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

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.