Add velocity check for boost detect via accelerometer

Bumping the rocket can cause a brief period of high acceleration, which may
cause a mistaken boost detection. Require both a high acceleration and
reasonable velocity to trigger boost phase.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/ao_flight.c b/ao_flight.c
index 3bc6b974008e625812214112838b8a5eb0669fe5..d50d37e30aec9f39bf730c978339c88869defd00 100644 (file)
--- a/ao_flight.c
+++ b/ao_flight.c
@@ -83,6 +83,7 @@ __pdata int16_t ao_raw_accel, ao_raw_accel_prev, ao_raw_pres;
 #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_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)

 
 /*
  * Barometer calibration
 
 /*
  * Barometer calibration


@@ -242,7 +243,7 @@ ao_flight(void)
 
                        /* pad to boost:
                         *
 
                        /* pad to boost:
                         *

-                        * accelerometer: > 2g
+                        * accelerometer: > 2g AND velocity > 5m/s

                         *             OR
                         * barometer: > 20m vertical motion
                         *
                         *             OR
                         * barometer: > 20m vertical motion
                         *


@@ -250,7 +251,8 @@ ao_flight(void)
                         * the barometer, but we use both to make sure this
                         * transition is detected
                         */
                         * the barometer, but we use both to make sure this
                         * transition is detected
                         */

-                       if (ao_flight_accel < ao_ground_accel - ACCEL_BOOST ||
+                       if ((ao_flight_accel < ao_ground_accel - ACCEL_BOOST &&
+                            ao_flight_vel > ACCEL_VEL_BOOST) ||

                            ao_flight_pres < ao_ground_pres - BARO_LAUNCH)
                        {
                                ao_flight_state = ao_flight_boost;
                            ao_flight_pres < ao_ground_pres - BARO_LAUNCH)
                        {
                                ao_flight_state = ao_flight_boost;