Research On The Double Track Absolute Encoder And Experiment Device

ABSTRACT:The photoelectric shaft encoder, which combines the computer and photoelectric technology, has been widely used in the field of precise measurement and automatization with the development of science and technology. But in recent years, the development of photoelectric encoder is challenged by the double requirements of high-accuracy and miniaturization. So it is very urgent that the study of new encoding theory and the usage of advanced electronic technology to develop new absolute encoder. Aiming at some defects which contains that the multi-turn absolute encoder is not easy to realize miniaturization and it is difficult to construct high bit encoding for single track absolute encoder, the paper studies double track absolute encoder. This encoder can measure the absolute angular position by a new encoding method, and it is easy to construct high bit absolute encoding.Firstly, the paper puts forward an encoding method for the double track absolute encoder and the disc is composed by a coarse track and a fine track. Gray code is depicted on the coarse track, as a low bit encoding. The deformation m sequence is depicted on the fine track, as a high bit encoding. The reading probes are distributed on two circles separately. To elaborate the generation process of the new double track absolute encoding method, an absolute12bit double track encoding is composed. The double track absolute encoding method can solve the problem of creating high bit encoding for single track absolute encoder and it is in favor of miniaturization and high-precision for the encoder.Secondly, an error correction algorithm for the double track absolute encoding is put forward. The circuits of error correction module, processing module, zero setting module, decoding module and parallel to serial module are designed. On this basis, the design of mechanical structure, coded disc and slit plate have been completed. The prototype is realized at last.Finally, the absolute angular position sensor experiment platform is designed for the prototype. The error and precision analysis is carried out for the prototype by the platform. The measuring accuracy is raised by improving experiment parameters lastly.The double track absolute angular encoder overcomes the disadvantage of increasing the accuracy at the expense of more tracks and difficulties of fabrication. Therefore, it establishes a new approach for the high-accuracy and the miniaturization of the absolute angular encoder.