System for emulating an environment for testing a time-of-flight (ToF) detection and ranging (LiDAR) system
A system for emulating an over-the-air environment for testing a light detection and ranging (LiDAR) unit under test (UUT). The system may comprise a lens system that receives light from the LiDAR UUT and a plurality of optical processing chains. The system may generate light into free space based on the optical signals processed by each chain. The system may process received light optically to maintain coherence with light received from the LiDAR unit under test and may process all points in a LiDAR image simultaneously. The system may operate to emulate an over-the-air environment for a time-of-flight LiDAR UUT, a frequency modulated continuous wave LiDAR UUT, and/or a flash LiDAR UUT.
1. A method for emulating an over-the-air environment for testing a light detection and ranging (LiDAR) unit under test (UUT), the method comprising:
receiving, by a plurality of optical processing chains, a plurality of laser pulses from one or more lasers of the LiDAR UUT, wherein the plurality of optical processing chains comprise a plurality of respective optical fibers, wherein each optical fiber of the plurality of optical fibers is configured to receive a distinct subset of the plurality of laser pulses;
for each of the optical processing chains, modulating the received laser pulses to emulate the over-the-air environment by implementing:
optical time delays; and
optical amplitude modulation; and
transmitting the modulated laser pulses to the LiDAR UUT.
2. The method of claim 1 ,
wherein the LiDAR UUT comprises a time-of-flight (ToF) LiDAR UUT.
3. The method of claim 1 ,
wherein implementing the optical time delays emulates a time-of-flight to objects in the emulated over-the-air environment.
4. The method of claim 1 ,
wherein each distinct subset of the plurality of laser pulses comprises laser pulses from a distinct laser of the LiDAR UUT,
wherein each laser of the LiDAR UUT sweeps over a distinct portion of a field of view of the LiDAR UUT.
5. The method of claim 1 ,
wherein implementing optical amplitude modulation comprises selectively attenuating and/or amplifying the received laser pulses to emulate reflectivity and path loss at locations being emulated in the over-the-air environment.
6. The method of claim 1 ,
wherein modulating the received laser pulses is performed optically to maintain coherence between the received laser pulses and the modulated laser pulses.
7. The method of claim 1 ,
wherein the plurality of optical processing chains concurrently modulate their respective received laser pulses.
8. The method of claim 1 , the method further comprising:
receiving time delay values and amplitude modulation values from a LiDAR image generator for each point in a point cloud of the over-the-air environment,
wherein said implementing optical time delays and optical amplitude modulation is performed based on the time delay values and the amplitude modulation values.
9. The method of claim 1 ,
wherein the plurality of laser pulses is received from the LiDAR UUT and the modulated laser pulses are transmitted to the LiDAR UUT through a lens system.
10. A system for emulating an over-the-air environment for testing a light detection and ranging (LiDAR) unit under test (UUT), the system comprising:
a lens system configured to receive light from the LiDAR UUT;
a plurality of optical processing chains coupled to the lens system, wherein each optical processing chain of the plurality of optical processing chain comprises:
an optical fiber coupled to the lens system and configured to receive laser pulses from the LiDAR UUT through the lens system;
a selectable optical delay device configured to selectively delay the received laser pulses; and
an optical amplitude modulator configured to modulate an amplitude of the received laser pulses,
wherein selectively delaying the received laser pulses and modulating the amplitude of the received laser pulses emulates the over-the-air environment, and
wherein each optical processing chain is configured to transmit the selectively delayed and amplitude modulated laser pulses to the LiDAR UUT.
11. The system of claim 10 , wherein the system is further configured to:
perform one or more measurements on light received from the LiDAR UUT, wherein the one or more measurements comprise one or more of:
a laser line width measurement;
a chirp linearity measurement;
an optical spectrum analyzer measurement;
an optical power measurement; and
a pulse width measurement.
12. The system of claim 10 ,
wherein the LiDAR UUT comprises a time-of-flight (ToF) LiDAR UUT.
13. The system of claim 10 , wherein each of the plurality of optical processing chains further comprises:
an in-phase quadrature (IQ) frequency modulator configured to modulate a frequency of the received laser pulses,
wherein the system is configured to emulate the over-the-air environment for either a time-of-flight (ToF) LiDAR UUT or a frequency modulated continuous wave (FMCW) LiDAR UUT, wherein the selectable optical delay devices are utilized to emulate over-the-air environments for ToF LiDAR UUTs, and wherein the IQ frequency modulators are utilized to emulate over-the-air environments for FMCW LiDAR UUTs.
14. The system of claim 10 ,
wherein each optical fiber receives a distinct subset of laser pulses received from a distinct laser of a plurality of lasers of the LiDAR UUT,
wherein each laser of the plurality of lasers sweeps over a distinct portion of a field of view of the LiDAR UUT.
15. The system of claim 14 ,
wherein each laser of the plurality of lasers sweeps over a single line of the field of view of the LiDAR UUT, and
wherein the lens system is configured to focus light received along each line into respective points.
16. The system of claim 10 ,
wherein modulating the amplitude of the received laser pulses comprises selectively attenuating and/or amplifying the received laser pulses to emulate reflectivity and path loss at locations being emulated in the over-the-air environment.
17. The system of claim 10 ,
wherein selectively delaying and modulating the amplitude of the received laser pulses is performed optically to maintain coherence between the received laser pulses and the modulated laser pulses.
18. The system of claim 10 , the system further comprising:
a LiDAR image generator coupled to the plurality of optical processing chains, wherein the LiDAR image generator is configured to provide time delay values and amplitude modulation values to the plurality of optical processing chains for each point in a point cloud of the over-the-air environment,
wherein the LiDAR image generator is user programmable to produce time delay values and amplitude modulation values corresponding to different over-the-air environments, and
wherein selectively delaying and modulating the amplitude of the received laser pulses is performed based on the time delay values and the amplitude modulation values.
19. The system of claim 10 ,
wherein the frequency shifted and amplitude modulated laser pulses are transmitted to the LiDAR UUT through the lens system.