Lidar system
A LIDAR system emits laser bursts, wherein each burst has at least a pair of pulses. The pulses of each pair are spaced by a time interval having a variable duration to reduce effects of cross-talk. For example, certain embodiments may have multiple emitter/sensor channels that are used sequentially, and each channel may use a different duration for inter-pulse spacing to reduce the effects of cross-talk between channels. The durations may also be varied over time. The emitters and sensors are physically arranged in a two-dimensional array to achieve a relatively fine vertical pitch. The array has staggered rows that are packed using a hexagonal packing arrangement. The channels are used in a sequential order that is selected to maximize spacing between consecutively used channels, further reducing possibilities for inter-channel cross-talk.
1. A LIDAR device comprising:
a laser light source comprising a plurality of laser emitters to emit light, the plurality of laser emitters arranged relative to an x-axis and a y-axis, which is perpendicular to the x-axis, the plurality of laser emitters comprising:
a first row of laser emitters disposed in a first line at a first oblique angle relative to the x-axis; and
a second row of laser emitters disposed in a second line parallel to the first line, the second row of laser emitters being staggered relative to the first row of laser emitters; and
a light sensor comprising a plurality of sensor elements, wherein:
at least one laser emitter of the plurality of laser emitters is configured to emit a first burst of pulses to an object; and
at least one corresponding sensor element of the plurality of sensor elements is configured to receive a second burst of pulses reflected from the object, wherein a time relationship between the first burst of pulses and the second burst of pulses is analyzed to determine a distance to the object.
2. The LIDAR device of claim 1 , wherein the plurality of sensor elements are arranged relative to the x-axis and the y-axis to sense reflected light, the plurality of sensor elements comprising:
a first row of sensor elements disposed in a third line at a second oblique angle relative to the x-axis; and
a second row of sensor elements disposed in a fourth line parallel to the third line, the second row of sensor elements being staggered relative to the first row of laser emitters.
3. The LIDAR device of claim 2 , wherein:
the LIDAR device comprises a rotatable portion to which the laser light source and the light sensor are coupled;
the y-axis is associated with a rotation axis about which the rotatable portion is rotatable; and
the x-axis is associated with a scan axis, substantially perpendicular to the rotation axis, the scan axis being a direction in which light from the plurality of laser emitters is emitted from the LIDAR device.
4. The LIDAR device of claim 2 , wherein each sensor element of the plurality of sensor elements is associated with a respective laser emitter of the plurality of laser emitters and is configured to receive reflected light corresponding to light emitted by the respective laser emitter.
5. The LIDAR device of claim 2 , wherein:
the first oblique angle results in each sensor element of the plurality of sensor elements having a unique y-axis position; and
the second oblique angle results in each laser emitter of the plurality of laser emitters having a unique y-axis position.
6. The LIDAR device of claim 1 , wherein:
the plurality of laser emitters has a first uniform y-axis pitch; and
the plurality of laser emitters comprises 38 laser emitters.
7. The LIDAR device of claim 2 , wherein:
the plurality of sensor elements has a second uniform y-axis pitch; and
the plurality of sensor elements comprises 38 sensor elements.
8. The LIDAR device of claim 2 , wherein the plurality of sensor elements has a sensor-to-sensor pitch of about 6 millimeters.
9. The LIDAR device of claim 2 , wherein a first spacing between individual laser emitters of the plurality of laser emitters is approximately equal to a second spacing between individual sensor elements of the plurality of sensor elements.
10. The LIDAR device of claim 2 , wherein the first oblique angle is approximately equal to the second oblique angle.
11. The LIDAR device of claim 1 , further comprising a plurality of emitter boards, the first row of laser emitters being mounted along an upper edge of a first emitter board of the plurality of emitter boards, and the second row of laser emitters being mounted along an upper edge of a second emitter board of the plurality of emitter boards.
12. The LIDAR device of claim 11 , wherein the upper edge of the first emitter board and the upper edge of the second emitter board are curved, such that the first row of laser emitters and the second row of laser emitters are arranged along a circumference of an imaginary sphere.
13. The LIDAR device of claim 2 , further comprising:
control logic communicatively coupled to the laser light source to control firing of the plurality of laser emitters; and
analysis logic communicatively coupled to the light sensor to analyze signals associated with reflected light received by the sensor elements to determine a propagation time to the object in an environment.
14. A LIDAR device comprising:
a laser light source comprising a plurality of laser emitters arranged in multiple parallel emitter rows and packed in a hexagonal lattice, with alternate rows of the multiple parallel emitter rows being staggered in at least one direction relative to one another, wherein the LIDAR device is configured to perform distance measurement using at least the plurality of laser emitters.
15. The LIDAR device of claim 14 , further comprising:
a light sensor comprising a plurality of sensor elements arranged in multiple parallel sensor rows, with alternate rows of the multiple parallel sensor rows being staggered in at least one direction relative to one another.
16. The LIDAR device of claim 15 , wherein:
the plurality of laser emitters comprises:
a first row of laser emitters disposed in a first line; and
a second row of laser emitters disposed in a second line parallel to the first line; and
the plurality of sensor elements comprises:
a first row of sensor elements disposed in a third line; and
a second row of sensor elements disposed in a fourth line parallel to the third line.
17. The LIDAR device of claim 15 , wherein:
the plurality of laser emitters and the plurality of sensor elements are arranged relative to an x-axis and a y-axis, which is perpendicular to the x-axis;
the multiple parallel emitter rows being disposed at a first oblique angle relative to the x-axis; and
the multiple parallel sensor rows being disposed at a second oblique angle relative to the x-axis.
18. The LIDAR device of claim 17 , wherein:
each sensor element of the plurality of sensor elements is positioned at a unique y-axis position relative to other sensor elements of the plurality of sensor elements; and
each laser emitter of the plurality of laser emitters is positioned at a unique y-axis position relative to other laser emitters of the plurality of laser emitters.
19. The LIDAR device of claim 17 , wherein:
the plurality of laser emitters has a first uniform y-axis pitch; and
the plurality of sensor elements has a second uniform y-axis pitch.
20. The LIDAR device of claim 14 , further comprising an emitter board having a curved upper edge, wherein laser emitters of a first row of the multiple parallel emitter rows are mounted to the curved upper edge of the emitter board.