Drive-by-wire
- Thread starter ElRazur
- Start date
Mickey_D said:Direct mechanical control of steering and braking cannot be interrupted by one of the most unreliable components on a car - its electrical system!!
And as for mechanical parts and pulleys, how is the FBW system going to actually move the wheels left to right or apply the brakes? That's right, with a mechanical linkage!! So you're going from a mechanical input to an electrical comms unit to a mechanical output. How many points of failure are there in that system after 100,000 miles belonging to some chav holigan that drives like he stole it?
A lot more than there are in the current system......
Im just not talking about the Steering and breaking mechanism, im talking about the whole car....You know the one you get in and it drives you around without much human input(driver)
Cruise control is a DBW and it does work well (i used the one in accord coupe auto) I htink as time goes by we will be more introduced to more DBW system and before we know it, it will become a standard feature on tomorrow's car.
Soldato
El, without some VAST improvements in the reliability of automotive electrical components in the near future, I will certainly not be relying on any FBW system to control my steering and braking, ok?
To use my wife's Neon as an example : It was lovingly maintained by my father for the first 120,000 miles of its life, to as new a condition as is possible. We inherited it and have tried to maintain it as good as we can. And so far (in the electrical system) we've had the following problems. ABS system crapping out at the most inappropriate times, a couple sensors in the engine management system failing, ALL of the sensors and electrical components in the AC system failing, the high/low headlamp switch getting a short between the two settings, the dash light dimmer getting a "flat" spot in it, the reverse light switch in the transmission failing, and one of the cooling fan sensors going out. Now, for the most part (with the exception of the AC system and the ABS system) I've been able to stay ahead of them. But that is only after we've discovered a problem with them. None of them have been exactly catastrophic in nature as they are (for the most part) secondary systems and not vital to the day-to-day operation of the car.
What happens when something like the above problems start occouring in a FBW steering system? You lose steering ability!!! What happens when you have an unreliable component in the FBW braking system like we had in our ABS system? You have no brakes!!
This is my main concern with FBW in critical systems. This is why ALL systems currently in cars still have a direct mechanical connection between the steering wheel and the steering linkage, and there's still a direct mechanical link between the brake pedal and the hydraulic system in the brakes. This is why there's only power ASSIST brakes and steering. Because a completely power system on either would mean a comlpete and utter loss of vehicle control were the system to fail. At least with PAS and PAB you still have SOME modicum of control should the power system fail. In a completely dedicated FBW system, there is no such backup should you lose electrical power.......
To use my wife's Neon as an example : It was lovingly maintained by my father for the first 120,000 miles of its life, to as new a condition as is possible. We inherited it and have tried to maintain it as good as we can. And so far (in the electrical system) we've had the following problems. ABS system crapping out at the most inappropriate times, a couple sensors in the engine management system failing, ALL of the sensors and electrical components in the AC system failing, the high/low headlamp switch getting a short between the two settings, the dash light dimmer getting a "flat" spot in it, the reverse light switch in the transmission failing, and one of the cooling fan sensors going out. Now, for the most part (with the exception of the AC system and the ABS system) I've been able to stay ahead of them. But that is only after we've discovered a problem with them. None of them have been exactly catastrophic in nature as they are (for the most part) secondary systems and not vital to the day-to-day operation of the car.
What happens when something like the above problems start occouring in a FBW steering system? You lose steering ability!!! What happens when you have an unreliable component in the FBW braking system like we had in our ABS system? You have no brakes!!
This is my main concern with FBW in critical systems. This is why ALL systems currently in cars still have a direct mechanical connection between the steering wheel and the steering linkage, and there's still a direct mechanical link between the brake pedal and the hydraulic system in the brakes. This is why there's only power ASSIST brakes and steering. Because a completely power system on either would mean a comlpete and utter loss of vehicle control were the system to fail. At least with PAS and PAB you still have SOME modicum of control should the power system fail. In a completely dedicated FBW system, there is no such backup should you lose electrical power.......
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