Based on the dew point temperature supplied by FG, JSBSim updates the atmosphere density and computes all the usual parameters (RH, vapor pressure, saturated vapor pressure, etc.)
The mass fraction of water per unit of air mass is capped according to the record high from ISA 1976 standard atmosphere. As a consequence, at very high altitudes, air is always extremely dry (approx. 30 ppm i.e. 30 parts per million) whatever the conditions at sea level.
JSBSim was not checking the tag names inside <test> and <condition> statements and this has led to abusive use of tags unsupported by JSBSim such as <and> and <or>. The problem is that JSBSim was not interpreting the <or> statement as the user meant it: JSBSim interpreted it as <test logic="AND"> while the user obviously meant <test logic="OR">. As a result JSBSim silently swallowed the tag and gave results which were not was the user expected without any obvious indication about what was going wrong.
As a result, this commit implements stricter syntax checking and rejects illegal tags within <test> and <condition> statements.
This commit also introduces stricter checking on XML elements which allow either a real value or a property name to be used. JSBSim now rejects the statements where the property name is specified inside a <property> statement. For example, the follwoing statement is rejected:
<clipto>
<min> <property> /fdm/jsbsim/some/property </property> </min>
...
The correct syntax being
<clipto>
<min> /fdm/jsbsim/some/property </min>
- Fixed the scripts end time computation
- Fixed nested tests in switches
- Simplifications to the computation of the aerodynamics angles alpha & beta
- Account for the contact transition in the gear compression speed
- Fixed docs in FGTank
- New system component linear_actuator from Adriano Bassignana.
- Bug fix of Euler angles computations in FGMatrix33 (a pure westward heading of 270 deg was erroneously converted to a pure eastward heading of 90 deg). This could make the aircraft trimming fail when spawning with a heading of 270 deg.
Properties /consumable/fuel/tank[*]/unusable-* supplied in the -set.xml file are propagated to the aircraft model and accounted for in the tanks management.
* <function> and <fcs_function> that are only applied on constant parameters are now recognized and replaced by their result during initialization.
* Fixed a regression which prevented the wheels rotation speed to slow down while the gears were retracted.
* Added the ability to control the turbine engines spin down factor (thanks to Jonathan Redpath for the pull request).
* Internals : JSBSim has been refactored to use FGPropertyValue in many FCS components. This will allow consistent behavior accross the FCS components including the ability to prepend property names with minus signs '-' to indicate that the opposite sign of the property should be used.
The feature fail_hardover of the <actuator> component was not giving the correct output in some occurences when clipmax was smaller in absolute value than clipmin.
Tables CORNERING_COEFF could not be used for BOGEY contact points.
No longer throw an exception when the `internal` keyword of a table is ignored.
The location where errors have been found are now reported.
The following new features have been added to JSBSim:
* Added the ability to set up the starter and acceleration times of a turbine (parameters <n1spinup>, <n2spinup>, <n1startrate>, <n2startrate>).
* The <integrator> filter can now be reset to 0.0 by setting its <trigger> property to a negative value.
* The integration scheme of the <integrator> filter can now be chosen among "rect" (Euler), "trap" (Trapezoidal), "ab2" 2nd order Adams-BashForth and "ab3" 3rd order Adams-Bashforth
* The following functions can now be used in <function>: floor, ceil and fmod. Their functionalities are the same than the corresponding C/C++ functions.
The following bugs are fixed by this commit:
* PID integration with the 3rd order Adams-Bashforth was inccorect.
* The fail_stuck property of sensors (accelerometers, magnetometers, gyro, etc.) without a <lag> element was setting the output to zero instead of sticking to the last output value. Thanks to Jonathan Redpath (aka legoboyvdlp) for the bug report.
* When a sensor was stuck, the drift, gain, bias and quantization of the last output before being stuck were ignored. Thanks to Dennis J. Linse for the bug report.
* Disables dew point transmission as the humidity model is not handling the case where the vapor saturation pressure gets higher than the ambient pressure.
* Removed computations for temperatures at very high altitudes as they don't match with the rest of JSBSim atmosphere model.
- Fixed the Calibrated Air Speed (CAS) computations for supersonic velocities
- Fixed the Nlf (Normal load factor) sign
- Nlf can now be specified as an initial condition via the property ic/targetNlf
- Added blocking sockets to the input features
- Added a property to piston engines to get the AFR (Air to Fuel Ratio)
- Added conversion from m/s to ft/s
- Restored the initial conditions for engines running (-1 means all engines)
- Trim reports, FGOutputFG and sockets messages now respond to the debug level
- Channels : fix for incorrect time steps caused by execrate
- Improved configuration error detection in FGSwitch with respect to late bound
- Fixed the ordre in which the components of the p-factor moment are reported in CSV output files.
- Now all the sea level properties from the standard atmosphere are updated along with the other atmosphere properties.
- The properties propulsion/start_cmd and propulsion/cutoff_cmd are now read/write (they were read only before).
Mickael Danilov reported that one cannot send brake commands to /fdm/jsbsim/fcs/{right,left}-brake-cmd-norm since FG overwrites them with /autopilot/autobrake/* properties.
A new property /fdm/jsbsim/systems/override-fg-brake-properties has been added which is set ot false by default to keep the legacy behavior. When set to true, the properties /fdm/jsbsim/fcs/{right,left}-brake-cmd-norm can be modified by the user and will ignore the setting from FlightGear.
- Air density now takes humidity into account.
- The protocol of input sockets is no longer case sensitive
- Late bounded properties are now cached for better performance.
* Removed the IAS dependency to the Pitot tube angle (real Pitot tube are less sensitive to AoA than was simulated)
* Removed the class FGUDPOutputSocket which was redundant with FGOutputSocket
* Added a new type of functions "template" which are intended to prevent duplication of functions. For now, they are available to compute output values and script notifications.
* Aerodynamics forces can now be specified in stability axes.
* Density altitude and pressure altitude are computed according to ISA standard atmosphere 1976.
New properties:
* Flight path angle (gamma) in degrees
- fdm/jsbsim/flight-path/gamma-deg
* Aerodynamics forces in stability axes
- fdm/jsbsim/forces/fsx-aero-lbs
- fdm/jsbsim/forces/fsy-aero-lbs
- fdm/jsbsim/forces/fsz-aero-lbs
* Aerodynamics moments in stability axes
- moments/roll-stab-aero-lbsft
- moments/pitch-stab-aero-lbsft
- moments/yaw-stab-aero-lbsft
* Pause JSBSim
- fdm/jsbsim/simulation/pause
* Fixed multiple bugs.
It is the call to exit that causes FG to lock up and become a zombie.
Alternative is to throw an exception, i.e.:
throw sg_error(std::string("YASim SOLUTION FAILURE:") + a->getFailureMsg(););
These files were originally included for special trim routines. But these routines are no longer maintained in JSBSim and have already been partially removed from FlightGear.
Change the arrestor wire handling as follows;
- expose property to indicate when arrestor wire has been snagged: /fdm/jsbsim/systems/hook/arrestor-wire-engaged-hook
- add property to allow the model to request that the wire is released: /fdm/jsbsim/systems/hook/tailhook-release-cmd. This permits an overspeed approach to catch the wire and then drop it.
refactoring of FGFDM parser
replace old helpers with lib functions from <cstring>
remove typecast that kills 'const'
add some comments and clarify variable names
Rewrite the position-init code for carrier starts, to precisely wait
on the carrier model being loaded, before proceeding with FDM init.
This allows the FDM to see the correct carrier model in the ground
cache, and hence avoids starting in the water.
To implement this, the CheckSceneryVisitor is used to force the carrier
model to be loaded while the splash-screen is visible.
In some testing, JSBsim sometimes passed extremely large values into
this function (larger than the radius of the earth). This causes
every tile on the planet to be scheduled if using the standard STG
terrain, effectively blocking startup.
This code allows us a chance to catch this case via logging, but does
not fix the underlying issues.
The wake induced force and moment are computed as an external reaction to the JSBSim model. For these force and moment to be accounted for by JSBSim, the following external reaction needs to be added to FDM XML definition:
<external reaction>
<force name="ai-wake">
...
</force>
<moment name="ai-wake">
...
</moment>
</external reaction>
This is similar to how the hook and wire feature is modeled in JSBSim.
Wake computations are now performed for all AI aircrafts within a range lower or equal to the value indicated by the property /fdm/ai-wake/max-radius-nm.
These computations are triggered by the property /fdm/ai-wake/enabled (it is disabled by default).
The result of the wake computations is not yet used by the FDMs so do not expect the user aircraft to react to the AI wake.
AI wake code is still dead code except that it is now compiled with FG.
Input data for wake computations are extracted from the performance database. The data must be specified as follows (values are for illustration only) :
<geometry>
<wing>
<span-ft> 100. </span-ft>
<chord-ft> 12. <chord-ft>
</wing>
<weight-lbs> 90000. </weight-lbs>
</geometry>
