soe_counting.c

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/**
 * @file    soe_counting.c
 * @author  foxBMS Team
 * @date    2020-10-07 (date of creation)
 * @updated 2022-07-28 (date of last update)
 * @version v1.4.0
 * @ingroup APPLICATION
 * @prefix  SOE
 *
 * @brief   SOE module responsible for calculation of SOE
 *
 */
 
/*========== Includes =======================================================*/
#include "soe_counting.h"
 
#include "battery_cell_cfg.h"
#include "battery_system_cfg.h"
#include "soe_counting_cfg.h"
 
#include "bms.h"
#include "database.h"
#include "foxmath.h"
#include "fram.h"
 
/*========== Macros and Definitions =========================================*/
/**
 * This structure contains all the variables relevant for the SOX.
 */
typedef struct {
    bool soeInitialized;                      /*!< true if the initialization has passed, false otherwise */
    bool sensorEcUsed[BS_NR_OF_STRINGS];      /*!< true if energy counting functionality of current sensor is used */
    float ecScalingAverage[BS_NR_OF_STRINGS]; /*!< current sensor offset scaling for average SOE */
    float ecScalingMinimum[BS_NR_OF_STRINGS]; /*!< current sensor offset scaling for minimum SOE */
    float ecScalingMaximum[BS_NR_OF_STRINGS]; /*!< current sensor offset scaling for maximum SOE */
    uint32_t previousTimestamp
        [BS_NR_OF_STRINGS]; /*!< last used timestamp of current or energy counting value for SOE estimation */
} SOE_STATE_s;
 
/** defines for maximum and minimum SOE */
#define MAXIMUM_SOE_PERC (100.0f)
#define MINIMUM_SOE_PERC (0.0f)
 
/*========== Static Constant and Variable Definitions =======================*/
 
/**
 * contains the state of the SOE estimation
 */
static SOE_STATE_s soe_state = {
    .soeInitialized    = false,
    .sensorEcUsed      = {GEN_REPEAT_U(false, GEN_STRIP(BS_NR_OF_STRINGS))},
    .ecScalingAverage  = {GEN_REPEAT_U(0.0f, GEN_STRIP(BS_NR_OF_STRINGS))},
    .ecScalingMinimum  = {GEN_REPEAT_U(0.0f, GEN_STRIP(BS_NR_OF_STRINGS))},
    .ecScalingMaximum  = {GEN_REPEAT_U(0.0f, GEN_STRIP(BS_NR_OF_STRINGS))},
    .previousTimestamp = {GEN_REPEAT_U(0u, GEN_STRIP(BS_NR_OF_STRINGS))},
};
 
/** local copies of database tables */
/**@{*/
static DATA_BLOCK_CURRENT_SENSOR_s soe_tableCurrentSensor = {.header.uniqueId = DATA_BLOCK_ID_CURRENT_SENSOR};
/**@}*/
 
/*========== Extern Constant and Variable Definitions =======================*/
 
/*========== Static Function Prototypes =====================================*/
 
/**
 * @brief   calculates string energy in Wh from passed SOE in percentage
 *
 * @param[in] stringSoe_perc   string SOE in percentage [0.0, 100.0]
 *
 * @return returns corresponding string energy in Wh
 */
static uint32_t SOE_GetStringEnergyFromSoePercentage(float stringSoe_perc);
 
/**
 * @brief   calculates string SOE in percentage from passed string energy in Wh
 *
 * @param[in] energy_Wh   string energy in Wh
 *
 * @return returns corresponding string SOE in percentage [0.0, 100.0]
 */
static float SOE_GetStringSoePercentageFromEnergy(uint32_t energy_Wh);
 
/**
 * @brief   initializes database and FRAM SOE values via lookup table (average, min and max).
 * @param[out] pSoeValues   pointer to SOE database entry
 */
static void SOE_RecalibrateViaLookupTable(DATA_BLOCK_SOX_s *pSoeValues);
 
/**
 * @brief   look-up table for SOE initialization
 *
 * @param[in] voltage_mV  cell voltage of battery cell
 *
 * @return  SOE value in percentage [0.0 - 100.0]
 */
static float SOE_GetFromVoltage(int16_t voltage_mV);
 
/**
 * @brief   sets SOE value with a parameter between 0.0 and 100.0.
 * @details limits the SOE value to 0.0 respectively 100.0 if a value outside
 *          of the allowed SOE range is passed. Updates local fram and database
 *          struct but does *NOT* write them
 * @param[out]  pSoeValues  pointer to SOE database enty
 * @param[in]   soeMinimumValue_perc  SOE min value to set
 * @param[in]   soeMaximumValue_perc  SOE max value to set
 * @param[in]   soeAverageValue_perc  SOE average value to set
 * @param[in]   stringNumber     string addressed
 */
static void SOE_SetValue(
    DATA_BLOCK_SOX_s *pSoeValues,
    float soeMinimumValue_perc,
    float soeMaximumValue_perc,
    float soeAverageValue_perc,
    uint8_t stringNumber);
 
/**
 * @brief   Check if all database SOE percentage values are within [0.0, 100.0]
 *          Limits SOE values to limit values if outside of this range.
 *
 * @param[in,out] pTableSoe  pointer to database struct with SOE values
 * @param[in] stringNumber   string that is checked
 */
static void SOE_CheckDatabaseSoePercentageLimits(DATA_BLOCK_SOX_s *pTableSoe, uint8_t stringNumber);
 
/*========== Static Function Implementations ================================*/
static float SOE_GetStringSoePercentageFromEnergy(uint32_t energy_Wh) {
    float stringSoe_perc        = 0.0f;
    const float stringEnergy_Wh = (float)energy_Wh;
    if (stringEnergy_Wh >= SOE_STRING_ENERGY_Wh) {
        stringSoe_perc = MAXIMUM_SOE_PERC;
    } else {
        stringSoe_perc = UNIT_CONVERSION_FACTOR_100_FLOAT * (stringEnergy_Wh / SOE_STRING_ENERGY_Wh);
    }
    return stringSoe_perc;
}
 
static uint32_t SOE_GetStringEnergyFromSoePercentage(float stringSoe_perc) {
    float energy_Wh = 0.0f;
    if (stringSoe_perc >= MAXIMUM_SOE_PERC) {
        energy_Wh = SOE_STRING_ENERGY_Wh;
    } else if (stringSoe_perc <= MINIMUM_SOE_PERC) {
        energy_Wh = MINIMUM_SOE_PERC;
    } else {
        energy_Wh = SOE_STRING_ENERGY_Wh * (stringSoe_perc / UNIT_CONVERSION_FACTOR_100_FLOAT);
    }
    return (uint32_t)energy_Wh;
}
 
static void SOE_RecalibrateViaLookupTable(DATA_BLOCK_SOX_s *pSoeValues) {
    FAS_ASSERT(pSoeValues != NULL_PTR);
    DATA_BLOCK_MIN_MAX_s tableMinimumMaximumAverage = {.header.uniqueId = DATA_BLOCK_ID_MIN_MAX};
 
    DATA_READ_DATA(&tableMinimumMaximumAverage);
 
    for (uint8_t s = 0u; s < BS_NR_OF_STRINGS; s++) {
        SOE_SetValue(
            pSoeValues,
            SOE_GetFromVoltage(tableMinimumMaximumAverage.minimumCellVoltage_mV[s]),
            SOE_GetFromVoltage(tableMinimumMaximumAverage.maximumCellVoltage_mV[s]),
            SOE_GetFromVoltage(tableMinimumMaximumAverage.averageCellVoltage_mV[s]),
            s);
    }
    FRAM_WriteData(FRAM_BLOCK_ID_SOE);
}
 
static float SOE_GetFromVoltage(int16_t voltage_mV) {
    float soe_perc = 50.0f;
    /* Variables for interpolating LUT value */
    uint16_t between_high = 0;
    uint16_t between_low  = 0;
 
    /* Cell voltages are inserted in LUT in descending order -> start with 1 as we do not want to extrapolate. */
    for (uint16_t i = 1u; i < bc_stateOfEnergyLookupTableLength; i++) {
        if (voltage_mV < bc_stateOfEnergyLookupTable[i].voltage_mV) {
            between_low  = i + 1u;
            between_high = i;
        }
    }
 
    /* Interpolate between LUT values, but do not extrapolate LUT! */
    if (!(((between_high == 0u) && (between_low == 0u)) ||       /* cell voltage > maximum LUT voltage */
          (between_low >= bc_stateOfEnergyLookupTableLength))) { /* cell voltage < minimum LUT voltage */
        soe_perc = MATH_LinearInterpolation(
            (float)bc_stateOfEnergyLookupTable[between_low].voltage_mV,
            bc_stateOfEnergyLookupTable[between_low].value,
            (float)bc_stateOfEnergyLookupTable[between_high].voltage_mV,
            bc_stateOfEnergyLookupTable[between_high].value,
            (float)voltage_mV);
    } else if ((between_low >= bc_stateOfEnergyLookupTableLength)) {
        /* LUT SOE values are in descending order: cell voltage < minimum LUT voltage */
        soe_perc = MINIMUM_SOE_PERC;
    } else {
        /* cell voltage > maximum LUT voltage */
        soe_perc = MAXIMUM_SOE_PERC;
    }
    return soe_perc;
}
 
static void SOE_SetValue(
    DATA_BLOCK_SOX_s *pSoeValues,
    float soeMinimumValue_perc,
    float soeMaximumValue_perc,
    float soeAverageValue_perc,
    uint8_t stringNumber) {
    FAS_ASSERT(pSoeValues != NULL_PTR);
 
    /* Update FRAM value */
    fram_soe.averageSoe_perc[stringNumber] = soeAverageValue_perc;
    fram_soe.minimumSoe_perc[stringNumber] = soeMinimumValue_perc;
    fram_soe.maximumSoe_perc[stringNumber] = soeMaximumValue_perc;
 
    /* Update database values */
    pSoeValues->averageSoe_perc[stringNumber] = soeAverageValue_perc;
    pSoeValues->minimumSoe_perc[stringNumber] = soeMinimumValue_perc;
    pSoeValues->maximumSoe_perc[stringNumber] = soeMaximumValue_perc;
 
    pSoeValues->maximumSoe_Wh[stringNumber] = SOE_GetStringEnergyFromSoePercentage(soeMaximumValue_perc);
    pSoeValues->averageSoe_Wh[stringNumber] = SOE_GetStringEnergyFromSoePercentage(soeAverageValue_perc);
    pSoeValues->minimumSoe_Wh[stringNumber] = SOE_GetStringEnergyFromSoePercentage(soeMinimumValue_perc);
 
    /* Calculate scaling values depending on EC counting value and current SOE */
    if (soe_state.sensorEcUsed[stringNumber] == true) {
        DATA_READ_DATA(&soe_tableCurrentSensor);
 
        float ecOffset =
            SOE_GetStringSoePercentageFromEnergy((uint32_t)abs(soe_tableCurrentSensor.energyCounter_Wh[stringNumber]));
 
        if (soe_tableCurrentSensor.energyCounter_Wh[stringNumber] < 0) {
            ecOffset *= (-1.0f);
        }
 
#if POSITIVE_DISCHARGE_CURRENT == false
        ecOffset *= (-1.0f); /* negate calculated delta SOE in perc */
 
#endif /* POSITIVE_DISCHARGE_CURRENT == false */
 
        soe_state.ecScalingAverage[stringNumber] = fram_soe.averageSoe_perc[stringNumber] + ecOffset;
        soe_state.ecScalingMinimum[stringNumber] = fram_soe.minimumSoe_perc[stringNumber] + ecOffset;
        soe_state.ecScalingMaximum[stringNumber] = fram_soe.maximumSoe_perc[stringNumber] + ecOffset;
    }
}
 
static void SOE_CheckDatabaseSoePercentageLimits(DATA_BLOCK_SOX_s *pTableSoe, uint8_t stringNumber) {
    FAS_ASSERT(pTableSoe != NULL_PTR);
    FAS_ASSERT(stringNumber < BS_NR_OF_STRINGS);
 
    if (pTableSoe->averageSoe_perc[stringNumber] > MAXIMUM_SOE_PERC) {
        pTableSoe->averageSoe_perc[stringNumber] = MAXIMUM_SOE_PERC;
    }
    if (pTableSoe->averageSoe_perc[stringNumber] < MINIMUM_SOE_PERC) {
        pTableSoe->averageSoe_perc[stringNumber] = MINIMUM_SOE_PERC;
    }
    if (pTableSoe->minimumSoe_perc[stringNumber] > MAXIMUM_SOE_PERC) {
        pTableSoe->minimumSoe_perc[stringNumber] = MAXIMUM_SOE_PERC;
    }
    if (pTableSoe->minimumSoe_perc[stringNumber] < MINIMUM_SOE_PERC) {
        pTableSoe->minimumSoe_perc[stringNumber] = MINIMUM_SOE_PERC;
    }
    if (pTableSoe->maximumSoe_perc[stringNumber] > MAXIMUM_SOE_PERC) {
        pTableSoe->maximumSoe_perc[stringNumber] = MAXIMUM_SOE_PERC;
    }
    if (pTableSoe->maximumSoe_perc[stringNumber] < MINIMUM_SOE_PERC) {
        pTableSoe->maximumSoe_perc[stringNumber] = MINIMUM_SOE_PERC;
    }
}
 
/*========== Extern Function Implementations ================================*/
 
extern void SE_InitializeStateOfEnergy(DATA_BLOCK_SOX_s *pSoeValues, bool ec_present, uint8_t stringNumber) {
    FAS_ASSERT(pSoeValues != NULL_PTR);
    FAS_ASSERT(stringNumber < BS_NR_OF_STRINGS);
    FRAM_ReadData(FRAM_BLOCK_ID_SOE);
 
    pSoeValues->averageSoe_perc[stringNumber] = fram_soe.averageSoe_perc[stringNumber];
    pSoeValues->minimumSoe_perc[stringNumber] = fram_soe.minimumSoe_perc[stringNumber];
    pSoeValues->maximumSoe_perc[stringNumber] = fram_soe.maximumSoe_perc[stringNumber];
 
    /* Limit SOE values [0.0f, 100.0f] */
    SOE_CheckDatabaseSoePercentageLimits(pSoeValues, stringNumber);
 
    /* Calculate string energy in Wh */
    pSoeValues->maximumSoe_Wh[stringNumber] =
        SOE_GetStringEnergyFromSoePercentage(pSoeValues->maximumSoe_perc[stringNumber]);
    pSoeValues->minimumSoe_Wh[stringNumber] =
        SOE_GetStringEnergyFromSoePercentage(pSoeValues->minimumSoe_perc[stringNumber]);
    pSoeValues->averageSoe_Wh[stringNumber] =
        SOE_GetStringEnergyFromSoePercentage(pSoeValues->averageSoe_perc[stringNumber]);
 
    if (ec_present == true) {
        DATA_READ_DATA(&soe_tableCurrentSensor);
        soe_state.sensorEcUsed[stringNumber] = true;
 
        /* Set scaling values */
        float ecOffset =
            SOE_GetStringSoePercentageFromEnergy((uint32_t)abs(soe_tableCurrentSensor.energyCounter_Wh[stringNumber]));
 
        if (soe_tableCurrentSensor.energyCounter_Wh[stringNumber] < 0) {
            ecOffset *= (-1.0f);
        }
 
#if POSITIVE_DISCHARGE_CURRENT == false
        ecOffset *= (-1.0f); /* negate calculated delta SOE in perc */
 
#endif /* POSITIVE_DISCHARGE_CURRENT == false */
 
        soe_state.ecScalingMinimum[stringNumber] = fram_soe.minimumSoe_perc[stringNumber] + ecOffset;
        soe_state.ecScalingMaximum[stringNumber] = fram_soe.maximumSoe_perc[stringNumber] + ecOffset;
        soe_state.ecScalingAverage[stringNumber] = fram_soe.averageSoe_perc[stringNumber] + ecOffset;
    }
    soe_state.soeInitialized = true;
}
 
void SE_CalculateStateOfEnergy(DATA_BLOCK_SOX_s *pSoeValues) {
    FAS_ASSERT(pSoeValues != NULL_PTR);
    bool continueFunction = true;
    if (soe_state.soeInitialized == false) {
        /* Exit if SOE not initialized yet */
        continueFunction = false;
    }
 
    if (continueFunction == true) {
        /* Use energy counting/integrate */
        DATA_READ_DATA(&soe_tableCurrentSensor);
 
        if (BMS_GetBatterySystemState() == BMS_AT_REST) {
            /* Recalibrate SOE via LUT */
            SOE_RecalibrateViaLookupTable(pSoeValues);
        } else {
            for (uint8_t s = 0u; s < BS_NR_OF_STRINGS; s++) {
                if (soe_state.sensorEcUsed[s] == false) {
                    /* no energy counting activated -> manually integrate energy */
                    uint32_t timestamp          = soe_tableCurrentSensor.timestampCurrent[s];
                    uint32_t previous_timestamp = soe_tableCurrentSensor.previousTimestampCurrent[s];
 
                    /* check if current measurement has been updated */
                    if (soe_state.previousTimestamp[s] != timestamp) {
                        float timestep_s = (((float)timestamp - (float)previous_timestamp)) / 1000.0f;
                        if (timestep_s > 0.0f) {
                            /* Current in charge direction negative means SOE increasing --> BAT naming, not ROB */
                            float deltaSOE_Wh =
                                ((((float)soe_tableCurrentSensor.current_mA[s] / 1000.0f) *         /* convert to A */
                                  ((float)soe_tableCurrentSensor.highVoltage_mV[s][0] / 1000.0f)) / /* convert to V */
                                 timestep_s) /                                                      /* unit: s */
                                3600.0f; /* convert Ws -> Wh */
 
#if POSITIVE_DISCHARGE_CURRENT == false
                            /* negate calculated delta SOE_Wh */
                            deltaSOE_Wh *= (-1.0f);
#endif /* POSITIVE_DISCHARGE_CURRENT == false */
 
                            pSoeValues->averageSoe_Wh[s] -= (uint32_t)deltaSOE_Wh;
                            pSoeValues->minimumSoe_Wh[s] -= (uint32_t)deltaSOE_Wh;
                            pSoeValues->maximumSoe_Wh[s] -= (uint32_t)deltaSOE_Wh;
 
                            pSoeValues->averageSoe_perc[s] =
                                SOE_GetStringSoePercentageFromEnergy(pSoeValues->averageSoe_Wh[s]);
                            pSoeValues->minimumSoe_perc[s] =
                                SOE_GetStringSoePercentageFromEnergy(pSoeValues->minimumSoe_Wh[s]);
                            pSoeValues->maximumSoe_perc[s] =
                                SOE_GetStringSoePercentageFromEnergy(pSoeValues->maximumSoe_Wh[s]);
 
                            /* update timestamp SOE state variable for next iteration */
                            soe_state.previousTimestamp[s] = timestamp;
                        }
                    } /* end check if current measurement has been updated */
                } else {
                    /* check if ec measurement has been updated */
                    if (soe_state.previousTimestamp[s] != soe_tableCurrentSensor.timestampEnergyCounting[s]) {
                        /* Calculate SOE value with current sensor EC value */
                        float deltaSoe_perc =
                            (((float)soe_tableCurrentSensor.energyCounter_Wh[s] / SOE_STRING_ENERGY_Wh) *
                             UNIT_CONVERSION_FACTOR_100_FLOAT);
 
#if POSITIVE_DISCHARGE_CURRENT == false
                        /* negate calculated delta SOE_perc */
                        deltaSoe_perc *= (-1.0f);
#endif
                        /* Apply EC scaling offset to get actual string energy */
                        pSoeValues->averageSoe_perc[s] = soe_state.ecScalingAverage[s] - deltaSoe_perc;
                        pSoeValues->minimumSoe_perc[s] = soe_state.ecScalingMinimum[s] - deltaSoe_perc;
                        pSoeValues->maximumSoe_perc[s] = soe_state.ecScalingMaximum[s] - deltaSoe_perc;
 
                        /* Limit SOE values to [0.0, 100.0] */
                        SOE_CheckDatabaseSoePercentageLimits(pSoeValues, s);
 
                        /* Calculate new Wh values */
                        pSoeValues->maximumSoe_Wh[s] =
                            SOE_GetStringEnergyFromSoePercentage(pSoeValues->maximumSoe_perc[s]);
                        pSoeValues->averageSoe_Wh[s] =
                            SOE_GetStringEnergyFromSoePercentage(pSoeValues->averageSoe_perc[s]);
                        pSoeValues->minimumSoe_Wh[s] =
                            SOE_GetStringEnergyFromSoePercentage(pSoeValues->minimumSoe_perc[s]);
 
                        /* Update timestamp for next iteration */
                        soe_state.previousTimestamp[s] = soe_tableCurrentSensor.timestampEnergyCounting[s];
                    }
                }
 
                fram_soe.averageSoe_perc[s] = pSoeValues->averageSoe_perc[s];
                fram_soe.minimumSoe_perc[s] = pSoeValues->minimumSoe_perc[s];
                fram_soe.maximumSoe_perc[s] = pSoeValues->maximumSoe_perc[s];
            }
 
            /* Update database and FRAM value */
            FRAM_WriteData(FRAM_BLOCK_ID_SOE);
        }
    }
}
 
/*========== Externalized Static Function Implementations (Unit Test) =======*/