{
  "node": {
    "id": "term:particle-filter",
    "type": "Term",
    "label": "Particle filter",
    "properties": {
      "id": "particle-filter",
      "name": "Particle filter",
      "aka": [
        "sequential Monte Carlo"
      ],
      "section": "topic-state",
      "definition": "A recursive estimator that represents an uncertain state as a cloud of weighted samples, propagating each through the model and reweighting it against every new measurement. Unlike a Kalman filter it copes with strong nonlinearity and non-Gaussian noise, at the cost of hundreds of model runs per step, so it appears more in remaining-useful-life prognostics than in production BMS firmware.",
      "related": [
        "kalman-filter",
        "remaining-useful-life",
        "state-of-charge",
        "state-observer",
        "equivalent-circuit-model"
      ],
      "url": "https://lemonergy.com/learn/glossary/particle-filter/",
      "mentions": [
        "bms",
        "firmware"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:6510",
      "source": "term:particle-filter",
      "target": "topic:topic-state",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6511",
      "source": "term:particle-filter",
      "target": "term:kalman-filter",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6512",
      "source": "term:particle-filter",
      "target": "term:remaining-useful-life",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6513",
      "source": "term:particle-filter",
      "target": "term:state-of-charge",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6514",
      "source": "term:particle-filter",
      "target": "term:state-observer",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6515",
      "source": "term:particle-filter",
      "target": "term:equivalent-circuit-model",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/particle-filter/bms",
      "source": "term:particle-filter",
      "target": "term:bms",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/particle-filter/firmware",
      "source": "term:particle-filter",
      "target": "term:firmware",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-state",
      "type": "Topic",
      "label": "State estimation",
      "properties": {
        "id": "topic-state",
        "name": "State estimation",
        "lede": "The quantities a battery management system estimates but cannot measure directly.",
        "context": "Distinguish internal states from noisy measurement estimates.",
        "example": "Current-sensor bias accumulates in coulomb counting. Exact model SOC does not establish real estimator accuracy.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/",
        "lesson_label": "Open charge balance"
      }
    },
    {
      "id": "term:kalman-filter",
      "type": "Term",
      "label": "Kalman filter",
      "properties": {
        "id": "kalman-filter",
        "name": "Kalman filter",
        "section": "topic-state",
        "definition": "A recursive estimator that blends a model prediction with noisy measurements according to how much each is trusted. In a BMS an extended Kalman filter combines coulomb counting with a voltage model to track SOC and sometimes resistance.",
        "related": [
          "coulomb-counting",
          "equivalent-circuit-model",
          "state-of-charge",
          "bms",
          "fuzzy-logic",
          "data-driven-soc-estimation"
        ],
        "url": "https://lemonergy.com/learn/glossary/kalman-filter/",
        "mentions": [
          "coulomb"
        ]
      }
    },
    {
      "id": "term:remaining-useful-life",
      "type": "Term",
      "label": "Remaining useful life",
      "properties": {
        "id": "remaining-useful-life",
        "name": "Remaining useful life",
        "abbr": "RUL",
        "section": "topic-state",
        "definition": "A prediction of how many cycles, or how much time, a battery has left before reaching end of life. It is estimated from the trend of state of health, and is uncertain near a knee point where fade accelerates.",
        "related": [
          "state-of-health",
          "end-of-life",
          "knee-point",
          "cycle-life"
        ],
        "url": "https://lemonergy.com/learn/glossary/remaining-useful-life/",
        "mentions": []
      }
    },
    {
      "id": "term:state-of-charge",
      "type": "Term",
      "label": "State of charge",
      "properties": {
        "id": "state-of-charge",
        "name": "State of charge",
        "abbr": "SOC",
        "section": "topic-state",
        "definition": "How full a cell is, as a fraction of its available capacity. State of charge, like temperature, affects how fast a stored cell ages.",
        "unit": "%",
        "related": [
          "depth-of-discharge",
          "ocv-soc-curve",
          "coulomb-counting",
          "state-of-health",
          "bms"
        ],
        "lesson": "fundamentals/battery-aging/#storage-soc",
        "example": {
          "title": "Interpret a charge inventory",
          "text": "If available capacity is 5 Ah and 3 Ah remains by the chosen estimator, SOC is 60%. A different estimate of available capacity changes this percentage, so compare SOC values only with the capacity convention recorded."
        },
        "url": "https://lemonergy.com/learn/glossary/state-of-charge/",
        "mentions": [
          "usable-capacity"
        ]
      }
    },
    {
      "id": "term:state-observer",
      "type": "Term",
      "label": "State observer",
      "properties": {
        "id": "state-observer",
        "name": "State observer",
        "aka": [
          "Luenberger observer",
          "sliding-mode observer",
          "H-infinity filter",
          "adaptive observer"
        ],
        "section": "topic-state",
        "definition": "An algorithm that reconstructs internal states such as SOC by running a model alongside the cell and correcting it with the measured voltage error. A Luenberger observer uses a fixed gain, a sliding-mode observer a switching term robust to model error, an H-infinity filter bounds the worst-case error, and an adaptive observer also updates the model parameters.",
        "related": [
          "kalman-filter",
          "equivalent-circuit-model",
          "state-of-charge",
          "observability",
          "particle-filter",
          "dual-joint-estimation"
        ],
        "url": "https://lemonergy.com/learn/glossary/state-observer/",
        "mentions": []
      }
    },
    {
      "id": "term:equivalent-circuit-model",
      "type": "Term",
      "label": "Equivalent circuit model",
      "properties": {
        "id": "equivalent-circuit-model",
        "name": "Equivalent circuit model",
        "abbr": "ECM",
        "aka": [
          "Thevenin model"
        ],
        "section": "topic-transport",
        "definition": "A cell model built from a voltage source for OCV, a series resistor and one or more RC pairs for the slower dynamics. Its few parameters are fitted from pulse tests, and it is what most battery management systems run in real time.",
        "related": [
          "rc-pair",
          "open-circuit-voltage",
          "hppc",
          "kalman-filter",
          "single-particle-model"
        ],
        "url": "https://lemonergy.com/learn/glossary/equivalent-circuit-model/",
        "mentions": []
      }
    },
    {
      "id": "term:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    },
    {
      "id": "term:firmware",
      "type": "Term",
      "label": "Firmware",
      "properties": {
        "id": "firmware",
        "name": "Firmware",
        "aka": [
          "embedded software",
          "BMS software"
        ],
        "section": "topic-data",
        "definition": "The software that runs on a BMS or charger controller. Its version decides how SOC, limits and faults behave, so it is tracked like a part number, updated by flashing over CAN or over the air, and recorded in the battery passport.",
        "related": [
          "mcu",
          "flashing",
          "bmu",
          "battery-passport",
          "functional-safety"
        ],
        "url": "https://lemonergy.com/learn/glossary/firmware/",
        "mentions": [
          "charger",
          "state-of-charge",
          "bms",
          "over-the-air-update"
        ]
      }
    }
  ]
}