File size: 3,470 Bytes
21ab839 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 | // Copyright 2026 Simon Sagmeister
#include "ocd_aerodynamics_models_cpp/default.hpp"
#include <cmath>
#include <algorithm>
#include <stdexcept>
#include <utility>
#include "tum_helpers_cpp/numerical.hpp"
namespace tam::ocd::aerodynamics
{
types::AeroModelOutput DefaultAerodynamicsModel::evaluate(types::AeroModelInput const & u)
{
// vx, vy - long/lat velocity in m/s, theta - pitch angle in rad
auto sign = [](double x) {
if (x < 0) {
return -1;
} else {
return 1;
}
};
types::AeroModelOutput out;
// Lift cofficient multiplier interpolation
double delta_c_l = tam::helpers::numerical::interp(
u.vx_mps, p_.c_l_velocity_scaling__vel_mps, p_.c_l_velocity_scaling__delta_c_l);
// Aero center translation interpolation
double aero_center_translation_m = tam::helpers::numerical::interp(
u.pitch_angle_rad, p_.pitch_aero_center_translation__pitch_rad,
p_.pitch_aero_center_translation__aero_center_translation_m);
out.force_cog_N.x =
-0.5 * p_.c_d * p_.air_density_kgpm3 * p_.A_m2 * std::pow(u.vx_mps, 2) * sign(u.vx_mps);
// To be precise the area of calculating the drag here is different for lateral movement
// but this is neglected here
out.force_cog_N.y =
-0.5 * p_.c_d * p_.air_density_kgpm3 * p_.A_m2 * std::pow(u.vy_mps, 2) * sign(u.vy_mps);
out.force_cog_N.z =
0.5 * (p_.c_l + delta_c_l) * p_.air_density_kgpm3 * p_.A_m2 * std::pow(u.vx_mps, 2);
// Aero Balance
out.torque_Nm.y = -out.force_cog_N.z * (p_.d_aero_center_cog_m + aero_center_translation_m);
// Zero for everything else
out.torque_Nm.x = 0;
out.torque_Nm.z = 0;
return out;
}
void DefaultAerodynamicsModel::declare_parameters(
tam::pmg::ParamReferenceManager * param_manager, std::string name_prefix)
{
param_manager->declare_parameter(
name_prefix + "air_density_kgpm3", &(p_.air_density_kgpm3), 1.225,
tam::pmg::ParameterType::DOUBLE, "");
// Base parameters
param_manager->declare_parameter(
name_prefix + "A_m2", &(p_.A_m2), 1.0, tam::pmg::ParameterType::DOUBLE, "");
param_manager->declare_parameter(
name_prefix + "c_d", &(p_.c_d), 1.0, tam::pmg::ParameterType::DOUBLE, "");
param_manager->declare_parameter(
name_prefix + "c_l", &(p_.c_l), -1.5, tam::pmg::ParameterType::DOUBLE, "");
param_manager->declare_parameter(
name_prefix + "d_aero_center_cog_m", &(p_.d_aero_center_cog_m), 0.0,
tam::pmg::ParameterType::DOUBLE, "");
// Velocity scaling of cl
param_manager->declare_parameter(
name_prefix + "c_l_velocity_scaling.vel_mps", &(p_.c_l_velocity_scaling__vel_mps),
std::vector<double>{0, 100}, tam::pmg::ParameterType::DOUBLE_ARRAY, "");
param_manager->declare_parameter(
name_prefix + "c_l_velocity_scaling.delta_c_l", &(p_.c_l_velocity_scaling__delta_c_l),
std::vector<double>{0, 0}, tam::pmg::ParameterType::DOUBLE_ARRAY, "");
// Pitch correction since pitch moves the center of aero forces
param_manager->declare_parameter(
name_prefix + "pitch_aero_center_translation.pitch_rad",
&(p_.pitch_aero_center_translation__pitch_rad), std::vector<double>{-M_PI, M_PI},
tam::pmg::ParameterType::DOUBLE_ARRAY, "");
param_manager->declare_parameter(
name_prefix + "pitch_aero_center_translation.aero_center_translation_m",
&(p_.pitch_aero_center_translation__aero_center_translation_m), std::vector<double>{0, 0},
tam::pmg::ParameterType::DOUBLE_ARRAY, "");
}
} // namespace tam::ocd::aerodynamics
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