#15 Reg: Set Altitude at each waypoint (in scripts/c3104.xml)

[KrishnaRao Veeramachaneni]

Hi,

may i know the paramter to set altitude of each waypoint in c3104.xml in scripts for C310 flight.

i felt "hydro/alt-agl-ft" parameter is correct for altitude set @ each waypoint.
eg:

<event name="Head to first waypoint">
<condition>position/h-agl-ft ge 800</condition>
<set name="ap/heading-setpoint-select" value="1">
<set name="ap/active-waypoint" value="1">
<set name="hydro/alt-agl-ft" value="5945">
</set></set></set></event>
<event name="Second waypoint">
<condition>position/h-agl-ft ge 1200</condition>
<set name="ap/heading-setpoint-select" value="1">
<set name="ap/active-waypoint" value="2">
<set name="hydro/alt-agl-ft" value="6945">
</set></set></set></event>

Kindly correct me if am wrong & thanks in advance.

Regards,
KrishnaRao Veeramachaneni.

[KrishnaRao Veeramachaneni]

We are eagerly waiting for answer of this question.. i appreciate helping hand to answer this issue.

[Jon S. Berndt]

There is no property names, "hydro/alt-agl-ft". In the script c3104.xml (as it is currently written in our JSBSim CVS repository) there is this line in the first event:

  <set name="ap/altitude_setpoint" action="FG_EXP" value="1000.0" tc="10.0"/>

This sets the altitude setpoint. You would need to reset this property when the new waypoint is set. I don't know what the "hydro" prefix is on some of the properties. I don't have that in my version of the script.

I hope this helps. Let me know if you need more help, or ask further questions on the mailing list.

[KrishnaRao Veeramachaneni]

I appreciate Berndt firstly for the quick response.

Here am working on waypoint navigation.

Departure airport : denvar
Arrival airport : eagles

Am using the c3104.xml (Script) file with below configuration

---

<runscript xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nonamespaceschemalocation="http://jsbsim.sf.net/JSBSimScript.xsd" name="C172-01A takeoff run">
</runscript>

<use aircraft="c172x" initialize="denver">
<run start="0.0" end="5400" dt="0.02"></run></use>

<event name="Start engine">
<description>
Start engine and set initial heading and waypoints, turn on heading-hold mode.
</description>
<condition>simulation/sim-time-sec ge 0.25</condition></event>

  <set name="fcs/mixture-cmd-norm[0]" value="1"/>
 <!-- <set name="fcs/mixture-cmd-norm[1]" value="1"/> -->
  <set name="fcs/advance-cmd-norm[0]" value="1.0"/>
 <!-- <set name="fcs/advance-cmd-norm[1]" value="1.0"/> -->
  <set name="fcs/advance-cmd-norm[0]" value="1.0"/>
 <!-- <set name="fcs/advance-cmd-norm[1]" value="1.0"/> -->

  <set name="fcs/throttle-cmd-norm" value="1.0" action="FG_RAMP" tc ="0.5"/>
<set name="propulsion/magneto_cmd" value="3"/>
  <set name="propulsion/starter_cmd" value="1"/>
  <set name="ap/altitude_setpoint" action="FG_RAMP" value="6352.0" tc="10.0"/>
  <set name="ap/attitude_hold" value="0"/>
  <set name="guidance/target_wp_latitude_rad" value="0.695906"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.823184"/>

  <set name="ap/heading_setpoint" value="90.0"/>
  <set name="ap/heading-setpoint-select" value="0"/>
  <set name="ap/heading_hold" value="1"/>
  <set name="ap/active-waypoint" value="0"/>
  <notify/>
</event>

<event name="Set altitude for 1,000 ft.">
  <condition>velocities/vc-fps ge 145.0</condition>
  <set name="ap/altitude_hold" value="1"/>
  <notify/>
</event>

<event name="Raise landing gear">
  <condition>position/h-agl-ft  ge  40</condition>
  <set name="gear/gear-cmd-norm" value="0"/>
  <notify/>
</event>

<event name="Head to first waypoint">
  <description>
    Set heading hold to selected waypoint (setpoint) instead of
    previously specified heading when altitude surpasses 800 feet.
  </description>
  <condition>position/h-agl-ft  ge  800</condition>
  <set name="ap/heading-setpoint-select" value="1"/>
  <set name="ap/active-waypoint" value="1"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
<property>position/h-sl-ft </property>
</notify>
</event>

<event name="Terminate">
<description>
When the aircraft arrives back at Ellington Field (fifth waypoint)
then terminate the simulation.
</description>
<condition>
guidance/wp-distance lt 100
ap/active-waypoint eq 10
</condition>
<set name="simulation/terminate" value="1">
<notify>
</notify></set></event>

<event name="Landing (Last) WayPoint (Eagles Airport)">
  <description>
    When aircraft approaches towards eagles airport
  </description>
  <condition>
    guidance/wp-distance lt 1000
    ap/active-waypoint eq 9
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.691898967"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.865835147"/>
  <set name="ap/altitude_setpoint" value="6540.0"/>
  <set name="ap/active-waypoint" value="10"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
<property>position/h-sl-ft </property>
  </notify>
</event>

<event name="Set Ninth waypoint">
  <description>
    Way point before the eagles airport
  </description>
  <condition>
    guidance/wp-distance lt 100
    ap/active-waypoint eq 8
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.692346662"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.862933537"/>
  <set name="ap/altitude_setpoint" value="6949.0"/>
  <set name="ap/active-waypoint" value="9"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
<property>position/h-sl-ft </property>
  </notify>
</event>

<event name="Set Eighth waypoint">
  <description>
    Eighth waypoint from the devar airport
  </description>
  <condition>
   guidance/wp-distance lt 12000
    ap/active-waypoint eq 7
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.692426656"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.862391757"/>
    <set name="ap/altitude_setpoint" value="7149.0"/>
  <set name="ap/active-waypoint" value="8"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
<property>position/h-sl-ft </property>
  </notify>
</event>

<event name="Set Seventh waypoint">
  <description>
    Seventh waypoint from the devar airport
  </description>
  <condition>
    guidance/wp-distance lt 100
    ap/active-waypoint eq 6
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.692670275"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.860742784"/>
  <set name="ap/altitude_setpoint" value="7549.0"/>
  <set name="ap/active-waypoint" value="7"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
<property>position/h-sl-ft </property>
  </notify>
</event>


<event name="Set Sixth waypoint">
  <description>
    Sixth Way Point from the devar airport
  </description>
  <condition>
    guidance/wp-distance lt 100
    ap/active-waypoint eq 5
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.692773904"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.860044653"/>
  <set name="ap/altitude_setpoint" value="7949.0"/>
  <set name="ap/active-waypoint" value="6"/>
  <notify>
    <property>guidance/wp-distance</property>
    <property>position/h-agl-ft </property>
    <property>position/h-sl-ft </property>
  </notify>
</event>

<event name="Set Fifth waypoint">
  <description>
    When the distance to the fourth waypoint (northeast end of Galveston
    Island) is less than 100 feet, then set the last waypoint
  </description>
  <condition>
    guidance/wp-distance lt 100
    ap/active-waypoint eq 4
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.694439"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.85935"/>
  <set name="ap/altitude_setpoint" value="8249.0"/>
  <set name="ap/active-waypoint" value="5"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
<property>position/h-sl-ft </property>
<property>guidance/wp-distance </property>
  </notify>
</event>

<event name="Set fourth waypoint">
  <description>
    When the distance to the third waypoint (southwest end of Galveston
    Island) is less than 800 feet, then set the fourth waypoint
    (northeast end of Galveston Island).
  </description>
  <condition>
    guidance/wp-distance lt 800
    ap/active-waypoint eq 3
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.698177"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.857772"/>
  <set name="ap/altitude_setpoint" value="8349.0"/>
  <set name="ap/active-waypoint" value="4"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
<property>position/h-sl-ft </property>
  </notify>
</event>

<event name="Set third waypoint">
  <description>
    When the distance to the second waypoint (Hobby Airport) is less than
    500 feet, then set the third waypoint.
  </description>
  <condition>
    guidance/wp-distance lt 500
    ap/active-waypoint eq 2
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.721481"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.845178"/>
 <set name="ap/altitude_setpoint" value="9249.0"/>
  <set name="ap/active-waypoint" value="3"/>
  <notify>
    <property>guidance/wp-distance</property>
 <property>position/h-agl-ft </property>
 <property>position/h-sl-ft</property>
  </notify>
</event>

<event name="Set second waypoint">
  <description>
    When the distance to the first waypoint is less than
    700 feet, then set the second waypoint.
  </description>
  <condition>
    guidance/wp-distance lt 700
    ap/active-waypoint eq 1
  </condition>
  <set name="guidance/target_wp_latitude_rad" value="0.711482"/>
  <set name="guidance/target_wp_longitude_rad" value="-1.833783"/>
  <set name="ap/altitude_setpoint" value="1500.0"/>
  <set name="ap/altitude_hold" value="0"/>

  <set name="ap/active-waypoint" value="2"/>
  <notify>
    <property>guidance/wp-distance</property>
<property>position/h-agl-ft </property>
  <property>position/h-sl-ft</property>
  </notify>

</event>

---

Here issue is after second way-point, am unable to reach the third way point (using altitude of 9249 ft).

Reason: Tail Skid is happening & flight is crashing.

Can you help me out, to solve this problem.

Thanks in advance.

Regards,
KrishnaRao Veeramachaneni.

[Bertrand Coconnier]

Ticket moved from /p/jsbsim/bugs/104/