JP2012030745A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle capable of improving turning performance, and achieving a stable travelling state even when receiving a disturbance in an inclination direction.SOLUTION: The vehicle comprises: a vehicle body including a steering part and a driving part which are connected with each other; a steering wheel which is a wheel rotatably attached to the steering part and steers the vehicle body; a driving wheel which is a wheel rotatably attached to the driving part and drives the vehicle body; an actuator device for inclination which inclines the steering part or the driving part in the turning direction; a lateral acceleration sensor for detecting a lateral acceleration which acts on the vehicle body; and a controller which controls the actuator device for inclination and controls the inclination of the vehicle body. When receiving the disturbance in the inclination direction of the vehicle body, the controller extracts a changed portion due to the disturbance out of the changes of the inclination angles of the vehicle body and controls the inclination of the vehicle body while adding a control value corresponding to the changed portion due to the extracted disturbance.

Description

  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 depletion 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 running state, 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. However, when a large lateral disturbance is caused by a road step, a cross wind, etc. The vehicle body tilt control cannot be performed properly, the vehicle becomes unstable, and the occupant may feel uncomfortable or uneasy.

  The present invention solves the above-mentioned problems of conventional vehicles and, when subjected to a disturbance in the tilt direction, extracts a change due to the disturbance out of a change in the tilt angle of the vehicle body, and responds to the change due to the disturbance. By controlling the tilt angle of the vehicle body by adding a control value, it is possible to improve the turning performance and to realize a stable driving state even when subjected to disturbance in the tilt direction. The purpose is to provide a high vehicle.

  Therefore, in the vehicle according to the present invention, a vehicle body including a steering unit and a drive unit coupled to each other, and a wheel rotatably attached to the steering unit, the steering wheel steering the vehicle body, A wheel rotatably attached to the driving unit, the driving wheel driving the vehicle body, a tilting actuator device for tilting the steering unit or the driving unit in a turning direction, and a lateral acceleration acting on the vehicle body And a control device for controlling the tilt of the vehicle body by controlling the tilt actuator device, and the control device receives a disturbance in the tilt direction of the vehicle body. Of the change in the inclination angle, a change due to disturbance is extracted, and a control value corresponding to the extracted change due to disturbance is added to control the inclination of the vehicle body.

  According to the configuration of claim 1, the tilt angle of the vehicle body can be appropriately controlled even when subjected to a disturbance in the tilt direction, and the rider does not feel uneasy, and the ride is comfortable and stable. A running state can be realized.

  According to the configuration of claim 2, when the disturbance is small or when there is no disturbance, it is possible to appropriately prevent a decrease in control stability due to an excessive control gain, and when a large or abrupt disturbance is received. The tilt angle of the vehicle body can be appropriately controlled while suppressing the influence of disturbance.

  According to the configuration of the third aspect, the inclination angle of the vehicle body can be controlled so that the centrifugal force and the gravity are balanced, and even when the change in the lateral acceleration is large, the control can be performed. There is no delay.

  According to the configuration of claims 4 and 5, the influence on the inclination control due to the elastic deformation of the member can be removed, and even when subjected to a large disturbance in the inclination direction, resonance does not occur. The inclination angle of the vehicle body can be appropriately controlled, and the stability of the vehicle body can be maintained.

It is a right view 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 rear view which shows the structure 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 which shows the dynamic model 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 lateral acceleration calculation process in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the lateral acceleration estimation process in the 1st Embodiment of this invention. It is a flowchart which shows the subroutine of the filter process in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the disturbance calculation process in the 1st Embodiment of this invention. It is a flowchart which shows the subroutine of the link angular velocity calculation process in the 1st Embodiment of this invention. It is a figure which shows the example of the gain in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the inclination control process in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the link motor control process in the 1st Embodiment of this invention. It is a block diagram which shows the modification of a structure of the vehicle body tilt control system in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the inclination control process in the 2nd Embodiment of this invention. It is a flowchart which shows the subroutine of the winddown control process in the 2nd Embodiment of this invention. It is a flowchart which shows the subroutine of the disturbance acceleration calculation process in the 2nd Embodiment of this invention.

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

  FIG. 1 is a right side view showing the configuration of the vehicle in the first embodiment of the present invention, FIG. 2 is a diagram showing the configuration of the link mechanism of the vehicle in the first embodiment of the present invention, and FIG. It is a rear view which shows the structure of the vehicle in the 1st Embodiment. 3A is a diagram showing a state where the vehicle body is standing upright, and FIG. 3B is a diagram showing a state where the vehicle body is inclined.

  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. Furthermore, the vehicle 10 operates as a lean mechanism for leaning the vehicle body from side to side, that is, as a lean mechanism, that is, a vehicle body tilt mechanism, supporting the left and right wheels 12L and 12R, and the link mechanism 30. And a link motor 25 as a tilt 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 FIGS. 2 and 3 (a), the left and right wheels 12L and 12R are upright with respect to the road surface 18, that is, the camber angle is 0 degree. In the example shown in FIG. 3B, the left and right wheels 12L and 12R are inclined in the right direction with respect to the road surface 18, that is, a camber angle is given.

  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 link angle sensor 25 a that detects a change in the link angle of the link mechanism 30. 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.

  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 riding 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 part 11 includes a seat 11a, a footrest 11b, and a windbreak part 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. 1) and below the seat 11a.

  Further, a battery device (not shown) is disposed behind or below the riding section 11 or on the main body section 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.

  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 outputting 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 as the steering device. It can also be used as

  Further, the steering device 41 includes a steering angle sensor 53 as a requested turning amount detection means for detecting a requested turning amount. 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 wheel 12F is connected to the riding section 11 via a front wheel fork 17 that 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. 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.

  Further, a vehicle speed sensor 54 as vehicle speed detecting means for detecting a vehicle speed that is the traveling speed of the vehicle 10 is disposed at the lower end of the front wheel fork 17 that supports the axle of the wheel 12F. The vehicle speed sensor 54 is a sensor that detects the vehicle speed based on the rotational speed of the wheel 12F, and includes, for example, an encoder.

  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, and detects the lateral acceleration of the vehicle 10, that is, the acceleration in the lateral direction (horizontal direction in FIG. 3) as the width direction of the vehicle body. To do.

  Since the vehicle 10 is stabilized by inclining the vehicle body toward the inside of the turn at the time of turning, the vehicle 10 is controlled so that the centrifugal force to the outside of the turn at the time of turning and the gravity are balanced by turning 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 gravity downward in the vertical direction, the sense of incongruity is reduced, and the stability of the vehicle 10 is improved.

  Therefore, in the present 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. The lateral acceleration sensor 44 is disposed so as to be positioned at the center in the width direction of the vehicle body, that is, on the longitudinal axis of the vehicle body.

  However, if there is one lateral acceleration sensor 44, an unnecessary acceleration component may be detected. For example, while the vehicle 10 is traveling, only one of the left and right wheels 12L and 12R may fall into the depression on the road surface 18. In this case, since the vehicle body is tilted, the lateral acceleration sensor 44 is displaced in the circumferential direction and detects the acceleration in the circumferential direction. That is, an acceleration component that is not directly derived from centrifugal force or gravity, that is, an unnecessary acceleration component is detected.

  In addition, the vehicle 10 includes, for example, a portion that has elasticity and functions as a spring like the tire portions of the wheels 12L and 12R, and unavoidable backlash is included in the connection portion of each member. For this reason, the lateral acceleration sensor 44 is considered to be attached to the vehicle body through inevitable play and springs, and therefore acceleration generated by the displacement of the play and springs is also detected as an unnecessary acceleration component.

  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, a plurality of lateral acceleration sensors 44 are provided at different heights. In the example shown in FIGS. 1 and 3, there are two lateral acceleration sensors 44, a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b, which are a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b. Are 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. 3 (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 . When turning, when the vehicle is turned with the vehicle body tilted inward (right side in the drawing) as shown in FIG. 3B, the first lateral acceleration sensor 44a detects the 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. Furthermore, it is desirable that both the first lateral acceleration sensor 44 a and the second lateral acceleration sensor 44 b are disposed above the link mechanism 30. 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, it is desirable that the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are both disposed between the axle of the front wheel 12F and the axle of the rear wheels 12L and 12R. Furthermore, 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. Furthermore, it is desirable that both the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are located on the vehicle center axis extending in the traveling direction when viewed from above, that is, not offset with respect to the traveling direction.

  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 device including an ECU (Electronic Control Unit) or the like. The tilt control device 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 includes a link angle sensor 25a, a lateral acceleration sensor 44, a steering angle sensor 53, a vehicle speed sensor 54, and a link motor. 25. Then, the tilt control device outputs a torque command value for operating the link motor 25.

  The tilt control device performs feedback control and feedforward control during turning, so that the tilt angle of the vehicle body is such that the value of the lateral acceleration detected by the lateral acceleration sensor 44 becomes zero. Then, the link motor 25 is operated. 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. 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.

  Also, when a disturbance in the tilt direction is received, a part due to the disturbance in the change in the tilt angle of the vehicle body is extracted, and for the remaining part, the tilt angle of the vehicle body is controlled in the normal mode, and the extracted part In contrast, the vehicle body tilt angle is controlled in the disturbance response mode. Therefore, the stability of the vehicle body can be maintained even when subjected to disturbance. In addition, the rider does not feel discomfort and the ride comfort is improved.

  Next, the configuration of the vehicle body tilt control system will be described.

  FIG. 4 is a block diagram showing the configuration of the vehicle body tilt control system according to the first embodiment of the present invention.

  In the figure, 46 is an inclination control ECU as an inclination control device, and is connected to a link angle sensor 25a, a first lateral acceleration sensor 44a, a second lateral acceleration sensor 44b, a steering angle sensor 53, a vehicle speed sensor 54, and a link motor 25. ing. The tilt control ECU 46 includes a lateral acceleration calculation unit 48, a lateral acceleration estimation unit 49, a disturbance calculation unit 43, a tilt control unit 47, and a link motor control unit 42.

  Here, the lateral acceleration calculation unit 48 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. The lateral acceleration estimation unit 49 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. Further, the disturbance calculation unit 43 calculates a roll rate for the disturbance based on the lateral acceleration detected by the first lateral acceleration sensor 44a and the link angle detected by the link angle sensor 25a.

  The tilt controller 47 is based on the combined lateral acceleration calculated by the lateral acceleration calculator 48, the predicted lateral acceleration calculated by the lateral acceleration estimator 49, and the roll rate of disturbance calculated by the disturbance calculator 43. The speed command value as the 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.

  Next, the operation of the vehicle 10 configured as described above will be described. First, the operation of the lateral acceleration calculation process, which is a part of the operation of the vehicle body tilt control process in turning, will be described.

  FIG. 5 is a diagram showing a dynamic model for explaining the tilting operation of the vehicle body when turning in the first embodiment of the present invention, and FIG. 6 shows the operation of the lateral acceleration calculation processing in the first embodiment of the present invention. It is a flowchart to show.

  When turning is started, the vehicle body tilt control system starts the vehicle body tilt control process. By performing 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 calculation unit 48 executes a lateral acceleration calculation process, calculates a combined lateral acceleration a, and outputs it to the tilt control unit 47. Then, the inclination control unit 47 performs feedback control, and outputs a speed command value as a control value such that the value of the combined lateral acceleration a becomes zero. Then, the link motor control unit 42 outputs a torque command value to the link motor 25 based on the speed command value output from the inclination control unit 47.

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.

  In FIG. 5, 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 first position indicating the position where the second lateral acceleration sensor 44b is disposed on the vehicle body. Two sensor positions.

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 backlash or the displacement of the spring, etc., when only one of the left and right wheels 12L and 12R falls into the depression of the road surface 18; 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 irrelevant to the heights of the first and second lateral acceleration sensors 44a and 44b, the detection values of the first and second lateral acceleration sensors 44a and 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 ′. The angular velocity ω _M or the angular acceleration ω _M ′ can be obtained from the detection value of the link angle sensor 25a.

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 ′.

Further, when the detection value of the acceleration by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b is detecting and outputting the a ₁ and a _2, a ₁ and a _2, four acceleration <1> to <4 It is represented by the following formulas (1) and (2).
_{a 1 = a T + a G} + L 1 ω R '+ L 1 ω M' ··· formula (1)
_{a 2 = a T + a G} + L 2 ω R '+ L 2 ω M' ··· formula (2)
Then, by subtracting equation (2) from equation (1), the following equation (3) can be obtained.
a ₁ −a ₂ = (L ₁ −L ₂ ) ω _R ′ + (L ₁ −L ₂ ) ω _M ′ Equation (3)
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 (3), 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 detection 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.

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 S1) and the second lateral acceleration calculation process. An acceleration sensor value a ₂ is acquired (step S2). Then, the lateral acceleration calculation unit 48 calculates the acceleration difference Δa (step S3). The Δa is expressed by the following equation (4).
Δa = a ₁ −a ₂ Formula (4)
Then, the lateral acceleration calculation unit 48 performs ΔL call (step S4), and performs the L ₂ call (step S5). The ΔL is expressed by the following equation (5).
ΔL = L ₁ −L ₂ Formula (5)
Subsequently, the lateral acceleration calculation unit 48 calculates a combined lateral acceleration a (step S6). Incidentally, the synthetic lateral acceleration a lateral acceleration sensor 44 is a value corresponding to the lateral acceleration sensor value a when the one, first lateral acceleration sensor value a ₁ and the second lateral acceleration sensor value a ₂ Is obtained by the following equations (6) and (7).
a = a ₂ − (L ₂ / ΔL) Δa (6)
a = a ₁ − (L ₁ / ΔL) Δa (7)
Theoretically, the same value can be obtained by both equation (6) and equation (7), but since the acceleration caused by the circumferential displacement is proportional to the distance from the roll center, in practice, 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 Expression (6).

  Finally, the lateral acceleration calculation unit 48 sends the combined lateral acceleration a to the tilt control unit 47 (step S7), and ends the lateral acceleration calculation 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, and feedback control is performed so that the value of the combined lateral acceleration a becomes zero to control the tilt angle of the vehicle body.

  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, the operation of the lateral acceleration estimation process for estimating the lateral acceleration in cornering will be described.

  FIG. 7 is a flowchart showing the operation of lateral acceleration estimation processing in the first embodiment of the present invention, and FIG. 8 is a flowchart showing a subroutine of filter processing in the first embodiment of the present invention.

  When the vehicle body tilt control system starts the vehicle body tilt control process, 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 S11), and the vehicle speed sensor value that is the value of the vehicle speed detected by the vehicle speed sensor 54. ν is acquired (step S12).

  And the lateral acceleration estimation part 49 performs a filter process with respect to (theta) (step S13), and calculates (PSI) (t). Ψ (t) is the steering angle filtered by the cut-off frequency variable low-pass filter according to speed.

In the filter process, the lateral acceleration estimation unit 49 first acquires a control cycle T _S (step S13-1).

  Subsequently, the lateral acceleration estimation unit 49 calculates a cutoff frequency w (ν) (step S13-2). The 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 S13-3). 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 S13-4). The Ψ (t) is calculated by the following equation (8).
_{Ψ (t) = Ψ old /} (1 + T S w (ν)) + T S w (ν) θ / (1 + T S w (ν))
... Formula (8)
The equation (8) 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.

And the lateral acceleration estimation part 49 preserve | saves as (PSI) _old = (PSI) (t) (step S13-5), and complete | finishes a 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 S14), and calculates a lateral acceleration estimated value a _f (step S15). The lateral acceleration predicted value a _f is calculated by the following equation (9).
a _f = ν ² tan {Ψ (t)} / L _H Formula (9)
Equation (9) 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 S16), and ends the lateral acceleration estimation process.

As described above, in the present embodiment, feedback control is performed so that the value of the combined lateral acceleration a becomes zero, the predicted lateral acceleration value a _f is calculated from the required turning amount and the vehicle speed, and the calculated lateral acceleration prediction is calculated. Feed-forward control using the value a _f is performed.

  Thereby, the inclination angle of the vehicle body at the time of turning can be appropriately controlled to an angle that balances the lateral acceleration and the 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.

  Moreover, the stability at the time of high speed driving | running can be ensured by applying the low pass filter which changes a cut-off frequency with the vehicle speed to the acquired required turning amount.

  Next, the operation of the disturbance calculation process for calculating the roll rate for the disturbance in the roll rate of the vehicle body will be described.

  FIG. 9 is a flowchart showing the operation of the disturbance calculation process in the first embodiment of the present invention, and FIG. 10 is a flowchart showing a subroutine of the link angular velocity calculation process in the first embodiment of the present invention.

When the disturbance calculation unit 43 starts the disturbance calculation process, the disturbance calculation unit 43 _first obtains the first lateral acceleration sensor value a ₁ from the first lateral acceleration sensor 44a (step S21), and obtains the combined lateral acceleration a from the lateral acceleration calculation unit 48. Obtain (step S22). The disturbance calculating unit 43 calculates the gradient acceleration a _S (step S23). The a _S is represented by the following formula (10).
a _S = a ₁ −a (10)
Then, the disturbance calculation unit 43 stores the calculated inclination acceleration a _S in the ring buffer (step S24). The ring buffer is a data holding buffer secured in the memory area of the inclination control ECU 46. Then, the inclination acceleration a _S from the present to t seconds before is stored in the ring buffer for t seconds prepared in advance.

Subsequently, the disturbance calculation unit 43 calculates a roll rate (step S25). Assuming that the roll rate of the vehicle body is ω _S , the ω _S is calculated by integrating the inclination acceleration a _S for the past t seconds. Specifically, the roll rate ω _S is calculated by the following equation (11).
ω _S = (Σa _S ) Δt / L ₁ Formula (11)
Here, the term Σ means the sum of the values of the inclination acceleration a _S stored in the ring buffer. Δt is a sampling period. The ring buffer has t / Δt storage areas.

  The equation (11) is for alleviating an error due to integration, and the integration region t, that is, the integration time t seconds changes depending on the performance of the lateral acceleration sensor 44 and the like. And determined experimentally.

  Subsequently, the disturbance calculation unit 43 executes a link angular velocity calculation process (step S26), and calculates Δη. Δη is an angular velocity of the link angle of the link mechanism 30 and is calculated by differentiating the link angle sensor value η detected by the link angle sensor 25a.

  In the link angular velocity calculation process, the disturbance calculation unit 43 first acquires the link angle sensor value η detected by the link angle sensor 25a (step S26-1).

Then, disturbance calculator 43, performs eta _old call (step S26-2), obtains the control period T _S (step S26-3). η _old is the value of η saved when the vehicle body tilt control process was executed last time. In the initial setting, η _old = 0.

Subsequently, the disturbance calculation unit 43 calculates a differential value of η, that is, Δη (step S26-4). Δη is calculated by the following equation (12).
Δη = (η−η _old ) / T _S Formula (12)
And the disturbance calculating part 43 preserve | saves as (eta) _old = (eta) (step S26-5), and complete | finishes a link angular velocity calculation process. That is, the value of η calculated at the time of executing the vehicle body tilt control process is stored in the storage unit as η _old .

Subsequently, the disturbance calculation unit 43 calculates a roll rate for the disturbance (step S27). When the roll rate of disturbance is ω _N , ω _N is calculated by the following equation (13).
ω _N = ω _S −Δη (13)
That is, the roll rate ω _N for the disturbance can be obtained by subtracting the angular velocity Δη of the link angle of the link mechanism 30 from the actual roll rate ω _S of the vehicle body.

Finally, the disturbance calculation unit 43 sends the roll rate ω _N for the disturbance to the tilt control unit 47 (step S28), and ends the disturbance calculation process.

As described above, in the present embodiment, the composite lateral acceleration a is subtracted from the detection value a ₁ of one of the lateral acceleration sensors 44 (specifically, the first lateral acceleration sensor 44a), so that The vibration component, that is, the inclination acceleration a _S can be obtained. Further, the value obtained by differentiating the link angle sensor value η detected by the link angle sensor 25a from the value obtained by integrating the inclination acceleration a _S , that is, the angular velocity Δη of the link angle is reduced, thereby causing instability of the vehicle body. The roll rate ω _N for the disturbance in the tilt direction is calculated. In other words, by reducing three of the lateral acceleration from the centrifugal force component due to turning, the gravitational component force due to tilt, and the lateral acceleration generated by the tilting operation by the link motor 25, road surface steps, crosswinds, etc. Changes in the tilt angle of the vehicle body are selectively extracted due to disturbance.

By using the roll rate ω _N of the disturbance calculated in this way and adding a value corresponding to the roll rate ω _N to the target speed of the link motor 25, a stable traveling state even when subjected to disturbance in the tilt direction Can be achieved.

  Next, operations of the tilt control process and the link motor control process will be described.

  FIG. 11 is a diagram showing an example of the gain in the first embodiment of the present invention, FIG. 12 is a flowchart showing the operation of the tilt control processing in the first embodiment of the present invention, and FIG. 13 is the first diagram of the present invention. It is a flowchart which shows the operation | movement of the link motor control process in the embodiment.

  When the tilt control unit 47 starts the tilt control process, the tilt control unit 47 first receives the combined lateral acceleration a from the lateral acceleration calculation unit 48 (step S31).

Subsequently, the inclination control unit 47 makes an _old call (step S32). 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.

Subsequently, the inclination control unit 47 acquires the control cycle T _S (step S33), and calculates a differential value of a (step S34). Here, if the differential value of a is Δa, Δa is calculated by the following equation (14).
Δa = (a−a _old ) / T _S Formula (14)
And the inclination control part 47 is preserve | saved as _aold = a (step S35). That is, the combined lateral acceleration 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 S36). Here, when the control gain of the proportional control operation, that is, the proportional gain is _GP , the first control value _UP is calculated by the following equation (15).
U _P = G _P a ··· formula (15)
Then, tilt control unit 47 calculates the second control value U _D (step S37). Here, if the control gain of the differential control operation, that is, the differential time is G _D , the second control value U _D is calculated by the following equation (16).
U _D = G _D Δa (16)
Subsequently, the inclination control unit 47 calculates a third control value U (step S38). 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 (17).
U = U _P + U _D ··· formula (17)
The operations in steps S31 to S38 represent feedback control for controlling the inclination angle of the vehicle body so that the value of the combined lateral acceleration a becomes zero.

Subsequently, the tilt control unit 47 receives the lateral acceleration predicted value a _f from the lateral acceleration estimation unit 49 (step S39).

Subsequently, the inclination control unit 47 performs a _fold call (step S40). 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 S41). Here, when the differential value of a _f and .DELTA.a _f, the .DELTA.a _f is calculated by the following equation (18).
_{Δa f = (a f -a fold} ) / T S ··· formula (18)
And the inclination control part 47 preserve _| saves as _afold = _af (step S42). 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 S43). 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 (19).
U _fD = G _yD Δa _f Equation (19)
Subsequently, the inclination control unit 47 calculates a fifth control value U (step S44). 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 (20).
U = U + U _fD Expression (20)
The operation of the step S39~S44 represents a feedforward control using lateral acceleration estimated value a _f obtained based on the steering angle and the vehicle speed.

Subsequently, the inclination control unit 47 receives the roll rate ω _N for the disturbance from the disturbance calculation unit 43 (step S45).

Subsequently, the inclination control unit 47 calculates a disturbance control gain _GwP (step S46) and calculates a sixth control value _UwP (step S47). Here, the sixth control value U _wP is calculated by the following equation (21).
U _wP = G _wP ω _N Expression (21)
The disturbance control gain G _wP may be a constant in the case of simplification, and G _wP = 1 when the control system is an ideal system. However, in an actual control system such as the vehicle body tilt control system in the present embodiment, there are delays in the link motor 25 that is a control target, observation delays in sensors such as the lateral acceleration sensor 44 and the link angle sensor 25a, and the like. Therefore, it is necessary to adjust the value of the disturbance control gain _GwP .

Further, in order to avoid a sensitive response to vibration or the like, when the value of the roll rate ω _N for the disturbance is large, it is desirable to adjust so that the value of the disturbance control gain G _wP also becomes large.

For example, if G _wP = | ω _N |, the sixth control value U _wP can be expressed by the following equation (22).
U _wP = | ω _N | ω _N = sign (ω _N ) ω _N ² Formula (22)
Here, sign (x) represents +1 when x is a positive value, and represents -1 when x is a negative value.

However, in the equation (22), if the value of the roll rate ω _{N for} the disturbance is small, the value of the sixth control value U _wP may be too small. In such a case, the value of the disturbance control gain G _wP may be changed according to the value of the roll rate ω _{N for} the disturbance as shown in FIG. 11, for example. That is, the value of the disturbance control gain G _wP can be determined using a function as shown in FIG. In FIG. 11, G1 is the value of the disturbance control gain G _wP to be applied at a minimum, and ω1 is the value of the roll rate ω _N for the disturbance for which the value of the disturbance control gain G _wP is to be increased. .

Subsequently, the inclination control unit 47 calculates a seventh control value U (step S48). The seventh control value U is the sum of the fifth control value U and the sixth control value U _wP and is calculated by the following equation (23).
U = U + U _wP Expression (23)
Finally, the inclination control unit 47 outputs the seventh control value U as a speed command value to the link motor control unit 42 (step S49), and ends the process.

  When the link motor control process is started, the link motor control unit 42 first receives the seventh control value U from the inclination control unit 47 (step S51).

  Subsequently, the link motor control unit 42 acquires the link angle sensor value η detected by the link angle sensor 25a (step S52), executes link angular velocity calculation processing (step S53), and sets the link angle of the link mechanism 30. Calculate the angular velocity Δη. The operation of the link angular velocity calculation process is the same as the operation of the link angular velocity calculation process executed by the disturbance calculation unit 43, that is, the operation of steps S26-1 to S26-5 shown in FIG. To do.

  Further, the link motor control unit 42 can obtain the value of the angular velocity Δη of the link angle from the disturbance calculation unit 43, thereby omitting the operations of the steps S52 and S53.

Subsequently, the link motor control unit 42 calculates a control error (step S54). Here, when the control error is ε, ε is calculated by the following equation (24).
ε = U−Δη (24)
U is the seventh 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 S55). 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 S56). Here, when the torque command value is U _T , the U _T is calculated by the following equation (25).
U _T = G _MP ε (25)
Finally, the link motor control unit 42 outputs the torque command value _UT to the link motor 25 (step S57) and ends the process.

As described above, in the present embodiment, when a disturbance in the vehicle body tilt direction is received, a change due to the disturbance in the change in the vehicle body tilt angle is extracted, and control corresponding to the extracted change due to the disturbance is performed. Add a value to control the body tilt. Specifically, the roll rate ω _N of the disturbance in the tilt direction, which becomes an unstable factor of the vehicle body, is obtained, and the control value corresponding to the roll rate ω _N of the disturbance is added to control the tilt angle of the vehicle body. Thus, a stable traveling state can be obtained even when the vehicle 10 is subjected to a disturbance in the inclination direction due to a road step, a crosswind, or the like. The disturbance is, for example, a lateral external force that is large enough to assume that one of the left and right wheels 12L and 12R is lifted from the road surface 18.

Also, by increasing the value of the disturbance control gain G _wP as the roll rate ω _N for the disturbance increases, it is possible to appropriately reduce the stability of the control due to the excessive control gain when the disturbance is small or when there is no disturbance. In addition, it is possible to appropriately control the inclination angle of the vehicle body by suppressing the influence of the disturbance when receiving a large or abrupt disturbance.

Furthermore, the value of the composite lateral acceleration a performs feedback control such that the zero, since the feedforward control using the lateral acceleration estimated value a _f, the inclination angle of the vehicle body during a turn and the lateral acceleration and gravity It is possible to appropriately control the angle so as to be balanced. 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.

In the present embodiment, an example in which the disturbance calculation unit 43 calculates the roll rate ω _{S of the} vehicle body based on one detected value of the lateral acceleration sensor 44 and the combined lateral acceleration a has been described. The rate ω _S can also be detected directly by a sensor.

Next, a modification in which the roll rate ω _{S of the} vehicle body is directly detected will be described.

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

In the vehicle body tilt control system in the modified example, as shown in the figure, a roll rate sensor 44c is connected to the tilt control ECU 46. The roll rate sensor 44c is a general roll rate sensor that detects the angular velocity of the tilt motion of the vehicle body, that is, the roll rate ω _{S of the} vehicle body. For example, the roll rate sensor 44c is a gyro sensor that is perpendicular to the ground and is It is attached to the vehicle body so that it can detect the rotational angular velocity in the plane perpendicular to the straight direction. The roll rate sensor 44c can be attached to any position of the vehicle body as long as it is perpendicular to the ground surface and in a plane perpendicular to the straight traveling direction of the vehicle 10.

Then, the disturbance calculation unit 43 acquires the roll rate ω _S of the vehicle body detected by the roll rate sensor 44c. Therefore, the operations in steps S21 to S25 in the disturbance calculation process shown in FIG. 9 can be omitted.

  In addition, since it is the same about the structure and operation | movement of another point, description is abbreviate | omitted.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which 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. 15 is a flowchart showing the operation of the tilt control process in the second embodiment of the present invention, FIG. 16 is a flowchart showing a subroutine of the wind down control process in the second embodiment of the present invention, and FIG. It is a flowchart which shows the subroutine of the disturbance acceleration calculation process in 2nd Embodiment.

  If the vehicle 10 is small, the elastic deformation of the tires provided on the left and right wheels 12L and 12R, the elastic deformation of each part of the vehicle body, and the elastic deformation of the springs of the suspension when the suspension is provided have an effect on the inclination control of the vehicle body. It becomes relatively large.

  For example, a tire theoretically has a vibration characteristic similar to that of a combination of a spring and a damper, and thus has a resonance point, like a suspension. And when the vehicle 10 is small, if the vehicle 10 whole is shaken at the said resonance point, since an amplitude will become large, an inclination will become large and safety | security will be impaired. In particular, when only one of the left and right wheels 12L and 12R passes through a step or when a large impulse or step input is applied to the vehicle 10, such as when the vehicle 10 receives a sudden crosswind, The entire vehicle 10 may be greatly shaken at the resonance point, and the inclination of the vehicle body may become very large.

  In order to remove the influence on the inclination control due to such elastic deformation, for example, it is conceivable to use acceleration elements such as a lateral acceleration and a differential value of a roll rate. However, since the detected value of the acceleration element by the actual sensor is vibrational, if it is used as a feedback element, it becomes even more vibrational, the feedback gain cannot be increased, and the control effect cannot be exhibited. In addition, if a filter is applied to the detected value of the acceleration element by the sensor in order to increase the feedback gain, the delay will increase and the control effect cannot be exhibited.

  Therefore, in the present embodiment, rewinding control as control that takes into account elastic deformation of the tire and other parts, that is, winddown control is performed.

  In the winddown control, when there is an input exceeding a certain level, the start of elastic deformation of the tire and other parts is detected and the sign of the control value is quickly reversed, and the end of elastic deformation is detected and the sign of the control value is changed. It is supposed to be restored. As a result, the shock can be absorbed and the resonance of the vehicle 10 can be reduced, so that even when a large impulse or step input is applied to the vehicle 10, the inclination of the vehicle body is prevented from increasing. can do.

  In the present embodiment, the configuration of the vehicle 10 is the same as that of the first embodiment, so that the description thereof will be omitted, and only the operation of the vehicle body tilt control process in turning traveling will be described.

  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 lateral acceleration estimation unit 49 executes the lateral acceleration estimation process, and the disturbance calculation unit 43 performs the disturbance calculation process. The link motor control unit 42 executes the link motor control process. The operations of the lateral acceleration calculation process, the lateral acceleration estimation process, the disturbance calculation process, and the link motor control process in the present embodiment are the same as those in the first embodiment. The operations of the lateral acceleration calculation process, the lateral acceleration estimation process, the disturbance calculation process, and the link motor control process in the embodiment are the same as the operations shown in the flowcharts of FIGS.

In addition, when the tilt control unit 47 starts the tilt control process, first, the tilt control unit 47 receives the combined lateral acceleration a from the lateral acceleration calculation unit 48 (step S61). The operation from the reception of the combined lateral acceleration a to the calculation of the sixth control value U _wP , that is, the operation from step S61 to S77 shown in FIG. 15, is described in the first embodiment. Since this is the same as steps S31 to S47, the description thereof is omitted.

Then, after calculating the sixth control value U _wP , the inclination control unit 47 executes a winddown control process (step S78). As described above, in the winddown control, the start of elastic deformation of the tire and other parts is detected to invert the sign of the control value, and the end of elastic deformation is detected to return the sign of the control value to the original. ing. In other words, in the winddown control, the winddown is executed only during the period from when the elastic member receives an external disturbance to start elastic deformation until the elastic deformation ends, and the elastic member starts to recover due to its own elasticity. Winddown is stopped in the following period. When the winddown is stopped or not executed, the same control as that in the first embodiment is performed.

  For example, a case where only one of the left and right wheels 12L and 12R falls into the recess when passing through the recess will be described as an example. The tire of one wheel falls from the state of floating in the air and contacts the bottom surface of the recess. To do. The tire contracts after being grounded, and when the contraction is completed, the tire expands and returns to its original shape. Winddown is performed only during the period from when the tire contacts the ground until it finishes contracting, and is not performed during the period until the tire contacts the ground and after the tire has contracted.

In the winddown control process, the inclination control unit 47 first acquires the roll rate ω _N for the disturbance (step S78-1), and executes the disturbance acceleration calculation process (step S78-2). The roll rate ω _N for the disturbance is that received from the disturbance calculation unit 43 in step S75.

In the disturbance acceleration calculation process, the tilt control unit 47 _first calls ω _N-1 (step S78-2-1) and acquires the control cycle T _S (step S78-2-2). ω _N-1 is the value of the roll rate ω _N for the disturbance stored when the vehicle body tilt control process is executed last time. In the initial setting, ω _N-1 = 0.

Subsequently, the inclination control unit 47 calculates a differential value of the roll rate ω _N for the disturbance (step S78-2-3), and ends the disturbance acceleration calculation process. Here, if the differential value of ω _N is Δω _N , Δω _N is calculated by the following equation (26).
Δω _N = (ω _N −ω _N−1 ) / T _S Expression (26)
Subsequently, the inclination control unit 47 determines whether or not 1 is set in the flag F, that is, whether or not F = 1 (step S78-3). In the initial setting, zero is set in the flag F, that is, F = 0. In addition, F = 1 indicates a period from the time when the tire is grounded until the tire is completely contracted in the above example.

When F = 1, the inclination control unit 47 determines whether or not Δω _N Δω _N-1 <0 (step S78-4). [Delta] [omega _N is the rate of change of the disturbance component of the roll rate omega roll rate of a differential value disturbance component of _N omega _N, i.e., shows the slope of the curve showing the change of the disturbance component of the roll rate omega _N. Therefore, Δω _N Δω _N−1 <0 indicates that the slope of the curve indicating the roll rate ω _N of the disturbance during the previous vehicle body tilt control process and the disturbance during the current vehicle body tilt control process are executed. This means that the slope of the curve indicating the roll rate ω _N is different, that is, passing through an inflection point on the curve indicating the roll rate ω _N of the disturbance.

If Δω _N Δω _N-1 <0, the inclination control unit 47 sets the flag F to zero, that is, sets F = 0 (step S78-5).

Subsequently, the inclination control unit 47 determines whether or not the absolute value of the roll rate ω _{N for} the disturbance is greater than a predetermined threshold (threshold) value A ₁ , that is, | ω _N |> A ₁ . It is determined whether or not there is (step S78-6). In step S78-3, it is determined whether F = 1, and if F = 1, and in step S78-4, it is determined whether Δω _N Δω _N-1 <0. _{If N} Δω _N-1 <0, it is determined whether or not | ω _N |> A _{1 as} it is.

Here, A ₁ is a threshold value set for determining whether or not the input to the vehicle body is equal to or greater than a certain value. When the absolute value of the roll rate ω _{N for} the disturbance is greater than A ₁ , It is determined that there is an input exceeding a certain level, the start of elastic deformation of the tire and other parts is detected, and the sign of the control value is reversed. A ₁ is a value of 0 or more. Further, A ₁ is set so that the absolute value becomes smaller than the absolute value of the roll rate ω _N of the maximum disturbance that does not cause the vehicle 10 to fall when the winddown is not executed.

Therefore, when | ω _N |> A ₁ , the inclination control unit 47 determines whether or not Δω _N Δω _N-1 <0 (step S78-7). If Δω _N Δω _N-1 <0, the inclination control unit 47 sets 1 to the flag F, that is, sets F = 1 (step S78-8).

Subsequently, the inclination control unit 47 determines whether or not ω _N ω _N-1 <0 (step S78-9). In step S78-6, whether or not | ω _N |> A ₁ is determined. If | ω _N |> A ₁ is not satisfied, whether or not Δω _N Δω _N-1 <0 is satisfied in step S78-7. If either the judges not _{Δω N Δω N-1 <0} , and, met Δω _N Δω _N-1 to determine whether <a _{0 Δω N Δω N-1 <} 0 at step S78-4 In this case, it is determined whether or not ω _N ω _N-1 <0.

Here, ω _N ω _N-1 <0 indicates that the roll rate ω _N of the disturbance during the previous execution of the vehicle body tilt control process is positive and negative, and the roll rate of the disturbance during the execution of the current vehicle body tilt control process. This means that the sign of ω _N is different from the positive or negative, that is, the curve indicating the roll rate ω _N of the disturbance has passed through the axis (X axis) indicating zero (so-called zero crossing).

If ω _N ω _N-1 <0, the inclination control unit 47 sets the flag F to zero, that is, sets F = 0 (step S78-10).

Subsequently, the inclination control unit 47 determines whether or not 1 is set in the flag F, that is, whether or not F = 1 (step S78-11). In the case ω _N ω _N-1 <not a ω _N ω _N-1 <0 and it is determined whether 0 is the step S78-9, it is determined whether or not F = 1 .

The inclination control unit 47 sets the wind-down control gain G _wS to 1 when F = 1 is not satisfied (step S78-12), and sets the wind-down control gain G _wS to −1 when F = 1. (Step S78-13).

Subsequently, the inclination control unit 47 calculates a seventh control value U (step S78-14). The seventh control value U is the sum of the fifth control value U and a value _obtained by multiplying the sixth control value U _wP by the wind-down control gain G _wS , and is calculated by the following equation (27).
U = U + U _wP G _wS Expression (27)
Finally, the inclination control unit 47 stores ω _N-1 = ω _{N and} also stores Δω _N-1 = Δω _N (step S78-15), and ends the wind-down control process. That is, the values of ω _N and Δω _N at the time of executing the vehicle body tilt control process are stored in the storage unit as ω _N-1 and Δω _N-1 .

  Then, the inclination control part 47 outputs the 7th control value U to the link motor control part 42 as a speed command value (step S79), and complete | finishes a process.

Note that the operation of step S78-6 in the winddown control process corresponds to determining whether or not the input is to perform the winddown. | Ω _N |> A ₁ corresponds to an input to be subjected to winddown.

The operation in step S78-7 is equivalent to determining whether or not the tire floating in the air is in contact with the ground, which will be described according to the example of the tire. Since Δω _N Δω _N-1 <0 corresponds to a change in the slope of the curve indicating the roll rate ω _N of the disturbance due to the grounding of the tire, step S78-8 is executed in order to execute winddown. And F = 1.

Further, the operation of step S78-9 will be described based on the example of the tire, and corresponds to determining whether or not the grounded tire has been contracted. Since ω _N ω _N-1 <0 corresponds to zero crossing of the curve indicating the roll rate ω _N of the disturbance after the tire has been shrunk, F in step S78-10 to stop the winddown = 0.

Since F = 1 and G _wS = −1 from when the tire _{contacts the} ground until it finishes shrinking, the seventh control value U is expressed by the following equation (28) by the above equation (27).
U = U−U _wP Expression (28)
When the equation (28) is compared with the seventh control value U in the first embodiment represented by the equation (23), it can be seen that the equation (28) is smaller than U _wP by two times. As a result, it is understood that the control gain in the inclination control is rewound and reduced by executing the winddown until the tire finishes contracting after being grounded.

On the other hand, since G _wS = 1 since F = 0 in the period until the tire comes into contact with the ground and the period after the tire has been contracted, the seventh control value U is expressed by the following equation (27). (29)
U = U + U _wP (29)
The formula (29) is the same as the formula (23). As a result, it is understood that the same control as in the first embodiment is performed without executing the winddown in the period until the tire comes into contact with the ground and the period after the tire has been contracted.

Further, the operations in steps S78-3 and S78-4 will be described in accordance with the example of the tire. Before the tire finishes shrinking, the wheel 12 falls into another recess and the tire floats again in the air. This corresponds to determining whether or not the state has been reached. Since Δω _N Δω _N-1 <0 corresponds to the fact that the tire floats again in the air and the slope of the curve indicating the roll rate ω _N of the disturbance has changed, step S78 is performed to stop the winddown. -5 and F = 0.

  Thus, in the present embodiment, the control value corresponding to the change due to the disturbance is changed according to the elastic deformation of the member due to the disturbance. Preferably, the control value corresponding to the change due to the disturbance is changed so that the control gain for controlling the inclination of the vehicle body is rewound during the period from the start to the end of the elastic deformation of the member due to the disturbance.

  Specifically, winddown control that takes into account elastic deformation of the tire and other parts is performed, and if there is an input exceeding a certain level, only the period from when the tire or other part starts elastic deformation until it ends Winding down is executed, and the control gain in the tilt control is rewound to decrease. The elastic deformation is deformation in one direction by receiving the input of the tire and other parts, and deformation in the opposite direction (so-called bounce back) by the elasticity of the tire and other parts itself. Not included. In other words, the winddown is executed only during a period from when the tire or other part receives the input and starts to be deformed to when bounceback is started.

  As a result, the influence on the tilt control due to the elastic deformation of the tire and other parts can be eliminated, and even when subjected to a large disturbance in the tilt direction, the tilt angle of the vehicle body does not generate resonance. Can be appropriately controlled, and a stable running state can be obtained.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them 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 53 Steering angle sensor 54 Vehicle speed sensor

Claims (5)

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 lateral acceleration sensor for detecting lateral acceleration acting on the vehicle body;
A control device for controlling the tilt of the vehicle body by controlling the tilt actuator device;
When receiving a disturbance in the tilt direction of the vehicle body, the control device extracts a change due to the disturbance of the change in the tilt angle of the vehicle body, and adds a control value corresponding to the extracted change due to the disturbance, A vehicle that controls the inclination of the vehicle body.   The control device extracts a roll rate of disturbance from the roll rate of the vehicle body as a change due to the disturbance, and sets a disturbance control gain whose value increases as the roll rate of the disturbance increases. The vehicle according to claim 1, wherein a value obtained by multiplying the roll rate is a control value corresponding to a change due to the disturbance. Requested turning amount detecting means for detecting a requested turning amount of the vehicle body requested by an occupant;
Vehicle speed detecting means for detecting the vehicle speed,
The control device performs feedback control based on the lateral acceleration detected by the lateral acceleration sensor, and performs feedforward control based on the requested turning amount detected by the requested turning amount detection means and the vehicle speed detected by the vehicle speed detection means. The vehicle according to claim 1, wherein the vehicle body tilt is controlled.   The vehicle according to any one of claims 1 to 3, wherein the control device changes a control value corresponding to a change due to the disturbance according to elastic deformation of a member due to the disturbance.   The control device controls the control value corresponding to the change due to the disturbance so that the control gain for controlling the tilt of the vehicle body is rewound during a period from the start to the end of elastic deformation of the member due to the disturbance. The vehicle according to claim 4, wherein:

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