JP7439740B2 - vehicle - Google Patents

Description

The present invention relates to a vehicle.

In recent years, various hybrid vehicles have been developed. A hybrid vehicle runs using power from at least one of a motor generator and an engine. For example, Japanese Patent No. 6156050 (Patent Document 1) discloses a hybrid vehicle that is set to modes such as an EV driving mode and an engine driving mode. This hybrid vehicle calculates the engine-generated power cost and the EV effect value. Then, this hybrid vehicle compares the engine-generated power cost and the EV effect value, and determines whether to execute the EV driving mode based on the comparison result. This reduces the possibility that a loss will occur in the EV driving mode in this hybrid vehicle.

Patent No. 6156050

In general, driving habits differ depending on the driver. Due to this habit, the power consumed in the mode in which the vehicle travels using the power of the motor generator (that is, the EV travel mode) differs. In the vehicle described in Patent Document 1, such driver habits are not taken into account, and as a result, a problem may arise in that the mode in which the vehicle runs using the power of the motor generator causes a large amount of loss.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a technique for suppressing losses caused by a mode in which a vehicle runs using the power of a motor generator.

A vehicle according to an aspect of the present disclosure includes a battery, a motor generator, an engine, and a control device. Batteries store electricity. A motor generator generates power for a vehicle by consuming electric power stored in a battery. An engine generates power for a vehicle by consuming fuel. The control device switches between a first mode in which the vehicle travels using the power of the motor generator and a second mode in which the vehicle travels using the power of the engine. The motor generator can generate electric power during driving switched to the second mode and then store the electric power in the battery. When a request for traveling in the first mode occurs, the control device obtains power consumption based on power consumed in one past traveling in the first mode. Further, the control device calculates the power cost based on the fuel required for the motor generator to generate the power consumption in the second mode. Then, the control device determines whether or not to run in the first mode based on the comparison between the electric power cost and the reference cost.

According to such a configuration, the power cost is calculated based on the fuel required for the motor generator to generate the power consumption in the second mode based on the power consumed in one past run in the first mode. , it is determined whether or not to travel in the first mode based on a comparison between the power cost and the reference cost. Therefore, it is possible to decide whether or not to drive in the first mode based on the driver's past habits in the first mode, and as a result, losses caused by the first mode can be suppressed.

In one aspect, the battery stores first electric power generated by deceleration regeneration of the vehicle and second electric power generated during driving in a second mode. The motor generator generates power for the vehicle by consuming the first electric power and the second electric power at the same rate when traveling in the first mode. The control device calculates the power cost by dividing the first value by the second value. The first value is the amount of fuel required for the motor generator to generate the second power remaining in the battery in the second mode, assuming that the power consumption has been consumed, and the amount of fuel required for the motor generator to generate the second power remaining in the battery in the second mode, and the amount of power consumed in the second mode. This value is added to the amount of fuel required for the motor generator to generate. The second value is the sum of the first power and the second power stored in the battery when power is not consumed.

According to such a configuration, not only the amount of fuel required for the motor generator to generate the second electric power in the second mode but also the amount of fuel stored in the battery when the consumed power is not consumed. It is possible to calculate the power cost that also reflects the added value of the first power and the second power.

In one aspect, the standard cost is a value obtained by dividing the fuel reduction amount in the first mode by the power consumed by the motor generator in the first mode. The control device determines to run in the first mode when the power cost is less than or equal to the reference cost. The control device does not decide to run in the first mode if the power cost is greater than the reference cost.

According to such a configuration, when the power cost is equal to or less than the standard cost, when driving in the first mode, the power consumption in the first mode is reduced to the second mode after the end of the first mode. Even if it is generated, the cost of the power consumption is low and there is a high possibility that no damage will occur. On the other hand, when the cost is larger than the standard cost, when driving in the first mode, the power consumption in the first mode is generated in the second mode after the end of the first mode. The cost of electricity will increase and there is a high possibility that damage will occur. Therefore, with such a configuration, it is possible to appropriately determine whether or not to drive in the first mode.

In one aspect, the control device does not decide to run in the first mode if the SOC of the battery is below a threshold value even if the power cost is below the reference cost.

According to such a configuration, the vehicle can run in the first mode so that the electric power in the battery is not exhausted.

In one aspect, the power consumption is the average power consumed in a plurality of past runs in the first mode.

According to such a configuration, it is possible to calculate a cost that suppresses the difference value of power consumption for a plurality of times in the past in the first mode.

In certain aspects, the engine is a diesel engine.
According to such a configuration, even if the vehicle is equipped with a diesel engine, it can be determined whether or not to drive in the first mode.

In one aspect, the power consumption includes the power required to run the vehicle in the first mode and the power required to crank the engine.

Vehicles equipped with diesel engines require more electricity to crank the engine than vehicles equipped with gasoline engines. Therefore, according to such a configuration, the power cost can be calculated based on the power consumption including the large amount of power, and therefore, the control device can calculate the power cost more accurately.

In one aspect, the standard cost is calculated based on the state of the engine when the engine outputs the requested running power of the vehicle.

According to such a configuration, since it is determined whether or not to drive in the first mode using the standard cost calculated based on the engine state, it is possible to more accurately determine whether or not to drive in the first mode. can.

According to this disclosure, the vehicle obtains power consumption based on the power consumed in one run in the past first mode (a mode in which the vehicle runs using power from a motor generator), and converts the power consumption into the The electric power cost based on the fuel required for the motor generator to generate in 2 modes is calculated. Then, the vehicle determines whether or not to travel in the first mode based on the comparison between the electric power cost and the reference cost. Therefore, whether or not to travel in the first mode, which uses the power of the motor generator, is determined based on the power consumption based on the power consumed in one run in the first mode in the past. , it is possible to suppress the loss caused by the driving mode using the power of the motor generator.

FIG. 1 is an overall configuration diagram of a vehicle according to the present embodiment. FIG. 2 is a diagram illustrating the idea of the present disclosure. FIG. 3 is a diagram showing power within a battery. FIG. 3 is a diagram illustrating the amount of generated power and the like for each mode. It is a functional block diagram of an ECU. It is a figure showing power cost and EV effect value. It is a figure showing power consumption in one EV run. 3 is a flowchart for explaining a method of operating the vehicle 1. FIG.

Embodiments of the present disclosure will be described below with reference to the drawings. In the following description, the same parts are given the same reference numerals. Their names and functions are also the same. Therefore, a detailed description thereof will not be repeated.

[Overall configuration diagram of vehicle 1]
FIG. 1 is an overall configuration diagram of a vehicle 1 according to this embodiment. The vehicle 1 includes an engine 10, a clutch 15, a motor generator 20, an inverter 21, a battery 22, a DC (Direct Current)/DC converter 23, a fuel tank 28, an automatic transmission 40, and drive wheels 50. , an ECU (Electronic Control Unit) 70, and a starter 80.

Engine 10 is a diesel engine with a plurality of cylinders and a supercharger. Note that the engine 10 may be a gasoline engine with a supercharger. The crankshaft of engine 10 and the rotating shaft of motor generator 20 are coupled with a clutch 15 interposed therebetween. Fuel is stored in the fuel tank 28. Engine 10 generates power for vehicle 1 by consuming fuel in fuel tank 28 . For example, when engine 10 is a diesel engine, the fuel is light oil.

Battery 22 is a power storage device that stores power supplied to motor generator 20 . The output voltage of the battery 22 is set to a higher voltage (for example, about several hundred volts) than the voltage (for example, about 12 volts) used for low-voltage auxiliary equipment.

Motor generator 20 generates power for vehicle 1 by consuming electric power stored in battery 22 . Motor generator 20 is, for example, a three-phase AC rotating electric machine. The rotating shaft of motor generator 20 is connected on a power transmission path between the crankshaft of engine 10 and the input shaft of automatic transmission 40 . Note that a torque converter may be provided between motor generator 20 and automatic transmission 40. An output shaft of automatic transmission 40 is connected to drive wheels 50 .

Inverter 21 performs power conversion between motor generator 20 and battery 22. Specifically, the inverter 21 converts DC power from the battery 22 into three-phase AC power and supplies it to the motor generator 20, or converts three-phase AC power generated by the motor generator 20 into DC power and supplies it to the battery. 22. Motor generator 20 is driven by power supplied from battery 22 via inverter 21 . Further, the battery 22 is charged by electric power supplied from the motor generator 20 via the inverter 21 . Note that a voltage converter (step-up/down converter) may be provided between the motor generator 20 and the inverter 21.

The DC/DC converter 23 is provided between the battery 22 and the low-voltage auxiliary equipment, and converts high-voltage DC power from the battery 22 into low-voltage DC power and supplies it to the low-voltage auxiliary equipment. do.

Power from at least one of engine 10 and motor generator 20 is transmitted to drive wheels 50 via automatic transmission 40 . That is, vehicle 1 is a hybrid vehicle that can run using power from at least one of engine 10 and motor generator 20.

ECU 70 can switch the driving mode to any one of engine mode, EV mode, assist mode, charging mode, and regeneration mode. Note that the component that switches the driving mode may be other than the ECU 70. Below, driving in engine mode, driving in EV mode, driving in assist mode, driving in charge mode, and driving in regeneration mode are respectively referred to as "engine driving", "EV driving", "assist driving", Also referred to as "charging driving" or "regenerative driving."

The engine mode is a mode in which the vehicle 1 travels using the power of the engine 10 with the clutch 15 in an engaged state. The EV mode is a mode in which the vehicle 1 runs with the power of the motor generator 20 while the clutch 15 is released and the engine 10 is stopped. The assist mode is a mode in which the vehicle 1 travels using the power of both the engine 10 and the motor generator 20 with the clutch 15 in an engaged state. Therefore, in the EV mode and the assist mode, the electric power stored in the battery 22 is discharged to the motor generator 20.

In the charging mode, the vehicle 1 travels using part of the power of the engine 10 with the clutch 15 in an engaged state, and the motor generator 20 uses surplus energy (energy not used for traveling) of the engine 10. This is a mode in which the battery 22 is charged with the generated power. The regeneration mode is a mode in which the vehicle 1 travels while decelerating, and the battery 22 is charged with electric power generated by the motor generator 20 using the deceleration energy of the vehicle 1. Therefore, during the charging mode and the regeneration mode, the battery 22 is charged with the electric power generated by the motor generator 20. Further, the EV mode corresponds to the "first mode" of the present disclosure, and the charging mode corresponds to the "second mode" of the present disclosure. Further, the power of the motor generator 20 is generated by consuming the electric power stored in the battery 22. In other words, the EV mode is a mode in which the vehicle consumes the power of the battery 22 to travel. Further, driving in EV mode may also be referred to as "EV driving."

ECU 70 includes an engine ECU (ENG-ECU) 71, a motor generator ECU (MG-ECU) 72, and a hybrid ECU (HV-ECU) 73. Each of the ECUs 71 to 73 includes a CPU (Central Processing Unit) and memory (not shown).

Engine ECU 71 controls engine 10 . Motor generator ECU 72 controls motor generator 20 by controlling inverter 21 . Hybrid ECU 73 controls the entire system for driving vehicle 1 by controlling engine ECU 71, motor generator ECU 72, and the like.

Although the ECUs 71 to 73 are provided separately in FIG. 1, at least two of the ECUs 71 to 73 may be provided as one unit. Hereinafter, engine ECU 71, motor generator ECU 72, and hybrid ECU 73 will be referred to as ECU 70 without distinction.

[About the idea of this embodiment]
Below, the units of parameters are shown in parentheses. For example, (kWh) indicates the amount of electric power, and (g) indicates the mass. FIG. 2 is a diagram showing the idea of this embodiment. As described above, the EV mode is a mode in which the vehicle runs by consuming the power of the battery 22. For example, when the vehicle 1 of this embodiment is running in the engine mode and an EV request occurs, the vehicle 1 determines whether or not running in the EV mode will cause damage in terms of fuel costs. The EV request is a request for the vehicle 1 to run in EV mode. An EV request occurs when a predetermined condition occurs. The predetermined condition is, for example, that the speed of the vehicle 1 is less than a predetermined threshold.

FIG. 2(A) shows a battery 22 storing electric power and a fuel tank 28 storing fuel in a state of driving (for example, engine driving, charging driving, etc.) before EV driving. There is. Assume that an EV request occurs. The ECU 70 acquires the average amount of electric power D (kWh) in past EV driving. This average power amount D is stored in a predetermined storage area (for example, a storage section of the ECU 70). That is, the average amount of electric power D (kWh) is the amount of electric power that is expected to be consumed when EV driving is performed. The average power amount D is also referred to as power consumption.

FIG. 2B shows that an average amount of power D has been consumed from the battery 22. Then, as shown in FIG. 2(C), the ECU 70 generates (recovers) the average amount of electric power D that is assumed to be consumed in the EV driving in the charging driving after the EV driving. A cost (hereinafter referred to as "power cost X (described later)") based on the amount G(g) is calculated. FIG. 2(C) is a diagram showing the fuel amount G. The power cost X is a value based on the fuel required for the motor generator 20 to generate the average power consumption in past EV driving in the charging mode.

Next, the comparison target of power cost X will be explained. FIG. 2(D) is a diagram showing a comparison target of power cost X. As shown in FIG. 2(D), the fuel S(g) consumed when the vehicle is running with the engine instead of the EV running is shown. That is, the fuel S is, for example, the fuel that is consumed when the vehicle travels the same distance in the engine mode as the distance traveled using the average amount of power D. This fuel S is a fuel whose consumption is reduced during EV driving, and is also referred to as save fuel S hereinafter. The ECU 70 calculates a cost (hereinafter also referred to as "EV effect value Y") based on this saved fuel S. The EV effect value Y corresponds to the "standard cost" of the present disclosure.

Then, as shown in FIG. 2(E), the ECU 70 compares the electric power cost X and the EV effect value Y, and if the electric power cost Since there is a high possibility that the vehicle will not be used, the decision is made to switch to EV mode. On the other hand, if the electric power cost ). That is, when the electric power cost X is larger than the EV effect value Y, the vehicle 1 does not switch to EV driving even though an EV request has occurred. Note that the power cost of power consumption can be expressed by the following equation (1), for example.

Electricity cost of power consumption = Weight of fuel required to generate power consumption (g) / Power consumption (kWh) (1)
FIG. 3 is a diagram showing the power inside the battery 22. The vertical axis in FIG. 3(A) indicates the electric power within the battery 22. The vertical axis in FIG. 3(B) indicates the cost of generated power. In Fig. 3, before EV driving (corresponding to Fig. 2 (A)), assuming EV driving (corresponding to Fig. 2 (B)), and assuming recovery of SOC (State of Charge) of the battery 22 (Fig. 2 (C) ) is shown.

A graph 201 in FIG. 3A is a graph showing the amount of power before an EV request is generated. In FIG. 3A, the power shown in graph 201 is composed of regenerated power and fuel power. Regenerated power is power generated in regeneration mode. Fuel power and regenerated power are collectively referred to as "total power." Fuel power is power generated in charging mode. Regenerated power corresponds to "first power" in the present disclosure. Fuel power corresponds to "second power" in the present disclosure.

In the graph 201 of FIG. 3A, it is assumed that the amount of regenerated power is A (kWh), and the amount of fuel power is B (kWh). Also, assume that the amount of fuel consumed to generate B (kWh) of fuel power is C (g). Furthermore, the amount of fuel required to generate regenerative power is 0 (g). In addition, in FIG. 3, regenerated power is shown in a graph with hatching, and fuel power is shown in a graph with dots.

Further, a graph 202 in FIG. 3(A) is a graph showing the assumed (estimated) amount of electric power when EV driving is performed. Furthermore, as explained in FIG. 2, the average amount of electric power consumed in one EV run is D (kWh).

Furthermore, when power is consumed, regenerative power and fuel power are consumed at the same rate. For example, in the EV mode, motor generator 20 generates power for vehicle 1 by consuming regenerative power and fuel power at the same rate. As shown in the graph 202, the amount of regenerated power after the average amount of power D (kWh) is consumed in the power in the battery is A1 (kWh), and the amount of fuel power is B1 (kWh). Suppose that Further, assume that the amount of fuel consumed to generate B1 (kWh) of fuel power is C1 (g).

A graph 203 in FIG. 3(A) shows the fuel required to recover the average amount of electric power D (kWh) expected to be consumed by fuel power generation in charging mode (to recover the SOC). It is a graph. In this embodiment, the vehicle 1 recovers the average electric power D (kWh) only by fuel power generation without using regenerative power generation. In the example of FIG. 3(C), it is assumed that the amount of fuel required to recover the average electric energy D (kWh) is G (g).

Further, as shown at points S1 to S3 in FIG. 3(B), the electric power cost of fuel electricity is a constant value before EV driving, assuming EV driving, and assuming SOC recovery. Further, as shown at points S4 and S5, the electric power cost of the entire electric power is a constant value both before EV driving and when assuming EV driving. However, in the SOC recovery assumption, the total electric power cost becomes higher than before EV driving and in the case of EV driving assumption. This is because, as described above, the average amount of electric power D (kWh) consumed in EV driving is recovered only by fuel power generation without using regenerative power generation.

In addition, in the following description, the regenerated power amounts A, A1, B, B1, and D may be used as reference symbols. For example, they are expressed as regenerated power amount A, regenerated power amount A1, fuel power amount B, fuel power amount B1, and average power amount D.

In the EV effect value section of FIG. 3(B), EV effect values M1 to M3 are shown. Furthermore, the line L represents the power cost assuming SOC recovery. If the EV effect value M1 is larger than the power cost assumed for SOC recovery, there is a high possibility that no loss will occur when EV driving is performed. Therefore, when an EV request occurs and the EV effect value M1 is larger than the power cost assumed for SOC recovery, the vehicle 1 executes EV driving. In addition, if the EV effect value M1 and the power cost assuming SOC recovery are the same, there is a possibility that no loss will occur if regenerative power generation is performed during one EV drive and after the end of the EV drive. be. Therefore, when an EV request occurs, if the EV effect value M1 and the power cost assuming SOC recovery are the same, the vehicle 1 executes EV driving. As a modification, if the EV effect value M1 is the same as the power cost assuming SOC recovery, the vehicle 1 may not perform EV driving. Further, if the EV effect value M1 is smaller than the power cost assumed for SOC recovery, there is a high possibility that a loss will occur when EV driving is performed. Therefore, when an EV request occurs and the EV effect value M1 is larger than the power cost assumed for SOC recovery, the vehicle 1 does not perform EV driving.

FIG. 4 is a diagram showing the amount of generated power and the like for each mode. FIG. 4(A) shows the vehicle speed for each mode. FIG. 4(B) shows the torque of the motor generator 20 (hereinafter also referred to as "MG torque"). Moreover, in the example of FIG. 4(B), the reference value of the MG torque is set to "0". FIG. 4C shows the amount of power in the battery 22. In FIG. 4(C), the amount of total power generated (the amount of total power stored in the battery 22) and the amount of fuel power generated (the amount of fuel power stored in the battery 22) are shown. is shown. FIG. 4(D) shows the integrated value of fuel required for power generation by the motor generator 20. FIG. 4(E) shows the generated power cost. Further, the horizontal axis in FIG. 4 indicates time.

In the example of FIG. 4, it is assumed that the vehicle 1 runs in the regeneration mode during the period from timing T1 to T2. Further, it is assumed that the vehicle 1 runs in the engine mode during the period from timing T2 to T3. Further, it is assumed that the vehicle 1 runs in the assist mode during the period from timing T3 to timing T4. Further, it is assumed that the vehicle 1 runs in the charging mode during the period from timing T4 to timing T5.

First, FIG. 4(A) will be explained. In the regeneration mode, the speed of the vehicle 1 is gradually decreasing. In engine mode, the speed of vehicle 1 is constant. In the assist mode, the speed of the vehicle 1 is gradually increasing. In charging mode, the speed of vehicle 1 is constant.

Next, FIG. 4(B) will be explained. In the regeneration mode, the MG torque takes a value less than zero. In the engine mode, the MG torque is zero. In the assist mode, the MG torque has a value greater than zero. In the charging mode, the MG torque takes a value less than 0.

Next, FIG. 4(C) will be explained. In regeneration mode, the total power is increased. This is because regenerative power is generated in the regenerative mode. Note that in the regeneration mode, the fuel power does not change. In engine mode, the overall power is gradually reduced. This is because power is consumed in the DCDC converter 23. Furthermore, as described above, regenerative power and fuel power are consumed at the same rate. Therefore, in engine mode, fuel power is also gradually decreasing.

Further, in the assist mode, since electric power is consumed for driving the vehicle 1, the total electric power and the fuel electric power are consumed. Also, in charging mode, the total power and fuel power are increasing.

The ECU 70 periodically acquires the current regenerative power amount A and the current fuel power amount B (see FIG. 3(A)). As the time when these electric powers were acquired, the current time is set as "t", and the time immediately before the current time is set as "t-1". Furthermore, the regenerated power amount obtained at time t is expressed as A(t), and the regenerated power amount obtained at time t-1 is expressed as A(t-1). The amount of fuel power obtained at time t is expressed as B(t), and the amount of fuel electricity obtained at time t-1 is expressed as B(t-1). Further, the fuel amount at time t is expressed as C(t), and the fuel amount at time t-1 is expressed as C(t-1).

Further, the amount of change in the amount of regenerated electric power from time t-1 to time t is expressed as ΔA (=A(t)-A(t-1)). The amount of change in fuel power amount from time t-1 to time t is expressed as ΔB (=B(t)-B(t-1)).

In the regeneration mode, the amount of change ΔA is expressed by the following equation (11).
ΔA = (amount of power generated by motor generator 20 - amount of power consumed by DCDC 23) x charging efficiency (11)
Note that charging efficiency is also referred to as a battery state function.

In the charging mode, the amount of change ΔA=0. In addition, for other specific modes (for example, engine mode, assist mode), the amount of change ΔA is expressed by the following equation (12).

ΔA = (amount of power generated by motor generator 20 - amount of power consumed by DCDC 23) x charging efficiency x (A(t-1)/A(t-1)+B(t-1)) (12)
Further, in the regeneration mode, the amount of change ΔB is 0. In the charging mode, the amount of change ΔB is expressed by the following equation (13).

ΔB = (amount of power generated by motor generator 20 - amount of power consumed by DCDC 23) x charging efficiency (13)
Further, in the specific mode, the amount of change ΔB is expressed by the following equation (14).

ΔB = (amount of power generated by motor generator 20 - amount of power consumed by DCDC 23) x charging efficiency x (A(t-1)/A(t-1)+B(t-1)) (14)
Next, FIG. 4(D) will be explained. In the regeneration mode, the integrated value of fuel required for power generation does not change. In the engine mode and assist mode, the integrated value of fuel required for power generation decreases. In the engine mode, power is consumed by the DCDC converter 23. In FIG. 4(D), the integrated value of fuel required to generate the consumed power in the engine mode is reduced. Furthermore, in the assist mode, power is consumed for the DCDC converter 23 and the vehicle 1 to travel. In FIG. 4(D), the integrated value of fuel required to generate the consumed power in the engine mode is reduced. Furthermore, in the charging mode, fuel is consumed and electric power is generated, so the fuel integrated value increases by the amount of consumed fuel.

Next, the fuel amount C will be explained. In the regeneration mode, ΔC=0. In the charging mode, ΔC=the amount of fuel injected according to the command from the ECU 70. Further, in the specific mode, C(t) is expressed by the following equation (15).

C(t)=C(t-1)×(B(t)/A(t)+B(t)) (15)
Next, FIG. 4(E) will be explained. As shown in FIG. 4(E), the fuel power cost is the same regardless of the driving mode and regardless of the amount of power in the battery 22. Furthermore, the total power is reduced in the regeneration mode. This is because in the regeneration mode, regenerative power is generated without consuming fuel, and as a result, the overall power cost is reduced. Further, in the engine mode and the assist mode, the electric power cost of the entire electric power is constant. Also, in the charging mode, the total power cost increases. This is because in the charging mode, as fuel is consumed, the electric power cost corresponding to the fuel increases.

[Example of functional configuration of ECU 70]
FIG. 5 is a functional block diagram of the ECU 70. The ECU 70 includes a determination section 101, an acquisition section 102, a storage section 104, a calculation section 106, and a determination section 108.

The determining unit 101 determines whether an EV request has occurred. When the determining unit 101 determines that an EV request has occurred, it outputs a signal indicating the determination result to the acquiring unit 102.

The acquisition unit 102 acquires power consumption based on the power consumed in one run in the past EV mode. “Electric power consumed in one run in the past EV mode” will be explained later with reference to FIG. 7. Furthermore, in the present embodiment, the acquisition unit 102 acquires the average amount of electric power D consumed during multiple trips in the past EV mode. Furthermore, the storage unit 104 of this embodiment stores the power consumption of each of N (N is an integer of 2 or more) EV driving. The power consumption in one EV run is also referred to as "EV power consumption." The acquisition unit 102 acquires the N EV power consumptions and calculates the average value of the N EV power consumptions, thereby acquiring the average power amount D.

Furthermore, each time one EV run ends, the ECU 70 stores the electric power consumed in the one EV run (EV power consumption) in the storage unit 104. The acquisition unit 102 outputs the acquired average power to the calculation unit 106. Moreover, as explained in FIG. 4, the acquisition unit 102 periodically acquires the current regenerative power amount A and the current fuel power amount B. Furthermore, as explained in FIG. 4, the acquisition unit 102 also acquires the fuel amount C required to generate the most recently acquired fuel power amount B. The acquisition unit 102 calculates the most recently acquired regenerative power amount A, the most recently acquired fuel power amount B, the fuel amount C required to generate the fuel power amount B, and the average power amount D by the calculation unit 106. Output to.

The calculation unit 106 calculates the above-mentioned power cost X (EV Calculate the power consumption cost (power consumption in mode driving). Further, the calculation unit 106 calculates the above-mentioned EV effect value Y. First, a method for calculating power cost X will be explained.

Based on graph 201 and graph 202 in FIG. 3, the following equation (21) holds true.
A1+B1=(A+B)-D (21)
As described above, since the regenerated power and the fuel power are consumed at the same rate, the following equations (22) to (24) hold true.

A1=A-(A/(A+B)×D)) (22)
B1=B-(B/(A+B)×D)) (23)
C1=C×(B1/(A1+B1)) (24)
Calculation unit 106 calculates regenerative power amount A1 and fuel power amount B1 using equation (22) and equation (23). Then, the calculation unit 106 calculates the fuel amount C1 (see graph 202 in FIG. 3(A)) by substituting the fuel amount C, the regenerated power amount A1, and the fuel power amount B1 into equation (24). calculate.

Next, the calculation unit 106 calculates the fuel amount G (see graph 203 in FIG. 3A) required to generate the average power amount D in the charging mode using the following equation (25).

G=D×(C1/B1) (25)
The second term "C1/B1" on the right side of equation (25) represents the power cost of the fuel power amount B1 (see equation (1) above). The fuel amount G is the amount of fuel required to generate the average amount of power D in the charging mode based on the electric power cost conversion assuming that the average amount of electric power D is consumed during EV driving.

Next, the calculation unit 106 calculates the power cost X using the following equation (26).
X=(C1+G)/(A+B) (26)
On the right side of equation (26), C1 is calculated using equation (24) above, and G is calculated using equation (25).

Further, "C1+G" of the numerator on the right side of formula (26) corresponds to the "first value" of the present disclosure. Furthermore, “A+B” in the denominator on the right side of equation (26) corresponds to the “second value” of the present disclosure. That is, the power cost is calculated by dividing the first value by the second value.

"C1" of the first values is the amount of fuel required for the motor generator 20 to generate the generated power remaining in the battery 22 in the charging mode, assuming that the average power amount D is consumed. It is. Moreover, "G" of the first value is the amount of fuel required for the motor generator 20 to generate the average amount of electric power D in the charging mode. The first value is the sum of C1 and G.

The second value is the sum of the regenerated power amount A and the fuel power amount B stored in the battery 22 when the average power amount D is not consumed. Moreover, the power cost X does not change depending on the power consumed.

Next, a method of calculating the EV effect value Y by the calculation unit 106 will be explained. The EV effect value Y can be expressed by the following equation (27) or equation (28).

EV effect value Y = Save fuel S (g) in Figure 2 (D) / Electric power consumed by motor generator 20 during EV driving (kWh) (27)
EV effect value Y = Fuel consumption per unit time when running with engine (g/hr) / Required driving power when running with engine (kW) (28)
Next, a specific example of how to obtain the EV effect value Y will be explained. Calculation unit 106 calculates engine required power (kw) when an EV request occurs using the following equation (29).

Engine required power (kW) = Driving required power (kW) x Transmission efficiency x Torque converter efficiency (29)
Transmission efficiency is power transmission efficiency by automatic transmission 40. Torque converter efficiency is power transmission efficiency by the torque converter. Transmission efficiency and torque converter efficiency are constant values.

Next, the calculation unit 106 converts the required engine power into engine rotation speed and torque using a predetermined first map or a predetermined conversion formula (both not shown). Next, the calculation unit 106 calculates the EV effect value Y using the engine rotation speed and torque using a predetermined second map (not shown).

Next, calculation section 106 outputs power cost X and EV effect value Y to determination section 108. The determining unit 108 compares the power cost X and the EV effect value Y. The determining unit 108 determines to drive in the EV mode when the power cost X is less than or equal to the EV effect value. When deciding to drive in the EV mode, the determining unit 108 executes the EV drive by transmitting a command signal to the inverter 21 or the like. On the other hand, if the power cost is greater than the EV effect value Y, the determining unit 108 does not determine to drive in the EV mode. If it is not determined to travel in the EV mode, for example, the vehicle 1 travels while maintaining the travel mode in which the EV request occurred.

In general, driving habits differ depending on the driver. Depending on this habit, the power consumption of EV driving differs. In conventional vehicles, such driver habits are not taken into consideration, and as a result, a problem may arise in which the EV mode causes a large loss. Therefore, the vehicle 1 of the present embodiment reduces the power cost based on the fuel necessary for the motor generator 20 to generate power consumption in the charging mode based on the power consumed in one past drive in the first mode. (see step S6 in FIG. 8). The vehicle 1 determines whether or not to run in the EV mode based on the comparison between the electric power cost and the EV effect (steps S10 to S14). Therefore, the vehicle 1 can determine whether or not to drive in the EV mode based on the driver's habits in the past EV mode, and as a result, losses due to the EV mode can be suppressed.

Furthermore, the vehicle 1 can calculate the power cost X using equation (26). Therefore, it is possible to calculate the power cost that reflects not only the amount of fuel required to generate the amount of military power but also the amount of power stored in the battery 22.

Further, the EV effect value Y is a value obtained by dividing the fuel reduction amount in the EV mode by the electric power consumed by the motor generator 20 in the EV mode, as shown by Equation (27) and the like. Furthermore, when the power cost X is less than or equal to the EV effect value Y (YES in step S10), the ECU 70 determines to drive in the EV mode. If the power cost The cost is low and there is a high possibility that no damage will occur. Therefore, in this case, the ECU 70 determines to drive in the EV mode. In particular, in this embodiment, the power cost for restoring power consumption only in the charging mode is calculated without including the regeneration mode for restoring power. Therefore, since the highest power cost is calculated as the power cost for restoring power consumption, the ECU 70 can more accurately determine whether or not damage will occur.

On the other hand, if the power cost X is greater than the EV effect value Y (NO in step S10), the ECU 70 does not decide to drive in the EV mode. If the power cost There is a high possibility that damage will occur. As described above, the ECU 70 can appropriately determine whether or not to drive in the first mode.

FIG. 6 is a diagram showing power costs and EV effect values. In FIG. 6, the horizontal axis shows the required running power (see equation (28)), and the vertical axis shows the fuel consumption per unit time during engine running (see equation (28)). Graph L is a graph corresponding to power cost X. Further, points M1 to M3 indicate EV effect values. Note that the points M1 to M3 are the same as the points M1 to M3 described in FIG. 3(B).

Point M1 indicates that EV effect value Y is greater than power cost X. Point M2 indicates that EV effect value Y and power cost X are the same. Point M3 indicates that the EV effect value Y is smaller than the power cost X.

Further, the calculation unit 106 calculates the power cost based on the average power consumed in a plurality of past runs in the first mode. Therefore, the calculation unit 106 can calculate the power cost by suppressing the difference value of power consumption in multiple times in the past EV mode.

Furthermore, as explained in equation (29) and the like, the determining unit 108 determines whether or not to travel in the first mode using the reference cost calculated based on the engine state. Therefore, the determining unit 108 can more accurately determine whether or not to drive in the first mode.

[Power consumption during EV driving]
FIG. 7 is a diagram showing power consumption during one EV run. One EV run is, for example, a run in a period from when the engine 10 starts to stop to when the engine 10 starts completely. 7(A) shows the rotation of the engine 10, FIG. 7(B) shows the required running power, and FIG. 7(C) shows the power running power of the motor generator 20. In addition, in FIGS. 7(A) to 7(C), the horizontal axis indicates time. Furthermore, timing T11 is the timing at which stopping of the engine 10 is started, and timing T12 is the timing at which starting of the engine 10 is completed.

As shown in FIG. 7(A), at timing T11, the engine rotation speed gradually decreases from timing T11 when the engine 10 stop processing starts. Further, the engine rotation speed gradually increases from the time when the engine starting process is started.

As shown in FIG. 7(B), the required running power changes depending on the driving of the driver of the vehicle 1. As shown in FIG. 7(C), the power consumption in one EV run includes power E1, power E2, power E3, and power E4. Note that the electric power E4 is not shown in FIG.

Electric power E1 is electric power required to drive vehicle 1 in EV mode. Electric power E2 is the electric power required to crank the engine 10 by driving the starter 80 of the engine 10. Further, until the engine 10 is started and the torque reaches the required driving power, the motor generator 20 guarantees the torque. Electric power E3 is electric power necessary for motor generator 20 to ensure the torque. Power E4 is power consumed by the DCDC converter 23. Incidentally, cranking of the engine 10 may be realized by another device instead of the starter 80.

In this embodiment, power consumption in one EV run is expressed by the following equation (29).

Power consumption in one EV run = E1 + E2 + E3 + E4 (29)
At timing T12, when one EV drive is completed, the vehicle 1 stores the power consumption in one EV drive in the storage unit 104.

The engine 10 of this embodiment is a diesel engine. Therefore, even if the vehicle 1 is equipped with a diesel engine, it can be determined whether or not to run in the EV mode.

Additionally, diesel engines generally have a higher compression ratio than gasoline engines. The compression ratio is a ratio that indicates how much the air or air-fuel mixture in the engine cylinder is compressed by the rising piston. Therefore, the electric power required to crank the engine 10 is larger than that of a gasoline engine because each part of the diesel engine has a strong structure, which increases friction. Therefore, as shown in FIG. 7, the power consumption for one EV run used to calculate the power cost includes the cranking power E2 required for cranking the engine 10. Therefore, the calculation unit 106 can calculate the power cost based on the power consumption including the cranking power E2, which is larger than that of the gasoline engine. Therefore, the ECU 70 can calculate more accurate power costs.

[Vehicle flowchart]
FIG. 8 is a flowchart for explaining the operating method of the vehicle 1. First, in step S2, the ECU 70 determines whether an EV request has occurred. The ECU 70 executes the process in step S2 until an EV request is generated (NO in step S2). In step S2, if the ECU 70 determines that an EV request has occurred (YES in step S2), the process proceeds to step S4.

In step S4, the ECU 70 obtains the average power amount D. Next, in step S6, the ECU 70 calculates the power cost X using the above equation (26). Next, in step S8, the ECU 70 calculates the EV effect value Y based on the engine required power calculated by the above equation (29). Next, in step S10, the EV effect value Y and the power cost X are compared. In step S10, if the power cost X is less than or equal to the EV effect value Y (YES in step S10), the process proceeds to step S12. On the other hand, in step S10, if the power cost X is larger than the EV effect value Y (NO in step S10), the process of FIG. 8 ends.

In step S12, the ECU 70 detects the SOC of the battery 22 and determines whether the SOC is less than or equal to a threshold value. The threshold value is a predetermined value, for example, 20%. If the SOC is greater than or equal to the threshold (YES in step S12), the ECU 70 switches to EV mode in step S14. On the other hand, if the SOC is less than the threshold (NO in step S12), the process in FIG. 8 ends.

Even if the determination in step S10 is YES, the SOC of the battery 22 may be low. If EV driving is performed in a state where the SOC of the battery 22 is low, there is a high possibility that the electric power of the battery 22 will be exhausted. Furthermore, if the vehicle 1 is configured to forcibly switch to charging mode when the SOC of the battery 22 is low, there is a possibility that fuel efficiency will deteriorate. Therefore, if the SOC of the battery 22 is less than the threshold value, the vehicle 1 does not decide to drive in the EV mode (NO in step S12). Thereby, the vehicle 1 can run in the first mode so that the electric power in the battery is not exhausted.
[Modified example]
(1) In the above-described embodiment, the configuration is described in which the acquisition unit 102 acquires the average power amount D by acquiring a plurality of EV power consumptions stored in the storage unit 104. However, the acquisition unit 102 may acquire a plurality of EV power consumption values from an external server device or the like.

(2) In the above-described embodiment, the calculation unit 106 uses the average power amount D to calculate the EV effect value Y, as shown in equations (21) to (26). However, if the power consumption is based on the power consumed in one run in the past EV mode, the calculation unit 106 may calculate the EV effect value Y using other power consumption. . For example, the calculation unit 106 may use the EV power consumption most recently stored in the storage unit 104 among the plurality of EV power consumptions.

(3) In the above embodiment, the ECU 70 calculated the power cost X using equation (26). However, the ECU 70 may calculate the power cost X using other methods. For example, the ECU 70 calculates the cost based on the fuel amount G as the power cost X. For example, the charge for the amount of fuel G may be calculated as the power cost X.

Furthermore, the above-described embodiments and their modifications can be combined as appropriate.
The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

1 Vehicle, 15 Clutch, 21 Inverter, 22 Battery, 23 Converter, 28 Fuel Tank, 40 Automatic Transmission, 50 Drive Wheel, 80 Starter, 101 Judgment Unit, 102 Acquisition Unit, 104 Storage Unit, 106 Calculation Unit, 108 Determination Unit .

Claims (8)

A vehicle,
A battery that stores electricity,
a motor generator that generates power for the vehicle by consuming power stored in the battery;
an engine that generates power for the vehicle by consuming fuel;
comprising a control device that switches between a first mode in which the vehicle runs using the power of the motor generator and a second mode in which the vehicle runs using the power of the engine;
The motor generator is capable of generating electric power during driving switched to the second mode and then storing the electric power in the battery,
The control device includes:
When a request for traveling in the first mode occurs, acquiring power consumption based on power consumed in one past traveling in the first mode,
Calculating the power cost based on the fuel necessary for the motor generator to generate the power consumption in the second mode,
The vehicle determines whether to travel in the first mode based on a comparison between the electric power cost and a reference cost. The battery is
a first electric power generated by deceleration regeneration of the vehicle;
storing a second electric power generated in the second mode of driving;
The motor generator generates power for the vehicle by consuming the first electric power and the second electric power at the same rate when traveling in the first mode,
The control device calculates the power cost by dividing a first value by a second value,
The first value is
an amount of fuel necessary for the motor generator to generate the second power remaining in the battery in the second mode when the power consumption is assumed to have been consumed;
an additional value of the power consumption and the amount of fuel required for the motor generator to generate in the second mode;
The second value is
The vehicle according to claim 1, wherein the power consumption is an added value of the first power and the second power stored in the battery when the power consumption is not consumed. The standard cost is a value obtained by dividing the fuel reduction amount in the first mode by the power consumed by the motor generator in the first mode,
The control device includes:
determining to travel in the first mode when the power cost is less than or equal to the reference cost;
The vehicle according to claim 2, wherein the vehicle does not decide to run in the first mode if the power cost is greater than the reference cost. The control device includes:
The vehicle according to claim 2, wherein even if the power cost is below the reference cost, the vehicle does not decide to run in the first mode if the SOC of the battery is below a threshold value. The vehicle according to any one of claims 1 to 4, wherein the power consumption is an average power consumed in a plurality of past trips in the first mode. The vehicle according to any one of claims 1 to 5, wherein the engine is a diesel engine. The power consumption is
Electric power necessary to run the vehicle in the first mode;
6. The vehicle of claim 5, comprising: electrical power necessary to crank the engine. The vehicle according to any one of claims 1 to 7, wherein the reference cost is calculated based on the state of the engine when the engine outputs the requested running power of the vehicle.

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