Car automatic speed limitation

[prof328]

Just throwing this out to see if anyone thinks this is feasible.

My car has a manual gearbox but is equipped with a fairly sophisticated cruise control system operated on one of the stalks on the steering column. It can be engaged by pressing the button on the end of the stalk in any gear at any speed and is disconnected as soon as the clutch or brake pedal is pressed, it can be overridden by pressing the accelerator and when released will resume.

When engaged the engine rpm does not change, if a uphill gradient is encountered the engine tone changes as the management system gives the engine more power to maintain the set speed. Obviously the engine rpm is what is being fixed by switching the cruise control on.

So a relay could be used to switch the cruise control on, bypassing the manual switch, but I would need to delve into the engine management software to see if it is possible to set the engine rpm prior to triggering the relay.

Now I was thinking if I used a gps module and a microcontroller I could decipher where the vehicle is at any point in time from the received gps transmission signals.

Assuming this is possible, the next thing I need is the speed information for the road being travelled, I would need the information from the maps that all car navigation units have, I need to research this aspect.

If I could get this information then the microcontroller could be programmed to set the engine rpm, (assuming a suitable gear is engaged, if not it could switch a red led on to advise a change of gear is necessary), and switch the cruise control on.

It would be interesting to drive a car that automatically obeys the speed limits, as the local councils seem to have gone crazy lately and it is impossible to make even a short journey in the uk without traversing several speed restrictions.

 

[alec_t]

Nice idea, but I doubt you'd get any UK insurer to cover a vehicle with a DIY mod like that .

 

[prof328]

Yes, you are right it would not be good for the car to decide, for instance you may enter a 40mph limit with an little old lady driving at 20mph in front of you, it would not be safe for the car to go straight to 40mph.

I was just thinking aloud, for an idea for a project.

Ok, what about just a speed limit controller so that the driver could not exceed the speed limit unless he manually over rides the system, all newer cars have rpm limiters for the maximum rpm.

It would be fairly simple to have a look up table of gear + rpm for the various speeds, the software could impose a temporary rpm limit so the car could not exceed the speed limit. The current gear could be derived from the vehicle speed and engine rpm.

Something along these lines will be a feature on future cars, after all the likes of Google are testing driver-less cars, one of the German car makers demonstrated a self driven car on a race track capable of driving at racing speeds with no driver intervention, and the truck manufacturers are trialing convoy systems where the trucks drive very close to each other with systems interconnected wirelessly.

 

[alec_t]

Again, a good idea, but I think you'll have a hard time convincing your insurer. The slightest change to a vehicle means that insurers have to re-assess the perceived risk it poses (to their profits, if not to other road users ). Some countries/jurisdictions don't seem so picky/short-sighted, so you might have to consider emigrating if you want to use your project on the public highway.

 

[KeepItSimpleStupid]

FYI:

I do believe speed limiters are in place on some vehicles such as rental trucks. I also believe that top speeds are limited. There is also a "black box" data recorder on a lot of newer vehicles. I don't have references.

Top speed may be a "variable" in the engine management computer.

I saw an advertisement of the Chevy Malibu. There were some warnings listed on the dash, like "Overspeed warnings". No Idea how it works, but GM vehicles sometimes have Onstar, so location, remote unlocking and disablement is possible. My GPS has speed limits.

The ECM is the perfect place to put that. On drive by wire cars, you might be able to TAP into the accelerator signal(s). In some cases, it's two opposing voltages. e.g 0-5 and 5 to 0.

 

[shortbus=]

Also some high end performance cars have a "valet" mode, to prevent people that park the cars from going over a certain speed.

 

[MikeMl]

Some Garmin automotive GPSs sold in the US already have an data-base of speed limits based on present position.

 

[tcmtech]

My view is that if you are unable to pay attention to the road signs and general goings on around you you shouldn't be in the driver's seat to begin with.

Driving a vehicle is a privilege not a right and I really hate having to share the road with privileged idiots who don't belong anywhere but on pubic transportation behind the seat of a person who has earned the privilege to being in driver's seat of said public vehicle.

I have a fully loaded Class A Commerical Drivers Licence and by my views of what and how I had to work to get it and what I have to do to keep it I really don't feel that anyone who can't pass my equivalent tests to get and keep that licence needs to be on the road with me.
Especially those who are so distracted by other things or outrightly cognitively incapable that they can't even keep their vehicle at the posted speed limit on their own.
If going 25 in a 25 zone is too hard to do on your own either walk, ride a bike, take a bus or a taxi because as far as I am concerned you don't need to be out there on the road with me.

 

[KeepItSimpleStupid]

Tcm:

An eye opener was for me to drive a semi fully loaded with paper around a parking lot when I was about 18 YO. Everybody should do that. It makes a BIG difference how you view other son the road and especially tractor-trailers. It was a one-time thing, but worth every moment of it.

 

[tcmtech]

Good to know you understand the differences! Too many don't and that drives me nuts when I am on the road.

I definitely agree that every person who drives should spend at least one day driving around in a fully loaded semi that has to deal with everyone else on the road that's not driving another big commercial vehicle.

A few years ago I took my Ex on a few day trips with me while hauling fuel at a company I worked for at the time. While the experience stayed in her memory it was clear she was a better driver but unfortunately she forgot the experiences and now she drive just like everyone else again.

 

[Mikebits]

I had to have a class B to drive a fire engine. Anyways, they had a speed limiter, so the vehicle could not exceed 65MPH. A new experience and challenge for me was with driving with the water tank being full. It had baffles in the tank but you could still feel the water slosh around when breaking, and turning.

 

[KeepItSimpleStupid]

The weird part for me was that the brake and the clutch "looked like" accelerators, so the first time I hit the brakes there was a hesitation on my part. The second weird part was that after you turn the cab, the trailer had a mind of it's own. Double-clutching the gears was also different. Clutch to get out of the gear and clutch to get in.

 

[tcmtech]

I drive the lazy way. Clutch to get rolling and that's it. All shifting past that is just match Engine RPM's to speed then bump and slide.
To be honest now driving anything that has a manual transmission with synchronizers just annoys me. It's way too much clutch work.

 

[Tony Stewart]

I once had a great TomTom with an audible alert when speeding. I used a cow moooo.
Newer ones have radar detectors for speed traps

 

[prof328]

Sorry tcmtech but your posts have nothing to do with electronics just a rant about the low standard of driving you witness on a daily basis. Just for info I worked in the heavy goods industry and have driven fully loaded semi’s albeit on test tracks, reversing one was “interesting”, and yes the standard of driving of a lot of the general public is dire.

In the UK we used to have four speed limits, 30mph for built up areas, 40mph for semi urban areas, 60mph on general roads, and 70mph for motorways and dual carriageways.

But today we have 20mph for schools, 30mph built up areas, 40mph, a new 50mph and 60mph, they have also introduced variable speed limits on motorways around big cities.

The police are equipped with high tech radar and camera equipment, and take pride in finding places where they can “ambush” drivers and will prosecute if you are caught exceeding any of the speed limits even by a very small margin.

They don’t stop you as you have been caught by a camera, the first thing you know is a fine arriving in the post, the cost of such an infringement is £100 + 3 points on your licence, get to 12 points and you are banned from driving for a period of time, usually a year.

I don’t currently have any points on my licence but I have been caught in the past.

The point of my post was to explore the technology that is currently available but not put to the use I was thinking of.

Car manufacturers are constantly looking for ways to use technology, some cars will automatically apply the brakes if the cpu thinks a crash is imminent. One of my cars, a sports car, has a yaw sensor in the middle of the car and if the car gets out of shape on a corner the cpu will apply brakes to one or more wheels to automatically try correct the situation.

There are also cars with heads up displays, I fancy one of those, some even have infra red vision.

Unfortunately none of these will improve the standards of bad drivers, so a car where it would be impossible to exceed the speed limits could eliminate just one aspect of bad driving.

A potential benefit would be that all the speed detection apparatus littering our roads, and earning the police a small fortune, would be made redundant. In addition, councils that arbitrarily set the speed limits may come under scrutiny by drivers complaining on the sheer number of limit changes that we currently have.

 

[Tony Stewart]

Sounds like a hidden LADAR\RADAR is the ticket to prevent tickets or the "moo" feature on GPS. You can also choose a rooster. Perhaps a "siren" GPS overspeed indicator might be more re-inforcing. Constantly looking for speed signs can be distracting.

I think every driver should be tested like truck drivers and be graded on the mean error from the lane centre for safety margin or use narrow pylons or e-paper tracks.

 

[tcmtech]

Unfortunately, there are too many situations where the necessity to go above the speed limit is valid and having a vehicle that will not let you do that is more of a danger.

To me this whole concept still comes down to the basic principle of the driver needs to be properly and adequately aware and in control of their vehicle and if they don't have the capacity to do so they really don't belong on the road with the rest of us who have earned and work to keep that right.

A good example is given by every country who has a far stricter licencing system than our own. I was over in Turkey a few years ago and even by our American big city driving standards those people drive like they are nuts yet vehicle accidents are surprisingly low simply due to the fact that their requirements to get and keep even a basic drivers license are as hard or harder than what it takes to get a full class A CDL like mine here in the USA.

By default of sorts that means that the vast majority of those who do have licences there and can afford to have a vehicle of their own put an active effort into getting and making sure they can keep the privileges that not all other people can earn and keep.

As far as I am concerned more self-control of the vehicle by the vehicle is not what we need. What we need is more control and outright restrictions of those who can get behind the wheel in the first place.

Simply put not everyone is destined to become let alone capable of being certified professionals in certain careers or such whether they like it or not and being able to drive vehicle should be seen as no different. If a person needs to have something other than themselves in control of the vehicle they don't deserve to be on the road.

That's what pubic transportation and law enforcement is for, Those who can't handle driving responsibly themselves and making and active public effort to weed out those who no longer belong on the road. It's not about the speed limits. It's about the drivers.