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Remove absolute pressure field as its not useful and confusing anywary

sbg
Lorenz Meier 11 years ago
parent
e09bc02c37
commit
127948f32f
4 changed files with 18 additions and 39 deletions
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  1. 20
      src/drivers/ets_airspeed/ets_airspeed.cpp
  2. 22
      src/drivers/meas_airspeed/meas_airspeed.cpp
  3. 14
      src/modules/sensors/sensors.cpp
  4. 1
      src/modules/uORB/topics/differential_pressure.h

20
src/drivers/ets_airspeed/ets_airspeed.cpp
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@ -155,7 +155,6 @@ ETSAirspeed::collect()
} }
uint16_t diff_pres_pa_raw = val[1] << 8 | val[0]; uint16_t diff_pres_pa_raw = val[1] << 8 | val[0];
uint16_t diff_pres_pa;
if (diff_pres_pa_raw == 0) { if (diff_pres_pa_raw == 0) {
// a zero value means the pressure sensor cannot give us a // a zero value means the pressure sensor cannot give us a
// value. We need to return, and not report a value or the // value. We need to return, and not report a value or the
@ -166,28 +165,21 @@ ETSAirspeed::collect()
return -1; 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 // The raw value still should be compensated for the known offset
diff_pres_pa_raw -= _diff_pres_offset; diff_pres_pa_raw -= _diff_pres_offset;
// Track maximum differential pressure measured (so we can work out top speed). // Track maximum differential pressure measured (so we can work out top speed).
if (diff_pres_pa > _max_differential_pressure_pa) { if (diff_pres_pa_raw > _max_differential_pressure_pa) {
_max_differential_pressure_pa = diff_pres_pa; _max_differential_pressure_pa = diff_pres_pa_raw;
} }
differential_pressure_s report; differential_pressure_s report;
report.timestamp = hrt_absolute_time(); report.timestamp = hrt_absolute_time();
report.error_count = perf_event_count(_comms_errors); 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. // XXX we may want to smooth out the readings to remove noise.
report.differential_pressure_filtered_pa = (float)diff_pres_pa; report.differential_pressure_filtered_pa = diff_pres_pa_raw;
report.differential_pressure_raw_pa = (float)diff_pres_pa_raw; report.differential_pressure_raw_pa = diff_pres_pa_raw;
report.temperature = -1000.0f; report.temperature = -1000.0f;
report.max_differential_pressure_pa = _max_differential_pressure_pa; report.max_differential_pressure_pa = _max_differential_pressure_pa;
@ -369,7 +361,7 @@ test()
err(1, "immediate read failed"); err(1, "immediate read failed");
warnx("single read"); 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 */ /* start the sensor polling at 2Hz */
if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2))
@ -394,7 +386,7 @@ test()
err(1, "periodic read failed"); err(1, "periodic read failed");
warnx("periodic read %u", i); 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 */ /* reset the sensor polling to its default rate */

22
src/drivers/meas_airspeed/meas_airspeed.cpp
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@ -228,18 +228,7 @@ MEASAirspeed::collect()
// the raw value still should be compensated for the known offset // the raw value still should be compensated for the known offset
diff_press_pa_raw -= _diff_pres_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 With the above calculation the MS4525 sensor will produce a
positive number when the top port is used as a dynamic port positive number when the top port is used as a dynamic port
and bottom port is used as the static port and bottom port is used as the static port
@ -248,15 +237,14 @@ MEASAirspeed::collect()
struct differential_pressure_s report; struct differential_pressure_s report;
/* track maximum differential pressure measured (so we can work out top speed). */ /* track maximum differential pressure measured (so we can work out top speed). */
if (diff_press_pa > _max_differential_pressure_pa) { if (diff_press_pa_raw > _max_differential_pressure_pa) {
_max_differential_pressure_pa = diff_press_pa; _max_differential_pressure_pa = diff_press_pa_raw;
} }
report.timestamp = hrt_absolute_time(); report.timestamp = hrt_absolute_time();
report.error_count = perf_event_count(_comms_errors); report.error_count = perf_event_count(_comms_errors);
report.temperature = temperature; report.temperature = temperature;
report.differential_pressure_pa = diff_press_pa; report.differential_pressure_filtered_pa = _filter.apply(diff_press_pa_raw);
report.differential_pressure_filtered_pa = _filter.apply(diff_press_pa);
report.differential_pressure_raw_pa = diff_press_pa_raw; report.differential_pressure_raw_pa = diff_press_pa_raw;
report.max_differential_pressure_pa = _max_differential_pressure_pa; report.max_differential_pressure_pa = _max_differential_pressure_pa;
@ -514,7 +502,7 @@ test()
} }
warnx("single read"); 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 */ /* start the sensor polling at 2Hz */
if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) { if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) {
@ -542,7 +530,7 @@ test()
} }
warnx("periodic read %u", i); 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); warnx("temperature: %d C (0x%02x)", (int)report.temperature, (unsigned) report.temperature);
} }

14
src/modules/sensors/sensors.cpp
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@ -1229,16 +1229,18 @@ Sensors::diff_pres_poll(struct sensor_combined_s &raw)
if (updated) { if (updated) {
orb_copy(ORB_ID(differential_pressure), _diff_pres_sub, &_diff_pres); 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_timestamp = _diff_pres.timestamp;
raw.differential_pressure_filtered_pa = _diff_pres.differential_pressure_filtered_pa; 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); 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.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, /* don't risk to feed negative airspeed into the system */
raw.baro_pres_mbar * 1e2f, air_temperature_celsius); _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; _airspeed.air_temperature_celsius = air_temperature_celsius;
/* announce the airspeed if needed, just publish else */ /* 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)) { 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_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.timestamp = t;
_diff_pres.differential_pressure_pa = diff_pres_pa;
_diff_pres.differential_pressure_raw_pa = diff_pres_pa_raw; _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; _diff_pres.temperature = -1000.0f;
/* announce the airspeed if needed, just publish else */ /* announce the airspeed if needed, just publish else */

1
src/modules/uORB/topics/differential_pressure.h
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@ -54,7 +54,6 @@
struct differential_pressure_s { struct differential_pressure_s {
uint64_t timestamp; /**< Microseconds since system boot, needed to integrate */ uint64_t timestamp; /**< Microseconds since system boot, needed to integrate */
uint64_t error_count; /**< Number of errors detected by driver */ 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_raw_pa; /**< Raw differential pressure reading (may be negative) */
float differential_pressure_filtered_pa; /**< Low pass filtered differential pressure reading */ float differential_pressure_filtered_pa; /**< Low pass filtered differential pressure reading */
float max_differential_pressure_pa; /**< Maximum differential pressure reading */ float max_differential_pressure_pa; /**< Maximum differential pressure reading */

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