Why would anybody advocate an all-electronic control of the steering on a car? There must *always* be a mechanical fail safe for steering (and brakes). Case closed.
Is the ostensible reason to save money? You still need to steer the wheels. That involves a mechanical linkage, a gearbox, tie rods, everything that has been there on every car ever made. The only item you would be saving money on is the steering wheel itself. And replacing that with, what, an electronic gizmo that has to operate over the automotive temperature range? I don't see the savings.
Even if there were a cost savings, is that sufficient reason to put the occupants' safety at risk?
According to the local Honda service manager, both the Fit and Accord have rack-and-pinion with electric assist option. He had to ask a mechanical technician.
Still waiting for a return call from the local Ford service manager. He also has to find a mechanical technician for the answer. I do expect the same, rack and pinion with electric assist.
Does anyone remember when a service manager got to that position by rising up through the ranks instead of learning how to answer a telephone?
I was quite reminded of this last night, where I was driving in a heavy rainstorm in a badly rutted road. Every once in a while one wheel would hydroplane, pulling the wheel towards the side that wasn't. It was easy to tell via wheel feedback. They would have to greatly improve haptic feedback to get a joystick to do that.
Make everything DBW as desired.
However, give me an independent
backup system (DBW also if desired)
for steering and brakes with their own independant power supplies.
It is extremely unlikely two independant
safety critical systems will fail.
Totally Agree with Duane, above. I too think this thread got a little hijacked by the 'reliability'conerns, while there is no data to support the fact that mechanical assemblies wouldnt fail as much as the electronics fail. We know that semiconductor devices fail, but let us not forget that the ones getting designed into autos are special grade which are rigorously tested and their chances of failure approach to zero. Most of the public transport - Railways, Airplanes have their controls based on electronics alone. With the number of passengers and the speed/environmental conditions that a train or an airplane encounters, it should atleast settle the argument regarding the reliability of ICs. I am sure an entire system could be worked out for cars as well, which would be as reliable and safe as our trains and airplanes are.
Why? Well, when professionals do it (racing drivers) it might be accepted. Racing teams have seven figure budgets, and they haven't thought about it. We'll see something like this AFTER we see it in the INDY 500! Not before!
One thing that I think some people may be missing is thinking of a "joystick" a small, video-game sized joystick.
Small linear motions, very sensetive - true, there's not much motion difference between a small nudge and full scale.
A joystick used to control something like a car could be such a device, or could be a much different shaped stick, with a larger range of motion - both small wiggle movements, and a large sweeping motion that would be hard to mistakenly execute.
Or it could just be a 4"X4" touch pad.
Not that any of these are necessarily "better" than a wheel, which does have some pretty good merits as a steering control device.
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
Brought to you by