Hybrid vehicle

Abstract

Provided is a hybrid vehicle capable of reducing the discomfort to a user caused by fluctuations in engine speed during waste power control.　This hybrid vehicle Ve capable of traveling by supplying the power generated by a power generation motor GEN from an output of an engine ENG and the power of a battery to a main drive motor MOT1 comprises: a pseudo gear shift control unit (100) that determines an engine speed Ne for a vehicle speed on the basis of a pseudo gear set on the basis of the vehicle speed and an accelerator opening degree; and a waste power control unit (110) that rotates the engine ENG by means of the power generation motor GEN to execute waste power control for consuming surplus power that cannot be stored in the battery BAT. When executing the waste power control, the waste power control unit (110) controls the power generation motor GEN so that the engine speed Ne is based on the pseudo gear.

Description

Hybrid vehicles

[0001] The present invention relates to hybrid vehicles.

[0002] Conventionally, hybrid vehicles capable of so-called series running, in which a motor drives the drive wheels and an engine drives a generator, are known. In series running, the engine speed is controlled regardless of the user's intention, which can cause discomfort to users accustomed to engine-driven vehicles. As a means for suppressing such discomfort, for example, Patent Document 1 (JP-A-2005-102226) describes a series-type hybrid vehicle in which a target engine speed simulating a transmission is determined based on an accelerator operation amount indicating the user's intention to accelerate or decelerate, and the generator is driven based on the determined target engine speed.

[0003] Japanese Patent Application Publication No. 2010-173389

[0004] In series running, the electric power generated by the generator and the regenerative electric power obtained through regenerative operation are charged to the battery, but if the battery is fully charged, for example, a power-waste control may be performed in which the regenerative electric power is not charged to the battery but the engine is idled by the generator to consume the electric power. However, even when the engine is controlled in this power-waste control, the engine and the drive wheels are controlled in a separated state, so fluctuations in engine speed due to engine control may be uncomfortable for the user.

[0005] The present invention provides a hybrid vehicle that can reduce the discomfort felt by the user due to fluctuations in engine speed during electricity waste control.

[0006] One aspect of the present invention is a hybrid vehicle that can run by supplying power generated by a generator motor using engine output and power from a battery to a traction motor, and is equipped with: a pseudo-speed control unit that determines the engine speed for a vehicle speed based on a pseudo-speed stage that is set based on the vehicle speed and accelerator opening; and a power dissipation control unit that performs power dissipation control to consume surplus power that cannot be stored in the battery by rotating the engine using the generator motor, and when performing the power dissipation control, the power dissipation control unit controls the generator motor so that the engine speed is based on the pseudo-speed stage.

[0007] According to the present invention, it is possible to reduce the discomfort felt by the user due to fluctuations in engine speed during electricity waste control.

[0008] FIG. 1 is a schematic diagram showing an example of the configuration of a vehicle Ve. FIG. 2 is a block diagram showing an example of a control unit ECU. FIG. 3 is a diagram showing an example of a shift map for downshifting when traveling in normal mode. FIG. 4 is a diagram showing an example of a shift map for upshifting when traveling in normal mode. FIG. 5 is a diagram showing an example of a shift map for downshifting when traveling in sport mode. FIG. 6 is a diagram showing an example of a shift map for upshifting when traveling in sport mode. FIG. 7 is a diagram showing an example of a shift map for determining the engine speed Ne when normal control is performed when traveling on a flat road in normal mode. FIG. 8 is a diagram showing an example of a shift map for determining the engine speed Ne when power-discharge control is performed when traveling on a flat road in normal mode. FIG. 9 is a diagram showing an example of a shift map for determining the engine speed Ne when normal control is performed when traveling on a downhill road in normal mode. FIG. 10 is a diagram showing an example of a shift map for determining the engine speed Ne when power-discharge control is performed when traveling on a downhill road in normal mode. FIG. 11 is a diagram showing an example of a shift map for determining the engine speed Ne when normal control is performed while traveling on a flat road in sport mode. FIG. 12 is a diagram showing an example of a shift map for determining the engine speed Ne when power-discharge control is performed while traveling on a flat road in sport mode. FIG. 13 is a diagram showing an example of a shift map for determining the engine speed Ne when normal control is performed while traveling on a downhill road in sport mode. FIG. 14 is a diagram showing an example of a shift map for determining the engine speed Ne when power-discharge control is performed while traveling on a downhill road in sport mode. FIG. 15 is a diagram for explaining an example of an increase rate of the engine speed Ne when the engine speed Ne is controlled to avoid the resonance band region during an upshift. FIG. 16 is a diagram for explaining an example of a decrease rate of the engine speed Ne when the engine speed Ne is controlled to avoid the resonance band region during a downshift. FIG. 17 is a diagram showing an example of the torque characteristics of the main drive motor MOT1.Fig. 18 is a flowchart for explaining an example of a control executed in the embodiment. Fig. 19 is a diagram showing another example of a shift map for determining the engine speed Ne when power waste control is executed in the normal mode and the sport mode. Fig. 20 is a flowchart for explaining another example of a control executed in the embodiment.

[0009] An embodiment will be described below with reference to the drawings. The following embodiment does not limit the present invention, and not all of the elements described in the following embodiment are necessarily essential to the present invention. Furthermore, two or more elements described in the following embodiment may be arbitrarily combined without departing from the spirit of the present invention. Note that, below, identical or similar elements are denoted by the same or similar reference numerals, and their description may be omitted or simplified.

[0010] [Vehicle] The vehicle targeted in the embodiment is a hybrid vehicle (hereinafter simply referred to as "vehicle") capable of so-called series running. As shown in FIG. 1 , the vehicle Ve in the embodiment includes a main drive unit DU1 and a subordinate drive unit DU2 that are mechanically independent. Here, "mechanically independent" means that power from one unit is not mechanically transmitted to the other unit by a propeller shaft or the like. In the embodiment, the main drive unit DU1 outputs a main drive force to drive the front wheels FWR, and the subordinate drive unit DU2 outputs a subordinate drive force to drive the rear wheels RWR.

[0011] As an example, in this embodiment, the main drive unit DU1 is positioned as the main drive source for the vehicle Ve, and the secondary drive unit DU2 is positioned as the secondary drive source, with a relatively large motor being used as the main drive motor MOT1 for the main drive unit DU1, and a motor smaller in size than the main drive motor MOT1 being used as the secondary drive motor MOT2 for the secondary drive unit DU2.

[0012] The vehicle Ve further includes a battery BAT, a voltage control unit VCU, and a control unit ECU.

[0013] The battery BAT is a rechargeable secondary battery that has multiple storage cells connected in series or series-parallel. The battery BAT is configured to be able to output a high voltage of, for example, 100 to 400 V. The storage cells of the battery BAT can be lithium-ion batteries, nickel-metal hydride batteries, or the like.

[0014] The voltage control unit VCU boosts the output voltage from the battery BAT while it remains DC, and outputs the boosted voltage to the main drive unit DU1 and the sub drive unit DU2. In other words, in the vehicle Ve, the boosted voltage generated by a single voltage control unit VCU can be supplied in common to both the main drive unit DU1 and the sub drive unit DU2. The voltage control unit VCU may also step down the input voltage input to the battery BAT. The voltage control unit VCU is, for example, a DC-DC converter.

[0015] [Main Drive Unit] The main drive unit DU1 includes an engine ENG, a generator motor GEN, a main drive motor MOT1 (an example of a traction motor), a first inverter INV1, a second inverter INV2, and a first transmission mechanism T1. The main drive motor MOT1 and the generator motor GEN are connected to a battery BAT via a voltage control unit VCU, the first inverter INV1, and the second inverter INV2, enabling power supply from the battery BAT and energy regeneration to the battery BAT. Note that dotted lines in FIG. 1 indicate power wiring, and dashed lines indicate control signal lines.

[0016] The first inverter INV1 converts DC voltage into AC voltage and supplies three-phase current to the generator motor GEN. The first inverter INV1 also converts AC voltage generated by the generator motor GEN into DC voltage.

[0017] The second inverter INV2 converts DC voltage to AC voltage and supplies three-phase current to the main drive motor MOT1. The second inverter INV2 also converts AC voltage generated by the main drive motor MOT1 during braking of the vehicle Ve into DC voltage.

[0018] The first speed change mechanism T1 includes an input shaft 21, a generator motor shaft 23, and a counter shaft 25 arranged parallel to one another, and a first differential mechanism D1.

[0019] The input shaft 21 is arranged coaxially with the crankshaft 12 of the engine ENG. Power from the crankshaft 12 is transmitted to the input shaft 21 via a damper 13. The input shaft 21 is provided with an output gear 32 that constitutes a gear train for driving a generator motor, which will be described later.

[0020] An output gear 53, which constitutes an engine power transmission gear train that transmits power from the engine ENG, is provided on the input shaft 21 on the side opposite to the engine ENG side. A hydraulic clutch CL is provided between the output gear 32 on the input shaft 21 and the output gear 53 to engageably and disengageably connect the input shaft 21 and the output gear 53.

[0021] The generator motor shaft 23 is a rotating shaft with a dual structure, including an inner shaft 27 and an outer shaft 29 that is concentric with and disposed on the outer side of the inner shaft 27. An input gear 34 that meshes with an output gear 32 on the input shaft 21 is provided on the engine ENG side of the inner shaft 27. The output gear 32 on the input shaft 21 and the input gear 34 on the inner shaft 27 form a generator motor drive gear train that transmits the power of the input shaft 21 to the inner shaft 27.

[0022] An outer shaft 29 is rotatably mounted on the outer diameter side of the approximate center of the inner shaft 27. A generator motor GEN is attached to the inner shaft 27 on the side opposite the engine ENG. The generator motor GEN includes a rotor R fixed to the inner shaft 27 and a stator S fixed to a case (not shown) and disposed opposite the outer diameter side of the rotor R.

[0023] The driving force of the input shaft 21 is transmitted to the inner shaft 27 of the generator motor shaft 23 via a gear train for driving the generator motor, and the rotor R of the generator motor GEN rotates with the rotation of the inner shaft 27. This allows the driving force from the input shaft 21 to be converted into electric power by the generator motor GEN.

[0024] An output gear 52 that meshes with an input gear 54 on the countershaft 25 (described later) is provided on the engine ENG side of the outer shaft 29, and a main drive motor MOT1 is attached to the opposite side to the engine ENG side. The main drive motor MOT1 is configured to include a rotor R fixed to the outer shaft 29 and a stator S that is fixed to a case (not shown) and disposed opposite the outer diameter side of the rotor R.

[0025] The output gear 52 on the outer shaft 29 and the input gear 54 on the counter shaft 25 constitute a motor power transmission gear train for transmitting the power of the outer shaft 29 to the counter shaft 25. Therefore, when the outer shaft 29 is rotated by the driving force of the main drive motor MOT1, the rotation is transmitted to the counter shaft 25 via the motor power transmission gear train.

[0026] The countershaft 25 is provided with, in order from the engine ENG side, an output gear 56 that meshes with a ring gear 58 of the first differential mechanism D1, and an input gear 54 that meshes with the output gear 53 on the input shaft 21 and the output gear 52 on the outer circumferential shaft 29. The output gear 53 on the input shaft 21 and the input gear 54 on the countershaft 25 form an engine power transmission gear train for transmitting the power of the input shaft 21 to the countershaft 25. In addition, the output gear 56 on the countershaft 25 and the ring gear 58 of the first differential mechanism D1 form a final gear train for transmitting the driving force of the countershaft 25 to the first differential mechanism D1.

[0027] The driving force of the main drive motor MOT1 input to the counter shaft 25 via the motor power transmission gear train, and the driving force of the engine ENG input to the counter shaft 25 via the engine power transmission gear train are output as the main driving force of the main drive unit DU1, transmitted to the first differential mechanism D1 via the final gear train, and transmitted from the first differential mechanism D1 to the front wheels FWR.

[0028] The first transmission mechanism T1 of the main drive unit DU1 in this embodiment includes a first transmission mechanism 41 that connects the generator motor GEN and the engine ENG so that power can be transmitted between them, and a second transmission mechanism 42 that connects the main drive motor MOT1 and the front wheels FWR so that power can be transmitted between them. That is, the first transmission mechanism 41 is made up of the input shaft 21, the output gear 32, the input gear 34, and the inner peripheral shaft 27, while the second transmission mechanism 42 is made up of the outer peripheral shaft 29, the output gear 52, the input gear 54, the countershaft 25, the output gear 56, and the first differential mechanism D1.

[0029] The hydraulic clutch CL selectively switches between a state in which the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is connected and a state in which the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is disconnected. That is, by engaging the hydraulic clutch CL, the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is connected, and by disengaging the hydraulic clutch CL, the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is disconnected. In the first speed change mechanism T1, the input gear 54 meshes with the output gear 53 on the input shaft 21 and the output gear 52 on the outer circumferential shaft 29. Therefore, when the hydraulic clutch CL is engaged, the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42 is connected, enabling power transmission between the first transmission mechanism 41 and the second transmission mechanism 42. On the other hand, when the hydraulic clutch CL is released, the output gear 53 disengages from the input shaft 21, cutting off the power transmission path between the first transmission mechanism 41 and the second transmission mechanism 42, and power transmission between the first transmission mechanism 41 and the second transmission mechanism 42 becomes impossible.

[0030] [Sub drive unit] The sub drive unit DU2 includes a sub drive motor MOT2, a third inverter INV3, and a second transmission mechanism T2. The sub drive motor MOT2 is connected to the battery BAT via the voltage control unit VCU and the third inverter INV3, and is capable of receiving power from the battery BAT and regenerating energy back into the battery BAT. In FIG. 1, dotted lines indicate power wiring, and dashed lines indicate control signal wiring.

[0031] The second speed change mechanism T2 includes a motor output shaft 26 and an output shaft 28 arranged parallel to each other, and a second differential mechanism D2.

[0032] In the slave drive unit DU2, a third drive gear 62 is attached to one end of the motor output shaft 26 of the slave drive motor MOT2 so as to rotate integrally therewith, and a third driven gear 64 that meshes with the third drive gear 62 and an output gear 66 are attached to an output shaft 28 that extends parallel to the motor output shaft 26 of the slave drive motor MOT2 so as to rotate integrally with the output shaft 28. Therefore, the driving force of the slave drive motor MOT2 is transmitted to the output shaft 28 via the third drive gear 62 and the third driven gear 64, and the driving force transmitted to the output shaft 28 is transmitted from the output gear 66 to the rear wheels RWR via the second differential mechanism D2. Conversely, the driving force from the rear wheels RWR is transmitted to the slave drive motor MOT2 via the second differential mechanism D2, the output gear 66, the output shaft 28, the third driven gear 64, the third drive gear 62 and the motor output shaft 26.

[0033] [Drive Modes of Main Drive Unit] Next, the drive modes of the main drive unit DU1 will be described.

[0034] The drive modes of the main drive unit DU1 include an electric drive mode in which the drive force of the main drive motor MOT1 is output as the main drive force, and an engine drive mode in which the drive force of the engine ENG is output as the main drive force. In the electric drive mode, the hydraulic clutch CL is disengaged and the drive force of the main drive motor MOT1 is output as the main drive force. The electric drive mode includes EV running and series running, which will be described later. In the engine drive mode, the hydraulic clutch CL is engaged and the drive force of the engine ENG is output as the main drive force. The engine drive mode includes engine running, which will be described later.

[0035] <EV Travel (Electric Power Drive Mode)> In EV travel, the engine ENG is in a non-operating state, and the main drive motor MOT1 is driven by electric power supplied from the battery BAT. That is, by driving the main drive motor MOT1 with electric power supplied from the battery BAT, the outer circumferential shaft 29 of the generator motor shaft 23 is rotated by the driving force of the main drive motor MOT1, and the rotation is transmitted to the countershaft 25 via the motor power transmission gear train. The driving force of the main drive motor MOT1 transmitted in this manner is output as main driving force via the final gear train and the first differential mechanism D1 and transmitted to the front wheels FWR. This enables EV travel.

[0036] <Series Travel (Electric Power Drive Mode)> In series travel, the engine ENG is operated, and the main drive motor MOT1 is driven by electric power generated by the generator motor GEN. That is, the driving force of the engine ENG is input from the input shaft 21 to the inner shaft 27 via the generator motor drive gear train, causing the inner shaft 27 to rotate. This causes the rotor R of the generator motor GEN, which is fixed to the inner shaft 27, to rotate, causing the generator motor GEN to generate electricity. The electric power generated by the generator motor GEN is supplied to the main drive motor MOT1, which drives the main drive motor MOT1. The driving force of the main drive motor MOT1 rotates the outer shaft 29 of the generator motor shaft 23, and the rotation is transmitted to the countershaft 25 via the motor power transmission gear train. The driving force of the main drive motor MOT1 transmitted in this way is output as the main driving force via the final gear train and the first differential mechanism D1 and is transmitted to the front wheels FWR. This enables so-called series running, in which all of the driving force of the engine ENG is converted into electricity by the generator motor GEN.

[0037] During deceleration, the vehicle Ve performs regenerative running, recovering energy through the regenerative operation of the main drive motor MOT1. While the regenerated power is normally stored in the battery BAT, for example, when continuously traveling downhill, the battery BAT may reach full charge, making it impossible to charge the battery BAT. In such cases, the regenerated power is consumed through waste power control (hereinafter simply referred to as "waste power control"), which consumes the surplus power that cannot be stored in the battery BAT. For example, in waste power control, the regenerated power of the main drive motor MOT1 is not charged to the battery BAT but is supplied to the generator motor GEN, which is then powered to idle the engine ENG, i.e., to drive the engine ENG, thereby consuming the regenerated power. Note that "fully charged" does not necessarily mean 100% of the battery capacity, but may be defined as any remaining charge, such as 80% to 90% of the battery capacity, taking into consideration the deterioration and durability of the battery BAT, for example.

[0038] <Engine Running (Engine Drive Mode)> In engine running, the hydraulic clutch CL is engaged, and the driving force of the engine ENG is output as the main driving force and transmitted to the front wheels FWR. That is, by engaging the hydraulic clutch CL, the driving force of the input shaft 21 is transmitted to the countershaft 25 via the engine power transmission gear train, and then to the front wheels FWR via the final gear train and the first differential mechanism D1. This enables engine running. Here, the input shaft 21 and the inner shaft 27 are constantly connected via the generator motor drive gear train, so that the rotor R of the generator motor GEN rotates as the inner shaft 27 rotates. Therefore, the generator motor GEN can generate electricity, which rotates the main drive motor MOT1. This allows for so-called parallel running, in which the driving force of the engine ENG and the driving force of the main drive motor MOT1 are output as the main driving force.

[0039] The vehicle Ve can also be set to two driving modes that change the driving force characteristics: a sport mode that improves acceleration / deceleration response and steering response, and a normal mode that emphasizes the balance between steering operability and acceleration. Setting and switching between the sport mode and normal mode is performed by, for example, the user operating an operation switch (not shown).

[0040] [Control Unit] The control unit ECU is a computer that controls the entire vehicle Ve, and includes, for example, a processor that performs various calculations, a storage unit having a non-transitory storage medium that stores various information such as predetermined maps and programs, an input / output unit (none of which are shown) that controls input and output of data between the inside and outside of the control unit ECU, etc. For example, the control unit ECU is realized by one ECU (Electronic Control Unit) or by multiple ECUs working together.

[0041] For example, the control unit ECU is provided so as to be able to communicate with each inverter INV, the voltage control unit VCU, the engine ENG, the hydraulic clutch CL, etc. For example, the control unit ECU controls the outputs of the generator motor GEN, the main drive motor MOT1, and the secondary drive motor MOT2 by controlling each inverter INV.

[0042] The control unit ECU executes various programs stored in, for example, a storage unit. As described above, the vehicle Ve can travel in multiple drive modes. However, when traveling in series running, for example, the engine ENG is controlled with the engine ENG and the drive wheels decoupled. This prevents the engine speed Ne from matching the accelerator pedal operation, potentially causing discomfort to the user. Therefore, in this embodiment, to reduce this discomfort for the user, a predetermined program is executed to control the generator / motor GEN so that the engine speed Ne is set to a pseudo-gear position. The pseudo-gear position is a gear position that simulates a gear position determined, for example, based on the vehicle speed and accelerator pedal position when the engine ENG and the drive wheels are decoupled. Note that some vehicles Ve are capable of shifting gears in response to a user request, such as a paddle shift. Therefore, the pseudo-gear position may be set based on the user's gear position.

[0043] Furthermore, when the above-described electricity waste control is performed, the engine ENG is rotated by the generator motor GEN. However, if the engine speed Ne is controlled to a predetermined speed range, an abnormal noise such as a resonance sound or a rattle may occur. This abnormal noise is generated, for example, by thrust forces in the axial direction caused by the gears in the power transmission path being helical gears. The occurrence of such an abnormal noise may cause discomfort to the user. Therefore, in this embodiment, when electricity waste control is performed, a predetermined program is executed to control the generator motor GEN so that the engine speed Ne is kept outside the predetermined engine speed range.

[0044] As shown in Fig. 2, the control unit ECU includes a pseudo-speed change control unit 100 and a waste electricity control unit 110 as functional units realized by executing such programs. In the following, the processes described as being performed by the pseudo-speed change control unit 100 and the waste electricity control unit 110 are processes realized by the control unit ECU.

[0045] The control unit ECU receives detection values ​​from various sensors, such as an accelerator position sensor 120 that detects the amount of operation of the accelerator pedal of the vehicle Ve, and a vehicle speed sensor 130 that detects the vehicle speed, which is the traveling speed of the vehicle Ve.

[0046] The pseudo-speed-change control unit 100 determines the engine speed Ne relative to the vehicle speed based on a pseudo-speed step set based on the vehicle speed and accelerator pedal position. For example, the pseudo-speed-change control unit 100 determines the pseudo-speed step based on a shift map stored in advance in a storage unit. Figures 3 to 6 are diagrams showing examples of the shift map.

[0047] FIG. 3 shows an example of a shift map for downshifting while driving in normal mode, and FIG. 4 shows an example of a shift map for upshifting while driving in normal mode. In these shift maps, solid lines indicate shift lines under power-waste control, and dashed lines indicate shift lines under normal control (hereinafter simply referred to as "normal control"), which does not consume surplus power. As such, the shift map under power-waste control is different from the shift map under normal control; that is, the pseudo-transmission control unit 100 changes the shift map selected between power-waste control and normal control, and performs an upshift or downshift based on the selected shift map. In other words, the pseudo-transmission control unit 100 performs an upshift or downshift in response to changes in vehicle speed and accelerator pedal position. Note that here, the shift lines under normal control, shown by dashed lines, only indicate shift lines that differ from those under power-waste control.

[0048] A predetermined hysteresis is set between the downshift lines in the shift map of Figure 3 and the upshift lines in the shift map of Figure 4. This is to prevent the user from feeling annoyed by shifts that cross the shift lines multiple times in a short period of time. For example, hysteresis is set between the upshift line indicating an upshift from "3rd gear" to "4th gear" and the downshift line indicating a downshift from "4th gear" to "3rd gear."

[0049] Similarly, Fig. 5 shows an example of a shift map for downshifting when driving in sport mode, and Fig. 6 shows an example of a shift map for upshifting when driving in sport mode. The configuration of the shift map is the same as the shift map for normal mode explained using Figs. 3 and 4, so a description thereof will be omitted.

[0050] The pseudo-shift control unit 100 determines the engine rotation speed Ne relative to the vehicle speed based on the pseudo-speed stage set in this manner. The pseudo-shift control unit 100 determines the engine rotation speed relative to the vehicle speed based on, for example, a shift map stored in advance in a storage unit. Figures 7 to 14 are diagrams showing examples of the shift map. Figures 7 to 10 are diagrams for determining the engine rotation speed Ne relative to the vehicle speed in normal mode, and Figures 11 to 14 are diagrams for determining the engine rotation speed Ne relative to the vehicle speed in sport mode.

[0051] Specifically, when the vehicle is traveling on a flat road in normal mode, for example, when the battery BAT is not fully charged and normal control is being performed, the pseudo transmission control unit 100 refers to the shift map in Figure 7 and determines the engine speed Ne for each pseudo gear in relation to the vehicle speed. In other words, an upshift threshold and a downshift threshold for the engine speed Ne are set for each pseudo gear, and the pseudo transmission control unit 100 performs an upshift or downshift when the engine speed Ne exceeds these thresholds. In Figure 7, the solid line indicates the engine speed Ne during acceleration, i.e., the engine speed Ne during an upshift, and the dashed line indicates the engine speed Ne during deceleration, i.e., the engine speed Ne during a downshift.

[0052] Furthermore, when the vehicle is traveling on a flat road in normal mode, for example, when the battery BAT is fully charged and power waste control is being executed, the pseudo transmission control unit 100 refers to the shift map in Fig. 8 to determine the engine speed Ne for each pseudo gear in relation to the vehicle speed. In Fig. 8, as in the normal control in Fig. 7, an upshift threshold and a downshift threshold for the engine speed Ne are set for each pseudo gear, and the pseudo transmission control unit 100 executes an upshift or downshift when the engine speed Ne exceeds these thresholds. In Fig. 8, the solid line indicates the engine speed Ne during acceleration, i.e., the engine speed Ne during an upshift, and the dashed line indicates the engine speed Ne during deceleration, i.e., the engine speed Ne during a downshift.

[0053] On the other hand, the shift map referenced during normal control in FIG. 7 and the shift map referenced during power waste control in FIG. 8 differ in that a resonance band region is provided in the shift map in FIG. 8. The processing content will be described in more detail using the shift map in FIG. 8. As described above, when power waste control is performed, abnormal noises such as resonance sounds and rattles may occur. In the example shown in FIG. 8, a predetermined engine rotation speed region surrounded by a thick dashed line is the resonance band region where resonance sounds occur. In this embodiment, the engine rotation speed Ne is determined so as to avoid this resonance band region.

[0054] Specifically, when the vehicle speed is less than a predetermined vehicle speed "α," the pseudo transmission control unit 100 sets the engine speed Ne1, which is equal to or less than the resonance band region, as the upper limit engine speed for upshifts and downshifts. That is, when the vehicle speed is less than the predetermined vehicle speed "α," the engine speed Ne is controlled to be less than the engine speed Ne1. On the other hand, when the vehicle speed is equal to or greater than the predetermined vehicle speed "α," the pseudo transmission control unit 100 sets the engine speed Ne2, which is equal to or greater than the resonance band region, as the lower limit engine speed for upshifts and downshifts. That is, when the vehicle speed is equal to or greater than the predetermined vehicle speed "α," the engine speed Ne is controlled to be equal to or greater than the engine speed Ne2. In this way, in this embodiment, the pseudo transmission control unit 100 is configured to change the engine speed Ne to be lower or higher than the resonance band region, with the predetermined vehicle speed "α" as the boundary.

[0055] Furthermore, as shown in Figure 8, when the gear position is "third gear," for example, the engine speed Ne may enter the resonance band region. Specifically, the engine speed Ne may enter the resonance band region enclosed by the thin dashed line. In this case, in this embodiment, the engine speed Ne is reduced to a lower speed as quickly as possible. This is because it is possible to suppress the generation of resonance noise.

[0056] When the vehicle speed changes from less than a predetermined vehicle speed "α" to equal to or greater than the predetermined vehicle speed "α," the upper limit engine speed for upshifting and downshifting is invalidated. Similarly, when the vehicle speed changes from equal to or greater than the predetermined vehicle speed "α" to less than the predetermined vehicle speed "α," the lower limit engine speed for upshifting and downshifting is invalidated.

[0057] Furthermore, when the engine speed Ne is to be reduced below the resonance band region, it is preferable to stop various adaptive controls that function to increase the engine speed Ne in order to suppress an increase in the engine speed Ne. As an example of adaptive control, a brake hold that maintains the vehicle Ve in a stopped state even when the user does not continue to depress the brake pedal is assumed.

[0058] 8, the resonance band region indicated by the thick dashed line is not provided in the region of vehicle speeds equal to or higher than "β," which is a relatively high vehicle speed. This is because, as the vehicle speed increases, the annoyance of the resonance sound is reduced by background noise. In this example, no resonance band region is provided in the high vehicle speed region, but it may be provided appropriately depending on the driving environment, such as an ordinary road or a highway.

[0059] Note that the shift map selected during the power-discharge control shown in FIG. 8 and the shift map selected during the normal control shown in FIG. 7 are switched based on, for example, the remaining charge of the battery BAT, assuming that the accelerator pedal is off. That is, when the battery BAT is fully charged with the accelerator pedal off, the shift map for the power-discharge control is selected. When the battery BAT is not fully charged, the shift map for the normal control is selected. While the power-discharge control can be switched to the normal control when the accelerator pedal is pressed, slight on / off operation of the accelerator pedal is not taken into consideration here. If slight on / off operation of the accelerator pedal were to switch whether or not to perform the power-discharge control and to switch the shift map accordingly, this slight on / off operation of the accelerator pedal could result in a so-called "shift busy" state, in which the selected gear would frequently change, which could be annoying to the user. Therefore, in this embodiment, in consideration of the annoyance of such a shift busy state, the shift map for the power-discharge control and the shift map for the normal control are switched based on the remaining charge of the battery BAT.

[0060] Figures 9 and 10 are shift maps referenced on downhill roads, and are shift maps corrected according to the gradient of the downhill road compared to the maps for flat roads in Figures 7 and 8. Figure 9 is a shift map referenced when traveling downhill in normal mode and normal control is being executed, and Figure 10 is a shift map referenced when traveling downhill in normal mode and power waste control is being executed. Note that detailed explanations of the shift maps are the same as those in Figures 7 and 8, and therefore will not be repeated here.

[0061] Similarly, Figures 11 to 14 are shift maps for determining the engine rotation speed Ne relative to the vehicle speed in the sport mode, where Figure 11 is a shift map referenced when running on a flat road while performing normal control, Figure 12 is a shift map referenced when running on a flat road while performing power waste control, Figure 13 is a shift map referenced when running on a downhill road while performing normal control, and Figure 14 is a shift map referenced when running on a downhill road while performing power waste control. Detailed descriptions of each shift map are the same as those for the normal mode, and therefore will not be repeated here. As described above, the resonance band region is avoided by avoiding the region to the low rotation speed side or the high rotation speed side, with the predetermined vehicle speed "α" as the boundary, and the predetermined vehicle speed "α" may be set according to each driving mode.

[0062] In this way, the pseudo transmission control unit 100 determines the engine rotation speed Ne corresponding to the vehicle speed by referring to each shift map depending on whether the driving mode is normal mode or sports mode, whether the road is flat or downhill, and whether electric power can be regenerated. Then, the output of the generator motor GEN is controlled by the function of the electricity waste control unit 110, which will be described later, so that the determined engine rotation speed Ne is achieved.

[0063] Furthermore, in normal control, pseudo transmission control unit 100 executes a downshift when the user requests braking by, for example, operating the brake pedal, but in power-down control, when the user requests braking, it does not immediately execute a downshift but executes a gear change based on the shift map. In power-down control, as described above, engine speed Ne is controlled to avoid the resonance band region, and therefore, for example, if engine speed Ne is controlled to a speed higher than the resonance band region, executing a downshift triggered by the user's braking request could cause engine speed Ne to rise excessively, which could cause the user to feel uncomfortable.

[0064] When performing the above-described electricity waste control, the electricity waste control unit 110 controls the generator motor GEN to achieve the engine speed Ne determined by the pseudo transmission control unit 100. That is, the electricity waste control unit 110 controls the output of the generator motor GEN by controlling the first inverter INV1, thereby controlling the engine speed Ne to the target engine speed.

[0065] Furthermore, in the electricity disposal control, the electricity disposal control unit 110 limits the rate of increase or decrease of the engine rotation speed Ne when the engine rotation speed Ne passes through the resonance band region to a predetermined rate of increase or decrease. As described above, for example, when the gear is in "third gear," the engine rotation speed Ne may enter the resonance band region. That is, when upshifting from "third gear" to "fourth gear," the engine rotation speed Ne passes through the resonance band region. Similarly, when downshifting from "fourth gear" to "third gear," the engine rotation speed Ne passes through the resonance band region. In this case, the electricity disposal control unit 110 preferably causes the engine rotation speed Ne to pass through the resonance band region as quickly as possible to suppress the generation of resonance noise. However, if the generator motor GEN sharply controls the engine rotation speed Ne, problems such as the battery BAT supplying power to the generator motor GEN exceeding its output power limit may occur. Therefore, it is preferable to control the engine rotation speed Ne at an increase or decrease rate that takes into account the protection of the battery BAT.

[0066] For example, as shown in Fig. 15, when controlling the engine speed Ne while avoiding the resonance band region during an upshift, the waste electricity control unit 110 controls the engine speed Ne from the current engine speed Ne toward the above-mentioned lower limit speed Ne2 on the high-speed side at a predetermined increase rate. Also, as shown in Fig. 16, when controlling the engine speed Ne while avoiding the resonance band region during a downshift, the waste electricity control unit 110 controls the engine speed Ne from the current engine speed Ne toward the above-mentioned upper limit speed Ne1 on the low-speed side at a predetermined decrease rate. This makes it possible to quickly pass through the resonance band region and control the engine speed Ne to a value that prevents resonance noise while protecting the battery BAT.

[0067] When the vehicle is traveling in series running, as described above, the main drive motor MOT1 drives the front wheels FWR. However, even in this case, it is preferable to realize acceleration / deceleration characteristics based on the pseudo gears in order to reduce the sense of discomfort felt by the user due to fluctuations in engine speed Ne. Figure 17 is a diagram showing an example of a map of torque characteristics of the main drive motor MOT1 corresponding to "first gear" through "seventh gear" in the pseudo gears, with the horizontal axis representing vehicle speed and the vertical axis representing driving force. The control unit ECU refers to this map and controls the main drive motor MOT1 to output driving force based on the selected pseudo gear.

[0068] [Flowchart] Next, an example of control executed by the control unit ECU will be described. Fig. 18 is a flowchart showing an example of this control, illustrating an example of controlling the engine speed Ne so as to avoid the resonance band region while performing electricity waste control. Note that the specific processing content is as described above, so here, the processing flow will be mainly described, and the processing content of each step will be explained in a simplified manner. In addition, since the control example shown here performs upshifts and downshifts based on the shift map as described above, it is assumed that gear changes based on a user request such as paddle shifts are not performed.

[0069] First, in step S1, the control unit ECU determines whether the power-discharge control is being executed and whether the vehicle is in series running. If the power-discharge control is not being executed or the vehicle is not in series running (No in step S1), the control unit ECU temporarily ends the process of the flowchart shown in FIG.

[0070] On the other hand, when the power waste control is being executed and the vehicle is in series running (Yes in step S1), the control unit ECU determines whether the current engine speed Ne is avoiding the resonance band region and is on the high rotation speed side (step S2). For example, when the current engine speed Ne is equal to or higher than the resonance band region (Yes in step S2), the control unit ECU proceeds to step S3.

[0071] In step S3, the control unit ECU sets the engine speed above the upper end of the resonance band region as the lower limit engine speed Ne2 and disables the upper limit engine speed Ne1. That is, the lower limit engine speed Ne2 is set so that the engine speed Ne on the high engine speed side does not enter the resonance band region. Note that the upper limit engine speed Ne1 is disabled because it is not particularly necessary to set it here.

[0072] On the other hand, if it is determined in step S2 that the current engine speed Ne is avoiding the resonance band region and is on the low speed side (No in step S2), the control unit ECU proceeds to step S4.

[0073] In step S4, the control unit ECU sets the engine speed below the lower end of the resonance band region as the upper limit engine speed Ne1 and disables the lower limit engine speed Ne2. That is, the upper limit engine speed Ne1 is set so that the engine speed Ne on the low engine speed side does not enter the resonance band region. Note that the lower limit engine speed Ne2 is disabled because it is not particularly necessary to set it here.

[0074] After executing the process of step S3 or the process of step S4, the control unit ECU proceeds to step S5. In step S5, the control unit ECU determines whether the target rotation speed is higher than the upper limit rotation speed Ne1 or lower than the lower limit rotation speed Ne2. That is, the control unit ECU determines whether the engine rotation speed Ne when shifting from the current rotation speed to the target gear is higher than the upper limit rotation speed Ne1 or lower than the lower limit rotation speed Ne2. For example, using the example of FIG. 8 described above, when upshifting from "third gear" to "fourth gear," the target rotation speed is higher than the upper limit rotation speed Ne1. Also, when downshifting from "fourth gear" to "third gear," the target rotation speed is lower than the lower limit rotation speed Ne2.

[0075] If the determination in step S5 is negative (No in step S5), the control unit ECU temporarily ends the processing of the flowchart shown in Fig. 18. On the other hand, if the determination in step S5 is positive (Yes in step S5), the control unit ECU proceeds to step S6.

[0076] In step S6, the control unit ECU sets the rate of increase / decrease of the engine speed Ne in the resonance band region. This is for protecting the battery BAT, as described above. Therefore, as described with reference to FIGS. 15 and 16 , when the target speed is higher than the upper limit speed Ne1, the control unit ECU sets the rate of increase of the engine speed Ne in the resonance band region to a predetermined rate of increase, and when the target speed is lower than the lower limit speed Ne2, the control unit ECU sets the rate of decrease of the engine speed Ne in the resonance band region to a predetermined rate of decrease. Then, when the engine speed Ne passes through the resonance band region, the control unit ECU controls the engine speed Ne to a speed corresponding to the pseudo gear position, taking into account the upper limit speed Ne1 or the lower limit speed Ne2.

[0077] As described above, in the embodiment, the generator motor GEN is used to rotate the engine ENG, and when surplus power that cannot be stored in the battery BAT is consumed through power waste control, the generator motor GEN is controlled so that the engine speed Ne is based on the pseudo gear position. As a result, when surplus power is consumed through power waste control, the engine speed Ne is based on the pseudo gear position, and therefore it is possible to reduce the sense of discomfort felt by the user due to fluctuations in the engine speed Ne compared to, for example, when the engine speed Ne is controlled regardless of the pseudo gear position.

[0078] In addition, in this embodiment, the upshift threshold and downshift threshold for the power waste control are set to be different from the upshift threshold and downshift threshold for the normal control, and an upshift or downshift is performed based on the threshold for each control. By setting an engine speed Ne dedicated to the power waste control that is different from that for the normal control in this way, it becomes possible to consume surplus power more efficiently than, for example, when an engine speed Ne dedicated to the power waste control is not set.

[0079] Furthermore, in this embodiment, when a predetermined engine speed range is used during power waste control, abnormal noise such as resonance may occur. Therefore, the engine speed Ne is controlled to avoid the predetermined engine speed range, i.e., the resonance band region. For example, when the vehicle speed is less than a predetermined vehicle speed "α," an upper limit engine speed Ne1 is set lower than the predetermined engine speed range, and an upshift or downshift is performed using the upper limit engine speed Ne1 as the upper limit. For example, when the vehicle speed is equal to or greater than the predetermined vehicle speed "α," a lower limit engine speed Ne2 is set higher than the predetermined engine speed range, and an upshift or downshift is performed using the lower limit engine speed Ne2 as the lower limit. In this way, by controlling the engine speed Ne to avoid the resonance band region, it is possible to optimize the engine volume while suppressing the generation of abnormal noise such as resonance.

[0080] In addition, in the embodiment, different preset shift maps are provided for normal control and power waste control, which allows the control unit ECU to execute gear shifts by referring to the shift maps, thereby reducing the processing load on the control unit ECU when shifting gears compared to a configuration that does not have such a shift map.

[0081] In addition, in this embodiment, a predetermined hysteresis is provided between the upshift line and the downshift line. Therefore, for example, if such hysteresis is not provided and upshifts and downshifts are determined using the same shift line, the shift line may be crossed multiple times in a short period of time, which may cause discomfort to the user. However, by providing hysteresis, it is possible to reduce the occurrence of such discomfort.

[0082] In addition, in the embodiment, in normal control, if there is a braking request from the user, a downshift is performed, and in power-down control, if there is a braking request from the user, a downshift is not performed but a gear change is performed based on the shift map. Therefore, for example, if there is a braking request while traveling at a relatively high vehicle speed, a downshift is performed from a high engine speed during power-down control, which may increase the discomfort caused by the increase in engine speed Ne. However, by performing a gear change based on the shift map regardless of the user's braking request, it is possible to suppress such an increase in engine speed Ne, and as a result, it is possible to reduce the discomfort felt by the user.

[0083] In addition, in this embodiment, the rate of increase or decrease of the engine speed Ne when passing through the resonance band region is limited to a predetermined rate. To avoid the resonance band region, it is preferable to steeply change the engine speed Ne to pass through the resonance band region. However, controlling the engine speed Ne in this manner may be undesirable from the viewpoint of protecting the battery BAT. That is, the output limit of the battery BAT may be exceeded. Therefore, by limiting the rate of increase or decrease of the engine speed Ne when passing through the resonance band region to a predetermined rate, the burden on the battery BAT can be reduced, and the resonance band region can be quickly passed while protecting the battery BAT.

[0084] In addition, in this embodiment, the motor torque of the main drive motor MOT1 is set based on the pseudo gear position. That is, in series running, the engine ENG and the drive wheels are mechanically separated, but by controlling the motor torque based on the pseudo gear position, it is possible to generate a driving force that corresponds to the accelerator operation of the user. For example, compared to when the motor torque is not set based on the pseudo gear position, it is possible to reduce the discomfort that the user feels when operating the accelerator.

[0085] In the above-described embodiment, for example, when it is determined that the battery BAT cannot store regenerative power during braking, the power-discharge control is executed to consume surplus power by rotating the engine ENG with the generator motor GEN. That is, the power-discharge control is executed when the battery BAT is fully charged. As a result, for example, when the battery BAT is not fully charged, the regenerative operation can be performed by normal control to charge the battery BAT, and when the battery BAT is fully charged, the surplus power can be consumed by the power-discharge control.

[0086] [Modification] Next, a modification will be described. In the above-described embodiment, the means for avoiding the resonance band region in each of the normal mode shown in FIG. 8 and the sport mode shown in FIG. 12 is described as being configured to shift the engine rotation speed Ne to a lower rotation speed or a higher rotation speed depending on the vehicle speed. However, the means for avoiding the resonance band region is not limited to this. For example, as shown in FIG. 19 , the engine rotation speed Ne may be shifted to a lower rotation speed or a higher rotation speed depending on the driving mode, normal mode or sport mode, regardless of the vehicle speed. In the example shown in FIG. 19 , when driving in the normal mode, the engine rotation speed Ne is uniformly controlled to a lower rotation speed with the upper limit rotation speed Ne1 as the upper limit, and when driving in the sport mode, the engine rotation speed Ne is uniformly controlled to a higher rotation speed with the lower limit rotation speed Ne2 as the lower limit. Note that when the vehicle speed is equal to or higher than a predetermined vehicle speed “γ,” there is a high possibility that the resonance sound will not be recognized due to background noise. Therefore, the resonance band region is not set here. However, the range of the resonance band region may be determined appropriately depending on the driving environment, etc. In addition, in the example shown in FIG. 19, the sport mode and normal mode are shown in the same diagram, but like the above-mentioned shift maps, they may be shown in different maps for each driving mode.

[0087] In this way, the selected shift map is different between the sport mode and the normal mode, so that the engine speed Ne can be controlled according to the driving mode selected by the user, in other words, according to the user's preferences, and it is possible to reduce the sense of discomfort felt by the user when the engine speed Ne is controlled to have the same characteristics regardless of the selected driving mode, for example.

[0088] Furthermore, the flowchart of FIG. 18 in the above-described embodiment may be configured as shown in FIG. 20, for example. As described above, the shift map for normal control and the shift map for power-discharge control are switched based on the remaining charge of the battery BAT. However, the currently executed control may not match the selected shift map. In the example shown in FIG. 20, processing is performed taking such an event into consideration. Specific details of the processing will be described below. In the example of FIG. 20, steps similar to those in the example of FIG. 18 are assigned the same step numbers, and their descriptions will be omitted or simplified.

[0089] First, in step S10, the control unit ECU determines whether the shift map for the discard control is selected and whether the vehicle is in series running. As described above, the shift map for the discard control is selected when the battery BAT is fully charged. Therefore, if the shift map for the discard control is not selected or the vehicle is not in series running (No in step S10), the control unit ECU temporarily ends the processing of the flowchart shown in FIG.

[0090] On the other hand, when the shift map for power waste control is being selected and the vehicle is in series running mode (Yes in step S10), the control unit ECU determines whether the current engine speed Ne is avoiding the resonance band region and is shifted to a high speed side (step S2). For example, when the current engine speed Ne is equal to or higher than the resonance band region (Yes in step S2), the control unit ECU proceeds to step S3.

[0091] In step S3, the control unit ECU sets the engine speed above the upper end of the resonance band region as the lower limit engine speed Ne2 and disables the upper limit engine speed Ne1. That is, the lower limit engine speed Ne2 is set so that the engine speed Ne on the high engine speed side does not enter the resonance band region. Note that the upper limit engine speed Ne1 is disabled because it is not particularly necessary to set it here.

[0092] On the other hand, if it is determined in step S2 that the current engine speed Ne is avoiding the resonance band region and is on the low speed side (No in step S2), the control unit ECU proceeds to step S40.

[0093] In step S40, the control unit ECU invalidates the lower limit engine speed Ne2 because the current engine speed Ne is avoiding the resonance band region and is on the low engine speed side.

[0094] Next, the control unit ECU determines whether the accelerator pedal depression is equal to or less than a predetermined value (i.e., the accelerator pedal is almost released) and whether power-discarding control is being performed (step S50). As described above, the map for normal control and the map for power-discarding control are switched based on the remaining charge of the battery BAT. However, for example, if the accelerator pedal is depressed during power-discarding control and the vehicle accelerates again, the control will switch from power-discarding control to normal control. In such a case, even though the control itself switches from power-discarding control to normal control when the accelerator pedal is depressed, the shift map is switched based on the remaining charge of the battery BAT. Therefore, if the remaining charge has not yet started to decrease and the battery BAT is still fully charged, the shift map for power-discarding control may be selected. In other words, there may be a time lag between the accelerator pedal depression and the relatively short time it takes for the battery BAT to start decreasing from full charge. In such a case, the control corresponding to the selected shift map may not match. In such a state, if the upper limit rotation speed Ne1 is set uniformly, as in step S4 in the control example of Fig. 18, it may not be possible to output the required driving force according to the user's accelerator operation. Therefore, in the example shown in Fig. 20, the determination in step S50 is performed to avoid a situation where the corresponding control does not match the selected shift map.

[0095] In step S50, if the accelerator opening is greater than the predetermined value or if the discard control is not being performed (No in step S50), the control unit ECU advances the process to step S60.

[0096] In step S60, the control unit ECU disables the upper limit rotation speed Ne1. As a result, for example, when re-accelerating while the power-discharge control is being executed, if the accelerator pedal is depressed and the power-discharge control is switched to normal control, even if the shift map for the power-discharge control is selected because the remaining charge of the battery BAT has not decreased from full charge, it is possible to achieve acceleration and driving force according to the accelerator opening because the upper limit rotation speed Ne1 is not set. Furthermore, by disabling the upper limit rotation speed Ne1 during acceleration, it is possible to avoid or suppress a decrease in the amount of power generation caused by setting the upper limit rotation speed Ne1.

[0097] On the other hand, in step S50, if the accelerator opening is equal to or smaller than the predetermined value and power waste control is being executed (Yes in step S50), the control unit ECU advances the process to step S70.

[0098] In step S70, the control unit ECU sets the upper limit rotation speed Ne1 to a rotation speed equal to or lower than the lower end of the resonance band region. That is, the upper limit rotation speed Ne1 is set so that the engine rotation speed Ne on the low rotation speed side does not enter the resonance band region.

[0099] After executing the process of step S3, step S60, or step S70, the control unit ECU proceeds to step S5. In step S5, the control unit ECU determines whether the target rotation speed is higher than the upper limit rotation speed Ne1 or lower than the lower limit rotation speed Ne2. That is, the control unit ECU determines whether the engine rotation speed Ne when shifting from the current rotation speed to the target gear is higher than the upper limit rotation speed Ne1 or lower than the lower limit rotation speed Ne2.

[0100] If the determination in step S5 is negative (No in step S5), the control unit ECU temporarily terminates the processing of the flowchart shown in Fig. 20. On the other hand, if the determination in step S5 is positive (Yes in step S5), the control unit ECU proceeds to step S6.

[0101] In step S6, the control unit ECU sets the rate of increase / decrease of the engine speed Ne in the resonance band region. Then, when the engine speed Ne passes through the resonance band region, the control unit ECU controls the engine speed Ne to a speed corresponding to the pseudo gear position while taking into account the upper limit speed Ne1 or the lower limit speed Ne2.

[0102] Although the embodiments of the present invention have been described above with reference to the drawings, it goes without saying that the present invention is not limited to the above-described embodiments. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0103] The control described in the above-described embodiment can be realized by executing a prepared control program on a computer. The control program is recorded on a computer-readable storage medium and executed by being read from the storage medium. The control program may be provided in a form stored on a non-transitory storage medium such as a flash memory, or may be provided via a network such as the Internet. The computer that executes the control program may be included in the control unit, or may be included in an electronic device such as a smartphone, tablet terminal, or personal computer that can communicate with the control unit, or may be included in a server device that can communicate with the control unit and the electronic device.

[0104] This specification describes at least the following: Note that the components in parentheses correspond to those in the above-described embodiments, but are not limited to these.

[0105] (1) A hybrid vehicle (vehicle Ve) capable of running by supplying to a traction motor (main drive motor MOT1) electric power generated by a generator motor (generator motor GEN) using the output of an engine (engine ENG) and electric power from a battery (battery BAT), the hybrid vehicle comprising: a pseudo-speed change control unit (pseudo-speed change control unit 100) that determines an engine rotation speed (engine rotation speed Ne) for a vehicle speed based on a pseudo-speed change stage that is set based on the vehicle speed and accelerator opening; and a power waste control unit (power waste control unit 110) that performs power waste control to consume surplus power that cannot be stored in the battery by rotating the engine using the generator motor, and the power waste control unit controls the generator motor so that the engine rotation speed is based on the pseudo-speed change stage when performing the power waste control.

[0106] According to (1), when surplus electricity is consumed through power waste control, the engine speed is based on the pseudo gear stage, so it is possible to reduce the discomfort felt by the user due to fluctuations in engine speed compared to, for example, when the engine speed is controlled regardless of the pseudo gear stage.

[0107] (2) The hybrid vehicle according to (1), wherein an upshift threshold and a downshift threshold for the engine speed at the pseudo gear stage are respectively set, the upshift threshold and the downshift threshold in the power-discharge control are set to be different from the upshift threshold and the downshift threshold in normal control that does not consume the surplus power, and the pseudo gear change control unit executes an upshift or a downshift from the current pseudo gear stage when the engine speed exceeds the upshift threshold or the downshift threshold.

[0108] According to (2), by setting an engine speed dedicated to power waste control that is different from normal control, it is possible to consume surplus electricity more efficiently than, for example, when an engine speed dedicated to power waste control is not set.

[0109] (3) The hybrid vehicle described in (2), wherein the pseudo-shift control unit, in each pseudo-shift stage when the electricity discharge control is executed, sets an engine speed below a predetermined engine speed range as the upper limit speed (upper limit speed Ne1) for the upshift and the downshift when the vehicle speed is below a predetermined vehicle speed, and sets an engine speed above the predetermined engine speed range as the lower limit speed (lower limit speed Ne2) for the upshift and the downshift when the vehicle speed is above the predetermined vehicle speed.

[0110] According to (3), by controlling the engine speed while avoiding the resonance band region, which is a predetermined engine speed range, it is possible to optimize the engine volume while suppressing the generation of abnormal noise such as resonance sound.

[0111] (4) The hybrid vehicle according to (2), wherein the hybrid vehicle includes a plurality of shift maps in which the pseudo-gear stages are preset based on the vehicle speed and the accelerator opening, and the pseudo-gear control unit changes the shift map selected between the power-discharge control and the normal control, and performs the upshift or the downshift based on the selected shift map.

[0112] According to (4), the control unit can perform gear changes by referring to a shift map, so the processing load on the control unit when changing gears can be reduced compared to, for example, a configuration that does not have such a shift map.

[0113] (5) The hybrid vehicle according to (4), wherein the hybrid vehicle has a plurality of driving modes that can change driving force characteristics, and the pseudo-transmission control unit changes the shift map in accordance with the selected driving mode during the power-discharge control.

[0114] According to (5), the engine speed can be controlled in accordance with the driving mode selected by the user, and it is possible to reduce the sense of discomfort felt by the user due to the engine speed being uniformly controlled to the same characteristics regardless of the selected driving mode, for example.

[0115] (6) The hybrid vehicle according to (4), wherein in the shift map, hysteresis is provided between an upshift line indicating the upshift from N gear to N+1 gear and a downshift line indicating the downshift from N+1 gear to N gear.

[0116] According to (6), for example, if hysteresis is not provided and upshifts and downshifts are determined using the same shift line, the shift line may be crossed multiple times in a short period of time, which may cause discomfort to the user. However, by providing hysteresis, it is possible to reduce the occurrence of such discomfort.

[0117] (7) The hybrid vehicle according to (4), wherein the pseudo-shift control unit performs the downshift when a user requests braking during the normal control, and performs a shift based on the shift map without performing the downshift when a user requests braking during the power-discharge control.

[0118] According to (7), for example, if a braking request is made while driving at a relatively high vehicle speed, a downshift will be performed from a high engine speed during power-down control, which may cause a greater sense of discomfort due to the increase in engine speed. However, by performing gear changes based on the shift map regardless of the user's braking request, such an increase in engine speed can be suppressed, and as a result, the sense of discomfort felt by the user can be reduced.

[0119] (8) The hybrid vehicle according to (3), wherein the electricity waste control unit limits a rate of increase or decrease in the engine speed to a predetermined rate of increase or decrease when the engine speed passes through the predetermined engine speed range in the electricity waste control.

[0120] According to (8), for example, by limiting the rate of increase or decrease of the engine speed when passing through a predetermined engine speed range to a predetermined rate of increase or decrease, the burden on the battery can be reduced, and the resonance band range can be passed through quickly while protecting the battery.

[0121] (9) The hybrid vehicle according to (1), wherein the motor torque of the traction motor is set based on the pseudo gear position.

[0122] According to (9), by controlling the motor torque of the driving motor based on the pseudo gear stage, it becomes possible to generate a driving force according to the user's accelerator operation, and for example, the discomfort felt by the user in response to accelerator operation can be reduced compared to when the motor torque is not set based on the pseudo gear stage.

[0123] (10) The hybrid vehicle according to (1), wherein the power discharging control unit executes the power discharging control to consume the surplus power by rotating the engine with the generator motor when it is determined that the battery cannot store the regenerative power of the traction motor during braking.

[0124] According to (10), for example, if the battery is not fully charged, regeneration can be performed to charge the battery, and if the battery is fully charged, surplus power can be consumed.

[0125] This application is based on a Japanese patent application (Patent Application No. 2024-148536) filed on August 30, 2024, the contents of which are incorporated herein by reference.

[0126] 100 Pseudo-speed change control unit 110 Waste electricity control unit BAT Battery ENG Engine GEN Generator motor MOT1 Main drive motor (travel motor) Ne Engine rotation speed Ne1 Upper limit rotation speed Ne2 Lower limit rotation speed Ve Vehicle (hybrid vehicle)

Claims

1. A hybrid vehicle that can travel by supplying power generated by a generator motor using engine output and power from a battery to a traction motor, comprising: a pseudo-speed change control unit that determines the engine speed relative to the vehicle speed based on a pseudo-speed change stage that is set based on the vehicle speed and accelerator opening; and a power waste control unit that performs power waste control to consume surplus power that cannot be stored in the battery by rotating the engine using the generator motor, and when performing the power waste control, the power waste control unit controls the generator motor so that the engine speed is based on the pseudo-speed change stage.

2. A hybrid vehicle as described in claim 1, wherein an upshift threshold and a downshift threshold for the engine rotation speed at the pseudo gear stage are respectively set, the upshift threshold and the downshift threshold in the power waste control are set to be different from the upshift threshold and the downshift threshold in normal control that does not consume the surplus power, and the pseudo gear change control unit executes an upshift or downshift from the current pseudo gear stage when the engine rotation speed exceeds the upshift threshold or the downshift threshold.

3. A hybrid vehicle as described in claim 2, wherein the pseudo-shift control unit, at each pseudo-shift stage when the electricity discharge control is executed, sets an engine speed below a predetermined engine speed range as the upper limit speed for the upshift and downshift when the vehicle speed is below a predetermined vehicle speed, and sets an engine speed above the predetermined engine speed range as the lower limit speed for the upshift and downshift when the vehicle speed is above the predetermined vehicle speed.

4. A hybrid vehicle as described in claim 2, wherein the hybrid vehicle is provided with a plurality of shift maps in which the pseudo gear stages based on the vehicle speed and the accelerator opening are preset, and the pseudo gear shift control unit changes the shift map selected between the power waste control and the normal control, and performs the upshift or downshift based on the selected shift map.

5. A hybrid vehicle as claimed in claim 4, wherein the hybrid vehicle has a plurality of driving modes capable of changing driving force characteristics, and the pseudo-transmission control unit changes the shift map in accordance with the selected driving mode during the power dissipation control.

6. A hybrid vehicle according to claim 4, wherein in the shift map, hysteresis is provided between an upshift line indicating the upshift from N gear to N+1 gear and a downshift line indicating the downshift from N+1 gear to N gear.

7. A hybrid vehicle as described in claim 4, wherein the pseudo-shift control unit executes the downshift when there is a braking request from the user during the normal control, and executes a gear change based on the shift map without executing the downshift when there is a braking request from the user during the power-discharge control.

8. A hybrid vehicle as described in claim 3, wherein the electricity waste control unit limits the rate of increase or decrease of the engine speed when the engine speed passes through the predetermined engine speed range to a predetermined rate of increase or decrease in the electricity waste control.

9. A hybrid vehicle according to claim 1, wherein the motor torque of the traction motor is set based on the pseudo speed change stage.

10. A hybrid vehicle as described in claim 1, wherein the electricity waste control unit executes the electricity waste control to consume the surplus electricity by rotating the engine with the generator motor when it is determined that the battery cannot store the regenerative power of the traction motor during braking.

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