I’m completely new to this and a complete no-know about electronics but I have a few questions not related to a typical UAV.
For reference and typical for 2 stage recovery.
I launch rockets in The Netherlands and as a side project I want the rocket to be recovered by a steerable parachute and returned to a fixed waypoint. Preferable this waypoint would be right next to the launch pad. Basically the return-to-launch (RTL) feature of the ArduPilot.
The rockets are launched twice a year on a military shooting range with restricted airspace and typically achieve heights between 1500 – 2000m. Because of wind, the rockets have either a small parachute for a rapid decent or drift for several km from the launch pad. Ideal situation would be a parachute that could steer / circle the rocket back to the place where it was launched. Two main reasons: 1) safety, 2) higher flights possible with less drift.
RC is not an option because at 1km the rocket under chute is hardly visible.
I have a 3 stage plan of approach:
Stage 1) Proof of principle - by means of building a prototype and launch it from a RC plane. There is an organisation which does just that: www.rc-parachute.nl
Stage 2) Single stage recovery of a test rocket from an altitude of +/- 1km. All pyro events are triggered by means of a RDAS tiny.
Stage 3) Dual stage recovery from an altitude of 2 km. First a small drogue is released for a rapid but controlled decent to 1km after which the steerable parachute will be deployed and the ArduPilot should take over. Again all pyro events will be triggered by the RDAS.
A few questions arise:
1) I think I figured this one out already but is it possible to have an independent direct power supply which does not go through the ESC?
2) Can the unit be switched on/off by means of a physical toggle switch next to the unit and not through and RC receiver?
3) I will not be using IN 1 & 2 on the ArduPilot. Does the unit still function? Basically all I will be using is the rudder servo to control the steering of the chute. The rest is not used.
4) I have the possibility to get a GPS lock when the rocket is at the launch pad and the GPS receiver is out (for reference see photo below. Before launch, I have to put the receiver into the aluminium or carbon fibre rocket. There it will lose GPS lock and only after apogee when the parachute is out the GPS receiver is hanging free again and able to get a lock again. Is this possible? How long would it take for the GPS to get a new lock and does the ArduPilot remember the first GPS lock thus returning to the launch pad (the unit is not switched off)?
5) Experience proves that when the rockets rapidly descents under the drogue chute only it rotate on its longitudinal axis even if swivels are installed in the lines. Is the GPS receiver still able to get a lock when, for example, it rotates at 1Hz on its own axis?
Looking forward to your comments and I thinks this will be quite a fun project.
PS - I’m not trying to make the next DIY cruise missile (there is a distinct difference between a rocket and a missile as my rockets lack guidance).
For more info www.nerorockets.org or my personal site www.verticallimits.nl