diff --git a/boards/auav/x21/default.cmake b/boards/auav/x21/default.cmake
index fc0f8b289004802f31067ff996855870545408b7..a72e3d740acae82bf24f4949017401653100014b 100644
--- a/boards/auav/x21/default.cmake
+++ b/boards/auav/x21/default.cmake
@@ -75,6 +75,7 @@ px4_add_board(
mc_pos_control
navigator
sensors
+ sih
vmount
vtol_att_control
wind_estimator
diff --git a/msg/CMakeLists.txt b/msg/CMakeLists.txt
index b4ae39fe6c8b45e0cef9f04fb7d5ba5bae08a018..2db2501ba83b3aebf6a1bcb3d3a0efa2d4aea19c 100644
--- a/msg/CMakeLists.txt
+++ b/msg/CMakeLists.txt
@@ -107,6 +107,7 @@ set(msg_files
sensor_preflight.msg
sensor_selection.msg
servorail_status.msg
+ sih.msg
subsystem_info.msg
system_power.msg
task_stack_info.msg
diff --git a/msg/sih.msg b/msg/sih.msg
new file mode 100644
index 0000000000000000000000000000000000000000..f685139ed1be63e87e92c44f0b03cfb70889c96b
--- /dev/null
+++ b/msg/sih.msg
@@ -0,0 +1,9 @@
+# simulator in Hardware - Romain Chiappinelli - Jan 8, 2019
+uint64 timestamp # time since system start (microseconds)
+
+uint32 dt_us # simulator sampling time [us]
+float32[3] euler_rpy # euler angles (roll-pitch-yaw) [deg]
+float32[3] omega_b # body rates in body frame [rad/s]
+float32[3] p_i_local # local inertial position [m]
+float32[3] v_i # inertial velocity [m]
+float32[4] u # motor signals [0;1]
diff --git a/src/modules/sih/CMakeLists.txt b/src/modules/sih/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..c44498611ee83080aab7910fff1531020a9eca8a
--- /dev/null
+++ b/src/modules/sih/CMakeLists.txt
@@ -0,0 +1,44 @@
+############################################################################
+#
+# Copyright (c) 2015 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
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in
+# the documentation and/or other materials provided with the
+# distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+# used to endorse or promote products derived from this software
+# without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+px4_add_module(
+ MODULE modules__sih
+ MAIN sih
+ STACK_MAIN 1200
+ STACK_MAX 3500
+ COMPILE_FLAGS
+ SRCS
+ sih.cpp
+ DEPENDS
+ mathlib
+ )
\ No newline at end of file
diff --git a/src/modules/sih/sih.cpp b/src/modules/sih/sih.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..84ad9c43c74db42dd2ed38d14ab561f4a1c1c85e
--- /dev/null
+++ b/src/modules/sih/sih.cpp
@@ -0,0 +1,632 @@
+/****************************************************************************
+ *
+ * Copyright (c) 2018 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
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file sih.cpp
+ * Simulator in Hardware
+ *
+ * @author Romain Chiappinelli <romain.chiap@gmail.com>
+ *
+ * Coriolis g Corporation - January 2019
+ */
+
+#include "sih.hpp"
+
+#include <px4_getopt.h>
+#include <px4_log.h>
+#include <px4_posix.h>
+
+#include <drivers/drv_pwm_output.h> // to get PWM flags
+#include <uORB/topics/vehicle_status.h> // to get the HIL status
+
+#include <unistd.h> //
+#include <string.h> //
+#include <fcntl.h> //
+#include <termios.h> //
+
+using namespace math;
+
+int Sih::print_usage(const char *reason)
+{
+ if (reason) {
+ PX4_WARN("%s\n", reason);
+ }
+
+ PRINT_MODULE_DESCRIPTION(
+ R"DESCR_STR(
+### Simulator in Hardware
+This module provide a simulator for quadrotors running fully
+inside the hardware autopilot.
+
+This simulator subscribes to "actuator_outputs" which are the actuator pwm
+signals given by the mixer.
+
+This simulator publishes the sensors signals corrupted with realistic noise
+in order to incorporate the state estimator in the loop.
+
+### Implementation
+The simulator implements the equations of motion using matrix algebra.
+Quaternion representation is used for the attitude.
+Forward Euler is used for integration.
+Most of the variables are declared global in the .hpp file to avoid stack overflow.
+
+
+)DESCR_STR");
+
+ PRINT_MODULE_USAGE_NAME("sih", "sih");
+ PRINT_MODULE_USAGE_COMMAND("start");
+ PRINT_MODULE_USAGE_PARAM_FLAG('f', "Optional example flag", true);
+ PRINT_MODULE_USAGE_PARAM_INT('p', 0, 0, 4096, "Optional example parameter", true);
+ PRINT_MODULE_USAGE_DEFAULT_COMMANDS();
+
+ return 0;
+}
+
+int Sih::print_status()
+{
+ PX4_INFO("Running");
+ // TODO: print additional runtime information about the state of the module
+
+ return 0;
+}
+
+int Sih::custom_command(int argc, char *argv[])
+{
+ /*
+ if (!is_running()) {
+ print_usage("not running");
+ return 1;
+ }
+
+ // additional custom commands can be handled like this:
+ if (!strcmp(argv[0], "do-something")) {
+ get_instance()->do_something();
+ return 0;
+ }
+ */
+
+ return print_usage("unknown command");
+}
+
+
+int Sih::task_spawn(int argc, char *argv[])
+{
+ _task_id = px4_task_spawn_cmd("sih",
+ SCHED_DEFAULT,
+ SCHED_PRIORITY_DEFAULT,
+ 4096,
+ (px4_main_t)&run_trampoline,
+ (char *const *)argv);
+
+ if (_task_id < 0) {
+ _task_id = -1;
+ return -errno;
+ }
+
+ return 0;
+}
+
+Sih *Sih::instantiate(int argc, char *argv[])
+{
+ int example_param = 0;
+ bool example_flag = false;
+ bool error_flag = false;
+
+ int myoptind = 1;
+ int ch;
+ const char *myoptarg = nullptr;
+
+ // parse CLI arguments
+ while ((ch = px4_getopt(argc, argv, "p:f", &myoptind, &myoptarg)) != EOF) {
+ switch (ch) {
+ case 'p':
+ example_param = (int)strtol(myoptarg, nullptr, 10);
+ break;
+
+ case 'f':
+ example_flag = true;
+ break;
+
+ case '?':
+ error_flag = true;
+ break;
+
+ default:
+ PX4_WARN("unrecognized flag");
+ error_flag = true;
+ break;
+ }
+ }
+
+ if (error_flag) {
+ return nullptr;
+ }
+
+ Sih *instance = new Sih(example_param, example_flag);
+
+ if (instance == nullptr) {
+ PX4_ERR("alloc failed");
+ }
+
+ return instance;
+}
+
+Sih::Sih(int example_param, bool example_flag)
+ : ModuleParams(nullptr)
+{
+}
+
+void Sih::run()
+{
+
+ // to subscribe to (read) the actuators_out pwm
+ int actuator_out_sub = orb_subscribe(ORB_ID(actuator_outputs));
+
+ int vehicle_status_sub = orb_subscribe(ORB_ID(vehicle_status));
+
+ // initialize parameters
+ int parameter_update_sub = orb_subscribe(ORB_ID(parameter_update));
+ parameters_update_poll(parameter_update_sub);
+
+
+ init_variables();
+ init_sensors();
+ // on the AUAVX21: "/dev/ttyS2/" is TELEM2 UART3 --- "/dev/ttyS5/" is Debug UART7 --- "/dev/ttyS4/" is OSD UART8
+ int serial_fd=init_serial_port(); // init and open the serial port
+
+ const hrt_abstime task_start = hrt_absolute_time();
+ hrt_abstime last_run = task_start;
+ hrt_abstime gps_time = task_start;
+ hrt_abstime serial_time = task_start;
+ hrt_abstime now;
+
+ while (!should_exit() && is_HIL_running(vehicle_status_sub)) {
+
+ now = hrt_absolute_time();
+ _dt = (now - last_run) * 1e-6f;
+ last_run = now;
+
+ read_motors(actuator_out_sub);
+
+ generate_force_and_torques();
+
+ equations_of_motion();
+
+ reconstruct_sensors_signals();
+
+ send_IMU(now);
+
+ if (now - gps_time > 50000) // gps published at 20Hz
+ {
+ gps_time=now;
+ send_gps(gps_time);
+ }
+
+ // send uart message every 40 ms
+ if (now - serial_time > 40000)
+ {
+ serial_time=now;
+
+ publish_sih(); // publish _sih message for debug purpose
+
+ send_serial_msg(serial_fd, (int64_t)(now - task_start)/1000);
+
+ parameters_update_poll(parameter_update_sub); // update the parameters if needed
+ }
+ // else if (loop_count==5)
+ // {
+ // tcflush(serial_fd, TCOFLUSH); // flush output data
+ // tcdrain(serial_fd);
+ // }
+
+ usleep(1000); // sleeping time us
+
+ }
+
+ orb_unsubscribe(actuator_out_sub);
+ orb_unsubscribe(parameter_update_sub);
+ orb_unsubscribe(vehicle_status_sub);
+ close(serial_fd);
+
+}
+
+void Sih::parameters_update_poll(int parameter_update_sub)
+{
+ bool updated;
+ struct parameter_update_s param_upd;
+
+ orb_check(parameter_update_sub, &updated);
+
+ if (updated) {
+ orb_copy(ORB_ID(parameter_update), parameter_update_sub, ¶m_upd);
+ updateParams();
+ parameters_updated();
+ }
+}
+
+uint8_t Sih::is_HIL_running(int vehicle_status_sub)
+{
+ bool updated;
+ struct vehicle_status_s vehicle_status;
+ static uint8_t running=false;
+
+ orb_check(vehicle_status_sub, &updated);
+
+ if (updated) {
+ orb_copy(ORB_ID(vehicle_status), vehicle_status_sub, &vehicle_status);
+ running=vehicle_status.hil_state;
+ }
+
+ return running;
+}
+
+// store the parameters in a more convenient form
+void Sih::parameters_updated()
+{
+
+ _T_MAX = _sih_t_max.get();
+ _Q_MAX = _sih_q_max.get();
+ _L_ROLL = _sih_l_roll.get();
+ _L_PITCH = _sih_l_pitch.get();
+ _KDV = _sih_kdv.get();
+ _KDW = _sih_kdw.get();
+ _H0 = _sih_h0.get();
+
+ _LAT0 = (double)_sih_lat0.get()*1.0e-7;
+ _LON0 = (double)_sih_lon0.get()*1.0e-7;
+ _COS_LAT0=cosl(radians(_LAT0));
+
+ _MASS=_sih_mass.get();
+
+ _W_I=Vector3f(0.0f,0.0f,_MASS*CONSTANTS_ONE_G);
+
+ _I=diag(Vector3f(_sih_ixx.get(),_sih_iyy.get(),_sih_izz.get()));
+ _I(0,1)=_I(1,0)=_sih_ixy.get();
+ _I(0,2)=_I(2,0)=_sih_ixz.get();
+ _I(1,2)=_I(2,1)=_sih_iyz.get();
+
+ _Im1=inv(_I);
+
+ _mu_I=Vector3f(_sih_mu_x.get(), _sih_mu_y.get(), _sih_mu_z.get());
+
+}
+
+// initialization of the variables for the simulator
+void Sih::init_variables()
+{
+ srand(1234); // initialize the random seed once before calling generate_wgn()
+
+ _p_I=Vector3f(0.0f,0.0f,0.0f);
+ _v_I=Vector3f(0.0f,0.0f,0.0f);
+ _q=Quatf(1.0f,0.0f,0.0f,0.0f);
+ _w_B=Vector3f(0.0f,0.0f,0.0f);
+
+ _u[0]=_u[1]=_u[2]=_u[3]=0.0f;
+
+}
+
+void Sih::init_sensors()
+{
+
+ _sensor_accel.device_id=1;
+ _sensor_accel.error_count=0;
+ _sensor_accel.integral_dt=0;
+ _sensor_accel.temperature=T1_C;
+ _sensor_accel.scaling=0.0f;
+
+ _sensor_gyro.device_id=1;
+ _sensor_gyro.error_count=0;
+ _sensor_gyro.integral_dt=0;
+ _sensor_gyro.temperature=T1_C;
+ _sensor_gyro.scaling=0.0f;
+
+ _sensor_mag.device_id=1;
+ _sensor_mag.error_count=0;
+ _sensor_mag.temperature=T1_C;
+ _sensor_mag.scaling=0.0f;
+ _sensor_mag.is_external=false;
+
+ _sensor_baro.error_count=0;
+ _sensor_baro.device_id=1;
+
+ _vehicle_gps_pos.fix_type=3; // 3D fix
+ _vehicle_gps_pos.satellites_used=8;
+ _vehicle_gps_pos.heading=NAN;
+ _vehicle_gps_pos.heading_offset=NAN;
+ _vehicle_gps_pos.s_variance_m_s = 0.5f;
+ _vehicle_gps_pos.c_variance_rad = 0.1f;
+ _vehicle_gps_pos.eph = 0.9f;
+ _vehicle_gps_pos.epv = 1.78f;
+ _vehicle_gps_pos.hdop = 0.7f;
+ _vehicle_gps_pos.vdop = 1.1f;
+}
+
+int Sih::init_serial_port()
+{
+ struct termios uart_config;
+ int serial_fd = open(_uart_name, O_WRONLY | O_NONBLOCK | O_NOCTTY);
+
+ if (serial_fd < 0) {
+ PX4_ERR("failed to open port: %s", _uart_name);
+ }
+
+ tcgetattr(serial_fd, &uart_config); // read configuration
+
+ uart_config.c_oflag |= ONLCR;
+ // try to set Bauds rate
+ if (cfsetispeed(&uart_config, BAUDS_RATE) < 0 || cfsetospeed(&uart_config, BAUDS_RATE) < 0) {
+ PX4_WARN("ERR SET BAUD %s\n", _uart_name);
+ close(serial_fd);
+ }
+
+ tcsetattr(serial_fd, TCSANOW, &uart_config); // set config
+
+ return serial_fd;
+}
+
+// read the motor signals outputted from the mixer
+void Sih::read_motors(const int actuator_out_sub)
+{
+ struct actuator_outputs_s actuators_out {};
+
+ // read the actuator outputs
+ bool updated;
+ orb_check(actuator_out_sub, &updated);
+
+ if (updated) {
+ orb_copy(ORB_ID(actuator_outputs), actuator_out_sub, &actuators_out);
+ for (int i=0; i<NB_MOTORS; i++) // saturate the motor signals
+ _u[i]=constrain((actuators_out.output[i]-PWM_DEFAULT_MIN)/(PWM_DEFAULT_MAX-PWM_DEFAULT_MIN),0.0f, 1.0f);
+ }
+}
+
+// generate the motors thrust and torque in the body frame
+void Sih::generate_force_and_torques()
+{
+ _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]),
+ _Q_MAX * (+_u[0]+_u[1]-_u[2]-_u[3]));
+
+ _Fa_I=-_KDV*_v_I; // first order drag to slow down the aircraft
+ _Ma_B=-_KDW*_w_B; // first order angular damper
+}
+
+// apply the equations of motion of a rigid body and integrate one step
+void Sih::equations_of_motion()
+{
+ _C_IB=_q.to_dcm(); // body to inertial transformation
+
+ // Equations of motion of a rigid body
+ _p_I_dot=_v_I; // position differential
+ _v_I_dot=(_W_I+_Fa_I+_C_IB*_T_B)/_MASS; // conservation of linear momentum
+ _q_dot=_q.derivative1(_w_B); // attitude differential
+ _w_B_dot=_Im1*(_Mt_B+_Ma_B-_w_B.cross(_I*_w_B)); // conservation of angular momentum
+
+ // fake ground, avoid free fall
+ if(_p_I(2)>0.0f && (_v_I_dot(2)>0.0f || _v_I(2)>0.0f))
+ {
+ _v_I.setZero();
+ _w_B.setZero();
+ _v_I_dot.setZero();
+ }
+ else
+ {
+ // integration: Euler forward
+ _p_I = _p_I + _p_I_dot*_dt;
+ _v_I = _v_I + _v_I_dot*_dt;
+ _q = _q+_q_dot*_dt; // as given in attitude_estimator_q_main.cpp
+ _q.normalize();
+ _w_B = _w_B + _w_B_dot*_dt;
+
+ }
+}
+
+// reconstruct the noisy sensor signals
+void Sih::reconstruct_sensors_signals()
+{
+
+ // The sensor signals reconstruction and noise levels are from
+ // Bulka, Eitan, and Meyer Nahon. "Autonomous fixed-wing aerobatics: from theory to flight."
+ // In 2018 IEEE International Conference on Robotics and Automation (ICRA), pp. 6573-6580. IEEE, 2018.
+
+ // IMU
+ _acc=_C_IB.transpose()*(_v_I_dot-Vector3f(0.0f,0.0f,CONSTANTS_ONE_G))+noiseGauss3f(0.5f,1.7f,1.4f);
+ _gyro=_w_B+noiseGauss3f(0.14f,0.07f,0.03f);
+ _mag=_C_IB.transpose()*_mu_I+noiseGauss3f(0.02f,0.02f,0.03f);
+
+ // barometer
+ float altitude=(_H0-_p_I(2))+generate_wgn()*0.14f; // altitude with noise
+ _baro_p_mBar=CONSTANTS_STD_PRESSURE_MBAR* // reconstructed pressure in mBar
+ powf((1.0f+altitude*TEMP_GRADIENT/T1_K),-CONSTANTS_ONE_G/(TEMP_GRADIENT*CONSTANTS_AIR_GAS_CONST));
+ _baro_temp_c=T1_K+CONSTANTS_ABSOLUTE_NULL_CELSIUS+TEMP_GRADIENT*altitude; // reconstructed temperture in celcius
+
+ // GPS
+ _gps_lat_noiseless=_LAT0+degrees((double)_p_I(0)/CONSTANTS_RADIUS_OF_EARTH);
+ _gps_lon_noiseless=_LON0+degrees((double)_p_I(1)/CONSTANTS_RADIUS_OF_EARTH)/_COS_LAT0;
+ _gps_alt_noiseless=_H0-_p_I(2);
+
+ _gps_lat=_gps_lat_noiseless+(double)(generate_wgn()*7.2e-6f); // latitude in degrees
+ _gps_lon=_gps_lon_noiseless+(double)(generate_wgn()*1.75e-5f); // longitude in degrees
+ _gps_alt=_gps_alt_noiseless+generate_wgn()*1.78f;
+ _gps_vel=_v_I+noiseGauss3f(0.06f,0.077f,0.158f);
+}
+
+void Sih::send_IMU(hrt_abstime now)
+{
+ _sensor_accel.timestamp=now;
+ _sensor_accel.x=_acc(0);
+ _sensor_accel.y=_acc(1);
+ _sensor_accel.z=_acc(2);
+ if (_sensor_accel_pub != nullptr) {
+ orb_publish(ORB_ID(sensor_accel), _sensor_accel_pub, &_sensor_accel);
+ } else {
+ _sensor_accel_pub = orb_advertise(ORB_ID(sensor_accel), &_sensor_accel);
+ }
+
+ _sensor_gyro.timestamp=now;
+ _sensor_gyro.x=_gyro(0);
+ _sensor_gyro.y=_gyro(1);
+ _sensor_gyro.z=_gyro(2);
+ if (_sensor_gyro_pub != nullptr) {
+ orb_publish(ORB_ID(sensor_gyro), _sensor_gyro_pub, &_sensor_gyro);
+ } else {
+ _sensor_gyro_pub = orb_advertise(ORB_ID(sensor_gyro), &_sensor_gyro);
+ }
+
+ _sensor_mag.timestamp=now;
+ _sensor_mag.x=_mag(0);
+ _sensor_mag.y=_mag(1);
+ _sensor_mag.z=_mag(2);
+ if (_sensor_mag_pub != nullptr) {
+ orb_publish(ORB_ID(sensor_mag), _sensor_mag_pub, &_sensor_mag);
+ } else {
+ _sensor_mag_pub = orb_advertise(ORB_ID(sensor_mag), &_sensor_mag);
+ }
+
+ _sensor_baro.timestamp=now;
+ _sensor_baro.pressure=_baro_p_mBar;
+ _sensor_baro.temperature=_baro_temp_c;
+ if (_sensor_baro_pub != nullptr) {
+ orb_publish(ORB_ID(sensor_baro), _sensor_baro_pub, &_sensor_baro);
+ } else {
+ _sensor_baro_pub = orb_advertise(ORB_ID(sensor_baro), &_sensor_baro);
+ }
+}
+
+void Sih::send_gps(hrt_abstime now)
+{
+ _vehicle_gps_pos.timestamp=now;
+ _vehicle_gps_pos.lat=(int32_t)(_gps_lat*1e7); // Latitude in 1E-7 degrees
+ _vehicle_gps_pos.lon=(int32_t)(_gps_lon*1e7); // Longitude in 1E-7 degrees
+ _vehicle_gps_pos.alt=(int32_t)(_gps_alt*1000.0f); // Altitude in 1E-3 meters above MSL, (millimetres)
+ _vehicle_gps_pos.alt_ellipsoid = (int32_t)(_gps_alt*1000); // Altitude in 1E-3 meters bove Ellipsoid, (millimetres)
+ _vehicle_gps_pos.vel_ned_valid=true; // True if NED velocity is valid
+ _vehicle_gps_pos.vel_m_s=sqrtf(_gps_vel(0)*_gps_vel(0)+_gps_vel(1)*_gps_vel(1)); // GPS ground speed, (metres/sec)
+ _vehicle_gps_pos.vel_n_m_s=_gps_vel(0); // GPS North velocity, (metres/sec)
+ _vehicle_gps_pos.vel_e_m_s=_gps_vel(1); // GPS East velocity, (metres/sec)
+ _vehicle_gps_pos.vel_d_m_s=_gps_vel(2); // GPS Down velocity, (metres/sec)
+ _vehicle_gps_pos.cog_rad=atan2(_gps_vel(1),_gps_vel(0)); // Course over ground (NOT heading, but direction of movement), -PI..PI, (radians)
+ if (_vehicle_gps_pos_pub != nullptr) {
+ orb_publish(ORB_ID(vehicle_gps_position), _vehicle_gps_pos_pub, &_vehicle_gps_pos);
+ } else {
+ _vehicle_gps_pos_pub = orb_advertise(ORB_ID(vehicle_gps_position), &_vehicle_gps_pos);
+ }
+}
+
+void Sih::publish_sih()
+{
+
+ Eulerf Euler(_q);
+ _sih.timestamp=hrt_absolute_time();
+ _sih.dt_us=(uint32_t)(_dt*1e6f);
+ _sih.euler_rpy[0]=degrees(Euler(0));
+ _sih.euler_rpy[1]=degrees(Euler(1));
+ _sih.euler_rpy[2]=degrees(Euler(2));
+ _sih.omega_b[0]=_w_B(0); // wing body rates in body frame
+ _sih.omega_b[1]=_w_B(1);
+ _sih.omega_b[2]=_w_B(2);
+ _sih.p_i_local[0]=_p_I(0); // local inertial position
+ _sih.p_i_local[1]=_p_I(1);
+ _sih.p_i_local[2]=_p_I(2);
+ _sih.v_i[0]=_v_I(0); // inertial velocity
+ _sih.v_i[1]=_v_I(1);
+ _sih.v_i[2]=_v_I(2);
+ _sih.u[0]=_u[0];
+ _sih.u[1]=_u[1];
+ _sih.u[2]=_u[2];
+ _sih.u[3]=_u[3];
+ if (_sih_pub != nullptr) {
+ orb_publish(ORB_ID(sih), _sih_pub, &_sih);
+ } else {
+ _sih_pub = orb_advertise(ORB_ID(sih), &_sih);
+ }
+}
+
+void Sih::send_serial_msg(int serial_fd, int64_t t_ms)
+{
+
+ char uart_msg[100];
+
+ uint8_t n;
+ int32_t GPS_pos[3]; // latitude, longitude in 10^-7 degrees, altitude AMSL in mm
+ int32_t EA_deci_deg[3]; // Euler angles in deci degrees integers to send to serial
+ int32_t throttles[4]; // throttles from 0 to 99
+
+ GPS_pos[0]=(int32_t)(_gps_lat_noiseless*1e7); // Latitude in 1E-7 degrees
+ GPS_pos[1]=(int32_t)(_gps_lon_noiseless*1e7); // Longitude in 1E-7 degrees
+ GPS_pos[2]=(int32_t)(_gps_alt_noiseless*1000.0f); // Altitude in 1E-3 meters above MSL, (millimetres)
+ Eulerf Euler(_q);
+ EA_deci_deg[0]=(int32_t)degrees(Euler(0)*10.0f); // decidegrees
+ EA_deci_deg[1]=(int32_t)degrees(Euler(1)*10.0f);
+ EA_deci_deg[2]=(int32_t)degrees(Euler(2)*10.0f);
+ throttles[0]=(int32_t)(_u[0]*99.0f);
+ throttles[1]=(int32_t)(_u[1]*99.0f);
+ throttles[2]=(int32_t)(_u[2]*99.0f);
+ throttles[3]=(int32_t)(_u[3]*99.0f);
+
+ n = sprintf(uart_msg, "T%07lld,P%+010d%+010d%+08d,A%+05d%+05d%+05d,U%+03d%+03d%+03d%+03d\n",
+ t_ms,GPS_pos[0],GPS_pos[1],GPS_pos[2],
+ EA_deci_deg[0],EA_deci_deg[1],EA_deci_deg[2],
+ throttles[0],throttles[1],throttles[2],throttles[3]);
+ write(serial_fd, uart_msg, n);
+}
+
+float Sih::generate_wgn() // generate white Gaussian noise sample with std=1
+{
+ float temp=((float)(rand()+1))/(((float)RAND_MAX+1.0f));
+
+ return sqrtf(-2.0f*logf(temp))*cosf(2.0f*M_PI_F*rand()/RAND_MAX);
+}
+
+Vector3f Sih::noiseGauss3f(float stdx,float stdy, float stdz) // generate white Gaussian noise sample with specified std
+{
+ return Vector3f(generate_wgn()*stdx,generate_wgn()*stdy,generate_wgn()*stdz);
+} // there is another wgn algorithm in BlockRandGauss.hpp
+
+int sih_main(int argc, char *argv[])
+{
+ return Sih::main(argc, argv);
+}
+
+// int Sih::pack_float(char* uart_msg, int index, void *value)
+// {
+// uint32_t value_raw=(uint32_t)(value*);
+
+// for (int i=3; i>=0; i=i-1) {
+// buffer[index+i]=(char)(value_raw&0xFF);
+// value_raw=value_raw>>8;
+// }
+
+// return index+4; // points to the index for the next value
+// }
\ No newline at end of file
diff --git a/src/modules/sih/sih.hpp b/src/modules/sih/sih.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..1c8de14612f71c0ddf8ba57c99cafa5b980e5de6
--- /dev/null
+++ b/src/modules/sih/sih.hpp
@@ -0,0 +1,200 @@
+/****************************************************************************
+ *
+ * Copyright (c) 2018 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
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+#include <px4_module.h>
+#include <px4_module_params.h>
+
+#include <matrix/matrix/math.hpp> // matrix, vectors, dcm, quaterions
+#include <conversion/rotation.h> // math::radians,
+#include <ecl/geo/geo.h> // to get the physical constants
+#include <drivers/drv_hrt.h> // to get the real time
+
+#include <uORB/topics/parameter_update.h>
+#include <uORB/topics/actuator_outputs.h>
+#include <uORB/topics/sensor_baro.h>
+#include <uORB/topics/sensor_gyro.h>
+#include <uORB/topics/sensor_accel.h>
+#include <uORB/topics/sensor_mag.h>
+#include <uORB/topics/vehicle_gps_position.h>
+#include <uORB/topics/sih.h>
+
+using namespace matrix;
+
+extern "C" __EXPORT int sih_main(int argc, char *argv[]);
+
+class Sih : public ModuleBase<Sih>, public ModuleParams
+{
+public:
+ Sih(int example_param, bool example_flag);
+
+ virtual ~Sih() = default;
+
+ /** @see ModuleBase */
+ static int task_spawn(int argc, char *argv[]);
+
+ /** @see ModuleBase */
+ static Sih *instantiate(int argc, char *argv[]);
+
+ /** @see ModuleBase */
+ static int custom_command(int argc, char *argv[]);
+
+ /** @see ModuleBase */
+ static int print_usage(const char *reason = nullptr);
+
+ /** @see ModuleBase::run() */
+ void run() override;
+
+ /** @see ModuleBase::print_status() */
+ int print_status() override;
+
+ static float generate_wgn(); // generate white Gaussian noise sample
+
+ // generate white Gaussian noise sample as a 3D vector with specified std
+ static Vector3f noiseGauss3f(float stdx, float stdy, float stdz);
+
+ // static int pack_float(char* uart_msg, int index, void *value); // pack a float to a IEEE754
+private:
+
+ /**
+ * Check for parameter changes and update them if needed.
+ * @param parameter_update_sub uorb subscription to parameter_update
+ * @param force for a parameter update
+ */
+ void parameters_update_poll(int parameter_update_sub);
+ void parameters_updated();
+
+ uint8_t is_HIL_running(int vehicle_status_sub);
+
+ // to publish the simulator states
+ struct sih_s _sih {};
+ orb_advert_t _sih_pub{nullptr};
+ // to publish the sensor baro
+ struct sensor_baro_s _sensor_baro {};
+ orb_advert_t _sensor_baro_pub{nullptr};
+ // to publish the sensor mag
+ struct sensor_mag_s _sensor_mag {};
+ orb_advert_t _sensor_mag_pub{nullptr};
+ // to publish the sensor gyroscope
+ struct sensor_gyro_s _sensor_gyro {};
+ orb_advert_t _sensor_gyro_pub{nullptr};
+ // to publish the sensor accelerometer
+ struct sensor_accel_s _sensor_accel {};
+ orb_advert_t _sensor_accel_pub{nullptr};
+ // to publish the gps position
+ struct vehicle_gps_position_s _vehicle_gps_pos {};
+ orb_advert_t _vehicle_gps_pos_pub{nullptr};
+
+ // hard constants
+ static constexpr uint16_t NB_MOTORS = 4;
+ static constexpr float T1_C = 15.0f; // ground temperature in celcius
+ static constexpr float T1_K = T1_C - CONSTANTS_ABSOLUTE_NULL_CELSIUS; // ground temperature in Kelvin
+ static constexpr float TEMP_GRADIENT = -6.5f / 1000.0f; // temperature gradient in degrees per metre
+ static constexpr uint32_t BAUDS_RATE = 57600; // bauds rate of the serial port
+
+ void init_variables();
+ void init_sensors();
+ int init_serial_port();
+ void read_motors(const int actuator_out_sub);
+ void generate_force_and_torques();
+ void equations_of_motion();
+ void reconstruct_sensors_signals();
+ void send_IMU(hrt_abstime now);
+ void send_gps(hrt_abstime now);
+ void publish_sih();
+ void send_serial_msg(int serial_fd, int64_t t_ms);
+
+ float _dt; // sampling time [s]
+
+ char _uart_name[12] = "/dev/ttyS5/"; // serial port name
+
+ Vector3f _T_B; // thrust force in body frame [N]
+ Vector3f _Fa_I; // aerodynamic force in inertial frame [N]
+ Vector3f _Mt_B; // thruster moments in the body frame [Nm]
+ Vector3f _Ma_B; // aerodynamic moments in the body frame [Nm]
+ Vector3f _p_I; // inertial position [m]
+ Vector3f _v_I; // inertial velocity [m/s]
+ Vector3f _v_B; // body frame velocity [m/s]
+ Vector3f _p_I_dot; // inertial position differential
+ Vector3f _v_I_dot; // inertial velocity differential
+ Quatf _q; // quaternion attitude
+ Dcmf _C_IB; // body to inertial transformation
+ Vector3f _w_B; // body rates in body frame [rad/s]
+ Quatf _q_dot; // quaternion differential
+ Vector3f _w_B_dot; // body rates differential
+ float _u[NB_MOTORS]; // thruster signals
+
+
+ // sensors reconstruction
+ Vector3f _acc;
+ Vector3f _mag;
+ Vector3f _gyro;
+ Vector3f _gps_vel;
+ double _gps_lat, _gps_lat_noiseless;
+ double _gps_lon, _gps_lon_noiseless;
+ float _gps_alt, _gps_alt_noiseless;
+ float _baro_p_mBar; // reconstructed (simulated) pressure in mBar
+ float _baro_temp_c; // reconstructed (simulated) barometer temperature in celcius
+
+ // parameters
+ float _MASS, _T_MAX, _Q_MAX, _L_ROLL, _L_PITCH, _KDV, _KDW, _H0;
+ double _LAT0, _LON0, _COS_LAT0;
+ Vector3f _W_I; // weight of the vehicle in inertial frame [N]
+ Matrix3f _I; // vehicle inertia matrix
+ Matrix3f _Im1; // inverse of the intertia matrix
+ Vector3f _mu_I; // NED magnetic field in inertial frame [G]
+
+ // parameters defined in sih_params.c
+ DEFINE_PARAMETERS(
+ (ParamFloat<px4::params::SIH_MASS>) _sih_mass,
+ (ParamFloat<px4::params::SIH_IXX>) _sih_ixx,
+ (ParamFloat<px4::params::SIH_IYY>) _sih_iyy,
+ (ParamFloat<px4::params::SIH_IZZ>) _sih_izz,
+ (ParamFloat<px4::params::SIH_IXY>) _sih_ixy,
+ (ParamFloat<px4::params::SIH_IXZ>) _sih_ixz,
+ (ParamFloat<px4::params::SIH_IYZ>) _sih_iyz,
+ (ParamFloat<px4::params::SIH_T_MAX>) _sih_t_max,
+ (ParamFloat<px4::params::SIH_Q_MAX>) _sih_q_max,
+ (ParamFloat<px4::params::SIH_L_ROLL>) _sih_l_roll,
+ (ParamFloat<px4::params::SIH_L_PITCH>) _sih_l_pitch,
+ (ParamFloat<px4::params::SIH_KDV>) _sih_kdv,
+ (ParamFloat<px4::params::SIH_KDW>) _sih_kdw,
+ (ParamInt<px4::params::SIH_LAT0>) _sih_lat0,
+ (ParamInt<px4::params::SIH_LON0>) _sih_lon0,
+ (ParamFloat<px4::params::SIH_H0>) _sih_h0,
+ (ParamFloat<px4::params::SIH_MU_X>) _sih_mu_x,
+ (ParamFloat<px4::params::SIH_MU_Y>) _sih_mu_y,
+ (ParamFloat<px4::params::SIH_MU_Z>) _sih_mu_z
+ )
+};
diff --git a/src/modules/sih/sih_params.c b/src/modules/sih/sih_params.c
new file mode 100644
index 0000000000000000000000000000000000000000..30485c9f781e9786f5422c022bfd7dd51b253ff9
--- /dev/null
+++ b/src/modules/sih/sih_params.c
@@ -0,0 +1,345 @@
+/****************************************************************************
+ *
+ * Copyright (c) 2013-2015 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
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file sih_params.c
+ * Parameters for quadcopter X simulator in hardware.
+ *
+ * @author Romain Chiappinelli <romain.chiap@gmail.com>
+ * February 2019
+ */
+
+/**
+ * Vehicle mass
+ *
+ * This value can be measured by weighting the quad on a scale.
+ *
+ * @unit kg
+ * @min 0.0
+ * @decimal 2
+ * @increment 0.1
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_MASS, 1.0f);
+
+/**
+ * Vehicle inertia about X axis
+ *
+ * The intertia is a 3 by 3 symmetric matrix.
+ * It represents the difficulty of the vehicle to modify its angular rate.
+ *
+ * @unit kg*m*m
+ * @min 0.0
+ * @decimal 3
+ * @increment 0.005
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_IXX, 0.025f);
+
+/**
+ * Vehicle inertia about Y axis
+ *
+ * The intertia is a 3 by 3 symmetric matrix.
+ * It represents the difficulty of the vehicle to modify its angular rate.
+ *
+ * @unit kg*m*m
+ * @min 0.0
+ * @decimal 3
+ * @increment 0.005
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_IYY, 0.025f);
+
+/**
+ * Vehicle inertia about Z axis
+ *
+ * The intertia is a 3 by 3 symmetric matrix.
+ * It represents the difficulty of the vehicle to modify its angular rate.
+ *
+ * @unit kg*m*m
+ * @min 0.0
+ * @decimal 3
+ * @increment 0.005
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_IZZ, 0.030f);
+
+/**
+ * Vehicle cross term inertia xy
+ *
+ * The intertia is a 3 by 3 symmetric matrix.
+ * This value can be set to 0 for a quad symmetric about its center of mass.
+ *
+ * @unit kg*m*m
+ * @decimal 3
+ * @increment 0.005
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_IXY, 0.0f);
+
+/**
+ * Vehicle cross term inertia xz
+ *
+ * The intertia is a 3 by 3 symmetric matrix.
+ * This value can be set to 0 for a quad symmetric about its center of mass.
+ *
+ * @unit kg*m*m
+ * @decimal 3
+ * @increment 0.005
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_IXZ, 0.0f);
+
+/**
+ * Vehicle cross term inertia yz
+ *
+ * The intertia is a 3 by 3 symmetric matrix.
+ * This value can be set to 0 for a quad symmetric about its center of mass.
+ *
+ * @unit kg*m*m
+ * @decimal 3
+ * @increment 0.005
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_IYZ, 0.0f);
+
+/**
+ * Max propeller thrust force
+ *
+ * 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.
+ *
+ * @unit N
+ * @min 0.0
+ * @decimal 2
+ * @increment 0.5
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_T_MAX, 5.0f);
+
+/**
+ * Max propeller torque
+ *
+ * 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.
+ *
+ * @unit Nm
+ * @min 0.0
+ * @decimal 3
+ * @increment 0.05
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_Q_MAX, 0.1f);
+
+/**
+ * Roll arm length
+ *
+ * This is the arm length generating the rolling moment
+ *
+ * This value can be measured with a ruler.
+ * This corresponds to half the distance between the left and right motors.
+ *
+ * @unit m
+ * @min 0.0
+ * @decimal 2
+ * @increment 0.05
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_L_ROLL, 0.2f);
+
+/**
+ * Pitch arm length
+ *
+ * This is the arm length generating the pitching moment
+ *
+ * This value can be measured with a ruler.
+ * This corresponds to half the distance between the front and rear motors.
+ *
+ * @unit m
+ * @min 0.0
+ * @decimal 2
+ * @increment 0.05
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_L_PITCH, 0.2f);
+
+/**
+ * First order drag coefficient
+ *
+ * Physical coefficient representing the friction with air particules.
+ * The greater this value, the slower the quad will move.
+ *
+ * Drag force function of velocity: D=-KDV*V.
+ * The maximum freefall velocity can be computed as V=10*MASS/KDV [m/s]
+ *
+ * @unit N/(m/s)
+ * @min 0.0
+ * @decimal 2
+ * @increment 0.05
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_KDV, 1.0f);
+
+/**
+ * First order angular damper coefficient
+ *
+ * Physical coefficient representing the friction with air particules during rotations.
+ * The greater this value, the slower the quad will rotate.
+ *
+ * Aerodynamic moment function of body rate: Ma=-KDW*W_B.
+ * This value can be set to 0 if unknown.
+ *
+ * @unit Nm/(rad/s)
+ * @min 0.0
+ * @decimal 3
+ * @increment 0.005
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_KDW, 0.025f);
+
+/**
+ * Initial geodetic latitude
+ *
+ * This value represents the North-South location on Earth where the simulation begins.
+ * A value of 45 deg should be written 450000000.
+ *
+ * LAT0, LON0, H0, MU_X, MU_Y, and MU_Z should ideally be consistent among each others
+ * to represent a physical ground location on Earth.
+ *
+ * @unit 1e-7 deg
+ * @min -850000000
+ * @max 850000000
+ * @group SIH
+ */
+PARAM_DEFINE_INT32(SIH_LAT0, 454671160);
+
+/**
+ * Initial geodetic longitude
+ *
+ * This value represents the East-West location on Earth where the simulation begins.
+ * A value of 45 deg should be written 450000000.
+ *
+ * LAT0, LON0, H0, MU_X, MU_Y, and MU_Z should ideally be consistent among each others
+ * to represent a physical ground location on Earth.
+ *
+ * @unit 1e-7 deg
+ * @min -1800000000
+ * @max 1800000000
+ * @group SIH
+ */
+PARAM_DEFINE_INT32(SIH_LON0, -737578370);
+
+/**
+ * Initial AMSL ground altitude
+ *
+ * This value represents the Above Mean Sea Level (AMSL) altitude where the simulation begins.
+ *
+ * If using FlightGear as a visual animation,
+ * this value can be tweaked such that the vehicle lies on the ground at takeoff.
+ *
+ * LAT0, LON0, H0, MU_X, MU_Y, and MU_Z should ideally be consistent among each others
+ * to represent a physical ground location on Earth.
+ *
+ *
+ * @unit m
+ * @min -420.0
+ * @max 8848.0
+ * @decimal 2
+ * @increment 0.01
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_H0, 32.34f);
+
+/**
+ * North magnetic field at the initial location
+ *
+ * This value represents the North magnetic field at the initial location.
+ *
+ * A magnetic field calculator can be found on the NOAA website
+ * Note, the values need to be converted from nano Tesla to Gauss
+ *
+ * LAT0, LON0, H0, MU_X, MU_Y, and MU_Z should ideally be consistent among each others
+ * to represent a physical ground location on Earth.
+ *
+ * @unit Gauss
+ * @min -1.0
+ * @max 1.0
+ * @decimal 2
+ * @increment 0.001
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_MU_X, 0.179f);
+
+/**
+ * East magnetic field at the initial location
+ *
+ * This value represents the East magnetic field at the initial location.
+ *
+ * A magnetic field calculator can be found on the NOAA website
+ * Note, the values need to be converted from nano Tesla to Gauss
+ *
+ * LAT0, LON0, H0, MU_X, MU_Y, and MU_Z should ideally be consistent among each others
+ * to represent a physical ground location on Earth.
+ *
+ * @unit Gauss
+ * @min -1.0
+ * @max 1.0
+ * @decimal 2
+ * @increment 0.001
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_MU_Y, -0.045f);
+
+/**
+ * Down magnetic field at the initial location
+ *
+ * This value represents the Down magnetic field at the initial location.
+ *
+ * A magnetic field calculator can be found on the NOAA website
+ * Note, the values need to be converted from nano Tesla to Gauss
+ *
+ * LAT0, LON0, H0, MU_X, MU_Y, and MU_Z should ideally be consistent among each others
+ * to represent a physical ground location on Earth.
+ *
+ * @unit Gauss
+ * @min -1.0
+ * @max 1.0
+ * @decimal 2
+ * @increment 0.001
+ * @group SIH
+ */
+PARAM_DEFINE_FLOAT(SIH_MU_Z, 0.504f);
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