Line data    Source code

       1             : /*
       2             :    This program is free software: you can redistribute it and/or modify
       3             :    it under the terms of the GNU General Public License as published by
       4             :    the Free Software Foundation, either version 3 of the License, or
       5             :    (at your option) any later version.
       6             : 
       7             :    This program is distributed in the hope that it will be useful,
       8             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
       9             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      10             :    GNU General Public License for more details.
      11             : 
      12             :    You should have received a copy of the GNU General Public License
      13             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      14             :  */
      15             : /*
      16             :   battery model for electric aircraft
      17             : */
      18             : 
      19             : #pragma once
      20             : 
      21             : #include <Filter/LowPassFilter.h>
      22             : 
      23             : namespace SITL {
      24             : 
      25             : class Battery {
      26             : public:
      27             :     // Note: capacity<=0 means **unlimited** capacity.
      28             :     void setup(float _capacity_Ah, float _resistance_ohm, float _max_voltage, float _ambient_temperature_degC);
      29             : 
      30             :     // Resets the battery state if the configuration (e.g. from SIM_BATT_* parameters) has changed.
      31             :     // Changing desired_resistance_ohm does not cause a state reset.
      32             :     // A negative desired_resistance value means to leave the existing resistance unchanged.
      33             :     void maybe_reset(float desired_voltage, float desired_capacity_Ah, float desired_resistance_ohm = -1.0f);
      34             : 
      35             :     // Call this periodically to "step" the battery forward in time
      36             :     void consume_energy(float attempted_current_amp, uint64_t now_us);
      37             : 
      38   177027951 :     float get_voltage(void) const { return voltage_filter.get(); }
      39          37 :     float get_capacity(void) const { return capacity_Ah; }
      40   167668475 :     float get_temperature_degC(void) const { return temperature_degC; }
      41   354242567 :     bool capacity_is_unlimited(void) const { return !(is_positive(capacity_Ah)); } // for readability
      42             : 
      43             : private:
      44             :     float capacity_Ah; // set <= 0 for unlmited capacity
      45             :     float resistance_ohm;
      46             :     float max_voltage;
      47             :     float ambient_temperature_degC;
      48             :     float voltage_set;
      49             :     float remaining_Ah; // if capacity is unlimited, this is FLT_MAX
      50             :     uint64_t last_us;
      51             : 
      52             :     float temperature_degC = 0.0f;
      53             :     void update_temperature(float current_amp, float dt);
      54             : 
      55             :     // 10Hz filter for battery voltage
      56             :     LowPassFilterFloat voltage_filter{10};
      57             : 
      58             :     float get_resting_voltage(void) const;
      59             :     float compute_remaining_Ah(float voltage) const;
      60             : };
      61             : }