Tentative testing complete

src/boat_simulator/boat_simulator/common/constants.py

@@ -37,21 +37,21 @@ class PhysicsEnginePublisherTopics:
 
 @dataclass
 class BoatProperties:
-    # A lookup table that maps angles of attack (in degrees) to their corresponding lift
+    # A lookup array that maps angles of attack (in degrees) to their corresponding lift
     # coefficients.
     sail_lift_coeffs: NDArray
-    # A lookup table that maps angles of attack (in degrees) to their corresponding drag
+    # A lookup array that maps angles of attack (in degrees) to their corresponding drag
     # coefficients.
     sail_drag_coeffs: NDArray
-    # A lookup table that maps angles of attack (in degrees) to their corresponding sail areas
-    # (in square meters).
+    # The area of sail (in square meters).
     sail_areas: Scalar
-    # A lookup table that maps angles of attack (in degrees) to their corresponding drag
+    # A lookup array that maps angles of attack (in degrees) to their corresponding lift
+    # coefficients for the rudder.
+    rudder_lift_coeffs: NDArray
+    # A lookup array that maps angles of attack (in degrees) to their corresponding drag
     # coefficients for the rudder.
-    rudder_lift_coeffs: NDArray  
     rudder_drag_coeffs: NDArray
-    # A lookup table that maps angles of attack (in degrees) to their corresponding rudder areas
-    # (in square meters).
+    # The area of rudder (in square meters).
     rudder_areas: Scalar
     # A scalar representing the distance from the center of effort of the sail to the pivot point
     # (in meters).
@@ -66,10 +66,15 @@ class BoatProperties:
     mass: Scalar
     # The inertia of the boat (in kilograms-meters squared).
     inertia: NDArray
-    air_density: Scalar  # Kilograms per meter cubed (kg/m^3)
-    water_density: Scalar  # Kilograms per meter cubed (kg/m^3)
-    centre_of_gravity: NDArray  # Meters (m)
-    mast_position: NDArray  # Meters (m)
+    # The density of air (in kilograms per meter cubed).
+    air_density: Scalar
+    # The density of water (in kilograms per meter cubed).
+    water_density: Scalar
+    # The center of gravity of the boat ((3, ) array in meters).
+    # (0, 0) at bottom right corner
+    centre_of_gravity: NDArray
+    # The mast position ((3, ) array in meters).
+    mast_position: NDArray
 
 
 # Directly accessible constants

src/boat_simulator/boat_simulator/nodes/physics_engine/model.py

@@ -5,7 +5,6 @@
 import numpy as np
 from numpy.typing import NDArray
 
-from boat_simulator.common.constants import BOAT_PROPERTIES
 from boat_simulator.common.constants import BOAT_PROPERTIES
 from boat_simulator.common.types import Scalar
 from boat_simulator.nodes.physics_engine.fluid_forces import MediumForceComputation
@@ -103,23 +102,24 @@ def __compute_net_force_and_torque(
                 the relative reference frame, expressed in newtons (N), and the second element
                 represents the net torque, expressed in newton-meters (N•m).
         """
-        # Compute apparent wind and water velocities as ND arrays
-        apparent_wind_vel = np.subtract(rel_wind_vel, self.relative_velocity)
-        apparent_water_vel = np.subtract(rel_water_vel, self.relative_velocity)
+        # Compute apparent wind and water velocities as ND arrays (2-D)
+        apparent_wind_vel = np.subtract(rel_wind_vel, self.relative_velocity[0:2])
+        apparent_water_vel = np.subtract(rel_water_vel, self.relative_velocity[0:2])
 
-        wind_angle = np.arctan2(rel_wind_vel[1], rel_wind_vel[0])  # Wind angle in radians
+        # angle references all in radians
+        wind_angle = np.arctan2(rel_wind_vel[1], rel_wind_vel[0])
         trim_tab_angle_rad = np.radians(trim_tab_angle)
-        main_sail_angle = wind_angle - trim_tab_angle_rad  # in radians
+        main_sail_angle = wind_angle - trim_tab_angle_rad
         rudder_angle_rad = np.radians(rudder_angle_deg)
 
         # Calculate Forces on sail and rudder
-        sail_force = self.__sail_force_computation.compute(apparent_wind_vel, trim_tab_angle)
+        sail_force = self.__sail_force_computation.compute(apparent_wind_vel[0:2], trim_tab_angle)
         rudder_force = self.__rudder_force_computation.compute(
-            apparent_water_vel, rudder_angle_deg
+            apparent_water_vel[0:2], rudder_angle_deg
         )
 
         # Calculate Hull Drag Force
-        hull_drag_force = self.relative_velocity * BOAT_PROPERTIES.hull_drag_factor
+        hull_drag_force = self.relative_velocity[0:2] * BOAT_PROPERTIES.hull_drag_factor
 
         # Total Force Calculation
         total_drag_force = sail_force[1] + rudder_force[1] + hull_drag_force
@@ -152,14 +152,15 @@ def __compute_net_force_and_torque(
             + BOAT_PROPERTIES.centre_of_gravity[1]
         )
 
+        # adding total rudder torque
         rudder_torque = np.add(
             rudder_lift * rudder_lift_constant,
             rudder_drag * rudder_drag_constant,
         )
 
         total_torque = np.add(sail_torque, rudder_torque)  # Sum torques about z-axis
 
-        final_torque = np.array([0, 0, total_torque])
+        final_torque = np.array([0, 0, total_torque])  # generate 3-D array(only z component)
 
         return (total_force, final_torque)
 

src/boat_simulator/tests/unit/nodes/physics_engine/test_model.py

@@ -8,42 +8,48 @@
 
 
 @pytest.mark.parametrize(
-    "rel_wind_vel, rel_water_vel, rudder_angle_deg, trim_tab_angle",
+    "rel_wind_vel, rel_water_vel, rudder_angle_deg, trim_tab_angle, timestep",
     [
-        (np.array([1, 2, 3]), np.array([1, 2, 3]), 45, 45),
-        (np.array([1, 2, 3]), np.array([1, 2, 3]), 45, 45),
-        (np.array([4, 5, 6]), np.array([7, 8, 9]), 30, 60),
-        (np.array([10, 20, 30]), np.array([15, 25, 35]), 90, 120),
-        (np.array([0, 0, 0]), np.array([1, 1, 1]), 0, 90),
-        (np.array([-1, -2, -3]), np.array([-1, -2, -3]), 180, 270),
-        (np.array([3.5, 4.5, 5.5]), np.array([1.5, 2.5, 3.5]), 15, 75),
-        (np.array([100, 200, 300]), np.array([300, 200, 100]), 0, 45),
+        (np.array([1, 2]), np.array([1, 2]), 45, 45, 1),
+        (np.array([1, 2]), np.array([1, 2]), 45, 45, 1),
+        (np.array([4, 5]), np.array([7, 8]), 30, 60, 2),
+        (np.array([10, 20]), np.array([15, 25]), 90, 120, 1),
+        (np.array([0, 1]), np.array([1, 1]), 0, 90, 3),
+        (np.array([-1, -2]), np.array([-1, -2]), 180, 270, 2),
+        (np.array([3.5, 4.5]), np.array([1.5, 2.5]), 15, 75, 4),
+        (np.array([100, 200]), np.array([300, 200]), 0, 45, 2),
+        # cannot use 0 vector, or will cause divison by zero error
     ],
 )
 def test_compute_net_force_torque(
     rel_wind_vel,
     rel_water_vel,
     rudder_angle_deg,
     trim_tab_angle,
+    timestep,
 ):
 
-    current_state = BoatState(1.0)
-    net_force = current_state.step(rel_wind_vel, rel_water_vel, rudder_angle_deg, trim_tab_angle)
+    current_state = BoatState(timestep)
+    net_force = current_state._BoatState__compute_net_force_and_torque(
+        rel_wind_vel, rel_water_vel, rudder_angle_deg, trim_tab_angle
+    )
 
-    app_wind_vel = np.subtract(rel_wind_vel, current_state.relative_velocity)
-    app_water_vel = np.subtract(rel_water_vel, current_state.relative_velocity)
+    app_wind_vel = np.subtract(rel_wind_vel, current_state.relative_velocity[0:2])
+    app_water_vel = np.subtract(rel_water_vel, current_state.relative_velocity[0:2])
 
     wind_angle = np.arctan2(app_wind_vel[1], app_wind_vel[0])
     trim_tab_angle_rad = np.radians(trim_tab_angle)
     main_sail_angle = wind_angle - trim_tab_angle_rad
     rudder_angle_rad = np.radians(rudder_angle_deg)
 
-    test_sail_force = current_state.__sail_force_computation.compute(app_wind_vel, trim_tab_angle)
-    test_rudder_force = current_state.__rudder_force_computation.compute(
+    test_sail_force = current_state._BoatState__sail_force_computation.compute(
+        app_wind_vel, trim_tab_angle
+    )
+    test_rudder_force = current_state._BoatState__rudder_force_computation.compute(
         app_water_vel, rudder_angle_deg
     )
 
-    hull_drag_force = current_state.relative_velocity * BOAT_PROPERTIES.hull_drag_factor
+    hull_drag_force = current_state.relative_velocity[0:2] * BOAT_PROPERTIES.hull_drag_factor
 
     total_drag_force = test_sail_force[1] + test_rudder_force[1] + hull_drag_force
     total_force = test_sail_force[0] + test_rudder_force[0] + total_drag_force
@@ -77,4 +83,5 @@ def test_compute_net_force_torque(
 
     final_torque = np.array([0, 0, total_torque])
 
-    assert np.equal(net_force, (total_force, final_torque))
+    assert np.allclose(total_force, net_force[0], 0.5)  # checking force
+    assert np.allclose(final_torque, net_force[1], 0.5)  # checking torque