/*
receive an update from the FDM
This is a blocking function
*/
void JSBSim::recv_fdm(const struct sitl_input &input)
{
FGNetFDM fdm;
check_stdout();
while (sock_fgfdm.recv(&fdm, sizeof(fdm), 100) != sizeof(fdm)) {
send_servos(input);
check_stdout();
}
fdm.ByteSwap();
accel_body = Vector3f(fdm.A_X_pilot, fdm.A_Y_pilot, fdm.A_Z_pilot) * FEET_TO_METERS;
double p, q, r;
SITL::convert_body_frame(degrees(fdm.phi), degrees(fdm.theta),
degrees(fdm.phidot), degrees(fdm.thetadot), degrees(fdm.psidot),
&p, &q, &r);
gyro = Vector3f(p, q, r);
velocity_ef = Vector3f(fdm.v_north, fdm.v_east, fdm.v_down) * FEET_TO_METERS;
location.lat = degrees(fdm.latitude) * 1.0e7;
location.lng = degrees(fdm.longitude) * 1.0e7;
location.alt = fdm.agl*100 + home.alt;
dcm.from_euler(fdm.phi, fdm.theta, fdm.psi);
airspeed = fdm.vcas * FEET_TO_METERS;
// assume 1kHz for now
time_now_us += 1000;
}
/*
receive an update from the FDM
This is a blocking function
*/
void last_letter::recv_fdm(const struct sitl_input &input)
{
fdm_packet pkt;
/*
we re-send the servo packet every 0.1 seconds until we get a
reply. This allows us to cope with some packet loss to the FDM
*/
while (sock.recv(&pkt, sizeof(pkt), 100) != sizeof(pkt)) {
send_servos(input);
}
accel_body = Vector3f(pkt.xAccel, pkt.yAccel, pkt.zAccel);
gyro = Vector3f(pkt.rollRate, pkt.pitchRate, pkt.yawRate);
velocity_ef = Vector3f(pkt.speedN, pkt.speedE, pkt.speedD);
location.lat = pkt.latitude * 1.0e7;
location.lng = pkt.longitude * 1.0e7;
location.alt = pkt.altitude*1.0e2;
dcm.from_euler(pkt.roll, pkt.pitch, pkt.yaw);
airspeed = pkt.airspeed;
airspeed_pitot = pkt.airspeed;
// auto-adjust to last_letter frame rate
uint64_t deltat_us = pkt.timestamp_us - last_timestamp_us;
time_now_us += deltat_us;
if (deltat_us < 1.0e4 && deltat_us > 0) {
adjust_frame_time(1.0e6/deltat_us);
}
last_timestamp_us = pkt.timestamp_us;
}
/*
receive an update from the FDM
This is a blocking function
*/
void Gazebo::recv_fdm(const struct sitl_input &input)
{
fdm_packet pkt;
/*
we re-send the servo packet every 0.1 seconds until we get a
reply. This allows us to cope with some packet loss to the FDM
*/
while (sock.recv(&pkt, sizeof(pkt), 100) != sizeof(pkt)) {
send_servos(input);
}
// get imu stuff
accel_body = Vector3f(pkt.imu_linear_acceleration_xyz[0],
pkt.imu_linear_acceleration_xyz[1],
pkt.imu_linear_acceleration_xyz[2]);
gyro = Vector3f(pkt.imu_angular_velocity_rpy[0],
pkt.imu_angular_velocity_rpy[1],
pkt.imu_angular_velocity_rpy[2]);
// compute dcm from imu orientation
Quaternion quat(pkt.imu_orientation_quat[0],
pkt.imu_orientation_quat[1],
pkt.imu_orientation_quat[2],
pkt.imu_orientation_quat[3]);
quat.rotation_matrix(dcm);
double speedN = pkt.velocity_xyz[0];
double speedE = pkt.velocity_xyz[1];
double speedD = pkt.velocity_xyz[2];
velocity_ef = Vector3f(speedN, speedE, speedD);
position = Vector3f(pkt.position_xyz[0],
pkt.position_xyz[1],
pkt.position_xyz[2]);
// auto-adjust to simulation frame rate
double deltat = pkt.timestamp - last_timestamp;
time_now_us += deltat * 1.0e6;
if (deltat < 0.01 && deltat > 0) {
adjust_frame_time(1.0/deltat);
}
last_timestamp = pkt.timestamp;
/* copied below from iris_ros.py */
/*
bearing = to_degrees(atan2(position.y, position.x));
distance = math.sqrt(self.position.x**2 + self.position.y**2)
(self.latitude, self.longitude) = util.gps_newpos(
self.home_latitude, self.home_longitude, bearing, distance)
self.altitude = self.home_altitude - self.position.z
velocity_body = self.dcm.transposed() * self.velocity
self.accelerometer = self.accel_body.copy()
*/
}
/*
update the Gazebo simulation by one time step
*/
void Gazebo::update(const struct sitl_input &input)
{
send_servos(input);
recv_fdm(input);
update_position();
// update magnetic field
update_mag_field_bf();
}
/*
update the last_letter simulation by one time step
*/
void last_letter::update(const struct sitl_input &input)
{
send_servos(input);
recv_fdm(input);
sync_frame_time();
update_position();
// update magnetic field
update_mag_field_bf();
}
/*
update the JSBSim simulation by one time step
*/
void JSBSim::update(const struct sitl_input &input)
{
while (!initialised) {
if (!create_templates() ||
!start_JSBSim() ||
!open_control_socket() ||
!open_fdm_socket()) {
time_now_us = 1;
return;
}
initialised = true;
}
send_servos(input);
recv_fdm(input);
adjust_frame_time(1000);
sync_frame_time();
drain_control_socket();
}
/*
receive an update from the FDM
This is a blocking function
*/
void CRRCSim::recv_fdm(const struct sitl_input &input)
{
fdm_packet pkt;
/*
we re-send the servo packet every 0.1 seconds until we get a
reply. This allows us to cope with some packet loss to the FDM
*/
while (!sock.recv(&pkt, sizeof(pkt), 100)) {
send_servos(input);
}
accel_body = Vector3f(pkt.xAccel, pkt.yAccel, pkt.zAccel);
gyro = Vector3f(pkt.rollRate, pkt.pitchRate, pkt.yawRate);
velocity_ef = Vector3f(pkt.speedN, pkt.speedE, pkt.speedD);
Location loc1, loc2;
loc2.lat = pkt.latitude * 1.0e7;
loc2.lng = pkt.longitude * 1.0e7;
memset(&loc1, 0, sizeof(loc1));
Vector2f posdelta = location_diff(loc1, loc2);
position.x = posdelta.x;
position.y = posdelta.y;
position.z = -pkt.altitude;
dcm.from_euler(pkt.roll, pkt.pitch, pkt.yaw);
// auto-adjust to crrcsim frame rate
double deltat = pkt.timestamp - last_timestamp;
time_now_us += deltat * 1.0e6;
if (deltat < 0.01 && deltat > 0) {
adjust_frame_time(1.0/deltat);
}
last_timestamp = pkt.timestamp;
}
/*
update the last_letter simulation by one time step
*/
void last_letter::update(const struct sitl_input &input)
{
send_servos(input);
recv_fdm(input);
sync_frame_time();
}
/*
update the CRRCSim simulation by one time step
*/
void CRRCSim::update(const struct sitl_input &input)
{
send_servos(input);
recv_fdm(input);
update_position();
}