Taking off before passing GPS checks would cause airspeed or sideslip to be fused when the filter was still using a constant position assumption. This would cause large airspeed innovations, invalid wind estimates and degrade filter performance after GPS was gained and position and velocity was reset.
The bug meant the Y velocity (state index 5) covariance was not being updated correctly when sideslip was being used to constrain velocity drift (extended GPS loss).
The rework of the covariance update to reduce RAM follows the same pattern as adopted for other fusion processes
Enables wind estimation without an airspeed sensor and enables synthetic sideslip to be used with an airspeed sensor for improved wind state estimation.
Wind states and covariances are reset differently depending on whether airspeed is available.
Everywhere where KHP is used, it is first completely reset, thus making
it unnecessary to keep it as a class member.
This saves 2.3KB RAM.
Stack sizes don't need changing, since there is already a function
Ekf::predictCovariance(), which needs around 3KB of stack and is called
close to where the fuse* functions are called.
- if both gps position and velocity measurements are rejected for 7 seconds
do a reset
- if only gps position measurements are rejected then wait for 14 seconds
as we still have velocity measurements to constrain the drift in position
- introduced ecl internal parameter for the timeout
Signed-off-by: Roman <bapstroman@gmail.com>
- position reset method was returning before the actual delta values
were written and applied to the output buffer
- apply reset delta also to the output sample which was already taken out
from the output buffer, otherwise the complementary filter solution is
offset from the ekf solution
Signed-off-by: Roman <bapstroman@gmail.com>
Paul Riseborough
Daniel Agar
Nic
Lorenz Meier
CarlOlsson
Beat Küng
Roman