The In-process And Real-time Checking Technology Of Free-form Surface Processing Quality

The level of mold technology gradually becomes an important symbol to evaluate a country's manufacturing level, and largely determines the quality, benefit of the products and new product development capability. With the development of society, the die surface more and more appears as complex free curved surface. Machining quality of die surface has considerable influence to the quality and life of product and mold itself, which is one of the important factors in deciding the functional characteristics of components. If the mold surface roughness is increased by one level, its life will be greatly enhanced. Now, there is a growing awareness of the importance of the die surface roughness inspection. The appropriate measuring methods and equipment can not only help users to easily improve product quality, but will also improve production efficiency. To this end, the surface roughness inspection to die surface is particularly more important. The future development of China mold will be more and more complex, and accuracy requirement is also more and more high. Species diversity makes the change become even more rapidly, which requires testing equipment in addition to high precision, accurate measurement, and more flexible to keep up with the pace of development.For the robot's next step processing control to provide information, the paper is proposed to design a set of online and real-time roughness inspection system, which is mainly for the workpiece surface quality status and the need for testing after the robot in the polishing and grinding partsIn this paper, it first briefly described the current domestic and international developments on the surface roughness detection. Considering the pros and cons of various detection methods, aimed at application needs of the automatic polishing system about complex free surface such as the die surface, this paper designed a series of subsystem that could be achieved in-process checking of free-form surface roughness. The measurement system was based on the embedded processor using a laser probe, and supporting the use of high-precision mobile control devices. The design is a embedded surface quality inspection system which is comprehensive application of sensing test technology, graphics and video processing, electrical and mechanical control techniques. This thesis conducted the following study:System is based on the principle of laser rangefinder, through the precise range-finding sensor AT-2 to measure the Z-distance between surface and the probe. The ARM chip processed and calculated the data that could be obtained the machining surface roughness value Ra. The ARM system was also used for the implementing agencies motion control. Detailed analysis of work principle and design method about the detection head, given the controlling method of detection head using ARM, and introduced the selections and work principles of the driving devices on control part.It briefly introduced the development environment of the detection system and the implementation of the Windows CE5.0 operating system, also specifically described the general design of the data acquisition system and implementation of some subsystems. Focused on the fitting algorithm and filter algorithm of baseline. To a certain extent, the curve fitting algorithm was proved to be suitable for the surface detection system by fitting a set of data. The filter algorithm was showed to be fit for the ARM system through a sine curve filtering result.