JP3849546B2 - Temperature sensor state detection device and state detection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for measuring the temperature of a battery mounted on a vehicle, and more particularly, to a technique for detecting an abnormality in the mounting state of a temperature sensor due to vibration of the vehicle.
[0002]
[Prior art]
A secondary battery such as a nickel metal hydride battery mounted on a vehicle has a system in which air is forcedly cooled by a cooling fan since the deterioration of electrodes and the like over time is accelerated as the battery temperature rises. In this system, the cooling fan is controlled so that the battery temperature does not rise beyond a predetermined range. Therefore, it is important to accurately measure the battery temperature. A temperature sensor for measuring the temperature of a battery mounted on the vehicle is attached so as to be fitted into a recess provided on the side surface of the battery case. However, it may come off from the recess of the battery case due to vibration or poor assembly during traveling of the vehicle. In this case, although the temperature of the battery is rising, the temperature sensor does not measure a low temperature, and the cooling fan cannot be operated by increasing the amount of cooling air, and the temperature of the battery rises.
[0003]
Japanese Patent Application Laid-Open No. 10-111182 discloses an apparatus for determining an abnormality of a temperature sensor mounted on a vehicle. The vehicle temperature sensor abnormality determination device disclosed in this publication includes a vehicle temperature sensor that detects the temperature of a vehicle drive system part, and the temperature of the vehicle drive system part that is detected by the vehicle temperature sensor. The elapsed time measurement circuit that measures the elapsed time continuously included in any one of the temperature regions divided into a plurality of temperature regions lower than the normal region set in advance, and when the measured elapsed time reaches a predetermined time And an abnormality determination circuit for determining that the vehicle temperature sensor is abnormal.
[0004]
According to this apparatus, the elapsed time continuously included in any one of the temperature regions obtained by dividing the temperature region in which the temperature of the drive system portion of the vehicle detected by the vehicle temperature sensor is lower than the normal region into a predetermined time is a predetermined time. When it reaches, it is determined that the vehicle temperature sensor is abnormal.
[0005]
[Problems to be solved by the invention]
However, the vehicle temperature sensor abnormality determination device disclosed in the above-mentioned publication assumes that the temperature of the drive system part continues to rise as the vehicle continues to travel. Therefore, even if such an apparatus is applied to a temperature sensor of a secondary battery mounted on a hybrid vehicle, for example, there are the following problems.
[0006]
That is, the secondary battery mounted on the hybrid vehicle that combines the drive by the engine and the drive by the motor is charged by the traveling state of the vehicle even when the vehicle continues to travel. In some cases, the secondary battery is discharged and neither charging nor discharging is performed. For this reason, since the temperature does not always rise uniformly, even if the measured temperature is continuously included in a certain temperature range for a predetermined time or longer, the charging and recharging of the secondary battery are performed in that time zone. If the secondary battery is not discharged, the battery temperature will not rise even if the vehicle is running. Therefore, it is difficult to apply the determination device disclosed in the above-mentioned publication to the temperature sensor abnormality of the secondary battery.
[0007]
The present invention has been made to solve the above-described problems, and is a battery temperature sensor that can accurately grasp the state of a temperature sensor that measures the temperature of a secondary battery or the like mounted on a vehicle. To provide a state detection device and a state detection method.
[0008]
[Means for Solving the Problems]
The temperature sensor state detection device according to the first invention is attached to an object and measures the temperature of the object, and whether or not the measurement result by the temperature sensor is in a predetermined temperature range. A determination means for determining, a temperature change calculated based on a usage state of the object and a measurement result by the temperature sensor when the measurement result is determined to be within a predetermined temperature range by the determination means; And a detecting means for detecting the mounting state of the temperature sensor.
[0009]
According to 1st invention, a temperature sensor measures the temperature of the secondary battery mounted in the vehicle, for example. In a state where such a secondary battery is used, the temperature rises due to the current flowing through the secondary battery. The determining means determines whether or not the measurement result is within a predetermined temperature range, for example, because the signal line of the temperature sensor is not broken or short-circuited. The detecting means is a temperature change calculated based on a current value that is one of the state quantities representing the use state of the object (for example, by integrating the square value of the current value), and measured by the temperature sensor. Compare with temperature change. As a result of the comparison, when the measured temperature change is significantly different from the calculated temperature change, the detection means detects that the temperature sensor is attached abnormally. As a result, it is possible to provide a battery temperature sensor state detection device that can accurately grasp the state of a temperature sensor that measures the temperature of a secondary battery or the like mounted on a vehicle.
[0010]
In the temperature sensor state detection device according to the second invention, in addition to the configuration of the first invention, the detection means is a temperature change calculated based on a temperature increase factor and a temperature decrease factor due to the use state of the object. And means for detecting the mounting state of the temperature sensor based on the temperature change measured by the temperature sensor.
[0011]
According to the second invention, for example, when the object is a secondary battery having a cooling system, the current flowing through the secondary battery during the charge / discharge of the secondary battery cools the secondary battery due to a temperature rise factor. Cooling by the system causes the temperature to drop. The detecting means is based on the temperature change calculated based on the current value for increasing the temperature, the degree of cooling by the cooling fan for decreasing the temperature, and the temperature change measured by the temperature sensor. Can be detected.
[0012]
In the temperature sensor state detection device according to the third invention, in addition to the configuration of the first or second invention, the detection means detects the temperature when the calculated temperature change does not match the measured temperature change. Means for detecting that the sensor mounting state is abnormal is included.
[0013]
According to the third invention, if the temperature change calculated based on the use state does not match the measured temperature change, it can be detected that the temperature sensor is not properly attached.
[0014]
A temperature sensor state detection device according to a fourth invention is a device in which the object is a secondary battery mounted on a vehicle, in addition to the configuration of any one of the first to third inventions.
[0015]
According to the fourth invention, it is possible to detect that the mounting state of the temperature sensor of the secondary battery for driving the vehicle mounted on the vehicle is abnormal.
[0016]
According to a fifth aspect of the temperature sensor state detection device, in addition to the configuration of the fourth aspect of the invention, the detection means includes a temperature rise factor due to charging and discharging from the secondary battery, and the secondary battery. Means for detecting that the mounting state of the temperature sensor is abnormal based on the temperature change calculated based on the temperature decrease factor due to cooling and the temperature change measured by the temperature sensor.
[0017]
According to the fifth invention, in a secondary battery mounted on a vehicle and repeatedly charged and discharged, it is expressed by a temperature increase factor represented by a current value flowing through the secondary battery and a cooling degree of the cooling fan of the secondary battery. Based on the temperature lowering factor, it is possible to detect that the mounting state of the temperature sensor of the secondary battery is abnormal.
[0018]
A temperature sensor state detection method according to a sixth aspect of the invention detects a state of a temperature sensor that is attached to an object and measures the temperature of the object. In this method, a determination step for determining whether or not a measurement result by the temperature sensor is in a predetermined temperature range, and when the measurement result is determined to be in a predetermined temperature range in the determination step, And a detection step of detecting the mounting state of the temperature sensor based on the temperature change calculated based on the usage state of the object and the measurement result by the temperature sensor.
[0019]
According to the sixth invention, the temperature sensor measures the temperature of the secondary battery mounted on the vehicle, for example. In a state where such a secondary battery is used, the temperature rises due to the current flowing through the secondary battery. In the determination step, for example, it is determined whether or not the measurement result is within a predetermined temperature range because the signal line of the temperature sensor is not disconnected or short-circuited. In the detection step, a temperature change calculated based on a current value that is one of the state quantities representing the use state of the object (for example, by integrating the square value of the current value), and a temperature sensor measures the temperature change. Compare the temperature change. As a result of the comparison, if the measured temperature change is significantly different from the calculated temperature change, it is detected in the detection step that the temperature sensor is attached abnormally. As a result, it is possible to provide a battery temperature sensor state detection method capable of accurately grasping the state of a temperature sensor that measures the temperature of a secondary battery or the like mounted on a vehicle.
[0020]
In the temperature sensor state detection method according to the seventh aspect of the invention, in addition to the configuration of the sixth aspect of the invention, the detection step includes a temperature change calculated based on a temperature increase factor and a temperature decrease factor due to the use state of the object. And detecting a mounting state of the temperature sensor based on the temperature change measured by the temperature sensor.
[0021]
According to the seventh invention, for example, when the object is a secondary battery having a cooling system, the current flowing in the secondary battery during charging / discharging of the secondary battery cools the secondary battery due to a temperature rise factor. Cooling by the system causes the temperature to drop. At the detection step, the temperature sensor is installed based on the temperature change calculated based on the current value for increasing the temperature, the degree of cooling by the cooling fan for decreasing the temperature, and the temperature change measured by the temperature sensor. The state can be detected.
[0022]
In the temperature sensor state detection method according to the eighth aspect of the invention, in addition to the configuration of the sixth or seventh aspect of the invention, the detection step is performed when the calculated temperature change does not match the measured temperature change. The step of detecting that the mounting state of the sensor is abnormal is included.
[0023]
According to the eighth aspect of the present invention, if the temperature change calculated based on the use state does not match the measured temperature change, it can be detected that the temperature sensor is abnormally attached.
[0024]
A temperature sensor state detection method according to a ninth aspect of the invention is a method in which the object is a secondary battery mounted on a vehicle, in addition to the configuration of any of the sixth to eighth aspects of the invention.
[0025]
According to the ninth aspect, it can be detected that the mounting state of the temperature sensor of the secondary battery for driving the vehicle mounted on the vehicle is abnormal.
[0026]
In the temperature sensor state detection method according to the tenth aspect of the invention, in addition to the configuration of the ninth aspect, the detection step includes a temperature rise factor due to charging and discharging from the secondary battery, and the secondary battery. And detecting that the mounting state of the temperature sensor is abnormal based on the temperature change calculated based on the temperature decrease factor due to the cooling of the temperature and the temperature change measured by the temperature sensor.
[0027]
According to the tenth invention, in a secondary battery mounted on a vehicle and repeatedly charged and discharged, it is represented by a temperature rise factor represented by a current value flowing through the secondary battery and a cooling degree of the cooling fan of the secondary battery. Based on the temperature lowering factor, it is possible to detect that the mounting state of the temperature sensor of the secondary battery is abnormal.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
[0029]
In the following description, a detection device that detects the attachment state of a temperature sensor attached to, for example, a nickel metal hydride battery, which is a secondary battery that supplies electric power to a vehicle drive motor via a vehicle power cable will be described. Note that the detection device according to the present invention is not limited to a nickel metal hydride battery.
[0030]
With reference to FIG. 1, a power unit of a vehicle including a battery ECU (Electronic Control Unit) 200 that realizes a detection device that detects the attachment state of the temperature sensor according to the embodiment of the present invention will be described. As shown in FIG. 1, the power unit of the vehicle includes a nickel metal hydride battery 100, a battery ECU 200, and a cooling fan 900 that cools the nickel metal hydride battery 100. Cooling fan 900 is controlled based on a control signal (operation instruction signal) from battery ECU 200, and sends cooling air to nickel metal hydride battery 100. This operation instruction signal includes four types of signals for instructing the cooling fan to operate at “OFF”, “weak”, “medium”, and “strong”. The cooling fan 900 changes the amount of cooling air sent to the nickel metal hydride battery 100 by changing the number of rotations of the motor that rotates the fan based on the operation instruction signal.
[0031]
In the nickel metal hydride battery 100, for example, six cells each having a rated voltage of 1.2V are connected in series to form one module, and 30 modules are connected in series, for a total of 180 cells and a voltage of 216V. It is configured to have a rated voltage.
[0032]
A temperature sensor 110 for measuring the temperature of the battery is attached to the nickel metal hydride battery 100. This temperature sensor 110 is attached so that a recess is formed in the resin battery case of the nickel metal hydride battery 100 and the recess is fitted into the recess. The battery ECU 200 includes an input / output interface 500 connected to the temperature sensor 110 and the battery-related warning output signal line, a CPU (Central Processing Unit) 300 that controls the battery unit, a clock 400, and a memory 600 that stores various data. including.
[0033]
The power supply terminal of the nickel metal hydride battery 100 is connected to a vehicle power cable and supplies power to the drive motor of the vehicle. In the nickel metal hydride battery 100, the temperature signal detected by the temperature sensor 110 that measures the temperature of the battery is transmitted to the CPU 300 via the input / output interface 500 of the battery ECU 200.
[0034]
The battery ECU 200 measures the battery temperature TB based on the temperature signal received from the temperature sensor 110 based on the clock signal measured by the clock 400, and calculates the battery temperature change amount ΔTB for each sampling time interval. The battery ECU 200 calculates a square integrated value Q of the battery current I at every sampling time interval based on the clock signal measured by the clock 400. The battery ECU 200 determines whether or not the battery temperature change amount ΔTB and the square integrated value Q of the battery current I are in a proportional relationship, and detects an abnormal mounting of the temperature sensor 110.
[0035]
Inside battery ECU 200, input / output interface 500, CPU 300, clock 400, and memory 600 are connected via an internal bus 800 and can perform data communication with each other.
[0036]
With reference to FIG. 2, the relationship between the square integrated value Q of the battery current I and the battery temperature change ΔTB will be described. In both cases of charging and discharging, the larger the current flowing through the nickel metal hydride battery 100, the more the chemical reaction inside the nickel metal hydride battery 100 becomes more active and more reaction heat is generated. The temperature rises. Further, as the current flowing through the nickel metal hydride battery 100 increases, more Joule heat is generated due to the internal resistance of the nickel metal hydride battery 100, and the temperature of the nickel metal hydride battery 100 increases. Such a temperature change ΔTB of the nickel-metal hydride battery 100 is proportional to the square integrated value of the battery current I. As shown in FIG. 2, although the temperature change state varies depending on the operation state of the cooling fan 900 (more specifically, the proportionality constant decreases as the degree of cooling increases), the temperature change ΔTB of the nickel-metal hydride battery 100 is There is a relationship proportional to the square integrated value of the battery current I. As described above, the temperature change of the nickel metal hydride battery 100 is calculated based on the current value that is a cause of temperature rise and the cooling degree (OFF, weak, medium, and strong) of the cooling fan 900 that is a cause of temperature decrease. Note that the proportionality constant between the squared integrated value Q of the battery current I and the temperature change ΔTB is α (0) when the cooling fan 900 is “OFF”, α (1) when “low”, and “medium”. Α (2) for “” and α (3) for “strong”. The proportional constants α (0), α (1), α (2), α (3) are stored in the memory 600.
[0037]
With reference to FIG. 3, a control structure of a program executed by CPU 300 of battery ECU 200 that realizes a detection device that detects the attachment state of the temperature sensor according to the present embodiment will be described.
[0038]
In step (hereinafter, step is abbreviated as S) 100, CPU 300 of battery ECU 200 determines whether or not the sampling time has been reached based on a signal from clock 400. When the sampling time is reached (YES in S100), the process proceeds to S102. If not (NO in S100), the process returns to S100.
[0039]
In S102, CPU 300 detects battery temperature TB based on a temperature signal from temperature sensor 110 provided in nickel metal hydride battery 100. In S104, CPU 300 determines whether or not detected battery temperature TB is within the range of the sensor. This determination is made based on whether or not the battery temperature TB is outside the sensor range by short-circuiting or disconnecting the signal line from the temperature sensor 110 to the input / output interface 500. If battery temperature TB is within the sensor range (YES in S104), the process proceeds to S106. If not (NO in S104), the process proceeds to S130.
[0040]
In S106, CPU 300 calculates battery temperature change ΔTB during the sampling time. This battery temperature change ΔTB is the difference between the battery temperature measured before one sampling time and stored in the memory 600, and the battery temperature measured this time.
[0041]
In S108, CPU 300 calculates a square integrated value Q of battery current I during the sampling time.
[0042]
In S110, CPU 300 determines whether or not battery temperature change ΔTB and square integrated value Q are proportional. At this time, based on the type of operation instruction signal to the cooling fan 900 and the proportionality constants α (0), α (1), α (2), and α (3) stored in the memory 600, the battery temperature change It is determined whether or not ΔTB is proportional to the square integrated value Q. When battery temperature change ΔTB is proportional to square integrated value Q (YES in S110), the process returns to S100. If not (NO in S110), the process proceeds to S112.
[0043]
In S112, CPU 300 determines whether or not the battery is being cooled. This determination is made based on whether an operation instruction signal from battery ECU 200 to cooling fan 900 is “weak”, “medium”, or “strong”. If the battery is being cooled (YES in S112), the process proceeds to S114. If not (NO in S112), the process proceeds to S116.
[0044]
In S114, CPU 300 determines whether or not the cooling system is normal. This determination is made based on whether or not the power supply to the cooling fan 900 is normally performed. For example, this determination is made by detecting the current value to cooling fan 900 and detecting whether or not the power line is disconnected. If the cooling system is normal (YES in S114), the process proceeds to S116. If not (NO in S114), the process proceeds to S120.
[0045]
In S116, CPU 300 determines that temperature sensor 110 has deviated from a predetermined position. At S118, CPU 300 performs temperature sensor attachment abnormality processing.
[0046]
In S120, CPU 300 performs cooling system abnormality processing. In S120, for example, the presence or absence of a system abnormality is confirmed by detecting disconnection of the fan motor.
[0047]
In S130, CPU 300 determines that temperature sensor 110 is short-circuited or disconnected. At S132, CPU 300 performs temperature sensor abnormality processing.
[0048]
In S118, S120, and S130, CPU 300 outputs a battery-related warning output signal. This battery-related warning output signal is output to, for example, the display monitor ECU, and a battery abnormality is displayed on the instrument panel of the vehicle. Further, after the processes in S118, S120, and S130, the process returns to S100, and the processes from S102 to S132 are performed at each sampling time.
[0049]
The operation of battery ECU 200 that realizes the state detection device for the temperature sensor according to the present embodiment based on the above-described structure and flowchart will be described.
[0050]
When the sampling time is reached during operation of the vehicle (YES in S100), battery temperature TB is detected based on a signal input from temperature sensor 110 to battery ECU 200 (S102). If detected battery temperature TB is within the sensor range (YES in S104), battery temperature change ΔTB during the sampling time is calculated (S106).
[0051]
A square integrated value Q of the battery current I during the sampling time is calculated (S108). At this time, as shown in FIG. 4, when the vehicle is traveling on the uphill road at a constant speed, the battery current value I tends to increase with time H. The square value of the battery current value in the sampling time interval corresponding to the hatched portion shown in FIG. Further, as shown in FIG. 5, charging and discharging from the nickel metal hydride battery 100 may be repeated depending on the traveling state of the vehicle. The square value of the battery current value in the sampling time interval corresponding to the hatched portion shown in FIG.
[0052]
When battery temperature change ΔTB and square integrated value Q are proportional (YES in S110), it is not determined that the temperature sensor is abnormally attached or the cooling system is abnormally processed.
[0053]
On the other hand, when battery temperature change ΔTB and square integrated value Q are not proportional (NO in S110) and battery is not being cooled (NO in S112), temperature sensor 110 is set in a predetermined position. It is determined that it is out of the range (S116). Even if the battery is being cooled (YES in S112), if the cooling system is normal (YES in S114), similarly, it is determined that temperature sensor 110 is out of the predetermined position. (S116).
[0054]
As described above, according to the battery ECU that realizes the temperature sensor state detection device according to the present embodiment, the temperature sensor measures the temperature of the secondary battery mounted on the vehicle. The battery ECU determines whether the temperature change calculated based on the integrated value of the square value of the current value flowing through the battery is proportional to the temperature change measured by the temperature sensor. At this time, it is determined whether the proportionality relationship is established by changing the proportionality constant according to the operating state of the cooling fan. As a result of such comparison, if the measured temperature change does not have a proportional relationship with the calculated temperature change, it is determined that the temperature sensor is attached abnormally. As a result, it is possible to accurately grasp the state of the temperature sensor that measures the temperature of a secondary battery such as a nickel metal hydride battery mounted on the vehicle.
[0055]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a control block diagram of a vehicle including a battery ECU according to the present embodiment.
FIG. 2 is a diagram showing a relationship between a square integrated value of battery current and a change in battery temperature.
FIG. 3 is a flowchart showing a control structure of a program executed by battery ECU according to the present embodiment.
FIG. 4 is a diagram showing a change over time of a battery current value mounted on a vehicle traveling on a constant climbing road.
FIG. 5 is a diagram showing a time change of a battery current value mounted on a running vehicle.
[Explanation of symbols]
100 Nickel metal hydride battery, 200 Battery ECU, 300 CPU, 400 clock, 500 Input / output interface, 600 Memory, 800 Internal bus, 900 Cooling fan.

Claims (10)

A temperature sensor attached to the object for measuring the temperature of the object;
Determining means for determining whether or not the measurement result by the temperature sensor is in a predetermined temperature range;
When it is determined by the determination means that the measurement result is in a predetermined temperature range, the temperature is calculated based on the temperature change calculated based on the usage state of the object and the measurement result by the temperature sensor. and a detection means for detecting a mounting state of the sensor seen including,
The detecting means is means for detecting an attachment state of the temperature sensor based on whether or not a temperature change based on the measurement result is proportional to a square integrated value of a current value flowing through the object. A temperature sensor state detection device. The temperature sensor state detection device according to claim 1, wherein the proportional relationship is a relationship in which a temperature increase factor resulting from a use state of the object and a temperature decrease factor due to cooling of the object are considered . 3. The temperature sensor state detection device according to claim 1, wherein the detection means includes means for detecting that the mounting state of the temperature sensor is abnormal when the proportional relationship is not established . 4.   The state detection device for a temperature sensor according to claim 1, wherein the object is a secondary battery mounted on a vehicle. The detection means is based on a temperature change calculated based on a temperature increase factor due to charging and discharging from the secondary battery, and a temperature decrease factor due to cooling of the secondary battery, and the measurement result. The temperature sensor state detection device according to claim 4, comprising means for detecting that the mounting state of the temperature sensor is abnormal based on a temperature change. A method of detecting a state of a temperature sensor that is attached to an object and measures the temperature of the object,
A determination step of determining whether or not the measurement result by the temperature sensor is in a predetermined temperature range;
When it is determined that the measurement result is in a predetermined temperature range in the determination step, based on the temperature change calculated based on the usage state of the object and the measurement result by the temperature sensor, and a detection step of detecting the mounting state of the temperature sensor seen including,
The detecting step includes a step of detecting an attachment state of the temperature sensor based on whether or not a temperature change based on the measurement result is proportional to a square integrated value of a current value flowing through the object. , Temperature sensor state detection method. The temperature sensor state detection method according to claim 6, wherein the proportional relationship is a relationship in which a temperature increase factor due to a use state of the object and a temperature decrease factor due to cooling of the object are considered . The temperature sensor state detection method according to claim 6 or 7, wherein the detection step includes a step of detecting that the mounting state of the temperature sensor is abnormal when the proportional relationship is not established .   The temperature sensor state detection method according to claim 6, wherein the object is a secondary battery mounted on a vehicle. The detection step includes a temperature change calculated based on a temperature increase factor due to charging and discharging from the secondary battery, and a temperature decrease factor due to cooling of the secondary battery, and a temperature based on the result. The temperature sensor state detection method according to claim 9, further comprising a step of detecting that the mounting state of the temperature sensor is abnormal based on a change.

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