feat(sih): add propeller model with advance ratio (#26720)

---------

Signed-off-by: romain-chiap <romain.chiap@gmail.com>
Signed-off-by: Ramon Roche <mrpollo@gmail.com>
Co-authored-by: romain-chiap <romain.chiap@gmail.com>

ROMFS/px4fmu_common/init.d/airframes/1101_rc_plane_sih.hil

@@ -14,6 +14,7 @@
 
 param set UAVCAN_ENABLE 0
 
+param set-default CA_AIRFRAME 1
 param set-default CA_ROTOR_COUNT 1
 param set-default CA_ROTOR0_PX 0.3
 
@@ -38,7 +39,6 @@ param set-default SYS_HITL 2
 # - without real battery
 param set-default CBRK_SUPPLY_CHK 894281
 
-param set SIH_T_MAX 6
 param set SIH_MASS 0.3
 param set SIH_IXX 0.00402
 param set SIH_IYY 0.0144
@@ -48,3 +48,21 @@ param set SIH_KDV 0.2
 
 param set SIH_VEHICLE_TYPE 1 	# sih as fixed wing
 param set RWTO_TKOFF 1  # enable takeoff from runway (as opposed to launched)
+
+# pusher propeller model with advance ratio, model from UIUC APC 8x6"
+param set SIH_F_T_MAX 6
+param set SIH_F_Q_MAX 0.03
+# if SIH_F_CT0 > 0, SIH_F_T_MAX and SIH_F_Q_MAX will be overridden
+param set SIH_F_CT0 0.131
+param set SIH_F_CT1 0.004
+param set SIH_F_CT2 -0.146
+param set SIH_F_CP0 0.0777
+param set SIH_F_CP1 0.0498
+param set SIH_F_CP2 -0.11
+param set SIH_F_DIA_INCH 8
+param set SIH_F_RPM_MAX 9000
+
+param set-default FW_AIRSPD_MIN 7
+param set-default FW_AIRSPD_TRIM 10
+param set-default FW_AIRSPD_MAX 12
+param set-default FW_PSP_OFF 0.5

ROMFS/px4fmu_common/init.d/airframes/1102_tailsitter_duo_sih.hil

@@ -28,6 +28,7 @@ param set-default VT_FW_DIFTHR_EN 1
 param set-default VT_FW_DIFTHR_S_Y 0.3
 param set-default MPC_MAN_Y_MAX 60
 param set-default MC_PITCH_P 5
+param set-default FW_PSP_OFF 5
 
 param set-default CA_AIRFRAME 4
 param set-default CA_ROTOR_COUNT 2
@@ -56,7 +57,6 @@ param set-default HIL_ACT_REV 32
 param set-default MAV_TYPE 19
 
 
-
 # set SYS_HITL to 2 to start the SIH and avoid sensors startup
 param set-default SYS_HITL 2
 
@@ -66,8 +66,9 @@ param set-default CBRK_SUPPLY_CHK 894281
 
 param set-default SENS_DPRES_OFF 0.001
 
-param set SIH_T_MAX 2.0
-param set SIH_Q_MAX 0.0165
+# tailsitter is equipped with two forward propellers
+param set SIH_F_T_MAX 2
+param set SIH_F_Q_MAX 0.0165
 param set SIH_MASS 0.2
 # IXX and IZZ are inverted from the thesis as the body frame is pitched by 90 deg
 param set SIH_IXX 0.00354
@@ -77,6 +78,19 @@ param set SIH_IXZ 0
 param set SIH_KDV 0.2
 param set SIH_L_ROLL 0.145
 
+# propeller diameter, rpm, and coeffs coming from the thesis
+# Modeling and control of a flying wing tailsitter unmanned aerial vehicle."
+# Chiappinelli, Romain, supervised by Nahon, Meyer, McGill University, Masters thesis, 2018.
+# if SIH_F_CT0 > 0, SIH_F_T_MAX and SIH_F_Q_MAX will be overridden
+param set SIH_F_CT0 0.1342
+param set SIH_F_CT1 -0.1196
+param set SIH_F_CT2 -0.1281
+param set SIH_F_CP0 0.0522
+param set SIH_F_CP1 -0.0146
+param set SIH_F_CP2 -0.0602
+param set SIH_F_DIA_INCH 5
+param set SIH_F_RPM_MAX 14000
+
 # sih as tailsitter
 param set SIH_VEHICLE_TYPE 2
 

ROMFS/px4fmu_common/init.d/airframes/1103_standard_vtol_sih.hil

@@ -56,6 +56,7 @@ param set-default CA_SV_CS2_TYPE 4  # rudder
 param set-default FW_AIRSPD_MIN 7
 param set-default FW_AIRSPD_TRIM 10
 param set-default FW_AIRSPD_MAX 12
+param set-default VT_FWD_THRUST_EN 1
 
 param set-default HIL_ACT_FUNC1 101
 param set-default HIL_ACT_FUNC2 102
@@ -77,6 +78,7 @@ param set-default CBRK_SUPPLY_CHK 894281
 
 param set-default SENS_DPRES_OFF 0.001
 
+# quadrotor propellers
 param set SIH_T_MAX 2.0
 param set SIH_Q_MAX 0.0165
 param set SIH_MASS 0.2
@@ -88,5 +90,18 @@ param set SIH_IXZ 0
 param set SIH_KDV 0.2
 param set SIH_L_ROLL 0.2
 
+# pusher propeller model with advance ratio, model from UIUC APC 8x6"
+param set SIH_F_T_MAX 6
+param set SIH_F_Q_MAX 0.03
+# if SIH_F_CT0 > 0, SIH_F_T_MAX and SIH_F_Q_MAX will be overridden
+param set SIH_F_CT0 0.131
+param set SIH_F_CT1 0.004
+param set SIH_F_CT2 -0.146
+param set SIH_F_CP0 0.0777
+param set SIH_F_CP1 0.0498
+param set SIH_F_CP2 -0.11
+param set SIH_F_DIA_INCH 8
+param set SIH_F_RPM_MAX 9000
+
 # sih as standard vtol
 param set SIH_VEHICLE_TYPE 3

ROMFS/px4fmu_common/init.d/airframes/1105_rc_hexa_x_sih.hil

@@ -0,0 +1,49 @@
+#!/bin/sh
+#
+# @name SIH Hexacopter X
+#
+# @type Simulation
+# @class Copter
+#
+# @maintainer Romain Chiappinelli <romain.chiap@gmail.com>
+#
+# @board px4_fmu-v2 exclude
+#
+
+. ${R}etc/init.d/rc.mc_defaults
+
+param set UAVCAN_ENABLE 0
+
+# set SYS_HITL to 2 to start the SIH and avoid sensors startup
+param set SYS_HITL 2
+
+# disable some checks to allow to fly:
+# - without real battery
+param set-default CBRK_SUPPLY_CHK 894281
+
+param set SIH_VEHICLE_TYPE 4
+
+# Symmetric hexacopter X clockwise motor numbering
+param set-default CA_ROTOR_COUNT 6
+param set-default CA_ROTOR0_PX 0.866
+param set-default CA_ROTOR0_PY 0.5
+param set-default CA_ROTOR1_PX 0
+param set-default CA_ROTOR1_PY 1
+param set-default CA_ROTOR1_KM -0.05
+param set-default CA_ROTOR2_PX -0.866
+param set-default CA_ROTOR2_PY 0.5
+param set-default CA_ROTOR3_PX -0.866
+param set-default CA_ROTOR3_PY -0.5
+param set-default CA_ROTOR3_KM -0.05
+param set-default CA_ROTOR4_PX 0
+param set-default CA_ROTOR4_PY -1
+param set-default CA_ROTOR5_PX 0.866
+param set-default CA_ROTOR5_PY -0.5
+param set-default CA_ROTOR5_KM -0.05
+
+param set-default HIL_ACT_FUNC1 101
+param set-default HIL_ACT_FUNC2 102
+param set-default HIL_ACT_FUNC3 103
+param set-default HIL_ACT_FUNC4 104
+param set-default HIL_ACT_FUNC5 105
+param set-default HIL_ACT_FUNC6 106

ROMFS/px4fmu_common/init.d/airframes/CMakeLists.txt

@@ -49,6 +49,7 @@ if(CONFIG_MODULES_SIMULATION_PWM_OUT_SIM)
 		1101_rc_plane_sih.hil
 		1102_tailsitter_duo_sih.hil
 		1103_standard_vtol_sih.hil
+		1105_rc_hexa_x_sih.hil
 	)
 	if(CONFIG_MODULES_ROVER_ACKERMANN)
 		px4_add_romfs_files(

src/modules/simulation/simulator_sih/aero.hpp

@@ -65,6 +65,243 @@
 #include <conversion/rotation.h>    	// math::radians,
 // #include <lib/mathlib/mathlib.h>
 #include <math.h>
+#include <px4_platform_common/defines.h>	// PX4_ISFINITE
+#include <px4_platform_common/log.h>		// PX4_INFO
+
+// class Thruster using the terminology from UIUC Propeller Data site https://m-selig.ae.illinois.edu/props/propDB.html
+class Thruster
+{
+private:
+	static constexpr float INCH_TO_M = 0.0254f;
+	float CT0, CT1, CT2, CP0, CP1, CP2;
+	float _d_m;
+	float _rpm_max;
+	float T_MAX;
+	float Q_MAX;
+public:
+
+	// public implicit constructor
+	Thruster() : Thruster(0.1f, 1000.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f) {}
+
+	/** public explicit constructor for static model
+	 * using the maximum thrust and torque.
+	 * In this case, the prop diameter and RPM are not needed.
+	 */
+	Thruster(float Tmax, float Qmax)
+	{
+		_d_m = 0.0f;
+		_rpm_max = 0.0f;
+		CT0 = 0.0f;
+		CT1 = 0.0f;
+		CT2 = 0.0f;
+		CP0 = 0.0f;
+		CP1 = 0.0f;
+		CP2 = 0.0f;
+		T_MAX = Tmax;
+		Q_MAX = Qmax;
+	}
+
+	/** public explicit constructor
+	 * - prop_dia_inch: propeller diameter in inches
+	 * - rpm_max: max RPM
+	 * - ct0, ct1, ct2: second order thrust coefficient
+	 * - cp0, cp1, cp2: second order power coefficient
+	 */
+	Thruster(float prop_dia_inch, float rpm_max, float ct0, float ct1, float ct2, float cp0, float cp1, float cp2)
+	{
+		_d_m = dia_inch_to_m(prop_dia_inch);
+		_rpm_max = rpm_max;
+		CT0 = ct0;
+		CT1 = ct1;
+		CT2 = ct2;
+		CP0 = cp0;
+		CP1 = cp1;
+		CP2 = cp2;
+		// Initialize T_MAX and Q_MAX before they may be used inside the compute_* helpers
+		T_MAX = 0.0f;
+		Q_MAX = 0.0f;
+		T_MAX = compute_thrust_from_throttle(1.0f);
+		Q_MAX = compute_torque_from_throttle(1.0f);
+	}
+
+	/** advance_ratio(float n_rev_s, float vx_ms)
+	 * compute the advance ratio J = vx_ms / n_rev_s / d_m
+	 * with
+	 * - n_rev_s is the propeller rotational speed in revolution/s
+	 * - vx_ms is the valocity seen by the thruster in m/s,
+	 *   usually projected on the propeller revolution axis
+	 */
+	float advance_ratio(float n_rev_s, float vx_ms)
+	{
+		return vx_ms / n_rev_s / _d_m;
+	}
+
+	/** fCT(float J, float ct0, float ct1, float ct2)
+	 * Compute the thrust coefficient ct from the advance ratio J
+	 *
+	 */
+	float fCT(float J)
+	{
+		if (!PX4_ISFINITE(J)) {
+			return 0;
+		}
+
+		// do not allow ct < 0 (i.e. windmill)
+		return fmaxf(CT0 + CT1 * J + CT2 * J * J, 0.0f);
+	}
+
+	/** fCP(float J, float cp0, float cp1, float cp2)
+	 * Compute the power coefficient cp from the advance ratio J
+	 *
+	 */
+	float fCP(float J)
+	{
+		if (!PX4_ISFINITE(J)) {
+			return 0;
+		}
+
+		return fmaxf(CP0 + CP1 * J + CP2 * J * J, 0.0f);
+	}
+
+	/** compute_thrust(float n_rev_s, float vx_ms=0.0f, float rho=1.225f)
+	 * Compute the thrust force in (N) given
+	 * - n_rev_s is the propeller rotational speed in revolution/s
+	 * - vx_ms is the velocity seen by the thruster in m/s,
+	 *   usually projected on the propeller revolution axis
+	 * - rho is the density in kg/m^3
+	 */
+	float compute_thrust(float n_rev_s, float vx_ms = 0.0f, float rho = 1.225f)
+	{
+		if (CT0 <= 0.0f || n_rev_s <= 1.0e-4f) {
+			return 0.0f;
+		}
+
+		float J = advance_ratio(n_rev_s, vx_ms);
+		return fCT(J) * rho * n_rev_s * n_rev_s * _d_m * _d_m * _d_m * _d_m;
+	}
+
+	/** compute_thrust_from_throttle(float u, float vx_ms=0.0f, float rho=1.225f)
+	 * Compute the thrust force in (N) given
+	 * - u is the thruster unit throttle in range [0,1]
+	 * - vx_ms is the velocity seen by the thruster in m/s,
+	 *   usually projected on the propeller revolution axis
+	 * - rho is the density in kg/m^3
+	 */
+	float compute_thrust_from_throttle(float u, float vx_ms = 0.0f, float rho = 1.225f)
+	{
+		if (CT0 <= 0.0f) {
+			return T_MAX * u;
+		}
+
+		float n_rev_s = throttle_to_rev_s(u, _rpm_max);
+		return compute_thrust(n_rev_s, vx_ms, rho);
+	}
+
+	/** compute_torque(float n_rev_s, float vx_ms=0.0f, float rho=1.225f)
+	 * Compute the propeller torque in (Nm) given
+	 * - n_rev_s is the propeller rotational speed in revolution/s
+	 * - vx_ms is the velocity seen by the thruster in m/s,
+	 *   usually projected on the propeller revolution axis
+	 * - rho is the density in kg/m^3
+	 */
+	float compute_torque(float n_rev_s, float vx_ms = 0.0f, float rho = 1.225f)
+	{
+		if (CP0 <= 0.0f || n_rev_s <= 1.0e-4f) {
+			return 0.0f;
+		}
+
+		float J = advance_ratio(n_rev_s, vx_ms);
+		float cq = fCP(J) / 2.0f / M_PI_F;
+		return cq * rho * n_rev_s * n_rev_s * _d_m * _d_m * _d_m * _d_m * _d_m;
+	}
+
+	/** compute_torque_from_throttle(float u, float vx_ms=0.0f, float rho=1.225f)
+	 * Compute the propeller torque in (Nm) given
+	 * - u is the thruster unit throttle in range [0,1]
+	 * - vx_ms is the velocity seen by the thruster in m/s,
+	 *   usually projected on the propeller revolution axis
+	 * - rho is the density in kg/m^3
+	 */
+	float compute_torque_from_throttle(float u, float vx_ms = 0.0f, float rho = 1.225f)
+	{
+		if (CP0 <= 0.0f) {
+			return Q_MAX * u;
+		}
+
+		float n_rev_s = throttle_to_rev_s(u, _rpm_max);
+		return compute_torque(n_rev_s, vx_ms, rho);
+	}
+
+	/** dia_inch_to_m(float dia_inch)
+	 * compute the propeller diameter in meter,
+	 * given dia_inch the propeller diameter in inches.
+	 */
+	static float dia_inch_to_m(float dia_inch)
+	{
+		return dia_inch * INCH_TO_M;
+	}
+
+	/** rpm_to_rev_s(float rpm)
+	 * compute the propeller revolutions per seconds,
+	 * given the propeller rpm.
+	 */
+	static float rpm_to_rev_s(float rpm)
+	{
+		return rpm / 60.0f;
+	}
+
+	/** rev_s_to_rpm(float n_rev_s)
+	 * compute the propeller rpm,
+	 * given the propeller revolutions per seconds.
+	 */
+	static float rev_s_to_rpm(float n_rev_s)
+	{
+		return n_rev_s * 60.0f;
+	}
+
+	/** throttle_to_rpm(float throttle, const float rpm_max)
+	 * compute the propeller rpm,
+	 * given the unit throttle u (in range [0,1])
+	 * and the max RPM rpm_max.
+	 */
+	static float throttle_to_rpm(float u, const float rpm_max)
+	{
+		return rpm_max * sqrtf(fminf(fmaxf(u, 0.0f), 1.0f));
+	}
+
+	/** throttle_to_rev_s(float throttle, const float rpm_max)
+	 * compute the propeller revolution per seconds,
+	 * given the unit throttle u (in range [0,1])
+	 * and the max RPM rpm_max.
+	 */
+	static float throttle_to_rev_s(float u, const float rpm_max)
+	{
+		return rpm_to_rev_s(throttle_to_rpm(u, rpm_max));
+	}
+
+	float get_T_max()
+	{
+		return T_MAX;
+	}
+
+	float get_Q_max()
+	{
+		return Q_MAX;
+	}
+
+	void print_status()
+	{
+		if (CT0 <= 0.0f) {
+			PX4_INFO("Thruster simple model: Tmax %.4f N, Qmax %.4f Nm", (double)T_MAX, (double)Q_MAX);
+
+		} else {
+			PX4_INFO("Thruster dyn. model: dia %.4f m, max rpm %.0f, Tmax %.4f N, Qmax %.4f Nm",
+				 (double)_d_m, (double)_rpm_max, (double)T_MAX, (double)Q_MAX);
+			PX4_INFO("   Tmax: %.3f N at 10 m/s, %.3f N at 20 m/s",
+				 (double)compute_thrust_from_throttle(1.0f, 10.0f), (double)compute_thrust_from_throttle(1.0f, 20.0f));
+		}
+	}
+};
 
 // class Aerodynamic Segment ------------------------------------------------------------------------
 class AeroSeg

src/modules/simulation/simulator_sih/sih.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2019-2025 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2019-2026 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -252,6 +252,37 @@ void Sih::parameters_updated()
 	_L_PITCH = _sih_l_pitch.get();
 	_KDV = _sih_kdv.get();
 	_KDW = _sih_kdw.get();
+	_F_T_MAX = _sih_f_thrust_max.get();
+	_F_Q_MAX = _sih_f_torque_max.get();
+
+	// update the thruster models
+	for (size_t i = 0; i < NUM_DYN_THRUSTER; i++) {
+		if (_sih_f_ct0.get() > 0.0f && _sih_f_cp0.get() > 0.0f) {
+			_thruster[i] = Thruster(_sih_forward_diameter_inch.get(), _sih_forward_rpm_max.get(),
+						_sih_f_ct0.get(), _sih_f_ct1.get(), _sih_f_ct2.get(),
+						_sih_f_cp0.get(), _sih_f_cp1.get(), _sih_f_cp2.get());
+
+		} else {
+			_thruster[i] = Thruster(_F_T_MAX, _F_Q_MAX);
+		}
+	}
+
+	if (_sih_f_ct0.get() > 0.0f && _sih_f_cp0.get() > 0.0f) {
+		_F_T_MAX = _thruster[0].get_T_max();
+		_F_Q_MAX = _thruster[0].get_Q_max();
+
+		if (fabsf(_F_T_MAX - _sih_f_thrust_max.get()) > 1.0e-5f) {
+			_sih_f_thrust_max.set(_F_T_MAX);
+			_sih_f_thrust_max.commit();
+			PX4_INFO("SIH_F_CT0 > 0, using propeller dynamic model, overriding SIH_F_T_MAX");
+		}
+
+		if (fabsf(_F_Q_MAX - _sih_f_torque_max.get()) > 1.0e-5f) {
+			_sih_f_torque_max.set(_F_Q_MAX);
+			_sih_f_torque_max.commit();
+			PX4_INFO("SIH_F_CP0 > 0, using propeller dynamic model, overriding SIH_F_Q_MAX");
+		}
+	}
 
 	if (!_lpos_ref.isInitialized()
 	    || (fabsf(static_cast<float>(_lpos_ref.getProjectionReferenceLat()) - _sih_lat0.get()) > FLT_EPSILON)
@@ -314,7 +345,11 @@ void Sih::read_motors(const float dt)
 
 void Sih::generate_force_and_torques(const float dt)
 {
+	// air-relative velocity in body frame [m/s]
+	_v_B = _q_E.rotateVectorInverse(_R_N2E * _v_apparent_N);
+
 	if (_vehicle == VehicleType::Quadcopter) {
+
 		_T_B = Vector3f(0.0f, 0.0f, -_T_MAX * (+_u[0] + _u[1] + _u[2] + _u[3]));
 		_Mt_B = Vector3f(_L_ROLL * _T_MAX * (-_u[0] + _u[1] + _u[2] - _u[3]),
 				 _L_PITCH * _T_MAX * (+_u[0] - _u[1] + _u[2] - _u[3]),
@@ -340,28 +375,34 @@ void Sih::generate_force_and_torques(const float dt)
 		_Ma_B = -_KDW * _w_B; // first order angular damper
 
 	} else if (_vehicle == VehicleType::FixedWing) {
-		_T_B = Vector3f(_T_MAX * _u[3], 0.0f, 0.0f); 	// forward thruster
-		// _Mt_B = Vector3f(_Q_MAX*_u[3], 0.0f,0.0f); 	// thruster torque
-		_Mt_B = Vector3f();
-		generate_fw_aerodynamics(_u[0], _u[1], _u[2], _u[3]);
+
+		_T[0] = _thruster[0].compute_thrust_from_throttle(_u[3], _v_B(0));
+		_Q[0] = _thruster[0].compute_torque_from_throttle(_u[3], _v_B(0));
+		_T_B = Vector3f(_T[0], 0.0f, 0.0f); 	// forward thruster
+		_Mt_B = Vector3f(_Q[0], 0.0f, 0.0f);	// thruster torque
+		generate_fw_aerodynamics(_u[0], _u[1], _u[2], _T[0]);
 
 	} else if (_vehicle == VehicleType::TailsitterVTOL) {
-		_T_B = Vector3f(0.0f, 0.0f, -_T_MAX * (_u[0] + _u[1]));
-		_Mt_B = Vector3f(_L_ROLL * _T_MAX * (_u[1] - _u[0]), 0.0f, _Q_MAX * (_u[1] - _u[0]));
-		generate_ts_aerodynamics();
 
-		// _Fa_E = -_KDV * _R_N2E * _v_apparent_N; // first order drag to slow down the aircraft
-		// _Ma_B = -_KDW * _w_B; // first order angular damper
+		for (size_t i = 0; i < NUM_DYN_THRUSTER; i++) {
+			_T[i] = _thruster[i].compute_thrust_from_throttle(_u[i], -_v_B(2));
+			_Q[i] = _thruster[i].compute_torque_from_throttle(_u[i], -_v_B(2));
+		}
+
+		_T_B = Vector3f(0.0f, 0.0f, -_T[0] - _T[1]);
+		_Mt_B = Vector3f(_L_ROLL * (_T[1] - _T[0]), 0.0f, _Q[1] - _Q[0]);
+		generate_ts_aerodynamics();
 
 	} else if (_vehicle == VehicleType::StandardVTOL) {
 
-		_T_B = Vector3f(_T_MAX * 2 * _u[7], 0.0f, -_T_MAX * (+_u[0] + _u[1] + _u[2] + _u[3]));
-		_Mt_B = Vector3f(_L_ROLL * _T_MAX * (-_u[0] + _u[1] + _u[2] - _u[3]),
+		_T[0] = _thruster[0].compute_thrust_from_throttle(_u[7], _v_B(0));
+		_Q[0] = _thruster[0].compute_torque_from_throttle(_u[7], _v_B(0));
+		_T_B = Vector3f(_T[0], 0.0f, -_T_MAX * (+_u[0] + _u[1] + _u[2] + _u[3]));
+		_Mt_B = Vector3f(_L_ROLL * _T_MAX * (-_u[0] + _u[1] + _u[2] - _u[3]) + _Q[0],
 				 _L_PITCH * _T_MAX * (+_u[0] - _u[1] + _u[2] - _u[3]),
 				 _Q_MAX * (+_u[0] + _u[1] - _u[2] - _u[3]));
 
-		// thrust 0 because it is already contained in _T_B. in
-		// equations_of_motion they are all summed into sum_of_forces_E
+		// thrust 0 means no propwash on the tail
 		generate_fw_aerodynamics(_u[4], _u[5], _u[6], 0);
 
 	} else if (_vehicle == VehicleType::RoverAckermann) {
@@ -370,21 +411,20 @@ void Sih::generate_force_and_torques(const float dt)
 }
 
 void Sih::generate_fw_aerodynamics(const float roll_cmd, const float pitch_cmd, const float yaw_cmd,
-				   const float throttle_cmd)
+				   const float thrust_for_prowash)
 {
-	const Vector3f v_B = _q.rotateVectorInverse(_v_apparent_N);
 	const float &alt = _lla.altitude();
 
-	_wing_l.update_aero(v_B, _w_B, alt, roll_cmd * FLAP_MAX);
-	_wing_r.update_aero(v_B, _w_B, alt, -roll_cmd * FLAP_MAX);
+	_wing_l.update_aero(_v_B, _w_B, alt, roll_cmd * FLAP_MAX);
+	_wing_r.update_aero(_v_B, _w_B, alt, -roll_cmd * FLAP_MAX);
 
-	_tailplane.update_aero(v_B, _w_B, alt, -pitch_cmd * FLAP_MAX, _T_MAX * throttle_cmd);
-	_fin.update_aero(v_B, _w_B, alt, yaw_cmd * FLAP_MAX, _T_MAX * throttle_cmd);
-	_fuselage.update_aero(v_B, _w_B, alt);
+	_tailplane.update_aero(_v_B, _w_B, alt, -pitch_cmd * FLAP_MAX, thrust_for_prowash);
+	_fin.update_aero(_v_B, _w_B, alt, yaw_cmd * FLAP_MAX, thrust_for_prowash);
+	_fuselage.update_aero(_v_B, _w_B, alt);
 
 	// sum of aerodynamic forces
 	const Vector3f Fa_B = _wing_l.get_Fa() + _wing_r.get_Fa() + _tailplane.get_Fa() + _fin.get_Fa() + _fuselage.get_Fa() -
-			      _KDV * v_B;
+			      _KDV * _v_B;
 	_Fa_E = _q_E.rotateVector(Fa_B);
 
 	// aerodynamic moments
@@ -393,11 +433,8 @@ void Sih::generate_fw_aerodynamics(const float roll_cmd, const float pitch_cmd,
 
 void Sih::generate_ts_aerodynamics()
 {
-	// velocity in body frame [m/s]
-	const Vector3f v_B = _q.rotateVectorInverse(_v_apparent_N);
-
 	// the aerodynamic is resolved in a frame like a standard aircraft (nose-right-belly)
-	Vector3f v_ts = _R_S2B.transpose() * v_B;
+	Vector3f v_ts = _R_S2B.transpose() * _v_B;
 	Vector3f w_ts = _R_S2B.transpose() * _w_B;
 	float altitude = _lpos_ref_alt - _lpos(2);
 
@@ -406,17 +443,17 @@ void Sih::generate_ts_aerodynamics()
 
 	for (int i = 0; i < NB_TS_SEG; i++) {
 		if (i <= NB_TS_SEG / 2) {
-			_ts[i].update_aero(v_ts, w_ts, altitude, _u[5]*TS_DEF_MAX, _T_MAX * _u[1]);
+			_ts[i].update_aero(v_ts, w_ts, altitude, _u[5]*TS_DEF_MAX, _T[1]);
 
 		} else {
-			_ts[i].update_aero(v_ts, w_ts, altitude, -_u[4]*TS_DEF_MAX, _T_MAX * _u[0]);
+			_ts[i].update_aero(v_ts, w_ts, altitude, -_u[4]*TS_DEF_MAX, _T[0]);
 		}
 
 		Fa_ts += _ts[i].get_Fa();
 		Ma_ts += _ts[i].get_Ma();
 	}
 
-	const Vector3f Fa_B = _R_S2B * Fa_ts - _KDV * v_B; 	// sum of aerodynamic forces
+	const Vector3f Fa_B = _R_S2B * Fa_ts - _KDV * _v_B; 	// sum of aerodynamic forces
 	_Fa_E = _q_E.rotateVector(Fa_B);
 	_Ma_B = _R_S2B * Ma_ts - _KDW * _w_B; 	// aerodynamic moments
 }
@@ -842,15 +879,21 @@ int Sih::print_status()
 
 	} else if (_vehicle == VehicleType::FixedWing) {
 		PX4_INFO("Fixed-Wing");
+		PX4_INFO("propeller model:");
+		_thruster[0].print_status();
 
 	} else if (_vehicle == VehicleType::TailsitterVTOL) {
 		PX4_INFO("TailSitter");
+		PX4_INFO("propeller model:");
+		_thruster[0].print_status();
 		PX4_INFO("aoa [deg]: %d", (int)(degrees(_ts[4].get_aoa())));
 		PX4_INFO("v segment (m/s)");
 		_ts[4].get_vS().print();
 
 	} else if (_vehicle == VehicleType::StandardVTOL) {
 		PX4_INFO("Standard VTOL");
+		PX4_INFO("pusher propeller model:");
+		_thruster[0].print_status();
 
 	} else if (_vehicle == VehicleType::RoverAckermann) {
 		PX4_INFO("Rover Ackermann");
@@ -872,6 +915,8 @@ int Sih::print_status()
 	(_R_N2E.transpose() * _Fa_E).print();
 	PX4_INFO("Aerodynamic moments body frame (Nm)");
 	_Ma_B.print();
+	PX4_INFO("Thruster forces in body frame (N)");
+	_T_B.print();
 	PX4_INFO("Thruster moments in body frame (Nm)");
 	_Mt_B.print();
 	return 0;

src/modules/simulation/simulator_sih/sih.hpp

@@ -1,6 +1,6 @@
 /****************************************************************************
 *
-*   Copyright (c) 2019-2025 PX4 Development Team. All rights reserved.
+*   Copyright (c) 2019-2026 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
@@ -40,19 +40,19 @@
  * Coriolis g Corporation - January 2019
  */
 
-// The sensor signals reconstruction and noise levels are from [1]
-// [1] Bulka E, and Nahon M, "Autonomous fixed-wing aerobatics: from theory to flight."
-//     In 2018 IEEE International Conference on Robotics and Automation (ICRA), pp. 6573-6580. IEEE, 2018.
-// The aerodynamic model is from [2]
-// [2] Khan W, supervised by Nahon M, "Dynamics modeling of agile fixed-wing unmanned aerial vehicles."
-//     McGill University (Canada), PhD thesis, 2016.
-// The quaternion integration are from [3]
-// [3] Sveier A, Sjøberg AM, Egeland O. "Applied Runge–Kutta–Munthe-Kaas Integration for the Quaternion Kinematics."
-//     Journal of Guidance, Control, and Dynamics. 2019 Dec;42(12):2747-54.
-// The tailsitter model is from [4]
-// [4] Chiappinelli R, supervised by Nahon M, "Modeling and control of a flying wing tailsitter unmanned aerial vehicle."
-//     McGill University (Canada), Masters Thesis, 2018.
-
+/** The sensor signals reconstruction and noise levels are from [1]. The aerodynamic model is from [2].
+ * The quaternion integration are from [3]. The tailsitter model is from [4]. The propeller models are from [5]
+ * [1] Bulka E, and Nahon M, "Autonomous fixed-wing aerobatics: from theory to flight."
+ *     In 2018 IEEE International Conference on Robotics and Automation (ICRA), pp. 6573-6580. IEEE, 2018.
+ * [2] Khan W, supervised by Nahon M, "Dynamics modeling of agile fixed-wing unmanned aerial vehicles."
+ *     McGill University (Canada), PhD thesis, 2016.
+ * [3] Sveier A, Sjøberg AM, Egeland O. "Applied Runge–Kutta–Munthe-Kaas Integration for the Quaternion Kinematics."
+ *     Journal of Guidance, Control, and Dynamics. 2019 Dec;42(12):2747-54.
+ * [4] Chiappinelli R, supervised by Nahon M, "Modeling and control of a flying wing tailsitter unmanned aerial vehicle."
+ *     McGill University (Canada), Masters Thesis, 2018.
+ * [5] J.B. Brandt, R.W. Deters, G.K. Ananda, O.D. Dantsker, and M.S. Selig 2026, UIUC Propeller Database,
+ *     Vols 1-4, University of Illinois at Urbana-Champaign, Department of Aerospace Engineering, retrieved from https://m-selig.ae.illinois.edu/props/propDB.html.
+ */
 #pragma once
 
 #include <px4_platform_common/module.h>
@@ -142,6 +142,7 @@ private:
 
 	// hard constants
 	static constexpr uint16_t NUM_ACTUATORS_MAX = 9;
+	static constexpr uint16_t NUM_DYN_THRUSTER = 2;		// number of dynamic thruster model with advance ratio
 
 	// Ranging beacon simulation constants
 	static constexpr uint8_t NUM_RANGING_BEACONS = 4;
@@ -190,7 +191,7 @@ private:
 	void send_dist_snsr(const hrt_abstime &time_now_us);
 	void send_ranging_beacon(const hrt_abstime &time_now_us);
 	void publish_ground_truth(const hrt_abstime &time_now_us);
-	void generate_fw_aerodynamics(const float roll_cmd, const float pitch_cmd, const float yaw_cmd, const float thrust);
+	void generate_fw_aerodynamics(const float roll_cmd, const float pitch_cmd, const float yaw_cmd, const float thrust_for_prowash);
 	void generate_ts_aerodynamics();
 	void generate_rover_ackermann_dynamics(const float throttle_cmd, const float steering_cmd, const float dt);
 	void sensor_step();
@@ -234,6 +235,7 @@ private:
 	matrix::Vector3f _Mt_B{}; // thruster moments [Nm]
 	matrix::Vector3f _Ma_B{}; // aerodynamic moments [Nm]
 	matrix::Vector3f _w_B{};  // body rates in body frame [rad/s]
+	matrix::Vector3f _v_B{};  // body frame velocity [m/s]
 
 	// Quantities in local navigation frame (NED, body-fixed)
 	matrix::Vector3f _v_N{};          // velocity [m/s]
@@ -257,6 +259,9 @@ private:
 	matrix::Vector3f _lpos{};  // position in a local tangent-plane frame [m]
 
 	float _u[NUM_ACTUATORS_MAX] {}; // thruster signals
+	float       _T[NUM_DYN_THRUSTER] {};         // thruster forces (N)
+	float       _Q[NUM_DYN_THRUSTER] {};         // thruster torque (Nm)
+	Thruster    _thruster[NUM_DYN_THRUSTER] {};	// thruster objects
 
 	enum class VehicleType {Quadcopter, FixedWing, TailsitterVTOL, StandardVTOL, Hexacopter, RoverAckermann, First = Quadcopter, Last = RoverAckermann}; // numbering dependent on parameter SIH_VEHICLE_TYPE
 	VehicleType _vehicle = VehicleType::Quadcopter;
@@ -296,7 +301,7 @@ private:
 	// parameters
 	MapProjection _lpos_ref{};
 	float _lpos_ref_alt;
-	float _MASS, _T_MAX, _Q_MAX, _L_ROLL, _L_PITCH, _KDV, _KDW, _T_TAU;
+	float _MASS, _T_MAX, _Q_MAX, _L_ROLL, _L_PITCH, _KDV, _KDW, _T_TAU, _F_T_MAX, _F_Q_MAX;
 	matrix::Matrix3f _I;    // vehicle inertia matrix
 	matrix::Matrix3f _Im1;  // inverse of the inertia matrix
 
@@ -326,6 +331,18 @@ private:
 		(ParamFloat<px4::params::SIH_DISTSNSR_MAX>) _sih_distance_snsr_max,
 		(ParamFloat<px4::params::SIH_DISTSNSR_OVR>) _sih_distance_snsr_override,
 		(ParamFloat<px4::params::SIH_T_TAU>) _sih_thrust_tau,
+		// forward propeller
+		(ParamFloat<px4::params::SIH_F_T_MAX>) _sih_f_thrust_max,
+		(ParamFloat<px4::params::SIH_F_Q_MAX>) _sih_f_torque_max,
+		(ParamFloat<px4::params::SIH_F_CT0>) _sih_f_ct0,
+		(ParamFloat<px4::params::SIH_F_CT1>) _sih_f_ct1,
+		(ParamFloat<px4::params::SIH_F_CT2>) _sih_f_ct2,
+		(ParamFloat<px4::params::SIH_F_CP0>) _sih_f_cp0,
+		(ParamFloat<px4::params::SIH_F_CP1>) _sih_f_cp1,
+		(ParamFloat<px4::params::SIH_F_CP2>) _sih_f_cp2,
+		(ParamFloat<px4::params::SIH_F_DIA_INCH>) _sih_forward_diameter_inch,
+		(ParamFloat<px4::params::SIH_F_RPM_MAX>) _sih_forward_rpm_max,
+		(ParamInt<px4::params::BAT1_SOURCE>) _bat1_source,
 		(ParamInt<px4::params::SIH_VEHICLE_TYPE>) _sih_vtype,
 		(ParamFloat<px4::params::SIH_WIND_N>) _sih_wind_n,
 		(ParamFloat<px4::params::SIH_WIND_E>) _sih_wind_e,

src/modules/simulation/simulator_sih/sih_params.yaml

@@ -83,12 +83,14 @@ parameters:
       increment: 0.005
     SIH_T_MAX:
       description:
-        short: Max propeller thrust force
+        short: Max multicopter propeller thrust force
         long: |-
           This is the maximum force delivered by one propeller
           when the motor is running at full speed.
 
           This value is usually about 5 times the mass of the quadrotor.
+
+          Refer to SIH_F_T_MAX for the thrust for FW, Tailsitter, and VTOL pusher.
       type: float
       default: 5.0
       unit: N
@@ -97,12 +99,14 @@ parameters:
       increment: 0.5
     SIH_Q_MAX:
       description:
-        short: Max propeller torque
+        short: Max multicopter propeller torque
         long: |-
           This is the maximum torque delivered by one propeller
           when the motor is running at full speed.
 
           This value is usually about few percent of the maximum thrust force.
+
+          Refer to SIH_F_Q_MAX for the propeller torque for FW, Tailsitter, and VTOL pusher.
       type: float
       default: 0.1
       unit: Nm
@@ -281,3 +285,87 @@ parameters:
       min: 0.0
       max: 100.0
       decimal: 1
+    SIH_F_T_MAX:
+      description:
+        short: Forward thruster max thrust (N)
+        long: |-
+          This is used for the Fixed-Wing, Tailsitter, or pusher of the Standard VTOL
+          if SIH_F_CT0 <= 0.
+          If SIH_F_CT0 > 0, propeller model with advance ratio J is used
+          and this parameter value is overridden at simulation startup.
+      type: float
+      default: 2.0
+      unit: N
+      min: 0.0
+      decimal: 3
+    SIH_F_Q_MAX:
+      description:
+        short: Forward thruster max torque (Nm)
+        long: |-
+          This is used for the Fixed-Wing, Tailsitter, or pusher of the Standard VTOL
+          if SIH_F_CP0 <= 0.
+          If SIH_F_CP0 > 0, propeller model with advance ratio J is used
+          and this parameter value is overridden at simulation startup.
+      type: float
+      default: 0.0165
+      unit: Nm
+      min: 0.0
+      decimal: 3
+    SIH_F_CT0:
+      description:
+        short: Forward thruster static thrust coefficient
+      type: float
+      default: 0.0
+      min: 0.0
+      decimal: 3
+    SIH_F_CT1:
+      description:
+        short: Forward thruster thrust coefficient 1
+        long: CT(J) = CT0 + CT1*J + CT2*J^2
+      type: float
+      default: 0.0
+      decimal: 3
+    SIH_F_CT2:
+      description:
+        short: Forward thruster thrust coefficient 2
+        long: CT(J) = CT0 + CT1*J + CT2*J^2
+      type: float
+      default: 0.0
+      max: 0.0
+      decimal: 3
+    SIH_F_CP0:
+      description:
+        short: Forward thruster static power coefficient
+      type: float
+      default: 0.0
+      min: 0.0
+      decimal: 3
+    SIH_F_CP1:
+      description:
+        short: Forward thruster power coefficient 1
+        long: CP(J) = CP0 + CP1*J + CP2*J^2
+      type: float
+      default: 0.0
+      decimal: 3
+    SIH_F_CP2:
+      description:
+        short: Forward thruster power coefficient 2
+        long: CP(J) = CP0 + CP1*J + CP2*J^2
+      type: float
+      default: 0.0
+      max: 0.0
+      decimal: 3
+    SIH_F_DIA_INCH:
+      description:
+        short: Forward thruster propeller diameter in inches
+      type: float
+      default: 0.1
+      min: 0.1
+      decimal: 1
+    SIH_F_RPM_MAX:
+      description:
+        short: Forward thruster max RPM
+      type: float
+      default: 6000.0
+      min: 0.1
+      decimal: 1