Scanner control for Lidar systems
A scanner and a method for controlling the scanner for a Lidar system are provided. The method comprises: producing a trigger signal by a positional sensor of the scanner; generating a single drive signal comprising a first component at a first frequency and a second component at a second frequency, the first component and the second component are superposed with a fixed phase relationship with aid of the trigger signal; transmitting the single drive signal to the scanner, and the scanner has resonant responses at the first frequency; and actuating the scanner to move in a first periodic motion at the first frequency about a first axis, and move in a second periodic motion at the second frequency about a second axis.
1. A method for controlling a scanner of a Lidar system, comprising:
producing a trigger signal by a positional sensor of the scanner;
generating a single drive signal comprising a first component at a first frequency and a second component at a second frequency, wherein the first component and the second component are superposed with a fixed phase relationship with aid of the trigger signal;
transmitting the single drive signal to the scanner, wherein the scanner has resonant responses at the first frequency; and
actuating the scanner to move in a first periodic motion at the first frequency about a first axis, and move in a second periodic motion at the second frequency about a second axis.
2. The method of claim 1 , wherein the scanner includes a single multi-axis mirror.
3. The method of claim 1 , wherein the first periodic motion is at a first resonant frequency of the scanner about the first axis and the second periodic motion is at a second resonant frequency of the scanner about the second axis.
4. The method of claim 1 , wherein the second component comprises a ramp waveform.
5. The method of claim 4 , wherein the second component comprises a low frequency waveform component and a high frequency waveform component.
6. The method of claim 5 , wherein the high frequency waveform component is at a frequency twice that of the first frequency of the first component.
7. The method of claim 6 , wherein the high frequency waveform component and the low frequency waveform component are synchronized with aid of the trigger signal.
8. The method of claim 5 , wherein the high frequency waveform component has variable amplitude.
9. The method of claim 8 , wherein the high frequency waveform component and the low frequency waveform component are combined with a pre-determined phase relationship.
10. The method of claim 8 , wherein the high frequency waveform component is generated in response to real-time conditions.
11. The method of claim 10 , wherein the real-time conditions include detection of a target.
12. The method of claim 1 , wherein the trigger signal is generated at the start or end of a sweep cycle of the first periodic motion.
13. The method of claim 1 , wherein the second component is generated in response to receiving the trigger signal.
14. The method of claim 1 , wherein the scanner is directing a sequence of light pulses along a scanning pattern that approximates a raster scan pattern.
15. The method of claim 14 , further comprising dynamically adjusting the scanning pattern along the second axis direction according to real-time conditions.
16. The method of claim 15 , wherein adjusting the scanning pattern along the second axis direction comprises varying the second periodic motion by superposing a high frequency waveform component to the single drive signal.
17. The method of claim 16 , wherein an amplitude or frequency of the high frequency waveform component is determined based on the real-time conditions.
18. The method of claim 15 , further comprising dynamically adjusting the scanning pattern along the first axis direction according to real-time conditions.
19. The method of claim 18 , wherein adjusting the scanning pattern along the first axis direction comprises varying time intervals of emitting the sequence of light pulses.
20. A scanner for a Lidar system comprising:
a scanner actuated to move in a first periodic motion at a first frequency about a first axis, and move in a second periodic motion at a second frequency about a second axis;
a positional sensor configured to generate a trigger signal; and
a controller configured to generate a single drive signal to actuate the scanner, wherein the single drive signal comprises a first component at the first frequency and a second component at the second frequency, wherein the first component and the second component are superposed with a fixed phase relationship with aid of the trigger signal.
21. The scanner of claim 20 , wherein the scanner comprises a single multi-axis mirror.
22. The scanner of claim 21 , wherein the single multi-axis mirror comprises a scan plate suspended from a gimbal via one or more torsion arms.
23. The scanner of claim 22 , wherein the one or more torsion arms are in an H shape.
24. The scanner of claim 20 , wherein the first periodic motion is at a first resonant frequency of the scanner about the first axis and the second periodic motion is at a second resonant frequency of the scanner about the second axis.
25. The scanner of claim 20 , wherein the second component comprises a ramp waveform.
26. The scanner of claim 25 , wherein the second component comprises a low frequency waveform component and a high frequency waveform component.
27. The scanner of claim 26 , wherein the high frequency waveform component is at a frequency twice that of the first frequency of the first component.
28. The scanner of claim 27 , wherein the high frequency waveform component and the low frequency waveform component are synchronized with aid of the trigger signal.
29. The scanner of claim 20 , wherein the trigger signal is generated at the start or end of a sweep cycle of the first periodic motion.
30. The scanner of claim 20 , wherein the controller is configured to generate the second component in response to receiving the trigger signal.