Motion detector by geometrical Moire technique

Abstract

In this project, the construction is based on the Optical Geometrical Moiré Theory. This project is to build a high accuracy motion detector by using Optical Geometrical Moiré technique to measure the object movement. For this motion detector it consists of three mainly components, that is Optical Transducer, Encoder and Counter with Display. The Optical Transducer is used to transform the optical moiré signal to the electrical signal for measuring purpose. The Encoder is used to identify the motion of the detector, then generating an identifying electrical signal to mention about the motion of the detector. The Counter is used to calculate the distance of the detector has been moved and then displaying the result on the LED. During designing this motion detector, the most difficult section is the Optical Transducer. In order to achieve the high accuracy and high stability, the grating line in the Transducer should be fine enough and the detection area of the sensor in the Transducer should be well designed. All this design criteria will be discussed in the report. In conclusion, this motion detector given a well performance on stability and accuracy during measure the object motion. Also it can provide a good demonstration on how the optical geometrical moiré theory to be implemented in measuring purpose.