Moto-X data logger

[umka]

Just thinking of building a data logger for my motorcross bike (need a 4th year engineering project) but not sure what data I would want so am asking for opinions please.

Here are the things I am thinking of:

Lap time, with/without splits (can compare laps and spilt times between sessions)
RPM (optimise gearing)
Gear position (allows one to optimise gearing)
Throttle position (able to see how quickly one gets on the throttle after corners)
Acceleration/de-acceleration (optimise cornering)
Time in air (allows one to try minimize time in air)
Fork/shock travel (optimise suspension setup)

It will have a digital display and all data stored on an sd card. The display will only really be for checking data afterwards like average lap time and may display real time engine temp and rpm but I don’t think it is practical to put too much as one cant really look at is while riding or do you guys think it should have current lap times and stuff like that. It could have a shift light but again doesn’t seem practical to me.

Any input or suggestions would be much appreciated

[dammad1]

brake and clutch inputs?

[scott411]

the brake and clutch one is a good one, alot of mx guys drag their rear brakes, would be good to point it out,
tps is good idea
gear position indicator and gear change points (in regards to RPM),

[cowpoos]

better still...build a traction control system that works off a ignition cut...it would allow some wheel spin...maybe user dialed in???

[Bert]

Just thinking of building a data logger for my motorcross bike (need a 4th year engineering project) but not sure what data I would want so am asking for opinions please.

Here are the things I am thinking of:

Lap time, with/without splits (can compare laps and spilt times between sessions)
RPM (optimise gearing)
Gear position (allows one to optimise gearing)
Throttle position (able to see how quickly one gets on the throttle after corners)
Acceleration/de-acceleration (optimise cornering)
Time in air (allows one to try minimize time in air)
Fork/shock travel (optimise suspension setup)

It will have a digital display and all data stored on an sd card. The display will only really be for checking data afterwards like average lap time and may display real time engine temp and rpm but I don’t think it is practical to put too much as one cant really look at is while riding or do you guys think it should have current lap times and stuff like that. It could have a shift light but again doesn’t seem practical to me.

Any input or suggestions would be much appreciated


Cool idea, we've been playing around with similier concepts for our road race bikes for the last two years, (using a campbell datalogger). some of your concepts will be hard to measure, like gears and air time. but diff do-able.

if your are focus is on two strokes, air temp and humidity at the airbox would be usefull (and are very cheep), this enables jet matching to air temps / RPM etc. this being one the biggest downfalls with two strokes proformance. not so important with 4's.

another good one is wheel spin vs speed.

Good luck with your 4th year

Bert

[cheese]

Traction control is pretty simple (RMP controlled ones). I think that you need to make sure that the unit is water proof and back light is a nice to have too. If you really wanted to get flash you could add some wireless communications so that a pit crew could monitor the bike real time. I'd suggest using something like zigbee. You could even make it so that the unit is removable so the really weight conscience could have it all wired up and for a race they just pop it off.

[umka]

Ok these are good.

The gear sensor worries me because the mx bikes don’t have built in sensors so it would have to be external so doable but reliability would be a worry.

The air I was thinking of using two-axis accelerometer (g-meter) one for accelerations and other for airtime maybe in conjunction with the suspension sensor.

Air temp and humidity would be good and easy.

The traction control is a worry. I suppose you could measure front wheel speed and compared to rear and if >> than cut every second or so ignition pulse.

[k14]

What about exhaust gas temp and or cylinder pressure? They are both handy to know for jetting (seeing you are running a two stroke).

[NordieBoy]

Oil and water temp.
Air/fuel ratio.

[mbazza]

Any chance of building it to transmit data as you ride? Like the one in the pic below which is a timer transmitted to an on site reciever during motocross? Good luck with the project. Cheers.:clap:

[scott411]

not to sure if traction control is wanted, alot of the time you use wheel spin, it would not want to be to harsh when it kicked in
but exhaust temp is a good one,

[paturoa]

What about front / rear comparision of fork & shock / suspension deflection and temp.

I have no idea if they even should be similar but suspect that they should be. By factoring a delay for the speed you should be able produce a graph of the 2 overlayed to see what the difference is for compression and rebound.

This would also be challenging for you to get a fast enough sample rate and enough data collected to be able to effectively compare the damping rates.

It would also be interesting to do some transforms for different soil types off repeatable jumps etc.

edit: hmmm if you did some fft you could drive some led arrays that would indicate to the rider where the major differences are and the rider could remote the adjusters (similar to brake bias adjusters)

[sAsLEX]

Traction control is pretty simple (RMP controlled ones). I think that you need to make sure that the unit is water proof and back light is a nice to have too. If you really wanted to get flash you could add some wireless communications so that a pit crew could monitor the bike real time. I'd suggest using something like zigbee. You could even make it so that the unit is removable so the really weight conscience could have it all wired up and for a race they just pop it off.

Zigbee wouldn't have the range to allow constant coverage, could do a data dump once a lap.

[cowpoos]

not to sure if traction control is wanted, alot of the time you use wheel spin, it would not want to be to harsh when it kicked in
but exhaust temp is a good one,
yeah...thats what I ment about user being able to dial it in?

[umka]

ok so far good infomation would be

data loger:
RPM
Acceleration
lap/split time
throttle position %
brake %
clutch%
gear position

display real time(not data logged):
water temp
last lap time
average lap time
number of laps

i dont think it needs wireless comunication coz whats the differance if the pits can get the data real time or after the sesion. one can not change much while riding so with the sd card one can pull it out and put it straight into a pc and read it within seconds of being of the bike.

could possibly build in a programmable ignition curve (maybe multi map) and rev limiter.

any other thoughts on the data to log or display?

[scott411]

on a mx bike you have not got time to look at a display, last lap would be fine, and it would have to be big,
and maybe jsut a warning temp light, and maybe a timer so you can time your moto's

and on the traction control, in the air when jumpin you stop the wheel, and rev the wheel to make it go faster so it would have to account for this,

also data loggers are banned in europe and america for some reason,

[paturoa]

How about realised torque vs wheel spin vs accleration to work out what the optimum traction control would be.

[umka]

I was initially thinking of this as a simple cheap training device not for huge race teams with huge budgets.

The traction thing is a no in my books.

Wanted water temp just for sitting at the line. It would actually be less effort to have the number on the screen than a light so that’s why I said that.

Wanted ave lap time and number of laps so one doesn’t need a computer to be able to see how the session went i.e. anybody just at the track for a ride can see if they are faster/slower than usual and have done enough laps.

[dammad1]

Yeah it may be a bit easy to get carried away with it all. But i think you should add a couple of sensors like the intake and exhaust temp sensors to help tune the bike.

[scott411]

yeah it would be good to be able to scroll though that while staitonary, but you have very little readable stuff on a mx bike while you are riding,

[umka]

yes i understand that scott thats why im data logging all the stuff but no displaying it.

the problem i have with the tuning stuff is that it stuff u dont want it very often. like i dont know myself but how often does one need the inlet and exhaust temp i am only a social rider so have never needed it? surley it would be better to have that as a sepperate device.

what sample rate do you guys think would be good for the data logging? i was thinking 100 times a second for each sensor?

[k14]

Well for competitive mx they would like to know the air/fuel mixture to get optimum performance from it.

My logger on the RS also has a g sensor which is pretty cool. Can get the ic's that have the 6 axis accelerometer built in I think?

[Brian d marge]

there are some good ones already out there ( google )

not expensive and offer all that u will need

Ask if you need help ,,I can point u in the /a direction

Stephen

[sAsLEX]

Well for competitive mx they would like to know the air/fuel mixture to get optimum performance from it.

My logger on the RS also has a g sensor which is pretty cool. Can get the ic's that have the 6 axis accelerometer built in I think?

Why would you need 6 axis? Surely from 3 you can do all the required math.... yay for Kalman filters....

[umka]

hey brian if you have links that would be good.

i have been looking on google but most of the stuff out there is really for road bikes or very evpensive. when i say cheap i mean this unit should cost NZ$250 or less for beacon and data logger with display.

[cheese]

Zigbee wouldn't have the range to allow constant coverage, could do a data dump once a lap.

Not hard to set up a few sites around the track.

[sAsLEX]

Not hard to set up a few sites around the track.

$$$$$$$$$$

[quackquack]

I work with a car team that uses a Motec device during testing that provides live data while on track. It means that we can monitor engine changes on the fly and saves us time during testing as you can know what you need to do before the car gets to pits. These devices are banned at the race meeting but provide us the best possible testing and save us alot of time at the Track. These are programmable to do multiple sensors and really does give awesome feed back.

Also means if the team see the driver doing something wrong they can get him to change driving style and see on one lap that he did a section a little faster if you tell him this immeditaly he can remember what he did instead of telling him when he comes in and he will struggle to remember the line he used 5 laps before.

[umka]

ok so wireless may be sensible but how much does the motec system cost? i was kind of planning to build this so the average rider can afford it and allows them to compair their trainning. what sample rate does the motec use?

[quackquack]

Motec is not cheap at all so if you can do a programme that is affordable you could have a very good business/product.

Look at http://www.motec.com.au/disp.htm to have a look at what they do that might give you some ideas. They also have so drawings on the site of how they hook things up to different things

We use the Telemetry system which you can see on site. If you are looking at doing this maybe you do a base system then have add on to allow the live broadcast. You will find that only the top guys need this and will be willing to pay the top dollar.

[cheese]

If you want I've got some pager LCDs you can have to use. Infact I've got some old pagers if you want to use thier CPU's etc.

[umka]

hey cheese thanks but no thanks. this is in development stages all on a microcontroller development board no hardware being built yet.