Scanning depth engine
Mapping apparatus includes a transmitter, which is configured to emit at least one beam including a sequence of pulses of light toward a plurality of points in a scene. A receiver is configured to receive the light reflected from the scene and to generate an output indicative of a time of flight of the pulses to and from the points in the scene. A processor is coupled to process the output of the receiver so as to generate a 3D map of the scene, while controlling a power level of the pulses emitted by the transmitter responsively to a level of the output from the receiver in response to one or more previous pulses.
1. Mapping apparatus, comprising:
a transmitter, which is configured to emit at least one beam comprising a sequence of pulses of light toward a plurality of points in a scene;
a receiver, which is configured to receive the light reflected from the scene and to generate an output indicative of a time of flight of the pulses to and from the points in the scene; and
a processor, which is coupled to process the output of the receiver so as to generate a 3D map of the scene, while controlling a power level of the pulses emitted by the transmitter toward each point among the plurality of points in the scene responsively to a level of the output from the receiver in response to one or more previous pulses that were transmitted toward the same point in the scene so as to reduce variations in an intensity of the reflected light that is received from different parts of the scene.
2. The apparatus according to claim 1 , wherein the one or more previous pulses comprise scout pulses emitted by the transmitter in order to assess and adjust the power level.
3. The apparatus according to claim 2 , wherein the power level of the scout pulses transmitted toward at least some of the points in the scene is lower than the power level of the pulses transmitted toward the at least some of the points in order to generate the output indicative of the time of flight.
4. The apparatus according to claim 1 , wherein the transmitter comprises a laser.
5. The apparatus according to claim 1 , and comprising a scanner, which is configured to scan the at least one beam over the plurality of the points in the scene, so that the pulses are incident on successive, neighboring points along a scan path.
6. The apparatus according to claim 5 , wherein the processor is configured to set the power level at each of the plurality of points based on the level of the output due to a previous pulse that was transmitted toward a different, preceding point on the scan path.
7. The apparatus according to claim 5 , wherein the receiver comprises a detector, which is configured to receive the light reflected from the scene via the scanner.
8. The apparatus according to claim 7 , and comprising a beamsplitter, which is positioned so as to direct the at least one beam emitted by the transmitter toward the scanner, while permitting the reflected light to reach the detector, wherein the at least one emitted beam and the reflected light have respective optical axes, which are parallel between the beamsplitter and the scanner.
9. The apparatus according to claim 5 , wherein the processor is coupled to control the scanner so as to cause the at least one beam to scan over a selected window within the scan range and to process the output of the receiver so as to generate the 3D map of a part of the scene that is within the selected window.
10. The apparatus according to claim 9 , wherein the processor is configured to select a different window to scan in each scan of the at least one beam.
11. The apparatus according to claim 1 , wherein the receiver comprises a two-dimensional matrix of photo-detectors with a stationary collection lens.
12. The apparatus according to claim 1 , wherein the at least one beam comprises multiple beams emitted simultaneously by the transmitter.
13. A method for mapping, comprising:
directing at least one beam comprising a sequence of pulses of light emitted by a transmitter toward a plurality of points in a scene;
receiving the light reflected from the scene and generating an output indicative of a time of flight of the pulses to and from the points in the scene;
processing the output so as to generate a 3D map of the scene; and
controlling a power level of the pulses emitted by the transmitter toward each point among the plurality of points in the scene responsively to a level of the output from the receiver in response to one or more previous pulses that were transmitted toward the same point in the scene so as to reduce variations in an intensity of the reflected light that is received from different parts of the scene.
14. The method according to claim 13 , wherein the one or more previous pulses comprise scout pulses emitted in order to assess and adjust the power level.
15. The method according to claim 14 , wherein the power level of the scout pulses transmitted toward at least some of the points in the scene is lower than the power level of the pulses transmitted toward the at least some of the points in order to generate the output indicative of the time of flight.
16. The method according to claim 13 , wherein directing the at least one beam comprises the at least one beam over the plurality of the points in the scene, so that the pulses are incident on successive, neighboring points along a scan path, and
wherein controlling the power level comprises setting the power level at each of the plurality of points based on the level of the output due to a previous pulse that was transmitted toward a different, preceding point on the scan path.