JP2013199214A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle that can smoothly incline a vehicle body inside of a turning direction even if a tread is narrow, a center of gravity position is high, and steering speed is fast and can maintain stability of a vehicle body, can improve the turning performance, and can achieve excellent ride quality and a steady traveling state without making an occupant feel odd.SOLUTION: A control device generates acceleration toward the inside of a turning direction by controlling to move the center of gravity of the vehicle body to the steering direction by generating the differential torque in right and left driving wheels to generate the yaw moment in the opposite direction of the steering direction included in the steer instruction information at a first stage of the steering.

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, the tread is affected by the centrifugal force acting outward in the turning direction. When the vehicle is narrow, when the position of the center of gravity is high, or when the steering speed is high, the stability of the vehicle is likely to decrease, and the passenger may feel uncomfortable or feel uneasy.

  The present invention solves the problems of the conventional vehicle, and controls the center of gravity of the vehicle body to move in the steering direction included in the steering command information at the initial stage of the steering operation, that is, the initial stage of the steering operation. By generating acceleration toward the vehicle, the vehicle body can be smoothly tilted inward in the turning direction even when the tread is narrow, the center of gravity is high, or the steering speed is fast. A highly safe vehicle that can maintain stability, improve turning performance, and that passengers do not feel uncomfortable, have a comfortable ride, and can realize a stable running state The purpose is to provide.

  Therefore, in the vehicle of the present invention, a vehicle body including a steering unit and a main body unit that are connected to each other, a wheel that is rotatably attached to the steering unit, and a steerable steering wheel that steers the vehicle body, A non-steering wheel that is rotatably attached to the main body and is not steerable; a steering device that inputs steering command information; and an actuator device for tilting that tilts the steering unit or the main body in a turning direction And a steering actuator device that changes a steering angle of the steered wheel based on steering command information input from the steering device, and a control device that controls the tilt actuator device and the steering actuator device. The steered wheel or the non-steered wheel is a pair of left and right drive wheels, and the control device, at the initial stage of steering, controls By instrument generates the differential torque to the right and left drive wheels so as to generate the steering direction to be controlled to move the vehicle body gravity center to generate an acceleration towards the turning inward.

  According to the configuration of the first to third aspects, the center of gravity of the vehicle body can be moved inward in the turning direction by generating differential torque on the left and right drive wheels at the initial stage of steering, and the vehicle body can be smoothly moved in the turning direction. Since it can be tilted inward, the stability of the vehicle body can be maintained without sacrificing maneuverability and crisis avoidance performance.

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 block diagram of the 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 link angular velocity estimation process in the 1st Embodiment of this invention. It is a flowchart which shows the subroutine of the differentiation process of the yaw rate 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 inclination control process in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of the steering 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 of the control system in the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the steering control process in the 2nd Embodiment of this invention. It is a block diagram of the control system in the 3rd Embodiment of this invention. It is a figure which shows the relationship between the input and output of a transfer function in the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement of the steering control process 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 flowchart which shows the operation | movement of the drive control process in the 4th Embodiment of this invention. It is a flowchart which shows the operation | movement of the drive motor control process in the 4th 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. A wheel 12F as a steerable steering wheel which is a front wheel disposed on the left side, and a left wheel 12L and a right wheel 12R as non-steering wheels which are drive wheels disposed rearward as rear wheels and cannot be steered. And have. 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 in the main body portion 20.

  A steering device 41 is disposed in front of the seat 11a. The steering device 41 includes members necessary for steering such as a handlebar 41a as a steering device that is operated by an occupant to input steering command information such as a steering direction and a steering angle, a meter such as a speed meter, an indicator, and a switch. It is arranged. 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 the steering device, other devices such as a steering wheel, a jog dial, a touch panel, and a push button can be used instead of the handle bar 41a.

  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. Then, as in the case of a general motorcycle, bicycle, etc., the wheel 12F as the steering 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 steering shaft member is rotatably attached to a frame member (not shown) provided in the riding section 11. The steering shaft member is attached to the frame member in an obliquely inclined state so that the upper end is located behind the lower end. The rotation angle of the upper end of the steering shaft member with respect to the frame member, that is, the steering angle as the steering angle command value input by the occupant operating the handle bar 41a is determined by the steering angle sensor 62 as the input steering angle detection means. Detected. The handle angle sensor 62 includes, for example, an encoder.

A steering motor 65 as a steering actuator device is disposed between the upper end and the lower end of the steering shaft member, and the steering motor 65 has a handle angle detected by the handle angle sensor 62. Based on this, the lower end of the steering shaft member is rotated. The lower end of the steering shaft member is rotatably attached to the frame member and is connected to the upper end of the front wheel fork 17. The rotation angle of the lower end of the steering shaft member relative to the frame member, that is, the steering angle output from the steering motor 65 and transmitted to the wheel 12F via the front wheel fork 17 is the steering angle as output steering angle detection means. It is detected by the sensor 63. The steering angle sensor 63 is, for example, a rotation angle sensor that detects the rotation angle of the rotation shaft with respect to the body in the steering motor 65, and includes a resolver, an encoder, and the like. 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, there are a plurality of lateral acceleration sensors 44, which are arranged at different height positions. 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”. Further, both the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b may be disposed between the axle of the front wheel 12F and the axles of the left and right wheels 12L and 12R as rear wheels. desirable. 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. 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. .

  In the present embodiment, a roll rate sensor 44c for detecting the angular velocity of the tilting motion of the vehicle body and a yaw rate sensor 44d as a yaw angular velocity detecting means for detecting the angular velocity of the turning motion of the vehicle body, that is, the yaw angular velocity of the vehicle body are arranged. It is installed. Specifically, it is desirable that both the roll rate sensor 44c and the yaw rate sensor 44d are 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. It is arranged between the seat 11a and the footrest 11b.

  The roll rate sensor 44c is a general roll rate sensor, and for example, a gyro sensor is attached so as to detect a rotational angular velocity in a plane perpendicular to the road surface 18. . The yaw rate sensor 44d is a general yaw rate sensor, and for example, a gyro sensor is attached so as to detect a rotational angular velocity in a plane parallel to the road surface 18. Note that the three-dimensional gyro sensor can exhibit the functions of the roll rate sensor 44c and the yaw rate sensor 44d. That is, the roll rate sensor 44c and the yaw rate sensor 44d may be configured separately or may be configured integrally.

  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 and a steering 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 a semiconductor memory, an input / output interface, and the like, and includes a link angle sensor 25a, a first lateral acceleration sensor 44a, a second lateral acceleration sensor 44b, a roll rate. The sensor 44c, the yaw rate sensor 44d, the vehicle speed sensor 54, and the link motor 25 are connected. Then, the tilt control device outputs a torque command value for operating the link motor 25. Further, the steering control device includes a calculation means such as a processor, a storage means such as a magnetic disk and a semiconductor memory, an input / output interface, and the like, and is connected to a handle angle sensor 62, a steering angle sensor 63, a vehicle speed sensor 54, and a steering motor 65. Has been. The steering control device outputs a control pulse for operating the steering motor 65. The tilt control device and the steering control device are connected to each other. In addition, the tilt control device and the steering control device are not necessarily configured separately, and may be configured integrally.

  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 lateral acceleration value detected by the lateral acceleration sensor 44 becomes an angle that becomes zero. The 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 balances with the gravity 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.

  Furthermore, in the present embodiment, at the initial stage of steering, control is performed so as to move the center of gravity of the vehicle body in the steering direction included in the steering command information to generate acceleration directed inward in the turning direction. That is, immediately after the occupant starts operating the handle bar 41a, the center of gravity of the vehicle body is moved in the steering direction input by the operation of the handle bar 41a, thereby generating an acceleration inward in the turning direction. The steering control unit 66, which will be described later, sets the steering angle of the wheel 12F as the steering wheel in a direction opposite to the steering direction input by the operation of the handle bar 41a immediately after the occupant starts the operation of the handle bar 41a. The center of gravity of the vehicle body is moved in the steering direction input by the operation of the handle bar 41a by executing the counter steering operation.

  More specifically, the steering control device sets a steering angle target value by subtracting a value proportional to the steering wheel angle acceleration value from the steering wheel angle value. Thus, at the initial stage of steering (when the occupant starts to operate the handle bar 41a, that is, when the steering wheel starts to be turned), the direction of the steering wheel (the direction in which the steering wheel is turned) is opposite to the steering direction (the direction in which the steering wheel is turned). The steering angle changes. That is, a reverse handle operation or a counter steer operation is performed. Therefore, at the initial stage of steering, turning in a turning direction opposite to the turning direction intended by the occupant is started, and the centrifugal force generated by the turning acts as a force for tilting the vehicle body inside the turning direction intended by the occupant. Therefore, by using this force for vehicle body tilt control, the vehicle body can be smoothly tilted inward in the turning direction. That is, since the center of gravity of the vehicle body can be moved toward the inside in the turning direction at the initial stage of steering, the vehicle body can be smoothly inclined toward the inside in the turning direction.

  When the vehicle body tilt control is performed without performing such steering control, for example, when the tread (the distance between the ground contact points of the left and right wheels 12L and 12R) is narrow, when the center of gravity of the vehicle 10 is high, When the speed (the speed at which the steering wheel is turned) is high, the centrifugal force generated by turning acts as a force for inclining the vehicle body outward in the turning direction. May decrease. However, if the speed or acceleration of the steering angle of the wheel 12F as the steering wheel is reduced, the centrifugal force can be suppressed and the vehicle body can be smoothly tilted inward in the turning direction, so that the stability of the vehicle body is maintained. be able to. However, in this case, since the motion performance of the vehicle 10 is lowered, the maneuverability is deteriorated and the crisis avoidance performance is also lowered.

  On the other hand, in the present embodiment, as described above, the steering angle of the wheel 12F changes in the opposite direction to the steering direction in the same manner as a so-called counter steer operation is performed in the initial stage of steering. As a result, the center of gravity of the vehicle body can be moved inward in the turning direction at the beginning of steering, and the vehicle body can be smoothly tilted inward in the turning direction, so that maneuverability and crisis avoidance performance are not sacrificed. In addition, the stability of the vehicle body can be maintained.

  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 includes a link angle sensor 25a, a first lateral acceleration sensor 44a, a second lateral acceleration sensor 44b, a roll rate sensor 44c, a yaw rate sensor 44d, a vehicle speed sensor 54, and a link motor. 25. The tilt control ECU 46 includes a lateral acceleration calculation unit 48, a link angular velocity estimation unit 50, a disturbance calculation unit 43, a tilt control unit 47, and a link motor control unit 42.

  Reference numeral 61 denotes a steering control ECU as a steering control device, which is connected to a handle angle sensor 62, a steering angle sensor 63, a vehicle speed sensor 54, and a steering motor 65. Further, the steering control ECU 61 includes a steering control unit 66 and a steering motor control unit 67.

  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 link angular velocity estimation unit 50 calculates a link angular velocity prediction value based on the yaw rate as the yaw angular velocity detected by the yaw rate sensor 44d 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 roll rate as the angular velocity of the tilting motion of the vehicle body detected by the roll rate sensor 44c 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 link angular velocity calculated by the link angular velocity estimator 50, and the disturbance roll rate calculated by the disturbance calculator 43. Then, the speed command value as the control value is calculated and output. Further, the link motor control unit 42 is a control value for operating the link motor 25 based on the speed command value output from the tilt control unit 47 and the steering wheel steering angle command value output from the steering control unit 66. The torque command value is output.

  The steering control unit 66 calculates and outputs a steering wheel steering angle command value as a control value based on the steering wheel angle detected by the steering wheel angle sensor 62 and the vehicle speed detected by the vehicle speed sensor 54. The steering motor control unit 67 is a control pulse as a control value for operating the steering motor 65 based on the steering angle detected by the steering angle sensor 63 and the steering wheel steering angle command value output by the steering control unit 66. Is output.

  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 block diagram of the control system in the first embodiment of the present invention, and FIG. 6 is a diagram showing a dynamic model for explaining the leaning operation of the vehicle body during turning traveling in the first embodiment of the present invention. 7 is a flowchart showing the operation of the lateral acceleration calculation process in the first embodiment of the present invention.

  In the vehicle body tilt control process according to the present embodiment, control in which tilt control by the tilt control ECU 46 and steering control by the steering control ECU 61 are combined as shown in FIG. 5 is performed. Note that the tilt control by the tilt control ECU 46 is a combination of feedback control and feedforward control.

In FIG. 5, f ₁ is a transfer function represented by Equation (6) described later, G _P , G _RP , G _YD , G _ST and G _SL are control gains of the proportional control operation, and LPF is a low pass. S is a differential element. Further, f ₂ is a link angular velocity prediction value expressed by equation (10) described later, f ₃ is a roll rate gain, and f ₄ is a counter steering operation expressed by equation (26) described later. This is a function to eliminate the influence.

  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. 6, 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 acceleration of the <3> of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b outputs the detected value detected by the a _X1 and a _X2, a first lateral acceleration sensor 44a and a 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 link angular velocity estimation process for estimating the link angular velocity in turning travel will be described.

  FIG. 8 is a flowchart showing the operation of the link angular velocity estimation process in the first embodiment of the present invention, FIG. 9 is a flowchart showing a subroutine of the yaw rate differentiation process in the first embodiment of the present invention, and FIG. It is a flowchart which shows the subroutine of the filter process in the 1st Embodiment of invention.

  When the link angular velocity estimation unit 50 starts the link angular velocity estimation process, the link angular velocity estimation unit 50 first acquires a yaw rate sensor value ψ that is a yaw rate value detected by the yaw rate sensor 44d (step S11), and a vehicle speed value detected by the vehicle speed sensor 54. The vehicle speed sensor value ν is obtained (step S12).

  Then, the link angular velocity estimation unit 50 performs yaw rate differentiation processing (step S13) and calculates Δψ. The Δψ is a value obtained by differentiating the yaw rate with time, and corresponds to the yaw angular acceleration.

In the yaw rate differentiation process, the link angular velocity estimation unit 50 first makes a ψ _old call (step S13-1). Note that ψ _old is the value of ψ (t) saved when the previous vehicle body tilt control process was executed. In the initial setting, ψ _old = 0.

Subsequently, the link angular velocity estimation unit 50 acquires a control cycle T _S (step S13-2).

Subsequently, the link angular velocity estimation unit 50 calculates the yaw rate differential value Δψ (step S13-3). Δψ is calculated by the following equation (8).
Δψ = (ψ (t) −ψ _old ) / T _S (8)
The link angular velocity estimation unit 50 stores ψ _old = ψ (t) (step S13-4), and ends the yaw rate differentiation process.

  Subsequently, the link angular velocity estimation unit 50 performs a filtering process on the yaw rate differential value Δψ (step S14).

In the filter processing, the link angular velocity estimation unit 50 first acquires a control cycle T _S (step S14-1).

  Subsequently, the link angular velocity estimation unit 50 acquires a cutoff frequency w (step S14-2).

Subsequently, the link angular velocity estimation unit 50 performs a Δψ _old call (step S14-3). Note that Δψ _old is a value of Δψ (t) saved when the previous vehicle body tilt control process was executed.

Subsequently, the link angular velocity estimation unit 50 calculates the filtered yaw rate differential value Δψ (t) (step S14-4). Δψ (t) is calculated by the following equation (9).
_{Δψ (t) = Δψ old /} (1 + T S w) + T S wψ / (1 + T S w) ··· (9)
The equation (9) is an equation of an IIR (Infinite Impulse Response) filter that is generally used as a bandpass filter, and represents a first-order lag low-pass filter. As the IIR filter, for example, a Chebyshev type II filter may be used, or another filter may be used. Further, a generally used FIR (Finite Impulse Response) filter may be used. Furthermore, the cut-off frequency (−3 [dB] frequency) of the band pass filter is preferably 10 [Hz] or less, and more preferably several [Hz].

Then, the link angular velocity estimation unit 50 stores it as Δψ _old = Δψ (t) (step S14-5), and ends the filter process. That is, the value of Δψ (t) calculated at the time of execution of the current vehicle body tilt control process is stored in the storage unit as Δψ _old .

Subsequently, the link angular velocity estimation unit 50 calculates a link angular velocity prediction value f ₂ (step S15). Here, assuming that gravity is g, the link angular velocity predicted value f ₂ is calculated by the following equation (10).
f ₂ = dη / dt = (ν / g) (dψ / dt) (10)
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 relationship represented by the following formula (11) is established between the centrifugal force a ₀ and the gravity g.
a ₀ cos η = gsin η (11)
From the equation (11), the following equation (12) is derived.
a ₀ / g = sin η / cos η = tan η (12)
Further, the following equation (13) is derived from the equation (12).
a ₀ = g tan η (13)
On the other hand, assuming that the yaw rate is ψ and the turning radius is r, the vehicle speed ν and the centrifugal force a ₀ as the lateral acceleration acting on the vehicle body at the time of turning are expressed by the following equations (14) and (15).
ν = rψ Equation (14)
a ₀ = rψ ² = νψ (15)
Then, the following equation (16) is derived from the equation (15) and the equation (13).
tan η = νψ / g (16)
Furthermore, it can be approximated as tan η≈η, 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 above, the formula (10) can be obtained.

Subsequently, the link angular velocity estimation unit 50 calculates a link angular velocity control value a _f (step S16). The link angular velocity control value _af is calculated by the following equation (17).
a _f = Adη / dt (17)
Here, A is an arbitrary value of 0 to 1, and is a tuning constant determined according to the structure of the vehicle 10.

Finally, the link angular velocity estimation unit 50 sends the link angular velocity control value a _f to the inclination control unit 47 (step S17), and ends the link angular velocity estimation process.

  Next, the operation of the inclination control process for outputting the speed command value to the link motor control unit 42 will be described.

  FIG. 11 is a flowchart showing the operation of the tilt control process in the first embodiment of the present invention.

  In the tilt control process, the tilt control unit 47 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.

Subsequently, the inclination control unit 47 acquires the control cycle T _S (step S23), and calculates the differential value of a (step S24). Here, when the differential value of a is da / dt, the da / dt is calculated by the following equation (18).
da / dt = (a−a _old ) / T _S (18)
And the inclination control part 47 is preserve | saved as _aold = a (step S25). That is, the lateral acceleration sensor value a acquired at the time of execution of the current 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 S26). Here, if 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 (19).
U _P = G _P a ··· (19)
Then, tilt control unit 47 calculates the second control value U _D (step S27). 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 (20).
U _D = G _D da / dt (20)
Subsequently, the inclination control unit 47 calculates a third control value U (step S28). 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 (21).
U = U _P + U _D ··· formula (21)
When the third control value U is calculated, the inclination control unit 47 receives the link angular velocity control value a _f from the link angular velocity estimation unit 50 (step S29).

Subsequently, the inclination control unit 47 calculates a fourth control value U (step S30). The fourth control value U is the sum of the third control value U and the link angular velocity control value _af, and is calculated by the following equation (22).
U = U + a _f Expression (22)
Finally, the tilt control unit 47 outputs the fourth control value U as a speed command value to the link motor control unit 42 (step S31), and ends the tilt control process.

  Next, the operation of the steering control process, which is a part of the vehicle body control operation in turning, will be described.

  FIG. 12 is a flowchart showing the operation of the steering control process in the first embodiment of the present invention.

  In the steering control process, after obtaining the steering wheel angle sensor value δ, a function may be applied according to the vehicle speed ν. For example, in general, when the vehicle speed ν increases, it is not necessary to increase the steering angle of the steered wheels even when the steering wheel is largely turned. Therefore, the handle angle sensor value δ used for calculation in the steering control process can be determined by multiplying a function that is obtained from the handle angle sensor 62 and inversely proportional to the vehicle speed ν.

  Further, the yaw rate of the vehicle body can be determined by the steering wheel angle sensor value δ. This constitutes feedback control so that a certain yaw rate is obtained at a certain steering wheel angle sensor value δ regardless of the vehicle speed ν.

  These are all techniques employed when performing steer-by-wire.

  When the steering control process starts in the present embodiment, the steering control unit 66 first acquires a handle angle sensor value δ that is a value of the handle angle detected by the handle angle sensor 62 (step S41). The steering wheel angle is a steering angle command value input by an occupant operating the steering bar 41a.

  Subsequently, the steering control unit 66 performs a filter process on the steering wheel angle sensor value δ (step S42). The filter processing is processing by a first-order lag low-pass filter similar to the filter processing in the link angular velocity estimation processing, and an IIR filter or FIR filter generally used as a band-pass filter can be used.

  Subsequently, the steering control unit 66 calculates a differential value dδ / dt of the steering wheel angle sensor value δ (step S43). Here, the differential value dδ / dt of the handle angle sensor value δ represents the angular velocity of the handle angle.

Subsequently, the steering control unit 66 calculates a second order differential value d ² δ / dt ² of the steering wheel angle sensor value δ (step S44). Here, the second-order differential value d ² δ / dt ² of the steering wheel angle sensor value δ represents the angular acceleration of the steering wheel angle.

Subsequently, the steering control unit 66 calculates the steering angle target value δ ^* (step S45). Here, if the control gain corresponding to the counter-steering operation and G _ST, steering angle target value [delta] ^* is calculated by the following equation (23).
δ ^* = δ−G _ST d ² δ / dt ² Formula (23)
Then, the steering control unit 66 calculates the link angle correction value U _SL (step S46). Here, if the control gain for controlling the link angle according to the steering wheel angle, that is, the control gain for controlling the link angle so as to incline the vehicle body in the turning direction according to the direction in which the steering wheel is turned, is G _SL. The correction value _USL is calculated by the following equation (24).
U _SL = G _SL d ² δ / dt ² Formula (24)
Then, the steering control unit 66 calculates the link angle mask value G _LM (step S47). Here, assuming that a function for eliminating the influence of the counter steer operation is f ₄ , the link angle mask value G _LM is calculated by the following equation (25).
G _LM = f ₄ (d ² δ / dt ² ) (25)
Note that f ₄ is a function for eliminating the influence of the tilt control process based on the lateral acceleration during the counter steer operation. Since the countersteer operation starts turning in the direction opposite to the turning direction intended by the occupant, the centrifugal force generated by the turning is lateral to the direction in which the vehicle body is inclined to the inside of the turning direction intended by the occupant. Detected as acceleration. Therefore, when the tilt control process based on the lateral acceleration is performed, the vehicle body is tilted to the outside in the turning direction intended by the occupant. Therefore, it is necessary to eliminate the influence of the tilt control process based on the lateral acceleration during the counter steer operation.

Therefore, f ₄ is configured as a function that outputs 0 when the input is the maximum value that can actually be taken. The output is 0-1. For example, if the input is x and the maximum value that x can actually take is X _MAX , the output y can be obtained by the following equation (26).
y = −1 / X _MAX · | x | +1 (26)
Subsequently, the steering control unit 66 outputs the calculated steering angle target value δ ^* to the steering motor control unit 67 (step S48).

Finally, the steering control unit 66 outputs the calculated link angle correction value _USL and the link angle mask value _GLM to the link motor control unit 42 (step S49), and ends the steering control process.

  Next, the operation of the link motor control process for outputting a torque command value to the link motor 25 will be described.

  FIG. 13 is a flowchart showing the operation of the link motor control process in the first embodiment of the present invention.

  In the link motor control process, the link motor control unit 42 first receives the fourth control value U from the inclination control unit 47 (step S51).

Subsequently, the link motor control unit 42 receives the link angle correction value _USL and the link angle mask value _GLM from the steering control unit 66 (step S52).

Subsequently, the link motor control unit 42 calculates a fifth control value U (step S53). The fifth control value U is calculated by the following equation (27) based on the fourth control value U, the link angle correction value U _SL and the link angle mask value G _LM .
U = G _LM U + U _SL (27)
Subsequently, the link motor control unit 42 acquires the angular velocity of the link angle, that is, the link angular velocity Δη (step S54). The link angular velocity Δη is calculated by obtaining the link angle sensor value η detected by the link angle sensor 25a and differentiating the link angle sensor value η with time. Further, the link motor control unit 42 can also acquire the value of the link angular velocity Δη from the disturbance calculation unit 43.

Subsequently, the link motor control unit 42 calculates a deviation as a control error (step S55). Here, when the deviation is ε, the ε is calculated by the following equation (28).
ε = U−Δη Formula (28)
U is the fifth control value U.

Subsequently, the link motor control unit 42 calculates a link motor control value as a torque command value for operating the link motor 25 (step S56). Here, when the link motor control value is U _M , U _M is calculated by the following equation (29).
U _M = G _MP ε (29)
Note that _GMP is a motor control proportional gain, and the value of _{GMP is} a value set based on experiments or the like, and is stored in the storage means in advance.

Finally, the link motor control unit 42 outputs the link motor control value _UM to the link motor 25 (step S57), and ends the link motor control process.

  Although the link motor control process has been described here as proportional control, that is, P control, it may be PID control.

  Thus, in the present embodiment, at the initial stage of steering, control is performed so as to move the center of gravity of the vehicle body in the steering direction included in the steering command information to generate acceleration directed inward in the turning direction. That is, immediately after the occupant starts operating the handle bar 41a, the center of gravity of the vehicle body is moved in the steering direction input by the operation of the handle bar 41a, thereby generating an acceleration inward in the turning direction. The steering control unit 66 changes the steering angle of the wheel 12F as the steered wheel in a direction opposite to the steering direction input by the operation of the handle bar 41a immediately after the occupant starts the operation of the handle bar 41a. That is, by executing the counter steer operation, the center of gravity of the vehicle body is moved in the steering direction input by the operation of the handle bar 41a.

  As a result, the center of gravity of the vehicle body can be moved inward in the turning direction at the beginning of steering, and the vehicle body can be smoothly tilted inward in the turning direction, so that maneuverability and crisis avoidance performance are not sacrificed. In addition, the stability of the vehicle body can be maintained.

  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. 14 is a block diagram of the control system in the second embodiment of the present invention, and FIG. 15 is a flowchart showing the operation of the steering control process in the second embodiment of the present invention.

In the vehicle body tilt control process according to the present embodiment, control in which tilt control by the tilt control ECU 46 and steering control by the steering control ECU 61 are combined as shown in FIG. 14 is performed. In FIG. 14, f ₅ is the calculated value of the steering angle in the counter-steering operation of the formula described below (30), i.e., a function for calculating the inverse steering calcd. Since other points are the same as those in FIG. 5 described in the first embodiment, description thereof is omitted.

  The operations of the lateral acceleration calculation process, the link angular velocity estimation process, the tilt control process, and the link motor control process in the present embodiment are the same as those in the first embodiment, and a description thereof will be omitted. Only the operation of the steering control process in the present embodiment will be described.

When the steering control process starts, the steering control unit 66 acquires a handle angle sensor value δ that is a value of the handle angle detected by the handle angle sensor 62 (step S61), and performs a filter process on the handle angle sensor value δ. (Step S62), a differential value dδ / dt of the handle angle sensor value δ is calculated (step S63), and a second-order differential value d ² δ / dt ² of the handle angle sensor value δ is calculated (step S64). The operation up to this point is the same as the operation in steps S41 to S44 of the steering control process in the first embodiment.

Subsequently, the steering control unit 66 calculates the reverse steering calculation value δ _SL (step S65). The reverse steering calculation value δ _SL is calculated according to the function f ₅ , and can be specifically obtained by the following equation (30).

  As a result, it is possible to prevent the counter steer operation from being generated at the end of the steering operation by causing the occupant to operate the handle bar 41a, that is, at the initial stage of steering.

Subsequently, the steering control unit 66 calculates a steering angle target value δ ^* (step S66). Here, the steering angle target value δ ^* is calculated by the following equation (31).
δ ^* = δ−G _ST δ _SL Expression (31)
Then, the steering control unit 66 calculates the link angle correction value U _SL (step S67). Here, the link angle correction value _USL is calculated by the following equation (32).
U _SL = G _SL δ _SL (32)
Then, the steering control unit 66 calculates the link angle mask value G _LM (step S68). Here, the link angle mask value _GLM is calculated by the following equation (33).
G _LM = f ₄ (δ _SL ) Equation (33)
Subsequently, the steering control unit 66 outputs the calculated steering angle target value δ ^* to the steering motor control unit 67 (step S69).

Finally, the steering control unit 66 outputs the calculated link angle correction value _USL and link angle mask value _GLM to the link motor control unit 42 (step S70), and ends the steering control process.

Thus, in the present embodiment, the differential value of the steering angle included in the steering command information is used. Specifically, the reverse steering calculation value δ _SL calculated according to the function f ₅ is used.

  As a result, it is possible to prevent the counter steer operation from being generated at the end of the steering operation by causing the occupant to operate the handle bar 41a, that is, at the initial stage of steering.

  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. 16 is a block diagram of the control system in the third embodiment of the present invention, FIG. 17 is a diagram showing the relationship between the input and output of the transfer function in the third embodiment of the present invention, and FIG. 18 is the present invention. It is a flowchart which shows the operation | movement of the steering control process in 3rd Embodiment.

In the vehicle body tilt control process according to the present embodiment, control in which tilt control by the tilt control ECU 46 and steering control by the steering control ECU 61 are combined as shown in FIG. 16 is performed. In FIG. 16, G (s) is a transfer function for calculating the gain of the steering operation including the counter steer operation, and is represented by the following equation (34), for example.
{1-0.1s} / {1 + 0.11s + 0.001s ² } Formula (34)
The formula (34) is obtained by multiplying the following formula (35) by the formula (36).
{1-0.1s} / {1 + 0.01s} Expression (35)
1 / {1 + 0.1s} Expression (36)
The equation (35) corresponds to a transfer function that draws a vector locus passing through a zero point in the Nyquist diagram, and the equation (36) corresponds to a first-order lag element and compensates for a phase lag. Used for.

  When the transfer function G (s) is expressed by the above equation (34), the relationship between the input and the output is as shown in FIG. In FIG. 17, the horizontal axis indicates time (seconds), and the vertical axis indicates gain (dimensionless). Lines α1 to α4 indicate inputs, and lines β1 to β4 indicate outputs corresponding to the inputs indicated by the lines α1 to α4, respectively.

Since the input of the transfer function G (s) is obtained by performing processing by the low-pass filter on the handle angle sensor value δ, it corresponds to a change in the handle angle caused by the occupant operating the handle bar 41a. The output of the transfer function G (s) corresponds to the steering angle target value δ ^* . The inclinations of the lines α1 to α4 represent the change speed of the handle angle.

  When the lines α1 to α4 and the corresponding lines β1 to β4 are viewed, if the change speed of the steering wheel angle is high, that is, if the occupant suddenly operates the handlebar 41a, the output of the transfer function G (s) is output at the initial stage of steering. It can be seen that the counter steer operation occurs. Further, if the change speed of the steering wheel angle is slow, that is, if the occupant gently operates the handle bar 41a, the output of the transfer function G (s) does not become negative even in the initial stage of steering, that is, the counter steering operation does not occur. I understand.

  The other points in the block diagram shown in FIG. 16 are the same as those in FIG. 5 described in the first embodiment, and a description thereof will be omitted.

  The operations of the lateral acceleration calculation process, the link angular velocity estimation process, the tilt control process, and the link motor control process in the present embodiment are the same as those in the first embodiment, and a description thereof will be omitted. Only the operation of the steering control process in the present embodiment will be described.

  When the steering control process is started, the steering control unit 66 acquires a handle angle sensor value δ that is a value of the handle angle detected by the handle angle sensor 62 (step S71), and filters the handle angle sensor value δ with respect to the filter. Processing is executed (step S72). The operations up to here are the same as the operations in steps S41 and S42 of the steering control process in the first embodiment.

Subsequently, the steering control unit 66 calculates the steering angle target value δ ^* (step S73). Here, the steering angle target value δ ^* is calculated by the following equation (37).
δ ^* = δG (z) (formula 37)
Since the transfer function G (s) is a continuous transfer function, it cannot be calculated by the steering control ECU 61 as it is. Therefore, for example, the continuous transfer function G (s) is converted into a discrete transfer function G (z) and used in advance by bilinear transformation or the like.

  The transfer function G (s) (or G (z)) has the following two conditions. The first condition is to prepare a first-order lag transfer function with a zero and experimentally adjust the time constant and the value of the zero. The second condition is to use a first-order lag transfer function so as to satisfy the Nyquist stability determination condition.

  Note that the value of the zero point may be changed dynamically (in real time) according to the vehicle speed and the yaw rate. As the zero value at this time, for example, a value experimentally determined according to the vehicle speed or the yaw rate may be held as a two-dimensional map, and the two-dimensional map may be used for the calculation.

Then, the steering control unit 66 calculates the link angle correction value U _SL (step S74). Here, the link angle correction value _USL is calculated by the following equation (38).
U _SL = G _SL {δ−δ ^* } Expression (38)
Then, the steering control unit 66 calculates the link angle mask value G _LM (step S75). Here, the link angle mask value _GLM is calculated by the following equation (39).
G _LM = f ₄ (δ−δ ^* ) Expression (39)
Subsequently, the steering control unit 66 outputs the calculated steering angle target value δ ^* to the steering motor control unit 67 (step S76).

Finally, the steering control unit 66 outputs the calculated link angle correction value _USL and the link angle mask value _GLM to the link motor control unit 42 (step S77), and ends the steering control process.

  Thus, in the present embodiment, a first-order lag transfer function with a zero is used. Specifically, the transfer function G (s) (or G (z)) is used. As a result, the counter steer operation can be generated only in the operation of the handlebar 41a by the occupant, that is, in the initial stage of steering.

  Next, a fourth embodiment of the present invention will be described. In addition, about the thing which has the same structure as the 1st-3rd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Explanation of the same operations and effects as those of the first to third embodiments is also omitted.

  FIG. 19 is a block diagram showing a configuration of a vehicle body tilt control system according to the fourth embodiment of the present invention.

  The control device 41 according to the present embodiment is also provided with an acceleration / deceleration command input device such as a throttle lever and a throttle grip, and a throttle position sensor 73 for detecting an acceleration / deceleration command value input from the acceleration / deceleration command input device. Has been.

  The vehicle body tilt control system in the present embodiment also includes a drive control device in addition to the tilt control device and the steering control device. The drive control device includes a calculation unit such as a processor, a storage unit such as a magnetic disk and a semiconductor memory, an input / output interface, and the like, and includes a handle angle sensor 62, a steering angle sensor 63, a throttle position sensor 73 and a drive motor It is connected to the left and right rotational drive devices 51L and 51R. The drive control device outputs left and right drive torque command values for operating the left and right rotary drive devices 51L and 51R.

  In the present embodiment, at the initial stage of steering, differential torque is generated in the left and right drive wheels so that a yaw moment in the direction opposite to the turning direction is generated, and braking torque is detected when lateral acceleration in the turning direction is detected. Is released and the vehicle body is tilted in the turning direction.

  As a method of generating differential torque on the left and right drive wheels so that a yaw moment in the direction opposite to the turning direction is generated, when reverse steering is generated without changing the total torque of the left and right wheels This is realized by increasing the torque of the wheel on the inside of the turn and reducing the torque on the outside of the turn accordingly. This distribution ratio increases as the difference between the steering wheel angle and the actual wheel steering angle increases, in other words, as the reverse steering amount increases.

  In this case, specifically, if the lateral inclination angle of the handlebar 41a as a steering command input by the occupant operating the handlebar 41a is changed, the left and right rotational drive devices 51L or 51R correspond to the outside of the turn. Less torque is distributed to the left and right wheels 12L or 12R than the wheel corresponding to the inside, thereby generating an imbalance of the drive torque. Then, a lateral acceleration directed in the turning direction is generated. When the initial stage of steering ends, the driving torque unbalance is canceled, the link motor 25 is operated in response to the steering command, and the inclination of the vehicle body is controlled.

  Thus, at the initial stage of steering, before the steering angle of the wheel 12F as the steering wheel starts to change, a lateral acceleration directed in the turning direction is generated, and then the vehicle body is directed toward the steering direction (the direction in which the steering wheel is turned). Can be tilted. Therefore, the vehicle body can be smoothly tilted in the turning direction. That is, in the initial stage of steering, the center of gravity of the vehicle body can be moved toward the turning direction in advance of the change in the steering angle of the wheel 12F as the steering wheel and the inclination of the vehicle body, so the vehicle body can be smoothly inclined in the turning direction. be able to.

  In the figure, reference numeral 71 denotes a drive control ECU as a drive control device, which is connected to a handle angle sensor 62, a steering angle sensor 63, a throttle position sensor 73, and left and right rotary drive devices 51L and 51R as drive motors. . The drive control ECU 71 includes a drive control unit 72 and a drive motor control unit 74.

  The drive control unit 72 performs control based on the steering wheel angle detected by the steering wheel angle sensor 62, the steering angle detected by the steering angle sensor 63, and the throttle position as the acceleration command value detected by the throttle position sensor 73. The drive torque command value and the left / right torque increase / decrease ratio as values are calculated and output. The drive motor control unit 74 is based on the drive torque command value output from the drive control unit 72 and the right / left torque increase / decrease ratio, and the right as a control value for operating the left and right rotary drive devices 51L and 51R as drive motors. A drive torque command value and a left drive torque command value are output.

  The other points in the block diagram shown in the figure are the same as those in FIG. 4 described in the first embodiment, and the description thereof is omitted.

  Next, the operation of the vehicle 10 in the present embodiment will be described. The operations of the lateral acceleration calculation process, link angular velocity estimation process, tilt control process, steering control process, and link motor control process in the present embodiment are the same as those in the first to third embodiments. The description is omitted, and only the operation of the drive control process and the drive motor control process will be described here.

  FIG. 20 is a flowchart showing the operation of the drive control process in the fourth embodiment of the present invention.

  The drive control unit 72 in the present embodiment executes a drive control process for outputting a drive torque command value and a left / right torque increase / decrease ratio to the drive motor control unit 74.

  Then, when the drive control process starts, the drive control unit 72 first acquires a handle angle sensor value δ that is a value of the handle angle detected by the handle angle sensor 62 (step S81), and with respect to the handle angle sensor value δ, Then, the filtering process is executed (step S82), the steering angle sensor value ΔR that is the value of the steering angle detected by the steering angle sensor 63 is acquired (step S83), and the filtering process is performed on the steering angle sensor value ΔR. Execute (Step S84). The filter process is a process using a low-pass filter similar to the filter process in the steering control process, and an IIR filter or FIR filter generally used as a band-pass filter can be used. A simple low-pass filter may be used.

Subsequently, the drive control unit 72 calculates the right and left torque decrease ratio U _WR (step S85). Here, when the left / right torque increase / decrease ratio is U _WR , the U _WR is calculated by the following equation (40).
U _WR = G _WR (δ−ΔR) Expression (40)
Note that G _WR is a left-right torque increase / decrease ratio gain, and the value of G _{WR is} a value set based on experiments or the like, and is stored in the storage means in advance. However, G _WR is not necessarily a constant, and may be a function corresponding to the vehicle speed, for example. In addition, 0 ≦ U _WR ≦ 1, but if this numerical range is exceeded during calculation, it is rounded to fit within this numerical range.

  Subsequently, the drive control unit 72 acquires a throttle position sensor value ρ that is a value of the throttle position detected by the throttle position sensor 73 (step S86). The throttle position is an acceleration command value input by an occupant operating an acceleration command input device such as a throttle lever or a throttle grip, and 0 ≦ ρ ≦ 1.

Subsequently, the drive control unit 72 calculates a total drive torque command value P (step S87). Here, assuming that the maximum value of the total drive torque command value P is P _MAX , the total drive torque command value P is calculated by the following equation (41).
P = P _MAX ρ Formula (41)
Finally, the drive control unit 72 outputs the total drive torque command value P and the left / right torque increase / decrease ratio _UWR to the drive motor control unit 74 (step S88), and ends the drive control process.

  Next, the operation of drive motor control processing for outputting left and right drive torque command values to the left and right rotary drive devices 51L and 51R as drive motors will be described.

  FIG. 21 is a flowchart showing the operation of the drive motor control process in the fourth embodiment of the present invention.

In the drive motor control process, the drive motor control unit 74 first receives the total drive torque command value P and the left / right torque increase / decrease ratio U _WR from the drive control unit 72 (step S91).

Subsequently, the drive motor control unit 74 calculates the right drive torque command value P _R as a drive torque command value for operating the right rotary drive 51R (step S92), it activates the left of the rotation drive device 51L A left driving torque command value P _L is calculated as a driving torque command value for the purpose (step S93). Here, the P _R and P _L, based on the total drive torque command value P and lateral torque decrease ratio U _WR, is calculated by the following equation (42) and (43).
P _R = P / 2 + U _WR P Formula (42)
P _L = P / 2−U _WR P Formula (43)
Finally, the drive control unit 72, respectively to the rotary drive device 51 as a drive motor and outputs the P _R, P _L (step S94), i.e., the right drive torque command value P _R to the right of the rotary drive device 51R At the same time, the left drive torque command value P _L is output to the left rotation drive device 51L, and the drive motor control process is terminated.

  Thus, in the present embodiment, at the initial stage of steering, differential torque is generated on the left and right drive wheels so that a yaw moment in the direction opposite to the turning direction is generated, and the vehicle body is tilted in the turning direction. That is, immediately after the occupant starts operating the handlebar 41a, differential torque is generated in the left and right drive wheels so that a yaw moment in the direction opposite to the turning direction is generated, and thereby the inward turning direction is directed toward the inside. To generate acceleration.

  As a result, the center of gravity of the vehicle body can be moved inward in the turning direction at the beginning of steering, and the vehicle body can be smoothly tilted inward in the turning direction, so that maneuverability and crisis avoidance performance are not sacrificed. In addition, the stability of the vehicle body can be maintained.

  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 41a Handlebar 65 Steering motor

Claims (3)

A vehicle body including a steering unit and a main body unit coupled to each other;
A wheel rotatably attached to the steering unit, and a steerable steering wheel for steering the vehicle body;
Non-steering wheels that are rotatably attached to the main body and are not steerable;
A steering device for inputting steering command information;
A tilting actuator device for tilting the steering part or the main body part in a turning direction;
A steering actuator device for changing a steering angle of the steered wheel based on steering command information input from the steering device;
A control device for controlling the tilt actuator device and the steering actuator device;
The steering wheel or non-steering wheel is a pair of left and right drive wheels,
The control device generates a differential torque on the left and right drive wheels so that a yaw moment in a direction opposite to the steering direction included in the steering command information is generated at an early stage of steering, whereby the center of gravity of the vehicle body in the steering direction is generated. A vehicle characterized by generating an acceleration directed inward in the turning direction by controlling the vehicle to move.   The vehicle according to claim 1, wherein the control device increases a driving torque of driving wheels in the steering direction and decreases a driving torque of driving wheels on the opposite side.   The control device moves the center of gravity of the vehicle body by controlling a steering actuator device so as to change a steering angle of the steered wheel in a direction opposite to a steering direction included in the steering command information at an early stage of steering. The vehicle according to claim 1 or 2.

Images