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Comment by c-linkage | Hacker News Reader

I have a 2020 Honda Civic sans ultrasonic sensors but with a front camera for collision avoidance, and I can count on two hands the number of phantom breaking events I've had in two years. All it takes is a little rain and the sun at the right angle for the system to be fooled into thinking a wall lies dead ahead.

I consider myself lucky that each time there was no one behind me.

While the car gives me the option to turn of the feature, I leave it on because if I get into an accident with it off I am sure the insurance companies would have more leverage to deny my claims and find me at fault.

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I have a 2020 BMW, with the same features. I have never had an issue in over 30,000 miles of driving. My previous generation BMW, also similarly equipped, did not have these issues. It did trigger the rear collision alert a handful of times, although all that does is tighten the seatbells and beep (i think).

So, these features can work reliably, and I don't think using a poor implementation is useful in this conversation.

The reality is that tesla has removed sensors from their playbook, which can only decrease the information the car has to work with.

> 2020 BMW

I generally find that the luxury European makes (BMW, Mercedes-Benz, Audi, Porsche) have more well-put-together cars than Tesla does, despite all of Tesla's posturing about being a 'premium car company'. I heard it put quite succinctly: 'Tesla is a software company that decided to build cars'.

Not to mention, it is an American software company that decided to build cars in the US, and the person I spoke to didn't have a very good opinion of American makes in general (I concur).

Tesla was at the forefront of EV innovation about 5-7 years ago, but today, I'd much rather buy an EQE, an i4, or an e-tron (or if I can ever afford it, a Taycan Turbo S).

> I'd much rather buy an EQE, an i4, or an e-tron (or if I can ever afford it, a Taycan Turbo S).

A comparison of what it would cost me locally to get these cars (base cost):

Tesla model 3: From $55k, 455 km range

Tesla model Y: From $58k, 488 km range

BMW i4: From $65k, 470 km range

Mercedes-Benz EQE: From $85k, 525 km range

Audi e-tron: From $131k, 365 km range

Porsche Taycan Turbo S: From $276k, 560 km range

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Of these, the e-tron is overpriced, even compared to non-electric Audis.

I'd be happy to own any of these. But you're mentioning 18-38% more expensive cars (disregarding Taycan; Taycan should be compared to Tesla Roadster: $211k, 997 km range).

The Tesla selling point for me is a highly competitive range and the most beautiful interior (subjective, but alternatively: most simple) at the lowest cost among these luxury electric cars.

> Tesla is a software company that decided to build cars

Companies that realise they're a software company when software is at their core have an edge.

Insurance companies, for example, should be wise to do the same.

> what it would cost

After having test-driven and being driven in cars, I have come to the conclusion that one generally gets what one pays for when it comes to cars.

> most beautiful interior (subjective, but alternatively: most simple

I like traditional interiors with knobs and buttons for AV and AC controls, and the singular giant iPad-esque display on Teslas is a complete deal-breaker for me.

> range

I live in a dense city-state: range is a moot discussion when I have a petrol station with EV chargers every 2-3 km.

At any rate, I get your point about the alternatives to the Model 3 being more expensive with less range, but that is a sacrifice I am willing to make for drastically improved quality control and (in my opinion) a drastically better driving and passenger experience.

> I live in a dense city-state: range is a moot discussion when I have a petrol station with EV chargers every 2-3 km.

That's a completely fair point.

But if we're not comparing high-range EVs, why not go with a Renaut Zoe ($39k, 200 km range) or the like?

I've used Zoes in city environments, and the newer models are overwhelmingly pleasant. E.g. they cover internal panels with fabric instead of leather/pleather to create a very nice atmosphere at no cost. Their small size make them easier to park, and you can't go fast in cities.

> the alternatives to the Model 3 being more expensive with less range

I didn't make that point (except comparing the e-tron).

I also prefers knobs and buttons. But I prefer fewer of them.

The simplicity of design is not just controls, but visual clutter in terms of the amount of lines created by overlapping panels of different materials. Classic car brands have a legacy to represent so that new Audis feel like old Audis on the inside. Tesla might've taken it a bit too far, hiding things behind a screen, creating a maze of non-tactile menu systems instead.

> Companies that realise they're a software company when software is at their core have an edge.

SW for automotive is a different beast than SW for Windows or Linux.

You shouldn’t compare roadster to anything because it doesn’t exist yet. It’s at best unfair, and ultimately the definition of unrealistic until roadsters are delivered.

That's neat that your car has a rear collision alert. It's actually useful and if you have the presence of mind to react quickly, you should put your head back against the headrest in order to prevent whiplash.

And roll forward if clear/safe. Had the presence of mind for that once and it haunts me to this day.

Someone close to me was in an accident that could have been avoided with sensors other than a camera. The camera only collision mitigation system was blinded by direct sunlight complicated by glare off of fresh snow. Zero indication the system was compromised until it failed to provide any warning or active braking.

Vowed to never own a car with only camera based collision mitigation again.

What was the driver doing?

That’s not really relevant, safety systems should be expected to work reliably, or report to the driver when they can’t (something my car does if covered in snow).

When radar and vision disagree, which one do you believe? Vision has much more precision, so better to double down on vision than do sensor fusion.

In the event of a blinded vision system, such as sun glare, the vision system should be able to recognize its reduced capacity. That involves warning the driver and relying more heavily on radar/sensor fusion.

The solution two information from two sources disagreeing is rarely to just throw away half of your data.

There's a huge amount of literature on how to do sensor fusion in the presence of misbehaving or disagreeing sensors.

Moreover, production vehicles don't get entire classes of redundant sensors when the engineers think they can do without. The cost optimization and haggling that goes into production vehicles is insane.

Like others have mentioned the entire field of sensor fusion deals with this problem. It is a very challenging problem to solve but it can be solved and it has been successfully used in spacecraft, aircraft, fighter jets, phones, AR/VR systems, and undoubtedly many others.

A basic approach is to have an uncertainty (or estimated uncertainty) for each of the sensing modalities. Then you use the uncertainties to weigh each sensing sample when deriving your estimated quantity (i.e. vehicle velocity for example). Assuming the uncertainties are correct, the resulting estimator can have variance lower than estimators deriving from a single sensor modality. Of course tuning sensor uncertainty values is a difficult problem in sensor fusion (and much more so when distributions are unknown) but it is definitely doable.

Repeating Elon's claim that sensor fusion is impossible/not-doable is entirely wrong. It is a technology that powers many different applications but its definitely not an easy thing to implement well.

Depends on your safety goal.

This. Boeing had removed a sensor deemed redundant for cost effectiveness, but failed to adapt the system to the changes and skipped the training of the pilots.

https://www.nytimes.com/2019/06/01/business/boeing-737-max-c...

How is this even remotely related to the topic? You just want to hate Boeing?

I think because it's a similar story that illustrates the danger of removing redundant sensors, like tesla is doing here

Honda's collision mitigation system uses a millimeter-wave radar mounted in the front bumper on the driver's side.

https://www.hondapartsnow.com/genuine/honda~0~36803-tbe-a04....

According to owner's guide [1] it uses both a front camera and radar.

I can definitely imagine it relying on the camera for medium to long range collision avoidance.

[1] https://owners.honda.com/utility/download?path=/static/pdfs/...

Are you perchance confusing ultrasonic sensors with front mounted radar? In general the collision avoidance systems use either camera or radar, or both. Some manufacturers are trying to add lidar into the mix these days. Ultrasonic sensors are in general just used for parking and don't last way further than maybe 2 meters. (Source: I work in this space.)

Its all fun and games, until you start hitting corner cases.

The car no doubt first confirms nobody is tailgating before such an abrupt action

With what? a rear facing camera that runs the same object detection software?

Likely it would not be affected by the same light artifacts give that it would not be pointing in the same direction.

I have some doubt.

/s?

So that you don’t brake in front of a wall if there is another care behind you? Not sure this is a smart move.

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