stabilization_indi module

Full INDI stabilization controller for rotorcraft

No detailed description...

Example for airframe file

Add to your firmware section: This example contains all possible configuration options, not all of them are mandatory!

<module name="stabilization_indi">
  b'<define name="TILT_TWIST_CTRL" value="FALSE|TRUE" />\n\n    '
  b'<configure name="INDI_OUTPUTS" default="4" />\n    '
  b'<configure name="INDI_NUM_ACT" default="4" />\n\n    '
</module>

Module configuration options

Configure Options

• name: INDI_OUTPUTS value: None
• name: INDI_NUM_ACT value: None

Define Options

• name: TILT_TWIST_CTRL value: FALSE|TRUE
  Description: assume twist is slower than tilt and solve separately

Airframe file section

• section name: RC_SETPOINT prefix: STABILIZATION_ATTITUDE_
  • name SP_MAX_PHI value: 45.
    Description: max setpoint for roll angle
  • name SP_MAX_THETA value: 45.
    Description: max setpoint for pitch angle
  • name SP_MAX_R value: 90.
    Description: max setpoint for yaw rate
  • name DEADBAND_R value: 250
    Description: deadband on yaw rate input
• section name: STABILIZATION_ATTITUDE_INDI prefix: STABILIZATION_INDI_
  • name ALLOCATION_PSEUDO_INVERSE value: FALSE|TRUE
    Description: Master setting: leave false for WLS allocation, and use TRUE if not overactuated and no WLS
  • name G1_ROLL value: {20 , -20, -20 , 20 }
    Description: control effectiveness of every actuator on the roll axis
  • name G1_PITCH value: {14 , 14, -14 , -14 }
    Description: control effectiveness of every actuator on the pitch axis
  • name G1_YAW value: {-1, 1, -1, 1}
    Description: control effectiveness of every actuator on the yaw axis
  • name G1_THRUST value: {-.4, -.4, -.4, -.4}
    Description: control effectiveness of every actuator on the thrust axis
  • name G2 value: {-60.0, 60.0, -60.0, 60.0}
    Description: control effectiveness of every actuator derivative on the yaw axis (important for propellers with strong torque changes)
  • name REF_ERR_P value: 600.0
    Description: INDI gains linear controller
  • name REF_ERR_Q value: 600.0
    Description: INDI gains linear controller
  • name REF_ERR_R value: 600.0
    Description: INDI gains linear controller
  • name REF_RATE_P value: 28.0
    Description: INDI gains linear controller
  • name REF_RATE_Q value: 28.0
    Description: INDI gains linear controller
  • name REF_RATE_R value: 28.0
    Description: INDI gains linear controller
  • name MAX_R value: 120.0
    Description: max yaw rate
  • name FILT_CUTOFF value: 8.0
    Description: second order cutoff frequency for angular accelerations in Hz
  • name FILTER_RATES_SECOND_ORDER value: FALSE|TRUE
    Description: use second order rate filters instead of first order
  • name STABILIZATION_INDI_FILT_CUTOFF_P value: 20.0
    Description: First order cutoff freq for angular rate in Hz
  • name STABILIZATION_INDI_FILT_CUTOFF_Q value: 20.0
    Description: First order cutoff freq for angular rate in Hz
  • name STABILIZATION_INDI_FILT_CUTOFF_R value: 20.0
    Description: First order cutoff freq for angular rate in Hz
  • name ESTIMATION_FILT_CUTOFF value: 8.0
    Description: second order cutoff parameter
  • name ACT_FREQ value: {53.9, 53.9, 53.9, 53.9}
    Description: actuator dynamics [rad/s]
  • name ACT_IS_SERVO value: {0,0,0,0}
    Description: 1 for every actuator that is a servo
  • name ACT_IS_THRUSTER_X value: {0,0,0,0}
    Description: 1 for every actuator that is a thruster in the body-x direction
  • name ACT_RATE_LIMIT value: {9600,9600,9600,9600}
    Description: rate limit in PPRZ units per timestep (depends on control frequency)
  • name ACT_PREF value: {0.0, 0.0, 0.0, 0.0}
    Description: preferred (low energy) actuator value. Important when the system is over-determined!
  • name USE_ADAPTIVE value: FALSE|TRUE
    Description: enable adaptive gains
  • name ADAPTIVE_MU value: 0.0001
    Description: adaptation parameter
  • name WLS_PRIORITIES value: {1000, 1000, 1, 100, 100}
    Description: WLS control objective priorities: roll, pitch, thrust, yaw, thrust_x
  • name WLS_WU value: {1, 1, 1, 1}
    Description: WLS actuator cost (size of INDI_NUM_ACT)
  • name RPM_FEEDBACK value: FALSE
    Description: enable RPM feedback
  • name ACT_FEEDBACK_ID value: ABI_BROADCAST
    Description: listening for RPM feedback on this ABI id
  • name V_THRUST_X value: 2.
    Description: manually define the maximum virtual thrust produced on X axis
  • name V_THRUST_Y value: 2.
    Description: manually define the maximum virtual thrust produced on Y axis
  • name V_THRUST_Z value: 2.
    Description: manually define the maximum virtual thrust produced on Z axis

Module functions

Init Functions

These initialization functions are called once on startup.

• stabilization_indi_init()

Files

Header Files

The following headers are automatically included in modules.h

• stabilization_attitude_quat_indi.h

Source Files

• /stabilization/stabilization_indi.c
• /stabilization/stabilization_attitude_quat_indi.c

Raw stabilization_indi.xml file:

<!DOCTYPE module SYSTEM "module.dtd">
 
<module name="stabilization_indi" dir="stabilization" task="control">
  <doc>
    <description>
      Full INDI stabilization controller for rotorcraft
    </description>
 
    <configure name="INDI_OUTPUTS" default="4"/>
    <configure name="INDI_NUM_ACT" default="4"/>
 
    <define name="TILT_TWIST_CTRL" value="FALSE|TRUE" description="assume twist is slower than tilt and solve separately"/>
 
    <section name="RC_SETPOINT" prefix="STABILIZATION_ATTITUDE_">
      <define name="SP_MAX_PHI"   value="45." description="max setpoint for roll angle" unit="deg"/>
      <define name="SP_MAX_THETA" value="45." description="max setpoint for pitch angle" unit="deg"/>
      <define name="SP_MAX_R"     value="90." description="max setpoint for yaw rate" unit="deg/s"/>
      <define name="DEADBAND_R"   value="250" description="deadband on yaw rate input"/>
    </section>
 
    <section name="STABILIZATION_ATTITUDE_INDI" prefix="STABILIZATION_INDI_">
      <define name="ALLOCATION_PSEUDO_INVERSE" value="FALSE|TRUE" description="Master setting: leave false for WLS allocation, and use TRUE if not overactuated and no WLS"/>
      <define name="G1_ROLL" value="{20 , -20, -20 , 20 }" description="control effectiveness of every actuator on the roll axis"/>
      <define name="G1_PITCH" value="{14 , 14, -14 , -14 }" description="control effectiveness of every actuator on the pitch axis"/>
      <define name="G1_YAW" value="{-1, 1, -1, 1}" description="control effectiveness of every actuator on the yaw axis"/>
      <define name="G1_THRUST" value="{-.4, -.4, -.4, -.4}" description="control effectiveness of every actuator on the thrust axis"/>
      <define name="G2" value="{-60.0,   60.0,  -60.0,  60.0}" description="control effectiveness of every actuator derivative on the yaw axis (important for propellers with strong torque changes)"/>
      <define name="REF_ERR_P" value="600.0" description="INDI gains linear controller"/>
      <define name="REF_ERR_Q" value="600.0" description="INDI gains linear controller"/>
      <define name="REF_ERR_R" value="600.0" description="INDI gains linear controller"/>
      <define name="REF_RATE_P" value="28.0" description="INDI gains linear controller"/>
      <define name="REF_RATE_Q" value="28.0" description="INDI gains linear controller"/>
      <define name="REF_RATE_R" value="28.0" description="INDI gains linear controller"/>
      <define name="MAX_R" value="120.0" description="max yaw rate" unit="deg/s"/>
      <define name="FILT_CUTOFF" value="8.0" description="second order cutoff frequency for angular accelerations in Hz"/>
      <define name="FILTER_RATES_SECOND_ORDER" value="FALSE|TRUE" description="use second order rate filters instead of first order"/>
      <define name="STABILIZATION_INDI_FILT_CUTOFF_P" value="20.0" description="First order cutoff freq for angular rate in Hz"/>
      <define name="STABILIZATION_INDI_FILT_CUTOFF_Q" value="20.0" description="First order cutoff freq for angular rate in Hz"/>
      <define name="STABILIZATION_INDI_FILT_CUTOFF_R" value="20.0" description="First order cutoff freq for angular rate in Hz"/>
      <define name="ESTIMATION_FILT_CUTOFF" value="8.0" description="second order cutoff parameter"/>
      <define name="ACT_FREQ" value="{53.9, 53.9, 53.9, 53.9}" description="actuator dynamics [rad/s]"/>
      <define name="ACT_IS_SERVO" value="{0,0,0,0}" description="1 for every actuator that is a servo"/>
      <define name="ACT_IS_THRUSTER_X" value="{0,0,0,0}" description="1 for every actuator that is a thruster in the body-x direction"/>
      <define name="ACT_RATE_LIMIT" value="{9600,9600,9600,9600}" description="rate limit in PPRZ units per timestep (depends on control frequency)"/>
      <define name="ACT_PREF" value="{0.0, 0.0, 0.0, 0.0}" description="preferred (low energy) actuator value. Important when the system is over-determined!"/>
      <define name="USE_ADAPTIVE" value="FALSE|TRUE" description="enable adaptive gains"/>
      <define name="ADAPTIVE_MU" value="0.0001" description="adaptation parameter"/>
      <define name="WLS_PRIORITIES" value="{1000, 1000, 1, 100, 100}" description="WLS control objective priorities: roll, pitch, thrust, yaw, thrust_x"/>
      <define name="WLS_WU" value="{1, 1, 1, 1}" description="WLS actuator cost (size of INDI_NUM_ACT)"/>
      <define name="RPM_FEEDBACK" value="FALSE" description="enable RPM feedback"/>
      <define name="ACT_FEEDBACK_ID" value="ABI_BROADCAST" description="listening for RPM feedback on this ABI id"/>
      <define name="V_THRUST_X" value="2." description="manually define the maximum virtual thrust produced on X axis"/>
      <define name="V_THRUST_Y" value="2." description="manually define the maximum virtual thrust produced on Y axis"/>
      <define name="V_THRUST_Z" value="2." description="manually define the maximum virtual thrust produced on Z axis"/>
    </section>
  </doc>
  <settings>
    <dl_settings>
      <dl_settings NAME="indi">
        <dl_setting var="indi_gains.att.p" min="0" step="1" max="2500" shortname="kp_p" param="STABILIZATION_INDI_REF_ERR_P"/>
        <dl_setting var="indi_gains.rate.p" min="0.1" step="0.1" max="100" shortname="kd_p" param="STABILIZATION_INDI_REF_RATE_P"/>
        <dl_setting var="indi_gains.att.q" min="0" step="1" max="2500" shortname="kp_q" param="STABILIZATION_INDI_REF_ERR_Q"/>
        <dl_setting var="indi_gains.rate.q" min="0.1" step="0.1" max="100" shortname="kd_q" param="STABILIZATION_INDI_REF_RATE_P"/>
        <dl_setting var="indi_gains.att.r" min="0" step="1" max="2500" shortname="kp_r" param="STABILIZATION_INDI_REF_ERR_R"/>
        <dl_setting var="indi_gains.rate.r" min="0.1" step="0.1" max="100" shortname="kd_r" param="STABILIZATION_INDI_REF_RATE_P"/>
        <dl_setting var="indi_use_adaptive" min="0" step="1" max="1" shortname="use_adaptive" values="FALSE|TRUE" param="STABILIZATION_INDI_USE_ADAPTIVE" type="uint8"/>
        <dl_setting var="stablization_indi_yaw_dist_limit" min="0" step=".01" max="10.0" shortname="lim_yaw_spec_moment" param="STABILIZATION_INDI_YAW_DISTURBANCE_LIMIT"/>
        <dl_setting MAX="50." MIN="1." STEP="0.1" VAR="stabilization_indi_filter_freq" shortname="filt_freq" module="stabilization/stabilization_indi" handler="update_filt_freq"/>
      </dl_settings>
    </dl_settings>
  </settings>
  <dep>
    <depends>stabilization_rotorcraft,@attitude_command,wls</depends>
    <provides>commands</provides>
  </dep>
  <header>
    <file name="stabilization_attitude_quat_indi.h"/>
  </header>
  <init fun="stabilization_indi_init()"/>
  <makefile target="ap|nps" firmware="rotorcraft">
    <file name="stabilization_indi.c" dir="$(SRC_FIRMWARE)/stabilization"/>
    <file name="stabilization_attitude_quat_indi.c" dir="$(SRC_FIRMWARE)/stabilization"/>
    <configure name="INDI_OUTPUTS" default="4"/>
    <configure name="INDI_NUM_ACT" default="4"/>
    <define name="INDI_OUTPUTS" value="$(INDI_OUTPUTS)"/>
    <define name="INDI_NUM_ACT" value="$(INDI_NUM_ACT)"/>
    <define name="STABILIZATION_ATTITUDE_INDI_FULL" value="true"/>
  </makefile>
</module>