阅读说明：本技术 一种安装偏心工况下小模数齿轮齿廓检测方法 (Method for detecting tooth profile of small-module gear under eccentric installation working condition ) 是由 杨聪彬 郭庆旭 刘志峰 赵永胜 张彩霞 程强 于 2021-08-01 设计创作，主要内容包括：本发明公开了一种安装偏心工况下小模数齿轮齿廓检测方法,该方法建立以测量转台为中心的初始坐标系O-(1),并利用三维扫描仪获取齿轮上端面完整数据参数；并提取齿轮中心孔边缘数据,进行优化拟合,获得在初始坐标系下中心孔轮廓及齿轮中心坐标；最后,建立以齿轮中心为坐标原点的中心坐标系O,提取齿轮齿廓边缘数据,并基于坐标变换原理将该数据转换至中心坐标系中,获得以齿轮中心为原点的完成齿轮轮廓数据。解决了小模数齿轮测量过程中因安装误差等机械误差导致的测量误差问题,为小模数齿形实际齿廓表征以奠定了理论和实验基础。(The invention discloses a method for detecting tooth profile of a small-module gear under an eccentric installation working condition, which establishes an initial coordinate system O taking a measuring turntable as a center 1 Acquiring complete data parameters of the upper end face of the gear by using a three-dimensional scanner; extracting edge data of a central hole of the gear, and performing optimization fitting to obtain the profile of the central hole and the central coordinate of the gear in an initial coordinate system; and finally, establishing a central coordinate system O taking the gear center as a coordinate origin, extracting gear tooth profile edge data, and converting the data into the central coordinate system based on a coordinate transformation principle to obtain finished gear profile data taking the gear center as the origin. The problem of measurement errors caused by mechanical errors such as installation errors and the like in the measurement process of the small-modulus gear is solved, and theoretical and experimental bases are laid for the representation of the actual tooth profile of the small-modulus tooth profile.)

1. A method for detecting the tooth profile of a small-module gear under the working condition of eccentric installation is characterized by comprising the following steps of:

the method comprises the following steps: placing the gear in a measuring system, adjusting the position and parameters of a three-dimensional scanner, measuring the complete data of the end face of the gear, and establishing an initial coordinate system x parallel to the horizontal plane by taking the center of a turntable as a circular point₁o₁y₁；

Step two: extracting the edge array I of the gear center hole, fitting the data by utilizing matlab data processing software to obtain a gear center hole outline model, and obtaining a gear center point coordinate O₁(x,y)；

Step three: extracting a gear tooth profile edge array M, and fitting the data by utilizing matlab data processing software to obtain a gear tooth profile under an initial coordinate system;

step four: and establishing a central coordinate system xoy taking the center of the gear as the origin of coordinates, and converting the data coordinates of the tooth profile points under the initial coordinate system into the central coordinate system to obtain the complete tooth profile taking the gear as the origin of coordinates.

2. The method for detecting the tooth profile of the small module gear under the eccentric installation working condition is utilized, and is characterized in that: the data fitting method needs to be optimized, and comprises the following steps:

1) setting an optimized initial step length L;

2) calculating x_i,y_iAnd normalizing the partial derivative vectors;

3) if the loss function is continuously reduced, the step length is considered to be too small, L is 1.5; if the loss function oscillates, the step length is considered to be too large, and L is 0.5;

4) repeating the steps 2) and 3) until the loss function is small enough;

and defining the corresponding coordinates of each point as initial values of an actual coordinate fitting algorithm of each point, and optimizing the coordinates of each measuring point and each station to obtain the coordinates of the final measuring point and each station and the fitting values of the actual coordinates.

3. The method for detecting the tooth profile of the small module gear under the eccentric installation working condition is utilized, and is characterized in that: a central coordinate system with the gear center as the origin of coordinates, and a coordinate system O based on the coordinate transformation principle₁The lower measurement point is converted to the coordinate system O, (X)_i,Y_i) Actual gear contour point coordinates:

4. the method for detecting the tooth profile of the small module gear under the eccentric installation working condition is utilized, and is characterized in that: the extraction of the gear end face data can also adopt an image method or a projection method to obtain the coordinate position of the gear center hole.

Technical Field

The invention relates to the technical field of design and manufacture of small-module gears, in particular to a method for detecting tooth profile of a small-module gear under an installation eccentric working condition.

Background

The tooth profile detection of the small module gear generally adopts the traditional three-coordinate probe contact detection process, a special ultra-small detection probe and special software need to be customized, the customization cost of software and hardware is high, and the measurement period is long. The non-contact measurement technology adopting the laser displacement sensor is an advanced means for detecting small-modulus gears, complex tooth surfaces and precise displacement at present. However, a small-modulus tooth profile has certain installation errors in the detection process, so that the measurement result has errors.

Disclosure of Invention

The invention aims to: in order to obtain tooth profile data of a small module gear which is actually processed and solve the influence of installation errors on a measurement result, the tooth profile detection method of the small module gear under the eccentric installation working condition is provided by calculating the coordinate of the center of the gear.

The technical scheme adopted by the invention is as follows:

a method for detecting the tooth profile of a small-module gear under the working condition of eccentric installation is characterized by comprising the following steps of:

the method comprises the following steps: placing the gear in a measuring system, adjusting the position and parameters of a three-dimensional scanner, measuring the complete data of the end face of the gear, and establishing an initial coordinate system x parallel to the horizontal plane by taking the center of a turntable as a circular point₁o₁y₁。

Step two: extracting the edge array I of the gear center hole, fitting the data by utilizing data processing software such as matlab and the like to obtain a gear center hole outline model, and obtaining a gear center point coordinate O₁(x,y)。

Step three: and extracting a gear tooth profile edge array M, fitting the data by using data processing software such as matlab and the like, and obtaining the gear tooth profile under an initial coordinate system O.

Step four: and establishing a central coordinate system xoy taking the center of the gear as the origin of coordinates, and converting the data coordinates of the tooth profile points under the initial coordinate system into the central coordinate system to obtain the complete tooth profile taking the gear as the origin of coordinates.

The data fitting method needs to be optimized, and comprises the following steps: 1) and setting an optimized initial step length L. 2) Calculating x_i,y_iAnd normalizing the partial derivative vector. 3) If the loss function decreases continuously, the step size is considered too small, L x 1.5. If the loss function oscillates, the step size is considered too large, L x 0.5. 4) And (4) repeating the steps (2) and (3) until the loss function is small enough. And defining the corresponding coordinates of each point as the initial values of the actual coordinate fitting algorithm of each point, and performing the optimization steps on the coordinates of each measuring point and each station to obtain the fitting values of the coordinates and the actual coordinates of the final measuring point and each station.

A central coordinate system with the gear center as the origin of coordinates, and a coordinate system O based on the coordinate transformation principle₁The lower measurement point is converted to the initial coordinate system O, (X)_i,Y_i) Actual gear contour point coordinates:

the invention has the advantages and positive effects that: the method comprises the steps of obtaining center hole outline parameters and gear center coordinates by extracting gear center hole edge data, and extracting gear tooth profile edge data; and converting the data into a central coordinate system with the gear center as an origin on the basis of a coordinate transformation principle to obtain finished gear profile data.

The method lays theoretical and experimental foundation for the representation of the actual tooth profile of the small-modulus tooth profile.

Drawings

FIG. 1 is a flow chart of a method for detecting a tooth profile of a small-module gear under an installation eccentric condition;

FIG. 2 is a schematic view of a small module gear;

wherein, 1 gear base circle, 2 gear inner hole edges, O is theoretical gear center, O₁The actual gear center.

Detailed Description

In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings:

as shown in fig. 1, a method for detecting a tooth profile of a small module gear under an installation eccentricity working condition is characterized by comprising the following steps:

placing the gear in a measuring system, adjusting the position and parameters of a three-dimensional scanner, measuring the complete data of the end face of the gear, and establishing an initial coordinate system x parallel to the horizontal plane by taking the center of a turntable as a circular point₁o₁y₁。

Step two: extracting the edge array I of the gear center hole, fitting the data by utilizing data processing software such as matlab and the like to obtain a gear center hole outline model, and obtaining a gear center point coordinate O₁(x,y)。

Step three: and extracting a gear tooth profile edge array M, fitting the data by using data processing software such as matlab and the like, and obtaining the gear tooth profile under an initial coordinate system O.

Step four: and establishing a central coordinate system xoy taking the center of the gear as the origin of coordinates, and converting the data coordinates of the tooth profile points under the initial coordinate system into the central coordinate system to obtain the complete tooth profile taking the gear as the origin of coordinates.

The data fitting method needs to be optimized, and comprises the following steps: 1) and setting an optimized initial step length L. 2) Calculating x_i,y_iAnd normalizing the partial derivative vector. 3) If the loss function decreases continuously, the step size is considered too small, L x 1.5. If the loss function oscillates, the step size is considered too large, L x 0.5. 4) And (4) repeating the steps (2) and (3) until the loss function is small enough. And defining the corresponding coordinates of each point as the initial values of the actual coordinate fitting algorithm of each point, and performing the optimization steps on the coordinates of each measuring point and each station to obtain the fitting values of the coordinates and the actual coordinates of the final measuring point and each station.

A central coordinate system with the gear center as the origin of coordinates, and a coordinate system O based on the coordinate transformation principle₁The lower measurement point is converted to the initial coordinate system O, (X)_i,Y_i) Actual gear contour point coordinates:

the invention has the advantages and positive effects that: the method comprises the steps of obtaining center hole outline parameters and gear center coordinates by extracting gear center hole edge data, and extracting gear tooth profile edge data; and converting the data into a central coordinate system with the gear center as an origin on the basis of a coordinate transformation principle to obtain finished gear profile data.

The method lays theoretical and experimental foundation for the representation of the actual tooth profile of the small-modulus tooth profile.