Subir Das

A Simple Approach to Design a Binary Coded Absolute Shaft Encoder

In this paper, an optical type absolute shaft encoder coding pattern is presented. Compared with the conventional binary or gray code pattern resolution (2n), the proposed code exhibits two times more resolution (2n2). Even, to represent high density positional information of rotating object, it is required very less number of tracks. This pattern sequence is based on n-by-2 matrices of binary codes where consecutive two columns of each code represented as high-low order bits. To retrieve the encoded position from these coding patterns, an extra pulse track was added at the outside of coded tracks. Moreover, it was used for providing a synchronized clock pulse into a simple photodetector-based sequential logic circuitry; it is the decoding unit of this encoder. Thus, depending on these synchronized pulses, the proposed encoder is able to provide error free positional information for a high-speed rotating object. Eventually, in order to prove this concept, a prototype is designed and tested, where a satisfactory performance was achieved.

Design & realization of an optical type dual axis inclination sensor

In the field of industrial automation, railways, intelligent platform, machining and other important areas where measurement of inclination of a body with respect to the gravity field plays a crucial role. In this present paper we have demonstrated an optical type dual axis inclination sensor with a precession of 0.6° and a working range of ±70° to fulfill the requirements of the above subjective areas. The sensor elements is made of a semi circular shape wooden block with a proof mass and a specially design imaging plate which are attached to its circumference edge. This fabricated block is clamped with orthogonal surface of a closed housing by a pivot arm which passes through the centre of the block, thus forming a dual axis pendulum structure. Therefore when the sensor is inclined, blocks are experiences deflection due to the gravity field of the earth. The movement of the two blocks is measured optically in two directions utilizing variation of light intensity produced by an imaging plate. The experimental result depicts a satisfactory performance of the sensor having a sensitivity of 40mv/°.