[Suryaa]

I own a yamaha fascino 110, bs3 and I have this idea of implementing a real time mileage indicator in this using a simple controller (such as an arduino).

Engines need fuel, air and spark to work, and so this being a simple carbureted engine the measure of either the fuel flowing in or the number of sparks generated at any given time would indicate the real time fuel consumption of the vehicle..(Pl correct me if I am wrong)
.
So my first thought was to install a flow meter in the fuel line going to the intake manifold but I didn't want to tamper with the fuel lines and all that..

My next train of thought was to measure the amount of sparks that are produced per unit time which would indicate the rate of combustion of the engine. So the spark plug's ignition is controlled by a cdi unit which is responsible for being able to provide an extremely high voltage to the spark plug from the battery's voltage at the required time. The cdi unit has a mechanical switch actuated by the camshaft and so whenever the engine's intake stroke is over, then the switch connected to the camshaft would trigger a signal in the Cdi unit and so the spark plug ignites the mixture, the process continues.

Soo whenever the engine rpm increases the cam spins faster and so the aforementioned signal would be produced many more times in unit time..

My reasoning is that if we take out another line from the cdi unit's output switch that operates the spark plug's firing and give it as a digital input to the arduino(After adjusting it's current and voltage so that it doesn't fry the controller though) and write ourselves a program which would measure the number of signals measured in a given time, then we could calibrate it somehow(by telling it that at idle these many number of signals would mean this much fuel consumption and when the number of sparks rises then the fuel consumption would rise by this much, calculations would be elaborated once this method is finalised)

Once the above is completed then for the output we could use a wifi module to show the output on my phone or stick on a lcd display in the instrument cluster and display it there..!

This was basically just a 1st iteration of my idea, if I find this viable I will definitely improve this and change if necessary

Please share your thoughts about this idea guys..!
Regards
Surya

[GTX+]

Possibly a noob question. To calculate mileage, apart from what you have mentioned, you also need to calculate the distance traveled. How do you plan to get that input?

Or have you already worked that out and may be you forgot to mention it in the post?

[Suryaa]

If this was a fuel injected vehicle then the measure of how much fuel the injectors inject per unit time could directly be used to measure the fuel consumption as we can directly take out a signal (either analog or digital ) from the injector right..?

[Suryaa]

Originally Posted by GTX+

Possibly a noob question. To calculate mileage, apart from what you have mentioned, you also need to calculate the distance traveled. How do you plan to get that input?

Or have you already worked that out and may be you forgot to mention it in the post?

This is a legitimate question and I guess the thought did not cross my mind earlier... I thought about it and if I had to measure the distance then I would have to do it from the odometer...

So my vehicle uses an older style design of the odometer(Please find the attached images, I got the yamaha's odo assembly from youtube), and these are basically a gear arrangement of sorts. So if I could fabricate a small stepper motor mount using a 3d printer (my friend's) and connect the motor's shaft to the assembly then the motor's output can be given to the arduino and thus it can use both distance and spark signals to produce the required mileage figure..?
I don't think the stepper motor would fail as the maximum number of revolutions it would face is gonna be 1.3 per every 10 seconds(for 80kmph)
, quite manageable I guess..?
(It is Quite a long shot though, thinking of it..)

[Jeroen]

On a carbureted engine if you want to correlate spark pulses to fuel flow you need to measure a couple of other variables as well. And work them into the equation.

The most important is the vacuum as it has a large influence on the fuel foe. Secondly you need to measure the throttle valve position. Throttle valve closed gives high vacuum but very little fuel.

Also during acceleration the relation between fuel flow and vacuum changes as well, whereas the throttle valve could stay fully open.

Of course when your air inlet filter starts clogggin up all your measures will be considerable off.

That is before you start factoring in atmospheric pressure and ambient temerpature.

The simple answer, you need to measure a lot of variables, very accurately and need to come up with a complex table to correlate all these variables.

Trust me, if you find a decent reasonable fuel flow meter that would be the way to go!

Good luck

Jeroen

Those are

[srini1785]

I saw that your location is Coimbatore, so I can understand the fascination with innovation.

Originally Posted by Suryaa

I own a yamaha fascino 110, bs3

Which year?

So the spark plug's ignition is controlled by a cdi unit which is responsible for being able to provide an extremely high voltage to the spark plug from the battery's voltage at the required time. The cdi unit has a mechanical switch actuated by the camshaft and so whenever the engine's intake stroke is over, then the switch connected to the camshaft would trigger a signal in the Cdi unit and so the spark plug ignites the mixture, the process continues.

Get your theory right first. What you are describing are two different things. A CDI (Capacitor discharge ignition) does not have a mechanical switch which makes and breaks a circuit. That was called "points" and I doubt that such a system is fitted in any vehicle after 2000. A CDI has no such points, there is a pulse coil and a power coil ( depends on the bike) and the rotor (magnet) has a small gap which provides the "Pulse". The pulse is a direct indication of the engine rpm (before gearing) and there is a ignition advance map which is stored in a black coloured box which provides the required ignition advance map as per the rpm. Something like this;



So there is no "contact". This is the very definition of a CDI.

My reasoning is that if we take out another line from the cdi unit's output switch that operates the spark plug's firing and give it as a digital input to the arduino(After adjusting it's current and voltage so that it doesn't fry the controller though) and write ourselves a program which would measure the number of signals measured in a given time, then we could calibrate it somehow(by telling it that at idle these many number of signals would mean this much fuel consumption and when the number of sparks rises then the fuel consumption would rise by this much, calculations would be elaborated once this method is finalised)

If you need to find the number of times there's a spark there is a simple way to do it. I don't know if you have a direct engine rpm indicator. In every four stroke engine there are two rotations per stroke. So it means that the firing happens once every two rotations. That would give you a direct idea of the number of times the spark plug operates.

Once the above is completed then for the output we could use a wifi module to show the output on my phone or stick on a lcd display in the instrument cluster and display it there..!

I don't understand the present gens obsession with arduino and Wifi. Get your self an oscilloscope and see the wave forms yourself. But I'm preaching. So first get your theory right and everything will fall in place.

[Suryaa]

Originally Posted by Jeroen

On a carbureted engine if you want to correlate spark pulses to fuel flow you need to measure a couple of other variables as well. And work them into the equation.

The most important is the vacuum as it has a large influence on the fuel foe. Secondly you need to measure the throttle valve position. Throttle valve closed gives high vacuum but very little fuel.

Also during acceleration the relation between fuel flow and vacuum changes as well, whereas the throttle valve could stay fully open.

Of course when your air inlet filter starts clogggin up all your measures will be considerable off.

That is before you start factoring in atmospheric pressure and ambient temerpature.

The simple answer, you need to measure a lot of variables, very accurately and need to come up with a complex table to correlate all these variables.

Trust me, if you find a decent reasonable fuel flow meter that would be the way to go!

Good luck

Jeroen

Those are

Thank You for remininding me of all these factors too ... I really need to reconsider and I will begin my search for a small fuel flow meter that satisfies my requirements(relatively low cost,reliable, should be non invasive and not cause any flow reduction or pressure changes in the fuel system, etc) ...

Yep measuring all these factors is too much work and I would need to know all the technical specifications and intricacies of the engine which I doubt manufacturers would provide online..
I Will update this thread for further developments ,

Regards
Surya

[Brumby]

Originally Posted by Suryaa

I own a yamaha fascino 110, bs3 and I have this idea of implementing a real time mileage indicator in this using a simple controller (such as an arduino).

Please share your thoughts about this idea guys..!
Regards
Surya

Counting the number of ignitions per second is going to give you only the rps which can be converted to rpm.

The fuel consumption depends on a lot of factors, so your approach to get instantaneous fuel consumption will get you the incorrect information.

I will just give you an example to understand why counting the sparks will give you all the wrong data.

1. Put the two-wheeler on the centre stand, rev the engine to maximum rpm and count the number of sparks.

2. Get the heaviest riders on the two-wheeler and ride it in a safe place, where you can rev it to highest rpm and count the sparks.

The number will be the same however the fuel consumed will be different.

So the only way is to measure the fuel flow for a more accurate figure.

Hope that gives you a fair idea to go ahead with your project.

Cheers.

[Suryaa]

I saw that your location is Coimbatore, so I can understand the fascination with innovation.

Haha I currently reside here but I was born and Brought up in Chennai though : )

Which year?

It is a 2016 model, it suffered a lot at someone else's hands (It had almost no maintenance) before I got hold of it almost 2 3 years back but now it is taken good care of

Get your theory right first. What you are describing are two different things. A CDI (Capacitor discharge ignition) does not have a mechanical switch which makes and breaks a circuit. That was called "points" and I doubt that such a system is fitted in any vehicle after 2000. A CDI has no such points, there is a pulse coil and a power coil ( depends on the bike) and the rotor (magnet) has a small gap which provides the "Pulse". The pulse is a direct indication of the engine rpm (before gearing) and there is a ignition advance map which is stored in a black coloured box which provides the required ignition advance map as per the rpm. Something like this;

So yeah Thank you for correcting me.... the cdi system I had seen online was for older kinds of motorcycles and currently redundant and I missed the fact that even the camshaft used in my vehicle doesn't have lobes to trigger
switches like I said earlier, it is connected with a chain to the generator which provides pulses to the CDI unit...(I saw this in the attached document)

I guess my vehicle doesn't have the type you specified as I guess there is no crank position sensor to measure the rpm here as far as I have seen in the parts breakup of my vehicle(I have attached it here)... it would have made the job a lot easier as I could use the number of crank rotations to find the number of sparks...

I'll surely keep in mind all this if I decide to go down this path (of measuring fuel efficiency with number of sparks) but seeing the complexity of the variables involved etc etc I have decided to start searching for a fuel flow meter and decide where to put it, what meter I should use, the specifications, etc ... I'll be sure to update about any further developments here....

Regards
Surya

Originally Posted by srini1785

I saw that your location is Coimbatore, so I can understand the fascination with innovation.
Which year?

Originally Posted by Brumby

Counting the number of ignitions per second is going to give you only the rps which can be converted to rpm.

Exactly..

I had not taken into account a large number of influencing factors when I thought about it and now that I factor in all of them I see that this may not be an accurate way to go about it and so I have begun to search for a fuel flow meter and I will use that to obtain the fuel consumed, relate it with the distance covered and then calculate & proceed

Cheers!
Surya

[Cry0gen]

Don't fret too much on how to measure distance. A simple GPS will do the trick.
Now, you may ditch the idea of counting sparks because in a carburator the air fuel mixture happens due to a lot of uncontrollable/unneasurable factors. You will never be able to filter out an usable correlative factor. Its better to just use a flow meter somehow. My 2 cents.

[Suryaa]

Originally Posted by Cry0gen

Don't fret too much on how to measure distance. A simple GPS will do the trick.
Now, you may ditch the idea of counting sparks because in a carburator the air fuel mixture happens due to a lot of uncontrollable/unneasurable factors. You will never be able to filter out an usable correlative factor. Its better to just use a flow meter somehow. My 2 cents.

Thanks, I'll look into using a gps module for measuring the distance, which will definitely make it simpler.. A gps module which I can interface with my arduino has an accuracy of 2m and it updates 10 times every second so it should be accurate enough for this application, and yeah a flow meter seems to be the way to go!

[Jeroen]

Originally Posted by Suryaa

Thanks, I'll look into using a gps module for measuring the distance, which will definitely make it simpler.. A gps module which I can interface with my arduino has an accuracy of 2m and it updates 10 times every second so it should be accurate enough for this application, and yeah a flow meter seems to be the way to go!

I am surprised to see the high update rate of this chip set. Not that it’s relevant for your application, but I noticed it doesn’t t provide speed. Most GPS chips do so, based on Doppler calculations

Jeroen

[Suryaa]

Originally Posted by Jeroen

I am surprised to see the high update rate of this chip set. Not that it’s relevant for your application, but I noticed it doesn’t t provide speed. Most GPS chips do so, based on Doppler calculations

Jeroen

I guess I would have to figure out how to code the Arduino to relate the sensor output to provide distance outputs then, if the chip had provided speed directly then i could have just converted it into distance directly and taken it