Method for extracting gear tooth profile edge based on engagement-pixel image edge tracking method

1. A method for extracting a gear tooth profile edge based on an engagement-pixel image edge tracking method, comprising the following steps:

step (1): defining a transmission ratio relationship between a cutter and an envelope tooth profile, setting a cutter profile step size and an envelope step size, acquiring instantaneous contact images at different engaging times, and performing a binarization processing on each curve envelope cluster image;

step (2): sweeping a boundary of an envelope curve cluster, acquiring pixel points of the edge; whereas in order to meet a stability requirement during a gear transmission process, a gear tooth profile is a smooth tooth profile with a regular curvature variation; preliminarily tracking a tooth profile edge by means of a traditional edge tracking method, and then performing a secondary extraction and compensation on the pixel points to improve an accuracy of the tooth profile in combination of two main features, namely, a feature of a step-shaped tooth profile pixel edge and a feature of a pixel absence in a position with a small curvature variation between adjacent tooth profiles;

step (3): calibrating coordinates of a cutter profile;

step (4): extracting a pixel coordinate of an instantaneous engaging point;

step (5): converting the pixel points among different instantaneous engaging images;

step (6): extracting a final tooth profile coordinate and the tooth profile edge of the gear according to a coordinate transformation process of steps (1) to (5), and performing a tooth shape error analysis and a contact line error analysis.

2. The method for extracting the gear tooth profile edge based on the engagement-pixel image edge tracking method according to claim 1 , wherein in step (3), the step of calibrating the coordinates of the cutter profile includes: simulating a forming machining process of a gear conjugate surface to obtain an image of the envelope curve cluster; changing coordinate values between the image of the envelope curve cluster and an image obtained by a binaryzation; and converting a theoretical value of the cutter into a coordinate value of a pixel to meet a requirement of subsequent processing.

3. The method for extracting the gear tooth profile edge based on the engagement-pixel image edge tracking method according to claim 1 , wherein in step (4), the step of extracting the pixel coordinate of the instantaneous engaging point includes: taking the pixel coordinate of the cutter as a basis; combining an engaging point between the cutter and the tooth profile during each instantaneous engaging process; and obtaining the pixel coordinate of the instantaneous engaging point.

4. The method for extracting the gear tooth profile edge based on the engagement-pixel image edge tracking method according to claim 1 , wherein in step (5), the step of converting the pixel points among different instantaneous engaging images includes: performing a corresponding coordinate transformation on the pixel points among the different instantaneous engaging images, since each instant corresponds to the different instantaneous engaging pixel images.

5. The method for extracting the gear tooth profile edge based on the engagement-pixel image edge tracking method according to claim 1 , wherein in step (6), the gear is a face gear.