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author | Lorenz Meier <lm@inf.ethz.ch> | 2014-08-24 11:52:13 +0200 |
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committer | Lorenz Meier <lm@inf.ethz.ch> | 2014-08-24 11:52:13 +0200 |
commit | ccbd5c09316d9f07eeda3c3f6bc07c729dab6c82 (patch) | |
tree | 3e2dab0acd59f0c619dacdb264003d464d39d797 | |
parent | edffb2eede777f3c316bc8a144984d9d12cbd680 (diff) | |
parent | 127948f32f24e36c0c03a047b57fcd64287d9967 (diff) | |
download | px4-firmware-ccbd5c09316d9f07eeda3c3f6bc07c729dab6c82.tar.gz px4-firmware-ccbd5c09316d9f07eeda3c3f6bc07c729dab6c82.tar.bz2 px4-firmware-ccbd5c09316d9f07eeda3c3f6bc07c729dab6c82.zip |
Merge pull request #1308 from PX4/airspeedfabs
No absolute value of airspeed
-rw-r--r-- | src/drivers/ets_airspeed/ets_airspeed.cpp | 20 | ||||
-rw-r--r-- | src/drivers/meas_airspeed/meas_airspeed.cpp | 37 | ||||
-rw-r--r-- | src/modules/commander/airspeed_calibration.cpp | 18 | ||||
-rw-r--r-- | src/modules/sensors/sensors.cpp | 14 | ||||
-rw-r--r-- | src/modules/uORB/topics/differential_pressure.h | 1 |
5 files changed, 31 insertions, 59 deletions
diff --git a/src/drivers/ets_airspeed/ets_airspeed.cpp b/src/drivers/ets_airspeed/ets_airspeed.cpp index f98d615a2..0f77bb805 100644 --- a/src/drivers/ets_airspeed/ets_airspeed.cpp +++ b/src/drivers/ets_airspeed/ets_airspeed.cpp @@ -155,7 +155,6 @@ ETSAirspeed::collect() } uint16_t diff_pres_pa_raw = val[1] << 8 | val[0]; - uint16_t diff_pres_pa; if (diff_pres_pa_raw == 0) { // a zero value means the pressure sensor cannot give us a // value. We need to return, and not report a value or the @@ -166,28 +165,21 @@ ETSAirspeed::collect() return -1; } - if (diff_pres_pa_raw < _diff_pres_offset + MIN_ACCURATE_DIFF_PRES_PA) { - diff_pres_pa = 0; - } else { - diff_pres_pa = diff_pres_pa_raw - _diff_pres_offset; - } - // The raw value still should be compensated for the known offset diff_pres_pa_raw -= _diff_pres_offset; // Track maximum differential pressure measured (so we can work out top speed). - if (diff_pres_pa > _max_differential_pressure_pa) { - _max_differential_pressure_pa = diff_pres_pa; + if (diff_pres_pa_raw > _max_differential_pressure_pa) { + _max_differential_pressure_pa = diff_pres_pa_raw; } differential_pressure_s report; report.timestamp = hrt_absolute_time(); report.error_count = perf_event_count(_comms_errors); - report.differential_pressure_pa = (float)diff_pres_pa; // XXX we may want to smooth out the readings to remove noise. - report.differential_pressure_filtered_pa = (float)diff_pres_pa; - report.differential_pressure_raw_pa = (float)diff_pres_pa_raw; + report.differential_pressure_filtered_pa = diff_pres_pa_raw; + report.differential_pressure_raw_pa = diff_pres_pa_raw; report.temperature = -1000.0f; report.max_differential_pressure_pa = _max_differential_pressure_pa; @@ -369,7 +361,7 @@ test() err(1, "immediate read failed"); warnx("single read"); - warnx("diff pressure: %f pa", (double)report.differential_pressure_pa); + warnx("diff pressure: %f pa", (double)report.differential_pressure_filtered_pa); /* start the sensor polling at 2Hz */ if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) @@ -394,7 +386,7 @@ test() err(1, "periodic read failed"); warnx("periodic read %u", i); - warnx("diff pressure: %f pa", (double)report.differential_pressure_pa); + warnx("diff pressure: %f pa", (double)report.differential_pressure_filtered_pa); } /* reset the sensor polling to its default rate */ diff --git a/src/drivers/meas_airspeed/meas_airspeed.cpp b/src/drivers/meas_airspeed/meas_airspeed.cpp index 159706278..1d9a463ad 100644 --- a/src/drivers/meas_airspeed/meas_airspeed.cpp +++ b/src/drivers/meas_airspeed/meas_airspeed.cpp @@ -228,44 +228,23 @@ MEASAirspeed::collect() // the raw value still should be compensated for the known offset diff_press_pa_raw -= _diff_pres_offset; - float diff_press_pa = fabsf(diff_press_pa_raw); - /* - note that we return both the absolute value with offset - applied and a raw value without the offset applied. This - makes it possible for higher level code to detect if the - user has the tubes connected backwards, and also makes it - possible to correctly use offsets calculated by a higher - level airspeed driver. - With the above calculation the MS4525 sensor will produce a positive number when the top port is used as a dynamic port and bottom port is used as the static port - - Also note that the _diff_pres_offset is applied before the - fabsf() not afterwards. It needs to be done this way to - prevent a bias at low speeds, but this also means that when - setting a offset you must set it based on the raw value, not - the offset value */ - + struct differential_pressure_s report; /* track maximum differential pressure measured (so we can work out top speed). */ - if (diff_press_pa > _max_differential_pressure_pa) { - _max_differential_pressure_pa = diff_press_pa; + if (diff_press_pa_raw > _max_differential_pressure_pa) { + _max_differential_pressure_pa = diff_press_pa_raw; } report.timestamp = hrt_absolute_time(); report.error_count = perf_event_count(_comms_errors); report.temperature = temperature; - report.differential_pressure_pa = diff_press_pa; - report.differential_pressure_filtered_pa = _filter.apply(diff_press_pa); - - /* the dynamics of the filter can make it overshoot into the negative range */ - if (report.differential_pressure_filtered_pa < 0.0f) { - report.differential_pressure_filtered_pa = _filter.reset(diff_press_pa); - } + report.differential_pressure_filtered_pa = _filter.apply(diff_press_pa_raw); report.differential_pressure_raw_pa = diff_press_pa_raw; report.max_differential_pressure_pa = _max_differential_pressure_pa; @@ -345,7 +324,7 @@ MEASAirspeed::cycle() /** correct for 5V rail voltage if the system_power ORB topic is available - + See http://uav.tridgell.net/MS4525/MS4525-offset.png for a graph of offset versus voltage for 3 sensors */ @@ -394,7 +373,7 @@ MEASAirspeed::voltage_correction(float &diff_press_pa, float &temperature) if (voltage_diff < -1.0f) { voltage_diff = -1.0f; } - temperature -= voltage_diff * temp_slope; + temperature -= voltage_diff * temp_slope; #endif // CONFIG_ARCH_BOARD_PX4FMU_V2 } @@ -523,7 +502,7 @@ test() } warnx("single read"); - warnx("diff pressure: %d pa", (int)report.differential_pressure_pa); + warnx("diff pressure: %d pa", (int)report.differential_pressure_filtered_pa); /* start the sensor polling at 2Hz */ if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) { @@ -551,7 +530,7 @@ test() } warnx("periodic read %u", i); - warnx("diff pressure: %d pa", (int)report.differential_pressure_pa); + warnx("diff pressure: %d pa", (int)report.differential_pressure_filtered_pa); warnx("temperature: %d C (0x%02x)", (int)report.temperature, (unsigned) report.temperature); } diff --git a/src/modules/commander/airspeed_calibration.cpp b/src/modules/commander/airspeed_calibration.cpp index 0e58c68b6..339b11bbe 100644 --- a/src/modules/commander/airspeed_calibration.cpp +++ b/src/modules/commander/airspeed_calibration.cpp @@ -180,11 +180,13 @@ int do_airspeed_calibration(int mavlink_fd) return ERROR; } - mavlink_log_critical(mavlink_fd, "Offset of %d Pa, create airflow now!", (int)diff_pres_offset); + mavlink_log_critical(mavlink_fd, "Offset of %d Pascal", (int)diff_pres_offset); /* wait 500 ms to ensure parameter propagated through the system */ usleep(500 * 1000); + mavlink_log_critical(mavlink_fd, "Create airflow now"); + calibration_counter = 0; const unsigned maxcount = 3000; @@ -204,18 +206,18 @@ int do_airspeed_calibration(int mavlink_fd) calibration_counter++; if (fabsf(diff_pres.differential_pressure_raw_pa) < 50.0f) { - if (calibration_counter % 100 == 0) { - mavlink_log_critical(mavlink_fd, "Missing airflow! (%d, wanted: 50 Pa, #h101)", - (int)diff_pres.differential_pressure_raw_pa); + if (calibration_counter % 500 == 0) { + mavlink_log_info(mavlink_fd, "Create airflow! (%d, wanted: 50 Pa)", + (int)diff_pres.differential_pressure_raw_pa); } continue; } /* do not allow negative values */ if (diff_pres.differential_pressure_raw_pa < 0.0f) { - mavlink_log_info(mavlink_fd, "negative pressure: ERROR (%d Pa)", - (int)diff_pres.differential_pressure_raw_pa); - mavlink_log_critical(mavlink_fd, "%d Pa: swap static and dynamic ports!", (int)diff_pres.differential_pressure_raw_pa); + mavlink_log_critical(mavlink_fd, "Swap static and dynamic ports!"); + mavlink_log_info(mavlink_fd, "ERROR: Negative pressure difference detected! (%d Pa)", + (int)diff_pres.differential_pressure_raw_pa); close(diff_pres_sub); /* the user setup is wrong, wipe the calibration to force a proper re-calibration */ @@ -236,7 +238,7 @@ int do_airspeed_calibration(int mavlink_fd) mavlink_log_info(mavlink_fd, CAL_FAILED_MSG, sensor_name); return ERROR; } else { - mavlink_log_info(mavlink_fd, "positive pressure: OK (%d Pa)", + mavlink_log_info(mavlink_fd, "Positive pressure: OK (%d Pa)", (int)diff_pres.differential_pressure_raw_pa); break; } diff --git a/src/modules/sensors/sensors.cpp b/src/modules/sensors/sensors.cpp index f40034d79..cdcb428dd 100644 --- a/src/modules/sensors/sensors.cpp +++ b/src/modules/sensors/sensors.cpp @@ -1229,16 +1229,18 @@ Sensors::diff_pres_poll(struct sensor_combined_s &raw) if (updated) { orb_copy(ORB_ID(differential_pressure), _diff_pres_sub, &_diff_pres); - raw.differential_pressure_pa = _diff_pres.differential_pressure_pa; + raw.differential_pressure_pa = _diff_pres.differential_pressure_raw_pa; raw.differential_pressure_timestamp = _diff_pres.timestamp; raw.differential_pressure_filtered_pa = _diff_pres.differential_pressure_filtered_pa; float air_temperature_celsius = (_diff_pres.temperature > -300.0f) ? _diff_pres.temperature : (raw.baro_temp_celcius - PCB_TEMP_ESTIMATE_DEG); _airspeed.timestamp = _diff_pres.timestamp; - _airspeed.indicated_airspeed_m_s = calc_indicated_airspeed(_diff_pres.differential_pressure_filtered_pa); - _airspeed.true_airspeed_m_s = calc_true_airspeed(_diff_pres.differential_pressure_filtered_pa + raw.baro_pres_mbar * 1e2f, - raw.baro_pres_mbar * 1e2f, air_temperature_celsius); + + /* don't risk to feed negative airspeed into the system */ + _airspeed.indicated_airspeed_m_s = math::max(0.0f, calc_indicated_airspeed(_diff_pres.differential_pressure_filtered_pa)); + _airspeed.true_airspeed_m_s = math::max(0.0f, calc_true_airspeed(_diff_pres.differential_pressure_filtered_pa + raw.baro_pres_mbar * 1e2f, + raw.baro_pres_mbar * 1e2f, air_temperature_celsius)); _airspeed.air_temperature_celsius = air_temperature_celsius; /* announce the airspeed if needed, just publish else */ @@ -1457,12 +1459,10 @@ Sensors::adc_poll(struct sensor_combined_s &raw) if (voltage > 0.4f && (_parameters.diff_pres_analog_scale > 0.0f)) { float diff_pres_pa_raw = voltage * _parameters.diff_pres_analog_scale - _parameters.diff_pres_offset_pa; - float diff_pres_pa = (diff_pres_pa_raw > 0.0f) ? diff_pres_pa_raw : 0.0f; _diff_pres.timestamp = t; - _diff_pres.differential_pressure_pa = diff_pres_pa; _diff_pres.differential_pressure_raw_pa = diff_pres_pa_raw; - _diff_pres.differential_pressure_filtered_pa = (_diff_pres.differential_pressure_filtered_pa * 0.9f) + (diff_pres_pa * 0.1f); + _diff_pres.differential_pressure_filtered_pa = (_diff_pres.differential_pressure_filtered_pa * 0.9f) + (diff_pres_pa_raw * 0.1f); _diff_pres.temperature = -1000.0f; /* announce the airspeed if needed, just publish else */ diff --git a/src/modules/uORB/topics/differential_pressure.h b/src/modules/uORB/topics/differential_pressure.h index cd48d3cb2..7342fcf04 100644 --- a/src/modules/uORB/topics/differential_pressure.h +++ b/src/modules/uORB/topics/differential_pressure.h @@ -54,7 +54,6 @@ struct differential_pressure_s { uint64_t timestamp; /**< Microseconds since system boot, needed to integrate */ uint64_t error_count; /**< Number of errors detected by driver */ - float differential_pressure_pa; /**< Differential pressure reading */ float differential_pressure_raw_pa; /**< Raw differential pressure reading (may be negative) */ float differential_pressure_filtered_pa; /**< Low pass filtered differential pressure reading */ float max_differential_pressure_pa; /**< Maximum differential pressure reading */ |