mirror of https://github.com/ArduPilot/ardupilot
373 lines
9.4 KiB
C++
373 lines
9.4 KiB
C++
/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
|
|
/*
|
|
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
|
|
*/
|
|
|
|
#include "SIM_Aircraft.h"
|
|
|
|
#include <stdio.h>
|
|
#include <sys/time.h>
|
|
#include <unistd.h>
|
|
|
|
#ifdef __CYGWIN__
|
|
#include <windows.h>
|
|
#include <time.h>
|
|
#include <Mmsystem.h>
|
|
#endif
|
|
|
|
namespace SITL {
|
|
|
|
/*
|
|
parent class for all simulator types
|
|
*/
|
|
|
|
Aircraft::Aircraft(const char *home_str, const char *frame_str) :
|
|
ground_level(0),
|
|
frame_height(0),
|
|
dcm(),
|
|
gyro(),
|
|
velocity_ef(),
|
|
mass(0),
|
|
accel_body(0, 0, -GRAVITY_MSS),
|
|
time_now_us(0),
|
|
gyro_noise(radians(0.1f)),
|
|
accel_noise(0.3),
|
|
rate_hz(1200),
|
|
autotest_dir(NULL),
|
|
frame(frame_str),
|
|
#ifdef __CYGWIN__
|
|
min_sleep_time(20000)
|
|
#else
|
|
min_sleep_time(5000)
|
|
#endif
|
|
{
|
|
parse_home(home_str, home, home_yaw);
|
|
location = home;
|
|
ground_level = home.alt*0.01;
|
|
|
|
dcm.from_euler(0, 0, radians(home_yaw));
|
|
|
|
set_speedup(1);
|
|
|
|
last_wall_time_us = get_wall_time_us();
|
|
frame_counter = 0;
|
|
}
|
|
|
|
|
|
/*
|
|
parse a home string into a location and yaw
|
|
*/
|
|
bool Aircraft::parse_home(const char *home_str, Location &loc, float &yaw_degrees)
|
|
{
|
|
char *saveptr=NULL;
|
|
char *s = strdup(home_str);
|
|
if (!s) {
|
|
return false;
|
|
}
|
|
char *lat_s = strtok_r(s, ",", &saveptr);
|
|
if (!lat_s) {
|
|
return false;
|
|
}
|
|
char *lon_s = strtok_r(NULL, ",", &saveptr);
|
|
if (!lon_s) {
|
|
return false;
|
|
}
|
|
char *alt_s = strtok_r(NULL, ",", &saveptr);
|
|
if (!alt_s) {
|
|
return false;
|
|
}
|
|
char *yaw_s = strtok_r(NULL, ",", &saveptr);
|
|
if (!yaw_s) {
|
|
return false;
|
|
}
|
|
|
|
memset(&loc, 0, sizeof(loc));
|
|
loc.lat = strtof(lat_s, NULL) * 1.0e7;
|
|
loc.lng = strtof(lon_s, NULL) * 1.0e7;
|
|
loc.alt = strtof(alt_s, NULL) * 1.0e2;
|
|
|
|
yaw_degrees = strtof(yaw_s, NULL);
|
|
free(s);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
return true if we are on the ground
|
|
*/
|
|
bool Aircraft::on_ground(const Vector3f &pos) const
|
|
{
|
|
return (-pos.z) + home.alt*0.01f <= ground_level + frame_height;
|
|
}
|
|
|
|
/*
|
|
update location from position
|
|
*/
|
|
void Aircraft::update_position(void)
|
|
{
|
|
float bearing = degrees(atan2f(position.y, position.x));
|
|
float distance = sqrtf(sq(position.x) + sq(position.y));
|
|
|
|
location = home;
|
|
location_update(location, bearing, distance);
|
|
|
|
location.alt = home.alt - position.z*100.0f;
|
|
|
|
// 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();
|
|
}
|
|
}
|
|
|
|
/*
|
|
rotate to the given yaw
|
|
*/
|
|
void Aircraft::set_yaw_degrees(float yaw_degrees)
|
|
{
|
|
float roll, pitch, yaw;
|
|
dcm.to_euler(&roll, &pitch, &yaw);
|
|
|
|
yaw = radians(yaw_degrees);
|
|
dcm.from_euler(roll, pitch, yaw);
|
|
}
|
|
|
|
/* advance time by deltat in seconds */
|
|
void Aircraft::time_advance(float deltat)
|
|
{
|
|
time_now_us += deltat * 1.0e6f;
|
|
}
|
|
|
|
/* 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 = 1.0e6f/rate_hz;
|
|
|
|
scaled_frame_time_us = frame_time_us/target_speedup;
|
|
last_wall_time_us = get_wall_time_us();
|
|
achieved_rate_hz = rate_hz;
|
|
}
|
|
|
|
/* adjust frame_time calculation */
|
|
void Aircraft::adjust_frame_time(float new_rate)
|
|
{
|
|
if (rate_hz != new_rate) {
|
|
rate_hz = new_rate;
|
|
frame_time_us = 1.0e6f/rate_hz;
|
|
scaled_frame_time_us = frame_time_us/target_speedup;
|
|
}
|
|
}
|
|
|
|
/*
|
|
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();
|
|
if (frame_counter >= 40 &&
|
|
now > last_wall_time_us) {
|
|
float rate = frame_counter * 1.0e6f/(now - last_wall_time_us);
|
|
achieved_rate_hz = (0.99f*achieved_rate_hz) + (0.01f*rate);
|
|
if (achieved_rate_hz < rate_hz * target_speedup) {
|
|
scaled_frame_time_us *= 0.999f;
|
|
} else {
|
|
scaled_frame_time_us /= 0.999f;
|
|
}
|
|
#if 0
|
|
::printf("achieved_rate_hz=%.3f rate=%.2f rate_hz=%.3f sft=%.1f\n",
|
|
(double)achieved_rate_hz,
|
|
(double)rate,
|
|
(double)rate_hz,
|
|
(double)scaled_frame_time_us);
|
|
#endif
|
|
uint32_t sleep_time = scaled_frame_time_us*frame_counter;
|
|
if (sleep_time > min_sleep_time) {
|
|
usleep(sleep_time);
|
|
}
|
|
last_wall_time_us = now;
|
|
frame_counter = 0;
|
|
}
|
|
}
|
|
|
|
/* 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 (r == 0.0 || r > 1.0);
|
|
{
|
|
double d = sqrt(-2.0*log(r)/r);
|
|
double n1 = x*d;
|
|
n2 = y*d;
|
|
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) const
|
|
{
|
|
fdm.timestamp_us = time_now_us;
|
|
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.airspeed = airspeed;
|
|
fdm.battery_voltage = battery_voltage;
|
|
fdm.battery_current = battery_current;
|
|
fdm.rpm1 = rpm1;
|
|
fdm.rpm2 = rpm2;
|
|
}
|
|
|
|
uint64_t Aircraft::get_wall_time_us() const
|
|
{
|
|
#ifdef __CYGWIN__
|
|
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;
|
|
#else
|
|
struct timeval tp;
|
|
gettimeofday(&tp,NULL);
|
|
return tp.tv_sec*1.0e6 + tp.tv_usec;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
set simulation speedup
|
|
*/
|
|
void Aircraft::set_speedup(float speedup)
|
|
{
|
|
setup_frame_time(rate_hz, speedup);
|
|
}
|
|
|
|
/*
|
|
update the simulation attitude and relative position
|
|
*/
|
|
void Aircraft::update_dynamics(const Vector3f &rot_accel)
|
|
{
|
|
float delta_time = frame_time_us * 1.0e-6f;
|
|
|
|
// update rotational rates in body frame
|
|
gyro += rot_accel * delta_time;
|
|
|
|
// update attitude
|
|
dcm.rotate(gyro * delta_time);
|
|
dcm.normalize();
|
|
|
|
Vector3f accel_earth = dcm * accel_body;
|
|
accel_earth += Vector3f(0, 0, 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(position) && 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, 0, -GRAVITY_MSS));
|
|
|
|
// new velocity vector
|
|
velocity_ef += accel_earth * delta_time;
|
|
|
|
// new position vector
|
|
Vector3f old_position = position;
|
|
position += velocity_ef * delta_time;
|
|
|
|
// assume zero wind for now
|
|
airspeed = velocity_ef.length();
|
|
|
|
// constrain height to the ground
|
|
if (on_ground(position)) {
|
|
if (!on_ground(old_position) && AP_HAL::millis() - last_ground_contact_ms > 1000) {
|
|
printf("Hit ground at %f m/s\n", velocity_ef.z);
|
|
last_ground_contact_ms = AP_HAL::millis();
|
|
}
|
|
position.z = -(ground_level + frame_height - home.alt*0.01f);
|
|
}
|
|
}
|
|
|
|
} // namespace SITL
|