The constrainAbs function was not prioritizing the minimum value
that produces the autocontinue behaviour. This caused zig-zag
paths when the waypoints were almost -but not exactly- aligned.
dt could drive the alpha filter crazy because of the small dt
approximation during the computation of the coefficient.
- Remove unused bitmask packing of the innovation checks
* ekf2: Add FirstOrderLpf and InnovationLpf classes for innovation lowpass filtering
* ekf2: use InnovLpf filter class in preflight checks
* ekf2: move selection of yaw test limit for pre-flight check in function
* ekf2: Move pre-flight checks into separate function
* ekf2: use static constexpr insetead of inline for sq (square) function
* ekf2: Split pre-flight checks in separate functions
Also use the same check for all the innovations:
innov_lpf < test and innov < 2xtest
* ekf2: Add optical flow pre-flight check
* ekf2: Combine FirstOrderLpf and InnovationLpf in single class
* ekf2: check vel_pos_innov when ev_pos is active as well
* ekf2: transform InnovationLpf into a header only library and pass the
spike limit during the update call to avoid storing it here
* ekf2: Static and const cleanup
- set spike_lim constants as static constexpr, set innovation
- set checker helper functions as static
- rename the mix of heading and yaw as heading to avoid confusion
* ekf2: use ternary operator in selectHeadingTestLimit instead of if-else
* ekf2: store intermediate redults in const bool flags. Those will be used for logging
* ekf2: set variable const whenever possible
* ekf2: create PreFlightChecker class that handle all the innovation
pre-flight checks.
Add simple unit testing
Use bitmask instead of general flag to have more granularity
* PreFlightChecker: use setter for the innovations to check instead of sending booleans in the update function
This makes it more scalable as more checks will be added
* ekf: Use booleans instead of bitmask for ekf preflt checks
Rename "down" to "vert"
part to avoid having to scale its saturation separately. This is
required to avoid premature saturation of the integrator when using
the K term.
Also remove double saturation of the integrator
A NAN is interpreted in the FlightTaskAuto as a non-valid global coordinate and sets a local position.
If a zero is sent instead, the global coordinate is recognized as valid and will be executed.
This is a problem when the global position is gained for the first time after takeoff and that a valid global reference did not exist before
Also split a few functions into smaller ones for readability, fix
formatting, use geters to get the current state of the trajectory
instead of return arguments.
This helps when the current velocity is smaller than the target but that
the acceleration is too large such that the velocity will overshoot.
Without this check, the algorithm increases the acceleration which leads
to an even larger overshoot.
This solves many numerical issues when the trajectory is close to the
primary NE axes (small velocities). It is also more robust when dt is
large and has some jitter.
It was broken because _velocity_setpoint is used for input and output
and was assumed to be the input at a place where it was already overwitten
To clarify this, the input setpoint is renamed "target"
Also remove crosstrack P controller that produces overshoots when the
acceptance radius is large (crosstrack error is suddenly large at
waypoint switch).
This is done to allow proper initialization of the new FlightTask and
give it a chance to continue the setpoints without discontinuity. The
function checkSetpoints replaces the setpoints containing NANs with an
estimate of the state. The estimate is usually the current estimate of
the EKF or zero.
The transition FlightTask also provides an estimate of the current
acceleration to properly initialize the next FlightTask after
back-transition. This avoid having to initialize the accelerations to
zero knowing that the actual acceleration is usually far from zero.
the vehicle yaws towards the next waypoint before accelerating. This is
required for drones with front vision and aerodynamic multicopters such
as standard vtol planes or highspeed multirotors.
The linear mapping from position error to cruise velocity is changed by
a combination of that linear mapping and a nonlinear function containing
the maximum acceleration and jerk to avoid overshoots at waypoints due to
overoptimistic breaking distance.
outside the fence" to "engage geofence failsafe on transition". This
way, the pilot is not stucked in the non flight zone and can switch to
a manual mode and fly back or trigger RTL.
This is done to avoid generating large yaw changes when the velocity
vector is small; for example when switching into loiter or reaching the
last waypoint.
A low gyro cutoff is needed for most medium/large size drones as the structural natural and blade-pass frequencies are low.
A higher value is still desirable for small platforms surch as racers
or well isolated autopilots and should be tuned by the user.
Specific values for config files are untouched.
The cutoff filter for the D term is disabled here as the required
cutoff frequency for the default D term of the rate controller is higher
than the gyro cutoff. In that case, enabling the D term cutoff would
just add some undesired phase lag to the derivative.
bresch