vehicle

Abstract

A vehicle (10) is provided with: an engine (ENG); a second motor generator (MG2) mechanically connected to the engine (ENG); a first motor generator (MG1) mechanically connected to a driving wheel (DW); a battery (BAT) capable of outputting electric power used for driving the first motor generator (MG1); and a control device (20). The control device (20) comprises a virtual stepped gear shift mode in which, while the vehicle is moving by means of the braking / driving force of the first motor generator (MG1), the engine rotational speed is controlled to a rotational speed determined by the vehicle speed and a second virtual gear shift line that is set in advance in accordance with the gear shift position. In the virtual stepped gear shift mode, upon acquiring an upshift request after the gear shift position has been shifted, the control device 20 performs upshift delay control in which the gear shift position after shifting is maintained for a prescribed period of time and the gear shift position is upshifted after the prescribed period of time has elapsed.

Description

Vehicle 【0001】 The present invention relates to a vehicle. 【0002】 Conventionally, a so-called series-running hybrid vehicle that drives drive wheels with a motor and drives a generator with an engine to run is known. In series running, since the engine speed is controlled regardless of the user's intention, for users accustomed to engine-driven vehicles, the control of the engine speed may feel uncomfortable. As a means to suppress such discomfort, for example, in Patent Document 1, a target engine speed simulating a transmission is determined based on an accelerator operation amount indicating the user's acceleration and deceleration intention, and a generator is driven based on the determined target engine speed. A series-type hybrid vehicle is described. 【0003】 Also, in Patent Document 2, it is described that the set time for shift delay is set to be longer as the decrease rate of the absolute value of the motor torque due to the brake pedal release operation is faster, so that the automatic transmission does not repeatedly perform upshifting and downshifting in a short time. 【0004】 Japanese Patent Application Laid-Open No. 2010-173389, Japanese Patent No. 5786965 【0005】 In the hybrid vehicle described in Patent Document 1, for example, after the accelerator pedal is depressed and downshifted, when the accelerator pedal is released, there is a tendency to upshift. However, since there is no need to engage / disengage a mechanical clutch during shifting, the shift switches in a short time and shift hunting (overcontrol) occurs. This can occur not only in hybrid vehicles but also in electric vehicles such as EV vehicles and FC vehicles without an engine. 【0006】 Also, in a hybrid vehicle, when shift hunting occurs, the engine speed rapidly increases and decreases in a short time, which may cause discomfort to the user during driving. 【0007】 As described in Patent Document 2, changing the set time for shift delay by a brake pedal release operation is not necessarily appropriate. 【0008】The present invention provides a vehicle capable of preventing shift hunting, which occurs when shifting gears in a short period of time. 【0009】 The present invention relates to a vehicle comprising: an engine; a first electric motor mechanically connected to a drive wheel; a second electric motor mechanically connected to the engine; a battery capable of outputting power used to drive the first electric motor; and a control device capable of controlling the engine, the battery, the first electric motor, and the second electric motor, wherein the control device has a virtual stepped transmission mode that controls the engine speed to a speed determined by a preset virtual transmission line and vehicle speed according to the gear shift while the vehicle is moving due to the braking and driving force of the first electric motor; and in the virtual stepped transmission mode, when an upshift request is received after a gear shift, the control device maintains the gear shift after the gear shift for a predetermined period of time and performs upshift delay control to shift up the gear after the predetermined period of time has elapsed. 【0010】 Furthermore, the present invention relates to a vehicle comprising: an electric motor mechanically connected to a drive wheel; a battery capable of outputting power used to drive the electric motor; and a control device capable of controlling the battery and the electric motor, wherein the control device has a virtual stepped transmission mode in which the driving force of the electric motor is driven by the braking force of the electric motor while the vehicle is moving, based on a preset drive force line and vehicle speed according to the gear shift, and in the virtual stepped transmission mode, when an upshift request is received after a gear shift, the control device maintains the gear shift after the gear shift for a predetermined period of time, and performs upshift delay control to shift up the gear after the predetermined period has elapsed. 【0011】 According to the present invention, shift hunting can be suppressed by providing a delay time during upshifts after gear changes. This reduces the discomfort experienced by the user while driving. 【0012】Figure 1 is a diagram showing the schematic configuration of the vehicle 10 of this embodiment. Figure 2 is a block diagram showing an example of the control device 20. Figure 3 is a diagram showing an example of a shift map when downshifting while driving in normal mode. Figure 4 is a diagram showing an example of a shift map when upshifting while driving in normal mode. Figure 5 is a diagram showing an example of a Ne search map that determines the engine speed Ne when performing pseudo-gear shift control in normal mode. Figure 6 is a time chart of upshifting after downshifting in a vehicle equipped with a conventional stepped transmission. Figure 7 is a time chart of upshifting after downshifting in a vehicle that does not have a stepped transmission and performs pseudo-gear shift control. Figure 8 is a time chart when upshift delay control is performed during upshifting after downshifting in a vehicle that performs pseudo-gear shift control. Figure 9 is a graph showing an example of delay time in sport mode. Figure 10 is a graph showing another example of delay time in sport mode. Figure 11 is a graph showing an example of delay time in normal mode. Figure 12 is a graph showing an example of delay time in comfort mode. Figure 13 shows an example of the torque characteristics of the first motor generator MG1. Figure 14 shows another example of the torque characteristics of the first motor generator MG1. Figure 15 shows a schematic configuration of a vehicle 10A of another embodiment. 【0013】 Hereinafter, one embodiment of the vehicle control device of the present invention will be described in detail with reference to the drawings. Not all of the features described in the following embodiment are necessarily essential to the present invention. Furthermore, two or more of the features described in the following embodiment may be arbitrarily combined. In the following, identical or similar elements will be denoted by the same or similar reference numerals, and their descriptions may be omitted or simplified as appropriate. 【0014】 [Vehicle] First, a vehicle equipped with a control device (control device 20, described later) which is one embodiment of the vehicle control device of the present invention will be described. 【0015】As shown in Figure 1, the vehicle 10 of this embodiment is a hybrid electric vehicle and is composed of an engine ENG, a first motor generator MG1, a second motor generator MG2, a battery BAT, a clutch CL, a power converter 11, various sensors, and a control device 20. In Figure 1, thick solid lines indicate mechanical connections, double dotted lines indicate electrical wiring, and thin solid arrows indicate the transmission and reception of control signals or detection signals. 【0016】 The engine ENG is an internal combustion engine, such as a gasoline engine or a diesel engine, which outputs power generated by burning the supplied fuel. The engine ENG is connected to the second motor generator MG2 and also to the drive wheels DW of the vehicle 10 via the clutch CL. The power output by the engine ENG (hereinafter also referred to as "engine ENG output") is transmitted to the second motor generator MG2 when the clutch CL is disengaged, and to the second motor generator MG2 and the drive wheels DW when the clutch CL is engaged (closed). The second motor generator MG2 and the clutch CL will be described later. 【0017】 The first motor generator MG1 is a motor generator (a so-called "traction motor") mainly used as a drive source for the vehicle 10, and is composed of, for example, an AC motor. The first motor generator MG1 is electrically connected to the battery BAT and the second motor generator MG2 via the power converter 11. Power can be supplied to the first motor generator MG1 from at least one of the battery BAT and the second motor generator MG2. When power is supplied to the first motor generator MG1, it operates as an electric motor and outputs power for the vehicle 10 to move. The first motor generator MG1 is also connected to the drive wheels DW, and the power output by the first motor generator MG1 (hereinafter also referred to as "output of the first motor generator MG1") is transmitted to the drive wheels DW. The vehicle 10 moves when at least one of the output of the engine ENG and the output of the first motor generator MG1 is transmitted to the drive wheels DW. 【0018】 Furthermore, the first motor generator MG1 can also perform regenerative operation as a generator when the vehicle 10 is braking, generating electricity (so-called regenerative power generation). The power generated by the regenerative operation of the first motor generator MG1 (hereinafter also referred to as "regenerative power") is supplied to the battery BAT, for example, via the power converter 11. This allows the battery BAT to be charged by the regenerative power. 【0019】 Furthermore, regenerative power may not be supplied to the battery BAT, but instead to the second motor generator MG2 via the power converter 11. By supplying regenerative power to the second motor generator MG2, "waste power" can be consumed without charging the battery BAT. During waste power consumption, the regenerative power supplied to the second motor generator MG2 is used to drive the second motor generator MG2, and the power generated is input to the engine ENG, where it is consumed by mechanical friction losses, etc. 【0020】 The second motor generator MG2 is a motor generator primarily used as a generator, and is composed of, for example, an AC motor. The second motor generator MG2 is driven by the power of the engine ENG and generates electricity. The electricity generated by the second motor generator MG2 is supplied to at least one of the battery BAT and the first motor generator MG1 via the power converter 11. By supplying the electricity generated by the second motor generator MG2 to the battery BAT, the battery BAT can be charged with that electricity. Also, by supplying the electricity generated by the second motor generator MG2 to the first motor generator MG1, the first motor generator MG1 can be driven with that electricity. 【0021】 Furthermore, the second motor generator MG2 can also function as a starter motor to start the engine. That is, for example, when transitioning from EV driving mode to series driving mode as described later, power from the battery BAT is supplied to the second motor generator MG2, and the second motor generator MG2, driven by that power, cranks the engine, thereby starting the engine. 【0022】 The power converter 11 is a device (a so-called power control unit, also called a "PCU") that converts the input power and outputs the converted power, and is connected to the first motor generator MG1, the second motor generator MG2, and the battery BAT. For example, the power converter 11 is composed of a first inverter 111, a second inverter 112, and a voltage control device 110. The first inverter 111, the second inverter 112, and the voltage control device 110 are electrically connected to each other. 【0023】 The voltage control device 110 converts the input voltage and outputs the converted voltage. A DC / DC converter or the like can be used as the voltage control device 110. For example, when supplying power from the battery BAT to the first motor generator MG1, the voltage control device 110 boosts the output voltage of the battery BAT and outputs it to the first inverter 111. Also, for example, when regenerative power generation is performed by the first motor generator MG1, the voltage control device 110 steps down the output voltage of the first motor generator MG1, which is received via the first inverter 111, and outputs it to the battery BAT. Also, when power generation is performed by the second motor generator MG2, the voltage control device 110 steps down the output voltage of the second motor generator MG2, which is received via the second inverter 112, and outputs it to the battery BAT. 【0024】 When the first inverter 111 supplies power from the battery BAT to the first motor generator MG1, it converts the power (DC) from the battery BAT received via the voltage control device 110 into AC and outputs it to the first motor generator MG1. Also, when regenerative power generation is performed by the first motor generator MG1, the first inverter 111 converts the power (AC) received from the first motor generator MG1 into DC and outputs it to the voltage control device 110. Furthermore, when the first inverter 111 decommissions the regenerative power from the first motor generator MG1, it converts the power (AC) received from the first motor generator MG1 into DC and outputs it to the second inverter 112. 【0025】When power is generated by the second motor generator MG2, the second inverter 112 converts the power (AC) received from the second motor generator MG2 into DC and outputs it to the voltage control device 110. Also, when the regenerative power of the first motor generator MG1 is to be discarded, the second inverter 112 converts the regenerative power (DC) received from the first motor generator MG1 via the first inverter 111 into AC and outputs it to the second motor generator MG2. 【0026】 A battery (BAT) is a rechargeable secondary battery having multiple energy storage cells connected in series or in series-parallel. A battery (BAT) is configured to output high voltages, such as 100 to 400 [V]. Lithium-ion batteries and nickel-metal hydride batteries can be used as the energy storage cells in a battery (BAT). 【0027】 The clutch CL can be in a connected state, which connects (closes) the power transmission path from the engine ENG to the drive wheel DW, and a disconnected state, which disconnects (interrupts) the power transmission path from the engine ENG to the drive wheel DW. The output of the engine ENG is transmitted to the drive wheel DW when the clutch CL is in the connected state, and not transmitted to the drive wheel DW when the clutch CL is in the disconnected state. 【0028】 The control device 20 is a device (computer) that provides overall control for the entire vehicle 10. For example, it is implemented by an ECU (Electronic Control Unit) that includes a processor 21 for performing various calculations, a memory 22 for storing various information, and an I / F 23 (I / F: Interface) 23 for controlling the input and output of data between the inside and outside of the control device 20. The control device 20 may be implemented by one ECU or by multiple ECUs. 【0029】The control device 20 is provided to communicate with the engine ENG, clutch CL, power converter 11, and various sensors. The control device 20 controls the output of the engine ENG, controls the output of the first motor generator MG1 and the second motor generator MG2 by controlling the power converter 11, and controls the state of the clutch CL, through the execution of a program stored in the memory 22 by the processor 21. As a result, the control device 20 can control the driving mode of the vehicle 10, as will be described later. 【0030】 [Driving Modes] Here, we will explain the driving modes that the vehicle 10 can take. The vehicle 10 can take three driving modes: EV driving mode, series driving mode, and engine driving mode. The vehicle 10 will then drive in one of these driving modes. The control device 20 controls which driving mode the vehicle 10 will be driven in. 【0031】 [EV Driving Mode] The EV driving mode is an example of the first driving mode in the present invention, in which only the power from the battery BAT is supplied to the first motor generator MG1, and the vehicle 10 is driven by the power output by the first motor generator MG1 according to that power. The EV driving mode is a driving mode in which the vehicle is driven by driving the drive wheels DW only with the first motor generator MG1 of the engine ENG and the first motor generator MG1. 【0032】 To explain in more detail, in EV driving mode, the control device 20 disengages the clutch CL. Also in EV driving mode, the control device 20 stops the supply of fuel to the engine ENG and stops the output of power from the engine ENG (hereinafter also referred to as "engine ENG operation"). Therefore, in EV driving mode, power generation by the second motor generator MG2 does not occur. In EV driving mode, the control device 20 supplies only the power from the battery BAT to the first motor generator MG1, and the first motor generator MG1 outputs power corresponding to that power, and the vehicle 10 is driven by that power. 【0033】 The control device 20 basically drives the vehicle 10 in EV driving mode on the condition that the power required by the vehicle 10 (hereinafter also referred to as "vehicle-required power") is below a predetermined threshold (hereinafter also referred to as "EV-permitted power"). The vehicle-required power in EV driving mode includes the power required to drive the vehicle 10 by the first motor generator MG1, and changes according to the required driving force and vehicle speed. 【0034】 [Series Driving Mode] The series driving mode is an example of the second driving mode in the present invention, in which at least the power generated by the second motor generator MG2 is supplied to the first motor generator MG1, and the vehicle 10 is driven mainly by the power output by the first motor generator MG1 in accordance with that power. The series driving mode is a driving mode in which the drive wheels DW are driven by only the first motor generator MG1 of the engine ENG and the first motor generator MG1. 【0035】 To explain in more detail, in series driving mode, the control device 20 disengages the clutch CL. Also in series driving mode, the control device 20 supplies fuel to the engine ENG, causing the engine ENG to output power, and the power from the engine ENG drives the second motor generator MG2. As a result, in series driving mode, power is generated by the second motor generator MG2. Also in series driving mode, the control device 20 disengages the power transmission path with the clutch CL, supplies the power generated by the second motor generator MG2 to the first motor generator MG1, causes the first motor generator MG1 to output power corresponding to that power, and uses that power to drive the vehicle 10. 【0036】 The maximum power that can be supplied from the second motor generator MG2 to the first motor generator MG1 is greater than the maximum power that can be supplied from the battery BAT to the first motor generator MG1. Therefore, in series driving mode, the output of the first motor generator MG1 can be increased compared to EV driving mode, and a greater driving force can be obtained. 【0037】 In series driving mode, the control device 20 may also supply power from the battery BAT to the first motor generator MG1 as needed. That is, in series driving mode, the control device 20 may supply power from both the second motor generator MG2 and the battery BAT to the first motor generator MG1. This allows for a greater amount of power to be supplied to the first motor generator MG1 compared to the case where only power from the second motor generator MG2 is supplied to the first motor generator MG1, thereby obtaining an even greater driving force. 【0038】 [Engine Driving Mode] The engine driving mode is a driving mode in which the vehicle 10 is driven primarily by the power output of the engine ENG, and is a driving mode in which the vehicle is driven by at least the mechanical driving force of the engine ENG driving the drive wheels DW. 【0039】 To explain in more detail, in engine-driven mode, the control device 20 engages the clutch CL. Also in engine-driven mode, the control device 20 supplies fuel to the engine ENG, causing the engine ENG to output power. In engine-driven mode, since the power transmission path is engaged by the clutch CL, the power from the engine ENG is transmitted to the drive wheels DW, driving the drive wheels DW. In this way, in engine-driven mode, the control device 20 causes the engine ENG to output power, and that power drives the vehicle 10. 【0040】Furthermore, in engine-driven mode, the control device 20 may supply power from the battery BAT to the first motor generator MG1 as needed. This allows the vehicle 10 to be driven using the power output of the first motor generator MG1, which is supplied with power from the battery BAT, in engine-driven mode, resulting in a greater driving force compared to when the vehicle 10 is driven solely by the engine ENG. In addition, this allows the engine ENG output to be suppressed compared to when the vehicle 10 is driven solely by the engine ENG, thereby improving the fuel efficiency of the vehicle 10. 【0041】 The control device 20 executes various programs stored in, for example, the memory 22. As mentioned above, the vehicle 10 can be driven in multiple drive modes, and the control device 20 controls which driving mode to use. Also, when the vehicle is driven in series, the engine ENG is controlled with the engine ENG and drive wheels DW disconnected, so the engine speed Ne will not correspond to the accelerator operation, which may cause discomfort to the user. Therefore, in order to reduce such discomfort to the user, the control device 20 executes a predetermined program to control the second motor generator MG2 so that the engine speed Ne is based on a simulated gear shift. A simulated gear shift is a gear shift that simulates a gear shift that is determined based on, for example, the vehicle speed and the accelerator opening when the engine ENG and drive wheels DW are disconnected. 【0042】 In vehicle 10, during series driving, it is possible to select between a stepped transmission mode, in which the second motor generator MG2 is controlled so that the engine speed Ne is based on such pseudo-gear stages, and a continuously variable transmission mode, in which there are no pseudo-gear stages. 【0043】Also, when the vehicle 10 travels in the stepped shift mode of series driving, as described above, the drive wheels DW are driven by the first motor generator MG1 to travel. Even in that case, in order to reduce the discomfort felt by the user due to fluctuations in the engine speed Ne, it is preferable to realize acceleration / deceleration characteristics based on the pseudo gear positions. FIG. 13 is a diagram showing an example of a map of the torque characteristics of the first motor generator MG1 corresponding to "first gear" to "eighth gear" in the pseudo gear positions. The horizontal axis represents the vehicle speed, and the vertical axis represents the driving force. The control device 20 controls the first motor generator MG1 so as to output a driving force based on the selected pseudo gear position by referring to the driving force line of the driving force map for each pseudo gear position. Note that the driving force map is not limited to the case where the driving force becomes a constant value regardless of the vehicle speed, as shown in FIG. 13. For example, as shown in FIG. 14, the driving force may vary according to the vehicle speed. FIG. 14 is a diagram showing another example of a map of the torque characteristics of the first motor generator MG1 corresponding to "first gear" to "eighth gear" in the pseudo gear positions. 【0044】 Also, it is preferable that the vehicle 10 can select the stepped shift mode even when traveling in EV driving. During EV driving, although the engine ENG is in a stopped state, by realizing acceleration / deceleration characteristics based on the pseudo gear positions, the discomfort felt by users accustomed to stepped shifting can be suppressed. 【0045】 Also, it is preferable that the vehicle 10 can be shifted according to a shift request from the user, such as so-called paddle shift. In the manual shift mode, the pseudo gear position is set based on the shift request from the user. A mode in which the pseudo gear position is automatically set by the control device 20 for the manual shift mode is called an automatic shift mode. 【0046】 As functional units realized by the execution of such a program, the control device 20 includes, as shown in FIG. 2, a pseudo shift control unit 210 and an upshift delay control unit 220. In the following, the processes described as being performed by the pseudo shift control unit 210 and the upshift delay control unit 220 are processes realized by the control device 20. 【0047】Note that detection values from various sensors are input to the control device 20. For example, a detection value from an accelerator position sensor 120 that detects an operation amount (accelerator opening) with respect to the accelerator pedal of the vehicle 10, a vehicle speed sensor 130 that detects the vehicle speed which is the traveling speed of the vehicle 10, an acceleration sensor 140 that detects the acceleration which is the traveling acceleration of the vehicle 10, a brake sensor 150 that detects an operation amount with respect to the brake pedal of the vehicle 10, etc. are input. 【0048】 The pseudo shift control unit 210 determines the engine speed Ne with respect to the vehicle speed based on a pseudo shift stage set based on the vehicle speed and the accelerator opening. In other words, the pseudo shift control unit 210 controls the engine speed Ne of the engine ENG to a speed determined by a plurality of second virtual shift lines preset according to the pseudo shift stage and the vehicle speed. 【0049】 For example, the pseudo shift control unit 210 determines the pseudo shift stage based on a shift map stored in the memory 22 in advance. FIGS. 3 and 4 are diagrams showing an example of the shift map. FIG. 3 shows an example of the shift map when downshifting while traveling in the normal mode, and FIG. 4 shows an example of the shift map when upshifting while traveling in the normal mode. In these shift maps, the solid line indicates the downshift line (first virtual shift line) or the upshift line (first virtual shift line) in the normal shift control. The pseudo shift control unit 210 executes an upshift or a downshift according to changes in the vehicle speed and the accelerator opening. 【0050】A predetermined hysteresis is set between the downshift line in the shift map of Figure 3 and the upshift line in the shift map of Figure 4. This is to prevent the user from being annoyed by the gear shifts occurring multiple times in a short period of time. For example, hysteresis is provided 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". Although Figures 3 and 4 show the shift map in normal mode as an example, the pseudo-shift control unit 210 may switch gears based on a shift map in sport mode (not shown) when driving in sport mode, and may switch gears based on a shift map in comfort mode (not shown) when driving in comfort mode. 【0051】 The pseudo-gear control unit 210 determines the engine speed Ne in relation to the vehicle speed based on the pseudo-gear stage set in this manner. The pseudo-gear control unit 210 determines the engine speed in relation to the vehicle speed based on, for example, an Ne search map pre-stored in the memory 22. Figure 5 is a diagram showing an example of an Ne search map for determining the engine speed Ne when pseudo-gear control is performed in normal mode. The Ne search map shows a plurality of pre-set engine speeds Ne (second virtual gear lines) according to the vehicle speed and pseudo-gear stage. Although Figure 5 shows an example of an Ne search map in normal mode, the pseudo-gear control unit 210 may determine the engine speed in relation to the vehicle speed based on an Ne search map in sport mode (not shown) when driving in sport mode, and may determine the engine speed in relation to the vehicle speed based on an Ne search map in comfort mode (not shown) when driving in comfort mode. 【0052】Specifically, when the vehicle 10 is in motion, the pseudo-gear control unit 210 refers to the Ne search map in Figure 5 and determines the engine speed Ne for each pseudo-gear stage 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 stage, and the pseudo-gear control unit 210 performs an upshift or downshift when the engine speed Ne exceeds these thresholds. In Figure 5, the solid line shows the engine speed Ne during acceleration, i.e., the engine speed Ne during an upshift, and the dashed line shows the engine speed Ne during deceleration, i.e., the engine speed Ne during a downshift. 【0053】 In this simulated gear shift control, which determines the engine speed Ne relative to the vehicle speed based on the simulated gear stage, the simulated gear shift is performed by changing the driving force of the second motor generator MG2. As described later, there is no mechanical switching involved in the gear change during shifting. Therefore, gear changes can be made in a short time, and shift hunting, where gear changes occur in rapid succession, can occur. In particular, if an upshift occurs shortly after a downshift, the engine speed increases with the downshift and then immediately decreases with the upshift. Such a rapid rise followed by a rapid drop in engine speed can cause discomfort to the user. 【0054】 Figure 6 is a time chart of upshifts after downshifts in a vehicle equipped with a conventional stepped transmission. In a vehicle equipped with a conventional stepped transmission, when the user presses the accelerator pedal, the target gear changes from gear β to gear β-1. The actual gear, which is the actual gear for control purposes, changes from gear β to gear β-1 when the difference in rotational speed between the engine speed and the target engine speed falls below a predetermined value. 【0055】Next, when the user releases the accelerator pedal, the target gear changes from gear β-1 to gear β. During this time, torque is reapplied in the torque phase through mechanical switching, and then rotational changes occur in the inertia phase. The actual gear change, which is the control stage, changes from gear β-1 to gear β when the difference in rotational speed between the engine speed and the target engine speed falls below a predetermined value. In this way, in vehicles equipped with a stepped transmission, the engine speed is maintained at a high rotational speed during the torque phase through mechanical gear switching, and then the rotational speed decreases. 【0056】 Figure 7 is a time chart of upshifts after downshifts in a vehicle that does not have a stepped transmission and uses simulated gear shift control. In a vehicle using simulated gear shift control, when the user presses the accelerator pedal, the target gear changes from gear β to gear β-1. The actual gear change, which is the actual gear change in terms of control, changes from gear β to gear β-1 when the difference in rotational speed between the engine speed and the target engine speed falls below a predetermined value, which is the same as in the conventional system. 【0057】 Next, when the user releases the accelerator pedal, the target gear changes from gear β-1 to gear β. In simulated gear shift control, there is no mechanical switching, so the engine speed begins to decrease as the target gear changes. The actual gear, which is the actual gear in the control system, changes from gear β-1 to gear β when the difference in rotational speed between the engine speed and the target engine speed falls below a predetermined value. In this way, in vehicles that use simulated gear shift control, the high engine speed state is not maintained, shift hunting occurs, and the engine speed decreases rapidly after rising. 【0058】 Therefore, in stepped transmission mode, when the upshift delay control unit 220 receives an upshift request after a gear change, it maintains the gear change for a predetermined period of time and performs upshift delay control to shift up after the predetermined period has elapsed. In the following, this predetermined period will be referred to as the delay period. 【0059】Figure 8 is a time chart showing the case when upshift delay control is performed during an upshift after a downshift in a vehicle that performs simulated gear shift control. In a vehicle that performs simulated gear shift control, when the accelerator pedal is pressed by the user, the target gear position is changed from gear position β to gear position β-1. The actual gear position, which is the actual gear position in the control system, is changed from gear position β to gear position β-1 when the difference in rotational speed between the engine speed and the target engine speed falls below a predetermined value. 【0060】 At this time, the upshift delay control unit 220 starts a delay timer when the actual gear is changed and prohibits changing the target gear until the delay period has elapsed. During this time, even if the user releases the accelerator pedal, the target gear remains at the current gear, gear β-1, until the elapsed time of the timer exceeds the delay end threshold. The engine speed is also maintained during this time. When the elapsed time of the timer exceeds the delay end threshold, the change of the target gear is permitted, and the target gear is changed from gear β-1 to gear β. The actual gear, which is the control's actual gear, is changed from gear β-1 to gear β when the difference in rotations between the engine speed and the target engine speed falls below a predetermined value. 【0061】 By performing upshift delay control in this manner, the target gear is maintained during the delay period, preventing a sudden drop in engine speed. Therefore, even in vehicles that perform simulated gear shift control, a period of high engine speed can be maintained, suppressing shift hunting. This prevents a sudden drop in engine speed immediately following a sudden increase. 【0062】 The delay time may be set differently depending on the gear. For example, if there are simulated gears from 1st to 8th gear, the delay time may be set differently for each gear, and it may be set differently for the lower gears (e.g., 1st to 4th gear) and the higher gears (e.g., 5th to 8th gear). 【0063】Furthermore, the delay time may be set differently depending on drive-related information such as accelerator pedal opening, engine speed, and driving mode. By changing the delay time according to the drive-related information, appropriate driving can be achieved according to that information. 【0064】 The delay time may be set according to driving force information values ​​such as accelerator pedal opening and engine speed. Furthermore, the delay time may change linearly or in a step-like manner. 【0065】 For example, when the accelerator pedal is opened widely, it is preferable to shorten the delay time compared to when the accelerator pedal is opened only slightly. If the gear is maintained for a long time when the accelerator pedal is opened widely, the user will feel a strong pulling sensation, which will be annoying. Similarly, when the engine speed is high, it is preferable to shorten the delay time compared to when the engine speed is low. If the gear is maintained for a long time when the engine speed is high, the user will feel a strong pulling sensation, which will be annoying. 【0066】 Furthermore, for example, in the driving modes, the delay time for sport mode may be made longer than the delay time for normal mode, and the delay time for normal mode may be made longer than the delay time for comfort mode. 【0067】 Figure 9 is a graph showing an example of delay time in sport mode. In the example in Figure 9, the delay time is set for each gear and also according to the accelerator pedal opening. Note that Figure 9 only shows the delay time for 3rd to 6th gear. The same applies to Figures 10 to 12. Also, in Figure 9, the engine speed is fixed. That is, Figure 9 shows the delay time at a predetermined engine speed. 【0068】In the example shown in Figure 9, the delay time increases as the gear speed increases from 3rd to 6th gear. In other words, the delay time at lower gears is shorter than the delay time at higher gears. Since the vehicle speed range used at lower gears is lower and ambient noise tends to be lower, if the gear is held for a long time at lower gears, the user may feel a strong pulling sensation and find it annoying. Therefore, by shortening the delay time at lower gears, this annoying feeling can be reduced. 【0069】 Furthermore, in 4th to 6th gear, if we define the region with a small accelerator pedal opening as the first region P1, the region with a larger accelerator pedal opening than the first region P1 as the second region P2, and the region with a larger accelerator pedal opening than the second region P2 as the third region P3, then the delay time in the first region P1 is longer than the delay time in the third region P3, and the delay time in the second region decreases from the first region to the third region. By dividing the user's driving requests into the first to third regions according to the accelerator pedal opening, and shortening the delay time when the accelerator pedal opening is high, it is possible to allow early shift changes while preventing shift hunting. In addition, by decreasing the second region from the first region to the third region, it is possible to suppress sudden changes in driving conditions around a certain value. 【0070】 Furthermore, the reduction in delay time in the second region is greater on the high-speed gear side than on the low-speed gear side. By increasing the reduction in delay time on the high-speed gear side, it is possible to suppress situations where the same gear is maintained for a long time when an upshift request is made at high vehicle speed. As a result, it is possible to perform driving that is closer to the user's wishes while suppressing shift hunting even on the high-speed gear side. 【0071】 Figure 10 is a graph showing another example of delay time in sport mode. In the example in Figure 10, the delay time is set for each gear and also according to the engine speed. Also, in Figure 10, the accelerator pedal opening is fixed. That is, Figure 10 shows the delay time at a predetermined accelerator pedal opening. The same applies to Figures 11 and 12 that follow. 【0072】In the example shown in Figure 10, the delay time increases as the gear speed increases from 3rd to 6th gear. Furthermore, in gears 4 through 6, if we define the region with low engine speed as the first region P1, the region with higher engine speeds than the first region P1 as the second region P2, and the region with higher engine speeds than the second region P2 as the third region P3, then the delay time in the first region P1 is longer than the delay time in the third region P3, and the delay time in the second region decreases from the first region to the third region. By dividing the user's driving requests into the first to third regions according to the engine speed, and shortening the delay time when the engine speed is high, it is possible to allow early gear changes while preventing shift hunting. In addition, by decreasing the second region from the first region to the third region, it is possible to suppress sudden changes in driving conditions around a certain value. 【0073】 Furthermore, the reduction in delay time in the second region is greater on the high-speed gear side than on the low-speed gear side. By increasing the reduction in delay time on the high-speed gear side, it is possible to suppress situations where the same gear is maintained for a long time when an upshift request is made at high vehicle speed. As a result, it is possible to perform driving that is closer to the user's wishes while suppressing shift hunting even on the high-speed gear side. 【0074】 Figure 11 is a graph showing an example of delay time in normal mode. In the example in Figure 11, the delay time is set for each gear and also according to the engine speed. 【0075】 In the example in Figure 11, similar to Figure 10, the delay time increases as the gear speed increases from 3rd to 6th gear. Also, from 4th to 6th gear, the delay time in the first region P1 is longer than the delay time in the third region P3, and the delay time in the second region is set to decrease from the first region to the third region. Furthermore, the decrease in delay time in the second region is greater on the higher gear side than on the lower gear side. 【0076】Furthermore, comparing the delay time in Normal Mode in Figure 11 with the delay time in Sport Mode in Figure 10, the delay time in Normal Mode in Figure 11 is set to be shorter than the delay time in Sport Mode in Figure 10. 【0077】 Figure 12 is a graph showing an example of delay time in Comfort mode. In the example in Figure 12, the delay time is fixed regardless of the gear shift and also regardless of the engine speed. Comparing the delay time in Comfort mode in Figure 12 with the delay time in Sport mode in Figure 10 and the delay time in Normal mode in Figure 11, the delay time in Comfort mode in Figure 12 is set to be shorter than the delay time in Sport mode in Figure 10 and the delay time in Normal mode in Figure 11. 【0078】 In this embodiment, we have illustrated the case where upshift delay control is performed during an upshift after a downshift, but upshift delay control is not limited to this, and may also be performed during an upshift after an upshift. In this case, the delay time may be set for each gear, with a delay time for when an upshift request is received after an upshift of a gear and a delay time for when an upshift request is received after a downshift of a gear. For example, an upshift request after a downshift means that a downshift was performed immediately beforehand by the driver pressing the accelerator, so the driver's intention to drive actively can be understood at the time of occurrence, whereas an upshift request after an upshift can be considered to be occurring because the driver's intention to drive actively has already disappeared. Therefore, in the higher gears where the driver is less likely to feel annoyed by the significantly high engine speed when requesting an upshift after a downshift, the delay time for requesting an upshift after a downshift may be set longer than for requesting an upshift after an upshift. Conversely, in the lower gears where the driver is more likely to feel annoyed by the significantly high engine speed, the delay time for requesting an upshift after a downshift may be set shorter than for requesting an upshift after an upshift. 【0079】Furthermore, when the user operates the paddle shifters or the like to change the gear ratio, i.e., in manual shift mode, upshift delay control is not performed. In other words, if the user's upshift operation by operating the paddle shifters or the like occurs during the delay time, the control device 20 will execute the upshift even during the delay time. This prevents the user from feeling uncomfortable by suppressing changes from the gear ratio set by the user themselves. 【0080】 Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to this embodiment. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. 【0081】 The control method described in this embodiment can be implemented by executing a pre-prepared program (control program) on a computer. This control program is stored, for example, in a computer-readable storage medium (e.g., memory 22) and executed by being read from this storage medium. This control program may also be provided in the form of a non-volatile (non-transient) storage medium such as flash memory, or it may be provided via a network such as the Internet. 【0082】 Furthermore, in this embodiment, the computer that executes the control program is designated as the control device 20, and the processor 21 of the control device 20 executes the control program to realize the aforementioned control method, but this is not limited to this. The computer that executes the control program is not limited to one included in the vehicle 10, but may, for example, be included in a server device that can communicate with the vehicle 10 (control device 20). 【0083】Furthermore, although the above-described embodiment exemplifies a hybrid electric vehicle equipped with an engine, it is not limited to this, and may also be an electric vehicle without an engine, as shown in Figure 15. Figure 15 is a diagram showing the schematic configuration of vehicle 10A, which is an electric vehicle without an engine. The reference numerals shown in Figure 15 are the same as those in Figure 1, so a detailed explanation is omitted. 【0084】 In the simulated gear shift control of this vehicle 10A, the simulated gear shift control unit 210 controls the first motor generator MG1 to output a driving force based on the selected simulated gear step, referring to the map shown in Figure 13. The upshift delay control unit 220, when it receives an upshift request after a gear shift in this stepped gear shift mode, maintains the gear step after the shift for a predetermined period of time and performs upshift delay control to shift up after the predetermined period has elapsed. 【0085】 This specification contains at least the following information. The components and other elements corresponding to those in the embodiments described above are shown in parentheses as examples, but are not limited thereto. 【0086】 (1) A vehicle (vehicle 10) comprising: an engine (engine ENG); a first electric motor (first motor generator MG1) mechanically connected to a drive wheel (drive wheel DW); a second electric motor (second motor generator MG2) mechanically connected to the engine; a battery (battery BAT) capable of outputting power used to drive the first electric motor; and a control device (control device 20) capable of controlling the engine, the battery, the first electric motor, and the second electric motor, wherein the control device has a virtual stepped gear mode that controls the engine speed to a speed determined by a preset virtual gear line (second virtual gear line) and the vehicle speed while moving by the braking and driving force of the first electric motor, and the control device performs upshift delay control in the virtual stepped gear mode, which, when an upshift request is received after a gear shift, maintains the gear shift after the gear shift for a predetermined period of time and upshifts the gear after the predetermined period has elapsed. 【0087】In the virtual stepped gear shift mode, the engine speed is changed by modifying the output of the second motor based on the virtual gear shift line to simulate gear changes, so there is no mechanical switching when shifting gears. As a result, gear changes can be made in a short time, which can lead to shift hunting, where gear changes occur in rapid succession. According to (1), by setting a delay time when upshifting after gear changes, shift hunting can be suppressed, as can rapid increases and decreases in engine speed, thereby reducing discomfort for the user while driving. 【0088】 (2) A vehicle (vehicle 10, 10A) comprising: an electric motor (first motor generator MG1) mechanically connected to a drive wheel (drive wheel DW); a battery (battery BAT) capable of outputting power used to drive the electric motor; and a control device (control device 20) capable of controlling the battery and the electric motor, wherein the control device has a virtual stepped gear mode in which the driving force of the electric motor is driven by the braking force of the electric motor while the vehicle is moving, based on a preset driving force line (driving force line) and vehicle speed according to the gear shift, and the control device, in the virtual stepped gear mode, when it receives an upshift request after shifting gears, maintains the gear shift after shifting gears for a predetermined period of time, and performs upshift delay control to shift gears after the predetermined period has elapsed. 【0089】 In the virtual stepped gear shift mode, simulated gear changes are performed by changing the driving force of the electric motor based on the driving force line, so there is no mechanical switching when shifting gears. As a result, gear changes can be made in a short time, which can lead to shift hunting, where gear changes occur in rapid succession. According to (2), by setting a delay time when upshifting after gear changes, shift hunting can be suppressed, as well as rapid increases and decreases in engine speed in a short period of time, thereby reducing discomfort for the user while driving. 【0090】 (3) A vehicle as described in (1) or (2), wherein the predetermined period is set to differ depending on the gear, and the predetermined period on the low-speed side is shorter than the predetermined period on the high-speed side. 【0091】 According to (3), the vehicle speed range used in the lower gears is low, and the ambient noise tends to be low. Therefore, if the time spent maintaining the gear in the lower gears is long, the user may feel a strong pulling sensation and find it annoying. For this reason, shortening the delay time in the lower gears can reduce this annoying feeling. 【0092】 (4) A vehicle as described in (3), wherein the predetermined period is set to vary based on drive-related information relating to the driving of the vehicle. 【0093】 According to (4), by changing a predetermined period according to drive-related information such as accelerator pedal opening, engine speed, and driving mode, appropriate driving can be achieved according to the drive-related information. 【0094】 (5) A vehicle as described in (4), wherein the drive-related information includes drive-related values, the predetermined period includes a first region, a second region in which the drive-related values ​​are greater than those of the first region, and a third region in which the drive-related values ​​are greater than those of the second region, the predetermined period of the first region is longer than the predetermined period of the third region, and the predetermined period of the second region decreases from the first region to the third region. 【0095】 According to (5), the user's driving requests are divided into first to third regions according to the drive-related values, and the predetermined period is shortened when the drive-related values ​​are high, thereby allowing for early shift changes while preventing shift hunting when the drive-related values ​​are high. In addition, by decreasing the second region from the first region to the third region, it is possible to suppress sudden changes in driving conditions around a specific value. 【0096】 (6) A vehicle as described in (5), wherein the amount of reduction in the second region over the predetermined period is greater on the high-speed side than on the low-speed side. 【0097】According to (6), by increasing the amount of reduction over a predetermined period on the high-speed side, it is possible to suppress the situation in which the same gear is maintained for a long time when an upshift request is made at high vehicle speed. As a result, it is possible to drive in a manner closer to the user's wishes while suppressing shift hunting even on the high-speed side. 【0098】 (7) A vehicle as described in (1), wherein, as the gear ratio moves toward the higher gear side, the predetermined period when an upshift request is received after an upshift of the gear ratio is set to be shorter than the predetermined period when an upshift request is received after a downshift of the gear ratio. 【0099】 According to (7), in the case of an upshift request after a downshift, which can be interpreted as an intention to drive aggressively, the delay time for an upshift request after a downshift is set to be longer than the delay time for an upshift request after an upshift, as the driver is less likely to feel annoyed by the significantly high engine speed in the higher gears. 【0100】 (8) A vehicle as described in (1), wherein, as the gear ratio moves toward the lower gear side, the predetermined period when an upshift request is received after an upshift of the gear ratio is set to be longer than the predetermined period when an upshift request is received after a downshift of the gear ratio. 【0101】 According to (8), in the lower gears where the user feels annoyed by the significantly high engine speed, the delay setting time for an upshift request after a downshift is set shorter than the delay setting time for an upshift request after an upshift. 【0102】 (9) A vehicle according to (1) or (2), wherein the control device comprises a manual shift mode for switching the gear position by an upshift or downshift operation based on the driver's manual operation, and an automatic shift mode for shifting gears based on the driving state of the vehicle, wherein in the manual shift mode, if an upshift operation occurs during a predetermined period, the gear position is shifted up. 【0103】According to (9), in manual shift mode, an upshift can be performed when requested by the user, thereby reducing the user's discomfort. 【0104】 10, 10A Vehicle 20 Control device BAT Battery DW Drive wheels ENG Engine MG1 First motor generator (first motor, motor) MG2 Second motor generator (second motor)

Claims

1. A vehicle comprising: an engine; a first electric motor mechanically connected to a drive wheel; a second electric motor mechanically connected to the engine; a battery capable of outputting power used to drive the first electric motor; and a control device capable of controlling the engine, the battery, the first electric motor, and the second electric motor, wherein the control device has a virtual stepped transmission mode that controls the engine speed to a speed determined by a preset virtual transmission line and vehicle speed according to the gear shift while the vehicle is moving, using the braking and driving force of the first electric motor; and the control device, in the virtual stepped transmission mode, performs upshift delay control to maintain the gear shift after the gear shift for a predetermined period of time and upshift the gear after the predetermined period has elapsed.

2. A vehicle comprising: an electric motor mechanically connected to a drive wheel; a battery capable of outputting power used to drive the electric motor; and a control device capable of controlling the battery and the electric motor, wherein the control device has a virtual stepped gear mode in which the driving force of the electric motor is driven by the braking force of the electric motor while the vehicle is moving, based on a preset drive force line and vehicle speed according to the gear position; and in the virtual stepped gear mode, when an upshift request is received after a gear shift, the control device maintains the gear position after the gear shift for a predetermined period of time, and performs upshift delay control to shift up the gear position after the predetermined period of time has elapsed.

3. A vehicle according to claim 1 or 2, wherein the predetermined period is set to differ depending on the gear shift, and the predetermined period on the low-speed side is shorter than the predetermined period on the high-speed side.

4. A vehicle according to claim 3, wherein the predetermined period is set to vary based on drive-related information relating to the driving of the vehicle.

5. The vehicle according to claim 4, wherein the drive-related information includes drive-related values, the predetermined period includes a first region, a second region in which the drive-related values ​​are greater than those of the first region, and a third region in which the drive-related values ​​are greater than those of the second region, the predetermined period of the first region is longer than the predetermined period of the third region, and the predetermined period of the second region decreases from the first region to the third region.

6. A vehicle according to claim 5, wherein the amount of reduction over the predetermined period in the second region is greater on the high-speed gear side than on the low-speed gear side.

7. A vehicle according to claim 1, wherein, as the gear ratio moves toward the higher gear side, the predetermined period when an upshift request is received after an upshift of the gear ratio is set to be shorter than the predetermined period when an upshift request is received after a downshift of the gear ratio.

8. A vehicle according to claim 1, wherein, as the gear ratio moves towards the lower gear side, the predetermined period when an upshift request is received after an upshift of the gear ratio is set to be longer than the predetermined period when an upshift request is received after a downshift of the gear ratio.

9. A vehicle according to claim 1 or 2, wherein the control device comprises a manual shift mode for switching the gear position by an upshift or downshift operation based on the driver's manual operation, and an automatic shift mode for shifting gears based on the driving state of the vehicle, wherein in the manual shift mode, if an upshift operation occurs during a predetermined period, the gear position is shifted up.

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