Research On Measurement Technology Of Tubule Inner Surface Roughness By Laser Scatterring

Surface roughness is the slight uneven of work pieces, which is also an important parameter to evaluate the quality of surface process. With the development of measurement theory and measurement technology, non-contact measurement method especially optical method has been widely used. What we researched in this design is the roughness of tubule inner surface, so the traditional measurement method can't be used because of the restrictions on the size. The design of a new measurement device is needed.Firstly, we will compare and analysis of the major methods for surface roughness measurement. In order to be used in the small space of the tubule, the method based on laser scattering is finalized for this design. The theoretical model that suit for this design is based on the derivation of the laser scattering theoretical model that is brought up by Beckmann.Secondly, the software and hardware for this system is designed. In the part of hardware design, the circuit for zero voltage bias photoelectric conversion is designed, which realized the precision transformation of the scattering light signal to electric signal. The data processing circuit module is designed to control the photoelectric conversion circuit, and control the communication with PC. Some mechanical structure is designed to match up to the circuit structure to realize the system functions. The software for data processing circuit is designed by C language, and the software for PC is designed by VB.Finally, the system is tested by series of experiments, which include the test for linearity, the test for stability, and the test for the whole system functions.