The Optomechanical Design And Research Of Industrial Endoscope For Three-dimensional Measurement

To meet the current situation that three-dimensional measurement of the workpiece cannot be realized in domestic industrial endoscope, we design a three-dimensional measurement industrial endoscope which outside diameter of probe is6mm and can bent in any direction, then machine a model machine that it has achieved the three-dimensional measurement function. This paper mainly introduces the endoscopic binocular optical system and design of the overall structure, the main research contents include:(1) Details the research and development status of domestic and foreign industrial endoscopes, pointing out the shortcoming that domestic industrial endoscope product does not have a three-dimensional measurements function, and analyzes the main technical difficulty caused by this shortcoming is that the assembly process of sub-millimeter parts (including optical parts).(2) We introduce the basic theory of three-dimensional measurement technology, and propose the overall design scheme of the system that including the overall technical indicators and major working principle of the system.(3) By analyzing the advantages and disadvantages of two common imaging solutions in the foreign endoscope system, we propose a partition imaging scheme on the target surface of the image sensor with a dual objective and single image sensor. The scheme uses two lens with the same optical parameters, and respectively place two prisms staggered of180°in the rear of the lens, so that the images received by two groups of lens are respectively imaged to two split regions left and right on the target surface of the same image sensor, then read and separate into two images left and right by the image processing software, and use computer software for three-dimensional reconstruction.(4) According to the main technical indicators and requirements of the system, we design the structure of the entire endoscope system which is divided into four functional parts as:head structure, head bend structure, the back-end control mechanism, handle structure. Wherein, the head structure is used to set up an optical imaging system; the effect of the head bend structure is to ensure the work probes of the endoscope can be bent in any direction to eliminate the visual blind area; the back-end control mechanism is used to drive the head bend structure to work through controlling two steering gear to rotate; the main function of the handle structure is to make the system become more portable and stable.(5) We test the performance of the model machine, including imaging experiment, bending angle of the probe, and three-dimensional size measurement experiment, the experiment results show that:endoscopic imaging is good, the picture is relatively clear; the bending angle of endoscopic probe in for directions are larger than120°. The whole measurement results show that, the error of area, length, distance measurement is low, but the depth measurement error is relatively large.