Two-dimensional Space Polarization Encoded Signal Synchronization And Decoding

The core of laser beam-riding guidance is the laser encoding and decoding technology. The spatial polarization encoding technology uses the difference of polarization states in space to make the light contain position information. The determination of spatial position needs both horizontal and vertical information, The synchronous transmission and distinction of two-dimensional encoded signal is the key of laser encoding and decoding technology. The fundamental theory of laser beam-riding guidance is introduced, spatial polarization encoding and decoding technology is studied, a mothod to achieve the synchronous transmission and distinction of two-dimensional encoded signal is present. To achieve the synchronous transmission of two-dimensional signal, rectangular pulse signals with different frequency are used and to modulate the horizontal & vertical encoders'driving voltage. Band-pass filter is used to distinguish the two-dimentional encoded signal. According to the principle of spatial polarization decoding and the characteristics of two-dimensional synchronous encoded signal, the signal receiving and decoding system is set up, including optical receiving system and signal processing circuit. A single chip microcomputer is used as the core chip in the signal processing circuit, it decodes the two-dimentional encoded signal with band-pass filter and other modules. Under the laboratory condition, the two-dimentional encoded signal is decoded, and the system errors possibly existing are analyzed. The results show that the method to synchronously transmit and decode two-dimensional polarization encoded signal is feasible.