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Why does Tesla bother with radar and ultrasonic sensors? Humans can drive without them.

deleted 6y ago
[deleted]
fiddlerwoaroof 6y ago
I just find it strange that Tesla is criticized for relying on visual self-driving systems when most humans rely primarily on vision to navigate.
- RivieraKid 6y ago
  Well but Tesla cars don't have brains. Maybe the lack of lidars makes the task 100 times harder, i.e. de facto impossible. We don't know. This is a big risk for Tesla but they didn't have a choice. If lidars were as cheap as cameras, of course they would use them. On the other hand, Waymo et. al. are not risking anything by using lidars. If they turn out to be redundant, it should be easy to remove them cheaply.
  - fiddlerwoaroof 6y ago
    This isn’t true: if you build a system for highly sophisticated inputs, simplifying the inputs can break all sorts of assumptions about the accuracy of the input data and other such invariants. If you start with a more primitive set of sensors and go as far as possible, adding more accurate sensors seems less risky.
    - johnhartigun 6y ago
      Maybe in general, but I don't think you're right in the case of self-driving systems. Waymo says that perception is the easy part and most of the work is elsewhere. So in the absolute worst case scenario, they would have to develop the perception part from scratch. At Tesla, this took 2 years. BTW, all companies that can, use lidars. Even MobileEye says that their L4 system will use lidars and they've been working on a camera based system for 2 decades. Tesla doesn't use lidars because they can't.
      - nirushiv 6y ago
        I mean - I have no idea what’s going on at Tesla, but its very likely they’re doing some internal work with Lidar. They surey understand the risk with w vision-only approach. Elon, and Karpathy, and Laettner previously, aren’t fools. The problem for Tesla is they can’t be too Lidar dependent because nobody mass-produces them
        johnhartigun 6y ago
        Tesla can't use lidars because: 1. It would make the cars much more expensive. 2. They would have to refund all people who've bough FSD or provide them a free upgrade.
        nirushiv 6y ago
        These are fairly artificial constraints. 1. Lidar is expensive for everyone. It’s not like Tesla will pay more than other manufacturers. They’d prefer not to use Lidar, but if cameras just don’t cut it, I don't think they would die on that hill. 2. I’m sure there is some fine print around the current FSD being for camera based sensors only. They can easily say the car tops off at L4 for cameras, and L5 needs Lidar, if we come to that bridge
        RivieraKid 6y ago
        Yeah, it's expensive for everyone but the point was that the FSD product is de facto impossible with lidars. Therefore, they have to pretend that it can be done with cameras.
kjksf 6y ago
Because engineering is about trade offs. Why isn't every car body made from carbon fiber? It's lighter and sturdier that alternatives. It's also more expensive so you can put it in $60k car but not in $25k car. Radar and ultrasonic sensors are cheap, low power and plentiful. Putting several lidars on a car would be too expensive, would use too much power (less range) and there isn't a supply chain to make 2 million a year just for Tesla (500k cars x 4 lidars per car). It's just isn't possible to put a lidar today on a mass market car and Tesla wants to solve self-driving before lidar becomes cheap enough.

deleted 6y ago

[deleted]

I just find it strange that Tesla is criticized for relying on visual self-driving systems when most humans rely primarily on vision to navigate.

RivieraKid 6y ago
Well but Tesla cars don't have brains. Maybe the lack of lidars makes the task 100 times harder, i.e. de facto impossible. We don't know. This is a big risk for Tesla but they didn't have a choice. If lidars were as cheap as cameras, of course they would use them. On the other hand, Waymo et. al. are not risking anything by using lidars. If they turn out to be redundant, it should be easy to remove them cheaply.
- fiddlerwoaroof 6y ago
  This isn’t true: if you build a system for highly sophisticated inputs, simplifying the inputs can break all sorts of assumptions about the accuracy of the input data and other such invariants. If you start with a more primitive set of sensors and go as far as possible, adding more accurate sensors seems less risky.
  - johnhartigun 6y ago
    Maybe in general, but I don't think you're right in the case of self-driving systems. Waymo says that perception is the easy part and most of the work is elsewhere. So in the absolute worst case scenario, they would have to develop the perception part from scratch. At Tesla, this took 2 years. BTW, all companies that can, use lidars. Even MobileEye says that their L4 system will use lidars and they've been working on a camera based system for 2 decades. Tesla doesn't use lidars because they can't.
    - nirushiv 6y ago
      I mean - I have no idea what’s going on at Tesla, but its very likely they’re doing some internal work with Lidar. They surey understand the risk with w vision-only approach. Elon, and Karpathy, and Laettner previously, aren’t fools. The problem for Tesla is they can’t be too Lidar dependent because nobody mass-produces them
      - johnhartigun 6y ago
        Tesla can't use lidars because: 1. It would make the cars much more expensive. 2. They would have to refund all people who've bough FSD or provide them a free upgrade.
        nirushiv 6y ago
        These are fairly artificial constraints. 1. Lidar is expensive for everyone. It’s not like Tesla will pay more than other manufacturers. They’d prefer not to use Lidar, but if cameras just don’t cut it, I don't think they would die on that hill. 2. I’m sure there is some fine print around the current FSD being for camera based sensors only. They can easily say the car tops off at L4 for cameras, and L5 needs Lidar, if we come to that bridge
        RivieraKid 6y ago
        Yeah, it's expensive for everyone but the point was that the FSD product is de facto impossible with lidars. Therefore, they have to pretend that it can be done with cameras.

kjksf 6y ago

Because engineering is about trade offs. Why isn't every car body made from carbon fiber? It's lighter and sturdier that alternatives. It's also more expensive so you can put it in $60k car but not in $25k car. Radar and ultrasonic sensors are cheap, low power and plentiful. Putting several lidars on a car would be too expensive, would use too much power (less range) and there isn't a supply chain to make 2 million a year just for Tesla (500k cars x 4 lidars per car). It's just isn't possible to put a lidar today on a mass market car and Tesla wants to solve self-driving before lidar becomes cheap enough.