Research On Dynamic Bit Errors Of Sealed Absolute Linear Encoder

With rapidly development of science and technology, it makes the manufacturing technology tending to motors. Linear encoder is the necessary device of general-purpose machine tool and numerically-controlled machine tool, especially which the required of high precision. The measuring accuracy of linear encoder is one factor to insure the accuracy of the high machine tool. Nowaday, linear encoder has been widely used in many fields, for example, medical science, military, manufacturing industry and so on. Traditional linear encoder magnifys the measured distance by optical magnify technoloy, transforms it into pulse singnal by difference channel, finally outputs position singnal. Tt’s one newly-developing high-technology to research on linear encoder, especially absolute linear encoder, which would make great role in the future technology development, with the development of image processing technique and data processing technique. Absolute linear encoder has great advantages:doesn’t need to set reset and re turn-to-zero when power outage, hasn’t cumulative errors, with high accuracy. Absolute linear encoder bases on the technoloy of magnifying the absolute code by optical magnifying principle, and controlling the CMOS camera of high frame to photo the absolute code which has be magnified by the optical device by FPGA. Finally, decodes the absolute code, and outputs its absolute position information.To effectively promote the domestic measurement technology and the development of linear encoder of China, further to promote the performance of the absolute linear encoder, this paper takes the absolute linear encoder which is independently researching as the object to study and make research on following aspects:Firstly, research on the principle of absolute linear encoder. Establish the initial experiment platform of unsealed absolute linear encoder and make perlimmiary study on its bit errors theory. Verify the feasibility of the principle of the absolute linear encoder.Secondly, design the structure of sealed absolute linear encoder in the SolidWorks software. In order to get the optimum structure of sealed absolute linear encoder, finish the works of dynamic simulation and optimization design in Abaqus software.Thirdly, in order to make the absolute linear encoder be able to measuring with high speed and high accuracy, combine the advantages of both incremental and absolute linear encoders to design a double linear encoder by the redundancy technology by considering of the boundeness of measure speed of the pure absolute linear encoder.Finally, make the the Ultra-precision gas float linear motor-- Aerotech ABL1500 as the the using object, to establish experiment on the the Optical vibration isolation platform --ZLT10-07. Analysis the bit errors characters of pure sealed absolute linear encoder and obtain its optimum work speed (without bit errors). Verify the work feasibility and the measuring limitation of the redundancy absolute linear encoder with the opimum switch work speed.