What you learn today
- AutoLand and re-entry
- Fuel reserve
- Safety abort
Landing is the part of the flight where most things go wrong. For it the avionics brings a landing automation: according to the game it controls the thrust and switches the engines on and off by itself to touch down softly. The chip only decides whether it is engaged.
Re-entry and flight rule
| LogicType | meaning according to the game |
|---|---|
ReEntryAltitude | altitude from which the rocket starts its descent to the launch pad, between 25 and 120 km |
AutoLand | engages the landing automation, write only |
FlightControlRule | the rule the automation is currently flying by |
Apex | lowest altitude before climbing again |
FlightControlRule tells you what the automation is doing right now:
| Value | Rule |
|---|---|
| 0 | no autopilot |
| 1 | normal: turning point of the descent at 60 m |
| 2 | too fast: full power |
| 3 | too slow: aim for a suitable descent speed |
| 4 | final approach: sink onto the launch mount in a controlled way |
If the rule stays at 2 for long, the rocket is too fast for its altitude – a value for a warning light.
Fuel reserve
Braking costs fuel, and halfway down there is no way back. That is why the chip only releases the automation if at least a reserve is on board. The calculation is the same as yesterday: Mass − DryMass. If the avionics is missing, the calculation is NaN, and sge gives 0 – no release.
Safety abort
“Abort” here means: the chip does not engage the automation and reports loudly why. What happens next is up to you. A landing that is already running, on the other hand, the chip never takes back – switching off the automation in the middle of the descent is more dangerous than any tight reserve.
bnez active report # already running: write nothing more
and tmp request ok
beqz tmp report
sbn AVIONIK HASH("Avionik") AutoLand 1
move active 1
report:AutoLand can only be written. The chip cannot check whether the automation is running – it remembers it in active. After a restart of the chip this register is 0, even if the rocket is landing right now.
Exercise
Task
Build the landing aid. The lever “Landen” is the pilot's request. If it is thrown and at least 500 kg of fuel are on board (avionics “Avionik”), the chip writes AutoLand 1 once, and the light “Landung” is lit from then on. Request without release: flashing light “Abbruch”. A running landing is never taken back. The display “Landung_Sprit” shows the fuel in kg, -1 without avionics.
Hints
Hint 1
Release: sge ok fuel RESERVE – NaN gives 0.
Hint 2
Write once: if active is already set, jump over the write. Otherwise only write with request and release.
Hint 3
Abort = request and no release and not yet active.
Quiz
4 questions. You pass from 60 % – the server does the grading.
Complete the day
- Passed the simulator exercise
- Passed the quiz with at least 60 %
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