Multi-range three-dimensional imaging systems

A three-dimensional imaging system comprising:

• a first three-dimensional sensor having a first optical axis oriented at a first angle toward a scene, the first three-dimensional sensor including:
• a laser source configured to emit a plurality of laser pulses;
• an emission optical element configured to collimate and direct the plurality of laser pulses at a plurality of corresponding incidence angles with respect to the first optical axis toward one or more first objects in the scene, wherein the plurality of corresponding incidence angles forms a first angular field of view of the first three-dimensional sensor, and wherein a portion of each of the plurality of laser pulses is reflected off of the one or more first objects;
• a receiving optical element configured to receive and focus the portion of each of the plurality of laser pulses reflected off of the one or more first objects;
• a photodetector configured to receive and detect the portion of each of the plurality of laser pulses focused by the receiving optical element;
• and
• a processor including one or more processing units coupled to the laser source and the photodetector and configured to:
• determine a time of flight for each of the plurality of laser pulses;
• and
• construct a three dimensional image of the one or more first objects based on the determined time of flight for each of the plurality of laser pulses, the first angle of the first optical axis, and the plurality of incidence angles;
• and
• a second three-dimensional sensor having a second optical axis oriented at a second angle toward the scene, the second three-dimensional sensor configured to construct a three-dimensional image of one or more second objects in the scene, the second three-dimensional sensor characterized by a second angular field of view that at least partially overlaps with the first angular field of view of the first three-dimensional sensor;
• wherein the processor is coupled to the second three-dimensional sensor and configured to construct a three-dimensional image of the scene based on the three-dimensional image of the one or more first objects and the three-dimensional image of the one or more second objects.

A method of three-dimensional sensing for an autonomous vehicle, the method comprising:

• sensing one or more first objects in a forward direction using a lidar sensor including a laser source, a photodetector, an emission optical element, a receiving optical element, and a processor including one or more processing units coupled to the laser source and the photodetector, by:
• emitting, using the laser source, a plurality of laser pulses;
• collimating and directing, using the emission optical element, the plurality of laser pulses at a plurality of corresponding incidence angles with respect to the forward direction toward the one or more first objects, wherein the plurality of corresponding incidence angles forms a first angular field of view of the lidar sensor, and wherein a portion of each of the plurality of laser pulses is reflected off of the one or more first objects;
• receiving and focusing, using the receiving optical element, the portion of each of the plurality of laser pulses reflected off of the one or more first objects;
• detecting, using the photodetector, the portion of each of the plurality of laser pulses focused by the receiving optical element;
• determining, using the processor, a time of flight for each of the plurality of laser pulses from emission to detection;
• and
• constructing, using the processor, a three dimensional image of the one or more first objects based on the determined time of flight for each of the plurality of laser pulses and the plurality of incidence angles;
• sensing one or more second objects in a left direction or a right direction using an optical three-dimensional sensor to obtain a three-dimensional image of the one or more second objects, the optical three-dimensional sensor being characterized by a second angular field of view that least partially overlaps with the first angular field of view of the lidar sensor;
• and
• combining, using the processor, the three dimensional image of the one or more first objects and the three-dimensional image of the one or more second objects.