Fig. 1. Principle diagram of image-based angular displacement measurement technology

Fig. 2. Schematic diagram of coding method

Fig. 3. Schematic diagram of the borderline

Fig. 4. Schematic diagram of edge positioning and recognition principle

Fig. 5. Schematic diagram of linear function fitting

Fig. 6. (a) Experimental setup of angular displacement measurement, and its (b) partial enlarged view; (c) raster code disc

Fig. 7. Principle diagram of hardware circuit

Fig. 8. Dual image sensor circuit diagram

Fig. 9. Image data acquisition results

Fig. 10. Decoding and subdivision experiments

Fig. 11. Angle output data

Fig. 12. Error detection experiment

Fig. 13. Comparison results of angle measurement accuracy