Patent ID: 12187135

DESCRIPTION OF EMBODIMENTS

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

FIG.1is a diagram illustrating a configuration of a vehicle100in which a driving force control method according to the present embodiment is executed. As the vehicle100according to the present embodiment, an electric vehicle, a hybrid vehicle, or the like, which includes a drive motor10serving as a driving source and can travel by driving force of the drive motor10, is assumed.

The drive motor10includes a front wheel motor10fprovided at a front position (front wheel side) of the vehicle100to drive front wheels11f, and a rear wheel motor10rprovided at a rear position (rear wheel side) to drive rear wheels11r.

The front wheel motor10fis implemented by a three-phase AC motor. During power running, the front wheel motor10fis supplied with electric power from an in-vehicle battery (not shown) to generate driving force. The driving force generated by the front wheel motor10fis transmitted to the front wheels11fvia a front wheel transmission16fand a front wheel drive shaft21f. On the other hand, during regeneration, the front wheel motor10fconverts regenerative braking force of the front wheels11finto AC power and supplies the AC power to the in-vehicle battery.

On the other hand, the rear wheel motor10ris implemented by a three-phase AC motor. During power running, the rear wheel motor10ris supplied with electric power from the in-vehicle battery to generate driving force. The driving force generated by the rear wheel motor10ris transmitted to the rear wheels11rvia a rear wheel transmission16rand a rear wheel drive shaft21r. During regeneration, the rear wheel motor10rconverts regenerative braking force of the rear wheels11rinto AC power and supplies the AC power to the in-vehicle battery.

An inverter12includes a front wheel inverter12fthat adjusts the electric power (positive in the power running and negative in the regeneration) supplied to the front wheel motor10f, and a rear wheel inverter12rthat adjusts the electric power (positive in the power running and negative in the regeneration) supplied to the rear wheel motor10r.

The front wheel inverter12fadjusts the electric power supplied to the front wheel motor10fsuch that positive or negative driving force (hereinafter, also referred to as “front wheel driving force Ff”) determined for total driving force (hereinafter, also referred to as “total requested driving force Ffr”) requested for the vehicle100is achieved. On the other hand, the rear wheel inverter12radjusts the electric power supplied to the rear wheel motor10rsuch that positive or negative driving force (hereinafter, also referred to as “rear wheel driving force Fr”) determined for the total requested driving force Ffris achieved.

In particular, the front wheel driving force Ffand the rear wheel driving force Frin the present embodiment are determined such that a sum thereof matches the total requested driving force Ffr. The total requested driving force Ffris determined based on, for example, an operation amount (accelerator opening) for an accelerator pedal mounted on the vehicle100, or a command from a prescribed autonomous driving system (autonomous driving control device) such as an advanced driver assistance systems (ADAS) or autonomous driving (AD).

A brake actuator14is constituted by known mechanical brakes operated by hydraulic pressure or the like, and includes front wheel friction brakes14fthat apply friction braking force (hereinafter also referred to as “front wheel braking force Bf”) to the front wheel11f, and rear wheel friction brakes14rthat apply friction braking force (hereinafter also referred to as “rear wheel braking force Br”) to the rear wheel11r.

Further, the vehicle100further includes a controller50serving as a driving force control device that controls the front wheel driving force Ff, the rear wheel driving force Fr, the front wheel braking force Bf, and the rear wheel braking force Br.

The controller50is implemented by a computer including a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input/output interface (I/O interface), and is programmed so as to execute each processing in vehicle control to be described below. In particular, a function of the controller50can be achieved by any in-vehicle computer such as a vehicle control module (VCM), a vehicle motion controller (VMC), and a motor controller, and/or a computer provided outside the vehicle100. The controller50may be implemented by one piece of computer hardware, or may be implemented by distributing various processes by a plurality of pieces of computer hardware.

The controller50controls the front wheel driving force Ff, the rear wheel driving force Fr, the front wheel braking force Bf, and the rear wheel braking force Brby using the total requested driving force Ffr, detection values of vertical acceleration sensors30fL,30fR on the front wheel side, detection values of vertical acceleration sensors30rL,30rR on the rear wheel side, a suspension stroke amount Ssudetected by a sensor (not shown), and the like as input information. More specifically, the controller50issues a command to the front wheel inverter12f, the rear wheel inverter12r, the front wheel friction brake14f, and the rear wheel friction brake14rso as to achieve desired front wheel driving force Ff, rear wheel driving force Fr, front wheel braking force Bf, and rear wheel braking force Br.

In particular, in the present embodiment, the controller50executes any one of basic drive control, a cooperative process, and a non-cooperative process as control that defines driving force distribution during forward traveling (particularly, during acceleration) of the vehicle100.

The controller50executes the basic drive control during normal traveling (in the present embodiment, in particular, a scene other than traveling on an undulating road to be described later). In the basic drive control, the controller50sets the front wheel driving force Ffand the rear wheel driving force Frto prescribed basic front wheel driving force and prescribed basic rear wheel driving force, respectively.

Here, the basic front wheel driving force and the basic rear wheel driving force are values determined by experiments, simulations, or the like so that vehicle characteristics (in particular, power consumption performance) of the vehicle100take desired characteristics according to a traveling scene. Specific values of the basic front wheel driving force and the basic rear wheel driving force may be appropriately changed in accordance with a specification of the vehicle100and the traveling scene. For example, when the vehicle100travels straight on a flat paved road at a constant speed, a distribution ratio of the basic front wheel driving force and the basic rear wheel driving force to the total requested driving force Ffrcan be set to 50:50.

On the other hand, when controller50detects a scene in which the vehicle100travels on a prescribed undulating road based on various pieces of input information, the controller50executes any one of the cooperative process and the non-cooperative process according to a size (amplitude) of an unevenness of the undulating road. In the present embodiment, the undulating road means a traveling road on which an unevenness is present over a certain distance in a traveling direction of the vehicle100. In the following, in particular, a portion of the undulating road protruding from a flat surface is referred to as a “mountain”, and a portion thereof recessed from the flat surface is referred to as a “valley”.

In the cooperative process, the controller50executes either a first control mode or a second control mode in response to a request to lift up a vehicle body or a request to lift down the vehicle body.

In the first control mode, the controller50sets the front wheel braking force Bfto a positive value, sets the front wheel driving force Ffto a negative value, and sets the rear wheel driving force Fr to a positive value. That is, the controller50causes the front wheel motor10fto execute regeneration (causes the front wheels11fto execute regenerative braking), causes the rear wheel motor10rto execute power running (causes the rear wheels11rto execute power driving), and then applies the friction braking force to the front wheels11f. In the second control mode, the controller50sets the front wheel driving force Ffto a positive value, sets the rear wheel driving force Frto a negative value, and sets the rear wheel braking force Brto a positive value. That is, the controller50causes the front wheel motor10fto execute power running (causes the front wheels11fto execute power driving), causes the rear wheel motor10rto execute regeneration (causes the rear wheels11rto execute regenerative braking), and then applies the friction braking force to the rear wheels11r.

On the other hand, in the non-cooperative process, the controller50executes either a third control mode or a fourth control mode in response to a request to lift up the vehicle body or a request to lift down the vehicle body.

In the third control mode, the controller50sets the front wheel driving force Ffto a negative value and sets the rear wheel driving force Frto a positive value without applying the front wheel braking force Bf. Further, in the fourth control mode, the controller50sets the front wheel driving force Ffto a positive value and sets the rear wheel driving force Frto a negative value without applying the rear wheel braking force Br.

A relationship between adjustment of the front wheel driving force Ff, the rear wheel driving force Fr, the front wheel braking force Bf, and the rear wheel braking force Brand reduction of vertical displacement of the vehicle body in the cooperative process and the non-cooperative process will be described more specifically.

FIG.2is a diagram illustrating a schematic structure (particularly, an outline of a suspension geometry) of a chassis system of the vehicle100. In the figure, “Of” represents a virtual rotation center (instantaneous rotation center) in a pitch direction of a vehicle body front portion, and “Or” represents a virtual rotation center (instantaneous rotation center) in the pitch direction of a vehicle body rear portion.

When the vehicle100is traveling forward, when the regenerative braking force (force in a direction opposite to the traveling direction) is applied to the front wheels11fand power driving force (force in the same direction as the traveling direction) is applied to the rear wheels11r, anti-squat force Fa(force for lifting the vehicle body) acts on the vehicle body. On the other hand, when power driving force is applied to the front wheels11fand regenerative braking force is applied to the rear wheels11r, squat force Fsq(force for causing the vehicle body to sink) acts on the vehicle body.

Accordingly, theoretically, in the scene in which the vehicle100travels on the undulating road or the like, by performing pitch adjustment (that is, the above-described non-cooperative process) by adjusting the driving force distribution of the front wheels11fand the rear wheels11r, it is possible to reduce the vertical displacement (heave vibration) of the vehicle body by appropriately lifting up or lifting down the vehicle body.

On the other hand, a magnitude of the anti-squat force Fanor the squat force Fsqobtained by the non-cooperative process depends on a magnitude of an anti-squat angle θ (front anti-squat angle θfand rear anti-squat angle θr) of a suspension40(front suspension40fand rear suspension40r) of the vehicle100.

More specifically, the front wheel driving force Ffgenerated by the front wheel motor10fand the rear wheel driving force Frgenerated by the rear wheel motor10rare transmitted to the front wheels11fand the rear wheels11r, respectively, with the front wheel drive shaft21and the rear wheel drive shaft21ras working points.

Therefore, the anti-squat angles θfand θr, which define a vertical component of pitching force generated by the adjustment of the driving force distribution (that is, the magnitude of the anti-squat force Fanor the squat force Fsq), are respectively determined as angles formed by a horizontal line and straight lines respectively connecting the virtual rotation centers Ofand Ordetermined by structures of the suspensions40f,40rand the working points.

Therefore, in a case in which the anti-squat angles θfand θrcannot be increased (in a case in which the virtual rotation centers Ofand Orare located at relatively low positions) due to the structures of the suspensions40fand40r, a range of the anti-squat force Fnnor the squat force Fsqobtained by adjusting the driving force distribution is limited.

In particular, as in the vehicle100of the present embodiment shown inFIG.2, in a case in which a suspension structure in which the front anti-squat angle θfis relatively small is adopted in consideration of ride comfort and nose dive feeling during braking, there is a problem that a sufficient effect of reducing the vertical displacement of the vehicle body cannot be achieved even if the non-cooperative process is executed.

In contrast, the present inventor has found that a high effect of reducing the vertical displacement of the vehicle body can be achieved even in the vehicle100equipped with the suspension structure having a relatively small anti-squat angle θ by adjusting net driving force distribution applied to the front wheels11fand the rear wheels11rbeyond an adjustment range by the non-cooperative process using the front wheel braking force Bfor the rear wheel braking force Br.

FIG.3is a diagram illustrating an operation and effect of executing the cooperative process. In the following description, in particular, the operation and effect of the cooperative process will be described focusing on the first control mode (application of the front wheel braking force Bf, regenerative braking of the front wheels11f, and power driving of the rear wheels11r). On the other hand, the following description also applies to the second control mode (power driving of the front wheels11f, application of the rear wheel braking force Br, and regenerative braking of the rear wheels11r).

As shown in the figure, when the first control mode is executed while the vehicle100is traveling forward, a working point of the front wheel braking force Bfis an outer peripheral portion of the front wheel11f. Therefore, an anti-squat angle θBfdetermined as an angle formed by a horizontal line and a straight line that connects the virtual rotation center Ofon the front wheel side and the working point of the front wheel braking force Bfto each other is larger than the anti-squat angle θfin the non-cooperative process. Therefore, when the first control mode of the cooperative process is executed, the effect of reducing the vertical displacement of the vehicle body can be further enhanced compared to when the third control mode of the non-cooperative process is executed.

On the other hand, the cooperative process is control of operating the mechanical brake actuator14. Therefore, in terms of control responsiveness, the non-cooperative process, which is electrical control without operation of a mechanical actuator, is superior.

Hereinafter, an example will be described in which, in a scene in which the vehicle100travels on an undulating road, a situation in which the reduction of the vertical displacement of the vehicle body is prioritized and a situation in which the control responsiveness is prioritized are distinguished according to the size of an unevenness of a traveling road surface, and one of the cooperative process and the non-cooperative process is appropriately executed.

FIG.4is a flowchart illustrating the driving force control method according to the present embodiment. Each process shown inFIG.4is executed based on a timing at which the controller50determines that the vehicle100is traveling on the undulating road based on information of a traveling road provided from a prescribed internal sensor or an external server mounted on the vehicle100. In particular, the controller50repeatedly executes each process shown inFIG.4at prescribed calculation intervals in the scene.

In steps S110and S120, the controller50determines whether a pitch rate ωpiand vertical acceleration aGexceed a pitch rate threshold value ωpiTHand a vertical acceleration threshold value aGTH, respectively.

Here, the pitch rate ωpiis a parameter defined as a time derivative (that is, a pitch angular velocity) of a pitch angle θpi. Further, the pitch angle θpiis determined as a displacement angle in the pitch direction with respect to a horizontal direction around a center of gravity G of the vehicle100(seeFIG.2). A sign of the pitch angle θpiis set such that a direction in which the front wheel11fof the vehicle100is lifted up (nose up direction) is positive and a direction in which the rear wheel11ris lifted up (nose down direction) is negative. Further, the vertical acceleration aGis acceleration in the vertical displacement of the vehicle100(center of gravity G of the vehicle100). The pitch rate ωpi, the pitch angle θpi, and the vertical acceleration aGcan be calculated by a known method based on the detection values of the vertical acceleration sensors30fL,30fR on the front wheel side, the detection values of the vertical acceleration sensors30rL,30rR on the rear wheel side, and other necessary parameters.

Both the pitch rate ωpiand the vertical acceleration aGare parameters representing magnitude of the actual vertical displacement of the vehicle100during traveling on the undulating road. That is, both the pitch rate ωpiand the vertical acceleration aGare parameters (unevenness degree parameters) indicating the size of the unevenness of the undulating road.

Further, the pitch rate threshold value ωpiTHand the vertical acceleration threshold value aGTHare determined as values to appropriately determine which of the effect of reducing the vertical displacement of the vehicle100and the high control responsiveness is prioritized. More specifically, the pitch rate threshold value ωpiTHand the vertical acceleration threshold value aGTHare determined so that the cooperative process is executed when the unevenness of the undulating road is relatively large (when the high control responsiveness is not required, but the high effect of reducing the vertical displacement is required). Conversely, the pitch rate threshold value ωpiTHand the vertical acceleration threshold value aGTHare determined such that the non-cooperative process is executed when the unevenness of the undulating road is relatively small (when the high control responsiveness is required, but the required effect of reducing the vertical displacement is small).

Further, the controller50executes a process of step S130when both determination results of step S110and step S120are positive, and otherwise executes the non-cooperative process (step S160).

In step S130, the controller50determines whether the suspension stroke amount Ssuexceeds a first stroke amount threshold value SsuTH1.

Similarly to the pitch rate ωpiand the vertical acceleration aG, the suspension stroke amount Ssuis also an unevenness degree parameter representing the magnitude of the actual vertical displacement of the vehicle100during traveling on the undulating road. Further, the first stroke amount threshold value SsuTH1is also set to a suitable value from the viewpoint of determining whether the unevenness of the undulating road is large to an extent that the reduction of the vertical displacement of the vehicle100by the cooperative process using the front wheel braking force Bfor the rear wheel braking force Bris desired.

Further, when a determination result of step S130is positive, the controller50executes the cooperative process (step S140), and otherwise, executes the non-cooperative process (step S160).

As a specific example of the cooperative process, the controller50executes the first control mode (lifts up the vehicle body) so as to cancel force in a lift down direction in a scene in which the vehicle100is traveling on a valley portion of the undulating road and the force in the lift down direction is generated on the vehicle body. On the other hand, the controller50executes the second control mode (lifts down the vehicle body) so as to cancel force in a lift up direction in a scene in which the vehicle100is traveling on the mountain of the undulating road and the force in the lift up direction is generated on the vehicle body.

Further, as an example of the non-cooperative process, the controller50executes the third control mode (lifts up the vehicle body) so as to cancel force in the lift down direction in a scene in which the vehicle100travels on the valley portion of the undulating road and the force in the lift down direction is generated on the vehicle body. On the other hand, the controller50executes the fourth control mode (lifts down the vehicle body) so as to cancel force in the lift up direction in a scene in which the vehicle100is traveling on the mountain of the undulating road and the force in the lift up direction is generated on the vehicle body.

An aspect of selection of the first control mode or the second control mode in the cooperative process and an aspect of selection of the third control mode or the fourth control mode in the non-cooperative process described above are examples, and the present invention is not limited thereto. Specific values of the front wheel driving force Ff, the rear wheel driving force Fr, the front wheel braking force Bf, and the rear wheel braking force Brset in the cooperative process or the non-cooperative process are not limited to specific values, and can be appropriately adjusted according to a situation.

Further, the controller50determines whether the suspension stroke amount Ssufalls below a second stroke amount threshold value SsuTH2during the execution of the cooperative process (step S150).

The second stroke amount threshold value SsuTH2is set to an appropriate value from the viewpoint of determining whether the unevenness of the undulating road is small enough to determine that it is necessary to switch from the cooperative process to the non-cooperative process in consideration of the control responsiveness.

Further, when the controller50determines that the suspension stroke amount Ssufalls below the second stroke amount threshold value SsuTH2, the controller50switches the control from the cooperative process to the non-cooperative process (step S160) and ends this routine.

In consideration of low control responsiveness in the above-described cooperative process, a configuration may be adopted in which the switching from the cooperative process to the non-cooperative process is executed when the suspension stroke amount Ssufalls below the second stroke amount threshold value SsuTH2a plurality of times. In particular, it takes a certain amount of time until the effect of reducing the vertical displacement of the vehicle body is actually obtained after the cooperative process is started according to the determination result of step S130. In consideration of this, it is possible to prevent a situation where a state in which the suspension stroke amount Ssuis temporarily decreased is detected and the control is switched to the non-cooperative process even though the front wheel braking force Bfor the rear wheel braking force Brhas not yet followed the command immediately after a start of the cooperative process or the like. Further, in determination of step S150(determination of whether to switch from the cooperative process to the non-cooperative process), a configuration may be adopted in which the pitch rate ωpiand/or the vertical acceleration aGare appropriately compared with the threshold values.

FIG.5shows timing charts showing examples of time-series changes of control parameters when the control according to the present embodiment is executed in an undulating road traveling scene. In the timing charts ofFIG.5, the pitch angle θpiand the pitch rate ωpiare positive in the nose up direction of the vehicle100, the vertical acceleration aGis positive in an upward direction with respect to the vehicle100, and the suspension stroke amount Ssuis positive in a compression direction of the suspension40.

As shown in the drawing, in a section (time t<t1) in which any one of the pitch rate ωpi, the vertical acceleration aG, and the suspension stroke amount Ssuis equal to or less than a respective one of the threshold values, that is, in a scene in which the unevenness of the undulating road is estimated to be relatively small, the non-cooperative process is executed with priority given to the control responsiveness.

Further, when all of the pitch rate ωpi, the vertical acceleration aG, and the suspension stroke amount Ssu(particularly, inFIG.5, the suspension stroke amount Ssuon the rear wheel side) exceed the respective threshold values (time t=t1), that is, when the vehicle100is estimated to enter a section in which the unevenness of the undulating road is relatively large, the control is switched from the non-cooperative process to the cooperative process from the viewpoint of improving the effect of reducing the vertical displacement of the vehicle body.

Thereafter, when the suspension stroke amount Ssu(inFIG.5, the suspension stroke amount Ssuon both the front wheel side and the rear wheel side) falls below the second stroke amount threshold value SsuTH2, that is, when the vehicle100is estimated to enter a section in which the unevenness of the undulating road is relatively small, the control is switched from the cooperative process to the non-cooperative process again.

FIG.6shows diagrams illustrating an operation and effect of executing the control described in the timing charts ofFIG.5. As shown in the figure, the pitch rate ωpi, the vertical acceleration aG, and the suspension stroke amount Ssu(see broken lines), which are parameters indicating the magnitude of the vertical displacement in the control according to the present embodiment, are reduced compared to those (see solid lines) in a comparative example in which the basic drive control is maintained even during traveling on the undulating road.

Hereinafter, a configuration of the above-described present embodiment and an operation and effect thereof will be collectively described.

The present embodiment provides the driving force control method for controlling the front wheel driving force Ffand the rear wheel driving force Frby the front wheel motor10fconnected to the front wheels11fof the vehicle100and the rear wheel motor10rconnected to the rear wheels11r, respectively.

In this driving force control method, the cooperative process (step S140) is executed in which the adjustment of at least one of the front wheel driving force Ffand the rear wheel driving force Frand the application of the friction braking force (front wheel braking force Bfor rear wheel braking force Br) to at least one of the front wheel11fand the rear wheel11rcooperate to lift up or lift down the vehicle body.

Accordingly, it is possible to further improve the effect of reducing the vertical displacement (heave vibration) of the vehicle100compared to the case in which the vehicle body is lifted up or lifted down by control of adjusting only the front wheel driving force Ffand the rear wheel driving force Fr.

In particular, the cooperative process (step S140) includes the first control mode in which the vehicle body is lifted up and the second control mode in which the vehicle body is lifted down. Further, in the first control mode, the friction braking force (front wheel braking force Bf) is applied to the front wheels11fto power the rear wheel motor10r. In the second control mode, the front wheel motor10fis powered and the friction braking force (rear wheel braking force Br) is applied to the rear wheel11r.

Accordingly, when the vehicle100travels forward, a more specific control mode for lifting up or lifting down the vehicle body is achieved in the cooperative process.

The driving force control method according to the present embodiment further executes the non-cooperative process of lifting up or lifting down the vehicle body only by adjusting the front wheel driving force Ffand the rear wheel driving force Fr(step S160). Further, the non-cooperative process includes the third control mode in which the front wheel motor10fis regenerated and the rear wheel motor10ris powered, and the fourth control mode in which the front wheel motor10fis powered and the rear wheel11ris regenerated.

Accordingly, in accordance with the traveling scene of the vehicle100or the like, it is possible to execute the lifting up or the lifting down of the vehicle body by the non-cooperative process having the high control responsiveness instead of the cooperative process as appropriate. In this description, the term “only by the adjustment of the front wheel driving force Ffand the rear wheel driving force Fr” means that the operation amount for the control of lifting up or lifting down the vehicle body includes the front wheel driving force Ffand the rear wheel driving force Fr, but does not include the friction braking force. Therefore, the above term is not intended to exclude from the technical scope of the present invention a form in which control logic that uses an operation amount other than the friction braking force to assist in lifting up or lifting down the vehicle body is included in the non-cooperative process.

Furthermore, in the driving force control method according to the present embodiment, when the vehicle100is traveling on the undulating road, the unevenness degree parameters (pitch rate ωpi, vertical acceleration aG, and suspension stroke amount Ssu) indicating the size of the unevenness of the undulating road are obtained. Further, when the unevenness degree parameters exceed respective prescribed first threshold values (pitch rate threshold value ωpiTH, vertical acceleration threshold value aGTH, and/or first stroke amount threshold value SsuTH1) during the execution of the non-cooperative process, the non-cooperative process is switched to the cooperative process (steps S110to S130and S140).

Accordingly, it is possible to appropriately select the cooperative process having the effect of reducing the vertical displacement and the non-cooperative process in which the control responsiveness is high according to the size of the unevenness in the undulating road traveled by the vehicle100.

In particular, in the present embodiment, when the unevenness degree parameter (particularly, the suspension stroke amount Ssu) falls below a prescribed second threshold value (second stroke amount threshold value SsuTH2) during the execution of the cooperative process, the cooperative process is switched to the non-cooperative process.

Accordingly, it is possible to more appropriately select the cooperative process having the effect of reducing the vertical displacement and the non-cooperative process in which the control responsiveness is high according to the size of the unevenness in the undulating road traveled by the vehicle100.

Further, in the present embodiment, the controller50that functions as the driving force control device that executes the driving force control method is provided. The controller50controls the front wheel driving force Ffand the rear wheel driving force Frby the front wheel motor10fconnected to the front wheels11fof the vehicle100and the rear wheel motor10rconnected to the rear wheels11r, respectively.

In particular, the controller50includes a cooperative process unit (step S140) that causes the adjustment of the at least one of the front wheel driving force Ffand the rear wheel driving force Frto cooperate with the application of the friction braking force (front wheel braking force Bfor rear wheel braking force Br) to the at least one of the front wheel11fand the rear wheel11rto lift up or lift down the vehicle body.

Accordingly, a configuration of the control device suitable for executing the driving force control method is achieved.

Although the embodiment of the present invention has been described above, the above embodiment is merely a part of application examples of the present invention, and does not intend to limit the technical scope of the present invention to the specific configurations of the above embodiment.

For example, in the above embodiment, the example has been described in which one of the non-cooperative process and the cooperative process is executed according to the size of the unevenness in the scene in which the vehicle100is traveling on the undulating road. However, the present invention is not limited thereto, and the same control can be executed in other traveling scenes in which the vertical displacement of the vehicle100is assumed to be reduced.

Furthermore, a specific aspect of the unevenness degree parameter is not limited to that described in the above embodiment. For example, information related to the unevenness of the undulating road may be acquired using a Lidar camera and/or any in-vehicle sensor such as a radar, and a value obtained by directly estimating the size of the unevenness from the information may be used as the unevenness degree parameter. Furthermore, parameters used for determining the switching from the non-cooperative process to the cooperative process are not limited to the unevenness degree parameters described above. For example, a configuration may be adopted in which a parameter indicating a length of a period of the mountain and valley of the unevenness of the undulating road is acquired based on information acquired from an in-vehicle server or an external server, and it is determined whether to switch from the non-cooperative process to the cooperative process based on the parameter.

In the above-described embodiment, the example has been described in which the adjustment (pitch adjustment) of the driving force distribution and the application of the friction braking force to the respective driving wheels cooperate with each other in both the first control mode (lift up control) and the second control mode (lift down control) of the cooperative process. However, the present invention is not limited thereto, and in the cooperative process, a control mode may be adopted in which the friction braking force is applied to only one of the first control mode and the second control mode. For example, a control mode may be adopted in which the front wheel braking force Bfis applied in the first control mode (lift up control) of the cooperative process, but the rear wheel braking force Bris not applied in the second control mode (lift down control). As shown inFIG.2, it is particularly preferable that the control logic is applied to a vehicle body structure in which, while the anti-squat angle θfon the front side is relatively small, the anti-squat angle θron the rear side is relatively large, and a sufficient lift up and down amount can be ensured only by adjusting the driving force distribution on the rear side.

Further, in the above-described embodiment, the example has been described in which the control mode in which pitch displacement is adjusted by adjusting only the driving force distribution of the vehicle100is adopted as the non-cooperative process. However, instead of this, it is also possible to adopt a control mode in which the non-cooperative process is any driving force distribution (for example, the basic drive control that determines the driving force distribution during normal traveling) executed for purposes other than the purpose of adjusting the pitch displacement. For example, the technical scope of the present invention also includes a control mode in which the non-cooperative process is used as the basic drive control to achieve direct switching between the basic drive control and the cooperative process (switching without intervention of the pitch adjustment performed by the adjustment of the driving force distribution) as appropriate according to a situation of the traveling road surface such as the size of the unevenness of the undulating road.