Battery sensor anomaly detection method

Abstract

This invention provides a battery sensor abnormality detection method that prevents a normal battery sensor from being mistakenly detected as abnormal when an external power supply for charging is connected to the vehicle battery. [Solution] A method for detecting an abnormality in a battery sensor provided in an on-board battery, comprising the steps of: acquiring the voltage of the on-board battery after the vehicle ignition is turned off; determining whether the voltage of the on-board battery exceeds the open-circuit voltage when fully charged; determining whether the voltage of the on-board battery has risen after the ignition is turned off; and, if the voltage of the on-board battery is less than or equal to the open-circuit voltage and the voltage of the on-board battery has not risen after the ignition is turned off, performing a diagnosis of the battery sensor, and not performing a diagnosis of the battery sensor otherwise.

Description

Technical Field

[0001] The present disclosure relates to a method for detecting an abnormality in a battery sensor provided in an auxiliary battery mounted on a vehicle.

Background Art

[0002] Patent Document 1 discloses a failure diagnosis device that determines the presence or absence of an abnormality in a battery sensor (current sensor) based on the voltage and current of an in-vehicle battery when the engine of the vehicle is rotating.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The determination method described in Patent Document 1 is a logic that determines that the battery sensor is abnormal when the battery sensor detects a charging current when the engine is not rotating (when the power is off). Therefore, when the determination described in Patent Document 1 is performed when an external power source for charging is connected to the in-vehicle battery, there is a problem that a normal battery sensor is erroneously detected as abnormal.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a method for detecting an abnormality in a battery sensor that can prevent a normal battery sensor from being erroneously detected as abnormal when an external power source for charging is connected to the in-vehicle battery.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the disclosed technology is a method for detecting an abnormality in a battery sensor provided in an on-board battery, comprising the steps of: acquiring the voltage of the on-board battery after the vehicle ignition is turned off; determining whether the voltage of the on-board battery exceeds the open-circuit voltage when fully charged; determining whether the voltage of the on-board battery has risen after the ignition is turned off; and, if the voltage of the on-board battery is less than or equal to the open-circuit voltage and the voltage of the on-board battery has not risen after the ignition is turned off, performing a diagnosis of the battery sensor, and not performing a diagnosis of the battery sensor otherwise. [Effects of the Invention]

[0007] According to the battery sensor abnormality detection method described above, if the voltage of the vehicle battery exceeds the open-circuit voltage or rises after the ignition is turned off, diagnostic control of the battery sensor is not performed. This prevents a normal battery sensor from being mistakenly detected as abnormal when an external power supply for charging is connected to the vehicle battery. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram of a control device and its peripheral components that execute a battery sensor abnormality detection method according to one embodiment of the present disclosure. [Figure 2] Flowchart of the process for detecting anomalies in the battery sensor, executed by the control unit. [Modes for carrying out the invention]

[0009] The battery sensor abnormality detection method disclosed herein uses battery voltage information to determine normal / abnormal from the current value of the battery sensor when the IG is OFF. In this control, abnormality detection is not performed if the battery voltage is higher than the open-circuit voltage when fully charged or if the battery voltage is rising. This prevents false abnormality detection when an external power supply is connected. The embodiments of this disclosure will be described in detail below with reference to the drawings.

[0010] <Embodiment> [composition] Figure 1 is a diagram showing the schematic configuration of a control device 150 and its surrounding parts that perform a battery sensor abnormality detection method according to one embodiment of the present disclosure. The configuration illustrated in Figure 1 includes a power supply source 110, an auxiliary battery 120, a battery sensor 121, an auxiliary load 130, an external power supply 140, and a control device 150. In Figure 1, power lines through which power is exchanged are shown as solid lines, and signal lines through which control instructions, detected values, etc., are exchanged are shown as dashed lines.

[0011] This power supply source 110, auxiliary battery 120, battery sensor 121, auxiliary load 130, and control device 150 are installed in vehicles such as internal combustion engine vehicles (convection vehicles) powered by an engine, or hybrid electric vehicles (HEV vehicles) powered by an electric motor.

[0012] The power supply source 110 is configured to supply power to an auxiliary battery 120, an auxiliary load 130, and the like. This power supply source 110 comprises some or all of 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 comprises an engine 111 and an alternator 112. In the case of a hybrid vehicle, the power supply source 110 comprises at least a high-voltage battery 113 and a DC-DC converter 114.

[0013] Engine 111 is an internal combustion engine that converts the rotational force generated by burning fuel into vehicle power. Alternator 112 is a generator that can generate electricity in accordance with the rotation of engine 111. When alternator 112 generates electricity, a charging current is supplied to auxiliary battery 120, allowing the auxiliary battery 120 to be charged.

[0014] 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) and an auxiliary load 130 involved in the vehicle's operation. The DC-DC converter 114 is a power converter that converts the power from the high-voltage battery 113 into a voltage that can be output to the auxiliary battery 120 and the auxiliary load 130. When the DC-DC converter 114 is driven, a charging current is supplied to the auxiliary battery 120, allowing the auxiliary battery 120 to be charged.

[0015] 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.

[0016] The battery sensor 121 is configured to detect the output voltage and inflow / outflow current of the auxiliary battery 120 as physical quantities of the auxiliary battery 120. Detection devices such as a voltage sensor and a current sensor are used in this battery sensor 121. The voltage and current values ​​of the auxiliary battery 120 detected by the battery sensor 121 are output to the control device 150.

[0017] The auxiliary load 130 consists of electrical equipment and devices that are not involved in the vehicle's operation. This auxiliary load 130 is configured to operate using power from the power supply source 110 and the auxiliary battery 120.

[0018] The external power supply 140 is a charger or charging equipment for charging the auxiliary battery 120. This external power supply 140 is connected to the vehicle (auxiliary battery 120) when charging of the auxiliary battery 120 is required.

[0019] The control device 150 is configured to perform diagnostic control of the battery sensor 121 based on the vehicle's status and to detect abnormalities in the battery sensor 121. This control device 150 comprises an acquisition unit 151, a determination unit 152, and a control unit 153.

[0020] The acquisition unit 151 acquires the voltage and current of the auxiliary battery 120 from the battery sensor 121. Further, the acquisition unit 151 acquires information indicating the ignition state of the vehicle (IG information), the rotational speed of the engine 111, and the driving state of the DCDC converter 114. The determination unit 152 performs a predetermined determination process using the voltage of the auxiliary battery 120 acquired by the acquisition unit 151 when the vehicle is in the ignition-off (IG-OFF) state. This determination process will be described later. The control unit 153 determines whether or not to perform the diagnostic control of the battery sensor 121 based on the result of the determination process performed by the determination unit 152.

[0021] Note that part or all of the above-described control device 150 can typically be configured by an electronic control unit (ECU) including a processor such as a microcomputer, a memory, and an input / output interface. By the processor reading and executing a program stored in the memory, part or all of the functions performed by the above-described acquisition unit 151, determination unit 152, and control unit 153 can be realized.

[0022] [Control] Next, referring further to FIG. 2, an abnormal detection method for a battery sensor according to an embodiment of the present disclosure will be described. FIG. 2 is a flowchart for explaining the processing procedure of the abnormal detection control of the battery sensor 121 executed by each component of the control device 150. The abnormal detection control of the battery sensor 121 illustrated in FIG. 2 is started, for example, when the ignition of the vehicle is in the off state (IG-OFF).

[0023] (Step S201) The determination unit 152 determines whether or not a charging current is being supplied from the power supply source 110 to the auxiliary battery 120. This determination can be made as follows based on the rotational speed of the engine 111 or the driving state of the DCDC converter 114 acquired by the acquisition unit 151.

[0024] For example, if the vehicle is an internal combustion engine vehicle, it is determined whether the engine 111 is rotating at zero and the alternator 112 is not generating power (no charging current), or whether the engine 111 is rotating at zero and the alternator 112 is generating power (charging current present). Also, for example, if the vehicle is a hybrid electric vehicle (HEV), it is determined whether the DCDC converter 114 is operating and the vehicle is in a driving state (charging current present), or whether the DCDC converter 114 is not operating and the vehicle is stopped (no charging current).

[0025] If the determination unit 152 determines that no charging current is being supplied from the power supply source 110 to the auxiliary battery 120 (step S201, yes), the process proceeds to step S202. On the other hand, if the determination unit 152 determines that charging current is being supplied from the power supply source 110 to the auxiliary battery 120 (step S201, no), it waits until the charging current is no longer supplied.

[0026] (Step S202) The determination unit 152 determines whether the voltage of the auxiliary battery 120 (battery voltage) acquired by the acquisition unit 151 is below a predetermined threshold. This determination is made to check whether the battery voltage is high due to the charging current from the power supply source 110 to the auxiliary battery 120 when the auxiliary battery 120 is fully charged. Therefore, this predetermined threshold is set to a constant value (e.g., 13V) that is higher than the open-circuit voltage OCV (e.g., 12.8V) of the auxiliary battery 120 when it is fully charged.

[0027] If the determination unit 152 determines that the battery voltage is below the threshold (step S202, yes), the process proceeds to step S203. On the other hand, if the determination unit 152 determines that the battery voltage exceeds the threshold (step S202, no), the connection of the external power supply 140 is suspected, and the abnormality detection control of the battery sensor 121 is terminated without performing the battery sensor diagnosis described later. This prevents the normal battery sensor 121 from being mistakenly detected as abnormal when the external power supply 140 is connected to the auxiliary battery 120.

[0028] (Step S203) The determination unit 152 determines whether the voltage of the auxiliary battery 120 (battery voltage) acquired by the acquisition unit 151 has risen. This determination is made to check whether the battery voltage has risen due to charging by the charging current from the power supply source 110 to the auxiliary battery 120 when the auxiliary battery 120 is not fully charged. Therefore, this determination is made by checking whether the value ΔV (=V1-V2), which is obtained by subtracting the battery voltage V2 after a predetermined time has elapsed since the ignition was turned off from the battery voltage V1 immediately after the vehicle's ignition was turned off, is zero or greater. It is desirable to set the predetermined time to a sufficient time to recognize the change in battery voltage.

[0029] If the determination unit 152 determines that the battery voltage has not risen (ΔV≧0) even after a predetermined time has elapsed (step S203, yes), the process proceeds to step S204. On the other hand, if the determination unit 152 determines that the battery voltage has risen (ΔV<0) after a predetermined time has elapsed (step S203, no), the connection of the external power supply 140 is suspected, and the abnormality detection control of the battery sensor 121 is terminated without performing the battery sensor diagnosis described later. This prevents the normal battery sensor 121 from being mistakenly detected as abnormal when the external power supply 140 is connected to the auxiliary battery 120.

[0030] In the following steps S204 to S206, the control unit 153 performs a battery sensor diagnosis.

[0031] (Step S204) The control unit 153 determines whether the current of the auxiliary battery 120 (battery current) acquired by the acquisition unit 151 is greater than zero. This determination is made to confirm whether the battery current also indicates that no charging current is being supplied, as confirmed by the battery voltage in steps S203 and S203 above. Note that the battery current is represented by a positive sign (+) for the charging side and a negative sign (-) for the discharging side.

[0032] If the control unit 153 determines that the battery current I is greater than zero (I>0; positive sign) (step S204, yes), the process proceeds to step S205. On the other hand, if the control unit 153 determines that the battery current I is not greater than zero (I ≤ 0; negative sign) (step S204, no), the process proceeds to step S206.

[0033] (Step S205) The control unit 153 determines that the battery current detection circuit (current sensor, etc.) in the battery sensor 121 is malfunctioning.

[0034] When the control unit 153 determines that there is an abnormality in the battery sensor 121, the abnormality detection control for the battery sensor 121 is terminated.

[0035] (Step S206) The control unit 153 determines that the battery current detection circuit (such as a current sensor) in the battery sensor 121 is functioning correctly.

[0036] When the control unit 153 determines that the battery sensor 121 is functioning normally, the abnormality detection control for the battery sensor 121 is terminated.

[0037] <Effects and Actions> As described above, according to the battery sensor 121 abnormality detection method according to one embodiment of the present disclosure, even if the engine 111 stops and the alternator 112 does not generate power or the DCDC converter 114 does not drive and does not output power after the vehicle ignition is turned off, if either the condition that the voltage of the auxiliary battery 120 exceeds the open-circuit voltage (OCV) when fully charged or the condition that an increase in the voltage of the auxiliary battery 120 is observed is met, the external power supply 140 may be connected to the auxiliary battery 120, and therefore diagnostic control of the battery sensor 121 is not performed.

[0038] This control prevents the battery sensor 121 from mistakenly detecting an abnormal current value, even when an external power supply 140 is connected to the auxiliary battery 120 during vehicle maintenance or inspection at a dealership.

[0039] Furthermore, the abnormality detection method for the battery sensor 121 according to this embodiment can be implemented in an existing system by only changing the software control specifications without any hardware modifications.

[0040] Although one embodiment of the present disclosure has been described above, the present disclosure can be understood not only as a method for detecting abnormalities in a battery sensor, but also as a program for executing this method, a computer-readable non-temporary storage medium storing the program, a control device for executing this method, and a vehicle equipped with the control device. [Industrial applicability]

[0041] The battery sensor abnormality detection method described herein can be used in vehicles where an external power supply for charging the vehicle battery may be connected. [Explanation of symbols]

[0042] 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 Department 152 Judgment section 153 Control Unit

Claims

1. A method for detecting abnormalities in a battery sensor installed in an on-board vehicle battery, The steps include obtaining the voltage of the onboard battery after the vehicle ignition is turned off, The steps include determining whether the voltage of the vehicle battery exceeds the open-circuit voltage when fully charged, The steps include determining whether the voltage of the vehicle battery has risen after the ignition has been turned off, A method for detecting an abnormality in a battery sensor, comprising the steps of: performing diagnostic control of the battery sensor if the voltage of the vehicle battery is less than or equal to the open-circuit voltage and the voltage of the vehicle battery has not risen after the ignition is turned off; and not performing diagnostic control of the battery sensor otherwise.

2. The battery sensor abnormality detection method according to claim 1, wherein the step of acquiring the voltage is to acquire the voltage of the vehicle battery when the engine speed is zero.

3. The battery sensor abnormality detection method according to claim 1, wherein the step of acquiring the voltage is obtained when the operation of the DC-DC converter connected to the vehicle battery has stopped.

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