Abnormality detection method for battery sensor

Abstract

Provided is an abnormality detection method for a battery sensor that prevents a normal battery sensor from being erroneously detected as abnormal when an external power source for charging is connected to a vehicle-mounted battery. An abnormality detection method for a battery sensor provided in a vehicle-mounted battery includes the steps of: acquiring a voltage of the vehicle-mounted battery after an ignition switch of the vehicle is turned off; determining whether the voltage of the vehicle-mounted battery exceeds an open-circuit voltage at a full charge state; determining whether the voltage of the vehicle-mounted battery rises after the ignition switch is turned off; and performing diagnosis of the battery sensor in a case where the voltage of the vehicle-mounted battery is below the open-circuit voltage and the voltage of the vehicle-mounted battery does not rise after the ignition switch is turned off, and not performing diagnosis of the battery sensor in other cases.

Description

Technical Field

[0001] This invention relates to a method for detecting anomalies in a battery sensor installed in an auxiliary battery of a vehicle. Background Technology

[0002] Patent document 1 discloses a fault diagnosis device that determines whether the battery sensor (current sensor) is abnormal based on the voltage and current of the vehicle battery when the vehicle engine is running.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2007-024824 Summary of the Invention The determination method described in Patent Document 1 above is based on the following logic: when the engine is not rotating (power off), if the battery sensor detects charging current, it is determined that the battery sensor is abnormal. Therefore, when the determination described in Patent Document 1 is performed when an external power source for charging is connected to the vehicle battery, there is a problem that a normal battery sensor may be mistakenly detected as abnormal.

[0004] The present invention was made in view of the above-mentioned problems, and its object is to provide an anomaly detection method for a battery sensor that can prevent a normal battery sensor from being mistakenly detected as abnormal when an external power source for charging is connected to the vehicle battery.

[0005] To address the aforementioned issues, one aspect of the present invention is a method for detecting anomalies in a battery sensor installed in a vehicle battery, comprising the following steps: acquiring the voltage of the vehicle battery after the vehicle's ignition switch is turned off; determining whether the voltage of the vehicle battery exceeds the open-circuit voltage under full charge conditions; determining whether the voltage of the vehicle battery rises after the ignition switch is turned off; and performing battery sensor diagnosis if the voltage of the vehicle battery is below the open-circuit voltage and the voltage of the vehicle battery does not rise after the ignition switch is turned off, and not performing battery sensor diagnosis in other cases.

[0006] Invention Effects According to the abnormal detection method for the battery sensor of the present invention described above, diagnostic control of the battery sensor is not performed when the voltage of the vehicle battery exceeds the open-circuit voltage or rises after the ignition switch is turned off. This prevents a normal battery sensor from being mistakenly detected as abnormal when an external power source for charging is connected to the vehicle battery. Attached Figure Description

[0007] Figure 1 This is a schematic structural diagram of the control device and its peripheral parts for implementing an abnormality detection method for a battery sensor according to an embodiment of the present invention.

[0008] Figure 2This is a flowchart of the abnormal detection and control process of the battery sensor executed by the control device. Detailed Implementation

[0009] In the abnormal detection method of the battery sensor of the present invention, in the control that determines normal / abnormal status from the current value of the battery sensor when IG-OFF using information about the battery voltage, no abnormality determination is made when the battery voltage is higher than the open-circuit voltage at full charge or when the battery voltage rises. This prevents false abnormality determinations when an external power supply is connected.

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011] <Implementation Method> [structure] Figure 1 This is a schematic diagram showing the control device 150 and its surrounding parts according to an embodiment of the present invention for performing an anomaly detection method for a battery sensor. Figure 1 The illustrated structure includes a power supply 110, an auxiliary battery 120, a battery sensor 121, an auxiliary load 130, an external power supply 140, and a control device 150. Figure 1 In the diagram, solid lines represent power lines for transmitting and receiving electricity, while dashed lines represent signal lines for control indications or detection values.

[0012] The power supply 110, auxiliary battery 120, battery sensor 121, auxiliary load 130, and control device 150 are, for example, installed in vehicles such as internal combustion engine vehicles (conventional vehicles) powered by an engine and hybrid electric vehicles (HEV vehicles) powered by an electric motor.

[0013] The power supply source 110 is a structure for supplying power to the auxiliary battery 120 or auxiliary load 130, etc. This power supply source 110 includes some or all of the following: an engine 111, an alternator 112, a high-voltage battery 113, and a DC-DC converter 114. For example, in the case of an internal combustion engine vehicle, the power supply source 110 includes the engine 111 and the alternator 112. Furthermore, in the case of a hybrid vehicle, the power supply source 110 includes at least the high-voltage battery 113 and the DC-DC converter 114.

[0014] Engine 111 is an internal combustion engine that generates rotational force by burning fuel and converts it into vehicle power. Alternator 112 is a generator capable of generating electricity based on the rotation of engine 111. When alternator 112 generates electricity, it supplies charging current to auxiliary battery 120, thereby charging auxiliary battery 120.

[0015] The high-voltage battery 113 is a rechargeable secondary battery, such as a lithium-ion battery. This high-voltage battery 113 supplies power to drive an electric motor (not shown) or auxiliary load 130, which is related to vehicle operation. The DC-DC converter 114 is a power converter that converts the power from the high-voltage battery 113 into a voltage for the auxiliary battery 120 and the auxiliary load 130, and outputs it. When the DC-DC converter 114 is activated, a charging current is supplied to the auxiliary battery 120, thereby enabling the auxiliary battery 120 to be charged.

[0016] The auxiliary battery 120 is a rechargeable secondary battery, such as a lithium-ion battery. This auxiliary battery 120 can supply power to drive the auxiliary load 130.

[0017] The battery sensor 121 is a structure used to detect the output voltage and inflow / outflow current of the auxiliary battery 120 as physical quantities of the auxiliary battery 120. This battery sensor 121 uses detection devices such as voltage sensors or current sensors. The voltage and current values ​​of the auxiliary battery 120 detected by the battery sensor 121 are output to the control device 150.

[0018] The auxiliary load 130 is an electrical device or equipment unrelated to the vehicle's operation. The auxiliary load 130 is configured to operate using power from the power supply source 110 and the auxiliary battery 120.

[0019] The external power source 140 is a charger or charging device for charging the auxiliary battery 120. The external power source 140 is connected to the vehicle (auxiliary battery 120) when it is necessary to charge the auxiliary battery 120.

[0020] The control device 150 is structured to perform diagnostic control of the battery sensor 121 based on the vehicle's status and to detect abnormalities in the battery sensor 121. The control device 150 includes an acquisition unit 151, a determination unit 152, and a control unit 153.

[0021] The acquisition unit 151 acquires the voltage and current of the auxiliary battery 120 from the battery sensor 121. Furthermore, the acquisition unit 151 acquires information indicating the state of the vehicle's ignition switch (IG information), the engine speed 111, and the operating state of the DC-DC converter 114. When the vehicle's ignition switch is off (IG-OFF), the determination unit 152 performs a predetermined determination process using the voltage of the auxiliary battery 120 acquired by the acquisition unit 151. This determination process will be described later. Based on the result of the determination process performed by the determination unit 152, the control unit 153 determines whether the diagnostic control of the battery sensor 121 is feasible.

[0022] Furthermore, part or all of the aforementioned control device 150 may typically be composed of an electronic control unit (ECU) including a processor such as a microcontroller (MCU), a memory, and input / output interfaces. This ECU reads and executes programs stored in the memory by the processor, and is able to perform some or all of the functions performed by the acquisition unit 151, the determination unit 152, and the control unit 153.

[0023] [control] Next, refer to Figure 2 An abnormality detection method for a battery sensor according to one embodiment of the present invention will be described. Figure 2 This is a flowchart illustrating the processing sequence of the abnormal detection control of the battery sensor 121 performed by each structure of the control device 150. Figure 2 The abnormality detection control of the battery sensor 121 illustrated in the figure begins, for example, when the vehicle's ignition switch is turned off (IG-OFF).

[0024] (Step S201) The determination unit 152 determines whether the auxiliary battery 120 is not receiving charging current from the power supply source 110. This determination can be made based on the engine speed 111 or the drive status of the DC-DC converter 114 obtained by the acquisition unit 151.

[0025] For example, in the case of an internal combustion engine vehicle, it is determined that the engine 111 speed is zero and the alternator 112 is not generating electricity (no charging current), or the engine 111 speed is not zero and the alternator 112 is generating electricity (with charging current). Furthermore, for example, in the case of a hybrid electric vehicle (HEV), it is determined that the DC-DC converter 114 is in an operating driving state (with charging current) or the DC-DC converter 114 is in an inactive stopped state (without charging current).

[0026] If the determination unit 152 determines that no charging current is supplied from the power supply source 110 to the auxiliary battery 120 (step S201, yes), the process proceeds to step S202.

[0027] On the other hand, if the determination unit 152 determines that the state is that charging current is supplied from the power supply source 110 to the auxiliary battery 120 (step S201, no), it waits until the supply of charging current stops.

[0028] (Step S202) The determination unit 152 determines whether the voltage (battery voltage) of the auxiliary battery 120 acquired by the acquisition unit 151 is less than a predetermined threshold. This determination is performed when the auxiliary battery 120 is in a fully charged state to confirm whether the battery voltage has increased due to the charging current from the power supply source 110 to the auxiliary battery 120. Therefore, the predetermined threshold is set to a constant value (e.g., 13V) higher than the open-circuit voltage OCV (e.g., 12.8V) of the auxiliary battery 120 in the fully charged state.

[0029] If the determination unit 152 determines that the battery voltage is less than the threshold (step S202, yes), the process proceeds to step S203.

[0030] On the other hand, if the determination unit 152 determines that the battery voltage exceeds the threshold (step S202, No), since the connection of the external power supply 140 is suspected, the abnormal detection control of the battery sensor 121 is terminated without performing the battery sensor diagnosis described later. Therefore, it is possible to prevent the normal battery sensor 121 from being mistakenly detected as abnormal when the external power supply 140 is connected to the auxiliary battery 120.

[0031] (Step S203) The determination unit 152 determines whether the voltage (battery voltage) of the auxiliary battery 120 acquired by the acquisition unit 151 has increased. This determination is performed when the auxiliary battery 120 is not fully charged in order to confirm whether the battery voltage has increased due to the charging current from the power supply source 110 to the auxiliary battery 120. Therefore, this determination is performed by checking whether the value ΔV (=V1-V2) of the difference between the battery voltage V1 immediately after the vehicle's ignition switch is turned off and the battery voltage V2 after a predetermined time has elapsed since the ignition switch was turned off is zero or higher. In addition, the predetermined time is preferably set to a sufficient time to detect changes in battery voltage.

[0032] If the determination unit 152 determines that the battery voltage has not increased (ΔV≥0) after a specified time (step S203, Yes), the process proceeds to step S204.

[0033] On the other hand, if the determination unit 152 determines that the battery voltage rises (ΔV < 0) after a predetermined time (step S203, No), the abnormal detection control of the battery sensor 121 is terminated without performing the battery sensor diagnosis described later, due to suspicion of an external power supply 140 connection. This prevents the normal battery sensor 121 from being mistakenly detected as abnormal when an external power supply 140 is connected to the auxiliary battery 120.

[0034] In the following steps S204 to S206, the control unit 153 performs battery sensor diagnosis.

[0035] (Step S204) The control unit 153 determines whether the current (battery current) of the auxiliary battery 120 acquired by the acquisition unit 151 exceeds zero. This determination is made to confirm, through the battery voltage, that no charging current was supplied to the auxiliary battery 120 from the power supply source 110 in the aforementioned steps S203 and S204, but also through the battery current, that no charging current was supplied. Furthermore, the battery current is set to a positive (+) value for the charging side and a negative (-) value for the discharging side.

[0036] If the control unit 153 determines that the battery current I exceeds zero (I>0; positive sign) (step S204, yes), the process proceeds to step S205.

[0037] On the other hand, if the control unit 153 determines that the battery current I does not exceed zero (I≤0; negative sign) (step S204, no), the process proceeds to step S206.

[0038] (Step S205) The control unit 153 determines that the battery current detection circuit (current sensor, etc.) in the battery sensor 121 is abnormal.

[0039] If the control unit 153 determines that the battery sensor 121 is abnormal, the abnormal detection control of the battery sensor 121 will be terminated.

[0040] (Step S206) The control unit 153 determines that the battery current detection circuit (current sensor, etc.) in the battery sensor 121 is normal.

[0041] If the control unit 153 determines that the battery sensor 121 is normal, the abnormal detection control of the battery sensor 121 will end.

[0042] <Function / Effect> As described above, according to an embodiment of the present invention, the abnormal detection method for the battery sensor 121 is such that even after the vehicle's ignition switch is turned off, the engine 111 stops and the alternator 112 does not generate electricity, or the DC-DC converter 114 is not driven and does not output power, if either the condition that the voltage of the auxiliary battery 120 exceeds the open circuit voltage (OCV) in the fully charged state or the condition that a voltage rise in the auxiliary battery 120 is observed is met, the diagnostic control of the battery sensor 121 is not implemented because the external power supply 140 may be connected to the auxiliary battery 120.

[0043] This control prevents misjudgments of abnormal detections based on the current value of the battery sensor 121, even when the auxiliary battery 120 is connected to an external power source 140 during vehicle repairs or inspections at a dealership.

[0044] Furthermore, the abnormality detection method of the battery sensor 121 involved in this embodiment can realize the existing system by changing the software control specifications without making hardware changes.

[0045] The above describes one embodiment of the present invention. However, the present invention can be understood not only as a method for detecting abnormalities in battery sensors, but also as a program for executing the method, a computer-readable non-transitory storage medium storing the program, a control device for executing the method, and a vehicle equipped with the control device.

[0046] The abnormality detection method for the battery sensor of the present invention can be used in vehicles and the like, which are sometimes connected to an external power source for charging the vehicle battery.

[0047] Symbol Explanation 110 - Power supply source, 111 - Engine, 112 - Alternator, 113 - High voltage battery, 114 - DC-DC converter, 120 - Auxiliary battery, 121 - Battery sensor, 130 - Auxiliary load, 140 - External power supply, 150 - Control device, 151 - Acquisition unit, 152 - Judgment unit, 153 - Control unit.

Claims

1. A method for detecting anomalies in a battery sensor, specifically a method for detecting anomalies in a battery sensor installed in a vehicle battery, characterized in that... Includes the following steps: The voltage of the vehicle battery is obtained after the vehicle's ignition switch is turned off; Determine whether the voltage of the vehicle battery exceeds the open-circuit voltage when fully charged; Determine whether the voltage of the vehicle battery rises after the ignition switch is turned off; and Diagnostic control of the battery sensor is implemented when the voltage of the vehicle battery is below the open circuit voltage and the voltage of the vehicle battery does not rise after the ignition switch is turned off; otherwise, diagnostic control of the battery sensor is not implemented.

2. The abnormality detection method for a battery sensor according to claim 1, characterized in that, The acquisition step involves acquiring the voltage of the vehicle battery while the engine speed is zero.

3. The abnormality detection method for a battery sensor according to claim 1, characterized in that, The acquisition step acquires the voltage of the vehicle battery when the operation of the DC-DC converter connected to the vehicle battery is stopped.

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