Changeset 57:04d8f6a603ee

Timestamp:

04/03/12 18:00:24 (12 years ago)

Author:

István Váradi <ivaradi@…>

Branch:

default

Phase:

public

Message:

TAS is calculated.

File:

• src/mlx/pyuipc_sim.py (modified) (4 diffs)

src/mlx/pyuipc_sim.py

@@ -12 +12 @@
 import struct
 import cPickle
+import math
 
 #------------------------------------------------------------------------------
@@ -266 +267 @@
             # wind the GS
             return int(self.ias * 65536.0 * 1852.0 / 3600.0)
+        elif offset==0x02b8:       # TAS
+            return int(self._getTAS() * 128.0)
         elif offset==0x02bc:       # IAS
             return int(self.ias * 128.0)
@@ -617 +620 @@
         self.fuelCapacities[index] = value * self.fuelWeight * const.LBSTOKG
 
+    def _getTAS(self):
+        """Calculate the true airspeed."""
+        pressure = 101325 * math.pow(1 - 2.25577e-5 * self.altitude *
+                                      const.FEETTOMETRES,
+                                      5.25588)
+        temperature = 15 - self.altitude * 6.5 * const.FEETTOMETRES / 1000.0 
+        temperature += 273.15  # Celsius -> Kelvin
+        airDensity = pressure / (temperature * 287.05)
+        print "pressure:", pressure, "temperature:", temperature, "airDensity:", airDensity
+        return self.ias * math.sqrt(1.225 / airDensity)
 
 #------------------------------------------------------------------------------
@@ -866 +879 @@
                                      lambda word: int(float(word) * 65536.0 *
                                                       1852.0 / 3600))
+        self._valueHandlers["tas"] = (0x02b8, "d",
+                                     lambda value: value / 128.0,
+                                     lambda word: None)
         self._valueHandlers["vs"] = (0x02c8, "d",
                                      lambda value: value * 60 /