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1. WO2020117279 - RESSORTS NON LINÉAIRES POUR UNIFIER LE MOUVEMENT DYNAMIQUE D'ÉLÉMENTS INDIVIDUELS DANS UN RÉSEAU DE MICROMIROIRS

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]

WHAT IS CLAIMED IS:

1. A device for beam steering in a Light Detection and Ranging (LiDAR) system of an autonomous vehicle, the device comprising:

a mirror;

a spring mechanically coupled with the mirror;

a combdrive actuator configured to move the mirror, the spring, or both the mirror and the spring; and

a limiter configured to limit a range of motion of the mirror, the spring, or both the mirror and the spring, wherein:

the mirror is part of the plurality of mirrors; and the plurality of mirrors are synchronized to move together in time based on the limiter limiting the range of motion of the mirror, so that angular rotation of the plurality of mirrors in time are the same.

2. The device of claim 1, wherein the mirror is formed as part of a microelectromechanical system, and a reflective surface of the mirror has a width equal to or less than 15 millimeters.

3. The device of claim 1, wherein the limiter comprises a hard stop configured to contact the mirror to prevent the mirror from continued rotation about an axis.

4. The device of claim 3, wherein the hard stop is glass.

5. The device of claim 1, wherein the mirror comprises a support and a reflective surface.

6. The device of claim 1, wherein the mirror is rectangular.

7. The device of claim 1, wherein the mirror is mechanically coupled with the spring by a shaft.

8. The device of claim 7, wherein the shaft has a rectangular cross section.

9. The device of claim 7, wherein the limiter comprises a contact to limit a range of motion of the shaft.

10. The device of claim 9, wherein the limiter comprises a spring.

11. The device of claim 10, wherein the spring of the limiter is configured to have a stiffness based on a mass of the mirror.

12. The device of claim 1, wherein the combdrive actuator comprises a plurality of stator fingers and a plurality of rotor fingers.

13. The device of claim 1, wherein:

the limiter comprises a first set of magnets and a second set of magnets;

the first set of magnets are positioned on a substrate;

the second set of magnets are positioned on the mirror; and

the first set of magnets are oriented to repulse the second set of magnets.

14. The device of claim 1, wherein the device is configured as a scanning mirror in a LiDAR system.

15. The device of claim 1, wherein the device is a microelectromechanical system (MEMS) device.

16. The device of claim 1, further comprising a plurality of drivers configured to move the plurality of mirrors, wherein the plurality of drivers are configured to dive mirrors of the plurality of mirrors at the same frequency.

17. A method of using a mirror array, the method comprising:

rotating a plurality of mirrors, wherein:

rotating comprises using a plurality of drivers operating at the same frequency; and

rotating the plurality of mirrors is performed so that motion of the plurality of mirrors is synchronized;

shining a laser beam at the plurality of mirrors;

reflecting the laser beam using the plurality of mirrors, so that the mirrors act as a single mirror to reflect the laser beam; and

partially blocking movement of each mirror of the plurality of mirrors using a limiter at each mirror so that movement of each mirror is nonlinear, wherein the nonlinear movement facilitates synchronization of movement of the plurality of mirrors while driving the plurality of mirrors at the same frequency.

18. The method of claim 17, wherein blocking movement of each mirror of the plurality of mirrors blocks rotation of a shaft used to move the mirror and/or blocks rotation of the plurality of mirrors by physical contact with the mirror.

19. The method of claim 17, wherein blocking movement of each mirror of the plurality of mirrors is performed using magnetic repulsion.

20. A method of manufacturing a device for use in a Light Detection and Ranging (LiDAR) system, the method comprising:

etching to define a mirror support;

etching to define a spring;

etching a shaft that mechanically couples the mirror support with the spring; etching rotors and stators of a driver, wherein the driver is configured to move the shaft;

etching a limiter configured to limit a rotation of the shaft; and coating at least a portion of the mirror support to create a reflective surface on the mirror support.

21. A device for beam steering in a Light Detection and Ranging (LiDAR) system of an autonomous vehicle, the device comprising:

a first mirror, wherein the first mirror is part of an array of mirrors;

a spring mechanically coupled with the first mirror;

a comb drive configured to move the first mirror, the spring, or both the first mirror and the spring, the comb drive comprising:

a rotor; and

a stator;

a sensor configured to monitor a rotation of the first mirror; and electronics configured to:

provide a drive signal, wherein the drive signal determines how the rotor is electromagnetically attracted and/or repulsed by the stator;

determine the first mirror is oscillating out of sync with a second mirror of the array of mirrors, based on data from the sensor, wherein the second mirror oscillates in a first steady state and the first mirror oscillates in a second steady state; and

alter the drive signal so that a phase difference between the rotation of the first mirror and the drive signal changes, such that the first mirror oscillates in the first steady state.

22. The device of claim 21, wherein the first mirror is formed as part of a microelectromechanical system.

23. The device of claim 21, wherein the electronics are further configured to verify that the first mirror is operating in sync with the second mirror based on data from the sensor.

24. The device of claim 21, further comprising a limiter, wherein the limiter is configured limit a range of motion of the first mirror, the spring, or both the first mirror and the spring.

25. The device of claim 21, wherein the array of mirrors is configured as a scanning mirror in a LiDAR system.

26. The device of claim 21, further comprising a plurality of drivers configured to move the plurality of mirrors, wherein the plurality of drivers are configured to dive mirrors of the plurality of mirrors at the same driving frequency.

27. The device of claim 21, wherein the first mirror is rectangular.

28. A method of using a non-linear system to synchronize motion of a plurality of mirrors, the method comprising:

identifying a steady state of operation of a mirror-spring system, wherein the mirror-spring system comprises a first mirror that is part of a mirror array and a spring coupled with the first mirror;

identifying an initial phase, or set of initial phases, between a rotation of the first mirror and a first drive signal, wherein:

a first comb drive is used to rotate the mirror-spring system;

the first comb drive comprises a rotor and a stator;

the first drive signal determines how the rotor is electromagnetically attracted and/or repulsed by the stator; and

starting to rotate the mirror-spring system at the initial phase, or phases of the set of initial phases, will case the mirror-spring system to operate at the steady state of operation in relation to the first drive signal;

applying the first drive signal to the first comb drive at the initial phase, or one of the phases from the set of initial phases;

operating the first comb drive so that the mirror-spring system is rotating at the steady state of operation;

applying a second drive signal to a second comb drive; and

operating the second comb drive so that a second mirror of the mirror array is rotating at the steady state of operation in sync with the first mirror.

29. The method of claim 28, further comprising applying the second drive signal to the second comb drive at one of the phases from the initial set of phases, concurrently with applying the first drive signal to the first comb drive.

30. The method of claim 28, further comprising:

determining that the first mirror and the second mirror are out of sync;

turning off the first drive signal and the second drive signal based on determining that the first mirror and the second mirror are out of sync;

waiting for the first mirror and the second mirror to return to starting parameters; and

applying the first drive signal to the first comb drive at the initial phase, or one of the phases from the set of initial phases, after waiting.

31. The method of claim 28, further comprising:

determining that the first mirror is not operating in the steady state of operation, based on data from a sensor; and

altering the first drive signal, based on determining that the first mirror is not operating in the steady state of operation, so that a phase difference between the rotation of the first mirror and the first drive signal changes, so that the first mirror will operate in the steady state.

32. The method of claim 28, further comprising rotating the first mirror and the second mirror to steer a beam in a LiDAR system.

33. The method of claim 28, wherein the steady state is a first steady state, and the method further comprises:

identifying a second steady state for a plurality of mirror systems; and determining to use the first steady state because there is more variance between second steady states of the plurality of mirror systems than the first steady state.

34. The method of claim 28, wherein the first mirror is formed as part of a microelectromechanical system.

35. The method of claim 34, wherein the first mirror is rectangular.

36. The method of claim 28, wherein:

the first drive signal has a first frequency,

the second drive signal has a second frequency, and

the first frequency is equal to the second frequency.

37. The method of claim 28, further comprising using a sensor to sense rotation of the first mirror.

38. A method of using a non-linear system to synchronize motion of a plurality of mirrors, the method comprising:

using a first combdrive actuator to move a first mirror at an amplitude and a frequency;

using a second combdrive actuator to move a second mirror at the amplitude and at the frequency of the first mirror so that the first mirror and the second mirror move in a synchronized motion, wherein the motion is non-linear having a first steady state of operation and a second steady state of operation; and

configuring the first mirror and the second mirror to have starting parameters so that the first mirror and the second mirror will both operate at the first steady state of operation.

39. The method of claim 38, further comprising:

determining that the first mirror and the second mirror are out of sync;

turning off the first combdrive actuator and the second combdrive actuator; allowing the first mirror and the second mirror to return to starting parameters; and

turning on the first combdrive actuator and the second combdrive actuator so that the first mirror and the second mirror move in the synchronized motion.

40. The method of claim 38, further comprising rotating the first mirror and the second mirror to steer a beam in a LiDAR system.