Wave maneuver for system identification.
The wave provide a sine input to the specified command axis. The module is used by including the module in the airframe file and adding the following line to the <command_laws> section:
<call fun="sys_id_wave_add_values(autopilot_get_motors_on(),FALSE,values)">
You can pick the axes to apply waves to by setting the WAVE_AXES variable with the COMMAND_XXX variables where XXX are the actuators defined in the <commands> section of your airframe.
Remeber to deactivate the control input when the system identification input is running using (can be checked using the sys_id_wave_running() function)
Then, the GCS exposes the settings for the wave.
- The wave axis settings is the index (0-based) of the axis to choose within the WAVE_AXES variable specified. In the default, this means i.e. 0 means roll wave.
- Amplitude is the amplitude of the wave
- Freqyency_hz is the frequency in Hertz of the wave
- Lag_rad is the lag in radiants for the wave signal
Start the wave by checking the Active box in the "Activate wave". Stop the wave by checking the Inactive box in the same input setting.
Add the message "WAVE" to your telemetry to see wave progress, and to your logger to obtain information about the provided input.
Add the following message structure to the messages.xml file on a free ID
Example for airframe file
Add to your firmware section: This example contains all possible configuration options, not all of them are mandatory!
<module name="sys_id_wave">
b'<define name="WAVE_AXES" value="{COMMAND_ROLL,COMMAND_PITCH,COMMAND_YAW}" />\n '
b'<define name="WAVE_ENABLED" value="TRUE|FALSE" />\n '
</module>
Module configuration options
Define Options
- name:
WAVE_AXES value: {COMMAND_ROLL,COMMAND_PITCH,COMMAND_YAW}
Description: Which axes the wave is applied to (specify as array with {})
- name:
WAVE_ENABLED value: TRUE|FALSE
Description: If false, the wave does not run and values are not added
Module functions
Init Functions
These initialization functions are called once on startup.
Periodic Functions
These functions are called periodically at the specified frequency from the module periodic loop.
- sys_id_wave_run()
- Frequency in Hz: 60
- Autorun: TRUE
Periodic function automatically starts after init.
Files
Header Files
The following headers are automatically included in modules.h
Source Files
Raw sys_id_wave.xml file:
<!DOCTYPE module SYSTEM "module.dtd">
<module name="sys_id_wave" dir="system_identification">
<doc>
<description>Wave maneuver for system identification.
The wave provide a sine input to the specified command axis.
The module is used by including the module in the airframe file and adding the following line to the <command_laws> section:
<call fun="sys_id_wave_add_values(autopilot_get_motors_on(),FALSE,values)"/>
You can pick the axes to apply waves to by setting the WAVE_AXES variable with the COMMAND_XXX variables where XXX are the actuators defined in
the <commands> section of your airframe.
Remeber to deactivate the control input when the system identification input is running using (can be checked using the sys_id_wave_running() function)
Then, the GCS exposes the settings for the wave.
- The wave axis settings is the index (0-based) of the axis to choose within the WAVE_AXES variable specified. In the default, this means i.e. 0 means roll wave.
- Amplitude is the amplitude of the wave
- Freqyency_hz is the frequency in Hertz of the wave
- Lag_rad is the lag in radiants for the wave signal
Start the wave by checking the Active box in the "Activate wave". Stop the wave by checking the Inactive box in the same input setting.
Add the message "WAVE" to your telemetry to see wave progress, and to your logger to obtain information about the provided input.
Add the following message structure to the messages.xml file on a free ID
</description>
<define name="WAVE_AXES" value="{COMMAND_ROLL,COMMAND_PITCH,COMMAND_YAW}" description="Which axes the wave is applied to (specify as array with {})"/>
<define name="WAVE_ENABLED" value="TRUE|FALSE" description="If false, the wave does not run and values are not added"/>
</doc>
<settings>
<dl_settings name="System identification">
<dl_settings name="Wave input">
<dl_setting min="0" max="1" step="1" values="Inactive|Active" shortname="Activate wave" var="wave_active" type="uint8_t" module="system_identification/sys_id_wave" handler="activate_handler">
</dl_setting>
<dl_setting min="0" max="9600" step="100" shortname="Amplitude" var="wave_amplitude" type="int32_t" module="system_identification/sys_id_wave"/>
<dl_setting min="0" max="5" step="1" shortname="Wave axis" var="wave_axis" type="uint8_t" module="system_identification/sys_id_wave" handler="axis_handler"/>
<dl_setting min="0" max="20" step="0.5" shortname="frenquency_hz" var="frequency_hz_" type="float" module="system_identification/sys_id_wave" handler="frequency_hz_set"/>
<dl_setting min="0" max="6.28" step="0.0174" shortname="lag_rad_" var="lag_rad_" type="float" module="system_identification/sys_id_wave" handler="lag_rad_set"/>
</dl_settings>
</dl_settings>
</settings>
<header>
<file name="sys_id_wave.h"/>
</header>
<init fun="sys_id_wave_init()"/>
<periodic fun="sys_id_wave_run()" freq="60" autorun="TRUE"/>
<makefile>
<file name="pprz_wave.c"/>
<file name="sys_id_wave.c"/>
</makefile>
</module>
1.9.1