#include "ao.h"
#endif
+#ifndef HAS_ACCEL
+#error Please define HAS_ACCEL
+#endif
+
+#ifndef HAS_GPS
+#error Please define HAS_GPS
+#endif
+
+#ifndef HAS_USB
+#error Please define HAS_USB
+#endif
+
/* Main flight thread. */
__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 */
-__pdata int16_t ao_ground_accel; /* startup acceleration */
-__pdata int16_t ao_min_pres; /* minimum recorded pressure */
+__xdata int16_t ao_ground_pres; /* startup pressure */
__pdata uint16_t ao_launch_tick; /* time of launch detect */
-__pdata int16_t ao_main_pres; /* pressure to eject main */
+#if HAS_ACCEL
+__pdata int16_t ao_ground_accel; /* startup acceleration */
+#endif
/*
* track min/max data over a long interval to detect
* resting
*/
__pdata uint16_t ao_interval_end;
-__pdata int16_t ao_interval_cur_min_accel;
-__pdata int16_t ao_interval_cur_max_accel;
-__pdata int16_t ao_interval_cur_min_pres;
-__pdata int16_t ao_interval_cur_max_pres;
-__pdata int16_t ao_interval_min_accel;
-__pdata int16_t ao_interval_max_accel;
-__pdata int16_t ao_interval_min_pres;
-__pdata int16_t ao_interval_max_pres;
+__pdata int16_t ao_interval_min_height;
+__pdata int16_t ao_interval_max_height;
__data uint8_t ao_flight_adc;
-__pdata int16_t ao_raw_accel, ao_raw_accel_prev, ao_raw_pres;
+__pdata int16_t ao_raw_pres;
+__xdata uint8_t ao_flight_force_idle;
+
+#if HAS_ACCEL
+__pdata int16_t ao_raw_accel, ao_raw_accel_prev;
+__pdata int16_t ao_accel_2g;
/* Accelerometer calibration
*
*/
#define GRAVITY 9.80665
-/* convert m/s to velocity count */
-#define VEL_MPS_TO_COUNT(mps) ((int32_t) (((mps) / GRAVITY) * ACCEL_G * 100))
-
-#define ACCEL_G 265
-#define ACCEL_ZERO_G 16000
-#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)
-#define ACCEL_VEL_BOOST VEL_MPS_TO_COUNT(5)
+
+#define ACCEL_NOSE_UP (ao_accel_2g >> 2)
+
+#endif
/*
* Barometer calibration
* 27 mV/kPa * 32767 / 3300 counts/mV = 268.1 counts/kPa
*/
-#define BARO_kPa 268
-#define BARO_LAUNCH (BARO_kPa / 5) /* .2kPa, or about 20m */
-#define BARO_APOGEE (BARO_kPa / 10) /* .1kPa, or about 10m */
-#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 * 10) /* 10kPa or about 1000m */
-
/* We also have a clock, which can be used to sanity check things in
* case of other failures
*/
#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
+#define to_fix16(x) ((int16_t) ((x) * 65536.0 + 0.5))
+#define to_fix32(x) ((int32_t) ((x) * 65536.0 + 0.5))
+#define from_fix(x) ((x) >> 16)
+
+#include "ao_kalman.h"
+
+__pdata int16_t ao_ground_height;
+__pdata int16_t ao_height;
+__pdata int16_t ao_speed;
+__pdata int16_t ao_accel;
+__pdata int16_t ao_max_height;
+
+static __pdata int32_t ao_k_height;
+static __pdata int32_t ao_k_speed;
+static __pdata int32_t ao_k_accel;
+
+#define AO_K_STEP_100 to_fix16(0.01)
+#define AO_K_STEP_2_2_100 to_fix16(0.00005)
+
+#define AO_K_STEP_10 to_fix16(0.1)
+#define AO_K_STEP_2_2_10 to_fix16(0.005)
+
+/*
+ * Above this height, the baro sensor doesn't work
*/
-__pdata int32_t ao_flight_vel;
-__pdata int32_t ao_min_vel;
-__pdata int32_t ao_old_vel;
-__pdata int16_t ao_old_vel_tick;
-__xdata int32_t ao_raw_accel_sum, ao_raw_pres_sum;
+#define AO_MAX_BARO_HEIGHT 12000
+
+/*
+ * Above this speed, baro measurements are unreliable
+ */
+#define AO_MAX_BARO_SPEED 300
+
+static void
+ao_kalman_predict(void)
+{
+#ifdef AO_FLIGHT_TEST
+ if (ao_flight_tick - ao_flight_prev_tick > 5) {
+ ao_k_height += ((int32_t) ao_speed * AO_K_STEP_10 +
+ (int32_t) ao_accel * AO_K_STEP_2_2_10) >> 4;
+ ao_k_speed += (int32_t) ao_accel * AO_K_STEP_10;
+
+ return;
+ }
+#endif
+ ao_k_height += ((int32_t) ao_speed * AO_K_STEP_100 +
+ (int32_t) ao_accel * AO_K_STEP_2_2_100) >> 4;
+ ao_k_speed += (int32_t) ao_accel * AO_K_STEP_100;
+}
+
+static __pdata int16_t ao_error_h;
+static __pdata int16_t ao_raw_alt;
+static __pdata int16_t ao_raw_height;
+static __pdata int16_t ao_error_h_sq_avg;
+
+static void
+ao_kalman_err_height(void)
+{
+ int16_t e;
+ int16_t height_distrust;
+#if HAS_ACCEL
+ int16_t speed_distrust;
+#endif
+
+ ao_error_h = ao_raw_height - (int16_t) (ao_k_height >> 16);
+
+ e = ao_error_h;
+ if (e < 0)
+ e = -e;
+ if (e > 127)
+ e = 127;
+ ao_error_h_sq_avg -= ao_error_h_sq_avg >> 4;
+ ao_error_h_sq_avg += (e * e) >> 4;
+
+ height_distrust = ao_raw_height - AO_MAX_BARO_HEIGHT;
+#ifdef AO_FLIGHT_TEST
+ if (height_distrust > 0)
+ printf ("height_distrust %d\n", height_distrust);
+#endif
+#if HAS_ACCEL
+ speed_distrust = (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) >> 4;
+#ifdef AO_FLIGHT_TEST
+ if (speed_distrust > 0)
+ printf ("speed distrust %d\n", speed_distrust);
+#endif
+ if (speed_distrust <= 0)
+ speed_distrust = 0;
+ else if (speed_distrust > height_distrust)
+ height_distrust = speed_distrust;
+#endif
+ if (height_distrust <= 0)
+ height_distrust = 0;
+
+ if (height_distrust) {
+ if (height_distrust > 0x100)
+ height_distrust = 0x100;
+ ao_error_h = (int16_t) ((int32_t) ao_error_h * (0x100 - height_distrust)) >> 8;
+ }
+}
+
+static void
+ao_kalman_correct_baro(void)
+{
+ ao_kalman_err_height();
+#ifdef AO_FLIGHT_TEST
+ if (ao_flight_tick - ao_flight_prev_tick > 5) {
+ ao_k_height += (int32_t) AO_BARO_K0_10 * ao_error_h;
+ ao_k_speed += (int32_t) AO_BARO_K1_10 * ao_error_h;
+ ao_k_accel += (int32_t) AO_BARO_K2_10 * ao_error_h;
+ return;
+ }
+#endif
+ ao_k_height += (int32_t) AO_BARO_K0_100 * ao_error_h;
+ ao_k_speed += (int32_t) AO_BARO_K1_100 * ao_error_h;
+ ao_k_accel += (int32_t) AO_BARO_K2_100 * ao_error_h;
+}
+
+#if HAS_ACCEL
+static __pdata int16_t ao_error_a;
+static __pdata int32_t ao_accel_scale;
+
+static void
+ao_kalman_err_accel(void)
+{
+ int32_t accel;
+
+ accel = (ao_ground_accel - ao_raw_accel) * ao_accel_scale;
+
+ /* Can't use ao_accel here as it is the pre-prediction value still */
+ ao_error_a = (accel - ao_k_accel) >> 16;
+}
+
+static void
+ao_kalman_correct_both(void)
+{
+ ao_kalman_err_height();
+ ao_kalman_err_accel();
+
+#if 0
+ /*
+ * Check to see if things are crazy here --
+ * if the computed height is far above the
+ * measured height, we assume that the flight
+ * trajectory is not vertical, and so ignore
+ * the accelerometer for the remainder of the
+ * flight.
+ */
+ if (ao_error_h_sq_avg > 10)
+ {
+ ao_kalman_correct_baro();
+ return;
+ }
+#endif
+
+#ifdef AO_FLIGHT_TEST
+ if (ao_flight_tick - ao_flight_prev_tick > 5) {
+ ao_k_height +=
+ (int32_t) AO_BOTH_K00_10 * ao_error_h +
+ (int32_t) (AO_BOTH_K01_10 >> 4) * ao_error_a;
+ ao_k_speed +=
+ ((int32_t) AO_BOTH_K10_10 << 4) * ao_error_h +
+ (int32_t) AO_BOTH_K11_10 * ao_error_a;
+ ao_k_accel +=
+ ((int32_t) AO_BOTH_K20_10 << 4) * ao_error_h +
+ (int32_t) AO_BOTH_K21_10 * ao_error_a;
+ return;
+ }
+#endif
+ ao_k_height +=
+ (int32_t) AO_BOTH_K00_100 * ao_error_h +
+ (int32_t) AO_BOTH_K01_100 * ao_error_a;
+ ao_k_speed +=
+ (int32_t) AO_BOTH_K10_100 * ao_error_h +
+ (int32_t) AO_BOTH_K11_100 * ao_error_a;
+ ao_k_accel +=
+ (int32_t) AO_BOTH_K20_100 * ao_error_h +
+ (int32_t) AO_BOTH_K21_100 * ao_error_a;
+}
+
+static void
+ao_kalman_correct_accel(void)
+{
+ ao_kalman_err_accel();
+
+#ifdef AO_FLIGHT_TEST
+ if (ao_flight_tick - ao_flight_prev_tick > 5) {
+ ao_k_height +=(int32_t) AO_ACCEL_K0_10 * ao_error_a;
+ ao_k_speed += (int32_t) AO_ACCEL_K1_10 * ao_error_a;
+ ao_k_accel += (int32_t) AO_ACCEL_K2_10 * ao_error_a;
+ return;
+ }
+#endif
+ ao_k_height += (int32_t) AO_ACCEL_K0_100 * ao_error_a;
+ ao_k_speed += (int32_t) AO_ACCEL_K1_100 * ao_error_a;
+ ao_k_accel += (int32_t) AO_ACCEL_K2_100 * ao_error_a;
+}
+#endif /* HAS_ACCEL */
+
+__xdata int32_t ao_raw_pres_sum;
+
+#ifdef HAS_ACCEL
+__xdata int32_t ao_raw_accel_sum;
+#endif
/* Landing is detected by getting constant readings from both pressure and accelerometer
* for a fairly long time (AO_INTERVAL_TICKS)
*/
-#define AO_INTERVAL_TICKS AO_SEC_TO_TICKS(20)
+#define AO_INTERVAL_TICKS AO_SEC_TO_TICKS(5)
#define abs(a) ((a) < 0 ? -(a) : (a))
__pdata static uint16_t nsamples = 0;
ao_flight_adc = ao_adc_head;
+ ao_raw_pres = 0;
+#if HAS_ACCEL
ao_raw_accel_prev = 0;
ao_raw_accel = 0;
- ao_raw_pres = 0;
+#endif
ao_flight_tick = 0;
for (;;) {
- ao_sleep(&ao_adc_ring);
+ ao_wakeup(DATA_TO_XDATA(&ao_flight_adc));
+ ao_sleep(DATA_TO_XDATA(&ao_adc_head));
while (ao_flight_adc != ao_adc_head) {
- __pdata uint8_t ticks;
- __pdata int16_t ao_vel_change;
+ __xdata struct ao_adc *ao_adc;
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;
-
- ao_flight_accel -= ao_flight_accel >> 4;
- ao_flight_accel += ao_raw_accel >> 4;
- ao_flight_pres -= ao_flight_pres >> 4;
- ao_flight_pres += ao_raw_pres >> 4;
- /* Update velocity
- *
- * The accelerometer is mounted so that
- * acceleration yields negative values
- * while deceleration yields positive values,
- * so subtract instead of add.
+ ao_adc = &ao_adc_ring[ao_flight_adc];
+ ao_flight_tick = ao_adc->tick;
+ ao_raw_pres = ao_adc->pres;
+ ao_raw_alt = ao_pres_to_altitude(ao_raw_pres);
+ ao_raw_height = ao_raw_alt - ao_ground_height;
+#if HAS_ACCEL
+ ao_raw_accel = ao_adc->accel;
+#if HAS_ACCEL_REF
+ /*
+ * Ok, the math here is a bit tricky.
+ *
+ * ao_raw_accel: ADC output for acceleration
+ * ao_accel_ref: ADC output for the 5V reference.
+ * ao_cook_accel: Corrected acceleration value
+ * Vcc: 3.3V supply to the CC1111
+ * Vac: 5V supply to the accelerometer
+ * accel: input voltage to accelerometer ADC pin
+ * ref: input voltage to 5V reference ADC pin
+ *
+ *
+ * Measured acceleration is ratiometric to Vcc:
+ *
+ * ao_raw_accel accel
+ * ------------ = -----
+ * 32767 Vcc
+ *
+ * Measured 5v reference is also ratiometric to Vcc:
+ *
+ * ao_accel_ref ref
+ * ------------ = -----
+ * 32767 Vcc
+ *
+ *
+ * ao_accel_ref = 32767 * (ref / Vcc)
+ *
+ * Acceleration is measured ratiometric to the 5V supply,
+ * so what we want is:
+ *
+ * ao_cook_accel accel
+ * ------------- = -----
+ * 32767 ref
+ *
+ *
+ * accel Vcc
+ * = ----- * ---
+ * Vcc ref
+ *
+ * ao_raw_accel 32767
+ * = ------------ * ------------
+ * 32737 ao_accel_ref
+ *
+ * Multiply through by 32767:
+ *
+ * ao_raw_accel * 32767
+ * ao_cook_accel = --------------------
+ * ao_accel_ref
+ *
+ * Now, the tricky part. Getting this to compile efficiently
+ * and keeping all of the values in-range.
+ *
+ * First off, we need to use a shift of 16 instead of * 32767 as SDCC
+ * does the obvious optimizations for byte-granularity shifts:
+ *
+ * ao_cook_accel = (ao_raw_accel << 16) / ao_accel_ref
+ *
+ * Next, lets check our input ranges:
+ *
+ * 0 <= ao_raw_accel <= 0x7fff (singled ended ADC conversion)
+ * 0x7000 <= ao_accel_ref <= 0x7fff (the 5V ref value is close to 0x7fff)
+ *
+ * Plugging in our input ranges, we get an output range of 0 - 0x12490,
+ * which is 17 bits. That won't work. If we take the accel ref and shift
+ * by a bit, we'll change its range:
+ *
+ * 0xe000 <= ao_accel_ref<<1 <= 0xfffe
+ *
+ * ao_cook_accel = (ao_raw_accel << 16) / (ao_accel_ref << 1)
+ *
+ * Now the output range is 0 - 0x9248, which nicely fits in 16 bits. It
+ * is, however, one bit too large for our signed computations. So, we
+ * take the result and shift that by a bit:
+ *
+ * ao_cook_accel = ((ao_raw_accel << 16) / (ao_accel_ref << 1)) >> 1
+ *
+ * This finally creates an output range of 0 - 0x4924. As the ADC only
+ * provides 11 bits of data, we haven't actually lost any precision,
+ * just dropped a bit of noise off the low end.
*/
- ticks = ao_flight_tick - ao_flight_prev_tick;
- ao_vel_change = (((ao_raw_accel >> 1) + (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_raw_accel = (uint16_t) ((((uint32_t) ao_raw_accel << 16) / (ao_accel_ref[ao_flight_adc] << 1))) >> 1;
+ ao_adc->accel = ao_raw_accel;
+#endif
+#endif
+ if (ao_flight_state > ao_flight_idle) {
+ ao_kalman_predict();
+#if HAS_ACCEL
+ if (ao_flight_state <= ao_flight_coast) {
+#ifdef FORCE_ACCEL
+ ao_kalman_correct_accel();
+#else
+ ao_kalman_correct_both();
+#endif
+ } else
+#endif
+ ao_kalman_correct_baro();
+ ao_height = from_fix(ao_k_height);
+ ao_speed = from_fix(ao_k_speed);
+ ao_accel = from_fix(ao_k_accel);
+ if (ao_height > ao_max_height)
+ ao_max_height = ao_height;
+ }
ao_flight_adc = ao_adc_ring_next(ao_flight_adc);
}
- if (ao_flight_pres < ao_min_pres)
- ao_min_pres = ao_flight_pres;
- 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) {
case ao_flight_startup:
/* startup state:
*
- * Collect 1000 samples of acceleration and pressure
+ * Collect 512 samples of acceleration and pressure
* data and average them to find the resting values
*/
- if (nsamples < 1000) {
+ if (nsamples < 512) {
+#if HAS_ACCEL
ao_raw_accel_sum += ao_raw_accel;
+#endif
ao_raw_pres_sum += ao_raw_pres;
++nsamples;
continue;
}
- ao_ground_accel = (ao_raw_accel_sum / nsamples);
- ao_ground_pres = (ao_raw_pres_sum / nsamples);
- ao_min_pres = ao_ground_pres;
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_min_vel = 0;
- ao_old_vel = ao_flight_vel;
- ao_old_vel_tick = ao_flight_tick;
+#if HAS_ACCEL
+ ao_ground_accel = ao_raw_accel_sum >> 9;
+ ao_accel_2g = ao_config.accel_minus_g - ao_config.accel_plus_g;
+ ao_accel_scale = to_fix32(GRAVITY * 2 * 16) / ao_accel_2g;
+#endif
+ ao_ground_pres = ao_raw_pres_sum >> 9;
+ ao_ground_height = ao_pres_to_altitude(ao_ground_pres);
- /* Go to pad state if the nose is pointing up */
- ao_config_get();
- if (ao_flight_accel < ao_config.accel_zero_g - ACCEL_NOSE_UP) {
+ /* Check to see what mode we should go to.
+ * - Invalid mode if accel cal appears to be out
+ * - pad mode if we're upright,
+ * - idle mode otherwise
+ */
+#if HAS_ACCEL
+ if (ao_config.accel_plus_g == 0 ||
+ ao_config.accel_minus_g == 0 ||
+ ao_ground_accel < ao_config.accel_plus_g - ACCEL_NOSE_UP ||
+ ao_ground_accel > ao_config.accel_minus_g + ACCEL_NOSE_UP)
+ {
+ /* Detected an accel value outside -1.5g to 1.5g
+ * (or uncalibrated values), so we go into invalid mode
+ */
+ ao_flight_state = ao_flight_invalid;
+ } else
+#endif
+ if (!ao_flight_force_idle
+#if HAS_ACCEL
+ && ao_ground_accel < ao_config.accel_plus_g + ACCEL_NOSE_UP
+#endif
+ )
+ {
+ /* Set pad mode - we can fly! */
+ ao_flight_state = ao_flight_pad;
+#if HAS_USB
/* Disable the USB controller in flight mode
* to save power
*/
ao_usb_disable();
+#endif
- /* Turn on telemetry system
- */
+ /* Disable packet mode in pad state */
+ ao_packet_slave_stop();
+
+ /* Turn on telemetry system */
ao_rdf_set(1);
ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_PAD);
- ao_flight_state = ao_flight_pad;
- ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+ /* signal successful initialization by turning off the LED */
+ ao_led_off(AO_LED_RED);
} else {
- ao_flight_state = ao_flight_idle;
-
- /* Turn on packet system in idle mode
- */
- ao_packet_slave_start();
- ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+ /* Set idle mode */
+ ao_flight_state = ao_flight_idle;
+
+ /* signal successful initialization by turning off the LED */
+ ao_led_off(AO_LED_RED);
}
- /* signal successful initialization by turning off the LED */
- ao_led_off(AO_LED_RED);
+ /* wakeup threads due to state change */
+ ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+
break;
case ao_flight_pad:
- /* Trim velocity
- *
- * Once a second, remove any velocity from
- * a second ago
- */
- if ((int16_t) (ao_flight_tick - ao_old_vel_tick) >= AO_SEC_TO_TICKS(1)) {
- ao_old_vel_tick = ao_flight_tick;
- ao_flight_vel -= ao_old_vel;
- ao_old_vel = ao_flight_vel;
- }
/* pad to boost:
*
- * accelerometer: > 2g AND velocity > 5m/s
- * OR
* barometer: > 20m vertical motion
+ * OR
+ * accelerometer: > 2g AND velocity > 5m/s
*
* The accelerometer should always detect motion before
* the barometer, but we use both to make sure this
- * transition is detected
+ * transition is detected. If the device
+ * doesn't have an accelerometer, then ignore the
+ * speed and acceleration as they are quite noisy
+ * on the pad.
*/
- if ((ao_flight_accel < ao_ground_accel - ACCEL_BOOST &&
- ao_flight_vel > ACCEL_VEL_BOOST) ||
- ao_flight_pres < ao_ground_pres - BARO_LAUNCH)
+ if (ao_height > AO_M_TO_HEIGHT(20)
+#if HAS_ACCEL
+ || (ao_accel > AO_MSS_TO_ACCEL(20) &&
+ ao_speed > AO_MS_TO_SPEED(5))
+#endif
+ )
{
ao_flight_state = ao_flight_boost;
ao_launch_tick = ao_flight_tick;
/* disable RDF beacon */
ao_rdf_set(0);
+#if HAS_GPS
+ /* Record current GPS position by waking up GPS log tasks */
+ ao_wakeup(&ao_gps_data);
+ ao_wakeup(&ao_gps_tracking_data);
+#endif
+
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
break;
}
* deceleration, or by waiting until the maximum burn duration
* (15 seconds) has past.
*/
- if (ao_flight_accel > ao_ground_accel + (ACCEL_G >> 2) ||
+ if ((ao_accel < AO_MSS_TO_ACCEL(-2.5) && ao_height > AO_M_TO_HEIGHT(100)) ||
(int16_t) (ao_flight_tick - ao_launch_tick) > BOOST_TICKS_MAX)
{
ao_flight_state = ao_flight_fast;
}
break;
case ao_flight_fast:
-
- /* fast to coast:
- *
- * 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.
- *
- * 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.
+ /*
+ * This is essentially the same as coast,
+ * but the barometer is being ignored as
+ * it may be unreliable.
*/
- 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 = abs(ao_flight_vel);
+ if (ao_speed < AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) {
ao_flight_state = ao_flight_coast;
ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+ break;
}
break;
case ao_flight_coast:
/* apogee detect: coast to drogue deploy:
*
- * accelerometer: abs(velocity) > min_velocity + 2m/s
- * OR
- * barometer: fall at least 10m
+ * speed: < 0
*
- * If the barometer saturates because the flight
- * goes over its measuring range (about 53k'),
- * requiring a 10m fall will avoid prematurely
- * detecting apogee; the accelerometer will take
- * over in that case and the integrated velocity
- * measurement should suffice to find apogee
+ * Also make sure the model altitude is tracking
+ * the measured altitude reasonably closely; otherwise
+ * we're probably transsonic.
*/
- if (/* abs(ao_flight_vel) > ao_min_vel + ACCEL_VEL_APOGEE || */
- ao_flight_pres > ao_min_pres + BARO_APOGEE)
+ if (ao_speed < 0 && (ao_raw_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 100))
{
/* 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);
-
/*
- * Start recording min/max accel and pres for a while
+ * Start recording min/max height
* 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;
+ ao_interval_min_height = ao_interval_max_height = ao_height;
/* and enter drogue state */
ao_flight_state = ao_flight_drogue;
* at that point. Perhaps also use the drogue sense lines
* to notice continutity?
*/
- if (ao_flight_pres >= ao_main_pres)
+ if (ao_height <= ao_config.main_deploy)
{
ao_ignite(ao_igniter_main);
ao_flight_state = ao_flight_main;
/* drogue/main to land:
*
- * accelerometer: value stable
- * AND
* barometer: altitude stable and within 1000m of the launch altitude
*/
- 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 (ao_height < ao_interval_min_height)
+ ao_interval_min_height = ao_height;
+ if (ao_height > ao_interval_max_height)
+ ao_interval_max_height = ao_height;
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;
+ if (ao_height < AO_M_TO_HEIGHT(1000) &&
+ ao_interval_max_height - ao_interval_min_height < AO_M_TO_HEIGHT(5))
+ {
+ ao_flight_state = ao_flight_landed;
+
+ /* turn off the ADC capture */
+ ao_timer_set_adc_interval(0);
+ /* Enable RDF beacon */
+ ao_rdf_set(1);
+
+ ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
+ }
+ ao_interval_min_height = ao_interval_max_height = ao_height;
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 ((uint16_t) (ao_interval_max_accel - ao_interval_min_accel) < (uint16_t) ACCEL_INT_LAND &&
- ao_flight_pres > ao_ground_pres - BARO_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);
- /* Enable RDF beacon */
- ao_rdf_set(1);
-
- ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
}
break;
case ao_flight_landed:
}
}
-#define AO_ACCEL_COUNT_TO_MSS(count) ((count) / 27)
-#define AO_VEL_COUNT_TO_MS(count) ((int16_t) ((count) / 2700))
-
-static void
-ao_flight_status(void) __reentrant
-{
- 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_main_pres));
-}
-
static __xdata struct ao_task flight_task;
-__code struct ao_cmds ao_flight_cmds[] = {
- { 'f', ao_flight_status, "f Display current flight state" },
- { 0, ao_flight_status, NULL }
-};
-
void
ao_flight_init(void)
{
ao_flight_state = ao_flight_startup;
- ao_interval_min_accel = 0;
- ao_interval_max_accel = 0x7fff;
- ao_interval_min_pres = 0;
- ao_interval_max_pres = 0x7fff;
- ao_interval_end = AO_INTERVAL_TICKS;
-
ao_add_task(&flight_task, ao_flight, "flight");
- ao_cmd_register(&ao_flight_cmds[0]);
}