JP6387804B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a technical field of a vehicle control device that controls, for example, a hybrid vehicle.

  A hybrid vehicle including both an internal combustion engine and a rotating electric machine is known as a power source for traveling. In such a hybrid vehicle, the operating states of the internal combustion engine and the rotating electrical machine are controlled based on the state of the hybrid vehicle. For example, in Patent Literature 1, when it is estimated that the remaining amount of the rechargeable battery is excessive or insufficient from the prediction result of the remaining amount of the rechargeable battery based on the power consumption state, the shortage of the remaining amount of the rechargeable battery is resolved. Discloses a hybrid vehicle that sets an operating point of an internal combustion engine. Patent Document 2 discloses a hybrid vehicle that corrects the output of a rotating electrical machine in accordance with an output correction coefficient set from the remaining capacity of a rechargeable battery. Patent Document 3 discloses a hybrid that changes the driving frequency of an internal combustion engine based on a comparison result between the charging efficiency of electric energy while traveling a predetermined distance (1 km) and the driving energy efficiency of the internal combustion engine while traveling a predetermined distance. A vehicle is disclosed.

JP 2013-163495 A JP 2014-004912 A JP2013-141858A

  However, the control methods disclosed in Patent Document 1 to Patent Document 3 described above have a technical problem that the fuel efficiency of the hybrid vehicle cannot always be improved.

  For example, in the control method disclosed in Patent Document 1, in order to suppress an increase in fuel consumption by increasing the opportunity to set the operating point of the internal combustion engine on the optimal fuel consumption line, the remaining amount of the rechargeable battery is excessive or The operating point of the internal combustion engine is set so that the amount of charge increases and decreases uniformly before the shortage occurs. However, the control method disclosed in Patent Document 1 does not consider the driving efficiency of the internal combustion engine when increasing or decreasing the charge amount, the charging efficiency when storing the electric power stored in the rechargeable battery, or the like. For this reason, when viewed as the overall fuel consumption of the hybrid vehicle, the fuel consumption when traveling while leaving the state where the charge amount is excessive or insufficient is uniformly before the remaining battery level becomes excessive or insufficient. There is also a possibility of improving the fuel consumption when the operating point of the internal combustion engine is set so as to increase or decrease the charge amount. Therefore, in some cases, the control method disclosed in Patent Document 1 cannot improve fuel efficiency.

  For example, the control method disclosed in Patent Document 2 is intended for a hybrid vehicle that performs series travel driven by an internal combustion engine when the remaining capacity of the rechargeable battery decreases. For this reason, in the control method disclosed in Patent Document 2, the output of the rotating electrical machine is corrected based on the remaining capacity of the rechargeable battery, but the internal combustion engine is driven uniformly when the remaining capacity of the rechargeable battery decreases. That is no different. Therefore, similarly to Patent Document 1, in the control method disclosed in Patent Document 2, the driving efficiency of the internal combustion engine when increasing or decreasing the charge amount, the charging efficiency when storing the electric power stored in the rechargeable battery, and the like Is not taken into account. For this reason, when viewed as the overall fuel consumption of a hybrid vehicle, the internal combustion engine is driven uniformly when the remaining capacity of the rechargeable battery is reduced. There is also a possibility that the fuel consumption will be improved. Therefore, in some cases, the control method disclosed in Patent Document 2 cannot improve fuel efficiency.

  For example, in the control method disclosed in Patent Document 3, when the driving energy efficiency during traveling a predetermined distance is higher than the charging efficiency of electric energy, the driving frequency of the internal combustion engine increases. As a result, when the driving energy efficiency is higher than the charging efficiency, the relatively high efficiency of the internal combustion engine is effectively used, while when the charging efficiency is higher than the driving energy efficiency, High efficiency is effectively utilized. For this reason, the energy efficiency of a hybrid vehicle improves. However, in the control method disclosed in Patent Document 3, the charging efficiency of newly accumulated electric energy during traveling a predetermined distance is only taken into consideration, and has already been accumulated before traveling a predetermined distance. The charging efficiency of electric energy is not considered at all. For this reason, even when the charging efficiency of newly accumulated electric energy during traveling a predetermined distance is higher than the driving energy efficiency, the charging efficiency of electric energy already accumulated before traveling a predetermined distance can be lowered. For example, the rotating electrical machine is driven using electric energy stored in a low-efficiency manner, and thus cannot always improve energy efficiency. For this reason, the control method currently disclosed by patent document 3 may not necessarily improve a fuel consumption depending on the case.

  Examples of problems to be solved by the present invention include the above. An object of the present invention is to provide a vehicle control device capable of controlling a hybrid vehicle so as to preferably improve fuel efficiency.

  A vehicle control device that solves the above problems is a vehicle control that controls a hybrid vehicle including an internal combustion engine and a rotating electrical machine that can be charged with a rechargeable battery that can store electric power by being driven using the power of the internal combustion engine. (Ii) a charging cost representing a fuel consumption amount of the internal combustion engine required for accumulating a unit amount of electric power accumulated in the rechargeable battery; (ii) power of the rotating electric machine; It is determined whether or not the hybrid vehicle is smaller than an engine cost that represents a fuel consumption amount of the internal combustion engine required for the hybrid vehicle to output a unit travel output corresponding to the unit power amount by using the power of the internal combustion engine. And (i) when it is determined that the charging cost is smaller than the engine cost, the driving mode of the hybrid vehicle travels without operating the internal combustion engine. (Ii) when the charging cost is determined to be larger than the engine cost, the hybrid vehicle is set so that the traveling mode is an engine mode that travels using the power of the internal combustion engine. Control means for controlling, calculation means for calculating the charging cost using an energy fuel conversion value obtained by converting a kinetic energy increase due to acceleration of the hybrid vehicle and a kinetic energy decrease due to deceleration of the hybrid vehicle into a fuel amount; Is provided.

  The vehicle control device can control a hybrid vehicle including an internal combustion engine and a rotating electric machine. An internal combustion engine can be driven by consuming fuel. The rotating electrical machine can be driven using the power of the internal combustion engine. As a result, the rotating electrical machine can charge the rechargeable battery. That is, the rotating electrical machine can substantially function as a generator.

  The hybrid vehicle can travel in the electric mode. Furthermore, the hybrid vehicle can travel in the engine mode. The “electric mode” is a traveling mode in which the hybrid vehicle travels while maintaining the state where the internal combustion engine is not operating (that is, the internal combustion engine is not driven or the internal combustion engine is not consuming fuel). is there. In this case, the hybrid vehicle may travel using, for example, the power of a rotating electrical machine different from the rotating electrical machine that functions as a generator or the power of a rotating electrical machine that functions as a generator. The “engine mode” is a traveling mode in which traveling is performed using the power of the internal combustion engine.

  In order to control such a hybrid vehicle (in particular, to switch the travel mode of the hybrid vehicle), the vehicle control device includes a determination unit, a control unit, and a calculation unit.

  The determination unit determines whether or not the charging cost is smaller than the engine cost. In other words, the determination unit compares the charging cost with the engine cost.

  Here, the “charging cost” directly or indirectly represents the fuel consumption of the internal combustion engine required to store the unit power amount of the power stored in the rechargeable battery (in other words, the total power). It is an index value. In other words, the “charging cost” directly or indirectly represents the fuel consumption of the internal combustion engine required to store the power of the unit power amount among the power (total power) stored in the rechargeable battery. It is an index value. Furthermore, in other words, “charging cost” means “fuel consumption of the internal combustion engine per unit of electric energy required to store electric power (total electric power) stored in the rechargeable battery at the time when the charging cost is calculated. "Is an index value that directly or indirectly represents" ". That is, the “charging cost” is not an index value simply representing the fuel consumption of the internal combustion engine required to store the electric power (total electric power) stored in the rechargeable battery, but the electric power stored in the rechargeable battery. An index that directly or indirectly represents the amount of fuel consumed by the internal combustion engine required to store the power as the amount of fuel consumed to store the power of the unit power (that is, a numerical value per unit of power) Value. For example, the total amount of power stored in the rechargeable battery is “X1”, and the fuel consumption of the internal combustion engine required to store the power of “X1” stored in the rechargeable battery is “Y1”. In this case, the charging cost may be an index value that directly or indirectly represents a numerical value of “Y1 (that is, fuel consumption) / X1 (that is, total amount of power)”.

  On the other hand, the “engine cost” directly represents the fuel consumption of the internal combustion engine required for the hybrid vehicle to output a unit travel output corresponding to the unit power amount using the power of the internal combustion engine without using the power of the rotating electrical machine. It is an index value that is indicated either indirectly or indirectly. In other words, the “engine cost” is assumed to be a “unit” that is estimated to be required for the hybrid vehicle to travel using the power of the internal combustion engine without using the power of the rotating electrical machine when the engine cost is calculated. This is an index value that directly or indirectly indicates “fuel consumption of the internal combustion engine per driving output”. For example, the unit travel output corresponding to the unit power amount is “X2”, and the fuel consumption amount of the internal combustion engine that is estimated to be required for the hybrid vehicle to output the travel output of “X2” is “ In the case of “Y2”, the engine cost may be an index value that directly or indirectly represents a numerical value “Y2 (ie, fuel consumption) / X2 (ie, travel output)”. Alternatively, for example, the travel output required for the hybrid vehicle is “X3”, and the fuel consumption of the internal combustion engine that is estimated to be required for the hybrid vehicle to output the travel output of “X3” from now on. Is “Y3”, the engine cost may be an index value that directly or indirectly represents a numerical value “Y3 (ie, fuel consumption) / X3 (ie, travel output)”. .

  Note that “charging cost” is preferably an index value that typically increases as “fuel consumption of the internal combustion engine required for accumulating electric power of unit electric power” increases. Similarly, the “engine cost” is preferably an index value that typically increases as the “fuel consumption of the internal combustion engine required to output the unit travel output” increases. However, since the index value (for example, charging efficiency) that becomes smaller as “the fuel consumption of the internal combustion engine required to store the electric power of the unit electric power” increases, the charging cost is inversely proportional to the charging cost. And has a certain correlation. Similarly, an index value (for example, engine efficiency) that decreases as the “fuel consumption of the internal combustion engine required to output the unit travel output” increases is constant with the engine cost because it is inversely proportional to the engine cost. Have a correlation. Therefore, the operation of comparing the charging cost and the engine cost has a constant correlation between the index value (for example, charging efficiency) having a certain correlation with the charging cost and the engine cost. It can be said that it includes an operation of comparing an index value (for example, engine efficiency). For example, the operation for determining whether or not the charging cost is lower than the engine cost substantially includes an operation for comparing whether or not the charging efficiency is higher than the engine efficiency (in other words, whether or not it is higher). I can say that.

  The control unit controls the hybrid vehicle based on the determination result of the determination unit so that the travel mode of the hybrid vehicle becomes a desired travel mode. Specifically, when it is determined that the charging cost is smaller than the engine cost, the control unit controls the hybrid vehicle so that the traveling mode of the hybrid vehicle becomes the electric mode. On the other hand, when it is determined that the charging cost is higher than the engine cost, the control unit controls the hybrid vehicle so that the traveling mode of the hybrid vehicle becomes the electric mode.

  Here, considering that the charging cost represents the fuel consumption of the internal combustion engine required to store the power of the unit electric energy stored in the rechargeable battery, the charging cost is substantially It can also be said that it represents the fuel consumption of the internal combustion engine required for the hybrid vehicle to output the unit travel output using the power of the rotating electrical machine that is driven using the electric power stored in the rechargeable battery. That is, it can be said that the charging cost represents the fuel consumption of the internal combustion engine required for the hybrid vehicle to output the unit travel output in the electric mode. On the other hand, the engine cost can be said to represent the fuel consumption of the internal combustion engine that is required for the hybrid vehicle to output the unit travel output using the power of the internal combustion engine. That is, it can be said that the engine cost represents the fuel consumption of the internal combustion engine required for the hybrid vehicle to output the unit travel output in the engine mode. Then, if it is determined that the charging cost is lower than the engine cost, the fuel consumption required to output the unit travel output using the power of the rotating electrical machine that is driven using the electric power stored in the rechargeable battery Is less than the fuel consumption required to output the unit travel output using the power of the internal combustion engine driven by consuming the fuel. That is, when it is determined that the charging cost is lower than the engine cost, the fuel consumption of the hybrid vehicle that outputs the unit travel output in the electric mode is the fuel consumption of the hybrid vehicle that outputs the unit travel output in the engine mode. Less than. On the other hand, if it is determined that the charging cost is higher than the engine cost, the fuel consumption required to output the unit travel output using the power of the internal combustion engine that consumes and drives the fuel is charged to the rechargeable battery. This is less than the fuel consumption required to output the unit travel output using the power of the rotating electrical machine driven using the stored electric power. That is, when it is determined that the charging cost is larger than the engine cost, the fuel consumption of the hybrid vehicle that outputs the unit travel output in the engine mode is the fuel consumption of the hybrid vehicle that outputs the unit travel output in the electric mode. Less than.

  In consideration of the relationship between the magnitude relationship between the charging cost and the engine cost and the magnitude relationship between the fuel consumptions required to output the unit travel output, the control means determines that the travel mode of the hybrid vehicle has the unit travel output. It can be said that the hybrid vehicle is controlled so as to achieve a desired travel mode in which the fuel consumption required for output is reduced. That is, it can be said that the control means controls the hybrid vehicle so that the traveling mode of the hybrid vehicle becomes a desired traveling mode in which the fuel consumption required for traveling of the hybrid vehicle is reduced.

  In particular, since the charging cost represents fuel consumption per unit electric energy, the charging cost reflects the driving efficiency (for example, thermal efficiency) of the internal combustion engine driven to store electric power in the rechargeable battery. Yes. Specifically, depending on the driving efficiency of the internal combustion engine, even when the same amount of power is stored in the rechargeable battery, the fuel consumption required to store the power is not always the same. Absent. Similarly, depending on the driving efficiency of the internal combustion engine, even when electric power is accumulated in the rechargeable battery due to consumption of the same amount of fuel, the total amount of accumulated electric power is not always the same. That is, depending on the driving efficiency of the internal combustion engine, the value of the electric power stored in the rechargeable battery is not always the same. Thus, even if the value of electric power is not necessarily the same, the charging cost depends on the total amount of electric power stored in the rechargeable battery and the fuel consumption required for the electric power storage ( For example, it can be said that the value of electric power is appropriately represented because it fluctuates (according to the driving efficiency of the internal combustion engine when electric power is accumulated). For this reason, the vehicle control device considers the value of the electric power stored in the rechargeable battery (in other words, the driving efficiency of the internal combustion engine driven to store the electric power in the rechargeable battery), and then the driving mode of the hybrid vehicle. However, it is possible to control the hybrid vehicle so as to achieve a desired travel mode in which the fuel consumption required for outputting the unit travel output is reduced.

  A reduction in fuel consumption required to output the unit travel output leads to an improvement in the fuel consumption of the hybrid vehicle (particularly, the fuel consumption when viewed as a whole travel of the hybrid vehicle). Therefore, the vehicle control device can control the hybrid vehicle so as to be in a desired travel mode in which fuel efficiency is good. That is, the vehicle control device can control the hybrid vehicle so as to improve the fuel efficiency.

  Furthermore, the vehicle control device takes into account the charging cost for all the power stored in the rechargeable battery, and the fuel consumption required for the driving mode of the hybrid vehicle to output the unit driving output is small. The hybrid vehicle can be controlled so that the desired traveling mode is obtained. That is, the vehicle control device takes into consideration not only the charging cost for only the newly accumulated power in the rechargeable battery but also the charging cost for the power already accumulated in the rechargeable battery, The hybrid vehicle can be controlled so that a desired travel mode is achieved in which the amount of fuel consumed to output the unit travel output is reduced. In other words, the vehicle control device performs charging for all the power stored in the rechargeable battery instead of the magnitude relationship between the charging cost and the engine cost only for the power newly stored in the rechargeable battery. The hybrid vehicle is controlled based on the magnitude relationship between the cost and the engine cost. Accordingly, the travel mode of the hybrid vehicle is a travel mode in which the amount of fuel consumption required to output the unit travel output is reduced (that is, the fuel efficiency is improved). Therefore, the vehicle control apparatus can control the hybrid vehicle so as to reduce the fuel consumption required to output the unit travel output (that is, to improve the fuel efficiency suitably).

  The calculating means calculates a charging cost which is a comparison target by the determining means. That is, the calculation of the charging cost by the calculating means is performed prior to the determination by the determining means. The calculating means calculates the charging cost using an energy fuel conversion value obtained by converting a kinetic energy increase due to acceleration of the hybrid vehicle and a kinetic energy decrease due to deceleration of the hybrid vehicle into a fuel amount.

  Specifically, when the hybrid vehicle is accelerated, the calculation means calculates an energy fuel conversion value obtained by converting an increase in kinetic energy of the hybrid vehicle due to the acceleration into a fuel amount. The energy fuel equivalent value at the time of acceleration can be obtained, for example, by multiplying the fuel injection amount in the internal combustion engine by the ratio of the acceleration required power and the sum of the output of the internal combustion engine and the output of the rechargeable battery.

  On the other hand, when the hybrid vehicle is decelerated, the calculation means calculates an energy-fuel conversion value obtained by converting a decrease in kinetic energy of the hybrid vehicle due to deceleration into a fuel amount. The energy fuel equivalent value at the time of acceleration can be obtained, for example, by multiplying the energy fuel equivalent value before deceleration by the reduction rate of kinetic energy.

  By subtracting the energy fuel equivalent value during deceleration from the energy fuel equivalent value during acceleration described above, the amount of fuel corresponding to the kinetic energy obtained by the hybrid vehicle by acceleration / deceleration can be calculated. Here, considering that kinetic energy is the source of funds when the hybrid vehicle is regenerating, the kinetic energy obtained by acceleration / deceleration of the hybrid vehicle is the amount of fuel corresponding to the amount of kinetic energy fluctuation that is the source of regeneration. It can be said that.

  As a result, more accurate charging cost can be obtained by reflecting the energy conversion value on the charging cost during regeneration. That is, since the amount of fuel for obtaining the kinetic energy that is the source of regeneration is taken into account, it is “the amount of fuel consumed by the internal combustion engine required to store the unit amount of power stored in the rechargeable battery”. Charge cost can be calculated accurately. Therefore, the charge cost and the period cost can be appropriately compared, and the switching between the electric mode and the engine mode is executed at an appropriate timing. Therefore, the fuel consumption of the hybrid vehicle can be preferably improved.

  Conversely, if the increase or decrease in kinetic energy due to acceleration / deceleration of the hybrid vehicle is not taken into account, the charging cost may be calculated as an inaccurate value. In this case, the switching control between the electric mode and the engine mode cannot be appropriately performed, and the situation where the fuel consumption cannot be sufficiently improved or the fuel consumption deteriorates may occur. The vehicle control device of the present invention has a beneficial technical effect that such a situation can be avoided.

  These effects and other advantages of the present invention will be further clarified from the embodiments described below.

It is a block diagram which shows an example of a structure of the hybrid vehicle of this embodiment. It is a flowchart which shows an example of the flow of operation | movement of the hybrid vehicle of this embodiment (especially operation | movement which controls the driving mode of a hybrid vehicle). It is a timing chart which shows the driving mode determined based on the determination result whether a battery fuel consumption rate is larger than the engine fuel consumption rate at the time of driving | running | working. It is a flowchart which shows an example of the flow of a process which calculates a battery fuel consumption rate. It is a graph which shows the time-sequential change of the integrated value of the energy fuel conversion value at the time of acceleration. It is a graph which shows the map which shows the correspondence of an engine operating point and an engine fuel consumption rate. It is a graph which shows the time-sequential change of the integrated value of the energy fuel conversion value at the time of deceleration.

  Hereinafter, an embodiment of a vehicle control device of the present invention will be described with reference to the drawings. In the following, description will be given using the hybrid vehicle 10 to which the embodiment of the vehicle control device of the present invention is applied.

(1) Configuration of Hybrid Vehicle First, the configuration of the hybrid vehicle 10 of the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing an example of the configuration of the hybrid vehicle 10 of the present embodiment.

  As shown in FIG. 1, the hybrid vehicle 10 is a specific example of an axle 11, wheels 12, an ECU (Electronic Control Unit) 100 that is a specific example of a “vehicle control device”, and a “internal combustion engine”. Engine ENG, motor generator MG1 which is a specific example of “rotating electric machine”, motor generator MG2, power split mechanism 300, inverter 400, and battery 500 which is a specific example of “storage battery”.

  The axle 11 is a transmission shaft for transmitting the power output from the engine ENG and the motor generator MG2 to the wheels. The wheels 12 are means for transmitting power transmitted through the axle 11 to the road surface.

  The ECU 100 is an electronic control unit configured to be able to control the entire operation of the hybrid vehicle 10. Particularly in the present embodiment, the ECU 100 includes a travel mode control unit 101, which is a specific example of “control means”, and a specific example of “calculation means” as logical or physical processing blocks implemented therein. A fuel consumption rate calculation unit 102 as an example and a fuel consumption rate comparison unit 103 as a specific example of “determination means” are provided.

  The travel mode control unit 101 controls the travel mode of the hybrid vehicle 10. Specifically, the travel mode control unit 101 controls the hybrid vehicle 10 so that the travel mode of the hybrid vehicle 10 becomes a desired travel mode. For example, the travel mode control unit 101 may control the hybrid vehicle 10 so that the travel mode of the hybrid vehicle 10 is an HV (Hybrid Vehicle) mode in which the vehicle travels using the power of the engine ENG. For example, traveling mode control unit 101 sets the traveling mode of hybrid vehicle 10 to an EV (Electric Vehicle) mode in which traveling is performed using at least one power of motor generator MG1 and motor generator MG2 without operating engine ENG. In addition, the hybrid vehicle 10 may be controlled.

  In the EV mode, the engine ENG is not operating (in other words, the engine ENG is not driven, in other words, the engine ENG is not consuming fuel). For this reason, the fuel efficiency of the hybrid vehicle 10 improves as the traveling frequency in the EV mode increases.

  Particularly in the present embodiment, the travel mode control unit 101 controls the hybrid vehicle 10 so that the travel mode of the hybrid vehicle 10 becomes a travel mode determined based on the comparison result of the fuel consumption rate comparison unit 103. The travel mode determined based on the comparison result of the fuel consumption rate comparison unit 103 will be described in detail later (see FIG. 2 and the like).

  The fuel consumption rate calculation unit 102 determines a fuel consumption rate to be compared by the fuel consumption rate comparison unit 103 (specifically, a battery fuel consumption rate F and a running engine fuel consumption rate, which will be described later), when the driving mode of the hybrid vehicle 10 is determined. H) is calculated. The details of the calculation method of the battery fuel consumption rate F and the running engine fuel consumption rate H by the fuel consumption rate calculation unit 102 will be described in detail later (see FIG. 4 and the like).

  The fuel consumption rate comparison unit 103 compares the battery fuel consumption rate F calculated by the fuel consumption rate calculation unit 102 with the running engine fuel consumption rate H. Specifically, the fuel consumption rate comparison unit 103 determines the magnitude relationship between the battery fuel consumption rate F and the running engine fuel consumption rate H. The fuel consumption rate comparison unit 103 transmits the comparison result (that is, the determination result of the magnitude relationship) to the travel mode control unit 101.

  The engine ENG is driven by burning fuel such as gasoline or light oil. The engine ENG functions as a main power source of the hybrid vehicle 10. In addition, engine ENG functions as a power source for rotating (in other words, driving) a rotation shaft of motor generator MG1 described later.

  Motor generator MG1 functions as a generator for charging battery 500. When motor generator MG1 functions as a generator, the rotation shaft of motor generator MG1 is rotated by the power of engine ENG. However, motor generator MG <b> 1 may function as an electric motor that supplies power of hybrid vehicle 10 by being driven using electric power stored in battery 500.

  Motor generator MG <b> 2 functions as an electric motor that supplies power of hybrid vehicle 10 by being driven using electric power stored in battery 500. In addition, motor generator MG2 may function as a generator for charging battery 500. When motor generator MG2 functions as a generator, the rotation shaft of motor generator MG2 is rotated by the power transmitted from axle 11 to motor generator MG2.

  The power split mechanism 300 is a planetary gear mechanism including a sun gear, a planetary carrier, a pinion gear, and a ring gear (not shown). The rotation shaft of the sun gear is connected to the rotation shaft of motor generator MG1. The rotation shaft of the ring gear is connected to the rotation shaft of motor generator MG2. The rotating shaft of the planetary carrier located between the sun gear and the ring gear is connected to the rotating shaft (that is, the crankshaft) of the engine ENG. The rotation of the engine ENG is transmitted to the sun gear and the ring gear by the planetary carrier and the pinion gear. That is, the power of the engine ENG is divided into two systems. In the hybrid vehicle 10, the rotating shaft of the ring gear is connected to the axle 11 in the hybrid vehicle 10, and the driving force is transmitted to the wheels 12 through the axle 11.

  Inverter 400 converts the DC power extracted from battery 500 into AC power and supplies it to motor generator MG1 and motor generator MG2. Further, inverter 400 converts AC power generated by motor generator MG1 and motor generator MG2 into DC power and supplies it to battery 500. The inverter 400 may be configured as a part of a so-called PCU (Power Control Unit).

  Battery 500 is a power supply source that supplies electric power for driving motor generator MG1 and motor generator MG2 to motor generator MG1 and motor generator MG2. The battery 500 is a rechargeable storage battery.

  The battery 500 may be charged by receiving power from an external power source of the hybrid vehicle 10. That is, the hybrid vehicle 10 may be a so-called plug-in hybrid vehicle.

(2) Operation of Hybrid Vehicle 10 Next, the operation of the hybrid vehicle 10 (particularly, the operation for controlling the travel mode of the hybrid vehicle 10) will be described with reference to FIG. FIG. 2 is a flowchart illustrating an example of the flow of operations of the hybrid vehicle 10 (particularly, operations for controlling the travel mode of the hybrid vehicle 10).

  As shown in FIG. 2, the fuel consumption rate calculation unit 102 sets initial values of the battery fuel consumption rate F, the battery power integration amount a, the battery fuel consumption amount J, and the energy fuel conversion value fc (step S11). Hereinafter, the battery fuel consumption rate F, the battery power integration amount a, the battery fuel consumption amount J, and the energy fuel conversion value fc will be described in order. The battery fuel consumption rate F corresponds to a specific example of “charging cost”.

  The battery fuel consumption rate F is an index value that represents the fuel consumption amount of the engine ENG per unit electric energy required for accumulating the electric power (total electric power) accumulated in the battery 500. In other words, the battery fuel consumption rate F represents the fuel consumption amount of the engine ENG that is required to store the unit power amount of the electric power stored in the battery 500. In other words, the battery fuel consumption rate F represents the fuel consumption amount of the engine ENG that is required to store the power of the unit power amount when the power stored in the battery 500 is stored. For example, an amount of electric power “X4 (where X is 0 or more)” is stored in the battery 500, and an amount of fuel “Y4” is stored by the engine ENG in order to store this amount of electric power “X4”. When consumed, the battery fuel consumption rate F may be an index value representing a numerical value specified by the mathematical expression “Y4 / X3”. As an example, for example, when “2 kWh” of electric power is stored in the battery 500 and “560 g” of fuel is consumed by the engine ENG in order to store the electric power of 2 kWh, the battery fuel consumption rate F is 560 ÷ 2 = 280 g / kWh. In the following, for convenience of explanation, the description will be made assuming that the unit of the battery fuel consumption rate F is “g / kWh”.

  The fuel consumption rate calculation unit 102 may set an arbitrary fixed value predetermined for each vehicle type or specification of the hybrid vehicle 10 as an initial value of the battery fuel consumption rate F. In this case, as a fixed value, a battery fuel consumption rate (for example, 280 g / kWh) calculated from a simulation when it is assumed that the hybrid vehicle 10 has traveled on a specific travel route may be employed. Alternatively, the fuel consumption rate calculation unit 102 may set the battery fuel consumption rate F at the time when the operation shown in FIG. In this case, the fuel consumption rate calculation unit 102 preferably stores the battery fuel consumption rate F at the time when the operation shown in FIG.

  The battery power integration amount a represents the total amount of power stored in the battery 500. For example, the battery power integration amount a corresponds to a value calculated by multiplying the total amount of power that can be stored in the battery 500 and the actual SOC when the SOC (State Of Charge) is 100%. It may be. In the following description, for convenience of explanation, the description will be made assuming that the unit of the battery power integrated amount a is “kWh”.

  The fuel consumption rate calculation unit 102 may set a fixed value corresponding to the amount of power stored in the battery 500 as the initial value of the battery power integration amount a when the SOC becomes a constant value. This is because, in order to suppress the deterioration of the battery 500, the input (that is, charging) and output (that is, discharging) of the power to the battery 500 are controlled such that the SOC maintains a constant value (for example, 65%). Often done. For this reason, there is a high possibility that the SOC of the battery 500 is a constant value (that is, there is a high possibility that the battery power integration amount a is also a fixed value). Alternatively, the fuel consumption rate calculation unit 102 may set the battery power integrated amount a at the time when the operation shown in FIG. 2 is completed last time as the initial value of the battery power integrated amount a. In this case, the fuel consumption rate calculation unit 102 preferably stores the battery power integration amount a at the time when the operation shown in FIG. Alternatively, the fuel consumption rate calculation unit 102 calculates or estimates the total amount of power stored in the battery 500 by referring to the SOC output from the SOC sensor (not shown), and calculates the total amount of power calculated or estimated. The battery power integrated amount a may be set to an initial value.

  The battery fuel consumption amount J is an index value that represents the fuel consumption amount (in other words, the total amount) of the engine ENG required to store the electric power (total electric power) stored in the battery 500. The battery fuel consumption amount J is calculated from a mathematical expression of battery fuel efficiency F × battery power integration amount a. Therefore, the fuel consumption rate calculation unit 102 is a value calculated by multiplying the initial value of the battery fuel consumption rate F set in the above-described manner by the initial value of the battery fuel consumption rate F set in the above-described manner. May be set to the initial value of the battery fuel consumption amount J. In the following description, for convenience of explanation, it is assumed that the unit of the battery fuel consumption J is “g”.

  The energy fuel conversion value fc is a value obtained by converting the kinetic energy increase due to acceleration of the hybrid vehicle 10 and the kinetic energy decrease due to deceleration of the hybrid vehicle 10 into a fuel amount. More specifically, the energy fuel conversion value fc is a positive value corresponding to the amount of fuel consumed by the hybrid vehicle 10 to obtain kinetic energy by acceleration, or to obtain the kinetic energy that the hybrid vehicle 10 loses by deceleration. It is a negative value corresponding to the amount of fuel consumed. Therefore, the energy fuel equivalent value fc increases with acceleration and decreases with deceleration. The initial value of the energy fuel conversion value fc may be given as “0”, for example. In the following, for convenience of explanation, the description will be made assuming that the unit of the energy fuel conversion value fc is “g”.

  After setting the initial value described above, the fuel consumption rate calculation unit 102 calculates the battery fuel consumption rate F (step S22). Since the calculation of the battery fuel efficiency F is a value that varies in real time according to various conditions in the hybrid vehicle 10, the battery fuel efficiency F is calculated each time. A specific method of calculating the battery fuel consumption rate F will be described in detail later (see FIG. 4 and the like).

  After the battery fuel consumption rate F is calculated, the fuel consumption rate comparison unit 103 determines whether or not the battery fuel consumption rate F is greater than the running engine fuel consumption rate H calculated by the fuel consumption rate calculation unit 102 (step S31). ). The running engine fuel consumption rate H is a specific example of “engine cost”.

  The engine fuel consumption rate H at the time of travel is the engine ENG per unit travel output that is estimated to be required for the hybrid vehicle 10 to travel using the power of the engine ENG while not using the power of the motor generators MG1 and MG2. This is an index value representing the fuel consumption. In other words, the running engine fuel efficiency H is determined by the hybrid vehicle 10 using the power of the engine ENG while the power of the motor generators MG1 and MG2 is not used, in other words, the unit power that defines the battery fuel efficiency F. This represents the fuel consumption amount of the engine ENG that is estimated to be required to output a unit travel output corresponding to (quantity). For example, in order to output the travel output “X6” when the hybrid vehicle 10 travels using the power of the engine ENG while the power of the motor generators MG1 and MG2 is not used. When it is estimated that the amount of fuel “Y6” will be consumed by the engine ENG, the running engine fuel efficiency H is an index value representing a numerical value specified by the mathematical formula “Y6 / X6”. May be. As an example, the travel output when the hybrid vehicle 10 travels using the power of the engine ENG without using the power of the motor generators MG1 and MG2 is “0.5 kWh” and the travel output of 0.5 kWh is output. Therefore, when it is estimated that “100 g” of fuel will be consumed by the engine ENG, the running engine fuel consumption rate H is 100 ÷ 0.5 = 200 g / kWh. Hereinafter, for convenience of explanation, the description will be made assuming that the unit of the engine fuel efficiency during running H is “g / kWh”. However, the unit of the engine fuel efficiency H during travel is preferably the same as the unit of the battery fuel efficiency F.

  As a result of the determination in step S31, when it is determined that the battery fuel consumption rate F is greater than the running engine fuel consumption rate H (step S31: Yes), the travel mode control unit 101 determines that the travel mode of the hybrid vehicle 10 is HV. The hybrid vehicle 10 is controlled so as to be in the mode (step S11).

  On the other hand, as a result of the determination in step S <b> 31, when it is determined that the running engine fuel efficiency H is higher than the battery fuel efficiency F (step S <b> 31: No), the travel mode control unit 101 travels the hybrid vehicle 10. The hybrid vehicle 10 is controlled so that the mode becomes the EV mode (step S13).

  However, even if it is determined that the running engine fuel efficiency H is greater than the battery fuel efficiency F, if the SOC of the battery 500 is excessively reduced (for example, smaller than a predetermined threshold) ( In step S12: Yes), the traveling mode control unit 101 controls the hybrid vehicle 10 so that the traveling mode of the hybrid vehicle 10 becomes the HV mode (step S13). As a result, the SOC of battery 500 is recovered (that is, increased) by motor generator MG1 functioning as a generator using the power of engine ENG.

  As described above, in the hybrid vehicle 10 of the present embodiment, the travel mode of the hybrid vehicle 10 is determined based on the determination result of whether or not the battery fuel consumption rate F is greater than the running engine fuel consumption rate H. As a result, the hybrid vehicle 10 can travel while selecting a travel mode that can suitably improve fuel efficiency. Hereinafter, the reason will be described with reference to FIG. FIG. 3 is a timing chart showing a driving mode determined based on a determination result of whether or not the battery fuel efficiency F is larger than the engine fuel efficiency H during traveling.

  In FIG. 3, the battery fuel consumption rate F represents the fuel consumption amount of the engine ENG per unit electric energy required for accumulating the electric power accumulated in the battery 500. Therefore, it can be said that the battery fuel consumption rate F substantially represents the fuel consumption of the hybrid vehicle 10 that travels in the EV mode using the electric power stored in the battery 500. In other words, it can be said that the battery fuel consumption rate F substantially represents the fuel consumption of the hybrid vehicle 10 that outputs the unit travel output in the EV mode. On the other hand, the engine fuel consumption rate H during travel exactly represents the fuel consumption of the hybrid vehicle 10 that travels in the HV mode using the power of the engine ENG. In other words, it can be said that the engine fuel efficiency during running H represents the fuel consumption of the hybrid vehicle 10 that outputs the unit running output in the HV mode.

  Therefore, when the battery fuel consumption rate F is larger than the running engine fuel consumption rate H, the fuel consumption amount (specifically, the fuel consumption amount per unit travel output) of the hybrid vehicle 10 traveling in the EV mode is HV. It is assumed that the fuel consumption of the hybrid vehicle 10 traveling in the mode (specifically, the fuel consumption per unit travel output) is larger. Here, the increase in the fuel consumption amount per unit travel output leads to the deterioration of the fuel consumption of the hybrid vehicle 10 (particularly, the fuel consumption when viewed from the entire travel of the hybrid vehicle 10). Therefore, when the battery fuel consumption rate F is larger than the running engine fuel consumption rate H, it is assumed that the fuel consumption of the hybrid vehicle 10 traveling in the EV mode is worse than the fuel consumption of the hybrid vehicle 10 traveling in the HV mode. Is done.

  On the other hand, when the running engine fuel efficiency H is larger than the battery fuel efficiency F, the fuel consumption (specifically, the fuel consumption per unit travel output) of the hybrid vehicle 10 traveling in the HV mode is: It is assumed that the fuel consumption of the hybrid vehicle 10 traveling in the EV mode (specifically, the fuel consumption per unit travel output) is larger. Therefore, when the running engine fuel consumption rate H is larger than the battery fuel consumption rate F, it is assumed that the fuel consumption of the hybrid vehicle 10 traveling in the HV mode is worse than the fuel consumption of the hybrid vehicle 10 traveling in the EV mode. Is done.

  Therefore, in the present embodiment, as shown in FIG. 3, when the battery fuel consumption rate F is larger than the running engine fuel consumption rate H, the hybrid vehicle 10 has a relatively small fuel consumption per unit travel output. Drive in HV mode. On the other hand, as shown in FIG. 3, when the running engine fuel efficiency H is higher than the battery fuel efficiency F, the hybrid vehicle 10 is in the EV mode in which the fuel consumption per unit travel output is relatively small. Run. As a result, in the present embodiment, the hybrid vehicle 10 can travel while appropriately determining a travel mode in which the fuel consumption per unit travel output is relatively small. Here, the reduction in fuel consumption per unit travel output leads to an improvement in the fuel consumption of the hybrid vehicle 10 (particularly, the fuel consumption when viewed as a whole travel of the hybrid vehicle 10). Therefore, the hybrid vehicle 10 can travel while appropriately determining a travel mode that can suitably improve fuel consumption.

  In particular, in the present embodiment, the battery fuel consumption rate F represents the fuel consumption amount of the engine ENG per unit amount of electric power. Therefore, the battery fuel consumption rate F includes the engine driven to accumulate electric power in the battery 500. ENG drive efficiency (for example, thermal efficiency, hereinafter referred to as “engine efficiency”) is reflected.

  For example, when a predetermined amount of electric power is accumulated in the battery 500 by driving the engine ENG in a state where the engine efficiency is relatively poor, the total amount of fuel consumption becomes relatively large. F becomes relatively large. On the other hand, when the same predetermined amount of power is accumulated in the battery 500 by driving the engine ENG with relatively good engine efficiency, the total amount of fuel consumption is relatively small. The battery fuel consumption rate F becomes relatively small. As described above, even when the same amount of power is stored in the battery 500, the fuel consumption required to store the power is not necessarily the same. That is, even when the same amount of power is stored in the battery 500, the value of the power stored in the battery 500 is not necessarily the same. Thus, even if the battery fuel consumption rate F is the case where the same amount of electric power is stored in the battery 500, the fuel consumption required to store the electric power (in other words, when the electric power is stored) It can be said that the value of electric power is appropriately represented because it varies depending on the engine efficiency of the engine ENG.

  Similarly, for example, when the engine ENG consumes a predetermined amount of fuel while the engine efficiency is relatively poor in order to store power in the battery 500, the total amount of power stored in the battery 500 is relatively Therefore, the battery fuel consumption rate F is relatively increased. On the other hand, when the engine ENG consumes the same predetermined amount of fuel while the engine efficiency is relatively good in order to store power in the battery 500, the total amount of power stored in the battery 500 is relatively Therefore, the battery fuel consumption rate F becomes relatively small. As described above, even when electric power is stored in the battery 500 because the engine ENG consumes the same amount of fuel, the total amount of stored electric power is not always the same. That is, even if electric power is stored in the battery 500 because the engine ENG consumes the same amount of fuel, the value of the electric power stored in the battery 500 is not necessarily the same. Thus, the battery fuel consumption rate F is the total amount of electric power stored in the battery 500 (in other words, electric power even if electric power is stored in the battery 500 due to the engine ENG consuming the same amount of fuel). Therefore, it can be said that the value of electric power is appropriately represented.

  For this reason, in the present embodiment, the hybrid vehicle 10 has a traveling mode in which the fuel efficiency is relatively good (or optimal) in consideration of the value of the electric power stored in the battery 500. It is possible to travel while appropriately determining. Therefore, the hybrid vehicle 10 can travel while appropriately determining a travel mode that can suitably improve fuel consumption.

  In addition, in the present embodiment, the battery fuel consumption rate F represents the fuel consumption amount of the engine ENG per unit electric energy required to accumulate all the electric power accumulated in the battery 500. That is, the battery fuel consumption rate F is a unit of the amount of electric power required to store only the electric power newly stored in the battery 500 (in other words, only a part of the total electric power stored in the battery 500). It does not represent the fuel consumption of the engine ENG. Therefore, the hybrid vehicle 10 accumulates not only the fuel consumption of the engine ENG per unit electric energy required for accumulating the electric power newly accumulated in the battery 500 but also the electric power already accumulated in the battery 500. In consideration of the fuel consumption amount of the engine ENG per unit electric energy required for this, it is possible to travel while appropriately determining a travel mode in which the fuel efficiency is relatively good (or optimal).

  Here, as a comparative example, for example, the battery fuel consumption rate of the comparative example representing the fuel consumption amount of the engine ENG per unit electric energy required for storing only the electric power newly stored in the battery 500 is the engine fuel consumption during driving. A hybrid vehicle of a comparative example that travels in the EV mode when the rate H is smaller is assumed. The hybrid vehicle of the comparative example travels with the battery fuel efficiency of the comparative example without depending on the amount of fuel consumption of the engine ENG per unit power amount required to store the electric power already stored in the battery 500. When the hour engine fuel consumption rate H is smaller, the vehicle travels in the EV mode. However, even if the battery fuel consumption rate of the comparative example is smaller than the engine fuel consumption rate H during driving, the fuel consumption of the engine ENG per unit electric energy required to store the power already stored in the battery 500 The amount may be relatively large. That is, the fuel consumption rate of the engine ENG per unit electric energy required to store all the electric power stored in the battery 500 while the battery fuel consumption rate of the comparative example is smaller than the engine fuel consumption rate H during traveling. There is a possibility that the battery fuel consumption rate F becomes larger than the running engine fuel consumption rate H. In such a case, the hybrid vehicle of the comparative example does not always have a relatively small fuel consumption per unit travel output (that is, the fuel efficiency is not always improved). ) However, the hybrid vehicle 10 of the present embodiment is stored in the battery 500 instead of the fuel consumption of the engine ENG per unit electric energy required to store only the electric power newly stored in the battery 500. The travel mode is determined based on the battery fuel consumption rate F representing the fuel consumption amount of the engine ENG per unit power amount required to store all the electric power. Therefore, compared to the hybrid vehicle of the comparative example, the hybrid vehicle 10 of the present embodiment has a relatively small fuel consumption per unit travel output (that is, the fuel efficiency becomes relatively good or optimum). ) It is possible to travel while appropriately determining the travel mode. Therefore, compared with the hybrid vehicle of the comparative example, the hybrid vehicle 10 of the present embodiment can travel while appropriately determining a travel mode that can suitably improve fuel efficiency.

  In the above description, the hybrid vehicle 10 directly represents the battery fuel consumption rate F that directly represents the fuel consumption amount of the engine ENG per unit power amount, and the fuel consumption amount of the engine ENG per unit travel output. The travel mode is determined based on the result of comparison with the engine fuel consumption rate H during travel. However, hybrid vehicle 10 uses a parameter that indirectly represents the fuel consumption amount of engine ENG per unit power amount required to store the power stored in battery 500 and the power of motor generators MG1 and MG2. On the other hand, based on the comparison result with a parameter indirectly representing the fuel consumption amount of the engine ENG per unit traveling output, which is estimated to be required for the hybrid vehicle 10 to travel using the power of the engine ENG, The travel mode may be determined. For example, a parameter that indirectly represents the fuel consumption amount of the engine ENG per unit power amount and a parameter that indirectly represents the fuel consumption amount of the engine ENG per unit traveling output are determined by the following: The hybrid vehicle 10 may travel in the HV mode when the situation becomes larger than that. For example, a parameter that indirectly represents the fuel consumption amount of the engine ENG per unit power amount and a parameter that indirectly represents the fuel consumption amount of the engine ENG per unit traveling output are determined so that the engine fuel consumption rate during traveling is greater than the battery fuel consumption rate F. If the situation shows that the vehicle speed increases, the hybrid vehicle 10 may travel in the EV mode.

  As an example, a charging parameter (for example, a parameter such as efficiency) that decreases as the fuel consumption of the engine ENG per unit electric energy required to store the electric power stored in the battery 500 increases is a battery fuel consumption rate. It is in inverse proportion to F. Similarly, the fuel consumption of engine ENG per unit travel output that is estimated to be required for hybrid vehicle 10 to travel using the power of engine ENG while not using the power of motor generators MG1 and MG2 increases. An engine parameter (for example, a parameter such as efficiency) that becomes smaller as it goes down has a relationship that is inversely proportional to the engine fuel consumption rate H during travel. In this case, the hybrid vehicle 10 may travel in the EV mode when the charging parameter is larger than the engine parameter. On the other hand, the hybrid vehicle 10 may travel in the HV mode when the engine parameter is larger than the charging parameter.

(3) Calculation Method for Battery Fuel Efficiency F Next, a specific calculation method for the battery fuel efficiency F used for the above-described control of the travel mode will be described with reference to FIG. FIG. 4 is a flowchart showing an example of a process flow for calculating the battery fuel efficiency.

  As shown in FIG. 4, the fuel consumption rate calculation unit 102 that calculates the battery fuel consumption rate first determines whether the hybrid vehicle 10 is accelerating (that is, whether the vehicle acceleration required power pa is a positive value). Determination is made (step S41).

  As a result of the determination in step S41, when it is determined that the hybrid vehicle 10 is accelerating (that is, pa> 0) (step S41: Yes), the fuel consumption rate calculation unit 102 calculates the energy-fuel conversion value fc during acceleration. Calculate (step S42). Below, with reference to FIG. 5, calculation of the energy fuel conversion value fc at the time of acceleration will be specifically described. FIG. 5 is a graph showing a time-series change in the integrated value of the energy fuel conversion value fc during acceleration.

  As shown in FIG. 5, the integrated value of the energy fuel conversion value fc is a value corresponding to the kinetic energy of the hybrid vehicle 10, and thus increases or decreases by acceleration / deceleration of the hybrid vehicle 10. Specifically, the integrated value of the energy fuel conversion value fc increases as the hybrid vehicle 10 accelerates and decreases as the vehicle decelerates.

  Here, the energy fuel conversion value fc (i) at the time of acceleration is a fuel amount corresponding to the kinetic energy obtained by the hybrid vehicle by acceleration. Therefore, the energy fuel conversion value fc (i) at the time of acceleration includes the engine fuel injection amount vehicle fcc [g / sec], the vehicle acceleration required power pa [kw], the total engine output pe [kw], and the engine generated power d [kw]. ], MG2 assist power amount c [kwh], and EV travel power amount e [kwh] can be obtained by the following formula (1).

    fc (i) = fcc × {pa / (pe−d) + (c + e)} (1)

  In other words, the energy fuel conversion value fc (i) at the time of acceleration is the engine output (pe-d) and the battery output (c + e) obtained by subtracting the vehicle acceleration required power pa, the power generation amount, from the engine fuel injection amount vehicle fcc. It can be obtained by multiplying the ratio.

  Returning to FIG. 2, thereafter, the fuel consumption rate calculation unit 102 adds the calculated energy fuel conversion value fc (i) at the time of acceleration to the integrated value fc (i−1) of the immediately previous energy fuel conversion value ( Step S43). The energy fuel conversion value fc obtained in this way is an integrated value that takes into account fluctuations in kinetic energy due to acceleration. Further, the fuel consumption rate calculation unit 102 replaces the integrated value fc (i−1) of the immediately preceding energy fuel conversion value with the calculated energy fuel conversion value fc (step S44).

  Subsequently, the fuel consumption rate calculation unit 102 calculates the battery fuel consumption rate F ′ after acceleration (step S45).

  Specifically, the fuel consumption rate calculation unit 102 first calculates the battery fuel consumption J ′ [g] after acceleration. Battery fuel consumption J ′ after acceleration includes battery fuel consumption J [g] before acceleration, engine fuel consumption rate G [g / kwh] at the time of power generation, engine generated power d [kw], and battery fuel consumption rate before acceleration. Using F [g / kwh], MG2 assist power amount c [kwh], and EV travel power amount e [kwh], the following equation (2) can be used.

    J ′ = J + G × d−F × (c + e) (2)

  Here, the engine fuel consumption rate G during power generation is an index value that represents the fuel consumption amount of the engine ENG per unit electric energy required to newly accumulate the electric power of the battery input electric energy d in the battery 500. In other words, the engine fuel consumption rate G during power generation represents the fuel consumption of the engine ENG that is required to accumulate the unit power amount of the battery input power amount d in the battery 500. In other words, the engine fuel consumption rate G during power generation is the fuel consumption of the engine ENG required to store the unit power amount in the battery 500 when the battery input power amount d is newly stored in the battery 500. Represents an amount. For example, when an amount of fuel “Y5” is consumed by the engine ENG in order to store the electric power of the battery input electric energy d, the engine fuel consumption rate G during generation is specified by an equation “Y5 / d”. It may be an index value representing a numerical value. As an example, when the battery input power amount d is “0.5 kWh” and “100 g” of fuel is consumed by the engine ENG in order to newly store the power of 0.5 kWh in the battery 500, power generation The hour engine fuel consumption rate G is 100 ÷ 0.5 = 200 g / kWh. In the following, for convenience of explanation, the description will be made assuming that the unit of the power generation engine fuel consumption rate G is “g / kWh”.

  The fuel consumption rate calculation unit 102 refers to a map representing a correspondence relationship between the operating point of the engine ENG (for example, the operating point specified by the torque of the engine ENG and the engine speed) and the engine fuel consumption rate, thereby generating power. It is preferable to calculate the hour engine fuel efficiency G.

  Here, a map representing the correspondence between the operating point of the engine ENG and the engine fuel efficiency will be described with reference to FIG. FIG. 6 is a graph showing a map representing the correspondence between the operating point of the engine ENG and the engine fuel consumption rate.

  As shown in FIG. 6, it is assumed that a map representing the correspondence between the operating point of the engine ENG and the engine fuel efficiency is defined. In this case, the fuel consumption rate calculation unit 102 refers to the position on the map of the operating point of the engine ENG when the electric power of the battery input electric energy d is newly accumulated in the battery 500, so that the engine fuel consumption rate G during power generation Is calculated. For example, when the operating point of the engine ENG when the electric power of the battery input electric energy d is newly stored in the battery 500 is K1, the fuel consumption rate calculation unit 102 calculates the engine fuel efficiency during power generation of k4 [g / kWh]. The rate G is calculated. For example, when the operating point of the engine ENG when the electric power of the battery input electric energy d is newly stored in the battery 500 is K2, the fuel consumption rate calculation unit 102 generates the engine fuel efficiency during power generation of k5 [g / kWh]. The rate G is calculated.

  Since the engine fuel consumption rate G during power generation is calculated by referring to such a map, the fuel consumption rate calculation unit 102 specifies information for specifying the operating point of the engine ENG (for example, control of the ECU 100 that indicates the operating point). It is preferable to acquire a signal, information indicating the rotational speed of the engine ENG, and information indicating the torque of the engine ENG).

  However, the fuel consumption rate calculation unit 102 may calculate the power generation engine fuel consumption rate G using a method different from a method of referring to a map representing the correspondence relationship between the operating point of the engine ENG and the engine fuel consumption rate.

  The battery 500 is typically newly charged when the motor generator MG1 functions as a generator. In this case, engine ENG functions as a power source for rotating (in other words, driving) the rotation shaft of motor generator MG1. Therefore, the operating point of the engine ENG is plotted on the map shown in FIG. Therefore, when the motor generator MG1 functions as a generator, the fuel consumption rate calculation unit 102 preferably calculates the engine fuel consumption rate G during power generation by referring to the map shown in FIG.

  On the other hand, battery 500 may be newly charged when motor generator MG2 functions as a generator. That is, the battery 500 may be newly charged by so-called regenerative power generation. In this case, engine ENG does not function as a power source for rotating (in other words, driving) the rotation shaft of motor generator MG2. Therefore, when the motor generator MG2 functions as a generator, the fuel consumption of the engine ENG required to newly store the battery input power d in the battery 500 becomes zero. Therefore, when the motor generator MG2 functions as a generator, the fuel consumption rate calculation unit 102 preferably sets the engine fuel consumption rate G during power generation to 0 [g / kWh].

  Returning to FIG. 2 again, the fuel consumption rate calculation unit 102 further calculates the battery power integrated amount a ′ [kwh] after acceleration. The battery power integration amount a ′ after acceleration includes the battery power integration amount a [kwh] before the acceleration, the engine generated power d [kw], the regenerative energy r [kw], the MG2 assist power amount c [kwh], and the EV travel. It can obtain | require with the following Numerical formula (3) using electric energy e [kwh].

    a '= a + (d + r)-(c + e) (3)

  Thereafter, the fuel consumption rate calculation unit 102 calculates the battery fuel consumption rate F ′ after acceleration by dividing the battery fuel consumption amount J ′ after acceleration by the battery power integrated amount a ′ after acceleration. That is, the fuel consumption rate calculation unit 102 calculates the battery fuel consumption rate F ′ using the following formula (4).

    F ′ = J ′ / a ′ (4)

  Thereafter, the fuel consumption rate calculation unit 102 updates the battery fuel consumption rate F, the battery power integration amount a, and the battery fuel consumption amount J (step S61). Specifically, the fuel consumption rate calculation unit 102 sets the battery fuel consumption rate F ′ calculated in step 45 to a new battery fuel consumption rate F. The fuel consumption rate calculation unit 102 sets the battery power integrated amount a ′ calculated in step S45 as a new battery power integrated amount a. The fuel consumption rate calculation unit 102 sets the battery fuel consumption J ′ calculated in step S45 as a new battery fuel consumption J.

  On the other hand, as a result of the determination in step S41, when it is determined that the hybrid vehicle 10 is not accelerating (that is, pa ≦ 0) (step S41: No), the fuel consumption rate calculation unit 102 performs regeneration. (That is, whether or not the regenerative energy r is a positive value) is determined (step S51).

  As a result of the determination in step S51, when it is determined that regeneration is being performed (that is, r> 0) (step S51: Yes), the fuel consumption rate calculation unit 102 calculates the fuel conversion value gr [g] of regenerative energy. Calculate (step S52). Below, with reference to FIG. 7, calculation of the fuel conversion value gr of regenerative energy is demonstrated concretely. FIG. 7 is a graph showing a time-series change in the integrated value of the energy fuel conversion value during deceleration.

As shown in FIG. 7, the integrated value of the energy fuel conversion value fc decreases as the hybrid vehicle 10 decelerates. Here, when the weight of the hybrid vehicle 10 is m [kg], the speed of the hybrid vehicle 10 before deceleration is V1 [km / h], and the speed of the hybrid vehicle 10 after deceleration is V2 [km / h]. The kinetic energy of the previous hybrid vehicle 10 is 1/2 × mV1 ² , and the kinetic energy of the hybrid vehicle 10 after deceleration is 1/2 × mV2 ² . Furthermore, when the energy fuel conversion value before deceleration is fc1 and the energy fuel conversion value before deceleration is fc2, the following equation (5) is obtained between the kinetic energy of the hybrid vehicle 10 and the energy fuel conversion value described above. ) Is established.

1/2 × mV1 ² : 1/2 × mV2 ² = fc1: fc2 (5)

  If this relationship is utilized, the energy fuel conversion value fc2 after deceleration can be obtained by the following formula (6).

fc2 = fc1 × (V2 ² / V1 ² ) (6)

  Here, the fuel conversion value gr of regenerative energy is the amount of change in the energy fuel conversion value before and after deceleration. Therefore, the fuel conversion value gr1 of regenerative energy when the speed of the hybrid vehicle 10 is decelerated from V1 to V2 is obtained as the energy fuel conversion value fc2 before deceleration subtracted from the energy fuel conversion value fc1 before deceleration. be able to. Therefore, the fuel conversion value gr1 of the regenerative energy can be obtained by the following formula (7).

gr1 = fc1-fc1 × (V2 ² / V1 ² ) (7)

  In consideration of the case where the hybrid vehicle 10 is further decelerated from the speed V2 to the speed V3, the fuel conversion value gr2 of the regenerative energy in this case is expressed as follows using the energy fuel conversion value fc3 after further deceleration: It can obtain | require by Numerical formula (8).

gr2 = fc2−fc2 × (V3 ² / V2 ² ) (8)

  As a result, the fuel conversion value gr of the regenerative energy is the energy fuel conversion value fc (t−1) before deceleration, the energy fuel conversion value fc (t) after deceleration, and the speed V (t of the hybrid vehicle 10 before deceleration. ) And the speed V (t) of the hybrid vehicle 10 after deceleration can be obtained by the following formula (9).

gr = fc (t) −fc (t) × (V (t) ² / V (t−1) ² ) (8)

  Returning to FIG. 2 again, when the fuel conversion value gr of regenerative energy is calculated, the fuel consumption rate calculation unit 102 changes the current energy fuel conversion value fc (t) to fc (t−1) −gr (that is, before deceleration). A value obtained by subtracting the fuel conversion value of regenerative energy from the energy fuel conversion value) (step S53).

  Thereafter, the fuel consumption rate calculation unit 102 calculates the battery fuel consumption rate F ′ after deceleration using the calculated fuel conversion value gr of the regenerative energy. Specifically, the fuel consumption rate calculation unit 102 calculates the battery fuel consumption rate F ′ after deceleration using the following formula (9).

    F ′ = (J + gr) / (a + r) (9)

  Here, as can be seen from Equation (9), the fuel conversion value gr of regenerative energy is added to the numerator of the battery fuel consumption rate F ′ after deceleration. In the present embodiment, by adding the fuel conversion value gr of the regenerative energy to the battery fuel consumption amount J in this way, the amount of fuel consumed to increase the kinetic energy that is the source of regeneration is reflected. Therefore, the battery fuel consumption rate F ′ can be calculated more accurately.

  On the other hand, if the fuel conversion value gr of the regenerative energy is not added, only the denominator of the battery fuel consumption rate F ′ increases during regeneration. That is, the battery fuel consumption J of the numerator does not fluctuate during regeneration, whereas the denominator increases as the regeneration energy r increases. As a result, the battery fuel consumption rate F 'continues to decrease during regeneration, and there is a possibility that accurate fuel consumption rate determination cannot be performed. The vehicle control device according to the present embodiment has a beneficial technical effect that such a situation can be avoided.

  As described above, in the hybrid vehicle 10 of the present embodiment, the accurate battery fuel consumption rate F considering the energy circulation is calculated by using the energy fuel conversion value fc. As a result, the hybrid vehicle 10 can travel while selecting a travel mode that can suitably improve fuel efficiency.

  Further, in the above description, an example is described in which the hybrid vehicle 10 employs a so-called split (power splitting) type hybrid system (for example, THS: Toyota Hybrid System). However, even when the hybrid vehicle 10 employs a parallel hybrid system, the travel mode may be controlled in the above-described manner. As a result, even when the hybrid vehicle 10 employs a parallel hybrid system, the above-described various effects are favorably enjoyed.

  It should be noted that the present invention can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and a vehicle control device that includes such a change is also included in the technical concept of the present invention. included.

10 Hybrid vehicle 100 ECU
DESCRIPTION OF SYMBOLS 101 Driving mode control part 102 Fuel consumption rate calculation part 103 Fuel consumption rate comparison part 500 Battery ENG Engine MG1, MG2 Motor generator F, F 'Battery fuel consumption rate H Engine fuel consumption rate a, a' Battery power accumulation amount J, J 'Battery fuel consumption Amount fc energy fuel conversion value gr regenerated energy fuel conversion value c MG2 assist power d engine generated power e EV running power amount fcc engine fuel injection amount G power generation engine fuel consumption rate r regenerative energy pa vehicle acceleration required power pe engine total output V1 , V2 speed

Claims (1)

A vehicle control device that controls a hybrid vehicle including an internal combustion engine and a rotating electrical machine that can charge a rechargeable battery capable of storing electric power by being driven using the power of the internal combustion engine,
(I) a charging cost representing a fuel consumption amount of the internal combustion engine required to store a unit amount of electric power stored in the rechargeable battery is (ii) the internal combustion engine without using power of the rotating electrical machine Determination means for determining whether or not the hybrid vehicle is smaller than an engine cost representing a fuel consumption amount of the internal combustion engine required for the hybrid vehicle to output a unit travel output corresponding to the unit power amount by using engine power;
(I) When it is determined that the charging cost is smaller than the engine cost, the traveling mode of the hybrid vehicle is an electric mode for traveling without operating the internal combustion engine, and (ii) the charging cost is Control means for controlling the hybrid vehicle so that the traveling mode is an engine mode that travels using the power of the internal combustion engine when it is determined that the engine cost is greater than the engine cost;
And a calculating means for calculating the charging cost using an energy fuel conversion value obtained by converting a kinetic energy increase due to acceleration of the hybrid vehicle and a kinetic energy decrease due to deceleration of the hybrid vehicle into a fuel amount. Vehicle control device.

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