Distance solutions?

[whatthe_fuzz]

Hey guys.

 

I'm currently studying Aeroscience Engineering and we are working on small rocket designs to evaluate team building. Our project is to build a rocket with a body length of 1m and carry a payload and retrieve it safely. 

 

We also must calculate max altitude and i'm the IT manager. I was wondering if there is a small Arduino app or a similar device that would relay back to the base and give me a ping readout or possible distance from launch. 

 

through simple trig i could calculate max altitude without any issues but i need to find a solution to calculate the distance from the launch pad to the rocket's apogee. 

 

thanks guys,

John

 

TL;DR 

 

Is there a small device that tells me distance from Point A to Point B with <1ms refresh time?

[Hans Christian | Teri]

What's the theoretical distance you will be achieving? You will quickly come out of range from any existing wireless signal. (not including radio etc)

[whatthe_fuzz]

What's the theoretical distance you will be achieving? You will quickly come out of range from any existing wireless signal.

 

this gen we should be around 1km 

but our next gen should hit 1.5km

 

antennas should reduce this issue correct?

[Jogostar]

Hey guys.

 

I'm currently studying Aeroscience Engineering and we are working on small rocket designs to evaluate team building. Our project is to build a rocket with a body length of 1m and carry a payload and retrieve it safely. 

 

We also must calculate max altitude and i'm the IT manager. I was wondering if there is a small Arduino app or a similar device that would relay back to the base and give me a ping readout or possible distance from launch. 

 

through simple trig i could calculate max altitude without any issues but i need to find a solution to calculate the distance from the launch pad to the rocket's apogee. 

 

thanks guys,

John

 

TL;DR 

 

Is there a small device that tells me distance from Point A to Point B with <1ms refresh time?

You could just do the mathmatic way, for example:

 

If you knwo that the rocket will fly 10 m/s and it flies for 1 min

 

So: 10m/s x 60s= 600 meters...I think

 

EDIT: There is an awesome site, for some ''basic'' equations: http://my.execpc.com/~culp/rockets/rckt_eqn.html#Method

[WunderWuffle]

You could just do the mathmatic way, for example:

 

If you knwo that the rocket will fly 10 m/s and it flies for 1 min

 

So: 10m/s x 60s= 600 meters...I think

 

EDIT: There is an awesome site, for some ''basic'' equations: http://my.execpc.com/~culp/rockets/rckt_eqn.html#Method

But after a period of time, it starts to slow down...

[Jogostar]

But after a period of time, it starts to slow down...

yeah i saw that he already did the thoretical part..fail  ^^

[whatthe_fuzz]

You could just do the mathmatic way, for example:

 

If you knwo that the rocket will fly 10 m/s and it flies for 1 min

 

So: 10m/s x 60s= 600 meters...I think

 

EDIT: There is an awesome site, for some ''basic'' equations: http://my.execpc.com/~culp/rockets/rckt_eqn.html#Method

 

 

The engines will only burn for 2sec. It will continue flying after that though. 

 

I need a physical relay to tell me where its at

 

I can calculate max alt if it was to fly straight without wind or air resistance. But it wont be a true number

[Jogostar]

The engines will only burn for 2sec. It will continue flying after that though. 

 

I need a physical relay to tell me where its at

 

I can calculate max alt if it was to fly straight without wind or air resistance. But it wont be a true number

You could just use an Altimeter

 

http://www.apogeerockets.com/Electronics_Payloads/Altimeters

 

EDIT: This is the simplest one: http://www.apogeerockets.com/Electronics_Payloads/Electronics/Jolly_Logic_AltimeterTwo

 

2nd EDIT: This one is good, too. and cheaper: http://www.apogeerockets.com/Electronics_Payloads/Electronics/Jolly_Logic_AltimeterOne

[whatthe_fuzz]

You could just use an Altimeter

 

http://www.apogeerockets.com/Electronics_Payloads/Altimeters

 

EDIT: This is the simplest one: http://www.apogeerockets.com/Electronics_Payloads/Electronics/Jolly_Logic_AltimeterTwo

 

2nd EDIT: This one is good, too. and cheaper: http://www.apogeerockets.com/Electronics_Payloads/Electronics/Jolly_Logic_AltimeterOne

 

ive looked at altimeters but i was trying to find a potentially cheaper solution but the simple one you posted seems to have quite a bit of features for the price. 

 

thanks  

[Jogostar]

ive looked at altimeters but i was trying to find a potentially cheaper solution but the simple one you posted seems to have quite a bit of features for the price. 

 

thanks

Maybe you already saw that, but I'm going to say it anyway, the USB is just for loading, you can't access data on the thing, if you have the results, you need to write it down.

Just want to let you know.

 

Quote: ''Q. Does this AltimeterOne store data that can be downloaded to a computer through the USB port?

A. No. The AltimeterOne USB connector is only to charge the battery. This altimeter does not store data other than the peak altitude, which is displayed on the LCD screen.''

[whatthe_fuzz]

 

Maybe you already saw that, but I'm going to say it anyway, the USB is just for loading, you can't access data on the thing, if you have the results, you need to write it down.

Just want to let you know.

 

Quote: ''Q. Does this AltimeterOne store data that can be downloaded to a computer through the USB port?

A. No. The AltimeterOne USB connector is only to charge the battery. This altimeter does not store data other than the peak altitude, which is displayed on the LCD screen.''

 

 

ya i saw that it should be fine though  

 

thanks again!

[prolemur]

1. Compute Some Useful Terms
   • Find the mass M of your rocket in kilograms (kg):

     M = (weight in ounces)/16/2.2

   • Find the area A of your rocket in square meters (m^2):

     A = pi*(0.5*(diameter in inches/12)*0.3048)^2 = pi*r^2

     where r is the radius in meters

   • Note that the wind resistance force = 0.5 * rho*Cd*A * v^2, where

     rho is density of air = 1.2 kg/m^3

     Cd is the drag coefficient of your rocket which is around 0.75 for a model rocket - for a really great NAR report on Cd values click here

     v is the velocity of the rocket. You don't calculate this drag force, though, since you don't know what "v" is yet. What you do need is to lump the wind resistance factors into one coefficient k:

     k = 0.5*rho*Cd*A = 0.5*1.2*0.75*A

   • Find the impulse I and thrust T (big T) of the engine for your rocket from the engine designator, for an explanation you can reference NAR's Rocket Motor Coding, the NAR Model Rocket Safety Page, which gives the nominal impulse for each category, and the Model Rocket Motor Dimension WWW Page which gives you the actual rating for specific motors.
   • Compute the burn time t (little t) for the engine by dividing impulse I by thrust T:

     t = I / T

   • Note also - the gravitational force is equal to M*g, or the mass of the rocket times the acceleration of gravity (g). The value of g is a constant, equal to 9.8 meters/sec/sec. This force is the same as the weight of the rocket in newtons, and the term M*g shows up in the following equations a lot.

      

2. Compute a Couple of My Terms (to simplify the upcoming equations). In the absence of something more colorful I call them "q" and "x"
   • q = sqrt([T - M*g] / k)
   • x = 2*k*q / M

      

3. You Are Ready to Go: Calculate velocity at burnout (max velocity, v), boost phase distance yb, and coast phase distance yc (you will sum these last two for total altitude). Note that "g" is acceleration of gravity in metric units = 9.8.

   If you're not familiar with the term "exp" in these equations click RIGHT HERE.

   • v = q*[1-exp(-x*t)] / [1+exp(-x*t)]
   • yb = [-M / (2*k)]*ln([T - M*g - k*v^2] / [T - M*g])
   • yc = [+M / (2*k)]*ln([M*g + k*v^2] / [M*g])

      

4. AND THE TOTAL ALTITUDE IS... yb + yc

source

[Arshdeep]

I feel dumb now...

[Jogostar]

ya i saw that it should be fine though

 

thanks again!

 

Always here to help.

 

Good luck with the project!

[whatthe_fuzz]

*snip*

 

we always use those equations prior to launch and that gives us a synthetic benchmark but unfortunately we experience wind or even an offset launch or potential engine failure so equations are great for hypotheticals but i'm looking for realworld readouts

[gastew15]

Well I could give you some Physics equations on how to figure it out, but how complicated it gets depends on how much information you already have on the rocket, and how specific you want the answer...

 

EDIT: I see that @prolemur already gave a decent explanation on some of the idea, and my vague comment is useless xP