초록 ▼

A light detection and ranging (LIDAR) device that scans through a scanning zone while emitting light pulses and receives reflected signals corresponding to the light pulses is disclosed. The LIDAR device scans the scanning zone by directing light toward a rotating mirror to direct the light pulses t

A light detection and ranging (LIDAR) device that scans through a scanning zone while emitting light pulses and receives reflected signals corresponding to the light pulses is disclosed. The LIDAR device scans the scanning zone by directing light toward a rotating mirror to direct the light pulses through the scanning zone. The rotating mirror is driven by a conductive coil in the presence of a magnetic field. The conductive coil is coupled to the rotating mirror and arranged in a plane perpendicular to the axis of rotation of the mirror. The axis of rotation of the mirror is oriented substantially parallel to a reflective surface of the mirror and passes between the reflective surface and the conductive coil.

대표청구항 ▼

1. A light detection and ranging (LIDAR) device comprising: a rotating mirror system including: a mirror body with a reflective side and a back side opposite the reflective side, wherein the mirror body is arranged to rotate about an axis of rotation substantially parallel to the reflective side suc

1. A light detection and ranging (LIDAR) device comprising: a rotating mirror system including: a mirror body with a reflective side and a back side opposite the reflective side, wherein the mirror body is arranged to rotate about an axis of rotation substantially parallel to the reflective side such that a change in angle of rotation creates a corresponding change in orientation of a normal direction of the reflective side;a conductive coil coupled to the mirror body, wherein the conductive coil is oriented in a plane substantially perpendicular to the axis of rotation, and wherein the conductive coil is arranged such that the axis of rotation is between the reflective side and the conductive coil;a driving circuit configured to apply a current through the conductive coil; andat least one magnet with an associated magnetic field arranged such that current flowing through the conductive coil urges the conductive coil in a direction perpendicular to both the magnetic field and the direction of current flow so as to generate a torque on the mirror body; anda light source configured to emit light pulses directed toward the rotating mirror system such that the light pulses are reflected by the reflective side and emitted from the LIDAR device according to the orientation of the reflective side. 2. The LIDAR device according to claim 1, wherein the driving circuit is further configured to periodically alternate the direction of current in the conductive coil to cause the mirror to oscillate. 3. The LIDAR device according to claim 2, wherein periodically alternating current in the conductive coil generates corresponding periodic oscillations in the orientation of the rotating mirror system in which the reflective side of the mirror body oscillates through a range of orientations to cause the light pulses to scan a scanning zone. 4. The LIDAR device according to claim 1, wherein the conductive coil is arranged in a loop with four sides, and the four sides include: a first radial side arranged approximately along a line intersecting the axis of rotation of the rotating mirror;a second radial side arranged approximately along a line intersecting the axis of rotation of the rotating mirror;an inner side connecting ends of the first and second radial sides proximate the axis of rotation of the rotating mirror; andan outer side connecting ends of the first and second radial sides distal the axis of rotation of the rotating mirror;wherein the two radial sides contribute torque forces on the mirror body while current is flowing through the conductive coil such that a net torque on the mirror body depends on the interaction between the current flowing through the first and second radial sides of the conductive coil and the magnetic field associated with the at least one magnet in the vicinity of the first and second radial sides. 5. The LIDAR device according to claim 4, wherein the at least one magnet includes a first permanent magnet and second permanent magnet arranged: (i) with the first permanent magnet situated to provide a magnetic field in the vicinity of the first radial side of the conductive coil with a first direction oriented parallel to the axis of rotation of the rotating mirror; and (ii) with the second permanent magnet situated to provide a magnetic field in the vicinity of the second radial side of the conductive coil with a second direction oriented antiparallel to the first direction. 6. The LIDAR device according to claim 1, further comprising a ferromagnetic yoke for substantially containing the magnetic field associated with the at least one magnet to a region through which the conductive coil passes during rotation of the rotating mirror; wherein the at least one magnet includes a first permanent magnet and second permanent magnet, and wherein the first and second permanent magnets and the ferromagnetic yoke are arranged such that the magnetic field surrounding the conductive coil includes: (i) a first region having a local magnetic field oriented in a first direction parallel to the axis of rotation of the rotating mirror, and (ii) a second region having a local magnetic field oriented in a second direction antiparallel to the first direction. 7. The LIDAR device according to claim 1, wherein the conductive coil is embedded in a printed circuit board attached to the back side of the mirror body. 8. The LIDAR device according to claim 1, further comprising: an optical encoder arranged to detect an orientation angle of the rotating mirror system. 9. The LIDAR device according to claim 1, further comprising: a pivot rod forming the axis of rotation of the rotating mirror system, wherein the pivot rod passes through the mirror body;a housing to which is mounted the at least one magnet and the pivot rod such that the mirror body rotates with respect to the housing; andone or more springs connected between housing and points on the mirror body distal from the axis of rotation, wherein the one or more springs cause the rotating mirror system to have a resonant oscillatory response. 10. The LIDAR device according to claim 1, further comprising a light sensor configured to detect returning reflected light signals corresponding to the emitting light pulses, and wherein the LIDAR device is associated with an autonomous vehicle that is configured to use the received returning reflected signals to detect obstacles and then control the vehicle to avoid the detected obstacles. 11. An autonomous vehicle system comprising: a light detection and ranging (LIDAR) device including: a rotating mirror system including: a mirror body with a reflective side and a back side opposite the reflective side, wherein the mirror body is arranged to rotate about an axis of rotation substantially parallel to the reflective side such that a change in angle of rotation creates a corresponding change in orientation of a normal direction of the reflective side;a conductive coil coupled to the mirror body, wherein the conductive coil is oriented in a plane substantially perpendicular to the axis of rotation, and wherein the conductive coil is arranged such that the axis of rotation is between the reflective side and the conductive coil;a driving circuit configured to create a current through the conductive coil; andat least one magnet with an associated magnetic field arranged such that current flowing through the conductive coil urges the conductive coil in a direction perpendicular to both the magnetic field and the direction of current flow so as to generate a torque on the mirror body;a light source configured to emit light pulses directed toward the rotating mirror system such that the light pulses are reflected by the reflective side and emitted from the LIDAR device according to the orientation of the reflective side; anda sensor configured to receive returning reflected signals corresponding to the light pulses emitted from the LIDAR device; anda controller configured to: instruct the LIDAR device to scan a scanning zone while emitting light pulses;identify obstacles surrounding the autonomous vehicle based on returning reflected light signals corresponding to the emitted light pulses; andcontrol the autonomous vehicle to avoid the identified obstacles. 12. The autonomous vehicle system according to claim 11, wherein the driving circuit is further configured to periodically alternate the direction of current through the conductive coil. 13. The autonomous vehicle system according to claim 12, wherein periodically alternating current through the conductive coil generates corresponding periodic oscillations in the orientation of the rotating mirror system in which the reflective side of the mirror body oscillates through a range of orientations to cause the light pulses to scan a scanning zone. 14. The autonomous vehicle system according to claim 11, wherein the conductive coil is embedded in a printed circuit board attached to the back side of the mirror body. 15. The autonomous vehicle system according to claim 11, wherein the LIDAR device further includes: an optical encoder arranged to detect an orientation angle of the rotating mirror system, andwherein the controller is further configured to receive an indication of an orientation angle of the rotating mirror system detected by the optical encoder. 16. The autonomous vehicle system according to claim 11, wherein the LIDAR device further includes: a pivot rod defining the axis of rotation of the rotating mirror system, wherein the pivot rod passes through the mirror body; anda housing to which is mounted the at least one magnet and the pivot rod such that the mirror body rotates with respect to the housing. 17. The autonomous vehicle system according to claim 16, wherein the rotating mirror system further includes an optical encoder disk mounted to rotate with the mirror body and a light sensor fixed with respect to the at least one magnet and configured to detect movement of the encoder disk. 18. A method comprising: emitting light pulses from a light source in a light detection and ranging (LIDAR) device toward a reflective side of a mirror;while emitting the series of light pulses, applying an alternating current to a conductive coil coupled to the mirror, wherein the conductive coil is oriented in a plane substantially perpendicular to an axis of rotation of the mirror, wherein the axis of rotation of the mirror is oriented substantially parallel to the reflective side of the mirror and situated between the reflective side of the mirror and the conductive coil, and wherein at least one magnet is arranged such that current flowing through the conductive coil urges the conductive coil in a direction perpendicular to both the magnetic field and the direction of current flow so as to generate a torque on the mirror about the axis of rotation such that the applied alternating current causes the mirror to oscillate;receiving returning reflected signals corresponding to the emitted light pulses;identifying obstacles surrounding an autonomous vehicle associated with the LIDAR device based on the received returning reflected signals and based on the orientations of the mirror in the LIDAR device while emitting the light pulses; andcontrolling the autonomous vehicle to avoid the identified obstacles. 19. The method according to claim 18, further comprising: receiving orientation feedback information from an optical encoder situated to detect the orientation angle of the mirror; andwherein the identifying the obstacles is also based on the received orientation feedback information. 20. The method according to claim 18, wherein the applied alternating current has a frequency of at least 60 hertz.