guidance_full_pid_fw module

Vertical control for fixedwing aircraft based on PID

By default, throttle and pitch are used to track vertical speed and altitude. Airspeed or ground speed control can be activated.

Example for airframe file

Add to your firmware section:

<module name="guidance_full_pid_fw"/>

Module configuration options

Airframe file section

• section name: VERTICAL CONTROL prefix: V_CTL_
  • name ALTITUDE_PGAIN value: 0.12
    Description: altitude loop P gain
  • name ALTITUDE_MAX_CLIMB value: 4.
    Description: max climb rate
  • name AUTO_CLIMB_LIMIT value: 1.
    Description: climb rate limiter
  • name AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE value: 0.5
    Description: nominal throttle for cruise flight
  • name AUTO_THROTTLE_MIN_CRUISE_THROTTLE value: 0.25
    Description: min cruise throttle
  • name AUTO_THROTTLE_MAX_CRUISE_THROTTLE value: 0.85
    Description: max cruise throttle
  • name AUTO_THROTTLE_CLIMB_THROTTLE_INCREMENT value: 0.088
    Description: feedforward throttle gain
  • name AUTO_THROTTLE_PGAIN value: 0.004
    Description: feedback throttle P gain
  • name AUTO_THROTTLE_DGAIN value: 0.0
    Description: feedback throttle D gain
  • name AUTO_THROTTLE_IGAIN value: 0.
    Description: feedback throttle I gain
  • name AUTO_THROTTLE_PITCH_OF_VZ_PGAIN value: 0.077
    Description: feedforward pitch gain
  • name AUTO_PITCH_PGAIN value: 0.027
    Description: feedback pitch P gain
  • name AUTO_PITCH_DGAIN value: 0.01
    Description: feedback pitch D gain
  • name AUTO_PITCH_IGAIN value: 0.0
    Description: feedback pitch I gain
  • name AUTO_PITCH_MAX_PITCH value: 20.
    Description: max pitch up setpoint
  • name AUTO_PITCH_MIN_PITCH value: -20.
    Description: max pitch down setpoint
  • name AUTO_AIRSPEED_SETPOINT value: 16.
    Description: default airspeed setpoint
  • name AUTO_AIRSPEED_THROTTLE_PGAIN value: 0.1
    Description: throttle P gain for airspeed control
  • name AUTO_AIRSPEED_THROTTLE_DGAIN value: 0.12
    Description: throttle D gain for airspeed control
  • name AUTO_AIRSPEED_THROTTLE_IGAIN value: 0.0
    Description: throttle I gain for airspeed control
  • name AUTO_AIRSPEED_PITCH_PGAIN value: 0.06
    Description: pitch P gain for airspeed control
  • name AUTO_AIRSPEED_PITCH_DGAIN value: 0.0
    Description: pitch D gain for airspeed control
  • name AUTO_AIRSPEED_PITCH_IGAIN value: 0.042
    Description: pitch I gain for airspeed control
  • name AIRSPEED_MAX value: 30
    Description: max airspeed setpoint
  • name AIRSPEED_MIN value: 10
    Description: min airspeed setpoint
  • name AUTO_GROUNDSPEED_SETPOINT value: 15
    Description: default ground speed setpoint
  • name AUTO_GROUNDSPEED_PGAIN value: 1.
    Description: ground speed P gain
  • name AUTO_GROUNDSPEED_IGAIN value: 0.
    Description: ground speed I gain
  • name PITCH_LOITER_TRIM value: 0.
    Description: loiter pitch setpoint trim
  • name PITCH_DASH_TRIM value: 0.
    Description: dash pitch setpoint trim
  • name THROTTLE_SLEW value: 0.1
    Description: throttle slew rate limiter

Module functions

Init Functions

These initialization functions are called once on startup.

• v_ctl_init()

Files

Header Files

The following headers are automatically included in modules.h

• guidance_v_n.h
• guidance_h.h

Source Files

• /guidance/guidance_v_n.c
• /guidance/guidance_h.c

Raw guidance_full_pid_fw.xml file:

<!DOCTYPE module SYSTEM "module.dtd">

<module name="guidance_full_pid" dir="guidance">
  <doc>
    <description>
      Vertical control for fixedwing aircraft based on PID
      By default, throttle and pitch are used to track vertical speed and altitude.
      Airspeed or ground speed control can be activated.
    </description>
    <section name="VERTICAL CONTROL" prefix="V_CTL_">
      <define name="ALTITUDE_PGAIN" value="0.12" description="altitude loop P gain"/>
      <define name="ALTITUDE_MAX_CLIMB" value="4." description="max climb rate" unit="m/s"/>
      <define name="AUTO_CLIMB_LIMIT" value="1." description="climb rate limiter" unit="ms/s/s"/>
      <define name="AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE" value="0.5" description="nominal throttle for cruise flight"/>
      <define name="AUTO_THROTTLE_MIN_CRUISE_THROTTLE" value="0.25" description="min cruise throttle"/>
      <define name="AUTO_THROTTLE_MAX_CRUISE_THROTTLE" value="0.85" description="max cruise throttle"/>
      <define name="AUTO_THROTTLE_CLIMB_THROTTLE_INCREMENT" value="0.088" description="feedforward throttle gain" unit="%/(m/s)"/>
      <define name="AUTO_THROTTLE_PGAIN" value="0.004" description="feedback throttle P gain"/>
      <define name="AUTO_THROTTLE_DGAIN" value="0.0" description="feedback throttle D gain"/>
      <define name="AUTO_THROTTLE_IGAIN" value="0." description="feedback throttle I gain"/>
      <define name="AUTO_THROTTLE_PITCH_OF_VZ_PGAIN" value="0.077" description="feedforward pitch gain"/>
      <define name="AUTO_PITCH_PGAIN" value="0.027" description="feedback pitch P gain"/>
      <define name="AUTO_PITCH_DGAIN" value="0.01" description="feedback pitch D gain"/>
      <define name="AUTO_PITCH_IGAIN" value="0.0" description="feedback pitch I gain"/>
      <define name="AUTO_PITCH_MAX_PITCH" value="20." description="max pitch up setpoint" unit="deg"/>
      <define name="AUTO_PITCH_MIN_PITCH" value="-20." description="max pitch down setpoint" unit="deg"/>
      <define name="AUTO_AIRSPEED_SETPOINT" value="16." description="default airspeed setpoint"/>
      <define name="AUTO_AIRSPEED_THROTTLE_PGAIN" value="0.1" description="throttle P gain for airspeed control"/>
      <define name="AUTO_AIRSPEED_THROTTLE_DGAIN" value="0.12" description="throttle D gain for airspeed control"/>
      <define name="AUTO_AIRSPEED_THROTTLE_IGAIN" value="0.0" description="throttle I gain for airspeed control"/>
      <define name="AUTO_AIRSPEED_PITCH_PGAIN" value="0.06" description="pitch P gain for airspeed control"/>
      <define name="AUTO_AIRSPEED_PITCH_DGAIN" value="0.0" description="pitch D gain for airspeed control"/>
      <define name="AUTO_AIRSPEED_PITCH_IGAIN" value="0.042" description="pitch I gain for airspeed control"/>
      <define name="AIRSPEED_MAX" value="30" description="max airspeed setpoint"/>
      <define name="AIRSPEED_MIN" value="10" description="min airspeed setpoint"/>
      <define name="AUTO_GROUNDSPEED_SETPOINT" value="15" description="default ground speed setpoint"/>
      <define name="AUTO_GROUNDSPEED_PGAIN" value="1." description="ground speed P gain"/>
      <define name="AUTO_GROUNDSPEED_IGAIN" value="0." description="ground speed I gain"/>
      <define name="PITCH_LOITER_TRIM" value="0." description="loiter pitch setpoint trim" unit="deg"/>
      <define name="PITCH_DASH_TRIM" value="0." description="dash pitch setpoint trim" unit="deg"/>
      <define name="THROTTLE_SLEW" value="0.1" description="throttle slew rate limiter"/>
    </section>
  </doc>
  <settings>
    <dl_settings>
      <dl_settings NAME="control vert">
        <dl_settings name="alt">
          <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
        </dl_settings>

        <dl_settings name="climb">
          <dl_setting MAX="2" MIN="0" STEP="1" var="v_ctl_speed_mode" shortname="speed mode" values="THROTTLE|AIRSPEED|GROUNDSPEED">
            <strip_button name="TH" value="0" group="speed_mode"/>
            <strip_button name="AS" value="1" group="speed_mode"/>
            <strip_button name="GS" value="2" group="speed_mode"/>
          </dl_setting>
          <dl_setting MAX="1" MIN="0.0" STEP="0.05" VAR="v_ctl_auto_throttle_min_cruise_throttle" shortname="min cruise thr" module="guidance/guidance_v" param="V_CTL_AUTO_THROTTLE_MIN_CRUISE_THROTTLE"/>
          <dl_setting MAX="1" MIN="0.0" STEP="0.05" VAR="v_ctl_auto_throttle_max_cruise_throttle" shortname="max cruise thr" module="guidance/guidance_v" param="V_CTL_AUTO_THROTTLE_MAX_CRUISE_THROTTLE"/>
          <dl_setting MAX="1" MIN="0.0" STEP="0.05" VAR="v_ctl_auto_throttle_cruise_throttle" shortname="cruise throttle" module="guidance/guidance_v" handler="SetCruiseThrottle" param="V_CTL_AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE"/>
          <dl_setting MAX="15" MIN="-15" STEP="0.1" VAR="v_ctl_pitch_trim" shortname="pitch trim" param="V_CTL_PITCH_TRIM" unit="rad" alt_unit="deg"/>

          <dl_setting MAX="0.1" MIN="0" STEP="0.001" VAR="v_ctl_auto_pitch_pgain" shortname="pitch_p" param="V_CTL_AUTO_PITCH_PGAIN"/>
          <dl_setting MAX="0.1" MIN="0" STEP="0.001" VAR="v_ctl_auto_pitch_igain" shortname="pitch_i" param="V_CTL_AUTO_PITCH_IGAIN"/>
          <dl_setting MAX="0.1" MIN="0" STEP="0.001" VAR="v_ctl_auto_pitch_dgain" shortname="pitch_d" param="V_CTL_AUTO_PITCH_DGAIN" module="guidance/guidance_v_n"/>

          <dl_setting MAX="0.1" MIN="0" STEP="0.001" VAR="v_ctl_auto_throttle_pgain" shortname="throttle_p" param="V_CTL_AUTO_THROTTLE_PGAIN"/>
          <dl_setting MAX="0.1" MIN="0" STEP="0.001" VAR="v_ctl_auto_throttle_igain" shortname="throttle_i" param="V_CTL_AUTO_THROTTLE_IGAIN"/>
          <dl_setting MAX="0.1" MIN="0" STEP="0.001" VAR="v_ctl_auto_throttle_dgain" shortname="throttle_d" param="V_CTL_AUTO_THROTTLE_DGAIN"/>

          <dl_setting MAX="1" MIN="0" STEP="0.01" VAR="v_ctl_auto_throttle_climb_throttle_increment" shortname="throttle_incr" param="V_CTL_AUTO_THROTTLE_CLIMB_THROTTLE_INCREMENT"/>
          <dl_setting MAX="1" MIN="0" STEP="0.01" VAR="v_ctl_auto_throttle_pitch_of_vz_pgain" shortname="pitch_of_vz" param="V_CTL_AUTO_THROTTLE_PITCH_OF_VZ_PGAIN"/>
        </dl_settings>
      </dl_settings>
    </dl_settings>
  </settings>
  <header>
    <file name="guidance_v_n.h"/>
    <file name="guidance_h.h"/>
  </header>
  <init fun="v_ctl_init()"/>
  <makefile target="ap|sim|nps" firmware="fixedwing">
    <file name="guidance_v_n.c" dir="$(SRC_FIRMWARE)/guidance"/>
    <file name="guidance_h.c" dir="$(SRC_FIRMWARE)/guidance"/>
    <define name="CTRL_TYPE_H" value="firmwares/fixedwing/guidance/guidance_v_n.h" type="string"/>
  </makefile>
</module>