Detection system with reflective member illuminated from multiple sides
A detection system for a vehicle in an environment includes at least one reflective member having a rotational axis and a plurality of reflective sides. Each of the reflective sides slopes towards the rotational axis at a slope angle different than the slope angle of at least one of the others of the reflective sides. The system includes a plurality of LiDAR systems with at least one light transmitter and at least one light receiver, each LiDAR system interacting with a different one of the reflective sides to scan the environment.
1. A detection system for a vehicle in an environment, comprising:
a reflective member having a rotational axis and a plurality of reflective sides, each of the reflective sides sloping towards the rotational axis at a slope angle different than the slope angle of at least one of the others of the reflective sides;
a first LiDAR system including at least one first light transmitter and at least one first light receiver, the first LiDAR system configured to interact with a first active side of the plurality of reflective sides;
a second LiDAR system including at least one second light transmitter and at least one second light receiver, the second LiDAR system configured to interact with a second active side of the plurality of reflective sides; and
an actuator configured to rotate the reflective member to change: the first active reflective side to a first different one of the plurality of reflective sides; and the second active reflective side to a second different one of the plurality of reflective sides, wherein:
the first LiDAR system is configured to interact with the first active side to scan, in azimuth, a first zone and a second zone, the first zone being at least partially to a first side of the vehicle and the second zone being at least partially in front of the vehicle;
the second LiDAR system is configured to interact with the second active side to scan, in azimuth, the second zone and a third zone, the third zone being at least partially to a second side of the vehicle;
the vehicle includes a windshield having an upper portion, a central portion, and a lower portion, the reflective member, the first LiDAR system, and the second LiDAR system being positioned proximate to the upper portion;
the detection system further comprises: an upper reflective mirror coupled, and parallel, to the upper portion of the windshield; and a lower reflective mirror coupled to, and offset from, the windshield and positioned parallel to the upper reflective mirror;
the upper reflective mirror directs a field of view of the first and second LiDAR systems between the reflective member and the lower reflective mirror; and
the lower reflective mirror directs the field of view of the first and second LiDAR systems between the upper reflective mirror and the environment.
2. The detection system of claim 1 further comprising:
a second upper reflective mirror coupled to the upper portion of the windshield; and
a second lower reflective mirror offset from the windshield,
wherein:
the second upper reflective mirror directs a field of view of the second LiDAR system between the reflective member and the second lower reflective mirror; and
the second lower reflective mirror directs the field of view of the second LiDAR system between the second upper reflective mirror and the environment.
3. The detection system of claim 1 wherein the light transmitters of the first LiDAR system and the second LiDAR system transmit p-polarized light beams, the lower reflective mirror directing the light beams from the first and second LiDAR systems to pass through the windshield.
4. The detection system of claim 1 wherein light beams from the first LiDAR system and the second LiDAR system are directed through the windshield within 10 degrees of a Brewster angle for the windshield.
5. The detection system of claim 1 further comprising: a prism positioned on the inside of the upper portion of the windshield, the prism configured to direct p-polarized transmitted light beams from at least one of the first and second LiDAR systems through the windshield and into the environment.
6. The detection system of claim 5 wherein the prism is further configured such that the transmitted light beams are directed through the windshield within 10 degrees of a Brewster angle for the windshield.
7. The detection system of claim 1 wherein the slope of each reflective side differs incrementally by between 2 and 8 degrees.
8. The detection system of claim 1 wherein the slope of each reflective side differs incrementally by between 0.2 and 0.4 degrees.
9. The detection system of claim 1 wherein the slope of each reflective side differs from the slope of one directly adjacent reflective sides by substantially the same degree.
10. The detection system of claim 1 wherein the reflective member includes 5 or 6 reflective sides.
11. The detection system of claim 1 wherein the at least one first light transmitter includes an array of light transmitters configured to transmit light beams to the first active side in a column parallel to the rotational axis.
12. The detection system of claim 1 wherein the slope angle of each of the reflective sides is different than the slope angle of each of the others of the reflective sides.