diff options
| -rw-r--r-- | ao_flight.c | 122 | ||||
| -rw-r--r-- | ao_flight_test.c | 5 |
2 files changed, 100 insertions, 27 deletions
diff --git a/ao_flight.c b/ao_flight.c index bd361b65..1f56dab6 100644 --- a/ao_flight.c +++ b/ao_flight.c @@ -23,6 +23,7 @@ __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 */ @@ -79,6 +80,9 @@ __pdata int16_t ao_raw_accel, ao_raw_accel_prev, ao_raw_pres; #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 @@ -105,7 +109,7 @@ __pdata int16_t ao_raw_accel, ao_raw_accel_prev, ao_raw_pres; #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 @@ -119,7 +123,7 @@ __pdata int16_t ao_raw_accel, ao_raw_accel_prev, ao_raw_pres; * 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 @@ -127,6 +131,8 @@ __xdata int32_t ao_raw_accel_sum, ao_raw_pres_sum; */ #define AO_INTERVAL_TICKS AO_SEC_TO_TICKS(20) +#define abs(a) ((a) < 0 ? -(a) : (a)) + void ao_flight(void) { @@ -140,15 +146,36 @@ ao_flight(void) 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; @@ -158,8 +185,13 @@ ao_flight(void) 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_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; + } if (ao_flight_pres < ao_interval_cur_min_pres) ao_interval_cur_min_pres = ao_flight_pres; @@ -199,12 +231,23 @@ ao_flight(void) ao_min_pres = ao_ground_pres; ao_main_pres = ao_ground_pres - BARO_MAIN; ao_flight_vel = 0; - ao_max_vel = 0; + ao_min_vel = 0; ao_interval_end = ao_flight_tick; /* Go to launchpad state if the nose is pointing up */ if (ao_flight_accel < 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_FLIGHT); + ao_flight_state = ao_flight_launchpad; ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); } else { @@ -236,7 +279,13 @@ ao_flight(void) { ao_flight_state = ao_flight_boost; ao_launch_tick = ao_flight_tick; + + /* start logging data */ ao_log_start(); + + /* disable RDF beacon */ + ao_rdf_set(0); + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); break; } @@ -260,33 +309,40 @@ ao_flight(void) 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 * @@ -297,10 +353,18 @@ ao_flight(void) * 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); + + /* Enable RDF beacon */ + ao_rdf_set(1); + ao_flight_state = ao_flight_drogue; ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); } @@ -309,12 +373,12 @@ ao_flight(void) /* 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); @@ -328,19 +392,25 @@ ao_flight(void) * * 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 && + if ((abs(ao_flight_vel) < ACCEL_VEL_LAND && (ao_interval_max_accel - ao_interval_min_accel) < ACCEL_INT_LAND) || (ao_flight_pres > ao_ground_pres - BARO_LAND && (ao_interval_max_pres - ao_interval_min_pres) < BARO_INT_LAND)) { ao_flight_state = ao_flight_landed; + + /* turn off the ADC capture */ + ao_timer_set_adc_interval(0); + + /* stop logging data */ + ao_log_stop(); + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); } break; case ao_flight_landed: - ao_log_stop(); break; } } @@ -349,7 +419,7 @@ ao_flight(void) #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", diff --git a/ao_flight_test.c b/ao_flight_test.c index 2cd7c81e..0b18969e 100644 --- a/ao_flight_test.c +++ b/ao_flight_test.c @@ -63,6 +63,9 @@ uint8_t ao_adc_head; #define ao_timer_set_adc_interval(i) #define ao_wakeup(wchan) ao_dump_state() #define ao_cmd_register(c) +#define ao_usb_disable() +#define ao_telemetry_set_interval(x) +#define ao_rdf_set(rdf) enum ao_igniter { ao_igniter_drogue = 0, @@ -201,7 +204,7 @@ ao_dump_state(void) { if (ao_flight_state == ao_flight_startup) return; - printf ("\t%s accel %g vel %g alt %d\n", + printf ("\t\t\t\t\t%s accel %g vel %g alt %d\n", ao_state_names[ao_flight_state], (ao_flight_accel - ao_ground_accel) / COUNTS_PER_G * GRAVITY, (double) ao_flight_vel / 100 / COUNTS_PER_G * GRAVITY, |