WO2011102108A1

WO2011102108A1 - Vehicle

Info

Publication number: WO2011102108A1
Application number: PCT/JP2011/000812
Authority: WO
Inventors: 弘毅林; 裕司高倉; 伸司山本
Original assignee: 株式会社エクォス・リサーチ
Priority date: 2010-02-16
Filing date: 2011-02-14
Publication date: 2011-08-25
Also published as: CN102770333A; JP2012012004A

Abstract

Because a force in the direction parallel to the longitudinal axis line of a vehicle body acts upon the vehicle body and an occupant, and the acceleration components in the lateral direction are zero, even when the position of a vehicle body changes, the disclosed vehicle achieves a stable travelling state, provides good riding comfort, does not make an occupant feel any sense of unease, and maintains vehicle body stability and improves turning performance. The vehicle comprises: a vehicle body which is provided with a mutually connected steering unit and drive unit; a tilting actuator device which tilts the steering wheel or the drive wheel in the turning direction; a sensor which either directly or indirectly detects the lateral acceleration acting on the vehicle body; a required turning amount detection means which detects the required turning amount for the vehicle body; and a vehicle speed detection means which detects the speed of the vehicle. The vehicle carries out feedback control on the basis of the lateral acceleration, and feedforward control on the basis of the required turning amount and the vehicle speed, and thus controls the tilt of the vehicle body.

Description

vehicle

The present invention relates to a vehicle having at least a pair of left and right wheels.

In recent years, in view of the problem of exhaustion of energy resources, there has been a strong demand for fuel saving of vehicles. On the other hand, the number of vehicle owners is increasing due to the low price of vehicles, and one person tends to own one vehicle. Therefore, for example, there is a problem that energy is wasted when only one driver drives a four-seater vehicle. The most efficient way to save fuel consumption by reducing the size of the vehicle is to configure the vehicle as a one-seater tricycle or four-wheel vehicle.

However, depending on the driving condition, the stability of the vehicle may decrease. Therefore, a technique for improving the stability of the vehicle during turning by tilting the vehicle body in the lateral direction has been proposed (for example, see Patent Document 1).

JP 2008-155671 A

However, in the conventional vehicle, in order to improve the turning performance, the vehicle body can be tilted inward in the turning direction, but the operation of tilting the vehicle body is difficult and the turning performance is low. , Passengers may feel uncomfortable or anxious.

The present invention solves the problems of the conventional vehicle, calculates the predicted value of the acceleration component in the lateral direction from the steering angle and the vehicle speed, and makes an angle that balances the centrifugal force and the gravity to the outside of the turn By controlling the tilt angle of the vehicle body, the lateral acceleration component becomes zero even when the posture of the vehicle body changes, and the force in the direction parallel to the longitudinal axis of the vehicle body is applied to the vehicle body and the occupant. Therefore, the stability of the vehicle body can be maintained, the turning performance can be improved, the occupant does not feel uncomfortable, the ride comfort is good, and the stable running state can be realized. The object is to provide a highly safe vehicle.

To this end, in the vehicle of the present invention, a vehicle body including a steering unit and a drive unit coupled to each other, a wheel rotatably attached to the steering unit, the steering wheel for steering the vehicle body, and the drive A wheel that is rotatably attached to the vehicle, and includes a drive wheel that drives the vehicle body, a tilt actuator device that tilts the steering unit or the drive unit in a turning direction, and a lateral acceleration that acts on the vehicle body directly. Alternatively, a plurality of sensors that detect indirectly, a requested turning amount detection means that detects a requested turning amount of the vehicle body requested by an occupant, a vehicle speed detection means that detects a vehicle speed, and the tilt actuator device are controlled to A control device for controlling the tilt of the vehicle body, the control device performing feedback control based on lateral acceleration detected by the plurality of sensors, and detecting the required turning amount Stage controls the inclination of the vehicle body making the request turning amount and feedforward control based on the vehicle speed the vehicle speed detecting means detects detects.

According to the configuration of claim 1, the tilt angle of the vehicle body can be controlled so that the centrifugal force to the outside of the turn and the gravity are balanced, and the change in the lateral acceleration is large. However, there is no delay in control. Accordingly, a force in a direction parallel to the longitudinal axis of the vehicle body acts on the vehicle body and the occupant, so that the occupant does not feel uncomfortable, has a good ride, and realizes a stable running state. it can.

According to the configuration of claim 2, since zero point detection is not required, an inexpensive sensor can be used, and initial setting is not required, so that cost can be reduced.

According to the configuration of claim 3, it is possible to improve the follow-up performance of the control during high-speed traveling.

According to the configurations of claims 4 to 6, since unnecessary acceleration components can be removed, it is possible to prevent the occurrence of vibrations, divergence, etc. of the control system without being affected by road surface conditions, and to control the vehicle body tilt. Control responsiveness can be improved by increasing the control gain of the system.

According to the configuration of claim 7, there is no delay in the control even at the start and end of the turn, and the control responsiveness can be improved.

According to the configuration of claim 8, it is possible to ensure stability during high-speed traveling.

It is a figure which shows the structure of the vehicle in the 1st Embodiment of this invention. It is a figure which shows the structure of the link mechanism of the vehicle in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the vehicle body tilt control system in the 1st Embodiment of this invention. It is a figure explaining the inclination operation | movement of the vehicle body at the time of turning driving | running | working in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the vehicle body tilt control process of the vehicle in the 1st Embodiment of this invention. It is a figure explaining the influence which the detection value of the lateral acceleration sensor in the 2nd Embodiment of this invention receives. It is a figure which shows the back surface of the vehicle in the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the vehicle body tilt control system in the 2nd Embodiment of this invention. It is a figure which shows the dynamic model in the 2nd Embodiment of this invention. It is a block diagram of the control system in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the lateral acceleration calculation process in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the vehicle body tilt control process of the vehicle in the 2nd Embodiment of this invention. It is a figure which shows the back surface of the vehicle in the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the vehicle body tilt control system in the 4th Embodiment of this invention. It is a figure which shows the dynamic model in the 4th Embodiment of this invention. It is a flowchart which shows the operation | movement of the lateral acceleration calculation process in the 4th Embodiment of this invention. It is a right view which shows the structure of the vehicle in the 5th Embodiment of this invention. It is a block diagram which shows the structure of the vehicle body tilt control system in the 5th Embodiment of this invention. It is a block diagram of the control system in the 5th Embodiment of this invention. It is a figure which shows the model explaining the lateral acceleration by the steering in the 5th Embodiment of this invention. It is a flowchart which shows the operation | movement of the lateral acceleration estimation process in the 5th Embodiment of this invention. It is a flowchart which shows the subroutine of the filter process in the 5th Embodiment of this invention. It is a flowchart which shows the operation | movement of the vehicle body tilt control process of the vehicle in the 5th Embodiment of this invention. It is a block diagram which shows the structure of the vehicle body tilt control system in the 6th Embodiment of this invention. It is a block diagram of the control system in the 6th Embodiment of this invention. It is a figure which shows the model explaining the vehicle body link angle | corner in the 6th Embodiment of this invention. It is a figure which shows the graph explaining the change of the time constant of the yaw rate in the 6th Embodiment of this invention. It is a flowchart which shows the operation | movement of the link angular velocity estimation process in the 6th Embodiment of this invention. It is a flowchart which shows the subroutine of the differentiation process of the steering angle in the 6th Embodiment of this invention. It is a flowchart which shows the subroutine of the primary delay process in the 6th Embodiment of this invention. It is a flowchart which shows the operation | movement of the inclination control process in the 6th Embodiment of this invention. It is a flowchart which shows the operation | movement of the link motor control process in the 6th Embodiment of this invention.

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

FIG. 1 is a diagram showing a configuration of a vehicle according to a first embodiment of the present invention, FIG. 2 is a diagram showing a configuration of a vehicle link mechanism according to the first embodiment of the present invention, and FIG. It is a block diagram which shows the structure of the vehicle body tilt control system in 1 embodiment. In FIG. 1, (a) is a right side view and (b) is a rear view.

In the figure, reference numeral 10 denotes a vehicle according to the present embodiment, which includes a main body 20 as a vehicle body drive unit, a riding unit 11 as a steering unit on which an occupant gets on and steer, and a center in the width direction in front of the vehicle body. The wheel 12F is a front wheel disposed as a steering wheel, and the left wheel 12L and the right wheel 12R are drive wheels disposed rearward as rear wheels. Further, the lean mechanism for leaning the vehicle body from side to side, that is, the lean mechanism, that is, the vehicle body tilt mechanism, the link mechanism 30 that supports the left and

right wheels

12L and 12R, and the tilt that is the actuator that operates the link mechanism 30 And a link motor 25 as an actuator device. The vehicle 10 may be a three-wheeled vehicle with two front wheels on the left and right and one wheel on the rear, or may be a four-wheeled vehicle with two wheels on the left and right. As shown in the figure, a case will be described in which the front wheel is a single wheel and the rear wheel is a left and right tricycle.

When turning, the angle of the left and

right wheels

12L and 12R with respect to the road surface 18, that is, the camber angle is changed, and the vehicle body including the riding portion 11 and the main body portion 20 is inclined toward the turning inner wheel, thereby improving turning performance and the occupant. It is possible to ensure the comfort of the car. That is, the vehicle 10 can tilt the vehicle body in the lateral direction (left and right direction). In the example shown in the figure, the left and

right wheels

12L and 12R stand upright with respect to the road surface 18, that is, the camber angle is 0 degree.

The link mechanism 30 includes a left vertical link unit 33L that supports a left wheel 12L and a left rotation driving device 51L including an electric motor that applies driving force to the wheel 12L, a right wheel 12R, and the wheel 12R. A right vertical link unit 33R that supports a right rotation drive device 51R composed of an electric motor or the like that applies a driving force to an upper side, and an upper horizontal link unit 31U that connects the upper ends of the left and right

vertical link units

33L and 33R; The lower horizontal link unit 31D that connects the lower ends of the left and right

vertical link units

33L and 33R, and the central vertical member 21 that has an upper end fixed to the main body 20 and extends vertically. The left and right

vertical link units

33L and 33R and the upper and lower

horizontal link units

31U and 31D are rotatably connected. Further, the upper and lower

horizontal link units

31U and 31D are rotatably connected to the central vertical member 21 at the center thereof. When the left and

right wheels

12L and 12R, the left and right

rotational drive devices

51L and 51R, the left and right

vertical link units

33L and 33R, and the upper and lower

horizontal link units

31U and 31D are described in an integrated manner, The rotation drive device 51, the vertical link unit 33, and the horizontal link unit 31 will be described.

The rotary drive device 51 as a drive actuator device is a so-called in-wheel motor, and a body as a stator is fixed to the vertical link unit 33 and is a rotor attached to the body so as to be rotatable. A rotating shaft is connected to the shaft of the wheel 12, and the wheel 12 is rotated by the rotation of the rotating shaft. The rotational drive device 51 may be a motor other than an in-wheel motor.

The link motor 25 is a rotary electric actuator including an electric motor or the like, and includes a cylindrical body as a stator and a rotating shaft as a rotor rotatably attached to the body. The body is fixed to the main body portion 20 via the mounting flange 22, and the rotating shaft is fixed to the lateral link unit 31 </ b> U on the upper side of the link mechanism 30. The rotation axis of the link motor 25 functions as an inclination axis for inclining the main body 20 and is coaxial with the rotation axis of the connecting portion between the central vertical member 21 and the upper horizontal link unit 31U. When the link motor 25 is driven to rotate the rotation shaft with respect to the body, the upper horizontal link unit 31U rotates with respect to the main body 20 and the central vertical member 21 fixed to the main body 20, The link mechanism 30 operates, that is, bends and stretches. Thereby, the main-body part 20 can be inclined. Note that the rotation axis of the link motor 25 may be fixed to the main body 20 and the central vertical member 21, and the body may be fixed to the upper horizontal link unit 31U.

The link motor 25 includes a lock mechanism (not shown) that fixes the rotation shaft to the body so as not to rotate. The lock mechanism is a mechanical mechanism, and preferably does not consume electric power while the rotation shaft is fixed to the body so as not to rotate. The lock mechanism can fix the rotation shaft so as not to rotate at a predetermined angle with respect to the body.

The boarding part 11 is connected to the front end of the main body part 20 via a connecting part (not shown). The connecting part may have a function of connecting the riding part 11 and the main body part 20 so as to be relatively displaceable in a predetermined direction.

The boarding unit 11 includes a seat 11a, a footrest 11b, and a windbreak unit 11c. The seat 11 a is a part for a passenger to sit while the vehicle 10 is traveling. The footrest 11b is a part for supporting the occupant's foot, and is disposed on the front side (right side in FIG. 1A) and below the seat 11a.

Furthermore, a battery device (not shown) is arranged behind or below the boarding unit 11 or in the main body unit 20. The battery device is an energy supply source for the rotation drive device 51 and the link motor 25. In addition, a control device, an inverter device, various sensors, and the like (not shown) are accommodated in the rear portion or the lower portion of the riding portion 11 or the main body portion 20.

And, a steering device 41 is disposed in front of the seat 11a. The steering device 41 is provided with members necessary for steering such as a handle bar 41a as a steering device, a meter such as a speed meter, an indicator, and a switch. The occupant operates the handle bar 41a and other members to instruct the traveling state of the vehicle 10 (for example, traveling direction, traveling speed, turning direction, turning radius, etc.). As a steering device that is a means for detecting the required turning amount of the vehicle body requested by the occupant, other devices such as a steering wheel, a jog dial, a touch panel, and a push button are used instead of the handle bar 41a. It can also be used as

The wheel 12F is connected to the riding section 11 via a front wheel fork 17 which is a part of a suspension device (suspension device). The suspension device is a device similar to a suspension device for front wheels used in, for example, general motorcycles, bicycles, and the like, and the front wheel fork 17 is, for example, a telescopic type fork with a built-in spring. As in the case of a general motorcycle, bicycle, etc., the wheel 12F as the steered wheel changes the steering angle in accordance with the operation of the handlebar 41a by the occupant, thereby changing the traveling direction of the vehicle 10.

Specifically, the handle bar 41a is connected to the upper end of a steering shaft member (not shown), and the upper end of the front wheel fork 17 is connected to the lower end of the steering shaft member. The steering shaft member is rotatably attached to a frame member (not shown) included in the riding section 11 in a state where the steering shaft member is inclined obliquely so that the upper end is located behind the lower end.

In the present embodiment, the vehicle 10 has a lateral acceleration sensor 44. The lateral acceleration sensor 44 is a sensor composed of a general acceleration sensor, a gyro sensor, or the like. The lateral acceleration of the vehicle 10, that is, the lateral direction as the width direction of the vehicle body (the lateral direction in FIG. 1B). Detect acceleration.

Since the vehicle 10 is stabilized by tilting the vehicle body toward the inside of the turn when turning, the vehicle 10 is controlled so that the centrifugal force to the outside of the turn and the gravity are balanced with each other by tilting the vehicle body. By performing such control, for example, even if the road surface 18 is inclined in a direction perpendicular to the traveling direction (left and right direction with respect to the traveling direction), the vehicle body can always be kept horizontal. As a result, the vehicle body and the occupant are apparently always subjected to the gravity downward in the vertical direction, the uncomfortable feeling is reduced, and the stability of the vehicle 10 is improved.

Therefore, in this embodiment, in order to detect the lateral acceleration of the leaning vehicle body, the lateral acceleration sensor 44 is attached to the vehicle body, and feedback control is performed so that the output of the lateral acceleration sensor 44 becomes zero. As a result, the vehicle body can be tilted to an inclination angle at which the centrifugal force acting during turning and gravity are balanced. Further, even when the road surface 18 is inclined in a direction perpendicular to the traveling direction, the vehicle body can be controlled to have an inclination angle that makes the vehicle body vertical.

In the example shown in FIG. 1, the lateral acceleration sensor 44 is disposed on the back surface of the riding section 11. The lateral acceleration sensor 44 is disposed so as to be located at the center in the width direction of the vehicle body, that is, on the longitudinal axis of the vehicle body.

Also, the vehicle 10 in the present embodiment has a vehicle body tilt control system as a part of the control device. The vehicle body tilt control system is a kind of computer system, and includes a tilt control ECU (Electronic Control Unit) 46 that functions as a tilt control device, as shown in FIG. The inclination control ECU 46 includes arithmetic means such as a processor, storage means such as a magnetic disk and semiconductor memory, an input / output interface, and the like, and is connected to the lateral acceleration sensor 44 and the link motor 25. The tilt control ECU 46 includes a tilt control unit 47 that outputs a torque command value for operating the link motor 25 based on the lateral acceleration detected by the lateral acceleration sensor 44.

The tilt control unit 47 performs feedback control during cornering, so that the vehicle body tilt angle is such that the lateral acceleration value detected by the lateral acceleration sensor 44 is zero. 25 is activated. That is, the tilt angle of the vehicle body is controlled so that the centrifugal force to the outside of the turn and gravity are balanced and the lateral acceleration component becomes zero. That is, the vehicle body inclination angle is controlled with the lateral acceleration component value of zero as the target value. As a result, a force in a direction parallel to the longitudinal axis of the vehicle body acts on the vehicle body and the occupant on the riding section 11. Therefore, the stability of the vehicle body can be maintained and the turning performance can be improved. In addition, the rider does not feel discomfort and the ride comfort is improved.

Next, the operation of the vehicle 10 having the above configuration will be described. Here, only the operation of the vehicle body tilt control process during turning is described.

FIG. 4 is a diagram for explaining the tilting operation of the vehicle body during turning in the first embodiment of the present invention, and FIG. 5 is a flowchart showing the operation of the vehicle body tilt control process of the vehicle in the first embodiment of the present invention. It is.

When the turning traveling is started, the vehicle body tilt control system starts the vehicle body tilt control process. By performing the posture control, the vehicle 10 turns with the link mechanism 30 in a state where the vehicle body is tilted inward (right side in the drawing) as shown in FIG. Further, during turning, a centrifugal force to the outside of the turning acts on the vehicle body, and a lateral component of gravity is generated by tilting the vehicle body to the inside of the turn. Then, the lateral acceleration sensor 44 detects the resultant force of the centrifugal force and the lateral component of gravity as lateral acceleration, and outputs the detected value a to the tilt control unit 47 as the lateral acceleration sensor value. Then, the inclination control unit 47 performs feedback control and outputs a control value such that the detected value a becomes zero to the link motor 25.

The vehicle body tilt control process is a process that is repeatedly executed by the vehicle body tilt control system at a predetermined control cycle T _S (for example, 5 [ms]) while the vehicle 10 is turned on. This is a process for improving turning performance and ensuring passenger comfort.

The inclination control unit 47 first acquires the lateral acceleration sensor value a (step S1).

Subsequently, the inclination control unit 47 makes an _old call (step S2). a _old is a lateral acceleration sensor value a stored when the vehicle body tilt control process is executed last time. In the initial setting, a _old = 0.

Then, tilt control unit 47 obtains the control period T _S (step S3), and calculates a differential value of a (step S4). Here, when the differential value of a is da / dt, the da / dt is calculated by the following equation (1).
da / dt = (aa _old ) / T _S (1)
And the inclination control part 47 preserve _| saves as _aold = a (step S5). That is, the lateral acceleration sensor value a acquired at the time of execution of the current vehicle body tilt control process is stored as a _old in the storage unit.

Then, tilt control unit 47 calculates the first control value U _P (Step S6). Here, if the control gain of the proportional control operation, that is, the proportional gain is C _P , the first control value _UP is calculated by the following equation (2).
U _{_P} = C _P a ··· formula (2)
Then, tilt control unit 47 calculates the second control value U _D (step S7). Here, the control gain of the differential control operation, i.e., when the derivative time and C _D, the second control value U _D is calculated by the following equation (3).
U _D = C _D da / dt (3)
Subsequently, the inclination control unit 47 calculates a third control value U (step S8). Third control value U is the sum of the first control value U _P and the second control value U _D, is calculated by the following equation (4).
U = U _P + U _D ··· formula (4)
Finally, the inclination control unit 47 outputs the third control value U as the link motor torque command value to the link motor 25 (step S9), and ends the process.

Thus, in the present embodiment, the vehicle body inclination angle is controlled so that the value of the lateral acceleration detected by the lateral acceleration sensor 44 becomes zero during turning. That is, the vehicle body inclination angle is controlled with the lateral acceleration component value of zero as the target value. As a result, the tilt angle of the vehicle body can be controlled so that the centrifugal force to the outside of the turn and the gravity are balanced, and the lateral acceleration component becomes zero. A force in a direction parallel to the axis acts.

Therefore, the stability of the vehicle body can be maintained and the turning performance can be improved. In addition, the rider does not feel discomfort and the ride comfort is improved. Thereby, the stable driving | running | working state can be implement | achieved and the vehicle 10 with high safety | security can be provided.

Next, a second embodiment of the present invention will be described. In addition, about what has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. The description of the same operation and the same effect as those of the first embodiment is also omitted.

FIG. 6 is a diagram for explaining the influence of the detection value of the lateral acceleration sensor in the second embodiment of the present invention, FIG. 7 is a diagram showing the rear surface of the vehicle in the second embodiment of the present invention, and FIG. It is a block diagram which shows the structure of the vehicle body tilt control system in the 2nd Embodiment of this invention. 6, (a) to (c) are diagrams showing a state in which one wheel falls, and (d) is a diagram for explaining the influence of rattling or the like of each part of the vehicle. In FIG. ) Is a diagram showing a state where the vehicle body is standing upright, and (b) is a diagram showing a state where the vehicle body is inclined.

In the first embodiment, the case where the lateral acceleration is detected by the single lateral acceleration sensor 44 has been described. However, if there is one lateral acceleration sensor 44, an unnecessary acceleration component may be detected.

For example, as shown in FIGS. 6 (a) to 6 (c), only one of the left and

right wheels

12L and 12R may fall into the recess of the road surface 18 while the vehicle 10 is traveling. obtain. In this case, since the vehicle body is inclined, the lateral acceleration sensor 44 is displaced in the circumferential direction and detects the acceleration in the circumferential direction, as indicated by an arrow in FIG. That is, an acceleration component that is not directly derived from centrifugal force or gravity, that is, an unnecessary acceleration component is detected.

Further, for example, the vehicle 10 includes a portion that functions as a spring and has elasticity like the tire portions of the left and

right wheels

12L and 12R, and includes inevitable backlash at the connecting portions of each member. Therefore, as schematically shown in FIG. 6 (d), the lateral acceleration sensor 44 is considered to be attached to the vehicle body through inevitable play and springs, so that acceleration caused by displacement of the play and springs is considered. Are also detected as unnecessary acceleration components.

Such an unnecessary acceleration component may deteriorate the controllability of the vehicle body tilt control system. For example, if the control gain of the vehicle body tilt control system is increased, control system vibration, divergence, and the like due to unnecessary acceleration components occur, so that it is not possible to increase the control gain even if responsiveness is to be improved. .

Therefore, in the present embodiment, there are a plurality of lateral acceleration sensors 44, which are arranged at different heights. In the example shown in FIG. 7, there are two lateral acceleration sensors 44, a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b, and the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are mutually connected. Arranged at different height positions. By appropriately selecting the positions of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b, unnecessary acceleration components can be effectively removed.

Specifically, as shown in FIG. 7 (a), the first lateral acceleration sensor 44a is in the back of the riding section 11, the distance from the road surface 18, i.e., is disposed at the position of L ₁ Height ing. The second lateral acceleration sensor 44b is the upper surface of the rear or body portion 20 of the riding portion 11, the distance from the road surface 18, i.e., is disposed at a position of L ₂ height. Note that L ₁ > L ₂ . Then, when turning, as shown in FIG. 7B, when the vehicle body turns with the vehicle body tilted inward (right side in the figure), the first lateral acceleration sensor 44a detects lateral acceleration. The detection value a ₁ is output, and the second lateral acceleration sensor 44b detects the lateral acceleration and outputs the detection value a ₂ . Although the center of the tilting motion when the vehicle body tilts, that is, the roll center, is strictly located slightly below the road surface 18, it is considered that the center is substantially equal to the road surface 18 in practice.

It is desirable that both the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are attached to a sufficiently rigid member. Further, if the difference between L ₁ and L ₂ is small, the difference between the detection values a ₁ and a ₂ is small. Therefore, it is desirable that the difference be sufficiently large, for example, 0.3 [m] or more. Further, when the vehicle body is supported by a spring such as a suspension, it is desirable that both the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are arranged on a so-called “spring top”. Furthermore, the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are both disposed between the axle of the wheel 12F as the front wheel and the axle of the left and

right wheels

12L and 12R as the rear wheels. desirable. Further, it is desirable that both the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are disposed as close to the occupant as possible. Further, both the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are preferably located on the central axis of the vehicle body extending in the traveling direction when viewed from above, that is, not offset with respect to the traveling direction. .

Further, the vehicle body tilt control system in the present embodiment is as shown in FIG. The tilt control ECU 46 includes a lateral acceleration calculation unit 48 that calculates a combined lateral acceleration based on the lateral acceleration detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b. Then, the tilt control unit 47 outputs a torque command value for operating the link motor 25 based on the combined lateral acceleration calculated as the lateral acceleration calculated by the lateral acceleration calculating unit 48.

The configuration of other points is the same as that of the first embodiment, and the description thereof is omitted.

Next, the operation of the vehicle 10 in the present embodiment will be described. Here, only the operation of the vehicle body tilt control process during turning is described.

FIG. 9 is a diagram showing a dynamic model in the second embodiment of the present invention, FIG. 10 is a block diagram of a control system in the second embodiment of the present invention, and FIG. 11 is a second embodiment of the present invention. FIG. 12 is a flowchart showing the operation of the vehicle body tilt control process of the vehicle according to the second embodiment of the present invention.

In FIG. 9, 44A is a first sensor position indicating the position where the first lateral acceleration sensor 44a is disposed on the vehicle body, and 44B is a second sensor indicating the position where the second lateral acceleration sensor 44b is disposed on the vehicle body. Position.

The acceleration detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b and outputting the detected value is <1> centrifugal force acting on the vehicle body when turning, and <2> tilting the vehicle body toward the inside of the turn. The lateral component of the generated gravity, <3> the first lateral acceleration sensor 44a and the like due to the inclination of the vehicle body, the displacement of the backlash and the spring, etc., when only one of the left and

right wheels

12L and 12R falls into the depression of the road surface The acceleration generated by the displacement of the second lateral acceleration sensor 44b in the circumferential direction, and the <4> operation of the link motor 25 or the reaction thereof causes the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b to be displaced in the circumferential direction. It is considered that there are four accelerations caused by this. Of these four acceleration, the <1> and <2>, the height of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b, that is, independent of L ₁ and L _2. On the other hand, since <3> and <4> are accelerations generated by displacement in the circumferential direction, they are proportional to the distance from the roll center, that is, roughly proportional to L ₁ and L ₂ .

Here, the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44a and the second lateral acceleration sensor 44b detect and output the detected value. The acceleration <3> is defined as a _X1 and a _X2, and the first lateral acceleration sensor 44a and the second lateral acceleration. The acceleration of <4>, which is detected by the sensor 44b and outputs the detected value, is a _M1 and a _M2 . Further, the acceleration of <1> to the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b outputs the detected value detected by the a _T, a first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b is detected Then, the acceleration of <2> that outputs the detected value is defined as a _G. Since <1> and <2> are not related to the height of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b, the detection values of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are equal.

Then, only one of the left and

right wheels

12L and 12R are inclined in the vehicle body due to the fall in a recess of a road surface 18, the angular velocity omega _R the circumferential direction of displacement by the displacement or the like of Gataya spring, the angular acceleration omega _{Let R} '. Further, the angular velocity of the circumferential displacement due to the operation of the link motor 25 or its reaction is ω _M , and the angular acceleration is ω _M ′.

Then, a _X1 = L ₁ ω _R ′, a _X2 = L ₂ ω _R ′, a _M1 = L ₁ ω _M ′, a _M2 = L ₂ ω _M ′.

If the detected acceleration values detected and output by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are a ₁ and a ₂ , a ₁ and a ₂ are four accelerations <1> to <4. > Is represented by the following formulas (5) and (6).
_{_{_{a 1 = a T + a G}}} + L 1 ω R '+ L 1 ω M' ··· (5)
_{_{_{a 2 = a T + a G}}} + L 2 ω R '+ L 2 ω M' ··· (6)
Then, by subtracting equation (6) from equation (5), the following equation (7) can be obtained.
a ₁ −a ₂ = (L ₁ −L ₂ ) ω _R ′ + (L ₁ −L ₂ ) ω _M ′ (7)
Here, the values of L ₁ and L ₂ are known because they are the heights of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b. The value of ω _M ′ is known because it is a differential value of the angular velocity ω _M of the link motor 25. Then, on the right side of the equation (7), only the value of ω _R ′ of the first term is unknown, and all other values are known. Therefore, the value of ω _R ′ can be obtained from the detected values a ₁ and a _{2 of} the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b. That is, unnecessary acceleration components can be removed based on the detection values a ₁ and a ₂ of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b.

In the vehicle body tilt control process in the present embodiment, feedback control as shown in FIG. 10 is performed. In FIG. 10, f ₁ is a transfer function represented by the equation (10) described later. Also, G _P is a control gain of the proportional control operation, G _D is the control gain of the differential control operation, s is a differential element.

When the vehicle body tilt control system starts the vehicle body tilt control process, the lateral acceleration calculation unit 48 starts the lateral acceleration calculation process, and first acquires the first lateral acceleration sensor value a ₁ (step S11) and the second lateral acceleration calculation process. An acceleration sensor value a ₂ is acquired (step S12). Then, the lateral acceleration calculation unit 48 calculates the acceleration difference Δa (step S13). The Δa is expressed by the following equation (8).
Δa = a ₁ −a ₂ (8)
Then, the lateral acceleration calculation unit 48 performs ΔL call (step S14), and performs the L ₂ call (step S15). The ΔL is expressed by the following equation (9).
ΔL = L ₁ −L ₂ Formula (9)
Subsequently, the lateral acceleration calculation unit 48 calculates a combined lateral acceleration a (step S16). The combined lateral acceleration a is a value corresponding to the lateral acceleration sensor value a when there is one lateral acceleration sensor 44 as in the first embodiment, and is the first lateral acceleration sensor value a. ₁ and a value obtained by synthesizing the second lateral acceleration sensor value a _2, and are obtained by the following equations (10) and (11).
a = a ₂ − (L ₂ / ΔL) Δa (10)
a = a ₁ − (L ₁ / ΔL) Δa (11)
Theoretically, the same value can be obtained by both the equation (10) and the equation (11), but the acceleration caused by the displacement in the circumferential direction is proportional to the distance from the roll center. It is desirable to use a ₂ which is a detection value of the lateral acceleration sensor 44 closer to the second lateral acceleration sensor 44b as a reference. Therefore, in the present embodiment, the combined lateral acceleration a is calculated by equation (10).

Finally, the lateral acceleration calculation unit 48 sends the combined lateral acceleration a to the tilt control unit 47 (step S17), and ends the lateral acceleration calculation process.

The tilt control unit 47 starts the vehicle body tilt control process, and first receives the combined lateral acceleration a from the lateral acceleration calculation unit 48 (step S21).

Subsequently, the inclination control unit 47 makes an _old call (step S22). a _old is the combined lateral acceleration a stored when the vehicle body tilt control process is executed last time. In the initial setting, a _old = 0.

Since the subsequent operations, that is, the operations in steps S23 to S29 shown in FIG. 12, are the same as the operations in steps S3 to S9 described in the first embodiment, the description thereof is omitted.

Thus, in this embodiment, a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b is placed in different height positions, a first lateral acceleration sensor value a ₁ and the second lateral acceleration sensor A combined lateral acceleration a obtained by combining the value a ₂ is calculated, and the tilt angle of the vehicle body is controlled so that the value of the combined lateral acceleration a becomes zero. That is, the tilt angle of the vehicle body is controlled with a value of zero of the combined lateral acceleration a as a target value.

As a result, unnecessary acceleration components can be removed, so that it is not affected by road surface conditions, the occurrence of vibrations and divergence of the control system can be prevented, and the control gain of the vehicle body tilt control system is increased. Control responsiveness can be improved.

In the present embodiment, the case where there are two lateral acceleration sensors 44 has been described. However, if there are a plurality of lateral acceleration sensors 44 arranged at different heights, the number of lateral acceleration sensors 44 is three or more. There may be any number.

Next, a third embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st and 2nd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operations and effects as those of the first and second embodiments is omitted.

FIG. 13 is a view showing the rear surface of the vehicle according to the third embodiment of the present invention. In the figure, (a) is a view showing a state where the vehicle body is upright, and (b) is a view showing a state where the vehicle body is inclined.

The vehicle 10 in the present embodiment does not have the link mechanism 30, and the main body 20 and the riding section 11 are connected so as to be swingable in the roll direction around the roll shaft 20 a, and an actuator device for tilting is provided. By rotating the link motor 25 as shown in FIG. 13B, the riding section 11 can be swung and rolled, that is, tilted with respect to the main body section 20, as shown in FIG. The roll shaft 20a is the center of the movement in which the riding section 11 swings and rolls with respect to the main body 20, that is, the roll center. Note that the rotation shaft of the link motor 25 extending in the traveling direction of the vehicle body may coincide with the roll shaft 20a.

Even during turning, the angle of the left and

right wheels

12L and 12R with respect to the road surface 18, that is, the camber angle does not change, and the riding part 11 is swung with respect to the main body part 20 together with the wheel 12F as the front wheel to the turning inner wheel side By tilting, it is possible to improve the turning performance and ensure the comfort of the passenger. In the example shown in the figure, the left and

right wheels

12L and 12R stand upright with respect to the road surface 18 when the vehicle is traveling straight or turning, that is, the camber angle is 0 degree.

Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

As in the second embodiment, the lateral acceleration sensor 44 includes a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b, and the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b Are arranged at different height positions.

In the present embodiment, the center of the tilting motion when the riding section 11 tilts, that is, the roll center coincides with the roll shaft 20a. Therefore, the heights L ₁ and L ₂ of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are set as distances from the roll shaft 20a.

It is desirable that both the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are disposed on the upper side or the lower side of the roll shaft 20a. Further, it is desirable that one of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b be disposed as close to the roll shaft 20a as possible.

Other aspects of the lateral acceleration sensor 44 are the same as those of the second embodiment, and a description thereof will be omitted. The vehicle body tilt control system is also the same as that in the second embodiment, and a description thereof will be omitted. Furthermore, since the operation of the vehicle 10 in the present embodiment is the same as that in the second embodiment, the description thereof is omitted.

Next, a fourth embodiment of the present invention will be described. Note that components having the same structure as those of the first to third embodiments are denoted by the same reference numerals and description thereof is omitted. The description of the same operations and effects as those of the first to third embodiments is also omitted.

FIG. 14 is a block diagram showing a configuration of a vehicle body tilt control system according to the fourth embodiment of the present invention.

In the second and third embodiments, the case where the lateral acceleration is detected by the two lateral acceleration sensors 44, that is, the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b has been described. However, a sensor other than the acceleration sensor may be used as long as it can detect lateral acceleration. A sensor capable of detecting lateral acceleration is not only a sensor that directly detects acceleration, such as an acceleration sensor, but also a sensor that can obtain acceleration by differentiating a detected value, such as a speed sensor. That is, it includes a sensor that indirectly detects acceleration.

In the present embodiment, an example in which a roll rate sensor 44c as a sensor for indirectly detecting acceleration is used instead of the second lateral acceleration sensor 44b will be described. The roll rate sensor 44c is a general roll rate sensor that detects the angular velocity of the tilting motion of the vehicle body. For example, the roll rate sensor 44c can detect a rotational angular velocity in a plane perpendicular to the ground. It is attached as possible.

The vehicle body tilt control system in the present embodiment is as shown in FIG. A first lateral acceleration sensor 44 a and a roll rate sensor 44 c are connected to the tilt control ECU 46. Then, the lateral acceleration calculation unit 48 calculates a combined lateral acceleration based on the differential value of the angular velocity of the tilt motion of the vehicle body detected by the roll rate sensor 44c and the lateral acceleration detected by the first lateral acceleration sensor 44a. Then, the tilt control unit 47 outputs a torque command value for operating the link motor 25 based on the combined lateral acceleration calculated as the lateral acceleration calculated by the lateral acceleration calculating unit 48.

Since the configuration of other points is the same as that of the second and third embodiments, the description thereof is omitted.

FIG. 15 is a diagram showing a dynamic model in the fourth embodiment of the present invention, and FIG. 16 is a flowchart showing an operation of lateral acceleration calculation processing in the fourth embodiment of the present invention.

In FIG. 15, 44A is a first sensor position indicating the position where the first lateral acceleration sensor 44a is disposed on the vehicle body, and 44C is a second sensor position indicating the position where the roll rate sensor 44c is disposed on the vehicle body. is there. Further, ω ₁ is the value of the angular velocity of the tilt motion of the vehicle body detected by the roll rate sensor 44c, that is, the roll rate sensor value.

The roll rate sensor 44c can be attached at an arbitrary height position. In the example shown in the figure, it is attached at a position lower than the first lateral acceleration sensor 44a, but it may be attached at the same height as the first lateral acceleration sensor 44a, or the first lateral acceleration sensor. It may be attached at a position higher than 44a.

However, it is desirable that the roll rate sensor 44c be attached to a sufficiently rigid member, like the first lateral acceleration sensor 44a. Further, when the vehicle body is supported by a spring such as a suspension, it is desirable that the roll rate sensor 44c be disposed on a so-called “spring top” similarly to the first lateral acceleration sensor 44a. Further, like the first lateral acceleration sensor 44a, the roll rate sensor 44c is preferably disposed between the axle of the wheel 12F that is the front wheel and the axles of the left and

right wheels

12L and 12R that are the rear wheels. Furthermore, it is desirable that the roll rate sensor 44c be disposed as close to the occupant as possible, similarly to the first lateral acceleration sensor 44a. Regarding other points, the roll rate sensor 44c may be attached at any position as long as it can detect the tilting movement of the vehicle body, that is, the roll.

Since the first lateral acceleration sensor 44a and the roll rate sensor 44c are different from each other, the response characteristics of both must be theoretically or experimentally matched in advance. For example, when the time constant of either equivalent model is small (fast), adjustment is made with a filter or the like so that the time constant is equivalent to the output with the larger time constant.

In the present embodiment, when the vehicle body tilt control system starts the vehicle body tilt control process, the lateral acceleration calculation unit 48 starts the lateral acceleration calculation process, and first, the first lateral acceleration sensor value a ₁ as the lateral acceleration sensor value. Is acquired (step S31), and the roll rate sensor value ω ₁ is acquired (step S32).

Subsequently, the lateral acceleration calculation unit 48 makes a ω _old call (step S33). ω _old is a roll rate sensor value ω ₁ stored when the vehicle body tilt control process is executed last time. In the initial setting, ω _old = 0.

Subsequently, the lateral acceleration calculation unit 48 acquires the control cycle T _S (step S34), and calculates the differential value of ω ₁ (step S35). Here, when the differential value of ω ₁ is Δω ₁ , Δω ₁ is calculated by the following equation (12).
Δω ₁ = (ω ₁ −ω _old ) / T _S Formula (12)
Then, the lateral acceleration calculation section 48 performs L ₁ call (step S36).

Then, the lateral acceleration calculation unit 48 calculates the combined lateral acceleration a (step S37). Note that the combined lateral acceleration a is a value corresponding to the lateral acceleration sensor value a when there is one lateral acceleration sensor 44 as in the first embodiment, and is the first lateral acceleration sensor value. a ₁ and a synthesized value of the differential value [Delta] [omega ₁ of the roll rate sensor value omega _1, obtained by the following equation (13).
a = a ₁ −L ₁ Δω ₁ Formula (13)
Finally, the lateral acceleration calculation unit 48 sends the combined lateral acceleration a to the tilt control unit 47 (step S38), and ends the lateral acceleration calculation process.

Note that the operation of the vehicle body tilt control process by the tilt control unit 47 is the same as that of the second embodiment, and thus the description thereof is omitted.

As described above, in the present embodiment, the roll rate sensor 44c is employed as one of the plurality of sensors capable of detecting the acceleration in the lateral direction, and therefore the mounting position of the roll rate sensor 44c in the height direction. This increases the degree of freedom of design of the vehicle 10.

In the present embodiment, only the example in which the roll rate sensor 44c is used instead of the second lateral acceleration sensor 44b in the second and third embodiments has been described. However, the first lateral acceleration sensor 44a Instead, a roll rate sensor 44c can be used. Moreover, the vehicle 10 may have the link mechanism 30 like the vehicle 10 in the second embodiment, or may have the link mechanism 30 like the vehicle 10 in the third embodiment. It may not be.

Next, a fifth embodiment of the present invention will be described. Note that components having the same structure as those of the first to fourth embodiments are denoted by the same reference numerals and description thereof is omitted. Explanation of the same operations and effects as those in the first to fourth embodiments is also omitted.

FIG. 17 is a right side view showing the configuration of the vehicle in the fifth embodiment of the present invention, and FIG. 18 is a block diagram showing the configuration of the vehicle body tilt control system in the fifth embodiment of the present invention.

Wherein, as described in the second embodiment, a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b is placed in different height positions, a first lateral acceleration sensor value a ₁ and the second lateral The combined lateral acceleration a obtained by combining the acceleration sensor value a ₂ is calculated, and the control gain of the vehicle body tilt control system is increased by controlling the vehicle body tilt angle so that the value of the combined lateral acceleration a becomes zero. Thus, control responsiveness can be improved.

However, if the control gain is too large, the vehicle body tilt control system may react excessively to disturbances and cause discomfort to the passengers. On the other hand, if the control gain is small, a control delay may occur when the lateral acceleration changes greatly as at the start or end of turning, and an appropriate tilt angle may not be realized.

Therefore, in the present embodiment, the lateral acceleration prediction value is calculated from the required turning amount and the vehicle speed, and feedforward control using the calculated lateral acceleration prediction value is added to improve the responsiveness of the vehicle body tilt control system. It is like that. Further, by applying a low-pass filter to the acquired required turning amount, specifically, by applying a low-pass filter that changes the cut-off frequency according to the vehicle speed, it is possible to ensure stability during high-speed traveling.

As shown in FIG. 17, the vehicle 10 in the present embodiment has a steering angle sensor 53 as a requested turning amount detection unit that detects a requested turning amount, and a vehicle speed detection that detects a vehicle speed that is the traveling speed of the vehicle 10. A vehicle speed sensor 54 is provided as means. The distance between the left and

right wheels

12L and 12R axle is the axle and the rear wheel of the wheel 12F is a front wheel, i.e., the wheel base is L _H.

The steering angle sensor 53 is a sensor that detects a rotation angle of a steering shaft member (not shown) that connects the handle bar 41a and the upper end of the front wheel fork 17 with respect to a frame member included in the riding section 11, that is, a change in the steering angle. For example, an encoder. The steering angle sensor 53 can detect the steering amount of the handle bar 41a, that is, the steering amount of the steering device as the required turning amount.

The vehicle speed sensor 54 is a sensor that is disposed at the lower end of the front wheel fork 17 that supports the axle of the wheel 12F and detects the vehicle speed based on the rotational speed of the wheel 12F, and includes, for example, an encoder.

Furthermore, the vehicle body tilt control system in the present embodiment is as shown in FIG. The tilt control ECU 46 includes a lateral acceleration estimation unit 49 that calculates a predicted lateral acceleration value acting on the vehicle body based on the steering angle detected by the steering angle sensor 53 and the vehicle speed detected by the vehicle speed sensor 54. Then, the tilt control unit 47 outputs a torque command value for operating the link motor 25 based on the combined lateral acceleration calculated by the lateral acceleration calculation unit 48 and the predicted lateral acceleration calculated by the lateral acceleration estimation unit 49. To do.

The configuration of other points is the same as that of the second embodiment, and the description thereof is omitted.

FIG. 19 is a block diagram of a control system in the fifth embodiment of the present invention, FIG. 20 is a diagram showing a model for explaining lateral acceleration by steering in the fifth embodiment of the present invention, and FIG. 21 is a diagram of the present invention. Flowchart showing the operation of lateral acceleration estimation processing in the fifth embodiment, FIG. 22 is a flowchart showing a subroutine of filter processing in the fifth embodiment of the present invention, and FIG. 23 is the fifth embodiment of the present invention. 5 is a flowchart showing an operation of a vehicle body tilt control process in FIG.

In the vehicle body tilt control process in the present embodiment, control combining feedback control and feedforward control as shown in FIG. 19 is performed. In FIG. 19, the portion below the dotted line is the same as the feedback control shown in FIG. 10 described in the second embodiment, and a description thereof will be omitted.

And the part above a dotted line has shown feedforward control. Here, f ₂ is a transfer function represented by the equation (20) described later. G _yd is a control gain of the differential control operation, and s is a differential element.

When the vehicle body tilt control system starts the vehicle body tilt control process, the lateral acceleration calculation unit 48 executes the lateral acceleration calculation process. The operation of the lateral acceleration calculation process in the present embodiment is the same as the operation of the lateral acceleration calculation process described in the second embodiment, that is, the operations in steps S11 to S17 shown in FIG. The description is omitted.

Also, the lateral acceleration estimation unit 49 starts the lateral acceleration estimation process. The lateral acceleration estimation unit 49 first acquires the steering angle sensor value θ that is the value of the steering angle detected by the steering angle sensor 53 (step S41), and the vehicle speed sensor value that is the vehicle speed value detected by the vehicle speed sensor 54. ν is acquired (step S42).

Then, the lateral acceleration estimation unit 49 performs a filtering process on θ (step S43) and calculates Ψ (t). Ψ (t) is the steering angle filtered by the cut-off frequency variable low-pass filter according to speed.

Here, as shown in FIG. 20, assuming that the steering angle is Ψ and the turning radius is r, the centrifugal speed a ₀ as the lateral acceleration acting on the vehicle body at the time of the vehicle speed ν and the turning is expressed by the following equation (14 ) And (15).
ν = rw Formula (14)
a ₀ = rw ² Formula (15)
In addition, w is a turning angular velocity.

From the formulas (14) and (15), the centrifugal force a ₀ acting on the vehicle body during turning is expressed by the following formula (16).
a ₀ = ν ² / r (16)
Further, from FIG. 20, the turning radius r is expressed by the following equation (17).
r = L _H / tan Ψ Equation (17)
Then, the following equation (18) is derived from the equations (16) and (17).
a ₀ = (ν ² / L _H ) tan Ψ (Equation 18)
In the filter process, the lateral acceleration estimation unit 49 first acquires a control cycle T _S (step S43-1). Since the control cycle T _S is the same as that in the first embodiment, the description thereof is omitted.

Subsequently, the lateral acceleration estimation unit 49 calculates a cutoff frequency w (ν) (step S43-2). w (ν) is a cutoff frequency for each speed, and is a function in which the input is the vehicle speed ν and the output is the cutoff frequency. For example, the function is inversely proportional to the vehicle speed, but any function may be used. It should be noted that a table showing the relationship between the input vehicle speed ν and the output cutoff frequency is created in advance, and the cutoff frequency w (ν) is obtained without performing calculations by referring to the table. You can also.

Subsequently, the lateral acceleration estimation unit 49 makes a Ψ _old call (step S43-3). Ψ _old is the value of Ψ (t) stored when the previous vehicle body tilt control process is executed. In the initial setting, Ψ _old = 0.

Subsequently, the lateral acceleration estimation unit 49 calculates the filtered steering angle Ψ (t) (step S43-4). Ψ (t) is calculated by the following equation (19).
Ψ (t) = Ψ _old / (1 + T _s w (ν))
_{+ T S w (ν) θ} / (1 + T S w (ν)) ··· (19)
The equation (19) is an equation of an IIR (Infinite Impulse Response) filter that is generally used as a bandpass filter, and represents a cutoff frequency variable low-pass filter that is a first-order lag low-pass filter.

Then, the lateral acceleration estimation unit 49 stores Ψ _old = Ψ (t) (step S43-5) and ends the filter process. That is, the value of Ψ (t) calculated when the vehicle body tilt control process is executed is stored in the storage unit as Ψ _old .

Then, the lateral acceleration estimation unit 49, L _H call was carried out (step S44), and calculates a lateral acceleration estimated value a _f (step S45). The lateral acceleration predicted value a _f is calculated by the following equation (20) based on the equation (18).
a _f = ν ² tan {Ψ (t)} / L _H Formula (20)
The equation (20) represents the lateral acceleration generated by steering the handlebar 41a, that is, the centrifugal force generated by turning.

Finally, the lateral acceleration estimation unit 49 sends the predicted lateral acceleration value a _f to the tilt control unit 47 (step S46), and ends the lateral acceleration estimation process.

Further, the tilt control unit 47 starts the vehicle body tilt control process, and first receives the combined lateral acceleration a from the lateral acceleration calculation unit 48 (step S51). Note that the operations from the reception of the combined lateral acceleration a to the calculation of the third control value U, that is, the operations in steps S51 to S58 shown in FIG. 23, are the steps described in the second embodiment. Since this is the same as the operation of S21 to S28, its description is omitted.

When the third control value U is calculated, the tilt control unit 47 receives the lateral acceleration predicted value a _f from the lateral acceleration estimation unit 49 (step S59).

Subsequently, the inclination control unit 47 performs a _fold call (step S60). a _fold is a predicted lateral acceleration value a _f stored when the vehicle body tilt control process is executed last time. In the initial setting, a _fold = 0.

Subsequently, the inclination control unit 47 calculates a differential value of a _f (step S61). Here, when the differential value of a _f is da _f / dt, the da _f / dt is calculated by the following equation (21).
da _f / dt = (a _f −a _fold ) / T _S (21)
And the inclination control part 47 preserve _| saves as _afold = _af (step S62). That is, the lateral acceleration predicted value a _f acquired at the time of executing the vehicle body tilt control process this time is stored in the storage unit as a _fold .

Subsequently, the inclination control unit 47 calculates a fourth control value U _fD (step S63). Here, if the control gain of the differential control operation is C _fD , the fourth control value U _fD is calculated by the following equation (22).
U _fD = C _fD da _f / dt (22)
Subsequently, the inclination control unit 47 calculates a fifth control value U (step S64). The fifth control value U is the sum of the third control value U and the fourth control value U _fD and is calculated by the following equation (23).
U = U + U _fD Expression (23)
Finally, the inclination control unit 47 outputs the fifth control value U to the link motor 25 as the link motor torque command value (step S65), and ends the process.

Thus, in this embodiment, a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b is placed in different height positions, a first lateral acceleration sensor value a ₁ and the second lateral acceleration sensor A combined lateral acceleration a obtained by combining the value a ₂ is calculated, feedback control is performed so that the value of the combined lateral acceleration a becomes zero, and a predicted lateral acceleration value a _f is calculated from the required turning amount and the vehicle speed, the calculated lateral acceleration estimated value a _f performs feedforward control using.

This makes it possible to appropriately control the inclination angle of the vehicle body during turning to an angle that balances the lateral acceleration and gravity. Even if the road surface 18 is inclined in the lateral direction, the vehicle body can be kept vertical. Further, there is no delay in control even when the lateral acceleration changes greatly, such as at the start and end of turning. For this reason, the stability of the vehicle 10 can be kept high, a passenger's discomfort can be reduced, and comfort can be improved.

Also, by applying a low-pass filter that changes the cut-off frequency according to the vehicle speed to the acquired required turning amount, it is possible to ensure stability during high-speed driving.

In the present embodiment, by using the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b, synthesized and resultant lateral first lateral acceleration sensor value a ₁ and a second lateral acceleration sensor value a ₂ Although only the example of calculating the acceleration a has been described, as described in the fourth embodiment, a roll rate sensor 44c is used instead of either the first lateral acceleration sensor 44a or the second lateral acceleration sensor 44b. The combined lateral acceleration a may be calculated by combining the first lateral acceleration sensor value a ₁ or the second lateral acceleration sensor value a ₂ and the differential value Δω _{1 of the} roll rate sensor value ω ₁ .

Next, a sixth embodiment of the present invention will be described. Note that components having the same structure as those of the first to fifth embodiments are denoted by the same reference numerals and description thereof is omitted. Explanation of the same operations and effects as those of the first to fifth embodiments is also omitted.

FIG. 24 is a block diagram showing a configuration of a vehicle body tilt control system according to the sixth embodiment of the present invention.

As described in the fifth embodiment, a combined lateral acceleration a obtained by combining the first lateral acceleration sensor value a ₁ and the second lateral acceleration sensor value a ₂ is calculated, and the value of the combined lateral acceleration a is calculated. performs feedback control such that the zero, by calculating the lateral acceleration estimated value a _f from the required turning amount and the vehicle speed, performs the feedforward control using the calculated lateral acceleration estimated value a _f, the road surface 18 is horizontal Even if it is tilted in the direction, the vehicle body can be kept vertical, and there is no delay in control even when the change in lateral acceleration is large, such as at the start and end of turning. .

However, when the steering amount of the handlebar 41a is detected by the steering angle sensor 53, the zero point of the steering amount detected by the steering angle sensor 53 is adjusted so that the handlebar 41a is in a neutral state, that is, the vehicle 10 is in a straight traveling state. It is necessary to match. Therefore, initial setting of the steering angle sensor 53 needs to be performed.

Therefore, in the present embodiment, by performing feedforward control using the steering angular velocity, it is not necessary to detect the zero point. Therefore, an inexpensive steering angle sensor 53 can be used, and the steering angle sensor 53 can be used. Therefore, the manufacturing and maintenance costs of the vehicle 10 can be reduced. In addition, by making the gain characteristic and delay characteristic of the lateral acceleration predicted value a _f variable according to the vehicle speed, it is possible to improve control followability during high-speed traveling.

In the vehicle body tilt control system according to the present embodiment, as shown in the figure, the tilt control ECU 46 includes a link angular velocity estimation unit 50 instead of the lateral acceleration estimation unit 49, and also includes a lateral acceleration calculation unit 48 and a tilt control unit 47. In addition, a disturbance calculation unit 43 and a link motor control unit 42 are provided.

The link angular velocity estimation unit 50 calculates a link angular velocity prediction value based on the steering angle detected by the steering angle sensor 53 and the vehicle speed detected by the vehicle speed sensor 54. Further, the disturbance calculation unit 43 rolls the disturbance based on the value of the angular velocity of the vehicle body tilting motion detected by the roll rate sensor 44c, that is, the roll rate sensor value and the link angle detected by the link angle sensor 25a. Calculate the rate.

The link angle sensor 25a is a rotation angle sensor that detects the rotation angle of the rotation shaft with respect to the body in the link motor 25, and includes, for example, a resolver, an encoder, and the like. As described above, when the link motor 25 is driven to rotate the rotation shaft with respect to the body, the upper horizontal link unit 31U rotates with respect to the main body 20 and the central vertical member 21 fixed to the main body 20. Therefore, a change in the angle of the upper horizontal link unit 31U relative to the central vertical member 21, that is, a change in the link angle can be detected by detecting the rotation angle of the rotation shaft with respect to the body.

In the present embodiment, the tilt control unit 47 rolls the combined lateral acceleration calculated by the lateral acceleration calculation unit 48, the predicted link angular velocity calculated by the link angular velocity estimation unit 50, and the disturbance amount calculated by the disturbance calculation unit 43. Based on the rate, a speed command value as a control value is calculated and output. Further, the link motor control unit 42 outputs a torque command value as a control value for operating the link motor 25 based on the speed command value output from the inclination control unit 47.

The configuration of other points is the same as that of the fifth embodiment, and a description thereof will be omitted.

FIG. 25 is a block diagram of a control system in the sixth embodiment of the present invention, FIG. 26 is a diagram showing a model for explaining the vehicle body link angle in the sixth embodiment of the present invention, and FIG. FIG. 28 is a graph illustrating a change in yaw rate time constant in the sixth embodiment, FIG. 28 is a flowchart illustrating an operation of link angular velocity estimation processing in the sixth embodiment of the present invention, and FIG. FIG. 30 is a flowchart showing a first-order lag processing subroutine in the sixth embodiment of the present invention, and FIG. 31 is a flowchart showing a subroutine of the steering angle differentiation process in the sixth embodiment. The flowchart which shows the operation | movement of the inclination control process in a form, FIG. 32 is the flowchart which shows the operation | movement of the link motor control process in the 6th Embodiment of this invention. That.

In the vehicle body tilt control process in the present embodiment, control combining feedback control and feedforward control as shown in FIG. 25 is performed. In FIG. 25, f ₁ is a transfer function represented by the above equation (10), G _P and G _RP are control gains of the proportional control operation, and s is a differential element. Further, f ₂ is a link angular velocity prediction value expressed by an equation (25) described later, f ₃ is a yaw rate gain expressed by an equation (33) described later, and f ₄ is a delay time constant of the yaw rate. It is.

Also, the link angular velocity estimation unit 50 starts link angular velocity estimation processing. The link angular velocity estimation unit 50 first acquires the steering angle sensor value θ that is the value of the steering angle detected by the steering angle sensor 53 (step S71), and the vehicle speed sensor value that is the vehicle speed value detected by the vehicle speed sensor 54. ν is acquired (step S72).

Then, the link angular velocity estimation unit 50 performs a steering angle differentiation process (step S73), and calculates ΔΨ. ΔΨ is a value obtained by differentiating the steering angle with respect to time, and corresponds to the steering angular velocity.

In the steering angle differentiation process, the link angular velocity estimation unit 50 first makes a Ψ _old call (step S73-1). Since Ψ _old is the same as that of the fifth embodiment, the description thereof is omitted.

Subsequently, the link angular velocity estimation unit 50 acquires a control cycle T _S (step S73-2). Since the control cycle T _S is the same as that in the first embodiment, the description thereof is omitted.

Subsequently, the link angular velocity estimation unit 50 calculates the steering angle differential value ΔΨ (step S73-3). ΔΨ is calculated by the following equation (24).
ΔΨ = (Ψ (t) −Ψ _old ) / T _S (24)
Then, the link angular velocity estimation unit 50 stores Ψ _old = Ψ (t) (step S73-4), and ends the steering angle differentiation process.

Subsequently, the link angular velocity estimating section 50, L _H call was carried out (step S74), the link angular velocity estimated value f ₂ ([Delta] [Psi], [nu) is calculated (step S75). Here, assuming that gravity is g, the link angular velocity predicted value f ₂ (ΔΨ, ν) is calculated by the following equation (25).
f ₂ (ΔΨ, ν) = dη / dt = (ν ² / (L _H g)) (dΨ / dt) Expression (25)
As described above, the link angle sensor 25a detects a change in the angle of the upper horizontal link unit 31U with respect to the central vertical member 21, that is, a change in the link angle. Here, assuming that the link angle is η and the inclination angle of the vehicle body at the time of turning is controlled so that the centrifugal force a ₀ as the lateral acceleration and the gravity g are balanced, if the road surface 18 is horizontal, The centrifugal force a ₀ and the gravity g are as shown in FIG. 26, and the relationship represented by the following equation (26) is established.
a ₀ cos η = gsin η Formula (26)
From the equation (26), the following equation (27) is derived.
a ₀ / g = sin η / cos η = tan η (27)
Further, the following equation (28) is derived from the equation (27).
a ₀ = g tan η Equation (28)
On the other hand, the following equation (29) is derived from FIG. 20 and equation (17) described in the fifth embodiment.
tan Ψ = L _H / r (29)
The following equation (30) is derived from the equation (29) and the equations (15), (16), and (18) described in the fifth embodiment.
a ₀ = rw ² = ν ² / r = (ν ² / L _H ) tan Ψ Equation (30)
Then, the following equation (31) is derived from the equations (28) and (30).
g tan η = (ν ² / L _H ) tan Ψ Equation (31)
Furthermore, it can be approximated as tan η≈η and tan Ψ≈Ψ, and the change in the vehicle speed ν is sufficiently slow compared to the change in the link angle η, so that the vehicle speed ν can be regarded as a constant. From the equation (31), the equation (25) can be obtained.

Subsequently, the link angular velocity estimation unit 50 calculates the yaw rate gain f ₃ (ν) (step S76).

Normally, during high speed traveling, it becomes difficult to turn even if the steering amount of the handle bar 41a is the same. That is, when the vehicle speed ν increases, even if the steering angle Ψ is the same, the influence on the centrifugal force a ₀ as the lateral acceleration is reduced. Therefore, in the present embodiment, the ratio between the calculated yaw rate calculated based on the steering angle Ψ and the actual yaw rate measured by the experiment is calculated as the yaw rate gain f ₃ (ν).

The theoretical value of the yaw rate, that is, the turning angular velocity w is calculated from the equation (30) by the following equation (32).
w = (ν / L _H ) tan Ψ Equation (32)
The inventor of the present invention conducted an experiment using a prototype vehicle 10, that is, a prototype vehicle, and measured the yaw rate. In the prototype vehicle, since the value of the wheel base L _H is constant, in the experiment, the measured value w (ν, Ψ) of the yaw rate was measured by changing the vehicle speed ν and the steering angle Ψ. Here, if the theoretical value of the yaw rate calculated by the equation (32) is w _nom (ν, Ψ), the yaw rate gain f ₃ (ν) is calculated by the following equation (33).
f ₃ (ν) = G _yr (ν) = w (ν, Ψ) / w _nom (ν, Ψ) Expression (33)
Actually, the value of the yaw rate gain f ₃ (ν) is calculated in real time based on an approximate expression of the first order or higher determined offline. Further, since the value of the yaw rate gain f ₃ (ν) is determined regardless of the steering angle Ψ, a table showing the relationship between the vehicle speed ν and the yaw rate gain f ₃ (ν) is created in advance and the table is referred to. The yaw rate gain f ₃ (ν) can also be obtained without performing the calculation. Since the yaw rate gain f ₃ (ν) is a value determined by the vehicle speed ν, the yaw rate gain f ₃ (ν) can be directly applied to the link angular velocity predicted value f ₂ (ΔΨ, ν).

Subsequently, the link angular velocity estimation unit 50 calculates a link angular velocity correction predicted value ΔH (step S77). As described above, by directly applying the yaw rate gain f ₃ (ν) to the link angular velocity predicted value f ₂ (ΔΨ, ν), the link angular velocity corrected predicted value ΔH is calculated by the following equation (34).
ΔH = f ₂ (ΔΨ, ν) f ₃ (ν) (34)
Subsequently, the link angular velocity estimation unit 50 calculates a delay time constant f ₄ (ν) (step S78).

Normally, even when the steering amount of the handle bar 41a is the same when traveling at a high speed, the delay time until the centrifugal force a ₀ as the lateral acceleration is generated becomes long. Therefore, in the present embodiment, the calculated yaw rate calculated based on the steering angle Ψ and the actual yaw rate measured by the experiment are compared on the time axis, and the delay is defined by the vehicle speed ν. To calculate the delay time constant f ₄ (ν).

For example, as shown in FIG. 27, the relationship between the value of the delay time constant calculated from the calculated yaw rate and the measured actual yaw rate and the vehicle speed ν is plotted as a point ◆, and the point ◆ The delay time constant f ₄ (ν) can be obtained by linearly approximating the relationship between the value of the represented time constant and the vehicle speed ν.

Actually, the value of the delay time constant f ₄ (ν) is calculated in real time on the basis of an approximate expression of the first order or higher determined offline. In addition, by creating a table determined based on the vehicle speed ν in advance and referring to the table, the delay time constant f ₄ (ν) can be acquired without performing the calculation.

Then, the link angular velocity estimation unit 50 performs first-order lag processing on the link angular velocity correction predicted value ΔH (step S79), and calculates ΔH _out .

In the first-order lag process, the link angular velocity estimation unit 50 first acquires the control cycle T _S (step S79-1). Since the control cycle T _S is the same as that in the first embodiment, the description thereof is omitted.

Subsequently, the link angular velocity estimation unit 50 calculates a cutoff frequency w (ν) (step S79-2). w (ν) is calculated by the following equation (35).
w (ν) = 1 / f ₄ (ν) Expression (35)
Subsequently, the link angular velocity estimation unit 50 performs a ΔH _outold call (step S79-3). Note that ΔH _outold is the value of ΔH _out (t) saved when the previous vehicle body tilt control process was executed.

Subsequently, the link angular velocity estimation unit 50 calculates the filtered ΔH _out (t) (step S79-4). ΔH _out (t) is calculated by the following equation (36).
ΔH _out (t) = ΔH _outold / (1 + T _S w (ν))
_{+ (Dη / dt) T S} w (ν) / (1 + T S w (ν)) ··· formula (36)
Then, the link angular velocity estimation unit 50 stores it as ΔH _outold = ΔH _out (t) (step S79-5), and ends the first-order delay processing. That is, the value of ΔH _out (t) calculated at the time of execution of the vehicle body tilt control process is stored as ΔH _outold in the storage unit.

Finally, the link angular velocity estimation unit 50 sends ΔH _out (t) to the inclination control unit 47 (step S80), and ends the link angular velocity estimation process.

Further, the tilt control unit 47 starts the vehicle body tilt control process, and first receives the combined lateral acceleration a from the lateral acceleration calculation unit 48 (step S81). Note that the operations from the reception of the combined lateral acceleration a to the calculation of the third control value U, that is, the operations in steps S81 to S88 shown in FIG. 31, are the steps described in the second embodiment. Since this is the same as the operation of S21 to S28, its description is omitted.

When the third control value U is calculated, the inclination control unit 47 receives ΔH _out (t) from the link angular velocity estimation unit 50 (step S89).

Subsequently, the inclination control unit 47 calculates a fourth control value U _fD (step S90). Here, if the control gain of the differential control operation is G _yD , the fourth control value U _fD is calculated by the following equation (37).
U _fD = G _yD ΔH _out Formula (37)
Note that the control gain G _yD of the differential control operation is an arbitrary value that is positive 1 or less.

Subsequently, the inclination control unit 47 calculates a fifth control value U (step S91). The fifth control value U is the sum of the third control value U and the fourth control value U _fD and is calculated by the following equation (38).
U = U + U _fD Expression (38)
Finally, the inclination control unit 47 outputs the fifth control value U as a speed command value to the link motor control unit 42 (step S92), and ends the process.

Further, when the link motor control unit 42 starts the link motor control process, first, the link motor control unit 42 receives the fifth control value U from the inclination control unit 47 (step S101).

Subsequently, the link motor control unit 42 acquires the link angle sensor value η detected by the link angle sensor 25a (step S102), executes link angular velocity calculation processing (step S103), and sets the link angle of the link mechanism 30. Calculate the angular velocity Δη.

Further, the link motor control unit 42 can obtain the value of Δη from the disturbance calculation unit 43, thereby omitting the operations of steps S102 and S103.

Subsequently, the link motor control unit 42 calculates a control error (step S104). Here, when the control error is ε, ε is calculated by the following equation (39).
ε = U−Δη Formula (39)
U is the fifth control value U received from the inclination control unit 47.

Subsequently, the link motor control unit 42 obtains the motor control proportional gain G _MP (step S105). The value of the motor control proportional gain _{GMP is} a value set based on experiments or the like, and is stored in advance in the storage means.

Subsequently, the link motor control unit 42 calculates a torque command value for operating the link motor 25 (step S106). Here, when the torque command value is U _T , the U _T is calculated by the following equation (40).
U _T = G _MP ε (40)
Finally, the link motor control unit 42 outputs the torque command value _UT to the link motor 25 (step S107) and ends the process.

Thus, in the present embodiment, feedforward control is performed using the steering angle differential value ΔΨ corresponding to the time differential value of the required turning amount. This eliminates the need to detect the zero point, so that an inexpensive steering angle sensor 53 can be used, and the initial setting of the steering angle sensor 53 is not necessary, thereby reducing the manufacturing and maintenance costs of the vehicle 10. Can be reduced.

Further, the gain characteristic and delay characteristic of the lateral acceleration predicted value a _f are made variable in accordance with the vehicle speed ν. Thereby, the followability of the control at the time of high speed traveling can be improved.

Furthermore, in the present embodiment, as means for solving the problems of the prior art, it is possible to show what includes the case where the lateral acceleration sensor 44 is single as follows.

A vehicle body including a steering unit and a drive unit coupled to each other, a wheel rotatably attached to the steering unit, a steering wheel for steering the vehicle body, and a wheel rotatably attached to the drive unit A driving wheel that drives the vehicle body, a tilting actuator device that tilts the steering unit or the driving unit in a turning direction, a lateral acceleration sensor that detects a lateral acceleration acting on the vehicle body, and the occupant's request A required turning amount detecting means for detecting a required turning amount of the vehicle body, a vehicle speed detecting means for detecting a vehicle speed, and a control device for controlling the inclination of the vehicle body by controlling the tilting actuator device; Performs feedback control based on the lateral acceleration detected by the lateral acceleration sensor, and detects the required turning amount detected by the required turning amount detection means and the vehicle speed detection means. Vehicle for controlling the tilting of the vehicle body by performing the feedforward control based on that vehicle speed.

The present invention is not limited to the above-described embodiment, and various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

The present invention can be used for a vehicle having at least a pair of left and right wheels.

DESCRIPTION OF SYMBOLS 10 Vehicle 11

Boarding part

12F, 12L, 12R Wheel 20 Main-body part 25 Link motor 44 Lateral acceleration sensor 44a 1st lateral acceleration sensor 44b 2nd lateral acceleration sensor 44c Roll rate sensor 53 Steering angle sensor 54 Vehicle speed sensor

Claims

A vehicle body including a steering unit and a drive unit coupled to each other;
A wheel rotatably attached to the steering unit, the steering wheel for steering the vehicle body;
A wheel rotatably attached to the drive unit, the drive wheel driving the vehicle body;
A tilting actuator device for tilting the steering unit or the driving unit in a turning direction;
A plurality of sensors for directly or indirectly detecting lateral acceleration acting on the vehicle body;
Requested turning amount detecting means for detecting a requested turning amount of the vehicle body requested by an occupant;
Vehicle speed detection means for detecting the vehicle speed;
A control device for controlling the tilt of the vehicle body by controlling the tilt actuator device;
The control device performs feedback control based on lateral acceleration detected by the plurality of sensors, and performs feedforward control based on a requested turning amount detected by the requested turning amount detection means and a vehicle speed detected by the vehicle speed detection means. A vehicle that controls the inclination of the vehicle body.
The vehicle according to claim 1, wherein the control device calculates a predicted lateral acceleration value from a time differential value of the required turning amount and a vehicle speed, and performs feedforward control using the calculated predicted lateral acceleration value.
The vehicle according to claim 2, wherein the control device performs feedforward control using values obtained by changing the gain characteristic and delay characteristic of the lateral acceleration predicted value according to a vehicle speed.
The vehicle according to any one of claims 1 to 3, wherein the control device controls the inclination of the vehicle body such that a combined lateral acceleration obtained by combining the lateral accelerations detected by the plurality of sensors becomes zero.
The vehicle according to any one of claims 1 to 4, wherein the plurality of sensors are lateral acceleration sensors arranged at different heights.
The vehicle according to any one of claims 1 to 4, wherein one of the plurality of sensors is a roll rate sensor that detects an angular velocity of a tilting motion of a vehicle body.
The vehicle according to claim 1, wherein the control device calculates a predicted lateral acceleration value from the required turning amount and a vehicle speed, and performs feedforward control using the calculated predicted lateral acceleration value.
The vehicle according to claim 7, wherein the control device applies a low-pass filter that changes a cutoff frequency according to a vehicle speed to the required turning amount.