From 2c2c65d446f991b273ee1f275fd2bc8440f74844 Mon Sep 17 00:00:00 2001 From: Thomas Gubler Date: Fri, 22 Feb 2013 22:26:04 +0100 Subject: [PATCH 1/7] corrected some wrong units (used in airspeed calculation) --- apps/systemlib/conversions.c | 2 +- apps/systemlib/conversions.h | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/apps/systemlib/conversions.c b/apps/systemlib/conversions.c index 2b8003e458..ac94252c57 100644 --- a/apps/systemlib/conversions.c +++ b/apps/systemlib/conversions.c @@ -150,5 +150,5 @@ void quat2rot(const float Q[4], float R[9]) float get_air_density(float static_pressure, float temperature_celsius) { - return static_pressure / (CONSTANTS_AIR_GAS_CONST * (temperature_celsius + CONSTANTS_ABSOLUTE_NULL_KELVIN)); + return static_pressure / (CONSTANTS_AIR_GAS_CONST * (temperature_celsius - CONSTANTS_ABSOLUTE_NULL_CELSIUS)); } diff --git a/apps/systemlib/conversions.h b/apps/systemlib/conversions.h index c2987709bb..5d485b01f3 100644 --- a/apps/systemlib/conversions.h +++ b/apps/systemlib/conversions.h @@ -44,10 +44,10 @@ #include #include -#define CONSTANTS_ONE_G 9.80665f -#define CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C 1.225f -#define CONSTANTS_AIR_GAS_CONST 8.31432f -#define CONSTANTS_ABSOLUTE_NULL_KELVIN 273.15f +#define CONSTANTS_ONE_G 9.80665f // m/s^2 +#define CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C 1.225f // kg/m^3 +#define CONSTANTS_AIR_GAS_CONST 287.1f // J/(kg * K) +#define CONSTANTS_ABSOLUTE_NULL_CELSIUS -273.15f // °C __BEGIN_DECLS From 2707d2c1dde65dfb9ba48258994badb4b57f9627 Mon Sep 17 00:00:00 2001 From: Thomas Gubler Date: Sun, 24 Feb 2013 16:01:08 +0100 Subject: [PATCH 2/7] more fixes for the airspeed readout --- apps/sensors/sensors.cpp | 25 ++++----- apps/systemlib/airspeed.c | 40 +++++++++----- apps/systemlib/airspeed.h | 69 ++++++++++++------------ apps/uORB/topics/differential_pressure.h | 4 +- 4 files changed, 77 insertions(+), 61 deletions(-) diff --git a/apps/sensors/sensors.cpp b/apps/sensors/sensors.cpp index d8d200ea9d..c29910dccd 100644 --- a/apps/sensors/sensors.cpp +++ b/apps/sensors/sensors.cpp @@ -993,7 +993,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw) /* look for battery channel */ for (unsigned i = 0; i < sizeof(buf_adc) / sizeof(buf_adc[0]); i++) { - + if (ret >= (int)sizeof(buf_adc[0])) { if (ADC_BATTERY_VOLTAGE_CHANNEL == buf_adc[i].am_channel) { @@ -1025,8 +1025,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw) } else if (ADC_AIRSPEED_VOLTAGE_CHANNEL == buf_adc[i].am_channel) { /* calculate airspeed, raw is the difference from */ - - float voltage = buf_adc[i].am_data / 4096.0f; + float voltage = (float)(buf_adc[i].am_data ) * 3.3f / 4096.0f * 2.0f; //V_ref/4096 * (voltage divider factor) /** * The voltage divider pulls the signal down, only act on @@ -1034,21 +1033,23 @@ Sensors::adc_poll(struct sensor_combined_s &raw) */ if (voltage > 0.4f) { - float pres_raw = fabsf(voltage - (3.3f / 2.0f)); - float pres_mbar = pres_raw * (3.3f / 5.0f) * 10.0f; +// float pres_raw = fabsf(voltage - (3.3f / 2.0f)); +// float pres_mbar = pres_raw * (3.3f / 5.0f) * 10.0f; + //XXX depends on sensor used..., where are the above numbers from? + float diff_pres_pa = fabsf(voltage - 2.5f) * 1000.0f; //for MPXV7002DP //xxx: need an offset calibration - float airspeed_true = calc_true_airspeed(pres_mbar + _barometer.pressure, - _barometer.pressure, _barometer.temperature - 5.0f); + float airspeed_true = calc_true_airspeed(diff_pres_pa + _barometer.pressure*1e2f, + _barometer.pressure*1e2f, _barometer.temperature - 5.0f); //factor 1e2 for conversion from mBar to Pa // XXX HACK - true temperature is much less than indicated temperature in baro, // subtract 5 degrees in an attempt to account for the electrical upheating of the PCB - float airspeed_indicated = calc_indicated_airspeed(pres_mbar + _barometer.pressure, - _barometer.pressure, _barometer.temperature - 5.0f); - // XXX HACK + float airspeed_indicated = calc_indicated_airspeed(diff_pres_pa); + + //printf("voltage: %.4f, diff_pres_pa %.4f, v_ind %.4f, v_true %.4f\n", (double)voltage, (double)diff_pres_pa, (double)airspeed_indicated, (double)airspeed_true); _differential_pressure.timestamp = hrt_absolute_time(); _differential_pressure.static_pressure_mbar = _barometer.pressure; - _differential_pressure.differential_pressure_mbar = pres_mbar; + _differential_pressure.differential_pressure_mbar = diff_pres_pa*1e-2f; _differential_pressure.temperature_celcius = _barometer.temperature; _differential_pressure.indicated_airspeed_m_s = airspeed_indicated; _differential_pressure.true_airspeed_m_s = airspeed_true; @@ -1064,7 +1065,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw) } _last_adc = hrt_absolute_time(); - break; + //break; } } } diff --git a/apps/systemlib/airspeed.c b/apps/systemlib/airspeed.c index 5c68f8ea52..32943b2f5b 100644 --- a/apps/systemlib/airspeed.c +++ b/apps/systemlib/airspeed.c @@ -40,14 +40,25 @@ * */ -#include "math.h" +#include +#include #include "conversions.h" #include "airspeed.h" -float calc_indicated_airspeed(float pressure_front, float pressure_ambient, float temperature) +/** + * Calculate indicated airspeed. + * + * Note that the indicated airspeed is not the true airspeed because it + * lacks the air density compensation. Use the calc_true_airspeed functions to get + * the true airspeed. + * + * @param differential_pressure total_ pressure - static pressure + * @return indicated airspeed in m/s + */ +float calc_indicated_airspeed(float differential_pressure) { - return sqrtf((2.0f*(pressure_front - pressure_ambient)) / CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C); + return sqrtf((2.0f*differential_pressure) / CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C); } /** @@ -55,14 +66,14 @@ float calc_indicated_airspeed(float pressure_front, float pressure_ambient, floa * * Note that the true airspeed is NOT the groundspeed, because of the effects of wind * - * @param speed current indicated airspeed + * @param speed_indicated current indicated airspeed * @param pressure_ambient pressure at the side of the tube/airplane - * @param temperature air temperature in degrees celcius + * @param temperature_celsius air temperature in degrees celcius * @return true airspeed in m/s */ -float calc_true_airspeed_from_indicated(float speed, float pressure_ambient, float temperature) +float calc_true_airspeed_from_indicated(float speed_indicated, float pressure_ambient, float temperature_celsius) { - return speed * sqrtf(CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C / get_air_density(pressure_ambient, temperature)); + return speed_indicated * sqrtf(CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C / get_air_density(pressure_ambient, temperature_celsius)); } /** @@ -70,12 +81,17 @@ float calc_true_airspeed_from_indicated(float speed, float pressure_ambient, flo * * Note that the true airspeed is NOT the groundspeed, because of the effects of wind * - * @param pressure_front pressure inside the pitot/prandl tube - * @param pressure_ambient pressure at the side of the tube/airplane - * @param temperature air temperature in degrees celcius + * @param total_pressure pressure inside the pitot/prandl tube + * @param static_pressure pressure at the side of the tube/airplane + * @param temperature_celsius air temperature in degrees celcius * @return true airspeed in m/s */ -float calc_true_airspeed(float pressure_front, float pressure_ambient, float temperature) +float calc_true_airspeed(float total_pressure, float static_pressure, float temperature_celsius) { - return sqrtf((2.0f*(pressure_front - pressure_ambient)) / get_air_density(pressure_ambient, temperature)); + float density = get_air_density(static_pressure, temperature_celsius); + if (density < 0.0001f || isnan(density)) { + density = CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C; + printf("Invalid air density, using density at sea level\n"); + } + return sqrtf((2.0f*(total_pressure - static_pressure)) / density); } diff --git a/apps/systemlib/airspeed.h b/apps/systemlib/airspeed.h index b1beb79ae0..0884989439 100644 --- a/apps/systemlib/airspeed.h +++ b/apps/systemlib/airspeed.h @@ -48,43 +48,42 @@ __BEGIN_DECLS -/** - * Calculate indicated airspeed. - * - * Note that the indicated airspeed is not the true airspeed because it - * lacks the air density compensation. Use the calc_true_airspeed functions to get - * the true airspeed. - * - * @param pressure_front pressure inside the pitot/prandl tube - * @param pressure_ambient pressure at the side of the tube/airplane - * @param temperature air temperature in degrees celcius - * @return indicated airspeed in m/s - */ -__EXPORT float calc_indicated_airspeed(float pressure_front, float pressure_ambient, float temperature); + /** + * Calculate indicated airspeed. + * + * Note that the indicated airspeed is not the true airspeed because it + * lacks the air density compensation. Use the calc_true_airspeed functions to get + * the true airspeed. + * + * @param total_pressure pressure inside the pitot/prandtl tube + * @param static_pressure pressure at the side of the tube/airplane + * @return indicated airspeed in m/s + */ + __EXPORT float calc_indicated_airspeed(float differential_pressure); -/** - * Calculate true airspeed from indicated airspeed. - * - * Note that the true airspeed is NOT the groundspeed, because of the effects of wind - * - * @param speed current indicated airspeed - * @param pressure_ambient pressure at the side of the tube/airplane - * @param temperature air temperature in degrees celcius - * @return true airspeed in m/s - */ -__EXPORT float calc_true_airspeed_from_indicated(float speed, float pressure_ambient, float temperature); + /** + * Calculate true airspeed from indicated airspeed. + * + * Note that the true airspeed is NOT the groundspeed, because of the effects of wind + * + * @param speed_indicated current indicated airspeed + * @param pressure_ambient pressure at the side of the tube/airplane + * @param temperature_celsius air temperature in degrees celcius + * @return true airspeed in m/s + */ + __EXPORT float calc_true_airspeed_from_indicated(float speed_indicated, float pressure_ambient, float temperature_celsius); -/** - * Directly calculate true airspeed - * - * Note that the true airspeed is NOT the groundspeed, because of the effects of wind - * - * @param pressure_front pressure inside the pitot/prandl tube - * @param pressure_ambient pressure at the side of the tube/airplane - * @param temperature air temperature in degrees celcius - * @return true airspeed in m/s - */ -__EXPORT float calc_true_airspeed(float pressure_front, float pressure_ambient, float temperature); + /** + * Directly calculate true airspeed + * + * Note that the true airspeed is NOT the groundspeed, because of the effects of wind + * + * @param total_pressure pressure inside the pitot/prandl tube + * @param static_pressure pressure at the side of the tube/airplane + * @param temperature_celsius air temperature in degrees celcius + * @return true airspeed in m/s + */ + __EXPORT float calc_true_airspeed(float total_pressure, float static_pressure, float temperature_celsius); __END_DECLS diff --git a/apps/uORB/topics/differential_pressure.h b/apps/uORB/topics/differential_pressure.h index fd7670cbc8..78a37fdf46 100644 --- a/apps/uORB/topics/differential_pressure.h +++ b/apps/uORB/topics/differential_pressure.h @@ -49,7 +49,7 @@ */ /** - * Battery voltages and status + * Differential pressure and airspeed */ struct differential_pressure_s { uint64_t timestamp; /**< microseconds since system boot, needed to integrate */ @@ -67,4 +67,4 @@ struct differential_pressure_s { /* register this as object request broker structure */ ORB_DECLARE(differential_pressure); -#endif \ No newline at end of file +#endif From c0a852dab48e55aa12c995adc6dc0c32aa9a7ac3 Mon Sep 17 00:00:00 2001 From: Thomas Gubler Date: Sun, 24 Feb 2013 21:57:38 +0100 Subject: [PATCH 3/7] airspeed (pitot) offset calibration --- apps/commander/commander.c | 96 ++++++++++++++++++++++++ apps/sensors/sensor_params.c | 2 + apps/sensors/sensors.cpp | 13 +++- apps/systemlib/airspeed.c | 20 ++++- apps/uORB/topics/differential_pressure.h | 5 +- apps/uORB/topics/vehicle_status.h | 1 + 6 files changed, 130 insertions(+), 7 deletions(-) diff --git a/apps/commander/commander.c b/apps/commander/commander.c index 42ca10f55d..41f4e56742 100644 --- a/apps/commander/commander.c +++ b/apps/commander/commander.c @@ -80,6 +80,7 @@ #include #include #include +#include #include #include @@ -785,6 +786,79 @@ void do_accel_calibration(int status_pub, struct vehicle_status_s *status) close(sub_sensor_combined); } +void do_airspeed_calibration(int status_pub, struct vehicle_status_s *status) +{ + /* announce change */ + + mavlink_log_info(mavlink_fd, "keep it still"); + /* set to accel calibration mode */ + status->flag_preflight_airspeed_calibration = true; + state_machine_publish(status_pub, status, mavlink_fd); + + const int calibration_count = 2500; + + int sub_differential_pressure = orb_subscribe(ORB_ID(differential_pressure)); + struct differential_pressure_s differential_pressure; + + int calibration_counter = 0; + float airspeed_offset = 0.0f; + + while (calibration_counter < calibration_count) { + + /* wait blocking for new data */ + struct pollfd fds[1] = { { .fd = sub_differential_pressure, .events = POLLIN } }; + + int poll_ret = poll(fds, 1, 1000); + + if (poll_ret) { + orb_copy(ORB_ID(differential_pressure), sub_differential_pressure, &differential_pressure); + airspeed_offset += differential_pressure.voltage; + calibration_counter++; + + } else if (poll_ret == 0) { + /* any poll failure for 1s is a reason to abort */ + mavlink_log_info(mavlink_fd, "airspeed calibration aborted"); + return; + } + } + + airspeed_offset = airspeed_offset / calibration_count; + + if (isfinite(airspeed_offset)) { + + if (param_set(param_find("SENS_VAIR_OFF"), &(airspeed_offset))) { + mavlink_log_critical(mavlink_fd, "Setting offs failed!"); + } + + /* auto-save to EEPROM */ + int save_ret = param_save_default(); + + if (save_ret != 0) { + warn("WARNING: auto-save of params to storage failed"); + } + + //char buf[50]; + //sprintf(buf, "[cmd] accel cal: x:%8.4f y:%8.4f z:%8.4f\n", (double)accel_offset[0], (double)accel_offset[1], (double)accel_offset[2]); + //mavlink_log_info(mavlink_fd, buf); + mavlink_log_info(mavlink_fd, "airspeed calibration done"); + + tune_confirm(); + sleep(2); + tune_confirm(); + sleep(2); + /* third beep by cal end routine */ + + } else { + mavlink_log_info(mavlink_fd, "airspeed calibration FAILED (NaN)"); + } + + /* exit airspeed calibration mode */ + status->flag_preflight_airspeed_calibration = false; + state_machine_publish(status_pub, status, mavlink_fd); + + close(sub_differential_pressure); +} + void handle_command(int status_pub, struct vehicle_status_s *current_vehicle_status, struct vehicle_command_s *cmd) @@ -980,6 +1054,28 @@ void handle_command(int status_pub, struct vehicle_status_s *current_vehicle_sta handled = true; } + /* airspeed calibration */ + if ((int)(cmd->param6) == 1) { //xxx: this is not defined by the mavlink protocol + /* transition to calibration state */ + do_state_update(status_pub, ¤t_status, mavlink_fd, SYSTEM_STATE_PREFLIGHT); + + if (current_status.state_machine == SYSTEM_STATE_PREFLIGHT) { + mavlink_log_info(mavlink_fd, "CMD starting airspeed cal"); + tune_confirm(); + do_airspeed_calibration(status_pub, ¤t_status); + tune_confirm(); + mavlink_log_info(mavlink_fd, "CMD finished airspeed cal"); + do_state_update(status_pub, ¤t_status, mavlink_fd, SYSTEM_STATE_STANDBY); + result = VEHICLE_CMD_RESULT_ACCEPTED; + + } else { + mavlink_log_critical(mavlink_fd, "REJECTING airspeed cal"); + result = VEHICLE_CMD_RESULT_DENIED; + } + + handled = true; + } + /* none found */ if (!handled) { //warnx("refusing unsupported calibration request\n"); diff --git a/apps/sensors/sensor_params.c b/apps/sensors/sensor_params.c index 9f23ebbbab..a1ef9d136e 100644 --- a/apps/sensors/sensor_params.c +++ b/apps/sensors/sensor_params.c @@ -64,6 +64,8 @@ PARAM_DEFINE_FLOAT(SENS_ACC_XSCALE, 1.0f); PARAM_DEFINE_FLOAT(SENS_ACC_YSCALE, 1.0f); PARAM_DEFINE_FLOAT(SENS_ACC_ZSCALE, 1.0f); +PARAM_DEFINE_FLOAT(SENS_VAIR_OFF, 2.5f); + PARAM_DEFINE_FLOAT(RC1_MIN, 1000.0f); PARAM_DEFINE_FLOAT(RC1_TRIM, 1500.0f); PARAM_DEFINE_FLOAT(RC1_MAX, 2000.0f); diff --git a/apps/sensors/sensors.cpp b/apps/sensors/sensors.cpp index c29910dccd..f77bc9b8b6 100644 --- a/apps/sensors/sensors.cpp +++ b/apps/sensors/sensors.cpp @@ -187,6 +187,7 @@ private: float mag_scale[3]; float accel_offset[3]; float accel_scale[3]; + float airspeed_offset; int rc_type; @@ -235,6 +236,7 @@ private: param_t accel_scale[3]; param_t mag_offset[3]; param_t mag_scale[3]; + param_t airspeed_offset; param_t rc_map_roll; param_t rc_map_pitch; @@ -480,6 +482,9 @@ Sensors::Sensors() : _parameter_handles.mag_scale[1] = param_find("SENS_MAG_YSCALE"); _parameter_handles.mag_scale[2] = param_find("SENS_MAG_ZSCALE"); + /*Airspeed offset */ + _parameter_handles.airspeed_offset = param_find("SENS_VAIR_OFF"); + _parameter_handles.battery_voltage_scaling = param_find("BAT_V_SCALING"); /* fetch initial parameter values */ @@ -687,6 +692,9 @@ Sensors::parameters_update() param_get(_parameter_handles.mag_scale[1], &(_parameters.mag_scale[1])); param_get(_parameter_handles.mag_scale[2], &(_parameters.mag_scale[2])); + /* Airspeed offset */ + param_get(_parameter_handles.airspeed_offset, &(_parameters.airspeed_offset)); + /* scaling of ADC ticks to battery voltage */ if (param_get(_parameter_handles.battery_voltage_scaling, &(_parameters.battery_voltage_scaling)) != OK) { warnx("Failed updating voltage scaling param"); @@ -1036,7 +1044,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw) // float pres_raw = fabsf(voltage - (3.3f / 2.0f)); // float pres_mbar = pres_raw * (3.3f / 5.0f) * 10.0f; //XXX depends on sensor used..., where are the above numbers from? - float diff_pres_pa = fabsf(voltage - 2.5f) * 1000.0f; //for MPXV7002DP //xxx: need an offset calibration + float diff_pres_pa = (voltage - _parameters.airspeed_offset) * 1000.0f; //for MPXV7002DP float airspeed_true = calc_true_airspeed(diff_pres_pa + _barometer.pressure*1e2f, _barometer.pressure*1e2f, _barometer.temperature - 5.0f); //factor 1e2 for conversion from mBar to Pa @@ -1045,7 +1053,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw) float airspeed_indicated = calc_indicated_airspeed(diff_pres_pa); - //printf("voltage: %.4f, diff_pres_pa %.4f, v_ind %.4f, v_true %.4f\n", (double)voltage, (double)diff_pres_pa, (double)airspeed_indicated, (double)airspeed_true); + //printf("voltage: %.4f, diff_pres_pa %.4f, baro press %.4f Pa, v_ind %.4f, v_true %.4f\n", (double)voltage, (double)diff_pres_pa, (double)_barometer.pressure*1e2f, (double)airspeed_indicated, (double)airspeed_true); _differential_pressure.timestamp = hrt_absolute_time(); _differential_pressure.static_pressure_mbar = _barometer.pressure; @@ -1053,6 +1061,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw) _differential_pressure.temperature_celcius = _barometer.temperature; _differential_pressure.indicated_airspeed_m_s = airspeed_indicated; _differential_pressure.true_airspeed_m_s = airspeed_true; + _differential_pressure.voltage = voltage; /* announce the airspeed if needed, just publish else */ if (_airspeed_pub > 0) { diff --git a/apps/systemlib/airspeed.c b/apps/systemlib/airspeed.c index 32943b2f5b..382df2ee4f 100644 --- a/apps/systemlib/airspeed.c +++ b/apps/systemlib/airspeed.c @@ -58,7 +58,13 @@ */ float calc_indicated_airspeed(float differential_pressure) { - return sqrtf((2.0f*differential_pressure) / CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C); + + if (differential_pressure > 0) { + return sqrtf((2.0f*differential_pressure) / CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C); + } else { + return -sqrtf((2.0f*fabs(differential_pressure)) / CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C); + } + } /** @@ -89,9 +95,17 @@ float calc_true_airspeed_from_indicated(float speed_indicated, float pressure_am float calc_true_airspeed(float total_pressure, float static_pressure, float temperature_celsius) { float density = get_air_density(static_pressure, temperature_celsius); - if (density < 0.0001f || isnan(density)) { + if (density < 0.0001f || !isfinite(density)) { density = CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C; printf("Invalid air density, using density at sea level\n"); } - return sqrtf((2.0f*(total_pressure - static_pressure)) / density); + + float pressure_difference = total_pressure - static_pressure; + + if(pressure_difference > 0) { + return sqrtf((2.0f*(pressure_difference)) / density); + } else + { + return -sqrtf((2.0f*fabs(pressure_difference)) / density); + } } diff --git a/apps/uORB/topics/differential_pressure.h b/apps/uORB/topics/differential_pressure.h index 78a37fdf46..d5e4bf37ef 100644 --- a/apps/uORB/topics/differential_pressure.h +++ b/apps/uORB/topics/differential_pressure.h @@ -52,12 +52,13 @@ * Differential pressure and airspeed */ struct differential_pressure_s { - uint64_t timestamp; /**< microseconds since system boot, needed to integrate */ + uint64_t timestamp; /**< microseconds since system boot, needed to integrate */ float static_pressure_mbar; /**< Static / environment pressure */ float differential_pressure_mbar; /**< Differential pressure reading */ float temperature_celcius; /**< ambient temperature in celcius, -1 if unknown */ float indicated_airspeed_m_s; /**< indicated airspeed in meters per second, -1 if unknown */ - float true_airspeed_m_s; /**< true airspeed in meters per second, -1 if unknown */ + float true_airspeed_m_s; /**< true airspeed in meters per second, -1 if unknown */ + float voltage; /**< Voltage from the airspeed sensor (voltage divider already compensated) */ }; /** diff --git a/apps/uORB/topics/vehicle_status.h b/apps/uORB/topics/vehicle_status.h index 06b4c5ca5c..ae18ba050e 100644 --- a/apps/uORB/topics/vehicle_status.h +++ b/apps/uORB/topics/vehicle_status.h @@ -173,6 +173,7 @@ struct vehicle_status_s bool flag_preflight_gyro_calibration; /**< true if gyro calibration is requested */ bool flag_preflight_mag_calibration; /**< true if mag calibration is requested */ bool flag_preflight_accel_calibration; + bool flag_preflight_airspeed_calibration; bool rc_signal_found_once; bool rc_signal_lost; /**< true if RC reception is terminally lost */ From 3f674ba78cc8af2be8b8062f9366629b6c2a34be Mon Sep 17 00:00:00 2001 From: Thomas Gubler Date: Mon, 25 Feb 2013 14:34:53 +0100 Subject: [PATCH 4/7] fixed a typo --- apps/systemlib/airspeed.c | 2 +- apps/systemlib/airspeed.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/apps/systemlib/airspeed.c b/apps/systemlib/airspeed.c index 382df2ee4f..d7096d597d 100644 --- a/apps/systemlib/airspeed.c +++ b/apps/systemlib/airspeed.c @@ -87,7 +87,7 @@ float calc_true_airspeed_from_indicated(float speed_indicated, float pressure_am * * Note that the true airspeed is NOT the groundspeed, because of the effects of wind * - * @param total_pressure pressure inside the pitot/prandl tube + * @param total_pressure pressure inside the pitot/prandtl tube * @param static_pressure pressure at the side of the tube/airplane * @param temperature_celsius air temperature in degrees celcius * @return true airspeed in m/s diff --git a/apps/systemlib/airspeed.h b/apps/systemlib/airspeed.h index 0884989439..def53f0c1b 100644 --- a/apps/systemlib/airspeed.h +++ b/apps/systemlib/airspeed.h @@ -78,7 +78,7 @@ * * Note that the true airspeed is NOT the groundspeed, because of the effects of wind * - * @param total_pressure pressure inside the pitot/prandl tube + * @param total_pressure pressure inside the pitot/prandtl tube * @param static_pressure pressure at the side of the tube/airplane * @param temperature_celsius air temperature in degrees celcius * @return true airspeed in m/s From 6f1d7dc7de3609f73367794acc8d625c1ca27d03 Mon Sep 17 00:00:00 2001 From: Thomas Gubler Date: Mon, 25 Feb 2013 15:48:16 +0100 Subject: [PATCH 5/7] commander app sets an airspeed_valid flag in the vehicle status --- apps/commander/commander.c | 24 +++++++++++++++++++++++- apps/uORB/topics/vehicle_status.h | 1 + 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/apps/commander/commander.c b/apps/commander/commander.c index 41f4e56742..338272b175 100644 --- a/apps/commander/commander.c +++ b/apps/commander/commander.c @@ -1475,6 +1475,11 @@ int commander_thread_main(int argc, char *argv[]) struct sensor_combined_s sensors; memset(&sensors, 0, sizeof(sensors)); + int differential_pressure_sub = orb_subscribe(ORB_ID(differential_pressure)); + struct differential_pressure_s differential_pressure; + memset(&differential_pressure, 0, sizeof(differential_pressure)); + uint64_t last_differential_pressure_time = 0; + /* Subscribe to command topic */ int cmd_sub = orb_subscribe(ORB_ID(vehicle_command)); struct vehicle_command_s cmd; @@ -1528,6 +1533,13 @@ int commander_thread_main(int argc, char *argv[]) orb_copy(ORB_ID(sensor_combined), sensor_sub, &sensors); } + orb_check(differential_pressure_sub, &new_data); + + if (new_data) { + orb_copy(ORB_ID(differential_pressure), differential_pressure_sub, &differential_pressure); + last_differential_pressure_time = differential_pressure.timestamp; + } + orb_check(cmd_sub, &new_data); if (new_data) { @@ -1714,6 +1726,7 @@ int commander_thread_main(int argc, char *argv[]) bool vector_flight_mode_ok = current_status.flag_vector_flight_mode_ok; bool global_pos_valid = current_status.flag_global_position_valid; bool local_pos_valid = current_status.flag_local_position_valid; + bool airspeed_valid = current_status.flag_airspeed_valid; /* check for global or local position updates, set a timeout of 2s */ if (hrt_absolute_time() - last_global_position_time < 2000000) { @@ -1732,6 +1745,14 @@ int commander_thread_main(int argc, char *argv[]) current_status.flag_local_position_valid = false; } + /* Check for valid airspeed/differential pressure measurements */ + if (hrt_absolute_time() - last_differential_pressure_time < 2000000) { + current_status.flag_airspeed_valid = true; + + } else { + current_status.flag_airspeed_valid = false; + } + /* * Consolidate global position and local position valid flags * for vector flight mode. @@ -1747,7 +1768,8 @@ int commander_thread_main(int argc, char *argv[]) /* consolidate state change, flag as changed if required */ if (vector_flight_mode_ok != current_status.flag_vector_flight_mode_ok || global_pos_valid != current_status.flag_global_position_valid || - local_pos_valid != current_status.flag_local_position_valid) { + local_pos_valid != current_status.flag_local_position_valid || + airspeed_valid != current_status.flag_airspeed_valid) { state_changed = true; } diff --git a/apps/uORB/topics/vehicle_status.h b/apps/uORB/topics/vehicle_status.h index ae18ba050e..6326f13e6b 100644 --- a/apps/uORB/topics/vehicle_status.h +++ b/apps/uORB/topics/vehicle_status.h @@ -210,6 +210,7 @@ struct vehicle_status_s bool flag_auto_flight_mode_ok; /**< conditions of vector flight mode apply plus a valid takeoff position lock has been aquired */ bool flag_external_manual_override_ok; /**< external override non-fatal for system. Only true for fixed wing */ bool flag_valid_launch_position; /**< indicates a valid launch position */ + bool flag_airspeed_valid; /**< set to true by the commander app if there is a valid airspeed measurement available */ }; /** From de77cba5387018007f0a2b27aeb6984ee9ebc1d0 Mon Sep 17 00:00:00 2001 From: Thomas Gubler Date: Tue, 26 Feb 2013 11:18:13 +0100 Subject: [PATCH 6/7] small cleanup --- apps/sensors/sensors.cpp | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/apps/sensors/sensors.cpp b/apps/sensors/sensors.cpp index f77bc9b8b6..6a4cf0c65d 100644 --- a/apps/sensors/sensors.cpp +++ b/apps/sensors/sensors.cpp @@ -1041,10 +1041,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw) */ if (voltage > 0.4f) { -// float pres_raw = fabsf(voltage - (3.3f / 2.0f)); -// float pres_mbar = pres_raw * (3.3f / 5.0f) * 10.0f; - //XXX depends on sensor used..., where are the above numbers from? - float diff_pres_pa = (voltage - _parameters.airspeed_offset) * 1000.0f; //for MPXV7002DP + float diff_pres_pa = (voltage - _parameters.airspeed_offset) * 1000.0f; //for MPXV7002DP sensor float airspeed_true = calc_true_airspeed(diff_pres_pa + _barometer.pressure*1e2f, _barometer.pressure*1e2f, _barometer.temperature - 5.0f); //factor 1e2 for conversion from mBar to Pa @@ -1074,7 +1071,6 @@ Sensors::adc_poll(struct sensor_combined_s &raw) } _last_adc = hrt_absolute_time(); - //break; } } } From 8e3b09bd50fed9280328ecdaf2dbc7bd789bbbf9 Mon Sep 17 00:00:00 2001 From: Thomas Gubler Date: Tue, 26 Feb 2013 13:38:48 +0100 Subject: [PATCH 7/7] small printf change --- apps/systemlib/airspeed.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/apps/systemlib/airspeed.c b/apps/systemlib/airspeed.c index d7096d597d..264287b10f 100644 --- a/apps/systemlib/airspeed.c +++ b/apps/systemlib/airspeed.c @@ -97,7 +97,7 @@ float calc_true_airspeed(float total_pressure, float static_pressure, float temp float density = get_air_density(static_pressure, temperature_celsius); if (density < 0.0001f || !isfinite(density)) { density = CONSTANTS_AIR_DENSITY_SEA_LEVEL_15C; - printf("Invalid air density, using density at sea level\n"); + printf("[airspeed] Invalid air density, using density at sea level\n"); } float pressure_difference = total_pressure - static_pressure;