Well said Duane. For a bunch of engineers most of the comments are fairly luddite-ish.
That said, I'm a bit of a luddite myself. Like Zeeglen, I wouldn't trust a joystick in my current car, but how DO you do it mechanically on a car with a motor per wheel? And as someone else pointed out, look at the seniors with joystick controlled scooters.
And who says you can't do DBW with a wheel? There's no rule that says it has to be a joystick. And there's no rule which says you can't give it some tactile feedback as well.
derF above gave some good examples of what happens when we get it wrong. But Engineers should be able to think round these issues. For example on the traction control issue on gravel - disable the traction control when the driver gives full accellerator. As soon as his foot is off full, enable the traction control again. And if the car can sense what's in front and what's coming up behind, use that information as well.
Another comment noted the need for centimetre control when on a highway between two trucks at 70Mph (rats, mixing units) and the much larger range of control to turn a corner. So make the control range dependent on the speed, and make it non-linear so that larger movements produce a proportionally larger effect. Computer mice have this already....
I'd agree with derF: "When we can put them into a fully automated car, or better yet mass transit, then I'll feel safer...". Too true. A driver gets information from many sources - vision, hearing, touch, etc. Only when cars can do this as well can they overcome these problems. The traction control issue was due to only one source of information driving it. As Emmsys says below: "Am I totally against more computers and less mechanical in a car? If done properly, no."
I'll freely admit that I have nowhere near the skills to implement these solutions, but there are lots of guys (and gals, SallyF below!) here that can - so c'mon, think outside the box...
In terms of steering, I imagine there will always be a mechanical link in the background. What if the main fuse blows while your driving your DBW-only vehicle? I owned a BMW so I can attest to critical things like that happening at the worst possible times.
As for DBW throttle, that's been around for a while. My BMW had it and it became obvious that it was there when coolant shorted the ECU right at the throttle position sensor pins. The car launched forward a couple of meters before I put the car in neutral and let it coast to a stop. The engine RPMS were bouncing everywhere (there was no brake/accelerator error check) despite not pressing on the gas pedal.
Am I totally against more computers and less mechanical in a car? If done properly, no. However my experience is that cars have become sensitive because of sensors failing, which often completely disables the car. People have become more lazy with respect to driving and vehicle maintenance because they rely on sensors to keep them from sleeping at the wheel and from visually inspecting their tires.
Part of the major commercial airliners initial flight test involved review of what are called 'flight squawks'. This is a list of complaints the pilots made.
First squawk on a program I worked on. 'Joy stick is missing'. Chief engineer's response. Ha Ha Ha.
I do agree with the need for the innovavative spirit. I see the biggest hurdle in case of Automotives is the cost perceived by the manufacturer.
Is the premium increase, worth the added feature(in this case a high reliable drive by wire system). How much of the safety premium will reduce the accident probability that already exists?
In this case, we are addressing just
the driver error introduced by the
drive by wire system, compared to
In order to see a high reliability system for the above application, we
need a paradigm shift, where the reliability factor should become a commodity(fly by wire systems in Airplanes use high amount of redundancy,
and overdesign, which results in a substantial increase in the cost-justifying the multi million dollar
Joystick stering is in fact available today as a handicap adaptation. See one man's story about modification of a van with a commercial joystick steering system at tetraplegicliving.com/disabled-driving-disability-info
Media catchphrase of the day is "crowd souring". I'd be glad to design a steering system for automobiles with benefits of weight, space, and cost reduction, while at the same time offering high reliability, fail safe, and human factors considerations. But not for free - send me a contract proposal.
Next time you fly on a 777 or similar Airbus keep in mind the pilot has no mechanical link to move the primary surfaces. All those passengers are relying on Fly-By-Wire whether they know it or not. To me it is not an issue of eventually dealing with the safety / redundancy requirements. The only issue I see is the precision and upset characteristics of whatever the steer by wire control is - joystick or something else?
You can't make a locomotive that goes faster than 25 miles an hour because the air will be moving so fast that a human won't be able to breath and will die.
I'm never going to fly an airplane without a propeller. I don't trust anything without one.
Microwave? I really don't believe anything without flame or a glowing burner can cook, and the rays will kill us.
How can you possibly trust one of those carriages that is pulled by a motor instead of a horse. What if you run out of fuel? They break down all of the time. With my horse, I can keep going as long as there's grass and water.
Bar codes will never work for pricing because a lot of items are sold by weight and are measured out in the store. You can't design and print a bar code on the fly like that.
You can't put continuous feed forms and labels through a laser printer so we can't use one in our office.
I'm sorry, but where is the spirit of innovation and thirst for discovery and problem solving here in this thread? We all know what the problems will be when the steering wheel is replaced by a joystick or some other drive-by-wire set up. Pointing out the problems is the easy part.
How about instead of being skeptics because we don't believe it will work, how about we think about solutions? The reliability scares you. How can we make it not scare you? Instant-failure terrifying. How can we make it fail gracefully? Don't think something will work. How can we make it work?
Somebody's going to solve these problems. Why not us? We can look at all of the fears and worries as engineering challenges and solve them, or we can fade silently into the night as the rest of the world moves on ahead of us.