Device for estimating degree of damage in vehicular battery pack due to road surface interference

Abstract

To estimate a degree of damage in a battery in the case that the occurrence of a deformation is detected in a battery pack 14 mounted on a lower surface of an electric vehicle 10, by considering not only a part where the deformation has occurred but also a situation in which an impact detected by other means in the vehicle has been applied and a situation relating to operation of the battery.SOLUTION: A device for estimating a degree of damage in a battery pack mounted on a lower surface of an electric vehicle due to road surface interference includes: road surface interference part specifying means 20, 30b which, when a deformation has occurred in the battery pack due to the road surface interference, specifies a portion where the deformation has occurred; vehicle state detection means 16, 17, 41, 42, 70, 72 which detect states of the electric vehicle before and after the occurrence of the deformation due to the road surface interference; and damage degree estimating means 30 which estimates the degree of damage in the battery pack on the basis of the portion where the deformation has occurred due to the road surface interference specified by the road surface interference part specifying means and the states of the electric vehicle detected by the vehicle state detection means.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an apparatus for estimating the state of a battery pack mounted on an electric vehicle, and more particularly, to an apparatus for estimating the degree of damage suffered by a battery pack mounted on the lower surface of a vehicle due to interference with the road surface (an apparatus for estimating the degree of damage to an in-vehicle battery pack due to road surface interference).

Background Art

[0002] In an electric vehicle, when a battery pack is mounted on the lower surface of the vehicle body, the surface of the battery pack may be deformed due to road surface interference during vehicle travel, that is, contact with falling objects, obstacles, protrusions, steps, etc. on the road surface. Therefore, a configuration for detecting deformation of the surface of the battery pack due to such road surface interference has been proposed. For example, in Patent Document 1, in a cell stacked in a battery pack, a conductive protruding member is disposed via an insulating member toward the metal casing thereof, and the potential difference between the protruding member and the electrode terminal of the cell is monitored. When an external load is applied to the battery pack, an increase in the potential difference due to the protruding member breaking through the insulating member and contacting the casing is detected to determine that deformation of the battery pack has occurred due to the load. Further, in Patent Document 2, a configuration for interrupting the current flowing through the electrical wiring based on the detected value of the current flowing through the electrical wiring connected to the in-vehicle lithium-ion battery and the detected value of the impact applied to the vehicle detected by an acceleration sensor has been proposed. In Patent Document 3, an impact detection label or a temperature detection label that discolors without power when the battery pack, module, or cell is subjected to an impact or temperature exposure equal to or higher than a predetermined threshold is installed. When the history of impact and temperature is detected, an open-circuit voltage and internal resistance measurement are performed to determine the damage level of the battery pack, etc. based on the combination with the impact and temperature history. In Patent Document 4, in a battery that can be used for an electric vehicle to be carried by itself, in order to manage whether it is damaged by being dropped during carrying, etc., an acceleration sensor, a vibration sensor, a strain sensor, an impact sensor, a pressure sensor, a tilt sensor, a position sensor, a speed sensor, etc. are mounted on the battery, and the damage degree of the battery is calculated based on the physical load information on the battery detected by such sensors, and the usability of the battery is determined based on the damage degree. And in Patent Document 5, regarding an in-vehicle secondary battery, since the secondary battery may be damaged when the vehicle is subjected to vibration and impact, it is proposed to refer to the history information of the vehicle including the acceleration and duration during vibration and impact received by the vehicle when evaluating whether the secondary battery is suitable for reuse.

Prior Art Documents

Patent Documents

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2020-114101 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2016-116310 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2016-58298 [Patent Document 4] International Publication No. 2016 / 143399 [Patent Document 5] Japanese Unexamined Patent Application Publication No. 2023-76447 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] When a battery pack mounted on the lower surface of an electric vehicle is deformed due to road surface interference, the degree of damage to the battery pack varies depending on whether the deformed part is a cell part, a high-voltage relay part, a control device, a cooling mechanism, a metal structure part, or the like. Therefore, the inventor of the present invention proposed a road surface interference detection device that can identify the site where deformation occurred due to road surface interference in the battery pack in Japanese Patent Application No. 2023-80952. Briefly described, in such a device, a first conductor whose electrical resistance increases along the length direction from the start end and a second conductor electrically connected to the first conductor at the end extend along the surface on the road surface side of each part of the battery pack so as not to contact each other. When distortion occurs in each part, they are arranged so as to be close to each other so as to short-circuit. A predetermined voltage is applied between the start ends of the first and second conductors via a pull-up resistor, and the potential difference between the start ends of the first and second conductors is detected. When deformation due to road surface interference occurs in any part of the battery pack, a change in the potential difference corresponding to a change in the electrical resistance between the start ends of the first and second conductors due to the short-circuiting of the first and second conductors at that part is detected, and thereby, the part where deformation due to road surface interference has occurred is configured to be identifiable.

[0005] According to the road surface interference detection device as described above, the portion of the battery pack that has been deformed due to road surface interference can be identified, and the degree of damage to the battery pack can be estimated corresponding to that portion. However, when a certain portion is deformed, depending on the mode of the interference and the subsequent battery state, it may be better to assume a large degree of damage and take countermeasures. For example, when the deformed portion is a metal structure portion (metal frame portion), the deformation of such a portion usually does not have a significant impact on the operation of the battery. However, if the impact applied to the vehicle when the deformation occurred is relatively large, it may be preferable to estimate that the degree of damage is large. Also, even if the deformed portion is a portion that usually does not have a significant impact on the operation of the battery, if there is any change in the battery state thereafter, it may be preferable to estimate that the degree of damage is large.

[0006] In view of the above circumstances, the main problem of the present invention is to provide a configuration for estimating the degree of damage to the battery by referring not only to the portion where the deformation has occurred but also to the situation of receiving an impact detected by other methods in the vehicle and the situation related to the operation of the battery when it is detected by the road surface interference detection device as described above that deformation has occurred in a part of the battery pack.

Means for Solving the Problems

[0007] According to the present invention, the above problem is an apparatus for estimating the degree of damage caused by road surface interference in a battery pack mounted on the lower surface of an electric vehicle, a road surface interference portion specifying means for specifying the portion where the deformation has occurred when the battery pack is deformed due to road surface interference, a vehicle state detection means for detecting the state of the electric vehicle before and after the deformation due to the road surface interference occurs, and a damage degree estimating means for estimating the degree of damage to the battery pack based on the portion where the deformation due to the road surface interference has occurred specified by the road surface interference portion specifying means and the state of the electric vehicle detected by the vehicle state detection means including the apparatus is achieved.

[0008] In the above configuration, the electric vehicle may be a vehicle such as a battery electric vehicle (BEV), a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), or a fuel cell vehicle (FCEV), in which a battery pack with a plurality of stacked stacks of cells juxtaposed is mounted on the lower surface of the vehicle body as a driving battery. As described above, "road surface interference" is the contact between the battery pack on the lower surface of the vehicle body and falling objects, obstacles, protrusions, steps, etc. on the road surface (hereinafter referred to as "obstacles, etc."). The "degree of damage" to the battery pack is the degree for determining the measures to be taken for the battery pack after road surface interference is confirmed for the battery pack. For example, if the damage to the battery pack is such that a measure prompting the user to inspect is to be executed, the "degree of damage" is said to be "minor". If the damage to the battery pack is such that a measure to stop the use of the battery or to run with reduced output and to inform the user to request repair is to be executed, the "degree of damage" is said to be "moderate". If the damage to the battery pack is such that a measure to prohibit the vehicle from running and to notify the outside of the vehicle with a hazard, etc. is to be executed, the "degree of damage" may be said to be "severe".

[0009] The "road surface interference part specifying means" may be the road surface interference detection device disclosed in the above-mentioned Japanese Patent Application No. 2023-80952. Specifically, first and second conductors each having a start end and an end end and electrically connected to each other at the end end extend along the surface on the road surface side of each part of the battery pack in order from the start end to the end end and are arranged so as to be close to each other so as to short-circuit when distortion occurs in each part without contacting each other. The electrical resistance from the start end to each part in the first or second conductor increases every time it passes through each part of the battery pack. A predetermined voltage is applied between the start ends of the first and second conductors via a pull-up resistor, the potential difference between the start ends of the first and second conductors is detected, and based on the potential difference, determination of the presence or absence of deformation of the stack due to road surface interference and specification of the part where the deformation has occurred may be configured to be executed. Here, the first and second conductors may be ordinary electrical conduction wires. The "predetermined magnitude" with respect to the distortion of the surface on the road surface side may be set as appropriate, and typically, it may be adjusted to such an extent that the distortion of the surface of each part of the battery pack exceeds that magnitude and becomes unacceptable or ignorable. Further, the first conductor or the second conductor is prepared so that the electrical resistance from the start end to each part increases every time it passes through each part of the battery pack. For this purpose, specifically, in the first conductor or the second conductor, electrical resistance elements of any magnitude may be interposed along the length direction as appropriate. And means for applying a predetermined voltage between the start end of the first conductor and the start end of the second conductor via a pull-up resistor is provided, and potential difference detection means such as a voltage sensor for detecting the potential difference generated between the start end of the first conductor and the start end of the second conductor is provided. Here, the predetermined height of the applied voltage may be arbitrary, and typically, an auxiliary battery may be used as the voltage source.

[0010] In the above-mentioned "road surface interference part specifying means", the first and second conductors are arranged to extend along the surfaces of the cell part, high-voltage relay part, control device, cooling mechanism, metal structure part, etc. of the battery pack. When road surface interference occurs in any of these parts and that part is deformed, and the first and second conductors are short-circuited to each other, that state appears as an electrical resistance between the starting ends of the first and second conductors and is detected by the potential difference detecting means. Therefore, it becomes possible to specify which part of the battery pack has been deformed due to road surface interference.

[0011] The "vehicle state detecting means" may be any means capable of detecting that the vehicle has received some impact, estimating that the vehicle has come into contact with an obstacle or the like, or detecting the state of the battery pack. Specifically, as the vehicle state detecting means, there may be an airbag G sensor representing the magnitude of the acceleration received by the vehicle, a vehicle speed sensor (wheel speed sensor), an in-vehicle camera for detecting obstacles or the like on the driving road, road information providing information on obstacles or the like on the road, a voltage sensor of the battery pack, a temperature sensor, a leakage detection sensor, and the like.

[0012] The "damage degree estimating means" is configured to estimate the degree of damage to the battery pack based on the part where deformation due to the road surface interference detected by the "road surface interference part specifying means" has occurred and the state of the vehicle detected by the "vehicle state detecting means" as described above. As already described, when deformation due to road surface interference occurs in the battery pack, first, the degree of damage is estimated by that part. Further, when a situation is detected in which it is better to estimate the degree of damage to be larger in the state of the vehicle detected by the "vehicle state detecting means", the "damage degree estimating means" estimates that the degree of damage to the battery pack is larger than in the case corresponding to the part where deformation due to road surface interference has occurred. As a result, in accordance with the actual degree of damage, the measures such as those exemplified above are to be executed.

[0013] For example, when the cell part, high-voltage relay part, or control equipment has deformation due to road surface interference as detected by the road surface interference part identification means, the degree of damage is considered severe; when the cooling mechanism has deformation due to road surface interference, the degree of damage is considered moderate; when the metal structure part has deformation due to road surface interference, the degree of damage is considered minor. However, when the "vehicle state detection means" detects a situation where it is better to estimate a larger degree of damage, even if the metal structure part has deformation, the degree of damage may be considered moderate, and even if the cooling mechanism has deformation, the degree of damage may be considered severe.

[0014] In the configuration of the device of the present invention described above, the "vehicle state detection means" may be one or more. The more numerous the detections of situations where it is better to estimate a larger degree of damage, the larger the estimated degree of damage may be.

Advantages of the Invention

[0015] Thus, in the present invention described above, in addition to the degree of damage corresponding to the part where deformation has occurred as identified by the means capable of identifying the part where deformation has occurred when deformation due to road surface interference occurs in the battery pack as described in Japanese Patent Application No. 2023-80952, considering the situations that may cause damage to the battery pack in other parts of the vehicle, a more accurate estimation of the degree of damage to the battery pack is attempted. According to the device of the present invention, it is possible to estimate the degree of damage to the battery pack, which is difficult to judge only by identifying the part where deformation due to road surface interference has occurred. Therefore, it is advantageous in that more appropriate fail-safe measures can be implemented when the battery pack is subjected to road surface interference.

[0016] Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments of the present invention.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Explanation of Signs

[0018] 10... Vehicle, 12FL~RR... Tires, 14... Battery pack (driving battery), 15... Stack (cells), 16... Temperature sensor / voltage sensor, 17... Leakage detection sensor, 20... Linear sensor, 20a... Tubular member, 21... First conductor, 22... Second conductor, 25... High-voltage relay circuit, 26... Control device, 27... Cooling mechanism part, 28... Metal frame part, 30... Damage degree estimation device (voltage application / detection device), 30a... Voltage source (auxiliary battery), 30b... Potential difference detection device (voltage sensor), 31... Notifier, 40... Air pressure sensor, 41... Airbag G sensor, 42... Wheel speed sensor (vehicle speed sensor), 70... In-vehicle camera, 72... Navigation device (road information acquisition device), Rp... Pull-up resistor, Rt... Terminal resistor, R1, R2, R3, R4... Inter-part resistance, SC... Short-circuit part

Best Mode for Carrying Out the Invention

[0019] The present invention will be described in detail below with reference to the accompanying drawings in several preferred embodiments. In the drawings, the same reference numerals indicate the same parts.

[0020] Configuration of the device The vehicle-mounted battery pack damage degree estimation device due to road surface interference in this embodiment (hereinafter referred to as the "road surface interference damage degree estimation device") is an electric vehicle equipped with a driving battery (battery pack) such as a BEV, HEV, PHEV, or FCEV, and is applied to the battery pack in a vehicle where the battery pack is installed on the lower surface of the vehicle body. Specifically, in the road surface interference damage degree estimation device, as schematically shown in Fig. 1(A), on the road surface side surface of the battery pack 14 arranged on the lower surface of the vehicle 10, typically between the front wheels 12FL, FR and the rear wheels 12RL, RR, the linear sensor 20 is installed so as to extend along each part in the battery pack 14, that is, the stack (cell part) 15, the high-voltage relay circuit 25, the control device 26, the cooling mechanism part 27, and the metal frame part 28 in sequence. The stack 15 is usually configured by stacking rectangular flat cells 15a as schematically shown in Fig. 1(B). The linear sensor 20 is preferably arranged so as to extend over substantially the entire area of each part of the battery pack as shown in the figure. More specifically, the linear sensor 20 is composed of a tubular member 20a and, inside it, a first conductor 21 and a second conductor 22 in a bare wire state that extend in a state of being close to each other without normally contacting each other between its start end 20s and end end 20t. The first conductor 21 and the second conductor 22 are electrically connected on the end 20t side, whereby the first conductor 21 and the second conductor 22 form a single closed circuit when viewed from their start end sides. Note that the first conductor 21 and the second conductor 22 are usually connected via a terminal resistor Rt on the end 20t side, and at least one of the first conductor 21 and the second conductor 22 is adjusted so that the electrical resistance value from the start end 20s side to an arbitrary part on the conductor increases as the number of parts (15, 25 - 28) through which the conductor passes increases toward the terminal resistor Rt. For example, as shown in the circuit diagram of Fig. 2(A), in at least one of the first conductor 21 and the second conductor 22 in the linear sensor 20, significant electrical resistors R1, R2,... are inserted at the parts between each part, whereby the electrical resistance value from the start end 20s side to an arbitrary part on the conductor may be increased as the number of parts of the conductor passing from the start end side increases.

[0021] Further, the first conductor 21 and the second conductor 22 are connected to a damage degree estimation device 30 having a voltage application / detection function at the start end side 20s of the linear sensor 20. As shown in Fig. 2(A), one of the conductors is connected to the positive terminal of a voltage source 30a (which may be an auxiliary battery or the like) via a pull-up resistor Rp, and the other conductor is grounded (Gnd). The damage degree estimation device 30 may be a normal type of computer device and may be configured to operate according to a program. Then, with a predetermined voltage Vb that may be arbitrarily set from the voltage source 30a being applied, the voltage Vm between the start ends of the first conductor 21 and the second conductor 22 is monitored by a potential difference detection device 30b in the damage degree estimation device 30. Thus, by referring to the voltage Vm monitored by the potential difference detection device 30b, the presence or absence of surface deformation due to road surface interference in each part (15, 25 to 28) is determined as will be described in detail later, and when deformation occurs in any part, that part is specified.

[0022] Furthermore, in the case of this embodiment, in addition to identifying the portion where deformation due to road surface interference has occurred using the above linear sensor 20 for estimating the degree of damage caused by road surface interference in the battery pack, various states of the vehicle that are considered to affect the degree of damage to the battery pack due to the road surface interference before and after the road surface interference occurs are referred to. Specifically, for example, in this embodiment, an airbag G sensor 41 representing the magnitude of the acceleration received by the vehicle, a wheel speed sensor (vehicle speed sensor) 42 that varies due to the impact received by the vehicle, a temperature sensor that detects the temperature of the battery pack and / or a voltage sensor 16 that detects the battery voltage of the battery pack, a leakage detection sensor 17 that detects leakage in the battery pack, an in-vehicle camera sensor 70 that detects obstacles in front of the vehicle, information from a navigation device 72 that acquires road information about the presence or absence of obstacles in the vicinity where the vehicle is traveling, etc. are provided to the damage degree estimation device 30, and the degree of damage to the battery pack, that is, the degree of damage, is estimated in consideration of the information from the above various sensors together with the information on the portion where deformation due to road surface interference has occurred. Then, various measures (fail-safe measures) against deformation due to road surface interference are executed according to the damage degree thus estimated, and the determination result and the identification result may be notified to the user by an arbitrary type of notifier 31.

[0023] In the configuration of the above linear sensor 20, the first conductor 21 and the second conductor 22 are in a bare wire state and can be short-circuited due to the adhesion of moisture or other conductive substances. Therefore, in order to avoid this, it is preferable that the tubular member 20a of the linear sensor 20 is hermetically sealed so that the bare wire portions of the first conductor 21 and the second conductor 22 are not exposed to the outside. And a pressure sensor 40 for detecting the internal pressure is provided at an arbitrary portion of the tubular member 20a so that it can be detected when the airtight state is broken due to a crack or the like in the tubular member 20a, and the detected value is monitored. When an abnormality such as a significant decrease in the detected value is detected, this may also be notified to the user by the notifier 31.

[0024] Operation of the device (a) Identification of the portion where deformation has occurred due to road surface interference Referring to Fig. 2(A), in the operation of a road surface interference detection device (a means for specifying a deformed portion due to road surface interference) that specifies a deformed portion due to road surface interference using the linear sensor 20 in the present embodiment, during the operation or traveling of the vehicle, a voltage Vb is applied between the first conductor 21 and the second conductor 22 of the linear sensor 20 via a pull-up resistor Rp. In this case, the voltage Vm measured between the starting ends of the first conductor 21 and the second conductor 22 is the value obtained by multiplying the applied voltage Vb by the ratio of [the electrical resistance value between the starting ends of the first conductor 21 and the second conductor 22] to [the electrical resistance value between the starting ends of the first conductor 21 and the second conductor 22] with respect to the pull-up resistor Rp. Therefore, when no part of the battery pack 14 is subjected to road surface interference, in the case of the example in Fig. 2(A), the electrical resistance value between the starting ends of the first conductor 21 and the second conductor 22 is R1 + R2 + R3 + R4 + R t So, the voltage Vm measured between the starting ends of the first conductor 21 and the second conductor 22 is Vm = Vb{(R1 + R2 + R3 + R4 + R t ) / (R p + R1 + R2 + R3 + R4 + R t )}…(1) and becomes

[0025] On the other hand, when any part 15 is subjected to road surface interference and a significant deformation strain occurs on its surface, and at the deformed part, the linear sensor 20 deforms and the first conductor 21 and the second conductor 22 come into contact and short-circuit, the electrical resistance value between the starting ends of the first conductor 21 and the second conductor 22 becomes the resistance value from the starting end to the short-circuit part. Therefore, the voltage Vm measured between the starting ends of the first conductor 21 and the second conductor 22 will change depending on the position of the short-circuit part. Specifically, for example, as in the example of Fig. 2(B), when the metal frame part 28 closest to the terminal 20t of the linear sensor 20 deforms and a short-circuit occurs between the first conductor 21 and the second conductor 22, the voltage Vm measured between the starting ends of the first conductor 21 and the second conductor 22 is Vm = Vb{(R1 + R2 + R3 + R4) / (R p + R1 + R2 + R3 + R4)} …(2) As a result, as in the example of Fig. 2(C), when the high-voltage relay portion 25 is deformed and a short circuit occurs between the first conductor 21 and the second conductor 22, the voltage Vm measured between the starting ends of the first conductor 21 and the second conductor 22 is Vm = Vb{(R1) / (R p + R1)} …(3) Thus, as described above, since the voltage Vm measured between the starting ends of the first conductor 21 and the second conductor 22 changes depending on the position of the short-circuited portion when deformation occurs in any part and a short circuit occurs between the first conductor 21 and the second conductor 22, by monitoring the voltage Vm, it is possible to determine the presence or absence of surface deformation due to road surface interference in any part, and when deformation occurs, the part can be identified.

[0026] Regarding how much deformation strain causes the first conductor 21 and the second conductor 22 to short-circuit (that is, how much to separate the first conductor 21 and the second conductor 22 under normal conditions) for each part of the battery pack, it may be appropriately adjusted through experiments and the like in consideration of the allowable degree of deformation in each part.

[0027] As described above, when deformation due to road surface interference occurs in any part of the battery pack and that part is identified, the damage degree, which is the degree of damage to the battery pack corresponding to that part, is “tentatively estimated”. Specifically, for example, when there is deformation due to road surface interference in the cell part, the high-voltage relay part, or the control device, the damage degree may be considered severe; when there is deformation due to road surface interference in the cooling mechanism, the damage degree may be considered moderate; and when there is deformation due to road surface interference in the metal frame part, the damage degree may be considered minor.

[0028] By the way, when deformation occurs simultaneously in a part with a high damage degree and a part with a low damage degree, if the part with a low damage degree is closer to the starting end of the linear sensor 20, the deformation of the part with a high damage degree cannot be detected. Therefore, preferably, the linear sensor 20 is wired such that the part with a higher damage degree is arranged closer to the end of the linear sensor 20 than the part with a lower damage degree.

[0029] (b) Revision of the tentatively determined damage degree In this embodiment, as described above, when it is detected by the road surface interference detection device that deformation due to road surface interference has occurred in any part of the battery pack, and further, when a situation that may affect or has affected the degree of damage to the battery pack due to road surface interference is detected in the vehicle before and after that, the estimated damage level provisionally determined corresponding to the part where the deformation due to road surface interference has occurred is corrected accordingly. Specifically, when the following situations are detected, the provisionally estimated damage level may be raised by one level. (For example, when the provisional determination is minor, the damage level may be corrected to moderate, and when the provisional determination is moderate, the damage level may be corrected to severe.)

[0030] (i) When an obstacle or the like is detected on the road surface ahead by the in-vehicle camera 70 immediately before the detection of the deformation due to road surface interference, or when information indicating the existence of an obstacle or the like on the driving road is obtained from the road information acquired by the navigation device 72, it is presumed that the degree of deformation due to road surface interference was large, so the provisionally estimated damage level may be raised by one level. (ii) When the acceleration value detected by the airbag G-sensor exceeds a predetermined value or the vehicle speed value detected by the wheel speed sensor (vehicle speed sensor) exceeds a predetermined value at the time of detection of the deformation due to road surface interference, it is presumed that the degree of deformation due to road surface interference was large, so the provisionally estimated damage level may be raised by one level. Here, the predetermined value may be appropriately set according to the suitability. (iii) When any of the voltage value detected by the voltage sensor, the battery temperature detected by the temperature sensor, or the current value detected by the leakage sensor increases after the detection of the deformation due to road surface interference, an abnormality of the battery is suspected, so the provisionally estimated damage level may be raised by one level or multiple levels according to the degree of each increase. (When the deformation due to road surface interference is detected at one end, according to the damage level described later

[0031] (c) Flow of processing The processing in the device of this embodiment may be executed in order as shown in FIG. 3. Referring to the figure, in the device, in the road surface interference detection device, the presence or absence of deformation due to road surface interference is monitored (step 1). When it is detected that deformation due to road surface interference has occurred in any part of the battery pack, the degree of damage to the battery pack corresponding to that part is tentatively estimated (step 2). At this time, when an obstacle or the like has already been detected on the road surface by the in-vehicle camera 70, when information on the presence of an obstacle or the like on the road surface is detected in the road information, or when the acceleration value by the airbag G sensor or the vehicle speed value by the wheel speed sensor exceeds their respective predetermined values (step 3), the tentatively estimated degree of damage is corrected as described above (step 4 - usually, the degree of damage is increased). Also, after the detection of deformation due to road surface interference, when any of the voltage value detected by the voltage sensor, the battery temperature detected by the temperature sensor, or the current value detected by the leakage sensor increases, the tentatively estimated degree of damage is also corrected as described above (step 4 - when deformation due to road surface interference is detected at one end, measures for fail-safe according to the degree of damage to be described later are executed, and during that time, when there is a change in the above voltage, temperature, or current, the degree of damage may be increased in response, and the measures may be changed). In the vehicle, when the above situation is not detected by sensors other than the road surface interference detection device (step 3), measures for fail-safe to be described later are executed with the tentatively estimated degree of damage.

[0032] After that, measures for fail-safe according to the degree of damage to the battery pack are executed. Specifically, for example, when the degree of damage is minor (step 5), a notification prompting the user to inspect the battery pack may be executed through the notifier 31 (step 6). Also, when the degree of damage is moderate (step 7), measures such as stopping the use of the battery pack or reducing the output are taken, and a notification requesting the user to repair the battery pack may be executed through the notifier 31 (step 8). And when the degree of damage is severe (step 9), the vehicle's travel may be stopped, and a process of notifying the outside of the vehicle of a hazard (emergency) may be executed.

[0033] Thus, according to the device of the present embodiment, it is possible to estimate the degree of damage to the battery pack, which is difficult to determine only by identifying the portion deformed due to road surface interference, taking into account various situations detected by the vehicle. Therefore, when the battery pack is subjected to road surface interference, it is expected that a more appropriate fail-safe measure can be executed.

[0034] The above description has been made in connection with the embodiments of the present invention, but many modifications and changes are easily possible for those skilled in the art, and the present invention is not limited to only the embodiments illustrated above, and it will be apparent that the present invention can be applied to various devices without departing from the concept of the present invention.

Claims

【Claim 1】 An apparatus for estimating the degree of damage caused by road surface interference in a battery pack mounted on the underside of an electric vehicle, comprising: a road surface interference portion specifying means for specifying a portion where deformation has occurred when deformation due to road surface interference has occurred in the battery pack; a vehicle state detecting means for detecting the state of the electric vehicle before and after the deformation due to the road surface interference has occurred; a damage degree estimating means for estimating the degree of damage to the battery pack based on the portion where the deformation due to the road surface interference specified by the road surface interference portion specifying means and the state of the electric vehicle detected by the vehicle state detecting means; and an apparatus including the same.

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