Method of monitoring state of charge and preventing discharge of 12v battery for automotive vehicles

Abstract

The present invention relates to a method for monitoring the status of a 12V battery of an automobile and preventing discharge, comprising: a step (S11) in which a VCU drives an IBS module in a sleep state; a step (S12) in which the IBS module waits for a first set time and determines whether the current flowing through the battery, I, Batt < 200mA; a step (S13) in which, if I, Batt < 200mA, the IBS module maintains a wake-up state; a step (S14) in which, if I, Batt < 200mA in step S12, the IBS module maintains a sleep state; a step (S15) in which, in step S13, the IBS module determines whether the SOC of the corresponding battery is < 91%; and a step (S16) in which, if SOC < 91%, the IBS module transmits a wake-up signal to the VCU to start the vehicle and drive an LDC to charge the battery. The method is characterized by including: a step (S17) of determining whether the current flowing through the battery, I, Batt < 200mA, during a second set time when SOC ≥ 91% in the above S15 step; a step (S18) of starting again from the above S13 step when I, Batt ≥ 200mA; a step (S19) of transitioning to the above S14 step when I, Batt < 200mA in the above S17 step; a step (S20) of determining whether the SOC of the battery in the above S14 step is in a sleep mode state when the IBS module is in a sleep mode state when SOC < 91%; a step (S21) of transmitting a wake-up signal to the VCU to start the vehicle and drive the LDC to charge the battery when SOC < 91%; and a step (S22) of terminating when SOC ≥ 91% in the above S20 step.

Description

Technology Field

[0001] The present invention relates to a method for monitoring the condition of a 12V battery in an automobile and preventing discharge, and more specifically, to a method for monitoring the condition of a 12V battery used in an automobile in real time and simultaneously preventing discharge in advance so as not to impede the operation of the automobile. Background Technology

[0002] Prior art related to the present invention is disclosed in Korean Registered Patent No. 1755894 (July 19, 2017).

[0003] A conventional vehicle battery over-discharge prevention device is configured to include a battery (100), a voltage sensor (110), a relay (120), a current sensor (130), an engine room junction box (140), a power status detector (150), a switch (160), and a controller (170), as shown in FIG. 1.

[0004] The above battery (100) is configured, for example, as a 12V lithium-ion battery (low-voltage auxiliary battery) to supply power required by the electrical load of the vehicle.

[0005] The above voltage sensor (110) detects the voltage of the battery (100).

[0006] The above relay (120) can supply or cut off power from the battery (100) to the electrical load to prevent over-discharge of the battery (100), and can also completely cut off the battery (100) from the dark current flowing to the electrical load.

[0007] The above current sensor (130) is located between the relay (120) and the engine room connector (140) to detect the current of the battery (100).

[0008] The above engine room connector (140) includes a line for branching the power of the battery (100) to each electrical load and supplies operating power to the power status detector (150).

[0009] The above power status detector (150) detects the state in which the power of the battery (100) is supplied to the electrical load.

[0010] The above switch (160) is operated by user operation to turn on the relay (120).

[0011] That is, in order to prevent over-discharge of the battery (100), when the controller (170) turns off the relay (120) and the driver gets into the vehicle and turns on the switch (160), the relay (120) turns on and power from the battery (100) is supplied to the electrical load.

[0012] The above controller (170) performs overall control so that each of the above components can perform their respective functions normally.

[0013] In addition, the controller (170) turns off the relay (120) using an internal switch (171) to prevent over-discharge of the battery (100) that supplies power to the electrical load of the vehicle.

[0014] That is, as a relay off preparation stage, when the voltage of the battery (100) reaches a first threshold while the ignition is on, the controller (170) outputs a warning message through the cluster to induce the driver to start the engine.

[0015] Subsequently, as a relay off step, when the voltage of the battery (100) becomes a second threshold (a value smaller than the first threshold) because the vehicle is not started by the driver, the controller (170) transmits a termination command to the vehicle's ECU (Electronic Control Unit) through the vehicle network and then turns off the relay (120).

[0016] At this time, the controller (170) may turn off the relay (120) after receiving a completion message from each ECU in the vehicle, or may turn off the relay (120) when the ECU is not operating by monitoring the output of the ECU through the vehicle network, or may turn off the relay (120) after a predetermined time has elapsed after sending a termination command to each ECU in the vehicle.

[0017] Afterward, when the driver turns on the relay using the switch (160) and the ignition is turned on, the controller (170) outputs a warning message through the cluster and performs a post-processing process of turning off the relay (120) again if the vehicle does not start within the critical time.

[0018] Meanwhile, general automobiles use a 12V battery as a power supply for control devices, and this 12V battery is also used as a power source for powering a dashcam while parked.

[0019] In addition, battery performance deteriorates and the discharge rate increases during the winter, so it is necessary to start the engine periodically if the vehicle is not driven for a long time.

[0020] To solve this problem, there is a function that calculates the State of Charge (SOC) of the 12V battery and automatically starts the engine to charge the 12V battery when it reaches a certain value or lower.

[0021] That is, in the case of internal combustion engine vehicles, the alternator is operated by measuring the above SOC, and in the case of electric vehicles, the battery is charged by operating the LDC (Low Voltage DC-DC Converter) independently via communication. This prevents the discharge of the 12V battery.

[0022] And the IBS (Intelligent Battery Sensor) developed by the applicant is connected to the (-) terminal of the battery to measure the state of the 12V battery and transmit it to the VCU (Vehicle Control Unit).

[0023] In addition, when the vehicle is in a sleep state (vehicle not started, IGN Off), if the SOC calculated by the Kalman Filter logic drops below a specific value, the IBS sends a specific wake-up signal to the VCU via the LIN communication line to indicate that the 12V battery is discharged.

[0024] Then, the above VCU recognizes the wake-up signal and drives the vehicle's LDC to charge the 12V battery.

[0025] Figure 2 shows a configuration diagram of a 12V battery status monitoring and charging system according to the prior art.

[0026] The prior art illustrated in FIG. 2 is equipped with an auto-charging function that calculates the State of Charge (SOC) of a 12V battery and, when it reaches a specific value or lower, starts the engine to charge the 12V battery.

[0027] Figure 3 shows the flowchart for SOC calculation using the Kalman Filter algorithm.

[0028] However, the aforementioned conventional technology has a problem in that it reduces the vehicle's functionality when parked because it cuts off the load on the battery when the battery state voltage drops.

[0029] In addition, if the number of electronic controllers in the vehicle increases and a situation arises where dark current (0.05mA or more) is not recognized during the vehicle's sleep state, it becomes difficult for the IBS to apply the logic of Fig. 3 and transmit the accurate SOC to the VCU.

[0030] The SOC calculation using the above Kalman Filter algorithm is guaranteed to have a dark current of 0.05mA or less.

[0031] As a result, there is a problem in that the wake-up function does not perform properly, making it difficult to avoid a situation where the vehicle's battery runs out.

[0032] In addition, conventional technology has a problem in that the IBS fails to calculate the guaranteed SOC value based on vehicle conditions (dark current, battery condition), or fails to satisfy the consistency of the initial SOC value if the battery stabilization time is not satisfied.

[0033] In addition, if an SOC stuck phenomenon occurs in a conventional vehicle equipped with an IBS, it continuously sends a wake-up signal even though the battery is fully charged.

[0034] This results in the problem that the vehicle is unnecessarily started to operate the LDC, consuming the high-voltage battery and making it impossible to avoid a loss of the high-voltage battery's charging capacity. The problem to be solved

[0035] The present invention is proposed to solve the problems of the aforementioned prior art, and its purpose is to enable the IBS to transmit an accurate SOC to the VCU.

[0036] Another objective of the present invention is to prevent the vehicle from discharging by ensuring that the wake-up function operates normally.

[0037] Another objective of the present invention is to solve the problem of reducing the vehicle's functionality when parked by cutting off the load on the battery when the battery state voltage drops. means of solving the problem

[0038] To achieve the above objective, the 12V battery status monitoring and discharge prevention method according to the present invention comprises: a step (S11) in which a Vehicle Control Unit (VCU) drives an Intelligent Battery Sensor Module (IBS) in a sleep state; a step (S12) in which the IBS module waits for a first set time and determines whether the current flowing through the battery, I, Batt < 200mA; a step (S13) in which, if I, Batt < 200mA, the IBS module maintains a wake-up state; a step (S14) in which, if I, Batt < 200mA in step S12, the IBS module maintains a sleep state; and a step (S15) in which, in step S13, the IBS module determines whether the SOC of the battery is < 91%. A step (S16) of transmitting a wake-up signal to the VCU to start the vehicle and drive the LDC to charge the battery when SOC < 91%; a step (S17) of determining whether the current flowing through the battery, I, and Batt < 200mA during a second set time when SOC ≥ 91% in step S15; a step (S18) of starting again from step S13 when I and Batt ≥ 200mA; a step (S19) of transitioning to step S14 when I and Batt < 200mA in step S17; a step (S20) in which the IBS module of step S14 determines whether the battery's SOC < 91% in a sleep mode state; and a step (S21) of transmitting a wake-up signal to the VCU to start the vehicle and drive the LDC to charge the battery when SOC < 91%. and is characterized by including a step (S22) of terminating when SOC ≥ 91% in the above S20 step.

[0039] In addition, the first setting time is 6 minutes and the second setting time is 30 seconds.

[0040] Additionally, in the sleep state, the IBS module, which calculates the accumulated current by Kalman Filter logic, determines whether the current flowing through the 12V battery in the wake-up state I,Batt > 200mA (S31); if I,Batt > 200mA, turns on the IBS module to sense the battery current, voltage, temperature, SOC (State of Charge), and SOH (State of Health) (S32); the IBS module determines whether the 12V battery voltage < 11.5V or SOC < 91% (S33); and if the 12V battery voltage < 11.5V or SOC < 91%, transmits an automatic charging start signal to the VCU to control the VCU to start the vehicle and drive the LDC to charge the battery (S34); The method is characterized by including the step (S35) of determining that the battery is fully charged and transmitting a control signal to the IBS module to turn it OFF when the IBS module determines that the change in SOC over 10 minutes is < 1%, the battery voltage is > 13V, and the SOC is < 98%; and the step (S36) of periodically waking up the IBS module to sense the voltage, current, temperature, SOC, and SOH of the 12V battery.

[0041] It is also characterized by preventing the battery's SOC from getting stuck.

[0042] And the 12V battery status monitoring and discharge prevention system calculates the accumulated current by Kalman filter logic, determines whether the current flowing through the 12V battery in the wake-up state is greater than 200mA, and if the current flowing through the battery is greater than 200mA, turns on to sense battery current, voltage, temperature, SOC, and SOH, determines whether the 12V battery voltage < 11.5V or SOC < 91%, and if the 12V battery voltage < 11.5V or SOC < 91%, transmits an automatic charging start signal to the VCU so that the VCU controls the vehicle start and LDC to drive to charge the battery, and if the SOC change over 10 minutes is < 1%, the corresponding battery voltage is > 13V, and SOC is < 98%, determines that the corresponding battery is fully charged, turns off the operation, and periodically wakes up to sense the voltage, current, temperature, SOC, and SOH of the corresponding 12V battery; an IBS module; It is characterized by including a 12V battery that supplies power to the vehicle; and a VCU that receives a control signal from the IBS module and controls the vehicle start and LDC to charge the 12V battery.

[0043] In addition, after the battery is fully charged and the operation is turned off, the IBS module is characterized by waking up every 3 minutes. Effects of the invention

[0044] According to the present invention, even when various vehicle control devices are installed in the vehicle or the controller operates while parked and the battery discharge is easy, the battery status is monitored in real time, and when the battery voltage drops below a preset voltage, the battery is automatically charged, thereby preventing the battery from being discharged.

[0045] In addition, it has the effect of preventing the 12V battery from discharging in situations where the SOC is not stabilized initially after the battery is installed and dark current is flowing.

[0046] In addition, by monitoring and controlling the battery's SOC change amount, battery voltage during LDC operation, and current SOC status, it is possible to prevent the battery's SOC from getting stuck.

[0047] In addition, in the event of an SOC stuck in a vehicle equipped with an IBS module, it is effective in preventing the high-voltage battery from being consumed by continuously sending a wake-up signal to start the vehicle and drive the LDC, even though the battery is fully charged.

[0048] In addition, when the dark current is not stabilized, it has the effect of determining the SOC to be close to an approximation in sleep mode so that the automatic charging function can be performed normally.

[0049] In addition, the estimated SOC value can be used regardless of whether the vehicle is started, and it has the effect of obtaining valid data within a short period of time without the need for battery SOC value stabilization time.

[0050] In addition, since the SOC value is tracked and controlled using current, voltage, and temperature data collected by the IBS to reduce the influence from the vehicle environment, it is effective in overcoming the uncertainty when sending a wake-up signal by tracking the SOC via the Kalman filter algorithm. Brief explanation of the drawing

[0051] FIG. 1 is a configuration diagram of an over-discharge prevention device for a vehicle battery according to the prior art, FIG. 2 is a configuration diagram of a 12V battery status monitoring and charging system according to the prior art, FIG. 3 is a flowchart of SOC calculation by the Kalman Filter algorithm applied to the prior art, FIG. 4 is a control flowchart of a 12V battery status monitoring and discharge prevention method according to the present invention, FIG. 5 is a control flowchart of a 12V battery status monitoring and discharge prevention method according to the present invention, FIG. 6 is a configuration diagram of a 12V battery status monitoring and discharge prevention system according to the present invention. FIG. 7 is a diagram showing a state in which the SOC of a battery does not change for 10 minutes in the monitoring method according to the present invention. FIG. 8 is a diagram showing the state where the SOC of the battery is 100% in the monitoring method according to the present invention. Specific details for implementing the invention

[0052] A preferred embodiment of the 12V battery status monitoring and discharge prevention method according to the present invention will be described in detail below with reference to the attached drawings.

[0053] FIG. 4 shows a control flowchart of a 12V battery status monitoring and discharge prevention method according to the present invention.

[0054] In FIG. 4, the 12V battery status monitoring and discharge prevention method comprises: a step (S11) in which the VCU drives the IBS module in a sleep state; a step (S12) in which the IBS module waits for a first set time (6 minutes) and determines whether the current flowing through the battery, I, Batt < 200mA; a step (S13) in which the IBS module maintains a wake-up state if I, Batt < 200mA is not true; a step (S14) in which the IBS module maintains a sleep state if I, Batt < 200mA is true in step S12; a step (S15) in which the IBS module determines whether the SOC of the corresponding battery is < 91% in step S13; a step (S16) in which, if SOC < 91%, the IBS module transmits a wake-up signal to the VCU to start the battery and drive the LDC to charge the battery; and in which, if SOC ≥ 91% is true in step S15, the corresponding The method comprises a step (S17) of determining whether the current flowing through the battery, I, Batt < 200mA, a step (S18) of starting again from step S13 if I, Batt ≥ 200mA, a step (S19) of transitioning to step S14 if I, Batt < 200mA in step S17, a step (S20) of determining whether the SOC of the battery is < 91% in the sleep mode state of the IBS module in step S14, a step (S21) of transmitting a wake-up signal to the VCU to start and drive the LDC to charge the battery if SOC < 91%, and a step (S22) of terminating if SOC ≥ 91% in step S20.

[0055] FIG. 5 shows another control flowchart of the 12V battery status monitoring and discharge prevention method according to the present invention.

[0056] In FIG. 5, the 12V battery status monitoring and discharge prevention method comprises: a step (S31) in which an IBS module, which calculates an integrated current by Kalman filter logic in a sleep state, determines whether the current flowing through the 12V battery in the wake-up state I,Batt > 200mA; a step (S32) in which, if I,Batt > 200mA, the IBS module is turned on to sense the battery current, voltage, temperature, SOC (State of Charge), and SOH (State of Health); a step (S33) in which the IBS module determines whether the 12V battery voltage < 11.5V or SOC < 91%; a step (S34) in which, if the 12V battery voltage < 11.5V or SOC < 91%, an automatic charging start signal is transmitted to the VCU to control the VCU to start and drive the LDC to charge the battery; and a step in which the IBS module determines that the SOC change over 10 minutes is < 1% and the corresponding battery voltage > 13V The method comprises the step (S35) of determining that the battery is fully charged when SOC < 98% and transmitting a control signal to the IBS module to turn it OFF, and the step (S36) of waking up the IBS module periodically (every 3 minutes) to sense the voltage, current, temperature, SOC, and SOH of the 12V battery.

[0057] FIG. 6 shows a configuration diagram of a 12V battery status monitoring and discharge prevention system according to the present invention.

[0058] In Fig. 6, the 12V battery status monitoring and discharge prevention system calculates the accumulated current using Kalman filter logic. It determines whether the current flowing through the 12V battery in the wake-up state is greater than 200mA. If the current flowing through the battery is greater than 200mA, it turns on to sense the battery current, voltage, temperature, SOC, and SOH. It then determines whether the 12V battery voltage < 11.5V or SOC < 91%. If the 12V battery voltage < 11.5V or SOC < 91%, it transmits an automatic charging start signal to the VCU, which controls the VCU to drive the vehicle ignition and LDC to charge the battery. If the SOC change over 10 minutes is < 1%, the corresponding battery voltage is > 13V, and SOC < 98%, it determines that the battery is fully charged and turns off the operation. It is periodically woken up (every 3 minutes) to monitor the voltage, current, temperature, and It is configured to include an IBS module (100) for sensing SOC and SOH, a 12V battery (200) for supplying power to a vehicle, and a VCU (300) that receives a control signal from the IBS module and controls the vehicle start and LDC to charge the 12V battery.

[0059] FIG. 7 shows a state in which the SOC of the battery does not change for 10 minutes in the battery monitoring and discharge prevention method according to the present invention.

[0060] As shown in Fig. 7, if there is no change in SOC for 10 minutes, it can be determined that charging is complete.

[0061] FIG. 8 shows a state in which the SOC of the battery is 100% in the battery monitoring and discharge prevention method according to the present invention.

[0062] That is, Fig. 8 shows that the battery can be charged to 100% by sensing the battery status and driving the vehicle start and LDC.

[0063] According to the present invention, the condition for sending a wake-up signal includes cases where the voltage of the battery becomes 11.5V or lower in a state where not only the SOC but also the LDC is not in operation.

[0064] This allows the battery to send a wake-up signal even when the voltage level drops abnormally.

[0065] In addition, the present invention monitors both current and voltage, rather than determining only the current value as in the prior art.

[0066] By judging only the current value, the problem of the 12V battery discharging due to the SOC measurement value by Kalman filter logic being distorted and not sending a wake-up signal in situations where the SOC is not stabilized initially after battery installation and dark current is flowing can be solved.

[0067] In addition, when the battery consumption current is 200mA or more, the present invention calculates the SOC by current integration rather than by calculation by Kalman filter logic.

[0068] Generally, the IBS enters sleep mode 6 minutes after the vehicle engine is turned off, and wakes up every 3 minutes to estimate the SOC by applying Kalman filter logic.

[0069] However, if the current is consumed at 0.05mA or more, it becomes impossible to calculate an effective SOC value using the Kalman filter logic described above.

[0070] To solve this problem, the present invention calculates the SOC by reflecting the current amount as is using a current integration formula, without the IBS entering sleep mode, if the current is consumed at a rate of 200mA or more even after the engine is turned off. This prevents the SOC value from becoming distorted.

[0071] In addition, the present invention determines that the 12V battery is fully charged when the SOC value does not change for 10 minutes during auto-charging, and resets the SOC to 98%.

[0072] If, in the sleep state, an error occurs between the calculated value and the actual SOC value due to dark current, and it is assumed that the actual value is 100% and the calculated value is 90%, the VCU determines that the SOC is 90% and drives the LDC, but at this time, since the battery is charged to 100%, there is no actual current flowing in.

[0073] Considering these points, the present invention incorporates a logic for adjusting the SOC based on SOC Stuck.

[0074] The foregoing describes preferred embodiments of the present invention by way of example, and the scope of the present invention is not limited to the specific embodiments described above.

[0075] A person skilled in the art will understand that various changes and modifications can be made without departing from the scope of the technical concept of the present invention. Explanation of the symbols

[0076] 100: IBS module (Intelligent Battery Sensor Module) 200 : 12V Battery 300: VCU (Vehicle Control Unit)

Claims

Claim 1 A method for monitoring the condition of a 12V battery used in a vehicle and preventing discharge in real time to prevent discharge so as not to impede vehicle operation, comprising: a step (S11) in which a VCU (Vehicle Control Unit) drives an IBS module (Intelligent Battery Sensor Module) in a sleep state; a step (S12) in which the IBS module waits for a first set time and determines whether the current flowing through the battery, I, Batt < 200mA; and a step (S13) in which, if I, Batt < 200mA, the IBS module maintains a wake-up state; In the above S12 step, if I, Batt < 200mA, a step (S14) in which the IBS module is maintained in a sleep state; in the above S13 step, a step (S15) in which the IBS module determines whether the SOC of the corresponding battery is < 91%; if SOC < 91%, a step (S16) in which a wake-up signal is transmitted to the VCU to start the vehicle and drive the LDC to charge the battery; in the above S15 step, if SOC ≥ 91%, a step (S17) in which the current flowing through the corresponding battery, I, Batt < 200mA, during a second set time is determined; if I, Batt ≥ 200mA, a step (S18) in which the process restarts from the above S13 step; if I, Batt < 200mA in the above S17 step, a step (S19) in which the process transitions to the above S14 step; and in the above S14 step, the IBS module determines whether the SOC of the corresponding battery is < 91% in a sleep mode state A method for monitoring the state of a 12V battery of an automobile and preventing discharge, characterized by comprising: a step of determining (S20); a step of transmitting a wake-up signal to the VCU to start the vehicle and drive the LDC to charge the battery when SOC < 91% (S21); and a step of terminating (S22) when SOC ≥ 91% in the step of S20. Claim 2 A method for monitoring the condition of a 12V battery of an automobile and preventing discharge, characterized in that, in claim 1, the first setting time is 6 minutes and the second setting time is 30 seconds. Claim 3 A method for monitoring the condition of a 12V battery used in a vehicle in real time and preventing discharge to ensure that there is no impediment to vehicle operation, wherein an IBS module that calculates an integrated current by Kalman Filter logic in a sleep state determines whether the current flowing through the 12V battery I,Batt > 200mA in a wake-up state (S31); if I,Batt > 200mA, turns on the IBS module to sense the battery current, voltage, temperature, SOC (State of Charge), and SOH (State of Health) (S32); if the IBS module determines whether the 12V battery voltage < 11.5V or SOC < 91% (S33); and if the 12V battery voltage < 11.5V or SOC < 91%, transmits an automatic charging start signal to the VCU so that the VCU controls the vehicle to start and drive the LDC to charge the battery. A method for monitoring the state of a 12V battery of an automobile and preventing discharge, characterized by comprising: a step (S34); a step (S35) in which, if the IBS module determines that the battery is fully charged and transmits a control signal to the IBS module to turn it OFF when the SOC change over 10 minutes is < 1%, the corresponding battery voltage is > 13V, and the SOC is < 98%; and a step (S36) in which the IBS module is periodically woken up to sense the voltage, current, temperature, SOC, and SOH of the corresponding 12V battery. Claim 4 A method for monitoring the state of a 12V battery of an automobile and preventing discharge, characterized in that, in claim 3, it prevents the battery from getting stuck in SOC. Claim 5 In a 12V battery status monitoring and discharge prevention system designed to monitor the status of a 12V battery used in a vehicle in real time and prevent discharge to ensure unimpeded vehicle operation, the system calculates the accumulated current using Kalman filter logic, determines whether the current flowing through the 12V battery in the wake-up state is greater than 200mA, and if the current flowing through the battery is greater than 200mA, turns on the system to sense battery current, voltage, temperature, SOC, and SOH, determines whether the 12V battery voltage < 11.5V or SOC < 91%, and if the 12V battery voltage < 11.5V or SOC < 91%, transmits an automatic charging start signal to the VCU so that the VCU controls the vehicle start and LDC to drive the LDC to charge the battery, and if the SOC change over 10 minutes is < 1%, the corresponding battery voltage is > 13V, and SOC is < 98%, it determines that the battery is fully charged, turns off the operation, and periodically wakes up to [ ] the corresponding A 12V battery status monitoring and discharge prevention system for a vehicle, characterized by comprising: an IBS module (100) for sensing the voltage, current, temperature, SOC, and SOH of a 12V battery; a 12V battery (200) for supplying power to a vehicle; and a VCU (300) for receiving a control signal from the IBS module and controlling the vehicle start and LDC to charge the 12V battery. Claim 6 A 12V battery status monitoring and discharge prevention system for a vehicle according to claim 5, characterized in that after the battery is fully charged and the drive is turned off, the IBS module (100) is woken up every 3 minutes.

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