optical_flow_landing
Optical flow landing. This module implements optical flow landings in which the divergence is kept constant (for rotorcraft). When using a fixed gain for control, the covariance between thrust and divergence is tracked, so that the drone knows when it has arrived close to the landing surface. Then, a final landing procedure is triggered. It can also be set to adaptive gain control, where the goal is to continuously gauge the distance to the landing surface. In this mode, the drone will oscillate all the way down to the surface. de Croon, G.C.H.E. (2016). Monocular distance estimation with optical flow maneuvers and efference copies: a stability-based strategy. Bioinspiration and Biomimetics, 11(1), 016004.
Name |
Value |
Description |
|---|---|---|
OFL_AGL_ID |
ABI_BROADCAST |
Sender id of the AGL (sonar) ABI message |
OFL_ |
||
|---|---|---|
Name |
Value |
Description |
PGAIN |
0.50 |
P gain on divergence error |
IGAIN |
0.10 |
I gain on summed divergence error |
DGAIN |
0.0 |
D gain on differential of divergence error |
VISION_METHOD |
1 |
0 = fake vision, 1 = real vision |
CONTROL_METHOD |
0 |
0 = fixed gain control, 1 = adaptive gain control, 2 = exponential control, 3 = learning-based control. |
COV_METHOD |
0 |
0 = cov(uz, div), 1 = cov(div_past, div) |
COV_WINDOW_SIZE |
30 |
Number of time steps for window size for getting the covariance over time. |
COV_LANDING_LIMIT |
2.2 |
Covariance where the vehicle engages final landing procedure. |
COV_SETPOINT |
-0.10 |
Target Covariance for adaptive gain increment. |
LP_CONST |
0.05 |
Low pass filter constant for divergence input. |
ELC_OSCILLATE |
true |
Oscillate to find optimum gain before initiating landing. |
CLOSE_TO_EDGE |
0.025 |
When the cov_div value gets this close to the setpoint, we consider the drone to oscillate |
PGAIN_ADAPTIVE |
0.50 |
P gain on cov error |
IGAIN_ADAPTIVE |
0.10 |
I gain on summed cov error |
DGAIN_ADAPTIVE |
0.0 |
D gain on differential cov error |
P_LAND_THRESHOLD |
0.15 |
P-value at which the drone will initiate a final landing procedure, for adaptive control |
PGAIN_HORIZONTAL_FACTOR |
0.0625 |
Factor multiplied with P gain for horizontal control |
IGAIN_HORIZONTAL_FACTOR |
0.0001 |
Factor multiplied with I gain for horizontal control |
ROLL_TRIM |
0.0 |
Roll trim in degrees |
PITCH_TRIM |
0.0 |
Pitch trim in degrees |
FRONT_DIV_THRESHOLD |
0.3 |
Threshold on front divergence for stopping. |
Depends
- cv_textons