JP6330682B2 - 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, Patent Document 1 compares an output efficiency when traveling while driving an internal combustion engine and charging a battery with a traveling efficiency when traveling only with a rotating electrical machine, and provides an efficient traveling mode. A hybrid vehicle to select is disclosed. Patent Document 2 discloses a hybrid vehicle that operates an internal combustion engine at an operating point at which the efficiency of the entire hybrid system is maximized based on a battery state, an outside air temperature, future travel information, and the like. Patent Document 3 discloses a hybrid vehicle that calculates the fuel consumption when the engine travel mode and the EV travel mode are executed during the execution of the EV travel mode, and selects the travel mode based on the calculated value. ing.

JP 2011-213285 A JP 2014-198495 A JP 2014-122033 A

  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, the traveling efficiency is calculated in consideration of the fuel consumed by the internal combustion engine when the battery is charged. However, the operating point when actually running with the internal combustion engine driven may be different from that at the time when the running efficiency was calculated. Specifically, for example, when the battery is charged, even if the internal combustion engine is operating at an operating point with a high fuel consumption rate, it may be driven at an operating point with a low fuel consumption rate during actual driving. obtain. For this reason, there is a possibility that an appropriate travel mode cannot be realized if the travel mode is determined based only on the travel efficiency calculated in advance. The same applies to Patent Documents 2 and 3, and there is a possibility that appropriate control cannot be performed unless consideration is given to changes in traveling efficiency. Therefore, the control methods disclosed in Patent Documents 1 to 3 may not always improve the 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. When the fuel consumption rate of the internal combustion engine for calculating the charging cost is larger than a predetermined threshold value, the charging cost value used in the previous determination by the determination unit Setting means for setting as a value of the charging cost used in the determination.

  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 setting 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 “the fuel consumption of the internal combustion engine required to store a unit amount of 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 setting means determines whether or not the fuel consumption rate of the internal combustion engine for calculating the charging cost (hereinafter referred to as “fuel consumption rate” as appropriate) is greater than a predetermined threshold value. That is, it is determined whether or not the fuel efficiency corresponding to the operating point of the internal combustion engine when the rotating electrical machine is driven to charge the rechargeable battery is greater than a predetermined threshold value. Here, the “predetermined threshold value” is a threshold value for determining whether or not the fuel consumption rate of the internal combustion engine is an extremely large value due to special operating conditions, etc. Is preset. More specifically, for example, when idling occurs immediately before the stop of the internal combustion engine or immediately before stopping, the rotational speed of the internal combustion engine is controlled to gradually decrease by motoring or the like, and as a result, the fuel consumption of the internal combustion engine is reduced. The rate is temporarily very high. The “predetermined threshold value” is set as a value that can determine such a temporary increase in the fuel consumption rate of the internal combustion engine.

  When the fuel consumption rate of the internal combustion engine for calculating the charging cost is larger than a predetermined threshold, the setting means uses the charging cost value used in the previous determination in the determination means as the charging cost value used in the current determination. Set as. That is, the previous charging cost (that is, the charging cost calculated at the time of the previous determination) is used as the new charging cost as it is, without calculating the new charging cost using the fuel efficiency of the internal combustion engine at the time of charging. Like that. Therefore, the determination unit compares the previous charging cost with the engine cost.

  Here, the charging cost is a parameter that increases as the fuel efficiency of the internal combustion engine increases. Therefore, if a new charging cost is calculated as usual when the fuel consumption rate of the internal combustion engine is larger than a predetermined threshold value, the calculated charging cost becomes an extremely large value. In this case, there is a high possibility that the charging cost will be higher than the engine cost, and the situation in which the vehicle should be controlled so that the engine mode is changed from the electric mode is increased. However, when the vehicle is actually controlled to be in the engine mode, the operating point of the internal combustion engine may change, and the operating point may be such that the fuel consumption rate of the internal combustion engine becomes very low. In particular, when the fuel consumption rate of the internal combustion engine is temporarily increased under the special conditions as described above, it is highly possible that the fuel consumption rate of the internal combustion engine is reduced during subsequent travel. In such a case, if the vehicle is controlled to enter the engine mode just because the calculated charging cost is high, the actual fuel consumption rate of the internal combustion engine is low, so that the fuel consumption may deteriorate. is there.

  However, according to the vehicle control device described above, when the fuel consumption rate of the internal combustion engine is larger than a predetermined threshold (that is, when a large charging cost is temporarily calculated), the previous charging is performed. The cost value is used for comparison with the engine cost. That is, in determining the travel mode, the influence of a temporary increase in the fuel consumption rate of the internal combustion engine is eliminated. As a result, although the internal combustion engine is driven in a state where the fuel consumption rate is low, the hybrid vehicle is controlled to enter the engine mode, and the fuel consumption can be prevented from deteriorating. In other words, by not reflecting the temporary increase in the charging cost in the determination result, it is possible to determine a more appropriate driving mode and improve the fuel consumption appropriately.

  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 time chart which shows an example of the condition where a battery fuel consumption rate rises rapidly. It is a time chart which shows the fluctuation | variation of the engine fuel consumption rate at the time of idling.

  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 that is a specific example of “rotating electric machine”, motor generator MG2, power split mechanism 300, inverter 400, and battery 500 that is a specific example of “rechargeable 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. In the present embodiment, in particular, the ECU 100, as a logical or physical processing block realized therein, is a travel mode control unit 101, which is a specific example of “control means”, and a specific example of “setting means”. 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, engine ENG is not operating (in other words, engine ENG is not driven, and in other words, 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. In addition, the fuel consumption rate calculation unit 102 according to the present embodiment sets the previously calculated battery fuel consumption rate as a new battery fuel consumption rate as it is, without calculating the new battery fuel consumption rate F under a predetermined condition. (That is, maintaining the battery fuel efficiency). 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. 2 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 battery.

  Battery 500 may be charged by receiving power from an external power source of 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, and the battery fuel consumption amount J (step S11). Hereinafter, the battery fuel consumption rate F, the battery power integration amount a, and the battery fuel consumption amount J 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”.

  Subsequently, the fuel consumption rate calculation unit 102 determines whether or not the power generation engine fuel consumption rate G is greater than the threshold A before calculating a new battery fuel consumption rate F '(step S12).

  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.

  On the other hand, the threshold A is a threshold for determining whether or not the power generation engine fuel consumption rate G is an extremely large value due to a special driving condition or the like, and is set in advance by a prior simulation or the like. .

  If it is determined that the power generation engine fuel consumption rate G is not greater than the threshold A (step S12: No), the fuel consumption rate calculation unit 102 calculates a new battery fuel consumption rate F '(step S13). 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.

  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 (1) can be used.

    J ′ = J + G × d−F × (c + e) (1)

  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 by the following Numerical formula (2) using electric energy e [kwh].

    a '= a + (d + r)-(c + e) (2)

  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 (3).

    F ′ = J ′ / a ′ (3)

  On the other hand, when it is determined that the engine fuel consumption rate G during power generation is greater than the threshold A (step S12: Yes), the fuel consumption rate calculation unit 102 uses the battery fuel consumption rate F used in the previous determination as a new battery fuel consumption. The rate is F ′ (step S14). That is, the fuel consumption rate calculation unit 102 maintains the battery fuel consumption rate F calculated at the previous determination without newly calculating the battery fuel consumption rate F ′.

  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 S15). Specifically, the fuel consumption rate calculation unit 102 sets the battery fuel consumption rate F ′ calculated in step S13 or the battery F ′ maintained at the previous value in step S14 as a new battery fuel consumption rate F. The fuel consumption rate calculation unit 102 sets the battery power integrated amount a ′ calculated in step S13 to a new battery power integrated amount a. The fuel consumption rate calculation unit 102 sets the battery fuel consumption amount J ′ calculated in step S <b> 13 as a new battery fuel consumption amount J.

  After the battery fuel consumption rate F is updated, 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 S21). ). 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 S21, when it is determined that the battery fuel consumption rate F ′ is greater than the running engine fuel consumption rate H (step S21: Yes), the travel mode control unit 101 indicates that the travel mode of the hybrid vehicle 10 is the HV mode. The hybrid vehicle 10 is controlled so as to become (step S31).

  On the other hand, as a result of the determination in step S21, when it is determined that the running engine fuel consumption rate H is greater than the battery fuel consumption rate F (step S21: No), the fuel consumption rate comparison unit 103 causes the SOC of the battery 500 to decrease excessively. It is determined whether it is (for example, whether it is smaller than a predetermined threshold value) (step S22). When the SOC of battery 500 is not smaller than the predetermined threshold (step S22: No), traveling mode control unit 101 controls hybrid vehicle 10 so that the traveling mode of hybrid vehicle 10 is in the EV mode (step). S32). On the other hand, when the SOC of battery 500 is smaller than the predetermined threshold (step S22: Yes), traveling mode control unit 101 controls hybrid vehicle 10 such that traveling mode of hybrid vehicle 10 is in the HV mode (step). S31). In this way, it is possible to prevent the hybrid vehicle 10 from being controlled so as to be in the EV mode even though sufficient SOC is not ensured for traveling in the EV mode.

  As described so far, 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 efficiency F is greater than the running engine fuel efficiency 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, the hybrid vehicle 10 according to this embodiment considers the value of the electric power stored in the battery 500, and the traveling mode in which the fuel efficiency is relatively good (or optimal). 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).

  The series of processes for controlling the travel mode described above ends when it is determined that the operation of the hybrid vehicle 10 has ended (step S41: Yes). On the other hand, when it is not determined that the operation of the hybrid vehicle 10 has ended (step S41: No), each process after step S12 is repeatedly executed.

  As described above, in the present embodiment, the travel mode of the hybrid vehicle 10 is determined based on the comparison result between the battery fuel consumption rate F and the engine fuel consumption rate H. In the present embodiment, in particular, the battery fuel consumption rate F used for determination of the travel mode is maintained at the previous value under a predetermined condition (see step S14). The effect obtained by the operation of maintaining the battery fuel efficiency F will be described in detail below.

(3) Effect of Maintaining Battery Fuel Efficiency Rate F Hereinafter, the effect of determining the travel mode of the hybrid vehicle 10 in consideration of the engine operating point will be described in detail with reference to FIGS. 4 and 5. . FIG. 4 is a time chart showing an example of a situation in which the battery fuel consumption rate rapidly increases. FIG. 5 is a time chart showing fluctuations in the engine fuel consumption rate during idling.

  In the example shown in FIG. 4, the engine fuel efficiency G during power generation temporarily increases significantly at the timing indicated by the broken line. Here, as can be seen from Equation (1), when the engine fuel consumption rate G during power generation increases, the calculated battery fuel consumption J 'also increases. As can be seen from Equation (3), when the battery fuel consumption amount J ′ increases, the calculated battery fuel consumption rate F ′ also increases. For this reason, at the timing indicated by the broken line, the battery fuel efficiency F is rapidly increasing.

  In the example shown in FIG. 5, the engine ON flag is off at time T1 (that is, it is determined to stop the engine ENG). In this case, the engine speed Ne is gradually reduced while motoring, so the engine ENG temporarily enters an idling state (for example, about 1 second). In such a case, the engine fuel consumption rate increases significantly. As a result, the battery fuel consumption rate F also temporarily becomes a very large value.

  When the battery fuel efficiency F rapidly increases, the battery fuel efficiency F is more likely to be determined to be higher in the comparison between the battery fuel efficiency F and the engine fuel efficiency H. That is, if only the comparison result between the battery fuel consumption rate F and the engine fuel consumption rate H is seen, there is a high possibility that it is determined that the vehicle should travel in the HV mode.

  However, the operating point of the engine ENG when the hybrid vehicle 10 is actually controlled to be in the HV mode is different from when the battery 500 is charged. For this reason, there is a difference between the fuel efficiency used when calculating the battery fuel efficiency F and the fuel efficiency actually realized. As a result, even if the hybrid vehicle 10 is controlled based only on the comparison result between the battery fuel consumption rate F calculated using the power generation engine fuel consumption rate G and the engine fuel consumption rate H, the fuel consumption may not be improved appropriately. There is sex.

  In order to solve such a problem, in the present embodiment, when the power generation engine fuel efficiency G is larger than the threshold A, the previous battery fuel efficiency F is maintained. That is, when the battery fuel consumption rate F is temporarily calculated as a large value, the value of the previous battery fuel consumption rate F is used to compare with the running engine fuel consumption rate H. Thereby, in determining the traveling mode of the hybrid vehicle 10, the influence of the temporary increase in the engine fuel efficiency G during power generation is eliminated. As a result, it is possible to prevent the hybrid vehicle 10 from being controlled so as to be in the HV mode even when the engine ENG is driven in a state where the fuel consumption rate is low, and the fuel consumption being deteriorated. In other words, by not reflecting the temporary increase in the battery fuel consumption rate F in the determination result, it is possible to determine a more appropriate travel mode and improve the fuel consumption appropriately.

  In the above description, an example is described in which the hybrid vehicle 10 employs a so-called split (power split) hybrid system (for example, THY: 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 apparatus 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 300 Power split mechanism 400 Inverter 500 Battery ENG Engine MG1, MG2 Motor generator F, F 'Battery fuel consumption rate H Engine fuel consumption rate a, a' Battery power integration amount J , J 'Battery fuel consumption c MG2 assist power d Engine generated power e EV running power G Engine fuel efficiency during power generation r Regenerative energy

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;
The determination means when the fuel consumption rate of the internal combustion engine for calculating the charging cost is greater than a predetermined threshold for determining an increase in the fuel consumption rate due to a predetermined operating condition in the hybrid vehicle. And a setting means for setting the charging cost value used in the previous determination as the charging cost value used in the current determination.