/*
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 .
*/
/*
multicopter frame simulator class
*/
#include "SIM_Frame.h"
#include
#include
#include
#include
#include
#include "picojson.h"
using namespace SITL;
static Motor quad_plus_motors[] =
{
Motor(AP_MOTORS_MOT_1, 90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2),
Motor(AP_MOTORS_MOT_2, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4),
Motor(AP_MOTORS_MOT_3, 0, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 1),
Motor(AP_MOTORS_MOT_4, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3),
};
static Motor quad_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_3, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_4, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
};
// motor order to match betaflight conventions
// See: https://fpvfrenzy.com/betaflight-motor-order/
static Motor quad_bf_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_2, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW,1),
Motor(AP_MOTORS_MOT_3, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW,3),
Motor(AP_MOTORS_MOT_4, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
};
// motor order to match betaflight conventions, reversed direction
static Motor quad_bf_x_rev_motors[] =
{
Motor(AP_MOTORS_MOT_1, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2),
Motor(AP_MOTORS_MOT_2, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 1),
Motor(AP_MOTORS_MOT_3, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3),
Motor(AP_MOTORS_MOT_4, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4),
};
// motor order to match DJI conventions
// See: https://forum44.djicdn.com/data/attachment/forum/201711/26/172348bppvtt1ot1nrtp5j.jpg
static Motor quad_dji_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_3, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_4, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
};
// motor order so that test order matches motor order ("clockwise X")
static Motor quad_cw_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_3, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_4, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
};
static Motor tiltquad_h_vectored_motors[] =
{
Motor(AP_MOTORS_MOT_1, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 1, -1, 0, 0, 7, 10, -90),
Motor(AP_MOTORS_MOT_2, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3, -1, 0, 0, 8, 10, -90),
Motor(AP_MOTORS_MOT_3, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4, -1, 0, 0, 8, 10, -90),
Motor(AP_MOTORS_MOT_4, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2, -1, 0, 0, 7, 10, -90),
};
static Motor hexa_motors[] =
{
Motor(AP_MOTORS_MOT_1, 0, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 1),
Motor(AP_MOTORS_MOT_2, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4),
Motor(AP_MOTORS_MOT_3,-120, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 5),
Motor(AP_MOTORS_MOT_4, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2),
Motor(AP_MOTORS_MOT_5, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 6),
Motor(AP_MOTORS_MOT_6, 120, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3)
};
static Motor hexax_motors[] =
{
Motor(AP_MOTORS_MOT_1, 90, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_2, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_3, -30, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6),
Motor(AP_MOTORS_MOT_4, 150, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_5, 30, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_6,-150, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4)
};
static Motor hexa_dji_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 30, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, -30, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6),
Motor(AP_MOTORS_MOT_3, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_4, -150, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_5, 150, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_6, 90, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2)
};
static Motor hexa_cw_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 30, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, 90, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_3, 150, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_4, -150, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_5, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_6, -30, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6)
};
static Motor octa_motors[] =
{
Motor(AP_MOTORS_MOT_1, 0, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 1),
Motor(AP_MOTORS_MOT_2, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 5),
Motor(AP_MOTORS_MOT_3, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2),
Motor(AP_MOTORS_MOT_4, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4),
Motor(AP_MOTORS_MOT_5, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 8),
Motor(AP_MOTORS_MOT_6, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 6),
Motor(AP_MOTORS_MOT_7, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 7),
Motor(AP_MOTORS_MOT_8, 90, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3)
};
static Motor octa_dji_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 22.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, -22.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 8),
Motor(AP_MOTORS_MOT_3, -67.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 7),
Motor(AP_MOTORS_MOT_4, -112.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6),
Motor(AP_MOTORS_MOT_5, -157.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_6, 157.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_7, 112.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_8, 67.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2)
};
static Motor octa_cw_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 22.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, 67.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_3, 112.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_4, 157.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_5, -157.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_6, -112.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6),
Motor(AP_MOTORS_MOT_7, -67.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 7),
Motor(AP_MOTORS_MOT_8, -22.5f, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 8)
};
static Motor octa_quad_motors[] =
{
Motor(AP_MOTORS_MOT_1, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 7),
Motor(AP_MOTORS_MOT_3, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_4, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3),
Motor(AP_MOTORS_MOT_5, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 8),
Motor(AP_MOTORS_MOT_6, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_7, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4),
Motor(AP_MOTORS_MOT_8, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6)
};
static Motor octa_quad_cw_x_motors[] =
{
Motor(AP_MOTORS_MOT_1, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, 45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_3, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_4, 135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_5, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_6, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6),
Motor(AP_MOTORS_MOT_7, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 7),
Motor(AP_MOTORS_MOT_8, -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 8)
};
static Motor dodeca_hexa_motors[] =
{
Motor(AP_MOTORS_MOT_1, 30, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, 30, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2),
Motor(AP_MOTORS_MOT_3, 90, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3),
Motor(AP_MOTORS_MOT_4, 90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4),
Motor(AP_MOTORS_MOT_5, 150, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5),
Motor(AP_MOTORS_MOT_6, 150, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6),
Motor(AP_MOTORS_MOT_7, -150, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 7),
Motor(AP_MOTORS_MOT_8, -150, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 8),
Motor(AP_MOTORS_MOT_9, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 9),
Motor(AP_MOTORS_MOT_10, -90, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 10),
Motor(AP_MOTORS_MOT_11, -30, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 11),
Motor(AP_MOTORS_MOT_12, -30, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 12)
};
static Motor tri_motors[] =
{
Motor(AP_MOTORS_MOT_1, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1),
Motor(AP_MOTORS_MOT_2, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_4, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2, AP_MOTORS_MOT_7, 60, -60, -1, 0, 0),
};
static Motor tilttri_motors[] =
{
Motor(AP_MOTORS_MOT_1, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1, -1, 0, 0, AP_MOTORS_MOT_8, 0, -90),
Motor(AP_MOTORS_MOT_2, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3, -1, 0, 0, AP_MOTORS_MOT_8, 0, -90),
Motor(AP_MOTORS_MOT_4, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2, AP_MOTORS_MOT_7, 60, -60, -1, 0, 0),
};
static Motor tilttri_vectored_motors[] =
{
Motor(AP_MOTORS_MOT_1, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1, -1, 0, 0, 7, 10, -90),
Motor(AP_MOTORS_MOT_2, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 3, -1, 0, 0, 8, 10, -90),
Motor(AP_MOTORS_MOT_4, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2)
};
static Motor y6_motors[] =
{
Motor(AP_MOTORS_MOT_1, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2),
Motor(AP_MOTORS_MOT_2, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 5),
Motor(AP_MOTORS_MOT_3, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 6),
Motor(AP_MOTORS_MOT_4, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_5, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 1),
Motor(AP_MOTORS_MOT_6, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3)
};
/*
FireflyY6 is a Y6 with front motors tiltable using servo on channel 9 (output 8)
*/
static Motor firefly_motors[] =
{
Motor(AP_MOTORS_MOT_1, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 3),
Motor(AP_MOTORS_MOT_2, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 1, -1, 0, 0, 6, 0, -90),
Motor(AP_MOTORS_MOT_3, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 5, -1, 0, 0, 6, 0, -90),
Motor(AP_MOTORS_MOT_4, 180, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
Motor(AP_MOTORS_MOT_5, 60, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 2, -1, 0, 0, 6, 0, -90),
Motor(AP_MOTORS_MOT_6, -60, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 6, -1, 0, 0, 6, 0, -90)
};
/*
table of supported frame types. String order is important for
partial name matching
*/
static Frame supported_frames[] =
{
Frame("+", 4, quad_plus_motors),
Frame("quad", 4, quad_plus_motors),
Frame("copter", 4, quad_plus_motors),
Frame("x", 4, quad_x_motors),
Frame("bfxrev", 4, quad_bf_x_rev_motors),
Frame("bfx", 4, quad_bf_x_motors),
Frame("djix", 4, quad_dji_x_motors),
Frame("cwx", 4, quad_cw_x_motors),
Frame("tilthvec", 4, tiltquad_h_vectored_motors),
Frame("hexax", 6, hexax_motors),
Frame("hexa-cwx", 6, hexa_cw_x_motors),
Frame("hexa-dji", 6, hexa_dji_x_motors),
Frame("hexa", 6, hexa_motors),
Frame("octa-cwx", 8, octa_cw_x_motors),
Frame("octa-dji", 8, octa_dji_x_motors),
Frame("octa-quad-cwx",8, octa_quad_cw_x_motors),
Frame("octa-quad", 8, octa_quad_motors),
Frame("octa", 8, octa_motors),
Frame("dodeca-hexa", 12, dodeca_hexa_motors),
Frame("tri", 3, tri_motors),
Frame("tilttrivec",3, tilttri_vectored_motors),
Frame("tilttri", 3, tilttri_motors),
Frame("y6", 6, y6_motors),
Frame("firefly", 6, firefly_motors)
};
// get air density in kg/m^3
float Frame::get_air_density(float alt_amsl) const
{
float sigma, delta, theta;
AP_Baro::SimpleAtmosphere(alt_amsl * 0.001f, sigma, delta, theta);
const float air_pressure = SSL_AIR_PRESSURE * delta;
return air_pressure / (ISA_GAS_CONSTANT * (C_TO_KELVIN + model.refTempC));
}
/*
load frame specific parameters from a json file if available
*/
void Frame::load_frame_params(const char *model_json)
{
char *fname = nullptr;
struct stat st;
if (AP::FS().stat(model_json, &st) == 0) {
fname = strdup(model_json);
} else {
IGNORE_RETURN(asprintf(&fname, "@ROMFS/models/%s", model_json));
}
if (fname == nullptr) {
AP_HAL::panic("%s failed to load\n", model_json);
}
::printf("Loading model %s\n", fname);
int fd = AP::FS().open(model_json, O_RDONLY);
if (fd == -1) {
AP_HAL::panic("%s failed to load\n", model_json);
}
char buf[st.st_size];
if (AP::FS().read(fd, buf, st.st_size) != st.st_size) {
AP_HAL::panic("%s failed to load\n", model_json);
}
AP::FS().close(fd);
char *start = strchr(buf, '{');
if (!start) {
AP_HAL::panic("Invalid json %s", model_json);
}
free(fname);
/*
remove comments, as not allowed by the parser
*/
for (char *p = strchr(start,'#'); p; p=strchr(p+1, '#')) {
// clear to end of line
do {
*p++ = ' ';
} while (*p != '\n' && *p != '\r' && *p);
}
picojson::value obj;
std::string err = picojson::parse(obj, start);
if (!err.empty()) {
AP_HAL::panic("Failed to load %s: %s", model_json, err.c_str());
exit(1);
}
struct {
const char *label;
float &v;
} vars[] = {
#define FRAME_VAR(s) { #s, model.s }
FRAME_VAR(mass),
FRAME_VAR(diagonal_size),
FRAME_VAR(refSpd),
FRAME_VAR(refAngle),
FRAME_VAR(refVoltage),
FRAME_VAR(refCurrent),
FRAME_VAR(refAlt),
FRAME_VAR(refTempC),
FRAME_VAR(maxVoltage),
FRAME_VAR(battCapacityAh),
FRAME_VAR(refBatRes),
FRAME_VAR(propExpo),
FRAME_VAR(refRotRate),
FRAME_VAR(hoverThrOut),
FRAME_VAR(pwmMin),
FRAME_VAR(pwmMax),
FRAME_VAR(spin_min),
FRAME_VAR(spin_max),
FRAME_VAR(slew_max),
};
static_assert(sizeof(model) == sizeof(float)*ARRAY_SIZE(vars), "incorrect model vars");
for (uint8_t i=0; i()) {
// use default value
continue;
}
if (!v.is()) {
AP_HAL::panic("Bad json type for %s: %s", vars[i].label, v.to_str().c_str());
}
vars[i].v = v.get();
}
::printf("Loaded model params from %s\n", model_json);
}
/*
initialise the frame
*/
void Frame::init(const char *frame_str, Battery *_battery)
{
model = default_model;
battery = _battery;
const char *colon = strchr(frame_str, ':');
size_t slen = strlen(frame_str);
if (colon != nullptr && slen > 5 && strcmp(&frame_str[slen-5], ".json") == 0) {
load_frame_params(colon+1);
}
mass = model.mass;
const float drag_force = model.mass * GRAVITY_MSS * tanf(radians(model.refAngle));
float ref_air_density = get_air_density(model.refAlt);
areaCd = drag_force / (0.5 * ref_air_density * sq(model.refSpd));
terminal_rotation_rate = model.refRotRate;
float hover_thrust = mass * GRAVITY_MSS;
float hover_power = model.refCurrent * model.refVoltage;
float hover_velocity_out = 2 * hover_power / hover_thrust;
float effective_disc_area = hover_thrust / (0.5 * ref_air_density * sq(hover_velocity_out));
velocity_max = hover_velocity_out / sqrtf(model.hoverThrOut);
thrust_max = 0.5 * ref_air_density * effective_disc_area * sq(velocity_max);
effective_prop_area = effective_disc_area / num_motors;
// power_factor is ratio of power consumed per newton of thrust
float power_factor = hover_power / hover_thrust;
battery->setup(model.battCapacityAh, model.refBatRes, model.maxVoltage);
for (uint8_t i=0; iget_voltage());
::printf("pwm[%u] cmd=%.3f thrust=%.3f hovthst=%.3f\n",
pwm, motors[0].pwm_to_command(pwm), -thrust.z*num_motors, hover_thrust);
}
motors[0].set_slew_max(model.slew_max);
}
#endif
// setup reasonable defaults for battery
AP_Param::set_default_by_name("SIM_BATT_VOLTAGE", model.maxVoltage);
AP_Param::set_default_by_name("SIM_BATT_CAP_AH", model.battCapacityAh);
AP_Param::set_default_by_name("BATT_CAPACITY", model.battCapacityAh*1000);
}
/*
find a frame by name
*/
Frame *Frame::find_frame(const char *name)
{
for (uint8_t i=0; i < ARRAY_SIZE(supported_frames); i++) {
// do partial name matching to allow for frame variants
if (strncasecmp(name, supported_frames[i].name, strlen(supported_frames[i].name)) == 0) {
return &supported_frames[i];
}
}
return nullptr;
}
// calculate rotational and linear accelerations
void Frame::calculate_forces(const Aircraft &aircraft,
const struct sitl_input &input,
Vector3f &rot_accel,
Vector3f &body_accel,
float* rpm,
bool use_drag)
{
Vector3f thrust; // newtons
const float air_density = get_air_density(aircraft.get_location().alt*0.01);
Vector3f vel_air_bf = aircraft.get_dcm().transposed() * aircraft.get_velocity_air_ef();
float current = 0;
for (uint8_t i=0; iget_voltage());
current += motors[i].get_current();
rot_accel += mraccel;
thrust += mthrust;
// simulate motor rpm
if (!is_zero(AP::sitl()->vibe_motor)) {
rpm[i] = motors[i].get_command() * AP::sitl()->vibe_motor * 60.0f;
}
}
body_accel = thrust/aircraft.gross_mass();
if (terminal_rotation_rate > 0) {
// rotational air resistance
const Vector3f &gyro = aircraft.get_gyro();
rot_accel.x -= gyro.x * radians(400.0) / terminal_rotation_rate;
rot_accel.y -= gyro.y * radians(400.0) / terminal_rotation_rate;
rot_accel.z -= gyro.z * radians(400.0) / terminal_rotation_rate;
}
if (use_drag) {
// use the model params to calculate drag
const Vector3f vel_air_ef = aircraft.get_velocity_air_ef();
const float speed = vel_air_ef.length();
float drag_force = areaCd * 0.5 * air_density * sq(speed);
Vector3f drag_ef;
if (is_positive(speed)) {
drag_ef = -(vel_air_ef / speed) * drag_force;
}
body_accel += aircraft.get_dcm().transposed() * drag_ef / mass;
}
// add some noise
const float gyro_noise = radians(0.1);
const float accel_noise = 0.3;
const float noise_scale = thrust.length() / thrust_max;
rot_accel += Vector3f(aircraft.rand_normal(0, 1),
aircraft.rand_normal(0, 1),
aircraft.rand_normal(0, 1)) * gyro_noise * noise_scale;
body_accel += Vector3f(aircraft.rand_normal(0, 1),
aircraft.rand_normal(0, 1),
aircraft.rand_normal(0, 1)) * accel_noise * noise_scale;
}
// calculate current and voltage
void Frame::current_and_voltage(float &voltage, float ¤t)
{
float param_voltage = AP::sitl()->batt_voltage;
if (!is_equal(last_param_voltage,param_voltage)) {
battery->init_voltage(param_voltage);
last_param_voltage = param_voltage;
}
voltage = battery->get_voltage();
current = 0;
for (uint8_t i=0; i