Study On The Detection Of Steel Balls’ Shape Based On Laser Technology

Abstract:With the advancement and development of the technology, the requirements to the precision of components are much stricter, while the traditional manual inspection approaches cannot meet the rapid changing market any more. Applying laser detection technology to detect the diameter of steel balls can meet the requirements of non-contact, no disturbance, no damage, high precision and swift detection.This paper introduces some approaches of the measurement of the diameter of steel ball, with the contrasts of advantages and defects and their corresponding principles of measurement. According to the requirements of shape detection of steel balls based on laser technique, making full use of the stability, multiple inputs and long transmission distance of CAN, we design a module combining CAN with the drive of stepping motor to control dozens of stepping motors in a remote distance simultaneously.With the drive chip THB6218, the drive current is only2.2A, which can only be applied to small stepping motors and has the risk of overheat. In this paper, we use the output pulses of THB6128to drive H-bridge built by HIP4081. With this smart design, the drive ability improves a lot. Now the drive current reaches as high as10A and THB6128can keep in room temperature even after working in a long time.A temperature control system is designed to maintain a constant temperature, improve the laser characteristics and avoid the thermal expansion of steel balls’diameter. The temperature control system is simulated with Matlab.The sources of errors are analyzed in detail and propose practical solutions to delimitate these errors. Besides, every compensation measure is verified by experiments and all the results of experiments are discussed at length.