Subsystem/ins

2014-03-07T22:22:13Z

Slycheese:

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== INS subsystem ==
The INS (Inertial Navigation System) subsystem specifies which position and velocity estimation algorithm you are using.

Most of the INS filters are only providing position and speed, and they need to be used together with an AHRS (Altitude and Heading Reference System) filter for attitude. Currently, only the experimental invariant filter is a full INS.

Currently possible AHRS subsystem types are
* alt_float
* gps_passthrough
* xsens
* xsens700
* no_type
* hff
* extended
* ardrone2
* float_invariant

e.g. for the extended filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ins" type="extended"/>
</firmware>
</source>
}}

== Implementations ==

=== alt_float ===
Filters altitude and climb rate for fixedwings.

A 2-state Kalman filter that estimates vertical position and vertical velocity from GPS and barometric data.

When USE_BAROMETER is true:
* GPS horizontal position and horizontal velocity is directly passed through
* GPS vertical position sets the altitude for the barometric reference pressure (QFE)
* Vertical position and velocity is a filtered based on barometric pressure with respect to the reference pressure and GPS vertical velocity readings.

When USE_BAROMETER is false or undefined:
* GPS velocity is directly passed through to the vehicle's state.
* GPS horizontal position is directly passed through.
* Altitude is filtered based on GPS height and vertical velocity data.

'''Parameters'''

USE_BAROMETER - Enables the use of barometric data

DEBUG_ALT_KALMAN - Enables debug messages from the subsystem (Default: not defined)

=== GPS passthrough (gps_passthrough) ===

=== xsens ===
XSens Mti-G

<source lang="xml">
<subsystem name="ins" type="xsens">
<configure name="XSENS_UART_NR" value="0"/>
<configure name="XSENS_UART_BAUD" value="B115200"/>
</subsystem>
</source>

=== xsend700 ===
XSens Mti-G

<source lang="xml">
<load name="ins_xsens_MTiG_fixedwing.xml">
<configure name="XSENS_UART_NR" value="0"/>
</load>
</source>

=== no_type ===
Vertical filter (in float) estimating altitude, vertical velocity and accelerometer bias.

If USE_GPS, horizontal position and velocity is set directly by GPS.

<source lang="xml">
<subsystem name="ins"/>
</source>

=== Horizontal Filter Float (hff) ===
simple with float vertical and horizontal filters for INS

=== extended ===
Extended vertical filter (in float).

A 4-state Kalman filter that estimates:
* vertical position
* vertical speed
* accelerometer bias
* barometric offset

'''Parameters'''

INS_PROPAGATE_FREQUENCY - Defines the frequency (Hz) of the propagation model (Default: PERIODIC_FREQUENCY)

=== ardrone2 ===
simple INS with float vertical filter for use with ardrone2_sdk

=== float_invariant ===
attitude and speed estimation for fixedwings via invariant filter

[[Category:User_Documentation]] [[Category:Subsystems]]

PaparazziUAV - User contributions [en]

Subsystem/ins