JP2014034233A - Car body tilt control device and car body tilt control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability by suppressing variation in steering reaction force due to a camber thrust.SOLUTION: A car body is tilted inward within turning along a roll direction during a turning travel by setting a target tilt angle φwhen the car body is tilted inward within the turning along the roll direction during the turning travel according to a steering angle θs of a driver and bringing a tilt motor 3 under driving control according to the target tilt angle φ. Assist torque Ta when assist torque is given to a steering mechanism during steering operation by the driver is set according to steering torque Ts of the driver, and the assist torque Ta is corrected a camber thrust Fc developed by front wheels 1FL and 1FR accompanying the driving control over the tilt motor 3. Then an assist motor 38 is brought under driving control according to the corrected assist torque Ta to impart the assist torque to a steering mechanism during the steering operation by the driver.

Description

  The present invention relates to a vehicle body tilt control device and a vehicle body tilt control method.

  The prior art described in Patent Document 1 discloses that the vehicle body is tilted inwardly by turning the bell crank of the suspension by an actuator according to the steering operation of the driver during turning.

Japanese Utility Model Publication No. 56-93311

By the way, in the configuration in which the vehicle body is tilted inward of the turn, the tire itself is also tilted, so that the self-aligning torque changes due to the tire canvas last. Therefore, if the assist control is simply performed according to the steering torque and the vehicle speed in the configuration in which the electric power steering device is also mounted, the steering reaction force changes due to the canvas last during turning, which affects the operability. I will give it.
The subject of this invention is suppressing the change of the steering reaction force resulting from canvas last, and improving operativity.

  A vehicle body tilt control device according to an aspect of the present invention includes a tilt actuator that tilts a vehicle body along a roll direction, and an assist actuator that applies assist torque to a steering mechanism. Then, a target inclination angle when the vehicle body is inclined inward along the roll direction during turning is set according to the steering angle of the driver, and the tilt actuator is driven and controlled according to the target inclination angle. On the other hand, a target assist torque for applying assist torque to the steering mechanism during the driver's steering operation is set according to the driver's steering torque. Then, the target assist torque is corrected according to the canvas last expressed in the steered wheels in accordance with the drive control of the tilt actuator, and the assist actuator is driven and controlled according to the corrected target assist torque.

  According to the present invention, at the time of drive control of the tilt actuator, the target assist torque is corrected according to the canvas last expressed on the steered wheels, so that the change in the steering reaction force caused by the canvas last is suppressed and the operability is improved. Can be made.

It is a schematic diagram of vehicle body tilting. It is the schematic of a suspension structure. 1 is a schematic configuration diagram of an entire vehicle. It is a schematic block diagram of a steering mechanism. It is a block diagram which shows a vehicle body tilt control process and an assist control process. It is a map used for setting of assist torque Ta. It is a flowchart which shows a vehicle body tilt control process. It is a flowchart which shows an assist control process. It is a figure explaining change of steering reaction force resulting from canvas last. It is a figure which shows a simulation result. It is a block diagram which shows the assist control process of 2nd Embodiment. It is a flowchart which shows the assist control process of 2nd Embodiment. It is a figure which shows the simulation result of 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
<< First Embodiment >>
"Constitution"
FIG. 1 is a schematic diagram of vehicle body tilting.
A vehicle body 2 is suspended from a wheel 1 via a suspension, and the suspension can tilt the vehicle body 2 by driving a tilting motor 3. Specifically, the vehicle body 2 is tilted inward during turning.

FIG. 2 is a schematic view of the suspension structure.
Since the suspension structure of the left and right wheels is the same structure that is bilaterally symmetrical, only the left wheel side will be described here. This suspension is a double wishbone suspension, and a knuckle (upright) 11 that supports the wheel 1 is swingable via an upper link 12 and a lower link 13 on the vehicle body frame 14. It is connected to.

The upper link 12 is composed of an A arm, and each of the wheel side attachment point and the vehicle body side attachment point is connected to the knuckle 11 and the vehicle body frame 14 via a rubber bush. The lower link 13 is also composed of an A arm, and each of the wheel side mounting point and the vehicle body side mounting point is connected to the knuckle 11 and the vehicle body frame 14 via a rubber bush.
A lean arm 15 having a pivot shaft in the longitudinal direction of the vehicle body and projecting evenly toward the left and right sides is pivotally supported at the center position in the vehicle width direction of the vehicle body frame 14. A shock absorber 16 and a coil spring 17 are interposed between the tip of the lean arm 15 and the lower link 13. Further, the tilting motor 3 is connected to the rotation shaft of the lean arm 15 via a reduction gear (not shown).

  Accordingly, when the tilting motor 3 is rotated, the lean arm 15 is rotated with respect to the vehicle body frame 14 and the left end and the right end of the lean arm 15 are displaced in the vertical direction, so that the lower link is provided via the shock absorber 16 and the coil spring 17. 13 swings. When the left end is lowered, the right end of the lean arm 15 is raised, and when the left end is raised, the right end is lowered, so that the left and right wheels have reverse suspension strokes.

  That is, when the tilt motor 3 is rotated clockwise in front view of the vehicle, the left arm side becomes a rebound stroke and the right wheel side becomes a bound stroke due to the rotation of the lean arm 15 (tilt that lowers the left side). At this time, a force in the rebound direction that pushes down the lower link 13 acts on the left wheel side, and the left side of the vehicle body 2 is lifted by the reaction force received from the left wheel, and as a result, the vehicle body 2 tilts to the right side.

  Conversely, when the tilting motor 3 is rotated counterclockwise when viewed from the front of the vehicle, the left wheel side becomes a bound stroke and the right wheel side becomes a rebound stroke by the rotation of the lean arm 15 (tilting that lowers the right side). At this time, a force in the rebound direction that pushes down the lower link 13 acts on the right wheel side, and the right side of the vehicle body 2 is lifted by the reaction force received from the right wheel, and as a result, the vehicle body 2 tilts to the left side.

FIG. 3 is a schematic configuration diagram of the entire vehicle.
The suspension structure described above is provided on the front wheel and the rear wheel, and each is driven and controlled by an individual tilt motor 3. When distinguishing front, rear, left and right wheels, the front left wheel will be described as 1FL, the front right wheel as 1FR, the rear left wheel 1RL, and the rear right wheel 1RR. The front wheels 1FL and 1FR are steered wheels steered by a steering mechanism. Further, when distinguishing the front and rear wheel tilting motors 3, the front wheels are described as tilting motors 3f, and the rear wheels are described as tilting motors 3r. Furthermore, when distinguishing the lean arms 15 of the front and rear wheels, the front wheel side will be described as the lean arm 15f, and the rear wheel side will be described as the lean arm 15r.

Although the tilt motor 3 is used as an actuator for rotating the lean arm 15, other actuators using hydraulic pressure or air pressure may be used. Further, the vehicle body may be tilted by stroking the left and right suspensions in opposite directions with, for example, an electromagnetic shock absorber or the like capable of generating thrust in the expansion and contraction direction.
In addition to the tilt motors 3f and 3r described above, the vehicle 20 includes a steering angle sensor 21, a wheel speed sensor 22, motor rotation angle sensors 23f and 23r, a turning state detection sensor 24, and a vehicle control controller 25. Is provided.

  The steering angle sensor 21 detects the steering angle θs of the steering shaft. The steering angle sensor 21 detects, for example, the rotation of a magnet built in a detection gear that rotates in synchronization with the steering shaft by two MR (ferro-magnetoresistance) elements, and detects the direction of the magnetic field accompanying the rotation of the steering shaft. The vector change is converted into an electric signal and input to the vehicle controller 25. The vehicle controller 25 determines the steering angle θs of the steering shaft from the input electric signal. The steering angle sensor 21 detects right turn as a positive value and detects left turn as a negative value.

The wheel speed sensor 22 detects the wheel speeds Vw _{FL to} Vw _RR of each wheel. The wheel speed sensor 22 detects, for example, the magnetic lines of force of the sensor rotor by a detection circuit, converts a change in magnetic field accompanying the rotation of the sensor rotor into a current signal, and inputs the current signal to the vehicle controller 25. The vehicle controller 25 determines the wheel speeds Vw _{FL to} Vw _RR from the input current signal. Further, the vehicle controller 25 determines the average value of the wheel speeds Vw _{FL to} Vw _RR as the vehicle speed V.

  The motor rotation angle sensors 23f and 23r detect the rotation angles of the tilting motors 3f and 3r, respectively. The motor rotation angle sensors 23f and 23r include, for example, a rotor made of a permanent magnet and a stator made of a Hall element, and utilizes the Hall effect in which Hall electromotive force is generated in a direction perpendicular to the current and magnetic flux. The position of the magnetic pole of the rotor is converted into a voltage signal and input to the vehicle controller 25. The vehicle controller 25 determines the rotation angles of the tilting motors 3f and 3r from the input voltage signal.

  The turning state detection sensor 24 detects a turning state such as a lateral acceleration, a yaw rate, a vehicle body roll angle, and a roll rate. Regarding the detection of the lateral acceleration, for example, the positional displacement of the movable electrode with respect to the fixed electrode is detected as a change in capacitance, and is converted into a voltage signal proportional to the lateral acceleration and the direction and input to the vehicle controller 25. For the detection of the yaw rate, it is provided on the body that is on the spring, for example, a vibrator composed of a crystal tuning fork is vibrated by an alternating voltage, and the distortion amount of the vibrator caused by the Coriolis force at the time of angular velocity input by the yaw rate is converted into an electrical signal And input to the vehicle controller 25. For the roll angle of the vehicle body, it is provided on the body on the spring, for example, a vibrator made of crystal tuning fork is vibrated by AC voltage, and the distortion amount of the vibrator caused by Coriolis force at the time of angular velocity input by the roll is converted into an electric signal And input to the vehicle controller 25. The vehicle controller 25 determines a turning state such as a lateral acceleration, a yaw rate, a vehicle body roll angle, and a roll rate from various input electric signals.

The vehicle controller 25 executes the vehicle body tilt control process and drives the tilt motors 3f and 3r according to the current command value, thereby realizing the tilt operation of the vehicle body 2.
The vehicle controller 25 is composed of a microcomputer, and operates the tilt motors 3f and 3r based on information input from the steering angle sensor 21, the wheel speed sensor 22, the motor rotation angle sensors 23f and 23r, and the turning state detection sensor 24. At the same time as the control, the control operation is canceled.
The vehicle of this embodiment also has an electric power steering function.

FIG. 4 is a schematic configuration diagram of the steering mechanism.
The steering wheel 31 operated by the driver is connected to the front wheels 1FL and 1FR via a steering shaft 32, a rack and pinion 33, a tie rod 34, and a knuckle 35 in this order. Therefore, the steering shaft 32 is rotated together with the steering wheel 31, and the rotation of the steering shaft 32 is converted into a linear motion in a substantially vehicle width direction by the rack and pinion 33, and the tie rod 34 is pushed or pulled to thereby pass the knuckle 35. Thus, the front wheels 1FL and 1FR that are steered wheels can be steered.

  A wheel gear 36 is connected to the steering shaft 32, and an assist motor 38 is connected to a worm gear 37 that meshes with the wheel gear 36. Therefore, when the assist motor 38 is driven to generate torque in the direction according to the steering direction of the driver, the assist torque can be applied to the steering shaft 32 via the worm gear 37 and the wheel gear 36.

  Although the column assist structure for applying the assist torque to the steering shaft 32 is used, the assist position is arbitrary as long as the assist torque can be applied to any of the steering mechanisms (systems). Therefore, for example, a pinion assist structure that applies assist torque in the vicinity of the pinion gear, or a rack assist structure that applies assist torque to the rack gear may be used. The rack assist structure includes a rack coaxial assist type in which the rack axis and the motor axis are simultaneously provided, a rack cross assist type in which the rack axis and the motor axis are arranged obliquely, and a rack parallel assist type in which the rack axis and the motor axis are parallel to each other. .

Moreover, although it is set as the structure which provides assist torque with one motor, it is good also as a double motor assist structure which provides assist torque with two motors.
A torque sensor 39 is provided on the steering shaft 32.
The torque sensor 39 detects the torque Ts input to the steering shaft 32. The torque sensor 39 detects the torsion angle of the torsion bar interposed between the input side and the output side of the steering shaft 32 by, for example, a Hall element, and generates a magnetic flux density caused by a relative angular displacement between the multipolar magnet and the yoke. Is converted into an electric signal and input to the vehicle controller 25. The vehicle controller 25 determines the driver's steering torque Ts from the input electric signal. The torque sensor 39 detects the right steering of the driver as a positive value and detects the left steering as a negative value.

The vehicle controller 25 executes a power steering control process and drives the assist motor 38 with the current command value, thereby applying assist torque according to the steering operation of the driver to the steering mechanism.
The vehicle controller 25 drives and controls the assist motor 38 based on information input from the torque sensor 39 and the wheel speed sensor 22.
The vehicle controller 25 includes, for example, a microcomputer, and executes a vehicle body tilt control process and a power steering control process every predetermined time (for example, 10 msec).

FIG. 5 is a block diagram illustrating the vehicle body tilt control process and the assist control process.
The vehicle control controller 25 includes a vehicle body tilt control processing unit 40 that tilts the vehicle body along the roll direction during turning, and an assist control processing unit 50 that applies assist torque to the steering mechanism when the driver performs a steering operation.
First, the vehicle body tilt control processing unit 40 includes a target tilt angle setting unit 41, a command angle setting unit 42, and a drive control unit 43.

The target inclination angle setting unit 41 sets the target inclination angle (lean angle) φ ^* when the vehicle body is inclined inward along the roll direction during turning, according to the vehicle model (Gφ (s)) and the steering angle θs and Set according to vehicle speed V.
The command angle setting unit 42 sets the actuator command angle φu ^*, which is a command value for the tilt motor 3, according to the target tilt angle φ ^* according to the vehicle model (Gφu (s)). The vehicle model (Gφu (s)) is derived from a dynamic model (a balance equation of force when the lean arm 15 is driven by the tilting motor 3) when the vehicle is viewed from the front (or the rear). Model with a large phase lead term.

  In consideration of the fact that the vehicle model (Gφu (s)) has a phase advance term, the vehicle model Gφ (s) is a vehicle model having a phase delay characteristic with an order difference of 1 or more. For example, in order to match the phase with the turning direction (yaw direction), a yaw response model of a vehicle represented by a first-order phase delay characteristic is used.

m: vehicle mass h: center of gravity height g: gravitational acceleration I _φ : roll inertia K _φ : roll rigidity C _φ : roll equivalent viscosity The drive control unit 43 controls the drive of the tilt motor 3 according to the actuator command angle φu ^*. .
The above is the vehicle body tilt control process based on the block diagram of FIG.

Next, the assist control processing unit 50 includes a phase compensation unit 51, an assist torque setting unit 52, an inclination angle estimation unit 53, a canvas last estimation unit 54, a self-aligning torque estimation unit 55, and a correction amount setting unit. 56, an assist torque correction unit 57, and a drive control unit 58.
The phase compensation unit 51 obtains the steering torque Ts and performs phase compensation for avoiding mechanical resonance.
The assist torque setting unit 52 sets an assist torque Ta serving as a command value to the assist motor 38 according to the steering torque Ts and the vehicle speed V with reference to the map of FIG.

FIG. 6 is a map used for setting the assist torque Ta.
According to this map, when the steering torque Ts is zero, the assist torque Ta is zero. When the steering torque Ts is in a negative region (Ts <0), the assist torque Ta decreases exponentially as the steering torque Ts decreases, and the assist torque Ta decreases as the vehicle speed V decreases. On the other hand, when the steering torque Ts is in the positive region (Ts> 0), the assist torque Ta increases exponentially as the steering torque Ts increases, and the assist torque Ta increases as the vehicle speed V decreases.
The inclination angle estimation unit 53 estimates the vehicle body inclination angle φ ^* according to the actuator command angle φu ^* according to the following equation.

The canvas last estimation unit 54 estimates the canvas last Fc expressed on the front wheels 1FL and 1FR in accordance with the drive control of the tilting motor 3 according to the vehicle body inclination angle φ ^* according to the canvas last estimation model as shown below. To do. Here, K _cf is a canvas last coefficient, and is set to, for example, about 1/6 of a preset cornering power.
Fc = K _cf φ ^*

The self-aligning torque estimation unit 55 estimates the self-aligning torque SAT expressed in the front wheels 1FL and 1FR in accordance with the drive control of the tilting motor 3 in accordance with the canvas last Fc as shown below. Here, ξn is a pneumatic trail, ξc is a caster trail, and ξ (= ξn + ξc) is set to a value of about 40 to 50 mm, for example.
SAT = (ξn + ξc) Fc

As shown in FIG. 4, the pneumatic trail ξn is a distance between a ground contact point Pt on a vertical line passing through the tire rotation center and a tire application point Pf that is an action point of the cornering force. Further, as shown in FIG. 4, the caster rail ξc is a distance between a ground contact point Pt on a vertical line passing through the tire rotation center and a ground contact point Pk on a straight line passing through the kingpin axis Ak.
The correction amount setting unit 56 obtains the rack axial force from the self-aligning torque SAT based on the relationship between the self-aligning torque SAT and the knuckle arm radius, and converts it into a torque value around the pinion shaft, thereby correcting the assist torque. The amount ΔT is set.

The assist torque correcting unit 57 corrects the assist torque Ta by adding the assist torque correction amount ΔT set by the correction amount setting unit 56 to the assist torque Ta set by the assist torque setting unit 52, and sends the assist torque Ta to the assist motor 38. Is output.
The drive control unit 58 controls the assist motor 38 according to the corrected assist torque Ta.
The above is the assist control process based on the block diagram of FIG.

Next, the vehicle body tilt control process will be described based on a flowchart.
FIG. 7 is a flowchart showing the vehicle body tilt control process.
First, step S101 corresponds to the processing in the target inclination angle setting unit 41, and the vehicle model described above is used as the target inclination angle (lean angle) φ ^* when the vehicle body is inclined inward along the roll direction during turning. In accordance with (Gφ (s)), it is set according to the steering angle θs and the vehicle speed V.

The subsequent step S102 corresponds to the processing in the command angle setting unit 42, and the actuator command angle φu ^* that is the command value to the tilt motor 3 is set to the target tilt angle φ ^* according to the vehicle model (Gφu (s)) ^. Set according to.
The subsequent step S103 corresponds to the processing in the drive control unit 43, drives the tilt motor 3 in accordance with the actuator command angle φu ^* , and then returns to the predetermined main program.
The above is the vehicle body tilt control process based on the flowchart of FIG.

Next, the assist control process will be described based on a flowchart.
FIG. 8 is a flowchart showing the assist control process.
First, step S111 corresponds to the processing in the assist torque setting unit 52, and refers to the map of FIG. 6 described above, and determines the assist torque Ta as a command value to the assist motor 38 according to the steering torque Ts and the vehicle speed V. Set.

The subsequent step S112 corresponds to the processing in the tilt angle estimation unit 53, and estimates the vehicle body tilt angle φ ^* according to the actuator command angle φu ^* .
The subsequent step S113 corresponds to the processing in the canvas last estimation unit 54, and in accordance with the canvas last estimation model, the canvas last Fc expressed on the front wheels 1FL and 1FR in accordance with the drive control of the tilt motor 3 is converted into the vehicle body inclination angle φ ^*. Estimate according to That is, the canvas last Fc is estimated by multiplying the vehicle body tilt angle φ ^* realized by the drive control of the tilt motor 3 by a predetermined canvas last coefficient K _cf.

The subsequent step S114 corresponds to the processing in the self-aligning torque estimation unit 55, and estimates the self-aligning torque SAT expressed in the front wheels 1FL and 1FR in accordance with the drive control of the tilting motor 3 according to the canvas last Fc. To do. That is, the self-aligning torque SAT is estimated by multiplying the canvas last Fc estimated by the canvas last estimating unit 54 by the sum (ξn + ξc) of the pneumatic trail ξn and the caster trail ξc.
The subsequent step S115 corresponds to the processing in the correction amount setting unit 56, obtains the rack axial force from the self-aligning torque SAT based on the relationship between the self-aligning torque SAT and the knuckle arm radius, and generates torque around the pinion axis. By converting into a value, the assist torque correction amount ΔT is set.

The subsequent step S116 corresponds to the processing in the assist torque correction unit 57, and adds the assist torque correction amount ΔT set by the correction amount setting unit 56 to the assist torque Ta set by the assist torque setting unit 52, thereby assisting. The torque Ta is corrected.
The subsequent step S117 corresponds to the processing in the drive control unit 58, drives the assist motor 38 according to the final assist torque Ta after correction, and then returns to the predetermined main program.
The above is the assist control process based on the flowchart of FIG.

<Action>
Next, the operation of the first embodiment will be described.
In this embodiment, the target tilt angle φ ^* is set according to the steering angle θs and the vehicle speed V (step S101), and the tilt motor 3 is driven according to the actuator command angle φu ^* set from the target tilt angle φ ^*. Control (step S103). As a result, the vehicle body tilts inward of the turn along the roll direction during turning, and thus the turning performance can be improved.
As described above, in the configuration in which the vehicle body is tilted inwardly, the tire itself is also tilted, so that the self-aligning torque SAT is changed due to the canvas last Fc of the tire. Therefore, if the assist control unit 50 simply performs assist control according to the steering torque Ts and the vehicle speed V, the steering reaction force changes due to the canvas last Fc during turning, which affects operability. .

FIG. 9 is a diagram illustrating a change in the steering reaction force due to the canvas last.
(A) in the figure is a conventional vehicle that does not tilt the vehicle body inward of the turn, and (b) in the figure is a vehicle that tilts the vehicle body inward of the turn. In a conventional vehicle, the self-aligning torque SAT acts as a moment around the kingpin axis Ak corresponding to the cornering force Cf, and this becomes a steering reaction force. However, in a vehicle in which the vehicle body is tilted inward of the turn, the self-aligning torque SAT changes due to the change in the canvas last Fc, and the steering reaction force also fluctuates.

  Therefore, when the target assist torque Ta is set according to the driver's steering torque Ts (step S111), the assist torque Ta is determined according to the canvas last Fc expressed on the front wheels 1FL and 1FR in accordance with the drive control of the tilting motor 3. Is corrected (step S116). Then, the assist motor 38 is driven and controlled in accordance with the corrected assist torque Ta (step S117).

Specifically, the vehicle body inclination angle φ ^* is estimated in accordance with the actuator command angle φu ^* (step S112), and the canvas last Fc expressed on the front wheels 1FL and 1FR in accordance with the drive control of the inclination motor 3 is determined. Estimation is made according to the angle φ ^* (step S113). Then, the self-aligning torque SAT expressed in the front wheels 1FL and 1FR in accordance with the drive control of the tilting motor 3 is estimated according to the canvas last Fc (step S114), and the rack axial force is obtained from the self-aligning torque SAT. The assist torque correction amount ΔT is set by converting the torque value around the pinion axis (step S115).

Then, the assist torque Ta is corrected by adding the assist torque correction amount ΔT (step S116), and the assist motor 38 is driven and controlled according to the corrected assist torque Ta.
As a result, during the drive control of the tilting motor 3, the assist torque Ta is corrected according to the canvas last Fc expressed in the front wheels 1FL and 1FR, so that the change in the steering reaction force caused by the canvas last Fc is suppressed, and the operability is improved. Can be improved.

FIG. 10 is a diagram showing a simulation result.
If correction for the assist correction amount ΔT is not made, as shown by the broken line, the self-aligning torque SAT changes suddenly and the steering reaction force also changes suddenly (is lost) due to the expression of the canvas last Fc. . On the other hand, by correcting for the assist correction amount ΔT, it is possible to suppress a sudden change in the self-aligning torque SAT caused by the canvas last Fc, as shown by the solid line. Therefore, a sudden change in the steering reaction force is suppressed, and the operability can be improved. Here, the fluctuation of about 4 Nm was improved to about 1 Nm, and an improvement of about 25% was observed.

  As described above, the tilting motor 3 corresponds to the “tilting actuator”, the processing in step S101 which is processing in the target tilt angle setting unit 41 corresponds to “target tilt angle setting means”, and processing in the drive control unit 43. The processing of step S103 that corresponds to "tilt control means". Further, the assist motor 38 corresponds to the “assist actuator”, and step S111 which is processing in the assist torque setting unit 52 corresponds to the “target assist torque setting means”. Further, step S116 which is processing in the assist torque correction unit 57 corresponds to “correction means”, and processing in step S117 which is processing in the drive control unit 58 corresponds to “assist control means”. Further, the process in step S113 which is the process in the canvas last estimating unit 54 corresponds to “canvas last estimating means”, and the process in step S114 which is the process in the self aligning torque estimating unit 55 is “self aligning torque estimation”. Corresponds to “means”.

"effect"
Next, the effect of the main part in 1st Embodiment is described.
(1) The vehicle body tilt control device according to the present embodiment includes the tilt motor 3 that tilts the vehicle body along the roll direction, and the assist motor 38 that applies assist torque to the steering mechanism. Then, by the processing in the target inclination angle setting unit 41, the target inclination angle φ ^* when the vehicle body is inclined inward along the roll direction during turning is set according to the steering angle θs of the driver. Then, the tilt motor 3 is driven and controlled in accordance with the target tilt angle φ ^* set by the target tilt angle setting unit 41 by the processing in the tilt control unit 43. On the other hand, the processing in the assist torque setting unit 52 sets a target assist torque Ta for applying assist torque to the steering mechanism during the driver's steering operation according to the driver's steering torque Ts. Then, by the processing in the assist torque correction unit 57, the target assist set by the assist torque setting unit 52 according to the canvas last expressed in the front wheels 1FL and 1FR in accordance with the drive control of the tilt motor 3 by the tilt control unit 43. Correct the torque. Then, the assist motor 38 is driven and controlled in accordance with the assist torque Ta corrected by the assist torque correction unit 57 by the processing in the drive control unit 58.
Thus, during the drive control of the tilting motor 3, the assist torque Ta is corrected according to the canvas last Fc expressed on the front wheels 1FL and 1FR, so that the change in the steering reaction force caused by the canvas last Fc is suppressed, and the operation Can be improved.

(2) The vehicle body tilt control device according to the present embodiment is configured to process the canvas last Fc expressed on the front wheels 1FL and 1FR in accordance with the drive control of the tilt motor 3 by the tilt control unit 43 by the processing in the canvas last estimating unit 54. Estimation is performed according to the target inclination angle φ ^* set by the target inclination angle setting unit 41. Then, the canvas last estimating unit 54 estimates the self aligning torque SAT expressed in the front wheels 1FL and 1FR in accordance with the drive control of the tilt motor 3 by the tilt control unit 43 by the processing in the self aligning torque estimating unit 55. Estimated according to the canvas last Fc. The assist torque correction unit 57 corrects the assist torque Ta set by the assist torque setting unit 52 in accordance with the self-aligning torque SAT estimated by the self-aligning torque estimation unit 55.

Thus, the canvas last Fc is estimated according to the target inclination angle φ ^* , the self-aligning torque SAT is estimated according to the canvas last Fc, and the assist torque setting unit 52 is determined according to the estimated self-aligning torque SAT. By correcting the assist torque Ta set in step 1, the change in the steering reaction force due to the canvas last Fc can be suppressed and the operability can be improved.

(3) The vehicle body tilt control apparatus according to the present embodiment is configured so that the canvas last estimation unit 54 performs a canvas last angle φ ^* set in advance on the vehicle body tilt angle φ ^* realized by the drive control of the tilt motor 3 by the tilt control unit 43. by multiplying the coefficient _{K cf,} estimates the camber thrust which is expressed to the front wheels 1FL and 1FR.
In this way, by estimating the canvas last Fc by multiplying the vehicle body inclination angle φ ^* by a preset canvas last coefficient _Kcf , the canvas last Fc can be estimated easily and accurately.

(4) The vehicle body tilt control apparatus according to the present embodiment adds the sum of the pneumatic trail ξn and the caster trail ξc to the canvas last Fc estimated by the canvas last estimation unit 54 by the process of the self-aligning torque estimation unit 55 ( By multiplying by ξn + ξc), the self-aligning torque SAT expressed in the front wheels 1FL and 1FR is estimated.
Thus, by multiplying the canvas last Fc by the sum of the pneumatic trail ξn and the caster trail ξc (ξn + ξc) and estimating the self-aligning torque SAT, the self-aligning torque SAT can be easily and accurately determined. Can be estimated.

(5) The vehicle body tilt control method according to the present embodiment sets a target inclination angle φ ^* when the vehicle body is inclined inward along the roll direction during turning, according to the steering angle θs of the driver. By driving and controlling the tilt motor 3 in accordance with the tilt angle φ ^* , the vehicle body is tilted inward along the roll direction during cornering. On the other hand, assist torque Ta for applying assist torque to the steering mechanism during the steering operation of the driver is set according to the steering torque Ts of the driver, and is expressed in the front wheels 1FL and 1FR in accordance with the drive control of the tilt motor 3. The assist torque Ta is corrected according to the canvas last Fc. Then, the assist motor 38 is driven and controlled according to the corrected assist torque Ta, so that the assist torque is applied to the steering mechanism when the driver performs the steering operation.
Thus, during the drive control of the tilting motor 3, the assist torque Ta is corrected according to the canvas last Fc expressed on the front wheels 1FL and 1FR, so that the change in the steering reaction force caused by the canvas last Fc is suppressed, and the operation Can be improved.

<< Second Embodiment >>
"Constitution"
In the present embodiment, only a transient component that changes according to the canvas last Fc is extracted from the self-aligning torque SAT, and the assist torque Ta is corrected accordingly.
Here, a different point from 1st Embodiment mentioned above is demonstrated, and description is abbreviate | omitted about the same location.

Hereinafter, an assist control process executed by the vehicle controller 25 will be described.
First, an assist control process according to the second embodiment will be described with reference to a block diagram.
FIG. 11 is a block diagram illustrating assist control processing according to the second embodiment.
Here, a new steady slope SAT estimator 61 and a steady roll SAT estimator 62 are added, and the processing in the correction amount setting unit 56 is changed to a new correction amount setting unit 63. Since other processes are the same as those in the first embodiment described above, the description thereof is omitted.

In the steady inclination SAT estimation unit 61, as shown below, out of the self-aligning torque SAT expressed in the front wheels 1FL and 1FR, a steady inclination component that is a steady component when the vehicle body is tilted inward of the turn. The self-aligning torque _TL is estimated according to the actuator command angle φu ^* . Here, K _cf is a canvas last coefficient, and is set to, for example, about 1/6 of a preset cornering power. Further, ξ is the sum (ξn + ξc) of the pneumatic trail ξn and the caster trail ξc, and is set to a value of about 40 to 50 mm, for example.
T _L = K _cf × ξ × φu ^*

As shown below, the roll steady component SAT estimation unit 62 becomes a steady component of the self-aligning torque SAT expressed in the front wheels 1FL and 1FR when the vehicle body rolls outward by the lateral acceleration Ay. roll constant partial self-aligning torque T _Y, estimated in accordance with the lateral acceleration Ay acting on the vehicle body.
T _Y = m {h / (mhg)} Ay × K _cf × ξ
m: vehicle mass h: center of gravity height g: gravitational acceleration The lateral acceleration Ay may be obtained from the vehicle speed V as shown below.

A: stability factor L: wheelbase L _f: distance L r from the center of gravity position to the front wheel _axle: Distance K f to the rear wheel axle from the center of gravity _position: front wheel cornering power K _r: rear wheel cornering power of

The correction amount setting unit 63, the self aligning torque SAT estimated inclination constant partial self-aligning torque T _L, and transient components Serufua as a transient component by subtracting the roll steady partial self-aligning torque T _Y to calculate the aligning torque _{T T.} Then, a rack shaft force from the transient component self-aligning torque T _T the calculated, by converting the torque value of around pinion shaft, sets the assist torque correction amount [Delta] T.
The above is the assist control process based on the block diagram of FIG.

Next, an assist control process according to the second embodiment will be described based on a flowchart.
FIG. 12 is a flowchart illustrating an assist control process according to the second embodiment.
Here, the processing of the new steps S201 and S202 described above is added, the processing of step S115 described above is changed to the processing of new step S203, and the processing of other steps S111 to S114, S116, and S117 is performed. Since this is the same as that of the first embodiment described above, detailed description thereof will be omitted.

First, step S201 corresponds to the process in the stationary steady portion SAT estimation unit 61, and among the self-aligning torque SAT expressed in the front wheels 1FL and 1FR, a stationary component when the vehicle body is inclined to the inside of the turn. The self-aligning torque _{TL corresponding} to the steady inclination is estimated according to the actuator command angle φu ^* .
The subsequent step S202 corresponds to the processing in the roll steady part SAT estimation unit 62, and is a steady state when the vehicle body rolls outward by the lateral acceleration Ay from the self-aligning torque SAT expressed in the front wheels 1FL and 1FR. roll constant partial self-aligning torque T _Y serving as a component is estimated in accordance with the lateral acceleration Ay acting on the vehicle body.

Step S203 subsequent corresponds to the processing of the correction amount setting unit 63, the self aligning torque SAT estimated inclination constant partial self-aligning torque T _L, and subtracts the roll steady partial self-aligning torque T _Y A transient component self-aligning torque T _T that is a transient component is calculated. Then, a rack shaft force from the transient component self-aligning torque T _T the calculated, by converting the torque value of around pinion shaft, sets the assist torque correction amount [Delta] T.
The above is the assist control process based on the flowchart of FIG.

<Action>
Next, the operation of the second embodiment will be described.
The self-aligning torque SAT estimated by the self-aligning torque estimation unit 55 includes a steady component when the vehicle body is tilted inward of the turn and a steady component when the vehicle body is rolled outward by the lateral acceleration Ay. And ingredients. Accordingly, the steering reaction force is increased by the addition of these steady components, and the steering operation becomes heavy.

Therefore, only the transient component that changes according to the canvas last Fc is extracted from the self-aligning torque SAT, and the assist torque Ta is corrected accordingly.
Specifically, a steady-inclination self-aligning torque _TL, which is a steady component when the vehicle body is tilted inward, is estimated according to the actuator command angle φu ^* (step S201). roll constant partial self-aligning torque T _Y as a steady component in the roll to pivot outward by the acceleration Ay, estimated in accordance with the lateral acceleration Ay acting on the vehicle body (step S202).

Then, from the estimated self-aligning torque SAT, the transient steady-state self-aligning torque T _L and the roll steady-state self-aligning torque _TY are subtracted to obtain a transient component self-aligning torque T _T that becomes a transient component. calculate. Then, a rack axial force is obtained from the calculated transient component self-aligning torque T _T and converted into a torque value around the pinion axis, thereby setting an assist torque correction amount ΔT (step S203).

  In this way, by extracting only the transient component that changes in accordance with the canvas last Fc from the self-aligning torque SAT and correcting the assist torque Ta accordingly, an appropriate component excluding the steady component can be obtained. The assist torque Ta can be realized. That is, it is possible to suppress the steering reaction force from becoming heavy due to a large steering reaction force, and to improve operability.

FIG. 13 is a diagram illustrating a simulation result of the second embodiment.
If correction for the assist correction amount ΔT is not made, as shown by the broken line, the self-aligning torque SAT changes suddenly and the steering reaction force also changes suddenly (is lost) due to the expression of the canvas last Fc. . On the other hand, by correcting for the assist correction amount ΔT, it is possible to suppress a sudden change in the self-aligning torque SAT caused by the canvas last Fc, as shown by the solid line. Therefore, a sudden change in the steering reaction force is suppressed, and the operability can be improved. Furthermore, since only the transient components that change according to the canvas last Fc are extracted from the self-aligning torque SAT and corrected accordingly, the steering reaction force increases and the steering operation becomes heavy. This can be suppressed and the operability can be improved.

Other functions and effects are the same as those of the first embodiment described above.
From the above, the processing in step S201, which is the processing in the steady inclination SAT estimation unit 61, corresponds to the “steady inclination self aligning torque estimation means”. Further, the process of step S202, which is the process in the roll steady part SAT estimation unit 62, corresponds to "roll steady part self-aligning torque estimating means".

"effect"
Next, the effect of the main part in 2nd Embodiment is described.
(1) The vehicle body tilt control device according to the present embodiment is configured to tilt the vehicle body inward of the turn among the self-aligning torque SAT expressed in the front wheels 1FL and 1FR by the processing in the steady inclination SAT estimation unit 61. inclined stationary partial self-aligning torque T _L which is a stationary component of the estimates in accordance with the target tilt angle set by the target inclination angle setting unit 41 phi ^*. In addition, due to the processing in the steady roll amount SAT estimation unit 62, the steady roll component that is a steady component when the vehicle body rolls outward by the lateral acceleration of the self-aligning torque expressed in the front wheels 1FL and 1FR. the self-aligning torque T _Y, estimated in accordance with the lateral acceleration Ay acting on the vehicle body. Then, by the processing in the assist torque correction unit 57, the transient steady component self-aligning torque T _L and the roll steady component self-aligning torque _TY are subtracted from the self-aligning torque SAT to become a transient component. calculating the component self-aligning torque T _T, calculated in accordance with the transient component self-aligning torque T _T, corrects the assist torque Ta.

In this way, by extracting only the transient component that changes in accordance with the canvas last Fc from the self-aligning torque SAT and correcting the assist torque Ta accordingly, an appropriate component excluding the steady component can be obtained. The assist torque Ta can be realized. That is, it is possible to suppress the steering reaction force from becoming heavy due to a large steering reaction force, and to improve operability.
Although the present invention has been described with reference to a limited number of embodiments, the scope of rights is not limited thereto, and modifications of the embodiments based on the above disclosure are obvious to those skilled in the art.

1FL, 1FR Wheel 2 Car body 3f Front tilt motor 3r Rear tilt motor 11 Knuckle 12 Upper link 13 Lower link 14 Body frame 15f Front lean arm 15r Rear lean arm 16 Shock absorber 17 Coil spring 20 Vehicle 21 Steering angle sensor 22 Wheel speed Sensor 23f Front motor rotation angle sensor 23r Rear motor rotation angle sensor 24 Turning state detection sensor 25 Vehicle control controller 31 Steering wheel 32 Steering shaft 33 Rack and pinion 34 Tie rod 35 Knuckle 36 Wheel gear 37 Warm gear 38 Assist motor 40 Car body tilt control processing Unit 41 target tilt angle setting unit 42 command angle setting unit 50 assist control processing unit 51 phase compensation unit 52 assist torque setting unit 53 tilt angle estimation unit 54 canvas Strike estimating unit 55 self-aligning torque estimating unit 56 the correction amount setting unit 57 assist torque correcting section 61 inclined constant fraction SAT estimating portion 62 rolls constant fraction SAT estimating portion 63 correction amount setting unit

Claims (6)

A tilting actuator that tilts the vehicle body along the roll direction;
A target inclination angle setting means for setting a target inclination angle when the vehicle body is inclined inward of the turning along the roll direction during turning, according to the steering angle of the driver;
Tilt control means for driving and controlling the tilt actuator according to the target tilt angle set by the target tilt angle setting means;
An assist actuator for applying assist torque to the steering mechanism;
Target assist torque setting means for setting a target assist torque for applying assist torque to the steering mechanism during the steering operation of the driver according to the steering torque of the driver;
Correction means for correcting the target assist torque set by the target assist torque setting means according to the canvas last expressed in the steered wheels in accordance with the drive control of the tilt actuator by the tilt control means;
A vehicle body tilt control device comprising: assist control means for driving and controlling the assist actuator in accordance with the target assist torque corrected by the correction means. Canvas last estimation means for estimating the canvas last expressed on the steered wheels in accordance with the drive control of the tilt actuator by the tilt control means according to the target tilt angle set by the target tilt angle setting means;
Self-aligning torque estimating means for estimating the self-aligning torque expressed in the steered wheels in accordance with the drive control of the tilt actuator by the tilt control means according to the canvas last estimated by the canvas last estimating means; Prepared,
The correction means includes
The vehicle body tilt control device according to claim 1, wherein the target assist torque set by the target assist torque setting means is corrected according to the self-aligning torque estimated by the self-aligning torque estimation means. The canvas last estimating means includes
The canvas last expressed in the steered wheels is estimated by multiplying a vehicle body tilt angle realized by drive control of the tilt actuator by the tilt control means by a preset coefficient. 2. The vehicle body tilt control device according to 2. The self-aligning torque estimating means includes
3. The self-aligning torque expressed in the steered wheels is estimated by multiplying the canvas last estimated by the canvas last estimating means by a sum of a pneumatic trail and a caster trail. 4. The vehicle body tilt control device according to 3. Of the self-aligning torque expressed in the steered wheels, the target inclination set by the target inclination angle setting means is the steady inclination self-aligning torque, which is a steady component when the vehicle body is inclined inward of the turn. A self-aligning torque estimating means for estimating a steady inclination according to an angle;
Of the self-aligning torque expressed in the steered wheels, the roll self-aligning torque, which is a steady component when the vehicle body rolls outward by lateral acceleration, depends on the lateral acceleration acting on the vehicle body. A self-aligning torque estimating means for estimating the steady state of the roll, and
The correction means includes
From the self-aligning torque estimated by the self-aligning torque estimation means, estimated by the steady-state inclination self-aligning torque estimated by the steady-state inclination self-aligning torque estimation means and the steady-state roll self-aligning torque estimation means The transient component self-aligning torque that is a transient component is calculated by subtracting the roll steady-state self-aligning torque, and the target set by the target assist torque setting means according to the calculated transient component self-aligning torque The vehicle body tilt control device according to any one of claims 1 to 4, wherein the assist torque is corrected. Set the target tilt angle when tilting the vehicle body inside the turn along the roll direction during turning, according to the steering angle of the driver,
By driving and controlling the tilting actuator according to the target tilt angle, the vehicle body is tilted inward along the roll direction during turning,
A target assist torque for applying assist torque to the steering mechanism during the driver's steering operation is set according to the driver's steering torque,
In accordance with the canvas last expressed in the steered wheels in accordance with the drive control of the tilt actuator, the target assist torque is corrected,
A vehicle body tilt control method characterized in that an assist torque is applied to the steering mechanism when a driver performs a steering operation by drivingly controlling an assist actuator in accordance with the corrected target assist torque.