JP2014177160A - Hybrid-vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reduction in a fuel consumption amount of an engine while controlling a battery charge-discharge energy balance to a desired value, of a hybrid vehicle incorporating an engine and a motor generator therein.SOLUTION: A hybrid-vehicle control device performs: setting an instructed fuel consumption change ratio at a given update cycle on the basis of travel pattern information and a target charge-discharge energy balance; and setting an engine output power increase-decrease amount to minimize an engine fuel consumption amount while controlling a battery charge-discharge energy balance to a given value (the target charge-discharge energy balance) in a given period on the basis of the instructed fuel consumption change ratio and a target drive power, where, if there are plural corresponding engine output power increase-decrease amounts, engine output power increase-decrease amounts of which a change ratio of the fuel consumption change ratio is a positive value are selected from among the plural engine output power increase-decrease amounts, and an engine output power increase-decrease amount of which an efficiency (a value produced by dividing a fuel consumption amount by an engine output power increase-decrease amount) is a minimum is selected from among the engine output power increase-decrease amounts.

Description

  The present invention relates to a control device for a hybrid vehicle equipped with an engine and a motor generator as a power source of the vehicle.

  In recent years, a hybrid vehicle equipped with an engine and a motor generator as a power source of the vehicle has attracted attention because of the social demand for low fuel consumption and low exhaust emissions. In such a hybrid vehicle, for example, as described in Patent Document 1 (Japanese Patent No. 3812134), the running power of the vehicle and the charging / discharging of the battery so as to maintain the charging state of the battery within a predetermined range. There is one that determines the engine power based on the power. In addition, by determining the charge / discharge amount of the battery according to the running power and increasing or decreasing the engine power by this charge / discharge amount, the engine is operated at a more efficient operating point to improve fuel efficiency. Some have done.

Japanese Patent No. 3812134

  By the way, in a hybrid vehicle, in order to effectively improve fuel efficiency, the fuel consumption of the engine while operating the charge / discharge energy balance (change amount of energy stored in the battery) before and after traveling to a desired value. It has been demanded to reduce this.

  However, in the above prior art, the charge / discharge energy balance of the battery is not taken into consideration, and the fuel consumption of the engine cannot be reduced while operating the charge / discharge energy balance of the battery to a desired value. It cannot be improved effectively.

  Accordingly, an object of the present invention is to provide a control device for a hybrid vehicle that can reduce the fuel consumption of the engine while operating the charge / discharge energy balance of the power storage means to a desired value. .

  In order to solve the above problems, an invention according to claim 1 is directed to an engine (11) and a motor generator (12, 12A, 12B) mounted as a power source of a vehicle, and the motor generator (12, 12A, 12B). Change rate of the fuel consumption of the engine (11) with respect to the difference between the output power of the engine (11) and the drive power of the vehicle ( Change rate setting means (25) that is simply referred to as “fuel consumption rate of change” (hereinafter referred to as “fuel consumption rate of change”), and power storage means for a predetermined period based on the fuel consumption rate of change and the target drive power of the vehicle An increase / decrease amount for setting an engine output power increase / decrease amount that minimizes the fuel consumption of the engine (11) while operating the charge / discharge energy balance of (20) to a predetermined value. The increase / decrease amount setting means (25) includes a plurality of engine output power increase / decrease amounts corresponding to the fuel consumption rate change rate and the target drive power. The engine output power increase / decrease amount is selected from a plurality of engine output power increase / decrease amounts based on the change rate of the fuel consumption change rate.

  For the reasons described later, by making the rate of change in fuel consumption during a predetermined period equal (constant), the charge / discharge energy balance of the power storage means during the predetermined period (the amount of change in energy stored in the power storage means) is predetermined. Engine fuel consumption can be minimized while manipulating the value.

  Accordingly, the fuel consumption rate change rate is set at a predetermined update cycle, and the engine output power increase / decrease amount is set based on the fuel consumption rate change rate and the target drive power, thereby realizing the target drive power while maintaining the predetermined drive power. The engine output power increase / decrease amount that minimizes the fuel consumption of the engine can be set while operating the charge / discharge energy balance of the power storage means to a predetermined value during the period (period corresponding to the update period of the fuel consumption change rate). it can. By controlling the engine based on the engine output power increase / decrease amount, the fuel consumption of the engine can be minimized while operating the charge / discharge energy balance of the power storage means for a predetermined period to a predetermined value. By performing such control, it becomes possible to reduce the fuel consumption of the engine while operating the charge / discharge energy balance of the power storage means before and after traveling to a desired value, and to effectively improve the fuel efficiency performance. it can.

  By the way, depending on the characteristics of the vehicle drive system, the convexity may be lost in the relationship between the engine output power increase / decrease amount and the fuel consumption amount (see FIG. 6). In such a case, there is a region where a plurality of engine output power increase / decrease amounts having the same fuel consumption rate change rate are present (see FIG. 7). Therefore, when setting the engine output power increase / decrease amount based on the fuel consumption change rate and the target drive power, a plurality of engine outputs as engine output power increase / decrease amounts corresponding to the fuel consumption change rate and the target drive power are set. There is a case where the power increase / decrease amount exists and the engine output power increase / decrease amount cannot be uniquely determined.

  As a countermeasure against this, in the invention according to claim 1, when there are a plurality of engine output power increase / decrease amounts corresponding to the fuel consumption change rate and the target drive power, One engine output power increase / decrease amount is selected from a plurality of engine output power increase / decrease amounts based on the rate of change. In this way, even when there are multiple engine output power increase / decrease amounts corresponding to the fuel consumption change rate and the target drive power, the change rate of the fuel consumption change rate is used as a criterion. Thus, the engine output power increase / decrease amount can be uniquely determined.

FIG. 1 is a diagram showing a schematic configuration of a drive system for a hybrid vehicle in Embodiment 1 of the present invention. FIG. 2 is a graph showing characteristics of fuel consumption with respect to engine output power. FIG. 3 is a diagram for explaining conditions for minimizing fuel consumption. FIG. 4 is a block diagram showing a function for calculating the engine required power. FIG. 5 is a diagram conceptually illustrating an example of a map of engine output power increase / decrease amount. FIG. 6 is a diagram showing the relationship between the engine output power increase / decrease amount and the fuel consumption amount. FIG. 7 is a diagram for explaining a method of selecting the engine output power increase / decrease amount at which the change rate of the fuel consumption change rate becomes a positive value. FIG. 8 is a diagram for explaining a method of selecting the engine output power increase / decrease amount that minimizes the efficiency. FIG. 9 is a flowchart showing the flow of processing of the main control routine. FIG. 10 is a flowchart showing the flow of processing of the command fuel consumption change rate calculation routine. FIG. 11 is a flowchart showing the flow of processing of an engine output power increase / decrease amount calculation routine. FIG. 12 is a diagram showing a schematic configuration of a hybrid vehicle drive system according to the second embodiment.

  Hereinafter, some embodiments embodying the mode for carrying out the present invention will be described.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of a hybrid vehicle drive system will be described with reference to FIG.
An engine 11 that is an internal combustion engine and a motor generator (hereinafter referred to as “MG”) 12 are mounted as power sources for the vehicle. The power of the output shaft (crankshaft) of the engine 11 is transmitted to the transmission 13 via the MG 12, and the power of the output shaft of the transmission 13 is transmitted to the wheels 17 via the drive shaft 14, the differential gear mechanism 15, the axle 16 and the like. Is transmitted to. The transmission 13 may be a stepped transmission that switches the shift speed step by step from a plurality of shift speeds, or may be a CVT (continuously variable transmission) that shifts continuously. A rotary shaft of the MG 12 is connected to a mechanical connection shaft 18 that transmits the power of the engine 11 to the transmission 13 so that the power can be transmitted. An inverter 19 that drives the MG 12 is connected to a battery 20 (power storage means), and the MG 12 exchanges power with the battery 20 via the inverter 19.

  The accelerator sensor 21 detects the accelerator opening (the amount of operation of the accelerator pedal), and the shift switch 22 detects the operation position of the shift lever. Further, a brake operation (or a brake operation amount by a brake sensor) is detected by the brake switch 23, and a vehicle speed is detected by the vehicle speed sensor 24.

  The hybrid ECU 25 is a computer that comprehensively controls the entire vehicle, and reads the output signals of the various sensors and switches described above to detect the driving state of the vehicle. The hybrid ECU 25 transmits and receives control signals and data signals to and from the engine ECU 26 that controls the operation of the engine 11 and the MG-ECU 27 that controls the MG 12 by controlling the inverter 19. The engine 11 and the MG 12 are controlled according to the above.

  At that time, the MG 12 converts the electric power supplied from the battery 20 into motive power and outputs the motive power to the mechanical connection shaft 18 or changes the motive power input from the mechanical connection shaft 18 into electric power to charge the battery 20. The transmission 13 increases the speed of power input from the machine connecting shaft 18 (power obtained by adding the power of the engine 11 and power of the MG 12 or power obtained by subtracting the power converted from the power of the engine 11 into power by the MG 12) or Decelerate and output to drive shaft 14.

  Further, the hybrid ECU 25 adds the engine output power (output power of the engine 11) to the drive power of the vehicle by adding the loss power consumed by other than the engine 11 (for example, the MG 12, the transmission 13, the inverter 19, the battery 20, etc.). The battery 20 is charged with electric power by setting it to be larger than the power. On the other hand, electric power is discharged from the battery 20 by making the engine output power smaller than the power obtained by adding the loss power consumed outside the engine 11 to the drive power. In this case, the engine output power is obtained by adding the driving power to the loss power consumed outside the engine 11 and the charge / discharge power of the battery 20.

  By the way, in a hybrid vehicle, in order to improve fuel efficiency effectively, the charge / discharge energy balance of the battery 20 before and after traveling (amount of change in energy stored in the battery 20) is manipulated to a desired value while the engine 11 There is an increasing demand for reducing fuel consumption.

  Therefore, in the first embodiment, the hybrid ECU 25 executes the routines shown in FIGS. 9 to 11 to be described later, thereby setting the target drive power of the vehicle at a predetermined update period and the engine output power and the drive power. The change rate of the fuel consumption of the engine 11 with respect to the difference (hereinafter simply referred to as “fuel consumption change rate”) is set at a predetermined update cycle (update cycle longer than the update cycle of the target drive power), and this change in fuel consumption Based on the rate and the target drive power, the fuel consumption of the engine 11 is minimized while operating the charge / discharge energy balance of the battery 20 to a predetermined value during a predetermined period (a period corresponding to the update period of the fuel consumption change rate). Set the engine output power increase / decrease amount.

  Hereinafter, the reason why the engine output power increase / decrease amount that minimizes the fuel consumption of the engine 11 can be set while operating the charge / discharge energy balance of the battery 20 in a predetermined period to a predetermined value will be described. First, for ease of explanation, consider the case of two traveling powers.

  FIG. 2 is a diagram illustrating an example of a characteristic of fuel consumption with respect to engine output power. Let P1 and P2 be the amount of increase or decrease in engine output power at a certain traveling power and a traveling power larger than that. This increase / decrease amount corresponds to the difference between the engine output power and the drive power in the claims. FIG. 3 shows changes in the fuel consumption FC (P1) and FC (P2) with respect to the increase / decrease amounts P1 and P2 expressed by contour lines as FC (P1) + FC (P2). Since the charge / discharge energy balance of the battery 20 can be expressed by P1 + P2, the combination of P1 and P2 at which the charge / discharge energy balance (P1 + P2) is constant (E) is a straight line P1 + P2 = E (indicated by a broken line in FIG. 3) Can be represented by the straight line shown).

The increase / decrease amounts P1 and P2 that minimize the total fuel consumption FC (P1) + FC (P2) on this straight line are the point where the fuel consumption contour line and the straight line touch each other (the point indicated by an asterisk in FIG. 3). Become. Since the condition indicating this point is a contact point between the straight line and the contour line, the fuel consumption change rate dFC (P1) / dP1 (the increase / decrease amount P1 of the fuel consumption FC) which is the change rate of the fuel consumption FC with respect to the increase / decrease amount P1. And the fuel consumption change rate dFC (P2) / dP2 (the differential value of the fuel consumption FC in the increase / decrease amount P2), which is the change rate of the fuel consumption FC with respect to the increase / decrease amount P2. Is equivalent.
dFC (P1) / dP1 = dFC (P2) / dP2

  Furthermore, even if it is desired to manipulate the charge / discharge energy balance before and after traveling, the straight line in FIG. 3 only moves in parallel, so the condition for minimizing fuel consumption is that the rate of change in fuel consumption is equal. Since this condition can be applied even if the number of traveling power points increases, it also holds for various traveling patterns.

  For the above-described reason, the fuel consumption rate of the engine 11 is minimized while operating the charge / discharge energy balance of the battery 20 in a predetermined period to be a predetermined value by equalizing (making constant) the rate of change in fuel consumption during the predetermined period. Can be.

  Accordingly, the fuel consumption rate change rate is set at a predetermined update cycle, and the engine output power increase / decrease amount is set based on the fuel consumption rate change rate and the target drive power, thereby realizing the target drive power while maintaining the predetermined drive power. The engine output power increase / decrease amount that minimizes the fuel consumption of the engine 11 can be set while operating the charge / discharge energy balance of the battery 20 to a predetermined value during the period (period corresponding to the update period of the fuel consumption change rate). it can. By controlling the engine 11 based on the engine output power increase / decrease amount, the fuel consumption of the engine 11 can be minimized while operating the charge / discharge energy balance of the battery 20 for a predetermined period to a predetermined value.

  Specifically, as shown in FIG. 4, first, the target drive power of the vehicle is calculated, and the loss power consumed by other than the engine 11 (for example, the MG 12, the transmission 13, the inverter 19, the battery 20, etc.) is calculated. calculate. Further, the vehicle travel pattern information and the target charge / discharge energy balance of the battery 20 are set.

  The travel pattern information is calculated, for example, as the travel pattern information by the frequency or the ratio of the travel time for each region of travel power divided into a plurality of regions. Alternatively, the average speed and the average traveling power may be calculated as traveling pattern information. A travel pattern based on at least one of past travel history (for example, past travel route and travel distance) and travel information (for example, future travel route and travel distance) from a navigation device (not shown). Information may be predicted and set.

  The target charge / discharge energy balance is, for example, that when the discharge is set to a positive value, the energy amount discharged from the battery 20 (discharge energy amount) and the kinetic energy of the vehicle by the MG 12 are electrically converted by the MG 12. Calculating the sum of the amount of energy (charge energy amount) charged in the battery 20 by energy regeneration for converting into energy and charging the battery 20 and the amount of energy (required charge energy amount) to be charged in the battery 20 during traveling; This sum is set as the target charge / discharge energy balance.

Target charge / discharge energy balance = discharge energy amount + charge energy amount + required charge energy amount Further, the charge energy amount, the discharge energy amount, and the required charge energy based on at least one of the past travel history and the travel information from the navigation device. The target charge / discharge energy balance may be set by predicting the amount.

  Thereafter, the command fuel consumption rate of change is set at a predetermined update period (an update period longer than the update period of the target drive power) based on the travel pattern information and the target charge / discharge energy balance. That is, the command fuel consumption rate of change is updated every predetermined time (time corresponding to the update cycle). In the first embodiment, a map that defines the relationship between the running pattern information, the target charge / discharge energy balance, and the command fuel consumption change rate is stored in advance as a “command fuel consumption change rate map”. A command fuel consumption change rate corresponding to the running pattern information and the target charge / discharge energy balance is calculated with reference to the consumption change rate map. The map of the command fuel consumption change rate is created in advance based on test data, design data, and the like, and is stored in the ROM of the hybrid ECU 25.

  Thereafter, based on the command fuel consumption change rate and the target drive power, the charge / discharge energy balance of the battery 20 in a predetermined period (a period corresponding to the update period of the command fuel consumption change rate) is set to a predetermined value (target charge / discharge). The engine output power increase / decrease amount that minimizes the fuel consumption of the engine 11 is set while operating on the energy balance.

  In the first embodiment, as shown in FIG. 5, a map that defines the relationship among the command fuel consumption change rate, the target drive power, and the engine output power increase / decrease amount is stored in advance as an “engine output power increase / decrease map”. The engine output power increase / decrease amount corresponding to the command fuel consumption change rate and the target drive power is calculated with reference to the map of the engine output power increase / decrease amount.

  The map of the engine output power increase / decrease amount is set for each temperature information of each part (for example, at least one of the engine 11, the MG 12, the transmission 13, the inverter 19, the battery 20, etc.), and according to the temperature information of each part. The engine output power increase / decrease map is changed (switched). This map of engine output power increase / decrease amount is a test data for loss characteristics of each part (for example, at least one of the engine 11, the MG 12, the transmission 13, the inverter 19, the battery 20, etc.) offline in advance when designing the vehicle. And based on design data and the like, and stored in the ROM of the hybrid ECU 25.

  Thereafter, the engine required power is obtained by adding the target drive power and the loss power to the engine output power increase / decrease amount, and the torque and rotation speed of the engine 11 are controlled so as to realize the engine required power.

  By the way, as shown in FIG. 6, depending on the characteristics of the vehicle drive system, the convexity may be lost in the relationship between the engine output power increase / decrease amount and the fuel consumption amount. In such a case, as shown in FIG. 7, there is a region where a plurality of engine output power increase / decrease amounts having the same fuel consumption rate change rate are present. For this reason, when setting the engine output power increase / decrease amount based on the command fuel consumption change rate and the target drive power using the map of FIG. 5, the command fuel consumption change rate and the target drive power are handled. There may be a plurality of engine output power increase / decrease amounts as the engine output power increase / decrease amount, and the engine output power increase / decrease amount cannot be uniquely determined.

  As a countermeasure, in the first embodiment, when there are a plurality of engine output power increase / decrease amounts corresponding to the command fuel consumption change rate and the target drive power, the change in the fuel consumption change rate is present. One engine output power increase / decrease amount is selected from a plurality of engine output power increase / decrease amounts based on the rate.

  Specifically, first, as shown in FIG. 7, the engine output power at which the rate of change in fuel consumption rate change rate (the slope of the rate of change in fuel consumption rate) is a positive value among a plurality of engine output power fluctuations. Select the increase / decrease amount. As a result, the engine output power increase / decrease amount that may minimize the total fuel consumption amount is limited from among the plurality of engine output power increase / decrease amounts (the reason will be described later).

  Next, as shown in FIG. 8, for the engine output power increase / decrease amount at which the rate of change of the fuel consumption change rate is a positive value, the value obtained by dividing the fuel consumption amount by the engine output power increase / decrease amount (in FIG. 8, the origin) The slope of the straight line connecting the star and the star) is calculated as the efficiency, and the engine output power increase / decrease with the smallest efficiency (slope) from the engine output power increase / decrease with the positive rate of change of the fuel consumption change rate Select. Thereby, the engine output power increase / decrease amount with the smallest fuel consumption amount is selected and set from the engine output power increase / decrease amount with the positive change rate of the fuel consumption change rate.

  Here, by selecting the engine output power increase / decrease amount at which the change rate of the fuel consumption change rate becomes a positive value, the engine output power increase / decrease amount that may minimize the total fuel consumption amount is limited. Explain why.

Consider a problem setting in which the amount of increase / decrease in fuel consumption associated with charge / discharge can be expressed by a charge / discharge function F (X) defined for each drive power. This charging / discharging function F (X) is a function having charging / discharging power x _i as a variable with the charging direction being positive, and X is a vector composed of x _i .

  In this problem setting, considering the condition that the sum of the fuel consumption is minimized (charging with the same power consumption change rate), the first floor of each charge / discharge function F (X) for each drive power It is a condition that the sum of fuel consumption is minimized that the differential values are equal. This condition is merely a condition that “the charge / discharge function takes an extreme value” when the convexity is lost. In general, the minimum condition of a function for analytically obtaining a minimum value is to satisfy the condition that “the Hessian of a function for obtaining a minimum value is positive definite” in addition to the above condition. This is equivalent to the fact that all eigenvalues λ of the Hessian matrix are positive values. In this problem setting, focusing on the fact that each charge / discharge function F (X) is a univariate function, the Hessian matrix is a diagonal matrix having the second derivative of each charge / discharge function F (X) as a diagonal component. Therefore, this eigenvalue λ is the second derivative of each charge / discharge function F (X) itself (see the following (1) to (3)).

  (1) Definition of Hessian matrix and shape of Hessian matrix in this problem

  (2) Eigenvalue calculation method

  (3) Conditions for the Hessian matrix to be positive definite

From the above, it can be seen that in this problem setting, the condition for minimizing the charge / discharge function is that all second-order derivatives of each charge / discharge function are positive values. In other words, selecting the engine output power increase / decrease amount at which the rate of change in the fuel consumption change rate is a positive value is not only obtaining the minimum value, but also from the engine output power increase / decrease amount being the minimum value. The output power increase / decrease amount is selected. Based on the above thinking, by selecting the engine output power increase / decrease amount with a positive change rate of the fuel consumption change rate, the engine output power increase / decrease amount that can minimize the total fuel consumption is limited. I understand that I can do it.
Hereinafter, the processing content of each routine of FIG. 9 thru | or FIG. 11 which hybrid ECU25 performs in the present Example 1 is demonstrated.

[Main control routine]
The main control routine shown in FIG. 9 is repeatedly executed at a predetermined calculation cycle T1 during the power-on period of the hybrid ECU 25. When this routine is started, first, at step 101, the target drive power is calculated by a map or a mathematical expression based on the accelerator opening, the vehicle speed, and the like. Thereafter, the process proceeds to step 102, and the loss power consumed by other than the engine 11 is calculated by a map or a mathematical formula based on the accelerator opening, the vehicle speed, and the like.

  Thereafter, the process proceeds to step 103, and a command fuel consumption change rate calculation routine shown in FIG. 10 to be described later is executed to calculate the command fuel consumption change rate. Then, the process proceeds to step 104 and the engine output shown in FIG. By executing the power increase / decrease amount calculation routine, the engine output power increase / decrease amount is calculated.

  Thereafter, the process proceeds to step 105, where the engine required power is obtained by adding the target drive power and the loss power to the engine output power increase / decrease amount. Thereafter, the process proceeds to step 106, and after calculating the required torque and the required rotational speed of the engine 11 based on the engine required power, the process proceeds to step 107, and the required torque or the required rotational speed of the MG 12 is calculated.

  Thereafter, the process proceeds to step 108, and the engine 11 is controlled so as to realize the required torque and the required rotational speed of the engine 11 by instructing the engine ECU 26 with the required torque and the required rotational speed of the engine 11. Thereafter, the process proceeds to step 109, where the MG 12 is instructed to the MG-ECU 27 to control the MG 12 so as to realize the required torque or the required rotational speed of the MG 12.

[Command fuel consumption change rate calculation routine]
The command fuel consumption change rate calculation routine shown in FIG. 10 is a subroutine executed in step 103 of the main control routine of FIG. This routine is repeatedly executed at a calculation cycle T2 longer than the calculation cycle T1 of the main control routine of FIG.

  When this routine is started, first, in step 201, for example, the frequency or ratio of the travel time for each region of travel power divided into a plurality of regions is calculated as travel pattern information. Alternatively, the average speed and the average traveling power may be calculated as traveling pattern information. Further, the travel pattern information may be predicted and set based on at least one of past travel history and travel information from the navigation device.

  Thereafter, the process proceeds to step 202, where the amount of energy discharged from the battery 20 by EV traveling (discharge energy amount), the amount of energy charged by the battery 20 by energy regeneration (charging energy amount), and charging the battery 20 during traveling are desired. The sum total with the energy amount (required charge energy amount) is calculated, and this sum is set as the target charge / discharge energy balance. Further, the target charge / discharge energy balance may be set by predicting the charge energy amount, the discharge energy amount, and the required charge energy amount based on at least one of past travel history and travel information from the navigation device. .

  Thereafter, the process proceeds to step 203, where the command fuel consumption change rate corresponding to the running pattern information and the target charge / discharge energy balance is calculated with reference to the map of the command fuel consumption change rate. As a result, the update cycle (calculation cycle T2) of the command fuel consumption change rate is made longer than the update cycle (calculation cycle T1) of the target drive power, and between the update timings of the command fuel consumption change rate (current update timing) To the next update timing), the value of the command fuel consumption change rate is fixed. The process of step 203 serves as a change rate setting means in the claims.

[Engine output power increase / decrease calculation routine]
The engine output power increase / decrease amount calculation routine shown in FIG. 11 is a subroutine executed in step 104 of the main control routine of FIG. 9, and serves as an increase / decrease amount setting means in the claims. This routine is repeatedly executed at the same calculation cycle T1 as the main control routine of FIG.

  When this routine is started, first, in step 301, referring to the map of engine output power increase / decrease shown in FIG. 5, the engine output power increase / decrease according to the command fuel consumption change rate and the target drive power is determined. calculate. At this time, the map of the engine output power increase / decrease amount is switched according to the temperature information of each part (for example, at least one of the engine 11, MG12, transmission 13, inverter 19, battery 20, etc.), and the temperature information of each part. Select the map of engine output power increase / decrease according to.

  In this case, for example, the coolant temperature may be detected as substitute information for the temperature of the engine 11. Further, the temperature of the hydraulic oil (such as ATF) may be detected as substitute information for the temperature of the transmission 13. Alternatively, at least one of the temperature of the engine 11, the temperature of the MG 12, the temperature of the transmission 13, the temperature of the inverter 19, the temperature of the battery 20, etc. may be estimated (calculated).

  Thereafter, the routine proceeds to step 302, where it is determined whether or not the corresponding engine output power increase / decrease amount (the engine output power increase / decrease amount corresponding to the current command fuel consumption change rate and the target drive power) is single.

  When it is determined in step 302 that the corresponding engine output power increase / decrease amount is single, the engine output power increase / decrease amount is directly adopted as the current engine output power increase / decrease amount, and this routine is terminated. .

  On the other hand, if it is determined in step 302 that the corresponding engine output power increase / decrease amount is not single (that is, a plurality of engine output power increases / decreases), the process proceeds to step 304, and the plurality of current engine output power increase / decrease amounts are respectively determined. The change rate of the fuel consumption change rate is calculated. Thereafter, the process proceeds to step 305, and an engine output power increase / decrease amount at which the change rate of the fuel consumption change rate becomes a positive value is selected from the current engine output power increase / decrease amounts.

  Thereafter, the process proceeds to step 306, where the fuel consumption amount is converted into the engine output power for the engine output power increase / decrease amount selected in step 305 (the engine output power increase / decrease amount at which the change rate of the fuel consumption change rate becomes a positive value). The value divided by the increase / decrease amount is obtained as the efficiency. Thereafter, the process proceeds to step 307, and the engine output at which the efficiency is minimized from the engine output power increase / decrease amount selected in step 305 (the engine output power increase / decrease amount at which the rate of change of the fuel consumption change rate becomes a positive value). The power increase / decrease amount is selected as the current engine output power increase / decrease amount, and this routine ends.

  In the first embodiment described above, the command fuel consumption change rate is set at a predetermined update cycle, and the engine output power increase / decrease amount is set based on the command fuel consumption change rate and the target drive power. Therefore, while realizing the target drive power, the engine 11 is operated while operating the charge / discharge energy balance of the battery 20 to a predetermined value (target charge / discharge energy balance) in a predetermined period (period corresponding to the update period of the fuel consumption change rate). The engine output power increase / decrease amount that minimizes the amount of fuel consumption can be set. By controlling the engine 11 based on the engine output power increase / decrease amount, the fuel consumption of the engine 11 can be minimized while operating the charge / discharge energy balance of the battery 20 for a predetermined period to a predetermined value. By performing such control, it becomes possible to reduce the fuel consumption of the engine 11 while operating the charge / discharge energy balance of the battery 20 before and after traveling to a desired value, and to effectively improve the fuel consumption performance. it can.

  In the first embodiment, when the engine output power increase / decrease amount is set based on the command fuel consumption change rate and the target drive power, the engine output power corresponding to the command fuel consumption change rate and the target drive power is set. When there is more than one engine output power increase / decrease amount as an increase / decrease amount, one engine output power increase / decrease amount is selected from the multiple engine output power increase / decrease amounts based on the change rate of the fuel consumption change rate Therefore, even when there are multiple engine output power increase / decrease amounts corresponding to the command fuel consumption change rate and the target drive power, the engine change rate of the fuel consumption change rate is used as a judgment criterion. The output power increase / decrease amount can be uniquely determined.

  At this time, in the first embodiment, first, the engine output power increase / decrease amount at which the change rate of the fuel consumption change rate is a positive value is selected from the plurality of engine output power increase / decrease amounts. From the engine output power increase / decrease amount, it is possible to limit the engine output power increase / decrease amount that may minimize the total fuel consumption (the engine output power increase / decrease amount that cannot be minimized). Can be eliminated).

  Next, for the engine output power increase / decrease amount with a positive change rate of the fuel consumption change rate, the value obtained by dividing the fuel consumption amount by the engine output power increase / decrease amount is obtained as the efficiency, and the change in the fuel consumption change rate is determined. Since the engine output power increase / decrease amount that minimizes the efficiency is selected from the engine output power increase / decrease amount for which the rate is a positive value, the engine output power for which the rate of change of the fuel consumption change rate is a positive value From the increase / decrease amount, the engine output power increase / decrease amount with the smallest increase or decrease fuel consumption per unit charge / discharge energy amount can be selected and set.

  In the first embodiment, the engine output power increase / decrease amount at which the efficiency is minimum is selected from the engine output power increase / decrease amount at which the change rate of the fuel consumption change rate is a positive value. For example, the largest engine output power increase / decrease amount is selected from the engine output power increase / decrease amounts where the change rate of the fuel consumption change rate is a positive value, or the smallest engine output The power increase / decrease amount may be selected. In this way, the engine output power increase / decrease amount can be uniquely determined.

  In the first embodiment, the command fuel consumption change rate update cycle (calculation cycle T2) is made longer than the target drive power update cycle (calculation cycle T1). While sufficiently maintaining a constant period, the target drive power responsiveness to the accelerator opening and the like can be ensured by sufficiently shortening the target drive power update cycle. In addition, since the value of the command fuel consumption change rate is fixed during the update timing of the command fuel consumption change rate, the command fuel consumption change rate can be reliably maintained constant during the update timing.

  In the first embodiment, a map that defines the relationship among the change rate of the command fuel consumption, the target drive power, and the engine output power increase / decrease amount is stored in advance as an “engine output power increase / decrease map”. Since the engine output power increase / decrease amount is calculated according to the command fuel consumption change rate and the target drive power with reference to the output power increase / decrease map, it is stored in advance without performing complicated calculation processing. The engine output power increase / decrease amount can be set using the map of the engine output power increase / decrease amount, and the calculation load of the control device (for example, the hybrid ECU 25) can be reduced.

  Further, in the first embodiment, the map of the engine output power increase / decrease amount is changed according to the temperature information of each part (for example, at least one of the engine 11, the MG 12, the transmission 13, the inverter 19, the battery 20, and the like). As a result, the loss of each part changes depending on the temperature of each part, and the engine output power increase / decrease corresponds to the change in the command fuel consumption change rate, the target drive power, and the engine output power increase / decrease The amount map can be changed, and the engine output power increase / decrease amount can be set with high accuracy.

  In the first embodiment, since the command fuel consumption rate of change is set based on the running pattern information and the target charge / discharge energy balance, according to the change in the running pattern information and the target charge / discharge energy balance, The fuel consumption change rate can be set to an appropriate value by changing the command fuel consumption change rate at a predetermined update period.

  Further, in the first embodiment, a map that defines the relationship between the running pattern information, the target charge / discharge energy balance, and the command fuel consumption change rate is stored in advance as a “command fuel consumption change rate map”. Since the command fuel consumption rate of change according to the running pattern information and the target charge / discharge energy balance is calculated with reference to the map of the command fuel consumption rate of change, without performing complicated arithmetic processing in advance. The command fuel consumption change rate can be set using the stored map of the command fuel consumption change rate, and the calculation load of the control device (for example, the hybrid ECU 25) can be reduced.

  In the first embodiment, the clutch is not provided in the power transmission path from the engine 11 to the transmission 13. However, the present invention is not limited to this. For example, a clutch is provided between the engine 11 and the MG 12, A clutch may be provided between the MG 12 and the transmission 13. Alternatively, the transmission 13 may have a built-in clutch. Further, the transmission 13 may be omitted.

  Next, Embodiment 2 of the present invention will be described with reference to FIG. However, parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified, and parts different from those in the first embodiment are mainly described.

  In the second embodiment, as shown in FIG. 12, an engine 11 and two MGs (first MG 12A and second MG 12B) are mounted as a power source of the vehicle. The output shaft (crank shaft) of the engine 11, the rotation shaft of the first MG 12A, and the rotation shaft of the second MG 12B are connected via a planetary gear mechanism 28 that is a power split mechanism, and the rotation shaft of the second MG 12B is The drive shaft 14 is connected.

  The first MG 12A and the second MG 12B exchange power with the battery 20 via inverters 19A and 19B, respectively. The MG-ECU 27 controls the first inverter 19A to control the first MG 12A, and also controls the second inverter 19B to control the second MG 12B.

  Also in the second embodiment, the command fuel consumption change rate is set at a predetermined update cycle, and the engine output power increase / decrease amount is set based on the command fuel consumption change rate and the target drive power. Thereby, substantially the same effect as the first embodiment can be obtained.

  In each of the first and second embodiments, when there are a plurality of engine output power increase / decrease amounts as engine output power increase / decrease amounts corresponding to the command fuel consumption change rate and the target drive power, From the output power increase / decrease amount, select the engine output power increase / decrease amount at which the rate of change of the fuel consumption change rate is a positive value, and select the engine output power increase / decrease amount at which the efficiency is minimum from the engine output power increase / decrease amount. For example, the engine output power increase / decrease amount in which the change rate of the fuel consumption change rate is a positive value is selected from a plurality of engine output power increase / decrease amounts in advance when designing the vehicle, for example. The engine output power increase / decrease amount that minimizes the efficiency is selected from the engine output power increase / decrease amount, and based on this information, the change rate of the command fuel consumption and the target Engine output power decrease amount corresponding to the dynamic power always may be you make a map of the engine output power increases or decreases the amount so that a single.

  Further, the process of step 302 of the engine output power increase / decrease amount calculation routine of FIG. 11 is omitted, and the corresponding engine output power increase / decrease amount (the engine output power increase / decrease corresponding to the current command fuel consumption change rate and the target drive power). The processing in steps 304 to 307 may be executed regardless of whether the amount is single.

  In each of the first and second embodiments, the command fuel consumption change rate is updated every predetermined time. However, the present invention is not limited to this. For example, when the travel pattern information changes more than a predetermined value, the command fuel consumption is changed. The amount change rate may be updated.

  In the first and second embodiments, the engine output power increase / decrease amount is calculated using the engine output power increase / decrease map. However, the present invention is not limited to this. For example, the command fuel consumption change rate and the target One or a plurality of mathematical expressions (for example, approximate expressions) that define the relationship between the drive power and the engine output power increase / decrease amount are stored in advance, and the command fuel consumption change rate and the target drive power are calculated using the mathematical expressions. A corresponding engine output power increase / decrease amount may be calculated.

  Further, in each of the first and second embodiments, the command fuel consumption change rate is calculated using the command fuel consumption change rate map. However, the present invention is not limited to this. One or more mathematical formulas (for example, approximate formulas) that define the relationship between the discharge energy balance and the command fuel consumption change rate are stored in advance, and using these mathematical formulas, the travel pattern information and the target charge / discharge energy balance The command fuel consumption rate of change corresponding to may be calculated.

  In the first and second embodiments, the battery 20 is mounted as the power storage unit. However, the present invention is not limited to this. For example, a capacitor or the like may be mounted as the power storage unit.

  In addition, the present invention is not limited to the hybrid vehicle having the configuration shown in FIG. 1 and FIG.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... MG (motor generator), 20 ... Battery (electric power storage means), 25 ... Hybrid ECU (Change rate setting means, Increase / decrease amount setting means)

Claims (3)

A hybrid comprising an engine (11) and a motor generator (12, 12A, 12B) mounted as a power source of a vehicle, and an electric power storage means (20) for transferring electric power to and from the motor generator (12, 12A, 12B). In the car control device,
A rate of change in fuel consumption of the engine (11) relative to the difference between the output power of the engine (11) and the driving power of the vehicle (hereinafter simply referred to as “fuel consumption rate of change”) is set at a predetermined update period. Change rate setting means (25);
Based on the fuel consumption change rate and the target drive power of the vehicle, the fuel consumption of the engine (11) is adjusted while operating the charge / discharge energy balance of the power storage means (20) to a predetermined value during a predetermined period. An increase / decrease amount setting means (25) for setting the engine output power increase / decrease amount to be minimized,
The increase / decrease amount setting means (25) is configured to change the fuel consumption amount change rate when a plurality of engine output power increase / decrease amounts exist as engine output power increase / decrease amounts corresponding to the fuel consumption change rate and the target drive power. A control apparatus for a hybrid vehicle, wherein one engine output power increase / decrease amount is selected from the plurality of engine output power increase / decrease amounts based on a change rate of the engine.   The increase / decrease amount setting means (25) selects, from the plurality of engine output power increase / decrease amounts, an engine output power increase / decrease amount with a positive change rate of the fuel consumption change rate. Item 2. A hybrid vehicle control device according to Item 1.   The increase / decrease amount setting means (25) obtains, as efficiency, a value obtained by dividing the fuel consumption amount by the engine output power increase / decrease amount, and the engine output power increase / decrease amount at which the change rate of the fuel consumption change rate becomes a positive value. The hybrid vehicle control device according to claim 2, wherein an engine output power increase / decrease amount that minimizes the efficiency is selected from among the two.

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