Control device of vehicle

Abstract

To provide a control device of a vehicle capable of suppressing significant variation of a driving torque in continuous switching of a shift range by manual operation.SOLUTION: When a long-push signal Sdrl is continuously present subsequently to switching of a shift range Rsh performed by manual operation, control as to whether the shift range Rsh is continuously switched is performed on the basis of a torque step ΔTrdem accompanied with switching of the shift range Rsh. As a result, significant variation of a requirement driving torque Trdem can be suppressed in continuous switching of the shift range Rsh by continuation of manual operation.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle equipped with an electric motor. [Background technology]

[0002] There is provided a vehicle including an electric motor, a power transmission device that transmits the power of the electric motor to drive wheels, and a shift switching device that is manually operated to selectively switch between a plurality of shift positions (also synonymous with shift ranges) of a drive device including the electric motor and the power transmission device. A paddle switch is well known as the shift switching device, and it has been disclosed that the power output characteristics can be switched in stages by operating the paddle switch. For example, the automobile described in Patent Document 1 is such an example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 088553A1 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the shift range is changed by manually operating the shift switching device, if the shift range needs to be changed multiple times until the target shift range is reached, repeating the manual operation of the change becomes troublesome. Therefore, when the manual operation of the shift switching device is continued, that is, when a long press operation is performed, a control is implemented to change the shift range continuously.

[0005] However, when continuously switching to the target shift range, for example when performing a large downshift, the drive torque fluctuates and increases significantly, which raises concerns about negative effects on stable driving, such as sudden acceleration and load on the vehicle.

[0006] The present invention has been made against the background of the above circumstances, and its object is to provide a vehicle control device that can suppress large fluctuations in driving torque when continuously changing the shift range by manual operation. [Means for solving the problem]

[0007] The gist of the present invention is a control device for a vehicle including: (a) an electric motor, a power transmission device that transmits the power of the electric motor to drive wheels; and a shift switching device that is manually operated to selectively switch between a plurality of shift positions of a drive device including the electric motor and the power transmission device; (b) a required drive torque is calculated based on a vehicle speed and an accelerator operation amount that are predetermined for each shift position, and a drive torque characteristic is stored in which the required drive torque when the vehicle speed and the accelerator operation amount are the same is increased on the low side of the shift position compared to the high side; (c) the drive torque characteristic is switched in accordance with the shift position selected by the shift switching device; and (d) if the manual operation of the shift switching device continues following the manual switching of the shift position, control is performed as to whether or not to continuously switch the shift position based on the difference in the required drive torque associated with the switching of the shift position. Effect of the Invention

[0008] According to the present invention, when the manual operation of the shift switching device is continued following the shifting of the shift position by the manual operation, control is performed as to whether or not to continuously switch the shift position based on the difference in the required drive torque accompanying the switching of the shift position. This makes it possible to provide a vehicle control device that can suppress large fluctuations in the required drive torque when the shift range is continuously switched due to the continued manual operation.

[0009] Preferably, in the control of whether or not the shift position is changed continuously while the manual operation is continued, a determination is made as to whether or not the change of the shift position is permitted, and the greater the difference in the required driving torque, the more the determination is made to disallow the change.

[0010] Preferably, the determination as to whether or not to permit successive switching of the shift position during the continuation of the manual operation is made so as to permit switching as the vehicle speed decreases.

[0011] Preferably, the determination as to whether or not to permit successive switching of the shift position with continued manual operation is applied when the shift position is switched from the high side to the low side.

[0012] Preferably, when the vehicle has a plurality of driving modes such as a normal mode and a sports mode, the determination as to whether or not to permit successive shifting of the shift position with continued manual operation is made such that the determination range of permission is made larger in the sports mode. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and a control system for various controls in the vehicle. [Diagram 2] FIG. 2 is a diagram illustrating an example of a shift switching device. [Diagram 3] 11A and 11B are diagrams illustrating manual switching of the shift position. [Figure 4] FIG. 4 is a diagram illustrating an example of a required drive torque map. [Diagram 5] 4 is a flowchart illustrating a main part of the control operation of the electronic control device. [Figure 6] FIG. 13 is a diagram showing an example of a map for determining whether or not to permit switching of the shift position when manual operation is continued. [Figure 7]6 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 5 is executed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0015] FIG. 1 is a diagram for explaining a schematic configuration of a vehicle 10 to which the present invention is applied, and is also a diagram for explaining main parts of a control system for various controls in the vehicle 10. In FIG. 1, the vehicle 10 is equipped with a first drive unit 12l, a second drive unit 12r, a first drive wheel 14l, a second drive wheel 14r, and a case 16 attached to the vehicle body. The first drive unit 12l is a drive unit on the left side facing the front of the vehicle 10, that is, on the left side in the vehicle width direction, and the second drive unit 12r is a drive unit on the right side in the vehicle width direction. The first drive wheel 14l is a drive wheel on the left side in the vehicle width direction, and the second drive wheel 14r is a drive wheel on the right side in the vehicle width direction.

[0016] The first drive device 12l includes a first electric motor MG1 and a first power transmission device 18l. The second drive device 12r includes a second electric motor MG2 and a second power transmission device 18r. The first drive device 12l and the second drive device 12r are basically configured symmetrically. When the first drive device 12l and the second drive device 12r are not particularly distinguished from each other, they are referred to as drive devices 12. When the first drive wheel 14l and the second drive wheel 14r are not particularly distinguished from each other, they are referred to as drive wheels 14. When the first electric motor MG1 and the second electric motor MG2 are not particularly distinguished from each other, they are referred to as electric motors MG. When the first power transmission device 18l and the second power transmission device 18r are not particularly distinguished from each other, they are referred to as power transmission devices 18.

[0017] The electric motor MG is a rotating electric machine, and is a so-called motor generator. The electric motor MG is connected to a battery 32 provided in the vehicle 10 via an inverter 30 provided in the vehicle 10. The battery 32 is an electricity storage device that supplies and receives electric power to the electric motor MG. The electric motor MG has an MG torque Tmg, which is the torque of the electric motor MG, controlled by an electronic control device 80 described later controlling the inverter 30. The electric motor MG is provided inside a case 16. The vehicle 10 is an electric vehicle equipped with the electric motor MG that functions as a power source for traveling.

[0018] The power transmission device 18 includes a counter gear 20 (first counter gear 20l, second counter gear 20r) and a hypoid gear 22 (first hypoid gear 22l, second hypoid gear 22r) which are a pair of parallel shaft gears housed within the case 16. The power transmission device 18 also includes a drive shaft 24 (first drive shaft 24l, second drive shaft 24r).

[0019] One gear of the counter gear 20 is integrally connected to the rotor shaft of the electric motor MG. The other gear of the counter gear 20 is integrally connected to one gear of the hypoid gear 22. The other gear of the hypoid gear 22 is integrally connected to the drive shaft 24. The power transmission device 18 transmits the power of the electric motor MG to the drive wheels 14 via the counter gear 20, the hypoid gear 22, the drive shaft 24, etc. The counter gear 20 functions as a reduction gear. The hypoid gear 22 transmits the power to the drive wheels 14 while reducing the speed. The drive wheels 14 may be the front wheels or the rear wheels.

[0020] FIG. 2 is a diagram for explaining an example of a shift switching device. As shown in FIG. 2(a), the vehicle 10 is equipped with a shift device 50 having an operating member (not shown) operated by the driver to one of a plurality of operating positions POSop. The shift device 50 is an example of a shift switching device that is manually operated to selectively switch a plurality of shift positions (also synonymous with the shift range Rsh) of the drive device 12. The operating position POSop is a signal that indicates the selection state of the shift range Rsh, and includes, for example, P, R, D, +, - operating positions. The shift range Rsh indicates the power transmission state of the drive device 12, and includes, for example, P, R, D, 3, 2, L ranges. The P (parking) operating position indicates the selection state of the P range of the drive device 12, in which a rotating member that rotates together with the drive wheels 14 is mechanically fixed so as not to rotate. The R (reverse running) operating position indicates the selection state of the R range of the drive device 12, which enables reverse running. The D (forward travel) operating position represents the selection state of the D range of the drive unit 12 that enables forward travel. The + and - operating positions are used to select the D, 3, 2, and L ranges of the drive unit 12 that enable forward travel, that is, the manual range.

[0021] In a vehicle equipped with an automatic transmission mechanism or the like, the manual range is a shift range that changes the gear ratio (gear stage, etc.) stepwise by manual operation during forward driving to change the drive torque characteristics of the vehicle, but the manual range of this embodiment (electric vehicle) realizes an equivalent function in a pseudo manner by switching the drive torque characteristics of the electric motor MG, which will be described later. FIG. 3 is a diagram explaining the switching of the manual range, and the shift range Rsh is switched between the D range, which is the highest speed side (highest side), and the L range, which is the lowest speed side (lowest side). The + operation position represents a selection state in the manual range where the shift range Rsh is switched to the high side (high vehicle speed side), i.e., the high range side. Switching to the high range side is, for example, an up-range where the shift range Rsh is switched from the L range to the 2 range, or from the 2 range to the 3 range. The - operation position represents a selection state in the manual range where the shift range Rsh is switched to the low side (low vehicle speed side), i.e., the low range side. Switching to the low range side is, for example, down-ranging by switching the shift range Rsh from D range to range 3, or from range 3 to range 2.

[0022] 2(b), the vehicle 10 may be equipped with a - switch 56 for selecting the manual range on the left or right side of the steering wheel 52. The - switch 56 is an example of a shift switching device that is manually operated to switch the shift range Rsh, especially the manual range, to the low range side, and has a function equivalent to the - operation position of the shift device 50. The operation of the - switch 56 is valid, for example, in the D range, and the manual range is switched by this operation.

[0023] 1, the vehicle 10 is equipped with an electronic control device 80 as a controller including control devices of the vehicle 10 related to the control of the electric motor MG, etc. The electronic control device 80 is configured to include a so-called microcomputer, and performs various controls of the vehicle 10 by the CPU performing signal processing according to a program stored in advance in the ROM while utilizing the temporary storage function of the RAM.

[0024] The electronic control device 80 is supplied with various signals (e.g., -switch (down range) signal Sdr, +switch (up range) signal Sur, vehicle speed V, MG1 rotational speed Nmg1, MG2 rotational speed Nmg2, accelerator opening θacc as the amount of accelerator operation by the driver, brake-on signal Bon, operation position POSop, etc.) based on detection values ​​by various sensors (e.g., -switch 56, vehicle speed sensor 60, MG1 rotational speed sensor 62, MG2 rotational speed sensor 64, accelerator opening sensor 66, brake pedal sensor 68, operation position sensor 70, etc.) provided in the vehicle 10. The electronic control device 80 outputs various command signals (e.g., MG control command signal Smg, etc.) to each device (e.g., inverter 30, etc.) provided in the vehicle 10.

[0025] The electronic control device 80 includes an electric motor control unit 82 to realize various controls in the vehicle 10. The electric motor control unit 82 calculates a drive demand amount for the vehicle 10 from the driver, for example, by applying the accelerator opening θacc and the vehicle speed V to a drive demand amount map. The drive demand amount is, for example, a drive torque Tr required for the vehicle 10, that is, a required drive torque Trdem [Nm] at the drive wheels 14. The electric motor control unit 82 outputs an MG control command signal Smg to realize the required drive torque Trdem.

[0026] The driving demand map is a relationship for calculating the driving demand that is experimentally or design-wise obtained and stored in advance, i.e., is predetermined, and is, for example, a required driving torque map MAPtr. The electronic control unit 80 stores the required driving torque map MAPtr. The required driving torque map MAPtr is a driving torque characteristic that determines the required driving torque Trdem based on the vehicle speed V and the accelerator opening θacc, and different driving torque characteristics are set for each shift range Rsh.

[0027] Fig. 4 is a diagram for explaining an example of the required driving torque map MAPtr. Fig. 4(a) shows the required driving torque map MAPtr used, for example, in the D range. In Fig. 4(a), the required driving torque map MAPtr shows a predetermined relationship for determining the required driving torque Trdem that changes with the vehicle speed V and the accelerator opening θacc on a two-dimensional coordinate system with the horizontal axis representing the vehicle speed V and the vertical axis representing the required driving torque Trdem.

[0028] FIG. 4B shows the required drive torque map MAPtr used in the D range and the manual range (D, 3, 2, L range) when the accelerator opening θacc is 50[%]. In FIG. 4B, the required drive torque map MAPtr in the D range shown by the thick line is the reference required drive torque map MAPtr. In the required drive torque map MAPtr in the manual range, the required drive torque Trdem is set larger when the vehicle speed V is the same, compared to the required drive torque map MAPtr in the D range. In the required drive torque map MAPtr in the manual range, the required drive torque Trdem is set larger on the low range side (L range side) when the vehicle speed V is the same. Although not shown, the setting of the required drive torque map MAPtr for each shift range Rsh has a similar tendency even when the accelerator opening θacc is other than 50[%]. In this way, in the required drive torque map MAPtr, when the vehicle speed V and the accelerator opening θacc are the same, the required drive torque Trdem is increased on the low range side compared to the high range side.

[0029] The electric motor control unit 82 switches the required drive torque map MAPtr in accordance with the shift range Rsh selected by operation of the shift device 50 or the - switch 56. For example, when in the D range, if the shift device 50 is manually operated to the - operating position or the - switch 56 is manually operated once, that is, a downrange operation is performed once, the required drive torque map MAPtr for the 3 range is used, and if a downrange operation is performed once more, the required drive torque map MAPtr for the 2 range is used.

[0030] However, when multiple shifts are required to reach the target shift range, for example, when down-ranging from D range to L range, repeating the operation (three times) is troublesome. Therefore, when manual operation is continued, that is, when a long press operation is performed, control is performed to continuously switch the shift range. However, continuous down-ranging such as from D range to L range causes the required drive torque Trdem to fluctuate significantly, and there is concern about negative effects on stable driving such as sudden acceleration and load generation on the vehicle.

[0031] Therefore, when the shift range is continuously changed by a long press operation, the electronic control device 80 suppresses a large fluctuation in the required drive torque Trdem by a control operation described in Fig. 5. Fig. 5 is a flowchart explaining the control operation during a downrange operation, and in Fig. 5, each step of the flowchart corresponds to a function of the electric motor control unit 82.

[0032] First, in step (hereinafter, step will be omitted) S10, it is determined whether or not the negative switch (downrange) signal Sdr is input. If the determination in S10 is negative, this routine is terminated.

[0033] If the determination in S10 is positive, the current shift range Rsh is down-ranged by one step to the low range in S20.

[0034] Next, in S30, it is determined whether the input of the -switch (downrange) signal Sdr is continuing (which is equivalent to whether the long press signal Sdrl is present). If the determination in S30 is negative, this routine is terminated.

[0035] If the determination in S30 is positive, the process proceeds to S40, where a drive torque step ΔTrdem is calculated when the current shift range Rsh (the shift range Rsh switched in S20) is continuously downranged by one step. Furthermore, in S40, the drive torque step ΔTrdem and the vehicle speed V are applied to a permission / non-permission determination map in FIG. 6, which will be described later, to determine whether or not to perform continuous downrange, that is, whether or not to permit acceptance of the long press signal Sdrl. If the determination in S40 is negative, the process proceeds to S70, where acceptance of the long press signal Sdrl is rejected, and this routine is terminated.

[0036] If the determination in S40 is positive, in S50, a downrange is performed from the current shift range Rsh (the shift range Rsh switched to in S20) to the low range side.

[0037] Next, in S60, it is determined again whether the input of the -switch (downrange) signal Sdr is continuing, i.e., whether the long press signal Sdrl is still continuing. If the determination in S60 is positive, the process proceeds to S40, where the process is repeated from the determination of whether or not to permit the acceptance of the long press signal Sdrl. If the determination in S60 is negative, the present routine is terminated.

[0038] FIG. 6 is a map for determining whether or not to perform continuous downrange when a long press signal Sdrl is present, i.e., whether or not to permit acceptance of the long press signal Sdrl, based on the drive torque step ΔTrdem and the vehicle speed V. The map is determined in advance experimentally or by design, set, and stored so that the permitted region becomes closer to the lower vehicle speed side as the drive torque step ΔTrdem becomes larger.

[0039] Fig. 7 is a diagram showing an example of a time chart when the control operation shown in the flowchart of Fig. 5 is executed. In Fig. 7, the horizontal axis shows time, the upper vertical axis shows the -switch (downrange) signal Sdr, and the lower vertical axis shows the change in the required drive torque Trdem accompanying range switching. Fig. 7 shows an example of a case where the -switch (downrange) signal Sdr continues to be input (long press signal Sdrl is present) from the D range and a downrange is executed.

[0040] When the - switch (down range) signal Sdr is turned ON in the D range (see time t0), when the Ts1 period has elapsed (see time t1), the - switch (down range) signal Sdr is accepted and switching to range 3 is performed (corresponding to the control of S10 to S20 in Figure 5).

[0041] If the -switch (downrange) signal Sdr remains ON after a period Ts2 has elapsed from time t1 (see time t2), it is determined that the long press signal Sdrl is present. Next, if the drive torque step ΔTrdem when switching from range 3 to range 2 is small or the vehicle speed V is low, it is determined from the map in Fig. 6 that acceptance of the long press signal Sdrl is permitted, and switching to range 2 is performed (corresponding to the controls of S30 to S50 in Fig. 5).

[0042] If the -switch (downrange) signal Sdr remains ON after a period Ts3 has elapsed from time t2 (see time t3), it is determined that the long press signal Sdrl is present. If the drive torque step ΔTrdem when switching from 2 range to L range is large or the vehicle speed V is high, it is determined from the map in FIG. 6 that the long press signal Sdrl is not permitted to be received, switching to L range is not performed, and 2 range is maintained (corresponding to the control of S60 to S40 to S70 in FIG. 5), so that a large fluctuation or increase in the required drive torque Trdem is suppressed.

[0043] As described above, according to this embodiment, when the long press signal Sdrl continues to be present following manual switching of the shift range Rsh, control is performed as to whether or not to continuously switch the shift range Rsh based on the drive torque step ΔTrdem accompanying the switching of the shift range Rsh. This makes it possible to provide a vehicle control device that can suppress large fluctuations in the required drive torque Trdem during continuous switching of the shift range Rsh due to continued manual operation.

[0044] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the present invention can be applied to other embodiments.

[0045] For example, in the above-described embodiment, the vehicle 10 is an electric vehicle, but the present invention is not limited to this. For example, the present invention can be applied to a hybrid electric vehicle that has an engine and an electric motor as a power source.

[0046] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0047] 10: vehicle 12: drive unit 14: drive wheels 18: power transmission unit 50: shift unit (shift switching unit) 80: electronic control unit (control unit) MG: electric motor Rsh: shift range (shift position) Trdem: required drive torque

Claims

[Claim 1] A control device for a vehicle including an electric motor, a power transmission device that transmits power of the electric motor to drive wheels, and a shift switching device that is manually operated to selectively switch among a plurality of shift positions of a drive device including the electric motor and the power transmission device, a required drive torque is calculated based on a vehicle speed and an accelerator operation amount that are predetermined for each shift position, and a drive torque characteristic is stored in which the required drive torque when the vehicle speed and the accelerator operation amount are the same is increased on the low side of the shift position compared to the high side, The drive torque characteristic is switched in accordance with the shift position selected by the shift switching device, A vehicle control device characterized in that, when the manual operation of the shift switching device continues following the shift position being changed by the manual operation, control is performed as to whether or not to change the shift position continuously based on the difference in the required driving torque associated with the change of the shift position.

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