/**
* Read received data
*/
void ahrs_vectornav_propagate(void)
{
// Rates [rad/s]
static struct FloatRates body_rate;
float_rmat_ratemult(&body_rate, orientationGetRMat_f(&ahrs_vn.body_to_imu), &ahrs_vn.vn_data.gyro); // compute body rates
stateSetBodyRates_f(&body_rate); // Set state [rad/s]
// Attitude [deg]
static struct FloatQuat imu_quat; // convert from euler to quat
float_quat_of_eulers(&imu_quat, &ahrs_vn.vn_data.attitude);
stateSetNedToBodyQuat_f(&imu_quat);
}
/**
* Propagate the received states into the vehicle
* state machine
*/
void ins_vectornav_propagate()
{
// Acceleration [m/s^2]
// in fixed point for sending as ABI and telemetry msgs
ACCELS_BFP_OF_REAL(ins_vn.accel_i, ins_vn.accel);
// Rates [rad/s]
static struct FloatRates body_rate;
// in fixed point for sending as ABI and telemetry msgs
RATES_BFP_OF_REAL(ins_vn.gyro_i, ins_vn.gyro);
float_rmat_ratemult(&body_rate, orientationGetRMat_f(&ins_vn.body_to_imu), &ins_vn.gyro); // compute body rates
stateSetBodyRates_f(&body_rate); // Set state [rad/s]
// Attitude [deg]
ins_vectornav_yaw_pitch_roll_to_attitude(&ins_vn.attitude); // convert to correct units and axis [rad]
static struct FloatQuat imu_quat; // convert from euler to quat
float_quat_of_eulers(&imu_quat, &ins_vn.attitude);
static struct FloatRMat imu_rmat; // convert from quat to rmat
float_rmat_of_quat(&imu_rmat, &imu_quat);
static struct FloatRMat ltp_to_body_rmat; // rotate to body frame
float_rmat_comp(<p_to_body_rmat, &imu_rmat, orientationGetRMat_f(&ins_vn.body_to_imu));
stateSetNedToBodyRMat_f(<p_to_body_rmat); // set body states [rad]
// NED (LTP) velocity [m/s]
// North east down (NED), also known as local tangent plane (LTP),
// is a geographical coordinate system for representing state vectors that is commonly used in aviation.
// It consists of three numbers: one represents the position along the northern axis,
// one along the eastern axis, and one represents vertical position. Down is chosen as opposed to
// up in order to comply with the right-hand rule.
// The origin of this coordinate system is usually chosen to be the aircraft's center of gravity.
// x = North
// y = East
// z = Down
stateSetSpeedNed_f(&ins_vn.vel_ned); // set state
// NED (LTP) acceleration [m/s^2]
static struct FloatVect3 accel_meas_ltp;// first we need to rotate linear acceleration from imu-frame to body-frame
float_rmat_transp_vmult(&accel_meas_ltp, orientationGetRMat_f(&ins_vn.body_to_imu), &(ins_vn.lin_accel));
static struct NedCoor_f ltp_accel; // assign to NedCoord_f struct
VECT3_ASSIGN(ltp_accel, accel_meas_ltp.x, accel_meas_ltp.y, accel_meas_ltp.z);
stateSetAccelNed_f(<p_accel); // then set the states
ins_vn.ltp_accel_f = ltp_accel;
// LLA position [rad, rad, m]
//static struct LlaCoor_f lla_pos; // convert from deg to rad, and from double to float
ins_vn.lla_pos.lat = RadOfDeg((float)ins_vn.pos_lla[0]); // ins_impl.pos_lla[0] = lat
ins_vn.lla_pos.lon = RadOfDeg((float)ins_vn.pos_lla[1]); // ins_impl.pos_lla[1] = lon
ins_vn.lla_pos.alt = ((float)ins_vn.pos_lla[2]); // ins_impl.pos_lla[2] = alt
LLA_BFP_OF_REAL(gps.lla_pos, ins_vn.lla_pos);
stateSetPositionLla_i(&gps.lla_pos);
// ECEF position
struct LtpDef_f def;
ltp_def_from_lla_f(&def, &ins_vn.lla_pos);
struct EcefCoor_f ecef_vel;
ecef_of_ned_point_f(&ecef_vel, &def, &ins_vn.vel_ned);
ECEF_BFP_OF_REAL(gps.ecef_vel, ecef_vel);
// ECEF velocity
gps.ecef_pos.x = stateGetPositionEcef_i()->x;
gps.ecef_pos.y = stateGetPositionEcef_i()->y;
gps.ecef_pos.z = stateGetPositionEcef_i()->z;
#if GPS_USE_LATLONG
// GPS UTM
/* Computes from (lat, long) in the referenced UTM zone */
struct UtmCoor_f utm_f;
utm_f.zone = nav_utm_zone0;
/* convert to utm */
//utm_of_lla_f(&utm_f, &lla_f);
utm_of_lla_f(&utm_f, &ins_vn.lla_pos);
/* copy results of utm conversion */
gps.utm_pos.east = (int32_t)(utm_f.east * 100);
gps.utm_pos.north = (int32_t)(utm_f.north * 100);
gps.utm_pos.alt = (int32_t)(utm_f.alt * 1000);
gps.utm_pos.zone = (uint8_t)nav_utm_zone0;
#endif
// GPS Ground speed
float speed = sqrt(ins_vn.vel_ned.x * ins_vn.vel_ned.x + ins_vn.vel_ned.y * ins_vn.vel_ned.y);
gps.gspeed = ((uint16_t)(speed * 100));
// GPS course
gps.course = (int32_t)(1e7 * (atan2(ins_vn.vel_ned.y, ins_vn.vel_ned.x)));
// Because we have not HMSL data from Vectornav, we are using LLA-Altitude
// as a workaround
gps.hmsl = (uint32_t)(gps.lla_pos.alt);
// set position uncertainty
ins_vectornav_set_pacc();
// set velocity uncertainty
ins_vectornav_set_sacc();
// check GPS status
gps.last_msg_time = sys_time.nb_sec;
gps.last_msg_ticks = sys_time.nb_sec_rem;
if (gps.fix == GPS_FIX_3D) {
gps.last_3dfix_time = sys_time.nb_sec;
gps.last_3dfix_ticks = sys_time.nb_sec_rem;
}
// read INS status
ins_vectornav_check_status();
// update internal states for telemetry purposes
// TODO: directly convert vectornav output instead of using state interface
// to support multiple INS running at the same time
ins_vn.ltp_pos_i = *stateGetPositionNed_i();
ins_vn.ltp_speed_i = *stateGetSpeedNed_i();
ins_vn.ltp_accel_i = *stateGetAccelNed_i();
// send ABI messages
uint32_t now_ts = get_sys_time_usec();
AbiSendMsgGPS(GPS_UBX_ID, now_ts, &gps);
AbiSendMsgIMU_GYRO_INT32(IMU_ASPIRIN_ID, now_ts, &ins_vn.gyro_i);
AbiSendMsgIMU_ACCEL_INT32(IMU_ASPIRIN_ID, now_ts, &ins_vn.accel_i);
}
