JP2006340514A - Power generation controller of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce increment in fuel consumption due to power generation surely while ensuring required amount of power generation in the power generation controller of an internal combustion engine. <P>SOLUTION: An increment in specific fuel consumption due to power generation is determined from the difference of specific fuel consumption when power generation of a generator is performed and specific fuel consumption when power generation of the generator is stopped, and then electric cost (increment in fuel consumption per amount of unit power generation) is determined by dividing the specific fuel consumption due to power generation by the amount of power generation of the generator. During traveling, use frequency is determined for each class of electric cost, possible amount of power generation and average power consumption are calculated for each class, a target electric cost is set such that the balance of charge/discharge of a battery becomes 0 based on the use frequency, the possible amount of power generation and the average power consumption. Subsequently, the target electric cost is corrected depending on the difference between SOC (battery charging rate) and a target SOC and then a decision is made whether power generation of the generator 16 is performed or not by comparing the final target electric cost thus corrected with a current electric cost. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power generation control device for an internal combustion engine having a function of controlling a power generator in consideration of an increase in fuel consumption due to power generation by the power generator.

  Control of the generator (alternator) mounted on the vehicle monitors the charge state of the battery, and controls the generator control current (field current) to prevent the battery from being insufficiently charged, thereby controlling the amount of power generation. There are many cases (see Patent Documents 1 and 2).

Since this power generator is driven by the power of the internal combustion engine (engine), extra fuel is consumed according to the load for driving the power generator during power generation. Therefore, there is one in which the generator generates power only in a region where the amount of fuel consumed during power generation is reduced (see Patent Documents 3 and 4).
JP 2000-4502 A JP 2001-78365 A Japanese National Patent Publication No. 6-505619 JP 2005-12971 A

  The techniques of Patent Documents 3 and 4 are techniques for reducing the increase in fuel consumption due to power generation. However, since the driving conditions for executing power generation are determined by a preset map, the accuracy of the map and the vehicle The fuel consumption saving effect is likely to be affected by the environment of use (differences in driving road conditions, differences in vehicle speed / acceleration / deceleration by the driver) and variations in vehicle characteristics, and a sufficient fuel consumption saving effect is not always obtained.

  The present invention has been made in view of such circumstances. Therefore, the object of the present invention is to generate electric power from an internal combustion engine that can reliably reduce the increase in fuel consumption due to electric power generation while securing the necessary electric power generation amount. It is to provide a control device.

  In order to achieve the above object, an invention according to claim 1 is a power generation control device for an internal combustion engine, comprising: a generator driven by the power of the internal combustion engine; and a battery charged with electric power generated by the generator. The battery charge state detecting means for detecting the state of charge of the battery, and the fuel consumption for calculating the fuel consumption increase per unit power generation based on the fuel consumption increase due to the power generation of the generator and the power generation Detected by an amount calculation means, a power generation control means for controlling the power generation of the generator by comparing a fuel consumption increase per unit power generation amount with a target fuel consumption increase, and the battery charge state detection means And target value correcting means for correcting the target fuel consumption increase based on the charged state of the battery. In this way, by controlling the power generation of the generator by comparing the increase in fuel consumption per unit power generation with the target increase in fuel consumption corrected according to the state of charge of the battery, Compared with the conventional power generation control method that determines the driving conditions for executing the vehicle with a preset map, the accuracy of the map and the environment of use of the vehicle (differences in driving road conditions, differences in vehicle speed and acceleration / deceleration by the driver, etc.) In addition, the influence of variations in vehicle characteristics is reduced, and an increase in fuel consumption due to power generation can be reliably reduced while securing a required power generation amount according to the actual state of charge of the battery.

  In this case, the target fuel consumption increase may be set so as to balance the balance between the charge amount and the discharge amount of the battery (hereinafter referred to as “charge / discharge balance”). As a result, the battery can be charged without excess or deficiency with the minimum required amount of power generation, and both reduction in fuel consumption and charge / discharge balance can be achieved.

  Further, as described in claim 3, the target increase in fuel consumption may be set based on the usage frequency for each class of the increase in fuel consumption per unit power generation in the past travel history. In this way, the target fuel consumption increase is automatically and accurately set according to the vehicle usage environment (differences in driving road conditions, differences in vehicle speed and acceleration / deceleration by the driver, etc.) and vehicle characteristics. can do. Here, “class” means a predetermined range obtained by dividing a range from the minimum value (0) to the maximum value of the increase in fuel consumption per unit power generation amount into a predetermined number.

  Further, as described in claim 4, the target fuel consumption increase is set based on the usage frequency and the power generation possible amount for each class of the fuel consumption increase per unit power generation in the past travel history. May be. In this way, the target fuel consumption increase can be set more accurately in consideration of the power generation possible amount for each class.

  Further, as in claim 5, the target increase in fuel consumption is determined based on the usage frequency for each class of the increase in fuel consumption per unit power generation in the past travel history, the power generation possible amount, and the average power consumption. You may make it set. In this way, the target increase in fuel consumption can be set more accurately in consideration of the power generation possible amount and average power consumption for each class.

  According to another aspect of the present invention, the battery charge state detection means may calculate the battery charge rate, and the target fuel consumption increase may be corrected based on the battery charge rate. In this way, it is possible to more accurately correct the target fuel consumption increase corresponding to the state of charge of the battery.

  In this case, as in claim 7, the target fuel consumption increase may be feedback-corrected so as to reduce the deviation between the battery charge ratio and the target charge ratio. Thereby, it is possible to control the battery charging rate to converge to the target charging rate while satisfying the demand for low fuel consumption.

  According to another aspect of the present invention, the charge / discharge amount required to make the battery charge rate coincide with the target charge rate is calculated, and the reference point of the battery charge / discharge balance is corrected based on the calculated charge / discharge amount. By doing so, the target increase in fuel consumption may be corrected. If it does in this way, the convergence property to the target charge ratio of a battery can be improved, satisfy | filling the request | requirement of low fuel consumption.

  Hereinafter, two Examples 1 and 2, which embody the best mode for carrying out the present invention, will be described.

A first embodiment of the present invention will be described with reference to FIGS.
A control device 11 shown in FIG. 1 is supplied with power from a battery 12 via a key switch 13, controls the operation of the ignition device 14 and the injection device 15 during engine operation, and generates power from a generator 16 (alternator). It functions as power generation control means for controlling.

  The control device 11 charges the battery 12 based on the charge / discharge current of the battery 12 detected by the current sensor 17 (current detection means) and / or the open terminal voltage of the battery 12 detected by the voltage sensor 18 (voltage detection means). The ratio SOC is calculated. For example, the charge / discharge current of the battery 12 is detected by the current sensor 17 (current detection means), and the detected values are integrated. At this time, the charging current of the battery 12 is set to a positive value, and the discharging current of the battery 12 is set to a negative value, so that the integrated charging / discharging current value is increased or decreased according to the charging rate SOC of the battery 12. As a result, the charge / discharge current integrated value can be used as detection data for the battery charge rate SOC. Alternatively, the charging ratio SOC according to the current open terminal voltage of the battery 12 may be calculated with reference to a map representing the relationship between the open terminal voltage of the battery 12 and the charging ratio SOC. Of course, the charging rate SOC of the battery 12 may be calculated based on both the charge / discharge current integrated value of the battery 12 and the open terminal voltage.

Next, power generation control according to the first embodiment will be described.
FIG. 2 is a diagram showing the relationship between the fuel consumption rate, which is the fuel consumption per unit time, and the engine operating conditions. As shown in FIG. 2, the fuel consumption rate changes depending on the engine speed and the engine torque. Since the fuel consumption rate changes in a curve according to the engine torque, when the engine rotational speed is constant, there are a condition where the increase amount of the fuel consumption rate is large and a condition where the increase amount is small. For example, when a certain amount of power is generated by the power generator 16, the torque generated by the power generator 16 is added to the engine torque by power generation, and the operating point of the engine changes. For this reason, a fuel consumption rate changes with electric power generation amounts. At this time, if only a condition with a low fuel consumption rate is selected and power generation is performed, the fuel consumption rate can be reduced.

Therefore, in the first embodiment, an increase in fuel consumption rate per unit power generation amount (hereinafter referred to as “electricity cost”) is used as a parameter for power generation control. This electricity cost is calculated as follows. First, while the engine is running (running), the fuel consumption rate when the generator 16 generates power (fuel consumption rate during power generation) and the fuel consumption rate when the generator 16 stops power generation (non-power generation fuel) The fuel consumption rate increase due to power generation is calculated from the difference from the consumption rate), and the fuel consumption rate increase due to power generation is divided by the power generation amount of the generator 16 to calculate the power consumption (the fuel consumption increase per unit power generation amount). Ask.
Electricity cost (g / skW) = (Fuel consumption rate during power generation-Fuel consumption rate during non-power generation) / Power generation amount

  Further, in the first embodiment, during use, the frequency of use of electricity consumption for each class is obtained, the power generation amount and average power consumption for each class are calculated, and the frequency of use, power generation possible amount and average power consumption for each class are calculated. Based on the above, the target power consumption is set so that the charge / discharge balance of the battery 12 becomes 0 (the charge amount and the discharge amount are balanced), and the deviation between the current battery charge rate SOC and the target charge rate is reduced. Then, the target power consumption is feedback-corrected by PI control, and the current power consumption is compared with the corrected target power consumption (final target power consumption) to determine whether or not to generate power by the generator 16. Here, the “class” means a predetermined range obtained by dividing a range from the minimum value (0) to the maximum value of the power consumption into a predetermined number.

  The power generation control according to the first embodiment described above is executed by the control device 11 according to the routines shown in FIGS. The processing contents of these routines will be described below.

[Electricity calculation routine]
The power consumption calculation routine of FIG. 3 is executed at a predetermined cycle (for example, a cycle of 8 ms) during engine operation, and serves as fuel consumption calculation means in the claims. When this routine is started, first, in step 101, the current operating conditions (for example, engine speed, intake air amount, required power generation amount, etc.) are read. Here, the required power generation amount is determined in advance from the maximum power generation possible amount of the generator 16, the power generation efficiency of the generator 16, and the like.

  After that, the process proceeds to step 102, the current engine torque is calculated from the current operating conditions, and then the process proceeds to step 103, where the required power generation amount is converted into torque (that is, the torque necessary for generating the required power generation amount). And this is stored in the RAM of the control device 11 as the required power generation amount torque.

  Then, in the next step 104, it is determined whether or not the generator 16 is generating power. If it is generating power, the process proceeds to step 105, the current power generation amount is converted into torque, and this is converted into the current power generation. The amount torque is stored in the RAM of the control device 11, and in the next step 106, the current power generation torque calculated in step 105 is subtracted from the current engine torque calculated in step 102 to obtain a non-power generation torque. This non-power generation torque corresponds to the engine torque when power generation by the generator 16 is stopped. On the other hand, if it is determined in step 104 that power generation is not being performed, the process proceeds to step 107, where the current engine torque is directly used as the non-power generation torque.

  After calculating the non-power generation torque as described above, the routine proceeds to step 108, where the required power generation amount torque calculated in step 103 is added to the current engine torque calculated in step 102 to determine the power generation torque. This power generation torque corresponds to the engine torque when the generator 16 generates power.

  Thereafter, the routine proceeds to step 109, where the non-power generation fuel consumption rate (g / s) corresponding to the current engine speed and non-power generation torque is calculated by the fuel consumption rate calculation map similar to FIG. This non-power generation fuel consumption rate corresponds to the fuel consumption rate when power generation by the generator 16 is stopped. The fuel consumption rate calculation map is set in advance by measuring the fuel consumption rate under steady operation conditions.

  Thereafter, the routine proceeds to step 110, where the fuel consumption rate (g / s) during power generation corresponding to the current engine speed and torque during power generation is calculated using the same fuel consumption rate calculation map as in FIG. This fuel consumption rate during power generation corresponds to the fuel consumption rate when power generation by the generator 16 is executed.

Then, proceed to step 111, and divide the difference between the fuel consumption rate during power generation (g / s) and the fuel consumption rate during non-power generation (g / s) by the current power generation amount (kW) The electricity consumption CFC (g / skW), which is the fuel consumption rate, is calculated.
CFC (g / kWs) = (Fuel consumption rate during power generation-Fuel consumption rate during non-power generation) / Power generation amount

[Electricity class data storage routine]
The power consumption class data accumulation routine of FIG. 4 is executed at a predetermined cycle (for example, a cycle of 8 ms) during engine operation, and the usage frequency, the power consumption average value, and the power generation possible average value for each class of the power consumption CFC in the past travel history are shown below. Thus, the data is stored in the RAM of the control device 11.

  When this routine is started, first, in step 201, a power generation possible amount GP corresponding to the current engine rotation speed is calculated from a map or the like representing the relationship between the engine rotation speed and the power generation characteristics of the generator 16. Thereafter, the process proceeds to step 202, where the count value of the total number of samples NFCtotal up to the present time is counted up, and then the process proceeds to step 203a to determine whether or not the current power consumption CFC is included in the class A which is the smallest class (electricity cost CFC). <A or not> is determined, and if the current power consumption CFC is included in class A, the data of class A is updated as follows.

First, in step 204a, the count value of the class A sample number NFC (A) is counted up, and then the process proceeds to step 205a. The class A previous power consumption average oldCFCave (A), the sample number NFC (A) and the current time The average power consumption CFCave (A) of class A is calculated from the following power consumption CFC.
CFCave (A) = [oldCFCave (A) × {NFC (A) −1} + CFC] / NFC (A)

Thereafter, the process proceeds to step 206a, and the class A power generation capacity average value GPave (A) is calculated from the class A previous power generation capacity oldGPave (A), the number of samples NFC (A), and the current power generation capacity GP. Calculate by the formula.
GPave (A) = [oldGPave (A) × {NFC (A) −1} + GP] / NFC (A)

Thereafter, the process proceeds to step 207a, where the class A use frequency R (A) is obtained by dividing the class A sample number NFC (A) by the total sample number NFCtotal of all classes A to Z.
R (A) = NFC (A) / NFCtotal

  On the other hand, if it is determined in step 203b that the current power consumption CFC is not included in class A, the process proceeds to step 203b, and whether or not the current power consumption CFC is included in class B, which is the next larger than class A ( A ≦ power consumption CFC <B or not), and if the current power consumption CFC is included in the class B, the processing of steps 204b to 207b is executed, and the number of samples NFC of the class B in the same manner as described above (B) The power consumption average value CFCave (B), the power generation possible amount average value GPave (B), and the usage frequency R (B) are calculated, and the stored data is updated.

  In the following, while traveling, the average power consumption values CFCave (C) to CFCave (Z), average power generation values GPave (C) to GPave () for class C, class D,. Z), usage frequencies R (C) to R (Z) are calculated, and these data are updated.

[Average power consumption calculation routine]
The average power consumption calculation routine of FIG. 5 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation. When this routine is started, first, at step 301, the power consumption CP per calculation period consumed by the vehicle is calculated. Thereafter, the process proceeds to step 302, where the average power consumption CPave is calculated from the previous average power consumption oldCPave, the total number of samples NFCtotal, and the current power consumption CP by the following equation.
CPave = {oldCPave × (NFCtotal −1) + CP} / NFCtotal

[Target electricity cost calculation routine]
The target power consumption calculation routine of FIG. 6 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation, and calculates the target power consumption TCFC as follows. When this routine is started, first, in step 401, the average power generation amount values GPave (A) to GPave (Z) of the classes A to Z are multiplied by the usage frequencies R (A) to R (Z), respectively. The power generation possible amounts GP (A) to GP (Z) of the respective classes A to Z are obtained.

GP (A) = GPave (A) x R (A)
GP (B) = GPave (B) x R (B)
...
GP (Z) = GPave (Z) x R (Z)

Thereafter, the routine proceeds to step 402, where the charge / discharge balance BAL (A) in class A is obtained by subtracting the average power consumption CPave from the class A power generation possible amount GP (A).
BAL (A) = GP (A) -CPave

Thereafter, the process proceeds to step 402, where the charge / discharge balance BAL (B) from class A to class B is obtained by adding the class B chargeable / discharge balance BAL (A) to the class B power generation amount GP (B). .
BAL (B) = BAL (A) + GP (B)

Thereafter, the same processing is repeated for each class C to Z to calculate the charge / discharge balance BAL (C) to BAL (Z) from class A to class C to Z (step 404).
BAL (C) = BAL (B) + GP (C)
...
BAL (Z) = BAL (Y) + GP (Z)

Thereafter, the process proceeds to step 405a, and it is determined whether the charge / discharge balance BAL (A) in class A is greater than 0 (whether it is a positive value). As a result, if it is determined that the charge / discharge balance BAL (A) in class A is greater than 0 (plus value), the charge / discharge balance can be obtained by power generation only in class A (the target power consumption TCFC is within the range of class A). The process proceeds to step 406a, and the target power consumption TCFC is calculated by the following equation using the upper limit value [A] of class A, the charge / discharge balance BAL (A), and the power generation possible amount GP (A). calculate.
TCFC = A- (A-0) x BAL (A) / GP (A)
As a result, the power cost at which the charge / discharge balance is 0 within the class A range is calculated, and this power cost is set as the target power cost TCFC.

On the other hand, if it is determined in step 405a that the charge / discharge balance BAL (A) in class A is 0 or less (minus value), the process proceeds to step 405b and the charge / discharge balance BAL (B) from class A to class B is reached. Is greater than 0 (whether it is a positive value). As a result, if it is determined that the charge / discharge balance BAL (B) from class A to class B is greater than 0 (plus value), the charge / discharge balance can be obtained by power generation from class A to class B (range of class B). The target power consumption TCFC may be set within the range), and the process proceeds to step 406b, where the target is calculated using the upper limit [B] of class B, the charge / discharge balance BAL (B), and the power generation possible amount GP (B). The electricity cost TCFC is calculated by the following formula.
TCFC = B- (BA) x BAL (B) / GP (B)
As a result, the power cost at which the charge / discharge balance is 0 within the class B range is calculated, and this power cost is set as the target power cost TCFC.

Hereinafter, by repeating the same process for each class C to Y, the minimum class in which the charge / discharge balance is 0 or more is searched, and the charge / discharge is performed within the range of the minimum class in which the charge / discharge balance is 0 or more. The power cost at which the balance is 0 is calculated, and this power cost is set as the target power cost TCFC (steps 405y and 406y).
TCFC = C- (CB) x BAL (C) / GP (C)
・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・
TCFC = Y− (Y−X) × BAL (Y) / GP (Y)

If the charge / discharge balance BAL (Y) from class A to class Y is 0 or less (negative value), the charge / discharge balance cannot be obtained even if power is generated using the range from class A to class Y. In step 406z, the target power consumption TCFC is set to the upper limit value [Z] of the class Z that is the maximum allowable power consumption.
TCFC = Z

[Target electric cost correction amount calculation routine]
The target power cost correction amount calculation routine of FIG. 7 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation, and calculates the target power cost correction amount TCFCcmp as follows. When this routine is started, first, in step 501, an I-term (integral term) correction amount Icmp for feedback-correcting the target electricity consumption TCFC so as to reduce the deviation between the current SOC (battery charge ratio) and the target SOC. (i) is calculated by the following equation.
Icmp (i) = Icmp (i-1) + (SOC−target SOC) × KI
Here, Icmp (i-1) is the previous I term correction amount, and KI is the I term gain.

Thereafter, the process proceeds to step 502, where target power consumption correction amount TCFCcmp for feedback correction of target power consumption TCFC by PI control (proportional integral control) is set as P term (proportional term) correction amount Pcmp (i) and I term correction amount Icmp. Calculate by adding (i).
TCFCcmp = Pcmp (i) + Icmp (i)
= (SOC-target SOC) x KP + Icmp (i)
Here, KP is a P-term gain.

[Power generation execution determination routine]
The power generation execution determination routine of FIG. 8 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation. When this routine is started, first, in step 601, the target electricity cost TCFC is set to the target electricity cost correction amount TCFCcmp by adding the target electricity cost correction amount TCFCcmp to the target electricity cost TCFC calculated in the target electricity cost calculation routine of FIG. The final target electricity cost TCFCf is obtained by correcting.
TCFCf = TCFC + TCFCcmp
The processing in step 601 serves as target value correction means in the claims together with the target power consumption correction amount calculation routine of FIG.

  Thereafter, the process proceeds to step 602, where it is determined whether or not the current power cost CFC is greater than the final target power cost TCFCf. If the current power cost CFC is greater than the final target power cost TCFCf, the process proceeds to step 603 and the power generation command value is set. Set to 0 to stop power generation by the generator 16. Thereby, overcharging of the battery 12 is prevented.

  On the other hand, if the current power consumption CFC is less than or equal to the final target power consumption TCFCf, the process proceeds to step 604, and the power generation command value is set to the required power generation amount. As a result, while driving (engine operation), a control current corresponding to the power generation command value is supplied to the field coil of the generator 16 to generate power corresponding to the required power generation amount, thereby reducing the power consumption CFC to the final target. The power consumption TCFCf is controlled to converge the SOC (battery charge ratio) to the target SOC. Here, the required power generation amount is calculated by a map or the like according to the current engine speed.

  In the first embodiment described above, the power consumption CFC, which is an increase in fuel consumption per unit power generation, is compared with the final target power consumption TCFCf corrected according to the charging rate (SOC) of the battery 12, and the generator 16 Since power generation is controlled, compared to conventional power generation control methods that determine the operating conditions for power generation using a preset map, the accuracy of the map and the environment in which the vehicle is used (difference in driving road conditions, driving The difference in vehicle speed and acceleration / deceleration by the user) and variations in vehicle characteristics are reduced, and an increase in fuel consumption due to power generation is ensured while securing a necessary power generation amount according to the actual charging rate (SOC) of the battery 12 Therefore, it is possible to reduce fuel consumption and charge / discharge balance.

  In addition, in the first embodiment, the target cost TCFC is set so that the charge / discharge balance of the battery 12 becomes zero, so that the battery 12 can be charged without excess or deficiency with the minimum necessary power generation amount.

  Furthermore, in the first embodiment, the target power consumption TCFC is set based on the frequency of use of the power consumption CFC for each class in the past travel history, the power generation possible amount, and the average power consumption. The target electricity cost TCFC can be automatically set with high accuracy in accordance with differences in road conditions, differences in vehicle speed and acceleration / deceleration by the driver, and variations in vehicle characteristics.

  In this case, the target electricity consumption TCFC is set based only on the usage frequency for each class of the electricity consumption CFC in the past travel history, or the target electricity consumption TCFC is set based on the usage frequency for each class of the electricity consumption CFC and the power generation possible amount. May be.

  In the first embodiment, the reference point of the charge / discharge balance of the battery 12 is set to “0”. However, in the second embodiment of the present invention shown in FIGS. 9 to 11, the SOC of the battery 12 is matched with the target SOC. The reference point of the charge / discharge balance of the battery 12 is corrected according to the required charge / discharge amount. The processing contents of the routines shown in FIGS. 9 to 11 executed in the second embodiment will be described below.

The charge / discharge balance reference point correction amount calculation routine of FIG. 9 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation. When this routine is started, in step 701, the charge / discharge amount required to make the SOC of the battery 12 coincide with the target SOC by multiplying the deviation between the target SOC and the current SOC by the full charge amount and the battery voltage. And charge / discharge balance reference point correction amount BALcmp is obtained by multiplying the charge / discharge amount by correction gain KG.
BALcmp = (target SOC-SOC) x full charge x battery voltage x KG

  In the target electricity cost calculation routine of FIG. 6 executed in the first embodiment described above, the reference points of the charge / discharge balances BAL (A) to BAL (Y) of the classes A to Y are set to “0” in steps 405a to 405y. Thus, a search is made for a minimum class in which the charge / discharge balance of the battery 12 is balanced depending on whether the charge / discharge balance BAL (A) to BAL (Y) of each class A to Y is greater than “0”. However, in the target electricity cost calculation routine of FIG. 10 executed in the second embodiment, in steps 405a ′ to 405y ′, as the reference points of the charge / discharge balances BAL (A) to BAL (Y) of the classes A to Y, Using the charge / discharge balance reference point correction amount BALcmp calculated by the charge / discharge balance reference point correction amount calculation routine of FIG. 9, the charge / discharge balance BAL (A) to BAL (Y) of each class A to Y is the charge / discharge balance reference point. Whether the battery is larger than the correction amount BALcmp The minimum class in which the charge / discharge balance of the battery 12 is equal to or greater than the charge / discharge balance reference point correction amount BALcmp is searched. Then, a power cost in which the charge / discharge balance matches the charge / discharge balance reference point correction amount BALcmp within the range of the minimum class is calculated, and this power cost is set as the target power cost TCFC (steps 406a 'to 406y').

TCFC = A− (A−0) × {BAL (A) −BALcmp} / GP (A)
TCFC = B− (BA) × {BAL (B) −BALcmp} / GP (B)
TCFC = C− (CB) × {BAL (C) −BALcmp} / GP (C)
...
TCFC = Y− (Y−X) × {BAL (Y) −BALcmp} / GP (Y)

  The target electricity consumption calculation routine of FIG. 10 is the same as the processing of each step of the above-described target electricity consumption calculation routine of FIG. 6 except for steps 405a 'to 405y' and 406a 'to 406y'.

  The power generation execution determination routine of FIG. 11 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation. When this routine is started, first, in step 801, it is determined whether or not the current electricity cost CFC is larger than the target electricity cost TCFC. If the current electricity cost CFC is larger than the target electricity cost TCFC, the process proceeds to step 802. The command value is set to 0, and the power generation of the generator 16 is stopped. Thereby, overcharging of the battery 12 is prevented. On the other hand, if the current power consumption CFC is less than or equal to the target power consumption TCFC, the process proceeds to step 803, where the power generation command value is set to the required power generation amount. As a result, during traveling (engine operation), a control current corresponding to the power generation command value is supplied to the field coil of the generator 16 to generate power corresponding to the required power generation amount, thereby reducing the power consumption CFC to the target power consumption. By controlling to TCFC, the SOC of the battery 12 is converged to the target SOC. Here, the required power generation amount is calculated based on the current engine speed and the like.

  In the second embodiment described above, the charge / discharge balance reference point correction amount BALcmp is calculated according to the charge / discharge amount necessary to make the SOC of the battery 12 coincide with the target SOC, and the charge / discharge balance of each class A to Y is calculated. BAL (A) to BAL (Y) are searched for the minimum class in which the charge / discharge balance reference point correction amount BALcmp is greater than or equal to, and the charge / discharge balance is within the range of the minimum class and the charge / discharge balance reference point correction amount BALcmp Since the matching power costs are calculated and the power costs are set as the target power costs TCFC, the convergence of the battery 12 to the target SOC can be improved while satisfying the demand for low fuel consumption.

It is a block diagram explaining the system configuration | structure of Example 1 of this invention. It is a figure which shows the relationship between a fuel consumption rate and an engine driving | running condition. It is a flowchart which shows the flow of a process of the electricity consumption calculation routine of Example 1. FIG. It is a flowchart which shows the flow of a process of the electricity consumption class data storage routine of Example 1. FIG. 3 is a flowchart illustrating a flow of processing of an average power consumption calculation routine according to the first embodiment. It is a flowchart which shows the flow of a process of the target electricity consumption calculation routine of Example 1. It is a flowchart which shows the flow of a process of the target electricity cost correction amount calculation routine of Example 1. 3 is a flowchart illustrating a flow of processing of a power generation execution determination routine according to the first embodiment. 12 is a flowchart illustrating a processing flow of a charge / discharge balance reference point correction amount calculation routine according to the second embodiment. It is a flowchart which shows the flow of a process of the target electricity consumption calculation routine of Example 2. 6 is a flowchart illustrating a flow of processing of a power generation execution determination routine according to the second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Control apparatus (charging condition detection means, power generation control means, fuel consumption calculation means, target value correction means), 12 ... battery, 13 ... key switch, 16 ... generator, 17 ... current sensor, 18 ... voltage sensor

Claims (8)

In a power generation control device for an internal combustion engine comprising: a generator driven by the power of the internal combustion engine; and a battery charged with electric power generated by the generator,
Battery charge state detection means for detecting the charge state of the battery;
Fuel consumption calculation means for calculating a fuel consumption increase per unit power generation based on a fuel consumption increase and power generation by power generation of the generator;
Power generation control means for controlling the power generation of the generator by comparing the fuel consumption increase per unit power generation with the target fuel consumption increase;
A power generation control device for an internal combustion engine, comprising: target value correction means for correcting the target fuel consumption increase based on the state of charge of the battery detected by the battery charge state detection means.   The power generation control means sets the target fuel consumption increase so as to balance a balance between a charge amount and a discharge amount of the battery (hereinafter referred to as a “charge / discharge balance”). A power generation control device for an internal combustion engine as described.   The power generation control means sets the target fuel consumption increase based on the usage frequency for each class of the fuel consumption increase per unit power generation in the past travel history. 3. A power generation control device for an internal combustion engine according to 2.   The power generation control means sets the target fuel consumption increase based on the usage frequency and the power generation possible amount for each class of the fuel consumption increase per unit power generation in the past travel history, The power generation control device for an internal combustion engine according to claim 1 or 2.   The power generation control means sets the target fuel consumption increase based on the usage frequency for each class of the fuel consumption increase per unit power generation in the past travel history, the power generation possible amount, and the average power consumption. The power generation control device for an internal combustion engine according to claim 1 or 2. The battery charge state detection means calculates a charge rate of the battery,
6. The power generation control device for an internal combustion engine according to claim 1, wherein the target value correcting means corrects the target fuel consumption increase based on a charging rate of the battery.   7. The internal combustion engine according to claim 6, wherein the target value correcting unit feedback corrects an increase in the target fuel consumption so as to reduce a deviation between the charging rate of the battery and the target charging rate. Power generation control device.   The target value correcting means calculates a charge / discharge amount necessary for making the charge rate of the battery coincide with the target charge rate, and corrects a reference point of the charge / discharge balance of the battery based on the calculated charge / discharge amount. The power generation control device for an internal combustion engine according to claim 2, wherein the target fuel consumption increase is corrected.

Images