JP2006188139A - On-vehicle power supply control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a battery from being exhausted while an automobile engine is in a stop state. <P>SOLUTION: This on-vehicle power supply control system calculates an intermittent time relating to intermittent driving of a prescribed load inside an automobile in accordance with an assured operation period input through a touch panel or the like of a car navigation system 9 after a charging condition of a battery 5 is detected. In this case, the on-vehicle power supply control system calculates a charging state of the battery 5 so as to avoid exhaustion of the battery within the assured operation period after engine stopping. Thus, the exhaustion of the battery can be avoided at least for the assured operation period. Therefore, for example, even if an automobile is parked at an airport parking lot for a long trip, the exhaustion of the battery 5 can be avoided on a scheduled date of return to the airport by inputting the assured operation period in accordance with the scheduled date of return to the airport. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-vehicle power management device that manages the state of charge of a battery mounted on an automobile.

  In a parking lot or the like, when boarding a self-locked automobile, the door lock is released without performing a key operation carried by the user. This is a system generally called "smart entry" or "keyless entry", etc., the user carries the remote control key in a pocket or bag, the welcome lamp lights up when approaching the car, The door lock is automatically released simply by grasping the door handle. In this case, wireless communication is performed between the automobile and the remote control key.

  The power consumed for wireless communication between the automobile and the remote control key usually depends on the power supply from the battery in the automobile.

  By the way, charging of an automobile battery is usually performed by generating electricity with an alternator while the automobile is running and regenerating the generated electric power in the battery. For this reason, at the time of parking when the automobile is not running, it is important to prevent so-called charging out when the electric power from the battery is consumed for wireless communication between the automobile and the remote control key.

  As a measure for preventing the battery of the automobile from running out, it is possible to reduce the overall power consumption by combining with other sensors with low power consumption. For example, when a car is parked, a peripheral sensor that consumes less power compared to wireless communication between the car and a remote control key is operated, and the car is only detected when the sensor detects the surrounding people. A method of attempting wireless communication with a remote control key can be considered (Patent Document 1: Prior Art 1).

  Alternatively, as another example of measures for preventing the battery from running out of the car, a method of changing the frequency of wireless communication with time as shown in FIG. It is done. In this method, for example, within a certain period T1 (for example, 5 days) from the time t1 when the engine of the automobile is stopped, a request signal is periodically transmitted from the automobile to the remote control key, for example, every 0.3 seconds. Attempts to communicate wirelessly relatively frequently. On the other hand, the transmission frequency of the request signal is decreased every 0.6 seconds, for example, after time t2 when a certain period T1 has elapsed since the engine stop of the automobile. Furthermore, the transmission of the request signal from the automobile to the remote control key is completely stopped after the time point t3 when a certain period T2 (for example, 14 days) longer than T1 has elapsed since the engine stop (Prior Art 2).

  In this prior art 2, when the car is left for a long time and there is no input signal, it can be determined at time t2 and t3, and the stop interval of subsequent request signals can be extended or stopped. Battery can be prevented from running out.

  Note that the symbol “x” in FIG. 4 indicates the timing at which a call signal for starting wireless communication is transmitted from the automobile to the remote control key.

JP 2003-155858 A

  In the above-described prior art 1, wireless communication from the automobile to the remote control key is activated even when there is no connection with the automobile such as a passerby or an animal other than the owner of the automobile, and as a result, the battery May go up. Further, in the prior art 1, since power is consumed by other sensors such as the peripheral detection sensor, there is a limit in saving power consumption, and it is difficult to prevent the battery from being exhausted depending on the leaving period of the automobile. There is.

  On the other hand, in the prior art 2, since the request signal is stopped after the time point t3, it is possible to easily prevent the battery from running up except for the dark current in the automobile and the self-discharge of the battery.

  However, in this prior art 2, since the wireless communication between the automobile and the remote control key is completely stopped after a certain period T2 from the engine stop, the portable key operation is performed after leaving for a long time. It is impossible and inconvenient to release the door lock. In addition, even during the period from time t2 to time t3, since the frequency of transmission of request signals transmitted from the automobile to the remote control key is reduced, the door lock may not be released promptly.

  Such a problem is not only limited to smart entry and keyless entry, but is a problem common to loads in which power is consumed for some purpose in a parked (engine-off) vehicle.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an in-vehicle power management device that can easily prevent the battery from running out while enabling the operation of the load according to the period desired by the driver even when the automobile engine is stopped for a long period of time. There is.

  In order to solve the above-mentioned problem, the invention according to claim 1 is an in-vehicle power management device that manages a charging state of a battery mounted on an automobile, a capacity detection unit that detects the charging state of the battery, In accordance with the operation guarantee period input through the input means, an intermittent time related to intermittent driving of a predetermined load in the vehicle is compared with the charging state detected by the capacity detection unit. And an intermittent time calculation unit that calculates so as to avoid running out of charge of the battery within the operation guarantee period after the engine is stopped.

  The invention according to claim 2 is the in-vehicle power management device according to claim 1, wherein the intermittent time calculation unit is configured to load the load over the operation guarantee period from the charge state detected by the capacity detection unit. The power consumption generated regardless of the driving of the vehicle and the minimum holding power necessary for starting the starter of the automobile are subtracted, and the operation guarantee period is added to the subtracted value and the power consumption per operation of the load. The intermittent time is calculated by calculating a ratio with the integrated value.

  The invention according to claim 3 is the in-vehicle power management device according to claim 1 or 2, wherein the load is driven intermittently according to the intermittent time calculated by the intermittent time calculation unit. It is.

  The in-vehicle power management device according to the first to third aspects of the present invention detects the state of charge of the battery and intermittently applies a predetermined load in the vehicle according to an operation guarantee period input through a predetermined input means. Since the intermittent time for proper driving is calculated so as to avoid the battery being out of charge within the operation guarantee period after the engine is stopped with respect to the state of charge of the battery, the battery will not run out at least during the operation guarantee period. . Therefore, for example, when a car is parked at an airport parking lot and a long trip is required, if the user inputs an operation guarantee period according to the scheduled return date to the airport, etc. Conveniently, it is possible to easily prevent the battery from being exhausted during the day.

  The in-vehicle power management device according to the second aspect of the present invention has an advantage that the battery can be reliably prevented from being discharged in consideration of power consumption such as dark current.

<Configuration>
FIG. 1 is a block diagram showing an in-vehicle power management device 1 according to an embodiment of the present invention. This in-vehicle power management device 1 is installed in a vehicle in which the engine 2 is off, such as when parked, when loads 3a and 3b for intermittent driving (intermittent driving) are installed for some purpose. The operation guarantee period of the loads 3a and 3b can be specified by an input operation, and the operation of the loads 3a and 3b can be executed reliably during the designated operation guarantee period. The intermittent time of intermittent driving of the loads 3a and 3b is changed.

  Specifically, the in-vehicle power management device 1 has a built-in CPU (microphone processor) having a function of a computer device to which a rewritable ROM (flash ROM, etc.) and a RAM are connected. It is a functional component that operates according to an operation procedure defined by a software program. As shown in FIG. 1, the in-vehicle power management device 1 includes a capacity detection unit 7 that detects a state of charge (SOC) of a battery (battery) 5 and a touch panel of a car navigation device 9 as input means installed in the vehicle. Two functional elements such as an intermittent time calculation unit 11 that calculates an intermittent time related to driving of the loads 3a and 3b according to the operation guarantee period when the operation guarantee period is input are provided.

  The capacity detection unit 7 measures predetermined values such as an open circuit voltage, a regenerative current, and a discharge current of the battery 5 using predetermined measuring means such as a voltage sensor and a current sensor (such as a shunt resistor), and based on the measurement result. Thus, the state of charge (SOC) of the battery 5 is detected at regular intervals. Alternatively, the capacity detection unit 7 obtains information from not only the voltage sensor and the current sensor as described above but also a temperature sensor for detecting the temperature of the battery 5, and includes information on the temperature. Based on the information from the voltage sensor or current sensor, the state of charge of the battery 5 detected based on the information may be corrected. Then, immediately after the automobile engine 2 is stopped, the capacity detection unit 7 outputs the value of the state of charge of the battery 5 at that time to the intermittent time calculation unit 11.

  For example, the intermittent time calculation unit 11 stores in advance in a rewritable ROM or the like based on the value “SOCnow” of the state of charge (remaining battery capacity) given from the capacity detection unit 7 and the operation guarantee period “D”. The intermittent time “T” related to driving of the loads 3a and 3b is calculated according to the following stored equation (1).

  Note that “SOCone” in the above equation (1) is the power consumption per operation of the loads 3a and 3b, and “SOCmin” is the minimum required to start the starter 13 when starting the engine 2 or the like. The minimum holding power, “SOCdark”, means the power consumption per day of the entire vehicle related to dark current when the loads 3a and 3b are not operating. The operation guarantee period “D” is expressed in days.

  That is, in the above equation (1), the power consumption “D × SOCdark” such as dark current consumed over the operation guarantee period “D” and the minimum holding power “SOCmin” necessary for starting the starter 13 are: A value obtained by subtracting from the value “SOCnow” of the state of charge (remaining battery capacity) of the battery 5 and a value obtained by adding the operation guarantee period “D” to the power consumption “SOCone” per operation of the loads 3a and 3b. Since the intermittent time “T” for driving the loads 3a and 3b is calculated by calculating the ratio, the battery 5 rises (out of charge) in consideration of power consumption “SOCdark” such as dark current. Therefore, there is an advantage that the battery can be surely prevented from running out.

  Here, in the intermittent time calculation unit 11, it is assumed that a predetermined value (for example, 14 days) is stored as an initial value for the value of the operation guarantee period “D” and is operated through the touch panel of the car navigation device 9. In the case of an input, instead of the above initial value, the value input by the touch panel is overwritten in the operation guarantee period “D”.

  And the intermittent time calculation part 11 outputs the information of this intermittent time "T" to load 3a, 3b through predetermined | prescribed communication networks, such as vehicle-mounted LAN.

  Each of the loads 3a and 3b has a CPU (microphone processor) having a function of a computer device to which a timer, a ROM, a RAM, and the like are connected, and the CPU is defined by a predetermined software program. It operates according to the operation procedure. Then, when the intermittent time “T” from the intermittent time calculation unit 11 is obtained, each of the loads 3a and 3b, for each intermittent time “T” as shown in FIG. It performs its own behavior. Note that the symbol “x” in FIG. 2 indicates the execution timing of the operation unique to each of the loads 3a and 3b.

  As an example of the loads 3a and 3b, any device may be used as long as it is a device that controls a function executed in the automobile while the engine 2 is stopped. For example, in addition to “smart entry” and “keyless entry”, theft For example, a peripheral monitoring system for prevention or a current location notification system is suitable.

  In addition, the code | symbol 15 in FIG. 1 has shown the generator which converts the rotational force of the engine 2 into electric power.

<Operation>
The operation of the in-vehicle power management device having the above configuration will be described. First, when the engine 2 is in a driving state, the rotational force of the engine 2 is converted into electric power by the generator 15. At this time, the battery (battery) 5 is charged using surplus power.

  If the user inputs an operation guarantee period value through the touch panel of the car navigation device 9 in step S01 in FIG. 3, the process proceeds to step S02, and the operation guarantee period value can be rewritten. The update is stored in.

  On the other hand, if the user does not input the operation guarantee period value through the touch panel of the car navigation device 9 in step S01 in FIG. 3, the process directly proceeds to step S03.

  In step S <b> 03 in FIG. 3, the capacity detection unit 7 detects the state of charge of the battery 5.

  Subsequently, in step S04, it is determined whether or not the engine 2 is stopped. If the engine 2 remains driven, the process returns to step S01 again. Such loop processing of steps S01 to S04 is repeated every predetermined time (for example, 0.3 seconds).

  If it is detected in step S04 that the engine 2 has stopped, the process proceeds to step S05.

  In step S05, based on the value “SOCnow” of the state of charge given from the capacity detection unit 7 and the operation guarantee period “D”, according to the above equation (1) stored in advance in a rewritable ROM or the like. Then, an intermittent time “T” related to driving of the loads 3a and 3b is calculated.

  Then, the intermittent time calculation unit 11 outputs information on the intermittent time “T” to the loads 3a and 3b through a predetermined communication network such as an in-vehicle LAN (step S06).

  Then, each load 3a, 3b performs the operation | movement intrinsic | native for every intermittent time "T" obtained from the intermittent time calculation part 11, as shown in FIG. For example, when the first load 3a is a device for “smart entry” or “keyless entry”, the intermittent time when the request signal is intermittently transmitted from the load 3a to an external key is “ The operation is performed as “T”.

  In this way, at least during the operation guarantee period “D” in which the user performs an input operation, the state of charge of the battery 5 does not fall below the minimum holding power SOCmin. Therefore, for example, when a car is parked at an airport parking lot and a long-term trip is to be performed, if the user inputs the operation guarantee period “D” in accordance with the scheduled return date to the airport, etc. Conveniently, the battery 5 can be prevented from running out on the scheduled return date.

  In the above equation (1), it is possible to reliably and easily prevent the battery 5 from running out in consideration of power consumption “SOCdark” such as dark current.

  In the above embodiment, the touch panel of the car navigation device 9 is described as an example of the input means for the user to input the operation guarantee period. However, the present invention is not limited to this, and number input as a dedicated input means is described. A button, a jog shuttle, or the like may be provided in the passenger compartment, and the operation guarantee period may be input by using these buttons. Alternatively, for example, the operation guarantee period may be input from a mobile phone through wireless communication.

It is a block diagram which shows the vehicle-mounted power management apparatus which concerns on one embodiment of this invention. It is a timing chart which shows the operation timing of the load of the state where the intermittent time was set by the vehicle-mounted power management device concerning one embodiment of the present invention. It is a flowchart which shows operation | movement of the vehicle-mounted power management apparatus which concerns on one embodiment of this invention. It is a timing chart which shows the operation timing of the load in the conventional in-vehicle power management device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle power management device 2 Engine 3a, 3b Load 5 Battery 7 Capacity | capacitance detection part 9 Car navigation apparatus 11 Intermittent time calculation part 13 Starter 15 Generator

Claims (3)

An in-vehicle power management device that manages the state of charge of a battery installed in an automobile,
A capacity detector for detecting the state of charge of the battery;
In accordance with the operation guarantee period input through a predetermined input means, the vehicle has an intermittent time related to intermittent driving of a predetermined load in the vehicle with respect to the state of charge detected by the capacity detection unit. An in-vehicle power management device comprising: an intermittent time calculation unit that calculates so as to avoid the battery being out of charge within the operation guarantee period after the engine is stopped. The in-vehicle power management device according to claim 1,
The intermittent time calculation unit includes power consumption generated regardless of driving of the load over the operation guarantee period from the charging state detected by the capacity detection unit, and minimum holding power required for starting the starter of the automobile And the intermittent time is calculated by calculating a ratio between the subtracted value and the value obtained by adding the operation guarantee period to the power consumption per operation of the load. In-vehicle power management device. The in-vehicle power management device according to claim 1 or 2,
The in-vehicle power management device, wherein the load is driven intermittently according to the intermittent time calculated by the intermittent time calculation unit.

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