feat: flexible engines mounting (#7676)

src/systems/a380_systems/src/lib.rs

@@ -28,6 +28,7 @@ use systems::{
         AuxiliaryPowerUnitFireOverheadPanel, AuxiliaryPowerUnitOverheadPanel,
     },
     electrical::{Electricity, ElectricitySource, ExternalPowerSource},
+    engine::engine_wing_flex::EnginesFlexiblePhysics,
     engine::{leap_engine::LeapEngine, EngineFireOverheadPanel},
     hydraulic::brake_circuit::AutobrakePanel,
     landing_gear::{LandingGear, LandingGearControlInterfaceUnitSet},
@@ -67,6 +68,7 @@ pub struct A380 {
     pressurization_overhead: PressurizationOverheadPanel,
     pneumatic: A380Pneumatic,
     radio_altimeters: A380RadioAltimeters,
+    engines_flex_physics: EnginesFlexiblePhysics<4>,
 }
 impl A380 {
     pub fn new(context: &mut InitContext) -> A380 {
@@ -108,6 +110,7 @@ impl A380 {
             pressurization_overhead: PressurizationOverheadPanel::new(context),
             pneumatic: A380Pneumatic::new(context),
             radio_altimeters: A380RadioAltimeters::new(context),
+            engines_flex_physics: EnginesFlexiblePhysics::new(context),
         }
     }
 }
@@ -218,6 +221,8 @@ impl Aircraft for A380 {
             &self.pressurization_overhead,
             [self.lgcius.lgciu1(), self.lgcius.lgciu2()],
         );
+
+        self.engines_flex_physics.update(context);
     }
 }
 impl SimulationElement for A380 {
@@ -249,6 +254,7 @@ impl SimulationElement for A380 {
         self.pressurization.accept(visitor);
         self.pressurization_overhead.accept(visitor);
         self.pneumatic.accept(visitor);
+        self.engines_flex_physics.accept(visitor);
 
         visitor.visit(self);
     }

src/systems/systems/src/engine/engine_wing_flex.rs

@@ -0,0 +1,282 @@
+use std::time::Duration;
+
+use crate::{
+    hydraulic::SpringPhysics,
+    shared::random_from_normal_distribution,
+    shared::update_iterator::MaxStepLoop,
+    simulation::{
+        InitContext, Read, SimulationElement, SimulationElementVisitor, SimulatorReader,
+        SimulatorWriter, UpdateContext, VariableIdentifier, Write,
+    },
+};
+
+use uom::si::{f64::*, mass::kilogram};
+
+use nalgebra::Vector3;
+use std::fmt::Debug;
+
+/// Solves a basic mass connected to a static point through a spring damper system
+/// Mass center of gravity position reacting to external accelerations is then used to model engine wobbling movement
+pub struct EngineFlexPhysics {
+    x_position_id: VariableIdentifier,
+
+    spring_const_id: VariableIdentifier,
+    damping_const_id: VariableIdentifier,
+    mass_id: VariableIdentifier,
+    output_gain_id: VariableIdentifier,
+    lateral_damping_id: VariableIdentifier,
+    vertical_damping_id: VariableIdentifier,
+    dev_mode_enable_id: VariableIdentifier,
+
+    reference_point_cg: Vector3<f64>,
+    cg_position: Vector3<f64>,
+    cg_speed: Vector3<f64>,
+
+    virtual_mass: Mass,
+    spring: SpringPhysics,
+    anisotropic_damping_constant: Vector3<f64>,
+
+    position_output_gain: f64,
+
+    animation_position: f64,
+}
+impl EngineFlexPhysics {
+    pub fn new(context: &mut InitContext, engine_number: usize) -> Self {
+        Self {
+            x_position_id: context
+                .get_identifier(format!("ENGINE_{}_WOBBLE_X_POSITION", engine_number)),
+            spring_const_id: context.get_identifier("ENGINE_WOBBLE_DEV_K_CONST".to_owned()),
+            damping_const_id: context.get_identifier("ENGINE_WOBBLE_DEV_DAMP_CONST".to_owned()),
+            mass_id: context.get_identifier("ENGINE_WOBBLE_DEV_MASS".to_owned()),
+            output_gain_id: context.get_identifier("ENGINE_WOBBLE_DEV_OUT_GAIN".to_owned()),
+            lateral_damping_id: context.get_identifier("ENGINE_WOBBLE_DEV_XDAMP".to_owned()),
+            vertical_damping_id: context.get_identifier("ENGINE_WOBBLE_DEV_YDAMP".to_owned()),
+            dev_mode_enable_id: context.get_identifier("ENGINE_WOBBLE_DEV_ENABLE".to_owned()),
+
+            reference_point_cg: Vector3::default(),
+            cg_position: Vector3::default(),
+            cg_speed: Vector3::default(),
+
+            virtual_mass: Mass::new::<kilogram>(random_from_normal_distribution(2000., 100.)),
+            spring: SpringPhysics::new(
+                random_from_normal_distribution(800000., 50000.),
+                random_from_normal_distribution(500., 20.),
+            ),
+            anisotropic_damping_constant: Vector3::new(
+                random_from_normal_distribution(500., 50.),
+                random_from_normal_distribution(500., 50.),
+                random_from_normal_distribution(500., 50.),
+            ),
+            position_output_gain: 90.,
+
+            animation_position: 0.5,
+        }
+    }
+
+    pub fn update(&mut self, context: &UpdateContext) {
+        self.update_speed_position(context);
+
+        self.update_animation_position();
+    }
+
+    fn update_forces(&mut self, context: &UpdateContext) -> Vector3<f64> {
+        let acceleration_force =
+            context.local_acceleration_without_gravity() * self.virtual_mass.get::<kilogram>();
+
+        let spring_force =
+            self.spring
+                .update_force(context, self.reference_point_cg, self.cg_position);
+
+        let viscosity_damping = -self
+            .cg_speed
+            .component_mul(&self.anisotropic_damping_constant);
+
+        acceleration_force + spring_force + viscosity_damping
+    }
+
+    fn update_speed_position(&mut self, context: &UpdateContext) {
+        let acceleration = self.update_forces(context) / self.virtual_mass.get::<kilogram>();
+
+        self.cg_speed += acceleration * context.delta_as_secs_f64();
+
+        self.cg_position += self.cg_speed * context.delta_as_secs_f64();
+    }
+
+    fn update_animation_position(&mut self) {
+        let limited_pos = (self.position_output_gain * (self.cg_position[0] + self.cg_position[1]))
+            .min(1.)
+            .max(-1.);
+
+        self.animation_position = (limited_pos + 1.) / 2.;
+    }
+}
+impl SimulationElement for EngineFlexPhysics {
+    fn read(&mut self, reader: &mut SimulatorReader) {
+        let activate_dev_mode: f64 = reader.read(&self.dev_mode_enable_id);
+
+        if activate_dev_mode > 0. {
+            self.spring.set_k_and_damping(
+                reader.read(&self.spring_const_id),
+                reader.read(&self.damping_const_id),
+            );
+            self.virtual_mass = reader.read(&self.mass_id);
+            self.position_output_gain = reader.read(&self.output_gain_id);
+            self.anisotropic_damping_constant[0] = reader.read(&self.lateral_damping_id);
+            self.anisotropic_damping_constant[1] = reader.read(&self.vertical_damping_id);
+
+            // Z dimension not really used we use same param as Y damping
+            self.anisotropic_damping_constant[2] = reader.read(&self.vertical_damping_id);
+        }
+    }
+
+    fn write(&self, writer: &mut SimulatorWriter) {
+        writer.write(&self.x_position_id, self.animation_position);
+    }
+}
+impl Debug for EngineFlexPhysics {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "\nEngine Flex=> CG [{:.2};{:.2};{:.2}]",
+            self.cg_position[0] * self.position_output_gain,
+            self.cg_position[1] * self.position_output_gain,
+            self.cg_position[2] * self.position_output_gain
+        )
+    }
+}
+
+pub struct EnginesFlexiblePhysics<const N: usize> {
+    engines_flex_updater: MaxStepLoop,
+    engines_flex: Vec<EngineFlexPhysics>,
+}
+impl<const N: usize> EnginesFlexiblePhysics<N> {
+    const ENGINES_FLEX_SIM_TIME_STEP: Duration = Duration::from_millis(10);
+
+    pub fn new(context: &mut InitContext) -> Self {
+        Self {
+            engines_flex_updater: MaxStepLoop::new(Self::ENGINES_FLEX_SIM_TIME_STEP),
+            engines_flex: (1..=N)
+                .map(|engine_number| EngineFlexPhysics::new(context, engine_number))
+                .collect(),
+        }
+    }
+
+    pub fn update(&mut self, context: &UpdateContext) {
+        self.engines_flex_updater.update(context);
+
+        for cur_time_step in self.engines_flex_updater {
+            for engine_flex in &mut self.engines_flex {
+                engine_flex.update(&context.with_delta(cur_time_step));
+            }
+        }
+    }
+}
+impl SimulationElement for EnginesFlexiblePhysics<4> {
+    fn accept<T: SimulationElementVisitor>(&mut self, visitor: &mut T) {
+        accept_iterable!(self.engines_flex, visitor);
+
+        visitor.visit(self);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use crate::simulation::{
+        test::{ReadByName, SimulationTestBed, TestBed, WriteByName},
+        Aircraft, InitContext, SimulationElement, SimulationElementVisitor, UpdateContext,
+    };
+
+    use ntest::assert_about_eq;
+    use std::time::Duration;
+
+    struct EngineFlexTestAircraft {
+        engines_flex: EnginesFlexiblePhysics<4>,
+    }
+    impl EngineFlexTestAircraft {
+        fn new(context: &mut InitContext) -> Self {
+            Self {
+                engines_flex: EnginesFlexiblePhysics::new(context),
+            }
+        }
+
+        fn update(&mut self, context: &UpdateContext) {
+            self.engines_flex.update(context);
+        }
+    }
+    impl Aircraft for EngineFlexTestAircraft {
+        fn update_after_power_distribution(&mut self, context: &UpdateContext) {
+            self.update(context);
+        }
+    }
+    impl SimulationElement for EngineFlexTestAircraft {
+        fn accept<T: SimulationElementVisitor>(&mut self, visitor: &mut T) {
+            self.engines_flex.accept(visitor);
+            visitor.visit(self);
+        }
+    }
+
+    fn show_animation_positions(test_bed: &mut SimulationTestBed<EngineFlexTestAircraft>) {
+        let engine_1_position: f64 = test_bed.read_by_name("ENGINE_1_WOBBLE_X_POSITION");
+        let engine_2_position: f64 = test_bed.read_by_name("ENGINE_2_WOBBLE_X_POSITION");
+        let engine_3_position: f64 = test_bed.read_by_name("ENGINE_3_WOBBLE_X_POSITION");
+        let engine_4_position: f64 = test_bed.read_by_name("ENGINE_4_WOBBLE_X_POSITION");
+
+        println!(
+            "E1 {:.2} E2 {:.2} E3 {:.2} E4 {:.2}",
+            engine_1_position, engine_2_position, engine_3_position, engine_4_position
+        );
+    }
+
+    #[test]
+    fn check_init_positions_are_zero_point_five() {
+        let mut test_bed = SimulationTestBed::new(EngineFlexTestAircraft::new);
+
+        test_bed.run();
+
+        let engine_1_position: f64 = test_bed.read_by_name("ENGINE_1_WOBBLE_X_POSITION");
+        let engine_2_position: f64 = test_bed.read_by_name("ENGINE_2_WOBBLE_X_POSITION");
+        let engine_3_position: f64 = test_bed.read_by_name("ENGINE_3_WOBBLE_X_POSITION");
+        let engine_4_position: f64 = test_bed.read_by_name("ENGINE_4_WOBBLE_X_POSITION");
+
+        assert_about_eq!(engine_1_position, 0.5);
+        assert_about_eq!(engine_2_position, 0.5);
+        assert_about_eq!(engine_3_position, 0.5);
+        assert_about_eq!(engine_4_position, 0.5);
+    }
+
+    // Following test is ignored because it's hard to set static boundaries to desired results
+    // Tuning is better done visually using dev mode to edit physical properties
+    #[test]
+    #[ignore]
+    fn check_engines_move_in_light_turbulances() {
+        let mut test_bed = SimulationTestBed::new(EngineFlexTestAircraft::new);
+
+        for _ in 0..500 {
+            test_bed.write_by_name("ACCELERATION BODY X", 5.);
+            test_bed.run_with_delta(Duration::from_secs_f64(0.5));
+            show_animation_positions(&mut test_bed);
+            test_bed.write_by_name("ACCELERATION BODY X", -5.);
+            test_bed.run_with_delta(Duration::from_secs_f64(0.5));
+            show_animation_positions(&mut test_bed);
+        }
+    }
+
+    // Following test is ignored because it's hard to set static boundaries to desired results
+    // Tuning is better done visually using dev mode to edit physical properties
+    #[test]
+    #[ignore]
+    fn check_engines_move_in_strong_turbulances() {
+        let mut test_bed = SimulationTestBed::new(EngineFlexTestAircraft::new);
+
+        for _ in 0..500 {
+            test_bed.write_by_name("ACCELERATION BODY X", 15.);
+            test_bed.run_with_delta(Duration::from_secs_f64(0.5));
+            show_animation_positions(&mut test_bed);
+            test_bed.write_by_name("ACCELERATION BODY X", -15.);
+            test_bed.run_with_delta(Duration::from_secs_f64(0.5));
+            show_animation_positions(&mut test_bed);
+        }
+    }
+}

src/systems/systems/src/engine/mod.rs

@@ -7,6 +7,7 @@ use crate::{
     simulation::{SimulationElement, SimulationElementVisitor},
 };
 
+pub mod engine_wing_flex;
 pub mod leap_engine;
 
 pub trait Engine: EngineCorrectedN2 + EngineUncorrectedN2 + EngineCorrectedN1 {