Line data    Source code

       1             : /*
       2             :    This program is free software: you can redistribute it and/or modify
       3             :    it under the terms of the GNU General Public License as published by
       4             :    the Free Software Foundation, either version 3 of the License, or
       5             :    (at your option) any later version.
       6             : 
       7             :    This program is distributed in the hope that it will be useful,
       8             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
       9             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      10             :    GNU General Public License for more details.
      11             : 
      12             :    You should have received a copy of the GNU General Public License
      13             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      14             :  */
      15             : /*
      16             :   sailboat simulator class
      17             : */
      18             : 
      19             : #pragma once
      20             : 
      21             : #include "SIM_Aircraft.h"
      22             : 
      23             : namespace SITL {
      24             : 
      25             : /*
      26             :   a sailboat simulator
      27             :  */
      28             : class Sailboat : public Aircraft {
      29             : public:
      30             :     Sailboat(const char *frame_str);
      31             : 
      32             :     /* update model by one time step */
      33             :     void update(const struct sitl_input &input) override;
      34             : 
      35             :     /* static object creator */
      36           4 :     static Aircraft *create(const char *frame_str) {
      37           4 :         return NEW_NOTHROW Sailboat(frame_str);
      38             :     }
      39             : 
      40           0 :     bool on_ground() const override {return true;};
      41             : 
      42             : protected:
      43             :     bool motor_connected;       // true if this frame has a motor
      44             :     bool skid_steering;         // true if this vehicle is a skid-steering vehicle
      45             :     float sail_area; // 1.0 for normal area
      46             : 
      47             : private:
      48             : 
      49             :     // calculate the lift and drag as values from 0 to 1 given an apparent wind speed in m/s and angle-of-attack in degrees
      50             :     void calc_lift_and_drag(float wind_speed, float angle_of_attack_deg, float& lift, float& drag) const;
      51             : 
      52             :     // return turning circle (diameter) in meters for steering angle proportion in the range -1 to +1
      53             :     float get_turn_circle(float steering) const;
      54             : 
      55             :     // return yaw rate in deg/sec given a steering input (in the range -1 to +1) and speed in m/s
      56             :     float get_yaw_rate(float steering, float speed) const;
      57             : 
      58             :     // return lateral acceleration in m/s/s given a steering input (in the range -1 to +1) and speed in m/s
      59             :     float get_lat_accel(float steering, float speed) const;
      60             : 
      61             :     // simulate waves and swell
      62             :     void update_wave(float delta_time);
      63             : 
      64             :     float steering_angle_max;   // vehicle steering mechanism's max angle in degrees
      65             :     float turning_circle;       // vehicle minimum turning circle diameter in meters
      66             : 
      67             :     // lift and drag curves.  index is angle/10deg
      68             :     // angle-of-attack            0      10     20     30     40     50     60     70     80     90      100     110     120     130     140     150     160     170+
      69             :     const float lift_curve[18] = {0.00f, 0.50f, 1.00f, 1.10f, 0.95f, 0.75f, 0.60f, 0.40f, 0.20f, 0.00f, -0.20f, -0.40f, -0.60f, -0.75f, -0.95f, -1.10f, -1.00f, -0.50f};
      70             :     const float drag_curve[18] = {0.10f, 0.10f, 0.20f, 0.40f, 0.80f, 1.20f, 1.50f, 1.70f, 1.90f, 1.95f,  1.90f,  1.70f,  1.50f,  1.20f,  0.80f,  0.40f,  0.20f,  0.10f};
      71             : 
      72             :     const float mass = 2.0f;
      73             : 
      74             :     Vector3f velocity_ef_water; // m/s
      75             :     Vector3f wave_gyro;         // rad/s
      76             :     float wave_heave;           // m/s/s
      77             :     float wave_phase;           // rads
      78             : };
      79             : 
      80             : } // namespace SITL