* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
+#ifndef AO_FLIGHT_TEST
#include "ao.h"
+#endif
/* Main flight thread. */
-__xdata struct ao_adc ao_flight_data; /* last acquired data */
-__pdata enum flight_state ao_flight_state; /* current flight state */
+__pdata enum ao_flight_state ao_flight_state; /* current flight state */
__pdata uint16_t ao_flight_tick; /* time of last data */
__pdata int16_t ao_flight_accel; /* filtered acceleration */
__pdata int16_t ao_flight_pres; /* filtered pressure */
__pdata int16_t ao_interval_min_pres;
__pdata int16_t ao_interval_max_pres;
+__data uint8_t ao_flight_adc;
+__xdata int16_t ao_accel, ao_prev_accel, ao_pres;
+
#define AO_INTERVAL_TICKS AO_SEC_TO_TICKS(5)
/* Accelerometer calibration
#define ACCEL_ZERO_G 16000
#define ACCEL_NOSE_UP (ACCEL_ZERO_G - ACCEL_G * 2 /3)
#define ACCEL_BOOST (ACCEL_NOSE_UP - ACCEL_G * 2)
+#define ACCEL_LAND (ACCEL_G / 10)
/*
* Barometer calibration
* case of other failures
*/
-#define BOOST_TICKS_MAX AO_SEC_TO_TICKS(10)
+#define BOOST_TICKS_MAX AO_SEC_TO_TICKS(15)
+
+/* This value is scaled in a weird way. It's a running total of accelerometer
+ * readings minus the ground accelerometer reading. That means it measures
+ * velocity, and quite accurately too. As it gets updated 100 times a second,
+ * it's scaled by 100
+ */
+__data int32_t ao_flight_vel;
+
+/* convert m/s to velocity count */
+#define VEL_MPS_TO_COUNT(mps) ((int32_t) ((int32_t) (mps) * (int32_t) 100 / (int32_t) ACCEL_G))
void
ao_flight(void)
{
__pdata static uint8_t nsamples = 0;
+ ao_flight_adc = ao_adc_head;
+ ao_prev_accel = 0;
+ ao_accel = 0;
+ ao_pres = 0;
for (;;) {
ao_sleep(&ao_adc_ring);
- ao_adc_get(&ao_flight_data);
+ while (ao_flight_adc != ao_adc_head) {
+ ao_accel = ao_adc_ring[ao_flight_adc].accel;
+ ao_pres = ao_adc_ring[ao_flight_adc].pres;
+ ao_flight_tick = ao_adc_ring[ao_flight_adc].tick;
+ ao_flight_vel += (int32_t) (((ao_accel + ao_prev_accel) >> 4) - (ao_ground_accel << 1));
+ ao_prev_accel = ao_accel;
+ ao_flight_adc = ao_adc_ring_next(ao_flight_adc);
+ }
ao_flight_accel -= ao_flight_accel >> 4;
- ao_flight_accel += ao_flight_data.accel >> 4;
+ ao_flight_accel += ao_accel >> 4;
ao_flight_pres -= ao_flight_pres >> 4;
- ao_flight_pres += ao_flight_data.pres >> 4;
- ao_flight_tick = ao_time();
+ ao_flight_pres += ao_pres >> 4;
- ao_flight_tick = ao_time();
+ if (ao_flight_pres < ao_min_pres)
+ ao_min_pres = ao_flight_pres;
+
if ((int16_t) (ao_flight_tick - ao_interval_end) >= 0) {
ao_interval_max_pres = ao_interval_cur_max_pres;
ao_interval_min_pres = ao_interval_cur_min_pres;
ao_ground_pres = ao_flight_pres;
ao_min_pres = ao_flight_pres;
ao_main_pres = ao_ground_pres - BARO_MAIN;
+ ao_flight_vel = 0;
ao_interval_end = ao_flight_tick;
- /* Go to launchpad state if the nose is pointing up and the battery is charged */
- if (ao_flight_accel < ACCEL_NOSE_UP && ao_flight_data.v_batt > 23000) {
+ /* Go to launchpad state if the nose is pointing up */
+ if (ao_flight_accel < ACCEL_NOSE_UP) {
ao_flight_state = ao_flight_launchpad;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
} else {
ao_led_off(AO_LED_RED);
break;
case ao_flight_launchpad:
+
+ /* pad to boost:
+ *
+ * accelerometer: > 2g
+ * barometer: > 20m vertical motion
+ */
if (ao_flight_accel < ACCEL_BOOST ||
ao_flight_pres + BARO_LAUNCH < ao_ground_pres)
{
}
break;
case ao_flight_boost:
- if (ao_flight_accel > ACCEL_ZERO_G ||
- (int16_t) (ao_flight_data.tick - ao_launch_time) > BOOST_TICKS_MAX)
+
+ /* boost to coast:
+ *
+ * accelerometer: start to fall at > 1/4 G
+ * time: boost for more than 15 seconds
+ */
+ if (ao_flight_accel > ao_ground_accel + (ACCEL_G >> 2) ||
+ (int16_t) (ao_flight_tick - ao_launch_time) > BOOST_TICKS_MAX)
{
ao_flight_state = ao_flight_coast;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
break;
case ao_flight_coast:
- if (ao_flight_pres < ao_min_pres)
- ao_min_pres = ao_flight_pres;
- if (ao_flight_pres - BARO_APOGEE > ao_min_pres) {
+
+ /* coast to apogee detect:
+ *
+ * accelerometer: integrated velocity < 200 m/s
+ * barometer: fall at least 500m from max altitude
+ */
+ if (ao_flight_vel < VEL_MPS_TO_COUNT(200) ||
+ ao_flight_pres - (5 * BARO_kPa) > ao_min_pres)
+ {
ao_flight_state = ao_flight_apogee;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
break;
case ao_flight_apogee:
-// ao_ignite(AO_IGNITE_DROGUE);
- ao_flight_state = ao_flight_drogue;
- ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+
+ /* apogee to drogue deploy:
+ *
+ * accelerometer: integrated velocity < 10m/s
+ * barometer: fall at least 10m
+ */
+ if (ao_flight_vel < VEL_MPS_TO_COUNT(-10) ||
+ ao_flight_pres - BARO_APOGEE > ao_min_pres)
+ {
+ ao_ignite(ao_igniter_drogue);
+ ao_flight_state = ao_flight_drogue;
+ ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+ }
break;
case ao_flight_drogue:
- if (ao_flight_pres >= ao_main_pres) {
-// ao_ignite(AO_IGNITE_MAIN);
+
+ /* drogue to main deploy:
+ *
+ * accelerometer: abs(velocity) > 50m/s
+ * barometer: reach main deploy altitude
+ */
+ if (ao_flight_vel < VEL_MPS_TO_COUNT(-50) ||
+ ao_flight_vel > VEL_MPS_TO_COUNT(50) ||
+ ao_flight_pres >= ao_main_pres)
+ {
+ ao_ignite(ao_igniter_main);
ao_flight_state = ao_flight_main;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
- if ((ao_interval_max_pres - ao_interval_min_pres) < BARO_LAND) {
- ao_flight_state = ao_flight_landed;
- ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
- }
- break;
+ /* fall through... */
case ao_flight_main:
- if ((ao_interval_max_pres - ao_interval_min_pres) < BARO_LAND) {
+
+ /* drogue/main to land:
+ *
+ * accelerometer: value stable
+ * barometer: altitude stable
+ */
+ if ((ao_interval_max_accel - ao_interval_min_accel) < ACCEL_LAND ||
+ (ao_interval_max_pres - ao_interval_min_pres) < BARO_LAND)
+ {
ao_flight_state = ao_flight_landed;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
projects / fw / altos / blobdiff