Control Device for Electric Vehicle

Abstract

To provide an electric vehicle control device for favorable drivability without being affected by pressure before and after a throttle valve of an electric vehicle.SOLUTION: A control device 20 of an electric vehicle 1 can execute: first control to determine an opening of a throttle valve 2b on the basis of an air intake amount corresponding to a demand load for an internal combustion engine 2 and a coefficient corresponding to a ratio of pressure upstream of the throttle valve 2b to the pressure downstream thereof; and second control to determine the opening of the throttle valve 2b on the basis of the demand load and an actual load when the internal combustion engine 2 actually drives a first rotating electrical machine. The control device of the electric vehicle executes the first control when the demand load is less than a predetermined load and the second control when the demand load is equal to or larger than the predetermined load.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a control device for an electric vehicle.

Background Art

[0002] Conventionally, a control device for an electric vehicle having an internal combustion engine has been known (see, for example, Patent Document 1). The control device for the electric vehicle of Patent Document 1 has an internal combustion engine and a generator that can be driven by the internal combustion engine. In the control device for the electric vehicle of Patent Document 1, the shaft torque of the internal combustion engine is detected by the generator, and the flow rate characteristics of the throttle valve of the internal combustion engine are learned based on the shaft torque. Thereby, the intake air amount is calculated without using an air flow sensor for detecting the intake air amount.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the flow rate characteristics of the throttle valve also change depending on the pressure state before and after the throttle valve. For example, when the pressure upstream and downstream of the throttle valve approaches, the amount of air flowing downstream of the throttle valve decreases, thereby changing the flow rate characteristics of the throttle valve. In the control device for the electric vehicle of Patent Document 1, such pressure before and after the throttle valve is not considered. For this reason, depending on the pressure state before and after the throttle valve, the intake air amount may decrease and the drivability may deteriorate.

[0005] An object of the present disclosure is to provide a control device for an electric vehicle with good drivability without being affected by the pressure before and after the throttle valve.

Means for Solving the Problems

[0006] The control device for an electric vehicle according to the present disclosure is a control device for an electric vehicle having an internal combustion engine including a throttle valve and a first rotating electric machine driven by the internal combustion engine. The control device for an electric vehicle determines the intake Empty air volume corresponding to the required load required for the internal combustion engine and the coefficient corresponding to the ratio of the pressure upstream and downstream of the throttle valve, and performs a first control for determining the opening degree of the throttle valve based on these, and the required load, and the internal combustion engine actually drives the first rotating electric machine. And a second control for determining the opening degree of the throttle valve based on the actual load. When the required load is less than a predetermined load, the control device for an electric vehicle executes the first control, and when the required load is greater than or equal to the predetermined load, the control device executes the second control.

[0007] According to this control device for an electric vehicle, when the load is less than a predetermined load, the opening degree of the throttle valve is determined using the coefficient corresponding to the ratio of the pressure downstream and upstream of the throttle valve. On the other hand, when the load is greater than or equal to a predetermined load, the opening degree of the throttle valve is determined based on the required load and the actual load. As a result, it is possible to provide a control device for an electric vehicle with good drivability without being affected by the pressure before and after the throttle valve.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a control device for an electric vehicle with good drivability without being affected by the pressure before and after the throttle valve.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following specification, the front-rear direction of the vehicle is denoted as Q in the drawings, and the front is denoted as F. Also, the vehicle width direction of the vehicle is denoted as P in the drawings, and the right side as viewed from the rear of the vehicle is denoted as R. Further, the vertical direction of the vehicle is denoted as G in the drawings, and the upper side is denoted as U.

[0011] As shown in FIG. 1, the electric vehicle 1 according to the present embodiment is a four-wheel drive type plug-in hybrid electric vehicle (PHEV). The electric vehicle 1 includes an internal combustion engine (ENG) 2, a generator (an example of a first rotating electric machine: GEN) 4, a front motor (an example of a second rotating electric machine: FrM) 6, a rear motor (RM) 8, a drive battery (BT) 10, a control device (HVECU) 20, an accelerator pedal 21, and an external charging device 22. Further, in the present embodiment, the electric vehicle 1 is an electric vehicle 1 of an in-line engine type in which the crankshaft of the internal combustion engine 2 extends in the vehicle width direction.

[0012] In the electric vehicle 1 of the present embodiment, the front motor 6 drives the front wheel drive shaft 12a of the front wheels 12 via the transaxle 16. The rear motor 8 drives the rear wheel drive shaft 14a of the rear wheels 14 via the speed reducer 8c. The front motor 6 is connected to the drive battery 10 via the front inverter 18, and electric power (second electric power) is supplied from the drive battery 10.

[0013] The front inverter 18 includes a front motor control unit (FrMCU) 6a and a generator control unit (GCU) 4a that controls the generator 4. The front motor control unit 6a acquires a signal from the control unit 20 and controls the regeneration and power running of the front motor 6 so that the front motor 6 reaches a desired operating state. Similarly, the rear motor 8 is connected to the drive battery 10 via the rear inverter 8b, and power (second power) is supplied from the drive battery 10. The rear inverter 8b includes a rear motor control unit (RMCU) 8a. The rear motor control unit 8a acquires a signal from the control unit 20 and controls the regeneration and power running of the rear motor 8 so that the rear motor 8 reaches a desired operating state.

[0014] As shown in FIG. 2, the internal combustion engine 2 includes at least a throttle valve 2b, an intake manifold 2c, and an exhaust gas recirculation device 2d. The exhaust gas recirculation device 2d includes an exhaust circulation valve 2e and an exhaust circulation passage 2f. The exhaust gas recirculation device 2d is a device that circulates exhaust gas from the exhaust pipe 2g to the intake manifold 2c. The exhaust circulation valve 2e is a valve that adjusts the circulation amount of exhaust gas with respect to the intake air amount (hereinafter referred to as the EGR rate in the specification. EGR is an abbreviation for Exhaust Gas Recirculation). In the present embodiment, the internal combustion engine 2 is a gasoline engine with a multi-injection system. The internal combustion engine 2 injects fuel by a fuel injection valve 2h disposed in the intake manifold 2c and adjusts the output by adjusting the intake air amount by the throttle valve 2b. However, the internal combustion engine 2 may be a direct injection type gasoline engine that directly injects fuel into the cylinder 2j. Further, the internal combustion engine 2 may be a gasoline engine that combines the multi-injection system and the direct injection system. A pressure sensor 2i is provided in the intake manifold 2c to detect the pressure Pr in the intake manifold, which is the pressure downstream (behind the throttle valve 2b) of the throttle valve 2b. An air flow sensor (not shown) is provided upstream of the throttle valve 2b to detect the atmospheric temperature, atmospheric pressure, the intake pressure Pf, which is the pressure upstream (in front of the throttle valve 2b) of the throttle valve 2b, and the actual intake air amount Qr, etc.

[0015] The internal combustion engine 2 drives the generator 4 via the transaxle 16. The internal combustion engine 2 is driven by the combustion of fuel supplied from the fuel tank 23. Various devices and various sensors of the internal combustion engine 2 are electrically connected to the engine control unit (ENG-ECU) 2a. The engine control unit 2a acquires a signal from the control unit 20 and controls the internal combustion engine 2 to achieve a desired operating state.

[0016] In this embodiment, the engine control unit 2a acquires the engine required torque ETq (an example of the required load) from the control unit 20. When the engine control unit 2a acquires the engine required torque ETq, it calculates the target filling efficiency Ec. The target filling efficiency Ec is the amount of air filled with respect to the volume of the cylinder 2j. The engine control unit 2a acquires the atmospheric temperature detected by an air flow sensor (not shown) from the target filling efficiency Ec and calculates the target intake air amount Qt. The engine control unit 2a calculates the target throttle flow rate Qth from the target intake air amount Qt. The engine control unit 2a executes a first control for calculating the throttle opening ThO by multiplying the target throttle flow rate Qth by the throttle flow coefficient Kth. Note that the control procedure executed by the engine control unit 2a may be executed by the control unit 20.

[0017] FIG. 3 is a graph showing the throttle opening Th, the target filling efficiency Ec, the throttle flow coefficient, and the pressure ratio Pr / Pf before and after the throttle when the engine required torque ETq increases from time t0 to time t2 and decreases from time t3. The dashed line indicates the conventional control, and the solid line is the graph when the control procedure described later is executed. As shown in the graph of the pressure ratio Pr / Pf before and after the throttle in FIG. 3, as the engine required torque ETq increases, the pressure ratio Pr / Pf before and after the throttle valve 2b approaches 1. The throttle flow coefficient Kth is a coefficient showing the correlation between the target throttle flow rate Qth and the throttle opening ThO in accordance with the flow characteristics of the throttle valve 2b. As shown in the dashed line graph of the throttle flow coefficient Kth from time t1 to time t2 in FIG. 3, such a throttle flow coefficient Kth changes abruptly in slope immediately before the pressure ratio Pr / Pf before and after the throttle valve 2b approaches 1. An example of a state where the pressure ratio Pr / Pf before and after the throttle valve 2b is close to 1 is a state where the engine required torque ETq is high. Alternatively, it is a state where the EGR rate is high.

[0018] Thus, in the region where the pressure ratio Pr / Pf before and after the throttle valve 2b is equal to or higher than a predetermined pressure ratio Pt (for example, in the region where the predetermined torque Tqd described later is equal to or higher than), since the change in the throttle flow coefficient Kth is large, the throttle opening ThO cannot be determined using the throttle flow coefficient Kth. For this reason, in this region, the throttle flow coefficient Kth is maintained at a constant value, and open-loop control is executed without feedback control based on the pressure ratio Pr / Pf before and after. However, as shown in the graph of the charging efficiency Ec between time t1 and time t2 and between time t3 and time t4 in FIG. 3, when the throttle flow coefficient Kth is maintained at a constant value, a deviation occurs between the target charging efficiency Ec (solid line) calculated from the engine required torque ETq and the actual charging efficiency Ecr (dashed line) calculated from the air flow sensor. As shown in the dashed line graph of the throttle opening ThO at time t2 and time t4 in FIG. 3, when the deviation between the target charging efficiency Ec and the charging efficiency Ecr increases, the throttle valve 2b rapidly moves toward full open (opening 100%), or moves in the direction of rapidly closing from full open. As a result, the output of the internal combustion engine 2 fluctuates rapidly, and drivability deteriorates.

[0019] As shown in FIG. 1, the transaxle 16 amplifies the rotational vehicle speed of the internal combustion engine 2 and transmits it to the generator 4. Further, the transaxle 16 of the present embodiment has a clutch 16a. The clutch 16a transmits and interrupts power between the internal combustion engine 2 and the front motor 6 and between the internal combustion engine 2 and the front wheel drive shaft 12a. The internal combustion engine 2 is connected to the front wheel drive shaft 12a via the clutch 16a of the transaxle 16 and drives the front wheel drive shaft 12a.

[0020] The generator 4 is connected to the internal combustion engine 2 and generates electricity by being driven by the internal combustion engine 2. The electric power (first electric power) generated by the generator 4 can charge the driving battery 10 and can also be supplied to each motor via the front inverter 18 and the rear inverter 8b. In the present embodiment, the generator 4 is a motor generator, and in addition to generating electricity, it can crank or motor the internal combustion engine 2 by rotationally driving the internal combustion engine 2. When the generator 4 is driven by the internal combustion engine 2, it generates electricity by applying a load to the generator 4. On the other hand, the generator 4 drives the internal combustion engine 2 by being supplied with electric power from the driving battery 10 and performing power running to crank or motor it. The generator 4 is controlled by a generator control device 4a provided in the front inverter 18. The generator control device 4a is electrically connected to the control device 20, acquires a signal from the control device 20, and controls power generation and power running so that the generator 4 is in a desired operating state.

[0021] The driving battery 10 is composed of a secondary battery such as a lithium-ion battery and has a battery module (not shown) formed by combining a plurality of battery cells. The driving battery 10 functions as a power source for each motor. Further, the driving battery 10 has a battery monitoring unit (BMU) 10a. The battery monitoring unit (BMU) 10a calculates the state of charge (hereinafter referred to as SOC) of the battery module, detects the state of deterioration (state of health, hereinafter referred to as SOH) of the battery module, the voltage Bv of the battery module, and the battery temperature Btmp. The battery monitoring unit 10a acquires the voltage Bv, the state of charge SOC, the state of deterioration SOH, and the battery temperature Btmp of the driving battery 10 and transmits them to the control device 20.

[0022] The control device 20 executes at least control for switching the driving mode, power generation control for causing the internal combustion engine 2 to generate electricity in each driving mode, motoring control for driving the internal combustion engine 2 by the generator 4, and control for performing regenerative cooperative braking of the electric vehicle 1 using regenerative braking and friction braking.

[0023] In this embodiment, the control device 20 controls the clutch 16a based on information such as the vehicle speed V, the state of charge SOC, and the accelerator opening AO, thereby switching to one of the series mode (an example of the series driving mode and the first driving mode), the parallel mode (an example of the parallel driving mode and the second driving mode), and the EV mode (an example of the EV driving mode and the third driving mode).

[0024] As shown in FIG. 4, the control device 20 switches between the EV mode, the series mode, and the parallel mode based on the driver required torque DTq (load) and the vehicle speed V. For example, when the driver required torque DTq increases, the control device 20 switches from the EV mode to the series mode. When the control device 20 switches from the series mode to the parallel mode, it switches when the driver required torque DTq increases or when the vehicle speed V increases.

[0025] In the parallel mode, the control device 20 connects the clutch 16a and drives the front wheel drive shaft 12a by both the internal combustion engine 2 and the front motor 6. At this time, either one or both of the electric power from the drive battery 10 (the second electric power) and the electric power generated by the generator 4 (the first electric power) are supplied to the front motor 6. Similarly, either one or both of the electric power from the drive battery 10 (the second electric power) and the electric power generated by the generator 4 (the first electric power) are supplied to the rear motor 8 to drive the rear wheel drive shaft 14a. In the EV mode, the control device 20 releases the clutch 16a, supplies the electric power of the drive battery 10 (the second electric power) to each motor, and each motor drives the front wheel drive shaft 12a and the rear wheel drive shaft 14a (hereinafter referred to as each drive shaft in the specification).

[0026] In series mode, the control device 20 releases the clutch 16a, drives the generator 4 with the internal combustion engine 2, and supplies the first electric power generated by the generator 4 to each motor. Also, when the driving force for each motor to drive each drive shaft is insufficient depending on the first electric power, the second electric power is also supplied from the driving battery 10 to each motor. Note that in the parallel mode and the series mode, the driving battery 10 may be charged by supplying part of the generated electric power generated by the internal combustion engine 2 to the driving battery 10.

[0027] The control device 20 is actually constituted by a microcomputer including an arithmetic unit, a memory, an input / output buffer, etc. The control device 20 controls each device so that the electric vehicle 1 is in a desired operating state based on signals from each sensor and various devices, and maps and programs stored in the memory.

[0028] Also, in the present embodiment, various control devices including the engine control device 2a, the generator control device 4a, the front motor control device 6a, the rear motor control device 8a, and the battery monitoring unit 10a are provided separately from the control device 20. The various control devices are each electrically connected to the control device 20. However, the various control devices may be provided integrally with the control device 20. The various control devices are constituted by a microcomputer including an arithmetic unit, a memory, an input / output buffer, etc., similarly to the control device 20.

[0029] As shown in FIG. 1, the accelerator pedal 21 is a pedal for controlling the acceleration and deceleration of the electric vehicle 1 by being depressed by the driver of the electric vehicle 1. The accelerator pedal 21 is provided with an accelerator position sensor 21a for detecting the depressed position. The accelerator position sensor 21a is electrically connected to the control device 20 and transmits the accelerator depression position (accelerator opening AO) to the control device 20. The control device 20 calculates the driver required torque (an example of the driver required output) DTq from the accelerator opening AO.

[0030] The external charging device 22 is a device that charges the power of the drive battery 10 from an external power source of the electric vehicle 1 (hereinafter referred to as external charging in the specification). The external charging device 22 receives power supply from, for example, charging facilities outside the electric vehicle 1. The external charging device 22 converts the power supplied from the external power source into power suitable for charging the drive battery 10 and charges the drive battery 10.

[0031] Next, the control procedure of the control device 20 of the present embodiment will be described using the flowchart of FIG. 5. Note that the following control procedure may be executed using not only the control device 20 but also the engine control device 2a. However, in the present embodiment, the case where the control device 20 executes the control procedure will be described. The control device 20 starts the control operation when an ignition switch (not shown) is turned on.

[0032] In step S1, the control device 20 acquires the EGR rate. The EGR rate is the ratio of the exhaust gas recirculation amount to the intake air amount. By acquiring the EGR rate in step S1, the control device 20 changes a predetermined torque Tqd described later. Specifically, the higher the EGR rate, the smaller the predetermined torque Tdq. As the EGR rate increases, the front-rear pressure ratio Pr / Pf tends to increase. Therefore, the control device 20 decreases the predetermined torque Tdq as the EGR rate increases, and induces the second control described later. Thereby, it is easy to suppress the execution of the open-loop control of the first control. As a result, the control accuracy is improved. When the control device 20 acquires the EGR rate, the process proceeds to step S2.

[0033] In step S2, the control device 20 determines whether the engine required torque ETq is equal to or greater than a predetermined torque (an example of a predetermined load) Tqd. The predetermined torque Tqd is the torque at which the pressure ratio Pr / Pf across the throttle valve 2b becomes equal to or greater than a predetermined pressure ratio Pt. The predetermined pressure ratio Pt is, for example, a value of 0.95 or greater. As shown in the broken line graph of the throttle flow coefficient Kth from time t1 to time t2 in FIG. 3 as described above, such a throttle flow coefficient Kth has a sharp change in slope immediately before the pressure ratio Pr / Pf across the throttle valve 2b approaches 1. Also, as shown in the broken line graph of the throttle flow coefficient Kth from time t3 to time t4 in FIG. 3, when the engine required torque ETq decreases, similar to when the engine required torque ETq increases, the change in the slope of the throttle flow coefficient Kth is large when the pressure ratio Pr / Pf across the throttle valve 2b is high. Therefore, the control device 20 determines that the engine required torque ETq is equal to or greater than the predetermined torque Tqd until the engine required torque ETq becomes less than the value of the predetermined torque Tdq in both cases where the engine required torque ETq increases and decreases.

[0034] As shown in FIG. 5, when the engine required torque ETq is less than the predetermined torque Tqd (step S2 NO), the control device 20 proceeds to step S3 and executes the first control. The first control is a control for calculating the throttle opening ThO by multiplying the throttle flow coefficient Kth by the target throttle flow Qth as described above. When the engine required torque ETq is equal to or greater than the predetermined torque Tqd (step S2 YES), the control device 20 proceeds to step S4.

[0035] In step S4, the control device 20 determines whether it is in the series mode. In the parallel mode of the electric vehicle 1 of the present embodiment, the output shaft of the internal combustion engine 2 is connected to the front wheel drive shaft 12a. Therefore, in addition to the generator 4, the internal combustion engine 2 distributes the shaft output to the drive shaft. As a result, in the parallel mode, it is difficult to detect the actual torque (an example of the actual load), which is the shaft torque of the output shaft of the internal combustion engine 2, by the generator 4. Therefore, the control device 20 proceeds to step S5 only when it determines that it is in the series mode (step S4 YES).

[0036] In step S5, the control device 20 calculates and stores the absolute value of the difference between the engine required torque ETq and the actual torque Tr. The control device 20 determines whether the absolute value of the difference is greater than zero. The control device 20 detects the shaft torque of the output shaft of the internal combustion engine 2 by the generator 4 and calculates the actual torque Tr. Specifically, the control device 20 calculates the actual torque Tr from the power generation amount of the generator 4 driven by the internal combustion engine 2.

[0037] The control device 20 determines the presence or absence of a deviation between the target filling efficiency Ec and the actual filling efficiency Ecr by determining whether the absolute value of the difference between the engine required torque ETq and the actual torque Tr is greater than zero (step S5). When there is a deviation (step S5 YES), the control device 20 proceeds to step S6. In step S6, the control device 20 executes a second control for determining the throttle opening ThO based on the difference between the engine required torque ETq and the actual torque Tr. Specifically, when executing the second control, the control device 20 acquires the atmospheric temperature detected by an air flow sensor (not shown) from the target filling efficiency Ec and calculates the target intake air amount Qt. The control device 20 calculates the target throttle flow rate Qth from the target intake air amount Qt. The control device 20 stores in advance the throttle opening ThO corresponding to the difference between the engine required torque ETq and the actual torque Tr for this target throttle flow rate Qth, and controls the throttle valve 2b so that the throttle opening ThO corresponding to the difference is obtained.

[0038] The solid line graph of the coefficient Kd from time t1 to time t2 and from time t3 to time t4 in FIG. 3 is a coefficient determined according to the difference between the engine required torque ETq and the actual torque Tr. The coefficient Kd is a value that approaches 0 as the difference between the engine required torque ETq and the actual torque Tr increases, and is a coefficient that has no correlation with the pressure ratio Pr / Pf before and after, unlike the throttle flow coefficient Kth. In the present embodiment, the control device 20 determines the throttle opening ThO by multiplying the coefficient Kd by the target throttle flow rate Qth instead of the throttle flow coefficient Kth. However, the control device 20 may determine the throttle opening ThO, for example, by calculating the difference between the engine required torque ETq and the actual torque Tr and adding or subtracting this difference from the engine required torque ETq. In this way, the control device 20 executes the second control using the coefficient Kd determined according to the difference between the engine required torque ETq and the actual torque Tr in the region that was open-loop control in the first control. As a result, the control device 20 can change the region that was open-loop control to a feedback control region. Therefore, as shown in the solid line graph of the throttle opening ThO from time t1 to time t2 and from time t3 to time t4 in FIG. 3, the throttle valve 2b gradually opens according to the difference between the engine required torque ETq and the actual torque Tr. As a result, without being affected by the pressure ratio Pr / Pf before and after, the actual filling efficiency Ecr can be made close to the target filling efficiency Ec. Thereby, sudden fluctuations in the output of the internal combustion engine 2 are suppressed, and drivability is improved. When the control device 20 executes the second control, the process returns to step S1 and the control procedure is repeated.

[0039] In step S4, when the control device 20 determines that it is not in the series mode (step S4 NO), the process proceeds to step S7. In step S7, the control device 20 determines whether it is in the parallel mode. When the control device 20 determines that it is in the parallel mode (step S7 YES), the process proceeds to step S8, where the second control is prohibited and the first control is executed. In the present embodiment, the control device 20 uniformly prohibits the second control in the parallel mode. However, the control device 20 may prohibit the second control only when it has transitioned from the series mode to the parallel mode as a result of an increase in the driver required torque DTq (see the arrow in (i) of FIG. 4). As described above, in the parallel mode, it is difficult to detect the actual torque Tr. In particular, when the engine required torque ETq increases due to an increase in the driver required torque DTq, the calculation of the distributed torque to the drive shaft becomes more complicated compared to the case where the driver required torque DTq is constant, and it becomes difficult to detect the actual torque Tr. Therefore, the control device 20 may prohibit the second control and execute the first control by open-loop control that maintains, for example, the throttle flow coefficient Kth. On the other hand, when transitioning from the series mode to the parallel mode when the driver required torque DTq is constant (see (ii) of FIG. 4), since the control device 20 can easily calculate the torque distributed to the drive shaft 12a, the control device 20 may detect the actual torque Tr and continue the second control.

[0040] Further, the control device 20 may correct the engine required torque ETq during the parallel mode based on the difference between the engine required torque ETq and the actual torque Tr recorded during the second control in the series mode. In the present embodiment, for example, a coefficient Kd based on the engine required torque ETq and the actual torque Tr is stored during the second control. When the torque Tqd or more during the parallel mode, the first control by the open loop control maintaining this coefficient Kd is executed. Thereby, the throttle opening ThO becomes an opening reflecting the difference between the engine required torque ETq and the actual torque Tr during the second control. As a result, even in the parallel mode during the first control, the throttle opening ThO can be determined reflecting the difference between the engine required torque ETq and the actual torque Tr. In addition, the control device 20 may add or subtract the difference between the engine required torque ETq and the actual torque Tr during the second control to / from the engine required torque ETq during the parallel mode as it is, and determine the throttle opening ThO using the first control. Also by this, the throttle opening ThO taking into account the difference between the engine required torque ETq and the actual torque Tr recorded during the second control can be determined. After performing the process of step S8, the control device 20 proceeds to the process of step S9.

[0041] In step S9, the control device 20 prohibits the exhaust gas recirculation. When performing the first control, the front-rear pressure ratio Pr / Pf tends to increase due to the exhaust gas recirculation. The control device 20 preferably suppresses the front-rear pressure ratio Pr / Pf in the first control in the parallel mode and executes the first control in the feedback control region (the region where the front-rear pressure ratio Pr / Pf is smaller than the predetermined pressure ratio Pt). For this reason, the control device 20 prohibits the exhaust gas recirculation, returns the process to step S1, and enables the first control to be executed in the feedback region (step S2 NO, step S3). Note that when the control device 20 is not in the parallel mode in step S7 (step S7 NO), the process returns to step S1.

[0042] As described above, according to the present disclosure, it is possible to provide the control device 20 of the electric vehicle 1 with good drivability without being affected by the front-rear pressure Pr / Pf of the throttle valve 2b.

[0043] <Other embodiments> As described above, the embodiments of the present disclosure have been explained. However, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the gist of the invention. In particular, a plurality of modifications described in this specification can be arbitrarily combined as needed.

[0044] (a) In the above embodiment, a four-wheel drive type plug-in hybrid vehicle has been described as an example. However, the present disclosure is not limited thereto. The electric vehicle 1 may be a front-wheel drive hybrid type and plug-in hybrid type vehicle. Further, the electric vehicle 1 may be a four-wheel drive hybrid vehicle.

[0045] (b) In the above embodiment, an example in which the control device 20 executes all control procedures has been described. However, the present disclosure is not limited thereto. A part of the control procedures of the control device 20 may be executed by the engine control device 2a.

Explanation of reference numerals

[0046] 1: Electric vehicle 2: Internal combustion engine 2b: Throttle valve 2d: Exhaust gas recirculation device 4: Generator (an example of the first rotating electrical machine) 6: Front motor (an example of the second rotating electrical machine) 20: Control device

Claims

1. A control device for an electric vehicle having an internal combustion engine including a throttle valve and a first rotating electric machine driven by the internal combustion engine, a first control for determining an opening degree of the throttle valve based on an intake air amount corresponding to a required load required for the internal combustion engine and a coefficient corresponding to a ratio of a pressure upstream of the throttle valve to a pressure downstream of the throttle valve, a second control for determining an opening degree of the throttle valve based on the required load and an actual load at which the internal combustion engine actually drives the first rotating electric machine, comprising: when the required load is less than a predetermined load, executing the first control; when the required load is greater than or equal to the predetermined load, executing the second control, a control device for an electric vehicle.

2. The electric vehicle has a second rotating electric machine that drives a drive shaft, and the control device for the electric vehicle has a first driving mode in which the internal combustion engine drives the first rotating electric machine to generate electricity and supplies the generated electricity to the second rotating electric machine to cause the electric vehicle to travel, and a second driving mode in which the internal combustion engine drives the drive shaft, further comprising: even when the load is greater than or equal to the predetermined load, in the case of the second driving mode, prohibiting the second control, The control device for an electric vehicle according to claim 1.

3. When switching from the first driving mode to the second driving mode, correcting the required load in the second driving mode based on a difference between the actual load and the required load stored during the second control, The control device for an electric vehicle according to claim 2.

4. The internal combustion engine includes an exhaust gas recirculation device that recirculates exhaust gas discharged from the internal combustion engine, and the control device for the electric vehicle when prohibiting the second control, prohibits recirculation of exhaust gas by the exhaust gas recirculation device, The control device for an electric vehicle according to any one of claims 1 to 3.

5. The predetermined load changes according to a ratio of the amount of exhaust gas recirculated by the exhaust gas recirculation device to the intake air amount, The control device for an electric vehicle according to claim 4.

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