Vehicle control device

Abstract

A vehicle control device is provided that can appropriately achieve both suppression of roll motion when the vehicle turns and road surface followability of the wheels. [Solution] When the vehicle 1 turns, the control device 10 applies a force output from a front motor 101 or a rear motor 102 mounted in the sprung portion of the vehicle 1 and a force output from a friction braking device 30 mounted in the unsprung portion of the vehicle 1 to at least one of the left and right front wheels 21 and the left and right rear wheels 22, thereby suppressing roll motion of the vehicle 1. The control device 10 separates the target torque T* to be applied to one of the wheels into a target motor torque Tm*, which is a high-frequency component from the front motor 101, the rear motor 102, or the friction braking device 30, which has a higher responsiveness, and a target friction braking torque Tb*, which is a low-frequency component from the other, which has a lower responsiveness, and outputs them.

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device that adjusts the attitude of a vehicle when it is turning. [Background technology]

[0002] Conventionally, there are known technologies for adjusting the vehicle's posture when turning. For example, Patent Document 1 describes a vehicle in which a target yaw angular velocity is calculated based on the front wheel sideslip angle and vehicle speed, and the operation of a torque distribution control device is controlled so as to obtain a yaw moment corresponding to the target yaw angular velocity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-025272 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a vehicle turns, the sprung part may rotate around the roll center, causing a roll motion that may affect the driver's riding comfort. Also, when the vehicle turns, it is necessary to ensure that each wheel follows the road surface.

[0005] The present invention has been made in consideration of these problems, and its purpose is to provide a vehicle control device that can appropriately achieve both the suppression of roll motion when the vehicle is turning and the road-following ability of the wheels. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the vehicle control device of the present invention is a vehicle control device that applies a force output from a drive unit mounted on the sprung portion of the vehicle and a force output from a brake unit mounted on the unsprung portion of the vehicle to at least one of the left and right front wheels and the left and right rear wheels when the vehicle turns, thereby suppressing the roll motion of the vehicle, and separates the target torque to be applied to one of the wheels into a high-frequency component from one of the drive unit and the brake unit which is more responsive, and a low-frequency component from the other of the drive unit and the brake unit which is less responsive, and outputs them. [Effects of the Invention]

[0007] According to the vehicle control device of the present invention, it is possible to appropriately achieve both suppression of roll motion when the vehicle is turning and road-following ability of the wheels. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram showing a vehicle equipped with a vehicle control device according to an embodiment; [Figure 2] FIG. 4 is an explanatory diagram showing an anti-force acting on the vehicle when it is driven. [Figure 3] FIG. 4 is an explanatory diagram showing an anti-force acting on a vehicle during braking. [Figure 4] 4 is a flowchart illustrating an example of yaw control according to the embodiment. [Figure 5] FIG. 10 is an explanatory diagram showing a case where the vehicle has a turning posture that tends to understeer. [Figure 6] FIG. 10 is an explanatory diagram showing a case where the turning posture of the vehicle has an oversteer tendency. [Figure 7] FIG. 2 is an explanatory diagram showing an example of the relationship between the force acting on a vehicle during turning and the roll motion. [Figure 8] FIG. 2 is an explanatory diagram showing an example of the relationship between the force acting on a vehicle during turning and the roll motion. [Figure 9] FIG. 10 is a control block diagram showing an example of frequency separation processing. [Figure 10]10 is a flowchart illustrating an example of a process for setting a gain according to a control mode. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] (vehicle) 1 is a schematic diagram showing the configuration of a vehicle equipped with a vehicle control device according to an embodiment. The vehicle 1 is a four-wheel drive electric vehicle that travels by transmitting power from front motors 101R, 101L as a power source for traveling to left and right front wheels 21, and transmitting power from rear motors 102R, 102L as a power source for traveling to left and right rear wheels 22. Hereinafter, unless there is a need to distinguish between them, the front motors 101R, 101L will be referred to as the "front motor 101" and the rear motors 102R, 102L will be referred to as the "rear motor 102."

[0011] The front motor 101R outputs a driving force Fdf (FIG. 2) to the right front wheel 21 via the transaxle 121R and the front axle 131. The front motor 101L outputs a driving force Fdf (FIG. 2) to the left front wheel 21 via the transaxle 121L and the front axle 131. The rear motor 102R outputs a driving force Fdr (FIG. 2) to the right rear wheel 22 via the transaxle 122R and the rear axle 132. The rear motor 102L outputs a driving force Fdr (FIG. 2) to the left rear wheel 22 via the transaxle 122L and the rear axle 132.

[0012] The vehicle 1 is equipped with a battery 14 serving as a power source, which is configured as a secondary battery such as a lithium-ion battery. Power from the battery 14 is supplied to the front motor 101 and the rear motor 102 via a power conversion device such as an inverter, thereby outputting driving forces Fdf and Fdr. Furthermore, when the vehicle 1 is decelerating with the accelerator released, the front motor 101 and the rear motor 102 regenerate power using the rotational forces of the front wheels 21 and the rear wheels 22, generating regenerative braking forces Fgf and Fgr (FIG. 3). The regenerated power generated by the front motor 101 and the rear motor 102 is supplied to the battery 14. As described above, the front motor 101 and the rear motor 102 function as drive devices that impart driving force and regenerative braking force to the respective wheels, and are controlled by a control device (vehicle control device) 10 installed in the vehicle 1.

[0013] The vehicle 1 also includes a friction braking device 30 that applies braking force to the front wheels 21 and rear wheels 22. The friction braking device 30 generates friction force by pressing brake pads 30P, which are driven by an actuator (not shown), against disc rotors 30D provided corresponding to each front wheel 21 and each rear wheel 22. As a result, the friction braking device 30 applies a friction braking force Fbf (FIG. 3) to each front wheel 21 and a friction braking force Fbr (FIG. 3) to each rear wheel 22. The friction braking device 30 is driven by a hydraulic actuator, and has lower output responsiveness than the front motor 101 and rear motor 102. The friction braking device 30 is controlled by the control device 10.

[0014] The control device 10 is configured to include input / output devices, storage devices (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), etc. The control device 10 acquires detected quantities detected by various sensors of the vehicle 1 and operation information of various devices, calculates values ​​such as the required braking / driving force required for the vehicle 1 to travel, and controls each device of the vehicle 1 based on the calculated values. For example, the control device 10 acquires the vehicle speed of the vehicle 1 detected by a vehicle speed sensor 15, the steering angle of the vehicle 1 detected by a steering angle sensor 16, and the actual yaw rate γ of the vehicle 1 detected by a yaw rate detection sensor 17 (FIGS. 5 and 6), and performs yaw control, which will be described later, based on the acquired values.

[0015] (Anti-force) Next, the anti-force acting on the vehicle 1 will be described. FIG. 2 is an explanatory diagram showing the anti-force acting on the vehicle 1 when driving. FIG. 3 is an explanatory diagram showing the anti-force acting on the vehicle 1 when braking. Suspension devices 11 that suspend each of the front wheels 21 and each of the rear wheels 22 from the vehicle body are provided between each of the front wheels 21 and each of the rear wheels 22 of the vehicle 1 and the vehicle body. The front motor 101 and the rear motor 102 are mounted in the sprung portion (inboard portion) above the suspension devices 11 of the vehicle 1, and the friction braking device 30 is mounted in the unsprung portion (outboard portion) below the suspension devices 11 of the vehicle 1. Therefore, when the vehicle 1 is driven, driving forces Fdf and Fdr output from the sprung portion act on the front wheels 21 and the rear wheels 22. Furthermore, when braking the vehicle 1, regenerative braking forces Fgf, Fgr output from the sprung parts or friction braking forces Fbf, Fbr output from the unsprung parts act on the front wheels 21 and rear wheels 22.

[0016] Here, the anti-angles θdf, θdr, θbf, and θbr of the suspension unit 11 are determined by its geometry. The anti-angle θdf is the angle formed with the horizontal line connecting the center of the front wheel 21 and the attachment point of the suspension link 11L, which connects the suspension unit 11 to the body (sprung portion), and is the so-called anti-nose-up angle. The anti-angle θdr is the angle formed with the horizontal line connecting the center of the rear wheel 22 and the attachment point of the suspension link 11L to the body, and is the so-called anti-squat angle. The anti-angle θbf is the angle formed with the horizontal line connecting the center of the contact patch of the front wheel 21 and the attachment point of the suspension link 11L to the body, and is the so-called anti-nose-dive angle. The anti-angle θbr is the angle formed with the horizontal line connecting the center of the contact patch of the rear wheel 22 and the attachment point of the suspension link 11L to the body, and is the so-called anti-tail-lift angle. The anti angle θbf is larger than the anti angle θdf, the anti angle θbr is larger than the anti angle θdr, and the anti angle θbr is larger than the anti angle θbf.

[0017] As a result, when the vehicle 1 is driven, as shown in FIG. 2, a downward anti-force Zdf acts on the front side of the vehicle 1 as a component of the driving force Fdf in accordance with the anti-angle θdf. Also, an upward anti-force Zdr acts on the rear side of the vehicle 1 as a component of the driving force Fdr in accordance with the anti-angle θdr. Also, when the vehicle 1 is braking, as shown in FIG. 3, an upward anti-force Zgf acts on the front side of the vehicle 1 in accordance with the anti-angle θdf as a component of the regenerative braking force Fgf. Also, a downward anti-force Zgr acts on the rear side of the vehicle 1 in accordance with the anti-angle θdr as a component of the regenerative braking force Fgr. Furthermore, an upward anti-force Zbf acts on the front side of the vehicle 1 in accordance with the anti-angle θbf as a component of the frictional braking force Fbf. Also, a downward anti-force Zbr acts on the rear side of the vehicle 1 in accordance with the anti-angle θbr as a component of the frictional braking force Fbr. The anti-forces Zdf, Zdr, Zgf, Zgr, Zbf, and Zbr are expressed by the following equations (1) to (6).

[0018] Zdf=Fdf·tan(θdf) …(1) Zdr = Fdr tan(θdr) …(2) Zgf=Fgf·tan(θdf) …(3) Zgr = Fgr tan(θdr) …(4) Zbf=Fbf·tan(θbf) …(5) Zbr=Fbr·tan(θbr) …(6)

[0019] (Yaw Control) Next, yaw control will be described. Yaw control is a control that adjusts the yaw moment of the vehicle 1 by generating a driving force difference or a braking force difference between the inner and outer wheels during cornering while satisfying the required braking / driving force required for the vehicle 1 to travel. In this embodiment, at least one of the driving forces Fdf and Fdr output from the sprung portion, the regenerative braking forces Fgf and Fgr output from the sprung portion, and the frictional braking forces Fbf and Fbr output from the unsprung portion is applied to at least one of the left and right front wheels 21 and the left and right rear wheels 22. FIG. 4 is a flowchart showing an example of yaw control according to this embodiment. The process shown in FIG. 4 is repeatedly executed by the control device 10 every unit time (for example, every few milliseconds) while the vehicle 1 is traveling in a corner.

[0020] The control device 10 acquires the vehicle speed, steering angle, and actual yaw rate γ of the vehicle 1 (step ST1), and calculates a target yaw rate γt, which is a target value for the yaw rate during turning, based on the acquired vehicle speed and steering angle (step ST2). The target yaw rate γt is calculated using a well-known method. Next, the control device 10 calculates a yaw rate deviation Δγ, which is the deviation between the actual yaw rate γ and the target yaw rate γt (step ST3), and calculates a target yaw moment My, which is a target value for the yaw moment to be applied to the vehicle 1, based on the calculated yaw rate deviation Δγ (step ST4).

[0021] The target yaw moment My will now be described. FIG. 5 is an explanatory diagram showing a case where the turning attitude of the vehicle 1 tends to understeer. As shown in the figure, when the absolute value of the target yaw rate γt is small relative to the absolute value of the actual yaw rate γ of the vehicle 1, and the turning desired by the driver is not being performed, this state is called an understeer tendency (hereinafter referred to as a "US tendency"). In this case, a target yaw moment My that further promotes the turning of the vehicle 1 is set. On the other hand, FIG. 6 is an explanatory diagram showing a case where the turning attitude of the vehicle 1 tends to oversteer. As shown in the figure, when the absolute value of the target yaw rate γt is large relative to the absolute value of the actual yaw rate γ of the vehicle 1, and the vehicle is turning more than desired by the driver, this state is called an oversteer tendency (hereinafter referred to as an "OS tendency"). In this case, a target yaw moment My that suppresses the turning of the vehicle 1 is set. The target yaw moment My is set by well-known feedback control or the like so that the yaw rate deviation Δγ approaches the value 0.

[0022] In order to apply the target yaw moment My to the vehicle 1, it is sufficient to generate a driving force difference or a braking force difference between the left and right wheels. For example, in the US trend shown in Figure 5, the driving force difference can be set so that the total driving force on the outer wheel side is greater than the total driving force on the inner wheel side, or the total braking force difference can be set so that the total braking force on the inner wheel side is greater than the total braking force on the outer wheel side. On the other hand, in the OS trend shown in Figure 6, the driving force difference can be set so that the total driving force on the inner wheel side is greater than the total driving force on the outer wheel side, or the braking force difference can be set so that the total braking force on the outer wheel side is greater than the total braking force on the inner wheel side.

[0023] Therefore, the control device 10 sets target torques to be applied to each front wheel 21 and each rear wheel 22 in accordance with the target yaw moment My, taking into account the roll motion of the vehicle 1 during a turn (step ST5). Here, FIGS. 7 and 8 are explanatory diagrams showing an example of the relationship between the forces acting on the vehicle 1 during a turn and the roll motion. FIG. 7 is a schematic diagram of the rear wheel 22 side, and FIG. 8 is a schematic diagram of the front wheel 21 side, viewed from the rear side in the vehicle's fore-and-aft direction. When the vehicle 1 is turning left, an inertial force acting outward in the vehicle width direction acts on the center of gravity CG of the vehicle 1. As a result, as shown by the dashed line in the diagram, the sprung portion of the vehicle 1 rolls so as to rotate clockwise around the roll center Rc. This causes a change in the vehicle 1's posture in the roll direction by the roll angle φ.

[0024] For example, as shown by the solid arrows in FIG. 5, suppose a driving force Fdr is applied to the right rear wheel 22 and a regenerative braking force Fgr or a frictional braking force Fbr is applied to the left rear wheel 22 of a vehicle 1 leaning toward the US. In this case, as shown in FIG. 7, a counterclockwise rotational moment M1 in the figure acts on the vehicle 1 around the roll center Rc due to the anti-forces Zdr, Zgr, and Zbr. This suppresses roll motion. In contrast, if a driving force Fdf is applied to the right front wheel 21 and a regenerative braking force Fgf or a frictional braking force Fbf is applied to the left front wheel 21 as shown by the dashed arrows in FIG. 5, a rotational moment acts in the opposite direction to that in FIG. 7, causing the roll motion to increase.

[0025] Also, for example, as shown by the solid arrows in FIG. 6, it is assumed that a driving force Fdf is applied to the left front wheel 21 and a regenerative braking force Fgf or a friction braking force Fbf is applied to the right front wheel 21. In this case, as shown in FIG. 8, a counterclockwise rotational moment M2 in the figure acts on the vehicle 1 around the roll center Rc due to the anti-forces Zdf, Zgf, and Zbf. This suppresses roll motion. In contrast, if a driving force Fdr is applied to the left rear wheel 22 and a regenerative braking force Fgr or a friction braking force Fbr is applied to the right rear wheel 22 as shown by the dashed arrows in FIG. 6, a rotational moment acts in the opposite direction to that in FIG. 8, and roll motion increases.

[0026] Therefore, during yaw control, the control device 10 prioritizes output of the driving forces Fdf, Fdr, regenerative braking forces Fgf, Fgr, and friction braking forces Fbf, Fbr that suppress roll motion. Specifically, in the US tendency, priority is given to generating a driving force difference or a braking force difference on the rear wheel 22 side over the front wheel 21 side, as shown by the solid arrows in FIG. 5 . Conversely, in the OS tendency, priority is given to generating a driving force difference or a braking force difference on the front wheel 21 side over the rear wheel 22 side, as shown by the solid arrows in FIG. 6 . Note that the driving force difference or the braking force difference is set within an upper limit range depending on vehicle specifications such as the grip limit of each wheel, the output limit of each motor, and the regenerative power generation limit. Therefore, if the target yaw moment My cannot be obtained even when the upper limit is exceeded, the control device 10 may output forces that cannot suppress roll motion.

[0027] As described above, the driving force difference or braking force difference to be generated between the left and right front wheels 21 or the left and right rear wheels 22 is determined according to the target yaw moment My, and based on the determined driving force difference or braking force difference, the target torque T*, which is the target value of the torque to be applied to each front wheel 21 and each rear wheel 22 so as to satisfy the total required braking / driving force, is set.

[0028] Next, the control device 10 executes frequency separation processing for the target torque T* (step ST6). FIG. 9 is a control block diagram showing an example of the frequency separation processing. For simplicity of explanation, an example will be described in which a target torque T* to be output by the front motor 101 or the rear motor 102 and the friction braking device 30 in coordination with each other is set for either each front wheel 21 or each rear wheel 22. Note that "in coordination with each other" means that, as described above, a force in a direction that suppresses roll motion is output from both the front motor 101 or the rear motor 102 and the friction braking device 30.

[0029] As shown in the figure, the control device 10 calculates a target motor torque Tm*, which is a target value of the torque to be output from the front motor 101 or the rear motor 102, by applying a high-pass filter 41 to the target torque T*, and calculates a target friction braking torque Tb*, which is a target value of the torque to be output from the friction braking device 30, by applying a low-pass filter 42 to the target torque T*. The high-pass filter 41 is expressed, for example, by the transfer function of equation (7), and the low-pass filter 42 is expressed, for example, by the transfer function of equation (8). Each filter satisfies the relationship of equation (9). In the equation, "ω" is a frequency, and "k" is a weighting gain that is set to a value less than 1. Here, the settings are such that the larger the gain k, the larger the proportion of the target friction braking torque Tb* and the smaller the proportion of the target motor torque Tm*.

[0030] Qm(s)=(s+(1-k)ω) / (s+ω) …(7) Qb(s)=kω / (s+ω) …(8) Qm(s)+Qb(s)=1 …(9)

[0031] In this way, by applying the high-pass filter 41 to the target torque T*, the high-frequency components of the target torque T* are set as the target motor torque Tm*. Furthermore, by applying the low-pass filter 42 to the target torque T*, the low-frequency components of the target torque T* are set as the target friction braking torque Tb*. That is, of the front motor 101, the rear motor 102, and the friction braking device 30, the high-frequency components of the target torque T* are output from the front motor 101 and the rear motor 102, which have higher responsiveness, and the low-frequency components of the target torque T* are output from the friction braking device 30, which has lower responsiveness. Then, the control device 10 appropriately controls the front motor 101, the rear motor 102, and the friction braking device 30 so that the set target motor torque Tm* and target friction braking torque Tb* are output (step ST7), and this routine is executed again from the beginning.

[0032] (Effects of the embodiment) As described above, the control device (vehicle control device) 10 of the embodiment applies, to at least one of the left and right front wheels 21 and the left and right rear wheels 22, a force (one of driving forces Fdf, Fdr or regenerative braking forces Fgf, Fgf) output from the front motor 101 or the rear motor 102 mounted in the sprung portion of the vehicle 1 and a force (one of friction braking forces Fbf, Fbr) output from the friction braking device 30 mounted in the unsprung portion of the vehicle 1, to suppress roll motion of the vehicle 1. The control device 10 separates the target torque T* to be applied to one of the wheels into a target motor torque Tm*, which is a high-frequency component from one of the front motor 101, the rear motor 102, and the friction braking device 30 that has a higher responsiveness, and a target friction braking torque Tb*, which is a low-frequency component from the other of the front motor 101, the rear motor 102, and the friction braking device 30 that has a lower responsiveness, and outputs the separated torques (steps ST5 to ST7).

[0033] With this configuration, the fine fluctuation components of the target torque T* can be output from the highly responsive front motor 101 and rear motor 102. As a result, the target motor torque Tm* can be output in response to subtle changes in the vehicle 1's posture, improving the road-following ability of each wheel. Meanwhile, the gradual fluctuation components of the target torque T* are output as the target friction braking torque Tb* from the friction braking device 30. As described above, the anti-angle θbf is larger than the anti-angle θdf, and the anti-angle θbr is larger than the anti-angle θdr. Therefore, the anti-forces Zbf and Zbr tend to be larger than the other anti-forces. Therefore, roll motion during cornering can be more effectively suppressed than when the target torque T* components are output using only the front motor 101 and the rear motor 102. Furthermore, by outputting only the gradual fluctuation components of the target torque T* as the target friction braking torque Tb*, the friction braking device 30, which has relatively low responsiveness, is not driven at an unnecessarily high speed, thereby suppressing noise generation. Therefore, according to the control device 10 of the embodiment, it is possible to appropriately achieve both suppression of roll motion when the vehicle 1 turns and road surface following ability of the wheels.

[0034] Furthermore, the control device 10 preferentially outputs a force to suppress roll motion during execution of yaw control, which adjusts the yaw moment of the vehicle 1 by generating a driving force difference or a braking force difference between the inner and outer wheels when the vehicle is turning. This makes it possible to simultaneously adjust the yaw moment of the vehicle 1, suppress roll motion, and improve the road-following ability of the wheels.

[0035] Furthermore, in the frequency separation process of step ST6, the gain k of the high-pass filter 41 and the low-pass filter 42 may be changed as appropriate depending on the state of the vehicle 1. For example, the control device 10 may increase the gain k as the degree of turning of the vehicle 1 increases, thereby increasing the proportion of the target friction braking torque Tb*, which is the portion of the target torque T* that is output from the friction braking device 30. This allows the anti-forces Zbf and Zbr to act more strongly when the degree of turning of the vehicle 1 is greater and roll motion is more likely to occur, thereby more effectively suppressing roll motion. Furthermore, when the degree of turning is small, the friction braking device 30 is not driven as much as possible, thereby reducing energy consumption.

[0036] Furthermore, the control device 10 may decrease the gain k as the vehicle speed of the vehicle 1 increases, and increase the proportion of the target motor torque Tm*, which is the portion of the target torque T* that is output from one of the front motor 101, the rear motor 102, and the friction braking device 30 that has a higher responsiveness. As a result, the higher the vehicle speed and the more likely road surface disturbances are to be input at high frequency, i.e., the more likely the attitude of the vehicle 1 is to fluctuate finely, the higher the output proportion of the highly responsive target motor torque Tm* can be increased, thereby more effectively improving the road surface following ability of each wheel.

[0037] Furthermore, gain k may be set according to the control mode of vehicle 1. As shown in FIG. 1, vehicle 1 is provided with a mode setting switch 19 that can set the control mode. Mode setting switch 19 is provided inside the vehicle cabin so that it can be operated by the driver. The control modes include, for example, an eco mode that places more importance on improving the energy consumption efficiency of vehicle 1 than in the normal mode, a comfort mode that places more importance on the ride comfort of vehicle 1 than in the normal mode, and a sport mode that places more importance on the road-following ability of the wheels than in the normal mode. Note that the normal mode is a state in which eco mode, comfort mode, and sport mode are not set. Here, a case in which any of eco mode, comfort mode, and sport mode is set will be described as an example.

[0038] Fig. 10 is a flowchart showing an example of a process for setting the gain k according to the control mode. The process shown in Fig. 10 is executed by the control device 10 in step ST6 of Fig. 4. The control device 10 determines which control mode the vehicle 1 is set to (step ST61).

[0039] When the control device 10 determines in step ST61 that the control mode is set to the comfort mode, it increases the value of the gain k compared to when the control mode is set to the normal mode (step ST62). That is, it increases the proportion of the target friction braking torque Tb*, which is the portion of the target torque T* that is output from the friction braking device 30. This increases the anti-forces Zbf and Zbr, thereby suppressing the roll motion more effectively and improving the ride comfort of the vehicle 1 in response to a request for the comfort mode from the driver.

[0040] When the control device 10 determines in step ST61 that the control mode is set to the eco mode, it reduces the value of the gain k compared to when the control mode is set to the normal mode (step ST63). That is, it increases the ratio of the target motor torque Tm*, which is the portion of the target torque T* that is output from the front motor 101 and the rear motor 102. This reduces energy consumption by minimizing the drive of the friction braking device 30, thereby improving the energy consumption efficiency of the vehicle 1 in response to a request for the eco mode from the driver. It is more preferable that the control device 10 does not set the friction braking forces Fbf, Fbr so as not to drive the friction braking device 30.

[0041] When the control device 10 determines in step ST61 that the control mode is set to the sport mode, it increases the proportion of the target motor torque Tm* that is output from one of the front motor 101, rear motor 102, and friction braking device 30 that has a higher responsiveness. In other words, the control device 10 reduces the value of the gain k compared to when the control mode is set to the normal mode (step ST64). This increases the output proportion of the target motor torque Tm* that has a higher responsiveness, and makes it possible to better improve the road surface tracking of each wheel in response to a request for the sport mode from the driver.

[0042] It should be noted that which of the turning degree, vehicle speed, and control mode is given more importance in adjusting the gain k may be appropriately set depending on the specifications of the vehicle 1, the driving environment, and the like.

[0043] Although the description of the embodiment has been completed, aspects of the present invention are not limited to this embodiment. For example, the friction braking device 30 is driven by a hydraulic actuator and has lower output responsiveness than the front motor 101 and the rear motor 102. However, the friction braking device 30 may be a so-called electric caliper driven by an electric actuator and have higher output responsiveness than the front motor 101 and the rear motor 102. In this case, in step ST6 described above, the "one with higher responsiveness" refers to the friction braking device 30, and the "other with lower responsiveness" refers to the front motor 101 and the rear motor 102. This generates large anti-forces Zbf and Zbr, and the target friction braking torque Tb* with high output responsiveness can suppress roll motion and improve the road-following ability of the wheels. Furthermore, the target motor torque Tm* can compensate for any shortfall in the target torque T*. As such, the present invention is also applicable to a configuration in which the unsprung braking device has higher output responsiveness than the sprung driving device.

[0044] Although the embodiment of the present invention has been described above using an example in which yaw control is being executed, the present invention may be applied to a vehicle control device that suppresses roll motion by coordinating the force from the sprung drive device and the force from the unsprung brake device during cornering, not limited to when yaw control is being executed.

[0045] In this embodiment, the present invention is applied to vehicle 1, which is a four-wheel drive electric vehicle. However, the present invention may be applied to other vehicles as long as it is possible to suppress roll motion by applying a force from a sprung drive device and a force from an unsprung brake device in coordination to at least one of left and right front wheels 21 and left and right rear wheels 22. The present invention may also be applied, for example, to an electronically controlled on-demand four-wheel drive vehicle using an internal combustion engine mounted in the sprung portion as a drive source. [Explanation of symbols]

[0046] 1 vehicle 10 Control device (vehicle control device) 21 Front wheel (wheel) 22 Rear wheel (wheel) 30 Friction braking device (braking device) 41 High-pass filter 42 Low-pass filter 101, 101R, 101L Front motor (drive unit) 102, 102R, 102L rear motor (drive unit) Fbf, Fbr Friction braking force (force output from the braking device) Fdf, Fdr Driving force (force output from the driving device) Fgf, Fgr Regenerative braking force (force output from the drive unit) k gain T* Target torque Tb* Target friction braking torque Tm* Target motor torque Zdf, Zdr, Zgf, Zgr, Zbf, Zbr anti-force θdf, θdr, θbf, θbr anti-angle

Claims

1. A vehicle control device that applies a force output from a drive device mounted on a sprung portion of a vehicle and a force output from a braking device mounted on an unsprung portion of the vehicle to at least one of left and right front wheels and left and right rear wheels when the vehicle is turning, thereby suppressing roll motion of the vehicle, A vehicle control device that separates and outputs a target torque to be applied to one of the wheels into a high-frequency component from one of the drive device and the brake device that has a higher responsiveness and a low-frequency component from the other of the drive device and the brake device that has a lower responsiveness.

2. The vehicle control device according to claim 1, wherein the ratio of the target torque output from the braking device increases as the degree of turning of the vehicle increases.

3. The vehicle control device according to claim 1 , wherein the ratio of the target torque output from one of the drive device and the braking device, which has a higher responsiveness, is increased as the vehicle speed of the vehicle increases.

4. 2. The vehicle control device according to claim 1, wherein in a sport mode in which the road-following ability of the wheels is given more importance than in a normal mode, the proportion of the target torque output from one of the drive device and the braking device which has a higher responsiveness is increased.

5. 2. The vehicle control device according to claim 1, wherein in an eco mode that places more importance on improving the energy consumption efficiency of the vehicle than in a normal mode, a ratio of the target torque output from the drive device is made larger than in the normal mode.

6. 2. The vehicle control device according to claim 1, wherein in a comfort mode in which a greater emphasis is placed on ride comfort of the vehicle than in a normal mode, a ratio of the target torque output from the braking device is made larger than in the normal mode.

7. 7. A vehicle control device according to claim 1, wherein the force that suppresses the roll motion is preferentially output during execution of yaw control that adjusts the yaw moment of the vehicle by generating a driving force difference or a braking force difference between an inner wheel and an outer wheel when the vehicle is turning.

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