__pdata enum ao_flight_state ao_flight_state; /* current flight state */
__pdata uint16_t ao_flight_tick; /* time of last data */
+__pdata uint16_t ao_flight_prev_tick; /* time of previous data */
__pdata int16_t ao_flight_accel; /* filtered acceleration */
__pdata int16_t ao_flight_pres; /* filtered pressure */
__pdata int16_t ao_ground_pres; /* startup pressure */
#define ACCEL_G 265
#define ACCEL_ZERO_G 16000
-#define ACCEL_NOSE_UP (ACCEL_ZERO_G - ACCEL_G * 2 /3)
+#define ACCEL_NOSE_UP (ACCEL_G * 2 /3)
#define ACCEL_BOOST ACCEL_G * 2
#define ACCEL_INT_LAND (ACCEL_G / 10)
#define ACCEL_VEL_LAND VEL_MPS_TO_COUNT(10)
+#define ACCEL_VEL_MACH VEL_MPS_TO_COUNT(200)
+#define ACCEL_VEL_APOGEE VEL_MPS_TO_COUNT(2)
+#define ACCEL_VEL_MAIN VEL_MPS_TO_COUNT(100)
/*
* Barometer calibration
#define BARO_COAST (BARO_kPa * 5) /* 5kpa, or about 500m */
#define BARO_MAIN (BARO_kPa) /* 1kPa, or about 100m */
#define BARO_INT_LAND (BARO_kPa / 20) /* .05kPa, or about 5m */
-#define BARO_LAND (BARO_kPa * 5) /* 5kPa or about 1000m */
+#define BARO_LAND (BARO_kPa * 10) /* 10kPa or about 1000m */
/* We also have a clock, which can be used to sanity check things in
* case of other failures
* it's scaled by 100
*/
__pdata int32_t ao_flight_vel;
-__pdata int32_t ao_max_vel;
+__pdata int32_t ao_min_vel;
__xdata int32_t ao_raw_accel_sum, ao_raw_pres_sum;
/* Landing is detected by getting constant readings from both pressure and accelerometer
*/
#define AO_INTERVAL_TICKS AO_SEC_TO_TICKS(20)
+#define abs(a) ((a) < 0 ? -(a) : (a))
+
void
ao_flight(void)
{
- __pdata static uint8_t nsamples = 0;
+ __pdata static uint16_t nsamples = 0;
ao_flight_adc = ao_adc_head;
ao_raw_accel_prev = 0;
ao_raw_accel = 0;
ao_raw_pres = 0;
- ao_interval_cur_min_pres = 0x7fff;
- ao_interval_cur_max_pres = -0x7fff;
- ao_interval_cur_min_accel = 0x7fff;
- ao_interval_cur_max_accel = -0x7fff;
+ ao_flight_tick = 0;
for (;;) {
ao_sleep(&ao_adc_ring);
while (ao_flight_adc != ao_adc_head) {
+ __pdata uint8_t ticks;
+ __pdata int16_t ao_vel_change;
+ ao_flight_prev_tick = ao_flight_tick;
+
+ /* Capture a sample */
ao_raw_accel = ao_adc_ring[ao_flight_adc].accel;
ao_raw_pres = ao_adc_ring[ao_flight_adc].pres;
ao_flight_tick = ao_adc_ring[ao_flight_adc].tick;
- /* all of our accelerations are negative, so subtract instead of add to get speed */
- ao_flight_vel -= (int32_t) (((ao_raw_accel + ao_raw_accel_prev) >> 1) - ao_ground_accel);
+
+ /* Update velocity
+ *
+ * The accelerometer is mounted so that
+ * acceleration yields negative values
+ * while deceleration yields positive values,
+ * so subtract instead of add.
+ */
+ ticks = ao_flight_tick - ao_flight_prev_tick;
+ ao_vel_change = (((ao_raw_accel + ao_raw_accel_prev) >> 1) - ao_ground_accel);
ao_raw_accel_prev = ao_raw_accel;
+
+ /* one is a common interval */
+ if (ticks == 1)
+ ao_flight_vel -= (int32_t) ao_vel_change;
+ else
+ ao_flight_vel -= (int32_t) ao_vel_change * (int32_t) ticks;
+
ao_flight_adc = ao_adc_ring_next(ao_flight_adc);
}
ao_flight_accel -= ao_flight_accel >> 4;
if (ao_flight_pres < ao_min_pres)
ao_min_pres = ao_flight_pres;
- if (ao_flight_vel > ao_max_vel)
- ao_max_vel = ao_flight_vel;
-
- if (ao_flight_pres < ao_interval_cur_min_pres)
- ao_interval_cur_min_pres = ao_flight_pres;
- if (ao_flight_pres > ao_interval_cur_max_pres)
- ao_interval_cur_max_pres = ao_flight_pres;
- if (ao_flight_accel < ao_interval_cur_min_accel)
- ao_interval_cur_min_accel = ao_flight_accel;
- if (ao_flight_accel > ao_interval_cur_max_accel)
- ao_interval_cur_max_accel = ao_flight_accel;
-
- 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_interval_max_accel = ao_interval_cur_max_accel;
- ao_interval_min_accel = ao_interval_cur_min_accel;
- ao_interval_end = ao_flight_tick + AO_INTERVAL_TICKS;
- ao_interval_cur_min_pres = ao_interval_cur_max_pres = ao_flight_pres;
- ao_interval_cur_min_accel = ao_interval_cur_max_accel = ao_flight_accel;
+ if (ao_flight_vel >= 0) {
+ if (ao_flight_vel < ao_min_vel)
+ ao_min_vel = ao_flight_vel;
+ } else {
+ if (-ao_flight_vel < ao_min_vel)
+ ao_min_vel = -ao_flight_vel;
}
switch (ao_flight_state) {
/* startup state:
*
- * Collect 100 samples of acceleration and pressure
+ * Collect 1000 samples of acceleration and pressure
* data and average them to find the resting values
*/
- if (nsamples < 100) {
+ if (nsamples < 1000) {
ao_raw_accel_sum += ao_raw_accel;
ao_raw_pres_sum += ao_raw_pres;
++nsamples;
ao_ground_accel = (ao_raw_accel_sum / nsamples);
ao_ground_pres = (ao_raw_pres_sum / nsamples);
ao_min_pres = ao_ground_pres;
- ao_main_pres = ao_ground_pres - BARO_MAIN;
+ ao_config_get();
+ ao_main_pres = ao_altitude_to_pres(ao_pres_to_altitude(ao_ground_pres) + ao_config.main_deploy);
ao_flight_vel = 0;
- ao_max_vel = 0;
-
- ao_interval_end = ao_flight_tick;
+ ao_min_vel = 0;
/* Go to launchpad state if the nose is pointing up */
- if (ao_flight_accel < ACCEL_NOSE_UP) {
+ ao_config_get();
+ if (ao_flight_accel < ao_config.accel_zero_g - ACCEL_NOSE_UP) {
+
+ /* Disable the USB controller in flight mode
+ * to save power
+ */
+ ao_usb_disable();
+
+ /* Turn on telemetry system
+ */
+ ao_rdf_set(1);
+ ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_PAD);
+
ao_flight_state = ao_flight_launchpad;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
} else {
/* Turn on the Green LED in idle mode
*/
ao_led_on(AO_LED_GREEN);
- ao_timer_set_adc_interval(100);
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
/* signal successful initialization by turning off the LED */
{
ao_flight_state = ao_flight_boost;
ao_launch_tick = ao_flight_tick;
+
+ /* start logging data */
ao_log_start();
+
+ /* Increase telemetry rate */
+ ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_FLIGHT);
+
+ /* disable RDF beacon */
+ ao_rdf_set(0);
+
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
break;
}
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
break;
}
- /* fall through ... */
+ break;
case ao_flight_coast:
- /* boost/coast to apogee detect:
+ /* coast to apogee detect:
*
- * accelerometer: integrated velocity < 200 m/s AND < max_vel - 50m/s
+ * accelerometer: integrated velocity < 200 m/s
* OR
* barometer: fall at least 500m from max altitude
*
* This extra state is required to avoid mis-detecting
- * apogee due to mach transitions. For slow flights (<200m/s)
- * we expect to transition right through this stage to
- * apogee detect.
+ * apogee due to mach transitions.
+ *
+ * XXX this is essentially a single-detector test
+ * as the 500m altitude change would likely result
+ * in a loss of the rocket. More data on precisely
+ * how big a pressure change the mach transition
+ * generates would be useful here.
*/
- if ((ao_flight_vel < VEL_MPS_TO_COUNT(200) &&
- ao_flight_vel < ao_max_vel - VEL_MPS_TO_COUNT(50)) ||
+ if (ao_flight_vel < ACCEL_VEL_MACH ||
ao_flight_pres > ao_min_pres + BARO_COAST)
{
+ /* set min velocity to current velocity for
+ * apogee detect
+ */
+ ao_min_vel = ao_flight_vel;
ao_flight_state = ao_flight_apogee;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
break;
case ao_flight_apogee:
- /* apogee to drogue deploy:
+ /* apogee detect to drogue deploy:
*
- * accelerometer: integrated velocity < 10m/s
+ * accelerometer: abs(velocity) > min_velocity + 2m/s
* OR
* barometer: fall at least 10m
*
* over in that case and the integrated velocity
* measurement should suffice to find apogee
*/
- if (ao_flight_vel < VEL_MPS_TO_COUNT(-10) ||
- ao_flight_pres - BARO_APOGEE > ao_min_pres)
+ if (abs(ao_flight_vel) > ao_min_vel + ACCEL_VEL_APOGEE ||
+ ao_flight_pres > ao_min_pres + BARO_APOGEE)
{
+ /* ignite the drogue charge */
ao_ignite(ao_igniter_drogue);
+
+ /* slow down the telemetry system */
+ ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_RECOVER);
+
+ /* slow down the ADC sample rate */
+ ao_timer_set_adc_interval(10);
+
+ /* Enable RDF beacon */
+ ao_rdf_set(1);
+
ao_flight_state = ao_flight_drogue;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
+ /*
+ * Start recording min/max accel and pres for a while
+ * to figure out when the rocket has landed
+ */
+ /* Set the 'last' limits to max range to prevent
+ * early resting detection
+ */
+ ao_interval_min_accel = 0;
+ ao_interval_max_accel = 0x7fff;
+ ao_interval_min_pres = 0;
+ ao_interval_max_pres = 0x7fff;
+
+ /* initialize interval values */
+ ao_interval_end = ao_flight_tick + AO_INTERVAL_TICKS;
+
+ ao_interval_cur_min_pres = ao_interval_cur_max_pres = ao_flight_pres;
+ ao_interval_cur_min_accel = ao_interval_cur_max_accel = ao_flight_accel;
+
break;
case ao_flight_drogue:
/* drogue to main deploy:
*
- * accelerometer: abs(velocity) > 50m/s
+ * accelerometer: abs(velocity) > 100m/s (in case the drogue failed)
* OR
* barometer: reach main deploy altitude
*/
- if (ao_flight_vel < VEL_MPS_TO_COUNT(-50) ||
- ao_flight_vel > VEL_MPS_TO_COUNT(50) ||
+ if (ao_flight_vel < -ACCEL_VEL_MAIN ||
+ ao_flight_vel > ACCEL_VEL_MAIN ||
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));
}
+
/* fall through... */
case ao_flight_main:
*
* accelerometer: value stable and velocity less than 10m/s
* OR
- * barometer: altitude stable and within 500m of the launch altitude
+ * barometer: altitude stable and within 1000m of the launch altitude
*/
- if ((ao_flight_vel < ACCEL_VEL_LAND &&
- (ao_interval_max_accel - ao_interval_min_accel) < ACCEL_INT_LAND) ||
+
+ if (ao_flight_pres < ao_interval_cur_min_pres)
+ ao_interval_cur_min_pres = ao_flight_pres;
+ if (ao_flight_pres > ao_interval_cur_max_pres)
+ ao_interval_cur_max_pres = ao_flight_pres;
+ if (ao_flight_accel < ao_interval_cur_min_accel)
+ ao_interval_cur_min_accel = ao_flight_accel;
+ if (ao_flight_accel > ao_interval_cur_max_accel)
+ ao_interval_cur_max_accel = ao_flight_accel;
+
+ 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_interval_max_accel = ao_interval_cur_max_accel;
+ ao_interval_min_accel = ao_interval_cur_min_accel;
+ ao_interval_end = ao_flight_tick + AO_INTERVAL_TICKS;
+ ao_interval_cur_min_pres = ao_interval_cur_max_pres = ao_flight_pres;
+ ao_interval_cur_min_accel = ao_interval_cur_max_accel = ao_flight_accel;
+ }
+
+ if ((abs(ao_flight_vel) < ACCEL_VEL_LAND &&
+ (uint16_t) (ao_interval_max_accel - ao_interval_min_accel) < (uint16_t) ACCEL_INT_LAND) ||
(ao_flight_pres > ao_ground_pres - BARO_LAND &&
- (ao_interval_max_pres - ao_interval_min_pres) < BARO_INT_LAND))
+ (uint16_t) (ao_interval_max_pres - ao_interval_min_pres) < (uint16_t) BARO_INT_LAND))
{
ao_flight_state = ao_flight_landed;
+
+ /* turn off the ADC capture */
+ ao_timer_set_adc_interval(0);
+
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
break;
case ao_flight_landed:
- ao_log_stop();
break;
}
}
#define AO_ACCEL_COUNT_TO_MSS(count) ((count) / 27)
#define AO_VEL_COUNT_TO_MS(count) ((int16_t) ((count) / 2700))
-void
+static void
ao_flight_status(void)
{
- printf("STATE: %7s accel: %d speed: %d altitude: %d\n",
+ printf("STATE: %7s accel: %d speed: %d altitude: %d main: %d\n",
ao_state_names[ao_flight_state],
AO_ACCEL_COUNT_TO_MSS(ACCEL_ZERO_G - ao_flight_accel),
AO_VEL_COUNT_TO_MS(ao_flight_vel),
- ao_pres_to_altitude(ao_flight_pres));
+ ao_pres_to_altitude(ao_flight_pres),
+ ao_pres_to_altitude(ao_main_pres));
}
static __xdata struct ao_task flight_task;
projects / fw / altos / blobdiff