Absolute Position Encoders Using Double-Track Gray Codes

• Published in: IEEE transactions on instrumentation and measurement Vol. 74; pp. 1 - 7
• Main Authors: Fakhri, Ashkan, Mallah Livani, Abdolber
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2025; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Absolute position encoder; Algorithms; Coders; Codes; Detectors; double track; Encoding; encoding and decoding; gray code; Head; Heuristic algorithms; Light emitting diodes; Magnetic heads; Mathematical models; Radar tracking; Reflective binary codes; single track
• ISSN: 0018-9456; 1557-9662
• DOI: 10.1109/TIM.2024.3493887

A slight increase in the physical dimensions of the single-track gray code (STGC) encoders in exchange for using fewer reading heads (fewer bits) is the subject that is addressed in this article. A construction algorithm is proposed to combine two STGCs in order to obtain a double-track gray code (DTGC). The proposed algorithm can be repeatedly used to obtain triple-track gray codes (TTGCs) and so on. The proposed algorithm can be used to quickly obtain very high period codes with a sufficiently small number of tracks. Furthermore, it can be used to obtain desirable codes by trading off the number of tracks and the length of the code. For a given desired period, this tradeoff may provide the opportunity of using fewer bits compared to STGCs. In particular, length n period <inline-formula> <tex-math notation="LaTeX">2^{n} </tex-math></inline-formula> encoders can be constructed with almost half the number of tracks of the corresponding conventional gray code encoders.