Battery discharge rate estimation system

Abstract

This invention provides a battery discharge estimation system that can prevent the estimation of battery discharge amounts that differ significantly from the actual battery discharge amount. [Solution] A battery discharge rate estimation system for a vehicle, comprising: an acquisition unit that acquires the average dark current value, which is the average value of the current flowing out of the battery during the vehicle's parking time; a determination unit that determines whether the average dark current value exceeds a guard value set based on the parking time; and an estimation unit that, if the average dark current value exceeds the guard value, estimates the battery discharge rate using the guard value instead of the average dark current value.

Description

Technical Field

[0001] The present disclosure relates to a system for estimating the discharge amount of a battery mounted on a vehicle.

Background Art

[0002] Patent Document 1 discloses a system for estimating the discharge amount of a battery during parking based on the parking time of a vehicle and the average value of the current (standby current) flowing from the battery to in-vehicle loads during parking.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, when performing the process of estimating the discharge amount of a battery at a center or the like connected to the vehicle by wireless communication, a delay in data (parking time, average standby current value) transmission from the vehicle to the center or a delay in server processing in the center may cause a synchronization deviation between the average standby current value and the parking time. Such a synchronization deviation between the average standby current value and the parking time may also occur when estimating the discharge amount inside the vehicle.

[0005] If the discharge amount of the battery is estimated using the average standby current value and the parking time that have caused such a synchronization deviation, the result of the estimation may greatly differ from the actual discharge amount of the battery. Therefore, there is room for further consideration regarding the method of estimating the discharge amount of the battery.

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to provide a battery discharge amount estimation system that can suppress the estimation of a battery discharge amount that greatly differs from the actual battery discharge amount. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the disclosed technology is a battery discharge amount estimation system for a vehicle, comprising: an acquisition unit that acquires the average dark current value, which is the average value of the current flowing out of the battery during the vehicle's parking time; a determination unit that determines whether the average dark current value exceeds a guard value set based on the parking time; and an estimation unit that, if the average dark current value exceeds the guard value, estimates the battery discharge amount using the guard value instead of the average dark current value. [Effects of the Invention]

[0008] The battery discharge amount estimation system of this disclosure can suppress the estimation of a battery discharge amount that differs significantly from the actual battery discharge amount. [Brief explanation of the drawing]

[0009] [Figure 1] Schematic diagram of a discharge amount estimation system according to one embodiment of this disclosure. [Figure 2] The discharge rate estimation system executes a flowchart of the battery discharge rate estimation control process. [Figure 3] This figure shows an example of a map used to derive the average dark current guard value. [Figure 4] Illustrated diagram showing the region where the average dark current value is protected. [Modes for carrying out the invention]

[0010] The battery discharge rate estimation system of this disclosure sets a guard process on the average dark current value to prevent a synchronization mismatch between the vehicle's average dark current value and the parking time when estimating the discharge rate of an on-board battery. The embodiments of this disclosure will be described in detail below with reference to the drawings.

[0011] <Embodiment> [composition] Figure 1 is a block diagram showing a schematic configuration of a vehicle communication system 100 including a discharge amount estimation system 121 according to one embodiment of the present disclosure. The vehicle communication system 100 illustrated in Figure 1 includes a vehicle 110 and a center 120.

[0012] (1) Vehicle Vehicle 110 is connected to the center 120 in a communicative manner. This vehicle 110 is, for example, an automobile and includes at least a battery 111, a data acquisition unit 112, and a data transmission unit 113. Although Figure 1 shows an example where there is one vehicle 110 connected to the center 120 in a communicative manner, multiple vehicles 110 may each be connected to the center 120 in a communicative manner.

[0013] In order to reduce power consumption while parked, this vehicle 110 can transition certain devices and equipment between a wake-up state, where all functions are activated, and a sleep state, where some functions are disabled, at predetermined timings.

[0014] Battery 111 is a rechargeable secondary battery, such as a lithium-ion battery or a lead-acid battery. An auxiliary battery can be an example of battery 111. This battery 111 is charged by a generator (not shown), such as an alternator, and can supply (discharge) the power it stores to accessories and equipment (not shown) mounted on the vehicle 110.

[0015] The data acquisition unit 112 is configured to acquire vehicle data at predetermined intervals or irregularly. This vehicle data includes information regarding the parking of the vehicle 110 and information regarding the battery 111. As information regarding the parking of the vehicle 110, the parking time of the vehicle 110 (the time when the ignition of the vehicle 110 is OFF) can be exemplified. As information regarding the battery 111, the average value of the dark current flowing out from the battery 111 to a load (not shown) mounted on the vehicle 110 (hereinafter referred to as "average dark current value") can be exemplified. This dark current is, for example, the current consumed by functions related to the authentication of an electronic key or a drive recorder that performs recording during parking. The dark current is acquired using a current sensor or the like (not shown) provided in the battery 111.

[0016] This average dark current value can be calculated based on the following formula 1 using a plurality of dark current values measured at each timing when a specific device or equipment of the vehicle 110 enters the wake-up state. Average dark current value = Total of measured dark current values / Number of measurements … (Formula 1)

[0017] The data transmission unit 113 is a configuration having a function of controlling communication between the vehicle 110 and the center 120. The data transmission unit 113 transmits the vehicle data acquired by the data acquisition unit 112 to the center 120. This data transmission unit 113 is realized, for example, by a data communication module (DCM).

[0018] (2) Center The center 120 is communicably connected to the vehicle 110. This center 120 is, for example, a server on the cloud or the like, and includes at least a discharge amount estimation system 121 and a notification unit 125.

[0019] The discharge amount estimation system 121 is a system for estimating the discharge amount of the battery 111 mounted on the vehicle 110. This discharge amount estimation system 121 includes a data reception unit 122, a guard process determination unit 123, and a discharge amount estimation unit 124.

[0020] The data receiving unit 122 is configured to have a function of controlling communication between the center 120 and the vehicle 110. This data receiving unit 122 can receive vehicle data transmitted from the vehicle 110 and obtain the parking time and the average dark current value included in the vehicle data.

[0021] The guard processing determination unit 123 is a configuration for determining whether the average dark current value acquired by the data receiving unit 122 exceeds a guard value (hereinafter referred to as "average dark current guard value") set based on the parking time. This average dark current guard value is given in advance in a map format, for example, as shown in FIG. 3.

[0022] In the example of FIG. 3, as the average dark current guard value, when the parking time of the vehicle 110 is less than 1 hour (1H), "-1.0 A (ampere)" is set; when the parking time is 1 hour or more and less than 2 hours (2H), "-0.5 A" is set; when the parking time is 2 hours or more and less than 4 hours (4H), "-0.3 A" is set; when the parking time is 4 hours or more and less than 10 hours (10H), "-0.2 A" is set; when the parking time is 10 hours (10H) or more, "-0.1 A" is set. In the example of FIG. 3, the inflow and outflow current of the battery 111 is expressed with the current flowing into the battery 111 for charging as a positive value (plus) and the current flowing out of the battery 111 for discharging as a negative value (minus).

[0023] The discharge amount estimation unit 124 is a configuration for estimating the discharge amount of the battery 111. Specifically, the discharge amount estimation unit 124 appropriately controls the dark current value used for estimating the discharge amount of the battery 111 based on the result determined by the guard processing determination unit 123. The processing performed by this discharge amount estimation unit 124 will be described later.

[0024] The notification unit 125 issues an appropriate notification according to the discharge amount of the battery 111 estimated by the discharge amount estimation unit 124. It is desirable to issue this notification when the battery 111 is in a state of temporary over-discharge (voltage drop) or when the battery 111 is in a deteriorated state. Examples of recipients of the notification include the vehicle 110, or the mobile terminals of the vehicle 110's user or driver.

[0025] [control] Next, with further reference to Figure 2, the control performed by the discharge amount estimation system 121 according to this embodiment will be described. Figure 2 is a flowchart illustrating the processing procedure for battery 111 discharge amount estimation control performed by each component of the discharge amount estimation system 121. The battery 111 discharge amount estimation control shown in Figure 2 is started when vehicle data is transmitted from the vehicle 110 to the center 120, for example, when the ignition is turned ON.

[0026] (Step S201) The data receiving unit 122 of the discharge amount estimation system 121 acquires the parking time and average dark current value from the vehicle data received from the vehicle 110. Once the parking time and average dark current value are acquired by the data receiving unit 122, the process proceeds to step S202.

[0027] (Step S202) The guard processing determination unit 123 of the discharge amount estimation system 121 derives an average dark current guard value corresponding to the parking time obtained in step S201. This average dark current guard value can be derived, for example, by extracting it from a map (Figure 3) that is pre-stored in a memory unit or the like (not shown). Once the guard processing determination unit 123 derives an average dark current guard value corresponding to the parking time, the process proceeds to step S203.

[0028] (Step S203) The guard processing determination unit 123 of the discharge amount estimation system 121 determines whether the average dark current value obtained in step S201 exceeds the average dark current guard value derived in step S202. This determination is made to confirm whether there is a synchronization mismatch between the average dark current value and the parking time. If the guard processing determination unit 123 determines that the average dark current value exceeds the average dark current guard value (step S203, yes), the process proceeds to step S204. On the other hand, if the guard processing determination unit 123 determines that the average dark current value does not exceed the average dark current guard value (step S203, no), the process proceeds to step S205.

[0029] (Step S204) The discharge amount estimation unit 124 of the discharge amount estimation system 121 estimates the discharge amount of the battery 111 using the average dark current value obtained in step S201. A well-known method can be used to estimate the discharge amount of the battery 111. Once the discharge amount of the battery 111 is estimated by the discharge amount estimation unit 124, this control is terminated.

[0030] (Step S205) The discharge amount estimation unit 124 of the discharge amount estimation system 121 estimates the discharge amount of the battery 111 using the average dark current guard value derived in step S203. In other words, the average dark current value obtained from the vehicle 110 is used to estimate the discharge amount of the battery 111, instead of the average dark current guard value derived by the discharge amount estimation system 121.

[0031] By switching to this average dark current guard value, the average dark current value used to estimate the discharge amount of battery 111 is kept within the shaded area shown in Figure 4. Therefore, even if the center 120 performs the estimation process with an average dark current value that is out of sync with the parking time, the guard process limits (or adds to) the average dark current value, thus preventing the discharge amount estimation unit 124 from estimating a discharge amount that is significantly different from the actual discharge amount of battery 111. Once the discharge amount of battery 111 is estimated by the discharge amount estimation unit 124, this control is terminated.

[0032] Furthermore, after the processing in step S204 or step S205 described above, the notification unit 125 may provide an appropriate notification.

[0033] <Effects and Actions> As described above, according to the discharge amount estimation system 121 according to one embodiment of the present disclosure, the average dark current value, which is the average value of the current flowing out of the battery 111 during the parking time of the vehicle 110, is obtained, and if the average dark current value does not exceed the average dark current guard value set based on the parking time, the discharge amount of the battery 111 is estimated using this average dark current value, and if the average dark current value exceeds the average dark current guard value, the discharge amount of the battery 111 is estimated using the average dark current guard value.

[0034] This Guard processing of the average dark current value limits (or increases) the average dark current value used for estimating the discharge amount, thereby preventing the discharge amount estimation system 121 from estimating a discharge amount that differs significantly from the actual discharge amount of the battery 111. [Industrial applicability]

[0035] The discharge rate estimation system described herein can be used, for example, to estimate the discharge rate of a battery installed in a vehicle. [Explanation of Symbols]

[0036] 100 Vehicle Communication Systems 110 vehicles 111 Battery 112 Data Acquisition Unit 113 Data transmission unit 120 Center 121 Discharge Amount Estimation System 122 Data receiving unit 123 Guard Processing Determination Unit 124 Discharge amount estimator 125 Notification Department

Claims

1. A system for estimating the discharge amount of a battery installed in a vehicle, An acquisition unit that acquires the average dark current value, which is the average value of the current flowing out of the battery during the parking time of the vehicle, A determination unit that determines whether the average dark current value exceeds a guard value set based on the parking time, The system includes an estimation unit that, if the average dark current value exceeds the guard value, estimates the battery discharge amount using the guard value instead of the average dark current value. Battery discharge rate estimation system.

2. The acquisition unit, the determination unit, and the estimation unit are provided in a center that is wirelessly connected from the vehicle. Battery discharge amount estimation system according to claim 1.

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