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ardupilot/libraries/SITL/SIM_Aircraft.cpp

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/*
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/>.
*/
/*
parent class for aircraft simulators
*/
#define ALLOW_DOUBLE_MATH_FUNCTIONS
#include "SIM_Aircraft.h"
#include <stdio.h>
#include <sys/time.h>
#include <unistd.h>
#if defined(__CYGWIN__) || defined(__CYGWIN64__)
#include <windows.h>
#include <time.h>
#include <mmsystem.h>
#endif
#include <GCS_MAVLink/GCS.h>
#include <AP_Logger/AP_Logger.h>
#include <AP_Param/AP_Param.h>
#include <AP_Declination/AP_Declination.h>
#include <AP_Terrain/AP_Terrain.h>
#include <AP_Scheduler/AP_Scheduler.h>
#include <AP_BoardConfig/AP_BoardConfig.h>
using namespace SITL;
extern const AP_HAL::HAL& hal;
/*
parent class for all simulator types
*/
Aircraft::Aircraft(const char *frame_str) :
frame(frame_str)
{
// make the SIM_* variables available to simulator backends
sitl = AP::sitl();
set_speedup(1.0f);
last_wall_time_us = get_wall_time_us();
// allow for orientation settings, such as with tailsitters
enum ap_var_type ptype;
ahrs_orientation = (AP_Int8 *)AP_Param::find("AHRS_ORIENTATION", &ptype);
// ahrs_orientation->get() returns ROTATION_NONE here, regardless of the actual value
enum Rotation imu_rotation = ahrs_orientation?(enum Rotation)ahrs_orientation->get():ROTATION_NONE;
last_imu_rotation = imu_rotation;
// sitl is null if running example program
if (sitl) {
sitl->ahrs_rotation.from_rotation(imu_rotation);
sitl->ahrs_rotation_inv = sitl->ahrs_rotation.transposed();
}
// init rangefinder array to -1 to signify no data
for (uint8_t i = 0; i < RANGEFINDER_MAX_INSTANCES; i++){
rangefinder_m[i] = -1.0f;
}
}
void Aircraft::set_start_location(const Location &start_loc, const float start_yaw)
{
home = start_loc;
origin = home;
position.xy().zero();
home_yaw = start_yaw;
home_is_set = true;
::printf("Home: %f %f alt=%fm hdg=%f\n",
home.lat*1e-7,
home.lng*1e-7,
home.alt*0.01,
home_yaw);
location = home;
ground_level = home.alt * 0.01f;
#if 0
// useful test for home position being very different from origin
home.offset(-3000*1000, 1800*1000);
#endif
dcm.from_euler(0.0f, 0.0f, radians(home_yaw));
}
/*
return difference in altitude between home position and current loc
*/
float Aircraft::ground_height_difference() const
{
#if AP_TERRAIN_AVAILABLE
AP_Terrain *terrain = AP::terrain();
float h1, h2;
if (sitl &&
terrain != nullptr &&
sitl->terrain_enable &&
terrain->height_amsl(home, h1, false) &&
terrain->height_amsl(location, h2, false)) {
h2 += local_ground_level;
return h2 - h1;
}
#endif
return local_ground_level;
}
void Aircraft::set_precland(SIM_Precland *_precland) {
precland = _precland;
precland->set_default_location(home.lat * 1.0e-7f, home.lng * 1.0e-7f, static_cast<int16_t>(get_home_yaw()));
}
/*
return current height above ground level (metres)
*/
float Aircraft::hagl() const
{
return (-position.z) + home.alt * 0.01f - ground_level - frame_height - ground_height_difference();
}
/*
return true if we are on the ground
*/
bool Aircraft::on_ground() const
{
return hagl() <= 0.001f; // prevent bouncing around ground
}
/*
update location from position
*/
void Aircraft::update_position(void)
{
location = origin;
location.offset(position.x, position.y);
location.alt = static_cast<int32_t>(home.alt - position.z * 100.0f);
#if 0
Vector3d pos_home = position;
pos_home.xy() += home.get_distance_NE_double(origin);
// logging of raw sitl data
Vector3f accel_ef = dcm * accel_body;
// @LoggerMessage: SITL
// @Description: Simulation data
// @Field: TimeUS: Time since system startup
// @Field: VN: Velocity - North component
// @Field: VE: Velocity - East component
// @Field: VD: Velocity - Down component
// @Field: AN: Acceleration - North component
// @Field: AE: Acceleration - East component
// @Field: AD: Acceleration - Down component
// @Field: PN: Position - North component
// @Field: PE: Position - East component
// @Field: PD: Position - Down component
AP::logger().WriteStreaming("SITL", "TimeUS,VN,VE,VD,AN,AE,AD,PN,PE,PD", "Qfffffffff",
AP_HAL::micros64(),
velocity_ef.x, velocity_ef.y, velocity_ef.z,
accel_ef.x, accel_ef.y, accel_ef.z,
pos_home.x, pos_home.y, pos_home.z);
#endif
uint32_t now = AP_HAL::millis();
if (now - last_one_hz_ms >= 1000) {
// shift origin of position at 1Hz to current location
// this prevents sperical errors building up in the GPS data
last_one_hz_ms = now;
Vector2d diffNE = origin.get_distance_NE_double(location);
position.xy() -= diffNE;
smoothing.position.xy() -= diffNE;
origin.lat = location.lat;
origin.lng = location.lng;
}
}
/*
update body magnetic field from position and rotation
*/
void Aircraft::update_mag_field_bf()
{
// get the magnetic field intensity and orientation
float intensity;
float declination;
float inclination;
AP_Declination::get_mag_field_ef(location.lat * 1e-7f, location.lng * 1e-7f, intensity, declination, inclination);
// create a field vector and rotate to the required orientation
Vector3f mag_ef(1e3f * intensity, 0.0f, 0.0f);
Matrix3f R;
R.from_euler(0.0f, -ToRad(inclination), ToRad(declination));
mag_ef = R * mag_ef;
// calculate frame height above ground
const float frame_height_agl = fmaxf((-position.z) + home.alt * 0.01f - ground_level, 0.0f);
if (!sitl) {
// running example program
return;
}
// calculate scaling factor that varies from 1 at ground level to 1/8 at sitl->mag_anomaly_hgt
// Assume magnetic anomaly strength scales with 1/R**3
float anomaly_scaler = (sitl->mag_anomaly_hgt / (frame_height_agl + sitl->mag_anomaly_hgt));
anomaly_scaler = anomaly_scaler * anomaly_scaler * anomaly_scaler;
// add scaled anomaly to earth field
mag_ef += sitl->mag_anomaly_ned.get() * anomaly_scaler;
// Rotate into body frame
mag_bf = dcm.transposed() * mag_ef;
// add motor interference
mag_bf += sitl->mag_mot.get() * battery_current;
}
/* advance time by deltat in seconds */
void Aircraft::time_advance()
{
// we only advance time if it hasn't been advanced already by the
// backend
if (last_time_us == time_now_us) {
time_now_us += frame_time_us;
}
last_time_us = time_now_us;
if (use_time_sync) {
sync_frame_time();
}
}
/* setup the frame step time */
void Aircraft::setup_frame_time(float new_rate, float new_speedup)
{
rate_hz = new_rate;
target_speedup = new_speedup;
frame_time_us = uint64_t(1.0e6f/rate_hz);
last_wall_time_us = get_wall_time_us();
}
/* adjust frame_time calculation */
void Aircraft::adjust_frame_time(float new_rate)
{
frame_time_us = uint64_t(1.0e6f/new_rate);
rate_hz = new_rate;
}
/*
try to synchronise simulation time with wall clock time, taking
into account desired speedup
This tries to take account of possible granularity of
get_wall_time_us() so it works reasonably well on windows
*/
void Aircraft::sync_frame_time(void)
{
frame_counter++;
uint64_t now = get_wall_time_us();
uint64_t dt_us = now - last_wall_time_us;
const float target_dt_us = 1.0e6/(rate_hz*target_speedup);
// accumulate sleep debt if we're running too fast
sleep_debt_us += target_dt_us - dt_us;
if (sleep_debt_us < -1.0e5) {
// don't let a large negative debt build up
sleep_debt_us = -1.0e5;
}
if (sleep_debt_us > min_sleep_time) {
// sleep if we have built up a debt of min_sleep_tim
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
usleep(sleep_debt_us);
#elif CONFIG_HAL_BOARD == HAL_BOARD_CHIBIOS
hal.scheduler->delay_microseconds(sleep_debt_us);
#else
// ??
#endif
sleep_debt_us -= (get_wall_time_us() - now);
}
last_wall_time_us = get_wall_time_us();
uint32_t now_ms = last_wall_time_us / 1000ULL;
float dt_wall = (now_ms - last_fps_report_ms) * 0.001;
if (dt_wall > 2.0) {
#if 0
const float achieved_rate_hz = (frame_counter - last_frame_count) / dt_wall;
::printf("Rate: target:%.1f achieved:%.1f speedup %.1f/%.1f\n",
rate_hz*target_speedup, achieved_rate_hz,
achieved_rate_hz/rate_hz, target_speedup);
#endif
last_frame_count = frame_counter;
last_fps_report_ms = now_ms;
}
}
/* add noise based on throttle level (from 0..1) */
void Aircraft::add_noise(float throttle)
{
gyro += Vector3f(rand_normal(0, 1),
rand_normal(0, 1),
rand_normal(0, 1)) * gyro_noise * fabsf(throttle);
accel_body += Vector3f(rand_normal(0, 1),
rand_normal(0, 1),
rand_normal(0, 1)) * accel_noise * fabsf(throttle);
}
/*
normal distribution random numbers
See
http://en.literateprograms.org/index.php?title=Special:DownloadCode/Box-Muller_transform_%28C%29&oldid=7011
*/
double Aircraft::rand_normal(double mean, double stddev)
{
static double n2 = 0.0;
static int n2_cached = 0;
if (!n2_cached) {
double x, y, r;
do
{
x = 2.0 * rand()/RAND_MAX - 1;
y = 2.0 * rand()/RAND_MAX - 1;
r = x*x + y*y;
} while (is_zero(r) || r > 1.0);
const double d = sqrt(-2.0 * log(r)/r);
const double n1 = x * d;
n2 = y * d;
const double result = n1 * stddev + mean;
n2_cached = 1;
return result;
} else {
n2_cached = 0;
return n2 * stddev + mean;
}
}
/*
fill a sitl_fdm structure from the simulator state
*/
void Aircraft::fill_fdm(struct sitl_fdm &fdm)
{
bool is_smoothed = false;
if (use_smoothing) {
smooth_sensors();
is_smoothed = true;
}
fdm.timestamp_us = time_now_us;
if (fdm.home.lat == 0 && fdm.home.lng == 0) {
// initialise home
fdm.home = home;
}
fdm.is_lock_step_scheduled = lock_step_scheduled;
fdm.latitude = location.lat * 1.0e-7;
fdm.longitude = location.lng * 1.0e-7;
fdm.altitude = location.alt * 1.0e-2;
fdm.heading = degrees(atan2f(velocity_ef.y, velocity_ef.x));
fdm.speedN = velocity_ef.x;
fdm.speedE = velocity_ef.y;
fdm.speedD = velocity_ef.z;
fdm.xAccel = accel_body.x;
fdm.yAccel = accel_body.y;
fdm.zAccel = accel_body.z;
fdm.rollRate = degrees(gyro.x);
fdm.pitchRate = degrees(gyro.y);
fdm.yawRate = degrees(gyro.z);
float r, p, y;
dcm.to_euler(&r, &p, &y);
fdm.rollDeg = degrees(r);
fdm.pitchDeg = degrees(p);
fdm.yawDeg = degrees(y);
fdm.quaternion.from_rotation_matrix(dcm);
fdm.airspeed = airspeed_pitot;
fdm.velocity_air_bf = velocity_air_bf;
fdm.battery_voltage = battery_voltage;
fdm.battery_current = battery_current;
fdm.num_motors = num_motors;
fdm.vtol_motor_start = vtol_motor_start;
memcpy(fdm.rpm, rpm, num_motors * sizeof(float));
fdm.rcin_chan_count = rcin_chan_count;
fdm.range = rangefinder_range();
memcpy(fdm.rcin, rcin, rcin_chan_count * sizeof(float));
fdm.bodyMagField = mag_bf;
// copy laser scanner results
fdm.scanner.points = scanner.points;
fdm.scanner.ranges = scanner.ranges;
// copy rangefinder
memcpy(fdm.rangefinder_m, rangefinder_m, sizeof(fdm.rangefinder_m));
fdm.wind_vane_apparent.direction = wind_vane_apparent.direction;
fdm.wind_vane_apparent.speed = wind_vane_apparent.speed;
if (is_smoothed) {
fdm.xAccel = smoothing.accel_body.x;
fdm.yAccel = smoothing.accel_body.y;
fdm.zAccel = smoothing.accel_body.z;
fdm.rollRate = degrees(smoothing.gyro.x);
fdm.pitchRate = degrees(smoothing.gyro.y);
fdm.yawRate = degrees(smoothing.gyro.z);
fdm.speedN = smoothing.velocity_ef.x;
fdm.speedE = smoothing.velocity_ef.y;
fdm.speedD = smoothing.velocity_ef.z;
fdm.latitude = smoothing.location.lat * 1.0e-7;
fdm.longitude = smoothing.location.lng * 1.0e-7;
fdm.altitude = smoothing.location.alt * 1.0e-2;
}
if (ahrs_orientation != nullptr) {
enum Rotation imu_rotation = (enum Rotation)ahrs_orientation->get();
if (imu_rotation != last_imu_rotation) {
sitl->ahrs_rotation.from_rotation(imu_rotation);
sitl->ahrs_rotation_inv = sitl->ahrs_rotation.transposed();
last_imu_rotation = imu_rotation;
}
if (imu_rotation != ROTATION_NONE) {
Matrix3f m = dcm;
m = m * sitl->ahrs_rotation_inv;
m.to_euler(&r, &p, &y);
fdm.rollDeg = degrees(r);
fdm.pitchDeg = degrees(p);
fdm.yawDeg = degrees(y);
fdm.quaternion.from_rotation_matrix(m);
}
}
// in the first call here, if a speedup option is specified, overwrite it
if (is_equal(last_speedup, -1.0f) && !is_equal(get_speedup(), 1.0f)) {
sitl->speedup = get_speedup();
}
if (!is_equal(last_speedup, float(sitl->speedup)) && sitl->speedup > 0) {
set_speedup(sitl->speedup);
last_speedup = sitl->speedup;
}
// for EKF comparison log relhome pos and velocity at loop rate
static uint16_t last_ticks;
uint16_t ticks = AP::scheduler().ticks();
if (last_ticks != ticks) {
last_ticks = ticks;
// @LoggerMessage: SIM2
// @Description: Additional simulator state
// @Field: TimeUS: Time since system startup
// @Field: PN: North position from home
// @Field: PE: East position from home
// @Field: PD: Down position from home
// @Field: VN: Velocity north
// @Field: VE: Velocity east
// @Field: VD: Velocity down
// @Field: As: Airspeed
Vector3d pos = get_position_relhome();
Vector3f vel = get_velocity_ef();
AP::logger().WriteStreaming("SIM2", "TimeUS,PN,PE,PD,VN,VE,VD,As",
"Qdddffff",
AP_HAL::micros64(),
pos.x, pos.y, pos.z,
vel.x, vel.y, vel.z,
airspeed_pitot);
}
}
// returns perpendicular height to surface downward-facing rangefinder
// is bouncing off:
float Aircraft::perpendicular_distance_to_rangefinder_surface() const
{
switch ((Rotation)sitl->sonar_rot.get()) {
case Rotation::ROTATION_PITCH_270:
return sitl->height_agl;
case ROTATION_NONE ... ROTATION_YAW_315:
return sitl->measure_distance_at_angle_bf(location, sitl->sonar_rot.get()*45);
default:
AP_BoardConfig::config_error("Bad simulated sonar rotation");
}
}
float Aircraft::rangefinder_range() const
{
float roll = sitl->state.rollDeg;
float pitch = sitl->state.pitchDeg;
if (roll > 0) {
roll -= rangefinder_beam_width();
if (roll < 0) {
roll = 0;
}
} else {
roll += rangefinder_beam_width();
if (roll > 0) {
roll = 0;
}
}
if (pitch > 0) {
pitch -= rangefinder_beam_width();
if (pitch < 0) {
pitch = 0;
}
} else {
pitch += rangefinder_beam_width();
if (pitch > 0) {
pitch = 0;
}
}
if (fabs(roll) >= 90.0 || fabs(pitch) >= 90.0) {
// not going to hit the ground....
return INFINITY;
}
float altitude = perpendicular_distance_to_rangefinder_surface();
// sensor position offset in body frame
const Vector3f relPosSensorBF = sitl->rngfnd_pos_offset;
// n.b. the following code is assuming rotation-pitch-270:
// adjust altitude for position of the sensor on the vehicle if position offset is non-zero
if (!relPosSensorBF.is_zero()) {
// get a rotation matrix following DCM conventions (body to earth)
Matrix3f rotmat;
sitl->state.quaternion.rotation_matrix(rotmat);
// rotate the offset into earth frame
const Vector3f relPosSensorEF = rotmat * relPosSensorBF;
// correct the altitude at the sensor
altitude -= relPosSensorEF.z;
}
// adjust for apparent altitude with roll
altitude /= cosf(radians(roll)) * cosf(radians(pitch));
// Add some noise on reading
altitude += sitl->sonar_noise * rand_float();
return altitude;
}
// potentially replace this with a call to AP_HAL::Util::get_hw_rtc
uint64_t Aircraft::get_wall_time_us() const
{
#if defined(__CYGWIN__) || defined(__CYGWIN64__)
static DWORD tPrev;
static uint64_t last_ret_us;
if (tPrev == 0) {
tPrev = timeGetTime();
return 0;
}
DWORD now = timeGetTime();
last_ret_us += (uint64_t)((now - tPrev)*1000UL);
tPrev = now;
return last_ret_us;
#elif CONFIG_HAL_BOARD == HAL_BOARD_SITL
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return uint64_t(ts.tv_sec * 1000000ULL + ts.tv_nsec / 1000ULL);
#else
return AP_HAL::micros64();
#endif
}
/*
set simulation speedup
*/
void Aircraft::set_speedup(float speedup)
{
setup_frame_time(rate_hz, speedup);
}
void Aircraft::update_model(const struct sitl_input &input)
{
if (!home_is_set) {
if (sitl == nullptr) {
return;
}
Location loc;
loc.lat = sitl->opos.lat.get() * 1.0e7;
loc.lng = sitl->opos.lng.get() * 1.0e7;
loc.alt = sitl->opos.alt.get() * 1.0e2;
set_start_location(loc, sitl->opos.hdg.get());
}
local_ground_level = 0.0f;
update(input);
}
/*
update the simulation attitude and relative position
*/
void Aircraft::update_dynamics(const Vector3f &rot_accel)
{
const float delta_time = frame_time_us * 1.0e-6f;
// update rotational rates in body frame
gyro += rot_accel * delta_time;
gyro.x = constrain_float(gyro.x, -radians(2000.0f), radians(2000.0f));
gyro.y = constrain_float(gyro.y, -radians(2000.0f), radians(2000.0f));
gyro.z = constrain_float(gyro.z, -radians(2000.0f), radians(2000.0f));
// update attitude
dcm.rotate(gyro * delta_time);
dcm.normalize();
Vector3f accel_earth = dcm * accel_body;
accel_earth += Vector3f(0.0f, 0.0f, GRAVITY_MSS);
// if we're on the ground, then our vertical acceleration is limited
// to zero. This effectively adds the force of the ground on the aircraft
if (on_ground() && accel_earth.z > 0) {
accel_earth.z = 0;
}
// work out acceleration as seen by the accelerometers. It sees the kinematic
// acceleration (ie. real movement), plus gravity
accel_body = dcm.transposed() * (accel_earth + Vector3f(0.0f, 0.0f, -GRAVITY_MSS));
// new velocity vector
velocity_ef += accel_earth * delta_time;
const bool was_on_ground = on_ground();
// new position vector
position += (velocity_ef * delta_time).todouble();
// velocity relative to air mass, in earth frame
velocity_air_ef = velocity_ef + wind_ef;
// velocity relative to airmass in body frame
velocity_air_bf = dcm.transposed() * velocity_air_ef;
// airspeed
airspeed = velocity_air_ef.length();
// airspeed as seen by a fwd pitot tube (limited to 120m/s)
airspeed_pitot = constrain_float(velocity_air_bf * Vector3f(1.0f, 0.0f, 0.0f), 0.0f, 120.0f);
// constrain height to the ground
if (on_ground()) {
if (!was_on_ground && AP_HAL::millis() - last_ground_contact_ms > 1000) {
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "SIM Hit ground at %f m/s", velocity_ef.z);
last_ground_contact_ms = AP_HAL::millis();
}
position.z = -(ground_level + frame_height - home.alt * 0.01f + ground_height_difference());
// get speed of ground movement (for ship takeoff/landing)
float yaw_rate = 0;
#if AP_SIM_SHIP_ENABLED
const Vector2f ship_movement = sitl->shipsim.get_ground_speed_adjustment(location, yaw_rate);
const Vector3f gnd_movement(ship_movement.x, ship_movement.y, 0);
#else
const Vector3f gnd_movement;
#endif
switch (ground_behavior) {
case GROUND_BEHAVIOR_NONE:
break;
case GROUND_BEHAVIOR_NO_MOVEMENT: {
// zero roll/pitch, but keep yaw
float r, p, y;
dcm.to_euler(&r, &p, &y);
y = y + yaw_rate * delta_time;
dcm.from_euler(0.0f, 0.0f, y);
// X, Y movement tracks ground movement
velocity_ef.x = gnd_movement.x;
velocity_ef.y = gnd_movement.y;
if (velocity_ef.z > 0.0f) {
velocity_ef.z = 0.0f;
}
gyro.zero();
use_smoothing = true;
break;
}
case GROUND_BEHAVIOR_FWD_ONLY: {
// zero roll/pitch, but keep yaw
float r, p, y;
dcm.to_euler(&r, &p, &y);
if (velocity_ef.length() < 5) {
// at high speeds don't constrain pitch, otherwise we
// can get stuck in takeoff
p = 0;
} else {
p = MAX(p, 0);
}
y = y + yaw_rate * delta_time;
dcm.from_euler(0.0f, p, y);
// only fwd movement
Vector3f v_bf = dcm.transposed() * velocity_ef;
v_bf.y = 0.0f;
if (v_bf.x < 0.0f) {
v_bf.x = 0.0f;
}
Vector3f gnd_movement_bf = dcm.transposed() * gnd_movement;
// lateral speed equals ground movement
v_bf.y = gnd_movement_bf.y;
if (!gnd_movement_bf.is_zero()) {
// fwd speed slowly approaches ground movement to simulate wheel friction
const float tconst = 20; // seconds
const float alpha = delta_time/(delta_time+tconst/M_2PI);
v_bf.x += (gnd_movement.x - v_bf.x) * alpha;
}
velocity_ef = dcm * v_bf;
if (velocity_ef.z > 0.0f) {
velocity_ef.z = 0.0f;
}
gyro.zero();
gyro.z = yaw_rate;
use_smoothing = true;
break;
}
case GROUND_BEHAVIOR_TAILSITTER: {
// rotate normal refernce frame to get yaw angle, then rotate back
Matrix3f rot;
rot.from_rotation(ROTATION_PITCH_270);
float r, p, y;
(dcm * rot).to_euler(&r, &p, &y);
y = y + yaw_rate * delta_time;
dcm.from_euler(0.0, 0.0, y);
rot.from_rotation(ROTATION_PITCH_90);
dcm *= rot;
// X, Y movement tracks ground movement
velocity_ef.x = gnd_movement.x;
velocity_ef.y = gnd_movement.y;
if (velocity_ef.z > 0.0f) {
velocity_ef.z = 0.0f;
}
gyro.zero();
gyro.x = yaw_rate;
use_smoothing = true;
break;
}
}
}
// allow for changes in physics step
adjust_frame_time(constrain_float(sitl->loop_rate_hz, rate_hz-1, rate_hz+1));
}
/*
update wind vector
*/
void Aircraft::update_wind(const struct sitl_input &input)
{
// wind vector in earth frame
wind_ef = Vector3f(cosf(radians(input.wind.direction))*cosf(radians(input.wind.dir_z)),
sinf(radians(input.wind.direction))*cosf(radians(input.wind.dir_z)),
sinf(radians(input.wind.dir_z))) * input.wind.speed;
wind_ef.z += get_local_updraft(position + home.get_distance_NED_double(origin));
const float wind_turb = input.wind.turbulence * 10.0f; // scale input.wind.turbulence to match standard deviation when using iir_coef=0.98
const float iir_coef = 0.98f; // filtering high frequencies from turbulence
if (wind_turb > 0 && !on_ground()) {
turbulence_azimuth = turbulence_azimuth + (2 * rand());
turbulence_horizontal_speed =
static_cast<float>(turbulence_horizontal_speed * iir_coef+wind_turb * rand_normal(0, 1) * (1 - iir_coef));
turbulence_vertical_speed = static_cast<float>((turbulence_vertical_speed * iir_coef) + (wind_turb * rand_normal(0, 1) * (1 - iir_coef)));
wind_ef += Vector3f(
cosf(radians(turbulence_azimuth)) * turbulence_horizontal_speed,
sinf(radians(turbulence_azimuth)) * turbulence_horizontal_speed,
turbulence_vertical_speed);
}
}
/*
smooth sensors for kinematic consistancy when we interact with the ground
*/
void Aircraft::smooth_sensors(void)
{
uint64_t now = time_now_us;
Vector3d delta_pos = position - smoothing.position;
if (smoothing.last_update_us == 0 || delta_pos.length() > 10) {
smoothing.position = position;
smoothing.rotation_b2e = dcm;
smoothing.accel_body = accel_body;
smoothing.velocity_ef = velocity_ef;
smoothing.gyro = gyro;
smoothing.last_update_us = now;
smoothing.location = location;
printf("Smoothing reset at %.3f\n", now * 1.0e-6f);
return;
}
const float delta_time = (now - smoothing.last_update_us) * 1.0e-6f;
if (delta_time < 0 || delta_time > 0.1) {
return;
}
// calculate required accel to get us to desired position and velocity in the time_constant
const float time_constant = 0.1f;
Vector3f dvel = (velocity_ef - smoothing.velocity_ef) + (delta_pos / time_constant).tofloat();
Vector3f accel_e = dvel / time_constant + (dcm * accel_body + Vector3f(0.0f, 0.0f, GRAVITY_MSS));
const float accel_limit = 14 * GRAVITY_MSS;
accel_e.x = constrain_float(accel_e.x, -accel_limit, accel_limit);
accel_e.y = constrain_float(accel_e.y, -accel_limit, accel_limit);
accel_e.z = constrain_float(accel_e.z, -accel_limit, accel_limit);
smoothing.accel_body = smoothing.rotation_b2e.transposed() * (accel_e + Vector3f(0.0f, 0.0f, -GRAVITY_MSS));
// calculate rotational rate to get us to desired attitude in time constant
Quaternion desired_q, current_q, error_q;
desired_q.from_rotation_matrix(dcm);
desired_q.normalize();
current_q.from_rotation_matrix(smoothing.rotation_b2e);
current_q.normalize();
error_q = desired_q / current_q;
error_q.normalize();
Vector3f angle_differential;
error_q.to_axis_angle(angle_differential);
smoothing.gyro = gyro + angle_differential / time_constant;
float R, P, Y;
smoothing.rotation_b2e.to_euler(&R, &P, &Y);
float R2, P2, Y2;
dcm.to_euler(&R2, &P2, &Y2);
#if 0
// @LoggerMessage: SMOO
// @Description: Smoothed sensor data fed to EKF to avoid inconsistencies
// @Field: TimeUS: Time since system startup
// @Field: AEx: Angular Velocity (around x-axis)
// @Field: AEy: Angular Velocity (around y-axis)
// @Field: AEz: Angular Velocity (around z-axis)
// @Field: DPx: Velocity (along x-axis)
// @Field: DPy: Velocity (along y-axis)
// @Field: DPz: Velocity (along z-axis)
// @Field: R: Roll
// @Field: P: Pitch
// @Field: Y: Yaw
// @Field: R2: DCM Roll
// @Field: P2: DCM Pitch
// @Field: Y2: DCM Yaw
AP::logger().WriteStreaming("SMOO", "TimeUS,AEx,AEy,AEz,DPx,DPy,DPz,R,P,Y,R2,P2,Y2",
"Qffffffffffff",
AP_HAL::micros64(),
degrees(angle_differential.x),
degrees(angle_differential.y),
degrees(angle_differential.z),
delta_pos.x, delta_pos.y, delta_pos.z,
degrees(R), degrees(P), degrees(Y),
degrees(R2), degrees(P2), degrees(Y2));
#endif
// integrate to get new attitude
smoothing.rotation_b2e.rotate(smoothing.gyro * delta_time);
smoothing.rotation_b2e.normalize();
// integrate to get new position
smoothing.velocity_ef += accel_e * delta_time;
smoothing.position += (smoothing.velocity_ef * delta_time).todouble();
smoothing.location = origin;
smoothing.location.offset(smoothing.position.x, smoothing.position.y);
smoothing.location.alt = static_cast<int32_t>(home.alt - smoothing.position.z * 100.0f);
smoothing.last_update_us = now;
}
/*
return a filtered servo input as a value from -1 to 1
servo is assumed to be 1000 to 2000, trim at 1500
*/
float Aircraft::filtered_idx(float v, uint8_t idx)
{
if (sitl->servo_speed <= 0) {
return v;
}
const float cutoff = 1.0f / (2 * M_PI * sitl->servo_speed);
servo_filter[idx].set_cutoff_frequency(cutoff);
if (idx >= ARRAY_SIZE(servo_filter)) {
AP_HAL::panic("Attempt to filter invalid servo at offset %u", (unsigned)idx);
}
return servo_filter[idx].apply(v, frame_time_us * 1.0e-6f);
}
/*
return a filtered servo input as a value from -1 to 1
servo is assumed to be 1000 to 2000, trim at 1500
*/
float Aircraft::filtered_servo_angle(const struct sitl_input &input, uint8_t idx)
{
const float v = (input.servos[idx] - 1500)/500.0f;
return filtered_idx(v, idx);
}
/*
return a filtered servo input as a value from 0 to 1
servo is assumed to be 1000 to 2000
*/
float Aircraft::filtered_servo_range(const struct sitl_input &input, uint8_t idx)
{
const float v = (input.servos[idx] - 1000)/1000.0f;
return filtered_idx(v, idx);
}
// extrapolate sensors by a given delta time in seconds
void Aircraft::extrapolate_sensors(float delta_time)
{
Vector3f accel_earth = dcm * accel_body;
accel_earth.z += GRAVITY_MSS;
dcm.rotate(gyro * delta_time);
dcm.normalize();
// work out acceleration as seen by the accelerometers. It sees the kinematic
// acceleration (ie. real movement), plus gravity
accel_body = dcm.transposed() * (accel_earth + Vector3f(0,0,-GRAVITY_MSS));
// new velocity and position vectors
velocity_ef += accel_earth * delta_time;
position += (velocity_ef * delta_time).todouble();
velocity_air_ef = velocity_ef + wind_ef;
velocity_air_bf = dcm.transposed() * velocity_air_ef;
}
void Aircraft::update_external_payload(const struct sitl_input &input)
{
external_payload_mass = 0;
// update sprayer
if (sprayer && sprayer->is_enabled()) {
sprayer->update(input);
external_payload_mass += sprayer->payload_mass();
}
// update i2c
if (i2c) {
i2c->update(*this);
}
// update buzzer
if (buzzer && buzzer->is_enabled()) {
buzzer->update(input);
}
// update grippers
if (gripper && gripper->is_enabled()) {
gripper->set_alt(hagl());
gripper->update(input);
external_payload_mass += gripper->payload_mass();
}
if (gripper_epm && gripper_epm->is_enabled()) {
gripper_epm->update(input);
external_payload_mass += gripper_epm->payload_mass();
}
// update parachute
if (parachute && parachute->is_enabled()) {
parachute->update(input);
// TODO: add drag to vehicle, presumably proportional to velocity
}
if (precland && precland->is_enabled()) {
precland->update(get_location(), get_position_relhome());
if (precland->_over_precland_base) {
local_ground_level += precland->_origin_height;
}
}
// update RichenPower generator
if (richenpower) {
richenpower->update(input);
}
if (fetteconewireesc) {
fetteconewireesc->update(*this);
}
#if AP_SIM_SHIP_ENABLED
sitl->shipsim.update();
#endif
// update IntelligentEnergy 2.4kW generator
if (ie24) {
ie24->update(input);
}
}
void Aircraft::add_shove_forces(Vector3f &rot_accel, Vector3f &body_accel)
{
const uint32_t now = AP_HAL::millis();
if (sitl == nullptr) {
return;
}
if (sitl->shove.t == 0) {
return;
}
if (sitl->shove.start_ms == 0) {
sitl->shove.start_ms = now;
}
if (now - sitl->shove.start_ms < uint32_t(sitl->shove.t)) {
// FIXME: can we get a vector operation here instead?
body_accel.x += sitl->shove.x;
body_accel.y += sitl->shove.y;
body_accel.z += sitl->shove.z;
} else {
sitl->shove.start_ms = 0;
sitl->shove.t = 0;
}
}
float Aircraft::get_local_updraft(const Vector3d &currentPos)
{
int scenario = sitl->thermal_scenario;
#define MAX_THERMALS 10
float thermals_w[MAX_THERMALS];
float thermals_r[MAX_THERMALS];
float thermals_x[MAX_THERMALS];
float thermals_y[MAX_THERMALS];
int n_thermals = 0;
switch (scenario) {
case 0:
return 0;
case 1:
n_thermals = 1;
thermals_w[0] = 2.0;
thermals_r[0] = 80.0;
thermals_x[0] = -180.0;
thermals_y[0] = -260.0;
break;
case 2:
n_thermals = 1;
thermals_w[0] = 4.0;
thermals_r[0] = 30.0;
thermals_x[0] = -180.0;
thermals_y[0] = -260.0;
break;
case 3:
n_thermals = 1;
thermals_w[0] = 2.0;
thermals_r[0] = 30.0;
thermals_x[0] = -180.0;
thermals_y[0] = -260.0;
break;
default:
AP_BoardConfig::config_error("Bad thermal scenario");
}
// Wind drift at this altitude
float driftX = sitl->wind_speed * (currentPos.z+100) * cosf(sitl->wind_direction * DEG_TO_RAD);
float driftY = sitl->wind_speed * (currentPos.z+100) * sinf(sitl->wind_direction * DEG_TO_RAD);
int iThermal;
float w = 0.0f;
float r2;
for (iThermal=0;iThermal<n_thermals;iThermal++) {
Vector3d thermalPos(thermals_x[iThermal] + driftX/thermals_w[iThermal],
thermals_y[iThermal] + driftY/thermals_w[iThermal],
0);
Vector3d relVec = currentPos - thermalPos;
r2 = relVec.x*relVec.x + relVec.y*relVec.y;
w += thermals_w[iThermal]*exp(-r2/(thermals_r[iThermal]*thermals_r[iThermal]));
}
return w;
}
void Aircraft::add_twist_forces(Vector3f &rot_accel)
{
if (sitl == nullptr) {
return;
}
if (sitl->gnd_behav != -1) {
ground_behavior = (GroundBehaviour)sitl->gnd_behav.get();
}
const uint32_t now = AP_HAL::millis();
if (sitl == nullptr) {
return;
}
if (sitl->twist.t == 0) {
return;
}
if (sitl->twist.start_ms == 0) {
sitl->twist.start_ms = now;
}
if (now - sitl->twist.start_ms < uint32_t(sitl->twist.t)) {
// FIXME: can we get a vector operation here instead?
rot_accel.x += sitl->twist.x;
rot_accel.y += sitl->twist.y;
rot_accel.z += sitl->twist.z;
} else {
sitl->twist.start_ms = 0;
sitl->twist.t = 0;
}
}
/*
get position relative to home
*/
Vector3d Aircraft::get_position_relhome() const
{
Vector3d pos = position;
pos.xy() += home.get_distance_NE_double(origin);
return pos;
}
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