Display system
The display system includes an instrument panel, a battery, a current sensor, and an ECU. The battery stores electric power for traveling of the vehicle. The current sensor detects a charge/discharge current of the battery. ECU calculates SOC of the battery according to the current sensor. SOC includes a control SOC used for charge/discharge control of the battery, and a display SOC displayed on the instrument panel and calculated according to the control SOC. When the index value indicating the degree of decrease in the calculation accuracy of the control SOC exceeds the threshold value, ECU starts a calculation process of calculating the display SOC lower than the control SOC.
1 . A display system comprising:
a display device;
a power storage device configured to store electric power for traveling of an electrified vehicle;
a current sensor configured to detect charging and discharging currents of the power storage device; and
a processor configured to
calculate a control state of charge of the power storage device based on a detection value of the current sensor, the control state of charge being used for charge and discharge control of the power storage device; and
calculate an index value indicating a degree of decrease in accuracy of calculating the control state of charge, wherein
the calculated control state of charge is displayed on the display device while the index value indicates that the decrease in the accuracy of calculating the control state of charge is at or below a threshold value,
the processor is further configured to begin calculating a display state of charge based on the control state of charge in response to the index value exceeding a threshold value, the display state of charge being calculated as a value lower than the control state of charge,
the display state of charge is then displayed on the display device instead of the control state of charge, and
the processor continues the calculating of the control state of charge while the display state of charge is displayed on the display device.
2 . The display system according to claim 1 , further comprising:
a storage device configured to store a first relationship between the control state of charge and an open circuit voltage of the power storage device, wherein
the processor is configured to correct the control state of charge using the first relationship when the control state of charge is equal to or larger than a first reference value or when the control state of charge is smaller than a second reference value that is smaller than the first reference value; and
the index value is calculated based on an elapsed time since the control state of charge was previously corrected using the first relationship.
3 . The display system according to claim 2 , wherein
a difference between the control state of charge and the display state of charge increases as the elapsed time increases.
4 . The display system according to claim 2 , wherein
the processor is configured to, when the elapsed time exceeds a threshold time, cause the display device to display a screen prompting a user of the electrified vehicle to fully charge the power storage device.
5 . The display system according to claim 1 , wherein
the index value includes a temperature of the power storage device; and
a state in which the index value exceeds the threshold value includes a state in which the temperature is lower than a threshold temperature serving as the threshold value.
6 . The display system according to claim 2 , wherein
the control state of charge is calculated based on a current value detected by the current sensor while the control state of charge is less than the first reference value and equal to or larger than the second reference value.
7 . The display system according to claim 2 , further comprising:
a user terminal including a terminal display, wherein
the processor is configured to cause the user terminal to display a screen on the terminal screen prompting a user of the terminal to fully charge the power storage device of the electrified vehicle.
8 . The display system according to claim 3 , wherein
a magnitude of the difference between the control state of charge and the display state of charge is determined based on an offset error of the current sensor and the length of the elapsed time.
9 . The display system according to claim 4 , wherein
the processor is configured to cause the display device to display the screen prompting the user of the electrified vehicle to fully charge the power storage device upon determining that the elapsed time has exceeded the threshold time.