JP3903923B2 - Control system and charge control system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control system that ensures data synchronism when power is turned off, and more particularly, to a charge control system that improves vehicle fuel efficiency.
[0002]
[Prior art]
Conventionally, a vehicle is configured to be connectable to an axle via a rotating belt or the like, and is rotationally driven by the rotation of an engine to generate electric power and supply a driving current necessary for various electric loads mounted on the vehicle. The alternator (generator) is charged by the surplus current of this alternator, while supplying electric power for operation to the on-vehicle electronic control device and supplementarily supplying current to the electric load when the amount of power generated by the alternator is insufficient Auxiliary battery is installed.
[0003]
The present invention has been made on the basis of publicly known / public technologies, and the applicant does not have prior art documents. For this reason, disclosure of prior art documents is not performed.
[0004]
[Problems to be solved by the invention]
However, since the alternator becomes a rotational load on the engine during power generation, if the power generation operation is performed more than necessary, an unnecessary load in anticipation of the drive of the alternator is applied to the engine, resulting in a reduction in fuel consumption. Become. On the other hand, when the power generation of the alternator is not sufficient, the discharge amount of the auxiliary battery increases, so that the charge amount decreases and the so-called battery rise occurs.
[0005]
Therefore, in recent years, as a battery charge control method for improving vehicle fuel efficiency, the applicant has successively detected, for example, the current charge amount of the auxiliary battery and stored it in the backup memory (internal memory) as “charge amount data”. Based on this charge amount data, an attempt has been made to suppress the load on the engine due to the power generation of the alternator and compensate (discharge) the auxiliary battery within a range in which the battery does not run up. Specifically, for example, a current sensor for detecting the charge / discharge current of the auxiliary battery is provided, and the judgment is made based on the detected current from the current sensor, the terminal voltage of the auxiliary battery, the surrounding environment such as the outside temperature, and the like. Based on the fully charged state, the charge / discharge current detected by the current sensor is integrated to calculate the current charge amount. However, in this case, in the process of integrating the charge / discharge current detected by the current sensor, for example, the internal resistance of the auxiliary battery changes depending on the external environment (air temperature, etc.), there is an error in the sensing accuracy of the current sensor, The full charge state detected and stored in the backup memory may not always match the actual full charge state. Therefore, in order to accurately measure the state of charge of the auxiliary battery, a refresh process for periodically correcting the charge amount data has been performed. This refresh process transitions from the normal charge / discharge control state (normal state) to the forced charge state where the auxiliary battery is forcibly charged to the fully charged state, and the charge amount of the backup memory is fully charged when the full charge is completed. The so-called alignment is performed by rewriting it after correcting to (100%). After this refresh process, the state transitions to the normal state again.
[0006]
When the charge state is changed from the forced charge state to the normal state as described above, the charge amount data corrected to the charge control state (normal state) and the fully charged state (100%) of these auxiliary batteries Is written to the backup memory at the timing when the charge control state changes. As a result, at the next power-on (ignition key switch is turned on), these data are read from the backup memory, so that the charge control can be started from the state before the power-off.
[0007]
FIG. 11 shows a timing chart showing an example of the specific charge control. The upper row shows the charge amount data stored in the backup memory, the middle row shows the actual charge amount of the auxiliary battery, and the lower row shows the actual charge amount. Each charge control state is represented, and the horizontal axis represents the elapsed time.
[0008]
As shown in the figure, in the above-described forced charging state, the auxiliary battery is gradually charged by the current supplied from the alternator, and the charge amount data in the backup memory is sequentially updated (for example, every 4 ms). When the above-described correction process after full charge ends, the state transitions from the forced charge state to the normal state. However, if charging / discharging control is started suddenly from the fully charged state, the load on the auxiliary battery may be large and cause a failure. Therefore, in the normal state, first, a predetermined safe charging level (charge to be maintained) After discharging to an amount (for example, 80%), normal battery charge / discharge control is performed.
[0009]
In the above charging control, in the forced charging state, the auxiliary battery is gradually charged with the current supplied from the alternator, and when the battery reaches full charge, the amount of charge does not increase any more, and the supplied current becomes heat or the like. Will disappear. For this reason, as shown in the figure, the current supply from the alternator is continued, but a phenomenon occurs in which the actual charge amount does not increase and becomes level. For this reason, in this charge control, when full charge is determined in the forced charge state, the charge amount data is rewritten to the full charge state (100%) and the state is changed to the normal state. That is, the state transition is performed by updating the full charge state and charge amount data (100%) to the backup memory.
[0010]
However, in the above charge control system, for example, when the power-off is performed at the timing when the charge control state changes from the forced charge state to the normal state, depending on the timing, for example, the charge control state can be written, but the current charge amount It is also conceivable that data (100%) could not be written. In this case, at the next power-on, the read charge control state is the normal state after the change, whereas the charge amount data is a value before the change (value exceeding 100%: for example, 120%). For this reason, as described above, when trying to discharge to a stable charge amount (for example, 80%) as an initial operation in the normal state, the charge amount actually decreases to a lower charge amount (for example, 60%) than the charge amount to be maintained. As a result, when the electric load is turned on, the discharge amount is further increased and the charge amount is decreased. That is, there is a possibility that normal charge control cannot be performed because the error between the charge amount data and the actual battery capacity is large. In addition, when the amount of charge data read in this way is larger than the actual value, the subsequent control processing is performed on the assumption that the amount of charge is sufficient, so the battery may run out. There was a problem.
[0011]
Such a problem occurs because the charge amount data is not synchronized between the ignition switch OFF and the next ON. And such a problem is not limited to the above-described charging control system, and in a control system that performs a predetermined control based on at least one physical value (the amount of charge in the above), transitions to a plurality of different control states. It is thought to occur as well.
[0012]
The present invention has been made in view of these problems, and is a control system that can ensure data synchronization at the time of power-off and realize high-precision control processing, in particular, thereby improving vehicle fuel efficiency. It is an object of the present invention to provide a charge control system that can be used.
[0013]
[Means for Solving the Problems]
In view of the above problems, the control system according to claim 1 is configured to transition to a plurality of different control states based on a predetermined condition, and to perform a predetermined process based on at least one physical value that is sequentially updated in the internal memory with the control. The control means for performing the predetermined control, and when the control state transition is executed, each data representing the next control state, the physical value of the internal memory, and the current control state And non-volatile storage means for storing in this order.
[0014]
That is, the control system controls a control target based on a physical quantity (data) that changes with control. This physical quantity is sequentially updated in the internal memory, but is stored in the nonvolatile storage means at a predetermined timing in order to resume control from the state before the power is turned off when the power is turned on.
[0015]
Then, the storage means stores the “next control state” with the highest priority among the data representing the “next control state”, “physical value”, and “current control state”. For this reason, for example, even if the power is turned off at the time when the storage means stores the “next control state”, the “next control state” can be read when the power is turned on again. The “current control state” immediately before the power is turned off has already been updated and stored at the time of the previous state transition. Therefore, by comparing these “next control state” and “current control state” to determine whether they are different, it is determined that the power has been turned off during the state transition. Can do. In this case, it is understood that there is a possibility that the “physical quantity” has not been updated.
[0016]
When the power for operating the control system is turned off and turned on again, the control means determines that the current control state is different from the next control state obtained by referring to the storage means and the current control state. The control process is re-executed using the data representing.
According to such a configuration, even if the physical values before and after power-off cannot be stored normally (even if the simultaneity is not satisfied) by turning off the power during the transition of the control state, Return to the control state, re-execute the control and make a state transition again. As a result, the control state and the physical value can be matched (data simultaneity can be ensured), and an accurate control process can be realized.
[0017]
For example, the control system according to claim 2 may be used as a more specific configuration. That is, the state transition condition storage means stores the control state to be changed based on the control state by the control means and the event information generated when controlling the controlled object, and the event information detection means stores the event information. Is detected. The “event information” here is an event that occurs in the control of the controlled object, and is a factor that causes the control state to transition. The “event information” may be predetermined operation information of the control system itself, information indicating an actual control state of the control target, information of other external factors, or the like.
Then, based on the current control state stored by the storage unit and the current event information detected by the event information detection unit, the control unit refers to the state transition condition storage unit and executes control by changing the control state. .
Thus, as the frequency of state transitions increases according to event information, the significance of ensuring a normal transition to the next control state by matching the above-described control state and physical value increases, and accuracy is improved. The effect of realizing the control process is also great.
In that case, as described in claim 3, the state transition condition storage means may be configured by a plurality of state transition tables in which state transition destinations are set in relation to the control state and the event information.
In other words, when it is desired to change the transition destination according to various conditions, a state transition table is configured for each of those conditions, and control can be further improved by switching these state transition tables as appropriate. it can.
[0018]
And the charge control system which can aim at the improvement of the fuel consumption of a vehicle can be built by making the control system demonstrated above more concrete. For example, the charge control system according to claim 4, wherein charge control of the auxiliary battery is performed based on the charge amount as one of the above-described “physical quantities”.
[0019]
The charge control system according to claim 4 is an alternator that supplies a drive current to an in-vehicle electric load according to a command from an electronic control device mounted on a vehicle, as in a general charge control system, While it is charged by surplus current supplied to the electric load by the alternator, it supplies electric power for operation to the electronic control unit, and the supply current to the electric load by this alternator is insufficient as an auxiliary power source arranged in parallel with the alternator. The auxiliary battery that supplies current to the electrical load in an auxiliary manner, and the charge amount storage that detects the current that enters and exits the auxiliary battery, calculates the charge amount of the auxiliary battery, and stores it as charge amount data Means, state detection means for detecting the driving state of the vehicle, charge amount stored in the charge amount storage means, and driving state detected by the state detection means, By controlling the power generation of the alternator based on, and a charge control unit that controls charging of the auxiliary battery.
[0020]
The charging control means forcibly charges the auxiliary battery until the auxiliary battery is fully charged under a normal state in which the auxiliary battery is charged and discharged in order to continue the function as an auxiliary power source and a predetermined condition. At the same time, the charging of the auxiliary battery is controlled while changing the state between a plurality of charge control states including a forced charge state in which the charge amount data stored in the charge amount storage means is corrected to a full charge value and adjusted. To do.
[0021]
The “predetermined condition” referred to here may be regular or may be a case where the charge amount data of the auxiliary battery becomes smaller than a predetermined set value, and can be set as appropriate.
In addition, the term “matching” here eliminates or reduces the error between the charge amount data of the auxiliary battery that is sequentially updated and the actual charge amount of the auxiliary battery, and performs subsequent charge control processing with high accuracy. Is to do. In other words, as described above, the auxiliary battery is forcibly charged to the fully charged state, and the charge amount stored in the charge amount storage means when the full charge is completed is corrected to the fully charged state (100%) and rewritten. is there.
[0022]
In addition, other examples of the “charge control state” mentioned here include, for example, an abnormal state and an auxiliary charge state described in the embodiments described later, but other charge control states can be set as appropriate.
And in particular, when the state storage means at least when the charge control means executes the transition of the charge state, the next control state executed by the charge control means and the charge amount stored by the charge amount storage means in the forced charge state The data and the current control state executed by the charging control means are stored in this order. This state storage means includes a non-volatile memory, and the data stored in the state storage means is maintained even when the power is turned off unless rewriting processing is performed.
[0023]
The state storage means stores the “next control state” with the highest priority among the “next control state”, “charge amount data”, and “current control state”. Even if the power is turned off when the “next control state” is stored, the “next control state” can be read when the power is turned on again. In this case as well, the “current control state” immediately before the power is turned off is already updated and stored at the previous state transition. For this reason, by comparing these “next control state” and “current control state”, it can be determined that the power has been turned off during the state transition.
[0024]
The charging control unit re-executes the control process indicating the current control state when the next control state stored by the state storage unit is different from the current control state when the ignition switch of the vehicle is turned on. To do.
According to such a configuration, even if the charge amount of the auxiliary battery before and after power-off cannot be normally stored by turning off the power in the middle of the transition of the charge control state, the control state is temporarily returned to the previous control state. By re-executing the control and performing state transition again, the charge control state and the charge amount data can be matched, and an accurate charge control process can be realized. Specifically, by turning off the power in the middle from the forced charge state to the normal state, the information on the next normal state can be stored, but the full charge state (100%) is adjusted. This is also effective when the charged amount data cannot be stored. In this case, only the information of the “normal state” that is the next control state is updated and stored, and the charge amount data has a value (for example, 120%) larger than the fully charged state (100%), As the current control state, information of “forced charging state” stored at the previous state transition is stored. For this reason, when the power is turned on again, the next control state is different from the current control state, so the “forced charging state” is re-executed. Then, when the fully charged state is detected again, the fitting process is executed. As a result, the charge control state matches the charge amount data, and the subsequent charge control is executed with high accuracy.
[0025]
Also in this charge control system, as described in claim 5, the state transition condition storage means stores the charge control state to be transitioned based on the charge control state of the auxiliary battery and the event information of the vehicle. The event information detection means detects the event information. The “event information” here is an event that occurs during charge control, and is a factor that causes the charge control state to transition. This “event information” may be predetermined operation information of the charging control system itself, information indicating the actual control state of the vehicle including the alternator and the auxiliary battery, information of other external factors, etc. It may be.
[0026]
Then, the charge control means transitions the charge control state with reference to the state transition condition storage means based on the current charge control state stored by the state storage means and the current event information detected by the event information detection means. Execute charge control.
Thus, as the frequency of state transitions increases according to event information, it becomes more significant to ensure a normal transition to the next control state by matching the above-described charge control state and charge amount data. The effect of realizing good control processing is also great.
[0027]
At that time, as described in claim 6, the state transition condition storage means may be configured by a plurality of state transition tables in which state transition destinations are set in relation to the charge control state and the event information.
That is, for example, when it is desired to change the transition destination according to various conditions such as temperature conditions, a state transition table is configured for each of these conditions, and by switching these state transition tables as appropriate, control can be performed more accurately. Improvements can be made.
[0028]
With the charge control system described above, it is possible to ensure the accuracy of the charge amount data, and by executing the charge control based on the highly accurate charge amount data, a control command to be output to the alternator is also accurately performed. As a result, the amount of power generated by the alternator in consideration of charging of the auxiliary battery can be set without waste, and wasteful load on the vehicle engine can be prevented and the fuel efficiency of the vehicle can be improved.
[0029]
From such a viewpoint of improving the fuel consumption of the vehicle, for example, as described in claim 7, the charge control unit is configured to change the charge amount stored in the charge amount storage unit and the driving state detected by the state detection unit. Based on this, the required power generation amount of the alternator for reducing the power generation by the alternator within a range in which the battery does not rise in the auxiliary battery is calculated, and by controlling the power generation of the alternator according to the required power generation amount, the auxiliary battery It is better to perform charging control.
[0030]
According to such a configuration, the load on the vehicle engine can be reduced by the amount that suppresses the power generation amount of the alternator as much as possible, and as a result, the fuel efficiency of the vehicle can be improved. Further, although the burden on the auxiliary battery is increased by that amount, no problem occurs because the control is performed in a range in which the battery does not increase. On the other hand, in order to realize such control, the balance between the power generation amount of the alternator and the charge amount of the auxiliary battery is important. Therefore, the effect of highly accurate charge control by the above-described charge control system of the present invention is effective. Is remarkably exhibited.
[0031]
Furthermore, from the viewpoint of vehicle control, it is preferable that the influence of charging control is small. Therefore, as described in claim 8, the charge control means controls the power generation amount of the alternator to be smaller as the traveling load of the vehicle detected by the state detection means is larger, so that the shortage of the power supplied to the electric load is reduced. May be supplied by an auxiliary battery.
[0032]
With this configuration, the engine load can be preferentially used for vehicle control when the traveling load increases, such as when the vehicle travels uphill or suddenly accelerates. For this reason, while original vehicle control can be prioritized and executed, necessary power supply can be ensured by the auxiliary battery. As a result, it is possible to maintain a comfortable driving environment without applying stress on the vehicle operation to the occupant.
[0033]
Further, as described in claim 9, the charging control means controls the power generation of the alternator so that a part of the regenerative current generated in the alternator is used for charging the auxiliary battery when the vehicle is braked. You may do it.
With this configuration, the alternator can be used as an engine brake, for example, when the vehicle travels downhill or decelerates from high speed to low speed or stopped, and the regenerative current generated at that time is effectively utilized. be able to. As a result, the alternator for charging the auxiliary battery, and thus the burden on the vehicle engine, is reduced, and the fuel efficiency of the vehicle can be improved.
[0034]
The function for realizing the control means and storage means of the control system described above, and the charge control means, charge amount storage means, and state storage means of the charge control system described above in the computer system is activated on the computer system side, for example. (Claims 10 and 11). In the case of such a program, for example, it can be used by being recorded on a recording medium such as a flexible disk, a magneto-optical disk, a CD-ROM, a DVD, a hard disk, etc., and loaded into a computer system and started as required. In addition, the program may be recorded using a ROM or backup RAM as a recording medium, and the ROM or backup RAM may be incorporated into a computer system for use.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, in order to clarify the embodiment of the present invention, a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a charge control system which is a control system of the present embodiment.
[0036]
As shown in the figure, the charging control system 1 of the present embodiment supplies power for operation to an electronic control unit (hereinafter referred to as “ECU”) 10 for controlling the vehicle, and to the in-vehicle electric load 40. It is configured as a system that performs charging control of the auxiliary battery 20 that supplies current auxiliary.
[0037]
That is, the charging control system 1 includes an auxiliary battery 20, an alternator 30 that is an in-vehicle generator, and an ECU 10 that outputs a command signal to the alternator 30 to control the amount of power generation.
The ECU 10 is mainly configured by a microcomputer (not shown) that executes predetermined storage / arithmetic processing. The ECU 10 controls a CPU, a ROM in which various numerical values and programs are written in advance, and numerical values and flags of arithmetic processes. RAM written in a predetermined area, non-volatile backup memory (backup RAM, EEPROM, etc.), A / D converter that converts analog input signals into digital signals, various digital signals are input, and various digital signals are output It comprises an output interface (I / O), a timer as a time measuring means, and a bus line to which these devices are connected.
[0038]
The ECU 10 executes predetermined arithmetic processing based on input signals from various sensor / switch groups for detecting the vehicle operating state such as the vehicle speed, throttle opening, idle state, engine speed, etc. Drive control of various electric loads 40 such as a blower and a wiper is performed. On the other hand, the ECU 10 includes a battery capacity calculation unit 11 and an alternator control voltage calculation unit 12, and the current value obtained via the current sensor 60 provided in the charge / discharge path of the auxiliary battery 20 and the auxiliary battery 20. Based on the voltage value detected through the terminal, the battery capacity calculation unit 11 calculates the charge control state of the auxiliary battery 20 and its charge amount. Then, the alternator control voltage calculation unit 12 performs charge control of the auxiliary battery 20 based on the charge control state and the charge amount and the driving state of the vehicle obtained from input signals from the various sensor / switch groups 50. .
[0039]
In accordance with a control voltage command output from the ECU 10, the alternator 30 changes the power generation state by changing the presence or absence of connection to the axle, the gear position, etc., and supplies the necessary driving current to the electric load 40. The auxiliary battery 20 is charged by the surplus current.
[0040]
While the auxiliary battery 20 is charged by the alternator 30 as described above, the operation power is supplied to the ECU 10 and, as an auxiliary power source provided in parallel with the alternator 30, a current supplied to the electric load 40 by the alternator 30 is supplied. In the case of a shortage, an electric current is supplied to the electric load 40 as an auxiliary.
[0041]
Next, a charge control method for the auxiliary battery 20 executed in the charge control system of the present embodiment will be described with reference to FIGS. First, FIGS. 2-4 is explanatory drawing showing the state transition in this charge control.
As shown in FIG. 2, in the main charging control, the charging control state is set to transition between a normal state, a forced charging state, an abnormal state, and an auxiliary charging state.
[0042]
The normal state is a normal charge / discharge state in which the power generation amount of the alternator 30 is controlled in accordance with the traveling state of the vehicle and the charge amount for causing the auxiliary battery 20 to function as an auxiliary power source is maintained. That is, here, a range in which the battery does not increase in the auxiliary battery 20 based on the charge amount detected through the current sensor 60 and the driving state of the vehicle obtained from input signals from the various sensor / switch groups 50 is used. Thus, a necessary power generation amount for making the power generation by the alternator 30 as small as possible is calculated, and a control voltage command corresponding to the necessary power generation amount is output to control the power generation of the alternator 30. Thereby, charging control of the auxiliary battery 20 is performed while improving the fuel efficiency of the vehicle.
[0043]
The forced full charge state eliminates an error between the actual charge amount of the auxiliary battery 20 and the charge amount (charge amount data) calculated inside the ECU 10, and accurately measures the charge state of the auxiliary battery 20. This is a charge control state in which a refresh process for correcting the charge amount data is performed. That is, a transition is periodically made from the normal state, and the auxiliary battery 20 is forcibly charged until it reaches a fully charged state. Then, when the full charge is completed, the charge amount of the backup memory is rewritten to the full charge state (100%), and adjustment is performed. After this refresh process, in principle, the state transitions again to the normal state.
[0044]
The abnormal state is a state in which a transition occurs when some abnormality occurs in the charge control system 1 in the normal state. In this case, in order to ensure the safety of continued charge control, the power generation voltage of the alternator 30 is set to a predetermined small constant value.
[0045]
The supplementary charging state is a state in which charging is performed until the amount of charge is restored after the starter is turned on in order to smoothly start the engine. This is performed in order to recover the amount of charge because a large amount of power is consumed when the starter is on.
The state transition described above is performed based on the state transition table shown in FIG. This state transition table stores which charge control state is changed in response to an event representing a preset vehicle state, and constitutes a part of a database held by the ECU 10.
[0046]
That is, when an event indicating a system abnormality is detected based on the driving state of the vehicle obtained from input signals from the various sensor / switch groups 50, transition from all the above-described charging control states to the abnormal state (FIG. 2). (3)). When an event indicating starter-on is detected, the normal state is changed to the auxiliary charge state ((4) in FIG. 2). When an event indicating completion of auxiliary charging is detected in the auxiliary charging state, the auxiliary charging state is changed to the normal state ((5) in FIG. 2). When an event indicating that a predetermined time has elapsed from the normal state is detected, the normal state is changed to the forced charge state ((1) in FIG. 2). Then, when an event indicating completion of full charge is detected in the forced charge state, a transition is made from the forced charge state to the normal state ((2) in FIG. 2).
[0047]
In addition to the above, a plurality of types of state transition tables can be provided. For example, when it is desired to change the transition destination depending on the temperature condition or the like, a state transition table for each temperature condition can be provided. By providing a plurality of state transition tables in this way, optimal control can be realized, and control accuracy can be improved.
[0048]
Then, in the various charge control states that have undergone state transition in this way, the state of the driving load of the vehicle further obtained from the input signals from the various sensor / switch groups 50 and the charge amount data calculated by the battery capacity calculation unit 11 Based on the above, the alternator control voltage calculator 12 calculates the control voltage of the alternator 30. The setting of the control voltage is performed based on, for example, a control voltage setting table shown in FIG. In this control voltage setting table, the voltage control state of the alternator 30 in each charge control state is set depending on whether the vehicle is in an acceleration traveling state above a certain level, a decelerating traveling state above a certain level, or other normal traveling state. It is comprised so that.
[0049]
That is, in the normal state, when the vehicle is in the acceleration state, the power generation voltage of the alternator 30 is lowered in order to relatively reduce the engine load due to the drive of the alternator 30 and give priority to acceleration. Further, when the vehicle is in a decelerating state such as when the vehicle descends on a slope with engine brake, a regenerative current is generated using the alternator 30 as a load for the engine brake, and the generated current is used to drive the electric load 40 and the auxiliary battery 20. Used for charging. In this case, the generated voltage of the alternator 30 will increase as a result, but if the inadvertent increase in the generated voltage is allowed, the electric load 40 and the auxiliary battery 20 may be damaged by overcurrent. An upper limit is set. Further, when the vehicle is in a normal traveling state, the power generation voltage of the alternator 30 is set to be maintained at the current value.
[0050]
Further, in the forced charging state and the auxiliary charging state, the power generation voltage of the alternator 30 is set to be maintained at the current value in order to give priority to the charging state.
Further, in an abnormal state, the generated voltage becomes a predetermined small constant value (for example, a value that is not normally possible, such as 0 V) in order to ensure safety or notify the abnormal state. Is set to
[0051]
Next, FIGS. 5 and 6 are timing charts showing the main charging control. In the vertical axis, the upper part shows the charge amount data of the auxiliary battery 20 stored in the backup memory, and the middle part shows the actual amount of the auxiliary battery 20. The lower part represents the charge control state, and the horizontal axis represents the elapsed time.
[0052]
First, an example in which the auxiliary battery 20 is powered off (ignition switch is turned off) at the timing of full charge will be described with reference to FIG.
As shown in the figure, in the forced charge state, the auxiliary battery 20 is gradually charged by the current supplied from the alternator 30, and when the full charge is reached, the actual charge amount does not increase and remains unchanged. On the other hand, the ECU 10 integrates current information input from the current sensor 60 at a constant timing (for example, 4 ms) to calculate charge amount data, and sequentially updates the value in the backup memory.
[0053]
When it is detected that the battery is fully charged, the above-described refresh process is executed, and the charge amount of the backup memory is forcibly rewritten to the fully charged state (100%). At the same time, based on the state transition condition described above, the charge control state transitions from the forced charge state to the normal state. At this time, the non-volatile backup memory stores the control variable of the normal state that is the next control state, the charge. The quantity data (100%) and the control variable of the forced charge state which is the current control state are stored in this order.
[0054]
For this reason, as shown in the figure, even if only the next control state is written to the backup memory and the power is turned off, when the power is turned on again, the next control state is stored in the backup memory. Yes. For this reason, it is possible to determine a change between the current control state and the next control state stored before that, and when these are different, the charge control in the forced charge state is executed again to store the charge amount data of the backup memory. Updating (rewriting to 100%) can be performed. For this reason, the charge amount data (100%) matches the actual charge amount (100%), and matches the charge amount that is actually desired to be maintained when discharging to a stable charge amount (for example, 80%). As a result, even if the electric load is turned on, charging and discharging are performed as designed, and stable charging control is performed without causing the problem of battery exhaustion due to overdischarge of the auxiliary battery 20 as in the conventional case. .
[0055]
Next, an example in the case where the auxiliary battery 20 is powered off at a timing during charging that is less than full charge in the forced charge state will be described with reference to FIG.
As shown in the figure, when the power is turned off during the forced charge state process, the charge amount data updated in the backup memory is not fully charged, and the transition from the forced charge state to the normal state is executed. Therefore, the backup memory is stored in the forced charge state as the charge control state. For this reason, when the power is turned on again, the forced charge by the charge control is resumed in the forced charge state, and the charge amount data is integrated. When the full charge state is determined, the above-described refresh process is performed and the charge amount data is rewritten to 100%, and the charge control state transitions from the forced charge state to the normal state based on the state transition condition described above. To do. In this case as well, the control variable in the normal state that is the next control state, the charge amount data (100%), and the control variable in the forced charge state that is the current control state are updated in this order in the nonvolatile backup memory. And memorized.
[0056]
For this reason, as shown in the figure, the charge amount data of the backup memory is corrected, the charge amount data and the actual charge amount match, and the charge amount that is actually desired to be maintained when discharging to a stable charge amount Matches. As a result, even if the electric load is turned on thereafter, charging and discharging are performed as designed, and stable charging control is performed without causing a problem of battery exhaustion.
[0057]
Next, the flow of processing executed by the ECU 10 in the charging control of this embodiment will be described based on the flowcharts shown in FIGS.
First, as shown in FIG. 7, the ECU 10 executes a charge amount calculation process every 4 ms (S110). This charge amount calculation process is executed to update the charge amount data, and the charge / discharge current detected by the current sensor 60 based on the fully charged state determined from the terminal voltage of the auxiliary battery 20 or the like. To calculate the current charge amount of the auxiliary battery 20. The value of the charge amount calculated here is updated to the backup memory.
[0058]
Next, as shown in FIG. 8, the ECU 10 executes a state transition process (S210) and an alternator control voltage calculation process (S220) every 64 ms.
In the former state transition processing, as shown in FIG. 9, first, the current charge amount detected through the current sensor 60 and the current vehicle obtained from the input signals from the various sensor / switch groups 50 are detected. Based on the operation state, the next control state is acquired by referring to the state transition table of FIG. 2 described above (S310), and the control state is written in the backup memory (S320). Therefore, when there is no transition condition, the control state is not transitioned.
[0059]
Subsequently, a charge control process based on the current control state is executed (S330). Here, the charge control determined in any of the above-described normal state, forced charge state, abnormal state, and auxiliary charge state is executed. For example, in the forced charge state, a full charge state detection process or the like is performed.
[0060]
Then, it is determined whether or not there has been a transition from the forced charging state to the normal state (S340). If it is determined that there has been a transition (S340: YES), the charge amount data of the backup memory is stored in the fully charged state (100% ) Is rewritten and updated (S350), and the rewritten charge amount data is written in a specific area of the backup memory (S360). Subsequently, the current control state is updated to the next control state written above (S370), and the updated current control state is written to the backup memory (S380). Thus, the state transition process is completed.
[0061]
Here, processing at power-on will be described with reference to FIG.
As shown in the figure, when the power is turned on again from the power-off, first, the next control state, the charge amount data, and the current control state are sequentially read from the backup memory (S410, 420, 430). Then, it is determined whether or not the next control state is different from the current control state (S440).
[0062]
At this time, if it is determined that the next control state is different from the current control state (S440: YES), it is determined that the power is turned off in the state of transition from the forced charge state to the normal state, and charge control in the forced charge state is performed. After the processing is performed again, the charge amount data in the backup memory is rewritten and updated to the fully charged state (100%) (S450). On the other hand, if it is determined that the next control state is the same as the current control state (S440: NO), the process is terminated as it is.
[0063]
Returning to FIG. 8, when the state transition process is completed as described above, an alternator control voltage calculation process is subsequently executed (S220). This process is performed based on the control voltage setting table of FIG. 4 described above, and the control voltage of the alternator 30 in each charge control state depends on whether the vehicle is in an accelerated traveling state, a decelerating traveling state, or a normal traveling state. Calculated. Then, the control voltage command calculated here is output from the ECU 10 to the alternator 30, and charging control based on this is realized.
[0064]
As described above, in the charge control system 1 of the present embodiment, the charge amount of the auxiliary battery 20 before and after the power supply is turned off normally by turning off the power in the middle from the forced charge state to the normal state. Even if the data could not be stored, it returns to the previous control state (forced charge state), re-executes the control, makes a state transition again, and adjusts the charge amount data.
[0065]
For this reason, information on the normal state, which is the next state, could be stored, but even when the charge amount data that was adjusted to the fully charged state (100%) could not be stored, the adjustment was performed again when the power was turned on. Can be stored as charge amount data. As a result, the charge control state matches the charge amount data, and the subsequent charge control is executed with high accuracy. Thereby, it is possible to prevent the auxiliary battery 20 from being overdischarged and to prevent the battery from being discharged.
[0066]
Further, since the charging control is executed with high accuracy in this way, when the electric power is supplied to the electric load 40, the power generation amount of the alternator 30 can be suppressed as much as possible and the auxiliary battery 20 can compensate for this. The load can be reduced. As a result, the fuel consumption of the vehicle can be improved.
[0067]
In this embodiment, the ECU 10 corresponds to charge control means, charge amount storage means, and state storage means, and the various sensor / switch groups 50 correspond to state detection means and event information detection means.
As mentioned above, although the Example of this invention was described, it cannot be overemphasized that embodiment of this invention can take various forms, as long as it belongs to the technical scope of this invention, without being limited to the said Example at all. Nor.
[0068]
For example, although not described in the above embodiments, the fact that the refresh process is executed and completed is stored in a backup memory, and the information is sent to other control units of the vehicle control device including the charge control system. You may make it transmit. Thereby, control accuracy can be improved as a whole vehicle, and optimal vehicle control can be realized.
[0069]
At that time, for example, the reset history (history of refresh processing or the like) may be notified to another control unit of the vehicle control device via the in-vehicle LAN using the CAN communication protocol. Thereby, integrated control can be realized as a whole vehicle.
In addition, with regard to the charge control status and charge amount data, each so-called mirror data (data obtained by inverting the data) can be written to the backup memory so that it can be checked that there is no data corruption. May not be used. Thereby, a normal charge control state can be ensured and its accuracy can be maintained.
[0070]
From the same point of view, it is possible to detect the destruction of data in the backup memory by writing a keyword (arbitrary value) to the backup memory at the timing of initialization of the backup memory and checking this data thereafter. Also good.
[0071]
In writing data, a flag may be set before the first data is written, and the flag may be reset after the last data is written. This flag may also be written to the backup memory. As a result, when the data write timing coincides with the power-off timing, it is possible to determine whether or not the power is turned off during the writing by determining this flag at the next power-on.
[0072]
Alternatively, the data used at an arbitrary timing can be added (exclusive OR is also possible), and the value can be written into an arbitrary backup memory area, and a check function using a so-called checksum value can be added. Good. As a result, when the value obtained by adding the used data (or exclusive OR is possible) differs from the already written value at power-on, this can be detected as garbled data.
[0073]
Further, the current control may be performed in consideration of the offset value of the current sensor. That is, the ECU may be activated at power-off to calculate the offset current value, and the current amount may be calculated in consideration of the sensing error. Thereby, current sensing accuracy can be improved.
[0074]
In addition, when the amount of charge data is large, that is, when the amount of charge data exceeds the data capacity that can be written to the backup memory at one time, the charge amount data is written to the backup memory in several steps. May be. Thereby, it is possible to handle data having a long data length without being affected by the bird-like restriction.
[0075]
In the above embodiment, an example of the charge control system has been shown. However, the technical idea of the control system of the present invention is not limited to the charge control system, and transitions to a plurality of different control states, and at least one physical value ( In the above description, the present invention can be applied to a control system that performs predetermined control based on (charge amount).
[0076]
In this case, when the physical quantity is adjusted, the zero value, the vehicle state, in addition to the fixed finite value in the above-described backup memory in the ECU 10 (full charge state: 100% in the charge control). The value calculated from the above, the value read from the backup memory of another ECU via communication, or the value read from the outside can be used as a reference.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of a charge control system according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating state transition in charge control of an embodiment.
FIG. 3 is an explanatory diagram illustrating a state transition table for determining a state transition condition of charge control.
FIG. 4 is an explanatory diagram showing a control voltage setting table referred to when a control voltage command is issued to the alternator.
FIG. 5 is a timing chart illustrating an example of a charging control process.
FIG. 6 is a timing chart illustrating an example of a charge control process.
FIG. 7 is a flowchart showing a flow of charge control processing.
FIG. 8 is a flowchart showing a flow of charge control processing.
FIG. 9 is a flowchart showing a flow of charge control processing.
FIG. 10 is a flowchart showing a flow of charge control processing.
FIG. 11 is a timing chart showing problems of the conventional charge control process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Charge control system, 11 ... Battery capacity calculation part,
12 ... alternator control voltage calculation unit, 20 ... auxiliary battery,
30 ... alternator, 40 ... electric load, 60 ... current sensor

Claims (11)

In a control system that performs predetermined control based on at least one physical value that is sequentially updated to an internal memory in accordance with control, transitioning to a plurality of different control states based on predetermined conditions,
Control means for performing the predetermined control;
Non-volatile storage means for storing each data representing the next control state, the physical value of the internal memory, and the current control state, respectively, in this order when the control state transition is executed;
With
The control means, when the next control state obtained by referring to the storage means and the current control state are different when the power for operating the control system is turned off and turned on again, A control system which re-executes control processing using data representing a current control state. The control system according to claim 1,
further,
Based on the control state by the control means and event information generated when controlling the controlled object, state transition condition storage means for storing the control state to be changed,
Event information detecting means for detecting the event information;
With
Based on the current control state stored by the storage unit and the current event information detected by the event information detection unit, the control unit refers to the state transition condition storage unit and executes control by changing the control state. A control system characterized by The control system according to claim 2,
The state transition condition storage unit includes a plurality of state transition tables in which state transition destinations are set in relation to the control state and the event information. An alternator for supplying a driving current to the in-vehicle electric load according to a command from an electronic control unit mounted on the vehicle;
While being charged by the surplus current of the supply current to the electric load by the alternator, the electric power is supplied to the electronic control unit, and as an auxiliary power source arranged in parallel to the alternator, the electric load by the alternator is supplied to the electric load. An auxiliary battery that supplementarily supplies current to the electric load when the supply current of
Charge amount storage means for detecting a current flowing into and from the auxiliary battery, calculating a charge amount of the auxiliary battery, and storing it as charge amount data;
State detection means for detecting the driving state of the vehicle;
A normal state in which the auxiliary battery is charged and discharged in order to continue the function as the auxiliary power source, and the auxiliary battery is forcibly charged under a predetermined condition until the auxiliary battery is fully charged, and the charge amount is stored. The charge amount stored in the charge amount storage means while changing the state between a plurality of charge control states including a forced charge state in which the charge amount data stored by the means is corrected to a full charge value and adjusted. Charging control means for controlling charging of the auxiliary battery by controlling power generation of the alternator based on the operating state detected by the state detecting means;
A charge control system comprising:
At least when the charge control means executes the transition of the charge state, the next control state executed by the charge control means, the charge amount data stored by the charge amount storage means in the forced charge state, Non-volatile state storage means for storing the current control state executed by the charge control means in this order,
The charging control unit re-executes a control process representing the current control state when the next control state stored in the state storage unit is different from the current control state when the ignition switch of the vehicle is turned on. A charge control system characterized by that. The charge control system according to claim 4, further comprising:
Based on the charge control state of the auxiliary battery and the event information of the vehicle, state transition condition storage means for storing the charge control state to be changed,
Event information detecting means for detecting the event information;
With
The charge control means transitions the charge control state with reference to the state transition condition storage means based on the current charge control state stored by the state storage means and the current event information detected by the event information detection means. A charge control system that executes charge control. In the charge control system according to claim 5,
The state transition condition storage means is composed of a plurality of state transition tables in which state transition destinations are set in relation to the charge control state and the event information. The charge control system according to any one of claims 4 to 6, wherein the charge control means is based on the charge amount stored in the charge amount storage means and the operating state detected by the state detection means. By calculating the required power generation amount of the alternator for reducing the power generation by the alternator within a range where the battery does not rise in the auxiliary machine battery, and controlling the power generation of the alternator according to the required power generation amount, the auxiliary machine A charge control system for performing charge control of a battery. In the charge control system according to any one of claims 4 to 7,
The charge control means includes
Control is performed so that the power generation amount of the alternator decreases as the traveling load of the vehicle detected by the state detection means increases, and a shortage of power supplied to the electric load is supplied by the auxiliary battery. To charge control system. 9. The charge control system according to claim 4, wherein the charge control unit uses a part of the regenerative current generated in the alternator for charging the auxiliary battery during braking of the vehicle. And a charge control system for controlling power generation of the alternator. The program which makes a computer system function as the said control means and the said memory | storage means of the control system in any one of Claims 1-3. A program that causes a computer system to function as the charge control unit, the charge amount storage unit, and the state storage unit of the charge control system according to any one of claims 4 to 9.

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