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Variable Ratio / Adjustable Steering

All kinds of benefits
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Some people (not myself, I'd like to say) have big problems jumping from car to car - for instance, driving their spouse's car, or using a company car pool.

With this steering system you can calibrate it to suit your driving style, in the same way as you set up a mouse on a PC. You could alter the steering ratio (this would even be handy for different modes of driving - very fast steering for round town, but eased off a bit on the motorway so the car isn't so "darty"). You could also alter the steering weight - I know that most modern cars have speed sensitive power steering, I don't mean that - just weight it to suit you, it can then get heavier still at speed if you like.

This would be accomplished using a "steer by wire" system - the wheel is simply an input device, actuators on the steering rack will carry out the work. This of course will mean that the wheel will need to have "force feedback" so that you can feel what the car's doing - this is available on any arcade simulation, it wouldn't be hard to put it in a real car - again, you could taylor the level of feedback to suit your driving (or your mood). The lack of steering "feel" currently experienced in a lot of cars (my Calibra for instance, or most Audis) would also be eliminated with the force feedback idea...

kmlabs, Dec 22 2004

Part of the same idea, but for a different reason Steering_20wheel_20feedback
mhh5 thought of a force feedback wheel, but for warning of impending disaster. [kmlabs, Dec 22 2004]

PID illustration http://www.bmb.leed...llingworth/control/
[paraffin power, Dec 22 2004]

Parker's Guide http://www.parkers....w.aspx?range_id=346
Note the remark about the steering in the "Driving" comments... [kmlabs, Dec 22 2004]


       So when you come up to a bend in your Calibra, do you think "this bend needs a quarter turn of the steering wheel", and if you're in a different car you crash?   

       Steering a car uses your own built in PID loop. [-]
paraffin power, Dec 22 2004

       No, I don't steer like that... I know you drive each car according to how it responds, I don't know of anyone who has had an accident because they turned the steering wheel the usual amount but the car didn't steer far enough / steered too far.   

       I have on the other hand thought to myself whilst driving a car "crikey, this car's got slow / fast * steering!". My wife's car, for instance, has ponderous steering that isn't a problem when I'm driving, but necessitates much wheel-turning when trying to park.   

       Re. steering feel, some cars give you more feedback than others - my previous car for instance gave me a good idea through the steering wheel of whether the front wheels were gripping hard or sliding. The Calibra however doesn't have so much feel. I know it's possible to tell when a car's sliding (the fact it's not going in the direction you're pointing it is a clue) but feel through the steering wheel helps - as Jeremy Clarkson will tell you, in just about any car review he writes.   

       * - delete as appropriate.
kmlabs, Dec 22 2004

       And while you're at it, you could not only make cars with speed variable assist, but also speed variable ratio. Then, when you're in a parking lot, you don't need to crank the wheel in circles to pull into a parking spot, but while on the freeway, you have very fine control.   

       That said, I'm not in favor of drive by wire for steering. I have a hard time imagining getting enough benefit from drive by wire steering to overcome the safety factor of not having a physical link. Steering is currently one of the most reliable systems in a car and for good reason. If your accelerator pedal malfunctions, there are ways to turn off the engine, take it out of ear, etc. and coast to a stop. If the brakes fail, you've got engine braking, parking brake, and steering to avoid obstacles. But if steering fails, the only question is whether you can stop before you run off the road or into oncomming traffic.
scad mientist, Dec 22 2004

       [You could alter the steering ratio (this would even be handy for different modes of driving - very fast steering for round town, but eased off a bit on the motorway so the car isn't so "darty"]. Baked. Latest BMW 5 series has variable ratio steering option.
Emi-chan, Dec 22 2004

       This idea has floated round in my head since I posted it, and resurfaces occasionally.   

       [Emi-chan] it's not baked - the new BMWs have variable ratio steering, true, but it's just achieved by varying the width of the teeth on the steering rack - so as you wind on steering lock the steering becomes faster (evo magazine hates it, incidentally). What I'm talking about is a system where the ratio stays constant through every degree of steering lock, but you can set that ratio before you start your journey.   

       [Scad Mientist] I think you're going along the same lines as me, and I agree that drive-by-wire steering sounds like it may be a bit of a worry. Taking a cue from BMW, it would (I guess) probably be possible by mechanically altering the pitch of the teeth on the steering rack - that way, if the actuators jam or break down the teeth are still there and you'll still be able to steer the car to safety.
kmlabs, Aug 25 2005

       bad bad bad, auto electronics get glitchy after 5-10 years I would not like my stearing to fail due to an electrical short fish for you
amuse, Apr 21 2006


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