From 127948f32f24e36c0c03a047b57fcd64287d9967 Mon Sep 17 00:00:00 2001 From: Lorenz Meier Date: Sun, 24 Aug 2014 11:49:45 +0200 Subject: Remove absolute pressure field as its not useful and confusing anywary --- src/drivers/ets_airspeed/ets_airspeed.cpp | 20 ++++++-------------- src/drivers/meas_airspeed/meas_airspeed.cpp | 22 +++++----------------- src/modules/sensors/sensors.cpp | 14 +++++++------- src/modules/uORB/topics/differential_pressure.h | 1 - 4 files changed, 18 insertions(+), 39 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 479fa3ccf..1d9a463ad 100644 --- a/src/drivers/meas_airspeed/meas_airspeed.cpp +++ b/src/drivers/meas_airspeed/meas_airspeed.cpp @@ -228,18 +228,7 @@ MEASAirspeed::collect() // the raw value still should be compensated for the known offset diff_press_pa_raw -= _diff_pres_offset; - /* don't take the absolute value because the calibration takes this into account and warns the user if the - * tubes are connected backwards */ - float diff_press_pa = 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 @@ -248,15 +237,14 @@ MEASAirspeed::collect() 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); + 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; @@ -514,7 +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)) { @@ -542,7 +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/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 */ -- cgit v1.2.3