DIY Wiper Speed Control And Collision Avoidance


On many new cars, automatic wiper speed control can be had as an upgrade, though most cars do not offer front-end collision prevention at all. [Rishi Hora] and [Diwakar Labh], students at the Guru Tegh Bahadur Institute of Technology in New Delhi, developed their own version of these features, (PDF warning, skip to page 20) which they entered into last year’s Texas Instruments Analog Design Contest. Under the guidance of professors [Gurmeet Singh] and [Pawan Kumar], the pair built the systems using easily obtainable parts, including of course, an MSP430 microcontroller from TI.

The collision prevention system uses a laser emitter and an optical detector to estimate the distance between your car and the vehicle in front of you, sounding an alarm if you are getting too close. In a somewhat similar fashion, the wiper speed control system uses an IR emitter and detector pair to estimate the amount of water built up on the windshield, triggering the wipers when necessary.

While not groundbreaking, the systems would be quite handy during monsoon season in India, and seem easy enough to install in an older vehicle. The only thing we’re not so sure about is pointing lasers at cars in traffic, but there are quite a few available alternatives that can be used to measure distance.

Continue reading to see a video walkthrough and demonstration of both systems.


24 thoughts on “DIY Wiper Speed Control And Collision Avoidance

  1. What I really want is a DIY Adaptave speed Cruise control.

    Make it easy to draft a Semi truck by making the car speed up and slow down with the trucker that cant keep his speed stable.

  2. @fartface
    What’s the point of drafting behind a vehicle that’s not maintaining a steady speed? The mileage loss from frequent acceleration is almost guaranteed to cancel out the gain from drafting, and that’s if you assume you’ll never incur any cost as a result of tailgating a much larger vehicle with an enormous blindspot and irregular speed.

    Hypermiling is a classic example of a false economy.

  3. @Blue Footed Booby

    Are you actually asserting that the driver in front is maintaining a constant speed? Think about that for a moment longer. Drafting works equally well behind a teammate, or behind an opponent.

    ‘Frequent acceleration’ is just a parameter you are throwing in to support your argument.

    I have never seen a cargo vehicle on the highway which demonstrates ‘frequent acceleration’… what I see is a relatively stable speed which varies -/+ a few percentages (but that is enough to cause the gap to narrow or increase).

    Dismissing something you do not fully understand as ‘false economy’ does no one any benefit.

    Back to the other poster: Cruise control is really meant to minimize fatigue. Cruise control is -not- about efficiency (unless you erratically change speeds). You can easily beat cruise control efficiency since you can anticipate not just slower cars ahead of you, but uphill/downhill and speed limit changes.

    I drive 14 miles to work using secondary roads which do not have traffic lights. In a 15 year old Corolla (3 speed auto) I still manage 31 mpg averaged at the pump (I think that exceeds EPA estimates). If I took the highway, I would be hitting my breaks every few seconds since it is bumper to bumper (and not tailgating someone is an invitation for everyone to cut you off).

  4. @Isotope I think an adaptive cruise control would work hand in hand with a collision avoidance system. The collision avoidance system would just make sure you’re not too close to the other car in front. If you are 20 feet behind another vehicle then you are fine to engage the adaptive cruise control. Then the system just keeps you at 20 feet distance. If the vehicle in front of you slams on it’s brakes your car would keep pace with the other vehicle (providing the collision avoidance system is tied into the brake system as well and that your car can decelerate at the same rate as the vehicle in front of you). Under normal conditions of just adaptive cruise control it will accelerate and then take it’s “foot” off the gas like normal cruise control. When the vehicle in front of you slows down and in this case I will assume the system is not tied into the brake system then when you get to 10 feet of the car in front of you, your car will sound an alarm telling you to brake because you are close to the car.

  5. @ScottinNH
    Re-read his post, then my post. He was talking about drafting behind truckers that CAN’T maintain a constant speed. As you point out, cruise control really isn’t for efficiency, so he’s using the wrong tool for the job to receive dubious benefits, and risking getting pulled over to boot.

    Dismissing a post which you did not read and then making a snarky reply does no one any benefit.

  6. drafting a semi is illegal in many places. sure, you can get away with it and claim you weren’t drafting. that is, until the cop who pulled you over asks what that fancy little gadget is…

  7. I have a 98 Safari Van (not in the best state of tune) I can easily gain 4-5 mpg using cruise control (coast/resume/accel) vs. manual operation while driving hiway or city. Tested with RealTime ODB data and confirmed at the pump (calculation). Cruise Controll is less aggressive than me :D

  8. “so he’s using the wrong tool for the job to receive dubious benefits, and risking getting pulled over to boot.”

    at 50 feet behind a tall box truck I am getting a 15% increase in gas mileage. I see people drive closer than that all the time and at 50 feet I have a lot of time to react as Semi truck cant stop instantly and my car can stop a LOT faster (unless the semi just drove into a 9,000,000 block of concrete) adaptive will let me keep a safe distance as the trucker forgets to hit the gas going up hill and has he forgets to let off the gas going down hill. Semi truck vary between 70mph and 55mph simply because the trucker is busy watching a movie and talking on the cellphone while eating and smoking all at once

  9. @Fartface
    At 50′ you have less than 1/2 a second to respond! That assumes you aren’t texting, fiddling with the radio, talking to a passenger or on a cell phone, looking in the mirror, checking your speed…..

    Many Semi drivers vary their speed to discourage people from drafting. It’s not that they can’t hold a steady speed (on level ground), it’s that they don’t want idiots riding their bumpers. On hills they have to change gears numerous times, and often time the engines de-rate if the RPMs go out of range.

    Drafting is not only illegal but more dangerous than you know. You can’t see the road ahead, so you get no advance notice of a problem and you are traveling at 70 MPH that is traveling over 102′ per second. Accident re-constructionists use 2 seconds as an average response time to see, respond to and have the vehicle respond to an event. That means you have traveled 204′ before you start to slow / swerve (assuming you can swerve). That is how you end up with vehicles under semis and dead people in the car.

    Now lets assume you actually do manage to avoid hitting the Semi because you were attentive and lucky. What about the car behind you where the driver is texting hits your vehicle and SHOVES your car under the Semi??? Your still maimed or dead and your car is still totaled.

    Better to leave about 6 seconds or more between you and the vehicle in front of you then if something happens you have time to hit the brakes AND look in the mirror and use up the extra space so the idiot behind you doesn’t plow into you. That has saved me from an accident many times.

    The hack is interesting and I am going to be doing some research into at least the auto wipers, I have wanted that feature on my truck for a while. Also looking into adding Blind Spot indicators (So I can see fartface)

    Insurance companies in the States would probably deny coverage if you tried to use non factory crash avoidance. Not sure I am ready for that leap of faith. For that matter they would probably deny coverage for the wiper mod if they could determine that was a factor in the accident.

  10. @brad – Drafting WITH a semi is illegal in many places, but drafting BEHIND a semi is not illegal.

    @Blue Footed Booby – I read fartface’s comment and my response was to you. fartface is correct that truckers (and other vehicles) do not maintain consistent speeds, but you took it in a different direction with “Hypermiling is a classic example of a false economy”. That does not follow.

  11. @ScottinNH – Drafting most certainly is illegal. It is normally called “Tailgating” or “Following too closely” or even “Unsafe Driving” or “Failure to maintain a safe distance”

    In most states if you hit a vehicle from the rear the fault is yours because you obviously were following too closely or not paying attention.

    Many Cruise controls don’t maintain a constant speed either for many reason including putting the wrong size tire and wheels on the vehicle, or non-standard injectors, or different injector pump, mis calibrated apps (TPS) sensor….

  12. @Tech Joker –

    Mythbusters did a segment where an 11% increase in MPG was achieved from drafting a semi trailer at a distance of 100 FEET. Is 100 feet tailgating???

    At 68 miles per hour, that is just under FOUR SECONDS four seconds from the leading vehicle.

    (As a safety note, “4 seconds” is a good safety practice at ANY speed).

  13. @ScottinNH

    Oh I had a nice long paragraph explaining that you math did not compute, before I saw your correction.

    I know it’s been a few years but when I was in drivers ed the rule was 2 seconds separation at 30MPH and under, 3 seconds to 55MPH, and 4 seconds or more over that.

    I have seen the Mythbusters segment, I believe they also stated that NONE of what they tried was a safe distance to follow a Semi.

    If you want better fuel economy by a vehicle that gets more MPG and don’t endanger yourself, your passengers and all the people travelling around you. The graveyards are FULL of people that thought they were better than most and could react fast enough.

    I had the unfortunate experience of seeing first hand someone ‘drafting’ a semi and run right square under it. I was passing the semi when traffic ahead came to a quick stop (not panic) due to another accident and gawkers. I applied my brakes as did the semi. The guy following the semi did not react in time and I watched him with a panicked look as he smashed into the Semi.

    I was the first on the scene and it was not pretty! Lets just say an open casket was not an option. I am not sure retrieving all the body parts was either.

    Sorry I am probably a little over sensitive on this subject having seen that and having seen a semi cream a car on the side of the road (with a driver inside). I drive about 85,000 miles a year.

    I take driving very seriously and always know what is in front of me, what is beside me and what is behind me. Types of vehicles, number of vehicles, if they are gaining on me …

    Probably the only thing worse than following too closely is weaving in and out of traffic. You probably won’t be in an accident, but you will very likely cause one.

    And with this I leave this subject behind as this is Hack a Day and not “Driving Safely Daily”.

  14. Hi to all, this anti-collision system that uses laser is very cool, but is not effective in all weather conditions, I think unfortunately it does not snow much in New Delhi, laser beam can not pass through the snowflakes as they are solid unlike the droplets’ water, however, is a good starting point :-)

  15. When I was in a driving school the instructors taught us that as a rule of thumb, safety distance is speed (kph) converted to meters. 100kph -> 100 meters (62mph -> 328 feet) for example.
    The lamp-posts (in this country) are 50 meters away from each other, so it’s a no-brainer to estimate the safe distance between you and the car ahead.

  16. You have to remember that the semi truck ahead of you when slowing down doesnt come to an instantaneous stop. When on the highway if semi driver begins to hit the brakes and you are 100 feet behind it doesn’t take 1.2 seconds for you to hit him, it all depends on the rate at which he applies the brakes as he will still be traveling forward. Even if he slams on the brakes it will take a fair amount of time to come to a stop. Which will give someone a fair amount of reaction time coupled with the fact that your car can stop MUCH faster than the truck.

  17. I drive a gas hog and romp on it and get crap mileage. And i like it. Adaptive cruise would be nice just for the dopes that let up on the gas approaching an overpass and lead foot it leaving the overpass (speed varies by as much as 20mph – or +/- 10 – at average speed of 65mph. The adaptive cruise systems (Benz for example) would compensate for that, keeping a minimum 150 feet distance. Couple that with the accident avoidance system, reprogram it to be a little more aggressive earlier on, and it has the potential to react well before any human could to slowing/stopping traffic. Still sucks if the guy behind is tailgating… but that’s why you should keep track of what’s behind you as well as what’s in front of you. collision avoidance and adaptive cruise are not contradictory, but rather work well together using the same input. Both use speed vs distance to slow the car… the collision avoidance part will just be more serious with the brakes.

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