approach_moving_target module

Approach a moving target (e.g

ship) along a diagonal.

Example for airframe file

Add to your firmware section:

<module name="approach_moving_target"/>

Module configuration options

Airframe file section

• section name: APPROACH_MOVING_TARGET prefix: APPROACH_MOVING_TARGET_
  • name CUTOFF_FREQ_FILTERS_HZ value: 0.5
    Description: low pass filter on WP position
  • name SLOPE value: 35.0
    Description: [degrees] the angle of the slope for the approach
  • name DISTANCE value: 60.0
    Description: [m] the initial distance to start the approach
  • name SPEED value: -1.0
    Description: [m/s] the approach speed along the slope
  • name ERR_SLOWDOWN_GAIN value: 0.25
    Description: slowing down when arriving
  • name POS_GAIN value: -1.0
    Description: P-gain
  • name SPEED_GAIN value: -1.0
    Description: D-gain
  • name RELVEL_GAIN value: -1.0
    Description: RelVel-gain

Module functions

Init Functions

These initialization functions are called once on startup.

• approach_moving_target_init()

Periodic Functions

These functions are called periodically at the specified frequency from the module periodic loop.

• follow_diagonal_approach()
  • Frequency in Hz: 100.0
  • Autorun: LOCK
    Periodic function automatically starts after init and can't be stopped.

Files

Header Files

The following headers are automatically included in modules.h

• approach_moving_target.h

Source Files

• modules/ctrl/approach_moving_target.c

Raw approach_moving_target.xml file:

<!DOCTYPE module SYSTEM "module.dtd">
 
<module name="approach_moving_target" dir="ctrl">
  <doc>
    <description>
      Approach a moving target (e.g. ship) along a diagonal.
    </description>
    <section name="APPROACH_MOVING_TARGET" prefix="APPROACH_MOVING_TARGET_">
      <define name="CUTOFF_FREQ_FILTERS_HZ" value="0.5" description="low pass filter on WP position"/>
 
      <define name="SLOPE" value="35.0" description="[degrees] the angle of the slope for the approach"/>
      <define name="DISTANCE" value="60.0" description="[m] the initial distance to start the approach"/>
      <define name="SPEED" value="-1.0" description="[m/s] the approach speed along the slope"/>
 
      <define name="ERR_SLOWDOWN_GAIN" value="0.25" description="slowing down when arriving"/>
      <define name="POS_GAIN" value="-1.0" description="P-gain"/>
      <define name="SPEED_GAIN" value="-1.0" description="D-gain"/>
      <define name="RELVEL_GAIN" value="-1.0" description="RelVel-gain"/>
    </section>
  </doc>
  <settings>
    <dl_settings>
      <dl_settings NAME="Approach">
        <dl_setting var="amt.psi_ref" min="-180." max="180." step="1.0" shortname="psi_app" unit="degrees"/>
        <dl_setting var="amt.slope_ref" min="0." max="80." step="1.0" shortname="slope_app" unit="degrees" param="APPROACH_MOVING_TARGET_SLOPE"/>
        <dl_setting var="amt.speed" min="-5.0" max="5." step="0.1" shortname="speed" unit="m/s" param="APPROACH_MOVING_TARGET_SPEED" />
        <dl_setting var="amt.distance" min="0.0" max="200." step="1.0" shortname="dist" unit="m" param="APPROACH_MOVING_TARGET_DISTANCE"/>
        <dl_setting var="amt.err_slowdown_gain" min="0.0" max="4." step="0.01" shortname="slwdn_gain" param="APPROACH_MOVING_TARGET_ERR_SLOWDOWN_GAIN"/>
        <dl_setting var="amt.pos_gain" min="0.05" max="3.0" step="0.01" shortname="pos_gain" param="APPROACH_MOVING_TARGET_POS_GAIN"/>
        <dl_setting var="amt.speed_gain" min="0.0" max="1.0" step="0.01" shortname="speed_gain" param="APPROACH_MOVING_TARGET_SPEED_GAIN"/>
        <dl_setting var="amt.relvel_gain" min="0.0" max="1.0" step="0.01" shortname="relvel_gain" param="APPROACH_MOVING_TARGET_RELVEL_GAIN"/>
        <dl_setting var="amt.cutoff_freq_filters_hz" min="0.3" max="2.0" step="0.01" shortname="filter_freq" module="ctrl/approach_moving_target" handler="set_low_pass_freq" param="APPROACH_MOVING_TARGET_CUTOFF_FREQ_FILTERS_HZ"/>
      </dl_settings>
    </dl_settings>
  </settings>
  <dep>
    <depends>target_pos</depends>
  </dep>
  <header>
    <file name="approach_moving_target.h"/>
  </header>
  <init fun="approach_moving_target_init()"/>
  <periodic fun="follow_diagonal_approach()" freq="100.0"/>
  <makefile>
    <file name="approach_moving_target.c"/>
  </makefile>
</module>