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This is one system in the car that must have mechanical fallback. Yes there are a lot of systems already interacting with the hydraulics (servo assist, ABS, pum

This is one system in the car that must have mechanical fallback. Yes there are a lot of systems already interacting with the hydraulics (servo assist, ABS, pumps, etc). But fundamentally you can stop the car if you push hard enough on the pedal. Removing that seems like looking for cost savings in a silly place.

wat10000 2y ago
It must be reliable. Having a mechanical fallback is a way to achieve that. If an electronic system can be made equally or more reliable, then it’s fine. This community is going to have natural and reasonable skepticism of this. But consider that many airliners are fly by wire and their safety record is superb. There’s no guarantee an automotive system would be that good, my point is just that it doesn’t have to be worse.
- dkjaudyeqooe 2y ago
  In the abstract that might be true, but you're missing issues of unnecessary complexity which feed into systemic risk. Large airplanes are obviously different to cars and so are the engineering choices. It actually makes a lot of sense to use fly by wire in an plane because the level of existing complexity (and expense) justifies it. A Boeing with triply redundant mechanical control of control surfaces is still inferior to Airbus fly by wire when the latter can implement a more reliable system, but only because the inherent complexity and expense of planes allows it. The Airbus will have 5 or 7 redundant electrical paths to the control surfaces and numerous redundant power supplies and actuators and beats the mechanical system hands down. On a car you sharply increase complexity, and therefor reduce reliability. You need redundant power supplies and power connections, for instance. Planes have to be serviced by certified professionals on a strict basis, where as cars do not. So you have to implement a system that still operates under conditions of neglect, all while having severe cost limitations.
- maples37 2y ago
  One consideration for aviation is that they have inspections, replacements, repairs, etc regulated like crazy. And I suspect it's regulated so tightly because it would be skipped otherwise, because that does NOT sound cheap. Then compare that to an average car. If you change your own oil (like I do), it's possible to go multiple years in between trips to a repair shop for bigger items like tires or a weird noise that popped up. And let's be honest, a large number of people will hear a weird noise and drive with the check-engine light on for way longer than any manufacturer would recommend (even if they didn't have a profit motive in the form of expensive dealership repair shops). If the machine gets to point B, then whatever that noise is can wait a few more days/weeks.
- relistan 2y ago
  First of all there is no comparison between car and aviation safety systems. And in aviation, many systems have both an electric and a hydraulically system so that they don’t share dependencies. Second, if this is intended for gasoline/diesel vehicles, then you need two power systems as well. If you lose your alternator on the freeway and don’t notice, or are very far from a safe place to stop, and you drive the car on the battery until it dies, it’s going to slam on the brakes. In some scenarios that’s a safe default. In many scenarios, it’s the wrong thing to do.
- nothercastle 2y ago
  On an airplane all systems are triple redundant. That makes it easier because the power and control systems are redundant and there is no need to add that. If only the brakes need to be redundant then they need to have multiple self contained systems including power and that is really complicated

wat10000 2y ago

It must be reliable. Having a mechanical fallback is a way to achieve that. If an electronic system can be made equally or more reliable, then it’s fine. This community is going to have natural and reasonable skepticism of this. But consider that many airliners are fly by wire and their safety record is superb. There’s no guarantee an automotive system would be that good, my point is just that it doesn’t have to be worse.

dkjaudyeqooe 2y ago
In the abstract that might be true, but you're missing issues of unnecessary complexity which feed into systemic risk. Large airplanes are obviously different to cars and so are the engineering choices. It actually makes a lot of sense to use fly by wire in an plane because the level of existing complexity (and expense) justifies it. A Boeing with triply redundant mechanical control of control surfaces is still inferior to Airbus fly by wire when the latter can implement a more reliable system, but only because the inherent complexity and expense of planes allows it. The Airbus will have 5 or 7 redundant electrical paths to the control surfaces and numerous redundant power supplies and actuators and beats the mechanical system hands down. On a car you sharply increase complexity, and therefor reduce reliability. You need redundant power supplies and power connections, for instance. Planes have to be serviced by certified professionals on a strict basis, where as cars do not. So you have to implement a system that still operates under conditions of neglect, all while having severe cost limitations.
maples37 2y ago
One consideration for aviation is that they have inspections, replacements, repairs, etc regulated like crazy. And I suspect it's regulated so tightly because it would be skipped otherwise, because that does NOT sound cheap. Then compare that to an average car. If you change your own oil (like I do), it's possible to go multiple years in between trips to a repair shop for bigger items like tires or a weird noise that popped up. And let's be honest, a large number of people will hear a weird noise and drive with the check-engine light on for way longer than any manufacturer would recommend (even if they didn't have a profit motive in the form of expensive dealership repair shops). If the machine gets to point B, then whatever that noise is can wait a few more days/weeks.
relistan 2y ago
First of all there is no comparison between car and aviation safety systems. And in aviation, many systems have both an electric and a hydraulically system so that they don’t share dependencies. Second, if this is intended for gasoline/diesel vehicles, then you need two power systems as well. If you lose your alternator on the freeway and don’t notice, or are very far from a safe place to stop, and you drive the car on the battery until it dies, it’s going to slam on the brakes. In some scenarios that’s a safe default. In many scenarios, it’s the wrong thing to do.
nothercastle 2y ago
On an airplane all systems are triple redundant. That makes it easier because the power and control systems are redundant and there is no need to add that. If only the brakes need to be redundant then they need to have multiple self contained systems including power and that is really complicated