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97 lines
3.2 KiB
97 lines
3.2 KiB
/* |
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This program is free software: you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation, either version 3 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
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along with this program. If not, see <http://www.gnu.org/licenses/>. |
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*/ |
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/* |
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ROV/AUV/Submarine simulator class |
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*/ |
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#pragma once |
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#include "SIM_Aircraft.h" |
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#include "SIM_Motor.h" |
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#include "SIM_Frame.h" |
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namespace SITL { |
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/* |
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a submarine simulator |
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*/ |
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class Submarine : public Aircraft { |
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public: |
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Submarine(const char *home_str, const char *frame_str); |
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/* update model by one time step */ |
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void update(const struct sitl_input &input) override; |
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/* static object creator */ |
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static Aircraft *create(const char *home_str, const char *frame_str) { |
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return new Submarine(home_str, frame_str); |
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} |
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protected: |
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const float water_density = 1023.6; // (kg/m^3) At a temperature of 25 °C, salinity of 35 g/kg and 1 atm pressure |
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const struct { |
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float length = 0.457; // x direction (meters) |
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float width = 0.338; // y direction (meters) |
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float height = 0.254; // z direction (meters) |
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float weight = 10.5; // (kg) |
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float net_buoyancy = 2.0; // (N) |
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float buoyancy_acceleration = GRAVITY_MSS + net_buoyancy/weight; |
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// Frame drag coefficient |
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const Vector3f linear_drag_coefficient = Vector3f(0.2, 0.3, 0.4); |
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const Vector3f angular_drag_coefficient = Vector3f(1, 1, 1); |
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// Calculate total volume from water buoyancy |
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// $ V = F_b / (rho * g) $ |
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// V = volume (m^3), rho = water density (kg/m^3), g = gravity (m/s^2), F_b = force (N) |
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float volume = buoyancy_acceleration * weight / (GRAVITY_MSS * 1023.6f); |
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// Calculate equivalent sphere area for drag force |
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// $ A = pi * r^2 / 4 $ |
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// $ V = 4 * pi * r^3 / 3 $ |
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// $ r ^2 = (V * 3 / 4) ^ (2/3) $ |
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// A = area (m^3), r = sphere radius (m) |
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float equivalent_sphere_area = M_PI_4 * pow(volume * 3.0f / 4.0f, 2.0f / 3.0f); |
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} frame_property; |
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bool on_ground() const override; |
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// calculate rotational and linear accelerations |
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void calculate_forces(const struct sitl_input &input, Vector3f &rot_accel, Vector3f &body_accel); |
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// calculate buoyancy |
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float calculate_buoyancy_acceleration(); |
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// calculate drag from velocity and drag coefficient |
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void calculate_drag_force(const Vector3f &velocity, const Vector3f &drag_coefficient, Vector3f &force); |
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Frame *frame; |
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}; |
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class Thruster { |
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public: |
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Thruster(int8_t _servo, float roll_fac, float pitch_fac, float yaw_fac, float throttle_fac, float forward_fac, float lat_fac) : |
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servo(_servo) |
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{ |
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linear = Vector3f(forward_fac, lat_fac, -throttle_fac); |
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rotational = Vector3f(roll_fac, pitch_fac, yaw_fac); |
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}; |
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int8_t servo; |
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Vector3f linear; |
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Vector3f rotational; |
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}; |
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}
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