Geometry

environment-dev.yml

@@ -10,3 +10,4 @@ dependencies:
   - pre-commit
   - cosapp
   - numpy
+  - cosapp_fmu

requirements.txt

@@ -18,3 +18,4 @@ flake8
 isort
 black
 pre-commit
+cosapp_fmu @ git+https://github.com/twiinIT/cosapp-fmu.git@master

rocket_twin/drivers/mission.py

@@ -44,7 +44,7 @@ def __init__(
         init_fuel = init
         init_flight = {
             "rocket.flying": True,
-            "rocket.engine.force_command": 1.0,
+            "rocket.force_command": 1.0,
             "rocket.tank.w_out_max": 3.0,
             "g_tank.w_in": 0.0,
             "g_tank.w_command": 0.0,

rocket_twin/systems/__init__.py

@@ -1,9 +1,11 @@
+from rocket_twin.systems.control import Clock
 from rocket_twin.systems.engine import Engine
 from rocket_twin.systems.ground import Ground
 from rocket_twin.systems.physics import Dynamics
 from rocket_twin.systems.tank import Pipe, Tank
+from rocket_twin.systems.structure import Nose, Tube, Wings
 
 from rocket_twin.systems.rocket import Rocket  # isort: skip
 from rocket_twin.systems.station import Station  # isort: skip
 
-__all__ = ["Engine", "Tank", "Rocket", "Pipe", "Dynamics", "Station", "Ground"]
+__all__ = ["Clock", "Engine", "Tank", "Rocket", "Pipe", "Dynamics", "Station", "Ground", "Nose", "Tube", "Wings"]

rocket_twin/systems/control/__init__.py

@@ -0,0 +1,3 @@
+from rocket_twin.systems.control.clock import Clock
+
+__all__ = ["Clock"]

rocket_twin/systems/control/clock.py

@@ -0,0 +1,24 @@
+from cosapp.base import System
+
+
+class Clock(System):
+    """A system that measures the elapsed time.
+
+    Inputs
+    ------
+
+    Outputs
+    ------
+    time_var: float,
+        the time since the beginning of the simulation
+    """
+
+    def setup(self):
+
+        # Transient to ensure the system is visited in every time step
+        self.add_transient("x", der="1")
+        self.add_outward("time_var", 0.0, desc="Command time")
+
+    def compute(self):
+
+        self.time_var = self.time

rocket_twin/systems/engine/engine.py

@@ -7,7 +7,9 @@ class Engine(System):
     Inputs
     ------
     force_command: float,
-        External control, which inputs the % of the maximum force the engine outputs
+        external control, which inputs the % of the maximum force the engine outputs
+    w_out [kg/s]: float,
+        rate of fuel consumption
 
     Outputs
     ------
@@ -21,15 +23,18 @@ class Engine(System):
 
     def setup(self):
 
-        self.add_inward("force_max", 100.0, desc="Maximum engine force", unit="N")
+        #self.add_inward("force_max", 100.0, desc="Maximum engine force", unit="N")
         self.add_inward(
             "force_command", 1.0, desc="Ratio of command force to maximum force", unit=""
         )
+        self.add_inward("isp", 100., desc="Specific impulsion in vacuum", unit='s')
+        self.add_inward("w_out", 0., desc="Fuel consumption rate", unit='kg/s')
+        self.add_inward("g_0", 9.80665, desc="Gravity at Earth's surface", unit='m/s**2')
 
         self.add_outward("weight", 1.0, desc="weight", unit="kg")
         self.add_outward("cg", 1.0, desc="Center of Gravity", unit="m")
         self.add_outward("force", 1.0, desc="Thrust force", unit="N")
 
     def compute(self):
 
-        self.force = self.force_max * self.force_command
+        self.force = self.isp * self.g_0 * self.w_out * self.force_command

rocket_twin/systems/rocket/rocket.py

@@ -1,6 +1,6 @@
 from cosapp.base import System
 
-from rocket_twin.systems import Dynamics, Engine, Tank
+from rocket_twin.systems import Dynamics, Engine, Tank, Nose, Tube, Wings
 
 
 class Rocket(System):
@@ -16,24 +16,31 @@ class Rocket(System):
     """
 
     def setup(self):
-        self.add_child(Engine("engine"))
-        self.add_child(Tank("tank"), pulling=["w_in"])
+        self.add_child(Nose('nose'))
+        self.add_child(Tube('tube'))
+        self.add_child(Wings('wings'))
+        self.add_child(Engine("engine"), pulling=["force_command"])
+        self.add_child(Tank("tank"), pulling=["w_in", "w_command"])
         self.add_child(
             Dynamics(
                 "dyn",
                 forces=["thrust"],
-                weights=["weight_eng", "weight_tank"],
-                centers=["engine", "tank"],
+                weights=["weight_eng", "weight_tank", "weight_nose", "weight_tube", "weight_wings"],
+                centers=["engine", "tank", "nose", "tube", "engine"],
             ),
             pulling=["a"],
         )
 
+        self.connect(self.tank.outwards, self.engine.inwards, ['w_out'])
         self.connect(
             self.engine.outwards,
             self.dyn.inwards,
             {"force": "thrust", "weight": "weight_eng", "cg": "engine"},
         )
         self.connect(self.tank.outwards, self.dyn.inwards, {"weight": "weight_tank", "cg": "tank"})
+        self.connect(self.nose.outwards, self.dyn.inwards, {'weight' : 'weight_nose', 'cg' : 'nose'})
+        self.connect(self.tube.outwards, self.dyn.inwards, {'weight' : 'weight_tube', 'cg' : 'tube'})
+        self.connect(self.wings.outwards, self.dyn.inwards, {'weight' : 'weight_wings', 'cg' : 'wings'})
 
         self.add_inward("flying", False, desc="Whether the rocket is flying or not", unit="")
 

rocket_twin/systems/station/station.py

@@ -1,24 +1,40 @@
 from cosapp.base import System
+from cosapp_fmu.FMUsystem import FMUSystem
 
-from rocket_twin.systems import Pipe, Rocket, Tank
+from rocket_twin.systems import Clock, Pipe, Rocket, Tank
 
 
 class Station(System):
     """A space station composed by a rocket, a tank and a pipe connecting them.
 
     Inputs
     ------
+    fmu_path: string,
+        the path to the .fmu file, if there is any
 
     Outputs
     ------
     """
 
-    def setup(self):
+    def setup(self, fmu_path=None):
         self.add_child(Tank("g_tank"))
         self.add_child(Pipe("pipe"))
         self.add_child(Rocket("rocket"))
 
         self.connect(self.g_tank.outwards, self.pipe.inwards, {"w_out": "w_in"})
         self.connect(self.pipe.outwards, self.rocket.inwards, {"w_out": "w_in"})
 
+        if fmu_path is not None:
+            self.add_child(Clock("clock"))
+            self.add_child(FMUSystem("controller", fmu_path=fmu_path))
+            self.connect(self.clock.outwards, self.controller.inwards, {"time_var": "ti"})
+            self.connect(self.controller.outwards, self.g_tank.inwards, {"wg": "w_command"})
+            self.connect(
+                self.controller.outwards,
+                self.rocket.inwards,
+                {"wr": "w_command", "f": "force_command"},
+            )
+
+            self.exec_order = ["clock", "controller", "g_tank", "pipe", "rocket"]
+
         self.g_tank.weight_max = 10.0

rocket_twin/systems/structure/__init__.py

@@ -0,0 +1,5 @@
+from rocket_twin.systems.structure.nose import Nose
+from rocket_twin.systems.structure.tube import Tube
+from rocket_twin.systems.structure.wings import Wings
+
+__all__ = ['Nose', 'Tube', 'Wings']

rocket_twin/systems/structure/nose.py

@@ -0,0 +1,20 @@
+from cosapp.base import System
+
+class Nose(System):
+    """Model of a rocket nose.
+
+    Inputs
+    ------
+
+    Outputs
+    ------
+    weight [kg]: float,
+        nose weight
+    cg [m]: float,
+        nose center of gravity
+    """
+
+    def setup(self):
+
+        self.add_outward('weight', 0., desc="Weight", unit='kg')
+        self.add_outward('cg', 0., desc="Center of gravity", unit='m')

rocket_twin/systems/structure/tube.py

@@ -0,0 +1,20 @@
+from cosapp.base import System
+
+class Tube(System):
+    """Model of a rocket tube.
+
+    Inputs
+    ------
+
+    Outputs
+    ------
+    weight [kg]: float,
+        tube weight
+    cg [m]: float,
+        tube center of gravity
+    """
+
+    def setup(self):
+
+        self.add_outward('weight', 0., desc="Weight", unit='kg')
+        self.add_outward('cg', 0., desc="Center of gravity", unit='m')

rocket_twin/systems/structure/wings.py

@@ -0,0 +1,20 @@
+from cosapp.base import System
+
+class Wings(System):
+    """Model of the wings of a rocket.
+
+    Inputs
+    ------
+
+    Outputs
+    ------
+    weight [kg]: float,
+        wings weight
+    cg [m]: float,
+        wings center of gravity
+    """
+
+    def setup(self):
+
+        self.add_outward('weight', 0., desc="Weight", unit='kg')
+        self.add_outward('cg', 0., desc="Center of gravity", unit='m')

rocket_twin/tests/test_command.py

@@ -0,0 +1,14 @@
+import numpy as np
+from cosapp.drivers import RungeKutta
+
+from rocket_twin.systems import Clock
+
+
+class TestClock:
+    def test_time(self):
+
+        sys = Clock("sys")
+        sys.add_driver(RungeKutta(order=4, time_interval=[0, 15], dt=1.0))
+        sys.run_drivers()
+
+        np.testing.assert_allclose(sys.time_var, 15.0, atol=10 ** (-4))

rocket_twin/tests/test_flying_rocket.py

@@ -14,7 +14,7 @@ def test_run_once(self):
 
         init = {
             "rocket.flying": True,
-            "rocket.engine.force_command": 1.0,
+            "rocket.force_command": 1.0,
             "rocket.tank.weight_p": "rocket.tank.weight_max",
             "rocket.tank.w_out_max": 3.0,
             "g_tank.w_in": 0.0,

rocket_twin/tests/test_mission.py

@@ -13,7 +13,7 @@ def test_run_once(self):
 
         init = {
             "g_tank.weight_p": "g_tank.weight_max",
-            "rocket.engine.force_command": 0.0,
+            "rocket.force_command": 0.0,
             "rocket.tank.weight_p": 0.0,
             "rocket.tank.w_out_max": 0.0,
             "g_tank.w_command": 1.0,
@@ -37,3 +37,7 @@ def test_run_once(self):
         np.testing.assert_allclose(sys.rocket.a, 40.0, atol=10 ** (-10))
         np.testing.assert_allclose(sys.rocket.tank.weight_p, 0.0, atol=10 ** (-10))
         np.testing.assert_allclose(sys.g_tank.weight_p, 5.0, atol=10 ** (-10))
+
+
+tm = TestMission()
+tm.test_run_once()

rocket_twin/tests/test_refuel_rocket.py

@@ -12,9 +12,9 @@ def test_run_once(self):
         dt = 0.1
 
         init = {
-            "rocket.engine.force_command": 0.0,
             "rocket.tank.weight_p": 0.0,
             "rocket.tank.w_out_max": 0.0,
+            "rocket.force_command": 0.0,
             "g_tank.w_command": 1.0,
             "g_tank.weight_p": "g_tank.weight_max",
             "g_tank.w_in": 0.0,

rocket_twin/tests/test_sequences_fmu.py

@@ -0,0 +1,28 @@
+import numpy as np
+from cosapp.drivers import RungeKutta
+from cosapp.recorders import DataFrameRecorder
+
+from rocket_twin.systems import Station
+
+
+class TestSequencesFMU:
+    def test_sequence_fmu(self):
+
+        sys = Station("sys", fmu_path="rocket_twin/systems/control/controller.fmu")
+        driver = sys.add_driver(RungeKutta(order=4, time_interval=[0, 15], dt=0.01))
+        init = {"g_tank.weight_p": 10.0, "rocket.tank.weight_p": 0.0}
+        values = {
+            "g_tank.w_out_max": 1.0,
+            "rocket.tank.w_out_max": 0.5,
+            "rocket.engine.force_max": 100.0,
+        }
+        driver.set_scenario(init=init, values=values)
+        driver.add_recorder(DataFrameRecorder(includes=["rocket.dyn.a"]), period=1.0)
+        sys.run_drivers()
+
+        data = driver.recorder.export_data()
+        print(data)
+
+        np.testing.assert_allclose(sys.rocket.dyn.a, 40.0, atol=10 ** (-1))
+        np.testing.assert_allclose(sys.g_tank.weight_p, 5.0, atol=10 ** (-2))
+        np.testing.assert_allclose(sys.rocket.tank.weight_p, 0.0, atol=10 ** (-2))