How Does Steering Assist Detect One's Hands?

[gregory.opera]

My curiosity is killing me - how does my Nissan Leaf know when my hands are on the steering wheel?

My best guess so far is that it's either detecting my hands through electrical impulses or, more likely, it's detecting a slight amount of resistance on the steering wheel and thus assuming that my hands are on the steering wheel.

So which is it? Or are they using some sort of other system entirely?

 

[Learjet]

I think it is resistance

 

[Chad E. Mo]

It's usually physical resistance detected by a torque sensor.

Some folks cheat by attaching a weight to the wheel, or holding one's knee against the wheel if their legs are long enough.

 

[corkycal]

My buddy uses one ankle weight that has Velcro. He simply moves the weight from one end to the other when it flashes. Works like a charm.

Have no idea what sensor it uses to detect no hands on the steering wheel.

 

[Lucky]

Steering servo motor has a torque sensor monitored by microcomputer. When torque on the steering wheel is big enough motor spins in that direction to compensate for the torque that driver applies when turning. That makes the wheels move effortlessly.
When you hold the steering wheel you always apply at least some minute torque and that is detected by sensor.
That is alo the reason why the system in rare occasions doesn't detect your hands. It can happen that your hands are balanced on the steering wheel ecactly and the sensor doesn't detect any input.
Driving with weights on is dangerous and not exactly smart. Your reaction time increases dramatically.

 

[gregory.opera]

Some folks cheat by attaching a weight to the wheel, or holding one's knee against the wheel if their legs are long enough.

Yeah, this is what I've been doing since my original post (resting my knees on the underside of the steering wheel), so I'm now convinced that it's resistance-based...

 

[gregory.opera]

Driving with weights on is dangerous and not exactly smart. Your reaction time increases dramatically.

My original plan was to fit something to the steering wheel, but then I decided against it for exactly this reason.

The Steering Assist is fantastic, but I still want to be able to respond immediately in the unlikely event something goes wrong, rather than worrying about weights and other devices that will probably hinder an immediate reaction.

Instead, I just hold the underside of the steering wheel with my knees ever so slightly, whilst my hands rest on my knees, ready to respond if something goes pear-shaped. I still monitor the mirrors and rest my hands on the steering wheel if it gets too close to other vehicles for comfort / a particular section of road is narrow or sketchy; but it's nice to be able to put my arms down for the stretches in between, as I work out of my car along major roads all day, and my arms get sore holding them up all day. It also makes no sense if one is going to actively monitor a system that works pretty well.

And no, I'm not using my cell phone whilst the car is driving down the highway or anything like that; it's otherwise complete attention on what the vehicle is doing.

I do understand why they have those restrictions in place though, because some people take systems like this for granted, which does create unacceptable risk.

 

[cornbinder89]

OK, I got to say this, I have been a wrecker operator and commercial driver, millions of miles.
You have one job, that is to drive the car!
All it takes is a chuckhole to instantly send the vehicle off in a diagonal path.
I have handled steer axle blow-outs at 70 MPH and a full loaded semi, I didn't loose control, it isn't pre ordained that a blow out is "uncontrollable". Brought the vehicle to a controlled stop and they never involved any other vehicle.
I have heard all the excuses, why letting a machine take more and more of the job of driving is some how making it safer.
" I am more rested when I don't have to control the vehicle all the time" If you are more rested you are not doing the job you took on, and can't react fast enough to a problem.
Millions of miles and not a fault in any major accident. Some people are alive today because I took my job seriously.
I have seen the results of many bad accidents whoops, incidents, every one comes about because of error in judgement.
I expect some flaming, but far to many are killed on our roads because they didn't take their one job seriously enough.
If driving makes you tired, stop! get some rest and continue on.

 

[gregory.opera]

In my defense, I spent many, many years driving an ambulance for the military at high speeds and under some incredibly challenging environments, in addition to operating heavy vehicles with similar figures to you; so I think that my reaction skills and experience more than make up for most scenarios where something could go wrong... So with my experience, I'm personally not too concerned.

The 18 year old player that wants to get it on with his girlfriend in the back seat whilst the car cruises down the highway semi or completely automatically however... Well that has me worried.

And it will happen, if it has not already - heck, if I was 18 again and this sort of tech existed, I'd probably be silly enough to try this.

If most countries decide to allow autonomous vehicles - and I'd be surprised if I see this in my lifetime, but "if" - one should still legally be required to remain in the driver's seat, proactively monitoring the driving, ready to respond at all times... Technology can - and does - go wrong. Even in the aviation industry, where much of the technology behind autonomous driving has been used for decades, things can and do go wrong - which is why pilots are still required to have at least one person proactively monitoring everything at any given time.

 

[cornbinder89]

Reaction times needed are far shorter those that can be had with someone not actively controlling the car.
A chuck hole with the short sidewall tires, is going cut and loose all the air, rolling resistance goes high on one side and the vehicle is taking off in a diagonal path all in less time than it takes to move your hands from the bottom of the wheel to "10 and 2". That is all it takes to cause a death.
I think the whole idea of "adaptive cruise" never mind self driving is a bad one, then to try and defeat the minimal requirement that are "supposed" to make sure you are ready?
There is enough carnage on the roads already!
Adaptive cruise and lane and brake assist are being pushed as "safety" devices to "help" the driver, but they are being used to "replace" the driver, make it worse than if they weren't there to begin with. They are being advertised as allowing the driver to "rest and arrive relaxed", that isn't being ready to take over, that is ignoring the job at hand.
In theory, a device that can "see and react" to what the human didn't is a good thing, in practice it has worked out to be so much less. It has jammed on the brakes when attempting to cross an intersection (read about it on this site) and had many Tesla's drive into stopped emergency vehicles. Wamo has cars not reacting.

 

[nisous]

Your Nissan Leaf uses sensors in the steering wheel to detect small movements or resistance caused by your hands. If you grip the wheel, even lightly, these sensors pick up the pressure or micro-adjustments you make while driving. Without this input, the car assumes your hands are not on the wheel.

 

[Drew21]

I'm with cornbinder here. Anyone who drives can list dozens of examples of all the irresponsible choices folks make while driving: eating, texting, watching videos, talking on the phone, reading (my dad used to read the church bulletin on the way home on Sunday), applying makeup, etc, etc.

I've seen all that and more. I've watched people drive off the side of the road while playing with their phone. I've been passed by someone tailgating a semi-trailer at less than a car-length distance while using the visor mirror to apply makeup. Last winter I saw a string of five or six cars follow each other into the ditch like a bunch of lemmings.

I understand why all the new gizmos and features are being added to automobiles, but it doesn't take a capital "J" genius to figure out what's going to happen when you have a driving population that barely pays attention when they have to control the vehicle, and then you say "hey, guess what, now you can do even less while driving!"

 

[fjord]

I'm a tech geek but I prefer the car let me drive, thankyouverymuch. I barely use cruise control, and all the car's screeching at me regarding following, lane changes, etc., etc. are ignored. I know WTF I'm doing, Karen.

 

[gregory.opera]

I must say, I do find it curious that some people are so apprehensive about automation making its way into cars... But seemingly, they have no issue with automation being present in the aviation industry.

Automation is not necessarily a bad thing, when used responsibly.

I do agree with @fjord that one misses out on the experience of driving a vehicle if they rely completely on automation, though; which is why I personally will always prefer to have a "manual" option available where ever possible, even if we went completely autonomous tomorrow... But there are so many reasons why automation is a fantastic step forwards.

 

[fjord]

I don't need my car to blab at me other than playing my tunes. I find ProPilot far more distracting and annoying than useful. I always have it off.

I had a rental Audi last year that would vibrate the steering wheel on a lane departure. Startled the crap out of me the first time it did it - good thing I didn't let go of the wheel. I couldn't figure out how to disable it, and it would trigger when it wasn't supposed to. Very dangerous.

 

[Drew21]

I must say, I do find it curious that some people are so apprehensive about automation making its way into cars... But seemingly, they have no issue with automation being present in the aviation industry.

I'm going to go way out on a limb and suggest that the average pilot is more attentive, better trained, and consequently far more skilled at their job than the average automobile driver. Additionally, I would argue that the average pilot is far more cognizant of the dangers inherent to flying badly than the average driver is of the danger (to themselves and others) of driving badly.

Continuing from that premise, automation should help pilots do a better job of flying planes. Conversely, for way too many drivers on the road automation only serves to help them pay even less attention to driving.

I have no doubt that automated features offer safety benefits for these drivers, in that auto-braking, lane-departure warnings, etc. help them survive scenarios where they might have crashed in the past. However, I'm somewhat dubious of the overall net benefit for the driving population of keeping inattentive drivers on the road.

 

[fjord]

We'd be better off getting more drivers into public transit rather than pushing the mirage of fully autonomous vehicles as a fix to the traffic problem. They won't.

 

[gregory.opera]

Continuing from that premise, automation should help pilots do a better job of flying planes. Conversely, for way too many drivers on the road automation only serves to help them pay even less attention to driving.

Whilst I don't disagree, you're not looking at "the big picture"... Eventually - likely sooner rather than later - we'll get to a point where automation is so effective that in 99% of cases, we won't need to worry about "drivers" paying little or no attention to their vehicle.

As I write this in 2024, we're already almost there... Not quite, but awfully close.

And that has significant benefits, because overnight, all those poor drivers on the road suddenly become fantastic "drivers".

Sadly, legislation (law) and a reluctance to embrace the future is what will hold this progress up globally, however... Particularly in countries like Australia, where the Government are VERY reluctant to embrace any technologies that are "different".

 

[gregory.opera]

We'd be better off getting more drivers into public transit rather than pushing the mirage of fully autonomous vehicles as a fix to the traffic problem.

I disagree.

In my opinion, if we get to a point where we see Blade Runner-style automation - in other words, vehicles that completely drive themselves - we'll fix most of the safety issues surrounding private vehicles... And I don't doubt that it's only a matter of time until this happens.

In saying that, I'll be VERY surprised if I see automation adopted en mass in my lifetime (I'm in my 40s), because many countries (my home, Australia, being an obvious example) are reluctant to adopt anything new, let alone vehicles that drive entirely on their own without user-input... Places like California might see it in my lifetime, but adoption globally will be painstakingly slow.

That in itself has advantages, because it allows more time for problems to be ironed out - but I don't think anybody reading this in 2024 / 2025 will live long enough to see full automation adopted by most countries.

 

[duncan-s]

I too am convinced the detection is based on resistance.

But I don't use the system much; it gets confused sometimes, wandering to one side before exclaiming in its little beep-language and then righting itself. Maybe the roads in my area just have substandard lane markings.