Non Contact Surface Finish Monitoring of Machined Surface using Vision System K.I .V.Vandana Assistant Professor Department of Mechanical Engineering PVP Siddhartha Institute of Technology Vjayawada

With ever increasing demand for the accurate engineering products, the control of surface texture has become more important. The measurement of surface roughness during machining process is critical for the automatic control of surface quality in computer-integrated manufacturing (CIM). Many methods of online measurement of surface roughness range from simple touch comparator to sophisticated optical techniques. The latest technology of measuring surface roughness during machining is the combination of optical techniques and computer vision systems. Unlike stylus instruments, the optical techniques and computer vision system have the advantage of being non contact type and are capable of measuring over an area from the surface of machined part rather than a single line. In this paper an attempt has been made to develop an experimental technique for in process surface roughness measurement based on the intensity distributions of scattered light from the machined surface. For this purpose a low cost vision system is proposed. By impinging a laser beam at an angle on the machined surface, a random pattern of bright and dark regions known as speckle is observed. These speckle images are captured using charge coupled device (CCD) camera and are stored in digital format. A source code in C++ is developed to compute the reference values from the stored image for online monitoring of the surface roughness. The method developed may be used effectively for calculating the roughness of ground, turned and milled components. Owing to the simple method of measurement, the image grabbing technique seems to be more promising for online monitoring of surface roughness