JP4435026B2 - Power generation control device for internal combustion engine - Google Patents

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 during power generation according to the load that drives the power generator. 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 JP-T 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 usage environment (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.

To achieve the above object, the invention according to claim 1, a generator driven by the power of the internal combustion engine, and a battery power generated by the generator is charged, the power generation of the generator the power generation control device of the internal combustion engine that controls a fuel consumption calculating means for calculating a fuel consumption increase per unit power generation amount based on the power generation amount and the fuel consumption increase due to the power generation of the generator, A target fuel consumption increase calculating means for setting a target fuel consumption increase; and a power generation control means for controlling the fuel consumption increase per unit power generation amount to the target fuel consumption increase; The target fuel consumption increase calculation means includes means for setting the target fuel consumption increase so that the balance of charge and discharge of the battery becomes zero, and unit power generation amount in the past travel history Fuel consumption per unit Means for dividing the addition into predetermined ranges, and setting the target fuel consumption increase based on the usage frequency for each predetermined range of the fuel consumption increase per unit power generation amount in the past travel history; It is characterized by having. Thus, if the fuel consumption increase per unit power generation amount is controlled to the target fuel consumption increase amount, the conventional power generation control method for determining the operating conditions for executing power generation with a preset map Compared to, the accuracy of the map, the environment of use of the vehicle (differences in driving road conditions, differences in vehicle speed and acceleration / deceleration by the driver, etc.) and variations in vehicle characteristics are reduced, and the necessary power generation amount is secured. The increase in fuel consumption due to power generation can be reliably reduced.

In this case, as in claim 4 , it is determined whether or not to perform power generation by the generator by comparing the increase in fuel consumption per unit power generation amount under the current operating conditions with the target increase in fuel consumption amount. It is good to do so. In this way, for example, extremely simple control in which power generation by the generator is executed by preferentially selecting an operating condition in which the increase in fuel consumption per unit power generation is equal to or less than the target increase in fuel consumption. Is possible.

Further, as in claim 1 , the target increase in fuel consumption may be set so that the balance of charge and discharge of the battery becomes zero (the charge amount and the discharge amount are balanced). 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.

Moreover, as of claim 1, divides the fuel consumption increase per unit power generation amount in the past travel history for each predetermined range, a predetermined fuel consumption increase per unit power generation amount in the past travel history The target increase in fuel consumption may be set based on the usage frequency for each range . 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.

Furthermore, as in claim 2, the increase in fuel consumption per unit power generation amount in the past travel history is divided into predetermined ranges, and the predetermined increase in fuel consumption per unit power generation amount in the past travel history is determined. The target increase in fuel consumption may be set based on the frequency of use for each range and the amount of power that can be generated. In this way, the target increase in fuel consumption can be set more accurately in consideration of the power generation possible amount for each predetermined range .

Further, as described in claim 3 , the fuel consumption increase per unit power generation amount in the past travel history is divided into predetermined ranges, and the predetermined fuel consumption increase per unit power generation amount in the past travel history is determined. A target fuel consumption increase may be set based on the frequency of use, the amount of power that can be generated, and the average power consumption for each predetermined range . In this way, the target increase in fuel consumption can be set more accurately in consideration of the power generation possible amount and the average power consumption for each predetermined range .

Hereinafter, an embodiment embodying the best mode for carrying out the present invention will be described.
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 controls the power generation of the generator 16. It functions as a control means. Hereinafter, the power generation control of this 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 varies 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 generator 16, the torque generated by the 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 this 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 increase in fuel consumption rate due to power generation is calculated from the difference from the consumption rate), and the increase in fuel consumption rate due to power generation is divided by the power generation amount of the generator 16 to calculate the power consumption (increase in fuel consumption 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 Furthermore, in this embodiment, the frequency of use of power consumption for each class is determined while driving, and power generation for each class Calculate the possible amount and average power consumption, and target the charge / discharge balance of the battery 12 to be zero (the charge amount and the discharge amount are balanced) based on the usage frequency, power generation possible amount and average power consumption for each class The power consumption is set, and the current power consumption is compared with the 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 of the present 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 set in advance from the maximum power generation possible amount of the generator 16, the power generation efficiency of the generator 16, and the like.

  Thereafter, 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 power for 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, where 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 amount 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 calculated. 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 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 (electric power consumption 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. Calculated 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

Meanwhile, in step 203 a, if it is determined that the current electricity cost CFC is not included in the class A, the process proceeds to step 203b, whether the current fuel efficiency CFC is contained in a large class B in the following Class A (A ≦ electric cost CFC <B or not) is determined, and if the current power cost CFC is included in class B, the processing of steps 204b to 207b is executed, and the number of samples of class B is determined in the same manner as described above. NFC (B), electricity cost average value CFCave (B), power generation possible amount average value GPave (B), usage frequency R (B) are calculated, and the stored data is updated.

  Hereinafter, while traveling, the average power consumption values CFCave (C) to CFCave (Z), average power generation amount 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 electricity consumption calculation routine of FIG. 6 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation, and serves as a target fuel consumption increase calculation means referred to in the claims. The electricity cost TCFC is calculated. 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 40 3, by adding the amount capable of generating power GP class from class A to class B discharge balance BAL (B) a charge-discharge balance BAL (A) of Class A B (B) Ask.
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

[Power generation execution determination routine]
The power generation execution determination routine of FIG. 7 is executed at a predetermined cycle (for example, 8 ms cycle) during engine operation. When this routine is started, first, in step 501, it is determined whether or not the current power cost CFC is larger than the target power cost TCFC. If the current power cost CFC is larger than the target power cost TCFC, the process proceeds to step 502, 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 503, and the power generation command value is set to the required power generation amount. As a result, while running (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 charging rate (SOC) of the battery 12 is controlled near the target charging rate. Here, the required power generation amount is determined from the current engine rotation speed, the maximum power generation possible amount of the generator 16, the power generation efficiency of the generator 16, and the like.

  In the present embodiment described above, the power consumption CFC, which is an increase in the fuel consumption rate per unit power generation, is controlled to the target power consumption TCFC, so that the operating conditions for executing power generation are determined by a preset map. Compared with other power generation control methods, the influence of map accuracy, vehicle usage environment (differences in driving road conditions, differences in vehicle speed / acceleration / deceleration by the driver, etc.) and vehicle characteristics are reduced, and the required power generation amount The increase in fuel consumption due to power generation can be surely reduced while ensuring both the fuel efficiency and the charge / discharge balance.

In addition, in the present embodiment, the target power consumption TCFC is set so that the charge / discharge balance of the battery 12 becomes 0, so that the battery 12 can be charged without excess or deficiency with the minimum necessary power generation amount.

  Furthermore, in this 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 amount of power generation, and the average power consumption. The target electricity cost TCFC can be set automatically and accurately in accordance with the difference in the situation, the difference in vehicle speed and acceleration / deceleration by the driver, and the variation 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.

It is a block diagram explaining the system configuration | structure of one Example 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 a power consumption calculation routine. It is a flowchart which shows the flow of a process of a power consumption class data storage routine. It is a flowchart which shows the flow of a process of an average power consumption calculation routine. It is a flowchart which shows the flow of a process of a target electricity consumption calculation routine. It is a flowchart which shows the flow of a process of an electric power generation execution determination routine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Control apparatus (Power generation control means, Fuel consumption calculation means , Target fuel consumption increase calculation means ), 12 ... Battery, 13 ... Key switch, 16 ... Generator

Claims (4)

A generator driven by the power of the internal combustion engine, and a battery power generated by the generator is charged, the power generation control device of the internal combustion engine that controls the power generation of the generator,
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 ;
A target fuel consumption increase calculating means for setting a target fuel consumption increase;
Power generation control means for controlling the fuel consumption increase per unit power generation to the target fuel consumption increase,
The target fuel consumption increase calculation means includes means for setting the target fuel consumption increase so that the balance of charge and discharge of the battery becomes zero, and fuel per unit power generation amount in the past travel history Means for dividing the increase in consumption into predetermined ranges and setting the target increase in fuel consumption based on the usage frequency for each predetermined range of the increase in fuel consumption per unit power generation in the past travel history And a power generation control device for an internal combustion engine. 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 power generated by the generator;
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;
A target fuel consumption increase calculating means for setting a target fuel consumption increase;
Power generation control means for controlling the fuel consumption increase per unit power generation to the target fuel consumption increase,
The target fuel consumption increase calculation means includes means for setting the target fuel consumption increase so that the balance of charge and discharge of the battery becomes zero, and fuel per unit power generation amount in the past travel history Divide the increase in consumption for each predetermined range, and increase the target fuel consumption based on the usage frequency and the power generation amount for each predetermined range of the increase in fuel consumption per unit power generation in the past travel history power generation control device of the internal combustion engine you; and a means for setting a frequency. 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 power generated by the generator;
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;
A target fuel consumption increase calculating means for setting a target fuel consumption increase;
Power generation control means for controlling the fuel consumption increase per unit power generation to the target fuel consumption increase,
The target fuel consumption increase calculation means includes means for setting the target fuel consumption increase so that the balance of charge and discharge of the battery becomes zero, and fuel per unit power generation amount in the past travel history The consumption increase is divided into predetermined ranges, and the target is calculated based on the usage frequency, the power generation possible amount and the average power consumption for each predetermined range of the fuel consumption increase per unit power generation amount in the past travel history. power generation control device of the internal combustion engine you; and a means for setting the consumption increase fuel. The power generation control means compares the increase in fuel consumption per unit power generation under the current operating conditions with the target increase in fuel consumption to determine whether to execute power generation of the generator. The power generation control device for an internal combustion engine according to any one of claims 1 to 3 .

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