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px4-firmware
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Use discharged current to estimate remaining battery charge if capacity is known

This commit is contained in:
Anton Babushkin 2013-11-08 21:30:10 +04:00
parent 1a318ee2a6
commit 6b085e8ced
4 changed files with 32 additions and 21 deletions
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3
src/modules/commander/commander.cpp
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@ -896,8 +896,9 @@ int commander_thread_main(int argc, char *argv[])
/* only consider battery voltage if system has been running 2s and battery voltage is higher than 4V */
if (hrt_absolute_time() > start_time + 2000000 && battery.voltage_v > 4.0f) {
status.battery_voltage = battery.voltage_v;
status.battery_current = battery.current_a;
status.condition_battery_voltage_valid = true;
status.battery_remaining = battery_remaining_estimate_voltage(status.battery_voltage);
status.battery_remaining = battery_remaining_estimate_voltage(battery.voltage_v, battery.discharged_mah);
}
}

40
src/modules/commander/commander_helper.cpp
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@ -251,36 +251,44 @@ void rgbled_set_pattern(rgbled_pattern_t *pattern)
ioctl(rgbleds, RGBLED_SET_PATTERN, (unsigned long)pattern);
}
float battery_remaining_estimate_voltage(float voltage)
float battery_remaining_estimate_voltage(float voltage, float discharged)
{
float ret = 0;
static param_t bat_volt_empty;
static param_t bat_volt_full;
static param_t bat_n_cells;
static param_t bat_v_empty_h;
static param_t bat_v_full_h;
static param_t bat_n_cells_h;
static param_t bat_capacity_h;
static float bat_v_empty = 3.2f;
static float bat_v_full = 4.0f;
static int bat_n_cells = 3;
static float bat_capacity = -1.0f;
static bool initialized = false;
static unsigned int counter = 0;
static float ncells = 3;
// XXX change cells to int (and param to INT32)
if (!initialized) {
bat_volt_empty = param_find("BAT_V_EMPTY");
bat_volt_full = param_find("BAT_V_FULL");
bat_n_cells = param_find("BAT_N_CELLS");
bat_v_empty_h = param_find("BAT_V_EMPTY");
bat_v_full_h = param_find("BAT_V_FULL");
bat_n_cells_h = param_find("BAT_N_CELLS");
bat_capacity_h = param_find("BAT_CAPACITY");
initialized = true;
}
static float chemistry_voltage_empty = 3.2f;
static float chemistry_voltage_full = 4.05f;
if (counter % 100 == 0) {
param_get(bat_volt_empty, &chemistry_voltage_empty);
param_get(bat_volt_full, &chemistry_voltage_full);
param_get(bat_n_cells, &ncells);
param_get(bat_v_empty_h, &bat_v_empty);
param_get(bat_v_full_h, &bat_v_full);
param_get(bat_n_cells_h, &bat_n_cells);
param_get(bat_capacity_h, &bat_capacity);
}
counter++;
ret = (voltage - ncells * chemistry_voltage_empty) / (ncells * (chemistry_voltage_full - chemistry_voltage_empty));
if (bat_capacity > 0.0f) {
/* if battery capacity is known, use it to estimate remaining charge */
ret = 1.0f - discharged / bat_capacity;
} else {
/* else use voltage */
ret = (voltage - bat_n_cells * bat_v_empty) / (bat_n_cells * (bat_v_full - bat_v_empty));
}
/* limit to sane values */
ret = (ret < 0.0f) ? 0.0f : ret;

7
src/modules/commander/commander_helper.h
View File

@ -75,12 +75,13 @@ void rgbled_set_mode(rgbled_mode_t mode);
void rgbled_set_pattern(rgbled_pattern_t *pattern);
/**
* Provides a coarse estimate of remaining battery power.
* Estimate remaining battery charge.
*
* The estimate is very basic and based on decharging voltage curves.
* Use integral of current if battery capacity known (BAT_CAPACITY parameter set),
* else use simple estimate based on voltage.
*
* @return the estimated remaining capacity in 0..1
*/
float battery_remaining_estimate_voltage(float voltage);
float battery_remaining_estimate_voltage(float voltage, float discharged);
#endif /* COMMANDER_HELPER_H_ */

3
src/modules/commander/commander_params.c
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@ -52,4 +52,5 @@ PARAM_DEFINE_FLOAT(TRIM_PITCH, 0.0f);
PARAM_DEFINE_FLOAT(TRIM_YAW, 0.0f);
PARAM_DEFINE_FLOAT(BAT_V_EMPTY, 3.2f);
PARAM_DEFINE_FLOAT(BAT_V_FULL, 4.05f);
PARAM_DEFINE_FLOAT(BAT_N_CELLS, 3);
PARAM_DEFINE_INT32(BAT_N_CELLS, 3);
PARAM_DEFINE_FLOAT(BAT_CAPACITY, -1.0f);