faces the light source and is coaxially arranged with the photo-taking hole.

[0012] Furthermore, the light source comprises an annular light source, and the annular light source is coaxially arranged with a reserved photographing hole on the bracket, that is, the industrial lens is coaxially installed with the annular light source.

[0013] Furthermore, the driving device includes a three-coordinate robot, which is arranged directly above the positioning detection platform, the image acquisition system is installed on the mover of the three-coordinate robot, and the light source is arranged vertically downward.

[0014] Furthermore, the driving device includes a mechanical arm, and the image acquisition system is installed at the end of the mechanical arm.

[0015] Furthermore, it also includes a light sensor, which is connected to the main control system. The light sensor is used to collect environmental brightness information and transmit it to the main control system. The main control system adjusts the brightness of the light source according to the brightness information, thereby changing the light brightness of the detection environment.

[0016] Furthermore, the main control unit includes a control unit, an image storage unit, a preprocessing unit and an image analysis unit. The image preprocessing unit is used to preprocess the received original image and filter out the entire area of ​​the top of the cross arm guide rod; the image storage unit is used to store the preprocessed image; the image analysis unit analyzes and calculates the preprocessed image and completes the judgment of the detection result.

[0017] Furthermore, the analysis process of the image analysis unit specifically includes:

[0018] Use the ring measurement operator to extract the straight edge pair perpendicular to the measured ring arc, and at the same time extract the connecting center line corresponding to the two valve guides and record it as L 1 , the straight edge pair is the projection of the two side walls of the keyway on the cross arm guide rod when looking down at the cross arm guide rod;

[0019] Fit two circles, one large and one small. The large circle is the circle corresponding to the outer arm of the cross arm guide rod, and its radius is recorded as R; the small circle is the largest inscribed circle in the area corresponding to the cross arm guide rod, and its radius is recorded as r;

[0020] R 0 As the radius, fit a circle concentric with the large circle, where R 0 The value of is calculated by the following formula:

[0021]

[0022] The concentric circles of the fitted large circle intersect with the straight edge pairs respectively, thus obtaining two points denoted as O 1 and O 2 ; Calculate the line segment O 1 O 2The coordinates of the midpoint of the circle are calculated and recorded as A. At the same time, the coordinates of the center C of the small circle are calculated, and the straight line where points A and C are located is recorded as L 2 , and then fit L 2 The equation of the line;

[0023] According to the straight line L 1 and L 2 The angle between the two is calculated using the equation, which is the deflection angle of the keyway of the cross arm guide rod.

[0024] The present invention also discloses a method for detecting the installation accuracy of a cross arm guide rod of a locomotive cylinder cover, comprising the following steps:

[0025] Step 1: After the cylinder head is installed with the valve guide and the cross arm guide rod, the cylinder head is placed on the positioning detection platform. The system detects the cylinder head, and the main control system issues a command. The image acquisition component moves to the preset image acquisition position under the action of the drive device, and then the main control system adjusts the brightness of the light source. When the lighting conditions are optimal, the control unit issues a photo-taking command. After receiving the command, the industrial camera starts to take pictures and transmits the original image to the image storage module of the main control system;

[0026] Step 2: The image pre-processing unit pre-processes the received original image, filters out the entire area on the top of the cross arm guide rod, and stores the pre-processed image in the image storage unit;

[0027] Step 3: The image analysis unit extracts features from the preprocessed image and uses the ring measurement operator to extract the straight edge pair perpendicular to the measured ring arc. At the same time, the connecting center line corresponding to the two valve guides is extracted and recorded as L 1 ;

[0028] The main control system fits two circles, one large and one small. The large circle is the circle corresponding to the outer arm of the cross arm guide rod, and its radius is recorded as R; the small circle is the largest inscribed circle in the area corresponding to the cross arm guide rod, and its radius is recorded as r.

[0029] Step 4: The image analysis unit uses R 0 As the radius, a circle concentric with the large circle is fitted, where the value of R0 is calculated by the following formula:

[0030]

[0031] The concentric circles of the fitted large circle intersect with the straight edge pairs extracted in step 3 respectively, thus obtaining two points denoted as O 1 and O 2 ; Calculate the line segment O 1 O 2 The coordinates of the midpoint of the circle are calculated and recorded as A. At the same time, the coordinates of the center C of the small circle are calculated, and the straight line where points A and C are located is recorded as L 2 , and then fit L 2The equation of the line;

[0032] Step 5: According to the straight line L 1 and L 2 The angle between the two is calculated by the equation, which is the deflection angle of the keyway of the cross arm guide rod; if the deflection angle exceeds the qualified range, it is judged as unqualified; the unqualified cylinder head is transferred to the manual table for correction processing, if the deflection angle does not exceed the qualified range, the cylinder head is qualified, and the qualified cylinder head is transferred to the next process.

[0033] Furthermore, before step 1, the method further includes the following steps:

[0034] Step 0: Adjust the imaging focal length, and then lock the imaging focal length;

[0035] In step 2, image preprocessing specifically includes the following steps: first, image filling is performed, then dilation processing and image erosion are performed, and then the area screening operator is used to screen the entire area of ​​the outer contour of the top slot of the cross arm guide rod, and then the filling and closing operators are used to fill the gaps and optimize the contour to obtain the entire area.

[0036] Compared with the prior art, the present invention realizes automated detection through the detection system based on computers and image acquisition components (visual technology), which significantly improves the inspection efficiency and greatly reduces the false detection rate; at the same time, the automated detection method reduces labor costs.

[0037] At the same time, the present invention provides a non-contact detection method for the position of the cross arm guide rod slot, which reduces the risk factor of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 A top view of the cylinder cross arm.

[0040] Figure 2 This is a system diagram of the present invention.

[0041] Figure 3 Schematic diagram of the structure of the image acquisition component in an embodiment of the present invention.

[0042] Figure 4 This is a front view of the image acquisition component structure in an embodiment of the present invention.

[0043] Figure 5Schematic diagram of data analysis principle in an embodiment of the present invention.

[0044] In the figure: 1. bracket; 2. ring light source; 3. industrial camera; 4. industrial lens. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] An embodiment of the present invention discloses a locomotive cylinder head cross arm guide rod installation accuracy detection system, including a positioning detection platform, an image acquisition system, a main control system and a driving device, wherein the driving device is connected to the image acquisition system, and the main control system is respectively connected to the image acquisition system and the driving device, the positioning detection platform is used to place the cylinder head cross arm guide rod to be detected, the driving device is used to drive the image acquisition component to move to the top of the cross arm guide rod of the cylinder head to be detected under the control of the main control system, the image acquisition system is used to capture the original image and transmit the original image to the main control system, the main control system is used to preprocess and extract features of the image, and judge whether the deflection angle of the cross arm guide rod keyway exceeds the qualified range based on preset standards. In this embodiment, the main control unit includes a control unit, an image storage unit, a preprocessing unit and an image analysis unit. The control unit is used to send instructions to the control drive device and the image acquisition component, and receive feedback information from the two. The image preprocessing unit is used to preprocess the received original image and filter out the entire area of ​​the top of the cross arm guide rod; the image storage unit is used to store the preprocessed image; the image analysis unit analyzes and calculates the preprocessed image and completes the judgment of the detection result. In this embodiment, the main control unit is a computer.

[0047] like Figure 3 , Figure 4 As shown, the image acquisition system is fixedly mounted on the driving device, and the image acquisition system includes an industrial camera 3 and an industrial lens 4 mounted on the industrial camera, a bracket 1 and a light source; one end of the bracket is fixedly connected to the driving device, and the light source is mounted on the other end. A photo hole is reserved at one end of the bracket where the light source is mounted, and the industrial camera is fixed on the inner side of the bracket, and the industrial lens faces the light source and is coaxially arranged with the photo hole. In this embodiment, the pixel of the industrial camera is 8 million; the pixel of the industrial lens is also 8 million. A positioning part for positioning the cylinder head is arranged above the positioning detection platform, and on the positioning detection platform, the cylinder head guide rod cross arm is placed horizontally with the cylinder head facing upward.

[0048] The light source comprises an annular light source 2, and the annular light source is coaxially arranged with a reserved photographing hole on the bracket, that is, the industrial lens is coaxially installed with the annular light source.

[0049] As one optional implementation, the driving device includes a three-coordinate robot, the three-coordinate robot is arranged directly above the positioning detection platform, the image acquisition system is installed on the mover of the three-coordinate robot, and the light source is arranged vertically downward.

[0050] In order to increase the flexibility and adaptability of the detection system, as one optional implementation, the driving device includes a mechanical arm, the image acquisition system is installed at the end of the mechanical arm, and the mechanical arm drives the image acquisition component to complete the photo positioning. The mechanical arm can be a six-axis serial robot, a UR mechanical arm, etc.

[0051] It also includes a light sensor, which is connected to the main control system. The light sensor is used to collect environmental brightness information and transmit it to the main control system. The main control system adjusts the brightness of the light source according to the brightness information, thereby changing the light brightness of the detection environment.

[0052] The analysis process of the image analysis unit specifically includes:

[0053] Use the ring measurement operator to extract the straight edge pair perpendicular to the measured ring arc, and at the same time extract the connecting center line corresponding to the two valve guides and record it as L 1 , the straight edge pair is the projection of the two side walls of the keyway on the cross arm guide rod when looking down at the cross arm guide rod;

[0054] Fit two circles, one large and one small. The large circle is the circle corresponding to the outer arm of the cross arm guide rod, and its radius is recorded as R; the small circle is the largest inscribed circle in the area corresponding to the cross arm guide rod, and its radius is recorded as r;

[0055] R 0 As the radius, fit a circle concentric with the large circle, where R 0 The value of is calculated by the following formula:

[0056]

[0057] The concentric circles of the fitted large circle intersect with the straight edge pairs respectively, thus obtaining two points denoted as O 1 and O 2 ; Calculate the line segment O 1 O 2 The coordinates of the midpoint of the circle are calculated and recorded as A. At the same time, the coordinates of the center C of the small circle are calculated, and the straight line where points A and C are located is recorded as L 2 , and then fit L 2 The equation of the line;

[0058] According to the straight line L 1 and L 2 The angle between the two is calculated by the equation, which is the deflection angle of the keyway of the cross arm guide rod. If the deflection angle exceeds the qualified range (in this embodiment, it is stipulated that it shall not be greater than 0.13°), it is judged as unqualified; the unqualified cylinder head is transferred to the manual table for correction processing, and if the deflection angle does not exceed the qualified range, the cylinder head is qualified, and the qualified cylinder head is transferred to the next process.

[0059] The present invention also discloses a method for detecting the installation accuracy of a cross arm guide rod of a locomotive cylinder cover, comprising the following steps:

[0060] Step 1: After the cylinder head is installed with the valve guide and the cross arm guide rod, the cylinder head is placed on the positioning detection platform. The system detects the cylinder head, and the main control system issues a command. The image acquisition component moves to the preset image acquisition position under the action of the drive device, and then the main control system adjusts the brightness of the light source. When the lighting conditions are optimal, the control unit issues a photo-taking command. After receiving the command, the industrial camera starts to take pictures and transmits the original image to the image storage module of the main control system;

[0061] Under the action of the driving device, the image acquisition component moves to the preset image acquisition position. Specifically, under the action of the control unit, the driving device drives the image acquisition component to move to just above the cross arm guide rod of the cylinder head to be tested, and the industrial lens is coaxial with the cross arm guide rod.

[0062] Step 2: The image pre-processing unit pre-processes the received original image, filters out the entire area on the top of the cross arm guide rod, and stores the pre-processed image in the image storage unit;

[0063] Step 3: The image analysis unit extracts features from the preprocessed image and uses the ring measurement operator to extract the straight edge pair perpendicular to the measured ring arc. At the same time, the connecting center line corresponding to the two valve guides is extracted and recorded as L 1 ;

[0064] The main control system fits two circles, one large and one small. The large circle is the circle corresponding to the outer arm of the cross arm guide rod, and its radius is recorded as R; the small circle is the largest inscribed circle in the area corresponding to the cross arm guide rod, and its radius is recorded as r.

[0065] Step 4: The image analysis unit uses R 0 As the radius, a circle concentric with the large circle is fitted, where the value of R0 is calculated by the following formula:

[0066]

[0067] The concentric circles of the fitted large circle intersect with the straight edge pairs extracted in step 3 respectively, thus obtaining two points denoted as O 1 and O2 ; Calculate the line segment O 1 O 2 The coordinates of the midpoint of the circle are calculated and recorded as A. At the same time, the coordinates of the center C of the small circle are calculated, and the straight line where points A and C are located is recorded as L 2 , and then fit L 2 The equation of the line;

[0068] Step 5: According to the straight line L 1 and L 2 The angle between the two is calculated by the equation, which is the deflection angle of the keyway of the cross arm guide rod; if the deflection angle exceeds the qualified range, it is judged as unqualified; the unqualified cylinder head is transferred to the manual table for correction processing, if the deflection angle does not exceed the qualified range, the cylinder head is qualified, and the qualified cylinder head is transferred to the next process.

[0069] Before step 1, the following steps are also included:

[0070] Step 0, adjust the imaging focal length, and then lock the imaging focal length; specifically, the system should be debugged before using it, and the debugging operation mainly involves adjusting the imaging focal length to ensure that the image acquisition component can obtain high-quality images, and then lock the imaging focal length; the imaging focal length is manually adjusted by the operator; during the operation, in order to obtain high-quality images, it is necessary to adjust the light brightness, and the light brightness is controlled by a computer. A light sensor (brightness sensor) is set in the system, and the light sensor is connected to the computer (signal connection). The light sensor transmits the collected brightness information to the computer, and the computer adjusts the brightness of the light source according to the brightness information, thereby changing the light brightness of the detection environment.

[0071] Among them, in step 2, image preprocessing specifically includes the following steps: first, image filling is performed, then dilation processing and image erosion are performed, and then the area screening operator is used to screen the entire area of ​​the outer contour of the top slot of the cross arm guide rod, and then the filling and closing operators are used to fill the gaps and optimize the contour to obtain the entire area.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A locomotive cylinder head cross arm guide rod installation accuracy detection system, characterized in that: It includes a positioning detection platform, an image acquisition system, a main control system and a driving device, wherein the driving device is connected to the image acquisition system, and the main control system is respectively connected to the image acquisition system and the driving device, wherein the positioning detection platform is used to place the cylinder head cross arm guide rod to be detected, and the driving device is used to drive the image acquisition component to move to the top of the cross arm guide rod of the cylinder head to be detected under the control of the main control system, wherein the image acquisition system is used to acquire the original image and transmit the original image to the main control system, and wherein the main control system is used to pre-process and extract features of the image, and judge whether the deflection angle of the keyway of the cross arm guide rod exceeds the qualified range based on the preset standard; The analysis process of the image analysis unit specifically includes: A pair of straight edges perpendicular to the measuring circular arc is extracted using a circular ring measurement operator, and the connecting center line corresponding to the two valve guides is extracted and recorded as L1. The pair of straight edges is the projection of the two side walls of the keyway on the cross arm guide rod when looking down at the cross arm guide rod; Fit two circles, one large and one small. The large circle is the circle corresponding to the outer arm of the cross arm guide rod, and its radius is recorded as R; the small circle is the largest inscribed circle in the area corresponding to the cross arm guide rod, and its radius is recorded as r; With R0 as the radius, a circle concentric with the large circle is fitted, where the value of R0 is calculated by the following formula: The concentric circles of the fitted large circle intersect with the straight edge pair respectively, thereby obtaining two points denoted as O1 and O2; the coordinates of the midpoint of the line segment O1O2 are calculated and denoted as A, and at the same time, the coordinates of the center C of the small circle are calculated, and the straight line where the points A and C are located is denoted as L2, and then the straight line equation of L2 is fitted; The angle between the straight lines L1 and L2 is calculated based on their equations, and this angle is the deflection angle of the keyway of the cross arm guide rod.

2. The locomotive cylinder head cross arm guide rod installation accuracy detection system according to claim 1, characterized in that: The image acquisition system is fixedly installed on the driving device, and the image acquisition system includes an industrial camera and an industrial lens, a bracket and a light source installed on the industrial camera; one end of the bracket is fixedly connected to the driving device, and the light source is installed on the other end. A photo-taking hole is reserved at the end of the bracket where the light source is installed, the industrial camera is fixed on the inner side of the bracket, and the industrial lens faces the light source and is coaxially arranged with the photo-taking hole.

3. The locomotive cylinder head cross arm guide rod installation accuracy detection system according to claim 2, characterized in that: The light source comprises an annular light source, and the annular light source is coaxially arranged with a reserved photographing hole on the bracket, that is, the industrial lens is coaxially installed with the annular light source.

4. The locomotive cylinder head cross arm guide rod installation accuracy detection system according to claim 2, characterized in that: The driving device comprises a three-coordinate robot, which is arranged directly above the positioning detection platform. The image acquisition system is installed on the mover of the three-coordinate robot, and the light source is arranged vertically downward.

5. The locomotive cylinder head cross arm guide rod installation accuracy detection system according to claim 1, characterized in that: The driving device comprises a mechanical arm, and the image acquisition system is installed at the end of the mechanical arm.

6. The locomotive cylinder head cross arm guide rod installation accuracy detection system according to claim 1, characterized in that: It also includes a light sensor, which is connected to the main control system. The light sensor is used to collect environmental brightness information and transmit it to the main control system. The main control system adjusts the brightness of the light source according to the brightness information, thereby changing the light brightness of the detection environment.

7. The locomotive cylinder head cross arm guide rod installation accuracy detection system according to claim 1, characterized in that: The main control unit includes a control unit, an image storage unit, a preprocessing unit and an image analysis unit, wherein the image preprocessing unit is used to preprocess the received original image and filter out the entire area on the top of the cross arm guide rod; The image storage unit is used to store the preprocessed image; The image analysis unit analyzes and calculates the preprocessed image and completes the determination of the detection result.

8. A method for detecting the installation accuracy of a cross arm guide rod of a locomotive cylinder head, characterized in that: The steps include: Step 1: After the cylinder head is installed with the valve guide and the cross arm guide rod, the cylinder head is placed on the positioning detection platform. The system detects the cylinder head, and the main control system issues a command. The image acquisition component moves to the preset image acquisition position under the action of the drive device, and then the main control system adjusts the brightness of the light source. When the lighting conditions are optimal, the control unit issues a photo-taking command. After receiving the command, the industrial camera starts to take pictures and transmits the original image to the image storage module of the main control system; Step 2: The image pre-processing unit pre-processes the received original image, filters out the entire area on the top of the cross arm guide rod, and stores the pre-processed image in the image storage unit; Step 3: The image analysis unit extracts features from the preprocessed image, uses a circular ring measurement operator to extract a pair of straight edges perpendicular to the measurement circular arc, and simultaneously extracts the connecting center line corresponding to the two valve guides and records it as L1; The main control system fits two circles, one large and one small. The large circle is the circle corresponding to the outer arm of the cross arm guide rod, and its radius is recorded as R; the small circle is the largest inscribed circle in the area corresponding to the cross arm guide rod, and its radius is recorded as r. Step 4: The image analysis unit then fits a circle concentric with the large circle with R0 as the radius, where the value of R0 is calculated by the following formula: The fitted concentric circles of the large circle intersect with the pair of straight edges extracted in step 3 respectively, thereby obtaining two points denoted as O1 and O2; the coordinates of the midpoint of the line segment O1O2 are calculated and denoted as A, and at the same time, the coordinates of the center C of the small circle are calculated, and the straight line where points A and C are located is denoted as L2, and then the straight line equation of L2 is fitted; Step 5: Calculate the angle between the straight lines L1 and L2 based on their equations. This angle is the deflection angle of the keyway of the cross arm guide rod. If the deflection angle exceeds the qualified range, it is judged as unqualified. The unqualified cylinder head is transferred to the manual table for correction. If the deflection angle does not exceed the qualified range, the cylinder head is qualified. The qualified cylinder head is transferred to the next process.

9. The method for detecting the installation accuracy of the cross arm guide rod of a locomotive cylinder head according to claim 8, characterized in that: Before step 1, the following steps are also included: Step 0: Adjust the imaging focal length, and then lock the imaging focal length; In step 2, image preprocessing specifically includes the following steps: first, image filling is performed, then dilation processing and image erosion are performed, and then the area screening operator is used to screen the entire area of ​​the outer contour of the top slot of the cross arm guide rod, and then the filling and closing operators are used to fill the gaps and optimize the contour to obtain the entire area.

Images