ardupilot/libraries/SITL/SIM_Multicopter.cpp
Andrew Tridgell 767773da5e SITL: improved multicopter simulation
this takes account of motor expo, velocity of air over propellers,
mass, size and other factors

It also allows for frame parameters to be supplied as an external json file
2020-10-28 14:20:44 +11:00

78 lines
2.0 KiB
C++

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
multicopter simulator class
*/
#include "SIM_Multicopter.h"
#include <AP_Motors/AP_Motors.h>
#include <stdio.h>
using namespace SITL;
MultiCopter::MultiCopter(const char *frame_str) :
Aircraft(frame_str)
{
frame = Frame::find_frame(frame_str);
if (frame == nullptr) {
printf("Frame '%s' not found", frame_str);
exit(1);
}
frame->init(frame_str);
mass = frame->get_mass();
frame_height = 0.1;
num_motors = frame->num_motors;
ground_behavior = GROUND_BEHAVIOR_NO_MOVEMENT;
}
// calculate rotational and linear accelerations
void MultiCopter::calculate_forces(const struct sitl_input &input, Vector3f &rot_accel, Vector3f &body_accel)
{
frame->calculate_forces(*this, input, rot_accel, body_accel, rpm);
add_shove_forces(rot_accel, body_accel);
add_twist_forces(rot_accel);
}
/*
update the multicopter simulation by one time step
*/
void MultiCopter::update(const struct sitl_input &input)
{
// get wind vector setup
update_wind(input);
Vector3f rot_accel;
calculate_forces(input, rot_accel, accel_body);
// estimate voltage and current
frame->current_and_voltage(battery_voltage, battery_current);
update_dynamics(rot_accel);
update_external_payload(input);
// update lat/lon/altitude
update_position();
time_advance();
// update magnetic field
update_mag_field_bf();
}