By-wire also offers important advantages for vehicle manufacturers. Elimination of mechanical systems could cut weight and could more easily enable automakers to switch a car from a left-hand-drive to right-hand-drive, so it could be sold in other countries.
The transition to steer-by-wire has been a long-awaited one. As far back as a decade ago, auto industry engineers looked forward to the addition of steer-by-wire and brake-by-wire technologies but hesitated because it was believed that 42V electrical architectures would be needed in order to make it happen. "You can't do steer-by-wire with a 12V system," one veteran industry engineer was quoted as saying in a 2001 Design News article. "For steer-by-wire, 42V is absolutely essential." At the time, engineers estimated that steer-by-wire would draw as much as 1.8kW, which they said would necessitate use of better alternators.
Infiniti did not say what changes had enabled the use of steer-by-wire in its cars, but the company did say it is not depending on the higher-voltage of hybrid electrical architectures to make it happen. "We've not announced what vehicles it will go into, but it has been demonstrated in a conventionally powered car, not a hybrid," Bazemore said. "So you can reasonably assume that's how we'll offer it."
Greg, the backup is absolutely required. While it is rare, I have been in a car where the power failed and the power steering stopped working. This was a hydralic system, and it was very hard to steer the car, but at least it could be done. Electrical systems are more likely to go out on a car, I would venture to guess, than the purely mechanical ones. Especially electrical systems that are digital.
Right, Rob. For now, the clutch is there, but Nissan told us that if the mechanicals were ever removed, its engineers would incorporate a fail-safe sub-system. At this point however, it's not clear how the fail-safe sub-system would work.
I think the only down side is the number of automobiles on the road. The chances of the system failing are far greater than with cars. You cannot guarantee that the car is professionally maintained. However, if this system is fool proof, I mean that with masses in mind, then it is the future.
Today I drive a car with mechanical linkage and electric power boost (by chance, also a Nissan). Nissan propose to give me the same, with an extra sensor and wire to the steering mechanism. The electrical signal will be the primary mechanism, but so what? It doesn't replace the existing linkage. Its extra - extra weight, extra power, extra complexity. What happened to "keep it simple" ? Keeping the mechanical linkage in place as a backup is Nissans' way of saying "we like the new system - but we don't fully trust it"
Anyone remember the accelerating Toyotas? I know GM has been working on this for over 20 years. I think it will ultimately come down to consumers and federal mandates (such as CAFE).
The new 787 Dreamliner is entirely electronic. The difference is the rundundant back-ups are not going to exist in the physical sense on cars (weight, weight, weight). So the development in the automobile has to be sensor/control failsafe that stops the vehicle. It is better to get out of the car that is on the side of the road than trying to parachute out of an airplane with type of failsafe!
I'm going to play teh antagonist here. When it comes to driving, feeling the road is much more important to me than a smooth ride. The feel actually helps me know that a tire has a problem before it is a real problem. I get the whole technology thing for the future, but nothing can replace a solid mechanical system. Removing that is like putting a rocket on the road with no breaks. There always seems to be delay in control system response, and that nanosecond of steering response has saved my life. I embrace technology, but I'm not confident that this is the right way to go.
That is 100% correct. In the aerospace industry there is a massive effort to test and qualify all fly by wire systems to prove that they are fully redundent and fail safe. To incorporate this into a car without a mechanical backup will cause a very complex and expesive system. This is why the aircraft that are relatively inexpesive (single engine puddle jumpers) are still cable and pulley. We may see a day when drive by wire is 100% but I beleive it will be in the high end cars where cost is less of an issue.
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