Accelerometer Sensor

[Pesticida]

Ok,

Now when I correct understand I must the first Acceleration Change to measure How long the Acceleration is during then I know the distance for that Time for ex. 1 Seconds.
And I can now found the distance for one second,when the speed is constant then is the Acceleration = 0 and after 10 Seconds I can found the final Distance!

I hope is my thinking correct!

Regards

[Pesticida]

Hello,

Ok I'm coming now to the conclusion that the G sensor is not the really thing for measure if a Elevator is moving and how fast is moving ! :-)

Maybe have some one another better Ideas,I'm using for the moment current measurement to see if the Elevator is moving,but I'm searching for a Modern Solution that give me more Information like ~speed,Movement,Vibration and so on.

Thanks

Regards Pesti

[luminas]

You can add optical encoder to the main motor shaft for speed, acceleration measurement . Vibration can be measured with accelerometer

[CocaColaKid]

An accelerometer will just measure the time is takes to go from one speed to another speed, not the distance. It has no way of knowing how far it has traveled unless it is constantly accelerating and decelerating.

[sayzer]

Actually, there are ways of calculating the distance using accelerometer data.

The only important point is that you should not turn the device ON/OFF while it is moving.

1. The user must make sure that the device is first powered up when its speed is zero.
2. Then, you can log the data until it tells you that the device is no longer speeding up.
3. Then you know the formula to calculate the speed with the last data you received. Start a timer here.
a. If the subject hits somewhere, and stops suddenly you should time its speed to understand that it hit something and stopped.
4. Stop the timer when the device tells you that device speed is decelerating.
5. When the device tells you that device is no longer decelerating then
a. the subject is either stopped or
b. the subject speed is constant.

You can use basic math to distinguish between a and b.


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[Acetronics2]

An accelerometer will just measure the time is takes to go from one speed to another speed, not the distance. It has no way of knowing how far it has traveled unless it is constantly accelerating and decelerating.

Hi, KKKid

Not really true ...

if you integrate accel*time, starting from zero ... you will be stopped for integrated result = 0 ...

But, as in real life, there are always calc. roundings and little sensor errors ... you never get a true detection.

The Proof : Model planes Heading Lock Gyros ... Yess !!! The Heading is good ( or considered good ) for a Zero integration sum ...

Alain

[CocaColaKid]

Ok, I stand corrected. You could use one to do the calculations but it would have to work perfect. I talked to an aviation engineer about this and he laughed. It is possible, but the calculations would be nasty. For example, what happens when the elevator is going up or down and some kid jumps in the elevator? Unless the math is done precisely and the event cancels itself out then you'll end up with and error in you distance.

[Acetronics2]

For example, what happens when the elevator is going up or down and some kid jumps in the elevator? Unless the math is done precisely and the event cancels itself out then you'll end up with and error in you distance.

Héhé ... no error due to children nor !

integrating their movements give a precise 0 Sum : they do not fly or pass through the floor !!!

Alain

PS: take care to aviation engineers ... they perfectly know their manuals ... but I already had some surprises about their flight mechanics knowledge ...
Especially for balancing models ... they didn't learn the stab lift effect could be from down to up !!!

Dangerous for a big liner ( can become unstable at low speeds )... but widely used for gliders in contests !!!


re-PS: Talk of inertial guiding to your engineer ... will he still laugh ???