Development Of Portable Turning Surface Roughness Measuring Instrument

Surface roughness is one of important indexes reflecting microscopic error in geometrical form. And also, it is a famous parameter which is used widely to represent characteristics of surface, it directly influences machine and instrument's service performance and life, especially makes important sense to products with high running speed, fabrication precision and tightness request. Now most of roughness monitoring systems on the market work by a image capturing card in PCI socket which work unstably, Price is too high,and can not work in bad circumstance, and so on. On the other hand,many powerful embedded processors is higher and higher correspondingly. Especially,DSP chips include abundance of peripheral interface and has very high programmed ability, which make the hardware and sofeware of video monitoring system be implemented easily. But also,this embedded system conquer many deficiencies of the system based on PC.This thesis research and design a roughness monitoring system. The central processor is TI's dedicated multimedia processor TMS320DM642.This system could capture image information, which brings down the cost effectively. The capture data are stored into IDE hard disk, or transmitted to remote server to store. At first, the minimal system was designed,including DSP, power circuit, reset circuit and clock circuit. Then the peripheral devices were extended, including video circuit, local store circuit,display circuit, keyboard control circuit,etc. Finally, in accordance with the work of roughness measuring instrument, the control program was divided to corresponding multitask programs and respectively preparate control drivers.This thesis compared several ordinary measuring methods of surface roughness synthetically, acquire texture information from turning surface's image and extract feature,a new detection method of surface roughness was put forward, through combination of computer vision and neural network technique. Roughness information of a line in traditional measurements would be replaced with information of a region by this method. And the survey of surface roughness implied a degree of repeatability, with memory of images and data information.