Slender shaft end spline tooth root rolling alignment method based on image recognition

Abstract

The invention provides a slender shaft end spline tooth root rolling alignment method based on image recognition, which comprises the following steps: clamping a slender shaft on a tooth root rolling machine tool, collecting image information of a processing area of the tooth root rolling machine tool, establishing a rectangular coordinate system according to the image information and generating a two-dimensional model; obtaining an analytic relationship of a position relationship between the rolling head and the spline through the two-dimensional model, and identifying to obtain boundary information of a processing area; according to the analytical solution of the position relation, the angle difference value between the top end of the rolling head and the tooth root is obtained, an angular displacement instruction is sent to the servo motor based on the angle difference value, and accurate alignment of the top end of the rolling head and the tooth root is achieved. According to the method, the two-dimensional model of the machining area is established by collecting the image of the shaft end machining area of the slender shaft and combining the image recognition technology, accurate positioning of the rolling tool and the workpiece is achieved, alignment can be achieved without the help of an external physical device, and the machining precision and the machining efficiency of tooth root rolling can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing positioning, and in particular relates to a method for rolling and aligning a spline tooth root at an end of a slender shaft based on image recognition. Background Art

[0002] The surface properties of the spline tooth root of a torsion bar spring have a direct impact on fatigue life. For example, roughness causes stress concentration at the surface crack source, accelerating the expansion of fatigue cracks; surface hardening can effectively inhibit crack initiation; and residual compressive stress can effectively offset part of the external load. Therefore, improving the surface properties of the processed tooth root by tooth root rolling is an effective means to improve the surface fatigue resistance of parts. At present, in the actual production and processing of torsion bar springs, rolling processing is generally used to strengthen the surface of the spline tooth roots at both ends of the torsion bar spring. However, there are still some problems in the processing process, which have an adverse effect on production efficiency and product qualification rate, mainly including the following problems: (1) The tooth root rolling machine uses a mechanical indexing turntable. During the first processing, the relative position of the tooth root and the rolling head needs to be manually aligned, which is inefficient and inconvenient to operate. It is also easy to cause misalignment, resulting in the rolling head directly squeezing the tooth surface and causing damage; (2) The surface condition of the processed surface cannot be obtained in real time during the processing, which makes it difficult to conduct real-time monitoring and feedback, and it is impossible to detect flaws in real time; (3) There is a lack of data analysis and optimization modules, which cannot provide data support for process optimization. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] The invention proposes a method for rolling and aligning a spline tooth root at an end of a slender shaft based on image recognition, so as to solve the technical problems of poor positioning accuracy and low efficiency in the positioning process of a machine tool.

[0005] (II) Technical solution

[0006] In order to solve the above technical problems, the present invention proposes a method for rolling and aligning the spline tooth root at the end of a slender shaft based on image recognition. The method for rolling and aligning the spline tooth root at the end of a slender shaft comprises the following steps:

[0007] S1. Clamp the slender shaft on the tooth root rolling machine, and collect image information of the processing area of ​​the tooth root rolling machine, including the angle and position image data of the shaft end spline and the rolling head after the slender shaft is initially clamped;

[0008] S2. Establishing a rectangular coordinate system and generating a two-dimensional model based on the image data, obtaining an analytical relationship between the positional relationship between the rolling head and the spline through the two-dimensional model, and identifying boundary information;

[0009] S3. According to the analytical solution of the positional relationship, the angle difference between the top of the rolling head and the tooth root is obtained, and an angular displacement instruction is sent to the servo motor based on the angle difference to achieve accurate alignment between the top of the rolling head and the tooth root.

[0010] Further, the elongated shaft is a torsion bar spring.

[0011] Furthermore, in step S1, image information of a processing area of ​​the tooth root rolling machine is collected by an image acquisition device.

[0012] Furthermore, in step S1, the image acquisition device synchronizes the image data to the positioning analysis device in real time.

[0013] Furthermore, in step S2, the positioning analysis device establishes a rectangular coordinate system according to the image data and generates a two-dimensional model.

[0014] Furthermore, the boundary information includes the arc at the top of the rolling head, the tooth profile of the spline tooth addendum circle, the tooth root circle, the tooth pitch and the center of the spline circle.

[0015] Furthermore, step S3 specifically includes the following steps: obtaining the position information of the tooth tip point of each tooth based on the identified circular tooth profile of the spline tooth top, and calculating the vertical distance between the tooth tip points of the two teeth closest to the top of the rolling head and the center of the spline circle, comparing the two vertical distances and taking the larger one, and then obtaining the angle θ between the center line of the spline tooth and the line connecting the center of the spline circle and the top of the rolling head, sending an angular displacement command with a value of θ to the servo motor, controlling the main shaft through the servo motor to drive the torsion bar spring to rotate by θ, so that the top of the rolling head is facing the center line of the spline tooth, and then sending an angular displacement command of half a tooth pitch to the servo motor, controlling the main shaft through the servo motor to drive the torsion bar spring to rotate half a tooth pitch, so as to achieve precise alignment of the rolling head and the tooth root.

[0016] (III) Beneficial effects

[0017] The present invention proposes a method for rolling and aligning the spline tooth root at the end of a slender shaft based on image recognition, comprising clamping the slender shaft on a tooth root rolling machine, collecting image information of the processing area of ​​the tooth root rolling machine, establishing a rectangular coordinate system and generating a two-dimensional model based on the image information, obtaining an analytical relationship of the positional relationship between the rolling head and the spline through the two-dimensional model, and identifying the boundary information of the processing area; obtaining the angle difference between the top of the rolling head and the tooth root based on the analytical solution of the positional relationship, and sending an angular displacement instruction to the servo motor based on the angle difference to achieve accurate alignment of the top of the rolling head and the tooth root. The present invention collects images of the processing area at the end of the slender shaft, combines image recognition technology to establish a two-dimensional model of the processing area, and achieves accurate positioning of the rolling tool and the workpiece. Alignment can be achieved without the aid of an external physical device, which helps to improve the processing accuracy and efficiency of tooth root rolling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the torsion bar spring structure;

[0019] Figure 2 It is a schematic diagram of the position relationship between the spline at the shaft end of the torsion bar spring and the rolling head in the present invention;

[0020] Figure 3 It is a schematic diagram of the spline tooth top distance and angle measurement in the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0022] This embodiment provides a method for rolling and aligning the spline tooth root at the end of a slender shaft based on image recognition. The method for rolling and aligning the spline tooth root at the end of a slender shaft comprises the following steps:

[0023] S1. Put the torsion bar spring (its structure is as follows Figure 1 The torsion bar spring is clamped on the tooth root rolling machine. The position relationship between the spline at the shaft end of the torsion bar spring and the rolling head after the initial clamping is as shown in the figure. Figure 2 As shown; the image acquisition device is used to collect image information of the processing area of ​​the tooth root rolling machine, including the angle and position image data of the shaft end spline and the rolling head after the torsion bar spring is initially clamped, and the image data is synchronized to the positioning analysis device in real time.

[0024] S2. The positioning analysis device establishes a rectangular coordinate system and generates a two-dimensional model based on the image data. The analytical relationship between the positional relationship between the rolling head and the spline is obtained through the two-dimensional model, and the boundary information of the processing area including the top arc of the rolling head, the top circle profile of the spline tooth, the root circle, the tooth pitch and the center of the spline is identified.

[0025] S3. Based on the analytical solution of the positional relationship, the angle difference between the top of the rolling head and the tooth root is obtained, and based on the angle difference, an angular displacement instruction is sent to the servo motor to achieve accurate alignment between the top of the rolling head and the tooth root. Specifically, the following steps are included:

[0026] According to the identified spline tooth top circle profile, the position information of each tooth tip is obtained, and the vertical distance between the tooth tip points closest to the top of the rolling head and the center of the spline circle is calculated, which is recorded as d1 and d2, as shown in Figure 3 As shown, compare the sizes of d1 and d2 and take the larger one, then obtain the angle θ between the center line of the spline tooth and the line connecting the center of the spline circle and the top of the rolling head, send an angular displacement command of θ to the servo motor, and control the main shaft through the servo motor to drive the torsion bar spring to rotate θ. At this time, the top of the rolling head is facing the center line of the spline tooth, and then send an angular displacement command of half a tooth pitch to the servo motor, and control the main shaft through the servo motor to drive the torsion bar spring to rotate half a tooth pitch, so as to achieve precise alignment of the rolling head and the tooth root.

[0027] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for rolling and aligning the spline tooth root of a slender shaft end based on image recognition, characterized in that: The method for rolling and aligning the spline tooth root at the end of the slender shaft comprises the following steps: S1. Clamp the slender shaft on the tooth root rolling machine, and collect image information of the processing area of ​​the tooth root rolling machine, including the angle and position image data of the shaft end spline and the rolling head after the slender shaft is initially clamped; S2. Establishing a rectangular coordinate system and generating a two-dimensional model based on the image data, obtaining an analytical relationship between the positional relationship between the rolling head and the spline through the two-dimensional model, and identifying boundary information; S3. According to the analytical solution of the positional relationship, the angle difference between the top of the rolling head and the tooth root is obtained, and an angular displacement instruction is sent to the servo motor based on the angle difference to achieve accurate alignment between the top of the rolling head and the tooth root.

2. The method for rolling and aligning the spline tooth root of the slender shaft end based on image recognition according to claim 1, characterized in that: The elongated shaft is a torsion bar spring.

3. The method for rolling and aligning the spline tooth root of the shaft end of a slender shaft based on image recognition as claimed in claim 1, characterized in that: In step S1, image information of a processing area of ​​a tooth root rolling machine is collected by an image acquisition device.

4. The method for rolling and aligning the spline tooth root of the slender shaft end based on image recognition as claimed in claim 3, characterized in that: In step S1, the image acquisition device synchronizes the image data to the positioning analysis device in real time.

5. The method for rolling and aligning the spline tooth root of the shaft end of a slender shaft based on image recognition as claimed in claim 4, characterized in that: In step S2, the positioning analysis device establishes a rectangular coordinate system according to the image data and generates a two-dimensional model.

6. The method for rolling and aligning the spline tooth root of the slender shaft end based on image recognition as claimed in claim 1, characterized in that: The boundary information includes the arc at the top of the rolling head, the tooth profile of the spline tooth addendum circle, the tooth root circle, the tooth pitch and the center of the spline circle.

7. The method for rolling and aligning the spline tooth root of the shaft end of a slender shaft based on image recognition as claimed in claim 1, characterized in that: Step S3 specifically includes the following steps: According to the identified spline tooth top circle tooth profile, the position information of each tooth tip is obtained, and the vertical distance between the tooth tip points closest to the top of the rolling head and the center of the spline circle is calculated. The two vertical distances are compared and the larger one is taken. Then, the angle θ between the center line of the spline tooth and the line connecting the center of the spline circle and the top of the rolling head is obtained, and an angular displacement command with a value of θ is sent to the servo motor. The servo motor controls the main shaft to drive the torsion bar spring to rotate θ, so that the top of the rolling head faces the center line of the spline tooth. Then, an angular displacement command of half a tooth pitch is sent to the servo motor. The servo motor controls the main shaft to drive the torsion bar spring to rotate half a tooth pitch, so that the rolling head and the tooth root are accurately aligned.

Images