High definition lidar system

Abstract

A LiDAR-based 3-D point cloud measuring system includes a base, a housing, a plurality of photon transmitters and photon detectors contained within the housing, a rotary motor that rotates the housing about the base, and a communication component that allows transmission of signals generated by the photon detectors to external components. In several versions of the invention, the system includes a vertically oriented motherboard, thin circuit boards such as ceramic hybrids for selectively mounting emitters and detectors, a conjoined D-shaped lens array, and preferred firing sequences.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A LiDAR-based sensor system comprising:
 a base;   head assembly;   a rotary component configured to rotate the head assembly with respect to the base, the rotation of the head assembly defining an axis of rotation;   an electrical motherboard carried in the head assembly, the motherboard defining a plane and being positioned substantially parallel to the axis of rotation;   a lens positioned on the head assembly on a first side of the motherboard;   a mirror positioned on the head assembly on a second side of the motherboard;   a plurality of photon transmitters mounted to a plurality of emitter circuit boards, the plurality of emitter circuit boards being mounted directly to the motherboard; and   a plurality of detectors mounted to a plurality of detector circuit boards, the plurality of detector circuit boards being mounted directly to the motherboard.   
     
     
       2. The sensor system of  claim 1 , wherein
 the lens comprises an emitter lens and a detector lens, the emitter lens and the detector lens being positioned adjacent one another; and   the mirror comprises an emitter mirror and a detector mirror;   wherein the emitter mirror is positioned within the head assembly to reflect light from the plurality of photon transmitters through the emitter lens, and the detector mirror is positioned within the head to reflect light received through the detector lens toward the plurality of detectors.   
     
     
       3. The sensor system of  claim 2 , further comprising a unitary support structure, the motherboard, detector lens, emitter lens, detector mirror, and emitter mirror all being secured to the unitary support structure. 
     
     
       4. The sensor system of  claim 2 , wherein the plurality of emitters are oriented to transmit light from the second side of the motherboard toward the emitter mirror. 
     
     
       5. The sensor system of  claim 4 , wherein the motherboard comprises a central opening, the central opening being positioned to allow light from the emitters to pass from emitter mirror through the central opening and toward the emitter lens. 
     
     
       6. The sensor system of  claim 5 , wherein the central opening is further positioned to allow light to pass from the detector lens through the central opening and toward the detector mirror. 
     
     
       7. The sensor system of  claim 2 , wherein the plurality of emitter circuit boards are secured to the motherboard to form a first vertical stack. 
     
     
       8. The sensor system of  claim 7 , wherein the first vertical stack of emitter circuit boards forms an angularly fanned array. 
     
     
       9. The sensor system of  claim 7 , wherein the plurality of detector circuit boards are secured to the motherboard to form a second vertical stack, the first vertical stack of emitter circuit boards being positioned substantially parallel to the second vertical stack of detector circuit boards. 
     
     
       10. The sensor system of  claim 9 , wherein the second vertical stack of detector circuit boards forms an angularly fanned array. 
     
     
       11. The sensor system of  claim 2 , wherein the emitter lens comprises a first D-shaped lens and the detector lens comprises a second D-shaped lens, a respective vertical side of each of the first D-shaped lens and the second D-shaped lens being positioned closely adjacent one another to form a conjoined D-shaped lens array. 
     
     
       12. The sensor system of  claim 11 , wherein the first D-shaped lens comprises a first plurality of lenses, and wherein the second D-shaped lens comprises a second plurality of lenses. 
     
     
       13. The sensor system of  claim 2 , wherein the plurality of emitter circuit boards are secured to the motherboard to form a first vertical stack, the first vertical stack being divided into at least two groups of emitters, each of the at least two groups comprising several emitters from the plurality of emitters such that the at least two groups form non-overlapping subsets of the plurality of emitters, the sensor further having a control component to control the firing of the emitters such that one emitter is fired at a time, the control component further causing firing from one of the at least two groups and then the other of the at least two groups in an alternating fashion. 
     
     
       14. The sensor system of  claim 13 , wherein the at least two groups comprises:
 a first group forming a first portion of the first vertical stack and organized sequentially from a first top position to a first bottom position; and   a second group forming a remaining portion of the first vertical stack organized sequentially from a second top position to a second bottom position;   whereby the control component causes firing of the emitters to alternate between the first group and the second group, and further causes firing within the first group to proceed sequentially and firing within the second group to proceed sequentially.   
     
     
       15. The sensor system of  claim 2 , wherein the rotary component further comprises a capacitive coupler. 
     
     
       16. A LiDAR-based sensor system comprising:
 a base;   head assembly;   a motor configured to rotate the head assembly with respect to the base, the rotation of the head assembly defining an axis of rotation;   an electrical motherboard carried in the head assembly;   a plurality of photon transmitters mounted to a plurality of emitter circuit boards, the plurality of emitter circuit boards being mounted to the motherboard;   a plurality of detectors mounted to a plurality of detector circuit boards, the plurality of detector circuit boards being mounted to the motherboard;   an emitter mirror supported within the head assembly;   a detector mirror supported within the head assembly; and   a conjoined D-shaped lens assembly, the lens assembly forming an emitter portion and a detector portion;   wherein the motherboard is a unitary component for mounting the plurality of emitter circuit boards and the plurality of detector circuit boards, the motherboard being positioned between the emitter mirror and the detector mirror on a first side and the lens assembly on the other side, the motherboard further having an opening to allow light to pass between the lens assembly and either the detector mirror or the emitter mirror;   whereby light transmitted by one of the plurality of emitters is reflected from the emitter mirror and passes through the emitter portion of the lens assembly, and light received by the detector portion of the lens assembly is reflected by the detector mirror and received by one of the plurality of detectors.   
     
     
       17. The sensor system of  claim 16 , wherein the motherboard defines a plane that is parallel to the axis of rotation. 
     
     
       18. The sensor system of  claim 17 , further comprising:
 a control component for causing the firing of the plurality of emitters; and   further wherein there are n emitters in the plurality of emitters, the n emitters being positioned in a vertical stack from 1 to n, the plurality of emitters being divided into two groups, including a first group of emitters from 1 to n/2 and a second group of emitters from n/2+1 to n; wherein the control component causes the emitters to fire alternatingly between the first group and the second group, and to fire sequentially within each group such that emitter 1 and emitter n/2+1 fire sequentially.   
     
     
       19. A LiDAR-based sensor system comprising:
 a base having a head assembly and a rotary component configured to rotate the head assembly with respect to the base, the head assembly further having a circumference spaced apart from an axis of rotation of the head assembly;   a motherboard carried in the head assembly;   a lens positioned on the head assembly along the circumference of the head assembly;   a mirror positioned on the head assembly along the circumference of the head assembly;   a plurality of transmitters mounted to a plurality of emitter circuit boards carried on the head assembly for rotation with the head assembly, the plurality of transmitters positioned to transmit light pulses through the lens;   a plurality of detectors mounted to a plurality of detector circuit boards carried on the head assembly for rotation with the head assembly, the plurality of detectors positioned to receive reflected light pulses from one or more surfaces;   a processor coupled to the plurality of transmitters; and   a memory including processor executable code, wherein the processor executable code, upon execution by the processor, configures the processor to cause firing of fewer than the entire plurality of transmitters at a time.   
     
     
       20. The sensor system of claim 19, wherein the processor is configured to cause the firing of only one of the plurality of transmitters at a time. 
     
     
       21. The sensor system of claim 20, wherein the plurality of transmitters and the plurality of detectors form a plurality of transmitter-detector pairs, and wherein the processor is configured to cause only one transmitter-detector pair to be active at any time. 
     
     
       22. The sensor system of claim 19, wherein each one of the transmitters from among the plurality of transmitters is physically adjacent to at least one other of the transmitters from among the plurality of transmitters, and wherein the processor is configured to cause the firing of the plurality of transmitters in a non-adjacent firing order, such that at no time do adjacent transmitters fire in consecutively in sequence. 
     
     
       23. The sensor system of claim 19 wherein:
 wherein there are n transmitters in the plurality of transmitters, the n transmitters being positioned in a sequence from 1 to n, the plurality of transmitters being divided into two groups, including a first group of transmitters from I to n/2 and a second group of transmitters from n/2+1 to n; and   wherein the processor is configured to cause the transmitters to fire alternatingly between the first group and the second group, and to fire sequentially within each group such that transmitter 1 and transmitter n/2+1 fire sequentially.   
     
     
       24. The sensor system of claim 19, wherein the lens and the mirror are positioned along the circumference of the head assembly such that a center of gravity of the head assembly corresponds to the axis of rotation. 
     
     
       25. The sensor system of claim 19, wherein the head assembly is configured to rotate at a rotational speed, and wherein the processor is configured to cause the firing of fewer than the entire plurality of transmitters according to the rotational speed. 
     
     
       26. The sensor system of claim 25, wherein the processor is configured to start the firing of fewer than the entire plurality of transmitters upon determining that the rotational speed reaches a threshold. 
     
     
       27. A LiDAR-based sensor system comprising:
 a base;   a head assembly;   a rotary component configured to rotate the head assembly with respect to the base along an axis of rotation;   a motherboard carried in the head assembly;   a lens positioned at a periphery of the head assembly;   a mirror positioned at the periphery of the head assembly;   a plurality of photon transmitters mounted to a plurality of emitter circuit boards, the plurality of emitter circuit boards mounted to the motherboard;   a plurality of detectors mounted to a plurality of detector circuit boards, the plurality of detector circuit boards mounted to the motherboard;   a processor coupled to the plurality of photon transmitters; and   a memory including processor executable code, wherein the processor executable code, upon execution by the processor, configures the processor to cause firing of fewer than the entire plurality of photon transmitters at a time.   
     
     
       28. The sensor system of claim 27, wherein the processor is configured to cause the firing of only one photon transmitter at a time. 
     
     
       29. The sensor system of claim 28, wherein the plurality of photon transmitters and the plurality of detectors form a plurality of transmitter-detector pairs, and wherein only one transmitter-detector pair is active at any time. 
     
     
       30. The sensor system of claim 27, wherein the processor is configured to cause the firing of the photon transmitters in a non-adjacent firing order, such that at no time do adjacent photon transmitters fire in sequence. 
     
     
       31. The sensor system of claim 27, wherein:
 the plurality of transmitters includes n transmitters positioned in a sequence from 1 to n, the n transmitters divided into two groups, including a first group of transmitters from 1 to n/2 and a second group of transmitters from n/2+1 to n; and   wherein the processor is configured to cause the transmitters to fire alternatingly between the first group and the second group, and to fire sequentially within each group such that transmitter I and transmitter n/2+1 fire sequentially.   
     
     
       32. The sensor system of claim 27, wherein the motherboard, the rotary component, the lens, and the mirror are enclosed within the head assembly, and wherein the lens and the mirror are positioned at the periphery of the head assembly such that a center of gravity of the head assembly corresponds to the axis of rotation of the rotary component. 
     
     
       33. The sensor system of claim 27, wherein the rotary component is configured to rotate at a rotational speed, and wherein the processor is configured to cause the firing of fewer than the entire plurality of photon transmitters according to the rotational speed. 
     
     
       34. The sensor system of claim 33, wherein the processor is configured to start the firing of fewer than the entire plurality of transmitters upon determining that the rotational speed reaches a threshold.