JP2020125058A - Vehicular turning-attitude control method and turning-attitude control apparatus - Google Patents

Abstract

To realize an appropriate turning-attitude by changing the turning characteristic of a standard model in at least one of corner-in and corner-out during a travel in a curve.SOLUTION: A vehicular turning-attitude control method executed by an attitude control ECU (71) that executes: detecting a steering angle δ and a speed V; calculating a target vehicular body slip angle (β) on the basis of a standard model 2 for a vehicular body slip angle β formed by a vehicular body centerline and a vehicular progress direction; and performing turning-attitude control using information of the target vehicular body slip angle (β). The method includes the following procedure: detecting information on a target turning G as vehicular turning information; determining whether it is a corner-in in a curve travel on the basis of the information on the target turning G; and changing the standard model 2 so as to calculate the target vehicular body slip angle (β) that constitutes a given corner-in turning characteristic in the case of determining that it is the corner-in.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a turning posture control method and a turning posture control device for a vehicle.

In Patent Document 1, the deceleration torque generated in the vehicle is calculated based on the accelerator operation state and the front wheel slip angle. Specifically, there is disclosed a vehicle control device and a vehicle control method that improve the traceability and drivability by correcting the absolute value of the coast torque to be small when a turning state occurs when the coast torque is applied. ..

International publication WO2016/152632

The technique disclosed in Patent Document 1 calculates a target front wheel slip angle according to a steering angle, has a predetermined reference model, and changes a turning characteristic (=steer characteristic) depending on a vehicle speed or a steering angle. is there. However, the turning characteristics at the corner entrance (hereinafter referred to as "corner in") and the corner exit (hereinafter referred to as "corner out") change depending on the driver request and the system request. For this reason, the conventional method of Patent Document 1, which does not disclose the technique of changing the turning characteristic between the corner-in and the corner-out, cannot be applied.

The present disclosure has been made in view of the above problems, and an object thereof is to realize an appropriate turning posture by changing the turning characteristics of a reference model at least at one of corner-in and corner-out while traveling on a curve. To do.

In order to achieve the above object, the present disclosure detects turning information of a vehicle, calculates the target vehicle body slip angle by the turning information, and a reference model of a vehicle body slip angle formed by the vehicle body centerline and the vehicle traveling direction, The turning attitude control method of the vehicle by the controller that performs the turning attitude control using the information of the target vehicle body slip angle is a method having the following procedures. The turning information of the vehicle is detected. Based on the turning information, it is determined whether or not it is a corner-in during a curve. When it is determined that the vehicle is in the corner-in, the reference model is changed so as to calculate the target vehicle body slip angle having the predetermined corner-in turning characteristic.

As described above, when it is determined that the vehicle is in the corner-in during the curve traveling, the target vehicle slip angle having the predetermined corner-in turning characteristic is calculated by changing the reference model, so that it is appropriate in the corner-in during the curve traveling. A turning posture can be realized.

1 is an overall system configuration diagram showing a system configuration of an electric vehicle to which a turning attitude control method and a turning attitude control device of Example 1 are applied. It is a control block block diagram which shows the control block configuration of an attitude control ECU. 6 is a flowchart showing a flow of a turning posture control process by a posture control ECU. FIG. 9 is a rear wheel Cp correction table showing the rear wheel Cp correction rate characteristics when the turning G is increased (=corner-in determination) and the turning G is decreased (=corner-out determination). It is a model schematic diagram which shows the exercise|movement model of the vehicle which put together the tire of the right-and-left front wheels and the tire of the left-and-right rear wheels in the center respectively. FIG. 7 is a steer characteristic diagram showing a limit vehicle speed in oversteer characteristics when the vertical axis is the turning radius of the front wheel actual steering angle constant (or the front wheel actual steering angle when the turning radius is constant) and the vehicle speed is the horizontal axis. It is an operation explanatory view showing a change operation of a steer characteristic when going from a corner in to a corner out at the time of turning traveling on a curved road. Between the steering angle characteristic and the vehicle body slip angle characteristic of the vehicle of the first embodiment that executes the motion control for changing the turning characteristic of the reference model and the comparison vehicle that executes the motion control while the turning characteristic of the reference model remains the steady turning characteristic. It is a contrast characteristic view which shows contrast. FIG. 9 is an overall system configuration diagram showing a system configuration of an autonomous driving vehicle to which a turning attitude control method and a turning attitude control device of a second embodiment are applied. It is a block block diagram which shows the control block structure of an automatic driving controller and a vehicle motion controller. FIG. 6 is a control block configuration diagram showing another control block configuration (configuration plans 1, 2, and 3) of the attitude control ECU.

Hereinafter, modes for carrying out a vehicle turning attitude control method and a vehicle turning attitude control apparatus according to the present disclosure will be described based on Embodiments 1 and 2 shown in the drawings.

The turning posture control method and the turning posture control device according to the first embodiment are applied to a front-wheel-drive manually-operated vehicle (an example of a vehicle) that is driven and driven by a driver operation. Hereinafter, the configuration of the first embodiment will be described by being divided into an "overall system configuration", a "control block configuration of an attitude control ECU", and a "turning attitude control processing configuration".

[Overall system configuration]
FIG. 1 shows a system configuration of a manually operated vehicle A1 to which the turning attitude control method and the turning attitude control device of the first embodiment are applied. The overall system configuration will be described based on FIG.

As shown in FIG. 1, the manually-operated vehicle A1 is a front-wheel drive vehicle that includes left front wheels 61L and right front wheels 61R as driving wheels, and left rear wheels 62L and right rear wheels 62R as driven wheels. Driving torques from a driving drive source 63 and a transmission 64 such as a motor or an engine are input to the left front wheel 61L and the right front wheel 61R, which are drive wheels, via a left drive shaft 65L and a right drive shaft 65R, respectively. ..

As shown in FIG. 1, the left front wheel 61L and the right front wheel 61R of the manually-operated vehicle A1 are not only drive wheels but also steered wheels whose tires are steered in accordance with a driver's operation. When there is steering input from the driver to the steering wheel 66, steering torque is input to the left front wheels 61L and 61R via the steering mechanism 67 to the left front wheel 61L and the right front wheel 61R.

The front left wheel 61L and the front right wheel 61R have an FL hydraulic brake 68L and an FR hydraulic brake 68R, respectively. The left rear wheel 62L and the right rear wheel 62R have an RL hydraulic brake 69L and an RR hydraulic brake 69R, respectively. These hydraulic brakes 68L, 68R, 69L, 69R are connected to a brake actuator 70 which controls each brake hydraulic pressure independently by four wheels. As shown in FIG. 1, an attitude control ECU 71 is provided as a controller that controls the operation of the brake actuator 70 including an electric oil pump, a solenoid pressure reducing valve, a solenoid pressure increasing valve, and the like.

The attitude control ECU 71 inputs information detected by the RL wheel speed sensor 72, the RR wheel speed sensor 73, the steering angle sensor 74, the vehicle body slip angle sensor 75, and the like. The RL wheel speed sensor 72 detects the left rear wheel speed Vrl. The RR wheel speed sensor 73 detects the right rear wheel speed Vrr. The steering angle sensor 74 detects the steering angle δ from the neutral steering angle position of the steering wheel 66. The vehicle body slip angle sensor 75 detects the actual vehicle body slip angle β by GPS or the like. In the first embodiment, the wheel speed based on the average value of the left rear wheel speed Vrl and the right rear wheel speed Vrr is used as the "vehicle speed V" information.

The attitude control ECU 71 uses the information of the vehicle body slip angle, which is an angle formed by the vehicle body centerline in the vehicle front-rear direction passing through the vehicle center of gravity position and the instantaneous vehicle traveling direction drawn from the vehicle center of gravity position, as a turning attitude control. I do. That is, it is determined whether or not it is a corner in a curve running, and the turning characteristics based on the reference model of the vehicle body slip angle are changed based on the corner-in turning characteristics, the steady turning characteristics, and the corner-out turning characteristics. During the curve traveling, the target vehicle body slip angle β ^* is calculated by using the reference model in which the turning characteristic is changed, and the information of the actual vehicle body slip angle β is acquired. Then, the turning posture control command according to the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β is output to the brake actuator 70.

[Control block configuration of attitude control ECU]
FIG. 2 shows a control block configuration of the attitude control ECU 71 (controller). The control block configuration of the attitude control ECU 71 will be described below with reference to FIG. The front wheel cornering power value is referred to as "front wheel Cp value", and the rear wheel cornering power value is referred to as "rear wheel Cp value".

Attitude control ECU 71, as shown in FIG. 2, turns G estimation unit 711, corner-in determination unit 712, corner-out determination unit 713, RrCp decrease correction unit 714, FrCp decrease correction unit 715, and RrCp increase correction. And a portion 716. Further, it includes a target vehicle body slip angle calculation unit 717, an actual vehicle body slip angle information acquisition unit 718, a brake moment calculation unit 719, and a control command output unit 720.

The turning G estimation unit 711 inputs the steering angle δ and the vehicle speed V, and uses the input information and the reference model 1 of the turning G to generate a target turning G which is an acceleration acting in a direction orthogonal to the vehicle longitudinal direction when turning. Estimate and calculate. Here, the “reference model 1” is prepared in advance as a reference model of the turning G, and is expressed as a motion equation for estimating and calculating the target turning G by substituting the steering angle δ and the vehicle speed V.

The corner-in determination unit 712 inputs the target turn G estimated and calculated by the turn G estimation unit 711, calculates the change amount Δ|Gy| of the target turn G, and increases the change amount Δ|Gy| of the target turn G. If it is (Δ|Gy|>0), it is determined to be the corner-in area in the curve traveling.

The corner-out determination unit 713 inputs the target turn G estimated and calculated by the turn G estimation unit 711, calculates the change amount Δ|Gy| of the target turn G, and decreases the change amount Δ|Gy| of the target turn G. If it is (Δ|Gy|<0), it is determined to be a corner-out area in the curve running.

Upon receiving the corner-in area determination flag from the corner-in determination unit 712, the RrCp reduction correction unit 714 calculates the reduction correction amount of the rear wheel Cp value of the reference model 2 of the vehicle body slip angle, which will be described later. At this time, the larger the increase amount of the target turn G per unit time is, the larger the reduction correction amount of the rear wheel Cp value is made. By the correction of the reduction of the rear wheel Cp value, the corner-in turning characteristic in the corner-in determination area is changed to the oversteer-oriented turning characteristic inwardly turning rather than the steady turning characteristic.

Here, the "inward turning characteristic" means that the stability factor value of the reference model 2 changes in a direction smaller than the steady value (or increases in the negative direction), and is referred to as oversteering turning characteristic. Is to be. Note that, instead of the reduction correction of the rear wheel Cp value, or together with the reduction correction of the rear wheel Cp value, the increase correction of the front wheel Cp value may be performed.

The FrCp decrease correction unit 715 calculates the limit vehicle speed Vc based on the rear wheel Cp value after the decrease correction. When the current vehicle speed V is close to the limit vehicle speed Vc or exceeds the limit vehicle speed Vc, as a measure against oversteer, the decrease correction amount of the front wheel Cp value is set so that the calculated limit vehicle speed Vc becomes higher than the current vehicle speed V. To calculate.

When the corner-out area determination flag is input from the corner-out determination unit 713, the RrCp increase correction unit 716 calculates the increase correction amount of the rear wheel Cp value of the reference model 2 of the vehicle body slip angle, which will be described later. At this time, the larger the reduction amount of the target turn G per unit time is, the larger the increase correction amount of the rear wheel Cp value is made. By this increase correction of the rear wheel Cp value, the corner-out characteristic in the corner-out determination region is changed to a turning characteristic that is closer to the understeer that is outward of the turning than the steady turning characteristic.

Here, the "turning outward characteristic" means that the stability factor value of the reference model 2 changes in a direction larger than the steady value (or increases in the positive direction), which is a turning characteristic closer to the understeer. That is. Note that, instead of the increase correction of the rear wheel Cp value, or the decrease correction of the front wheel Cp value may be performed together with the increase correction of the rear wheel Cp value, in any case, the turning characteristic is closer to the understeer.

The target vehicle body slip angle calculation unit 717 prepares in advance, as a vehicle model slip angle reference model, a reference model 2 (=steady reference model) in which the steady turning characteristics are optimized. Then, when the reduction correction amount of the rear wheel Cp value is input from the RrCp reduction correction unit 714 based on the corner-in determination, the steady turning characteristic by the reference model 2 is changed to the oversteer turning by the reduction correction of the rear wheel Cp value. Change to characteristics. On the other hand, when the increase correction amount of the rear wheel Cp value is input from the RrCp increase correction unit 716 based on the corner-out determination, the steady turning characteristic by the reference model 2 is changed to the understeer turning characteristic by the increase correction of the rear wheel Cp value. Change to. Further, during the curve traveling, the steering angle δ and the vehicle speed V are input, and the target vehicle body slip angle β ^* is calculated by using the input information and the reference model 2 in which the turning characteristic is changed. However, when there is no correction amount input of the front wheel Cp value or the rear wheel Cp value from the RrCp decrease correction unit 714, the FrCp decrease correction unit 715, or the RrCp increase correction unit 716, the reference model 2 without changing the turning characteristics is used during the curve traveling. The target vehicle body slip angle β ^* is calculated using this.

The actual vehicle body slip angle information acquisition unit 718 acquires information on the actual vehicle body slip angle β based on the detection value from the vehicle body slip angle sensor 75. When the vehicle body slip angle sensor 75 recognizes the direction of the vehicle due to a change in the vehicle position by, for example, GPS, the vehicle body slip angle sensor 75 detects the actual direction based on the deviation angle between the vehicle body center line passing through the center of gravity and the vehicle traveling direction (=the vehicle direction). The vehicle body slip angle β is detected. The actual vehicle body slip angle β may be obtained by integrating the vehicle body slip angular velocity β′. Here, the vehicle body slip angular velocity β'is
(Vehicle body slip angular velocity β') = (Yaw rate γ)-(Lateral acceleration Gy) / (Vehicle speed V)
It is estimated and calculated using the formula.

The brake moment calculation unit 719 inputs the target vehicle body slip angle β ^* from the target vehicle body slip angle calculation unit 717 and the actual vehicle body slip angle β from the actual vehicle body slip angle information acquisition unit 718. Then, a braking moment around the center of gravity of the vehicle is calculated according to the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β.

The control command output unit 720 inputs the braking moment around the vehicle center of gravity calculated by the braking moment calculation unit 719. Then, the turning posture control command for obtaining the input braking moment is output to the brake actuator 70. Here, the turning attitude control command means, for example, when performing a turning attitude control for turning to the right, the brake hydraulic pressure according to the magnitude of the braking moment is supplied only to the right front wheel 61R and the right rear wheel 62R to rotate around the center of gravity It gives a braking moment that encourages the vehicle to turn to the right.

[Turning posture control processing configuration]
FIG. 3 shows a flow of a turning posture control process by the posture control ECU 71 (controller). Hereinafter, each step of FIG. 3 showing the turning attitude control processing configuration will be described.

In step S1, the wheel speed V (=vehicle speed V) is detected following the start. In step S2, the steering angle δ is detected.

In step S3, following the detection of the steering angle δ in step S2, the target turning G is estimated and calculated using the steering angle δ, the vehicle speed V and the reference model 1 of the turning G, and the process proceeds to step S4.

In step S4, following the calculation of the target turn G in step S3, the change amount Δ|Gy| of the target turn G in which the target turn G has changed in a predetermined unit time is calculated, and the process proceeds to step S5.

In step S5, following the calculation of the change amount Δ|Gy| of the target turn G in step S4, it is determined whether the change amount Δ|Gy| is Δ|Gy|>0 (increase). If YES (Δ|Gy|>0), the process proceeds to step S6, and if NO (Δ|Gy|≦0), the process proceeds to step S13.

In step S6, following the determination that Δ|Gy|>0 in step S5, the rear wheel Cp value of the reference model 2 of the vehicle body slip angle is reduced and corrected so that the turning characteristic is closer to oversteer, Go to step S7.

Here, the decrease correction amount of the rear wheel Cp value is corrected as the increase amount change amount Δ|Gy| of the target turn G per unit time is larger, as shown in the right side characteristic of FIG. Reduce the rate proportionally. At this time, in order to avoid strong oversteer or sudden change in vehicle attitude in advance, if the increase side variation amount Δ|Gy| exceeds the increase side limit amount Δ|+Gyo|, the decrease correction amount is set to Δ|Gy|=0. The rear wheel Cp correction rate is limited to about -5% to limit the correction.

An example of "reference model 2 of vehicle body slip angle" will be described using a simple vehicle model with two degrees of freedom shown in FIG. The equation of motion is expressed as follows, where vehicle mass is m, vehicle speed is V, vehicle body slip angular velocity is β′, yaw rate is γ, lateral force generated from front tires is Ff, and lateral force generated from rear tires is Fr.
mV(β'+γ)=Ff+Fr (1)
It is expressed by the formula. Further, if the slip angle of the front tires is βf and the slip angle of the rear tires is βr,
Ff=−2·Kf·βf Fr=−2·Kr·βr (2)
It is expressed by the formula. In this equation (2), the “proportional constant Kf” is the “front wheel Cp value” and the “proportional constant Kr” is the “rear wheel Cp value”.
The front wheel tire slip angle βf and the rear wheel tire slip angle βr are the vehicle body slip angle β, the vehicle speed V, the steering angle δ, the distance from the center of gravity to the front wheel is lf, and the distance from the center of gravity to the rear wheel is lr. Then,
βf=β+(lf/V)γ−δ βr=β−(lr/V)γ (3)
It is expressed by the formula. The equation of motion obtained by substituting the equations (2) and (3) into the equation (1) has the front wheel Cp value (=Kf) and the rear wheel Cp value (=Kr), and the steering angle δ and the vehicle speed V are By substituting the values, the target vehicle body slip angle β ^* is calculated to be the “vehicle body slip angle reference model 2”.

In step S7, following the reduction correction of the rear wheel Cp value in step S6, the steer characteristic (=turning characteristic) after the reduction correction of the rear wheel Cp value is calculated, and the process proceeds to step S8.

Here, in the calculation of the steering characteristic after the reduction correction of the rear wheel Cp value, as shown in FIG. 6, the front wheel actual steering angle and the vehicle speed V are used, and the turning radius becomes constant as the vehicle speed V increases, or , The neutral steer characteristic (=NS characteristic) in which the actual front wheel steering angle becomes constant as the vehicle speed V increases. The steering angle δ detected by the steering angle sensor 74 is used as the actual front wheel steering angle.

In step S8, following the calculation of the steer characteristic after the rear wheel Cp reduction correction in step S7, it is determined whether or not the calculated steer characteristic is an oversteer characteristic (OS characteristic). If YES (oversteer characteristic), the process proceeds to step S9. If NO (no oversteer characteristic), the process proceeds to step S16.

Here, as shown in FIG. 6, the "oversteer characteristic" means a steer characteristic that the turning radius becomes smaller as the vehicle speed V increases, or a steer that the front wheel actual steering angle becomes smaller as the vehicle speed V increases. A characteristic.

In step S9, following the determination of the oversteer characteristic in step S8, the limit vehicle speed Vc at that time is calculated, and the process proceeds to step S10.

Here, the "limit vehicle speed Vc" means a critical speed at which the turning radius becomes theoretically zero when the turning radius decreases as the vehicle speed V increases in a vehicle with oversteer characteristics, as shown in FIG. This limit vehicle speed Vc is, as shown in FIG. 5, front wheel cornering power Cpf, corrected rear wheel cornering power Cpr ^* , vehicle mass m, distance lf from the center of gravity to the front wheels, distance lr from the center of gravity to the rear wheels, front wheels. Is calculated by an equation using the distance l between the rear wheel and the rear wheel.

In step S10, following the calculation of the limit vehicle speed Vc in step S9, it is determined whether or not the current vehicle speed V is close to the limit vehicle speed Vc or the current vehicle speed V exceeds the limit vehicle speed Vc. If YES (vehicle speed condition is satisfied), the process proceeds to step S11. If NO (vehicle speed condition is not satisfied), the process proceeds to step S16.

Here, when it is determined that the current vehicle speed V is close to the limit vehicle speed Vc, a limit vehicle speed threshold (limit vehicle speed Vc-α) can be set, and when the current vehicle speed V becomes the limit vehicle speed threshold, the current vehicle speed V becomes the limit vehicle speed. It is determined to be close to Vc. The margin α is, for example, about 3 km/h.

In step S11, following the determination that the vehicle speed condition is satisfied in step S10, the front wheel Cp value (=front wheel correction Cp) at which the current vehicle speed V becomes less than the limit vehicle speed Vc is calculated, and the process proceeds to step S12.

Here, when the front wheel Cp value exceeds the limit vehicle speed Vc in a vehicle with oversteer characteristics, the vehicle behavior becomes unstable. Therefore, the current vehicle speed V or the vehicle speed V considering the safety margin is set to the formula of the limit vehicle speed Vc. It is calculated by the substituted expression of the front wheel correction Cp shown in FIG.

In step S12, following the calculation of the front wheel Cp value in step S11, the front wheel Cp value of the reference model 2 in which the rear wheel Cp value is corrected to be decreased is corrected to the front wheel Cp value calculated in step S11 as a measure against oversteer. Then, the process proceeds to step S16.

In step S13, following the determination that Δ|Gy|≦0 in step S5, it is determined whether or not the change amount Δ|Gy| is Δ|Gy|<0 (decrease). If YES (Δ|Gy|<0), the process proceeds to step S14, and if NO (Δ|Gy|=0), the process proceeds to step S15.

In step S14, following the determination of Δ|Gy|<0 in step S13, the rear wheel Cp value of the reference model 2 of the vehicle body slip angle is increased and corrected so that the turning characteristic is closer to understeer, and Proceed to S16.

Here, the increase correction amount of the rear wheel Cp value is, as shown in the left side characteristic of FIG. 4, the larger the decrease amount change amount Δ|Gy| of the target turning G per unit time is, the increase correction amount of the rear wheel Cp value is increased. Increase the rate proportionally. At this time, in order to avoid strong understeer or sudden change of the vehicle attitude in advance, if the decrease side change amount Δ|Gy| exceeds the decrease side limit amount Δ|-Gyo|, the increase correction amount is set to Δ|Gy|=0 The correction is limited by suppressing the wheel Cp correction rate to about +5%.

In step S15, following the determination that Δ|Gy|=0 in step S13, the correction amount of the front wheel Cp value and the rear wheel Cp value of the reference model 2 of the vehicle body slip angle is maintained so as to maintain the neutral steer characteristic. Is set to zero, and the process proceeds to step S16.

In step S16, following the correction process of the Cp value in S6, S12, S14, or S15, the target vehicle body slip angle β ^* is calculated using the corrected reference model 2, and the process proceeds to step S17.

In step S17, following the calculation of the target vehicle body slip angle β ^* in step S16, the vehicle body slip angle sensor 75 detects the actual vehicle body slip angle β, and the process proceeds to step S18.

In step S18, following the detection of the actual vehicle body slip angle β in step S17, a braking moment is calculated according to the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β, and the process proceeds to step S19.

In step S19, following the calculation of the braking moment in step S18, the braking moment control for obtaining the calculated braking moment is executed, and the process proceeds to END.

Next, “background technology and problem solving measures” will be described. Then, the "turning attitude control action" of the first embodiment will be described.

[Background technology and measures to solve problems]
As a background technology for controlling the turning attitude, it is known that there is a predetermined reference model based on vehicle body slip angle, yaw rate, etc., and the reference model itself does not change the turning characteristics but changes the turning characteristics depending on the vehicle speed or the steering angle. Has been.

However, the driver's desired direction (= steer characteristic) changes depending on whether the vehicle enters or exits the corner. On the other hand, the method known as the background art has a problem that it is not applicable because it is not configured to change the steer characteristic by dividing the area into the corner entry area and the corner exit area. ..

Against such background technology, for example, with respect to a reference model of a vehicle body slip angle in which steady turning characteristics are optimized, there is a demand for assisting the vehicle to turn inward at a corner entrance to improve turning turning ability as a turning posture. There is. On the other hand, at the corner exit, on the contrary, there is a demand to improve the turning stability as a turning attitude by assisting the vehicle to go straight ahead and outward.

Therefore, the present inventor changes the turning characteristic itself based on the reference model based on the vehicle body slip angle that defines the turning attitude, because the required turning characteristic at the corner entrance side and the required turning characteristic at the corner exit side are different while traveling on a curve. I focused on the point to do. That is, turning information (steering angle δ, vehicle speed V) of the vehicle is detected. The target vehicle body slip angle β ^* is calculated from the turning information and the reference model 2 of the vehicle body slip angle β formed by the vehicle body center line and the vehicle traveling direction, and the turning attitude control is performed using the information of the target vehicle body slip angle β ^*. The method of controlling the turning attitude of the vehicle by the attitude control ECU 71 is a method having the following procedures. The turning information (target turning G) of the vehicle is detected. Based on the turning information (target turning G), it is determined whether or not it is a corner-in in a curve running. When it is determined that the vehicle is in the corner-in mode, the reference model 2 is changed so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-in turning characteristic (oversteer side characteristic). On the other hand, when it is determined that the vehicle is in the corner-out, the method of changing the reference model 2 is adopted so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-out turning characteristic (understeer deviation characteristic). Therefore, in the vehicle turning attitude control method based on the problem solving measures, the following effects can be exhibited.

The target turning G can be calculated based on the steering request from the driver's steering angle δ, but if the change amount Δ|Gy| of the target turning G tends to increase, it can be determined as the corner entrance.
In the reference model 2 for calculating the target vehicle body slip angle β ^* , the target behavior of the turning characteristic near the oversteer can be calculated by lowering the rear wheel Cp value.
・Determining the reduction amount of the rear wheel Cp value according to the degree of increase of the change amount Δ|Gy| of the target turning G, so that the steering wheel slightly oversteers at the entrance of a gentle curve and becomes stronger over a steep turn-in. The target vehicle body slip angle β ^* close to the steering can be calculated.
-However, when cornering at high vehicle speeds, turning behavior may become unstable if oversteer characteristics are used. Therefore, when the current vehicle speed V approaches the limit vehicle speed Vc calculated by the corrected rear wheel Cp value, the front wheel Cp is lowered. As a result, the limit vehicle speed Vc increases, so that the inward posture can be realized without the turning behavior falling into an unstable state.

-In the reference model 2 for calculating the target vehicle body slip angle β ^* , by increasing the rear wheel Cp value, the target behavior of the turning characteristic near the understeer can be calculated.
The target turn G can be calculated from the steering request from the driver's steering angle δ, but if the change amount Δ|Gy| of the target turn G tends to decrease, it can be determined to be a corner exit.
・Determining the amount of increase in the rear wheel Cp value depending on the degree of decrease in the amount of change Δ|Gy| in the target turning G above makes it slightly understeer at the exit of a gentle curve and more strongly understeer at a steep turnout. The target vehicle body slip angle β ^* can be calculated.

As described above, it is possible to realize an appropriate turning posture by changing the turning characteristics of the reference model 2 between the corner-in and the corner-out while traveling on a curve. In particular, as in the first embodiment, as the reference model of the vehicle body slip angle, the reference model 2 in which the steady turning characteristic is optimized is prepared, the corner-in characteristic is changed to the turning characteristic close to the oversteer, and the corner-out characteristic is understeered. Change to a turning characteristic that is closer to you. Then, when the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β is executed by the brake moment control, in a corner traveling scene, an appropriate turning posture is included in the entire corner area including the corner entrance side and the corner exit side. Is realized. Hereinafter, the turning posture action in the first embodiment will be described based on FIG. 7.

First, if the turning characteristic of the reference model is not changed, as shown by the broken line in FIG. 7, if the cutting operation by the driver is delayed at the corner-in, the turning locus becomes a locus that bulges outside the corner. Then, if the turning back operation by the driver is delayed at the corner out, the turning locus becomes a locus that is directed to the inside of the corner.

On the other hand, when the turning characteristics of the reference model are changed, as shown by the solid line in FIG. 7, in the corner-in determination area B, the reference model 2 is changed to the turning characteristics closer to oversteer. It takes a turning posture along the turning trajectory. That is, even if the cutting operation by the driver is delayed, it is possible to prevent the turning trajectory from bulging outside the corner due to the change to the turning characteristic near the oversteer.

When the turning characteristics of the reference model are changed, as shown by the solid line in FIG. 7, the reference model 2 returns to the model in which the steady turning characteristics are optimized in the corner intermediate determination region C, so that the aimed turning is achieved. It takes a turning posture along the trajectory.

Further, when changing the turning characteristics of the reference model, as shown by the solid line in FIG. 7, by changing the turning characteristics toward the understeer in the corner-out determination area D, the turning attitude along the aimed turning locus is obtained. Become. That is, even if the turning back operation by the driver is delayed, the turning trajectory is prevented from being directed to the inside of the corner by changing the turning characteristic to the understeer side.

Further, the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β is executed by the brake moment control. Therefore, it is possible to reduce the steering amount, which is the variation width of the steering angle (Steering angle) by the driver's operation during cornering. This point is supported by the comparison between the steering angle characteristics when the turning characteristics of the reference model 2 indicated by arrow E in FIG. 8 are changed and the steering angle characteristics when the turning characteristics of the reference model indicated by arrow F in FIG. 8 are not changed. To be

In addition, during cornering, the amount of change in the vehicle body slip angle, which is the amount of change in the vehicle body slip angle (Slip angle), is reduced, and it is possible to exhibit high followability to the intended traveling locus. This point is to compare the vehicle body slip angle characteristic when the turning characteristic of the reference model 2 indicated by arrow G in FIG. 8 is changed with the vehicle body slip angle characteristic when the turning characteristic of the reference model indicated by arrow H in FIG. 8 is not changed. Backed by

[Turning posture control action]
Next, the operation of the turning attitude control processing will be described based on the flowchart of FIG.
First, when Δ|Gy|>0 and the steering characteristic after rear wheel Cp correction is not the oversteering characteristic, in the flowchart of FIG. 3, S1→S2→S3→S4→S5→S6→S7→S8→ The sequence of S16→S17→S18→S19→END is repeated.

Therefore, when the vehicle is in the corner-in determination region due to Δ|Gy|>0, the rear wheel Cp value of the reference model 2 of the vehicle body slip angle is reduced and corrected in S6 so that the turning characteristic is closer to oversteer. In the next S16, the target vehicle body slip angle β ^* is calculated by the corrected reference model 2, in S17 the actual vehicle body slip angle β is detected, and in S18, the target vehicle body slip angle β ^* and the actual vehicle body slip angle β are determined according to the deviation. The braking moment is calculated. In the last S18, brake moment control for obtaining the calculated brake moment is executed.

Δ|Gy|>0 and the steer characteristic after the rear wheel Cp correction is the oversteer characteristic, but when the vehicle speed condition is not satisfied, S1→S2→S3→S4→S5→ in the flowchart of FIG. The process proceeds to S6→S7→S8→S9→S10. Then, the flow from S10 to S16→S17→S18→S19→End is repeated.

Therefore, when the vehicle is in the corner-in determination region and the oversteering characteristic is not satisfied, the rear wheel Cp value of the reference model 2 of the vehicle body slip angle is set in S6 so that the turning characteristic approaches the oversteering. Is reduced and corrected. Then, the target vehicle body slip angle β ^* is calculated by the corrected reference model 2 in S16, the actual vehicle body slip angle β is detected in S17, and the actual vehicle body slip angle β ^* and the actual vehicle body slip angle β are determined in S18. The braking moment is calculated. In the last S18, brake moment control for obtaining the calculated brake moment is executed.

On the other hand, when Δ|Gy|>0, the steer characteristic after rear wheel Cp correction is the oversteer characteristic and the vehicle speed condition is satisfied, in the flowchart of FIG. 3, S1→S2→S3→S4→S5→ The process proceeds to S6→S7→S8→S9→S10→S11→S12. Then, the flow from S12 to S16→S17→S18→S19→End is repeated.

Therefore, when the vehicle speed condition is satisfied in the corner-in determination region and the oversteer characteristic is satisfied, the rear wheel Cp value of the reference model 2 of the vehicle body slip angle is set in S6 so that the turning characteristic is closer to the oversteer. Reduced and corrected. In addition, in S12, the front wheel Cp value of the reference model 2 for the vehicle body slip angle is reduced and corrected so as to increase the limit vehicle speed Vc as a measure against oversteering. Then, the target vehicle body slip angle β ^* is calculated by the corrected reference model 2 in S16, the actual vehicle body slip angle β is detected in S17, and the actual vehicle body slip angle β ^* and the actual vehicle body slip angle β are determined in S18. The braking moment is calculated. In the last S18, brake moment control for obtaining the calculated brake moment is executed.

When Δ|Gy|<0, the flow of S1→S2→S3→S4→S5→S13→S14→S16→S17→S18→S19→End in the flowchart of FIG. 3 is repeated.

Therefore, when the vehicle is in the corner-out determination region due to Δ|Gy|<0, in S14, the rear wheel Cp value of the reference model 2 of the vehicle body slip angle is increased and corrected so that the turning characteristic is closer to the understeer. In the next S16, the target vehicle body slip angle β ^* is calculated by the corrected reference model 2, in S17 the actual vehicle body slip angle β is detected, and in S18, the target vehicle body slip angle β ^* and the actual vehicle body slip angle β are determined according to the deviation. The braking moment is calculated. In the last S18, brake moment control for obtaining the calculated brake moment is executed.

When Δ|Gy|=0, in the flowchart of FIG. 3, the sequence of S1→S2→S3→S4→S5→S13→S15→S16→S17→S18→S19→End is repeated.

Accordingly, when Δ|Gy|=0 and the vehicle is in the middle corner determination region, the cornering power of the reference model 2 of the vehicle body slip angle is not corrected in S15. In S16, the target vehicle body slip angle β ^* is calculated by the reference model 2 without correction (steady reference model), the actual vehicle body slip angle β is detected in S17, and the target vehicle body slip angle β ^* and the actual vehicle body slip angle are detected in S18. A braking moment is calculated according to the deviation of β. In the last S18, brake moment control for obtaining the calculated brake moment is executed.

As described above, in the first embodiment, the corner-in turning characteristic is set to a turning characteristic that is closer to the oversteer and is closer to the turning inward than the steady turning characteristic. Therefore, at the corner-in, the assist for turning the vehicle inward with respect to the reference model 2 is performed. For this reason, in a corner traveling scene, the turning and turning property that matches the turning posture request at the corner entrance is realized.

In the first embodiment, as the reference model of the vehicle body slip angle, a reference model 2 (steady reference model) in which the steady turning characteristics are optimized is prepared. Then, when the corner-in characteristic is changed to the turning characteristic near the oversteer, the rear wheel Cp value included in the equation of motion representing the reference model 2 is corrected by reduction. Therefore, the turning characteristics closer to oversteer can be obtained by simply reducing the rear wheel Cp value of the reference model 2 prepared as the reference model of the vehicle body slip angle. Therefore, it is not necessary to prepare a plurality of reference models, and the corner-in turning characteristic is changed to an oversteer characteristic with a simple configuration in which the Cp value of one prepared reference model 2 is corrected.

In the first embodiment, information on the turning G, which is the acceleration acting in the direction orthogonal to the vehicle front-rear direction when turning, is acquired. Then, it is determined that the vehicle is in the corner when the turning G is increasing in the curve running, and the decrease correction is performed so that the decrease correction amount of the rear wheel Cp value is increased as the increasing amount of the turning G per unit time is large. Therefore, when the turning G increases, it is not only determined to be a corner-in, but also the decrease correction amount of the rear wheel Cp value is calculated based on the increasing amount of the turning G per unit time (=the increasing speed of the turning G). For this reason, the corner-in is accurately determined by the increase in the turning G and the corner-in is accurately determined by the increase of the turning G without acquiring the input information for determining the corner-in and the input information for calculating the correction amount. An appropriate reduction correction amount of the rear wheel Cp value is calculated according to the increasing speed of.

In the first embodiment, the limit vehicle speed Vc is calculated based on the rear wheel Cp value after reduction correction. Then, when the current vehicle speed V is close to or exceeds the limit vehicle speed Vc, the front wheel Cp value is reduced and corrected so that the calculated limit vehicle speed Vc becomes higher than the current vehicle speed V. That is, when the corner-in turning characteristic is changed to the over-steering turning characteristic, the vehicle behavior may become unstable during high-speed curve traveling. On the other hand, when the corner-in characteristic is changed to the oversteer turning characteristic by the correction of the reduction of the rear wheel Cp value, it is possible to prevent the vehicle behavior from becoming unstable.

In the first embodiment, the corner-out turning characteristic is set to a turning characteristic that is closer to the understeer and is more outward in turning than the steady turning characteristic. Therefore, at the corner out, the assist for turning the vehicle outward with respect to the reference model 2 is performed. Therefore, in the corner traveling scene, the turning stability that meets the turning posture request at the corner exit is realized.

In the first embodiment, as the reference model of the vehicle body slip angle, a reference model 2 (steady reference model) in which the steady turning characteristics are optimized is prepared. Then, when changing the corner-out characteristic to the turning characteristic closer to the understeer, it is performed by increasing the rear wheel Cp value included in the equation of motion representing the reference model 2. Therefore, the turning characteristic closer to the understeer can be changed only by increasing the rear wheel Cp value of the reference model 2 prepared as the reference model of the vehicle body slip angle. Therefore, it is not necessary to prepare a plurality of reference models, and the corner-out turning characteristic is changed to an understeer characteristic with a simple configuration in which the Cp value of one prepared reference model 2 is corrected.

In the first embodiment, information on the turning G, which is the acceleration acting in the direction orthogonal to the vehicle front-rear direction when turning, is acquired. Then, it is determined that the corner G is out when the turning G is decreased in the curve running, and the increase correction is performed so that the increase correction amount of the rear wheel Cp value is increased as the decrease amount of the turning G per unit time is larger. Therefore, when the turning G decreases, it is not only determined that the corner is out, but also the increase correction amount of the rear wheel Cp value is calculated based on the decrease amount of the turning G per unit time (=the decreasing speed of the turning G). For this reason, only by acquiring the information of one turn G without dividing the input information for determining the corner-out and the input information for calculating the correction amount, the corner-out can be accurately determined by the reduction of the turn G, and the turning-G can be determined. An appropriate increase correction amount of the rear wheel Cp value is calculated according to the decreasing speed of the.

In the first embodiment, when the target vehicle body slip angle β ^* is calculated, the braking moment around the vehicle center of gravity is calculated according to the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β. Then, a turning attitude control command for obtaining a braking moment around the center of gravity of the vehicle is output to the brake actuator 70. Therefore, the moment around the center of gravity of the vehicle during cornering is obtained by the braking moment having a control response speed faster than the steering angle moment. Therefore, when the turning characteristic of the reference model 2 is changed, the turning characteristic is changed to a desired characteristic with good response by reflecting the change.

The vehicle to which the control of the first embodiment is applied is a manually-operated vehicle A1 that travels in a curve by driver steering. For this reason, in the corner traveling scene, the turning posture for obtaining the moment around the center of gravity of the vehicle is shared by the braking moment, and the steering amount by the driver operation is reduced.

As described above, the turning posture control method and the turning posture control device for the manually driven vehicle A1 according to the first embodiment have the effects listed below.

(1) The turning information (steering angle δ, vehicle speed V) of the vehicle is detected, and based on the turning information and the reference model (reference model 2) of the vehicle body slip angle β formed by the vehicle center line and the vehicle traveling direction, the target vehicle body is obtained. calculating a slip angle beta ^*, in the turning posture control method for a vehicle by the controller to perform the turning posture control using the target vehicle body slip angle beta ^* information (attitude control ECU 71),
Detects vehicle turning information (target turning G),
Based on the turning information (target turning G), it is determined whether or not it is a corner-in in a curve running,
When it is determined that the vehicle is in the corner-in, the reference model (reference model 2) is changed so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-in turning characteristic (FIG. 2).
For this reason, when it is determined that the vehicle is in a corner during a curve, the target model slip angle β ^* with a predetermined corner-in turning characteristic is calculated by changing the reference model, which is suitable for the corner in during a curve. It is possible to provide a turning posture control method for a vehicle (manually operated vehicle A1) that realizes a different turning posture.

(2) The predetermined corner-in turning characteristic is set to a turning characteristic that is closer to the oversteer and is closer to the turning inward than the steady turning characteristic (Fig. 7).
Therefore, in the corner traveling scene, it is possible to realize the turning and turning property that matches the turning posture request at the corner entrance.

(3) As a reference model of the vehicle body slip angle β, a steady reference model (reference model 2) that optimizes steady turning characteristics is prepared,
When changing the steady reference model (reference model 2) so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-in turning characteristic, the rear wheel cornering power included in the equation of motion representing the steady reference model (reference model 2) The value is reduced and corrected (Fig. 3).
For this reason, it is not necessary to prepare a plurality of reference models, and a simple configuration in which the rear wheel cornering power value of one prepared reference reference model (reference model 2) is simply corrected to make the corner-in turning characteristic oversteer close. Can be changed to the characteristics of.

(4) As a reference model of vehicle body slip angle β, prepare a steady reference model (reference model 2) that optimizes steady turning characteristics,
When changing the steady reference model (reference model 2) so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-in turning characteristic, the rear wheel cornering power included in the equation of motion representing the steady reference model (reference model 2) The correction is performed by at least one of the correction for decreasing the value and the correction for increasing the front cornering power value (FIG. 3).
Therefore, it is not necessary to prepare a plurality of reference models, and the corner-in turning characteristics can be improved by a simple configuration in which at least one of the two cornering power values of the prepared single reference model (reference model 2) is corrected. It is possible to change to a characteristic closer to oversteer.

(5) Obtain information about the turning G that is the acceleration acting in the direction orthogonal to the vehicle front-rear direction when turning,
If the turning G is increasing during the curve traveling, it is determined that the vehicle is in the corner,
As the increase amount of the turning G per unit time is larger, the decrease correction amount of the rear wheel cornering power value is increased (FIG. 4).
Therefore, it is possible to accurately determine the corner-in by the increase of the turning G and to obtain the appropriate rearward according to the increasing speed of the turning G by only acquiring the information of one turning G without dividing the input information. A reduction correction amount of the wheel cornering power value can be calculated.

(6) Calculate the limit vehicle speed Vc based on the rear wheel cornering power value after reduction correction,
When the current vehicle speed V is close to the limit vehicle speed Vc or exceeds the limit vehicle speed Vc, the front wheel cornering power value is corrected to decrease (FIG. 6).
Therefore, it is possible to prevent the vehicle behavior from becoming unstable when the corner-in characteristic is changed to the oversteering turning characteristic by the correction of the reduction of the rear wheel Cp value.

(7) The turning information (steering angle δ, vehicle speed V) of the vehicle is detected, and the target vehicle body is obtained by the turning information and the reference model (reference model 2) of the vehicle body slip angle β formed by the vehicle center line and the vehicle traveling direction. calculating a slip angle beta ^*, in the turning posture control method for a vehicle by the controller to perform the turning posture control using the target vehicle body slip angle beta ^* information (attitude control ECU 71),
Detects vehicle turning information (target turning G),
Based on the turning information (target turning G), it is determined whether or not it is a corner out in a curve running,
When it is determined that the vehicle is in the corner-out, the reference model (reference model 2) is changed so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-out turning characteristic (FIG. 2).
For this reason, if it is determined that the vehicle is in a corner out during a curve, the target vehicle slip angle β ^* with a predetermined corner out turning characteristic is calculated by changing the reference model, which is suitable for a corner out during a curve. It is possible to provide a turning posture control method for a vehicle (manually operated vehicle A1) that realizes a different turning posture.

(8) The predetermined corner-out turning characteristic is set to a turning characteristic that is closer to the understeer and is more outward in turning than the steady turning characteristic (Fig. 7).
Therefore, in a corner traveling scene, it is possible to realize turning stability that meets the turning posture request at the corner exit.

(9) As a reference model of the vehicle body slip angle β, a steady reference model (reference model 2) that optimizes steady turning characteristics is prepared,
When changing the steady reference model (reference model 2) so as to calculate the target vehicle body slip angle β ^* having a predetermined corner-out turning characteristic, the rear wheel cornering power included in the equation of motion representing the steady reference model (reference model 2) The correction is performed by at least one of the correction of increasing the value and the correction of decreasing the front cornering power value (FIG. 3).
Therefore, it is not necessary to prepare a plurality of reference models, and the corner-out turning characteristic can be improved by a simple configuration in which at least one of the two cornering power values of one prepared reference model (reference model 2) is corrected. It can be changed to a characteristic closer to understeer.

(10) Obtain information about the turning G that is the acceleration acting in the direction orthogonal to the vehicle front-rear direction when turning,
If the turning G is reduced in a curve running, it is determined to be a corner out,
The larger the decrease amount of the turning G per unit time, the larger the correction amount for increasing the rear wheel cornering power value or the correction amount for decreasing the front wheel cornering power value (FIG. 4).
For this reason, it is possible to accurately determine the corner-out by the increase of the turning G and to obtain the appropriate cornering according to the decreasing speed of the turning G, only by acquiring the information of one turning G without dividing the input information. The correction amount of the power value can be calculated.

(11) When the target vehicle body slip angle β ^* is calculated, the braking moment around the vehicle center of gravity point is calculated according to the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β,
A turning posture control command for obtaining a braking moment around the center of gravity of the vehicle is output to the brake actuator 70 (FIG. 3).
Therefore, when the turning characteristic of the reference model is changed, the turning characteristic can be changed to a desired characteristic with good response by reflecting the change.

(12) The vehicle is a manually driven vehicle A1 that travels in a curve by driver steering (Fig. 1).
Therefore, in the corner traveling scene, the turning attitude for obtaining the moment around the center of gravity of the vehicle is shared by the braking moment, and the steering amount by the driver operation can be reduced.

(13) The turning information (steering angle δ, vehicle speed V) of the vehicle is detected, and based on the turning information and the reference model (reference model 2) of the vehicle body slip angle β formed by the vehicle center line and the vehicle traveling direction, the target vehicle body is obtained. calculating a slip angle beta ^*, in the turning posture control device for a vehicle comprising a controller (attitude control ECU 71) for performing a turning posture control using the target vehicle body slip angle beta ^* information,
The controller (attitude control ECU 71)
A turning information detecting unit (turning G estimating unit 711) for detecting turning information (target turning G) of the vehicle;
A corner-in determination unit 711 that determines whether or not it is a corner-in during a curve traveling based on the turning information (target turning G);
When it is determined that the vehicle is in the corner-in, the turning characteristic changing unit (RrCp decrease correction unit 714) that changes the reference model (reference model 2) so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-in turning characteristic. ), and (FIG. 2).
For this reason, when it is determined that the vehicle is in a corner during a curve, the target model slip angle β ^* with a predetermined corner-in turning characteristic is calculated by changing the reference model, which is suitable for the corner in during a curve. It is possible to provide a turning attitude control device for a vehicle (manually operated vehicle A1) that realizes a different turning attitude.

(14) The target vehicle body is detected by detecting the vehicle turning information (steering angle δ, vehicle speed V) and using the turning information and the reference model (reference model 2) of the vehicle body slip angle β formed by the vehicle body center line and the vehicle traveling direction. calculating a slip angle beta ^*, in the turning posture control device for a vehicle comprising a controller (attitude control ECU 71) for performing a turning posture control using the target vehicle body slip angle beta ^* information,
The controller (attitude control ECU 71)
A turning information detecting unit (turning G estimating unit 711) for detecting turning information (target turning G) of the vehicle;
A corner-out determination unit 713 that determines whether or not a corner-out is in a curve traveling based on the turning information (target turning G);
When it is determined that the vehicle is in the corner-out, the turning characteristic changing unit (RrCp increase correction unit 716) that changes the reference model (reference model 2) so as to calculate the target vehicle body slip angle β ^* having the predetermined corner-out turning characteristic. ), and (FIG. 2).
For this reason, if it is determined that the vehicle is in a corner out during a curve, the target vehicle slip angle β ^* with a predetermined corner out turning characteristic is calculated by changing the reference model, which is suitable for a corner out during a curve. It is possible to provide a turning attitude control device for a vehicle (manually operated vehicle A1) that realizes a different turning attitude.

The second embodiment is an example in which the turning attitude control method and the turning attitude control device of the present invention are applied to an autonomous vehicle.

The turning posture control method and the turning posture control device according to the second embodiment generate a target locus when the automatic driving mode is selected, and control the vehicle motion based on the speed and the steering angle so as to travel along the generated target locus. It is applied to an autonomous driving vehicle (an example of a vehicle). Hereinafter, the configuration of the first embodiment will be described by being divided into an "overall system configuration", a "control block configuration of an automatic driving controller", and a "control block configuration of a vehicle motion controller".

[Overall system configuration]
FIG. 9 shows a system configuration of an autonomous vehicle A2 to which the turning attitude control method and the turning attitude control device of the second embodiment are applied. The overall system configuration will be described with reference to FIG.

As shown in FIG. 9, the self-driving vehicle A2 includes an in-vehicle sensor 1, a navigation device 2, an in-vehicle control unit 3, an actuator 4, and an HMI module 5.

The vehicle-mounted sensor 1 is various sensors mounted on the own vehicle for recognizing objects around the own vehicle, the surrounding environment such as road shape, the state of the own vehicle, and the like. The vehicle-mounted sensor 1 has an external sensor 11, a GPS receiver 12, and an internal sensor 13. The in-vehicle sensor 1 may perform sensor fusion to acquire necessary information using a plurality of different sensors.

The external sensor 11 is a detection device that detects environmental information around the vehicle. The external sensor 11 is composed of a camera, a radar, a lidar (LIDER: Laser Imaging Detection and Rangin), and the like. Note that the camera, radar, and rider do not necessarily have to be provided in duplicate.

The camera is an imaging device for acquiring image data. This camera is configured by combining, for example, a front recognition camera, a rear recognition camera, a right recognition camera, a left recognition camera, etc., and analyzes captured images and videos in real time using artificial intelligence and an image processing processor. Done in. This allows the camera to display objects on the vehicle's own road, lanes, objects outside the vehicle's own road (road structures, preceding vehicles, following vehicles, oncoming vehicles, surrounding vehicles, pedestrians, bicycles, two-wheeled vehicles) It can detect road white lines, road boundaries, stop lines, pedestrian crossings, road signs (speed limits), etc. In general, a monocular camera cannot measure the distance to the object, but it is also possible to measure the distance to the object by simultaneously capturing images from different viewpoints using a compound eye camera.

A radar is a device that acquires distance data using reflected signals. Here, "radar" is a generic term including radar using radio waves and sonar using ultrasonic waves, and for example, laser radar, millimeter wave radar, ultrasonic radar, laser range finder, etc. should be used. You can A rider is a device that uses light to acquire distance data.

Radars and riders transmit signals and light such as radio waves around the vehicle and receive signals and light such as radio waves reflected by the target object to determine the distance and direction to the target object that is the reflection point. To detect. As a result, the radar and rider can detect the position of the object on the road on which the vehicle is traveling or the object outside the vehicle on which the vehicle is traveling (road structure, preceding vehicle, following vehicle, oncoming vehicle, surrounding vehicle, pedestrian, bicycle, two-wheeled vehicle). At the same time, the distance to each object can be detected.

The GPS receiver 12 is a device for receiving signals from three or more GPS satellites and acquiring position data indicating the position of the vehicle. The GPS receiver 12 has a GNSS antenna 12a and detects the latitude and longitude of the vehicle position.
In addition, "GNSS" is an abbreviation of "Global Navigation Satellite System: global navigation satellite system", and "GPS" is an abbreviation of "Global Positioning System: global positioning system". Further, when the signal reception by the GPS receiver 12 is poor, the function of the GPS receiver 12 may be complemented by using the internal sensor 13 or the odometer (vehicle movement amount measuring device).

The internal sensor 13 is a detection device that detects vehicle information such as speed/acceleration/posture data of the vehicle. The internal sensor 13 has, for example, a 6-axis inertial sensor (IMU: Inertial Measurement Unit), and can detect the moving direction, direction, and rotation of the vehicle. Furthermore, the moving distance, the moving speed, etc. can be calculated based on the detection result of the internal sensor 13. The 6-axis inertial sensor is realized by combining an acceleration sensor capable of detecting three-direction accelerations in the front-back, left-right, and top-bottom directions and a gyro sensor capable of detecting the rotational speeds of the three-directions. The internal sensor 13 can include necessary sensors such as a wheel speed sensor, a yaw rate sensor, and an accelerator operation amount sensor.

Further, in the vehicle-mounted sensor 1, necessary information may be acquired from the outside by performing wireless communication with an external data communication device (not shown). That is, when the external data communication device is, for example, a data communication device mounted on another vehicle, inter-vehicle communication is performed between the own vehicle and the other vehicle. Through this inter-vehicle communication, necessary information can be acquired from various information held by other vehicles. When the external data communication device is, for example, a data communication device provided in infrastructure equipment, infrastructure communication is performed between the vehicle and the infrastructure equipment. Through this infrastructure communication, necessary information can be acquired from various information held by the infrastructure equipment. As a result, for example, the map data required by the automatic operation controller 31 can be supplemented when there is insufficient information or changed information. It is also possible to obtain traffic information such as traffic jam information and travel regulation information on the route where the vehicle is scheduled to travel.

The navigation device 2 is a device that incorporates map data and facility information data and guides a route to a destination. In this navigation device 2, when the destination is input, a guide route from the current position of the vehicle (or an arbitrarily set starting point) to the destination is generated. The generated guide route information is combined with the map data and displayed on the display panel of the HMI module 5. The destination may be set by the vehicle occupant in the vehicle, or the destination set by the user through the user's terminal (eg, mobile phone, smartphone) can be received by the vehicle via wireless communication. However, the received destination may be used. Further, the guide route may be calculated by a navigation device using a controller provided in the vehicle, or may be calculated by a navigation device using a controller outside the vehicle.

The vehicle-mounted control unit 3 includes a CPU and a memory, and stores various detection information detected by the vehicle-mounted sensor 1, guide route information generated by the navigation device 2, and driver input information that is appropriately input as necessary. Integrated processing. The on-vehicle control unit 3 is a controller that controls the vehicle motion by hierarchical processing. Note that "hierarchical processing" is to perform a plurality of processings on input information in order (hierarchically) to calculate final output information, and output value output by processing of upper hierarchy. There is a relationship in which (calculated value) becomes an input value in the processing of the lower hierarchy.

The vehicle-mounted control unit 3 has an automatic driving controller 31 that calculates a control command value for controlling the vehicle motion, and a vehicle motion controller 32. Here, the automatic operation controller 31 that performs the calculation in the first control cycle (for example, about 70 msec) performs the processing of the upper layer, and the calculation in the second control cycle (for example, about 10 msec) shorter than the first control cycle. The vehicle motion controller 32 for performing the processing of the lower hierarchy.

The automatic driving controller 31 generates a target vehicle speed profile and a target trajectory by multistage hierarchical processing based on input information from the vehicle-mounted sensor 1 and the navigation device 2, high-precision map data, and the like. Here, the "target locus" is a locus that is a target when the vehicle is automatically driven, and includes, for example, a locus for traveling in the lane in which the vehicle is located and a drivable area around the vehicle. Is calculated and includes a trajectory for traveling in the travelable area, a trajectory during emergency steering for avoiding obstacles, and the like. The information on the generated target vehicle speed profile and target trajectory is output to the vehicle motion controller 32. The generated information on the target trajectory may be combined with the high-precision map data and displayed on the display panel of the HMI module 5.

In the vehicle motion controller 32, a control command value for running the own vehicle is calculated by a multi-step hierarchical process based on the information on the target vehicle speed profile and the target trajectory and the input information by the driver (hereinafter referred to as “driver input”). .. The calculated control command value is output to the actuator 4. The vehicle motion controller 32 arbitrates the traveling mode depending on the presence/absence of driver input and calculates a control command value according to the arbitration result. For example, when the automatic driving mode is selected and there is no driver input, a control command value for causing the vehicle to automatically drive along the target locus is output. On the other hand, when the driver input intervenes during automatic driving or when the manual driving mode is selected, a control command value for driving the vehicle with the driver input as a target is output.

The actuator 4 is a control actuator for running or stopping the vehicle, and includes a speed control actuator 41, a steering control actuator 42, and a brake actuator 43. In addition, traveling means acceleration traveling/constant speed traveling/deceleration traveling of the vehicle.

The speed control actuator 41 controls the drive torque or the braking torque output to the drive wheels based on the speed control command value input from the vehicle-mounted control unit 3. As the speed control actuator 41, for example, an engine is used in the case of an engine vehicle, an engine and a motor/generator are used in the case of a hybrid vehicle, and a motor/generator is used in the case of an electric vehicle.

The steering control actuator 42 controls the turning angle of the steered wheels based on the steering control command value input from the vehicle-mounted control unit 3. As the steering control actuator 42, a steering motor or the like provided in the steering force transmission system of the steering system is used.

The brake actuator 43 applies the braking torque based on the stop command value input from the on-vehicle control unit 3, and controls the braking torque independently for the four wheels based on the brake moment command value input from the on-vehicle control unit 3. It is an actuator. As the brake actuator 43, for example, a brake hydraulic actuator or a brake motor actuator is used.

The HMI module 5 is an interface for outputting and inputting information between a vehicle occupant (including a driver) and the vehicle-mounted control unit 3. The HMI module 5 is composed of, for example, a steering wheel, an accelerator, a brake, a display panel for displaying image information to an occupant, a speaker for outputting voice, operation buttons and a touch panel for an occupant to perform an input operation.

[Control block configuration of automatic operation controller]
As shown in FIG. 2, the automatic driving controller 31 includes a high-precision map data storage unit 311, a self-position estimation unit 312, a surrounding environment recognition unit 313, and a traveling environment recognition unit 314. As a hierarchical processing unit that generates a target trajectory, a traveling lane calculation unit 316, a motion determination unit 317, a travel area setting unit 318, and a target trajectory generation unit 319 are provided.

The high-precision map data storage unit 311 stores high-precision three-dimensional map data (hereinafter referred to as “HD map”) in which three-dimensional position information (longitude, latitude, height) of a stationary object existing outside the vehicle is set. It is the on-board memory that was installed. Stationary objects include, for example, pedestrian crossings, stop lines, various signs, junctions, road markings, traffic lights, power poles, buildings, signboards, roadways and lane centerlines, lane markings, shoulder lines, road-to-road connections, etc. Elements are included.

The self-position estimation unit 312 estimates the current position (self-position) of the own vehicle based on the input information. Here, sensor information from the vehicle-mounted sensor 1 and HD map information from the high-precision map data storage unit 311 are input to the self-position estimation unit 312. Then, the self-position estimation unit 312 estimates the self-position by matching the input sensor information and HD map information, for example. The self-position estimation unit 312 outputs self-position information to the traveling environment recognition unit 314.

The surrounding environment recognition unit 313 recognizes the surrounding environment of the own vehicle based on the input information and the dynamic surrounding environment information (local model) which is a database of dynamic information of the surrounding environment of the own vehicle. Here, the "dynamic information" means, for example, quasi-static data including traffic regulation information, road construction information, wide area weather information, etc., such as accident information, traffic jam information, narrow area weather information, and the like. Data such as peripheral vehicle information, pedestrian information, signal information, and the like. The dynamic information is layered, and the update frequency of each data is different. Sensor information (environmental information around the vehicle) from the vehicle-mounted sensor 1 is input to the surrounding environment recognition unit 313. Then, the surrounding environment recognition unit 313 analyzes the input surrounding environment information of the own vehicle using the dynamic surrounding environment information, and calculates the surrounding environment recognition information. The surrounding environment recognition unit 313 outputs the surrounding environment recognition information to the traveling environment recognition unit 314 and the traveling area setting unit 318.

The traveling environment recognition unit 314 recognizes the traveling environment of the own vehicle based on the input information and the dynamic traveling environment information (world model) that is a database of dynamic information that changes with time of the own vehicle. Here, the “dynamic driving environment information (world model)” means a dynamic environment obtained by expanding the environment recognition area with respect to the “dynamic surrounding environment information (local model)” centering on the self position of the own vehicle. Information. The traveling environment recognition unit 314 includes sensor information from the vehicle-mounted sensor 1, guidance route information from the navigation device 2, HD map information from the high-precision map data storage unit 311, and self-position from the self-position estimation unit 312. The information and the surrounding environment recognition information from the surrounding environment recognition unit 313 are input. Then, the traveling environment recognition unit 314 uses the dynamic traveling environment information to calculate the traveling environment recognition information on the HD map in a predetermined range based on the estimated current location of the vehicle. The traveling environment recognition unit 314 outputs traveling environment recognition information to the motion determining unit 317.

The traveling lane calculation unit 316 calculates the traveling lane in which the vehicle should travel (hereinafter, referred to as “target lane”) on the guide route to the destination. Here, guidance route information from the navigation device 2, HD map information from the high-precision map data storage unit 311 and the like are input to the traveling lane calculation unit 316. Then, the traveling lane calculator 316 calculates the target lane from the direction of the destination determined from the route guidance information and the HD map. The target lane information is output from the traveling lane calculation unit 316 to the operation determination unit 317 in the next layer.

The motion determination unit 317 extracts the events that the vehicle encounters when traveling by automatic driving along the target lane, and determines the “motion of the vehicle” for those events. Here, the "movement of the own vehicle" is the movement of the own vehicle necessary for traveling along the target lane such as starting, stopping, accelerating, decelerating, and turning left and right.

The driving environment recognition information from the driving environment recognition unit 314, the target lane information from the driving lane calculation unit 316, and the like are input to the motion determination unit 317. Then, the operation determination unit 317 collates the target lane with the traveling environment around the own vehicle to determine an appropriate operation of the own vehicle. The travel area setting unit 318 sets a travelable area in which the vehicle can travel along the target lane. Here, in the travel area setting unit 318, the HD map information from the high-precision map data storage unit 311, the surrounding environment recognition information from the surrounding environment recognition unit 313, the own vehicle motion determination information from the motion determination unit 317, etc. Is entered. Then, the traveling area setting unit 318 compares the operation information of the own vehicle with the surrounding environment information of the own vehicle, and sets the area in which the own vehicle can travel. For example, when an object such as an obstacle exists around the vehicle, a travelable area is set so as to avoid contact with the object. The travel area setting unit 318 outputs the travelable area information to the target trajectory generation unit 319 of the next layer.

The target trajectory generation unit 319 generates a target trajectory within the set travelable area. Here, the travelable area information and the like from the travel area setting unit 318 is input to the target trajectory generation unit 319. Then, the target locus generation unit 319 generates a target locus by a geometric method under the constraint condition that the vehicle moves within the travelable area from the current position of the vehicle to a target position that is arbitrarily set. .. The target trajectory generation unit 319 may generate the target trajectory using, for example, a composite clothoid curve. Further, the target locus generation unit 319 may generate a target locus capable of traveling satisfying standards such as safety, legal compliance, and traveling efficiency. The target trajectory generation unit 319 outputs target trajectory information to the vehicle motion controller 32.

Here, the target trajectory generation unit 319 may generate a target vehicle speed profile for the target trajectory. The target vehicle speed profile is a time-series target vehicle speed when traveling along a target locus. Thereby, the target vehicle speed profile can be generated according to the curvature of the target trajectory. For example, in a scene with a large curvature, the target vehicle speed may be set low in order not to give a large vehicle behavior to the occupants, and in a scene with a small curvature, the target vehicle speed profile may be set higher than a scene with a large curvature. Good. On the other hand, the target vehicle speed profile may be calculated first, and then the target locus may be generated in accordance with the target vehicle speed profile. For example, when the target vehicle speed is high, the locus may be generated so that the curvature becomes small, and conversely, when the target vehicle speed is low, the target locus may be generated so that the curvature becomes large. When the target vehicle speed profile is generated, the road surface μ value information may be used as a parameter for suppressing the vehicle speed change gradient (acceleration gradient, deceleration gradient) as the estimated road surface friction coefficient is lower.

[Control block configuration of vehicle motion controller]
As shown in FIG. 2, the vehicle motion controller 32 includes an input information arbitration unit 321, an attitude control determination unit 322, a reference model setting unit 323, a behavior control unit 324, a tire force calculation unit 325, and a command calculation unit. A posture control unit 327 and a posture control unit 327 are provided.

The input information arbitration unit 321 arbitrates whether to calculate the control command value based on the input information from the automatic driving controller 31 or to calculate the control command value with the driver input as a target according to the presence or absence of the driver input. Here, the input information arbitration unit 321 receives the information about the target vehicle speed profile and the target trajectory from the automatic driving controller 31, and the information about the steering angle by the driver via the HMI module 5. The input information arbitration unit 321 arbitrates the input information of the vehicle speed and the steering angle used in the process of the vehicle motion controller 32 as follows. When there is no driver input during selection of the automatic driving mode, the target vehicle speed and the target steering angle set based on the target vehicle speed profile and the target trajectory information from the automatic driving controller 31 are used as the input information of the vehicle speed and the steering angle. Use information. On the other hand, when the driver input intervenes during the automatic driving or when the manual driving mode is selected, the information on the actual vehicle speed and the actual steering angle based on the driver input is used as the input information on the vehicle speed and the steering angle.

The attitude control determination unit 322 determines whether or not the turning attitude control based on the braking moment is necessary based on the steering request based on the driver steering angle or the turning request from the automatic driving controller 31. For example, when there is a steering request due to driver input, for example, when the steering angular velocity is a steering request smaller than the threshold value, it is determined that the turning attitude control is not necessary, and when the steering angular velocity is greater than the threshold value, the turning attitude is determined. Determine that control is required. If there is a turning request from the automatic driving controller 31, for example, if the turning request is for a target trajectory with a large turning radius, it is determined that the turning attitude control is not required. Then, it is determined that the turning attitude control is necessary, such as a turning request with a target locus having a small turning radius, a turning request with an S-shaped target locus, and a turning request with which an obstacle is bypassed and avoided.

When the attitude control determination unit 322 determines that the turning attitude control is not necessary, the normal control determination flag is set and the process proceeds to the reference model setting unit 323 and the subsequent steps. On the other hand, when the posture control determination unit 322 determines that the turning posture control is necessary, the posture control determination flag is set and the process of the posture control unit 327 is performed.

The reference model setting unit 323 sets a reference model of the vehicle motion that is represented by a motion equation that can be arbitrarily set and that occurs when the vehicle runs. That is, when the attitude control determination unit 322 sets the normal control determination flag, the information on the vehicle speed and the steering angle from the input information arbitration unit 321 is input. Then, the reference model setting unit 323 calculates the reference model value by substituting the input information into the equation of motion that is the reference model. Here, the "normative model value" means, for example, the target yaw rate when the yaw rate norm model is used, the target lateral acceleration when the lateral acceleration norm model is used, and the target vehicle body when the vehicle body slip angle norm model is used. Slip angle, etc. Information on the reference model value such as the target yaw rate is output from the reference model setting unit 323 to the behavior control unit 324.

The behavior control unit 324 inputs the information of the reference model value from the reference model setting unit 323, converges the actual value of the own vehicle motion to the reference model value, and follows the vehicle behavior of the reference model. Calculate the value. For example, when the reference model value is the target yaw rate, a deviation from the actual yaw rate occurring in the own vehicle is calculated, and a vehicle speed command value and a steering angle command value that reduce this deviation are calculated. At this time, the behavior control unit 324 mainly performs calculation by the feedback control system. Then, the behavior control unit 324 outputs information on the vehicle speed command value and the steering angle command value to the tire force calculation unit 325.

When the vehicle speed command value and the steering angle command value are input from the behavior control unit 324, the tire force calculation unit 325 determines the optimum tire force (tire longitudinal force and tire lateral force) of each tire that achieves the vehicle speed command value and the steering angle command value. ) Is calculated. The tire force calculation unit 325 outputs tire force information for each tire to the command calculation unit 326.

The command calculation unit 326 calculates a command value (speed control command value and steering control command value) to be generated in each tire, based on the tire force information input from the tire force calculation unit 325. Command value information is output from the command calculation unit 326 to the actuator 4.

The attitude control unit 327 exhibits the same control function as the attitude control ECU 71 in the first embodiment. That is, when the attitude control determination flag is set by the attitude control determination unit 322, the information about the vehicle speed and the steering angle from the input information arbitration unit 321 is input. Then, it is determined whether or not it is a corner in a curve running, and the turning characteristics based on the reference model of the vehicle body slip angle are changed by the corner-in turning characteristics, the steady turning characteristics, and the corner-out turning characteristics. During the curve traveling, the target vehicle body slip angle β ^* is calculated by using the reference model in which the turning characteristic is changed, and the information of the actual vehicle body slip angle β is acquired. Then, the brake moment is calculated according to the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β, and a turning posture control command for obtaining the calculated brake moment is output to the brake actuator 43.

Next, the turning attitude control action will be described. In the second embodiment, the vehicle is the autonomous driving vehicle A2 that travels automatically. Then, a brake moment corresponding to the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β is calculated by using the reference model in which the turning characteristic is changed, and a turning attitude control command for obtaining the calculated braking moment is given to the brake actuator 43. Output to.

That is, unlike during manual driving, the driver is not involved in steering operation or accelerator operation during automatic driving, so the sensitivity of the driver or occupant to changes in turning posture during automatic driving is Be more sensitive than when driving. Therefore, during the automatic driving traveling, higher turning posture responsiveness and turning posture stability are required than during the manual driving traveling.

On the other hand, during autonomous driving, in corner driving scenes, the vehicle behavior on the corner entrance side becomes faster and stabilizes to a steady turning state, and the turning attitude control by the brake moment is performed to maintain the stability of the vehicle behavior on the corner exit side. Done. Therefore, in the corner traveling scene, the turning characteristic with a stable turning posture is realized for the driver and the occupant, and the comfortable automatic driving traveling without giving the driver and the occupant a feeling of strangeness is achieved. It should be noted that the other actions are similar to those of the first embodiment, and thus the description thereof will be omitted.

As described above, in the turning attitude control method and the turning attitude control device for the autonomous driving vehicle A2 of the second embodiment, the effects of (1) to (11), (13) to (14) of the first embodiment are obtained. In addition, the following effects are exhibited.

(15) The vehicle is the autonomous driving vehicle A2 that autonomously travels along the target locus (FIG. 9).
Therefore, in a corner traveling scene, a turning characteristic with a stable turning posture is realized for the driver and the occupant, and comfortable automatic driving traveling can be achieved without giving a feeling of strangeness to the driver and the occupant.

The vehicle turning attitude control method and the turning attitude control device of the present disclosure have been described above based on the first and second embodiments. However, the specific configuration is not limited to these examples, and design changes and additions are allowed without departing from the gist of the invention according to each claim of the claims.

In the first and second embodiments, an example including the corner-in determination unit 712 and the corner-out determination unit 713 is shown. However, as shown in the configuration plan 1 of FIG. 11, it may have a corner determination unit 721. In this case, when it is determined to be a corner in the corner traveling scene, the RrCp correction unit 722 corrects the rear wheel Cp of the reference model 2 from the decrease to the increase from the corner in to the corner out. Further, as shown in the configuration plan 2 of FIG. 11, it may have only the corner-out determination unit 713. In this case, the RrCp increase correction unit 716 corrects the rear wheel Cp of the reference model 2 in the corner-out determination area. Further, as shown in the configuration plan 3 of FIG. 11, it may have only the corner-in determination unit 712. In this case, the RrCp decrease correction unit 714 determines that the rear wheel Cp of the reference model 2 is decreased in the corner-in determination area. Note that the FrCp reduction correction unit 715 is provided as a measure against oversteering.

In the first and second embodiments, as the reference model of the vehicle body slip angle, the reference model 2 in which the steady turning characteristic is optimized is prepared, the corner-in characteristic is changed to the over-steering turning characteristic, and the corner-out characteristic is changed to the under-steering characteristic. An example of changing the turning characteristic has been shown. However, as the reference model of the vehicle body slip angle, for example, in the case of the configuration plan 3 of FIG. 11, a model having a turning characteristic close to understeer is prepared, and the turning characteristic of the reference model is set to close to the oversteer only in the corner-in determination area. All that is required is to change the turning characteristics. Further, as a reference model of the vehicle body slip angle, for example, in the case of the configuration plan 2 in FIG. 11, a model having a turning characteristic close to oversteer is prepared, and the turning characteristic of the reference model is set to the understeer turning only in the corner-out determination area. All you have to do is change the characteristics. In either case, the turning characteristic in the determination region that is not changed is the turning characteristic that is initially set by the reference model prepared in advance, and the turning characteristic of the reference model is changed between corner-in and corner-out.

In the first and second embodiments, one standard model is prepared as the standard model of the vehicle body slip angle, and the turning characteristic is changed by correcting the front wheel Cp value or the rear wheel Cp value. However, as the reference model of the vehicle body slip angle, an example in which variables other than the cornering power value included in the reference model are corrected may be used. As the reference model of the vehicle body slip angle, there are two reference models (a reference model based on a turning characteristic near the oversteer and a reference model based on a turning characteristic near the understeer), or one reference model (a reference model based on the neutral steering characteristic). ) May be added to prepare three reference models. In this case, the turning characteristics of the reference model are changed between the corner-in and the corner-out by switching and selecting one reference model from the plurality of reference models prepared for corner-in or corner-out. Become.

In the first and second embodiments, an example in which the deviation between the target vehicle body slip angle β ^* and the actual vehicle body slip angle β is executed by the brake moment control is shown. However, a part of the moment around the center of gravity depending on the deviation between the target vehicle body slip angle and the actual vehicle body slip angle may be shared by the brake moment control, and the rest may be shared by the steering angle moment control. Also, if the magnitude of the moment around the center of gravity is less than or equal to the threshold value due to the deviation between the target vehicle body slip angle and the actual vehicle body slip angle, the steering angle moment control is shared, and if it exceeds the threshold value, the brake moment control is also shared. good.

In the first embodiment, an example in which the turning posture control method and the turning posture control device of the present disclosure are applied to the manually driven vehicle A1 that is manually driven by a driver is shown. In the second embodiment, an example in which the turning attitude control method and the turning attitude control device of the present disclosure are applied to the autonomous driving vehicle A2 in which the vehicle motion is controlled by the speed and the steering angle so as to travel along the target locus has been shown. .. However, the turning posture control method and the turning posture control device of the present disclosure are not limited to a manually driven vehicle and an automatically driven vehicle, but are also applicable to a driving assistance vehicle including an automatic braking function, a constant speed traveling control function, a lane departure prevention function, and the like. Can also be applied. In the case of a driving assistance vehicle, a sensor that detects the situation around the vehicle and a travel assistance controller that calculates a trajectory for traveling the vehicle based on the situation around the vehicle are provided, and the calculated trajectory of the vehicle is turned. This is the turning information of the vehicle in the attitude control.

A1 Manual driving vehicle 70 Brake actuator 71 Attitude control ECU (controller)
711 Turn G estimation unit 712 Corner-in determination unit 713 Corner-out determination unit 714 RrCp decrease correction unit 715 FrCp decrease correction unit 716 RrCp increase correction unit 717 Target vehicle body slip angle calculation unit 718 Actual vehicle body slip angle information acquisition unit 719 Brake moment calculation unit 720 Control command output unit A2 Self-driving vehicle 32 Vehicle motion controller (controller)
321 Input information arbitration unit 322 Posture control determination unit 323 Reference model setting unit 324 Behavior control unit 325 Tire force calculation unit 326 Command calculation unit 327 Turning posture control unit 43 Brake actuator

Claims (16)

The turning information of the vehicle is detected, the target vehicle slip angle is calculated based on the turning information and the reference model of the vehicle body slip angle formed by the vehicle body centerline and the vehicle traveling direction, and the information of the target vehicle body slip angle is used. In a turning posture control method of a vehicle by a controller that performs turning posture control,
Detects vehicle turning information,
Based on the turning information, it is determined whether or not it is a corner-in in a curve running,
A turning attitude control method for a vehicle, comprising: changing the reference model so as to calculate the target vehicle body slip angle having a predetermined corner-in turning characteristic when the corner-in is determined. The turning attitude control method for a vehicle according to claim 1,
A turning attitude control method for a vehicle, wherein the predetermined corner-in turning characteristic is a turning characteristic nearer to oversteer that is more inwardly turning than a steady turning characteristic. The turning attitude control method for a vehicle according to claim 2,
As a reference model of the vehicle body slip angle, a steady reference model in which steady turning characteristics are optimized is prepared,
When changing the steady reference model so as to calculate the target vehicle body slip angle having the predetermined corner-in turning characteristic, a reduction correction of a rear wheel cornering power value included in a motion equation representing the steady reference model is performed. A characteristic vehicle turning attitude control method. The turning attitude control method for a vehicle according to claim 2,
As a reference model of the vehicle body slip angle, a steady reference model in which steady turning characteristics are optimized is prepared,
When the steady reference model is changed so as to calculate the target vehicle body slip angle having the predetermined corner-in turning characteristic, a reduction correction of the rear wheel cornering power value and a front wheel cornering power included in the equation of motion representing the steady reference model are performed. A turning attitude control method for a vehicle, characterized by performing at least one of an increase correction and a correction. The turning attitude control method for a vehicle according to claim 3,
The information of the turning G, which is the acceleration acting in the direction orthogonal to the vehicle front-rear direction when turning, is acquired,
It is determined that the vehicle is in a corner when the turning G is increased in the curve running,
A turning attitude control method for a vehicle, comprising: performing a decrease correction in which the decrease correction amount of the rear wheel cornering power value is increased as the increase amount of the turning G per unit time is larger. The turning attitude control method for a vehicle according to claim 5,
Calculate the limit vehicle speed based on the rear wheel cornering power value after the reduction correction,
A turning attitude control method for a vehicle, comprising: performing a reduction correction of a front wheel cornering power value when the current vehicle speed is close to or exceeds the limit vehicle speed. The turning information of the vehicle is detected, the target vehicle slip angle is calculated based on the turning information and the reference model of the vehicle body slip angle formed by the vehicle body centerline and the vehicle traveling direction, and the information of the target vehicle body slip angle is used. In a turning posture control method of a vehicle by a controller that performs turning posture control,
Detects vehicle turning information,
Based on the turning information, it is determined whether or not it is a corner out in a curve running,
A turning attitude control method for a vehicle, comprising: changing the reference model so as to calculate the target vehicle body slip angle having a predetermined corner-out turning characteristic when the corner-out is determined. The turning attitude control method for a vehicle according to claim 7,
A turning attitude control method for a vehicle, wherein the turning characteristic that causes the predetermined corner-out is a turning characteristic that is closer to the understeer and that is a turning outward direction than a steady turning characteristic. The vehicle turning attitude control method according to claim 8,
As a reference model of the vehicle body slip angle, a steady reference model in which steady turning characteristics are optimized is prepared,
When the steady reference model is changed to calculate the target vehicle body slip angle that provides the predetermined corner-out turning characteristic, the rear wheel cornering power value increase correction and the front wheel cornering power included in the equation of motion representing the steady reference model are corrected. A turning attitude control method for a vehicle, characterized by performing at least one of correction of a decrease in a value. The turning attitude control method for a vehicle according to claim 9,
The information of the turning G, which is the acceleration acting in the direction orthogonal to the vehicle front-rear direction when turning, is acquired,
If the turning G is reduced in a curve running, it is determined to be a corner out,
The turning attitude control of the vehicle is characterized in that the larger the decrease amount of the turning G per unit time, the larger the correction amount for increasing the rear wheel cornering power value or the larger correction amount for decreasing the front wheel cornering power value. Method. The turning attitude control method for a vehicle according to any one of claims 1 to 10,
When the target vehicle body slip angle is calculated, a braking moment around the vehicle center of gravity is calculated so as to eliminate the deviation between the target vehicle body slip angle and the actual vehicle body slip angle,
A turning posture control method for a vehicle, comprising outputting a turning posture control command for obtaining a braking moment around the center of gravity of the vehicle to a brake actuator. The vehicle turning attitude control method according to claim 11,
The turning posture control method for a vehicle, wherein the vehicle is a manually driven vehicle that travels in a curve by driver steering. The vehicle turning attitude control method according to claim 11,
The turning posture control method for a vehicle, wherein the vehicle is an automatic driving vehicle that automatically travels along a target trajectory. The turning attitude control method for a vehicle according to any one of claims 1 to 11,
A sensor that detects a situation around the vehicle, and a travel assistance controller that calculates a trajectory for traveling the vehicle based on a situation around the vehicle,
A turning posture control method of a vehicle, wherein the trajectory of the vehicle is used as turning information of the vehicle. The turning information of the vehicle is detected, the target vehicle slip angle is calculated based on the turning information and the reference model of the vehicle body slip angle formed by the vehicle body centerline and the vehicle traveling direction, and the information of the target vehicle body slip angle is used. In a vehicle turning attitude control device including a controller that performs turning attitude control,
The controller is
A turning information detection unit for detecting turning information of the vehicle,
With the turning information, a corner-in determination unit that determines whether or not it is a corner-in in a curve running,
If it is determined to be a corner-in, a turning characteristic changing unit that changes the reference model so as to calculate the target vehicle body slip angle having a predetermined corner-in turning characteristic, and Turning posture control device. The turning information of the vehicle is detected, the target vehicle slip angle is calculated based on the turning information and the reference model of the vehicle body slip angle formed by the vehicle body centerline and the vehicle traveling direction, and the information of the target vehicle body slip angle is used. In a vehicle turning attitude control device including a controller that performs turning attitude control,
The controller is
A turning information detection unit for detecting turning information of the vehicle,
With the turning information, a corner-out determination unit that determines whether or not it is a corner-out in a curve running,
When it is determined that the vehicle is in a corner-out, a turning characteristic changing unit that changes the reference model so as to calculate the target vehicle body slip angle having a predetermined corner-out turning characteristic is provided. Turning posture control device.