JP2021146950A - Turn control device for vehicle - Google Patents

Abstract

To provide a turn control device for a vehicle with system configuration simplified, the device capable of properly assisting the vehicle to turn by controlling a driving force early in response to an intention of a driver.SOLUTION: A turn control device (ECU) 20 includes: a target yaw rate calculation part 21 to calculate a target yaw rate on the basis of an actual steering angle detected with a steering angle sensor 14, an actual wheel velocity detected with a wheel velocity sensor 15, and an actual lateral acceleration detected with a lateral G sensor 17; a FF controller 22 to obtain a FF control amount of a driving force of an electric motor 2 on the basis of the target yaw rate; a FB controller 23 to obtain a FB control amount of the driving force of the electric motor 2 on the basis of a deviation U between the target yaw rate and an actual yaw rate detected with a yaw rate sensor 16; and a total control amount calculation part 24 to add the FF control amount to the FB control amount to obtain a total control amount of the driving force of the electric motor 2.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle turning control device that assists the turning of a vehicle by controlling the driving force of a driving source.

When the vehicle turns a corner by steering the steering wheel by the driver, the driving force of the left and right drive wheels is controlled, and the difference in driving force between the left and right drive wheels assists the turning of the vehicle to prevent understeer and oversteer. Suppression has been conventionally performed (see, for example, Patent Document 1).

For example, when a steering operation is performed, the estimated value of the road surface friction coefficient is calculated based on the actual wheel speed detected by the wheel speed sensor and the actual steering angle detected by the steering angle sensor, and the target yaw rate is calculated with this target yaw rate. The driving force is feedback-controlled so that the deviation from the actual yaw rate detected by the yaw rate sensor becomes 0 (the actual yaw rate matches the target yaw rate).

However, in feedback control, the robustness of the steering angle sensor and yaw rate sensor (the property of blocking changes due to the influence of disturbance) is low, and the driving force control does not start unless a deviation between the target yaw rate and the actual yaw rate occurs. However, there is a problem that a time delay occurs in control and it is difficult to reflect the intention of the driver.

Therefore, for example, Patent Documents 2 and 3 describe the actual steering angle detected by the steering angle sensor, the actual vehicle speed detected by the vehicle speed sensor, and the actual lateral acceleration (actual lateral acceleration) detected by the lateral acceleration sensor (G sensor). Feedforward control (hereinafter referred to as "FF control") that calculates the target yaw rate of the vehicle based on G) and controls the driving force so that the yaw rate of the vehicle approaches the target yaw rate, and feedback control (hereinafter, "FB"). A turning control device has been proposed that enhances the turning performance of the vehicle when turning by controlling the driving force in combination with (referred to as "control"). Specifically, in such a turning control device, the control amount by FF control (hereinafter referred to as "FF control amount") and the control amount by FB control (hereinafter referred to as "FB control amount") are added. The total control amount is obtained, and the driving force (braking force) of the pair of left and right front wheels and the rear wheels of the vehicle is individually controlled based on the total control amount.

According to such a vehicle turning control device, since the FF control is executed before the FB control is started, the turning of the vehicle is properly assisted by controlling the driving force at an early stage reflecting the driver's intention. can do.

Japanese Patent No. 4446978 Japanese Unexamined Patent Publication No. 2011-073534 Japanese Unexamined Patent Publication No. 2011-183826

However, in the vehicle turning control device proposed in Patent Documents 2 and 3, the driving force (braking force) of the pair of left and right front wheels and rear wheels is based on the total control amount obtained by adding the FF control amount and the FB control amount. Is controlled individually, so there is a problem that the system configuration becomes complicated.

In addition, when the braking force of each wheel is controlled by a mechanical braking device provided on each wheel, a loss of vehicle running energy occurs due to the operation of the braking device during braking, which causes deterioration of fuel efficiency. become.

The present invention has been made in view of the above problems, and an object of the present invention is to appropriately assist the turning of a vehicle by controlling the driving force at an early stage reflecting the intention of the driver while simplifying the system configuration. The purpose is to provide a turning control device for a vehicle capable of performing.

In order to achieve the above object, the turning control device (20) of the vehicle (1) according to the present invention is detected by the actual steering angle detected by the steering angle detecting means (14) and the wheel speed detecting means (15). The target yaw rate calculation unit (21) that calculates the target yaw rate based on the actual wheel speed and the actual lateral acceleration detected by the lateral acceleration detecting means (17), and the drive source (2) based on the target yaw rate. The drive source (2) is based on the deviation (U) between the feedforward control amount calculation unit (22) for obtaining the feedforward control amount of force and the actual yaw rate detected by the target yaw rate and the yaw rate detecting means (16). The feedback control amount calculation unit (23) for obtaining the feedback control amount of the driving force of the above, and the total control amount of the driving force of the driving source (2) are obtained by adding the feedforward control amount and the feedback control amount. It is characterized by including a control amount calculation unit (24).

According to the present invention, the feedforward control (FF control) that controls the driving force (output) of the driving source only by the target yaw rate and the driving force (output) of the driving source based on the deviation between the target yaw rate and the actual yaw rate are obtained. Since the feedback control (FB control) for controlling is used in combination, it is possible to properly assist the turning of the vehicle by taking advantage of both advantages and controlling the driving force at an early stage reflecting the intention of the driver.

In addition, when the vehicle turns, the driving force (braking force) of the left and right front wheels and the rear wheels is not controlled individually, but only the driving force (output) of the drive source is controlled to decelerate the entire vehicle. Since the load is moved forward (front wheels) and a yaw moment in the turning direction is generated to assist the turning of the vehicle, the system configuration can be simplified and the cost can be reduced. Then, it is not necessary to decelerate the vehicle by a mechanical braking device, and when the drive source is an electric motor, the output of the electric motor is reduced, and when the drive source is an engine, the throttle opening is narrowed. Since the vehicle is decelerated, there is no loss of vehicle running energy corresponding to the energy consumed by the mechanical braking device.

Then, in the turning control device (20), the feedback control amount calculation unit (23) adds an absolute value (| U |) of the deviation (U) to the deviation (U) between the target yaw rate and the actual yaw rate. May be integrated to obtain the feedback control amount.

As described above, in slalom running in which the vehicle alternately turns left and right by integrating the absolute value of the deviation with the deviation between the target yaw rate and the actual yaw rate to obtain the feedback control amount. It is possible to prevent the occurrence of a situation in which the smooth running of the vehicle is hindered due to the sudden execution of deceleration control when the steering angle is around 0.

Further, the turning control device (20) includes a limit processing unit (25) that suppresses the feedforward control amount obtained by the feedforward control amount calculation unit (22) to an upper limit value or less, and a feedback control amount calculation unit. A limit processing unit (26) that suppresses the feedback control amount obtained in (23) to an upper limit value or less may be provided.

According to the above configuration, the deceleration of the vehicle during turning is suppressed to a predetermined value or less, excessive sudden deceleration of the vehicle is suppressed, and high running stability is ensured for the vehicle.

Further, the total control amount calculation unit (24) has correction units (29, 30) that correct the feedforward control amount and the feedback control amount, respectively, according to the magnitude of the required driving force with respect to the drive source (2). You may be doing it. Here, the correction unit (29, 30) corrects the feedforward control amount and the feedback control amount in a direction in which the larger the required driving force or the required driving force change rate with respect to the driving source (2), the smaller the feedforward control amount and the feedback control amount. It is desirable to do.

According to the above configuration, in the turning control of the vehicle, it is possible to limit the FF control amount and the FB control amount of the driving force of the driving source with respect to the excessive required driving force, and the driver does not feel uncomfortable when turning the vehicle. The vehicle can be moderately decelerated to assist its turning.

According to the present invention, it is possible to obtain an effect that the turning of the vehicle can be appropriately assisted by controlling the driving force at an early stage reflecting the intention of the driver while simplifying the system configuration.

It is a top view which shows typically the basic structure of the vehicle which includes the turning control device which concerns on this invention. It is a block diagram which shows the basic structure of the electronic control unit (ECU) which concerns on Embodiment 1 of this invention. It is a block diagram which shows the control amount calculation procedure in the FF controller and the FB controller of the electronic control unit (ECU) which concerns on Embodiment 1 of this invention. It is a top view which shows the state at the time of turning of a vehicle. (A) is a plan view showing a turning state of the vehicle by FF control of the driving force, and (b) is a time chart of the steering angle, the yaw rate and the required driving force. (A) is a plan view showing a turning state of the vehicle by FB control of the driving force, and (b) is a time chart of the steering angle, the yaw rate and the required driving force. (A) is a plan view showing a turning state of the vehicle by FF + FB control of the driving force, and (b) is a time chart of the steering angle, the yaw rate and the required driving force. It is a block diagram which shows the basic structure of the electronic control unit (ECU) which concerns on Embodiment 2 of this invention. It is a block diagram which shows the basic structure of the electronic control unit (ECU) which concerns on Embodiment 3 of this invention. It is a figure which shows the relationship between the required driving force and the correction coefficient in the turning control device which concerns on Embodiment 3 of this invention. It is a figure which shows the relationship between the required driving force change rate and the correction coefficient in the turning control apparatus which concerns on Embodiment 3 of this invention.

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

[Basic vehicle configuration]
FIG. 1 is a plan view schematically showing a basic configuration of a vehicle provided with a turning control device according to the present invention. The illustrated vehicle 1 is a front-wheel drive type (FF type) electric vehicle, and the front portion of the vehicle body thereof. An electric motor (M) 2 as a drive source and a transmission (T) 4 that shifts the rotation of the electric motor (M) 2 and transmits the rotation to the front axle 3 are arranged at (the left end portion in FIG. 1). There is. Here, the front axle 3 is arranged horizontally in the vehicle width direction, and the front wheels WFL and WFR, which are driving wheels, are attached to the left and right ends thereof, respectively. Further, a rear axle 5 is arranged in the vehicle width direction in parallel with the front axle 3 at the rear portion (right end portion in FIG. 1) of the vehicle body, and rear wheels WRL and WRR are arranged at the left and right ends of the rear axle 5, respectively. It is attached.

By the way, the electric motor (M) 2 which is a drive source is rotationally driven by the electric power supplied from the battery 6 via the inverter 7, and the driving force (output) thereof constitutes the swivel control device according to the present invention. It is controlled via an inverter 7 operated by a control signal output from an electronic control unit (ECU) 20. Here, an accelerator opening sensor 10 for detecting the depression amount (accelerator opening) of the accelerator pedal 9 is installed in the vicinity of the accelerator pedal 9 installed in front of the driver's seat, and the accelerator is opened. The degree sensor 10 is electrically connected to the electronic control unit (ECU) 20.

Further, the steering handle 11 constituting the steering system of the vehicle 1 is rotatably arranged in front of the driver's seat, and the steering shaft 12 extending from the steering handle 11 is a power steering mechanism provided on the front axle 3. It is connected to (P / S) 13. A steering angle sensor 14 for detecting the steering angle of the steering handle 11 is provided on the steering shaft 12, and the steering angle sensor 14 is electrically connected to the electronic control unit (ECU) 20. There is.

Further, the vehicle 1 includes a wheel speed sensor 15 for detecting the rotational speed of the wheels (front wheel WFL on the left side in the illustrated example), a yaw rate sensor 16 for detecting the yaw rate of the vehicle body, and lateral sides of the vehicle body in the front-rear direction. Lateral acceleration sensors (hereinafter referred to as “lateral G sensors”) 17 for detecting acceleration (hereinafter referred to as “lateral G”) are provided, respectively, and these wheel speed sensors 15, yaw rate sensor 16 and lateral G sensor are provided. Each of the 17 is electrically connected to the electronic control unit (ECU) 20.

[Swivel control device]
Next, the electronic control unit (ECU) 20 constituting the turning control device provided in the vehicle 1 configured as described above will be described.

<Embodiment 1>
FIG. 2 is a block diagram showing a basic configuration of an electronic control unit (ECU) according to the first embodiment of the present invention, and FIG. 3 is a block showing a control amount calculation procedure in an FF controller and an FB controller of the electronic control unit (ECU). It is a figure.

As shown in FIG. 2, the electronic control unit (ECU) 20 has an actual steering angle detected by the steering angle sensor 14 (see FIG. 1) and an actual wheel detected by the wheel speed sensor 15 (see FIG. 1). A target yaw rate calculation unit 21 that calculates a target yaw rate from the actual lateral G detected by the speed and lateral G sensor 17 (see FIG. 1) is provided.

Further, the electronic control unit (ECU) 20 is equipped with an electric motor (M) 2 (FIG. 1) by feedforward control (hereinafter referred to as “FF control”) based on the target yaw rate calculated by the target yaw rate calculation unit 21. An FF controller (feedforward control amount calculation unit) 22 for obtaining a driving force control amount (hereinafter, referred to as “FF control amount”) of (see) is provided. Further, in the electronic control unit (ECU) 20, based on the deviation U between the actual yaw rate detected by the yaw rate sensor 16 (see FIG. 1) in the feedback control (hereinafter referred to as “FB control”) and the target yaw rate. An FB controller (feedback control amount calculation unit) 23 for obtaining a driving force control amount (hereinafter, referred to as “FB control amount”) of the electric motor (M) 2 is provided.

Further, the electronic control unit (ECU) 20 is added with the FF control amount obtained by the FF controller 22 and the FB control amount obtained by the FB controller 23, and the total control amount with respect to the required driving force (driver required driving force). The total control amount calculation unit 24 for obtaining the above is provided. Here, the total control amount obtained by the total control amount calculation unit 24 is output to the inverter 7 (see FIG. 1), and the inverter 7 outputs a current corresponding to the total control amount to the electric motor (M) 2 (M) 2 (see FIG. 1). (See FIG. 1). Then, the electric motor (M) 2 generates a driving force whose required driving force is adjusted (corrected) according to the total control amount, and reduces the driving force when the vehicle 1 turns along the curve as described later. By decelerating the vehicle 1, the vehicle 1 is assisted in turning and understeer is suppressed. The driver required driving force is obtained based on the depression amount (accelerator opening degree) of the accelerator pedal 9 (see FIG. 1) detected by the accelerator opening degree sensor 10 (see FIG. 1).

Here, a method of calculating the FF control amount in the FF controller 22 and the FB control amount in the FB controller 23 will be described with reference to FIG.

The FF controller 22 calculates the FF control amount in the FF control of the driving force, and sets the gain (correction coefficient) K _FF to the value obtained by integrating the target yaw rate and the target yaw moment calculated by the target yaw rate calculation unit 21. The FF control amount is calculated by multiplying. The target yaw moment is a value obtained by differentiating the target yaw rate with respect to time.

Further, the FB controller 23 calculates the FB control amount in the FB control of the driving force, and the target yaw rate calculated by the target yaw rate calculation unit 21 and the actual yaw rate detected by the yaw rate sensor 16 (see FIG. 1). The deviation U and the absolute value | U | of this deviation U are integrated, and the gain (correction coefficient) K _FB is multiplied by this integrated value to calculate the FB control amount.

As described above, in the calculation of the FB control amount in the FB control, the vehicle 1 alternately turns left and right by multiplying the deviation U between the target yaw rate and the actual yaw rate by the absolute value | U | of this deviation U. It is possible to prevent the occurrence of a situation in which the smooth running of the vehicle 1 is hindered due to the sudden execution of the deceleration control when the steering angle is around 0 in the slalom running continuously performed.

Here, the state when the vehicle 1 is turning right along the curve is shown in the plan view of FIG. 4. In this state, the actual driving force is reduced with respect to the required driving force to reduce the vehicle 1 to the required driving force. When the vehicle is decelerated, the vertical load moves to the front part of the vehicle body due to the inertial force acting on the vehicle 1. Here, in FIG. 4, the magnitudes of the vertical loads acting on the left and right front wheels WFL and WFR before deceleration and the left and right rear wheels WRL and WRR are indicated by broken semicircles, respectively, and the respective vertical loads after deceleration are shown. The size is indicated by a solid semicircle.

In the example shown in FIG. 4, since the vehicle 1 is turning to the right, the vertical load acting on the left front wheel WFL and the left rear wheel WRL acts on the right front wheel WFR and the right rear wheel WRR, respectively. It will be larger than the vertical load.

Therefore, the lateral force (front side force) FF acting clockwise on the front part of the vehicle 1 is larger than the lateral force (rear side force) FR acting clockwise on the rear part of the vehicle 1 (FF> FR), and the vehicle body. A clockwise yaw moment M for turning the vehicle 1 to the right is generated in the vehicle 1, and the yaw moment M assists the right turn (cornering) of the vehicle 1 to suppress understeer.

Next, when the vehicle 1 turns to the right, the driving force control by the electronic control unit (ECU) 20 will be described below for FF control, FB control, and FF control + FB control, respectively, based on FIGS. 5 to 7.

1) FF control:
FIG. 5A is a plan view showing a turning state of the vehicle by FF control of the driving force, and FIG. 5B is a time chart of the steering angle, yaw rate and driving force, and the vehicle 1 has a predetermined driving force (required driving). When traveling in a straight line with force), both the steering angle and the yaw rate show 0. Then, when the driver starts turning the steering handle 11 (see FIG. 1) to the right at the time t1 shown in the figure from this state, the actual steering angle and the wheel speed sensor 15 (see FIG. 1) detected by the steering angle sensor 14 (see FIG. 1) The target yaw rate is calculated by the target yaw rate calculation unit 21 (see FIG. 2) based on the actual wheel speed detected by (see FIG. 1). This target yaw rate gradually increases with the passage of time t as shown in FIG. 5 (b).

When the target yaw rate is obtained as described above, the FF control amount (correction amount for the required driving force) of the driving force is obtained from the inverter 7 so that the actual yaw rate approaches the target yaw rate in the FF controller 22 (see FIG. 2). The supply current to the electric motor (M) 2 (see FIG. 1) is reduced, and the driving force (output) of the electric motor (M) 2 is increased from the time t1 to the required driving force as shown in FIG. 5 (b). It will be reduced.

When the driving force of the electric motor (M) 2 is reduced as described above, the vehicle 1 decelerates and the load moves to the left and right front wheels WFL and WFR of the vehicle 1 as described in FIG. At 1, a yaw moment M that tries to turn this to the right is generated. As a result, the right turn of the vehicle 1 is assisted, and as shown in FIG. 5A, the vehicle 1 travels while smoothly turning along the curve.

Here, in the FF control of this driving force, what is the FB control that controls the driving force (output) of the electric motor (M) 2 based on the deviation U between the target yaw rate and the actual yaw rate detected by the yaw rate sensor 16. Unlike this, since the driving force is controlled only by the target yaw rate, as shown in FIG. 5B, the driving force (output) of the electric motor (M) 2 is such that the driver starts to turn the steering handle 11 (see FIG. 1). It is controlled (corrected) so as to be reduced with respect to the required driving force at the stage of the time t1. Therefore, it is possible to assist the turning of the vehicle 1 by quickly reflecting the driver's willingness to turn.

By the way, this FF control is executed between the time t1 when the driver starts turning the steering wheel 11 and the time t3 when the driver finishes turning the steering handle 11, and during that time, the driving force (output) of the electric motor (M) 2 is executed. ) Is sharply reduced from time t1 to t2 as shown in FIG. 5 (b), the reduction rate (deceleration) of the driving force gradually decreases at time t2 to t3, and the driving force becomes smaller at time t3. Matches the required driving force.

Then, as shown in FIG. 5B, at the times t1 to t3 when the FF control is executed, the target yaw rate and the actual yaw rate change as shown in the figure with the passage of time t, respectively, and a diagonal line is formed between them. The deviation U shown in is generated.

If such FF control of the driving force (deceleration control at the time of turning) is not performed, the vehicle 1 deviates from the corner and becomes an understeer state as shown in FIG. 5A, and its behavior is unstable. become.

2) FB control:
Next, the behavior of the vehicle 1 by FB control of the driving force will be described below with reference to FIG.

FIG. 6A is a plan view showing a turning state of the vehicle by FB control of the driving force, and FIG. 6B is a time chart of the steering angle, yaw rate and driving force, and the vehicle has a predetermined driving force (required driving force). ), Both the steering angle and the yaw rate show 0. Then, when the driver starts turning the steering handle 11 (see FIG. 1) to the right at the time t1 shown in the figure from this state, the actual steering angle and the wheel speed sensor 15 (see FIG. 1) detected by the steering angle sensor 14 (see FIG. 1) The target yaw rate is calculated by the target yaw rate calculation unit 21 (see FIG. 2) based on the actual wheel speed detected by (see FIG. 1). This target yaw rate gradually increases with the passage of time t as shown in FIG. 6 (b). At the same time, the actual yaw rate of the vehicle 1 is detected by the yaw rate sensor 16 (see FIG. 1), and the actual yaw rate gradually increases with the passage of time t as shown in FIG. 6 (b). A deviation U indicated by a diagonal line is generated between the target yaw rate and the target yaw rate.

When the target yaw rate is obtained as described above, the FB control of the driving force such that the deviation U between the target yaw rate and the actual yaw rate becomes 0 (the actual yaw rate matches the target yaw rate) in the FB controller 23 (see FIG. 2). The amount (correction amount for the required driving force) is obtained, the supply current from the inverter 7 to the electric motor (M) 2 (see FIG. 1) is reduced, and the driving force (output) of the electric motor (M) 2 is shown in FIG. As shown in (b), it is subtracted from the time t1 with respect to the required driving force.

When the driving force of the electric motor (M) 2 is reduced as described above, the vehicle 1 decelerates and the load moves to the left and right front wheels WFL and WFR of the vehicle 1 as described in FIG. At 1, a yaw moment M that tries to turn this to the right is generated. As a result, the right turn of the vehicle 1 is assisted, and as shown in FIG. 6A, the vehicle 1 travels while smoothly turning along the curve.

By the way, in this FB control, the deviation U between the target yaw rate and the actual yaw rate becomes 0 after the time t1 when the driver starts turning the steering wheel 11 (see FIG. 1) and the time t3 when the driver finishes turning the steering wheel 11 (actual). It is executed until the time t4 (where the yaw rate matches the target yaw rate), during which the driving force (output) of the electric motor (M) 2 is reduced as shown in FIG. 6 (b). Specifically, at time t1 to t2', the rate of decrease in driving force increases with the passage of time, at times t2'to t4, the rate of decrease in driving force gradually decreases, and at time t4, the actual yaw rate increases. It matches the target yaw rate, and the deviation U between them becomes 0.

If such FB control of the driving force (deceleration control at the time of turning) is not performed, the vehicle 1 deviates from the corner and becomes an understeer state as shown in FIG. 6A, and its behavior is unstable. become.

3) FF control + FB control:
In the electronic control unit (ECU) 20 constituting the turning control device according to the present embodiment,
Control is performed by combining FF control and FB control, and the behavior of the vehicle 1 in this control will be described below with reference to FIG. 7.

FIG. 7A is a plan view showing a turning state of the vehicle by FF control of driving force + FB control, and FIG. 7B is a time chart of steering angle, yaw rate and driving force, and the driving force is driven by this FF control + FB control. The behavior of the vehicle 1 in which is controlled is a combination of the behaviors shown in FIGS. 5 and 6.

That is, when the driver of the vehicle 1 traveling straight starts turning the steering wheel 11 (see FIG. 1) to the right from the time t1 shown in FIG. 7 (b), the FF control shown in FIG. 5 and the FB shown in FIG. 6 Control is executed in parallel. At this time, the steering angle and the yaw rate change with the passage of time t as shown in FIG. 7B, but the driving force of the electric motor (M) 2 is controlled as follows.

That is, the FF control amount obtained by the FF controller 22 shown in FIG. 2 and the FB control amount obtained by the FB controller 23 are added by the total control amount calculation unit 24 to calculate the total control amount. Then, a current corresponding to this total control amount (correction amount for the required driving force) is supplied from the inverter 7 (see FIG. 1) to the electric motors (M) 2 (see FIG. 1) to drive the electric motor (M). The force (output) is controlled.

Specifically, as shown in FIG. 7B, when the FF control and the FB control are executed in parallel, the driving force (output) of the electric motor (M) 2 changes in the driving force in the FF control. The amount is reduced by the combined amount of the amount and the amount of change in the driving force in the FB control.

When the driving force of the electric motor (M) 2 is reduced as described above, the vehicle 1 decelerates and the load moves to the left and right front wheels WFL and WFR of the vehicle 1 as described in FIG. At 1, a yaw moment M that tries to turn this to the right is generated. As a result, the right turn of the vehicle 1 is assisted, and as shown in FIG. 7A, the vehicle 1 travels while smoothly turning along the curve.

If such driving force control (deceleration control during turning) is not performed, the vehicle 1 deviates from the corner and becomes an understeer state as shown in FIG. 7A, and its behavior becomes unstable. Become.

As described above, in the present embodiment, the FF control that controls the driving force (output) of the electric motor (M) 2 only by the target yaw rate and the electric motor (the electric motor (M)) based on the deviation U between the target yaw rate and the actual yaw rate. Since it is used in combination with FB control that controls the driving force (output) of M) 2, it is possible to control the driving force at an early stage by reflecting the driver's intention by taking advantage of both, and the vehicle 1 can turn properly. Can assist.

Further, in the present embodiment, the driving force (braking force) of the left and right front wheels WFL and WFR and the left and right rear wheels ERL and WRR are not individually controlled when the vehicle 1 is turned, but an electric motor as a driving source. By controlling only the driving force (output) of (M) 2 and decelerating the entire vehicle 1, the vertical load of the vehicle body is moved forward (front wheels WFL, WFR) to generate a yaw moment M in the turning direction. Since the vehicle 1 is assisted in turning, the system configuration can be simplified and the cost can be reduced.

Further, in the present embodiment, it is not necessary to decelerate the vehicle 1 by a mechanical braking device, and the vehicle 1 is decelerated by reducing the supply current to the electric motor (M) 2 which is a drive source. There is no loss of vehicle running energy for the energy consumed by the mechanical braking device. When the drive source is an engine, the output of the engine can be reduced to decelerate the vehicle 1 by reducing the throttle opening degree.

<Embodiment 2>
Next, a second embodiment of the vehicle turning control device according to the present invention will be described below with reference to FIG.

FIG. 8 is a block diagram showing a basic configuration of an electronic control unit (ECU) according to a second embodiment of the present invention. In this figure, the same elements as those shown in FIG. 2 are designated by the same reference numerals. Therefore, the description of them again will be omitted below.

The electronic control unit (ECU) 20 according to the present embodiment includes a limit processing unit 25 that suppresses the FF control amount obtained by the FF controller 22 to a predetermined upper limit value or less, and an FB control amount obtained by the FB controller 23. Is provided with a limit processing unit 26 that keeps the number below a predetermined upper limit value.

Here, the limit processing units 25 and 26 cut the values exceeding the upper limit values calculated by the upper limit value calculation units 27 and 28 of the FF control amount and the FB control amount (as 0), and each FF control amount and the FB. It functions to keep the control amount below the upper limit.

As described above, in the present embodiment, the FF control amount obtained by the FF controller 22 is suppressed to a predetermined upper limit value or less by the limit processing unit 25, and the FB control amount obtained by the FB controller 23 is limited. Since the unit 26 suppresses the deceleration of the vehicle 1 to a predetermined upper limit or less, the deceleration of the vehicle 1 at the time of turning is suppressed to a predetermined value or less, the excessive sudden deceleration of the vehicle 1 is suppressed, and the vehicle 1 has high running stability. Secured.

In addition, in the present embodiment as well, the same effect as that obtained in the first embodiment can be obtained.

<Embodiment 3>
Next, a third embodiment of the vehicle turning control device according to the present invention will be described below with reference to FIGS. 9 to 11.

9 is a block diagram showing the basic configuration of the electronic control unit (ECU) according to the third embodiment of the present invention, FIG. 10 is a diagram showing the relationship between the required driving force and the correction coefficient, and FIG. 11 is the required driving force change rate. It is a figure which shows the relationship between a correction coefficient and a correction coefficient, and in FIG. 9, the same elements as those shown in FIG. 8 are designated by the same reference numerals, and the description thereof will be omitted again below.

In the present embodiment, the total control amount calculation unit 24 is charged with the FF control amount obtained by the FF controller 22 and the FB control amount obtained by the FB controller 23 as a required driving force for the electric motor (M) 2. Correction units 29 and 30 are provided to correct the magnitude of the required driving force change rate, respectively.

Here, the relationship between the required driving force and the correction coefficient is shown in FIG. 10. The correction coefficient is set smaller as the required driving force is larger. Further, the relationship between the required driving force change rate and the correction coefficient is shown in FIG. 11, but the correction coefficient is set smaller as the required driving force change rate is larger.

By the way, the driver's willingness to accelerate and decelerate is reflected in the accelerator pedal 9 (see FIG. 1), that is, the required driving force, but in the present embodiment, the correction unit 29 provided in the total control amount calculation unit 24 , 30 are the FF control amount obtained by the FF controller 22 and the FB control amount obtained by the FB controller 23. , The correction coefficient is reduced so that the feedforward control amount and the feedback control amount are corrected in the smaller direction. Therefore, in the turning control of the vehicle 1, the FF control amount and the FB control amount of the driving force of the electric motor (M) 2 with respect to the excessive required driving force can be limited, and the driver does not feel uncomfortable. When turning, the vehicle 1 can be appropriately decelerated to assist the turning.

In addition, in the present embodiment as well, the same effect as that obtained in the first and second embodiments can be obtained.

Although the turning control device provided in the electric vehicle using the electric motor as the drive source has been described above, the present invention can be similarly applied to the turning control device provided in the vehicle using the engine as the drive source. Is. In a vehicle whose drive source is an engine, the driving force of the engine is controlled by adjusting the throttle opening.

In addition, the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of claims and the technical ideas described in the specification and drawings.

1 Vehicle 2 Electric motor (drive source)
7 Inverter 11 Steering wheel 14 Steering angle sensor (rudder angle detecting means)
15 Wheel speed sensor (wheel speed detection means)
16 Yaw rate sensor (yaw rate detecting means)
17 Lateral G-force sensor (lateral acceleration detection means)
20 Electronic control unit (swivel control device)
21 Target yaw rate calculation unit 22 FF controller (feedforward control amount calculation unit)
23 FB controller (feedback control amount calculation unit)
24 Total control amount calculation unit 25,26 Limit processing unit 27,28 Upper limit value calculation unit 29,30 Correction unit U Deviation between target yaw rate and actual yaw rate | U | Absolute value of deviation between target yaw rate and actual yaw rate

Claims (5)

A target yaw rate calculation unit that calculates a target yaw rate based on an actual steering angle detected by the steering angle detecting means, an actual wheel speed detected by the wheel speed detecting means, and an actual lateral acceleration detected by the lateral acceleration detecting means. ,
A feedforward control amount calculation unit that obtains a feedforward control amount of the driving force of the drive source based on the target yaw rate, and a feedforward control amount calculation unit.
A feedback control amount calculation unit that obtains a feedback control amount of the driving force of the driving source based on the deviation between the target yaw rate and the actual yaw rate detected by the yaw rate detecting means.
A total control amount calculation unit that obtains the total control amount of the driving force of the drive source by adding the feedforward control amount and the feedback control amount.
A vehicle turning control device comprising. The vehicle turning control according to claim 1, wherein the feedback control amount calculation unit integrates the absolute value of the deviation with the deviation between the target yaw rate and the actual yaw rate to obtain the feedback control amount. Device. A limit processing unit that suppresses the feedforward control amount obtained by the feedforward control amount calculation unit to an upper limit value or less, and a limit processing unit.
A limit processing unit that suppresses the feedback control amount obtained by the feedback control amount calculation unit to an upper limit value or less, and a limit processing unit.
The vehicle turning control device according to claim 1 or 2, wherein the vehicle is provided with. Claims 1 to 3 characterized in that the total control amount calculation unit has a correction unit that corrects the feedforward control amount and the feedback control amount, respectively, according to the magnitude of the required driving force with respect to the drive source. The vehicle turning control device according to any one of. The fourth aspect of the present invention is characterized in that the correction unit corrects the feedforward control amount and the feedback control amount in a direction in which the larger the required driving force or the required driving force change rate with respect to the driving source is, the smaller the feedforward control amount and the feedback control amount are. Vehicle turn control device.

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