Vertical cavity surface emitting laser (VCSEL) array laser scanner
View Patent ↗Vehicle-based lidar systems and methods are disclosed using multiple lasers to provide more compact and cost-effective lidar functionality. Each laser in an array of lasers can be sequentially activated so that a corresponding optical element mounted with respect to the array of lasers produces respective interrogation beams in substantially different directions. Light from these beams is reflected by objects in a vehicle's environment, and detected so as to provide information about the objects to vehicle operators and/or passengers.
1. An apparatus for a vehicle lidar system comprising:
a plurality of semiconductor lasers;
an optical element mounted with respect to the plurality of lasers so that at least two of the plurality of lasers produce beams that emanate from the optical element in substantially different directions;
control circuitry coupled to the plurality of semiconductor lasers and configured to sequentially and separately activate the at least two of the plurality of lasers;
a translator coupled to the plurality of semiconductor lasers, the translator configured to translate the plurality of semiconductor lasers with respect to the optical element.
2. The apparatus of claim 1 wherein the plurality of semiconductor lasers further comprises at least one of:
a plurality of vertical cavity surface-emitting lasers (VCSELs) formed on a single semiconductor substrate; a plurality of VCSELs, wherein at least two of the plurality of VCSELs are formed on different semiconductor substrates; and a plurality of edge emitting lasers.
3. The apparatus of claim 1 wherein the plurality of semiconductor lasers is arranged in a two-dimensional linear array.
4. The apparatus of claim 1 wherein a first one of the plurality of semiconductor lasers produces light having a first wavelength, and a second one of the plurality of semiconductor lasers produces light having a second wavelength.
5. The apparatus of claim 1 wherein the optical element further comprises at least one of a lens, a prism, and a lens array.
6. The apparatus of claim 1 wherein the translator further comprises at least one of a voice coil, a piezoelectric translator, a stepper motor, a shape memory translator, and a vibrator motor.
7. The apparatus of claim 1 further comprising a photodetector configured to detect light generated by at least one of the plurality of semiconductor lasers and reflected from an object scanned by the lidar system.
8. The apparatus of claim 7 further comprising: a light collection optical element mounted with respect to the photodetector and operable to concentrate at least a portion the light generated by the at least one of the plurality of semiconductor lasers and reflected from the object scanned by the lidar system, wherein the light collection optical element further comprises at least one of a reflective optical element, a refractive optical element, a holographic optical element, and a diffractive optical element.
9. The apparatus of claim 7 wherein the photodetector is formed on the same semiconductor substrate as the plurality of semiconductor lasers.
10. The apparatus of claim 7 wherein the photodetector further comprises at least one of: a PIN photodiode, a PN photodiode, an avalanche photodiode, a CCD device, a CMOS detector, and a photomultiplier tube.
11. The apparatus of claim 7 further comprising: a signal processing circuit for determining an approximate distance between the vehicle and an object reflecting at least one of the respective beams produced by the at least two of the plurality of lasers, wherein the signal processing circuit uses information provided by the photodetector.
12. The apparatus of claim 11 further comprising: a vehicle safety system coupled to the signal processing circuit, wherein the vehicle safety system further comprises an indicator configured to provide information, to a vehicle user, related to the object reflecting at least one of the respective beams produced by the at least two of the plurality of lasers, and wherein the indicator further comprises at least one of: a video display, a heads-up display (HUD), a haptic interface, an audio interface, and an indicator lamp.
13. A method of detecting objects in a vehicle's environment, the method comprising:
activating a first semiconductor laser to produce a first beam;
deflecting the first beam in a first direction using a first optical element;
activating a second semiconductor laser to produce a second beam;
deflecting the second beam in a second direction using the first optical element;
translating said second semiconductor laser relative to said first optical element;
detecting light from at least one of the first beam and the second beam reflected by an object in the vehicle's environment; and
determining a location of the object in response to the detecting.
14. The method of claim 13 wherein the first semiconductor laser and the second semiconductor laser are together at least one of:
a plurality of vertical cavity surface-emitting lasers (VCSELs) formed on a single semiconductor substrate;
a plurality of VCSELs, wherein at least two of the plurality of VCSELs are formed on different semiconductor substrates;
a plurality of edge emitting lasers;
a portion of a one-dimensional linear laser array; and
a portion of a two-dimensional linear laser array.
15. The method of claim 13 wherein at least one of the deflecting the first beam further comprises transmitting the first beam through a refractive optical element.
16. The method of claim 13 further comprising: collecting the light from at least one of the first beam and the second beam reflected by an object in the vehicle's environment using at least one of a reflective optical element, a refractive optical element, and a diffractive optical element; and focusing at least a portion of the collected light on a photodetector.
17. The method of claim 13 further comprising: providing an object detection indication to a vehicle user.
18. An apparatus for detecting objects in a vehicle's environment, the apparatus comprising:
a means for producing a first laser beam;
a means for producing a second laser beam;
a means for sequentially activating the means for producing a first laser beam and the means for producing a second laser beam;
an optical element for deflecting the first laser beam in a first direction and the second laser beam in the second direction;
a means for translating said first laser beam relative to said optical element;
a means for detecting light from at least one of the first laser beam and the second laser beam reflected by an object in the vehicle's environment; and
a means for determining a location of the object using information from the means for detecting light.