After having starting point, barrirers and destination, how to get a safe trajectory?
State estimate:
sub milimeter accuracy in lab
GPS for large airplane
But indoors, no GPS.
How???
SLAM !!!
4X
1 camera
markers as beacons
Applications:
also multiple vehicles collaborating
response to 911 call
1,Basic Mechanics
https://www.quora.com/Why-cant-all-the-motors-of-a-quadcopter-rotate-in-the-same-direction
disturbance and recovery
over shoot and recovery
battery selection
Actually hovering is an inefficient mechanism !!!
Bolt: 20W/kg
bicyclist: 6W/kg
fat of tissue carries 10kw per kg
↓ have to build smaller and more light-weight quadrators in lab
$v_0^2 - v^2 = 2ax,\ where\ v=0\ here.$
$\frac{9600}{2815-130}$
in short 
