How does LIDAR avoid getting confused in an environment being scanned by hundreds of other LIDAR?
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How does LIDAR avoid getting confused in an environment being scanned by hundreds of other LIDAR?
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$begingroup$
(Meta: I do not know an appropriate place for this on Stack Exchange. There does not appear to be any groups related to autonomous driving technology and computer 3D vision / perception systems.)
For self driving vehicles using 3D depth perception LIDAR on a highway with hundreds of other vehicles also using various other LIDAR sweep beam or spot-field (kinect style) emission scanners, how is it able to distinguish its own signal returns, from the scanning being done by the other systems?
For an extremely large multilane highway, or complex multi-way intersections such emissions can be seen in all directions, covering all surfaces, and there is no way to avoid detecting the beam emissions from other scanners.
This seems to be the main technical hurdle for implementing LIDAR for autonomous driving vehicles. It does not matter if it works perfectly if it’s the only vehicle on the road using LIDAR.
The real question is how it deals with being inundated with spurious signals from similar systems in a future scenario where LIDAR is present on every vehicle, potentially with multiple scanners per vehicle and scanning in all directions around each vehicle.
Is it capable of functioning normally, can it somehow distinguish its own scanning and reject others, or in the worst case can it fail completely and just report garbage data that is useless, and it doesn’t know that it’s reporting garbage data?
This at least seems to be a strong case for having passive 3D computer vision that’s just based on natural light and stereo camera depth integration, as is done in the human brain.
radar
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
$endgroup$
|
show 9 more comments
$begingroup$
(Meta: I do not know an appropriate place for this on Stack Exchange. There does not appear to be any groups related to autonomous driving technology and computer 3D vision / perception systems.)
For self driving vehicles using 3D depth perception LIDAR on a highway with hundreds of other vehicles also using various other LIDAR sweep beam or spot-field (kinect style) emission scanners, how is it able to distinguish its own signal returns, from the scanning being done by the other systems?
For an extremely large multilane highway, or complex multi-way intersections such emissions can be seen in all directions, covering all surfaces, and there is no way to avoid detecting the beam emissions from other scanners.
This seems to be the main technical hurdle for implementing LIDAR for autonomous driving vehicles. It does not matter if it works perfectly if it’s the only vehicle on the road using LIDAR.
The real question is how it deals with being inundated with spurious signals from similar systems in a future scenario where LIDAR is present on every vehicle, potentially with multiple scanners per vehicle and scanning in all directions around each vehicle.
Is it capable of functioning normally, can it somehow distinguish its own scanning and reject others, or in the worst case can it fail completely and just report garbage data that is useless, and it doesn’t know that it’s reporting garbage data?
This at least seems to be a strong case for having passive 3D computer vision that’s just based on natural light and stereo camera depth integration, as is done in the human brain.
radar
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
$endgroup$
$begingroup$
Or you know...the eye hazard. As for distinguishing your own return signal from others, you could do some modulation or auto-correlation. I'm not sure how compatible that is with time-of-flight schemes but it would increase processing in something that already needs to differentiate extremely small time differences.
$endgroup$
– DKNguyen
10 hours ago
2
$begingroup$
@DKNguyen, you can modulate your laser with an RF subcarrier, and do any kind of RF or phase modulation you like on that subcarrier.
$endgroup$
– The Photon
9 hours ago
1
$begingroup$
@VoltageSpike Well, TDMA (Time Division Multiple Access) is one way, but CDMA (Code Division Multiple Access) is far more sophisticated. Alas, I studied those things more than 20 years ago and I hadn't a refresher since then. I remember when I studied them I thought "TDMA or FDMA? Meh! Easy concepts.", whereas CDMA was mind-boggling! Essentially you mix each stream (from each user) with a different numeric orthogonal code sequence. Extraction of the right stream is done by math operations involving the specific code sequence. The rest of the streams appears just as background noise.
$endgroup$
– Lorenzo Donati
8 hours ago
2
$begingroup$
@DKNguyen, I'm talking about modulating the subcarrier, AM, PM, FM, whatever.
$endgroup$
– The Photon
8 hours ago
1
$begingroup$
@DKNguyen Take a look at en.wikipedia.org/wiki/Electro-optic_modulator, the units I used were not near that fancy, but they would do AM and PM with a bandwidth in the 10's of Khz.
$endgroup$
– GB - AE7OO
7 hours ago
|
show 9 more comments
$begingroup$
(Meta: I do not know an appropriate place for this on Stack Exchange. There does not appear to be any groups related to autonomous driving technology and computer 3D vision / perception systems.)
For self driving vehicles using 3D depth perception LIDAR on a highway with hundreds of other vehicles also using various other LIDAR sweep beam or spot-field (kinect style) emission scanners, how is it able to distinguish its own signal returns, from the scanning being done by the other systems?
For an extremely large multilane highway, or complex multi-way intersections such emissions can be seen in all directions, covering all surfaces, and there is no way to avoid detecting the beam emissions from other scanners.
This seems to be the main technical hurdle for implementing LIDAR for autonomous driving vehicles. It does not matter if it works perfectly if it’s the only vehicle on the road using LIDAR.
The real question is how it deals with being inundated with spurious signals from similar systems in a future scenario where LIDAR is present on every vehicle, potentially with multiple scanners per vehicle and scanning in all directions around each vehicle.
Is it capable of functioning normally, can it somehow distinguish its own scanning and reject others, or in the worst case can it fail completely and just report garbage data that is useless, and it doesn’t know that it’s reporting garbage data?
This at least seems to be a strong case for having passive 3D computer vision that’s just based on natural light and stereo camera depth integration, as is done in the human brain.
radar
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
$endgroup$
(Meta: I do not know an appropriate place for this on Stack Exchange. There does not appear to be any groups related to autonomous driving technology and computer 3D vision / perception systems.)
For self driving vehicles using 3D depth perception LIDAR on a highway with hundreds of other vehicles also using various other LIDAR sweep beam or spot-field (kinect style) emission scanners, how is it able to distinguish its own signal returns, from the scanning being done by the other systems?
For an extremely large multilane highway, or complex multi-way intersections such emissions can be seen in all directions, covering all surfaces, and there is no way to avoid detecting the beam emissions from other scanners.
This seems to be the main technical hurdle for implementing LIDAR for autonomous driving vehicles. It does not matter if it works perfectly if it’s the only vehicle on the road using LIDAR.
The real question is how it deals with being inundated with spurious signals from similar systems in a future scenario where LIDAR is present on every vehicle, potentially with multiple scanners per vehicle and scanning in all directions around each vehicle.
Is it capable of functioning normally, can it somehow distinguish its own scanning and reject others, or in the worst case can it fail completely and just report garbage data that is useless, and it doesn’t know that it’s reporting garbage data?
This at least seems to be a strong case for having passive 3D computer vision that’s just based on natural light and stereo camera depth integration, as is done in the human brain.
radar
radar
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
asked 11 hours ago
Dale MahalkoDale Mahalko
9631 gold badge7 silver badges9 bronze badges
9631 gold badge7 silver badges9 bronze badges
$begingroup$
Or you know...the eye hazard. As for distinguishing your own return signal from others, you could do some modulation or auto-correlation. I'm not sure how compatible that is with time-of-flight schemes but it would increase processing in something that already needs to differentiate extremely small time differences.
$endgroup$
– DKNguyen
10 hours ago
2
$begingroup$
@DKNguyen, you can modulate your laser with an RF subcarrier, and do any kind of RF or phase modulation you like on that subcarrier.
$endgroup$
– The Photon
9 hours ago
1
$begingroup$
@VoltageSpike Well, TDMA (Time Division Multiple Access) is one way, but CDMA (Code Division Multiple Access) is far more sophisticated. Alas, I studied those things more than 20 years ago and I hadn't a refresher since then. I remember when I studied them I thought "TDMA or FDMA? Meh! Easy concepts.", whereas CDMA was mind-boggling! Essentially you mix each stream (from each user) with a different numeric orthogonal code sequence. Extraction of the right stream is done by math operations involving the specific code sequence. The rest of the streams appears just as background noise.
$endgroup$
– Lorenzo Donati
8 hours ago
2
$begingroup$
@DKNguyen, I'm talking about modulating the subcarrier, AM, PM, FM, whatever.
$endgroup$
– The Photon
8 hours ago
1
$begingroup$
@DKNguyen Take a look at en.wikipedia.org/wiki/Electro-optic_modulator, the units I used were not near that fancy, but they would do AM and PM with a bandwidth in the 10's of Khz.
$endgroup$
– GB - AE7OO
7 hours ago
|
show 9 more comments
$begingroup$
Or you know...the eye hazard. As for distinguishing your own return signal from others, you could do some modulation or auto-correlation. I'm not sure how compatible that is with time-of-flight schemes but it would increase processing in something that already needs to differentiate extremely small time differences.
$endgroup$
– DKNguyen
10 hours ago
2
$begingroup$
@DKNguyen, you can modulate your laser with an RF subcarrier, and do any kind of RF or phase modulation you like on that subcarrier.
$endgroup$
– The Photon
9 hours ago
1
$begingroup$
@VoltageSpike Well, TDMA (Time Division Multiple Access) is one way, but CDMA (Code Division Multiple Access) is far more sophisticated. Alas, I studied those things more than 20 years ago and I hadn't a refresher since then. I remember when I studied them I thought "TDMA or FDMA? Meh! Easy concepts.", whereas CDMA was mind-boggling! Essentially you mix each stream (from each user) with a different numeric orthogonal code sequence. Extraction of the right stream is done by math operations involving the specific code sequence. The rest of the streams appears just as background noise.
$endgroup$
– Lorenzo Donati
8 hours ago
2
$begingroup$
@DKNguyen, I'm talking about modulating the subcarrier, AM, PM, FM, whatever.
$endgroup$
– The Photon
8 hours ago
1
$begingroup$
@DKNguyen Take a look at en.wikipedia.org/wiki/Electro-optic_modulator, the units I used were not near that fancy, but they would do AM and PM with a bandwidth in the 10's of Khz.
$endgroup$
– GB - AE7OO
7 hours ago
$begingroup$
Or you know...the eye hazard. As for distinguishing your own return signal from others, you could do some modulation or auto-correlation. I'm not sure how compatible that is with time-of-flight schemes but it would increase processing in something that already needs to differentiate extremely small time differences.
$endgroup$
– DKNguyen
10 hours ago
$begingroup$
Or you know...the eye hazard. As for distinguishing your own return signal from others, you could do some modulation or auto-correlation. I'm not sure how compatible that is with time-of-flight schemes but it would increase processing in something that already needs to differentiate extremely small time differences.
$endgroup$
– DKNguyen
10 hours ago
2
2
$begingroup$
@DKNguyen, you can modulate your laser with an RF subcarrier, and do any kind of RF or phase modulation you like on that subcarrier.
$endgroup$
– The Photon
9 hours ago
$begingroup$
@DKNguyen, you can modulate your laser with an RF subcarrier, and do any kind of RF or phase modulation you like on that subcarrier.
$endgroup$
– The Photon
9 hours ago
1
1
$begingroup$
@VoltageSpike Well, TDMA (Time Division Multiple Access) is one way, but CDMA (Code Division Multiple Access) is far more sophisticated. Alas, I studied those things more than 20 years ago and I hadn't a refresher since then. I remember when I studied them I thought "TDMA or FDMA? Meh! Easy concepts.", whereas CDMA was mind-boggling! Essentially you mix each stream (from each user) with a different numeric orthogonal code sequence. Extraction of the right stream is done by math operations involving the specific code sequence. The rest of the streams appears just as background noise.
$endgroup$
– Lorenzo Donati
8 hours ago
$begingroup$
@VoltageSpike Well, TDMA (Time Division Multiple Access) is one way, but CDMA (Code Division Multiple Access) is far more sophisticated. Alas, I studied those things more than 20 years ago and I hadn't a refresher since then. I remember when I studied them I thought "TDMA or FDMA? Meh! Easy concepts.", whereas CDMA was mind-boggling! Essentially you mix each stream (from each user) with a different numeric orthogonal code sequence. Extraction of the right stream is done by math operations involving the specific code sequence. The rest of the streams appears just as background noise.
$endgroup$
– Lorenzo Donati
8 hours ago
2
2
$begingroup$
@DKNguyen, I'm talking about modulating the subcarrier, AM, PM, FM, whatever.
$endgroup$
– The Photon
8 hours ago
$begingroup$
@DKNguyen, I'm talking about modulating the subcarrier, AM, PM, FM, whatever.
$endgroup$
– The Photon
8 hours ago
1
1
$begingroup$
@DKNguyen Take a look at en.wikipedia.org/wiki/Electro-optic_modulator, the units I used were not near that fancy, but they would do AM and PM with a bandwidth in the 10's of Khz.
$endgroup$
– GB - AE7OO
7 hours ago
$begingroup$
@DKNguyen Take a look at en.wikipedia.org/wiki/Electro-optic_modulator, the units I used were not near that fancy, but they would do AM and PM with a bandwidth in the 10's of Khz.
$endgroup$
– GB - AE7OO
7 hours ago
|
show 9 more comments
2 Answers
2
active
oldest
votes
$begingroup$
Depends on the LIDAR. My experience with it is out of date (over 10 years), but I cannot imagine that the basics have changed that much.
Most will be using a form of lock in to discriminate their signals. They treat other LIDARs as noise just as they do anything that is not locked to their signal. While you don't have the same frequency agility that a radar does, you do have the ability to modulate your carrier using the many forms of modulation. They can definitely change modulation schema as required to find the least noise.
A modern DSP version of a Lock in Amplifier or the equivalent would be used at minimum.
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
$endgroup$
add a comment |
$begingroup$
Commercial LIDAR units modulate the light with a very long pseudo-random sequence.
The modulation is primarily to (1) have a modulation for determining distance and (2) to avoid interference with ambient sources of DC and AC light.
The long sequence makes it unlikely that any other source, even a modulated one like another LIDAR, will line up and interfere.
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
$endgroup$
add a comment |
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2 Answers
2
active
oldest
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2 Answers
2
active
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active
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$begingroup$
Depends on the LIDAR. My experience with it is out of date (over 10 years), but I cannot imagine that the basics have changed that much.
Most will be using a form of lock in to discriminate their signals. They treat other LIDARs as noise just as they do anything that is not locked to their signal. While you don't have the same frequency agility that a radar does, you do have the ability to modulate your carrier using the many forms of modulation. They can definitely change modulation schema as required to find the least noise.
A modern DSP version of a Lock in Amplifier or the equivalent would be used at minimum.
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
$endgroup$
add a comment |
$begingroup$
Depends on the LIDAR. My experience with it is out of date (over 10 years), but I cannot imagine that the basics have changed that much.
Most will be using a form of lock in to discriminate their signals. They treat other LIDARs as noise just as they do anything that is not locked to their signal. While you don't have the same frequency agility that a radar does, you do have the ability to modulate your carrier using the many forms of modulation. They can definitely change modulation schema as required to find the least noise.
A modern DSP version of a Lock in Amplifier or the equivalent would be used at minimum.
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
$endgroup$
add a comment |
$begingroup$
Depends on the LIDAR. My experience with it is out of date (over 10 years), but I cannot imagine that the basics have changed that much.
Most will be using a form of lock in to discriminate their signals. They treat other LIDARs as noise just as they do anything that is not locked to their signal. While you don't have the same frequency agility that a radar does, you do have the ability to modulate your carrier using the many forms of modulation. They can definitely change modulation schema as required to find the least noise.
A modern DSP version of a Lock in Amplifier or the equivalent would be used at minimum.
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
$endgroup$
Depends on the LIDAR. My experience with it is out of date (over 10 years), but I cannot imagine that the basics have changed that much.
Most will be using a form of lock in to discriminate their signals. They treat other LIDARs as noise just as they do anything that is not locked to their signal. While you don't have the same frequency agility that a radar does, you do have the ability to modulate your carrier using the many forms of modulation. They can definitely change modulation schema as required to find the least noise.
A modern DSP version of a Lock in Amplifier or the equivalent would be used at minimum.
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
edited 9 hours ago
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
answered 10 hours ago
GB - AE7OOGB - AE7OO
3061 silver badge9 bronze badges
3061 silver badge9 bronze badges
add a comment |
add a comment |
$begingroup$
Commercial LIDAR units modulate the light with a very long pseudo-random sequence.
The modulation is primarily to (1) have a modulation for determining distance and (2) to avoid interference with ambient sources of DC and AC light.
The long sequence makes it unlikely that any other source, even a modulated one like another LIDAR, will line up and interfere.
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
$endgroup$
add a comment |
$begingroup$
Commercial LIDAR units modulate the light with a very long pseudo-random sequence.
The modulation is primarily to (1) have a modulation for determining distance and (2) to avoid interference with ambient sources of DC and AC light.
The long sequence makes it unlikely that any other source, even a modulated one like another LIDAR, will line up and interfere.
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
$endgroup$
add a comment |
$begingroup$
Commercial LIDAR units modulate the light with a very long pseudo-random sequence.
The modulation is primarily to (1) have a modulation for determining distance and (2) to avoid interference with ambient sources of DC and AC light.
The long sequence makes it unlikely that any other source, even a modulated one like another LIDAR, will line up and interfere.
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
$endgroup$
Commercial LIDAR units modulate the light with a very long pseudo-random sequence.
The modulation is primarily to (1) have a modulation for determining distance and (2) to avoid interference with ambient sources of DC and AC light.
The long sequence makes it unlikely that any other source, even a modulated one like another LIDAR, will line up and interfere.
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
answered 4 hours ago
Bob JacobsenBob Jacobsen
1,3375 silver badges9 bronze badges
1,3375 silver badges9 bronze badges
add a comment |
add a comment |
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$begingroup$
Or you know...the eye hazard. As for distinguishing your own return signal from others, you could do some modulation or auto-correlation. I'm not sure how compatible that is with time-of-flight schemes but it would increase processing in something that already needs to differentiate extremely small time differences.
$endgroup$
– DKNguyen
10 hours ago
2
$begingroup$
@DKNguyen, you can modulate your laser with an RF subcarrier, and do any kind of RF or phase modulation you like on that subcarrier.
$endgroup$
– The Photon
9 hours ago
1
$begingroup$
@VoltageSpike Well, TDMA (Time Division Multiple Access) is one way, but CDMA (Code Division Multiple Access) is far more sophisticated. Alas, I studied those things more than 20 years ago and I hadn't a refresher since then. I remember when I studied them I thought "TDMA or FDMA? Meh! Easy concepts.", whereas CDMA was mind-boggling! Essentially you mix each stream (from each user) with a different numeric orthogonal code sequence. Extraction of the right stream is done by math operations involving the specific code sequence. The rest of the streams appears just as background noise.
$endgroup$
– Lorenzo Donati
8 hours ago
2
$begingroup$
@DKNguyen, I'm talking about modulating the subcarrier, AM, PM, FM, whatever.
$endgroup$
– The Photon
8 hours ago
1
$begingroup$
@DKNguyen Take a look at en.wikipedia.org/wiki/Electro-optic_modulator, the units I used were not near that fancy, but they would do AM and PM with a bandwidth in the 10's of Khz.
$endgroup$
– GB - AE7OO
7 hours ago