def _get_severity_coefficient(self, severity_type_key: str, level_name: str) -> float:
    """
    从配置中获取严重程度对应的系数
    :param severity_type_key: 对应 severity_level 下的键，如 "wear", "stain"
    :param level_name: 具体的等级名，如 "一般", "严重"
    :return: 系数 value
    """
    severity_config = self.config.get("severity_level", {})
    rules = severity_config.get(severity_type_key, [])

    # 默认系数为 1.0 (如果找不到配置)
    default_val = 1.0

    # 寻找匹配的 name
    for rule in rules:
        if rule.get("name") == level_name:
            return float(rule.get("value", 1.0))
    # 如果传入了"一般"但配置里没"一般"，则返回 1.0
    return default_val