Hybrid vehicle driving control device

Abstract

A travel mode selection unit of this travel control device for a hybrid vehicle includes: a series maximum output calculation unit that sets, as the maximum output of a series travel mode, a value obtained by adding, to a smaller one of the maximum output of a generator or the maximum output of an engine, the maximum output of a driving battery for selection of a travel mode, and subtracting, from the resulting value, losses of a travelling motor and of the generator as a result of selection of the series travel mode; a parallel maximum output calculation unit that sets, as the maximum output of a parallel travel mode, a value obtained by subtracting losses of the travelling motor and of the generator as a result of selection of the parallel travel mode from the maximum output of the driving battery for selection of the travel mode, and adding, to the resulting value, an output of the engine at the engine rotation speed for selection of the travel mode; and a travel mode determination unit that compares the maximum output of the series travel mode obtained by the series maximum output calculation unit and the maximum output of the parallel travel mode obtained by the parallel maximum output calculation unit and determines a travel mode exhibiting a larger maximum output.

Description

[Technical field]

[0001] The present disclosure relates to a cruise control device for a hybrid vehicle. [Background technology]

[0002] Patent Document 1 discloses a driving mode control unit that switches the driving mode to one of a parallel driving mode, a series driving mode, and an EV driving mode by controlling a clutch based on information such as speed, a charging rate, and an accelerator opening. In the parallel driving mode, the driving mode control unit connects the clutch and drives the front wheel drive shaft by both the engine and the front motor. In the series driving mode, the driving mode control unit releases the clutch, drives the generator by the engine, supplies the electric power generated by the generator to the front motor and the rear motor, and the front motor and the rear motor drive the front wheel drive shaft and the rear wheel drive shaft. In the EV driving mode, the driving mode control unit releases the clutch and supplies the electric power of the drive battery to the front motor and the rear motor, and the front motor and the rear motor drive the front wheel drive shaft and the rear wheel drive shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021-261247 Summary of the Invention [Problem to be solved by the invention]

[0004] Although not disclosed in Patent Document 1, the driving control device of a hybrid vehicle is configured to select, when an output exceeding a predetermined threshold is required, either the parallel driving mode or the series driving mode, whichever driving mode provides the greater maximum output that the hybrid vehicle is capable of outputting.

[0005] However, even though the losses in the traction motor and generator are different between the parallel driving mode and the series driving mode, the maximum output in the series driving mode was calculated using the losses in the parallel driving mode (losses in the traction motor and generator) when the parallel driving mode was selected, and the maximum output in the parallel driving mode was calculated using the losses in the series driving mode (losses in the traction motor and generator) when the series driving mode was selected. As a result, the maximum output in the series driving mode was overcalculated when the parallel driving mode was selected, and the maximum output in the parallel driving mode was undercalculated when the series driving mode was selected.

[0006] In consideration of the above-mentioned circumstances, at least one embodiment of the present invention aims to provide a driving control device for a hybrid vehicle that can appropriately calculate the maximum output in the parallel driving mode even when the series driving mode is selected, and that can appropriately calculate the maximum output in the series driving mode even when the parallel driving mode is selected. [Means for solving the problem]

[0007] (1) A hybrid vehicle travel control device according to at least one embodiment of the present invention includes a traction motor that drives drive wheels, an engine that drives the drive wheels and a generator, and a drive battery that stores electric power generated by the generator, and is capable of selecting either a series travel mode in which the traction motor drives the drive wheels with electric power generated by the engine driving the generator and electric power supplied from the drive battery, or a parallel travel mode in which the engine drives the drive wheels and the traction motor drives the drive wheels with electric power supplied from the drive battery, and includes a travel mode selection unit that selects, from the series travel mode or the parallel travel mode, the travel mode that has the largest maximum output that the hybrid vehicle can output when an output exceeding a predetermined threshold is requested. The traveling mode selection unit includes a series maximum output calculation unit that sets as the maximum output of the series traveling mode a value obtained by adding the smaller of the maximum output of the generator or the maximum output of the engine to the maximum output of the driving battery when the traveling mode is selected, and subtracting losses in the traveling motor and generator when the series traveling mode is selected from this value; a parallel maximum output calculation unit that sets as the maximum output of the parallel traveling mode a value obtained by subtracting losses in the traveling motor and generator when the parallel traveling mode is selected from the maximum output of the driving battery when the traveling mode is selected, and adding the output of the engine at the engine rotation speed when the traveling mode is selected; and a traveling mode determination unit that compares the maximum output of the parallel traveling mode calculated by the parallel maximum output calculation unit and the maximum output of the series traveling mode calculated by the series maximum output calculation unit, and determines the traveling mode with the larger maximum output.

[0008] According to the above configuration (1), even if an output exceeding the threshold is requested during the selection of the series driving mode, the parallel maximum output calculation unit calculates the maximum output of the parallel driving mode using the losses of the driving motor and the generator when the parallel driving mode is selected, so that the maximum output of the parallel driving mode can be appropriately calculated even during the selection of the series driving mode. Also, even if an output exceeding the threshold is requested during the selection of the parallel driving mode, the series maximum output calculation unit calculates the maximum output of the series driving mode using the losses of the driving motor and the generator when the series driving mode is selected, so that the maximum output of the series driving mode can be appropriately calculated even during the selection of the parallel driving mode. Then, the driving mode determination unit compares the maximum output of the series driving mode calculated in this way with the maximum output of the parallel driving mode, and determines the driving mode with the larger maximum output, so that the driving mode selection unit can select the driving mode with the larger true maximum output. This allows the driver to obtain the desired output within the output limit of the hybrid vehicle.

[0009] (2) In some embodiments, in the configuration described above in (1), while the parallel traveling mode is selected, losses in the traveling motor and the generator when the parallel traveling mode is selected are obtained from a motor control unit that controls the traveling motor and a generator control unit that controls the generator.

[0010] According to the above configuration (2), when the parallel traveling mode is selected, the losses acquired from the motor control unit and the generator control unit are regarded as the losses of the traveling motor and the generator. This is because the losses acquired from the motor control unit and the generator control unit when the parallel traveling mode is selected are the losses of the traveling motor and the generator when the parallel traveling mode is selected. This makes it possible to omit the calculation of losses in the parallel traveling mode when the parallel traveling mode is selected.

[0011] (3) In some embodiments, in the configuration of (1) or (2) above, while the series traveling mode is selected, the losses in the traction motor and generator when the series traveling mode is selected are obtained from a motor control unit that controls the traction motor and a generator control unit that controls the generator.

[0012] According to the above configuration (3), when the series traveling mode is selected, the losses acquired from the motor control unit and the generator control unit are regarded as the losses of the traveling motor and the generator. This is because the losses acquired from the motor control unit and the generator control unit when the series traveling mode is selected are the losses of the traveling motor and the generator when the series traveling mode is selected. This makes it possible to omit the calculation of losses in the series traveling mode when the series traveling mode is selected.

[0013] (4) In some embodiments, in the configuration of (1) above, the losses of the traction motor are determined by a motor loss map in which the losses of the traction motor are related to the torque and rotational speed of the traction motor, and the losses of the generator are determined by a generator loss map in which the losses of the generator are related to the torque and rotational speed of the generator.

[0014] According to the above configuration (4), the loss of the driving motor is calculated from the torque and rotation speed of the driving motor, and the loss of the generator is calculated from the torque and rotation speed of the generator. This simplifies the calculation of losses in the driving motor and the generator.

[0015] (5) In some embodiments, in the configuration of (4) above, the loss of the generator when the parallel running mode is selected is the loss when the torque of the generator is 0 in the generator loss map.

[0016] According to the above configuration (5), it is possible to easily obtain the loss of the generator when the parallel running mode is selected while the series running mode is selected. Effect of the Invention

[0017] According to at least one embodiment of the present invention, the maximum output in the parallel traveling mode can be appropriately calculated even when the series traveling mode is selected, and the maximum output in the series traveling mode can be appropriately calculated even when the parallel traveling mode is selected. [Brief description of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating a schematic configuration of a plug-in hybrid vehicle equipped with a driving control device according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram showing a control configuration of the hybrid vehicle shown in FIG. 1. [Figure 3A] FIG. 11 is a diagram for explaining calculation of maximum output in a series driving mode. [Figure 3B] FIG. 13 is a diagram for explaining calculation of maximum output in a parallel running mode. [Figure 4A] FIG. 11 is a diagram for explaining calculation of loss in a driving motor when a series driving mode is selected during a parallel driving mode selection. [Figure 4B] FIG. 11 is a diagram for explaining calculation of loss in a generator when a series traveling mode is selected while a parallel traveling mode is selected. [Diagram 5] 11 is a diagram for explaining calculation of losses in a traveling motor and a generator when a parallel traveling mode is selected during selection of a series traveling mode. FIG. [Figure 6] 3 is a flowchart showing the control contents of the driving control device of the plug-in hybrid vehicle according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0020] FIG. 1 is a diagram illustrating a schematic configuration of a plug-in hybrid vehicle 100 equipped with a cruise control device 1 according to an embodiment of the present invention.

[0021] The cruise control device 1 according to the embodiment of the present invention is mounted on a plug-in hybrid vehicle 100 that is externally chargeable and capable of external power supply, but can also be mounted on other hybrid vehicles, for example, hybrid vehicles that cannot be externally charged. Furthermore, the plug-in hybrid vehicle 100 on which the cruise control device 1 according to the embodiment of the present invention is mounted is a four-wheel drive plug-in hybrid vehicle, but can also be mounted on a two-wheel drive hybrid vehicle.

[0022] 1, a plug-in hybrid vehicle 100 equipped with a cruise control device 1 according to an embodiment of the present invention includes a traction motor 5 that drives drive wheels 3, an engine 9 that drives the drive wheels 3 and a generator 7, and a drive battery 11 that stores the electricity generated by the generator 7. In a four-wheel drive plug-in hybrid vehicle 100, the traction motor 5 is a front motor 15 that drives front wheels 13 and a rear motor 19 that drives rear wheels 17, and the engine 9 drives the front wheels 13, but the engine 9 may also drive the rear wheels 17.

[0023] The front motor 15 is connected to a front-wheel drive shaft 23 via a front transaxle 21, and the driving force of the front motor 15 is reduced and transmitted to the front-wheel drive shaft 23 to drive the front wheels 13. The rear motor 19 is connected to a rear-wheel drive shaft 27 via a rear transaxle 25, and the driving force of the rear motor 19 is reduced and transmitted to the rear-wheel drive shaft 27 to drive the rear wheels 17. The engine 9 is connected to the front-wheel drive shaft 23 and the generator 7 via the front transaxle 21, and the driving force of the engine 9 is reduced and transmitted to the front-wheel drive shaft 23 and the generator 7 to drive the front wheels 13 and the generator 7. The front transaxle 21 is provided with a clutch 29 that blocks the transmission of driving force from the engine 9 to the front-wheel drive shaft 23, and the transmission of driving force from the engine 9 to the front-wheel drive shaft 23 is blocked by engaging the clutch 29, and the transmission of driving force from the engine 9 to the front-wheel drive shaft 23 is blocked by disengaging the clutch 29.

[0024] The front motor 15 and the generator 7 are connected to the drive battery 11 via a power drive unit 31. The power drive unit 31 is provided with a front motor control unit 33 and a generator control unit 35. The front motor control unit 33 controls the front motor 15, and is a unit that converts power from DC to AC or AC to DC, and manages the power loss and rotation speed of the front motor 15. The generator control unit 35 controls the generator 7, and is a unit that rectifies the power generated by the generator 7 from AC to DC, and manages the power loss and rotation speed of the generator 7.

[0025] The rear motor 19 is connected to the drive battery 11 via a rear motor control unit 37. The rear motor control unit 37 is a unit that controls the rear motor 19 and converts power from DC to AC or AC to DC, and manages the power loss and rotation speed of the rear motor 19.

[0026] A fuel tank 39 is connected to the engine 9, and fuel is supplied to the engine 9 from the fuel tank 39. In addition, an engine control unit 41 is connected to the engine 9. The engine control unit 41 is a unit that controls the engine 9, and the engine 9 is operated by combusting the fuel supplied from the fuel tank 39.

[0027] The driving battery 11 is provided with a battery management unit 43, which manages the charging rate (SOC (State Of Charge)) of the driving battery 11, the battery temperature, and the maximum output of the driving battery 11.

[0028] The front motor control unit 33, the generator control unit 35, the rear motor control unit 37, the engine control unit 41, and the battery management unit 43 are connected to a vehicle control unit 45 via an in-vehicle network CAN (Controller Area Network). As a result, the front motor control unit 33, the generator control unit 35, the rear motor control unit 37, the engine control unit 41, and the battery management unit 43 are managed by the vehicle control unit 45, and the front motor control unit 33, the generator control unit 35, the rear motor control unit 37, and the engine control unit 41 control the front motor 15, the generator 7, the rear motor 19, and the engine 9 according to commands from the vehicle control unit 45.

[0029] An accelerator position sensor (not shown) is connected to the vehicle control unit 45, and receives the depression amount and depression speed of an accelerator pedal 47 as an input.

[0030] A plug-in hybrid vehicle 100 equipped with a driving control device 1 according to an embodiment of the present invention can alternatively select an EV driving mode, a series driving mode, or a parallel driving mode. The EV driving mode is a driving mode in which the driving motor 5 drives the driving wheels 3 only with the electric power supplied from the driving battery 11, and in a four-wheel drive plug-in hybrid vehicle 100, the front motor 15 drives the front wheels 13 and the rear motor 19 drives the rear wheels 17. The series driving mode is a driving mode in which the driving motor 5 drives the driving wheels 3 with the electric power generated by the engine 9 driving the generator 7 and the electric power supplied from the driving battery 11, and in a four-wheel drive plug-in hybrid vehicle 100, the front motor 15 drives the front wheels 13 and the rear motor 19 drives the rear wheels 17. In the series driving mode according to this embodiment, the clutch 29 is released to interrupt the transmission of driving force from the engine 9 to the front wheel drive shaft 23. The parallel driving mode is a driving mode in which the engine 9 drives the drive wheels 3 and the traction motor 5 drives the drive wheels 3 with power supplied from the drive battery 11, and in a four-wheel drive plug-in hybrid vehicle 100, the engine 9 and front motor 15 drive the front wheels 13 and the rear motor 19 drives the rear wheels 17. In the parallel driving mode according to this embodiment, driving force is transmitted from the engine 9 to the front wheel drive shaft 23 by connecting the clutch 29.

[0031] In a plug-in hybrid vehicle 100 equipped with a driving control device 1 according to an embodiment of the present invention, when an output exceeding a predetermined threshold is required of the plug-in hybrid vehicle 100 and the power supplied from the driving battery 11 alone is not enough to cover the output required of the plug-in hybrid vehicle 100, the series driving mode or the parallel driving mode is selected.

[0032] The driving control device 1 according to the embodiment of the present invention is made up of the above-mentioned front motor control unit 33, generator control unit 35, rear motor control unit 37, engine control unit 41, battery management unit 43, and vehicle control unit 45. Each of these is made up of a processor (not shown) made up of an arithmetic unit, a register for storing instructions and information, and peripheral circuits, etc., memories (not shown) such as a ROM (Read Only Memory) and a RAM (Random Access Memory) and an input interface (not shown).

[0033] 2, the cruise control device 1 according to the embodiment of the present invention includes a motor control unit 49 including a front motor control unit 33 and a rear motor control unit 37, a generator control unit 35, an engine control unit 41, a battery management unit 43, and a vehicle control unit 45. A torque command (Nm command) is output from the vehicle control unit 45 to the motor control unit 49, the generator control unit 35, and the engine control unit 41, while power loss and rotation speed are input from the motor control unit 49 and the generator control unit 35 to the control control unit, and an upper limit power and the like are input from the battery control unit to the vehicle control unit 45.

[0034] The vehicle control unit 45 is provided with a driving mode selection section 51 that selects the driving mode that provides the greatest maximum output that the plug-in hybrid vehicle 100 can output from either the series driving mode or the parallel driving mode when an output exceeding a predetermined threshold is requested from the accelerator position sensor.

[0035] The running mode selection unit 51 includes a series maximum output calculation unit 53 , a parallel maximum output calculation unit 55 , and a running mode determination unit 57 .

[0036] 3A, the series maximum output calculation unit 53 calculates the maximum output that the plug-in hybrid vehicle 100 can output in the series driving mode. In the series driving mode according to this embodiment, the clutch 29 is released to interrupt the transmission of driving force from the engine 9 to the drive shaft (front-wheel drive shaft 23), so that the maximum output that the plug-in hybrid vehicle 100 can output is limited to equal to or less than the maximum output of the traction motor 5, regardless of the rotation speed of the engine 9. Therefore, the maximum output of the four-wheel drive plug-in hybrid vehicle 100 in the series driving mode is limited to equal to or less than the sum of the maximum output of the front motor 15 and the maximum output of the rear motor 19.

[0037] The series maximum output calculation unit 53 calculates the maximum output of the series driving mode by subtracting the losses of the driving motor 5 and the generator 7 when the series driving mode is selected from the smaller of the maximum output of the generator 7 or the maximum output of the engine 9 plus the maximum output of the driving battery 11 when the driving mode is selected. Here, the smaller of the maximum output of the generator 7 or the maximum output of the engine 9 is used because the power generated by the generator 7 is limited by the maximum output of the generator 7 and the maximum output of the engine 9. The losses of the plug-in hybrid vehicle 100 include the losses of the driving motor 5 and the generator 7 as well as the power consumption of the auxiliary equipment. However, the power consumption of the auxiliary equipment is consumed in the same way in the series driving mode and the parallel driving mode, so it is excluded from the calculation of the losses in this embodiment. In addition, in the calculation of the maximum output, the losses of the auxiliary equipment must be included in the losses of the plug-in hybrid vehicle 100, but the losses are consumed in the same way in the series driving mode and the parallel driving mode, so the same value is used in the calculation of the maximum output of both modes.

[0038] 3B, parallel maximum output calculation unit 55 calculates the maximum output that can be output by plug-in hybrid vehicle 100 in parallel driving mode. In the parallel driving mode according to this embodiment, the maximum output of traction motor 5 is limited to less than or equal to the maximum output of traction motor 5. Therefore, the maximum output of traction motor 5 of four-wheel drive plug-in hybrid vehicle 100 is limited to less than or equal to the sum of the maximum output of front motor 15 and the maximum output of rear motor 19.

[0039] The parallel maximum output calculation unit 55 calculates the maximum output in the parallel driving mode by subtracting the loss of the driving motor 5 and the generator 7 when the parallel driving mode is selected from the maximum output of the driving battery 11 when the driving mode is selected, and adding the output of the engine 9 at the engine rotation speed when the driving mode is selected to the value obtained by subtracting the loss of the driving motor 5 and the generator 7 when the parallel driving mode is selected from the maximum output of the driving battery 11 when the driving mode is selected, and setting the result as the maximum output in the parallel driving mode. Here, the output of the engine 9 at the engine rotation speed when the driving mode is selected is set as the output of the engine 9 at the engine rotation speed when the driving mode is selected because, in the parallel driving mode, the clutch 29 is connected to transmit the driving force from the engine 9 to the drive shaft (front wheel drive shaft 23), and therefore, the output is limited by the engine rotation speed when the driving mode is selected. Note that the loss of the plug-in hybrid vehicle 100 includes the loss of the driving motor 5 and the generator 7 as well as the power consumption of the auxiliary equipment. However, since the power consumption of the auxiliary equipment is consumed in the same manner in the parallel driving mode and the series driving mode, it is excluded from the calculation of the loss in this embodiment. Furthermore, in the calculation of the maximum output, the loss of the auxiliary equipment needs to be included in the loss of the plug-in hybrid vehicle 100, but since the power consumption of the auxiliary equipment is consumed in the same manner in the series driving mode and the parallel driving mode, the same value is used in the calculation of the maximum output in both the series driving mode and the parallel driving mode.

[0040] The loss (power loss) of the traveling motor 5 is obtained from a three-dimensional motor loss map (Mloss_MAP) in which the loss (power loss) of the traveling motor 5 is associated with the torque and rotation speed of the traveling motor 5. Therefore, the motor loss (power loss) can be expressed by the following Equation 1.

[0041]

number

[0042] In this way, by determining the loss (power loss) of the driving motor 5 using a motor loss map, the loss of the driving motor 5 can be determined from the torque and rotation speed of the driving motor 5, and the calculation of the loss of the driving motor 5 can be simplified.

[0043] The loss (power loss) of the generator 7 is obtained from a three-dimensional generator loss map (Gloss_MAP) in which the loss (power loss) of the generator 7 is associated with the torque and rotation speed of the generator 7. Therefore, the loss (power loss) of the generator 7 can be expressed by the following Equation 2.

[0044]

number

[0045] In this way, if the loss (power loss) of the generator 7 is obtained from the generator loss map, the loss of the generator 7 can be obtained from the torque and rotation speed of the generator 7, and the calculation of the loss of the generator 7 can be simplified.

[0046] As shown in FIG. 4A, while the parallel driving mode is selected, the series maximum output calculation unit 53 calculates the loss (power loss) of the driving motor 5 when the series driving mode is selected. In the series driving mode, the engine 9 only generates electricity, and only the driving motor 5 outputs the driving torque requested by the driver. Therefore, the series maximum output calculation unit 53 converts the driver's output request (driving torque) into the torque [Mtrq_SR] of the driving motor 5 by the gear ratio from the axle (front wheel drive axle 23 or rear wheel drive axle 27) to the output shaft of the driving motor 5. The power loss of the driving motor 5 is calculated by applying the rotation speed [Mrpm_SR] (sensor value) of the driving motor 5 and the torque [Mtrq_SR] of the driving motor 5 acquired from the motor control unit 49 to the motor loss map (Mloss_MAP). Therefore, the power loss [Mloss_SR] of the driving motor 5 when the series driving mode is selected during the parallel driving mode can be expressed by the following formula 3.

[0047]

number

[0048] As shown in FIG. 4B, the series maximum output calculation unit 53 calculates the loss (power loss) of the traveling motor 5 when the series traveling is selected while the parallel traveling mode is selected. In the series traveling mode, when an output exceeding a predetermined threshold is required, either the engine 9 or the generator 7 is operated at the maximum output. The maximum output of the engine 9 and the maximum output of the generator 7 are each unique values ​​and are determined by the performance of the engine 9 and the performance of the generator 7. Therefore, the series maximum output calculation unit 53 calculates the torque of the engine 9 by converting the maximum output of the engine 9 and the rotation speed at the maximum output by a unit conversion coefficient, and converts this torque of the engine 9 into the torque [Gtrq_SR] of the generator 7 by the gear ratio from the output shaft (crankshaft) of the engine 9 to the input shaft of the generator 7. Therefore, the torque [Gtrq_SR] of the generator 7 when the series traveling mode is selected during the parallel traveling mode selection can be expressed by the following formula 4.

[0049]

number

[0050] In addition, the rotation speed at maximum output of the engine 9 is converted to the rotation speed [Grpm_SR] of the generator 7 by the gear ratio from the output shaft (crankshaft) of the engine 9 to the input shaft of the generator 7. The torque [Gtrq_SR] of the generator 7 and the rotation speed [Grpm_SR] of the generator 7 thus obtained are applied to the generator loss map (Gloss_MAP) to obtain the power loss of the generator 7. Therefore, the power loss [Gloss_SR] of the generator 7 when the series running mode is selected while the parallel running mode is selected can be expressed by the following formula 5.

[0051]

number

[0052] As shown in FIG. 5, while the series driving mode is selected, the parallel maximum output calculation unit 55 calculates the loss (power loss) of the driving motor 5 when the parallel driving is selected. In the parallel driving mode, the engine 9 outputs a driving torque, and the driving motor 5 outputs a driving torque that is insufficient with the engine 9 alone. As a result, the driving torque [Mtrq_PR] of the driving motor 5 is the difference between the driver's output request (driving torque) and the maximum torque of the engine 9. Therefore, the parallel maximum output calculation unit 55 converts the vehicle speed of the plug-in hybrid vehicle 100 into the rotation speed of the engine 9 by the gear ratio from the axle (front wheel drive shaft 23) to the output shaft (crankshaft) of the engine 9. The maximum torque of the engine 9 is obtained by applying the rotation speed of the engine 9 to an engine maximum torque calculation map that associates the maximum torque with the rotation speed of the engine 9, and the maximum torque of the engine 9 is converted into the driving torque (maximum torque of the engine 9) at the output shaft of the driving motor 5 by the gear ratio from the output shaft (crankshaft) of the engine 9 to the output shaft of the driving motor 5. On the other hand, the driver's output request (driving torque) is converted into driving torque (driver's output request) at the output shaft of the driving motor 5 by the gear ratio from the axle (front-wheel drive shaft 23 or rear-wheel drive shaft 27) to the output shaft of the driving motor 5. Then, the torque [Mtrq_PR] of the driving motor 5 is calculated by calculating the difference between the driver's output request (driving torque) at the output shaft of the driving motor 5 and the maximum torque (driving torque) of the engine 9. The power loss [Mloss_PR] of the driving motor 5 is calculated by applying the rotation speed [Mrpm_PR] (sensor value) of the driving motor 5 and the torque [Mtrq_PR] of the driving motor 5 acquired from the motor control unit 49 to a motor loss map (Mloss_MAP). Therefore, the power loss [Mloss_PR] of the driving motor 5 when the parallel driving mode is selected during the series driving mode selection can be expressed by the following formula 6.

[0053]

number

[0054] During the series traveling mode selection, the parallel maximum output calculation unit 55 calculates the loss (power loss) of the generator 7 when the parallel traveling mode is selected. In the parallel traveling mode, the generator 7 does not generate power when an output exceeding a predetermined threshold is requested, so only no-load loss occurs in the generator 7. As a result, the torque of the generator 7 is 0 [0 Nm]. In addition, it can be assumed that the clutch 29 is connected at the vehicle speed of the plug-in hybrid vehicle 100 when the series traveling mode is selected. Therefore, the parallel maximum output calculation unit 55 converts the rotation speed of the engine 9 to the rotation speed [Grpm] of the generator 7 by the gear ratio from the output shaft (crankshaft) of the engine 9 to the input shaft of the generator 7. The generator 7 rotation speed [Grpm] and the generator 7 torque 0 [0 Nm] are applied to the generator loss map to calculate the generator 7 power loss [Gloss_PR]. Therefore, the generator 7 power loss [Gloss_PR] when the parallel traveling mode is selected during the series traveling mode selection can be expressed by the following Equation 7.

[0055]

number

[0056] In this way, the loss of the generator 7 when the parallel traveling mode is selected is the loss when the torque of the generator 7 is 0 in the generator loss map, so it is possible to easily determine the loss of the generator 7 when the parallel traveling mode is selected while the series mode is selected.

[0057] When the series driving mode is selected, the series maximum output calculation unit 53 obtains the loss (power loss) of the driving motor 5 when the series driving mode is selected from the motor control unit 49. In the four-wheel drive plug-in hybrid vehicle 100, the power loss of the front motor 15 is obtained from the front motor control unit 33, and the power loss of the rear motor 19 is obtained from the rear motor control unit 37. In addition, when the series driving mode is selected, the series maximum output calculation unit 53 obtains the loss of the generator 7 when the series driving mode is selected from the generator control unit 35.

[0058] Then, while the series traveling mode is selected, the losses obtained from the motor control unit 49 and the generator control unit 35 are regarded as the losses of the traveling motor 5 and the generator 7. This is because the losses obtained from the motor control unit 49 and the generator control unit 35 while the series traveling mode is selected are the losses of the traveling motor 5 and the generator 7 when the series traveling mode is selected. As a result, while the series traveling mode is selected, it is possible to omit the calculation of losses in the series traveling mode.

[0059] When the parallel driving mode is selected, the parallel maximum output calculation unit 55 obtains the loss (power loss) of the driving motor 5 when the parallel driving mode is selected from the motor control unit 49. In the four-wheel drive plug-in hybrid vehicle 100, the power loss of the front motor 15 is obtained from the front motor control unit 33, and the power loss of the rear motor 19 is obtained from the rear motor control unit 37. When the parallel driving mode is selected, the parallel maximum output calculation unit 55 obtains the loss of the generator 7 when the parallel driving mode is selected from the generator control unit 35.

[0060] Then, while the parallel traveling mode is selected, the losses obtained from the motor control unit 49 and the generator control unit 35 are regarded as the losses of the traveling motor 5 and the generator 7. This is because the losses obtained from the motor control unit 49 and the generator control unit 35 while the parallel traveling mode is selected are the losses of the traveling motor 5 and the generator 7 when the parallel traveling mode is selected. As a result, while the parallel traveling mode is selected, it is possible to omit loss calculations in the parallel traveling mode.

[0061] The driving mode determination unit 57 compares the maximum output in the series driving mode calculated by the series maximum output calculation unit 53 with the maximum output in the parallel driving mode calculated by the parallel maximum output calculation unit 55, and determines the driving mode with the greater maximum output.

[0062] 6, the driving control device 1 determines whether the parallel driving mode is selected (step S11). If it is determined that the parallel driving mode is selected (step S11: Yes), the series maximum output calculation unit 53 calculates the power loss of the driving motor 5 and the generator 7 when the series driving mode is selected (step S13), and the parallel maximum output calculation unit 55 obtains the power loss of the driving motor 5 and the generator 7 from the motor control unit 49 and the generator control unit 35 (step S15).

[0063] Then, the maximum output of the series traveling mode calculated using the loss power calculated by the series maximum output calculation unit 53 is compared with the maximum output of the parallel traveling mode calculated using the loss power acquired by the parallel maximum output calculation unit 55 (step S17). When comparing, a margin may be added as a hysteresis to either the series traveling mode or the parallel traveling mode. If the maximum output of the series traveling mode is greater than the maximum output of the parallel traveling mode (step S17: Yes), the series traveling mode is selected (switched from the parallel traveling mode to the series traveling mode) (step S19). On the other hand, if the maximum output of the series traveling mode calculated using the loss power calculated by the series maximum output calculation unit 53 is equal to or less than the maximum output of the parallel traveling mode calculated using the loss power acquired by the parallel maximum output calculation unit 55 (step S17: No), the parallel traveling mode is selected (the parallel traveling mode is maintained).

[0064] If it is determined that the series driving mode is selected (step S11: No, step S21: Yes), the series maximum output calculation unit 53 obtains the power losses of the driving motor 5 and the generator 7 from the motor control unit 49 and the generator control unit 35 (step S23), and the parallel maximum output calculation unit 55 calculates the power losses of the driving motor 5 and the generator 7 when the series driving mode is selected (step S25).

[0065] Then, the maximum output of the parallel running mode calculated using the loss power calculated by the parallel maximum output calculation unit 55 is compared with the maximum output of the series running mode calculated using the loss power acquired by the series maximum output calculation unit 53 (step S27). When comparing, a margin may be added as a hysteresis to either the parallel running mode or the series running mode. If the maximum output of the parallel running mode is greater than the series maximum output (step S27: Yes), the parallel running mode is selected (switched from the series running mode to the parallel running mode) (step S29). On the other hand, if the maximum output of the parallel running mode calculated using the loss power calculated by the parallel maximum output calculation unit 55 is equal to or less than the loss power acquired by the series maximum output calculation unit 53 (step S27: No), the series running mode is selected (series running mode is maintained).

[0066] According to the driving control device 1 according to the embodiment of the present invention, even if an output exceeding the threshold value is requested during the selection of the series driving mode, the parallel maximum output calculation unit 55 calculates the maximum output of the parallel driving mode using the losses of the driving motor 5 and the generator 7 when the parallel driving mode is selected, so that the maximum output of the parallel driving mode can be appropriately calculated even during the selection of the series driving mode. Also, even if an output exceeding the threshold value is requested during the selection of the parallel driving mode, the series maximum output calculation unit 53 calculates the maximum output of the series driving mode using the losses of the driving motor 5 and the generator 7 when the series driving mode is selected, so that the maximum output of the series driving mode can be appropriately calculated even during the selection of the parallel driving mode. Then, the driving mode determination unit 57 compares the maximum output of the series driving mode calculated in this way with the maximum output of the parallel driving mode and determines the driving mode with the larger maximum output, so that the driving mode selection unit 51 can select the driving mode with the larger true maximum output. This allows the driver to obtain the desired output within the output limit of the plug-in hybrid vehicle 100. [Explanation of symbols]

[0067] 1 Driving control device 3 Drive wheels 5. Drive motor 7. Generator 9 Engine 11 Drive battery 13 Front wheel 15 Front motor 17 Rear wheel 19 Rear motor 21 Front transaxle 23 Front wheel drive shaft (axle) 25 Rear transaxle 27 Rear wheel drive shaft (axle) 29 Clutch 31 Power Drive Unit 33 Front motor control unit 35 Generator Control Unit 37 Rear motor control unit 39 Fuel Tank 41 Engine Control Unit 43 Battery Management Unit 45 Vehicle Control Unit 47 Accelerator pedal 49 Motor Control Unit 51 Driving mode selection section 53 Series Maximum Output Calculation Unit 55 Parallel maximum output calculation section 57 Driving mode determination unit 100 Plug-in Hybrid Vehicles

Claims

1. A driving motor that drives the drive wheels; an engine that drives the drive wheels and a generator; a drive battery that stores the electric power generated by the generator; Equipped with A hybrid vehicle travel control device capable of selecting one of a series travel mode in which the traction motor drives the drive wheels with electric power generated by the engine driving the generator and electric power supplied from the drive battery, and a parallel travel mode in which the engine drives the drive wheels and the traction motor drives the drive wheels with electric power supplied from the drive battery, a driving mode selection unit that selects, when an output exceeding a predetermined threshold is requested, a driving mode that has a larger maximum output that can be output by the hybrid vehicle from among the series driving mode and the parallel driving mode, The driving mode selection unit is a series maximum output calculation unit that sets the maximum output of the series traveling mode to a value obtained by adding the smaller of the maximum output of the generator or the maximum output of the engine and the maximum output of the drive battery when the traveling mode is selected, and subtracting losses of the traveling motor and the generator when the series traveling mode is selected from the sum; a parallel maximum output calculation unit that calculates the maximum output of the parallel traveling mode by adding the output of the engine at the engine rotation speed when the traveling mode is selected to a value obtained by subtracting the loss of the traveling motor and the generator when the parallel traveling mode is selected from the maximum output of the driving battery when the traveling mode is selected; and a driving mode determination unit that compares the maximum output in the series driving mode calculated by the series maximum output calculation unit with the maximum output in the parallel driving mode calculated by the parallel maximum output calculation unit, and determines the driving mode having the larger maximum output; A hybrid vehicle driving control device comprising:

2. During the selection of the parallel traveling mode, losses in the traveling motor and the generator at the time of selecting the parallel traveling mode are obtained from a motor control unit that controls the traveling motor and a generator control unit that controls the generator. The hybrid vehicle cruise control device according to claim 1.

3. During the selection of the series traveling mode, losses in the traveling motor and the generator at the time of selecting the series traveling mode are obtained from a motor control unit that controls the traveling motor and a generator control unit that controls the generator.

3. The hybrid vehicle driving control device according to claim 1 or 2.

4. the loss of the driving motor is determined by a motor loss map in which the loss of the driving motor is associated with the torque and rotation speed of the driving motor; The generator losses are determined by a generator loss map in which the generator losses are related to the torque and rotational speed of the generator. The hybrid vehicle cruise control device according to claim 1.

5. The loss of the generator when the parallel running mode is selected is the loss when the torque of the generator is 0 in the generator loss map.

5. The hybrid vehicle driving control device according to claim 4.

Images