College Project - Motorcycle Traction Control

Hi guys,

I'm in need of some help with my college electronic project. I'm very new into electronics, so bare with me as I'm unsure on quite a few things.

Basically, I'm looking to design a Traction Control system for a Motorcycle, and as a racer myself, I'm really interested in how they work, and more interested on how to make them.

The basic idea I have so far is using 2 hall effect sensors on the front and rear wheel, which will determine the wheel speed. Once the rear wheel begins to spin at a faster rate, supply is cut to the spark plug or one of the fuel injectors, thus reducing power until traction is regained. The only problem is, that its just a concept at the moment, and I ain't sure how to go about it.

If anyone is able to help, I would greatly appreciate it

Thanks for your time guys!

I would think that cutting off ignition spark is bad, since the fuel pump (or gravity and engine vacuum) is still supplying fuel into a non-firing combustion chamber. What you need essentially is an ABS system to control the wheels. The problem with a bike is it's on two-wheels as opposed to a car/truck that sits level on a 4-wheeled chassis. The bike cannot auto-balance itself without a rider on it.

Back in the old days we just learned how ride and to properly feel the machine we are on and thus control it better ourself. After all that is why they put the gear shifter, clutch, brakes, and throttle on them!

The last time I rode a dirt bike it even had variable controls on the clutch, throttle, and brakes! Its almost like the builders expected the rider to learn and know how to use a variable rate control system.

I doubt traction control would work properly on a off road motorcycle any way. There are countless times where you purposely need to have more slip at one end than the other. Without it your at time more likely to crash or have a problem.

In some applications technology is great but often times just learning practicing and becoming good at something is the only way to actually become good at it.

With a manual transmission, traction control is very difficult. Loss of traction is most likely to happen as the clutch is released. At that point, as long as the engine is turning faster than the input shaft of the gearbox, then the wheel torque is controlled by the clutch.

If the driver released the clutch too quickly, and the driving wheel(s) lose traction, reducing the engine power will not immediately reduce the torque. It will only slow the engine, and only when the engine speed matches the road speed will there be less torque. By that time the wheel(s) will be slipping a lot, will have to slow down a lot before they can grip.

One of our cars has traction control, and if I get wheel spin on starting, all the traction control does is slow the engine so much that the turbocharger stops working, and I have far less acceleration than expected. I then have to press the clutch again, and let the engine speed up. It is all far worse than a moment of wheel spin in a front wheel drive car.

If you are going to try to get traction control to work with manual transmission, you either have to take control of the clutch, or just don't bother if the clutch is slipping. An engine speed sensor as well as wheel speeds would tell you if the clutch is slipping.

Once the clutch is not slipping, traction control can work by reducing engine power.

The details are pretty much how you in-vision it. I'm not certain if turning off a single cylinder will reduce the power enough to stop slip, though.

Spark cut is a perfectly normal way of cutting ignition/power. The only issue is that the unburned fuel will kill any catalytic converter if you have one.

The details depend on how old this bike is. Is it electronic ignition? mechanical?

If it's electronic, then it's pretty easy to intercept the signal to the coil, or coils. There may be a tricky way to figure everything out without a microcontroller, but I don't know what it is, so unless someone else can suggest something, you are going to need an 8bit uC to check the wheel speed sensors and decide when to cut spark. You might be able to salvage wheel speed sensors off of a car wreck. Cars with ABS have them for each wheel.

After saying all this, I'm a rider myself, and I'm pretty sure there's a reason that active traction control has not been implemented on bikes. For manufacturers it would be a litigation nightmare for one thing.

That's for sure. Imagine hitting the gas on the bike to get out of the way of a truck and the traction control cutting your engine power...

Having reliable access to a huge power/weight ratio is one of the things that keeps you alive.

But the method of limiting power by cutting spark (or more commonly retarding spark) is part of most commercial motorcycle ECMs although it's used as a rev limit control not a traction control.

If this is for race use it might be workable to retard the spark for traction control like for a drag bike etc. But like Diver said the very best performance will probably still come from human control not automatic control.

Thanks for the reply guys, I understand where your all coming from. As for tcmtech, no disrespect mate, but I ride at British Championship level and race at a few International events. I also have a British Championship under my belt, so in all fairness, I ain't no mug.

Traction control is used alot in Motorcycle racing in particular (and being introduced in road bikes, such as the Kawasaki GTR1400), and its very advance, and wouldn't have a clue for anything that complicated. All this is for is a small college project, so it doesn't have to be fantastic, save hundreds of highsides or nothing special like that, just work really as I described. I don't intend on using it at all, as I honestly know hardly anything about electronics to be honest, and not really keen on giving it serious gas in the middle of a corner to test it out hahah!
Thanks for all the information so far though guys, its been mega helpful, and given me a few more ideas

It's been quite a few years since I've been to the track on a motorcycle. Just remember, chicks like motorcycles until you marry them; Then they're not so keen on them.

If you have any specific questions don't hesitate to ask.

As for tcmtech, no disrespect mate, but I ride at British Championship level and race at a few International events. I also have a British Championship under my belt, so in all fairness, I ain't no mug.

Click to expand...

Not a problem. If you stick around here for awhile or do some reading the old threads you will find countless people who just figure that if they toss enough electronic stuff on anything it will more than make up for not actually having any skills or experience.

After all all you need is good eye/finger coordination on the X-box controller to be better than the best real life riders, right? So that means that all you need to do is wire up the X-Box to the bike and your a world champion rider day one!

British championship huh? Over here we call that BMX. (British Mug X-treme) We let the kiddies use their pedal bikes on it!

Just teasing. I am a casual leisure rider at best. Off road exploring and just out cruising is as wild as I get.