Roelof

For a project I am looking for some sensors and one of them is a G-force sensor. I have found a cheap 3-axis model which can messure up to 3G maximum and with some basic calculating on acceleration I think it wil be in this range although I think with cornering and braking it will exceed the 3G.

Does someone know or think what can be produced?

PlatinumJoe

I know there are accelerometers that measure higher than 3g's but they may be to big or heavy of units for your application. What are you testing?

KMW

iTrader: (11)

This is designed for RC cars and measures up to +/- 38 G's:

http://www.eagletreesystems.com/Accessories/3.htm

JamesHealey

iTrader: (1)

I'd guess somewhere around 2-3 g ong tight sweepers with an 8th scale.
3 under heavy braking.. i think if we had four wheel braking this would be much higher.

Let me know your results.

Roelof

We want to get the real engine/car performance messured in numbers and diagrams realtime on the track but also all stuff arround it. I have a telemetry module which can connect up to 17 sensors. At this moment I can messure:
- temperature engine
- temperature air at the intake
- humidity at the air intake
- rpm
- speed

All will be transfered by a 433mhz radio system from Radiometrix and received and realtime messured and recorded on a laptop.

An example of a simple interface to show what is possible:



The interface is modulair so you can setup what ever you want, also the input can get a calculation before it will be displayed.

From what I have seen a F1 car accelerates with 1.7G, brakes with almost 3G and takes corners up to 5G. Only the acceleration is the most important thing to get some data from the engine although the speed (and with that the G-force) in a corner can tell a lot of how powerfull an engine is with that kind of load.

JamesHealey

iTrader: (1)

I think you'll find the highest g corner is 150r at suzuka Japan and it's about 4.8g sustained. And 5+ peak.

Braking is 5g+

JamesHealey

iTrader: (1)

The heaviest braking is at either Monza or spa I'd have to check but it's 5g

beebone

Is there any G sensor avaliable for telemetry system? Apexi used to launched a G sensor for car, but not welcome by user coz g force is meaningless for street car. Don't know is it any miniature g sensor, it helps to find out the lateral that the sponge tires suffer, in order to give more adjusment for the track.

Roelof

This is the one: http://www.sparkfun.com/products/9269

Because the many analog inputs I have this is the one which can be connected directly but does need a small calculation to get the right numbers on the display. Most sensors I have found use a digital out as also the Eagle Tree sensors.

stefan

This is what you are looking for:

http://www.celero.it/

Roelof

I know, but it is no fun to buy a compleete system which you can not setup in any way you want en does need an iPhone or iPad to read out the data.

And beside that, most parts I have already.

And about GPS, take a look at this: http://www.mytach.co.uk/
Very interesting software for track and section analyse.

beebone

Thx! I'm thinking the output voltage whether can be decoded by any telemetry system?!?!?

Roelof

If the system can handle an analoge input it can. Look arround on that site, a lot of interesting stuff (also other G-meters), mostly used with an Arduino computer.

This chip is simple. zero-G is half the voltage (1.5 volt) and 1G is 1/10th the voltage (0.3V).

So running on 3 volt the formula will be output=(input -1.5)/0.3

Youtube is full with some experiments:
www.youtube.com/watch?v=wOOJxIWZxP8
(most of them are based on only gravity)

The funny thing is that the Z-axis can be used as a tilt sensor messuring how well the shocks are working)

beebone

Ineresting, thanks anyway! BTW, do u know abou Sanwa 461 RX? It also a telemetry system, it comes with temp sensor too, but mine was broken.
Do you think the temp sensor is a glass sealed thermistor or something else?

Roelof

I do not know, it is 2 wired so it is not an active component. It must be someting like a resistor or a diode.