JP2023149586A - Vehicle battery monitoring system - Google Patents

Abstract

An object of the present invention is to provide a vehicle battery monitoring system that can quickly determine whether a battery from a vehicle has been stolen or whether the vehicle has suffered an attack that causes the power supply to fail.
A vehicle battery monitoring system (10) includes a sensor (40), a current consumption circuit (50), a capacitor (32), and a control device (80). The control device 80 acquires a measured voltage value obtained by measuring the voltage by the sensor 40, controls the operation of the current consumption circuit 50 based on the measured voltage value, and controls the operation of the sensor 40 based on the measured voltage value. do. The control device 80 compares the measured voltage value with a first voltage value that is lower than the voltage of the power supply. The control device 80 performs at least one of the responsiveness improvement process and the current consumption process when the first voltage value and the measured voltage value become equal as the measured voltage value decreases.
[Selection diagram] Figure 1

Description

The present invention relates to vehicle battery monitoring systems.

BACKGROUND ART A monitoring system that monitors vehicle theft has been known (for example, see Patent Document 1). This monitoring system includes a monitoring unit that monitors the rate of decrease in battery voltage. The monitoring unit monitors a decrease in battery voltage, and determines that the vehicle has been stolen when the rate of decrease becomes greater than a predetermined value. When theft is determined, the monitoring system activates the alarm. The alarm emits an alarm sound to the outside of the vehicle.

JP2014-46722A

By the way, a vehicle is equipped with a control unit that performs driving control. Generally, the control unit includes a capacitor capable of charging or discharging power and connected to a power system circuit. For example, if a battery is stolen from a vehicle, the power charged in the capacitor is supplied to the power system circuit.

Although the above-mentioned monitoring system is capable of monitoring vehicle theft, it is difficult to quickly determine whether or not a battery has been stolen from a vehicle. Specifically, the monitoring system described above continues to monitor the voltage discharged from the capacitor after a battery is stolen from a vehicle. Such voltage decreases slowly. Therefore, it takes a long time from when the battery is stolen until it is determined that the battery has been stolen, and it also takes a long time until the alarm is activated. Therefore, there is a problem in that the timing at which the alarm sound is emitted to notify the outside of the vehicle of battery theft is delayed.

Furthermore, it is conceivable to perform the theft determination based on the amount of voltage fluctuation per unit time in the power supply system circuit so that the theft determination can be made even if there is a gradual voltage drop as described above. However, since the amount of voltage fluctuation is small, there is a problem that an incorrect determination may be made.

The present invention has been made in view of the above-mentioned circumstances, and provides a vehicle battery monitoring system that can quickly determine whether the battery from the vehicle has been stolen or whether the vehicle has been subjected to an attack that causes the power supply to fail. The purpose is to provide

A vehicle battery monitoring system according to one aspect of the present invention (for example, the monitoring system 10 of the embodiment) is a power supply system circuit (for example, the a power supply system circuit 11), a sensor connected to the power system circuit and measuring the voltage of the power system circuit (for example, the sensor unit 40 of the embodiment), and a sensor connected to the power system circuit and measuring the current consumption in the power system circuit. A current consumption circuit that is connected to a current consumption circuit (for example, the current consumption circuit 50 of the embodiment) and a power supply system circuit that obtains a measured voltage value obtained by measuring the voltage by a sensor, and based on the measured voltage value, the current consumption circuit and a control device (for example, the system control unit 80 of the embodiment) that controls the operation of the sensor. The control device compares the measured voltage value with a first voltage value that is lower than the voltage that the power supply supplies to the power system circuit. The control device performs at least one of the responsiveness improvement process and the current consumption process when the first voltage value and the measured voltage value become equal as the measured voltage value decreases. In the responsiveness improvement process, the control device operates the sensor to increase the number of measurements per unit time of the sensor. In the current consumption process, the control device operates the current consumption circuit to increase the amount of current consumption in the power system circuit.
According to this configuration, it is possible to quickly determine whether the power source has been stolen or whether the vehicle has been attacked in a manner that causes the power source to fail.

The vehicle battery monitoring system according to one aspect of the present invention may include an alarm device (for example, the alarm device 60 of the embodiment) that can generate an alarm sound and is controlled by a control device. . The control device compares the second voltage value, which is a value lower than the first voltage value, with the measured voltage value, and the control device compares the second voltage value and the measured voltage value as the measured voltage value decreases. An alarm may be operated to generate an alarm when the two values become equal.
According to this configuration, by the alarm emitting an alarm sound, it is possible to notify a person outside the vehicle that the power source has been stolen or that the vehicle has been subjected to an attack that causes the power source to fail.

According to the vehicle battery monitoring system according to one aspect of the present invention, it is possible to quickly determine whether the battery from the vehicle has been stolen or whether the vehicle has been subjected to an attack that causes the power supply to fail.

1 is a functional block diagram showing an example of the configuration of a vehicle battery monitoring system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the operation of the vehicle battery monitoring system according to the embodiment of the present invention, and is a graph showing changes in voltage drop in the power supply system circuit. FIG. 2 is a diagram illustrating the operation of a conventional vehicle battery monitoring system, and is a graph showing changes in voltage drop in a power supply system circuit.

A vehicle battery monitoring system according to an embodiment of the present invention will be described based on the drawings.
In the following description, the monitoring system is an example of a vehicle battery monitoring system.

As shown in FIG. 1, a monitoring system 10 according to the embodiment is provided in a vehicle. The vehicle is, for example, a BEV (Battery Electric Vehicle) that runs on an electric motor that is driven by electric power supplied from a battery (secondary battery) for driving. The configuration of the vehicle is not limited to BEV. The vehicle may be a hybrid vehicle with an external charging function, for example, a PHV (Plug-in Hybrid Vehicle) or a PHEV (Plug-in Hybrid Electric Vehicle).

Vehicles include, for example, not only four-wheeled vehicles, but also saddle-type two-wheeled vehicles, three-wheeled vehicles (including vehicles with one front wheel and two rear wheels, as well as vehicles with two front wheels and one rear wheel), and assist-type vehicles. This includes all types of moving objects that are driven by electric motors that are powered by electric power supplied from batteries, such as bicycles and electric boats.

<Monitoring system 10>
The monitoring system 10 includes a power supply system circuit 11, a battery 20, a vehicle control unit 30, a sensor unit 40, a current consumption circuit 50, an alarm 60, and a system control unit 80.
The power supply system circuit 11 is a low voltage power supply system circuit used for driving auxiliary equipment. Auxiliary equipment is accessory equipment necessary for driving the vehicle, such as a starter motor, an alternator, a radiator, and the like.

As shown in FIG. 1, in the power supply system circuit 11, a power supply circuit using wiring 70 is obtained. Specifically, battery 20 and vehicle control unit 30 are connected via wiring 70. Battery 20 and current consumption circuit 50 are connected via wiring 70. Current consumption circuit 50 and sensor unit 40 are connected via wiring 70. Battery 20 and alarm device 60 are connected via wiring 70. Sensor unit 40 and system control unit 80 are connected via wiring 70.
In FIG. 1, illustrations of control lines for controlling the current consumption circuit 50, sensor unit 40, and alarm 60 by the system control unit 80, and signal lines between the sensor unit 40 and the system control unit 80 are omitted. ing.

<Battery 20>
Battery 20 is an example of a power source.
The battery 20 is electrically connected to the power system circuit 11 and supplies power to the power system circuit 11. The battery 20 is detachably attached to the vehicle.
The battery 20 is a monitoring target monitored by the monitoring system 10. In other words, the monitoring system 10 determines whether the battery 20 has been stolen from the vehicle or whether the vehicle has been subjected to an attack that causes the battery 20 to fail.

In this embodiment, the battery 20 is, for example, a low voltage battery with an output of about 12V. The battery 20 supplies power to the power supply system circuit 11 for driving the auxiliary equipment that constitutes the vehicle.

<Vehicle control unit 30>
Vehicle control unit 30 is connected to power supply system circuit 11 . The vehicle control unit 30 controls the driving of the vehicle, controls the air conditioning in the vehicle, and controls other systems such as audio used in the vehicle.
The vehicle control unit 30 includes, for example, an ECU (Electronic Control Unit) 31 and a capacitor 32. Vehicle control unit 30 may include an electric circuit as a component other than ECU 31 and capacitor 32.
That is, vehicle control unit 30 is a different control unit from system control unit 80. In other words, the vehicle control unit 30 can be referred to as another control unit that controls the vehicle.

ECU 31 and capacitor 32 are electrically connected to power system circuit 11 . The capacitor 32 is charged with a portion of the power of the battery 20 through the power supply system circuit 11. Even if the battery 20 is removed from the power system circuit 11, the capacitor 32 supplies power to the power system circuit 11. In other words, the capacitor 32 supplies power to the power supply system circuit 11 while the voltage of the capacitor 32 decreases.

<System control unit 80>
System control unit 80 is an example of a control device.
The system control unit 80 is configured to obtain a measured voltage value obtained by measuring the voltage by the sensor unit 40. System control unit 80 is configured to control the operation of current consumption circuit 50 based on the measured voltage value. System control unit 80 is configured to control the operation of sensor unit 40 based on the measured voltage value.

<Sensor unit 40>
The sensor unit 40 is an example of a sensor.
The operation of sensor unit 40 is controlled by system control unit 80. The sensor unit 40 outputs the measurement results obtained by the sensor unit 40 to the system control unit 80.

The sensor unit 40 includes, for example, an airborne ultrasonic sensor. An airborne ultrasonic sensor is a device that uses the reflection characteristics of ultrasonic waves to detect whether there is an act of intrusion into the interior of a vehicle, and is sometimes called an ultrasonic sensor (U/S). .
The sensor unit 40 includes not only an airborne ultrasonic sensor but also various sensors such as a current sensor, a voltage sensor, and a temperature sensor. The voltage sensor that constitutes the sensor unit 40 is connected to the power system circuit 11 and measures the voltage of the power system circuit 11.

<Current consumption circuit 50>
The current consumption circuit 50 is connected to the power supply system circuit 11.
The current consumption circuit 50 is configured of a circuit including, for example, a FET (Field Effect Transistor), a resistor, and the like. The operation of current consumption circuit 50 is controlled by system control unit 80. Specifically, when the current consumption circuit 50 is activated under the control of the system control unit 80, the current consumption circuit 50 accelerates the current consumption (power consumption) of the power supply system circuit 11.

<Alarm 60>
The alarm device 60 is connected to the power supply system circuit 11.
The alarm device 60 can generate an alarm sound to the outside of the vehicle. In particular, in this embodiment, when the alarm 60 is activated under the control of the system control unit 80, the alarm 60 emits an alarm sound and indicates that the battery 20 has been stolen from the vehicle or that the battery 20 has failed. Notify anyone outside the vehicle that the vehicle has been attacked in a way that could cause

<Modified example of monitoring system 10>
In the monitoring system 10 shown in FIG. 1, the system control unit 80 and the sensor unit 40 are configured separately from each other. The system control unit 80 and the sensor unit 40 may be configured as one unit. Furthermore, the current consumption circuit 50 may be built into the system control unit 80 or the sensor unit 40.

<Operation of the monitoring system 10 and operation of the conventional monitoring system>
Next, the operation of the monitoring system 10 and the operation of a conventional monitoring system will be described with reference to FIGS. 2 and 3. FIG. 2 is a graph showing the operation of the monitoring system 10 according to this embodiment. FIG. 3 is a graph showing the operation of a conventional monitoring system.

In each of FIGS. 2 and 3, the horizontal axis indicates the passage of time from the start of the theft of the battery 20 (elapsed time, unit: seconds). On the horizontal axis, "0" indicates the time point when the battery 20 is stolen.
The vertical axis indicates the voltage (unit: V) of the power supply system circuit. In other words, the vertical axis indicates the measured voltage value obtained by the voltage sensor that constitutes the sensor unit 40. On the vertical axis, "V0" indicates the voltage of the power system circuit at the time when the battery 20 is stolen. The value of V0 is the voltage value of the power that the battery 20 supplies to the power system circuit, and is, for example, 12V.

Regarding the explanation of FIGS. 2 and 3, "the time since the theft of the battery 20 started" can be read as "the time since the vehicle received an attack that caused the battery 20 to fail." Furthermore, "the time when the battery 20 is stolen" can be read as "the time when the vehicle receives an attack that causes the battery 20 to fail."

<Operation example 1 of monitoring system 10>
First, it is assumed that the engine of the vehicle is not started and the doors are locked. In this state, the airborne ultrasonic sensor constituting the sensor unit 40 is activated, and the airborne ultrasonic sensor continues to detect whether or not there is an act of intrusion into the interior of the vehicle.

In this state, if the battery 20 is removed from the vehicle, that is, if the battery 20 is stolen from the vehicle or if the vehicle receives an attack that causes the battery 20 to malfunction, power is not supplied from the battery 20 to the power system circuit 11. is blocked. In other words, the battery 20 and the power system circuit 11 are in a disconnected state.

Even if the battery 20 is disconnected from the power system circuit 11, the voltage of the power system circuit 11 does not immediately become zero because the power stored in the capacitor 32 is supplied to the power system circuit 11. As time passes, the voltage of the power system circuit 11 gradually decreases while the current in the sensor unit 40 and the system control unit 80 is consumed.

In this state, the system control unit 80 compares the first voltage value V1 and the measured voltage value.
The first voltage value V1 is a value lower than the voltage that the battery 20 supplies to the power supply system circuit 11. The value of the first voltage value V1 is a voltage value (voltage drop) set in the system control unit 80, and is set to 10V, for example. The first voltage value V1 can also be referred to as a disconnection determination process start voltage.

Next, as the measured voltage value decreases over time, the first voltage value V1 and the measured voltage value become equal at time t1. At this time, the system control unit 80 performs responsiveness improvement processing.
In the responsiveness improvement process, the system control unit 80 operates the sensor unit 40 so as to increase the number of measurements per unit time of the sensor unit 40.
As a result, the responsiveness of the sensor unit 40 is improved by increasing the number of communications per unit time of voltage monitoring. Furthermore, current consumption in the sensor unit 40 is accelerated, and the voltage of the power system circuit 11 is rapidly reduced. Therefore, it is possible to quickly determine whether the battery 20 has been stolen from the vehicle or whether the vehicle has been attacked in a way that causes the battery 20 to fail.

In this state, the system control unit 80 compares the second voltage value V2 and the measured voltage value.
The second voltage value V2 is a value lower than the first voltage value V1. The value of the second voltage value V2 is a voltage value (voltage drop) set in the system control unit 80, and is set to 8V, for example. The first voltage value V1 can also be referred to as an alarm-enabled start-enabled voltage.

Next, when the measured voltage value decreases rapidly, the second voltage value V2 and the measured voltage value become equal at time t2. At this time, the system control unit 80 activates the alarm device 60. The alarm device 60 emits an alarm sound to notify a person outside the vehicle that the battery 20 has been stolen from the vehicle or that the vehicle has been attacked in a manner that causes the battery 20 to fail. Thereby, the alarm device 60 can emit an alarm sound to notify a person outside the vehicle that the battery 20 has been stolen from the vehicle or that the vehicle has been attacked in a manner that causes the battery 20 to fail.

<Operation example 2 of the monitoring system 10>
In operation example 2 described below, the same members as those in operation example 1 described above are given the same reference numerals, and the description thereof will be omitted or simplified. Further, a description that overlaps with Operation Example 1 is omitted, and a description will be given of a situation after the battery 20 is stolen or after the vehicle receives an attack that causes the battery 20 to fail.

When the battery 20 is stolen from the vehicle or the vehicle is attacked in a manner that causes the battery 20 to fail, the battery 20 and the power system circuit 11 become disconnected, and the voltage of the power system circuit 11 gradually decreases.
The system control unit 80 compares the first voltage value V1 and the measured voltage value.
As the measured voltage value decreases over time, the first voltage value V1 and the measured voltage value become equal at time t1. At this time, the system control unit 80 performs current consumption processing.

In the current consumption process, the system control unit 80 operates the current consumption circuit 50 to increase the amount of current consumption in the power supply system circuit 11.
This promotes current consumption in the current consumption circuit 50, and the voltage of the power supply system circuit 11 decreases rapidly. Therefore, it is possible to quickly determine whether the battery 20 has been stolen from the vehicle or whether the vehicle has been attacked in a way that causes the battery 20 to fail.

In this state, the system control unit 80 compares the second voltage value V2 and the measured voltage value.
When the measured voltage value rapidly decreases, the second voltage value V2 and the measured voltage value become equal at time t2. At this time, the system control unit 80 activates the alarm device 60. The alarm device 60 emits an alarm sound to notify a person outside the vehicle that the battery 20 has been stolen from the vehicle or that the vehicle has been attacked in a manner that causes the battery 20 to fail. Thereby, the alarm device 60 can emit an alarm sound to notify a person outside the vehicle that the battery 20 has been stolen from the vehicle or that the vehicle has been attacked in a manner that causes the battery 20 to fail.

<Modified example of operation of monitoring system 10>
In the first operation example described above, the system control unit 80 executes the responsiveness improvement process. In the second operation example described above, the system control unit 80 executes current consumption processing. The responsiveness improvement process and the current consumption process may be performed simultaneously.
According to this modification, the current consumption in the current consumption circuit 50 is further promoted, and the voltage of the power supply system circuit 11 is further rapidly reduced. Therefore, it is possible to quickly determine whether the battery 20 has been stolen from the vehicle or whether the vehicle has been attacked in a way that causes the battery 20 to fail.

<Operation of conventional monitoring system>
Unlike the above-described monitoring system 10, the conventional monitoring system does not include a system control unit 80, a sensor unit 40, and a current consumption circuit 50 for performing responsiveness improvement processing or current consumption processing. In other words, in the conventional monitoring system, even if the first voltage value V1 and the measured voltage value become equal at time t1, the responsiveness improvement process and the current consumption process are not performed. The voltage of the power system circuit 11 gradually decreases.

Therefore, the period between time t1 and time t2 in the conventional monitoring system is longer than the period between time t1 and time t2 in the monitoring system 10. Therefore, it is not possible to quickly determine whether the battery has been stolen from the vehicle or whether the vehicle has been attacked in a way that causes the battery 20 to fail. Compared to the case of the monitoring system 10, the time at which the alarm sound is emitted is delayed to notify a person outside the vehicle that the battery has been stolen from the vehicle or that the vehicle has been subjected to an attack that causes the battery 20 to fail. is delayed.

Although the embodiments of the present invention have been described above, it should be understood that these are illustrative of the present invention and should not be considered as limiting. Additions, omissions, substitutions, and other changes may be made without departing from the scope of the invention. Accordingly, the invention should not be considered limited by the foregoing description, but rather by the scope of the claims.

10 Monitoring system (vehicle battery monitoring system)
11 Power supply system circuit 20 Battery (power supply)
30 Vehicle control unit 32 Capacitor 40 Sensor unit (sensor)
50 Current consumption circuit 60 Alarm 70 Wiring 80 System control unit (control device)

Claims (2)

A power supply system circuit to which the power supply to be monitored is connected;
a sensor connected to the power system circuit and measuring the voltage of the power system circuit;
a current consumption circuit connected to the power supply system circuit and promoting current consumption in the power supply system circuit;
a control device that is connected to the power supply system circuit, acquires a measured voltage value obtained by measuring the voltage by the sensor, and controls the operation of the current consumption circuit and the sensor based on the measured voltage value;
Equipped with
The control device compares the measured voltage value with a first voltage value that is a lower value than the voltage supplied by the power supply to the power supply system circuit,
The control device performs at least one of a responsiveness improvement process and a current consumption process when the first voltage value and the measured voltage value become equal due to a decrease in the measured voltage value,
In the responsiveness improvement process, the control device operates the sensor to increase the number of measurements per unit time of the sensor;
In the current consumption process, the control device operates the current consumption circuit to increase current consumption in the power supply system circuit.
Vehicle battery monitoring system. comprising an alarm device capable of generating an alarm sound and controlled by the control device,
The control device compares a second voltage value that is a lower value than the first voltage value and the measured voltage value,
The control device operates the alarm so as to generate the alarm sound when the second voltage value and the measured voltage value become equal as the measured voltage value decreases.
The vehicle battery monitoring system according to claim 1.

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