Engine connecting rod dimension measuring device and method based on machine vision

Abstract

The invention discloses an engine connecting rod dimension measuring device based on machine vision; the measuring device is featured by comprising the following units: a detection unit comprising a bi-telecentric lens with a scale and an optical imager, wherein the bi-telecentric lens is mechanically connected with the lens of the optical imager through a C-type interface; a screw rod slide way including a servo motor, wherein the detection unit is fixed on the screw rod slide way through a support bolt, the servo motor drives the detection unit to linearly axially move from the initial position of the screw rod slide way to another terminal position; a transmission unit including a conveyer belt and a frequency conversion motor, wherein the frequency conversion motor intermittently runsto transfer to-be-tested rods one by one; a control unit including a programmable controller and an industrial control computer.

Description

technical field [0001] The invention relates to a measuring device for measuring the size of an engine connecting rod based on machine vision and a mobile measuring method thereof. Background technique [0002] With the improvement of industrial manufacturing technology and the size of precision parts, many parts require partial or even full inspection, and workers must invest a lot of manpower and time to test product dimensions. The length of the inner hole distance of the engine connecting rod is generally more than 100mm. In the process of using traditional measuring equipment to realize the product size inspection, it is generally necessary to manually establish the measurement benchmark, and the measuring tool can be used only when it is placed on the platform. Since the coordinates established by each person and the way of taking points and lines are different, measurement errors are caused. After the measurement is completed, all the data reports are sorted into the ...

AI Technical Summary

Problems solved by technology

However, the telecentric lenses currently on the market can only measure the size within the field of view. Products larger than the field of view will not be able to measure the size. Even the measurement can only be grasped by the principle and main structure of the image measuring instrument. Take the edge point cloud of the image, and then transfer it to the world coordinate system for fitting measurement. At the same time, the product can only be measured when it is in the right position.

In order to ensure a more accurate measurement effect, it is necessary to use a large-diameter bilateral telecentric lens, and as the diameter of the bilateral telecentric lens increases, the optical polarization between the center and edge of the lens is relatively large, and it is difficult to ensure the accuracy of the measurement , and products larger than the field of view will not be able to measure the size (generally high-level bilateral telecentric lens measurement aperture / field of view is 1 inch CCD size = length 12.8mm × width 9.6mm)

[0004] At the same time, with the development of the engine connecting rod manufacturing process, a large number of engine connecting rods of different sizes need to be manufactured on the production line. If the length of the connecting rod can be measured on the conveyor belt of the production line, the reliability of the connecting rod will be greatly improved. Production efficiency, but when the connecting rod on the production line is transported, it may yaw left and right during the moving process, and the photos taken cannot accurately read the image displacement value. There is an urgent need for a simple and more efficient measurement method and suitable Measuring device to meet the needs of connecting rod production size measurement

Images