Research On The Development Of Shaft Parts Size Measurement System Based On Machine Vision

The transmission and washing shafts are key parts to transmit motion and torque in the washing machine. The precision and performance of the shafts have direct effect on the usage condition and service life of the washing machine. It is very important to measure the dimension of the shafts accurately. With the increasing requirements of product's quality and rising wages, the accuracy and efficiency of the dimension measurement have higher requirements. At present, the main measurement method is hand-measuring, which has many disadvantages, such as low efficiency, poor accuracy and low degree of automation.This paper uses machine vision detection technology. Firstly, we take photos for the shaft parts, and then we measure the dimension of the shaft parts based on the digital images. The machine vision measurement system involves multi-field, such as optical, sensor, image processing and pattern recognition, which can realize the fast measurement of object dimension.Firstly, this paper analyzes the system requirements, and then shows the overall design framework of the system. In order to solve the problem of the detection parts scattered in local area, this paper designs the layout of fixed single camera and moved shaft based on the motion controller card; in order to gain high quality image and meet the measurement accuracy requirements, we choose high pixel camera with large depth of field and telocentric lens, with high precision, and back to the parallel light illumination.In the paper, we calibrate the system by two steps. Firstly, we calibrate pixel dimension equivalent, then we calculate the dimension compensation value by using pin gauges. We reduce image noise by Gauss filter. Based on the deeply analysis and comparison of the existing commercial machine vision software, this paper utilizes Visual Basic.Net to develop and build a high performance 2D machine vision system based on Hexsight. The software includes eight modules, which are image acquisition, calibration system, type selection, parameter setting, image pre-processing, measurement, result display and save.Based on the above research, the dimension measurement system of the shaft parts is developed. This paper detected the washing shaft many times, and based on the detection results, the error of the dimension was calculated and discussed...