Building and testing platform for transport and recovery sensors in sensitive area, remember, this is only a game!
This project was born from the need to provide my aircraft with a RF system
transmission autonomous to identify their location in emergency condition,
this condition must be remote and connected only failure all the systems on board.
The area where I work does not allow to rely on the GPS system,the signal of this
is not sufficient in a large area when the aircraft is grounded.
For this reason I decided to develop a low cost Beacon that allows me to
identify the exact point of transmission to more than 2km from the starting position
in the worst condition, for example the source transmission located in dense forest.
The natural history of this project required me to build a system
economical to transport this system in a point of 2km away and not accurate position.
so I decided to build a replica of the V2 missile with release system parachute
assisted with barometric system.
The platform used for transportation is a Aeroplane, the model is FunCub Multiplex.
Design and construction of the beacon system :
The important objectives of this system is:
1) Reliable
2) Light
3) Resistant to mechanical stress
4) Significant autonomy
5) Powerful
6) Must not interfere with the avionics of the model
I tested many different MCU and RF modules to minimize consumption.
Some photos of the construction phase ...
Power system used was composed of 3 cell Li-Po with a capacity of 150 mA / h for a verified autonomy of 12 h
from the beginning of the RF transmission.
The total weight of battery unit is 12g.
Assembled battery pack.
The MCU is a PIC16F88, a microcontroller that I had in my lab.
You can use a wide variety of MCU depending on what resources
are required and available in your laboratory. The main problem is to reduce
consumption, which is essential use a proper method of programming.
In my case, the MCU is used to analyze the condition of aircraft avionic
and in case there is an emergency condition after a certain time enables the transmission of the RF module.
On board of the V2 the MCU ( Atmega ) communicates with the MCU beacon system
and generates the control signals. The unusual construction technique ensures a low weight Hardware
and a high resistance to mechanical stress. The box is constructed of a Depron multilayer material.
In the other side is located the modulated AM Aurel RF module also decided about this for low power
and wide range of supply voltage. The complete system weighs only 22g with battery and has
transmission capacity for 12h at 50mW RF power.
The complete system on the balance.
The directional antenna is derived from this project : http://www.missilistica.it/laserteam/yagi1.htm This antenna is homemade and designed originally for use with radio localization systems therefore suitable.
Is compact, robust and with proper RF band. I use a scanner ICOM as a receiver but also in this case
depends what comes in the laboratory. Certainly there are reception systems with greater sensitivity.
I consider it very convenient to use the internal system of RF attenuation and the frequency shift
when close to the source. This allows me to find the source, starting from several kilometers and approach until a few meters with correct direction.
Construction of the V2 :
The following pictures of the various phases of construction, the materials used are
balsa wood and paper to the tube of the parachute containment.
V2 completed ready for testing on the air.
The realization of the parachute requested further study and testing to verify the falling speed calculated and the components used.
Following the graphs recorded by the logger in the first launch without using system of expulsion.
- Time Vs. Altitude
- Time Vs. Speed
The video of the first test and second test with ejection system with barometric control :
https://www.youtube.com/watch?v=EbsQHrNRASs&list=UUrnWHoLed2O112VUSQ8XhxA&index=1&feature=plcp
The barometric ejection system is very important to reach the ground in the shortest time possible
without drift due to wind, the falling speed is calculated 1.5mt/sec.
The section rx assembled and ready.
The full retail platform ready for mission.
The final video in the laboratory :
https://www.youtube.com/watch?v=1Jp04Df8z4s
Day of the mission :
For the mission I identified suitable area and made several expeditions.
The target area was guarded by my two friends to prevent access by unauthorized parties. Was prepared a list of tasks and controls to be performed to leave nothing to chance!
Any problems would abort the mission!
My friends were ordered to keep clear of the area and tell me order of release
when the aircraft was flying so as to avoid any mistake on my part evaluation in an instrumental. After release and landing these were to go to a meeting area where I met after the rescue mission,
this is the only support at my mission.
Video of the Day :
https://www.youtube.com/watch?v=mgAZF4FNwuk
Luckily I prepared a list of checks to execute before the flight!!!
Some photo of damage after the rescue mission :
I like the results of the mission, the V2 is now repaired and working perfectly!
Some photos are seen previously after repair of V2.
Thanks for your attention and sorry for my bad English!
