The Study Of 24-bits Absolute Photoelectric Rotary Encoders

Based on experiments, a 24-bits absolute photoelectric rotary encoder is presented in this paper. It's advantages lie in:1. It has a system for thick code tracks to automatically compensate;2. It adopts solid lighting system instead of spherical spotlighting system. And because of getting rid of complicated optical lighting system, it reduces greatly in axial size, and the size it reduces is the half of the same kind old;3. It improves the axial accuracy by using close balls for bearing;4. It reduce errors in both code plate and axial system, as the multiple read head (four thin read head and one thick read head) same working;The design of the circuit is different from the old. It uses the device which Software interpolation of single-chip computer instead of interpolation of the electrical resistance chains. And the advantages lie in: 1 .The circuit is simple, so it's easy to adjust; 2. It improves both in the quality of original Moire fringe signals and the interpolation accuracy by the way of improves it's structure; 3. the signal is interpolated to 1024 parts by single-chip computer, this acquires high interpolation times, and the resolution and the accuracy of absolute photoelectric rotaiy encoder are improved as well. About this 24-unit absolute photoelectric rotary encoder ,It's angle resolution is 0.078" and the precision of testing angle is σ<0.8".The range of it' s working temperature is generally -30 ℃ ~ 40℃ . It' s maximum velocity and angle accelerator are 100°/ s and 100°/ s'. It realizes high-accuracy test of angle position and real-time control, and satisfies the needs of some fields for high-accuracy and high resolution absolute photoelectric rotary encoders, such as snare science automation and national defense construction , etc.