Fig. 1. Structure diagram of two-dimensional miniature electromagnetic galvanometer system

Fig. 2. Schematic diagram of mirror angle detection system structure and signal processing circuit

Fig. 3. Schematic diagram of mirror angle detection system. (a) Mirror is not deflected; (b) mirror rotates ${\theta }_y$ around the A-axis

Fig. 4. Relationship between system measurement value and mirror deflection angle. (a) Relationship between detector photocurrent and mirror deflection angle; (b) relationship between mirror deflection angle calculated value and true value

Fig. 5. Comparison between angle calculated value and angle calculated fitting value

Fig. 6. Relationship between the true value and the calculated value of the mirror angle at different detector horizontal positions

Fig. 7. Relationship between the horizontal position of the detector and the maximum angle value of single-direction detection, when the nonlinearity is 5%

Fig. 8. Relationship between the true value and the calculated value of the mirror angle at different distances d_lm

Fig. 9. Relationship between different distances d_lm and the maximum angle value of single-direction detection, when the nonlinearity is 5%

Fig. 10. Relationship between the true value of the mirror angle and the calculated value when the LED has different half-power angles

Fig. 11. Relationship between different half-power angles of LEDs and the maximum angle value of single-direction detection, when the nonlinearity is 5%

Fig. 12. Experimental platform of mirror angle detection system. (a) Schematic diagram of experimental platform; (b) physical diagram of experimental platform

Fig. 13. Verification ideas of theoretical model. (a) Radiation curves comparison of SFH 4441 and Lambert light source; (b) detector energy sum, difference, and ratio curves of ideal Lambert light source; (c) detector energy sum, difference, and ratio curves of experimental light source SFH 4441; (d) comparison of the relationship between the true value and the calculated value of the mirror angle in theory and experiment

Fig. 14. Mirror angle calculated curve at different horizontal positions of the detector

Fig. 15. Comparison of theoretical and experimental values for maximum angle value of single‑direction detection, when the nonlinearity is 5% and the detector is at different horizontal positions

Fig. 16. Calculation curves of the mirror angle at different distances d_lm

Fig. 17. Comparison of theoretical and experimental values for maximum angle value of single‑direction detection, when the nonlinearity is 5% and different distances d_lm

Table 1. Typical parameters of system model